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   4985篇
  免费   303篇
  国内免费   3篇
电工技术   25篇
综合类   12篇
化学工业   1425篇
金属工艺   54篇
机械仪表   64篇
建筑科学   327篇
矿业工程   4篇
能源动力   81篇
轻工业   868篇
水利工程   60篇
石油天然气   22篇
无线电   196篇
一般工业技术   744篇
冶金工业   797篇
原子能技术   12篇
自动化技术   600篇
  2024年   10篇
  2023年   53篇
  2022年   149篇
  2021年   211篇
  2020年   98篇
  2019年   141篇
  2018年   149篇
  2017年   132篇
  2016年   165篇
  2015年   137篇
  2014年   229篇
  2013年   338篇
  2012年   283篇
  2011年   398篇
  2010年   281篇
  2009年   231篇
  2008年   249篇
  2007年   221篇
  2006年   217篇
  2005年   157篇
  2004年   160篇
  2003年   141篇
  2002年   110篇
  2001年   73篇
  2000年   76篇
  1999年   59篇
  1998年   52篇
  1997年   54篇
  1996年   59篇
  1995年   53篇
  1994年   40篇
  1993年   42篇
  1992年   46篇
  1991年   36篇
  1990年   51篇
  1989年   37篇
  1988年   39篇
  1987年   34篇
  1986年   25篇
  1985年   25篇
  1984年   38篇
  1983年   12篇
  1982年   28篇
  1981年   10篇
  1980年   17篇
  1979年   24篇
  1978年   13篇
  1977年   10篇
  1975年   17篇
  1972年   9篇
排序方式: 共有5291条查询结果,搜索用时 0 毫秒
1.
2.
Wood has long traditions as a building material, and is often used in construction elements, and as interior and exterior surfaces in the Nordic countries. In most applications, there are reaction to fire requirements to products used as surfaces, e.g. in escape routes and larger public spaces. Most wood products will therefore have to be treated with fire retardant (FR) agents to fulfil the strict requirements to properties connected to heat release and flame spread. Unfortunately, FR agents usually also increase the smoke production, as they cause a more incomplete combustion of the wood. The wood product manufacturers seek to find the optimal amount of FR additives where both heat release and smoke production in the classifying test are within the requirements given in the building regulations. This paper describes models for prediction of the European reaction to fire classes of wood products. The models are based on multivariate statistical analysis, and use test results from the cone calorimeter test as input. The presented models are, with very good precision, able to predict which Euroclass and additional smoke class a wood based product would obtain if it were to be tested in the single burning item test. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
3.
4.
5.
For hundreds of years Spitalfields, the 250 acres that border the London Borough of Tower Hamlets and the City of London, has been a first point of settlement for immigrants. Its tradition of political and religious non-conformity and its proximity to the City of London and the docks have acted as a unique beacon to those seeking refuge and economic opportunity in a capital city. Spitalfields has provided a landscape upon which the incomers have engraved a 'home away from home', for themselves and their families. Using the 'Spitalfields experience' as a focal point, the concept and construction of home by migrants in the diaspora is explored, and some of the cultural tools that the Huguenots, eastern European Jews and Bangladeshis—the protagonist subject groups of this essay—have used to construct their homes in the elsewhere are examined. Due to the spatial limitations of this work, language, diet and religion have been selected as the topics under the microscope. All three facilitated the maintenance of links with the sending societies whilst, in some, though not in every instance, creating a bridge to assimilation. The usage and effectiveness of these tools is compared and contrasted and the role played by Spitalfields over the past four centuries in the creation of homes by those in an alien environment is assessed.  相似文献   
6.
A number of lipid products are formed during the desaturation of stearyl CoA by hen liver microsomes. This article presents an analysis of the products formed when [1-14C] stearyl CoA is incubated with hen liver microsomes for various time periods. [1-14C] Oleyl CoA was the first radioactive unsaturated product formed. Synthesis of phospholipids containing [1-14C] oleic acid occurs only after the desaturase activity has begun to decline. The specific radioactivity of [1-14C] oleyl CoA was similar to the specific radioactivity of [1-14C] stearyl CoA at all time periods tested. The specific radioactivities of [1-14C] oleic acid and phospholipids containing [1-14C] oleic acid were much lower than that of the [1-14C] stearyl CoA.  相似文献   
7.
Caroline Cannizzo 《Polymer》2005,46(4):1269-1276
Translucent boronic acid-carrying nanolatexes are prepared by copolymerisation of vinylbenzyl chloride in microemulsion followed by post functionalisation with 3-aminophenylboronic acid. The diol binding capacity and selectivity of the phenylboronic acid remain unchanged after anchoring to polymer nanoparticles (16 nm diameter, 0.22 mmol/g). The binding of a catechol dye, Alizarin Red S (ARS), to the boronic acid-carrying nanoparticles affords a colored, stable, nanolatex which is used for the selective visual detection of fructose in a competitive assay. The binding of fructose at pH 8.2 is readily evidenced by a color change and monitored by UV/Vis spectroscopy. The nanosensor can be regenerated in acidic medium. The entrapment of the nanolatex in a dialysis cell provides a re-usable support for binding and optical detection.  相似文献   
8.
International Journal of Computer Vision - Semantic scene completion (SSC) aims to jointly estimate the complete geometry and semantics of a scene, assuming partial sparse input. In the last years...  相似文献   
9.
Hinde  Anne 《ITNOW》1998,40(1):24-25
  相似文献   
10.
Witnessing in merging biological, social and algorithmic realities is crucial to trust, as modelled in the YUTPA framework. Being witness and bearing witness is fundamental to human interaction. System participation in human communities of practice challenges the notion of witnessing and therefore the ability to build trust. Nevertheless, through trial and error, people in a variety of practices have found ways to establish the presence and develop trust in merging realities. This paper presents the results of 20 in-depth interviews with professionals from a variety of disciplines and nations. The conclusion of cumulative analysis is that systems do not witness themselves, but their output deeply affects the mental maps that human beings make of each other, the world around them and their own self. Essential qualities human beings seek when being involved with other beings are defined by granularity and reciprocity in the design of time (duration of engagement, synchronizing performance, integrating rhythms and moments to signify), place (body sense, material interaction, emotional space and situated agency), relation (shared meaning, engagement, reputation and use) and action (tuning, reciprocity, negotiation and quality of deeds). By designing granular interaction in 4 dimensions, reciprocity in witnessing obtains significance and the basis for establishing trust in a variety of presences emerges while human agency acquires potential.  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