68 results about "Fluoroacetamide" patented technology

The invention discloses an industrialized synthetic method of ethyl difluoroacetate. Difluoroacetate is generated through catalysis of difluoroacetamide and low alcohols under strong acid, and the selectivity of the difluoroacetate reaches more than 95%. The method is characterized in that dichloro-acetamide is prepared from secondary amide that is easy to recover and can be in continuous operation at the same time, the problem that fluorine substitution reaction is difficult to carry out under the combination of a common solvent and a catalyst is solved through a solvent, and the solvent has the effect of a phase transfer agent, and is low in cost and convenient to recover.

The invention relates to a synthesis method of diamido ortho-ester monomer, which belongs to the technical field of organic chemistry and biomaterials. The diamido ortho-ester monomer is 4-aminomethyl-2-amino pentyloxy-2-R group-[1,3] dioxane as shown in formula I, wherein the R group is hydrogen or methyl, and the diamido ortho-ester monomer is a new generation of ortho-ester monomer in a brand-new structure. The synthesis method of the diamido ortho-ester monomer comprises the following steps that: 3-amino-1,2-propanediol is taken as the raw material, reacts with trimethyl ortho ester under the action of an acid catalyst after reacting with ethyl trifluoroacetate to protect the amino, the obtained product exchanges and reacts with 5-trifluoroacetyl amino pentanol ester under the action of the catalyst to obtain a monomer precursor, and finally the precursor is added into lye to remove a trifluoroacetyl protecting group so as to obtain the diamido ortho-ester monomer. The synthesis method has the advantages of easily available raw materials, simple synthesis process and higher economy and yield and is applicable to large-scale industrial production; and simultaneously, the monomer is extremely stable at normal temperature, and can be used for the research and development of a new generation of poly ortho ester polymer biomaterials.

The invention provides N-full-aromatic hydrocarbon diamine-bisphenol tetrafunctional fluorenyl benzoxazine and a preparation method thereof. The method comprises the following steps: firstly, protecting amino in 2,7-diamino-9,9-bis-(4-hydroxyphenyl) fluorene by using trifluoroacetic anhydride to generate 2,7-bistrifluoroacetamido-9,9-bis(4-hydroxyphenyl) fluorene, and then carrying out Mannich condensation reaction with aromatic amine and paraformaldehyde to form a 2,7-bistrifluoroacetamido bisphenol fluorenyl benzoxazine monomer; carrying out amino deprotection, and then carrying out secondary Mannich condensation reaction with a phenolic compound and paraformaldehyde to finally obtain a novel N-full-aromatic hydrocarbon diamine-bisphenol tetrafunctional fluorenyl benzoxazine monomer. By adopting the N-full-aromatic hydrocarbon diamine-bisphenol tetrafunctional fluorenyl benzoxazine and the preparation method thereof, the problems that the fluorenyl polybenzoxazine with a large steric hindrance structure is small in molecular weight, low in crosslinking density and poor in tenacity, and the thermal performance is reduced by introducing a flexible group are solved, the processing property of the polymer is improved, and controllable structure and performance of polybenzoxazine are achieved.

The invention relates to a synthesis method of a cyclic orthoester monomer containing diamino, which belongs to the technical field of biological medicine and organic chemistry. The monomer is 4, 4'-dimethylene oxygen-di-(2-aminoethoxy-2-R-1, 3-dioxolane), and is a novel polyorthodester monomer, wherein R is hydrogen or methyl. The synthesis method of the orthoester monomer comprises the steps that dimeric glycerin is used as a raw material, and reacts with trimethyl orthoester in the presence of an acid catalyst; ester exchange reaction is carried out on an acquired product and 2-trifluoro acetamido ethanol in the presence of a catalyst to acquire a precursor compound of the monomer; and finally, a trifluoroacetyl protective group is removed from the precursor compound in an alkaline solution to acquire the cyclic orthoester monomer containing diamino. According to the synthesis method provided by the invention, the raw material can be easily acquired; the synthesis method is simple and economic, and is suitable for industrialized production; and the monomer is stable at room temperature, and can be used for the preparation and the application development of a novel polyorthodester polymer biomaterial.

The present invention uses TiO2 or modified TiO2 as photocatalyst, uses acrylic acid modified organosilicon resin as adhesive, uses polyurethane as solidifying agent, makes photocatalytic coating layer which can be solidified at room temp. on the plate glass, places the plate glass coated with photocatalyst coating material into a photocatalytic reactor, under the action of UV ray it can degrade the organic fluoride in waste water. It is characterized by that said described photocatalyst is made of TiO2 whose grain size is 25-100 nm or TiO2 modified by SnO2. Said method can degrade the folloiwng organic fluorides; fluorobenzene, fluorobenzoic acid, fluoromethylbenzene, fluorochlorobenzeneamine, 5-fluorophenylacetone, 2,3,4,5-tetrafluorobenzoic acid, fluconazole, fluoroglycofen-ethyl and others.

Provided herein are lyophilized formulations of 2-(4-chlorophenyl)-N-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-2,2-difluoroacetamide or a stereoisomer or mixture of stereoisomers, pharmaceutically acceptable salt, tautomer, prodrug, solvate, hydrate, co-crystal, clathrate, or polymorph thereof. Methods of using the formulations and dosage forms for treating, managing, and / or preventing cancer are also provided herein.

The invention relates to a steroid substance derivation method, the derivation method employs N-methyl-N-trimethylsilyl trifluoroacetamide (MSTFA) as a derivative reagent, the N-methyl-N-trimethylsilyl trifluoroacetamide is derived for 20-60 minutes under the temperature of 30-80 DEG C. The invention also relates to an application of the derivation method in a steroid substance qualitative and quantitative analysis. The invention also relates to an analysis detection method of the steroid substance, the above mentioned method can be employed for performing a derivation treatment on a sample to be measured. According to the invention, the MSTFA is taken as the derivative reagent, and the derived steroid substance possesses good repeatability and high sensitivity in a GC or GC-MS detection. In addition, the MSTFA is taken as the derivative reagent, no macroscopic sediment is generated, a single derivative reagent is used, and the operation is convenient.

The invention provides a method for detecting glyceryl monostearate in liquid milk. The method comprises the following steps: a. preparing a bottle of liquid milk to be tested, extracting milk fat from the liquid milk so as to obtain milk fat to be tested; b. preparing a standard solution of glyceryl monostearate, blow-drying the standard solution with nitrogen gas so as to obtain a reference substance; c. separately adding N,O-bis(trimethylsilyl)trifluoroacetamide into the milk fat to be tested and the reference substance to carry out derivatization reactions so as to separately obtain a derivative sample and a derivative reference substance; d. blow-drying the derivative sample and the derivative reference substance with nitrogen gas, then separately dissolving the derivative sample and the derivative reference substance with n-hexane so as to separately obtain a sample liquid to be tested and a reference detection liquid; e. measuring the gas chromatography values of glyceryl monostearate in the sample liquid to be tested and the reference detection liquid, and calculating according to the gas chromatography values of glyceryl monostearate in the sample liquid to be tested and the reference detection liquid so as to obtain the content of glyceryl monostearate in the liquid milk to be tested. The detection method has the advantages of convenient operation and high accuracy.

A process for making a fluorinated product comprising contacting an alcohol with 1,1,2,2-tetrafluoroethyl-N,N-dimethylamine to produce a product mixture containing the fluorinated product and N,N-dimethyl difluoroacetamide, quenching the product mixture in water to form a first organic phase and an aqueous phase, recovering fluorinated product by separating the first organic phase from the aqueous phase, treating the aqueous phase to recover N,N-dimethyl difluoroacetamide, and converting recovered N,N-dimethyl difluoroacetamide to 1,1,2,2-tetrafluoroethyl-N,N-dimethylamine.

The invention provides a method for synthesizing finasteride. The method comprises the following steps: (1) dissolving trifluoroacetamide in solvent, reacting the solvent with trimethylchlorosilane in the presence of organic alkali or inorganic alkali, filtering out solid from reaction products, and collecting filtrate; and (2) dissolving the filtrate obtained in step (1) in the solvent, adding 3-carbonyl-4-aza-5 alpha-androstane-17 belta-tert-butylformamide and dehydrogenation agent into the solvent for reaction, and collecting target products from reaction products. The method has the advantages that the method has higher yield, high selectivity, and is simple and safe; after simple purification, the purity of the finasteride can reach more than 99 percent; moreover, the method has easily obtained reagents used in the whole reaction, simultaneously having high reaction yield and mild reaction conditions, reclaiming the solvent and facilitating the industrialized production.

The present invention relates to the design, synthesis, and the peptidyl-prolyl isomerase (PPIase or rotamase) inhibitory activity of novel alpha , alpha -difluoroacetamido compounds that are neurotrophic agents (i.e. compounds capable of stimulating growth or proliferation of nervous tissue) and that bind to immunophilins such as FKBP12 and inhibit their rotamase activity. This invention also relates to pharmaceutical compositions comprising these compounds.

The invention discloses a triiodothyroxin hapten luminous marker and a synthetic method thereof. The synthetic method of the triiodothyroxin hapten luminous marker comprises the following steps: A) preparing a trifluoroacetamide crude product; B) preparing trifluoroacetamide; C) further preparing trifluoroacetamide; D) preparing triiodothyroxin methyl ester; E) further preparing triiodothyroxin methyl ester; F) further preparing triiodothyroxin methyl ester; and G) preparing a target product, namely acridine-marked triiodothyroxin methyl ester. The invention discloses a novel compound for detecting triiodothyroxin hapten by virtue of a chemical luminescence method as well as a synthetic route and a synthetic method of the compound. The marker of the small molecules is easy to purify, can be industrially produced and improves the detection sensitivity. The defects that the protein macromolecular compounds used by the conventional detection reagent have high price, difference easily produced in a production process, and the like are overcome.

The invention provides an immunity-chromatography detection test paper strip of fluoroacetamide poison, and a preparation method thereof, belonging to the technical field of immunoassay. The method uses the combination of a cluster specific antibody of anti-sodium fluoroacetate and the color development matter colloid gold as the reagent strip of a detection reagent assembly and carries out the poisoning screening detection of fluoroacetamide poison; the cost is low and the operation is quick, with the time of only 5-10 minutes; the test paper strip is convenient for being carried along and is suitable for site detection; and the operation is simple and convenient and special technical personnel is not needed. The test paper strip and the method can be used for the poisoning screening detection of fluoroacetamide poison.

The invention discloses a novel thyroxine hapten luminescent marker and a synthetic method thereof, wherein the synthetic method of the novel thyroxine hapten luminescent marker comprises the steps: A) preparing a trifluoroacetamide compound 2 crude product; B) preparing a trifluoroacetamide compound 3; C) preparing a trifluoroacetamide compound 4; D) preparing a thyroxine methyl ester compound 5; E) preparing a thyroxine methyl ester compound 6; F) preparing a thyroxine methyl ester compound 7; and G) preparing the target product acridine marked novel thyroxine methyl ester. The invention provides the novel compound for chemiluminescence detection of thyroxine and the synthetic route and method thereof; the small-molecular marker is easy to purify, can achieve industrialized production, and improves the detection sensitivity. The defects that protein macromolecular compounds used in conventional detection reagents are expensive and allow differences to be easily produced in the production process are solved.

The invention belongs to the technical field of chemical component detection and analysis, and discloses a method for measuring the concentration of chloroacetic acid in air by gas chromatography andapplication thereof. According to the measuring method, under the detection means of gas chromatography, N, O-bis (trimethylsilane) trifluoroacetamide is used for silanizing chloroacetic acid under acertain condition, so that the polarity of chloroacetic acid is greatly reduced, the problem of inaccurate quantification caused by strong polarity trailing of chloroacetic acid is solved, and the detection sensitivity of chloroacetic acid is greatly improved. The detection method has a good linear relationship in the concentration range of 0-162.6 micrograms / mL, the correlation coefficient is 0.9997, the detection limit is 0.8 micrograms / mL, the minimum detection concentration is 0.05mg / m< 3 > (by collecting 15L of air), the Relative Standard Deviation (RSD) of five times of parallel determination is 0.5-1.3%, and the blank adding standard recovery rate is 98.6-101.2%. The method is sensitive, simple and accurate, and can be used for measuring chloroacetic acid in air in a workplace.

The invention relates to the technical field of biological chemistry, and particularly discloses a preparation method of fluoroacetamide hapten and application of a monoclonal antibody. The fluoroacetamide hapten is synthesized by taking ethyl fluoroacetate and p-aminophenylacetic acid as main raw materials; the fluoroacetamide hapten and carrier protein bovine serum albumin (BSA) or keyhole limpet hemocyanin (KLH) are coupled through an active lipid method, and thus a conjugate is prepared. Through experimental verification, it shows that the prepared conjugate enables a living body to generate the antibody against fluoroacetamide, that is to say, the prepared conjugate is fluoroacetamide artificial antigen. The prepared fluoroacetamide artificial antigen is suitable for enzyme-linked immunological analysis of fluoroacetamide.

The invention relates to a method for detecting nine cholesterol oxides in food by gas chromatography-mass spectrometry, which comprises the following steps: S1, adding 19-hydroxycholesterol as an internal standard substance to carry out sample lipid extraction; S2, dissolving the obtained lipid extract, and carrying out saponification extraction to remove moisture so as to obtain a concentrated filtrate; S3, purification and concentration: adding 3mL of n-hexane, shaking and dissolving, adding into activated NH2-SPE, washing the column, discarding waste liquid, collecting filtrate, and blow-drying by nitrogen; S4, derivatization: adding 100 [mu] L of N, O-bis (trimethylsilane) trifluoroacetamide BSTFA for derivatization for 40 min, blow-drying with nitrogen, and dissolving with 1.0 mL of n-hexane to a constant volume; and S5, taking a mixed standard solution of nine cholesterol oxides, detecting the mixed standard solution under gas chromatography conditions and mass spectrometry conditions, and drawing a standard curve. According to the method, a pretreatment mode suitable for complex samples is established, saponification conditions and a solid-phase extraction column are optimized, the accuracy of analysis and detection is improved by adopting an internal standard substance, and the method has the advantages of accuracy, high efficiency and wide applicability.

The invention belongs to the technical field of medical chemical engineering intermediates and related chemistry, and relates to N-phenyl-N-p-toluenesulfonyl trifluoroacetamide (NTFTS) and application. The N-phenyl-N-p-toluenesulfonyl trifluoroacetamide is taken as a trifluoroacetylation reagent, reacts with an arylboronic acid derivative in an anhydrous organic solvent under the action of a metalcatalyst, a ligand and an alkali, and is efficiently and highly selectively converted into a trifluoroacetophenone compound. According to a synthesis method of the trifluoroacetophenone compound, involved in the invention, reaction steps are few; the NTFTS which is stable in use, easy to store, cheap and easy to get is taken as a trifluoroacetyl source; environmental friendliness is realized; reaction conditions are mild; operation is easy; a high-yield and high-selectivity target product is obtained and has relatively good industrial production value and practical application value. The trifluoroacetophenone compound synthesized by utilizing the method can be further subjected to a functionalization reaction, and can be widely applied to the synthetic fields of medicine, pesticide, bioactive molecules, functional material molecules and the like.

The invention discloses a method for preparing a thiotrifluoroacetamide compound, which comprises the following steps: using (E)-N, 1-N-diphenylimine as a substrate, adding equivalent elemental sulfurinto the substrate, 1.5 equivalents of 1.1.1-trifluorotrichloroethane, adding a catalyst, a ligand, an additive, alkali and distilled water, and stirring and reacting for 4 hours at the normal pressure of 120 DEG C in a reaction solvent; after the reaction is finished, filtering the reaction liquid to obtain filtrate; concentrating the filtrate, removing the solvent by using a rotating evaporatorto obtain residues, carrying out chromatography with silica gel column, eluting with an eluent, and collecting effluent according to actual gradient; combining the effluent containing the product, concentrating the combined effluent to remove the solvent, and finally drying in vacuum to obtain a target product. The method has the advantages of simple preparation process, less pollution, low energy consumption and high yield.

The invention discloses a process for preparing N-methyl homopiperazine from 2-haloethylamine compound, and the process comprises the following steps: Step 1, taking the 2-halogenated ethylamine compound as a raw materia to react with ethyl trifluoroacetate to obtain N-(2-Haloethyl) trifluoroacetamide; Step (2) taking the N-(2-Haloethyl) trifluoroacetamide as a raw material to react with methylamine or methylamine hydrochloride to obtain N-methyl-N'-trifluoroacetyl ethylenediamine; Step (3) taking the N-methyl-N'-trifluoroacetyl ethylenediamine as a raw material to react with 1,3-disubstituted propane compound to obtain N-methyl-N'-trifluoroacetyl homopiperazine; Step (4) taking the N-methyl-N'-trifluoroacetyl homopiperazine as a raw material to react with a hydrogen chloride ethanol solution to obtain N-methyl homopiperazine dihydrochloride; and Step (5) taking the N-methyl homopiperazine dihydrochloride as a raw material to prepare the N-methyl homopiperazine by alkalization. The process has the advantages of simple operation, low cost, high yield, low pollution and suitability for industrialized production.

The invention belongs to the technical field of organic synthesis and in particular relates to a synthesis method of a 3,3-difluoro-4-pyrroline-2-one compound. The synthesis method comprises the following steps: dissolving a bromo-difluoroacetamide compound with a solvent; adding alkyne and uniformly mixing; then adding a ligand ortho-phenanthroline, a catalyst CuI and an alkali K2CO3; raising temperature to 110 DEG C+ / -10 DEG C under a sealed condition and stirring and reacting for 1h to 3h; after reacting, carrying out post-treatment to obtain the product. By adopting the synthesis method, a 3,3-difluoro-4-pyrroline-2-one derivative is synthesized for the first time; the synthesis method has the characteristics of high atomic economy, simple reaction steps, cheap and easy-to-obtain raw materials, wide substrate application range and the like, is applicable to synthesis of various 3,3-difluoro-4-pyrroline-2-one compounds and is suitable for industrialized production.

The invention provides a preparation method of chiral 1-amino-2-propanol, which comprises the following steps: carrying out ring-opening reaction on trifluoroacetamide and chiral epoxypropane to generate an intermediate product I; and carrying out hydrolysis reaction on the intermediate product I to obtain the chiral 1-amino-2-propanol. According to the preparation method, the target product can be obtained through a two-step reaction, so that the preparation process of chiral 1-amino-2-propanol is greatly simplified; and the raw materials trifluoroacetamide and chiral epoxypropane are cheap and easily available, the reaction process is simple, the operation is convenient, harsh reaction conditions such as high temperature and high pressure are not needed, complex purification, post-treatment and chiral resolution operations are also not needed, and the obtained target product has high purity, high yield and high optical activity, and is suitable for large-scale industrial preparation.

The invention discloses a synthesis method of difluoroacetate ester, which comprises the following steps: reacting tetrafluoroethylene and organic amine to obtain N,N-dialkyl-1,1,2,2-tetrafluoroethylamine; reacting the N,N-dialkyl-1,1,2,2-tetrafluoroethylamine and water to generate N,N-dialkyl difluoroacetamide; performing hydrolysis reaction on the N,N-dialkyl difluoroacetamide and metal hydroxide to generate difluoroacetate salt; and reacting the difluoroacetate salt and halogenated hydrocarbon in the presence of a catalyst and solvent to generate the difluoroacetate ester. The invention has the advantages of simple process, high yield and low discharge of three wastes; through the hydrolysis of the N,N-dialkyl-1,1,2,2-tetrafluoroethylamine, the N,N-dialkyl difluoroacetamide can be obtained at a high yield, and the yield of the N,N-dialkyl difluoroacetamide is 88% or above; and the maximum yield in the process of preparing the difluoroacetate ester from the N,N-dialkyl difluoroacetamide can be up to 92%.

The invention relates to a green synthesis method of a sitagliptin intermediate, and belongs to the technical field of drug intermediate synthesis. In order to solve the problems of serious pollution and instability in the prior art, the invention provides a green synthesis method of a sitagliptin intermediate, which comprises the following steps: reacting ethyl trifluoroacetate with ethylene diamine in an ether solvent to generate 2-trifluoroacetamido ethyl amine; in the presence of an acid-binding agent, carrying out condensation reaction on 2-trifluoroacetamido ethyl amine and halogenated ethyl acetate at the temperature of 45-65 DEG C to generate an intermediate, then heating to 90-110 DEG C, and carrying out cyclization reaction to generate N-trifluoroacetyl piperazinone; carrying out reaction on N-trifluoroacetyl piperazinone and hydrazine hydrate to generate 1-trifluoroacetyl hydrazino-2-piperazinone; and reacting the intermediate with hydrochloric acid to carry out internal ring formation and salt formation reaction to obtain the product sitagliptin intermediate. According to the invention, the reaction has the advantages of high product yield and purity on the whole, and is environment-friendly.

The invention discloses a synergetic pesticide composition with p-cymene. The pesticide composition comprises active components A and B, wherein the mass ratio of active component A to the active component B is (1:100)-(100:1); the active component A is p-cymene; and the active component B is selected from abamectin, etoxazole, spirodiclofen, bifenazate, etoxazole chlorfenapyr, dinotefuran, thiamethoxam, fluoroacetamide, chlorfenapyr, chlorantraniliprole, cyantraniliprole, methylamino abamectin benzoate, flubendiamide formate, tolfenpyrad, tertchlorantraniliprole, indoxacarb, cyflumetofen, N-[2-(4-methyl benzothiazolyl)]-2-amino-2-fluorophenyl-O,O-diethyl phosphonate, alkyl polyamine, azoxystrobin, pyraclostrobin, fluorothiazole, oxathiapiprolin, isopyrazam, cyhalofop-butyl, fenoxaprop-p-ethyl and the like. As the p-cymene synergist is used in the pesticide composition disclosed by the invention, the insect and bacterium killing effect of a pesticide can be greatly improved, the amountof the pesticide can be reduced, the cost can be lowered, and in addition, the drug resistance of insects to insecticides / fungi can be degraded.

The invention discloses a wide-temperature type sodium-ion battery electrolyte which comprises an organic solvent, sodium salt and a functional additive, the functional additive comprises one or more of tris (trimethylsilyl) phosphate, N, N-dimethyl trifluoroacetamide, fluoroethylene carbonate, ethylene sulfate and sodium difluorophosphate. The invention has the following beneficial effects: tris (trimethylsilyl) phosphate is used in the functional additive, can be adsorbed on the surface of a material prior to a solvent at a high temperature, and is catalytically decomposed on the surface of excessive ions at a high potential to generate an organic decomposition product with a relatively high concentration; therefore, the continuous oxygenolysis of the electrolyte and the dissolution of transition metal ions caused by the erosion of HF in the electrolyte to the material are prevented, and the interface impedance is reduced, so that the high-temperature cycle performance of the battery is improved. N, N-dimethyl trifluoroacetamide is used in the functional additive, so that better oxidation stability protection can be carried out on the positive electrode material at a low temperature, and the capacity retention rate can be improved at the low temperature.

The invention relates to a synthesis method for 2-bromo-2,2-difluoroethylamine hydrochloride. Ethyl bromodifluoroacetate is dissolved in ether; then ammonia gas is fed into the solution until the reaction is complete; the solvent is evaporated to get a solid 2-bromo-2,2-difluoroacetamide under reduced pressure; 2-bromo-2,2-difluoroacetamide is dissolved in tetrahydrofuran and is added with sodium borohydride; the temperature is controlled at 0-10 degrees; boron trifluoride etherate is added dropwise; the mixture is stirred continuously overnight at room temperature; the reaction is complete; saturated sodium hydroxide aqueous solution is added to the mixture for a quenching reaction; the mixture is extracted by dichloromethane; the organic phase is distilled after washing by a saturated aqueous solution of sodium chloride; and hydrochloric acid gas is added to the fraction to make the pH be less than 3, so a white solid of 2-bromo-2,2-difluoroethylamine hydrochloride is obtained. The core of the synthesis method is the use of an inexpensive and easily obtained ethyl bromodifluoroacetate and sodium borohydride as the reducing agents. The synthesis method helps to significantly reduce the cost, and is suitable for mass synthesis scale in kilograms.

The invention provides a method for rapidly detecting clenbuterol hydrochloride with a solid phase microextraction and gas chromatography-mass spectrometry technique. According to the method, firstly, a detachable solid phase microextraction probe is used for extracting a to-be-detected sample, then, MTBSTFA (N- tert-butyldimethylsilyl)-N- methyltrifluoroacetamide) is used for performing derivatization on an extract, finally, a gas chromatography-mass spectrometer is used for analytic determination, and an external standard method is used for quantification. The method is environment-friendly, simple and convenient to operate, time-saving and labor-saving; the detecting time is only 90 minutes, the sample pretreatment cost is lower than one yuan, and the method can be very conveniently applied to rapid screening of clenbuterol hydrochloride in various samples and has good popularization and application values.