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   501433篇
  免费   6699篇
  国内免费   1450篇
电工技术   9219篇
综合类   480篇
化学工业   75697篇
金属工艺   20238篇
机械仪表   15396篇
建筑科学   12082篇
矿业工程   2712篇
能源动力   12105篇
轻工业   44227篇
水利工程   5244篇
石油天然气   9969篇
武器工业   83篇
无线电   59593篇
一般工业技术   97384篇
冶金工业   91837篇
原子能技术   11507篇
自动化技术   41809篇
  2021年   3796篇
  2019年   3660篇
  2018年   6471篇
  2017年   6479篇
  2016年   6915篇
  2015年   4444篇
  2014年   7547篇
  2013年   21546篇
  2012年   12152篇
  2011年   16497篇
  2010年   13308篇
  2009年   15062篇
  2008年   15962篇
  2007年   15787篇
  2006年   14222篇
  2005年   13148篇
  2004年   12416篇
  2003年   12118篇
  2002年   11929篇
  2001年   11785篇
  2000年   11263篇
  1999年   11381篇
  1998年   26886篇
  1997年   19619篇
  1996年   15465篇
  1995年   11908篇
  1994年   10683篇
  1993年   10525篇
  1992年   8246篇
  1991年   7861篇
  1990年   7548篇
  1989年   7443篇
  1988年   7244篇
  1987年   6253篇
  1986年   6154篇
  1985年   7205篇
  1984年   6815篇
  1983年   6140篇
  1982年   5804篇
  1981年   6045篇
  1980年   5740篇
  1979年   5503篇
  1978年   5456篇
  1977年   6346篇
  1976年   8047篇
  1975年   5024篇
  1974年   4866篇
  1973年   4915篇
  1972年   4103篇
  1971年   3854篇
排序方式: 共有10000条查询结果,搜索用时 390 毫秒
51.
Potato processing industry has a high degree of discarding, which currently has low added value being used primarily for animal feed. However, potato wastes offer a broad range of interesting components such as antioxidants, starch, protein or fibre with potential applications in the food and non-food industries. The recovery of these high valuable fractions using efficient multistage and multiproduct processes could be of great interest. This short review provides a general overview on the integral valorisation of potato wastes, offering an updated vision of the main residual parts generated during potato harvesting and processing, the high valuable obtained components focusing on the bioactive ones and the potential of the emerging extraction techniques over conventional ones. In addition, innovative applications are discussed to highlight the scientific and applied interest of these underutilised and undervalued fractions and to emphasise the integral valorisation of raw materials.  相似文献   
52.
Theoretical Foundations of Chemical Engineering - New research results, as well as those published earlier by the authors, on the synthesis of azo compounds based on nitroanilines obtained by the...  相似文献   
53.
A method is proposed to generate categorical colour observer functions (individual colour matching functions) for any field size based on the CIE 2006 system of physiological observer functions. The method combines proposed categorical observer techniques of Sarkar et al with a physiologically-based individual observer model of Asano et al and a clustering technique to produce the optimal set of categorical observers. The number of required categorical observers varies depending on an application with as many as 50 required to predict individual observers' matches when a laser projector is viewed. However, 10 categorical observers are sufficient to represent colour-normal populations for personalized colour imaging. The proposed and recommended categorical observers represent a robust and inclusive technique to examine and quantify observer metamerism in any application of colorimetry.  相似文献   
54.
Polymer Bulletin - In this study, we synthesized a new ion-imprinted polymer (IIP) based on introduction of amidoxime groups in acrylonitrile, complexation with Cd2+ ions and polymerization with...  相似文献   
55.
The bromodomain and extra terminal (BET) family of bromodomain-containing proteins (BCPs) have been the subject of extensive research over the past decade, resulting in a plethora of high-quality chemical probes for their tandem bromodomains. In turn, these chemical probes have helped reveal the profound biological role of the BET bromodomains and their role in disease, ultimately leading to a number of molecules in active clinical development. However, the BET subfamily represents just 8/61 of the known human bromodomains, and attention has now expanded to the biological role of the remaining 53 non-BET bromodomains. Rapid growth of this research area has been accompanied by a greater understanding of the requirements for an effective bromodomain chemical probe and has led to a number of new non-BET bromodomain chemical probes being developed. Advances since December 2015 are discussed, highlighting the strengths/caveats of each molecule, and the value they add toward validating the non-BET bromodomains as tractable therapeutic targets.  相似文献   
56.
Seed processing technologies are essential for seed safety and functionality through protection of physicochemical quality, pathogen inactivation, aflatoxin detoxification and alleviation of mutagenicity. Design of a pilot-scale unit of pulsed electric fields (PEF) to treat sesame seeds with respect to quality parameters, Aspergillus parasiticus inactivation and aflatoxin reduction as well as alleviation of aflatoxin mutagenicity were prompted in this study. PEF energy ranged from 0.97 to 17.28 J achieved maximum reductions of peroxide value and acidity number of 67.4 and 85.7%, respectively, and did not change color L*, a*, b* and hue values. A 60% reduction of A. parasiticus counts occurred at the maximum PEF energy. Aflatoxins G1, G2, B1, and B2 contents decreased by 94.7, 92.7, 86.9, and 98.7%, respectively. Except for the samples treated by 2.16 J with 100 μg/plate and by 6.80 J with 10 μg/plate, PEF treatment provided elimination of aflatoxin mutagenity. It is concluded that PEF treatment can be used to treat sesame seeds with preservation of physicochemical properties, inactivation of A. parasiticus and decomposition of aflatoxins with reduced mutagenicity.  相似文献   
57.
Theoretical Foundations of Chemical Engineering - The extraction of nitric and oxalic acids by neutral compounds TBP, DBBP, and TBPO have been studied. The optimal conditions of their separation...  相似文献   
58.
59.
60.
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