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平野一贯《定性分析》无机物分析体系构架之研究
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作者 陈镱文 姚远 曲安京 《陕西师范大学学报(自然科学版)》 CAS CSCD 北大核心 2009年第2期64-67,共4页
采用文本分析的方法,研究了平野一贯《定性分析》一书对日本近代分析化学的影响,对《定性化学》的考质分试法和考质相生法相关内容进行了详细解析.《定性化学》提出化学反应速率理论、沉淀理论、金属活泼性理论等重要化学原理;对无机化... 采用文本分析的方法,研究了平野一贯《定性分析》一书对日本近代分析化学的影响,对《定性化学》的考质分试法和考质相生法相关内容进行了详细解析.《定性化学》提出化学反应速率理论、沉淀理论、金属活泼性理论等重要化学原理;对无机化合物的本质、配质进行独特的系统分类;化学反应原理涉及棕环反应、歧化反应、复分解反应等.其对日本定性化学的发展具有重要的意义. 展开更多
关键词 《定性分析》 平野一贯 本质 配质
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Extraction Storage and Qualitative Analysis of Free Radicals Scavenging Substances from Sweet Potato Leaves 被引量:9
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作者 王友升 董银卯 +1 位作者 宋彦 黑维俭 《Agricultural Science & Technology》 CAS 2008年第2期1-5,9,共6页
[ Objective ] The research aimed to provide reference for the application of extracts from sweet potato leaves in anti-aging cosmetics. [ Method ] The extraction and storage conditions for free radicals scavenging sub... [ Objective ] The research aimed to provide reference for the application of extracts from sweet potato leaves in anti-aging cosmetics. [ Method ] The extraction and storage conditions for free radicals scavenging substances from sweet potato leaves were optimized by orthogonal test and the bioactive components in extracts were investigated by correlation analysis. [ Result] Sweet potato leaves contain the bioactive substances scavenging DPPH free radical and hydroxyl free radical. Extracting solvent species is the most important factor that influencing extraction yield. The optimal extraction and storage conditions are as following: water as solvent, pH 8.0 of extracting liquid, storage at 25 ℃. There is a good positive linear relationship between the content of total phenols in sweet potato leaves and corresponding scavenging rates against both the DPPH free radical and hydroxyl free radical. For the content of total flavones in sweet potato leaves, just a correlation with scavenging rate against hydroxyl free radical shown in test. [ Conclusion] The phenols in ex- tracts could effectively scavenge both the DPPH free radical and hydroxyl free radical, whereas the flavones in extracts can only function on the hydroxyl free radical. 展开更多
关键词 Sweet potato leaves Free radicals scavenging Total phenol Total flavones
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Analysis of stability and bullwhip effect in production-inventory systems 被引量:5
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作者 张冲 王海燕 《Journal of Southeast University(English Edition)》 EI CAS 2011年第1期101-106,共6页
To discuss the relationship between stability and bullwhip effect in the supply chain system,a basic model in a production-inventory control system is developed using difference equations.Z-transform techniques are ap... To discuss the relationship between stability and bullwhip effect in the supply chain system,a basic model in a production-inventory control system is developed using difference equations.Z-transform techniques are applied to investigate the production ordering and inventory dynamics.For the two operational regimes of sufficient inventory coverage and insufficient inventory coverage,the scope of decision parameters which make the system stable or instable is investigated.Under two operational regimes and the actual system,production release rates,stability/instability and bullwhip effect in the stable region and instable region are examined based on different demand functions,and then the numerical simulation results are given.The results show that reasonable choices of fractional adjustment of inventory and supply line can make the system stable and decrease bullwhip effect.It is summarized that the piecewise linearization based on the stability analysis approach is a valid approximation to the analysis of production-inventory ordering systems with nonlinearities.Some interesting results are obtained and they have important implications for improving inventory and order decisions in supply chain systems. 展开更多
关键词 production-inventory systems stability analysis bullwhip effect Z-TRANSFORM
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Predicting pillar stability for underground mine using Fisher discriminant analysis and SVM methods 被引量:16
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作者 周健 李夕兵 +2 位作者 史秀志 魏威 吴帮标 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第12期2734-2743,共10页
The purpose of this study is to apply some statistical and soft computing methods such as Fisher discriminant analysis (FDA) and support vector machines (SVMs) methodology to the determination of pillar stability ... The purpose of this study is to apply some statistical and soft computing methods such as Fisher discriminant analysis (FDA) and support vector machines (SVMs) methodology to the determination of pillar stability for underground mines selected from various coal and stone mines by using some index and mechanical properties, including the width, the height, the ratio of the pillar width to its height, the uniaxial compressive strength of the rock and pillar stress. The study includes four main stages: sampling, testing, modeling and assessment of the model performances. During the modeling stage, two pillar stability prediction models were investigated with FDA and SVMs methodology based on the statistical learning theory. After using 40 sets of measured data in various mines in the world for training and testing, the model was applied to other 6 data for validating the trained proposed models. The prediction results of SVMs were compared with those of FDA as well as the measured field values. The general performance of models developed in this study is close; however, the SVMs exhibit the best performance considering the performance index with the correct classification rate Prs by re-substitution method and Pcv by cross validation method. The results show that the SVMs approach has the potential to be a reliable and practical tool for determination of pillar stability for underground mines. 展开更多
关键词 underground mine pillar stability Fisher discriminant analysis (FDA) support vector machines (SVMs) PREDICTION
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Qualitative and Quantitative Analysis of Rhizoma of Polygonum cuspidatum 被引量:4
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作者 张勉 王磊 +2 位作者 黄澜 张紫佳 王峥涛 《Journal of Chinese Pharmaceutical Sciences》 CAS 2004年第2期106-111,共6页
Aim To establish reliable methods for evaluating the quality of rhizoma of Polygonum cuspidatum( Huzhang in Chinese). Methods TLC and HPLC were employed for the chemical identification and content determination,respec... Aim To establish reliable methods for evaluating the quality of rhizoma of Polygonum cuspidatum( Huzhang in Chinese). Methods TLC and HPLC were employed for the chemical identification and content determination,respectively. Results A qualitative TLC method and a quantitative HPLC method with piceid as the reference substance were established, respectively. With piceid as the reference substance and ethyl acetate-methanol-formic acid-water ( 19:3:0.5:1) as the mobile phase, a TLC method for the identification of Huzhang from the commonly used crude drugs of the same family was also set up. Conclusion The established TLC method can reasonably appraise the quality of the drug and easily distinguish Huzhang from the other commonly used crude drugs of the same family. The HPLC method for determining piceid is simple, reproducible, accurate, and feasible. 展开更多
关键词 TLC HPLC PICEID EMODIN rhizoma of Polygonum cuspidatum
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A GIS-based Study on Suitability Estimation of Tea Cultivation in Qimen County 被引量:11
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作者 叶寅 何方 +3 位作者 张学英 宫志锋 吕莎莎 方亮 《Agricultural Science & Technology》 CAS 2011年第1期149-152,共4页
On the basis of data from Soil Test and Formula Fertilization project in Qimen county,we employed Geographic Information System Software ArcGIS 9.2 and CLRMIS(Cultivated Land Resource Management Information System at... On the basis of data from Soil Test and Formula Fertilization project in Qimen county,we employed Geographic Information System Software ArcGIS 9.2 and CLRMIS(Cultivated Land Resource Management Information System at County Scale) to establish region-specific estimation index system for tea cultivation in Qimen County by determining the estimation units,and carried out quantitative estimation analysis on tea cultivation there via comprehensive evaluation indices for natural elements of cultivated land.The results showed that the highly suitable,suitable,reluctantly suitable and unsuitable acreages are 5 665.8,8 327.1,8 415.9 and 11 979.9 hm2 respectively,accounting for 24.0%,35.3%,35.7% and 5.1% of the total acreage of cultivated land.These results would facilitate the production of high yield and quality tea in Qimen County. 展开更多
关键词 Tea planting suitability Cultivated land GIS Quantitative assessment
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INFLUENCE OF TOOL HELIX ANGLE ON STABILITY IN HIGH-SPEED MILLING PROCESS 被引量:1
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作者 宋清华 艾兴 +1 位作者 万熠 潘永智 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2008年第1期18-25,共8页
An integrated dynamic model considering the influence of the helix angle is developed through dividing the cutting process into three cutting processes: uninterrupted, entry, and exit cutting processes. The semi-disc... An integrated dynamic model considering the influence of the helix angle is developed through dividing the cutting process into three cutting processes: uninterrupted, entry, and exit cutting processes. The semi-discretized technique is used to approximate the finite dimensional Floquet transition matrix of the dynamic control equation to determine the stability of milling process. The stability charts for helix mills are obtained. Results show that the helix angle plays an important role in the stability of milling process. The stability regions with helix angle become larger than those without helix angle. Some "islands" are presented in the stability charts, and "island" locations are determined by the relation between the axial depth of cut and the helix pitch. The "islands" are connected by the "bridge" by the effects of entry and exit cutting processes. The theoretical results are validated by milling experiments. 展开更多
关键词 milling (machining) vibration analysis STABILITY helix angle
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Determination of Melamine by Infrared Spectroscopy Based on Nonlinear Modeling 被引量:1
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作者 张恒 高曼侠 +2 位作者 许兆棠 李文谦 王琪 《Agricultural Science & Technology》 CAS 2010年第8期133-136,共4页
[Objective] The aim was to develop a nonlinear model of quantitative analysis of melamine content by infrared spectroscopy and provide theoretical basis for the nondestructive detection of melamine. [Method] According... [Objective] The aim was to develop a nonlinear model of quantitative analysis of melamine content by infrared spectroscopy and provide theoretical basis for the nondestructive detection of melamine. [Method] According to dynamics,mathematical modeling and optimization theory,linear and nonlinear models were respectively set up by taking an absorption peak of 1 550 cm-1 as characteristic absorption peak. [Result] The correlation coefficient of nonlinear model was 0.922 7 and the recovery was 96%,which showed that the nonlinear model was more accurate than linearity model with correlation coefficient of 0.904 9 and recovery of 557%. [Conclusion] It is feasible to determine melamine content by using the nonlinear model quantitatively. 展开更多
关键词 Infrared spectroscopy Quantitative analysis Nonlinear model MELAMINE
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Active Vibration Control and Stability Analysis of Cantilever Plate
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作者 钱振东 黄卫 +1 位作者 陈国平 朱德懋 《Journal of Southeast University(English Edition)》 EI CAS 2000年第1期75-79,共5页
Active vibration control and stability analysis of cantilever plate are discussed. Based on the analysis of characteristic equation of the closed loop control system, it is shown that such an active control may incre... Active vibration control and stability analysis of cantilever plate are discussed. Based on the analysis of characteristic equation of the closed loop control system, it is shown that such an active control may increase damping properties of the system, meanwhile it may result in instability of the system. It is stable when the feedback only occurs between the collocated sensors and actuators, but it may be unstable when there exists the feedback between sensors and actuators, which mainly depends on the property of the gain matrix of feedback. If the gain matrix is symmetric and definitely positive, the system is stable. 展开更多
关键词 active control STABILITY SENSORS actuators
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Stability analysis for affine fuzzy system based on fuzzy Lyapunov functions
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作者 柳善建 沈炯 +1 位作者 刘西陲 李益国 《Journal of Southeast University(English Edition)》 EI CAS 2011年第3期295-299,共5页
An analysis method based on the fuzzy Lyapunov functions is presented to analyze the stability of the continuous affine fuzzy systems. First, a method is introduced to deal with the consequent part of the fuzzy local ... An analysis method based on the fuzzy Lyapunov functions is presented to analyze the stability of the continuous affine fuzzy systems. First, a method is introduced to deal with the consequent part of the fuzzy local model. Thus, the stability analysis method of the homogeneous fuzzy system can be used for reference. Stability conditions are derived in terms of linear matrix inequalities based on the fuzzy Lyapunov functions and the modified common Lyapunov functions, respectively. The results demonstrate that the stability result based on the fuzzy Lyapunov functions is less conservative than that based on the modified common Lyapunov functions via numerical examples. Compared with the method which does not expand the consequent part, the proposed method is simpler but its feasible region is reduced. Finally, in order to expand the application of the fuzzy Lyapunov functions, the piecewise fuzzy Lyapunov function is proposed, which can be used to analyze the stability for triangular or trapezoidal membership functions and obtain the stability conditions. A numerical example validates the effectiveness of the proposed approach. 展开更多
关键词 affine fuzzy system stability analysis linear matrix inequalities fuzzy Lyapunov function
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GENERAL RELIABILITY ANALYSIS FOR TWO DIMENSIONAL SLOPES
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作者 揭敏 邓泽贤 李大海 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1998年第1期36-41,共6页
The reliability analysis, based on the reliability index method, of two dimensional slopes is generalized by taking Sarma′s acceleration as the performance function. That is to say, a general expression of the perfo... The reliability analysis, based on the reliability index method, of two dimensional slopes is generalized by taking Sarma′s acceleration as the performance function. That is to say, a general expression of the performance function is given under various kinds of slice methods, even under various shapes of slice partition, beyond the traditional vertical slice method. A simple example shows explicitly the relationship of four commonly used slice methods in the slope reliability analysis. It is also found that the results of the reliability analysis are basically consistent with those of the stability analysis based on Sarma′s method. 展开更多
关键词 reliability stability analysis two dimen sional slope Sarma′s method
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Thermal oxidation of two aviation synthetic lubricant base oils 被引量:3
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作者 费逸伟 郭峰 +2 位作者 姚婷 杨宏伟 程治升 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2015年第4期396-404,共9页
The thermal degradation of two synthetic lubricants base oils, poly-a-olefins (PAO) and di-esters (DE), was investigated under oxidative pyrolysis condition and their properties were characterized in simulated "a... The thermal degradation of two synthetic lubricants base oils, poly-a-olefins (PAO) and di-esters (DE), was investigated under oxidative pyrolysis condition and their properties were characterized in simulated "areo-engine" by comparing the thermal stability and identifying the products of thermal decomposition as a function of exposure temperature. The characterization of the products were performed by means of Fourier transform infrared spectrometry (FTIR), gas chromatography/mass spectrometry (GC/MS) and viscosity experiments. The results show that PAO has the lower thermal stability, being degraded at 200℃ different from 300 ℃ for DE. Several by-products are identified during the thermal degradation of two lubricant base oils. The majority of PAO products consist of alkenes and olefins, while more oxygen-contained organic compounds are detected in DE samples based on GC/MS analysis. The related reaction mechanisms are discussed based on the experimental results. 展开更多
关键词 synthetic aviation lubricant base oils thermal stability oxidative pyrolysis GC/MS analysis viscosity degradation
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Stability for the Manifold of Equilibrium State of the Autonomous Birkhoff System 被引量:3
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作者 梅凤翔 《Journal of Beijing Institute of Technology》 EI CAS 1997年第2期106-109,共4页
Studies the stability for them manifold of equilibrium state of the autonomous Birkhoffsystem. Uses the Liapunov's direct method and the first approximation method to obtain thestability criterion for the manifold... Studies the stability for them manifold of equilibrium state of the autonomous Birkhoffsystem. Uses the Liapunov's direct method and the first approximation method to obtain thestability criterion for the manifold of equilibrium state of the system. Gives an example toillustrate the application of the result. 展开更多
关键词 analytical mechanics Birkhoff system stability In 1927 American mathematician Birkhoff GD obtained a kind of dynamical equationswhich were more general than the Hamilton's equations in his well -known work ' DynamicalSystems' [1] In 1978. American ph
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Perturbations of Generalized Frames in a Hilbert Space
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作者 姚喜妍 杜鸿科 《Chinese Quarterly Journal of Mathematics》 CSCD 2002年第4期15-19,共5页
In the paper, we study the stability of Hilbert space generalized frames under perturbations. We get some results that are in spirit close to classical results for discrete frames, due to OLE Christensen.
关键词 Hilbert space generalized frame frame operator PERTURBATION
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A Generalization of Caristi Fixed Point Theorem 被引量:5
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作者 孙经先 《Chinese Quarterly Journal of Mathematics》 CSCD 1992年第1期72-75,共4页
Let X be a metric space with an ordering structure,A: X→X is a operator and x≤Ax for any x∈X. In this paper we prove a new fixed point theorem, which generalizes famous caristi fixed point theorem.
关键词 metric space partially ordred set fixed point theorem
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Dynamic analysis and experimental study of vibro-acoustic system with uncertainties at middle frequencies 被引量:2
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作者 焦仁强 张建润 薛飞 《Journal of Southeast University(English Edition)》 EI CAS 2017年第2期166-170,共5页
To take into account the influence of uncetainties on the dynamic response of the vibro-acousitc structure, a hybrid modeling technique combining the finite element method(FE)and the statistic energy analysis(SEA)... To take into account the influence of uncetainties on the dynamic response of the vibro-acousitc structure, a hybrid modeling technique combining the finite element method(FE)and the statistic energy analysis(SEA) is proposed to analyze vibro-acoustics responses with uncertainties at middle frequencies. The mid-frequency dynamic response of the framework-plate structure with uncertainties is studied based on the hybrid FE-SEA method and the Monte Carlo(MC)simulation is performed so as to provide a benchmark comparison with the hybrid method. The energy response of the framework-plate structure matches well with the MC simulation results, which validates the effectiveness of the hybrid FE-SEA method considering both the complexity of the vibro-acoustic structure and the uncertainties in mid-frequency vibro-acousitc analysis. Based on the hybrid method, a vibroacoustic model of a construction machinery cab with random properties is established, and the excitations of the model are measured by experiments. The responses of the sound pressure level of the cab and the vibration power spectrum density of the front windscreen are calculated and compared with those of the experiment. At middle frequencies, the results have a good consistency with the tests and the prediction error is less than 3. 5dB. 展开更多
关键词 hybrid finite element method and statistic energy analysis(FE-SEA) method dynamic analysis vibroacoustic system UNCERTAINTIES mid-frequency range
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Bus transit travel time reliability evaluation based on automatic vehicle location data 被引量:4
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作者 严亚丹 过秀成 +2 位作者 李岩 孔哲 何明 《Journal of Southeast University(English Edition)》 EI CAS 2012年第1期100-105,共6页
In order to provide important parameters for schedule designing, decision-making bases for transit operation management and references for passengers traveling by bus, bus transit travel time reliability is analyzed a... In order to provide important parameters for schedule designing, decision-making bases for transit operation management and references for passengers traveling by bus, bus transit travel time reliability is analyzed and evaluated based on automatic vehicle location (AVL) data. Based on the statistical analysis of the bus transit travel time, six indices including the coefficient of variance, the width of travel time distribution, the mean commercial speed, the congestion frequency, the planning time index and the buffer time index are proposed. Moreover, a framework for evaluating bus transit travel time reliability is constructed. Finally, a case study on a certain bus route in Suzhou is conducted. Results show that the proposed evaluation index system is simple and intuitive, and it can effectively reflect the efficiency and stability of bus operations. And a distinguishing feature of bus transit travel time reliability is the temporal pattern. It varies across different time periods. 展开更多
关键词 bus transit travel time reliability evaluation andanalysis automatic vehicle location data statistical analysis
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Stability of Three-Dimensional Trunk Motion
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作者 郭巧 《Journal of Beijing Institute of Technology》 EI CAS 1998年第1期49-54,共6页
Aim To analyse stability of the three-dimensional rotational movements of a human torso system under perturbations using anatomical data of muscles (McGill, 1992). Methods To use the linearized analysis methods and a ... Aim To analyse stability of the three-dimensional rotational movements of a human torso system under perturbations using anatomical data of muscles (McGill, 1992). Methods To use the linearized analysis methods and a special model in which the effect of ligamentous and passive resitance by discs and fibers is included. Results The model is capable of predicting the muscle forces,and joint reaction forces at the L5/Sl which are the biomechani- cal factors used to asses the risk of the discs and annulus fibers. Conclusions It can also be used to analyze and neural excitation levels for a diverse Set of trunk movement. 展开更多
关键词 BIOCONTROL BIOMECHANICS system stability analysis
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A DSS DEVELOPMENT AND APPLICATION FOR SUSTAINABLE DEVELOPMENT
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作者 沈惠璋 王浣尘 +2 位作者 刘铎 亢政刚 丁雷 《Transactions of Tianjin University》 EI CAS 2000年第1期22-27,共6页
The characteristics of sustainable development problems in the developing countries is discussed.In order to develop and use decision support system (DSS) for supporting sustainable development problem decision making... The characteristics of sustainable development problems in the developing countries is discussed.In order to develop and use decision support system (DSS) for supporting sustainable development problem decision making in the developing countries,this paper presents a strategy of constructing the DSS for sustainable development.A methodology of representing the model of sustainable development problems and developing a nonprocedural modeling language that is used to define sustainable development problems,a methodology of numeric and non numeric operation based theorem proving is given in this paper. 展开更多
关键词 decision support system sustainable development qualitative analysis quantitative research evolution behaviors
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Assessment of the Stability of Cefazolin Sodium in Solids by TGA Decomposition Kinetics 被引量:2
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作者 胡昌勤 张峰 +1 位作者 刘巍 金少鸿 《Journal of Chinese Pharmaceutical Sciences》 CAS 1998年第2期24-29,共6页
\ According to the analysis of the residual products by thermogravimetric analysis (TGA), the thermal decomposition process of cefazolin sodium (CEZ·Na) was thought to be similar to the degradation in solid sta... \ According to the analysis of the residual products by thermogravimetric analysis (TGA), the thermal decomposition process of cefazolin sodium (CEZ·Na) was thought to be similar to the degradation in solid state in its storage time. This laid a foundation for estimating the relative chemical stability of the drug by determination of its decomposition kinetics using TGA. Although the observed thermal decomposition kinetics of CEZ·Na was complex, a conversion level of 1% was chosen for evaluation of the stability of CEZ·Na crystalline since the mechanism here was more likely to be that of the actual product failure. The evaluation results suggested that the α form of CEZ·Na had the best stability and the amorphous one was the least stable one among α form, dehydrated α form and amorphous form. 展开更多
关键词 Cefazolin sodium CRYSTALLINE STABILITY Decomposition kinetics Thermogravimetric analysis
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