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   248篇
  免费   21篇
电工技术   1篇
化学工业   88篇
金属工艺   5篇
机械仪表   4篇
建筑科学   10篇
矿业工程   1篇
能源动力   11篇
轻工业   67篇
水利工程   1篇
无线电   15篇
一般工业技术   23篇
冶金工业   8篇
原子能技术   2篇
自动化技术   33篇
  2024年   2篇
  2023年   4篇
  2022年   3篇
  2021年   10篇
  2020年   4篇
  2019年   9篇
  2018年   16篇
  2017年   5篇
  2016年   6篇
  2015年   12篇
  2014年   14篇
  2013年   23篇
  2012年   19篇
  2011年   23篇
  2010年   25篇
  2009年   16篇
  2008年   12篇
  2007年   12篇
  2006年   7篇
  2005年   8篇
  2004年   6篇
  2003年   5篇
  2002年   4篇
  2001年   2篇
  1999年   1篇
  1998年   4篇
  1997年   1篇
  1996年   2篇
  1995年   2篇
  1994年   1篇
  1993年   2篇
  1991年   1篇
  1989年   1篇
  1985年   2篇
  1981年   1篇
  1980年   1篇
  1976年   1篇
  1975年   2篇
排序方式: 共有269条查询结果,搜索用时 328 毫秒
1.
2.
Defects are often present in rolled products, such as wire rod. The market demand for wire rod without any defects has increased. In the final wire rod products, defects originating from steel making, casting, pre‐rolling of billets and during wire rod rolling can appear. In this work, artificial V‐shaped longitudinal surface cracks have been analysed experimentally and by means of FEM. The results indicate that the experiments and FEM calculations show the same tendency except in two cases, where instability due to fairly “round” false round bars disturbed the experiment. FE studies in combination with practical experiments are necessary in order to understand the behaviour of the material flows in the groove and to explain whether the crack will open up as a V‐shape or if it will be closed as an I‐shape.  相似文献   
3.
Supporting aggregates in recursive logic rules represents a very important problem for Datalog. To solve this problem, we propose a simple extension, called Datalog $^{FS}\,$ (Datalog extended with frequency support goals), that supports queries and reasoning about the number of distinct variable assignments satisfying given goals, or conjunctions of goals, in rules. This monotonic extension greatly enhances the power of Datalog, while preserving (i) its declarative semantics and  (ii) its amenability to efficient implementation via differential fixpoint and other optimization techniques presented in the paper. Thus, Datalog $^{FS}\,$ enables the efficient formulation of queries that could not be expressed efficiently or could not be expressed at all in Datalog with stratified negation and aggregates. In fact, using a generalized notion of multiplicity called frequency, we show that diffusion models and page rank computations can be easily expressed and efficiently implemented using Datalog $^{FS}\,$ .  相似文献   
4.
Proteomics analysis of serum from patients with type 1 diabetes (T1D) may lead to novel biomarkers for prediction of disease and for patient monitoring. However, the serum proteome is highly sensitive to sample processing and before proteomics biomarker research serum cohorts should preferably be examined for potential bias between sample groups. SELDI‐TOF MS protein profiling was used for preliminary evaluation of a biological‐bank with 766 serum samples from 270 patients with T1D, collected at 18 different paediatric centers representing 15 countries in Europe and Japan over 2 years (2000–2002). Samples collected 1 (n = 270), 6 (n = 248), and 12 (n = 248) months after T1D diagnosis were grouped across centers and compared. The serum protein profiles varied with collection site and day of analysis; however, markers of sample processing were not systematically different between samples collected at different times after diagnosis. Three members of the apolipoprotein family increased with time in patient serum collected 1, 6, and 12 months after diagnosis (ANOVA, p<0.001). These results support the use of this serum cohort for further proteomic studies and illustrate the potential of high‐throughput MALDI/SELDI‐TOF MS protein profiling for evaluation of serum cohorts before proteomics biomarker research.  相似文献   
5.
6.
Construction and operation of plants that produce energy from renewable energy sources is the subject for discussion in all the countries that have accepted the sustainable development concept and Kyoto protocol as their own development direction. Enlargement of the renewable energy production is clearly an imperative, but only economically viable construction and operation can result in long-term sustainability, which is initially the goal when deciding upon such investments. In line with this goal, this paper presents the estimation of the economic viability of constructing and operating biogas electricity plant on the farm Vizelj in Serbia. The timeframe for this estimation is from 2011 until 2020. This paper also presents all parameters which are necessary for performing this estimation, respectively, analysis of revenues and expenditures, projection of economic and financial flow, ratio analysis, dynamic and static analysis, and analysis of sensitivity of the project, i.e. impact of the changes in prices and raw material on the overall performance of the project. The observed investment is predicted to be financed from the EBRD's credit line for renewable energy in Western Balkans, while the total investment is estimated at Euro 958,000.00. After the performed economic assessment, the conclusion is that the observed investment in biogas electricity plant is very acceptable and it can serve as a role model for similar investments in the region.  相似文献   
7.
8.
9.
10.
The aim of this work is plasma activation of nonwoven polypropylene (PP) using two different ambient air plasma sources: volume dielectric barrier discharge (DBD) and diffuse coplanar surface barrier discharge (DCSBD) and its functionalization by silver ion deposition.  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