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   312篇
  免费   28篇
  国内免费   2篇
电工技术   1篇
综合类   2篇
化学工业   86篇
金属工艺   2篇
机械仪表   17篇
建筑科学   2篇
能源动力   12篇
轻工业   87篇
水利工程   3篇
石油天然气   1篇
无线电   43篇
一般工业技术   39篇
冶金工业   5篇
原子能技术   1篇
自动化技术   41篇
  2024年   2篇
  2023年   12篇
  2022年   18篇
  2021年   23篇
  2020年   16篇
  2019年   26篇
  2018年   17篇
  2017年   14篇
  2016年   15篇
  2015年   16篇
  2014年   16篇
  2013年   30篇
  2012年   23篇
  2011年   17篇
  2010年   9篇
  2009年   12篇
  2008年   8篇
  2007年   20篇
  2006年   11篇
  2005年   1篇
  2004年   7篇
  2003年   6篇
  2002年   4篇
  2001年   3篇
  2000年   5篇
  1999年   1篇
  1998年   1篇
  1996年   2篇
  1995年   1篇
  1993年   2篇
  1991年   2篇
  1990年   1篇
  1989年   1篇
排序方式: 共有342条查询结果,搜索用时 15 毫秒
71.
高清媒体接口(HDMI)已成为高清电视(HDTV)与其显示内容媒体源之间的标准接口。HDMI 1.3版本传输的视频数据将具有更高的分辨率,呈现出来的清晰、明快的画面内容也将比以往更为丰富。HDMI1.3版本的特点包括“深色”技术(Deep Color)带来的更加生动鲜明的色彩,以及多项其他改进,如更为出色的“对口型”功能、支持无损高清音频格式、“xvYCC”扩展色谱以及全新的小型连接器等。  相似文献   
72.
Pakistani wheats were identified via acid polyacrylamide gel electrophoresis (A‐PAGE) of gliadin proteins. Gliadin electrophoretograms of wheat cultivars were qualitatively independent of growth locations and years. The Pakistani wheat Faisalabad 83 and the American wheat KS84HW196 contained an intense gliadin band in the region of the relative mobility 50 band of Marquis. That band was readily distinguishable and was followed by distinct intense double bands in the same position as those of Marquis, and can be used as a reference for mobility assignments in wheat cultivar identification work. Minor differences in band intensities across locations and years were noticed. Identification tables based on band mobilities relative to Marquis and relative intensities were established. © 2000 Society of Chemical Industry  相似文献   
73.
We report on the observation of broad photoluminescence wavelength tunability from n-type gallium nitride nanoparticles (GaN NPs) fabricated using the ultraviolet metal-assisted electroless etching method. Transmission and scanning electron microscopy measurements performed on the nanoparticles revealed large size dispersion ranging from 10 to 100 nm. Nanoparticles with broad tunable emission wavelength from 362 to 440 nm have been achieved by exciting the samples using the excitation power-dependent method. We attribute this large wavelength tunability to the localized potential fluctuations present within the GaN matrix and to vacancy-related surface states. Our results show that GaN NPs fabricated using this technique are promising for tunable-color-temperature white light-emitting diode applications.  相似文献   
74.
75.
76.
Food contagion with aflatoxins is the modern concern and has received a great awareness during the last few decades. The intermittent incidence of these toxins in agricultural commodities has negative role on the economy of the affected regions where harvest and postharvest techniques for the prevention of mold growth, are seldom practiced. Aflatoxins are difuranocoumarin derivatives produced by a polyketide pathway by the fungus Aspergillus flavus and Aspergillus parasiticus via polyketide pathway which are highly hepatotoxic, hepatocarcinogenic, teratogenic, and mutagenic in nature and contaminate a wide variety of important agricultural commodities before, during, and after harvest in various environmental conditions. The production of aflatoxins in innate substrates depends upon the various factors, that is, type of substrate, fungal species, moisture contents of the substrate, minerals, humidity, temperature, and physical damage of the kernels. These toxins cause several ailments such as cancer, hepatitis, mutation abnormalities, and reproduction disorders. Minimization and inactivation of aflatoxins contaminants through proper crop management at farm level and with physical, chemical, and biological techniques are the limelight of the article.  相似文献   
77.
The current study is focused to analyze the heat transfer characteristics in a porous duct. The mathematical model of heat transfer in a porous duct was solved by converting the governing partial differential equations into a set of algebraic equations with the help of finite element method. A simple three noded triangular element is used to mesh the duct domain. The current problem consists of a square duct with outer walls being exposed to hot temperature Th, and inner walls subjected to cool temperature Tc. Emphasis is given to investigate the effect of width ratio of cavity on heat and fluid flow characteristics inside the porous medium. The results are reported for various duct width ratios, Rayleigh number etc. It is found that the Nusselt number increases with increase in height of cavity along the vertical walls of duct; however the Nusselt number for certain values of duct ratio oscillates along the width of the porous medium at bottom wall of the cavity.  相似文献   
78.
Selected physicochemical properties of native and modified water chestnut starch (Trapabispinosa) were studied. Single- and dual-modifications were carried out by pregelatinization, acetylation and acid-thinning methods. Chemical modification created unevenness on the surface of starch granule. Swelling power, solubility, and water retention capacity were improved by all modification techniques used. The peak viscosity was reduced in all modified starches as compared to native water chestnut starch. The setback value which is an indication of retrogradation (re-association of starch molecules) tendency in the starch paste was reduced after pregelatinization and acid-thinning but increased by acetylation.  相似文献   
79.
80.
Type 2 diabetes (T2D) is characterized by chronic hyperglycemia secondary to the decline of functional beta-cells and is usually accompanied by a reduced sensitivity to insulin. Whereas altered beta-cell function plays a key role in T2D onset, a decreased beta-cell mass was also reported to contribute to the pathophysiology of this metabolic disease. The decreased beta-cell mass in T2D is, at least in part, attributed to beta-cell apoptosis that is triggered by diabetogenic situations such as amyloid deposits, lipotoxicity and glucotoxicity. In this review, we discussed the molecular mechanisms involved in pancreatic beta-cell apoptosis under such diabetes-prone situations. Finally, we considered the molecular signaling pathways recruited by glucagon-like peptide-1-based therapies to potentially protect beta-cells from death under diabetogenic situations.  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