CN109709063A - Emerald identification method based on terahertz time-domain spectroscopic technology - Google Patents
Emerald identification method based on terahertz time-domain spectroscopic technology Download PDFInfo
- Publication number
- CN109709063A CN109709063A CN201910114853.0A CN201910114853A CN109709063A CN 109709063 A CN109709063 A CN 109709063A CN 201910114853 A CN201910114853 A CN 201910114853A CN 109709063 A CN109709063 A CN 109709063A
- Authority
- CN
- China
- Prior art keywords
- sample
- emerald
- jade
- terahertz
- domain
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 241000579895 Chlorostilbon Species 0.000 title claims abstract description 65
- 239000010976 emerald Substances 0.000 title claims abstract description 63
- 229910052876 emerald Inorganic materials 0.000 title claims abstract description 63
- 238000000034 method Methods 0.000 title claims abstract description 34
- 238000005516 engineering process Methods 0.000 title claims abstract description 22
- 239000010977 jade Substances 0.000 claims abstract description 88
- 229910052640 jadeite Inorganic materials 0.000 claims abstract description 30
- 238000001514 detection method Methods 0.000 claims abstract description 24
- 238000013528 artificial neural network Methods 0.000 claims abstract description 6
- 238000005259 measurement Methods 0.000 claims abstract description 6
- 238000012797 qualification Methods 0.000 claims abstract description 6
- 238000001228 spectrum Methods 0.000 claims description 18
- 238000012360 testing method Methods 0.000 claims description 16
- 238000000862 absorption spectrum Methods 0.000 claims description 10
- 230000003287 optical effect Effects 0.000 claims description 9
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 8
- 238000005086 pumping Methods 0.000 claims description 7
- 230000005855 radiation Effects 0.000 claims description 6
- 230000005540 biological transmission Effects 0.000 claims description 5
- 230000010287 polarization Effects 0.000 claims description 5
- 238000005070 sampling Methods 0.000 claims description 5
- 230000008033 biological extinction Effects 0.000 claims description 4
- 230000003111 delayed effect Effects 0.000 claims description 4
- 229910052757 nitrogen Inorganic materials 0.000 claims description 4
- 238000000513 principal component analysis Methods 0.000 claims description 4
- 238000007789 sealing Methods 0.000 claims description 3
- 239000011800 void material Substances 0.000 claims 1
- 238000004458 analytical method Methods 0.000 description 6
- 230000009102 absorption Effects 0.000 description 4
- 238000010521 absorption reaction Methods 0.000 description 4
- 238000001328 terahertz time-domain spectroscopy Methods 0.000 description 4
- 229920001903 high density polyethylene Polymers 0.000 description 3
- 239000004700 high-density polyethylene Substances 0.000 description 3
- 229910052500 inorganic mineral Inorganic materials 0.000 description 3
- 239000011707 mineral Substances 0.000 description 3
- 230000003595 spectral effect Effects 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000004615 ingredient Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 1
- 238000004566 IR spectroscopy Methods 0.000 description 1
- 241001062009 Indigofera Species 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 238000004061 bleaching Methods 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000000280 densification Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 239000000975 dye Substances 0.000 description 1
- 238000004043 dyeing Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000010437 gem Substances 0.000 description 1
- 229910001751 gemstone Inorganic materials 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000002329 infrared spectrum Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000002932 luster Substances 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 239000002210 silicon-based material Substances 0.000 description 1
- 230000002123 temporal effect Effects 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N21/3563—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing solids; Preparation of samples therefor
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N21/3581—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using far infrared light; using Terahertz radiation
- G01N21/3586—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using far infrared light; using Terahertz radiation by Terahertz time domain spectroscopy [THz-TDS]
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/87—Investigating jewels
Landscapes
- Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Toxicology (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The present invention relates to emerald detection technique field, specially a kind of emerald identification method based on terahertz time-domain spectroscopic technology, comprising the following steps: S100: emerald taxonomic identification model is established；S200: jade sample to be identified is prepared；S300: the terahertz time-domain signal of jade sample to be identified is measured；S400: the characteristic parameter of jade sample to be identified is calculated；S500: the characteristic parameter of jade sample to be identified and each model in emerald taxonomic identification model are compared, qualification result is obtained.S100 is specifically included: S101: preparing natural jadeite sample and artificial treatment jade sample；S102: the terahertz time-domain signal of measurement natural jadeite sample and artificial treatment jade sample；S103: the characteristic parameter of natural jadeite sample and artificial treatment jade sample is calculated；S104: according to characteristic parameter, emerald taxonomic identification model is formed using neural network algorithm.This hair provide the emerald identification method based on terahertz time-domain spectroscopic technology, be able to solve it is existing in the prior art detection not comprehensively, low efficiency the problem of.
Description
Technical field
The present invention relates to emerald identification technology field, specially a kind of emerald identification based on terahertz time-domain spectroscopic technology
Method.
Background technique
Emerald is the mineral aggregate being made of multi mineral based on jadeite, and emerald is known as " king of jade ", because of it
Quality is fine and smooth, densification is tough and tensile, color is gentle, soft grace, deep over the past thousands of years to be liked by common people.Between the mineral grain of emerald often
It because there is the impurity of the elements such as iron, manganese, and generates black, grey, brown, yellow etc. variegated, significantly impacts the aesthetic measure of emerald, drop
The low value of emerald, it is variegated while increasing the color of emerald in order to remove these, people by using chemical reagent to its into
Row artificial treatment realizes that operation, the lower emerald of quality qualities after artificial treatment such as bleaching, filling, dyeing can be mentioned
It rises, but the value of this artificial treatment emerald can not show a candle to the value of natural jadeite.Emerald is as a kind of its production of non-renewable resources
Smaller, the especially resource of quality jade even more increasingly exhaustion is measured, but demand of the market to quality jade increasingly increases, therefore
It often has and pretends to be quality jade in market circulation by the emerald that the above method carries out artificial treatment.
Following 4 kinds of methods are usually used to the identification of natural jadeite and artificial treatment emerald at present: 1, naked eyes detection method (naked eyes
Watch structure, color, the gloss etc. of emerald)；2, physical property detection method (relative density, the refractive index etc. of detection emerald)；3,
Conventional instrument detection method (charles's filter, ultraviolet fluorescent lamp, jewel spectroscope etc.)；4, large-scale instrument detection method (infrared light
Spectrometer etc.).In the detection process of application method 1,2 and 3, analysis result depends critically upon the experience of identification Shi Zishen, main
Sight factor is affected, and is unfavorable for obtaining objective, accurate detection result；Method 4 is that current jewelry testing agency uses most
More methods, but infrared spectroscopy is only sensitive to the strong vibration of molecule, monitors the weak vibration less than molecule, and artificial treatment emerald
The complex chemical compositions such as middle chemical reagent, dyestuff not can be carried out comprehensive detection with existing large-scale instrument, and there are instrument prices
The problems such as valuableness, analysis cost are higher, analysis speed is partially slow.
Summary of the invention
The invention is intended to provide a kind of emerald identification method based on terahertz time-domain spectroscopic technology, it is able to solve existing skill
Detected present in art not comprehensively, low efficiency the problem of.
In order to solve the above-mentioned technical problem, the application provides the following technical solutions:
Emerald identification method based on terahertz time-domain spectroscopic technology, comprising the following steps:
S100: emerald taxonomic identification model is established；
S200: jade sample to be identified is prepared；
S300: the terahertz time-domain signal of jade sample to be identified is measured；
S400: the characteristic parameter of jade sample to be identified is calculated；
S500: each model in the characteristic parameter of jade sample to be identified and emerald taxonomic identification model is carried out pair
Than obtaining qualification result；
S100 specifically includes the following steps:
S101: natural jadeite sample and artificial treatment jade sample are prepared；
S102: the terahertz time-domain signal of measurement natural jadeite sample and artificial treatment jade sample；
S103: the characteristic parameter of natural jadeite sample and artificial treatment jade sample is calculated；
S104: according to characteristic parameter, emerald taxonomic identification model is formed using neural network algorithm.
In technical solution of the present invention, compare infrared spectrum technology, terahertz time-domain spectroscopy to the ingredient of substance, structure very
Sensitivity, therefore comprehensive and accurate measurement can be carried out to the structure inside emerald, ingredient using this method, make up existing method pair
The deficiency of natural and artificial treatment emerald identification, and sub- skin may be implemented in subpicosecond magnitude in the typical pulse-widths of THz wave
Second, femtosecond time resolution rate, the interference of background radiation noise can be effectively inhibited, the accuracy rate of identification and analysis is improved, analyzed
As a result more objective, accurate；It prepares natural jadeite sample and artificial treatment jade sample respectively simultaneously, and is calculated using neural network
Method is trained study to parameter automatically, generates emerald taxonomic identification model by establishing emerald taxonomic identification model and passes through meter
The characteristic parameter and emerald taxonomic identification model for calculating jade sample to be identified compare and analyze, and can be quickly obtained analysis mirror
Fixed tests and analyzes efficiency as a result, improving.
Further, natural jadeite sample, artificial treatment jade sample and emerald to be identified are prepared in S200 and S101
When sample, it is performed both by following steps:
Jade sample thickness to be prepared is milled to preset thickness；
By the equal minute finish in the two sides of jade sample to be prepared.Unified thickness and surface gloss can be with
The comparison under Same Latitude is carried out, and then can preferably be compared jadeite jade emerald taxonomic identification model to be identified point
Analysis.
Further, natural jadeite sample, artificial treatment jade sample and to be identified are measured in the S300 and S102
When the terahertz time-domain signal of jade sample, it is performed both by following steps:
S1: laser equipment emits laser, and laser is divided into two bundles after passing through polarization spectroscope；
S2: weaker a branch of be used as of energy detects light, and detection light is after optical lens refraction and convergence, without sample
This direct irradiation is in the photoconducting antenna for detection；
S3: the stronger another Shu Zuowei pumping light of energy, pumping light through optical lens be delayed and focus post-concentration added with
On the photoconducting antenna of bias-voltage, terahertz pulse is generated；
S4: terahertz pulse radiation is emitted by Semi-spherical face lenses and passes through lens focus in sample surface, detection
Lens can will transmit through the terahertz signal convergence after sample, and be radiated on photoconducting antenna；
S5: by detection light to terahertz signal carry out discrete sampling, thus obtain the corresponding terahertz signal of sample when
Domain waveform.
Laser is divided into weak two beam of the last one one using polarization spectro, uses strong a branch of as excitaton source, excitation generates terahertz
Hereby pulse, and weak a branch of be used as detects light, to carry out discrete sampling to the terahertz pulse signal for penetrating sample, realizes sample
The acquisition of terahertz time-domain signal.
Further, the air humidity of the test environment of S1-S5 is 1.5-2.5%, and temperature is 20-23 DEG C.Reduce as far as possible
The influence of air moisture, vapor and temperature to measurement result, so that detection is more accurate.
Further, the test equipment in S1-S5 and tested sample are placed in the sealing space filled with nitrogen.Avoid the external world
Gas or dust influence testing result.
Further, laser described in S1 is that center wavelength is 1064nm, pulsewidth 80fs, repetition rate 100MHz, exports
Power is the femtosecond pulse of 20mW.
Further, natural jadeite sample, artificial treatment jade sample and to be identified are calculated in the S400 and S103
When the characteristic parameter of jade sample, following steps are executed:
S10: Terahertz frequency-region signal is converted using Fast Fourier Transform by terahertz time-domain signal；
S20: absorption spectrum is extracted according to Terahertz frequency domain spectra；
S30: absorption spectrum is analyzed using Principal Component Analysis, and obtains its characteristic parameter.
It is then the time-domain signal of Terahertz carries out spy by being fourier transformed into frequency domain again that equipment, which directly measures come,
Levy the calculating and extraction of parameter.
Further, in S20 according to the following formula, absorption spectrum is extracted:
T (ω)=Esam(ω)/Eref(ω)
Wherein, T (ω) is the transmission coefficient spectrum of jade sample, Eref(ω) is the Terahertz frequency spectrum of reference signal, Esam
(ω) is jade sample Terahertz frequency spectrum, and ω is angular frequency, and d is the thickness of jade sample, and c is the light velocity, and α (ω) is jade sample
Absorption coefficient, ρ (ω) item be jade sample signal and reference signal amplitude ratio, k (ω) be test sample complex refractivity index
Imaginary part, also referred to as extinction coefficient.
Further, natural jadeite sample, artificial treatment jade sample and to be identified are measured in the S300 and S102
When the terahertz time-domain signal of jade sample, 3-5 different points carry out signal acquisition, each point weight on selection sample
3-4 terahertz time-domain signal of second mining collection takes the average value of terahertz time-domain signal when calculating characteristic parameter.By to difference
Point repeatedly test, be averaged when calculating characteristic parameter, can be improved the accuracy of data, and then improve qualification result
Accuracy.
Detailed description of the invention
Fig. 1 is that the present invention is based on the flow charts in the emerald identification method embodiment of terahertz time-domain spectroscopic technology；
Fig. 2 is that the present invention is based on obtain terahertz time-domain in the emerald identification method embodiment of terahertz time-domain spectroscopic technology
The schematic diagram of signal；
Fig. 3 is that the present invention is based on the absorptions of emeralds different in the emerald identification method embodiment of terahertz time-domain spectroscopic technology
Spectrogram.
Specific embodiment
It is further described below by specific embodiment:
As shown in Figure 1, emerald identification method of the present embodiment based on terahertz time-domain spectroscopic technology the following steps are included:
S100: emerald taxonomic identification model is established；
S200: jade sample to be identified is prepared；
S300: the terahertz time-domain signal of jade sample to be identified is measured；
S400: the characteristic parameter of jade sample to be identified is calculated；
S500: each model in the characteristic parameter of jade sample to be identified and emerald taxonomic identification model is carried out pair
Than obtaining qualification result.
Wherein, S100 specifically includes the following steps:
S101: natural jadeite sample and artificial treatment jade sample are prepared；
S102: the terahertz time-domain signal of measurement natural jadeite sample and artificial treatment jade sample；
S103: the characteristic parameter of natural jadeite sample and artificial treatment jade sample is calculated；
S104: according to characteristic parameter, emerald taxonomic identification model is formed using neural network algorithm.
When preparing natural jadeite sample, artificial treatment jade sample and jade sample to be identified in S200 and S101,
It is performed both by following steps:
Jade sample thickness to be prepared is milled to preset thickness；
By the equal minute finish in the two sides of jade sample to be prepared.
Natural jadeite sample, artificial treatment jade sample and jade sample to be identified are measured too in S300 and S102
When hertz time-domain signal, test equipment and tested sample be placed in tested in the sealing space filled with nitrogen environment air it is wet
Degree is 1.5-2.5%, and temperature is 20-23 DEG C, then executes following steps:
S1: laser equipment emits laser, and laser is divided into two bundles after passing through polarization spectroscope；Laser is that center wavelength is
The femtosecond pulse that 1064nm, pulsewidth 80fs, repetition rate 100MHz, output power are 20mW；
S2: weaker a branch of be used as of energy detects light, and detection light is after optical lens refraction and convergence, without sample
This direct irradiation is in the photoconducting antenna for detection；
S3: the stronger another Shu Zuowei pumping light of energy, pumping light through optical lens be delayed and focus post-concentration added with
On the photoconducting antenna of bias-voltage, terahertz pulse is generated；
S4: terahertz pulse radiation is emitted by Semi-spherical face lenses and passes through lens focus in sample surface, detection
Lens can will transmit through the terahertz signal convergence after sample, and be radiated on photoconducting antenna；
S5: carrying out discrete sampling to the terahertz signal that receives, thus obtain the corresponding terahertz signal of sample when
Domain waveform.
Natural jadeite sample, artificial treatment jade sample and jade sample to be identified are measured in S300 and S102 step
Terahertz time-domain signal when, points 3-5 different on selection sample carry out signal acquisition, each point repeated acquisition 3-
4 terahertz time-domain signals take the average value of terahertz time-domain signal when calculating characteristic parameter, in the present embodiment, in each sample
5 points are chosen in sheet and carry out signal acquisition, and each point acquires 4 signals.
The spy of natural jadeite sample, artificial treatment jade sample and jade sample to be identified is calculated in S400 and S103
When levying parameter, following steps are executed:
S10: Terahertz frequency-region signal is converted using Fast Fourier Transform by terahertz time-domain signal；
S20: according to the following formula, absorption spectrum is extracted:
T (ω)=Esam(ω)/Eref(ω)
Wherein, T (ω) is the transmission coefficient spectrum of jade sample, Eref(ω) is the Terahertz frequency spectrum of reference signal, Esam
(ω) is jade sample Terahertz frequency spectrum, and ω is angular frequency, and d is the thickness of jade sample, and c is the light velocity, and α (ω) is jade sample
Absorption coefficient, ρ (ω) item be jade sample signal and reference signal amplitude ratio, k (ω) be test sample complex refractivity index
Imaginary part, also referred to as extinction coefficient.
S30: data are analyzed using Principal Component Analysis, and obtain its characteristic parameter.
For this method when it is implemented, preparing first to natural jadeite sample and artificial treatment jade sample, unification will
Thickness of sample is milled to 100 μm, and the two sides of sample is thrown to bright luster by sample produced as sheets.
Then it is measured respectively using terahertz time-domain spectroscopy system through air and through the terahertz time-domain of jade sample
Spectral signal, specifically, using the terahertz time-domain spectroscopy system based on transmission mode, the system is by titanium indigo plant in the present embodiment
Sapphire laser generation central wavelength is 1064nm, pulsewidth 80fs, repetition rate 100MHz, output power are flying for 20mW
Pulse per second (PPS) laser generates by photoconductive antenna (PCA) and detects terahertz pulse.The effective frequency bandwidth of the system is 0.1
~3.5THz, spectral resolution 12.5GHz, quick scanning range are 80ps, temporal resolution 0.1ps, and spot diameter is
1.2cm, optical resolution are less than 0.5mm, and signal-to-noise ratio is greater than 70dB.In order to avoid the influence of water vapor in air when experiment, survey
It is about 2% that examination equipment and tested sample, which are placed in and test the air humidity of environment in the seal closure filled with nitrogen, and temperature is about 21
℃。
As shown in Fig. 2, femtosecond laser is divided into two bundles after passing through polarization spectroscope, and energy is weaker when test equipment is run
A branch of to be used as detection light, which is being used to detect after optical lens refraction and assembling without sample direct irradiation
Photoconducting antenna on；In addition energy is stronger a branch of as pumping light, and post-concentration is delayed and focused through optical lens added with inclined
On the GaAs PCA of voltage, to generate the terahertz pulse that average output power is 130nW, terahertz pulse radiation passes through
The Semi-spherical face lenses made of high resistant silicon materials emit.Then, high density polyethylene (HDPE) is passed through in terahertz pulse radiation
(HDPE) lens TX focuses on sample surface, and finder lens RX can will transmit through the terahertz signal convergence after sample, and irradiate
On detection zinc telluridse PCA.Finally, discrete sampling is carried out to terahertz signal by detection light, to obtain the time domain of the signal
Waveform.
The terahertz time-domain spectroscopy of all jade samples is converted into Terahertz frequency domain spectra using Fast Fourier Transform (FFT),
Absorption spectrum α (ω) is extracted according to Terahertz frequency domain spectra, formula is as follows:
T (ω)=Esam(ω)/Eref(ω)
Wherein, T (ω) is the transmission coefficient spectrum of jade sample, Eref(ω) is the Terahertz frequency spectrum of reference signal, Esam
(ω) is jade sample Terahertz frequency spectrum, and ω is angular frequency, and d is the thickness of jade sample, and c is the light velocity, and α (ω) is jade sample
Absorption coefficient, ρ (ω) item be jade sample signal and reference signal amplitude ratio, k (ω) be test sample complex refractivity index
Imaginary part, also referred to as extinction coefficient.What test sample was directly measured is time-domain signal, by being fourier transformed into frequency domain, so
Above-mentioned formula, the absorption spectrum of available emerald are utilized afterwards；Terahertz spectral range after being fourier transformed is 0.1~
2.5THz.The absorption spectrum image of three kinds of different emeralds is just shown in Fig. 3, it can be seen that different types of emerald is inhaled
Receiving spectrum, there are notable differences.
Using all natural and tera-hertz spectra with artificial treatment jade sample 0.1~2.5THz wave band as data, and
Data are analyzed using Principal Component Analysis, and obtain its data characteristics, obtain characteristic parameter, then apply neural network
Method establishes natural and artificial treatment emerald taxonomic identification model.
For emerald to be identified, sample, acquisition terahertz time-domain signal are prepared according to the method in above-mentioned steps first
And the characteristic parameter of sample is calculated, the characteristic parameter of emerald to be identified is compared with emerald taxonomic identification model then, is selected
It takes closest model as qualification result, and then judges whether emerald to be identified is emerald that artificial treatment is crossed.
The above are merely the embodiment of the present invention, the common sense such as well known specific structure and characteristic are not made excessively herein in scheme
Description, all common of technical field that the present invention belongs to before one skilled in the art know the applying date or priority date
Technological know-how can know the prior art all in the field, and have using routine experiment means before the date
Ability, one skilled in the art can improve in conjunction with self-ability under the enlightenment that the application provides and implement we
Case, some typical known features or known method should not become the barrier that one skilled in the art implement the application
Hinder.It should be pointed out that for those skilled in the art, without departing from the structure of the invention, if can also make
Dry modification and improvement, these also should be considered as protection scope of the present invention, these all will not influence the effect that the present invention is implemented and
Patent practicability.The scope of protection required by this application should be based on the content of the claims, the specific reality in specification
Applying the records such as mode can be used for explaining the content of claim.
Claims (9)
1. the emerald identification method based on terahertz time-domain spectroscopic technology, it is characterised in that: the following steps are included:
S100: emerald taxonomic identification model is established；
S200: jade sample to be identified is prepared；
S300: the terahertz time-domain signal of jade sample to be identified is measured；
S400: the characteristic parameter of jade sample to be identified is calculated；
S500: the characteristic parameter of jade sample to be identified and each model in emerald taxonomic identification model are compared, obtained
To qualification result；
S100 specifically includes the following steps:
S101: natural jadeite sample and artificial treatment jade sample are prepared；
S102: the terahertz time-domain signal of measurement natural jadeite sample and artificial treatment jade sample；
S103: the characteristic parameter of natural jadeite sample and artificial treatment jade sample is calculated；
S104: according to characteristic parameter, emerald taxonomic identification model is formed using neural network algorithm.
2. the emerald identification method according to claim 1 based on terahertz time-domain spectroscopic technology, it is characterised in that: S200
And when preparing natural jadeite sample, artificial treatment jade sample and jade sample to be identified in S101, it is performed both by following step
It is rapid:
Jade sample thickness to be prepared is milled to preset thickness；
By the equal minute finish in the two sides of jade sample to be prepared.
3. the emerald identification method according to claim 1 based on terahertz time-domain spectroscopic technology, it is characterised in that: described
The terahertz time-domain of natural jadeite sample, artificial treatment jade sample and jade sample to be identified is measured in S300 and S102
When signal, it is performed both by following steps:
S1: laser equipment emits laser, and laser is divided into two bundles after passing through polarization spectroscope；
S2: weaker a branch of be used as of energy detects light, and detection light is straight without sample after optical lens refraction and convergence
Connect the photoconducting antenna being radiated at for detection；
S3: the stronger another Shu Zuowei pumping light of energy, pumping light are delayed and focus post-concentration through optical lens added with partially electric
On the photoconducting antenna of pressure, terahertz pulse is generated；
S4: terahertz pulse radiation is emitted by Semi-spherical face lenses and passes through lens focus in sample surface, finder lens
The terahertz signal convergence after sample can be will transmit through, and be radiated on photoconducting antenna；
S5: discrete sampling is carried out to terahertz signal by detection light, to obtain the time domain wave of the corresponding terahertz signal of sample
Shape.
4. the emerald identification method according to claim 3 based on terahertz time-domain spectroscopic technology, it is characterised in that: S1-
The air humidity of the test environment of S5 is 1.5-2.5%, and temperature is 20-23 DEG C.
5. the emerald identification method according to claim 3 based on terahertz time-domain spectroscopic technology, it is characterised in that: S1-
Test equipment and tested sample in S5 are placed in the sealing space filled with nitrogen.
6. the emerald identification method according to claim 3 based on terahertz time-domain spectroscopic technology, it is characterised in that: S1 institute
Stating laser is the femtosecond pulse that center wavelength is 1064nm, pulsewidth 80fs, repetition rate 100MHz, output power are 20mW
Laser.
7. the emerald identification method according to claim 1 based on terahertz time-domain spectroscopic technology, it is characterised in that: described
The characteristic parameter of natural jadeite sample, artificial treatment jade sample and jade sample to be identified is calculated in S400 and S103
When, execute following steps:
S10: Terahertz frequency-region signal is converted using Fast Fourier Transform by terahertz time-domain signal；
S20: absorption spectrum is extracted according to Terahertz frequency domain spectra；
S30: absorption spectrum is analyzed using Principal Component Analysis, and obtains its characteristic parameter.
8. the emerald identification method according to claim 7 based on terahertz time-domain spectroscopic technology, it is characterised in that: S20
According to the following formula, extract absorption spectrum:
T (ω)=Esam(ω)/Eref(ω)
Wherein, T (ω) is the transmission coefficient spectrum of jade sample, Eref(ω) is the Terahertz frequency spectrum of reference signal, Esam(ω)
For jade sample Terahertz frequency spectrum, ω is angular frequency, and d is the thickness of jade sample, and c is the light velocity, and α (ω) is the suction of jade sample
Coefficient is received, ρ (ω) item is the ratio of jade sample signal and reference signal amplitude, and k (ω) is the void of test sample complex refractivity index
Portion, also referred to as extinction coefficient.
9. the emerald identification method according to claim 1 based on terahertz time-domain spectroscopic technology, it is characterised in that: described
The terahertz time-domain of natural jadeite sample, artificial treatment jade sample and jade sample to be identified is measured in S300 and S102
When signal, points 3-5 different on selection sample carry out signal acquisition, when each 3-4 Terahertz of point repeated acquisition
Domain signal takes the average value of terahertz time-domain signal when calculating characteristic parameter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910114853.0A CN109709063A (en) | 2019-02-14 | 2019-02-14 | Emerald identification method based on terahertz time-domain spectroscopic technology |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910114853.0A CN109709063A (en) | 2019-02-14 | 2019-02-14 | Emerald identification method based on terahertz time-domain spectroscopic technology |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN109709063A true CN109709063A (en) | 2019-05-03 |
Family
ID=66264292
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910114853.0A Pending CN109709063A (en) | 2019-02-14 | 2019-02-14 | Emerald identification method based on terahertz time-domain spectroscopic technology |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109709063A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111272692A (en) * | 2019-12-11 | 2020-06-12 | 中国计量大学 | Method for detecting health product additive by using terahertz time-domain spectroscopy technology |
| CN111584993A (en) * | 2020-04-30 | 2020-08-25 | 重庆市计量质量检测研究院 | Navigation antenna with flexibly configured angles |
| CN113816769A (en) * | 2021-09-23 | 2021-12-21 | 国家珠宝检测中心(广东)有限责任公司 | Method for filling inorganic material into jadeite |
| CN115905881A (en) * | 2022-09-30 | 2023-04-04 | 国家珠宝玉石首饰检验集团有限公司 | Method and device for classifying yellow pearls, electronic equipment and storage medium |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101566589A (en) * | 2008-12-15 | 2009-10-28 | 深圳先进技术研究院 | Terahertz imaging device and terahertz imaging method |
| CN103439266A (en) * | 2013-08-26 | 2013-12-11 | 广东省珠宝玉石及贵金属检测中心 | Identification and analysis system for jewelry jade and rock minerals |
| CN103822884A (en) * | 2013-12-19 | 2014-05-28 | 中国矿业大学 | Classified identification method for tea based on terahertz time-domain spectroscopy |
| CN104007115A (en) * | 2014-05-28 | 2014-08-27 | 中国石油大学(北京) | Method and system for detecting jewelry structure by using terahertz time domain spectroscopic technique |
| CN105699317A (en) * | 2016-01-21 | 2016-06-22 | 电子科技大学 | Terahertz time-domain spectrograph capable of entering at fixed angle and simultaneously detecting transmission and reflection |
| CN108279217A (en) * | 2018-04-28 | 2018-07-13 | 江苏建筑职业技术学院 | A kind of coal petrography method of discrimination based on terahertz time-domain spectroscopy |
-
2019
- 2019-02-14 CN CN201910114853.0A patent/CN109709063A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101566589A (en) * | 2008-12-15 | 2009-10-28 | 深圳先进技术研究院 | Terahertz imaging device and terahertz imaging method |
| CN103439266A (en) * | 2013-08-26 | 2013-12-11 | 广东省珠宝玉石及贵金属检测中心 | Identification and analysis system for jewelry jade and rock minerals |
| CN103822884A (en) * | 2013-12-19 | 2014-05-28 | 中国矿业大学 | Classified identification method for tea based on terahertz time-domain spectroscopy |
| CN104007115A (en) * | 2014-05-28 | 2014-08-27 | 中国石油大学(北京) | Method and system for detecting jewelry structure by using terahertz time domain spectroscopic technique |
| CN105699317A (en) * | 2016-01-21 | 2016-06-22 | 电子科技大学 | Terahertz time-domain spectrograph capable of entering at fixed angle and simultaneously detecting transmission and reflection |
| CN108279217A (en) * | 2018-04-28 | 2018-07-13 | 江苏建筑职业技术学院 | A kind of coal petrography method of discrimination based on terahertz time-domain spectroscopy |
Non-Patent Citations (2)
| Title |
|---|
| 买买提明•艾尼瓦尔等: "和田玉的太赫兹光谱研究", 《光谱学与光谱分析》 * |
| 李铁军等: "陶瓷基复合材料的太赫兹无损检测方法", 《激光与光电子学进展》 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111272692A (en) * | 2019-12-11 | 2020-06-12 | 中国计量大学 | Method for detecting health product additive by using terahertz time-domain spectroscopy technology |
| CN111584993A (en) * | 2020-04-30 | 2020-08-25 | 重庆市计量质量检测研究院 | Navigation antenna with flexibly configured angles |
| CN111584993B (en) * | 2020-04-30 | 2021-06-04 | 重庆市计量质量检测研究院 | Navigation antenna with flexibly configured angles |
| CN113816769A (en) * | 2021-09-23 | 2021-12-21 | 国家珠宝检测中心(广东)有限责任公司 | Method for filling inorganic material into jadeite |
| CN115905881A (en) * | 2022-09-30 | 2023-04-04 | 国家珠宝玉石首饰检验集团有限公司 | Method and device for classifying yellow pearls, electronic equipment and storage medium |
| CN115905881B (en) * | 2022-09-30 | 2023-10-20 | 国家珠宝玉石首饰检验集团有限公司 | Yellow pearl classification method and device, electronic equipment and storage medium |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109709063A (en) | Emerald identification method based on terahertz time-domain spectroscopic technology | |
| CN101275912B (en) | Fluid food browning testing method | |
| CN105181672B (en) | A kind of Raman spectrum wave number and intensity real-time correction method | |
| Xie et al. | Applications of near-infrared systems for quality evaluation of fruits: A review | |
| CN104849233B (en) | A kind of method and device of detection cereal new-old degree | |
| CN101210873A (en) | Method and apparatus for rapid detection for vegetable oil purity using terahertz time-domain spectroscopy | |
| CN109669023A (en) | A kind of soil attribute prediction technique based on Multi-sensor Fusion | |
| Khodabakhshian et al. | A comparative study of reflectance and transmittance modes of Vis/NIR spectroscopy used in determining internal quality attributes in pomegranate fruits | |
| CN102539378A (en) | Semiconductor laser array near infrared spectrometer | |
| CN106290292A (en) | A kind of utilize the method for carotenoid content in copolymerization Jiao's microscopic Raman detection Folium Camelliae sinensis | |
| CN108107019A (en) | A kind of method that versicolorin content in corn is quickly detected based near infrared spectroscopy | |
| CN111562252A (en) | Raman detection system based on coaxial dual-wavelength fluorescence elimination | |
| CN109839370A (en) | It is a kind of based on the fresh tea leaves quality assessment method of in-situ Raman spectral technique and application | |
| JP2005291704A (en) | Visible light/near infrared spectral analysis method | |
| CN114544547A (en) | Method and system for on-line recursive demodulation of wavelength modulation spectrum signals | |
| Nguyen et al. | A method for non-destructive determination of cocoa bean fermentation levels based on terahertz hyperspectral imaging | |
| CN110018131A (en) | A kind of identification method in the nephrite place of production based on terahertz time-domain spectroscopic technology | |
| CN109001182A (en) | The Raman spectrum non-destructive determination method of alcohol content in closed container | |
| CN106442396A (en) | Rapidly detecting method for bagasse saccharose content based on near infrared technology | |
| CN109214423A (en) | A kind of food quality discriminant analysis method based on sound state data fusion | |
| CN110186870A (en) | A kind of method that extreme learning machine spectral model differentiates the beautiful dew fresh tea leaves place of production of bestowing favour | |
| CN106442399B (en) | A kind of method that near infrared spectrum differentiates the different same kind fresh tea leaves of planting environment | |
| CN106442400A (en) | Method for rapidly discriminating fresh tea leaves from different soil types through near infrared spectra | |
| CN106568740A (en) | Method for rapid judging of varieties of fresh tea leaves by near infrared spectroscopy | |
| Cozzolino | Fourier transform spectroscopy |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20190503 |