期刊文献+
共找到1,733篇文章
< 1 2 87 >
每页显示 20 50 100
CMC Exploring the Export Market for Complete Sets of Equipment
1
作者 Xiao Han 《China's Foreign Trade》 1997年第1期21-21,共1页
The China National Machinery Import and Export Corporation (CMC), founded in 1950, is a large state-owned foreign trade enterprise subordinated to the Ministry of Foreign Trade and Economic Cooperation (MOFTEC). The c... The China National Machinery Import and Export Corporation (CMC), founded in 1950, is a large state-owned foreign trade enterprise subordinated to the Ministry of Foreign Trade and Economic Cooperation (MOFTEC). The corporation focuses on the import and export of mechanical and electrical products. It has maintained an annual trade volume of more than US$ 2 billion for many years and ranks among the top 10 foreign trade companies in the country. 展开更多
关键词 CMC Exploring the Export Market for complete sets of equipment
下载PDF
New development of sets equipment technologies for coal mine longwall face in China 被引量:9
2
《Journal of Coal Science & Engineering(China)》 2012年第1期1-9,共9页
Background of the development and achievement on sets equipment technologies for coal mine longwall face in China was reviewed initially. On the theoretical side, a coupling model of hydraulic support and surrounding ... Background of the development and achievement on sets equipment technologies for coal mine longwall face in China was reviewed initially. On the theoretical side, a coupling model of hydraulic support and surrounding rock, support pa- rameters optimization and threedimensional (3D) dynamic design method were presented. On the practical side, this paper out lined some of practical issues and discussed some relative methods and technologies. In thin seam coal longwall mining, how to lower equipment height is the first problem that should be solved. Roof pressure regularity, control of rooffall and collapse, and hydraulic support stability were investigated preferentially in 5-7 m coal seam longwall mining. The application of equip- ment for longwall mining with 5-7 m cutting height in China was concluded. The characteristics of full-mechanized top coal caving for extra thick seam coal were presented. The automation of top-caving hydraulic support and relevant equipment have achieved important breakthrough. At the end of this paper, further development of China's coal industry and longwall mining technologies and equipment were prospected in brief. This paper gives readers a comprehensive understanding of China's coal mine longwall face equipment technologies. It will give help to other countries on its coal mining development. 展开更多
关键词 sets equipment longwall mining coupling of hydraulic support and rock working face automation
下载PDF
An evaluation method of contribution rate based on fuzzy Bayesian networks for equipment system-of-systems architecture
3
作者 XU Renjie LIU Xin +2 位作者 CUI Donghao XIE Jian GONG Lin 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第3期574-587,共14页
The contribution rate of equipment system-of-systems architecture(ESoSA)is an important index to evaluate the equipment update,development,and architecture optimization.Since the traditional ESoSA contribution rate ev... The contribution rate of equipment system-of-systems architecture(ESoSA)is an important index to evaluate the equipment update,development,and architecture optimization.Since the traditional ESoSA contribution rate evaluation method does not make full use of the fuzzy information and uncertain information in the equipment system-of-systems(ESoS),and the Bayesian network is an effective tool to solve the uncertain information,a new ESoSA contribution rate evaluation method based on the fuzzy Bayesian network(FBN)is proposed.Firstly,based on the operation loop theory,an ESoSA is constructed considering three aspects:reconnaissance equipment,decision equipment,and strike equipment.Next,the fuzzy set theory is introduced to construct the FBN of ESoSA to deal with fuzzy information and uncertain information.Furthermore,the fuzzy importance index of the root node of the FBN is used to calculate the contribution rate of the ESoSA,and the ESoSA contribution rate evaluation model based on the root node fuzzy importance is established.Finally,the feasibility and rationality of this method are validated via an empirical case study of aviation ESoSA.Compared with traditional methods,the evaluation method based on FBN takes various failure states of equipment into consideration,is free of acquiring accurate probability of traditional equipment failure,and models the uncertainty of the relationship between equipment.The proposed method not only supplements and improves the ESoSA contribution rate assessment method,but also broadens the application scope of the Bayesian network. 展开更多
关键词 equipment system-of-systems architecture(ESoSA) contribution rate evaluation fuzzy Bayesian network(FBN) fuzzy set theory
下载PDF
Manufacture and Export of Complete Power Equipment
4
作者 Yi Fu’an 《China's Foreign Trade》 1997年第10期12-13,共2页
Through construction during over four decades, remarkable achievements have been made by China’s manufacturing industry of complete sets of power equipment. During the Seventh Five-Year Plan period, over RMB2 billion... Through construction during over four decades, remarkable achievements have been made by China’s manufacturing industry of complete sets of power equipment. During the Seventh Five-Year Plan period, over RMB2 billion and several hundred million US dollars were invested in the introduction 展开更多
关键词 Manufacture and Export of complete Power equipment OVER
下载PDF
New development of longwall mining equipment based on automation and intelligent technology for thin seam coal 被引量:10
5
作者 Guo-fa WANG 《Journal of Coal Science & Engineering(China)》 2013年第1期97-103,共7页
The paper introduced complete sets of automatic equipment and technology used in thin seam coal face, and proposed the comprehensive mechanization and automation of safe and high efficiency mining models based on the ... The paper introduced complete sets of automatic equipment and technology used in thin seam coal face, and proposed the comprehensive mechanization and automation of safe and high efficiency mining models based on the thin seam drum shearer. The key technology of short length and high power thin seam drum shearer, and new type roof support with big extension ratio and plate canopy were introduced. The new research achievement on automatic control system of complete sets of equipment for the thin seam coal, which composed of electronic-hydraulic system, compact thin seam roof supports, high effective shearer with intelligent control system, and characterized by automatical follow-up and remote control technology, was described in this paper.. 展开更多
关键词 longwall mining thin coal seam complete sets of equipment automatic system intelligent system
下载PDF
E-Total Coloring of Complete Bipartite Graphs K_(5,n)(5≤n≤7 113)Which Are Vertex-Distinguished by Multiple Sets
6
作者 GUO Yaqin CHEN Xiang'en 《Wuhan University Journal of Natural Sciences》 CAS CSCD 2024年第5期412-418,共7页
In this study,using the method of contradiction and the pre-assignment of chromatic sets,we discuss the E-total coloring of complete bipartite graphs K_(5,n)(5≤n≤7 113) which are vertex-distinguished by multiple set... In this study,using the method of contradiction and the pre-assignment of chromatic sets,we discuss the E-total coloring of complete bipartite graphs K_(5,n)(5≤n≤7 113) which are vertex-distinguished by multiple sets.The vertex-distinguishing E-total chromatic numbers of this kind of graph are determined. 展开更多
关键词 complete bipartite graph E-total coloring E-total chromatic number multiple sets chromatic sets
原文传递
Completely Invariant Domains of Holomorphic Self-Maps on C
7
作者 方丽萍 《Journal of Beijing Institute of Technology》 EI CAS 1997年第3期187-191,共5页
Let/(z) be a holomorph.self-map on C.-G-(0) with essential singularities 0 and It is proved that f(z) has a completdy invariant domain.D.F(f),then D is doubly connected and D contains all the singularities of the inv... Let/(z) be a holomorph.self-map on C.-G-(0) with essential singularities 0 and It is proved that f(z) has a completdy invariant domain.D.F(f),then D is doubly connected and D contains all the singularities of the inverse of f(z),moreover,if f is of the finite type, then D=F(f). This result implies that f(z) has at most one completely invariant domain in F(f). 展开更多
关键词 holomorphic maps completely invariant domains Fatou set
下载PDF
A complete set of procedure for determination of multiresidue of pesticides in vegetables
8
作者 T.T.Liang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1992年第1期106-116,共11页
A complete set of procedure for determination of multiresidue of pesticides in vegetables was presented in this paper.The complete set of procedure included three steps:bioassay,cholinesterase inhibition and GLC analy... A complete set of procedure for determination of multiresidue of pesticides in vegetables was presented in this paper.The complete set of procedure included three steps:bioassay,cholinesterase inhibition and GLC analysis.The samples could be identified to be contaminated with pesticides if 5% of house flies was knocked down in 50 tested house flies. Those samples contaminated with pesticides needed to be detected by AChE inhibition method.The qualitative and quantitative analyses were carried out by GLC.Recoveries ranged from 83.7% in Chinese cabbages to 105.6% in tomatoes for pyrethroids,and 84.0% in tomatoes to 102.7% in sweetbell redpeppes for organophosphorus compounds.Coefficients of variations ranged from 0.59% to organophosphorus compounds.Coefficients of variations ranged from 0.59% to 7.87% for pyrethroids. and 0.33% to 9.88% for organophosphorus compounds with vegetables. The complete set of procedure has been used successfully to analyze 7000 samples collected in Beijing. About 1% of the samples had a pesticide content exceeding the MRL. 展开更多
关键词 complete set DETERMINATION multiresidue in vegetables.
下载PDF
Numerical research on dynamic response of naval equipments subjected to impact loads
9
作者 陈海龙 周维星 +1 位作者 朱枫 周其新 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2010年第4期504-510,共7页
When subjected to underwater explosion,the anti-shock performance of naval equipment is a key factor affecting the fighting capacity and safety of a war ship. For large-scale naval equipment,it is costly to do the sho... When subjected to underwater explosion,the anti-shock performance of naval equipment is a key factor affecting the fighting capacity and safety of a war ship. For large-scale naval equipment,it is costly to do the shock test for its huge mass and large size. Consequently,the numerical research was carried our to study the shock resistance of the equipment. Taking turbo-charger set for example,its anti-shock performance was studied using software ABAQUS based on the time-domain shock analysis method presented in BV043 /85. According to the analysis results,shock response of typical regions is obtained,some regularity curves are concluded by analyzing the Mises stress of the typical regions,and the weak regions are found out. The study can provide some references on design of turbo-charger set. 展开更多
关键词 naval equipment ANTI-SHOCK UNDERWATER explorsion NUMERICAL simulation turbo-charger SET
下载PDF
Optimal Selection Model of Equipment Design Scheme Based on Set Pair Analysis
10
作者 赵劲松 康建设 +1 位作者 张春润 贺宇 《Journal of Donghua University(English Edition)》 EI CAS 2015年第6期982-985,共4页
Selecting the optimal one from similar schemes is a paramount work in equipment design.In consideration of similarity of schemes and repetition of characteristic indices,the theory of set pair analysis(SPA)is proposed... Selecting the optimal one from similar schemes is a paramount work in equipment design.In consideration of similarity of schemes and repetition of characteristic indices,the theory of set pair analysis(SPA)is proposed,and then an optimal selection model is established.In order to improve the accuracy and flexibility,the model is modified by the contribution degree.At last,this model has been validated by an example,and the result demonstrates the method is feasible and valuable for practical usage. 展开更多
关键词 set pair analysis(SPA) equipment design scheme optimal selection model nearness degree
下载PDF
On the Accuracy of the Complete Basis Set Extrapolation for Anionic Systems: A Case Study of the Electron Affinity of Methane
11
作者 Alejandro Ramírez-Solís 《Computational Chemistry》 2014年第2期31-41,共11页
Recent experimental evidence suggests again the existence of the metastable methane anion in plasma swarms. In order to test the reliability of the complete basis set (CBS) extrapolation scheme with augmented correlat... Recent experimental evidence suggests again the existence of the metastable methane anion in plasma swarms. In order to test the reliability of the complete basis set (CBS) extrapolation scheme with augmented correlation-consistent basis sets for anionic molecules, we study the evolution of the electron affinity of methane with benchmark ab initio calculations with aug-cc basis sets up to aug-cc-pV6Z + diffuse. Geometry optimizations and vibrational analysis were done at the MP2 level. The electron affinity (EA) was calculated at the MP2 and CCSD(T) levels with and without frozen core and including the extrapolations to the CBS limit. Using the aug-cc-pVnZ basis sets it is found that two non-decreasing CCSD(T) CBS limits exist for the EA (0.29 and 0.53 eV) obtained with the n = 3, 4, 5 and n = 4, 5, 6 series, respectively. A new scheme is proposed which can be generalized for very accurate quantum chemical description of molecular anions: the standard aug-cc-pVnZ basis sets can be supplemented with extra-diffuse orbitals using a simple even-tempered scheme. This yields a reliable CBS extrapolation method to develop a (discrete approximation of a) continuum anionic state near ionization, viz., one that closely matches the energy of the corresponding neutral state. These results show that CH4 has no stable anions of 2A1 symmetry, implying that plasma swarms with anionic methane consist of metastable rather than stable methane anions. 展开更多
关键词 METHANE Electron AFFINITY ANION CORRELATED Calculations complete Basis Set LIMIT
下载PDF
A New Method to Generate the Complete Set of Unique Signals for Application in High Consequence System
12
作者 谈顺毅 陈文元 +2 位作者 张卫平 冯敏华 李胜勇 《Journal of Shanghai Jiaotong university(Science)》 EI 2007年第2期172-179,共8页
This paper proposed a new method to generate the complete sets of unique signals.It contains sequences comparing,improved exhaustive searches and ranking method.Characters of this new method are complete set;higher ef... This paper proposed a new method to generate the complete sets of unique signals.It contains sequences comparing,improved exhaustive searches and ranking method.Characters of this new method are complete set;higher effective;independent of certain mathematical constraints.And also some 24 bi-valued events sets generated by this method were discussed and these set are now used in our high consequence system. 展开更多
关键词 unique signal (UQS) comparing table improved exhaustive searches complete set high consequence system
下载PDF
Optimizing Export Commodities Mix and Developing Complete Equipment Export
13
作者 Cheng Jian President of Zhejiang Machinery Equipment Import & Export Corporation 《China's Foreign Trade》 1997年第1期9-9,共1页
Founded in 1978, the Zhejiang Machinery Equipment Import & Export Corporation is an industrial and trading company engaged in the import and export business of machinery, electronics and instruments. Since 1980, w... Founded in 1978, the Zhejiang Machinery Equipment Import & Export Corporation is an industrial and trading company engaged in the import and export business of machinery, electronics and instruments. Since 1980, when is was granted self-operational rights, the company has increased year by year in terms of export volume, with its management improving and economic returns steadily rising. In 1995, its import and export volume hit US$119. 展开更多
关键词 Optimizing Export Commodities Mix and Developing complete equipment Export
下载PDF
Equipment delivery and quality problems affectingcompletion of 1997 Power Construction Plan
14
《Electricity》 1998年第2期43-44,共2页
关键词 equipment delivery and quality problems affecting completion of 1997 Power Construction Plan
下载PDF
量子力学表示理论的一种实现
15
作者 汪克林 曹则贤 《物理》 CAS 北大核心 2024年第3期168-173,共6页
量子力学创立伊始,狄拉克就关注到了一般表示的问题,其后量子力学的发展又引入了福克态、相干态等表示。好的表示应能提供正交归一的完备基,同时又能给出问题的严格解析解或者允许方便地得到近似解,但这常常是做不到的。我们意识到此前... 量子力学创立伊始,狄拉克就关注到了一般表示的问题,其后量子力学的发展又引入了福克态、相干态等表示。好的表示应能提供正交归一的完备基,同时又能给出问题的严格解析解或者允许方便地得到近似解,但这常常是做不到的。我们意识到此前得到的相干态正交化方法恰恰满足表示理论的一般性要求,且因为包含自由参数为构造归一化的完备正交基实际上提供了无限的选择,这样甚至在解决问题的过程中都可以灵活地选择不同的表示,从而带来计算量的大幅减小。通过对不同耦合强度下的近共振态Rabi模型最初10个能级的计算,并同关联的JC模型的结果相比较,验证了相干态正交化方法的有效性。 展开更多
关键词 表示理论 归一化完备正交基 相干态 相干态正交化 Rabi模型
下载PDF
基于改进FMEA的污水厂设备故障风险评估模型
16
作者 刘新 伍俊楠 +3 位作者 潘殿琦 张以晨 张继权 柯楷 《中国安全科学学报》 CAS CSCD 北大核心 2024年第8期101-107,共7页
为保障污水处理厂正常运行,预防厂内设备发生故障,提出一种改进的故障模式与影响分析(FMEA)的风险评估模型。首先采用FMEA法识别污水厂设备故障模式,并结合毕达哥拉斯模糊集(PFS)刻画不确定评估信息;其次利用逐步权重评估比率分析法(SWA... 为保障污水处理厂正常运行,预防厂内设备发生故障,提出一种改进的故障模式与影响分析(FMEA)的风险评估模型。首先采用FMEA法识别污水厂设备故障模式,并结合毕达哥拉斯模糊集(PFS)刻画不确定评估信息;其次利用逐步权重评估比率分析法(SWARA)和最大偏差法计算主客观权重,通过博弈论组合权重计算3个风险因子的综合权重;然后采用多目标优化比率分析法(MOORA)对设备故障模式进行风险排序。最后以长春市Z污水厂设备故障风险评估为例,并将所提模型与传统FMEA、毕达哥拉斯模糊(PF)-优劣解距离法(TOPSIS)和PF-妥协折衷排序法(PF-VIKOR)等方法对比,验证该模型的有效性。结果表明:污水厂设备故障模式前3位是除砂机抽取的砂浆所含有机物过多、膜片脱落或破裂和大块异物进入水泵。 展开更多
关键词 污水厂 故障模式与影响分析(FMEA) 设备故障 风险评估 毕达哥拉斯模糊集(PFS)
下载PDF
基于启动时间和完全故障的双阶段休假排队系统的流体模型性能分析
17
作者 徐秀丽 张怡通 +1 位作者 王勋 刘洺辛 《数学物理学报(A辑)》 CSCD 北大核心 2024年第4期1092-1109,共18页
基于风力发电路灯的能量转化机制,该文构建并分析了具有启动时间和完全故障策略的M/M/1排队系统驱动的流体模型.首先,对驱动系统进行模型描述,运用矩阵几何解方法得到驱动系统的稳态概率分布.其次,引入流体模型的净输入率结构,并利用概... 基于风力发电路灯的能量转化机制,该文构建并分析了具有启动时间和完全故障策略的M/M/1排队系统驱动的流体模型.首先,对驱动系统进行模型描述,运用矩阵几何解方法得到驱动系统的稳态概率分布.其次,引入流体模型的净输入率结构,并利用概率分析方法得到流体库存水平在稳态条件下的微分差分方程组,进而运用Laplace-Stieltjes transform(LST)方法得到稳态条件下库存量的均值及空库概率.根据性能指标构建系统的费用函数,在数值分析中给出系统参数对性能指标和费用的影响. 展开更多
关键词 流体模型 双阶段休假 启动时间 完全故障 库存量
下载PDF
考虑同层后道工序的柔性设备网络综合调度算法
18
作者 谢志强 刘冬梅 《电子与信息学报》 EI CAS CSCD 北大核心 2024年第7期2961-2969,共9页
针对柔性设备网络综合调度算法,难以合理选择加工设备加工相关工序进而影响产品完工时间的问题,该文提出考虑同层后道工序的柔性设备网络综合调度算法(SP-FENIS)。首先,采用逆序层优先策略,将各工序分配至逆序层待调度工序集;然后,提出... 针对柔性设备网络综合调度算法,难以合理选择加工设备加工相关工序进而影响产品完工时间的问题,该文提出考虑同层后道工序的柔性设备网络综合调度算法(SP-FENIS)。首先,采用逆序层优先策略,将各工序分配至逆序层待调度工序集;然后,提出均值逆序紧后路径策略,确定了各逆序层待调度工序集中工序的调度顺序;最后,提出最早完工时间策略和设备空闲插入策略,当工序在柔性设备上最早完工时间相同时,考虑了在柔性设备上的加工时间和同层后道工序的加工设备,确定了目标工序的加工设备以及加工时间。实例表明,和已有算法相比,该算法能够缩短产品完工时间。 展开更多
关键词 综合调度 同层后道工序 柔性设备网络 均值逆序紧后路径 最早完工时间
下载PDF
基于故障树反演的复合材料成形生产线故障诊断
19
作者 王玉山 贾思敏 +2 位作者 宋照爱 翟华 韩江 《锻压装备与制造技术》 2024年第2期12-17,共6页
复合材料成形装备生产线因其复杂性和高度集成性,故障的产生可能涉及多个环节和因素,因此需要一种系统性的方法来准确地分析和定位故障源。本文梳理了复合材料产品制造过程中可能出现的故障类型和影响因素,构建了一个全面的复合材料成... 复合材料成形装备生产线因其复杂性和高度集成性,故障的产生可能涉及多个环节和因素,因此需要一种系统性的方法来准确地分析和定位故障源。本文梳理了复合材料产品制造过程中可能出现的故障类型和影响因素,构建了一个全面的复合材料成形装备产线故障树,借助故障树反演技术,将实际故障事件映射到故障树上,通过逆向推导,得出可能导致这些故障事件的基本故障事件,该方法在提高生产质量、降低故障风险方面具有重要意义,为复合材料制造领域的技术改进和创新提供了有力支持。 展开更多
关键词 复合材料 成形装备 故障树 最小割集 故障诊断
下载PDF
DESIGN AND RESEARCH OF THE INTERNAL CODE FOR THE COMPLETE CHINESE CHARACTERS SET
20
作者 钱培德 《苏州大学学报(自然科学版)》 CAS 1992年第2期146-153,共8页
This paper defines the complete Chinese characters set and expounds the necessity of the design of the internal code for the set.Then,article offers two kinds of internal codes(the CNCC code and TTB code) with their d... This paper defines the complete Chinese characters set and expounds the necessity of the design of the internal code for the set.Then,article offers two kinds of internal codes(the CNCC code and TTB code) with their definitions and their performances Finally,the paper discusses the techniques of implementing these eodes,including the trandsforming system kernel,Chinese-English compatible sceen-display and screen-deiting. 展开更多
关键词 国际编码 计算机技术 中国 信息技术 软件设计
全文增补中
上一页 1 2 87 下一页 到第
使用帮助 返回顶部