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   156篇
  免费   5篇
  国内免费   1篇
电工技术   3篇
化学工业   51篇
金属工艺   4篇
机械仪表   3篇
建筑科学   5篇
能源动力   5篇
轻工业   17篇
水利工程   5篇
无线电   4篇
一般工业技术   21篇
冶金工业   25篇
原子能技术   3篇
自动化技术   16篇
  2022年   2篇
  2021年   3篇
  2020年   4篇
  2019年   6篇
  2018年   6篇
  2017年   6篇
  2016年   6篇
  2015年   3篇
  2014年   2篇
  2013年   6篇
  2012年   9篇
  2011年   15篇
  2010年   10篇
  2009年   9篇
  2008年   14篇
  2007年   8篇
  2006年   8篇
  2005年   1篇
  2004年   6篇
  2003年   2篇
  2002年   4篇
  2001年   2篇
  2000年   2篇
  1999年   3篇
  1998年   9篇
  1997年   2篇
  1996年   2篇
  1995年   1篇
  1994年   7篇
  1993年   1篇
  1992年   1篇
  1991年   1篇
  1986年   1篇
排序方式: 共有162条查询结果,搜索用时 109 毫秒
51.
人们对用黑液碱回收炉来增加发电量的重要性认识不断提高,这些变化的主要原因是电的价格.本文将介绍增加电产量的某些传统方法、一些新的思想和见解,特别是采用冷凝汽轮机.本研究的基本事例为一台传统的碱回收炉,能力为4000t(固形物)/24h,同时配备有背压汽轮机和冷凝汽轮机.将要介绍的这些方法为:增加黑液固形物含量、空气预热、吹灰系统、给水预热、蒸汽参数和电除尘后的热回收.  相似文献   
52.
Biosensors with increasingly high sensitivity are crucial for probing small scale properties. The asynchronous magnetic bead rotation (AMBR) sensor is an emerging sensor platform, based on magnetically actuated rotation. Here the frequency dependence of the AMBR sensor's sensitivity is investigated. An asynchronous rotation frequency of 145 Hz is achieved. This increased frequency will allow for a calculated detection limit of as little as a 59 nm change in bead diameter, which is a dramatic improvement over previous AMBR sensors and further enables physical and biomedical applications.  相似文献   
53.
Water networks within kinase inhibitor design and more widely within drug discovery are generally poorly understood. The successful targeting of these networks prospectively has great promise for all facets of inhibitor design, including potency and selectivity for the target. Herein, we describe the design and testing of a targeted library of 4-anilinoquin(az)olines for use as inhibitors of cyclin G-associated kinase (GAK). GAK cellular target engagement assays, ATP binding-site modelling and extensive water mapping provide a clear route to access potent inhibitors for GAK and beyond.  相似文献   
54.
There is considerable debate in the information systems literature on how systems development methods (SDMs) are used in practice. On one side are those who take the position that these methods are not used at all. The other side posits that SDMs are used but not in the manner intended by the method developers. In practice, SDMs are adapted and modified to meet project exigencies, which results in unique methods‐in‐use in each project. We subscribe to the latter view and extend the argument by proposing that SDM modifications happen due to mismatches between the paradigmatic values inherent in the SDM, the method users and the organizational context. Further, planned modifications themselves result in shifts of paradigmatic values inherent in the SDM. To examine our contention, we conduct a case study in which we trace an SDM from its development to its deployment and use in an organization. We show where the mismatches occurred and provide explanations for the mismatches. Our results indicate that paradigm differences explain most of the mismatches, and different factors contribute to the paradigm drifts simultaneously, even towards diverging orientations. We conclude that the true value of an SDM, in addition to its tool and technique use, is a basis for examining and self‐reflecting about paradigmatic values. This is an essential part of learning to develop systems.  相似文献   
55.
56.
We have studied the noise spectra of Au/Ti bilayer transition-edge sensors with transition temperatures around ∼100 mK. The sensors did not include an absorber element, and were patterned into either a circular Corbino geometry, or a Corbino disk divided into four parallel sections. Both sensor types contained noise in excess of the thermodynamic phonon noise and the equilibrium Johnson noise of the sensor. However, the divided Corbino detector had a significantly lower noise level than the undivided Corbino disk, especially at bias points below the mid-point of the transition.   相似文献   
57.
We consider the efficient numerical solution of the Helmholtz equation in a rectangular domain with a perfectly matched layer (PML) or an absorbing boundary condition (ABC). Standard bilinear (trilinear) finite‐element discretization on an orthogonal mesh leads to a separable system of linear equations for which we describe a cyclic reduction‐type fast direct solver. We present numerical studies to estimate the reflection of waves caused by an absorbing boundary and a PML, and we optimize certain parameters of the layer to minimize the reflection. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   
58.
This quasi-experimental study compared the effects of two rehabilitation interventions on burnout and perceived job conditions during a 1-year intervention among female white-collar workers. The participatory intervention (n = 20), involving rehabilitation activities that focused on the individual as well as on individual-organizational levels, assessed exhaustion, cynicism and perceived job control during a 1-year period. Increased job control served as a mechanism through which exhaustion and cynicism decreased in this intervention. The traditional intervention (n = 32), involving rehabilitation activities focusing mainly on the individual level, resulted in a reduction in time pressures during one year. Furthermore, both interventions improved perceived workplace climate. Compared to the traditional approach, the participatory intervention was a more effective strategy for treating burnout. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
59.
Bone has an enormous capacity for growth, regeneration, and remodeling. This capacity is largely due to induction of osteoblasts that are recruited to the site of bone formation. The recruitment of osteoblasts has not been fully elucidated, though the immediate environment of the cells is likely to play a role via cell- matrix interactions. We show here that heparin-binding growth-associated molecule (HB-GAM), an extracellular matrix-associated protein that enhances migratory responses in neurons, is prominently expressed in the cell matrices that act as target substrates for bone formation. Intriguingly, N-syndecan, which acts as a receptor for HB-GAM, is expressed by osteoblasts/osteoblast precursors, whose ultrastructural phenotypes suggest active cell motility. The hypothesis that HB-GAM/N-syndecan interaction mediates osteoblast recruitment, as inferred from developmental studies, was tested using osteoblast-type cells that express N-syndecan abundantly. These cells migrate rapidly to HB-GAM in a haptotactic transfilter assay and in a migration assay where HB-GAM patterns were created on culture wells. The mechanism of migration is similar to that previously described for the HB-GAM-induced migratory response of neurons. Our hypothesis that HB-GAM/N-syndecan interaction participates in regulation of osteoblast recruitment was tested using two different in vivo models: an adjuvant-induced arthritic model and a transgenic model. In the adjuvant-induced injury model, the expression of HB-GAM and of N-syndecan is strongly upregulated in the periosteum accompanying the regenerative response of bone. In the transgenic model, the HB-GAM expression is maintained in mesenchymal tissues with the highest expression in the periosteum. The HB-GAM transgenic mice develop a phenotype characterized by an increased bone thickness. HB-GAM may thus play an important role in bone formation, probably by mediating recruitment and attachment of osteoblasts/osteoblast precursors to the appropriate substrates for deposition of new bone.  相似文献   
60.
Binding of quinacrine to phospholipids and porcine pancreatic phospholipase A2 (PLA2) was investigated using fluorescence resonance energy transfer, Langmuir films, assay for the enzymatic activity, and molecular modeling. No significant binding of this drug to the zwitterionic phosphatidylcholine was observed whereas a high affinity for acidic phospholipids was revealed by quenching of pyrene-labeled phospholipid analogues. Partial reversal of this binding was observed due to the addition of 4 mM CaCl2. Quinacrine efficiently and independently of the lipid surface pressure penetrated into monolayers of phosphatidylglycerol while only a weak penetration into phosphatidylcholine films was evident. Quinacrine also bound to eosin-labeled PLA2, and the addition of 4 mM CaCl2 reversed this interaction almost completely. In the presence of acidic phospholipids both the drug and the enzyme were attached to the lipid surface. Studies on the influence of quinacrine on the activity of PLA2 toward pyrene-labeled phospholipid analogues revealed that the hydrolysis of phosphatidylcholine was progressively reduced as a function of increasing [quinacrine]. At low [CaCl2] and low quinacrine:lipid molar ratios (<1:5) quinacrine enhanced slightly the rate of hydrolysis of acidic phospholipids whereas at higher drug:lipid molar ratios (>1:2) an inhibition was observed. In the presence of 1 mM CaCl2 quinacrine inhibited PLA2-catalyzed hydrolysis of phosphatidylglycerol only when the drug:lipid molar ratio exceeded 1:1. The presence of 4 mM CaCl2 abolished nearly completely the inhibition with all the substrate analogues used. Our data suggest that the inhibition of PLA2 by quinacrine is due to its binding to the enzyme. This is supported also by molecular modeling which suggested a binding site for quinacrine close to the active site and Ca2+ binding site of the enzyme. Importantly, our data indicate that quinacrine binds avidly to acidic phospholipids and their presence may influence the drug-enzyme interaction and the inhibition of the enzyme action. Accordingly, presence of quinacrine may interfere also with other processes that require the presence of acidic lipids and/or Ca2+, such as the function of the nicotinic acetylcholine receptor.  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