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   262篇
  免费   10篇
电工技术   3篇
化学工业   37篇
金属工艺   2篇
机械仪表   6篇
建筑科学   3篇
能源动力   16篇
轻工业   19篇
水利工程   2篇
无线电   30篇
一般工业技术   36篇
冶金工业   54篇
原子能技术   1篇
自动化技术   63篇
  2023年   4篇
  2022年   9篇
  2021年   12篇
  2020年   9篇
  2019年   6篇
  2018年   8篇
  2017年   10篇
  2016年   10篇
  2015年   2篇
  2014年   5篇
  2013年   9篇
  2012年   7篇
  2011年   6篇
  2010年   6篇
  2009年   11篇
  2008年   9篇
  2007年   9篇
  2006年   6篇
  2005年   6篇
  2004年   2篇
  2003年   1篇
  2002年   3篇
  2001年   2篇
  2000年   2篇
  1999年   3篇
  1998年   16篇
  1997年   6篇
  1996年   8篇
  1995年   9篇
  1994年   8篇
  1993年   8篇
  1992年   8篇
  1991年   5篇
  1990年   6篇
  1988年   2篇
  1987年   3篇
  1985年   3篇
  1984年   3篇
  1983年   1篇
  1982年   4篇
  1981年   1篇
  1980年   3篇
  1979年   5篇
  1978年   2篇
  1977年   4篇
  1976年   5篇
  1975年   1篇
  1973年   2篇
  1972年   1篇
  1940年   1篇
排序方式: 共有272条查询结果,搜索用时 46 毫秒
61.
Multimedia Tools and Applications -  相似文献   
62.
ABSTRACT

ICT for development ( ICT4D) research seeks to examine the social and economic changes in developing countries brought about by the deployment and use of ICT. This intent of ICT4D research parallels that of the critical research paradigm in IS, since both focus on transformation and change. The overall goals of this paper are to( 1)understand the extent of critical research in ICT4Dand ( 2)propose an approach, the“strong critical” approach, to conduct critical research in ICT4D. The proposed approach is based on the writings of two social theorists, Arturo Escobar and Gayatri Spivak, and consists of four concepts– the nature of the post-colonial state, provenience or local history of the ICT phenomena, the influence of the Washington Consensusand the issues of representation and subjectivity of subaltern subjects. A review of ICT4D papers showed that only about 20% follow the critical research approach. In-depth reviews ofeight papers that follow the critical approach showed that the“strong critical” lens can enable a deeper and richer analysis. The main contribution of this paper is in addressing a gap in the ICT4D literature about theorizing in the context of developing countries. The paper also reveals, through in-depth reviews, the value of the strong critical approach.  相似文献   
63.
Mining data streams is the process of extracting information from non-stopping, rapidly flowing data records to provide knowledge that is reliable and timely. Streaming data algorithms need to be one pass and operate under strict limitations of memory and response time. In addition, the classification of streaming data requires learning in an environment where the data characteristics might change constantly. Many of the classification algorithms presented in literature assume a 100 % labeling rate, which is impractical and expensive when data records are rapidly flowing in. In this paper, a new incremental grid density based learning framework, the GC3 framework, is proposed to perform classification of streaming data with concept drift and limited labeling. The proposed framework uses grid density clustering to detect changes in the input data space. It maintains an evolving ensemble of classifiers to learn and adapt to the model changes over time. The framework also uses a uniform grid density sampling mechanism to obtain a uniform subset of samples for better classification performance with a lower labeling rate. The entire framework is designed to be one-pass, incremental and work with limited memory to perform any-time classification on demand. Experimental comparison with state of the art concept drift handling systems demonstrate the GC3 frameworks ability to provide high classification performance, using fewer models in the ensemble and with only 4-6 % of the samples labeled. The results show that the GC3 framework is effective and attractive for use in real world data stream classification applications.  相似文献   
64.
65.
66.
Despite its widespread industrial and residential uses for production of potable water, the reverse osmosis (RO) desalination process has some drawbacks by discharging harmful concentrated saline water as reject stream. A hydrophobic porous membrane can treat such environmentally unfriendly RO reject stream via Membrane Distillation (MD) process. Here, we describe preparation of superior polyvinylidenefluoride (PVDF) membrane modified with superhydrophobic silica nanoparticles for desalination application. Superhydrophobicity (contact angle of 151°) of silica nanoparticles of 7 nm sizes was achieved by reaction of the silica particles with octadecyltrichlorosilane in toluene to form ? Si? O? Si? links with C18 alkyl chain. A homogeneous polymer dope mixture containing a desired amount of modified silica colloids suspended in toluene was used for the membrane preparation. The PVDF membrane with optimal silica content exhibited excellent flux with >99% salt rejection efficiency when used for MD at room temperature from the saline water feed of 3.5 wt % NaCl. The prepared hydrophobic PVDF membrane has the potential for MD application in treating the RO reject stream and other aqueous industrial effluents. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46043.  相似文献   
67.
Cancer diagnosis is currently undergoing a paradigm shift with the incorporation of molecular biomarkers as part of routine diagnostic panel. The molecular alteration ranges from those involving the DNA, RNA, microRNAs (miRNAs) and proteins. The miRNAs are recently discovered small non-coding endogenous single-stranded RNAs that critically regulates the development, invasion and metastasis of cancers. They are altered in cancers and have the potential to serve as diagnostic markers for cancer. Moreover, deregulating their activity offers novel cancer therapeutic approaches. The availability of high throughput techniques for the identification of altered cellular molecules allowed their use in cancer diagnosis. Their application to a variety of body specimens from blood to tissues has been helpful for appreciating their use in the clinical context. The development of innovative antibodies for immunohistochemical detection of proteins also assists in diagnosis and risk stratification. Overall, the novel cancer diagnostic tools have extended their application as prognostic risk factors and can be used as targets for personalized medicine.  相似文献   
68.
Highly luminescent Ag-ion-doped Cd1−xZnxS (0 ≤ x ≤ 1) alloy nanocrystals were successfully synthesized by a novel wet chemical precipitation method. Influence of dopant concentration and the Zn/Cd stoichiometric variations in doped alloy nanocrystals have been investigated. The samples were characterized by X-ray diffraction (XRD) and high resolution transmission electron microscope (HRTEM) to investigate the size and structure of the as prepared nanocrystals. A shift in LO phonon modes from micro-Raman investigations and the elemental analysis from the energy dispersive X-ray analysis (EDAX) confirms the stoichiometry of the final product. The average crystallite size was found increasing from 1.0 to 1.4 nm with gradual increase in Ag doping. It was observed that photoluminescence (PL) intensity corresponding to Ag impurity (570 nm), relative to the other two bands 480 and 520 nm that originates due to native defects, enhanced and showed slight red shift with increasing silver doping. In addition, decrease in the band gap energy of the doped nanocrystals indicates that the introduction of dopant ion in the host material influence the particle size of the nanocrystals. The composition dependent bandgap engineering in CdZnS:Ag was achieved to attain the deliberate color tunability and demonstrated successfully, which are potentially important for white light generation.  相似文献   
69.
Multimedia Tools and Applications - This paper presents a two-stage sequential method for noisy grayscale and color images. At first proposed method enhances the accuracy of the noise detection...  相似文献   
70.
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