This paper presents an approximation method to display realistic pictures of numerical control (NC) machining simulation very quickly. T he tool movement envelope is divided into many small regions and the normal to...This paper presents an approximation method to display realistic pictures of numerical control (NC) machining simulation very quickly. T he tool movement envelope is divided into many small regions and the normal to t hese small regions is calculated. The system saves the calculated result in a fi le before starting animation display. When the system starts displaying machinin g animation, it does not need to calculate small triangular facets normal to the workpiece surface. It only needs to find out what part of the cutter cuts the w orkpiece surface and to read the normal from the file. A highly efficient NC cod e verification method is also presented in this paper. The method first detects the error in z direction. If some points are reported to be out of the tolerance , the system divides neighborhood of these points into smaller grids and calcula tes the normal surface at each grid intersection and the error in the normal ve ctor direction.展开更多
该研究旨在分析不同产区修水宁红茶的香气组分及感官品质差异,探讨产区对其品质的影响。采用顶空固相微萃取-气相色谱-质谱联用技术(headspace solid-phase microextraction and gas chromatography mass spectrometry,HS-SPME-GC-MS)分...该研究旨在分析不同产区修水宁红茶的香气组分及感官品质差异,探讨产区对其品质的影响。采用顶空固相微萃取-气相色谱-质谱联用技术(headspace solid-phase microextraction and gas chromatography mass spectrometry,HS-SPME-GC-MS)分析3个产区的修水宁红茶香气组分,并运用主成分分析(principal component analysis,PCA)和偏最小二乘判别分析(partial least squares discrimination analysis,PLS-DA)评估产区对香气组分的影响,结合偏最小二乘回归变量投影重要性(variable importance in projection,VIP)分析、单因素方差分析(P<0.05)以及计算气味活性值(odor activity value,OAV)确定关键香气组分。共鉴定出99种香气组分,包括醇类、醛类、酮类、酯类、萜烯类、烷烃类和酸类。PCA和PLS-DA表明,产区对修水宁红茶的香气组分具有显著影响。结合VIP分析,共筛选出22种VIP值大于1的香气组分,通过方差分析进一步筛选出8种香气组分,确定了(E)-3-己烯-1-醇、(E)-呋喃芳樟醇氧化物、δ-杜松烯、正己醛、(Z)-3-己烯己酸酯和苯甲醇是修水宁红茶的关键呈香物质。该研究揭示了产区对修水宁红茶香气组分的显著影响,确定了关键呈香物质,明确了其对感官品质的贡献,为修水宁红茶的香味调控和品质提升提供了科学依据和研究基础。展开更多
In order to investigate the dynamic mechanical properties of amphibolite and sericite-quartz schist under confi ning pressure, two rocks are subjected to impact loadings with different strain rates and confi ning pres...In order to investigate the dynamic mechanical properties of amphibolite and sericite-quartz schist under confi ning pressure, two rocks are subjected to impact loadings with different strain rates and confi ning pressures by using split Hopkinson pressure bar equipment with a confi ning pressure device. Based on the experimental results, the stress-strain curves are analyzed and the effects of confi ning pressure and strain rates on the dynamic compressive strength, peak strain and failure mode are summarized. The results show that:(1) The characteristics of two rocks in the ascent stage of the stressstrain curve are basically the same, but in the descent stage, the rocks gradually show plastic deformation characteristics as the confi ning pressure increases.(2) The dynamic compressive strength and peak strain of two rocks increase as the strain rate increases and the confi ning pressure effects are obvious.(3) Due to the effect of confi ning pressure, the normal stress on the damage surface of the rock increases correspondingly, the bearing capacity of the crack friction exceeds the material cohesion and the slippage of the fractured rock is controlled, which all lead to the compression and shear failure mode of rock. The theoretical analysis and experimental methods to study the dynamic failure mode and other related characteristics of rock are useful in developing standards for engineering practice.展开更多
The present study was designed to determine the relationships between the performance of ethanol precipitation and seven process parameters in the ethanol precipitation process of Re Du Ning Injections,including conce...The present study was designed to determine the relationships between the performance of ethanol precipitation and seven process parameters in the ethanol precipitation process of Re Du Ning Injections,including concentrate density,concentrate temperature,ethanol content,flow rate and stir rate in the addition of ethanol,precipitation time,and precipitation temperature.Under the experimental and simulated production conditions,a series of precipitated resultants were prepared by changing these variables one by one,and then examined by HPLC fingerprint analyses.Different from the traditional evaluation model based on single or a few constituents,the fingerprint data of every parameter fluctuation test was processed with Principal Component Analysis(PCA)to comprehensively assess the performance of ethanol precipitation.Our results showed that concentrate density,ethanol content,and precipitation time were the most important parameters that influence the recovery of active compounds in precipitation resultants.The present study would provide some reference for pharmaceutical scientists engaged in research on pharmaceutical process optimization and help pharmaceutical enterprises adapt a scientific and reasonable cost-effective approach to ensure the batch-to-batch quality consistency of the final products.展开更多
An A1/Pb-0.3%Ag alloy composite anode was produced via composite casting. Its electrocatalytic activity for the oxygen evolution reaction and corrosion resistance was evaluated by anodic polarization curves and accele...An A1/Pb-0.3%Ag alloy composite anode was produced via composite casting. Its electrocatalytic activity for the oxygen evolution reaction and corrosion resistance was evaluated by anodic polarization curves and accelerated corro- sion test, respectively. The microscopic morphologies of the anode section and anodic oxidation layer during accelerated corrosion test were obtained by scanning electron microscopy. It is found that the composite anode （hard anodizing） dis- plays a more compact interracial combination and a better adhesive strength than plating tin. Compared with industrial Pb-0.3%Ag anodes, the oxygen evolution overpotentials of A1/Pb-0.3%Ag alloy （hard anodizing） and A1/Pb-0.3%Ag alloy （plating tin） at 500 A.m-2 were lower by 57 and 14 mV, respectively. Furthermore, the corrosion rates of Pb-0.3%Ag alloy, A1/Pb-0.3%Ag alloy （hard anodizing）, and A1/Pb-0.3%Ag alloy （plating tin） were 13.977, 9.487, and 11.824 g.m-2.h-1, respectively, in accelerated corrosion test for 8 h at 2000 A-m-2. The anodic oxidation layer of A1/Pb-0.3%Ag alloy （hard anodizing） is more compact than Pb-0.3%Ag alloy and A1/Pb-0.3%Ag alloy （plating tin） after the test.展开更多
[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination.[Methods]The L9(34)orthogonal test was carried out,the c...[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination.[Methods]The L9(34)orthogonal test was carried out,the comprehensive scores of ginsenoside Rb1 content,notoginsenoside R1 content,tanshinone I content and saikosaponin A content in the compound extract were used as evaluation indicators to explore the effects of water addition,the water addition,decoction time and decoction times on the water extraction process,and verification tests were carried out.[Results]The optimized water extraction process was as follows:adding 9 times of water in the first extraction,and extracting for 90 min;adding 7 times of water in the second extraction,and extracting for 60 min;adding 7 times of water in the third extraction,and extracting for 60 min.[Conclusions]The optimized water extraction process is stable and feasible,and can be used for the extraction of various herbs in Compound Man Gan Ning.It can also provide experimental basis for the formulation development of Compound Man Gan Ning sustained release tablet.展开更多
文摘This paper presents an approximation method to display realistic pictures of numerical control (NC) machining simulation very quickly. T he tool movement envelope is divided into many small regions and the normal to t hese small regions is calculated. The system saves the calculated result in a fi le before starting animation display. When the system starts displaying machinin g animation, it does not need to calculate small triangular facets normal to the workpiece surface. It only needs to find out what part of the cutter cuts the w orkpiece surface and to read the normal from the file. A highly efficient NC cod e verification method is also presented in this paper. The method first detects the error in z direction. If some points are reported to be out of the tolerance , the system divides neighborhood of these points into smaller grids and calcula tes the normal surface at each grid intersection and the error in the normal ve ctor direction.
文摘该研究旨在分析不同产区修水宁红茶的香气组分及感官品质差异,探讨产区对其品质的影响。采用顶空固相微萃取-气相色谱-质谱联用技术(headspace solid-phase microextraction and gas chromatography mass spectrometry,HS-SPME-GC-MS)分析3个产区的修水宁红茶香气组分,并运用主成分分析(principal component analysis,PCA)和偏最小二乘判别分析(partial least squares discrimination analysis,PLS-DA)评估产区对香气组分的影响,结合偏最小二乘回归变量投影重要性(variable importance in projection,VIP)分析、单因素方差分析(P<0.05)以及计算气味活性值(odor activity value,OAV)确定关键香气组分。共鉴定出99种香气组分,包括醇类、醛类、酮类、酯类、萜烯类、烷烃类和酸类。PCA和PLS-DA表明,产区对修水宁红茶的香气组分具有显著影响。结合VIP分析,共筛选出22种VIP值大于1的香气组分,通过方差分析进一步筛选出8种香气组分,确定了(E)-3-己烯-1-醇、(E)-呋喃芳樟醇氧化物、δ-杜松烯、正己醛、(Z)-3-己烯己酸酯和苯甲醇是修水宁红茶的关键呈香物质。该研究揭示了产区对修水宁红茶香气组分的显著影响,确定了关键呈香物质,明确了其对感官品质的贡献,为修水宁红茶的香味调控和品质提升提供了科学依据和研究基础。
基金National Natural Science Foundation of China under Grant No.51378497
文摘In order to investigate the dynamic mechanical properties of amphibolite and sericite-quartz schist under confi ning pressure, two rocks are subjected to impact loadings with different strain rates and confi ning pressures by using split Hopkinson pressure bar equipment with a confi ning pressure device. Based on the experimental results, the stress-strain curves are analyzed and the effects of confi ning pressure and strain rates on the dynamic compressive strength, peak strain and failure mode are summarized. The results show that:(1) The characteristics of two rocks in the ascent stage of the stressstrain curve are basically the same, but in the descent stage, the rocks gradually show plastic deformation characteristics as the confi ning pressure increases.(2) The dynamic compressive strength and peak strain of two rocks increase as the strain rate increases and the confi ning pressure effects are obvious.(3) Due to the effect of confi ning pressure, the normal stress on the damage surface of the rock increases correspondingly, the bearing capacity of the crack friction exceeds the material cohesion and the slippage of the fractured rock is controlled, which all lead to the compression and shear failure mode of rock. The theoretical analysis and experimental methods to study the dynamic failure mode and other related characteristics of rock are useful in developing standards for engineering practice.
基金supported by 973 Project from the Ministry of Science and Technology of China(No.2010 CB735604)
文摘The present study was designed to determine the relationships between the performance of ethanol precipitation and seven process parameters in the ethanol precipitation process of Re Du Ning Injections,including concentrate density,concentrate temperature,ethanol content,flow rate and stir rate in the addition of ethanol,precipitation time,and precipitation temperature.Under the experimental and simulated production conditions,a series of precipitated resultants were prepared by changing these variables one by one,and then examined by HPLC fingerprint analyses.Different from the traditional evaluation model based on single or a few constituents,the fingerprint data of every parameter fluctuation test was processed with Principal Component Analysis(PCA)to comprehensively assess the performance of ethanol precipitation.Our results showed that concentrate density,ethanol content,and precipitation time were the most important parameters that influence the recovery of active compounds in precipitation resultants.The present study would provide some reference for pharmaceutical scientists engaged in research on pharmaceutical process optimization and help pharmaceutical enterprises adapt a scientific and reasonable cost-effective approach to ensure the batch-to-batch quality consistency of the final products.
基金financially supported by the National Natural Science Foundation of China(No.51004056)the Opening Foundation of the Key Laboratory of Inorganic Coating Materials,Chinese Academy of Sciences(No.KKZ6201152009)+2 种基金the Specialized Research Fund for the Doctoral Program of Higher Education(No.20125314110011)the Applied Basic Research Foundation of Yunnan Province,China(No.2010ZC052)the Analysis and Testing Foundation of Kunming University of Science and Technology(Nos.2010203 and 2011173)
文摘An A1/Pb-0.3%Ag alloy composite anode was produced via composite casting. Its electrocatalytic activity for the oxygen evolution reaction and corrosion resistance was evaluated by anodic polarization curves and accelerated corro- sion test, respectively. The microscopic morphologies of the anode section and anodic oxidation layer during accelerated corrosion test were obtained by scanning electron microscopy. It is found that the composite anode （hard anodizing） dis- plays a more compact interracial combination and a better adhesive strength than plating tin. Compared with industrial Pb-0.3%Ag anodes, the oxygen evolution overpotentials of A1/Pb-0.3%Ag alloy （hard anodizing） and A1/Pb-0.3%Ag alloy （plating tin） at 500 A.m-2 were lower by 57 and 14 mV, respectively. Furthermore, the corrosion rates of Pb-0.3%Ag alloy, A1/Pb-0.3%Ag alloy （hard anodizing）, and A1/Pb-0.3%Ag alloy （plating tin） were 13.977, 9.487, and 11.824 g.m-2.h-1, respectively, in accelerated corrosion test for 8 h at 2000 A-m-2. The anodic oxidation layer of A1/Pb-0.3%Ag alloy （hard anodizing） is more compact than Pb-0.3%Ag alloy and A1/Pb-0.3%Ag alloy （plating tin） after the test.
基金Supported by Project of National Natural Science Foundation of China(81360524)Project for Improving Basic Research Ability of Middle Aged and Young Teachers in Colleges and Universities of Guangxi in 2019(2019KY0341)+2 种基金National Traditional Chinese Medicine Characteristic Technology Heritage Talent Training Program(20184828005)Youth Foundation Project of Guangxi University of Chinese Medicine(2019QN036)Program of Scientific Research Third-level Laboratory"Chinese(Zhuang)Medicine Chemical and Quality Analysis Laboratory"of State Administration of Traditional Chinese Medicine(Guo Zhong Yi Yao Fa 2009[21]).
文摘[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination.[Methods]The L9(34)orthogonal test was carried out,the comprehensive scores of ginsenoside Rb1 content,notoginsenoside R1 content,tanshinone I content and saikosaponin A content in the compound extract were used as evaluation indicators to explore the effects of water addition,the water addition,decoction time and decoction times on the water extraction process,and verification tests were carried out.[Results]The optimized water extraction process was as follows:adding 9 times of water in the first extraction,and extracting for 90 min;adding 7 times of water in the second extraction,and extracting for 60 min;adding 7 times of water in the third extraction,and extracting for 60 min.[Conclusions]The optimized water extraction process is stable and feasible,and can be used for the extraction of various herbs in Compound Man Gan Ning.It can also provide experimental basis for the formulation development of Compound Man Gan Ning sustained release tablet.
