首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   95篇
  免费   1篇
化学工业   43篇
金属工艺   1篇
机械仪表   1篇
能源动力   3篇
轻工业   5篇
无线电   4篇
一般工业技术   23篇
冶金工业   14篇
自动化技术   2篇
  2022年   2篇
  2021年   2篇
  2020年   1篇
  2019年   1篇
  2015年   1篇
  2014年   1篇
  2013年   4篇
  2012年   4篇
  2011年   8篇
  2010年   7篇
  2008年   2篇
  2007年   13篇
  2006年   4篇
  2005年   3篇
  2004年   3篇
  2002年   1篇
  2001年   4篇
  2000年   3篇
  1999年   2篇
  1998年   6篇
  1997年   9篇
  1995年   1篇
  1994年   1篇
  1993年   2篇
  1992年   1篇
  1989年   1篇
  1988年   1篇
  1987年   3篇
  1986年   1篇
  1983年   1篇
  1981年   2篇
  1968年   1篇
排序方式: 共有96条查询结果,搜索用时 15 毫秒
71.
Management of telecommunication network requires quick, continuous and decentralized allocation of network bandwidth to various sorts of demands. So as to achieve the efficient network resource allocation, this paper describes a market-based model combining futures market with the agent-based approach. That is, utilization time is divided into many timeslots, and futures markets in hereafter use of bandwidth are opened. In our model, all market participants (software agents) observe only market prices and decide to buy or sell bandwidth trying to maximize their utilities over time so that they can secure enough network resources. The authors discuss network resource allocation through simulation using the proposed model. Masayuki Ishinishi, Ph.D.: He graduated from National Defense Academy in 1995 and 2000. He received the B.E. (1995) and M.E.(2000) degrees in computer science from National Institution for Academic Degrees (NIAD). He received his Ph.D. degree from Tokyo Institute of Technology in 2003. He has been a communications officer at Air Communications and Systems Wing in Japan Air Self-Defence Force (JASDF) since 2003. His research interests include information assurance, agent-based modeling and simulation, multi-agent system and market-based control. He is a member of IEEJ, IPSJ and JSAI. Yuhsuke Koyama, Ph.D.: He received the B.Econ., M.Econ., and Ph.D. degrees in economics from Kyoto University, in 1996, 1998, 2002, respectively. He has been a research associate of Tokyo Institute of Technology since 2002. His research field is evolutionary economics, mathematical sociology and experimental economics. He is a member of JAFEE, JAMS, JASESS and JASAG. Hiroshi Deguchi, Ph.D.: He received his Ph.D. degree in systems science from Tokyo Institute of Technology, in 1986. He also received the Dr. Econ. degree from Kyoto University in 2001. He has been a Professor of Tokyo Institute of Technology since 2002. His research field is evolutionary economics, computational organization theory, agent-based modeling, social system theory, gaming simulation, and philosophy of science. He is a member of SICE, JAMS, IPSJ, PHSC, JASAG and JAFEE. Hajime Kita, Ph.D.: He received the B.E., M.E., and Ph.D. degrees in electrical engineering from Kyoto University, in 1982, 1984, 1991, respectively. He has been a Professor of Kyoto University since 2003, His research field is systems science/engineering, and his research interests are evolutionary computation, neural networks and socio-economic analysis of energy systems, and agentbased modeling. He is a member of IEEJ, IEICE, ISCIE, JNNS, JSER, ORSJ and SICE.  相似文献   
72.
In marine aquaculture, rotifers and Artemia nauplii employed as larval fish feed are often nutritionally enriched with forage such as yeast and algal cells supplemented with polyunsaturated fatty acids and xanthophylls, which are required for normal growth and a high survival ratio of fish larvae. To reduce the enrichment steps, we propose here the use of a marine thraustochytrid strain, Schizochytrium sp. KH105, producing docosahexaenoic acid, docosapentaenoic acid, canthaxanthin, and astaxanthin. The KH105 cells prepared by cultivation under optimized conditions were successfully incorporated by rotifers and Artemia nauplii. The contents of docosahexaenoic acid surpassed the levels required in feed for fish larvae, and the enriched Artemia showed an increased body length. The results demonstrate that we have developed an improved method of increasing the dietary value of larval fish feed.  相似文献   
73.
The room-temperature synthesis of mesoporous silica was investigated by using cationic surfactants and inorganic Si sources, like sodium silicate and colloidal silica. Mesoporous silica analogous to the hexagonal MCM-41 could be obtained over a wide range of pH below ca. 11 within short synthesis time (3 h), when the Q4-state Si was absent in the Si source solution prior to mixing with an aqueous solution of cationic surfactants. It was suggested that the strongly acidic conditions (pH < 1) were favorable to give mesoporous silica materials with higher surface area and larger mesopore volume.  相似文献   
74.
A new class of chiral C2‐symmetric bis(trialkyl)phosphine ligands has been prepared and used in Rh(I)‐catalyzed asymmetric hydrogenation reactions. The ligands, 1,2‐bis(alkylmethylphosphino)ethanes 1a‐g (abbreviated as BisP*, alkyl = t‐butyl, 1‐adamantyl, 1‐methylcyclohexyl, 1,1‐diethylpropyl, cyclopentyl, cyclohexyl, isopropyl) and 1,2‐bis(alkylmethylphosphino)methanes 2a‐d (abbreviated as MiniPHOS, alkyl = t‐butyl, cyclohexyl, isopropyl, phenyl) are prepared by a simple synthetic approach based on the air‐stable phosphine–boranes. These new ligands give the corresponding Rh(I) complexes, which are effective catalytic precursors for the asymmetric hydrogenation of a representative series of dehydroamino acids and itaconic acid derivatives. Enantioselectivities observed in these hydrogenations are universally high and in many cases exceed 99%. X‐Ray characterization of four precatalysts, study of the pressure effects, deuteration experiments, and characterization of the wide series of intermediates in the catalytic cycle are used for the discussion of the possible correlation between the structure of the catalysts and the outcome of the catalytic asymmetric hydrogenation.  相似文献   
75.
We propose a stepwise feedback-controlled electromigration (SFCE) approach to control the channel resistance of metal nanowires at room temperature. SFCE procedure finely divides a conventional feedback-controlled electromigration (FCE) scheme into several FCE cycles. This approach effectively removes thermal instability caused by large current passing through a metal nanowire, because process time of each FCE cycle can be successfully reduced. Using the SFCE approach, a wide-range control of the channel resistance of Ni nanowires was achieved ranging from the order of 10(2) omega to 10(5) omega at room temperature, without catastrophic breaks of the nanowires. Furthermore, total process time of the SFCE procedure was considerably shortened without degradation of the controllability of the resistance of the nanowires. The channel resistance of a Ni nanowire was precisely controlled from 0.2 to 600 k(omega) for 20 min at room temperature, which is 3000 times larger than the initial resistance of the channel. These results clearly indicate that a wide-range control of the channel resistance of metal nanowires can be achieved with a shortened process time using SFCE scheme.  相似文献   
76.
IntroductionPipelines with non-circular section have beenwidely used in the industrial fields. The inner fiowsbecome more complex compared with those ofcircular section due to production of secondary flows.On the other hand, flows, which pass throughmulhple bends and discharge from fluid machinerysuch as an axial fan and blower and a water turbine,are usually accompanied by a directional swirling.When such swiriing flows discharge into the pipeline,it oscillates and happens to be broken becaus…  相似文献   
77.
In order to clarify the effect of surface properties on the burning characteristics of a delay powder, the burning rates of the red lead-ferrosilicon-antimony(III) sulfide delay compositions have been measured when the ingredient was pulverized using a vibro-mill. It was found that the burning rates increased with the mixing time when the ferrosilicon ingredient alone was pulverized before preparation of the delay powder. On the other hand, the burning rate decreased if the red lead or the antimony(III) sulfide were pulverized. The reason for this is ascribed to the chemical reaction in the combustion wave.  相似文献   
78.
The thermal behavior was investigated for the Zn complexes of carbohydrazide and semicarbazide with Sr(NO3)2 and 10% CuO as the oxidizing agent. In both complexes, there was little difference in the various combustion characteristics. The combustion reactivity was relatively low compared with the case of using other oxidizing agents, such as KBrO3, etc. But the participation of CuO in the reaction was supposed to be different based on the analysis of the combustion residue. As for the gas evolution behavior, the evolution of N2, NH3, N2O, NOx and COx gases was confirmed upon ignition at 500°C in both complexes (no H2O analysis). It was interesting that CO gas not evolved from the semicarbazide complex. It was clear that the combustion reactivity and the gas evolution behavior vary in both complexes in spite of the same skeleton and similar oxygen balance.  相似文献   
79.
Catalytic oxidation of benzene was carried out over perovskite-type oxides prepared by evaporation-to-dryness techniques. LaMnO3 showed higher activity than LaCoO3 and LaFeO3 due to higher surface area and higher oxidizing ability for benzene. Effect of Sr substitution for La on the activity of LaMnO3 depended on the calcination conditions.  相似文献   
80.
We have prepared 4-[18F]fluoromethylbenzylsulfonate esters as fluoromethylbenzylating agents. These agents are readily prepared by an [18F]fluoride ion displacement of the corresponding bissulfonate esters. The application of these 4-[18F]fluoromethylbenzylsulfonate esters to N-alkylation reaction of spiperone and 1-phenylpiperazine shows that the products 3-N-(4-[18F]fluoromethylbenzyl)spiperone and 1-N-(4-[18F]fluoromethylbenzyl)-4-phenylpiperazine are rapidly produced with high radiochemical yields under a no-carrier-added condition.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号