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   624篇
  免费   33篇
  国内免费   8篇
电工技术   62篇
综合类   33篇
化学工业   116篇
金属工艺   7篇
机械仪表   44篇
建筑科学   13篇
矿业工程   11篇
能源动力   9篇
轻工业   31篇
水利工程   6篇
石油天然气   33篇
武器工业   3篇
无线电   106篇
一般工业技术   20篇
冶金工业   27篇
原子能技术   9篇
自动化技术   135篇
  2023年   4篇
  2022年   20篇
  2021年   25篇
  2020年   9篇
  2019年   8篇
  2018年   11篇
  2017年   6篇
  2016年   9篇
  2015年   28篇
  2014年   26篇
  2013年   25篇
  2012年   45篇
  2011年   61篇
  2010年   46篇
  2009年   56篇
  2008年   57篇
  2007年   48篇
  2006年   40篇
  2005年   29篇
  2004年   25篇
  2003年   21篇
  2002年   17篇
  2001年   10篇
  2000年   18篇
  1999年   6篇
  1998年   8篇
  1997年   3篇
  1994年   1篇
  1985年   1篇
  1981年   1篇
  1973年   1篇
排序方式: 共有665条查询结果,搜索用时 10 毫秒
1.
Innumerable casualties due to intrauterine hypoxia are a major worry during prenatal phase besides advanced patient monitoring with latest science and technology. Hence, the analysis of foetal electrocardiogram (fECG) signals is very vital in order to evaluate the foetal heart status for timely recognition of cardiac abnormalities. Regrettably, the latest technology in the cutting edge field of biomedical signal processing does not seem to yield the desired quality of fECG signals required by physicians, which is the major cause for the pathetic condition. The focus of this work is to extort non-invasive fECG signal with highest possible quality with a motive to support physicians in utilizing the methodology for the latest intrapartum monitoring technique called STAN (ST analysis) for forecasting intrapartum foetal hypoxia. However, the critical quandary is that the non-invasive fECG signals recorded from the maternal abdomen are affected by several interferences like power line interference, baseline drift interference, electrode motion interference, muscle movement interference and the maternal electrocardiogram (mECG) being the dominant interference. A novel hybrid methodology called BANFIS (Bayesian adaptive neuro fuzzy inference system) is proposed. The BANFIS includes a Bayesian filter and an adaptive neuro fuzzy filter for mECG elimination and non-linear artefacts removal to yield high quality fECG signal. Kalman filtering frame work has been utilized to estimate the nonlinear transformed mECG component in the abdominal electrocardiogram (aECG). The adaptive neuro fuzzy filter is employed to discover the nonlinearity of the nonlinear transformed version of mECG and to align the estimated mECG signal with the maternal component in the aECG signal for annulment. The outcomes of the investigation by the proposed BANFIS system proved valuable for STAN system for efficient prediction of foetal hypoxia.  相似文献   
2.
In this work, we focus on the Ge nanoparticles (Ge-np) embedded ZnO multilayered thin films. Effects of reactive and nonreactive growth of ZnO layers on the rapid thermal annealing (RTA) induced formation of Ge-np have been specifically investigated. The samples were deposited by sequential r.f. and d.c. sputtering of ZnO and Ge thin film layers, respectively on Si substrates. As-prepared thin film samples have been exposed to an ex-situ RTA at 600 °C for 60 s under forming gas atmosphere. Structural characterizations have been performed by X-ray Diffraction (XRD), Raman scattering, Secondary Ion Mass Spectroscopy (SIMS), and Scanning Electron Microscopy (SEM) techniques. It has been realized that reactive or nonreactive growth of ZnO layers significantly influences the morphology of the ZnO: Ge samples, most prominently the crystal structure of Ge-np. XRD and Raman analysis have revealed that while reactive growth results in a mixture of diamond cubic (DC) and simple tetragonal (ST12) Ge-np, nonreactive growth leads to the formation of only DC Ge-np upon RTA process. Formation of ST12 Ge-np has been discussed based on structural differences due to reactive and nonreactive growth of ZnO embedding layer.  相似文献   
3.
经济利润率是评价一个实际热力装置的主要指标之一。将有限时间热力学,非平衡量子统计理论和yong经济学相结合,导出了量子斯特林制冷机的最大利润率以及对应的性能界限,其结果与实际斯特林制冷机的优化设计和模型评估提供了一个最佳的预选方案。  相似文献   
4.
Problems arising with connecting the second exhaust-heat boiler to the first exhaust-heat boiler under load in the case of flow circuits of combined-cycle plants of type PGU-450 are considered. Similar problems exist for two-boiler single-turbine units of type PGU-325 and for two-boiler single-turbine units of traditional steampower plants with an output of 200–300 MW upon connection of the second furnace of a two-furnace boiler to the operating first furnace. Analysis of the temperature-induced stressed state and of the cyclic strength of thick-walled elements of the steam-water conduit of PGU-450 and of two-furnace boilers of two-boiler single-turbine units with an output of 200–300 MW (the check valve, the inlet header of the water economizer) is used for determining the steam temperature differences in the high-pressure conduits to the steam turbine and the order of connection of the second exhaust-heat boiler to the operating fist one. Modes of enabling a two-boiler single-turbine unit of a combined-cycle plant, which are most “rigid” from the standpoint of thermal strength, are determined. __________ Translated from élektricheskie Stantsii, No. 2, February 2006, pp. 11–17.  相似文献   
5.
针对TPS/TDC30 0 0系统串口通讯方式、机理进行了一般性的介绍 ,对规划与应用中常见的的问题 ,根据实际工程应用经验提出了解决方案。  相似文献   
6.
介绍了电化厂聚合技改后的聚合釜温度控制方案,CS3000DCS在控制中的应用。实现了从进料、升温、恒温、直至反应结束的全过程自动控制,在操作站实现了动态工程流程图、控制分组、历史趋势等显示功能,可变参数在权限范围内的下载及报表打印等功能。  相似文献   
7.
A simple, rapid and sensitive procedure for the simultaneous determination of total cholesterol, tocopherols and β-carotene in meat is described. The method involves a direct saponification of the meat, a single n-hexane extraction and the analysis of the extracted compounds by normal-phase HPLC, using fluorescence (tocopherols) and UV–Vis photodiode array (cholesterol and β-carotene) detections in tandem. Rates of recovery of spiked meat samples were 93% for cholesterol, 83–86% for (α-, β- and -γ) tocopherols and 89% for β-carotene. Repeatabilities were high (CV < 6%) for all determined compounds, except for δ-tocopherol. This tocopherol, which is not usually present in meat, showed a much lower recovery percentage (73%) and repeatability (12.8%). This methodology was applied for the quantification of total cholesterol, tocopherols and β-carotene in three muscles (longissimus thoracis, longissimus lumborum and semitendinosus) of the Portuguese traditional Barrosã-PDO veal, obtained from autochthonous calves fed extensively during summer (with the least abundant green pastures) and slaughtered in early autumn (October). Barrosã-PDO veal showed median contents of total cholesterol (0.50–0.56 mg/g) and, depending on the analysed muscle, moderate to high contents of α-tocopherol (3.3–3.9 μg/g) and β-carotene (0.07–0.09 μg/g), suggesting an high sensorial and hygienic quality.  相似文献   
8.
论述了均流仪在整流机组均流管理中的功效.  相似文献   
9.
介绍了在单质起爆药生产中SCAN3000系统的基本构成、系统功能以及系统的冗余设计。通过对控制图和梯形逻辑图的组态,实现了控制方案。  相似文献   
10.
介绍了横河公司的分布式控制系统CS3000在离子膜烧碱生产过程中的应用。阐述了系统的工艺流程、硬件配置、软件配置和控制系统的主要功能。  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