期刊文献+
共找到37篇文章
< 1 2 >
每页显示 20 50 100
GhDET2,a Steroid 5alpha-reductase,Plays an Important Role in Cotton Fiber Cell Initiation and Elongation 被引量:1
1
作者 LUO Ming,XIAO Yue-hua,LI Xian-bi,LI De-mou,HOU Lei,HU Ming-yu,PEI Yan(Key Laboratory of Biotechnology and Crop Quality Improvement of Ministry of Agriculture,Biotechnology Research Center,Southwest University,Chongqing 400716,China) 《棉花学报》 CSCD 北大核心 2008年第S1期130-,共1页
Cotton(Gossypium hirsutum L.) fibers,one of the most important natural raw materials for the textile industry,are highly elongated trichomes from epidermal cells of cotton ovules.Among the longest plant cells ever cha... Cotton(Gossypium hirsutum L.) fibers,one of the most important natural raw materials for the textile industry,are highly elongated trichomes from epidermal cells of cotton ovules.Among the longest plant cells ever characterized,cotton fiber is an ideal system for studying plant cell elongation. 展开更多
关键词 BRs GhDET2 a Steroid 5alpha-reductase Plays an important Role in Cotton Fiber Cell Initiation and Elongation Cell
在线阅读 下载PDF
Genetic polymorphisms of pharmacogenomic very important pharmacogenes variants in Chinese Lisu population
2
作者 LU Hong-yan WANG Yu-liang +4 位作者 ZHANG Zhan-hao XING Shi-shi LI Dan-dan WANG Li JIN Tian-bo 《中国药理学与毒理学杂志》 CAS 北大核心 2021年第10期735-735,共1页
OBJECTIVE The specificity of drug therapy in individuals and races has promoted the development and improvement of pharmacogenomics and precision medicine.While there is a few cognition on the minorities in China,espe... OBJECTIVE The specificity of drug therapy in individuals and races has promoted the development and improvement of pharmacogenomics and precision medicine.While there is a few cognition on the minorities in China,especially in Lisu nationality from the Yunnan province.Therefore,we performed the research to improve the role of pharmacogenomics in the Lisu population from the Yunnan province of China.METHODS 54 variants of very important pharmacogenes selected from the PharmGKB database were genotyped in 199 unrelated and healthy Lisu adults from the Yunnan province of China,and then,genotyping data wtih χ^(2) test were analyzed.RESULTS We compared our data with those of other 26 populations from the 1000 Genomes Project,and acquired that the Lisu ethnicity is similar with the CDX(Chinese Dai in Xishuangbanna,China)and CHS(Southern Han Chinese,China).Furthermore,rs776746(CYP3A5),rs1805123(KCNH2),rs4291(ACE),rs1051298(SLC19A1)and rs1065852(CYP2D6)were deemed as the most varying loci.The MAF of“G”at rs1805123(KCNH2)in the Lisu population was the largest with the value of 51.0%.CONCLUSION There are significant differences in single nucleotide polymorphism loci,supplementing the pharmacogenomic information of the Lisu population in Yunnan province,China,and can provide a theoretical basis for individualized medication in the future. 展开更多
关键词 very important pharmacogenes variants Lisu population PHARMACOGENOMICS racial difference
在线阅读 下载PDF
Biochemical Pathways That Are Important for Cotton Fiber Cell Elongation
3
作者 ZHU Yu-xian(The National Laboratory of Protein Engineering and Plant Genetic Engineering,Peking University,Beijing 100871,China) 《棉花学报》 CSCD 北大核心 2008年第S1期10-,共1页
The regulatory mechanism that controls the sustained cotton fiber cell elongation is gradually being elucidated by coupling genome-wide transcriptome profiling with systematic biochemical and physiological studies.Ver... The regulatory mechanism that controls the sustained cotton fiber cell elongation is gradually being elucidated by coupling genome-wide transcriptome profiling with systematic biochemical and physiological studies.Very long chain fatty acids(VLCFA),H2O2,and several types of plant 展开更多
关键词 Biochemical Pathways That Are important for Cotton Fiber Cell Elongation CELL
在线阅读 下载PDF
Residues important to the allosteric regulation on ligand binding affinity in β3 integrins
4
作者 Jizhong Lou1,Wei Chen2,Mei-Yin Chou3,Cheng Zhu1,2,3,4(1Parker H.Petit Institute for Bioengineering and Bioscience,2Woodruff School of Mechanical Engineering,and 3School of Physics,4Coulter Department of Biomedical Engineering,,Georgia Institute of Technology,GA,USA) 《医用生物力学》 EI CAS CSCD 2009年第S1期20-20,共1页
Integrins are heterodimers that mediate cell adhesion and transduce signals bidirectionally across the cell membrane.Integrins often exist in low affinity(or inactive) states for
关键词 Residues important to the allosteric regulation on ligand binding affinity in
在线阅读 下载PDF
Human Invasion by Lesser Known Medically Important Trematodes in the Proximity of Tshwane,Gauteng Province,South Africa 被引量:1
5
作者 E.B.E.Moema P.H.King C.Baker 《地学前缘》 EI CAS CSCD 北大核心 2009年第S1期78-79,共2页
It is well-documented that digenetic trematodes exhibit complex life cycles where the definitive hosts are vertebrates—mostly birds,other mammals and reptiles.It is also known that digenetic trematodes are host speci... It is well-documented that digenetic trematodes exhibit complex life cycles where the definitive hosts are vertebrates—mostly birds,other mammals and reptiles.It is also known that digenetic trematodes are host specific,but changes in our feeding habits, agricultural and social practices,have led to human beings infected with parasites that were previously regarded to be of no or insignificant medical importance. The objective of this study was to identify the less known digenetic parasites in the water bodies around Tshwane that may result in possible 展开更多
关键词 digenetic TREMATODES life cycles medical IMPORTANCE control measures
在线阅读 下载PDF
基于Null Importance分析慢病人群接受居家药学服务意愿的影响因素
6
作者 赵科 杨宏昕 +2 位作者 武明芬 郭浩 赵志刚 《医药导报》 北大核心 2025年第8期1347-1351,共5页
目的探究慢病人群接受居家药学服务意愿的关键影响因素。方法采用中国适老化研究项目中内蒙古自治区及东北地区的调查数据,基于Null Importance方法,筛选影响慢病人群参与居家药学服务意愿的关键因素。构建logistic回归模型,采用5折交... 目的探究慢病人群接受居家药学服务意愿的关键影响因素。方法采用中国适老化研究项目中内蒙古自治区及东北地区的调查数据,基于Null Importance方法,筛选影响慢病人群参与居家药学服务意愿的关键因素。构建logistic回归模型,采用5折交叉验证方法,以准确率及AUC为指标,评价特征选择对模型性能的影响。结果Null Importance方法筛选出10个关键因素,且特征选择后logistic回归模型性能得到提升。显著影响患者对居家药学服务接受意愿的因素包括:获取药品信息途径个数(OR=1.261,95%CI=1.182~1.345),药物适应证认知(OR=1.342,95%CI=1.124~1.603),是否保留药盒(OR=1.218,95%CI=1.015~1.462),用药依从性得分(OR=0.881,95%CI=0.839~0.925),用药素养得分(OR=0.631,95%CI=0.488~0.817),用药指导服务了解程度(OR=1.211,95%CI=1.017~1.442)。结论在Null Importance特征选择方法基础上构建的logistic回归模型,具有良好的性能,有助于慢病人群接受居家药学服务意愿影响因素的分析。 展开更多
关键词 Null Importance 居家药学服务 意愿 慢病
在线阅读 下载PDF
中国古代槟榔文化的接受与传播
7
作者 冯青 《农业考古》 北大核心 2024年第4期195-201,共7页
作为舶来品的槟榔,在饮食、医药、赋税等方面扮演过重要的角色,具有丰厚的历史文化。梳理文献发现,两汉三国时期,槟榔视作“奇草异木”记载在各种《异物志》中,开始被接受;南北朝时期,槟榔是贵族士宦的“奢侈品”,唐代受佛教平等思想影... 作为舶来品的槟榔,在饮食、医药、赋税等方面扮演过重要的角色,具有丰厚的历史文化。梳理文献发现,两汉三国时期,槟榔视作“奇草异木”记载在各种《异物志》中,开始被接受;南北朝时期,槟榔是贵族士宦的“奢侈品”,唐代受佛教平等思想影响日渐向大众传播,宋代逐渐成为百姓家的“寻常物”。槟榔之所以能被接受与传播,并在海南用于婚俗,是因其本身的物质文化之外,还与其因贵异而用于重要的人际礼仪、文人墨客极力推崇渲染和赋予了槟榔君子品格等精神文化有着莫大的关系。 展开更多
关键词 betel nut culture imported product ACCEPTANCE DISSEMINATION
在线阅读 下载PDF
基于灰色-改进二元语义的导弹装备维修保障效能评估
8
作者 李保刚 崔爽 董德鹏 《现代防御技术》 北大核心 2024年第5期127-137,共11页
针对导弹装备维修保障效能系统复杂庞大,指标间相互关联影响、数据信息获取困难且易丢失扭曲的现状,提出一种基于灰色—改进二元语义的方法对维修保障效能进行评估。该方法利用改进G1法和改进CRITIC(criteria importance though intercr... 针对导弹装备维修保障效能系统复杂庞大,指标间相互关联影响、数据信息获取困难且易丢失扭曲的现状,提出一种基于灰色—改进二元语义的方法对维修保障效能进行评估。该方法利用改进G1法和改进CRITIC(criteria importance though intercrieria correlation)法分别得出主客观权重,依据最小信息鉴别法获取综合权重,利用灰色聚类分析法将定量数据转化为二元语义形式,运用改进二元语义将定性语言评估信息进行转化并对完整系统进行评估。获取的各指标权重更加科学合理,避免了信息的丢失扭曲,评估结果更加准确。该模型评估结果与实际情况基本相符,能真实科学反映导弹装备维修保障效能水平并可针对性查找薄弱环节,可为导弹装备维修保障系统的管理和完善提供依据。 展开更多
关键词 灰色聚类 改进二元语义 维修保障 导弹装备 效能评估 G1 criteria importance though intercrieria correlation(CRITIC)
在线阅读 下载PDF
基于云模型的城市轨道交通乘客满意度评价 被引量:38
9
作者 李林波 郭晓凡 +1 位作者 傅佳楠 吴兵 《同济大学学报(自然科学版)》 EI CAS CSCD 北大核心 2019年第3期378-385,共8页
为了直观细致了解乘客在乘坐轨道交通时的体验感受,从乘客感知角度构建了满意度评价指标体系,采用CRITIC(criteria importance through inter-criteria correlation)法来实现指标的客观赋权,并用基于云模型的基本算法生成评价云和结果云... 为了直观细致了解乘客在乘坐轨道交通时的体验感受,从乘客感知角度构建了满意度评价指标体系,采用CRITIC(criteria importance through inter-criteria correlation)法来实现指标的客观赋权,并用基于云模型的基本算法生成评价云和结果云,通过云的数字特征和云图的比较直观展现评价结果.以上海市轨道交通2号线的乘客满意度评价为例,验证了评价方法的有效性和合理性,同时该评价结果除了反映乘客的满意程度,也提供了对乘客认知差异和共识度的衡量,使得其具备了更大的使用价值. 展开更多
关键词 轨道交通 乘客满意度 评价指标体系 CRITIC(criteria IMPORTANCE through inter-criteria correlation)法 云模型 实证分析
在线阅读 下载PDF
大型过程建模的Import/Export解决方案 被引量:3
10
作者 张莉 王文 《计算机工程与应用》 CSCD 北大核心 2001年第12期23-26,共4页
文章分析了大型复杂过程的建模需求,基于已研发的企事业过程建模系统EPMS,提出了将Import/Export技术用于大型过程建模的解决方案,通过过程模型的拆分和组装,从而支持过程模型的多人员、异地并行建模模式和过程重用。
关键词 大型模型建模 Import/Export 软件工程 可视化
在线阅读 下载PDF
软件需求中不一致性处理方案的评估方法(英文) 被引量:1
11
作者 牟克典 金芝 《计算机科学与探索》 CSCD 2007年第1期47-58,共12页
提出了一种评估软件需求中不一致性处理方案的方法。给定应用场景,对于每个处理方案,主要关注采用该方案修正后的需求规格说明所能推导出的待开发系统的期望响应,并且这些期望响应的相对重要程度被视为评估该方案适合程度的一个重要参... 提出了一种评估软件需求中不一致性处理方案的方法。给定应用场景,对于每个处理方案,主要关注采用该方案修正后的需求规格说明所能推导出的待开发系统的期望响应,并且这些期望响应的相对重要程度被视为评估该方案适合程度的一个重要参数。在这个意义上,定义效用向量函数来度量每一处理方案的适合程度。进一步采用效用向量函数来比较任意两个处理方案。通过这种比较,定义不一致需求处理方案集上的一种序关系(“更适合”)。文章提出的评估方法将为自动选择不一致性处理方案提供基础。 展开更多
关键词 软件需求 不一致性 处理方案 requirements ENGINEERING RELATIVE IMPORTANCE 向量函数 需求规格说明 评估方法 程度 自动选择 效用 开发系统 序关系 方案集 应用 基础 度量 导出 场景 参数
在线阅读 下载PDF
数据库移植方法的探讨 被引量:2
12
作者 宋璇 胡怀勇 王敦洲 《科技进步与对策》 CSSCI 北大核心 2003年第S1期224-225,共2页
通过探讨和研究数据库移植的特点和原理 ,阐述了实现数据库移植的一些原则和方法。
关键词 移植 Import/Export SQL*LOADER 数据转换服务程序(DTS) ODBC JDBC
在线阅读 下载PDF
Resilience based importance measure analysis for SoS 被引量:17
13
作者 PAN Xing WANG Huixiong +1 位作者 YANG Yanjing ZHANG Guozhong 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2019年第5期920-930,共11页
In a system of systems(SoS),resilience is an important factor in maintaining the functionality,stability,and enhancing the operation effectiveness.From the perspective of resilience,this paper studies the importance o... In a system of systems(SoS),resilience is an important factor in maintaining the functionality,stability,and enhancing the operation effectiveness.From the perspective of resilience,this paper studies the importance of the SoS,and a resilience-based importance measure analysis is conducted to provide suggestions in the design and optimization of the structure of the SoS.In this paper,the components of the SoS are simplified as four kinds of network nodes:sensor,decision point,influencer,and target.In this networked SoS,the number of operation loops is used as the performance indicator,and an approximate algorithm,which is based on eigenvalue of the adjacency matrix,is proposed to calculate the number of operation loops.In order to understand the performance change of the SoS during the attack and defense process in the operations,an integral resilience model is proposed to depict the resilience of the SoS.From different perspectives of enhancing the resilience,different measures,parameters and the corresponding algorithms for the resilience importance of components are proposed.Finally,a case study on an SoS is conducted to verify the validity of the network modelling and the resiliencebased importance analysis method. 展开更多
关键词 system of systems (SoS) RESILIENCE network modelling IMPORTANCE MEASURE ANALYSIS operation LOOP
在线阅读 下载PDF
Particle filter with importance density function generated by updated system equation 被引量:3
14
作者 左军毅 贾颖娜 +1 位作者 张炜 高全学 《Journal of Central South University》 SCIE EI CAS 2013年第10期2700-2707,共8页
The current measurement was exploited in a more efficient way. Firstly, the system equation was updated by introducing a correction term, which depends on the current measurement and can be obtained by running a subop... The current measurement was exploited in a more efficient way. Firstly, the system equation was updated by introducing a correction term, which depends on the current measurement and can be obtained by running a suboptimal filter. Then, a new importance density function(IDF) was defined by the updated system equation. Particles drawn from the new IDF are more likely to be in the significant region of state space and the estimation accuracy can be improved. By using different suboptimal filter, different particle filters(PFs) can be developed in this framework. Extensions of this idea were also proposed by iteratively updating the system equation using particle filter itself, resulting in the iterated particle filter. Simulation results demonstrate the effectiveness of the proposed IDF. 展开更多
关键词 IMPORTANCE density function nonlinear dynamic systems SEQUENCE IMPORTANCE sampling particle filter MONTE Carlo STEP
在线阅读 下载PDF
Influence of brittleness and confining stress on rock cuttability based on rock indentation tests 被引量:7
15
作者 WANG Shao-feng TANG Yu WANG Shan-yong 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第9期2786-2800,共15页
In order to understand the influence of brittleness and confining stress on rock cuttability,the indentation tests were carried out by a conical pick on the four types of rocks.Then,the experimental results were utili... In order to understand the influence of brittleness and confining stress on rock cuttability,the indentation tests were carried out by a conical pick on the four types of rocks.Then,the experimental results were utilized to take regression analysis.The eight sets of normalized regression models were established for reflecting the relationships of peak indentation force(PIF)and specific energy(SE)with brittleness index and uniaxial confining stress.The regression analyses present that these regression models have good prediction performance.The regressive results indicate that brittleness indices and uniaxial confining stress conditions have non-linear effects on the rock cuttability that is determined by PIF and SE.Finally,the multilayer perceptual neural network was used to measure the importance weights of brittleness index and uniaxial confining stress upon the influence for rock cuttability.The results indicate that the uniaxial confining stress is more significant than brittleness index for influencing the rock cuttability. 展开更多
关键词 rock cuttability brittleness index uniaxial confining pressures regression analysis multilayer perceptual neural network importance analysis
在线阅读 下载PDF
Simplified unscented particle filter for nonlinear/non-Gaussian Bayesian estimation 被引量:6
16
作者 Junyi Zuo Yingna Jia Quanxue Gao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2013年第3期537-544,共8页
Particle filters have been widely used in nonlinear/non- Gaussian Bayesian state estimation problems. However, efficient distribution of the limited number of particles (n state space remains a critical issue in desi... Particle filters have been widely used in nonlinear/non- Gaussian Bayesian state estimation problems. However, efficient distribution of the limited number of particles (n state space remains a critical issue in designing a particle filter. A simplified unscented particle filter (SUPF) is presented, where particles are drawn partly from the transition prior density (TPD) and partly from the Gaussian approximate posterior density (GAPD) obtained by a unscented Kalman filter. The ratio of the number of particles drawn from TPD to the number of particles drawn from GAPD is adaptively determined by the maximum likelihood ratio (MLR). The MLR is defined to measure how well the particles, drawn from the TPD, match the likelihood model. It is shown that the particle set generated by this sampling strategy is more close to the significant region in state space and tends to yield more accurate results. Simulation results demonstrate that the versatility and es- timation accuracy of SUPF exceed that of standard particle filter, extended Kalman particle filter and unscented particle filter. 展开更多
关键词 nonlinear filtering particle filter unscented Kalman filter importance density function.
在线阅读 下载PDF
Quadrature Kalman particle fitler 被引量:4
17
作者 Chunlincl Wu Chongzhao Han 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第2期175-179,共5页
In order to resolve the state estimation problem of nonlinear/non-Gaussian systems, a new kind of quadrature Kalman particle filter (QKPF) is proposed. In this new algorithm, quadrature Kalman filter (QKF) is used... In order to resolve the state estimation problem of nonlinear/non-Gaussian systems, a new kind of quadrature Kalman particle filter (QKPF) is proposed. In this new algorithm, quadrature Kalman filter (QKF) is used for generating the impor- tance density function. It linearizes the nonlinear functions using statistical linear regression method through a set of Gaussian- Hermite quadrature points. It need not compute the Jacobian matrix and is easy to be implemented. Moreover, the importantce density function integrates the latest measurements into system state transition density, so the approximation to the system poste- rior density is improved. The theoretical analysis and experimen- tal results show that, compared with the unscented partcle filter (UPF), the estimation accuracy of the new particle filter is improved almost by 18%, and its calculation cost is decreased a little. So, QKPF is an effective nonlinear filtering algorithm. 展开更多
关键词 particle filter statistical linear regression quadrature Kalman filter importance density function.
在线阅读 下载PDF
Importance measure of system reliability upgrade for multi-state consecutive k-out-of-n systems 被引量:3
18
作者 HonQvan Dui Shubin si Zhiqiang Cai Shudong Sun Yingfeng Zhang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第6期936-942,共7页
Importance measures in reliability systems are used to identify weak components in contributing to a proper function of the system. Traditional importance measures mainly concerned the changing value of the system rel... Importance measures in reliability systems are used to identify weak components in contributing to a proper function of the system. Traditional importance measures mainly concerned the changing value of the system reliability caused by the change of the reliability of the component, and seldom considered the joint effect of the probability distribution, improvement rate of the object component. This paper studies the rate of the system reliability upgrading with an improvement of the component reliability for the multi-state consecutive k-out-of-n system. To verify the multi-state consecutive k-out-of-n system reliability upgrading by improving one component based on its improvement rate, an increasing potential importance (IPI) and its physical meaning are described at first. Secondly, the relationship between the IPI and Birnbaum importance measures are discussed. And the IPI for some different improvement actions of the component is further discussed. Thirdly, the characteristics of the IPI are analyzed. Finally, an application to an oil pipeline system is given. 展开更多
关键词 system reliability multi-state consecutive k-out-of-nsystem IMPROVEMENT Birnbaum importance.
在线阅读 下载PDF
Capacitated stochastic coloured Petri net-based approach for computing two-terminal reliability of multi-state network 被引量:3
19
作者 Tao Zhang Bo Guo 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第2期304-313,共10页
Classical network reliability problems assume both net- works and components have only binary states, fully working or fully failed states. But many actual networks are multi-state, such as communication networks and ... Classical network reliability problems assume both net- works and components have only binary states, fully working or fully failed states. But many actual networks are multi-state, such as communication networks and transportation networks. The nodes and arcs in the networks may be in intermediate states which are not fully working either fully failed. A simulation ap- proach for computing the two-terminal reliability of a multi-state network is described. Two-terminal reliability is defined as the probability that d units of demand can be supplied from the source to sink nodes under the time threshold T. The capacities of arcs may be in a stochastic state following any discrete or continuous distribution. The transmission time of each arc is also not a fixed number but stochastic according to its current capacity and de- mand. To solve this problem, a capacitated stochastic coloured Petri net is proposed for modelling the system behaviour. Places and transitions respectively stand for the nodes and arcs of a net- work. Capacitated transition and self-modified token colour with route information are defined to describe the multi-state network. By the simulation, the two-terminal reliability and node importance can be estimated and the optimal route whose reliability is highest can also be given. Finally, two examples of different kinds of multi- state networks are given. 展开更多
关键词 two-terminal reliability multi-state network Petri net (PN) simulation node importance.
在线阅读 下载PDF
A compound objective reconfiguration of distribution networks using hierarchical encoded particle swarm optimization 被引量:3
20
作者 WEN Juan TAN Yang-hong +1 位作者 JIANG Lin XU Zu-hua 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第3期600-615,共16页
With the development of automation in smart grids,network reconfiguration is becoming a feasible approach for improving the operation of distribution systems.A novel reconfiguration strategy was presented to get the o... With the development of automation in smart grids,network reconfiguration is becoming a feasible approach for improving the operation of distribution systems.A novel reconfiguration strategy was presented to get the optimal configuration of improving economy of the system,and then identifying the important nodes.In this strategy,the objectives increase the node importance degree and decrease the active power loss subjected to operational constraints.A compound objective function with weight coefficients is formulated to balance the conflict of the objectives.Then a novel quantum particle swarm optimization based on loop switches hierarchical encoded was employed to address the compound objective reconfiguration problem.Its main contribution is the presentation of the hierarchical encoded scheme which is used to generate the population swarm particles of representing only radial connected solutions.Because the candidate solutions are feasible,the search efficiency would improve dramatically during the optimization process without tedious topology verification.To validate the proposed strategy,simulations are carried out on the test systems.The results are compared with other techniques in order to evaluate the performance of the proposed method. 展开更多
关键词 distribution network reconfiguration node importance degree compound objective function hierarchical encoded
在线阅读 下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部