为综合评价电网运行规划阶段分负荷方案的优劣,构造了一套涵盖电力系统经济性、安全性、可靠性和电力安全事故风险的电网运行规划分负荷方案评价指标体系。该指标体系首次将电力安全事故风险纳入评价考虑,涵盖范围广,能综合反映电网运...为综合评价电网运行规划阶段分负荷方案的优劣,构造了一套涵盖电力系统经济性、安全性、可靠性和电力安全事故风险的电网运行规划分负荷方案评价指标体系。该指标体系首次将电力安全事故风险纳入评价考虑,涵盖范围广,能综合反映电网运行规划分负荷的实际需求。在获取各分负荷方案评价指标值的前提下,利用TOPSIS(Technique for Order Preference by Similarity to Ideal Solution)方法求解分负荷方案优化这一多目标决策问题,简单实用、可操作性强。实际系统仿真算例验证了该方法的有效性,可为电网运行方式制定提供技术支撑。展开更多
Atmospheric electricity is composed of a wide range of electric phenomena in the troposphere, strato- sphere, and even lower ionosphere. Research progress on atmospheric electricity in the past 5 years in China are br...Atmospheric electricity is composed of a wide range of electric phenomena in the troposphere, strato- sphere, and even lower ionosphere. Research progress on atmospheric electricity in the past 5 years in China are briefly reviewed here. This research area has been greatly expanded through rocket-triggered lightning experiments and the increased use of high spatio-temporal resolution techniques for the detection and location of lightning. The main results described in this review are summarized in the following five aspects： （1） processes and parameters inferred from rocket-triggered lightning, （2） lightning physics and ef- fects （observations and theoretical study）, （3） lightning activities associated with different thunderstorms, （4） charge structure of thunderstorms （observations and simulation）, and （5） the VHF/UHF lightning location techniques and discharge channel mapping.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
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
Background:This study aims to explore the therapeutic effects of the Qi Teng Mai Ning recipe on ischemic stroke and vascular cognitive impairment through its potential to modulate cellular autophagy,with a focus on id...Background:This study aims to explore the therapeutic effects of the Qi Teng Mai Ning recipe on ischemic stroke and vascular cognitive impairment through its potential to modulate cellular autophagy,with a focus on identifying its active ingredients and their target proteins.Methods:The study began with the identification of active ingredients in the Qi Teng Mai Ning recipe.It proceeded to screen the gene expression omnibus database for ischemic stroke and vascular cognitive impairment-associated differentially expressed mRNAs and to identify cellular autophagy-related proteins via the Human Autophagy Database.These proteins were annotated with Gene Ontology and Kyoto Encyclopedia of Genes and Genomes functions and subjected to molecular docking with the recipe’s core active ingredients.In vitro cell experiments were conducted on hypoxic HT22 cells,involving CCK8 assay,lentiviral transfection to silence autophagy related 9B(ATG9B),immunofluorescence staining,and qPCR validation to investigate the effects of the recipe on autophagy.Results:The analysis identified 104 active ingredients targeting 408 proteins and forming a complex ingredient-target network.Intersecting 55 ischemic stroke-related and 909 vascular cognitive impairment-related differentially expressed mRNAs revealed 14 co-expressed mRNAs.Molecular docking showed quercetin,kaempferol,myrcene,and conferone as key ingredients targeting autophagy-related proteins.Cellular experiments indicated that the recipe significantly enhanced cell viability under hypoxic conditions,reduced apoptosis,and modulated the expression of autophagy-related factors,thereby decreasing apoptosis rates in HT22 cells.Conclusion:The Qi Teng Mai Ning recipe offers protective effects against ischemic stroke and vascular cognitive impairment by modulating autophagy-related proteins.Its efficacy highlights the potential of traditional Chinese medicine in treating these conditions,though further research is needed to fully understand its mechanisms and clinical applications.展开更多
The current energy supply trajectory in the Association of Southeast Asian Nations(ASEAN)region is not sustainable.Factors such as rising standards of living and demographic patterns,including population growth,lead t...The current energy supply trajectory in the Association of Southeast Asian Nations(ASEAN)region is not sustainable.Factors such as rising standards of living and demographic patterns,including population growth,lead to continuous increase in power demand,which is difficult to meet using limited fossil fuel resources.Thus,a transition toward clean energy sources is needed in the region.While ASEAN member countries are rich in clean energy resources,such resources are located far from demand centers;thus,allocation of clean energy is necessary to increase its utilization.In this study,power demand is forecasted using a combination of prediction methods.A model to evaluate the installed capacity and power exchange potential is proposed to deal with mismatch between the location of the clean energy base and the load center.Furthermore,the concept of cross-regional allocation of clean energy between the ASEAN region,China,and South Asia is presented.A power interconnection scheme among the ASEAN member countries as well as neighboring countries is proposed based on the power exchange potential.The proposed grid interconnection scheme contributes to the utilization of clean energy in the ASEAN region,increasing the proportion of clean energy in the generation mix,which ensures that the region becomes a sustainable and resilient society with a clean and low carbon development route.Furthermore,the proposed power interconnection scheme will generate valuable economic,social,environmental,and resource allocation benefits.展开更多
Highlights•This commentary article is intended to provide a broad yet brief look at research and issues about values and valuing in mathematics education from a broad view about related issues.•The articles in the Spe...Highlights•This commentary article is intended to provide a broad yet brief look at research and issues about values and valuing in mathematics education from a broad view about related issues.•The articles in the Special Issue provided new findings,insights,and directions in research on values and valuing in mathematics education.•In the future,more attention should be paid to the issues concerning values as a construct from a social-cultural perspective,and more studies addressing enacted values,using more observational data,and with large scale and long duration are needed.•There is also a need for more exchanges and interdisciplinary collaborations between mathematics educators,other discipline-based educators,and general educators,especially educational sociologists,for the advancement of research in this area.展开更多
The frequent occurrence of hitherto unknown phase Pre-θ′-2 and unusual 1.5 cθ′thick θ′precipitate was observed by atomic-resolution scanning transmission electron microscopy in the well-studied Al-Cu alloys. Thi...The frequent occurrence of hitherto unknown phase Pre-θ′-2 and unusual 1.5 cθ′thick θ′precipitate was observed by atomic-resolution scanning transmission electron microscopy in the well-studied Al-Cu alloys. This phenomenon is associated with heterogeneous precipitate nucleation and growth on preexisting dislocations introduced by slight deformation prior to aging. In this study, the precise structure details of Pre-θ′-2 was determined by atomic scale imaging, image simulation based on image forming theories and first principle calculations. Pre-θ′-2 has a well-defined ordered structure sandwiched between two 2 aAl(~1.5 cθ′) spaced Cu layers on {200}Alplanes. The strong structural similarities between Pre-θ′-2 and 1.5 cθ′ thick θ′ in terms of interfacial structure and thickness, coupled with energetic calculations and preliminary in-situ observations, lead us to propose a new precipitation path toward key strengthening phase θ′展开更多
文摘为综合评价电网运行规划阶段分负荷方案的优劣,构造了一套涵盖电力系统经济性、安全性、可靠性和电力安全事故风险的电网运行规划分负荷方案评价指标体系。该指标体系首次将电力安全事故风险纳入评价考虑,涵盖范围广,能综合反映电网运行规划分负荷的实际需求。在获取各分负荷方案评价指标值的前提下,利用TOPSIS(Technique for Order Preference by Similarity to Ideal Solution)方法求解分负荷方案优化这一多目标决策问题,简单实用、可操作性强。实际系统仿真算例验证了该方法的有效性,可为电网运行方式制定提供技术支撑。
基金supported by National Natural Science Foundation of China (Grant No.40930949)the One Hundred Person Project of the Chinese Academy of Sciences
文摘Atmospheric electricity is composed of a wide range of electric phenomena in the troposphere, strato- sphere, and even lower ionosphere. Research progress on atmospheric electricity in the past 5 years in China are briefly reviewed here. This research area has been greatly expanded through rocket-triggered lightning experiments and the increased use of high spatio-temporal resolution techniques for the detection and location of lightning. The main results described in this review are summarized in the following five aspects： （1） processes and parameters inferred from rocket-triggered lightning, （2） lightning physics and ef- fects （observations and theoretical study）, （3） lightning activities associated with different thunderstorms, （4） charge structure of thunderstorms （observations and simulation）, and （5） the VHF/UHF lightning location techniques and discharge channel mapping.
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.
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Background:This study aims to explore the therapeutic effects of the Qi Teng Mai Ning recipe on ischemic stroke and vascular cognitive impairment through its potential to modulate cellular autophagy,with a focus on identifying its active ingredients and their target proteins.Methods:The study began with the identification of active ingredients in the Qi Teng Mai Ning recipe.It proceeded to screen the gene expression omnibus database for ischemic stroke and vascular cognitive impairment-associated differentially expressed mRNAs and to identify cellular autophagy-related proteins via the Human Autophagy Database.These proteins were annotated with Gene Ontology and Kyoto Encyclopedia of Genes and Genomes functions and subjected to molecular docking with the recipe’s core active ingredients.In vitro cell experiments were conducted on hypoxic HT22 cells,involving CCK8 assay,lentiviral transfection to silence autophagy related 9B(ATG9B),immunofluorescence staining,and qPCR validation to investigate the effects of the recipe on autophagy.Results:The analysis identified 104 active ingredients targeting 408 proteins and forming a complex ingredient-target network.Intersecting 55 ischemic stroke-related and 909 vascular cognitive impairment-related differentially expressed mRNAs revealed 14 co-expressed mRNAs.Molecular docking showed quercetin,kaempferol,myrcene,and conferone as key ingredients targeting autophagy-related proteins.Cellular experiments indicated that the recipe significantly enhanced cell viability under hypoxic conditions,reduced apoptosis,and modulated the expression of autophagy-related factors,thereby decreasing apoptosis rates in HT22 cells.Conclusion:The Qi Teng Mai Ning recipe offers protective effects against ischemic stroke and vascular cognitive impairment by modulating autophagy-related proteins.Its efficacy highlights the potential of traditional Chinese medicine in treating these conditions,though further research is needed to fully understand its mechanisms and clinical applications.
基金supported by the Science and Technology Foundation of GEIG (No.524500180014)
文摘The current energy supply trajectory in the Association of Southeast Asian Nations(ASEAN)region is not sustainable.Factors such as rising standards of living and demographic patterns,including population growth,lead to continuous increase in power demand,which is difficult to meet using limited fossil fuel resources.Thus,a transition toward clean energy sources is needed in the region.While ASEAN member countries are rich in clean energy resources,such resources are located far from demand centers;thus,allocation of clean energy is necessary to increase its utilization.In this study,power demand is forecasted using a combination of prediction methods.A model to evaluate the installed capacity and power exchange potential is proposed to deal with mismatch between the location of the clean energy base and the load center.Furthermore,the concept of cross-regional allocation of clean energy between the ASEAN region,China,and South Asia is presented.A power interconnection scheme among the ASEAN member countries as well as neighboring countries is proposed based on the power exchange potential.The proposed grid interconnection scheme contributes to the utilization of clean energy in the ASEAN region,increasing the proportion of clean energy in the generation mix,which ensures that the region becomes a sustainable and resilient society with a clean and low carbon development route.Furthermore,the proposed power interconnection scheme will generate valuable economic,social,environmental,and resource allocation benefits.
基金supported by a research grant from East China Normal University(Project No.:15500-120215-10197).
文摘Highlights•This commentary article is intended to provide a broad yet brief look at research and issues about values and valuing in mathematics education from a broad view about related issues.•The articles in the Special Issue provided new findings,insights,and directions in research on values and valuing in mathematics education.•In the future,more attention should be paid to the issues concerning values as a construct from a social-cultural perspective,and more studies addressing enacted values,using more observational data,and with large scale and long duration are needed.•There is also a need for more exchanges and interdisciplinary collaborations between mathematics educators,other discipline-based educators,and general educators,especially educational sociologists,for the advancement of research in this area.
基金financial support from the National Natural Science Foundation of China (Nos. 51601060, 51235010, 51671086)Natural Science Foundation of Hunan Province (No. 2018JJ3655)+5 种基金the Major Project for Defense Basic Preresearch Programthe National Key R&D Program of China (No. 2017YFB0306300)the National Key Basic Research Development Plan Funded Project of China (No. 2014CB046602)the Innovationdriven Plan in Central South University (No. 2015CX002)the Science and Technology Plan in Hunan Province (No. 2016RS2015)the Fundamental Research Funds for the Central Universities of Central South University (No. 1053320180612)
文摘The frequent occurrence of hitherto unknown phase Pre-θ′-2 and unusual 1.5 cθ′thick θ′precipitate was observed by atomic-resolution scanning transmission electron microscopy in the well-studied Al-Cu alloys. This phenomenon is associated with heterogeneous precipitate nucleation and growth on preexisting dislocations introduced by slight deformation prior to aging. In this study, the precise structure details of Pre-θ′-2 was determined by atomic scale imaging, image simulation based on image forming theories and first principle calculations. Pre-θ′-2 has a well-defined ordered structure sandwiched between two 2 aAl(~1.5 cθ′) spaced Cu layers on {200}Alplanes. The strong structural similarities between Pre-θ′-2 and 1.5 cθ′ thick θ′ in terms of interfacial structure and thickness, coupled with energetic calculations and preliminary in-situ observations, lead us to propose a new precipitation path toward key strengthening phase θ′
