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   14036篇
  免费   990篇
  国内免费   111篇
电工技术   231篇
综合类   59篇
化学工业   3478篇
金属工艺   349篇
机械仪表   499篇
建筑科学   545篇
矿业工程   21篇
能源动力   977篇
轻工业   1307篇
水利工程   207篇
石油天然气   226篇
武器工业   4篇
无线电   1470篇
一般工业技术   2593篇
冶金工业   608篇
原子能技术   96篇
自动化技术   2467篇
  2024年   64篇
  2023年   262篇
  2022年   501篇
  2021年   896篇
  2020年   763篇
  2019年   828篇
  2018年   921篇
  2017年   842篇
  2016年   822篇
  2015年   479篇
  2014年   765篇
  2013年   1428篇
  2012年   916篇
  2011年   975篇
  2010年   678篇
  2009年   610篇
  2008年   441篇
  2007年   368篇
  2006年   314篇
  2005年   208篇
  2004年   188篇
  2003年   160篇
  2002年   129篇
  2001年   101篇
  2000年   98篇
  1999年   91篇
  1998年   180篇
  1997年   161篇
  1996年   118篇
  1995年   94篇
  1994年   77篇
  1993年   76篇
  1992年   56篇
  1991年   44篇
  1990年   45篇
  1989年   41篇
  1988年   30篇
  1987年   31篇
  1986年   41篇
  1985年   30篇
  1984年   31篇
  1983年   29篇
  1982年   23篇
  1981年   20篇
  1980年   22篇
  1979年   19篇
  1978年   22篇
  1977年   24篇
  1976年   26篇
  1975年   13篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Mosquito-borne Zika virus (ZIKV) became a real threat to human health due to the lack of vaccine and effective antiviral treatment. The virus has recently been responsible for a global outbreak leading to millions of infected cases. ZIKV complications were highlighted in adults with Guillain–Barré syndrome and in newborns with increasing numbers of congenital disorders ranging from mild developmental delays to fatal conditions. The ability of ZIKV to establish a long-term infection in diverse organs including the kidneys has been recently documented but the consequences of such a viral infection are still debated. Our study aimed to determine whether the efficiency of ZIKV growth in kidney cells relates to glucose concentration. Human kidney HK-2 cells were infected with different ZIKV strains in presence of normal and high glucose concentrations. Virological assays showed a decrease in viral replication without modifying entry steps (viral binding, internalization, fusion) under high glucose conditions. This decrease replication was associated with a lower virus progeny and increased cell viability when compared to ZIKV-infected HK-2 cells in normal glucose concentration. In conclusion, we showed for the first time that an elevated glucose level influences ZIKV replication level with an effect on kidney cell survival.  相似文献   
12.
13.
Multimedia Tools and Applications - Gastrointestinal stromal tumor is one of the critical tumors that doctors do not suggest to get frequent endoscopy, so there is a need for a diagnosis system...  相似文献   
14.
Mahdavi  Ali 《Water Resources Management》2019,33(10):3615-3631
Water Resources Management - This work presents an analytical solution for the linearized Boussinesq equation describing the nature of well hydraulics in equilateral triangular-shaped unconfined...  相似文献   
15.
This paper deals with the problem of designing a robust static output feedback controller for polytopic systems. The current research that tackled this problem is mainly based on LMI method, which is conservative by nature. In this paper, a novel approach is proposed, which considers the design space of the controller parameters and iteratively partitions the space to small simplexes. Then, by assessing the stability in each simplex, the solution space for design parameters is directly determined. It has been theoretically proved that, if there exists a feasible solution in the design space, the algorithm can find it. To validate the result of the proposed approach, comparative simulation examples are given to illustrate the performance of the design methodology as compared to those of previous approaches.  相似文献   
16.
17.
18.
19.
This paper presents robust and adaptive boundary control designs to stabilize the two‐dimensional vibration of hybrid shaft model. The hybrid shaft is mathematically represented by a set of partial differential equations, governing the shaft vibrations, coupled to ordinary differential equations, describing rigid body spinning and dynamic boundary conditions. The control objective is to stabilize the transverse vibrations of the perturbed shaft while regulating the spinning rate. To achieve this, the paper first establishes robust boundary control laws that fulfil the control objective in the presence of modeling uncertainties and external disturbances operating over the shaft domain and boundary. Lyapunov‐based analyses show that the proposed robust control exponentially stabilizes the shaft with vanishing distributive perturbations, while assuring ultimately bounded vibrations in the case of nonvanishing perturbations. Then, adaptive control philosophy is utilized to achieve redesigned robust controllers that only use online adaptation of control gains without acquiring the knowledge of bounds on perturbations, as well as dynamic parameters. An advantage of this design is avoiding an overconservative robust control law, which may induce poor stability and chattering in tackling system perturbations with unknown upper bounds. Simulations through finite element method illustrate the results. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
20.
Solubility is one of the most indispensable physicochemical properties determining the compatibility of components of a blending system. Research has been focused on the solubility of carbon dioxide in polymers as a significant application of green chemistry. To replace costly and time-consuming experiments, a novel solubility prediction model based on a decision tree, called the stochastic gradient boosting algorithm, was proposed to predict CO2 solubility in 13 different polymers, based on 515 published experimental data lines. The results indicate that the proposed ensemble model is an effective method for predicting the CO2 solubility in various polymers, with highly satisfactory performance and high efficiency. It produces more accurate outputs than other methods such as machine learning schemes and an equation of state approach.  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