CN112782337A - Method for controlling variable in coprecipitation method and application - Google Patents
Method for controlling variable in coprecipitation method and application Download PDFInfo
- Publication number
- CN112782337A CN112782337A CN202011545361.6A CN202011545361A CN112782337A CN 112782337 A CN112782337 A CN 112782337A CN 202011545361 A CN202011545361 A CN 202011545361A CN 112782337 A CN112782337 A CN 112782337A
- Authority
- CN
- China
- Prior art keywords
- relation
- coprecipitation
- temperature
- precipitation process
- relationship
- 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
- 238000000975 co-precipitation Methods 0.000 title claims abstract description 71
- 238000000034 method Methods 0.000 title claims abstract description 65
- 230000008569 process Effects 0.000 claims abstract description 27
- 238000006243 chemical reaction Methods 0.000 claims abstract description 21
- 238000013178 mathematical model Methods 0.000 claims abstract description 5
- 239000003513 alkali Substances 0.000 claims description 4
- 239000002585 base Substances 0.000 claims description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 2
- 239000002253 acid Substances 0.000 claims description 2
- 229910002113 barium titanate Inorganic materials 0.000 claims description 2
- 229910052799 carbon Inorganic materials 0.000 claims description 2
- 239000003054 catalyst Substances 0.000 claims description 2
- 239000006185 dispersion Substances 0.000 claims description 2
- SZVJSHCCFOBDDC-UHFFFAOYSA-N ferrosoferric oxide Chemical compound O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 claims description 2
- 238000005457 optimization Methods 0.000 claims description 2
- 239000002245 particle Substances 0.000 claims description 2
- 239000000843 powder Substances 0.000 claims description 2
- 239000000126 substance Substances 0.000 claims description 2
- 238000006467 substitution reaction Methods 0.000 claims description 2
- 238000009795 derivation Methods 0.000 claims 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims 1
- 239000000243 solution Substances 0.000 description 17
- -1 hydroxide ions Chemical class 0.000 description 11
- 230000008859 change Effects 0.000 description 10
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- 238000002474 experimental method Methods 0.000 description 6
- 238000004458 analytical method Methods 0.000 description 5
- 229910052739 hydrogen Inorganic materials 0.000 description 4
- 239000001257 hydrogen Substances 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 239000003795 chemical substances by application Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 229910021645 metal ion Inorganic materials 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N31/00—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods
- G01N31/02—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods using precipitation
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D21/00—Control of chemical or physico-chemical variables, e.g. pH value
- G05D21/02—Control of chemical or physico-chemical variables, e.g. pH value characterised by the use of electric means
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Physics & Mathematics (AREA)
- Physics & Mathematics (AREA)
- Biochemistry (AREA)
- Analytical Chemistry (AREA)
- Chemical & Material Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Molecular Biology (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Engineering & Computer Science (AREA)
- Automation & Control Theory (AREA)
- Catalysts (AREA)
Abstract
The invention relates to a method for controlling variables in a coprecipitation method and to the use thereof. The method comprises the following specific steps: measuring the pH value of the coprecipitation solution at different temperatures by using a pH measuring device; obtaining the relation between the equilibrium constant K of the coprecipitation reaction and the temperature through a Gibbs equation; deducing the relationship between pH and K through ionization balance of coprecipitation reaction; obtaining a parameter-containing relation between the pH and the T according to the relation between the pH and the K and the relation between the K and the temperature; on the basis of the parameter-containing relation between the pH and the T, a mathematical model is established by a least square method, and the relation between the pH and the T is obtained by fitting. The two variables of pH value and temperature are controlled more accurately in the coprecipitation process.
Description
Technical Field
The invention belongs to the technical field of coprecipitation methods, and particularly relates to a method for controlling variables in the coprecipitation method and application thereof.
Background
The information in this background section is only for enhancement of understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art that is already known to a person of ordinary skill in the art.
In order to strictly control the variables during the co-precipitation experiments and make the results more compelling, it is essential to consider the relationship between the pH of the co-precipitation and the co-precipitation temperature. Different metal ions have different precipitation capacities in different temperature and pH environments, the coprecipitation process is generally heated by a water bath method for controlling the temperature, and the change of the reaction temperature has great influence on the pH value of the solution, so that the result of the coprecipitation process is easy to generate great change and influence.
In the existing coprecipitation method, due to the fact that variables cannot be controlled, a rule cannot be found through repeated experiments. The results are also not related exactly to the variables, resulting in poor persuasiveness of the results.
Disclosure of Invention
In view of the above-mentioned problems in the prior art, it is an object of the present invention to provide a method and use for controlling variables in a co-precipitation process.
In order to solve the technical problems, the technical scheme of the invention is as follows:
in a first aspect, a method for controlling variables in a co-precipitation process comprises the steps of:
measuring the pH value of the coprecipitation solution at different temperatures by using a pH measuring device;
obtaining the relation between the equilibrium constant K of the coprecipitation reaction and the temperature through a Gibbs equation;
deducing the relationship between pH and K through ionization balance of coprecipitation reaction;
obtaining a parameter-containing relation between the pH and the T according to the relation between the pH and the K and the relation between the K and the temperature;
on the basis of the parameter-containing relation between the pH and the T, a mathematical model is established by a least square method, and the relation between the pH and the T is obtained by fitting.
Different metal ions have different precipitation capacities in different temperature and pH environments, and the change of reaction temperature has great influence on the pH value of a solution in the coprecipitation process, so that how to control the temperature and the pH value is difficult and problematic in the coprecipitation process.
The linear relation between the pH and the temperature is obtained through the combination of ionization balance and a thermodynamic function, the alkali can be completely ionized from the perspective of alkali excess, and the change of the temperature cannot influence the concentration of hydroxide ions after the complete ionization, so the linear relation between the pH and the temperature can be obtained.
The relation between K and T can be obtained through a thermodynamic function relation, and the relation between pH and T can be obtained through the mutual combination.
In some embodiments of the invention, the pH measuring device comprises a Shanghai Lei magnetic PHS-3C desktop pH meter, a Mettler-Tollido FE-20pH meter, a BPP-7800 laboratory precision PH meter, an American Hastellab PHM220 laboratory desktop pH meter, and the like.
At different pH, the linear relationship between temperature and pH is different. By measuring the pH values at different temperatures, a linear relation can be obtained under a certain pH value, and the constant of the linear relation can be obtained through fitting, so that an exact relation can be obtained.
In some embodiments of the invention, the Gibbs equation (Gibbs-Van' T Hoff equation) is Δ G ═ Δ H-T Δ S.
In some embodiments of the present invention, the relationship between the equilibrium constant K and the temperature is derived by: using thermodynamic functions, the formula for obtaining chemical reactions at constant pressure is:
then theIntegrate with respect to T (p is also a constant) to become
Using equation of reaction isotherm
Deducing the relationship between the equilibrium constant K of a chemical reaction and the temperature
In some embodiments of the invention, the relationship of pH to K is derived by: by ionization equilibrium of acid and alkali, pH-lgK + [ OH ] is obtained-]。
In some embodiments of the invention, substituting the relationship of pH to K into the relationship of equilibrium constant K to temperature yields a relationship of pH to equilibrium constant:
both Δ H and Δ S, R are constants.
The relationship between pH and K can be obtained by ionization equilibrium as shown below.
HL + NaOH (excess) ═ NaL + H2O
NaL＝Na++L-
L-+H2O＝HL+OH-
pH＝-lgK+[OH-]
In addition, NaOH is completely ionized in the aqueous solution, so that the concentration of hydroxide ions is not influenced by temperature rise, namely the concentration value of the hydroxide ions is not changed, and the linear relation between pH and T can be derived.
In some embodiments of the invention, the pH is related to the equilibrium constant
In order to be the parameter B,
is constant a, so the linear relationship between pH and T is pH a + B/T where T + 273.
In some embodiments of the invention, in the linear relationship between pH and T, setting y to pH and x to 1/T yields the parametric relationship between pH and T, y to am+bmx。
In some embodiments of the present invention, the mathematical model is established by using the principle of least squares, and the process of fitting data is as follows:
will measure the value yiAnd the calculated value yjDispersion y ofi-yjSum of squares sigma (y)i-yj)2The minimum is the optimization criterion.
Order to
Converting the linear equation y to am+bmSubstitution of x into
And (4) obtaining:
to am,bmCalculating a partial derivative to make the partial derivative zero;
∑2(am+bmxi-yi)＝0；
∑2bm(am+bmxi-yi)＝0；
to obtain
A is tomAnd bmAnd (4) carrying the equation into a parameter-containing relational expression between the pH and the T to obtain a regression equation, namely the relational expression between the pH and the T.
In a second aspect, the above-mentioned co-precipitation control methodThe application of the medium variable method in the coprecipitation reaction is very wide, and relates to the chemical coprecipitation method for preparing the nano ferroferric oxide particles, the influence of the acid-base ratio of the coprecipitation reaction on the performance of the CuFe synthetic low-carbon alcohol catalyst and the influence of the acid-base condition in the coprecipitation process on BaTiO3Influence on the performance of the ultrafine powder, and the like.
One or more technical schemes of the invention have the following beneficial effects:
the relationship between the pH value and the temperature of coprecipitation is constructed, and the following results are obtained according to the analysis of specific experimental numerical values: the pH value of the coprecipitation decreases linearly with the increase of the temperature, and likewise, the pH value of the coprecipitation has a certain influence on the temperature of the coprecipitation. In addition, a specific relation between the two is given, a solid foundation is laid for deeper research, and variables in the coprecipitation process are controlled more accurately.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the invention and not to limit the invention.
FIG. 1 is a detailed flow chart of the present invention.
Fig. 2 is a graph showing the relationship between pH and T in the upper graph and a graph showing the fitting process in the lower graph in example 1 at pH 10.0.
Fig. 3 is a graph showing the relationship between pH and T in the upper graph and a graph showing the fitting process in the lower graph in example 2 at pH 10.5.
Fig. 4 is a graph showing the relationship between pH and T in the upper graph and a graph showing the fitting process in the lower graph in example 3 at pH 11.0.
Fig. 5 is a graph showing the relationship between pH and T in the upper graph and a graph showing the fitting process in the lower graph in example 4 at pH 11.5.
Detailed Description
It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
Some of the parameters in the present invention have the following meanings:
h is enthalpy;
t is the absolute temperature;
g is the Gibbs free energy of the system;
Δ G is the change in Gibbs energy;
Δ H is the change in enthalpy (considered independent of temperature);
The invention will be further illustrated by the following examples
Example 1
The coprecipitation solutions were measured separately, and their pH values at different temperatures were measured using a pH agent, specifically as shown in table 1, and the change of pH value with temperature was observed, using a digital precision acidity pH meter for experiments. Taking 10 test tubes, respectively adding equal amounts of coprecipitation solution, keeping the temperature for a period of time at a given temperature, measuring the pH value of the coprecipitation solution, wherein ionization is endothermic reaction, the temperature is increased, hydrogen ions and hydroxyl ions are easier to ionize, and the pH value is reduced, and processing experimental data according to the method for establishing and calculating the relationship between the pH value of coprecipitation and the coprecipitation temperature based on the analytic method of claim 1, wherein when the pH value is 10.0, the relationship between the temperature and the pH value is:
pH＝2036.2089/(t+273)+3.21325。
TABLE 1 case of pH values measured at different temperatures
Example 2
The coprecipitation solutions were measured, and their pH values at different temperatures were measured using a pH meter, and the results are shown in table 2, and the change of the pH value with temperature was observed, and a digital precision acidity pH meter was used for the experiment. Taking 10 test tubes, respectively adding equal amounts of coprecipitation solution, keeping the temperature for a period of time at a given temperature, measuring the pH value of the coprecipitation solution, wherein ionization is endothermic reaction, the temperature is increased, hydrogen ions and hydroxyl ions are easier to ionize, and the pH value is reduced, and processing experimental data according to the method for establishing and calculating the relationship between the pH value of coprecipitation and the coprecipitation temperature based on the analytic method of claim 1, wherein when the pH value is 10.5, the relationship between the temperature and the pH value is:
pH＝2898.307/(t+273)+0.760。
TABLE 2 pH value measured at different temperatures
Example 3
The coprecipitation solution is measured respectively, the pH value of the coprecipitation solution is measured at different temperatures by using a pH agent, the change condition of the pH value along with the temperature is observed, and a digital precise acidity pH meter is used in the experiment. Taking 10 test tubes, respectively adding equal amounts of coprecipitation solution, keeping the temperature for a period of time at a given temperature, measuring the pH value of the coprecipitation solution, wherein ionization is endothermic reaction, the temperature is increased, hydrogen ions and hydroxyl ions are easier to ionize, and the pH value is reduced, and processing experimental data according to the method for establishing and calculating the relationship between the pH value of coprecipitation and the coprecipitation temperature based on the analytic method of claim 1, wherein when the pH value is 11.0, the relationship between the temperature and the pH value is: pH 3146.56/(t +273) + 0.55.
TABLE 3 pH value measured at different temperatures
Example 4
The coprecipitation solution is measured respectively, the pH value of the coprecipitation solution is measured at different temperatures by using a pH agent, the change condition of the pH value along with the temperature is observed, and a digital precise acidity pH meter is used in the experiment. Taking 10 test tubes, respectively adding equal amounts of coprecipitation solution, keeping the temperature for a period of time at a given temperature, measuring the pH value of the coprecipitation solution, wherein ionization is endothermic reaction, the temperature is increased, hydrogen ions and hydroxyl ions are easier to ionize, and the pH value is reduced, and processing experimental data according to the method for establishing and calculating the relationship between the pH value of coprecipitation and the coprecipitation temperature based on the analytic method of claim 1, wherein when the pH value is 11.5, the relationship between the temperature and the pH value is: the pH was 3370.627/(t +273) + 0.160.
TABLE 4 case of pH values measured at different temperatures
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A method of controlling variables in a co-precipitation process, characterized by: the method comprises the following specific steps:
measuring the pH value of the coprecipitation solution at different temperatures by using a pH measuring device;
obtaining the relation between the equilibrium constant K of the coprecipitation reaction and the temperature through a Gibbs equation;
deducing the relationship between pH and K through ionization balance of coprecipitation reaction;
obtaining a parameter-containing relation between the pH and the T according to the relation between the pH and the K and the relation between the K and the temperature;
on the basis of the parameter-containing relation between the pH and the T, a mathematical model is established by a least square method, and the relation between the pH and the T is obtained by fitting.
2. A method of controlling variables in a co-precipitation process as claimed in claim 1, wherein: the pH measuring device comprises Shanghai Lei magnetic PHS-3C desktop pH meter, Mettler-toledo FE-20pH meter, BPP-7800 laboratory precision PH meter, and American Hastella PHM220 laboratory desktop PH meter.
3. A method of controlling variables in a co-precipitation process as claimed in claim 1, wherein: the gibbs equation is Δ G ═ Δ H-T Δ S.
4. A method of controlling variables in a co-precipitation process as claimed in claim 1, wherein: the derivation method of the relation between the equilibrium constant K and the temperature is as follows: using thermodynamic functions, the formula for obtaining chemical reactions at constant pressure is:
then integrate with respect to T (p is also a constant) to become
Using equation of reaction isotherm
Deducing the relationship between the equilibrium constant K of a chemical reaction and the temperature
5. A method of controlling variables in a co-precipitation process as claimed in claim 1, wherein: derivation method of the relationship between pH and K: by ionization equilibrium of acid and alkali, pH-lgK + [ OH ] is obtained-]。
6. The method of controlling variables in a co-precipitation process of claim 5, wherein: and substituting the relation between the pH and the K into the relation between the equilibrium constant K and the temperature to obtain the relation between the pH and the equilibrium constant:
both Δ H and Δ S, R are constants.
7. A method of controlling variables in a co-precipitation process as claimed in claim 6, wherein: pH in relation to the equilibrium constant
In order to be the parameter B,
is constant a, so the linear relationship between pH and T is pH a + B/T where T + 273.
8. A method of controlling variables in a co-precipitation process as claimed in claim 7, wherein: in the linear relationship between pH and T, when y is pH and x is 1/T, the parametric relationship between pH and T is obtained by y is am+bmx。
9. A method of controlling variables in a co-precipitation process as claimed in claim 8, wherein: a mathematical model is established by utilizing the principle of a least square method, and the process of data fitting is as follows:
will measure the value yiAnd the calculated value yjDispersion y ofi-yjSum of squares sigma (y)i-yj)2The minimum is the optimization criterion.
Order to
Converting the linear equation y to am+bmSubstitution of x into
And (4) obtaining:
to am,bmCalculating a partial derivative to make the partial derivative zero;
∑2(am+bmxi-yi)＝0；
∑2bm(am+bmxi-yi)＝0；
am＝(∑yi)/n-bm(∑xi)/n
to obtain { bm＝[n∑(yixi)-∑yi∑xi]/[n∑xi 2-(∑xi)2]A is tomAnd bmAnd (4) carrying the equation into a parameter-containing relational expression between the pH and the T to obtain a regression equation, namely the relational expression between the pH and the T.
10. Use of a method of controlling variables in a co-precipitation process as claimed in any one of claims 1 to 9 in a co-precipitation process;
preferably, the chemical coprecipitation method is used for preparing the nano ferroferric oxide particles, the coprecipitation reaction acid-base ratio has influence on the performance of the CuFe synthetic low carbon alcohol catalyst, and the acid-base condition in the coprecipitation process has influence on BaTiO3Influence of the properties of the ultrafine powder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011545361.6A CN112782337A (en) | 2020-12-23 | 2020-12-23 | Method for controlling variable in coprecipitation method and application |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011545361.6A CN112782337A (en) | 2020-12-23 | 2020-12-23 | Method for controlling variable in coprecipitation method and application |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112782337A true CN112782337A (en) | 2021-05-11 |
Family
ID=75752030
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011545361.6A Pending CN112782337A (en) | 2020-12-23 | 2020-12-23 | Method for controlling variable in coprecipitation method and application |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112782337A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102940037A (en) * | 2012-05-23 | 2013-02-27 | 四川农业大学 | Method for preparing co-precipitated ferric hydroxide yoghourt |
| CN108017044A (en) * | 2017-12-29 | 2018-05-11 | 华东理工大学 | A kind of method that precipitation reaction prepares ferric phosphate under room temperature and gentle pH value |
| CN110756123A (en) * | 2019-09-11 | 2020-02-07 | 华中科技大学 | Device and method for synthesizing catalyst by novel oxidation-reduction coprecipitation method |
-
2020
- 2020-12-23 CN CN202011545361.6A patent/CN112782337A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102940037A (en) * | 2012-05-23 | 2013-02-27 | 四川农业大学 | Method for preparing co-precipitated ferric hydroxide yoghourt |
| CN108017044A (en) * | 2017-12-29 | 2018-05-11 | 华东理工大学 | A kind of method that precipitation reaction prepares ferric phosphate under room temperature and gentle pH value |
| CN110756123A (en) * | 2019-09-11 | 2020-02-07 | 华中科技大学 | Device and method for synthesizing catalyst by novel oxidation-reduction coprecipitation method |
Non-Patent Citations (2)
| Title |
|---|
| 李瑞杰 等: "温度对中性水体pH值影响的理论与换算关系", 《内蒙古环境科学》 * |
| 高世鹏 等: "pH值和温度对共沉淀SrTiO3料的影响,", 《贵州化工》 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| De Rossi et al. | Chromia/zirconia catalysts with Cr content exceeding the monolayer. A comparison with chromia/alumina and chromia/silica for isobutane dehydrogenation | |
| Campos et al. | Nanoparticles superficial density of charge in electric double-layered magnetic fluid: A conductimetric and potentiometric approach | |
| Liu et al. | Highly efficient approach for characterizing nanometer-sized gold particles by capillary electrophoresis | |
| CN105608334B (en) | A method of evaluation cigarette auxiliary material parameter influence degree | |
| Assaf et al. | Spectral theory of metastability and extinction in a branching-annihilation reaction | |
| Tulzer et al. | Kinetic parameter estimation and fluctuation analysis of CO at SnO2 single nanowires | |
| CN109447433A (en) | A kind of Improved Gray Model prediction technique | |
| Xiang et al. | Spectroscopic measurement of pH in aqueous sulfuric acid and ammonia from sub-to supercritical conditions | |
| CN112782337A (en) | Method for controlling variable in coprecipitation method and application | |
| Rumpf et al. | Solubility of ammonia in aqueous solutions of sodium sulfate and ammonium sulfate at temperatures from 333.15 K to 433.15 K and pressures up to 3 MPa | |
| Mukerjee | On ion-solvent interactions. Part II. Internal pressure and electrostriction of aqueous solutions of electrolytes1 | |
| Kuznetsova et al. | Electrical conductivity of ammonia–alkali solutions and its activation energy | |
| Livadiotis et al. | Thermodynamics of the inner heliosheath | |
| Fletcher et al. | Extraction of metal nitrates by TBP· HNO3 | |
| Mavis et al. | Kinetics of urea decomposition in the presence of transition metal ions: Ni2+ | |
| Mayoral | Renyi's entropy as an index of diversity in simple-stage cluster sampling | |
| Qiu et al. | Prediction of metal oxide stability in supercritical water reactors-pourbaix versus Ellingham | |
| Ma et al. | Modelling and simulation of counter-current and confined jet reactors for continuous hydrothermal flow synthesis of nano-materials | |
| CN105347390A (en) | Method for reducing iron content of metatitanic acid prepared by sulfuric acid method | |
| El-Akkad | Surface areas, pore structures, and heats of immersion of titania gel in correlation to thermal treatment | |
| Nikolic et al. | Modeling the effect of temperature on relative humidity sensing | |
| Shishakov | On the Oxidation of Gold | |
| Toor | Diffusion measurements with a diaphragm cell | |
| Million-Picallion et al. | Stability of Hydrazine, Morpholine and Ethanolamine at 275° C and In Situ Measurement of Redox and Acid–Base Properties | |
| CN109405992A (en) | A kind of measurement slight temperature varying circuit and its thermometry |
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 |
Application publication date: 20210511 |
|
| RJ01 | Rejection of invention patent application after publication |