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   1734篇
  免费   25篇
  国内免费   1篇
电工技术   39篇
化学工业   327篇
金属工艺   34篇
机械仪表   29篇
建筑科学   74篇
矿业工程   9篇
能源动力   43篇
轻工业   98篇
水利工程   22篇
石油天然气   31篇
无线电   108篇
一般工业技术   264篇
冶金工业   442篇
原子能技术   32篇
自动化技术   208篇
  2021年   25篇
  2020年   18篇
  2019年   25篇
  2018年   29篇
  2017年   25篇
  2016年   25篇
  2015年   18篇
  2014年   32篇
  2013年   96篇
  2012年   48篇
  2011年   82篇
  2010年   63篇
  2009年   53篇
  2008年   57篇
  2007年   65篇
  2006年   43篇
  2005年   37篇
  2004年   38篇
  2003年   41篇
  2002年   40篇
  2001年   28篇
  2000年   22篇
  1999年   21篇
  1998年   66篇
  1997年   50篇
  1996年   37篇
  1995年   39篇
  1994年   42篇
  1993年   27篇
  1992年   21篇
  1991年   16篇
  1990年   28篇
  1989年   24篇
  1988年   25篇
  1987年   34篇
  1986年   23篇
  1985年   36篇
  1984年   18篇
  1983年   23篇
  1982年   25篇
  1981年   23篇
  1980年   15篇
  1979年   26篇
  1978年   20篇
  1977年   22篇
  1976年   22篇
  1975年   30篇
  1974年   15篇
  1973年   19篇
  1972年   15篇
排序方式: 共有1760条查询结果,搜索用时 15 毫秒
1.
Programming and Computer Software - In this paper, we overview the approaches and techniques employed by the Svace static analysis tool for intraprocedural analysis. This analysis implies the...  相似文献   
2.
This study investigated the effects of moisture content (MC) on the physicochemical properties of extruded meat alternatives made from Maillard-reacted beef bone hydrolysate and plant proteins. Samples were extruded at 170 °C (maximum barrel temperature), at 3.6 kg h−1 (liquid feed rate) and at 1.8, 2.2, 2.6 and 3.0 kg h−1 (dry feed rates) to obtain MC of 60%MC, 56%MC, 52%MC and 49%MC, respectively. Meat alternatives at 52%MC showed the greatest degree of texturisation. However, meat alternatives at 49%MC were the closest in terms of both textural and microstructural properties to reference sample, boiled chicken breast. Results from protein solubility suggested that a large amount of aggregated proteins were associated with hydrogen bonds, while disulphide bonds were the main contributor in the formation of fibrous structure in meat alternatives. Results showed that the change in MC as process parameter played an important role in the formation of fibrous structure in extruded meat alternatives.  相似文献   
3.
Kim  Seock-Ho  Cohen  Allan S.  Eom  Hyo Jin 《Behaviormetrika》2021,48(2):369-370
Behaviormetrika - In the original publication of the article, Appendix A was published incorrectly.  相似文献   
4.
The electrochemical interactions between aluminum alloy 7075 and low-carbon steels under gelled electrolytes were studied. Such electrolytes provided the opportunity to investigate both thick and thin electrolyte systems. The electrolyte was chemically modified to visually track the acidic fronts during the anodic reaction and the subsequent hydrolysis process. Two mathematical models were validated for both thick and ultrathin electrolytes. The acidification of thick electrolytes was extended some millimeters beyond the aluminum alloy surface, whereas the acidic front was localized next to the metallic joint using ultrathin electrolytes. The combination of both numerical and experimental results allows proving (and explaining why) that the acidification process is more aggressive under dilute than under concentrated electrolytes.  相似文献   
5.

Fermentation derived succinic acid ammonium salt is an ideal precursor for manufacture of renewable N-methyl pyrrolidinone (NMP) or 2-pyrrolidinone (2P) via heterogeneous catalysis. However, there are many challenges to making this a practical reality. Chief among the challenges is avoiding catalyst poisoning by fermentation by- and co-products. Battelle/Pacific Northwest National Laboratory have developed an effective technology strategy for this purpose. The technology is a combination of purely thermal processing, followed by simple catalytic hydrogenation that together avoids catalyst poisoning from fermentation impurities and provides high selectivity and yields of NMP or 2P.

  相似文献   
6.
Systematic characterisation of the reactivity of the lysine moieties in CRM197 towards N‐hydroxysuccinimide linkers bearing alkynes or azides is described. This involves two‐step conjugation of various glycans to CRM197 by click chemistry in a well‐defined manner. By semiquantitative LC‐MS/MS analysis of proteolytic digests of the conjugates formed, the reactivity of lysine residues in the protein was mapped and ranked. Computational analysis of the solvent accessibility of each lysine residue (based on the CRM197 crystal structure) established a correlation between reactivity and surface exposure. By this approach, conjugation involving lysine residues (normally a random process) can be controlled. It enables the preparation of lysine‐mediated glycoconjugates with improved batch‐to‐batch reproducibility, thereby producing neo‐glycoconjugates with more‐consistent biological activity.  相似文献   
7.
安利路位于阿德莱德大城市地区南部近郊,它是澳大利亚大城市中相当常见的“中心大街”的一个缩影。本文通过南澳大利亚大学规划专业学生在社区调查基础上进行的项目研究,反映了安利路作为中心大街商业区的主要特征、对安利路形成竞争的因素、对安利路产生影响的问题,并探讨了从社区愿望出发对安利路进行改善的方法和管理战略。  相似文献   
8.
A diffusion-based kinetic model for resin-based ion exchange is proposed that simultaneously describes extra- and intraparticle diffusion for the purpose of predicting batch transient adsorption rates during resin operation. The extraparticle diffusion is simulated through Newton's-law-of-cooling assuming a stagnant laminar layer, while the intraparticle simulation assumes a homogeneous internal pore environment and uses the Nernst–Planck equation to describe multi-ion diffusion. The key parameters of the model are the mass transfer coefficient, the intrinsic diffusivities of the adsorbing and desorbing ions and the equilibrium coefficient associated with the Mass-Action-Law, which is assumed to be applicable at the liquid/resin interface. A novel method is described to determine the critically important ion concentration at the interface from experiment. Kinetic tests are undertaken in a closed circuit system, adsorbing Na, Mg, and Ba ions separately onto gel type acid resin, and the simulation is fitted to the measured raw data using the Hook–Jeeves search algorithm. The intraparticle diffusivities of the three ions are hence measured and reported.  相似文献   
9.
Vacuum impregnation (VI) has been widely utilized as a pre-treatment method prior to, e.g., the minimal processing, freezing, or drying of foods. In many cases, VI has been used to focus on the enrichment of fruits and vegetables with probiotics or micronutrients, texture enhancement, the modification of the sensory attributes, and extension of shelf life by pH reduction. However, little attention has been paid to the exploration of the metabolic consequences of VI that could lead to changes in the quality characteristics of plant tissues. Since nitrate has long been discussed as a compound that is harmful to human health, the aim of this investigation was to reduce the nitrate content in spinach leaves by feeding sucrose into the tissue using VI. The leaves, either non-treated or treated with VI, were stored under saturated humidity conditions and in darkness at 8 °C, for up to 72 h. VI-treated leaves showed a remarkable reduction in nitrate content as compared to the non-treated samples. Upon storage, sucrose was reduced, indicating that this sugar had been respired and had induced metabolization of the stored nitrate. The nitrite content of the treated leaves was unaffected, proving that this toxic compound was not accumulated in the baby spinach leaves upon external sucrose feeding.  相似文献   
10.
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