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   2491篇
  免费   167篇
  国内免费   1篇
电工技术   17篇
综合类   1篇
化学工业   649篇
金属工艺   91篇
机械仪表   91篇
建筑科学   100篇
矿业工程   7篇
能源动力   196篇
轻工业   374篇
水利工程   12篇
石油天然气   19篇
无线电   134篇
一般工业技术   470篇
冶金工业   76篇
原子能技术   12篇
自动化技术   410篇
  2024年   9篇
  2023年   28篇
  2022年   51篇
  2021年   114篇
  2020年   81篇
  2019年   69篇
  2018年   135篇
  2017年   120篇
  2016年   135篇
  2015年   100篇
  2014年   137篇
  2013年   351篇
  2012年   133篇
  2011年   169篇
  2010年   172篇
  2009年   139篇
  2008年   124篇
  2007年   109篇
  2006年   66篇
  2005年   46篇
  2004年   40篇
  2003年   23篇
  2002年   33篇
  2001年   16篇
  2000年   25篇
  1999年   19篇
  1998年   26篇
  1997年   11篇
  1996年   19篇
  1995年   11篇
  1994年   8篇
  1993年   8篇
  1992年   12篇
  1991年   5篇
  1990年   9篇
  1989年   3篇
  1988年   7篇
  1987年   8篇
  1986年   7篇
  1985年   12篇
  1984年   11篇
  1983年   5篇
  1982年   7篇
  1981年   14篇
  1980年   6篇
  1978年   3篇
  1977年   3篇
  1976年   6篇
  1974年   4篇
  1973年   3篇
排序方式: 共有2659条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
5.
6.
7.
Physically based simulation of human hair is a well studied and well known problem. But the “pure” physically based representation of hair (and other animation elements) is not the only concern of the animators, who want to “control” the creation and animation phases of the content. This paper describes a sketch-based tool, with which a user can both create hair models with different styling parameters and produce animations of these created hair models using physically and key frame-based techniques. The model creation and animation production tasks are all performed with direct manipulation techniques in real-time.  相似文献   
8.
Four experiments of coagulation and flocculation were conducted to investigate the characteristics of colloidal silica removal in a high-tech industrial wastewater treatment plant for reclamation and reuse of the effluent. Experimental results illustrated that poly-aluminium chloride (PACl) showed higher performances on colloidal silica removal than alum. Interestingly, the two coagulants demonstrated the same capacity on silica removal. The specific silica removal capacity was approximately 0.135 mg SiO2/mg Al2O3 when the dosage of coagulants was in the range 30-150 mg/L Al2O3. In addition, the silica was reduced significantly at the condition of pH above 8. Experimental data implied that precipitation of aluminium flocs was the major mechanism for colloid silica removal in PACl and alum coagulation, besides, charge adsorption was also important for improving removal efficiency. Moreover, the addition of polyacrylic acid (PAA) as a flocculant could slightly advance silica removal in the PACl coagulation. The combined PACl/PAA/flocs coagulation was effective for the removal of colloidal silica, soluble COD, and turbidity and also suitable as a pretreatment unit in wastewater reclamation and reuse processes.  相似文献   
9.
Sulfate-reducing reactive walls installed in situ in the path of acid mine drainage contaminated groundwater, present a promising passive treatment technology. However, a rigorous and methodical selection of the most appropriate reactive mixture composition still needs to be investigated. The aim of this study was the selection of the most reactive medium using a multiple factor design and the modeling of the sulfate-reduction rate. Reactivity of 17 mixtures was assessed in batch reactors (in duplicates) using a synthetic AMD. Results indicate that within 41 days, sulfate concentrations decreased from initial concentrations of 2,000-3,200 mg/l to final concentrations of <90 mg/l. Metal removal efficiencies ranged between 51-84% for Ni and 73-93% for Zn. Generated sulfate-reduction rate predictive models which had very satisfactory parameters (R2 = 0.86, F = 62.38 (p-level < 10(-13)) and R2 = 0.90. F = 62.30 (p-level < 10(-13))) identified poultry manure and two other carbon sources as the critical variables for sulfate-reduction rate.  相似文献   
10.
In this study forecast of Turkey's net electricity energy consumption on sectoral basis until 2020 is explored. Artificial neural networks (ANN) is preferred as forecasting tool. The reasons behind choosing ANN are the ability of ANN to forecast future values of more than one variable at the same time and to model the nonlinear relation in the data structure. Founded forecast results by ANN are compared with official forecasts.  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