In this paper, the extremum of second-order directional derivatives, i.e. the gradient of first-order derivatives is discussed. Given second-order directional derivatives in three nonparallel directions, or given seco...In this paper, the extremum of second-order directional derivatives, i.e. the gradient of first-order derivatives is discussed. Given second-order directional derivatives in three nonparallel directions, or given second-order directional derivatives and mixed directional derivatives in two nonparallel directions, the formulae for the extremum of second-order directional derivatives are derived, and the directions corresponding to maximum and minimum are perpendicular to each other.展开更多
The design and the synthesis of two conjugated donor acceptor imidazole derivatives(1, 2) were carried out for second order nonlinear optics. The thermal properties, the transparency and second order nonlinear opti...The design and the synthesis of two conjugated donor acceptor imidazole derivatives(1, 2) were carried out for second order nonlinear optics. The thermal properties, the transparency and second order nonlinear optical properties of the molecules were investigated. The experimental results indicate that a good nonlinearity transparency thermal stability trade off is achieved for them.展开更多
[Objectives]The paper was to establish an ultra high performance liquid chromatography-quadrupole/linear ion trap complex mass spectrometry for the determination of 10 kinds ofα2-receptor agonists in animal derived f...[Objectives]The paper was to establish an ultra high performance liquid chromatography-quadrupole/linear ion trap complex mass spectrometry for the determination of 10 kinds ofα2-receptor agonists in animal derived food.[Methods]The samples were extracted with sodium carbonate buffer solution and ethyl acetate,and analyzed by mass spectrometry after solid phase extraction and high performance liquid chromatography separation.[Results]Ten kinds ofα2-receptor agonists showed a good linear relationship in the range of 1-100μg/mL,with the average recovery of over 69%and the relative standard deviation less than 8.32%.The detection limit of 10 kinds of α_(2)-receptor agonists was up to 1μg/kg.[Conclusions]The method has good selectivity and strong anti-interference ability,and can meet the requirements of 10 kinds ofα2-receptor agonists residues in animal derived food.展开更多
This paper considers eigenstructure assignment in second-order linear systems via proportional plus derivative feedback. It is shown that the problem is closely related to a type of so-called second-order Sylvester ma...This paper considers eigenstructure assignment in second-order linear systems via proportional plus derivative feedback. It is shown that the problem is closely related to a type of so-called second-order Sylvester matrix equations. Through establishing two general parametric solutions to this type of matrix equations, two complete parametric methods for the proposed eigenstructure assignment problem are presented. Both methods give simple complete parametric expressions for the feedback gains and the closed-loop eigenvector matrices. The first one mainly depends on a series of singular value decompositions, and is thus numerically simple and reliable; the second one utilizes the right factorization of the system, and allows the closed-loop eigenvalues to be set undetermined and sought via certain optimization procedures. An example shows the effectiveness of the proposed approaches. Keywords Second-order linear systems - Eigenstructure assignment - Proportional plus derivative feedback - Parametric solution - Singular value decompoition - Right factorization This work was supported in part by the Chinese Outstanding Youth Foundation (No.69504002).展开更多
The second-order nonlinear optical properties of thiophene S,S -dioxides derivatives were studied by using the ZINDO-SOS method. The computed results show that the thiophene S,S -dioxide derivatives exhibit larger sec...The second-order nonlinear optical properties of thiophene S,S -dioxides derivatives were studied by using the ZINDO-SOS method. The computed results show that the thiophene S,S -dioxide derivatives exhibit larger second-order polarizabilities than their thiophene precursors. In order to clarify the origin of the different NLO responses among these chromophores, their electron properties and frontier orbital properties were investigated as well. These thiophene S,S -dioxides derivatives are good candidates for their application in electro-optical device due to their high nonlinearities, good thermal and photo stabilities.展开更多
In this paper, we establish a second-order sufficient condition for constrained optimization problems of a class of so called t-stable functions in terms of the first-order and the second-order Dini type directional d...In this paper, we establish a second-order sufficient condition for constrained optimization problems of a class of so called t-stable functions in terms of the first-order and the second-order Dini type directional derivatives. The result extends the corresponding result of [D. Bednarik and K. Pastor, Math. Program. Ser. A, 113（2008）, 283-298] to constrained optimization problems.展开更多
alculations of the nonlinear second-order optical susceptlbilities(β_(ijk))for sub- stituted tl1iophene derivative;with quinoidlike conformation are reported.These systetems possess small dipole moment;and large diff...alculations of the nonlinear second-order optical susceptlbilities(β_(ijk))for sub- stituted tl1iophene derivative;with quinoidlike conformation are reported.These systetems possess small dipole moment;and large differences between dipole mo- ments of ground and first-excited states.Geometry optimizations of the molecules investigated were carried out using AM 1 method.The calculations were performed using INDO/CI method comboned with a sum-over-states expression for β_(jik). The calculated results sbw that the second-order susceptibility is a function of the na- ture and location of substituents and is larger for disubstituted molecules than monosubstituted molecules. Bipolymeric thiophenemetmne with NH_2/NO_2 groups was calctilated to have a β_μof 79. 920 × 10￣(-30) esu. It was found that the NH_2 and NO_2 groups in above disubstituted molecules are pull-pull groups in ground states,but are usual push-pull groups in the first excited states.展开更多
[Objective]The research aimed to establish a liquid chromatography-high-resolution mass spectrometry for detecting residues of diclazuril,toltrazuril and its metabolites in animal-derived food.[Method]The samples were...[Objective]The research aimed to establish a liquid chromatography-high-resolution mass spectrometry for detecting residues of diclazuril,toltrazuril and its metabolites in animal-derived food.[Method]The samples were pre-treated by QuEChERS technology and detected by Exactive liquid chromatography-high resolution mass spectrometry.The liquid chromatography-high-resolution mass spectrometry for detecting the residues of diclazuril,toltrazuril,toltrazuril sulfone and toltrazuril sulfoxide in animal-derived food was established.[Result]Diclazuril,toltrazuril,toltrazuril sulfone and toltrazuril sulfoxide showed a good linear correlation in the range of 2.0-50.0μg/L（r^2〉0.99）.The average recoveries of these four compounds in bovine power at the spiked levels of 2,10 and 20μg/kg were 74.5%-90.1%,and the relative standard deviations（RSD）were 15.4%-17.5%.[Conclusion]This method was stable and reliable,and could be used to detect diclazuril,toltrazuril,toltrazuril sulfone and toltrazuril sulfoxide in animal-derived food.展开更多
The second-order nonlinear optical (NLO) properties of a series of benzothiazole derivatives were studied by use of the ZINDO-SOS method. These chromophores are formed by a donor-π-bridge-acceptor system, based on a ...The second-order nonlinear optical (NLO) properties of a series of benzothiazole derivatives were studied by use of the ZINDO-SOS method. These chromophores are formed by a donor-π-bridge-acceptor system, based on a nitro group connected with benzothiazole as the acceptor and a hydroxyl-functional amino group as the donor. For the purpose of comparison, we also designed molecules in which nitrobenzene is an acceptor. The calculation results indicate that benzothiazole derivatives exhibit larger second-order polarizabilities than nitrobenzene derivatives. In order to clarify the origin of the NLO response of these chromophores, their electron properties were investigated as well. The benzothiazole derivatives are good candidates for application in electro-optical device due to their high optical nonlinearities, good thermal and photonic stability.展开更多
m-Iodobenzylguanidinium hemisulfate (MIBGHS) is a precursor in the preparation of radioiodine-labeled m-iodobenzylguanidine (MIBG), which is used as a radio-imaging and therapy agent for neuroendocrine tumors and myoc...m-Iodobenzylguanidinium hemisulfate (MIBGHS) is a precursor in the preparation of radioiodine-labeled m-iodobenzylguanidine (MIBG), which is used as a radio-imaging and therapy agent for neuroendocrine tumors and myocardial sympathetic nerve function. To ensure the quality and efficacy of the medicine and prevent side effects, the precursor purity, source of impurity, and derivatives have to be determined. In this study, the purity of synthesized MIBGHS and the amount of contaminants therein were determined by high-performance liquid chromatography and ultraviolet detection, gradient eluted by ammonium formate aqueous solution and acetonitrile mobile phase on both C8 and phenyl type column. The impurities were identified on the basis of molecular and fragmented ion mass spectra using of electrospray ionization triple quadrupole tandem mass spectrometry. The results revealed the presence of process-related impurities including m-bromobenzylguanidine (MBrBG) and overreacted byproducts. Stress test results indicated that MIBGHS is stable under acidic and dry thermal conditions for at least 72 h but MIBG aqueous solution was deteriorated slowly when exposed to UV light, thermal, oxidative and alkaline environments. Thus, m-iodobenzylamine, the starting material intended for the synthesis of MIBGHS should be analyzed to ensure that it is free from m-bromobenzylamine impurity. Stored under normal condition (-18°C), MIBGHS is stable for at least 12 months. The chemically labile guanidine and amine groups in MIBGHS are the major causes of its instability, while iodide loss from the phenyl group is a minor cause.展开更多
On the basis of ZINDO methods, according to the sum-overstates (SOS) expression, the program for the calculation of the second-order nonlinear optical susceptibilities βijk and βμ of molecules was devised, and the ...On the basis of ZINDO methods, according to the sum-overstates (SOS) expression, the program for the calculation of the second-order nonlinear optical susceptibilities βijk and βμ of molecules was devised, and the structures and nonlinear optical properties of unsymmetric bis(phenylethynyl) benzene series derivatives were studied. The influence of the molecular conjugated chain lengths, the donor and the acceptor on βμ was examined.展开更多
本研究旨在利用质谱技术鉴定野血牦牛与家养牦牛血清中化学衍生物的差异,以明确长期受到高原生态环境自然选择下,野血牦牛更优环境适应性的代谢机制。本研究利用串联质谱技术对西藏阿里改则县的5头野血牦牛和5头家养牦牛的血清进行代谢...本研究旨在利用质谱技术鉴定野血牦牛与家养牦牛血清中化学衍生物的差异,以明确长期受到高原生态环境自然选择下,野血牦牛更优环境适应性的代谢机制。本研究利用串联质谱技术对西藏阿里改则县的5头野血牦牛和5头家养牦牛的血清进行代谢组功能分析,共鉴定到574个代谢相关化学衍生物质,其中比例最高的是有机酸及其衍生物和氨基酸及其衍生物,21种代谢物质差异显著,较家养牦牛,野血牦牛有7类化学代谢物(邻甲氧基苯甲酸、9,12-十八碳二烯酸、3,4,5-三甲氧基肉桂酸等)显著上调,14类化学代谢物(前列腺素E2、氧化三甲胺、羟基二十碳五烯酸等)显著下调。其中7类化学衍生物(5-羟基吲哚-3-乙酸、鸟苷、尿素、前列腺素E2、皮质醇、5-甲氧基色胺、3-甲基吲哚)富集于31个KEGG信号通路,包括组织系统(Organismal Sysyems)、代谢(Metabolism)、人类疾病(Human Disease)、环境信息过程(Environmental Information Processing)。本研究通过代谢组比较分析,进一步明确了野血牦牛优异的环境适应性代谢基础,同时鉴定到野血牦牛中富含一系列(鸟苷、5-甲基-2-脱氧饱苷、邻甲基苯甲酸等)已明确与心脑血管疾病相关药的化学衍生物,为今后开发抗高原病相关药物开发提供借鉴参考。展开更多
基金Supported by the National Natural Science Foundation of China (10871029,11071025)the Foundation of CAEP (2010A0202010)the Foundation of National Key Laboratory of Science and Technology on Computational Physics
文摘In this paper, the extremum of second-order directional derivatives, i.e. the gradient of first-order derivatives is discussed. Given second-order directional derivatives in three nonparallel directions, or given second-order directional derivatives and mixed directional derivatives in two nonparallel directions, the formulae for the extremum of second-order directional derivatives are derived, and the directions corresponding to maximum and minimum are perpendicular to each other.
基金Supported by the Natural Science Foundation of Hubei ProvinceChina(No.2 0 0 0 J15 6 )
文摘The design and the synthesis of two conjugated donor acceptor imidazole derivatives(1, 2) were carried out for second order nonlinear optics. The thermal properties, the transparency and second order nonlinear optical properties of the molecules were investigated. The experimental results indicate that a good nonlinearity transparency thermal stability trade off is achieved for them.
基金Supported by Scientific Research Project of Dalian Customs(2022DK09).
文摘[Objectives]The paper was to establish an ultra high performance liquid chromatography-quadrupole/linear ion trap complex mass spectrometry for the determination of 10 kinds ofα2-receptor agonists in animal derived food.[Methods]The samples were extracted with sodium carbonate buffer solution and ethyl acetate,and analyzed by mass spectrometry after solid phase extraction and high performance liquid chromatography separation.[Results]Ten kinds ofα2-receptor agonists showed a good linear relationship in the range of 1-100μg/mL,with the average recovery of over 69%and the relative standard deviation less than 8.32%.The detection limit of 10 kinds of α_(2)-receptor agonists was up to 1μg/kg.[Conclusions]The method has good selectivity and strong anti-interference ability,and can meet the requirements of 10 kinds ofα2-receptor agonists residues in animal derived food.
文摘This paper considers eigenstructure assignment in second-order linear systems via proportional plus derivative feedback. It is shown that the problem is closely related to a type of so-called second-order Sylvester matrix equations. Through establishing two general parametric solutions to this type of matrix equations, two complete parametric methods for the proposed eigenstructure assignment problem are presented. Both methods give simple complete parametric expressions for the feedback gains and the closed-loop eigenvector matrices. The first one mainly depends on a series of singular value decompositions, and is thus numerically simple and reliable; the second one utilizes the right factorization of the system, and allows the closed-loop eigenvalues to be set undetermined and sought via certain optimization procedures. An example shows the effectiveness of the proposed approaches. Keywords Second-order linear systems - Eigenstructure assignment - Proportional plus derivative feedback - Parametric solution - Singular value decompoition - Right factorization This work was supported in part by the Chinese Outstanding Youth Foundation (No.69504002).
基金Supported by the National Natural Science Foundation of China(No. 2 98730 2 5 )
文摘The second-order nonlinear optical properties of thiophene S,S -dioxides derivatives were studied by using the ZINDO-SOS method. The computed results show that the thiophene S,S -dioxide derivatives exhibit larger second-order polarizabilities than their thiophene precursors. In order to clarify the origin of the different NLO responses among these chromophores, their electron properties and frontier orbital properties were investigated as well. These thiophene S,S -dioxides derivatives are good candidates for their application in electro-optical device due to their high nonlinearities, good thermal and photo stabilities.
基金The Graduate Students Innovate Scientific Research Program (YJSCX2008-158HLJ) of Heilongjiang Provincesupported by the Distinguished Young Scholar Foundation (JC200707) of Heilongjiang Province of China
文摘In this paper, we establish a second-order sufficient condition for constrained optimization problems of a class of so called t-stable functions in terms of the first-order and the second-order Dini type directional derivatives. The result extends the corresponding result of [D. Bednarik and K. Pastor, Math. Program. Ser. A, 113（2008）, 283-298] to constrained optimization problems.
文摘alculations of the nonlinear second-order optical susceptlbilities(β_(ijk))for sub- stituted tl1iophene derivative;with quinoidlike conformation are reported.These systetems possess small dipole moment;and large differences between dipole mo- ments of ground and first-excited states.Geometry optimizations of the molecules investigated were carried out using AM 1 method.The calculations were performed using INDO/CI method comboned with a sum-over-states expression for β_(jik). The calculated results sbw that the second-order susceptibility is a function of the na- ture and location of substituents and is larger for disubstituted molecules than monosubstituted molecules. Bipolymeric thiophenemetmne with NH_2/NO_2 groups was calctilated to have a β_μof 79. 920 × 10￣(-30) esu. It was found that the NH_2 and NO_2 groups in above disubstituted molecules are pull-pull groups in ground states,but are usual push-pull groups in the first excited states.
基金Supported by Scientific Research Projects of General Administration of Quality Supervision,Inspection and Quarantine“Standard Sample Development and Production System Construction of Animal-derived Veterinary Drugs”(20130143)
文摘[Objective]The research aimed to establish a liquid chromatography-high-resolution mass spectrometry for detecting residues of diclazuril,toltrazuril and its metabolites in animal-derived food.[Method]The samples were pre-treated by QuEChERS technology and detected by Exactive liquid chromatography-high resolution mass spectrometry.The liquid chromatography-high-resolution mass spectrometry for detecting the residues of diclazuril,toltrazuril,toltrazuril sulfone and toltrazuril sulfoxide in animal-derived food was established.[Result]Diclazuril,toltrazuril,toltrazuril sulfone and toltrazuril sulfoxide showed a good linear correlation in the range of 2.0-50.0μg/L（r^2〉0.99）.The average recoveries of these four compounds in bovine power at the spiked levels of 2,10 and 20μg/kg were 74.5%-90.1%,and the relative standard deviations（RSD）were 15.4%-17.5%.[Conclusion]This method was stable and reliable,and could be used to detect diclazuril,toltrazuril,toltrazuril sulfone and toltrazuril sulfoxide in animal-derived food.
基金ProjectsupportedbytheNationalNaturalScienceFoundationofChina (No .2 99730 10 )andtheKeyLabofSupramolecularStructureandMate rialofJilinUniversity .
文摘The second-order nonlinear optical (NLO) properties of a series of benzothiazole derivatives were studied by use of the ZINDO-SOS method. These chromophores are formed by a donor-π-bridge-acceptor system, based on a nitro group connected with benzothiazole as the acceptor and a hydroxyl-functional amino group as the donor. For the purpose of comparison, we also designed molecules in which nitrobenzene is an acceptor. The calculation results indicate that benzothiazole derivatives exhibit larger second-order polarizabilities than nitrobenzene derivatives. In order to clarify the origin of the NLO response of these chromophores, their electron properties were investigated as well. The benzothiazole derivatives are good candidates for application in electro-optical device due to their high optical nonlinearities, good thermal and photonic stability.
文摘m-Iodobenzylguanidinium hemisulfate (MIBGHS) is a precursor in the preparation of radioiodine-labeled m-iodobenzylguanidine (MIBG), which is used as a radio-imaging and therapy agent for neuroendocrine tumors and myocardial sympathetic nerve function. To ensure the quality and efficacy of the medicine and prevent side effects, the precursor purity, source of impurity, and derivatives have to be determined. In this study, the purity of synthesized MIBGHS and the amount of contaminants therein were determined by high-performance liquid chromatography and ultraviolet detection, gradient eluted by ammonium formate aqueous solution and acetonitrile mobile phase on both C8 and phenyl type column. The impurities were identified on the basis of molecular and fragmented ion mass spectra using of electrospray ionization triple quadrupole tandem mass spectrometry. The results revealed the presence of process-related impurities including m-bromobenzylguanidine (MBrBG) and overreacted byproducts. Stress test results indicated that MIBGHS is stable under acidic and dry thermal conditions for at least 72 h but MIBG aqueous solution was deteriorated slowly when exposed to UV light, thermal, oxidative and alkaline environments. Thus, m-iodobenzylamine, the starting material intended for the synthesis of MIBGHS should be analyzed to ensure that it is free from m-bromobenzylamine impurity. Stored under normal condition (-18°C), MIBGHS is stable for at least 12 months. The chemically labile guanidine and amine groups in MIBGHS are the major causes of its instability, while iodide loss from the phenyl group is a minor cause.
基金Project supported by the National Natural Science Foundation of China (Nos. 29890210, 29573104) and the Key Laboratory for Supramolecular Structure and Spectroscopy of Jilin Universtiy.
文摘On the basis of ZINDO methods, according to the sum-overstates (SOS) expression, the program for the calculation of the second-order nonlinear optical susceptibilities βijk and βμ of molecules was devised, and the structures and nonlinear optical properties of unsymmetric bis(phenylethynyl) benzene series derivatives were studied. The influence of the molecular conjugated chain lengths, the donor and the acceptor on βμ was examined.
文摘目的建立柱前衍生高效液相色谱-串联质谱法(high performance liquid chromatography-tandem mass spectrometry,HPLC-MS/MS)测定鲜茶叶中春雷霉素的检测方法。方法样品经甲醇/水溶液提取,MCX SPE阳离子交换柱(mixed-mode cation exchanger SPE column)净化,9-氯甲酸芴甲酯[9-fluorenylmethyloxycarbonyl(Fmoc)chloride,Fmoc-Cl]衍生后测定,内标法定量。结果目标化合物在0.31~20.00μg/L范围内,线性关系良好,相关系数大于0.998(r^(2))。鲜茶叶中春雷霉素的检出限(limit of detection,LOD)、定量限(limit of quantification,LOQ)分别为2.0μg/kg和5.0μg/kg。在LOQ、2×LOQ和10×LOQ水平上加标,平均回收率为95.2%~104.0%,相对标准偏差为7.4%~13.3%。结论基于Fmoc-Cl衍生化的测定法,能有效提高检测的灵敏度、降低基质的干扰;将西马特罗作为内标使用,可以提供更为准确的检测结果,该方法满足鲜茶叶中春雷霉素的监测。
文摘本研究旨在利用质谱技术鉴定野血牦牛与家养牦牛血清中化学衍生物的差异,以明确长期受到高原生态环境自然选择下,野血牦牛更优环境适应性的代谢机制。本研究利用串联质谱技术对西藏阿里改则县的5头野血牦牛和5头家养牦牛的血清进行代谢组功能分析,共鉴定到574个代谢相关化学衍生物质,其中比例最高的是有机酸及其衍生物和氨基酸及其衍生物,21种代谢物质差异显著,较家养牦牛,野血牦牛有7类化学代谢物(邻甲氧基苯甲酸、9,12-十八碳二烯酸、3,4,5-三甲氧基肉桂酸等)显著上调,14类化学代谢物(前列腺素E2、氧化三甲胺、羟基二十碳五烯酸等)显著下调。其中7类化学衍生物(5-羟基吲哚-3-乙酸、鸟苷、尿素、前列腺素E2、皮质醇、5-甲氧基色胺、3-甲基吲哚)富集于31个KEGG信号通路,包括组织系统(Organismal Sysyems)、代谢(Metabolism)、人类疾病(Human Disease)、环境信息过程(Environmental Information Processing)。本研究通过代谢组比较分析,进一步明确了野血牦牛优异的环境适应性代谢基础,同时鉴定到野血牦牛中富含一系列(鸟苷、5-甲基-2-脱氧饱苷、邻甲基苯甲酸等)已明确与心脑血管疾病相关药的化学衍生物,为今后开发抗高原病相关药物开发提供借鉴参考。
