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   172篇
  免费   9篇
电工技术   1篇
化学工业   54篇
金属工艺   6篇
机械仪表   5篇
建筑科学   2篇
能源动力   4篇
轻工业   8篇
石油天然气   2篇
无线电   20篇
一般工业技术   28篇
冶金工业   23篇
自动化技术   28篇
  2024年   2篇
  2023年   3篇
  2022年   5篇
  2021年   5篇
  2020年   4篇
  2019年   4篇
  2018年   5篇
  2017年   6篇
  2016年   5篇
  2015年   4篇
  2014年   5篇
  2013年   11篇
  2012年   6篇
  2011年   6篇
  2010年   11篇
  2009年   10篇
  2008年   11篇
  2007年   7篇
  2006年   8篇
  2005年   6篇
  2004年   6篇
  2003年   3篇
  2002年   2篇
  2001年   4篇
  2000年   2篇
  1999年   3篇
  1998年   12篇
  1997年   5篇
  1996年   2篇
  1995年   2篇
  1993年   2篇
  1992年   2篇
  1991年   1篇
  1990年   2篇
  1988年   1篇
  1986年   1篇
  1982年   2篇
  1981年   1篇
  1975年   3篇
  1973年   1篇
排序方式: 共有181条查询结果,搜索用时 15 毫秒
81.
Aqueous electrodeposition may represent a more economical and reliable technique to fabricate Mo coatings than the alternatives (electrodeposition from fused-salt baths and other available methods). However, studies on the aqueous electrodeposition of pure metallic Mo are rather limited due to its oxophilic nature, catalytic behaviour for the hydrogen evolution reaction and high tendency for polymerisation, especially in acidic media. To date, researchers have tended to focus on the aqueous electrodeposition of Mo alloys. These alloys usually contain <51% Mo. The factors that influence the quality of Mo deposits and the difficulties in the electrodeposition process are reviewed here. This review not only presents a survey of existing literature on the electrodeposition of metallic Mo coatings but also provides a basis for any future exploration.  相似文献   
82.
This article presents a practical and effective method to analyze the steady state regimes, periodic or quasi-periodic, and the stability of free and forced oscillators, based on the use of voltage and current probes. The efficiency of this method comes from the fact that it converts the analysis of an autonomous circuit into the analysis of a series of closely related nonautonomous circuits, which in turn relies on the power of the harmonic balance equation for these kinds of systems. The effectiveness of the method is shown by full analysis of a practical example.  相似文献   
83.
84.
85.
This paper is about control design for timed continuous Petri nets that are described as piecewise affine systems. In this context, the marking vector is considered as the state space vector, weighted marking of place subsets are defined as the model outputs and the model inputs correspond to multiplicative control actions that slow down the firing rate of some controllable transitions. Structural and functional sensitivity of the outputs with respect to the inputs are discussed in terms of Petri nets. Then, gradient-based controllers (GBC) are developed in order to adapt the control actions of the controllable transitions according to desired trajectories of the outputs.  相似文献   
86.
In this paper, the performances of four improved analytical methods (backward stepwise selection of peak intensities, sum of characteristic peaks of a component, moving window partial least squares, and genetic algorithms) using wavelength selection for the analysis of xylene mixtures by Raman spectroscopy are tested for further use on the new "digital micromirror device associated with a photomultiplier tube" Raman spectrometer. It is shown that the errors of prediction using only a few selected points (from 4 to 49 depending on the method) are almost the same as when using the whole spectral range (1050 points). Compared to the last two methods, the "backward stepwise selection of peak intensities" and "sum of characteristic peaks of a component" methods are robust under industrial conditions and appear to be well suited for chemical quantitative analysis with the new Raman spectrometer, which allows the measurements of the total intensity to be made simultaneously for a number of pre-selected frequencies. Results show that the errors of prediction can be near to or even lower than 2%.  相似文献   
87.
This paper concerns Remaining Useful Life (RUL) estimation of discrete event systems. For that purpose, physics-based models with partially observed stochastic Petri nets are used to represent the system and its sensors. The advantage of the proposed modelling approach is to provide a realistic representation of the system, including the interaction between the normal behaviours and the failure processes. From the proposed modelling and collected measurements, timed trajectories, which are consistent with the observations, are obtained. Based on the event dates, our approach consists in evaluating the probabilities of the consistent behaviours using probabilistic models. State estimation is obtained as a consequence. The most probable future degradations, from the current state, are then considered and a method for fault prognosis is presented. Finally, the prognosis result is used to estimate the RUL as a time interval. A case study is proposed to show the applicability of the proposed method.  相似文献   
88.
A new solid solution system, Pb(Mg(1–x/2)Mn(x/2)W1/2)O3, is formed by replacing Mg2+ with Mn2+ in the Pb(Mg1/2W1/2)O3 complex perovskite. The solid solution remains in the orthorhombic Pmcn symmetry up to x = 0.1. It is observed that for such a chemical modification, the surface of the grain changes significantly. A stepped surface nanostructure appears in the Mn‐substituted perovskite. Detailed surface morphology of the stepped patterns was revealed by atomic force microscopy (AFM), which determined that the interlayer step height varies from 2.3 to 8.3 nm. Analyse by XRD, SEM, EDX, and AFM suggest that the nature of the stepped surface structure may be the result of etching rather than spiral growth or two‐dimensional nucleation as it was previously believed.  相似文献   
89.
Software and Systems Modeling - Software modeling activities typically involve a tedious and time-consuming effort by specially trained personnel. This lack of automation hampers the adoption of...  相似文献   
90.
Liver cancer is a major global health problem being the sixth most common cancer and the third cause of cancer‐related death, with hepatocellular carcinoma (HCC) representing more than 90% of primary liver cancers. Mounting evidence suggests that, compared with their normal counterparts, many types of cancer cell have increased levels of ROS. Therefore, cancer cells need to combat high levels of ROS, especially at early stages of tumor development. Recent studies have revealed that ROS‐mediated regulation of redox‐sensitive proteins (redox sensors) is involved in the pathogenesis and/or progression of many human diseases, including cancer. Unraveling the altered functions of redox sensors and the underlying mechanisms in hepatocarcinogenesis is critical for the development of novel cancer therapeutics. For this reason, redox proteomics has been developed for the high‐throughput screening of redox sensors, which will benefit the development of novel therapeutic strategies for the treatment of HCC. In this review, we will briefly introduce several novel redox proteomics techniques that are currently available to study various oxidative modifications in hepatocarcinogenesis and summarize the most important discoveries in the study of redox processes related to the development and progression of HCC.  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