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   185篇
  免费   16篇
  国内免费   1篇
电工技术   1篇
化学工业   81篇
金属工艺   2篇
机械仪表   3篇
建筑科学   3篇
能源动力   3篇
轻工业   54篇
石油天然气   1篇
无线电   6篇
一般工业技术   23篇
冶金工业   14篇
自动化技术   11篇
  2023年   3篇
  2022年   13篇
  2021年   13篇
  2020年   8篇
  2019年   11篇
  2018年   11篇
  2017年   9篇
  2016年   6篇
  2015年   8篇
  2014年   11篇
  2013年   16篇
  2012年   13篇
  2011年   19篇
  2010年   9篇
  2009年   8篇
  2008年   10篇
  2007年   5篇
  2006年   4篇
  2005年   6篇
  2004年   2篇
  2003年   1篇
  2002年   2篇
  2000年   1篇
  1999年   2篇
  1998年   1篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1992年   2篇
  1990年   1篇
  1988年   1篇
  1986年   1篇
  1985年   2篇
排序方式: 共有202条查询结果,搜索用时 0 毫秒
81.
82.
Music visualizations are nowadays included with virtually any media player. They usually rely on harmonic analysis of each sound channel, which automatically generate parameters for procedural image generation. However, only few music visualizations make use of 3d shapes. This paper proposes to use spectral mesh processing techniques, here manifold harmonics, to produce 3d stereo music visualization. The images are generated from 3d models by deforming an initial shape, mapping the sound frequencies to the mesh harmonics. A symmetry criterion is introduced to enhance the stereo effects on the deformed shape. A concise representation of the frequency mapping is proposed to allow for an animated gallery interface with genetic reproduction. Such galleries let the user quickly navigate between visual effects. Rendering such animated galleries in real time is a challenging task, since it requires computing and rendering the deformed shapes at a very high rate. This paper introduces a direct GPU implementation of manifold harmonics filters, which allows the displaying of the animated galleries.  相似文献   
83.
Vaccine efficacy (VE) is commonly estimated through proportional hazards modelling of the time to first infection or disease, even when the event of interest can recur. These methods can result in biased estimates when VE is heterogeneous across levels of exposure and susceptibility in subjects. These two factors are important sources of unmeasured heterogeneity, since they vary within and across areas, and often cannot be individually quantified. We propose an estimator of VE per exposure that accounts for heterogeneous susceptibility and exposure for a repeated measures study with binary recurrent outcomes. The estimator requires only information about the probability distribution of environmental exposures. Through simulation studies, we compare the properties of this estimator with proportional hazards estimation under the heterogeneity of exposure. The methods are applied to a reanalysis of a malaria vaccine trial in Brazil.  相似文献   
84.
85.
86.
In this study, we focus on membranes of polyethersulfone and poly(N‐vinyl pyrrolidone) and elucidate the influence of composition on the rheological, diffusion and precipitation properties of solutions which are used for membrane preparation via a non‐solvent‐induced phase separation process. The low‐molar‐mass component of the solution is a mixture of the solvent N‐methyl‐2‐pyrrolidone and the non‐solvent glycerol. Cloud point, viscosity and diffusion measurements as well as precipitation experiments were performed in order to achieve a comprehensive understanding of the time dependence of the precipitation process. The addition of glycerol yields an increase of viscosity and a stronger tendency for demixing. The enhanced tendency for demixing causes a more rapid precipitation process. The average relaxation time of the solution as a function of glycerol concentration follows a similar trend to its viscosity. The increase of viscosity is associated with the increase of the monomeric friction coefficient. Two diffusive processes with clearly separated time scales appear in dynamic light scattering experiments in the presence of glycerol. This phenomenon is discussed taking into account the phase behaviour of the solution and the quality of the solvent. The addition of glycerol yields a lower pure water permeance whereas the molecular weight cut‐off is not altered in the ultrafiltration range. © 2020 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.  相似文献   
87.
Xanthohumol (XN) is a prenylated chalcone, which has been shown to possess a broad range of potential cancer preventive and additional biological activities. In the present study, we have determined the subchronic 4-wk toxicity of XN and monitored its influence on fertility and development of offspring in two fertility studies. Four-week-old female Sprague Dawley (SD) rats were treated with 0.5% XN in the diet or with 1,000 mg XN/kg body weight (b.w.) per day by gavage for 28 days. No remarkable treatment-related changes in general appearance and b.w. occurred during the study. After autopsy, liver, kidney, lung, heart, stomach, and spleen were examined macroscopically and histopathologically. Relative liver weights of animals in both treatment groups were significantly reduced by 30--40% in comparison with the control group, indicating weak hepatotoxicity. Also, mammary glands of treated rats appeared less developed compared to the controls. Consequently, we investigated the influence of XN on rat reproduction. In two fertility studies, XN (100 mg/kg b.w. per day), given either for 4 wk prior to or during mating, gestation, and nursing, did not cause any adverse effects on female reproduction and the development of offspring. Noteworthy, treatment of male rats prior to mating significantly (p=0.027) increased the sex ratio of male to female offspring. Overall, lifelong treatment at a daily dose of 100 mg/kg b.w. in a two-generation study did not affect the development of SD rats.  相似文献   
88.
Journal of Failure Analysis and Prevention - Additive manufacturing platforms that rely on thermoplastic feedstock materials are now expected to fabricate components intended for deployment in a...  相似文献   
89.
Network management has steadily evolved over recent years. Along with the growing need for advanced features in network management solutions, several distribution models were investigated, varying from centralized to fully distributed models. Despite the common agreement that some sort of distribution is really needed to execute management tasks, there seems to exist a permanent quest for the next distributed network management model. Among the distributed models, an interesting and emerging possibility is the use of P2P technology in network management, also known as P2P-Based Network Management (P2PBNM). Several investigations have shown that P2PBNM can be seen as an enabler for advanced network management features. However, due to the dispersion concerning the concepts and features related to these investigations, it is difficult to draw a comprehensive picture of the P2PBNM area. The purpose of this article is to look at literature on P2PBNM and to highlight initiatives regarding the use of P2P technology in network management. Furthermore, such initiatives are classified in respect to proposed review questions. Finally, future trends are discussed in order to predict what the future holds for P2PBNM.  相似文献   
90.
Dual layer hollow fiber membranes, based on poly(ether sulfone), were fabricated to achieve hydrophilic membranes with improved fouling resistance. A new triblock copolymer, consisting of two hydrophilic poly(ethylene oxide) blocks and an inner poly(ether sulfone) block, was chosen for the functionalization of the inner layer. The most promising membrane of this study was characterized by an improved hydrophilicity, and a performance in the ultrafiltration studies of 2000 L m−2h−1bar−1 and retention of 100 kDa.  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