首页 | 官方网站   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   63篇
  免费   6篇
工业技术   69篇
  2021年   3篇
  2019年   1篇
  2018年   4篇
  2017年   9篇
  2016年   4篇
  2015年   4篇
  2014年   1篇
  2013年   5篇
  2012年   2篇
  2011年   3篇
  2010年   2篇
  2009年   2篇
  2008年   2篇
  2007年   3篇
  2006年   2篇
  2005年   2篇
  2004年   3篇
  2003年   1篇
  2002年   6篇
  2001年   1篇
  2000年   3篇
  1995年   2篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1985年   1篇
排序方式: 共有69条查询结果,搜索用时 15 毫秒
21.
Considering that recent european high-speed railway system has a traction power system of $2\times 25$  kV 50 Hz, which causes electromagnetic emission for the outside world, it is important to dimension the railway system emissions, using a frequency/distance dependent propagation model. This paper presents an enhanced theoretical model for VLF to UHF propagation, railway system oriented. It introduces the near field approach (crucial in low frequency propagation) and also considers the source characteristics and type of measuring antenna. Simulations are presented, and comparisons are set with earlier far field models. Using the developed model, a real case study was performed in partnership with Refer Telecom (portuguese telecom operator for railways). The new propagation model was used in order to predict the future high-speed railway electromagnetic emissions in the Lisbon north track. The results show the model’s prediction capabilities and also its applicability to realistic scenarios.  相似文献   
22.
To screen defective dies, IDDQ tests require a reliable estimate of each die's defect-free measurement. The nearest-neighbor residual (NNR) method provides a straightforward, data-driven estimate of test measurements for improved identification of die outliers  相似文献   
23.
This paper presents an economic viability analysis of two investment alternatives for a pig farming located in the city of Jatai, Goias State, Brazil. The first investment alternative consists of the implementation of a biodigester, being the biogas burned in a flare. The second alternative also consists of a biodigester, nevertheless the produced biogas is used to generate electricity. The methodologies to estimate the methane production in anaerobic reactors are presented, as well as those for the quantification of the baseline and project emissions and of the electricity that can be generated. The results showed that the use of biogas for the electricity generation is the alternative more economically viable.  相似文献   
24.
25.
Considering the constrained resources of mobile devices, a thorough performance evaluation of a mobile application is crucial. However, performance evaluation in the mobile domain is still a manual and time‐consuming task. The diversity of mobile devices only increases the complexity of this task. We propose EPE‐Mobile, a framework to automate early performance estimation in mobile applications. It is composed of a configurable library of basic operations and an engine that automatically creates a synthetic program based on the specification of a new app. The synthetic program that EPE‐Mobile generates provides feedback for mobile developers at the first design stages and before the actual implementation of a new application. The fast evaluation can also guide developers in optimizing their applications or in choosing devices with the best trade‐off between cost and performance to run a given application. Finally, developers can reuse the data collection infrastructure of the framework to collect performance data during all development stages. We validate the proposed framework using 4 applications from the Android Play Store. Based on their specifications, 4 synthetic programs were generated and executed on different devices. We compared the results to those obtained from the execution of the actual applications in the same devices. Experimental results show that it is possible to create synthetic applications with similar behavior to that of real applications and, thus, classify devices based on the actual application needs. The framework uses aspect‐oriented programming to collect the metrics of interest. This approach provides increased modularity and separation of concerns, thus facilitating the improvement of the framework itself, by adding other metrics or basic operations.  相似文献   
26.
A detailed hydrodynamic characterization in the transitional flow regime of two variants of the Norstone Polyblade® high‐shear impeller (HSI), of industrial relevance, is presented. The study was carried out on a simulated Newtonian fluid using computational fluid dynamics (CFD). Measurements of power number were carried out to validate the simulation results. Hydrodynamic parameters considered of key importance in powder dispersion processes (i.e., viscous dissipation and effective circulation) were used to assess the impellers' performance. Furthermore, their performances were compared with reported data for two ring‐style HSIs of two and four rings, and power number measurements of a sawtooth (Cowles‐type) impeller.  相似文献   
27.
Previous results have shown that the active surface in stabilized active sulfide catalysts is carbided. This fact led us to reconsider the influence of organosulfide agents in the activation of hydrotreatment catalysts. Structural and morphological consequences of dimethylsulfide treatment of (Co)/MoS2-based solids were studied. Results suggest that the electronic promotion of Mo by Co substantially influences the carbon replacement of sulfur atoms at the edges of molybdenum sulfide layers.  相似文献   
28.
Universal Access in the Information Society - This paper presents the first stage of an investigative work, the purpose of which is to introduce a new form of communication between schools and...  相似文献   
29.
Summary Triphenylphosphine (PPh3), a well-known reagent and catalyst, was successfully grafted onto silica particles in a functionalized polymer form using 4-(diphenylphosphinyl)styrene as a monomer. 4-(Diisopropylphosphinyl)styrene and 4-(ditertbutylphosphinyl)styrene were also grafted onto silica in the form of a functionalized polymer and oligomer, respectively. Two methods were used: A) Copolymerization of phosphine-functionalized monomers with a vinyl compound previously attached to silica; and B) Polymerization of phosphine-functionalized monomers using a radical initiator previously attached to silica. The resulting materials were characterized by FTIR, DTA-TGA, specific surface area (SBET) and XPS. The best results in grafting percent and molecular weight of the grafts were obtained by method B. Received: 7 February 2002 /Revised: 10 July 2002/ Accepted: 10 July 2002  相似文献   
30.
We present the web application ‘cplint on SWI‐Prolog for SHaring that allows the user to write (SWISH)' Probabilistic Logic Programs and submit the computation of the probability of queries with a web browser. The application is based on SWISH, a web framework for Logic Programming. SWISH is based on various features and packages of SWI‐Prolog, in particular, its web server and its Pengine library, that allow to create remote Prolog engines and to pose queries to them. In order to develop the web application, we started from the PITA system, which is included in cplint , a suite of programs for reasoning over Logic Programs with Annotated Disjunctions, by porting PITA to SWI‐Prolog. Moreover, we modified the PITA library so that it can be executed in a multi‐threading environment. Developing ‘cplint on SWISH’ also required modification of the JavaScript SWISH code that creates and queries Pengines. ‘cplint on SWISH’ includes a number of examples that cover a wide range of domains and provide interesting applications of Probabilistic Logic Programming. By providing a web interface to cplint , we allow users to experiment with Probabilistic Logic Programming without the need to install a system, a procedure that is often complex, error prone, and limited mainly to the Linux platform. In this way, we aim to reach out to a wider audience and popularize Probabilistic Logic Programming. Copyright © 2015 John Wiley & Sons, Ltd.  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-23

京公网安备 11010802026262号