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   339篇
  免费   18篇
  国内免费   1篇
电工技术   11篇
综合类   1篇
化学工业   100篇
金属工艺   8篇
机械仪表   5篇
建筑科学   7篇
能源动力   17篇
轻工业   74篇
水利工程   1篇
无线电   28篇
一般工业技术   70篇
冶金工业   7篇
自动化技术   29篇
  2024年   1篇
  2023年   2篇
  2022年   13篇
  2021年   14篇
  2020年   15篇
  2019年   9篇
  2018年   12篇
  2017年   5篇
  2016年   9篇
  2015年   13篇
  2014年   13篇
  2013年   31篇
  2012年   21篇
  2011年   27篇
  2010年   21篇
  2009年   27篇
  2008年   23篇
  2007年   16篇
  2006年   18篇
  2005年   12篇
  2004年   5篇
  2003年   7篇
  2002年   3篇
  2001年   1篇
  2000年   2篇
  1999年   4篇
  1998年   3篇
  1997年   6篇
  1996年   4篇
  1995年   1篇
  1994年   5篇
  1993年   3篇
  1992年   4篇
  1991年   3篇
  1987年   1篇
  1986年   1篇
  1985年   1篇
  1982年   1篇
  1976年   1篇
排序方式: 共有358条查询结果,搜索用时 15 毫秒
81.
The breakthrough time of butyl, nitrile, and natural-rubber sheets (cured) of different compositions against a potent chemical warfare (CW) agent have been determined using the spot disc test (SDT) method. It was observed that butyl rubber is the best material in comparison to nitrile and natural rubber for protection against sulfur mustard (SM). One of the butyl formulations provides more than 100 h protection against SM. The diffusion coefficient of oxygen mustard (SM analog) for the same formulation (F8) and one nonblack butyl formulation (F5) was determined by weight gain as well as by FTIR–ATR methods. Both methods provide consistent results and the diffusion coefficient of oxygen mustard (OM for butyl rubber is in the order of 10?9cm2/s. The diffusion coefficient of SM for the form lation F8 and F5 was also determined from the SDT retardation time. © 1995 John Wiley & Sons, Inc.  相似文献   
82.
Community detection in social networks is a well-studied problem. A community in social network is commonly defined as a group of people whose interactions within the group are more than outside the group. It is believed that people’s behavior can be linked to the behavior of their social neighborhood. While shared characteristics of communities have been used to validate the communities found, to the best of authors’ knowledge, it is not demonstrated in the literature that communities found using social interaction data are like-minded, i.e., they behave similarly in terms of their interest in items (e.g., movie, products). In this paper, we experimentally demonstrate, on a social networking movie rating dataset, that people who are interested in an item are socially better connected than the overall graph. Motivated by this fact, we propose a method for finding communities wherein like-mindedness is an explicit objective. We find small tight groups with many shared interests using a frequent item set mining approach and use these as building blocks for the core of these like-minded communities. We show that these communities have higher similarity in their interests compared to communities found using only the interaction information. We also compare our method against a baseline where the weight of edges are defined based on similarity in interests between nodes and show that our approach achieves far higher level of like-mindedness amongst the communities compared to this baseline as well.  相似文献   
83.
84.
85.
ABSTRACT

Nanoparticles of neodymium phosphate and 5% gadolinium (Gd) doped neodymium phosphate prepared by co-precipitation technique belong to the monoclinic monazite phase with space group P21/n. The average crystallite size calculated using Debye-Scherrer and Williamson Hall method matches very well with grain size observed from scanning electron microscope images and Image J software. FTIR analysis signifies the presence of vibration modes along with the phosphate group and a slight shift in wave number was observed with the substitution of gadolinium into neodymium phosphate. Ultraviolet absorption spectrophotometer show transitions from ground state to various excited state within the 4f shell and the absorption edge shifts towards the lower wavelength side (blue shift) with the addition of dopant. Raman spectrum further confirms the formation of phosphate group with relevant peaks.  相似文献   
86.
Goel  Anubha  Rewari  Sonam  Verma  Seema  Gupta  R. S. 《Microsystem Technologies》2020,26(5):1697-1705

High-K Spacer based Dual-Metal Gate Stack Junctionless Gate All Around (HK-DMGS-JGAA) MOSFET has been proposed and analyzed in this paper for high frequency analog ad RF applications. It has been done by comparing it with the existing Junctionless devices in particular, Junctionless-Gate All Around, Junctionless Gate All Around Underlap and Dual-Metal Junctionless Gate All Around Underlap MOSFET. It is so found that HK-DMGS-JGAA MOSFET shows higher Ids, gm, gd and fT over existing Junctionless device architectures making it a suitable device for high frequency analog applications. It has also been established that HK-DMGS-JGAA MOSFET has better ION/IOFF ratio, Subthreshold Slope (SS) most close to the ideal values, lower Channel Resistance, Rch, higher Early Voltage (VEA), higher Frequency Transconductance Product, superior Transconductance Generation Factor, Maximum gains in terms of current gain, Maximum Transducer Power Gain and Unilateral Power Gain, superior noise performance in terms of the Noise Conductivity and Noise Figure. All these improved figure of merits warrant HK-DMGS-JGAA MOSFET as the best suited device design for various analog and digital applications along with high frequency applications.

  相似文献   
87.
In the present paper, we report the Fourier transform infra‐red (FTIR) spectra and an analysis of the normal modes and their dispersion, based on the calculations for an infinite chain and Urey Bradley force field with nonbonded interactions. The results thus obtained agree well with the FTIR spectra. The heat capacity obtained from the dispersion curves via density‐of‐states is in very good agreement with the experimental measurements between 50 and 500 K. We observed that the main contribution to heat capacity comes from the modes involving the coupling of the backbone skeletal and side‐chain motions. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   
88.
Seema  Adolph  Shah  Tejas  Schwoebel  Lukas  Liu  Yu  Reisslein  Martin 《Multimedia Tools and Applications》2018,77(16):21417-21443
Multimedia Tools and Applications - Multimedia streaming from miniaturized sensors is attractive for a wide range of web-based applications, including surveillance and Internet of Things (IoT)...  相似文献   
89.
Secondary dispersions of cationic segmented polyurethanes (PUs) with thermoresponsivity (upper critical solution temperature (UCST) in water), high solid contents and antibacterial properties are highlighted in this paper. PUs were prepared by polyaddition reactions and subsequent quaternization with methyl iodide. No additional stabilizers, organic solvents or special procedures were required to obtain stable aqueous dispersions containing up to 10 wt% PU; in contrast, stable dispersions were straightforwardly accessed by a combination of UCST behavior and repulsive electrostatic forces among the positively charged segments, which meets the requirements of a green chemistry process. Particle size and UCST strongly depended on the solid content of the dispersions and the content of poly(ethylene glycol) segments in the copolymers. The dispersions exhibited fast‐acting antibacterial properties against Escherichia coli. © 2013 Society of Chemical Industry  相似文献   
90.
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   
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