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   234篇
  免费   16篇
  国内免费   1篇
化学工业   35篇
金属工艺   1篇
机械仪表   5篇
建筑科学   13篇
能源动力   3篇
轻工业   28篇
水利工程   2篇
无线电   25篇
一般工业技术   66篇
冶金工业   37篇
自动化技术   36篇
  2023年   2篇
  2021年   8篇
  2020年   10篇
  2019年   15篇
  2018年   23篇
  2017年   10篇
  2016年   9篇
  2015年   4篇
  2014年   14篇
  2013年   16篇
  2012年   12篇
  2011年   16篇
  2010年   18篇
  2009年   12篇
  2008年   10篇
  2007年   9篇
  2006年   11篇
  2005年   11篇
  2004年   9篇
  2003年   4篇
  2002年   4篇
  2001年   2篇
  2000年   1篇
  1999年   1篇
  1998年   2篇
  1997年   3篇
  1996年   2篇
  1994年   2篇
  1993年   3篇
  1992年   1篇
  1990年   1篇
  1987年   1篇
  1976年   2篇
  1974年   1篇
  1969年   1篇
  1958年   1篇
排序方式: 共有251条查询结果,搜索用时 15 毫秒
41.
From a reading of much literature emanating from the 1970s, one would get the impression that the tenants’ movement in Britain was a united force organised into ‘urban social movements’ which showed an orientation towards militant collective action. On the basis of research in six local authority areas, this paper shows that such a picture gives an inaccurate view of the tenants’ movement in Britain in the late 1980s and early 1990s. Rather the tenants’ movement is divided on the basis of social class, status and consumption position. Further, although tenants do show some degree of collective feeling, they rarely have a strong orientation towards collective, militant, protest action.  相似文献   
42.
The combination of cell microenvironment control and real‐time monitoring of cell signaling events can provide key biological information. Through precise multipatterning of gold nanoparticles (GNPs) around cells, sensing and actuating elements can be introduced in the cells' microenviroment, providing a powerful substrate for cell studies. In this work, a combination of techniques are implemented to engineer complex substrates for cell studies. Alternating GNPs and bioactive areas are created with micrometer separation by means of a combination of vacumm soft‐lithography of GNPs and protein microcontract printing. Instead of conventional microfluidics that need syringe pumps to flow liquid in the microchannels, degas driven flow is used to fill dead‐end channels with GNP solutions, rendering the fabrication process straightforward and accessible. This new combined technique is called Printing and Vacuum lithography (PnV lithography). By using different GNPs with various organic coating ligands, different macroscale patterns are obtained, such as wires, supercrystals, and uniformly spread nanoparticle layers that can find different applications depending on the need of the user. The application of the system is tested to pattern a range of mammalian cell lines and obtain readouts on cell viability, cell morphology, and the presence of cell adhesive proteins.  相似文献   
43.
Many flows of practical interest occur at high Reynolds number, at which the flow in most of the boundary layer is turbulent, showing apparently random fluctuations in velocity across a wide range of scales. The range of scales over which these fluctuations occur increases with the Reynolds number and hence high Reynolds number flows are difficult to compute or predict. In this paper, we discuss the structure of these flows and describe a physical model, based on the attached eddy hypothesis, which makes predictions for the statistical properties of these flows and their variation with Reynolds number. The predictions are shown to compare well with the results from recent experiments in a new purpose-built high Reynolds number facility. The model is also shown to provide a clear physical explanation for the trends in the data. The limits of applicability of the model are also discussed.  相似文献   
44.
This article describes an effort by Rotary International, involving a partnership of public and private health providers and voluntary organizations in the worldwide eradication of polio. The authors cite this effort as a successful private–public partnership model for psychologists and/or psychological organizations attempting to improve public mental health on a mass scale. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
45.
46.
This study examines the impact of cyclist, road and crash characteristics on the injury severity of cyclists involved in traffic crashes reported to the police in Victoria, Australia between 2004 and 2008. Logistic regression analysis was carried out to identify predictors of severe injury (serious injury and fatality) in cyclist crashes reported to the police. There were 6432 cyclist crashes reported to the police in Victoria between 2004 and 2008 with 2181 (33.9%) resulting in severe injury of the cyclist involved. The multivariate analysis found that factors that increase the risk of severe injury in cyclists involved in traffic crashes were age (50 years and older), not wearing a helmet, riding in the dark on unlit roads, riding on roads zoned 70 km/h or above, on curved sections of the road, in rural locations and being involved in head-on collisions as well as off path crashes, which include losing control of vehicle, and on path crashes which include striking the door of a parked vehicle. While this study did not test effectiveness of preventative measures, policy makers should consider implementation of programs that address these risk factors including helmet programs and environmental modifications such as speed reduction on roads that are frequented by cyclists.  相似文献   
47.
Training evaluation is an important component of personal development which has received insufficient attention by project managers, members of project teams and their organisations, making training a target for cut-back at times of tightening budgets. Assessing training has historically been operationally oriented, emphasising financial justification, content and quality of the training rather than the potential of improved project performance or organisational transformation. This qualitative, multi-case study demonstrates the limitations of normative boundary objects (the processes, artefacts, documents or technical language or vocabulary in common use within the project community) such as ‘best practise’ models and ‘bodies of knowledge’ as the driver and basis for training. The paper proposes using alternate boundary objects to incorporate reflective practises which can increase the utilisation of learning by embedding it in specific contexts. Study findings are of relevance to project workers by helping them think differently about the purpose and outcome of training attendance, and for managers charged with developing the project and programme talent pool within the organisation.  相似文献   
48.
49.
Do managers adjust the contextual variables of a project with a view to suiting their personal style? A survey among project leaders in clinical research organisations has given limited support to this proposition but has identified a relationship between the perception of the difficulties involved in a project and types of leaders, based on Fiedler’s theory. This observation has important implications both for project definition in terms of contextual characteristics and for the choice of appropriate project managers, particularly where knowledge workers are involved.  相似文献   
50.
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