全文获取类型
收费全文 | 372篇 |
免费 | 11篇 |
专业分类
电工技术 | 1篇 |
综合类 | 1篇 |
化学工业 | 40篇 |
金属工艺 | 6篇 |
机械仪表 | 3篇 |
建筑科学 | 9篇 |
能源动力 | 18篇 |
轻工业 | 29篇 |
水利工程 | 5篇 |
石油天然气 | 1篇 |
武器工业 | 2篇 |
无线电 | 46篇 |
一般工业技术 | 47篇 |
冶金工业 | 142篇 |
自动化技术 | 33篇 |
出版年
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 5篇 |
2019年 | 6篇 |
2018年 | 5篇 |
2017年 | 7篇 |
2016年 | 2篇 |
2015年 | 4篇 |
2014年 | 4篇 |
2013年 | 5篇 |
2012年 | 13篇 |
2011年 | 5篇 |
2010年 | 13篇 |
2009年 | 8篇 |
2008年 | 18篇 |
2007年 | 11篇 |
2006年 | 5篇 |
2005年 | 11篇 |
2004年 | 11篇 |
2003年 | 2篇 |
2002年 | 7篇 |
2001年 | 9篇 |
2000年 | 7篇 |
1999年 | 5篇 |
1998年 | 35篇 |
1997年 | 21篇 |
1996年 | 19篇 |
1995年 | 7篇 |
1994年 | 13篇 |
1993年 | 10篇 |
1992年 | 7篇 |
1991年 | 4篇 |
1990年 | 8篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1984年 | 7篇 |
1983年 | 6篇 |
1982年 | 4篇 |
1981年 | 6篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1977年 | 9篇 |
1976年 | 7篇 |
1973年 | 3篇 |
1972年 | 3篇 |
1970年 | 3篇 |
1969年 | 4篇 |
排序方式: 共有383条查询结果,搜索用时 31 毫秒
1.
X.W. Lou C. Yuan E. Rhoades Q. Zhang L.A. Archer 《Advanced functional materials》2006,16(13):1679-1684
We report a general template strategy for rational fabrication of a new class of nanostructured materials consisting of multicore shell particles. Our approach is demonstrated by encapsulating Au or Pt nanoparticles in silica shells. Other superstructures of these hollow shells, like dimers, trimers, and tetramers can also be formed by nanoparticle‐mediated self‐assembly. We have also used the as‐prepared multicore Au–silica hollow particles to perform the first studies of Ostwald ripening in confined microspace, in which chloride was found to be an efficient mediating ligand. After treatment with aqua regia, Au–Cl complex is formed inside the shell, and is found to be very active under in situ transmission electron microscopy observations while confined in a microcell. This aspect of the work is expected to motivate further in situ studies of confined crystal growth. 相似文献
2.
This paper develops a managerial model of production network organizations (PNOs), inter-firm alliances for product development and delivery, in which inter-firm network structure and knowledge management practices play a major role in venture performance. The paper addresses the issue of alignment between the adopted network structure, the scope of the joint production task, and consequent inter-firm information flow requirements, hypothesizing that venture performance is a joint function of network structure and task integration scope. In situations with a difficult alignment between the chosen network structure, joint task scope, and information flow requirements, knowledge management investments across the PNO are proposed as a moderating factor leading to improved venture performance. The paper demonstrates the proposed model with three case studies, providing preliminary verification of the key proposition that knowledge management interventions can mediate the impact of loose integrating structures for joint production ventures that are undertaking complex joint tasks. 相似文献
3.
S Jamali D Archer P Ravussin M Bonnafous P David C Ecoffey 《Canadian Metallurgical Quarterly》1997,84(6):1292-1296
Directed delivery and distribution of anaesthetics (novocaine, lidocaine, trimecaine) immobilized on finely dispersed iron powders under the influence of an external magnetic field in body tissues of test animals have been studied. The data of emission spectral analysis relating to concentration of iron in soft and bone tissues of animals influenced by constant and alternating magnetic field on front and reverse sides over a period from 0 to 180 min are given. 相似文献
4.
The performance of three GHARQ-II schemes, based on punctured convolutional codes, used over a simulated Rayleigh fading channel subject to additive white Gaussian noise are compared. Various fade rates and signal to noise ratios are considered 相似文献
5.
James L. Smialek Ph.D. Frances A. Archer B.S. Ralph G. Garlick B.S. 《JOM Journal of the Minerals, Metals and Materials Society》1994,46(12):39-41
Helicopter turbine engines used in the Desert Shield and Desert Storm operations experienced excessive sand ingestion. Fine particles were able to bypass filters and proceed through the combustor or cooling gaspaths. The first-stage turbine vanes were impacted with viscous silicate particles, forming a deposit on the leading-edge root platform and resulting in overheating and oxidation. The chemistry of the raw sand determines that of the ingested powders, the deposits, and the material reactions. 相似文献
6.
A.B. Bourlinos S. RayChowdhury R. Herrera D.D. Jiang Q. Zhang L.A. Archer E.P. Giannelis 《Advanced functional materials》2005,15(8):1285-1290
Recently, we have developed a novel family of functionalized nanostructures that exhibit liquid‐like behavior in the absence of solvents and preserve their nanostructure in the liquid state. The gallery of nanostructures developed so far includes functionalized silica and magnetic iron oxide nanoparticles, layer‐like organosilicate nanoparticles, polyoxometalate clusters, and organic–inorganic hybrid networks. In an effort to demonstrate the wider applicability of this concept and to provide a deeper insight into this class of materials, the present work cites additional paradigms of functionalized nanostructures with similar behavior as above. In one case, surface functionalization of anatase nanoparticles (TiO2, an inorganic nanostructure) with a quaternary ammonium organosilane leads to ionically modified nanoparticles that, when electrostatically combined with a poly(ethylene glycol) (PEG)‐tailed sulfonate anion, exhibit liquid‐like behavior in the absence of solvents. In a different but quite interesting case of a bionanostructure, ion‐exchange functionalization of a DNA oligonucleotide with a PEG‐tailed quaternary ammonium cation leads to an easily separable liquid derivative with attractive features. These examples show the versatility of this concept over a range of nanostructures. 相似文献
7.
8.
9.
"In this paper we trace and interpret changes in the geographical pattern and city-size distribution of the world's largest cities in the twentieth century. Since 1900 the geographical distribution of these cities has become increasingly dispersed; their city-size distribution by rank was nearly linear in 1900 and 1940, and convex in 1980. We interpret the convex distribution which emerged following World War 2 as reflecting an economically integrated but politically and demographically partitioned global urban system. Our interpretation of changes in size distribution of cities emphasizes demographic considerations, largely neglected in previous investigations, including migration and relative rates of population change." 相似文献
10.
This study aims to address the paradigms of consumers’ adoption behavior for mobile government, posits the factors which pursue citizens’ intention to adopt mobile government services, and reveals the impact of cultural dimensions in perceiving driving factors of mobile government adoption. The mobile government adoption model was developed and tested among users of three different countries, namely Bangladesh, Canada, and Germany. The finding suggests the rationale that cross-cultural differences impact consumers’ perception of mobile government adoption behavior. 相似文献