CN107655845B - Infrared spectrum acquisition methods based on Fourier transform infrared spectroscopy superposing type peak shape - Google Patents
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Abstract
The present invention relates to a kind of infrared spectrum acquisition methods based on Fourier transform infrared spectroscopy superposing type peak shape, generate infrared signal by a laser infrared source, which after interferometer, sample room and detector, generates infrared interference spectrum successively；Infrared interference spectrum is sampled by sampling apparatus through a main frame, obtains infrared interference signal；Infrared interference signal after sampling is subjected to Fourier transformation, and by a superpositing function, peak shape superposition is carried out to the infrared interference signal, and then obtains infrared percent transmittance spectrum, is shown by display device.A kind of infrared spectrum acquisition methods based on Fourier transform infrared spectroscopy superposing type peak shape proposed by the invention, have reached and have doubled infrared spectrum resolution ratio, and enhance the technique effect of each one times of peak signal.
Description
Technical field
The present invention relates to mathematic(al) manipulation, signal processing and infrared spectroscopy fields, especially a kind of to be become based on Fourier
Change the infrared spectrum acquisition methods of infrared spectrum superposing type peak shape.
Background technology
French mathematical physics scholar Joseph Fourier is put forward for the first time and proves any mechanical periodicity at any time within 1807
As long as signal meets the series combination that the condition of convergence can be expanded as cosine and sine trigonometric frequency function.Become when the period of signal
When infinity, then develop into famous Fourier transformation.For limited N number of such trigonometric function combination, integrated form
Fourier transformation can be expressed with discrete Fourier transform.
One frequency is ω0The function that cosine signal changes over time can be expressed as cos (ω0t).Its Fourier transformation
For
Using Euler's formula e-iωt=cos (ω t)+isin (ω t), Fourier transformation can be expressed as again
Actual signal is all analyzed in finite time domain, so Fourier transformation is all basic using three kinds at present
What peak shape carried out, that is, peak shape is absorbed, peak shape and amplitude peak shape is dissipated, is shown in Table 1.
1 three kinds of Fourier transformation peak shape expression of table
Fourier transform infrared spectroscopy is the principle being concerned with based on light wave itself, and Michelson's interferometer can be proportional
The frequency for reducing infrared spectrum, then easily can carry out Fourier transformation to the interference signal of acquisition with computer and be converted to
Infrared spectrum.Since Fourier transform infrared spectroscopy uses amplitude peak-shaped function, thus the phase shift base of infrared frequency signals
Originally peak shape is not interfered with as a result, not considering the phase shift of correcting signal herein.The great advantage of existing Fourier transformation is pair
Signal executes causality operation, in addition to signal phase, it is no longer necessary to prediction signal parameter acquiring signal message.Because of new skill
As soon as art principle increases step superposition, original causality is broken when computational methods require some preset parameters, while pre-
Parameter is set to be also required to suitably occupy the operation time of Fourier transformation.
Light displacement distance (the light of interferometer is depended on by the resolving power of existing theoretical Fourier Transform Infrared Spectrometer
Path difference), inversely.If one times of resolving power is improved, that is, constriction infrared spectrum peak width half, then interference light
Mobile light path must just extend one times, then the manufacturing cost of infrared spectrometer and technology require to be required for adding more than one times
Input, and instrument and equipment will also become bulky and hulking.Moreover, the noise of instrument of infrared spectrum is largely random, it can
Infrared signal is enhanced signal strength (being commonly called as signal-to-noise ratio) after Multiple-Scan is cumulative by average treatment.This common increasing
Strong signal method needs to occupy computer storage space and spends more operation times certainly.
Invention content
The purpose of the present invention is to provide a kind of infrared spectrums based on Fourier transform infrared spectroscopy superposing type peak shape to obtain
Method is taken, to overcome defect existing in the prior art.
To achieve the above object, the technical scheme is that：One kind being based on Fourier transform infrared spectroscopy superposing type peak
The infrared spectrum acquisition methods of shape generate infrared signal by a laser infrared source, and the infrared signal is successively through interferometer, sample
Behind product room and detector, infrared interference spectrum is generated；The infrared interference is composed by sampling apparatus through a main frame and is carried out
Sampling obtains infrared interference signal；Infrared interference signal after sampling is subjected to Fourier transformation, and by superpositing function, it is right
The infrared interference signal carries out peak shape and is superimposed mathematical operation, and then obtains infrared percent transmittance spectrum, by display device into
Row display.
In an embodiment of the present invention, remember that the infrared interference signal after the sampling is：
The π Kcos of f (t)=2 (ω0t) 0≤t≤T
Wherein, signal strength K, T are that sample frequency is ω0Cosine signal Kcos (ω0T) time implemented；
And Fourier transformation absorption peak shape of the infrared interference signal after Fourier's plate changes is：
When there is the infrared signal of N number of combination of frequency, angular frequency series ω=2m π/T and ω0=2n π/T, wherein m and n
=0,1,2 ..., N-1, the absorption peak shape of discretization is：
Fourier transformation dissipates peak shape：
The diverging peak shape of discretization is：
Fourier transformation amplitude peak shape is：
The amplitude peak shape of discretization is：
The superpositing function is：
And superpositing function Simp of the note with plus sige1For right superpositing function, the Simp with minus sign2For left superpositing function；
Enable x=ω-ω0, operation is overlapped to above-mentioned infrared interference signal by above-mentioned superpositing function：
Fourier transformation after superimposed absorbs peak shape：
The absorption peak shape of corresponding discretization is：
Fourier transformation after superimposed dissipates peak shape：
The diverging peak shape of corresponding discretization is：
Fourier transformation amplitude peak shape after superimposed is：
The amplitude peak shape of discretization is：
In an embodiment of the present invention, the peak shape, which is superimposed, further includes：To the infrared interference signal, obtains Fourier and become
Full spectrum is changed, carries out spectral peak reconstruct, and obtain peak symmetry axis and baseline peak width one by one；Toe letter is cut by phase difference correction and gibbs
After number carries out correction operation, peak shape, Fourier transformation diverging peak shape and Fourier transformation width are absorbed to the Fourier transformation
After spending peak shape progress de-convolution operation, then the superpositing function is used to be overlapped operation.
In an embodiment of the present invention, the peak shape, which is superimposed, further includes：Sampling number to Fourier transformation and resolution
Rate is configured, and according to sample frequency ω0It is grouped into line frequency, the Fourier transformation in the grouping of each frequency is absorbed
Peak shape, Fourier transformation diverging peak shape and Fourier transformation amplitude peak shape, operation is overlapped using the superpositing function.
In an embodiment of the present invention, the peak shape, which is superimposed, further includes：Discretization sampling is made to infrared interference signal f (t),
Enable sampling number be N, interception one group of discrete signaling point f (0), f (1), f (2), f (k), f (N-1)；Through discretization
Fourier transformation obtain N number of data F (0), F (1), F (2), F (k),, F (N-1), Fourier transform matrix table
Show as follows：
Wherein, the W=exp (- i2 π/N) of N × N Fourier transform matrix.
Increase a diagonal line in the Fourier transform matrix and be superimposed matrix, obtains the change of the Fourier after superimposed operation
Change matrix：
In an embodiment of the present invention, it by using by column, or in preset resolving power condition Δ n-quadrant, is arranged by Δ N
It is scanned, by comparing each scan data point and former point slope variation, determines diagonal line square in diagonal line superposition matrix
Array element element is 2 or 0.
In an embodiment of the present invention, for the right superposition in superposition, when former point slope is positive value, namely
More than 0, diagonal matrix elements take 2；When former point slope is 0 or is negative value, then diagonal matrix elements take 0 or close
0 decimal；For the left superposition in superposition, step is opposite.
In an embodiment of the present invention, it is increase by the peak value of contrast scans data point and former point, steady or reduction,
Determine that diagonal matrix elements still take 0 for 2.
In an embodiment of the present invention, the peak shape, which is superimposed, further includes：By synchronizing to before and after the progress of adjacent harmonic signal
Left superposition or/and right superposition.
In an embodiment of the present invention, the laser infrared source uses launch wavelength for 632.8 nanometers of He-Ne Lasers
Infrared light supply；The interferometer light path twocouese moves 3295 points of exponent number, resolution ratio 16cm-1, and with wave number spacing 3.85cm-1, read 709 wave number points.
In an embodiment of the present invention, it is red that Raman spectrometer, near infrared spectrometer or far-infrared spectrometer acquisition can be used
Outer percent transmittance spectrum.
Compared to the prior art, the invention has the advantages that：One kind proposed by the invention is become based on Fourier
The infrared spectrum acquisition methods for changing infrared spectrum superposing type peak shape (absorb peak shape, dissipate peak shape, width using classical peak shape
Spend peak shape) symmetry realizes one times of signal strength of enhancing using superimposing technique and improves one times of resolving power.Superpositing function can be with
Optimization application, can take whole frequency components to be all overlapped, and external spectrum can also locally implement left superposition and is superimposed with right, realize and divide
Four times of enhancing effects of resolution.Usual peak shape idea is changed, asymmetric peak shape table is pursued in the case where ensureing information without loss
Up to mode, to the quality of promotion signal analysis.It can realize to reach on original infrared instrumentation and extend one times of movement
The effect of light path.
Description of the drawings
Fig. 1 is that Fourier transformation absorbs peak shape schematic diagram in one embodiment of the invention.
Fig. 2 is that Fourier transformation dissipates peak shape schematic diagram in one embodiment of the invention.
Fig. 3 is Fourier transformation amplitude peak shape schematic diagram in one embodiment of the invention.
Fig. 4 is the left superposition absorption peak schematic diagram of Fourier transformation in one embodiment of the invention.
Fig. 5 is the right superposition absorption peak schematic diagram of Fourier transformation in one embodiment of the invention.
Fig. 6 is that the right superposition of Fourier transformation dissipates peak shape schematic diagram in one embodiment of the invention.
Fig. 7 is the right superposition amplitude peak shape schematic diagram of Fourier transformation in one embodiment of the invention.
Fig. 8 is the two neighboring peak schematic diagram in part in one embodiment of the invention.
Fig. 9 is that the infrared spectral peak that latter two is basically separated using left stacked system in one embodiment of the invention merges peak with original
Shape schematic diagram.
Figure 10 be one embodiment of the invention in simultaneously using it is left superposition and right stacked system latter two be basically separated it is infrared
Spectral peak merges peak shape schematic diagram with original.
Figure 11 is the original infrared interference signal schematic representation of background in one embodiment of the invention.
Figure 12 is the original infrared interference signal schematic representation of polystyrene in one embodiment of the invention.
Figure 13 be existing Fourier Transform Technique obtains in one embodiment of the invention polystyrene wave number from 470 to
3200cm-1Infrared spectrum.
Figure 14 is Fourier transformation superimposing technique and the existing Fourier used in one embodiment of the invention in the present invention
The wave number 2970-3200cm that converter technique obtains-1Infrared spectrum in section.
Figure 15 is Fourier transformation superimposing technique and the existing Fourier change used in one embodiment of the invention in the present invention
Change the wave number 1550-1650cm of technical limit spacing-1Infrared spectrum in section.
Figure 16 is to implement a left side to two neighboring peak simultaneously respectively in crucial wave number point in fig. 13 in one embodiment of the invention
Infrared spectrum after superposition and right overlap-add procedure.
Specific implementation mode
Below in conjunction with the accompanying drawings, technical scheme of the present invention is specifically described.
The present invention provides a kind of infrared spectrum acquisition methods based on Fourier transform infrared spectroscopy superposing type peak shape, passes through
One laser infrared source generates infrared signal, which after interferometer, sample room and detector, generates infrared successively
Interference spectrum；Infrared interference spectrum is sampled by sampling apparatus through a main frame, obtains infrared interference signal；It will adopt
Infrared interference signal after sample carries out Fourier transformation, and by a superpositing function, and it is folded to carry out peak shape to the infrared interference signal
Add, and then obtain infrared percent transmittance spectrum, is shown by display device.Using this method, one-component wave is reached
Number peak intensity is enhanced one times, and peak width is narrowed down one times of effect.
Further, in the present embodiment, by using infrared spectrometer, the laser based on interferometer and Fourier transformation
Light source, but the laser light source of above-mentioned offer is provided, it also may extend to the drawing using same operation principle and laser light source
Graceful spectrometer, near infrared spectrometer or far-infrared spectrometer, for obtaining percent transmittance spectrum.
Further, in the present embodiment, the optical path difference time signal that infrared interference generates belongs to cosine signal, Er Qiehong
External interference signal can meet Fourier transformation condition with linear combination.Fourier transform, which is applied to signal related with time t, to be had
Several kinds of different expression ways, for convenience's sake, using following expression equation：
The π Kcos of f (t)=2 (ω0t) 0≤t≤T.
To the above-mentioned infrared linear detection time domain signal of single beam instrument by first have Fourier transformation processing will produce three kinds
Classical peak shape：
(1) Fourier transformation absorbs peak shape, as shown in Figure 1, its mathematical expression equation is exactly common sinc functions：
When there is the infrared signal of N number of combination of frequency, angular frequency series ω=2m π/T and ω 0=2n π/T (wherein m and n
=0,1,2 ... ..., N-1), the absorption peak shape expression formula of discretization is：
(2) Fourier transformation dissipates peak shape, as shown in Figure 2：
The diverging peak shape expression formula of discretization is：
(3) Fourier transformation amplitude peak shape, as shown in Figure 3：
The amplitude peak shape expression formula of discretization is：
Further, in the present embodiment, a pair of of superposition (Superimpose) function of proposition:
Above-mentioned superpositing function can be equivalent to execution and the half of symmetric function and antisymmetric function is added to function itself
The other half, i.e., right superposition or left superposition.
Common sign function is defined as in Fourier transformation：
Superpositing function has following relationship with sign function：
Simp (x)=1 ± sgn (x) (equation 6)
In real number field, wherein the superpositing function with plus sige (+) is exactly another common rank in twice Fourier transformation
Jump function H (x)：
Simp1 (x)=2H (x) (equation 7)
Jump function is defined as：
Further, in the present embodiment, if x=ω-ω0, three are derived using above-mentioned Fourier transformation superposition
The new basic peak shape of kind.
(1) Fourier transformation superposition absorbs peak shape, and as shown in Figure 4 and 5, respectively left superposition absorption peak and the right side are folded
Add absorption peak：
The superposition of discretization absorbs peak shape expression formula：
(2) Fourier transformation superposition diverging peak shape：
As shown in fig. 6, dissipating peak shape schematic diagram for right superposition.
The superposition of discretization dissipates peak shape expression formula：
(3) novel Fourier transformation is superimposed amplitude peak shape：
As shown in fig. 7, being right superposition amplitude peak shape schematic diagram.
The superposition amplitude peak shape expression formula of discretization is：
Further, it is ω that Fig. 1, which is angular frequency,0Cosine signal carries out the absorption peak shape of Fourier transformation, it is axial symmetry
, therefore after overturning superposition to the right, peak width reduces half, peak height increasing is twice, the interference on the left of torsion shaft (former symmetry axis)
Peak (Gibbs phenomenon) is reduced to zero, sees Fig. 5.It is of course also possible to overturning is superimposed absorption peak to the left as shown in Figure 4, as obtaining
Effect.Fig. 2 is to obtain diverging peak shape as Fourier transform to same signal.It is central symmetry, can by rotate 180 ° into
Row superposition.Because amplitude peak shape is absorption peak shape and the difference of two squares after diverging peak shape respectively square adduction, the amplitude in Fig. 3
Peak shape is also axisymmetric.Principle of stacking in the present embodiment is equally applicable to diverging peak shape and amplitude peak shape.
Further, in the present embodiment, it can be realized there are many method.Some methods need pre- according to practical application
Survey a small amount of parameter, such as peak value.Some methods need, according to the how much preset superposition frequency range of spectral peak, to do so certainly occupy more
The memory space of more multicomputer increases and calculates the time.Due to increasing step superposition, when computational methods require some preset parameters
When just broken original causality, while preset parameter is also required to suitably occupy the operation time of Fourier transformation.Fu Li
Leaf transformation is maximum the disadvantage is that main peak will produce secondary lobe harmonic wave, such as the peak shape shown in Fig. 1 to Fig. 3, also referred to as Gibbs phenomenon,
Inhibit them so being generally used and cutting toe function.Our new technology can reduce the Gibbs phenomenon of signal side, but signal
The other side still needs a section toe function to do correction operation.
Further, in the present embodiment, it is K (the arbitrary real numbers of K=), frequency ω to signal strength0Cosine signal
Kcos(ω0T) implement the measurement that the time is T, table two and table three by numerical computations compare existing Fourier transformation theory with
The main peak shape technical parameter of novel Fourier transformation theory.Result of calculation shows the peak that three kinds of peak shapes can be doubled by increasing
Height, the peak width of constriction half, so significantly improved cosine signal can identification.
Two existing Fourier transformation peak shape major parameter of table
Three novel Fourier transformation of table is superimposed peak shape major parameter
In order to allow those skilled in the art to further appreciate that method proposed by the invention, above-mentioned three kinds of Fourier transformation bases
The superposition of this peak shape can be realized by following several methods, but the method provided in being not limited to the present embodiment.Fourier transformation
Infrared spectrum generally use amplitude peak shape calculates realize that the Fourier transformation embodiment of superposing type is all superposed to amplitude below
Example.
Embodiment one
Fourier transformation is routinely obtained to time signal to compose entirely, is aimed at spectral peak reconstruct and is found out peak symmetry axis and baseline one by one
Peak width is overlapped.It gets twice the result with half the effort although doing so, but still a kind of means of can yet be regarded as.The speciality of frequency domain spectral peak has been enumerated in table
Two and table three be fourier transformed since the peak width of basic peak shape depends primarily on sample time T, and utilize basic peak shape pair
Reach the increasing of each component peak intensity after the superposition of title property to double, peak width reduces one times.After phase difference correction and gibbs cut toe
With approximate Gaussian distribution peak shape and peak shape factor, symmetry is defined, is equivalent to after carrying out deconvolution to spectrogram and makees superposition.Figure
8 be two infrared adjacent peaks of simulation, indicates that wave number is respectively 1400cm with the data point heavy line with dot-1And 1412cm-1, when resolution ratio is more than 6cm-1When, the two peaks almost merge, reluctantly it is distinguishable go out they between have trench.Usually
Deconvolution be to rebuild spectral peak by doing curve matching to original spectral data, as fine dotted line is fitted in Fig. 8 two it is symmetrical
Peak shape.The same adjacent peak of superposing type Fourier transform pairs uses superposing type operation, sees the left superimposing technique of Fig. 9 displayings, obtains
Two infrared spectral peaks (being indicated with the heavy line with dot) being basically separated merge peak shape (fine dotted line) with original and compare, they
Ir transmissivity and wave number all successfully essence reduction.Further in Fig. 10, the two adjacent peaks are implemented respectively simultaneously
Left superposition and right superposition, they become completely by two separated peaks.This patent is proposed based on superposing type Fourier transformation
One novel and effective Deconvolution Technique.
Embodiment two
Computer does Fourier transformation and has all pre-set sampling number, these sampling numbers must be sufficiently large to ensure letter
Number frequency is undistorted.Existing Fourier Transform Infrared Spectrometer when carrying out interference spectrum analysis will preset selection resolution ratio also
It is that light claims poor size.According to any equation in three kinds of peak shapes of the Fourier transformation superposition of above-mentioned offer, i.e. equation
9, equation 10 or equation 11 can be to all sample frequency component ω0Superposition is done, is ensured in all measurement ranges
Infrared spectral peak all none omit, do so and be equivalent to the superposition of N number of component and will take N times of time to complete.Further, on
Stating Fourier transformation superposition can optimize in technology, be suitably grouped to frequency component, to each group of frequencies according to reality
It is required that the index reached executes novel Fourier transformation superposition respectively, it can effectively shorten operation time, especially modern computing
Machine arithmetic speed has greatly promoted, and the superposition after optimization will not increase too much.
Embodiment three
The signal f (t) that need to be formed to harmonic wave by existing Fourier transformation theory makees discretization sampling, if sampling number is N, cuts
Get one group of discrete signaling point f (0), f (1), f (2), f (k), f (N-1).Discretization Fourier transformation then obtains
Go out N number of data F (0), F (1), F (2), F (k), F (N-1), be expressed as follows with square matrix-style：
In formula, the W=exp (- i2 π/N) of N × N Fourier transform matrix.
Superposition proposed by the invention only need to add a diagonal line to be superimposed matrix in former Fourier transform matrix：
Further, it may be used by column, or in preset resolving power condition Δ n-quadrant, be scanned by Δ N row,
By comparing each scan data point and former point slope variation, determine that diagonal matrix elements are 2 or 0, as follows.
For right superposition, when slope is positive value (being more than 0), diagonal matrix elements take 2；When slope is 0 or is negative
When value, then diagonal matrix elements take 0 (or close to 0 decimal).Can also contrast scans data point and former point peak value
It is to increase, is steady or reduce to determine that diagonal matrix elements are 2 or take 0.For left superposition, just step is opposite.
Benefit in this way is only to handle causality, with existing Fourier transformation is theoretical, does not need Prediction Parameters, but
Spectrogram has the baseline for being forced to 0.
Superposition diagonal matrix column scan is not associated with row matrix, and above-mentioned superposition is applicable in and follows Fast Fourier Transform (FFT)
(FFT) synchronous to carry out.What Fast Fourier Transform (FFT) executed is square matrix.When transposed transform matrix be 3295 (light claims difference) row,
When segmentation 709 (wave number) row, zero filling technology can be taken to synchronize and realize Fourier transformation superposition and Fast Fourier Transform (FFT).
Example IV
Two kinds of symmetrical superpositing functions are proposed by equation 4.1 and equation 4.2, therefore can also be synchronized to adjacent harmonic wave
Signal carries out front and back left (right side) superposition and right (left side) is superimposed, and the two neighboring peak energy in part, which enough reaches, as shown in Figure 10 is equivalent to promotion
The resolving power of four times of Fourier transformations.Left side peak 1 is left superposition, and peak 2 is right superposition.To that can increase close to two spectral peaks 1 and 2
4 times of resolving power.
Further, in the present embodiment, using 460 commodity-type Fourier transform infrared spectroscopies of Nicolet Prot é g é
Instrument, 632.8 nanometer (6.328 × 10 of configuration transmitting-5Centimetre) the He-Ne Lasers infrared light supply of wavelength.Infrared signal passes through this base
The multiple of this wavelength gets interference spectrum.Interferometer light path twocouese moves 3295 points of exponent number, with wave number spacing 3.85cm-1If
It sets 709 wave numbers and reads point.Background infrared spectrum, then the infrared spectrum of sample are first surveyed by infrared spectrum analysis program, then
Infrared percent transmittance spectrum is obtained by deducting background (it is absorption infrared spectrum to take logarithm then).Figure 11 is that background is original red
External interference signal, and Figure 12 is the original infrared interference signal of polystyrene.
Since Fourier Transform Infrared Spectrometer is commonly provided with polystyrene film as the mark for measuring infrared spectrum resolution ratio
Quasi- sample, so the advantages of further illustrating Fourier transformation superimposing technique by using polystyrene.
As shown in figure 13, it is to use the polystyrene wave number of existing Fourier Transform Technique acquisition from 470 to 3200cm-1's
Infrared spectrum.Toe function is cut by using cosine or Happ-Genzel cuts toe function.According to 16cm-1The original spectrogram of resolution ratio is used
Existing Fourier Transform Technique is in wave number 2970-3200cm-1Section only shows four characteristic peaks, respectively 2854cm-1,
2924cm-1, 3028cm-1And 3062cm-1.In wave number 1550cm-1-1650cm-1Only there is a characteristic peak, wave number in section
1601cm-1。
It is folded by using the Fourier transformation in the present invention to the original infrared interference figure signal in same Figure 12 and Figure 13
After adding technology, as shown in figure 14, in wave number 2970-3200cm-1Section is shown as seven characteristic peaks, respectively 2854cm-1、
2924cm-1、3008cm-1、3028cm-1、3066cm-1、3082cm-1And 3105cm-1.Wherein, thick line is in Fu in the present invention
Infrared spectrum (the resolution ratio 16cm that leaf transformation superimposing technique obtains-1, using every 7.7cm-1Wave number spacing superposition transformation).Filament
Infrared spectrum (the resolution ratio 16cm obtained for existing Fourier Transform Technique-1)。
In wave number 1550-1650cm-1Then tell two characteristic peaks, 1585cm in section-1And 1605cm-1, such as Figure 15 institutes
Show.When the crucial wave number point to the two peaks does left superposition and right superposition, as shown in figure 16, characteristic peak 1585cm respectively simultaneously-1
And 1605cm-1It can also be separated more preferably.It is 16cm in resolution ratio-1Initial data on the basis of using the present invention in Fu in
Leaf transformation superimposing technique obtains infrared spectrum and high-resolution 4cm-1Polystyrene infrared spectrum result complies fully with.
The above are preferred embodiments of the present invention, all any changes made according to the technical solution of the present invention, and generated function is made
When with range without departing from technical solution of the present invention, all belong to the scope of protection of the present invention.
Claims (11)
1. a kind of infrared spectrum acquisition methods based on Fourier transform infrared spectroscopy superposing type peak shape, which is characterized in that pass through
One laser infrared source generates infrared signal, which after interferometer, sample room and detector, generates infrared successively
Interference spectrum；Infrared interference spectrum is sampled by sampling apparatus through a main frame, obtains infrared interference signal；It will adopt
Infrared interference signal after sample carries out Fourier transformation, and by superpositing function, and peak shape superposition is carried out to the infrared interference signal
Mathematical operation, and then infrared percent transmittance spectrum is obtained, it is shown by display device；
The superpositing function is：
And superpositing function Simp of the note with plus sige1For right superpositing function, the Simp with minus sign2For left superpositing function；X is infrared dry
Relate to the frequency of signal.
2. the infrared spectrum acquisition methods according to claim 1 based on Fourier transform infrared spectroscopy superposing type peak shape,
It is characterized in that, remembering that the infrared interference signal after the sampling is：
The π Kcos of f (t)=2 (ω0t)0≤t≤T
Wherein, signal strength K, T are that sample frequency is ω0Cosine signal Kcos (ω0T) time implemented；
And the infrared interference signal be fourier transformed after Fourier transformation absorb peak shape be：
When there is the infrared signal of N number of combination of frequency, angular frequency series ω=2m π/T and ω0=2n π/T, wherein m and n=0,1,
2 ... the absorption peak shape of, N-1, discretization is：
Fourier transformation dissipates peak shape：
The diverging peak shape of discretization is：
Fourier transformation amplitude peak shape is：
The amplitude peak shape of discretization is：
The superpositing function is：
And superpositing function Simp of the note with plus sige1For right superpositing function, the Simp with minus sign2For left superpositing function；
Enable x=ω-ω0, peak shape superposition is carried out to above-mentioned infrared interference signal by above-mentioned superpositing function：
Fourier transformation after superimposed absorbs peak shape：
The absorption peak shape of corresponding discretization is：
Fourier transformation after superimposed dissipates peak shape：
The diverging peak shape of corresponding discretization is：
Fourier transformation amplitude peak shape after superimposed is：
The amplitude peak shape of discretization is：
3. the infrared spectrum acquisition methods according to claim 2 based on Fourier transform infrared spectroscopy superposing type peak shape,
It is characterized in that, the peak shape superposition further includes：To the infrared interference signal, obtains Fourier transformation and compose entirely, carry out spectral peak
Reconstruct obtains peak symmetry axis and baseline peak width one by one；After correction operation being carried out by phase difference correction and gibbs section toe function,
Peak shape, Fourier transformation diverging peak shape and Fourier transformation amplitude peak shape are absorbed to the Fourier transformation and carry out deconvolution fortune
It calculates, then operation is overlapped using the superpositing function.
4. the infrared spectrum acquisition methods according to claim 2 based on Fourier transform infrared spectroscopy superposing type peak shape,
It is characterized in that, the peak shape superposition further includes：The sampling number and resolution ratio of Fourier transformation are configured, and according to
Sample frequency ω0Frequency division group is carried out, peak shape is absorbed to the Fourier transformation in each frequency division group, Fourier transformation dissipates peak
Shape and Fourier transformation amplitude peak shape, operation is overlapped using the superpositing function.
5. the infrared spectrum acquisition methods according to claim 2 based on Fourier transform infrared spectroscopy superposing type peak shape,
It is characterized in that, the peak shape superposition further includes：Discretization sampling is made to infrared interference signal f (t), it is N, interception to enable sampling number
One group of discrete signaling point f (0), f (1), f (2), f (k), f (N-1)；N is obtained through discretization Fourier transformation
A data F (0), F (1), F (2), F (k),, F (N-1), Fourier transform matrix indicate it is as follows：
Wherein, the W=exp (- i2 π/N) of N × N Fourier transform matrix；
Increase a diagonal line in the Fourier transform matrix and be superimposed matrix, obtains the Fourier transformation square after superimposed operation
Battle array：
6. the infrared spectrum acquisition methods according to claim 5 based on Fourier transform infrared spectroscopy superposing type peak shape,
It is characterized in that, by using by column, or in preset resolving power condition Δ n-quadrant, be scanned by Δ N row, pass through ratio
More each scan data point and former point slope variation determine that diagonal matrix elements are 2 or 0 in diagonal line superposition matrix.
7. the infrared spectrum acquisition methods according to claim 6 based on Fourier transform infrared spectroscopy superposing type peak shape,
It is characterized in that, for the right superposition in superposition, when former point slope is positive value, namely it is more than 0, diagonal matrix
Element takes 2；When former point slope is 0 or is negative value, then diagonal matrix elements take 0；For the left superposition in superposition
Operation, step are opposite.
8. the infrared spectrum acquisition methods according to claim 6 based on Fourier transform infrared spectroscopy superposing type peak shape,
It is characterized in that, being increase by the peak value of contrast scans data point and former point, steady or reduction, diagonal matrix member is determined
Element still takes 0 for 2.
9. the infrared spectrum acquisition methods according to claim 2 based on Fourier transform infrared spectroscopy superposing type peak shape,
It is characterized in that, the peak shape superposition further includes：Front and back left superposition or/and the right side are carried out to adjacent harmonic signal by synchronizing
Superposition.
10. the infrared spectrum acquisition methods according to claim 1 based on Fourier transform infrared spectroscopy superposing type peak shape,
It is characterized in that, the laser infrared source uses launch wavelength for 632.8 nanometers of He-Ne Lasers infrared light supply；The interference
Instrument light path twocouese moves 3295 points of exponent number, resolution ratio 16cm-1, and with wave number spacing 3.85cm-1, read 709 wave numbers
Point.
11. the infrared spectrum acquisition methods according to claim 1 based on Fourier transform infrared spectroscopy superposing type peak shape,
It is characterized in that, Raman spectrometer, near infrared spectrometer or far-infrared spectrometer, which can be used, obtains infrared percent transmittance spectrum.
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| CN113720799B (en) * | 2021-11-03 | 2022-02-22 | 华电智控（北京）技术有限公司 | Tail gas measuring method and device based on motor vehicle tail gas remote measuring system |
| CN116662789B (en) * | 2023-07-31 | 2023-10-27 | 杭州泽天春来科技有限公司 | Signal processing method and system of Fourier infrared spectrometer and readable storage medium |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6748334B1 (en) * | 1999-12-06 | 2004-06-08 | Jorge E. Perez | Specialty gas analysis system |
| CN101067650A (en) * | 2007-06-08 | 2007-11-07 | 骆建华 | Signal antinoise method based on partial frequency spectrum data signal reconfiguration |
| CN201215545Y (en) * | 2008-07-03 | 2009-04-01 | 蓝莫德(天津)科学仪器有限公司 | Automatic lithiasis infrared spectrum analysis system |
| CN105675455A (en) * | 2016-01-08 | 2016-06-15 | 珠海欧美克仪器有限公司 | Method and device for reducing random system noise in particle size analyzer |
| CN106054231A (en) * | 2015-04-01 | 2016-10-26 | 富士电机株式会社 | Radioactivity measuring apparatus |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3695360B2 (en) * | 2001-07-04 | 2005-09-14 | 株式会社島津製作所 | Fourier transform infrared spectrophotometer |
| DE10144214C1 (en) * | 2001-09-08 | 2003-04-03 | Bruker Optik Gmbh | IR spectrum recording method using Fourier-transform spectrometer with read-out of array detector for alternate points along displacement path during each displacement of interferometer reflector |
-
2017
- 2017-09-29 CN CN201710908949.5A patent/CN107655845B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6748334B1 (en) * | 1999-12-06 | 2004-06-08 | Jorge E. Perez | Specialty gas analysis system |
| CN101067650A (en) * | 2007-06-08 | 2007-11-07 | 骆建华 | Signal antinoise method based on partial frequency spectrum data signal reconfiguration |
| CN201215545Y (en) * | 2008-07-03 | 2009-04-01 | 蓝莫德(天津)科学仪器有限公司 | Automatic lithiasis infrared spectrum analysis system |
| CN106054231A (en) * | 2015-04-01 | 2016-10-26 | 富士电机株式会社 | Radioactivity measuring apparatus |
| CN105675455A (en) * | 2016-01-08 | 2016-06-15 | 珠海欧美克仪器有限公司 | Method and device for reducing random system noise in particle size analyzer |
Non-Patent Citations (9)
| Title |
|---|
| Fast Algorithms for lp Deconvolution;RAO YARLAGADDA et al.;《IEEE TRANSACTIONS ON ACOUSTICS, SPEECH, AND SIGNAL PROCESSING,》;19850228;第33卷(第1期);第174-182页 * |
| Fourier 自去卷积及其在化学信号处理中的应用;郑建斌 等;《西北大学学报》;20001231;第30卷(第6期);第496－500页 * |
| FSD技术在IMS信号处理中的应用;郑小保 等;《工程实践及应用技术》;20141231;第40卷(第1期);第79-85页 * |
| On Deconvolution Using the Discrete Fourier Transform;HARVEY F. SILVERMAN et al.;《IEEE TRANSACTIONS ON AUDIO AND ELECTROACOUSTICS》;19730430;第26卷(第2期);第112-118页 * |
| 光纤傅里叶变换光谱仪干涉图的对称化处理;李保生 等;《光谱学与光谱分析》;20070630;第27卷(第6期);第1077-1080页 * |
| 叠加共轭对称训练序列的OFDM系统时频同步方法;罗仁泽 等;《电讯技术》;20140930;第54卷(第9期);第1231－1236页 * |
| 基于函数平分迭代的色谱重叠峰分峰方法;朱强 等;《真空科学与技术学报》;20170531;第37卷(第5期);第544-547页 * |
| 基于高斯函数的光谱叠加信号处理仿真研究;胡卫军;《光电技术应用》;20140630;第35卷(第3期);第546-549页 * |
| 磁共振波普分析后处理算法的实现;刘海峰;《中国优秀硕士论文全文数据库 医药卫生科技辑》;20130315(第3期);第E80-52页 * |
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