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   32篇
  免费   2篇
化学工业   7篇
能源动力   1篇
无线电   8篇
一般工业技术   13篇
自动化技术   5篇
  2023年   1篇
  2022年   2篇
  2021年   2篇
  2019年   1篇
  2018年   1篇
  2015年   1篇
  2014年   2篇
  2013年   1篇
  2012年   1篇
  2010年   2篇
  2009年   2篇
  2008年   1篇
  2007年   2篇
  2006年   2篇
  2005年   1篇
  2004年   2篇
  2001年   1篇
  1996年   3篇
  1993年   1篇
  1992年   2篇
  1989年   1篇
  1985年   2篇
排序方式: 共有34条查询结果,搜索用时 15 毫秒
1.
A new Routh-like algorithm for determining the number of right-half plane (RHP) roots of a polynomial with real or complex coefficients is given. It includes the Routh algorithm for real polynomials as a special case. Moreover, the algorithm also applies directly to the singular case wherein the leading coefficient of a row, but not the entire row, vanishes, needing far fewer computations than the heuristicepsilon- method about which there was a vigorous discussion in these TRANSACTIONS a few years ago, and further not requiring investigation of an auxiliary polynomial. The algorithm is illustrated by a few examples. The proof of the algorithm is based on the Principle of the Argument, and thus also constitutes a simple proof of the Routh algorithm in the regular case.  相似文献   
2.
Flame synthesis is one of the most versatile and promising technologies for large-scale production of nanoscale materials. Pyrolysis has recently been shown to be a useful route for the production of single-walled nanotubes, quantum dots and a wide variety of nanostructured ceramic oxides for catalysis and electrochemical applications. An understanding of the mechanisms of nanostructural growth in flames has been hampered by a lack of direct observations of particle growth, owing to high temperatures (2,000 K), rapid kinetics (submillisecond scale), dilute growth conditions (10(-6) volume fraction) and optical emission of synthetic flames. Here we report the first successful in situ study of nanoparticle growth in a flame using synchrotron X-ray scattering. The results indicate that simple growth models, first derived for colloidal synthesis, can be used to facilitate our understanding of flame synthesis. Further, the results indicate the feasibility of studies of nanometre-scale aerosols of toxicological and environmental concern.  相似文献   
3.
Indium-doped zinc oxide (IZO) films were deposited on Corning 7059 substrates by the spray pyrolysis technique. To achieve higher electrical conductivity both the zinc acetate concentration and indium concentration in the solution were varied. The films were characterized for their structural and electrical properties. Film stability in H2 plasma was also checked for possible use in amorphous and microcrystalline silicon related fields. It was observed that the films can be sustained in a hydrogen plasma, and hence IZO films of high conductivity can be used for the development of amorphous and microcrystalline silicon solar cells.  相似文献   
4.
Van der Waals growth of GaAs on silicon using a two‐dimensional layered material, graphene, as a lattice mismatch/thermal expansion coefficient mismatch relieving buffer layer is presented. Two‐dimensional growth of GaAs thin films on graphene is a potential route towards heteroepitaxial integration of GaAs on silicon in the developing field of silicon photonics. Hetero‐layered GaAs is deposited by molecular beam epitaxy on graphene/silicon at growth temperatures ranging from 350 °C to 600 °C under a constant arsenic flux. Samples are characterized by plan‐view scanning electron microscopy, atomic force microscopy, Raman microscopy, and X‐ray diffraction. The low energy of the graphene surface and the GaAs/graphene interface is overcome through an optimized growth technique to obtain an atomically smooth low­ temperature GaAs nucleation layer. However, the low adsorption and migration energies of gallium and arsenic atoms on graphene result in cluster‐growth mode during crystallization of GaAs films at an elevated temperature. In this paper, we present the first example of an ultrasmooth morphology for GaAs films with a strong (111) oriented fiber‐texture on graphene/silicon using quasi van der Waals epitaxy, making it a remarkable step towards an eventual demonstration of the epitaxial growth of GaAs by this approach for heterogeneous integration.  相似文献   
5.
Journal of Inorganic and Organometallic Polymers and Materials - Gas detection is significant for controlling industrial and vehicle emission, house equipment security and environmental monitoring....  相似文献   
6.
7.
The advent and proliferation of digital technologies purport to increase the innovation potential of most organizations. However, approximately 90% of new ideas never convert to new product or service deliveries because of the lack of organizational readiness. This paper conceptualizes a formative multidimensional construct to gauge organizational readiness for digital innovations. Such a construct would facilitate cumulative research on the role of digital innovation, while benchmarking to track organizational readiness. The proposed construct includes 21 measures, categorized under seven subconstructs: resource readiness, IT readiness, cognitive readiness, partnership readiness, innovation valance, cultural readiness, and strategic readiness.  相似文献   
8.
We demonstrate an InP-based monolithically integrated reconfigurable optical add-drop multiplexer consisting of an array waveguide grating, a semiconductor optical amplifier, four 2x2 Mach-Zehnder optical switches, and four PIN photodetectors using the asymmetric twin waveguide technology. The total chip size is 10 x 6 mm, and each of the components in the circuit exhibited performance similar to that achieved in a discrete form. The add-drop functionality of the chip is demonstrated via the routing of the signal from the add port to the drop/output port.  相似文献   
9.
High-yield synthesis of nanocrystalline tin dioxide (nano-SnO2) using a two-step thermal decomposition process is reported. Stannous chloride with glacial acetic acid was the precursor to form tin diacetate, whose thermal decomposition gave nano-SnO2. The yield of respective steps matched well with theoretically expected values, by 85% for tin diacetate and by 94% for nano-SnO2. Material characterization was done using X-ray diffraction (phase and particle size) and transmission electron microscopy. The nano-SnO2 particles were successfully used to develop thick film H2 sensors. The sensor characteristics were closely related to the micro-structural properties of nano-SnO2.  相似文献   
10.
The development of user expertise is a strategic imperative for organizations in hyper-competitive markets. This paper conceptualizes opreationalises and validates user expertise in contemporary Information Systems (IS) as a formative, multidimensional index. Such a validated and widely accepted index would facilitate progression of past research on user competence and efficacy of IS to complex contemporary IS, while at the same time providing a benchmark for organizations to track their user expertise. The validation involved three separate studies, including exploratory and confirmatory phases, using data from 244 respondents.  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