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   54篇
  免费   11篇
电工技术   1篇
综合类   2篇
化学工业   5篇
金属工艺   5篇
机械仪表   1篇
能源动力   3篇
轻工业   1篇
无线电   1篇
一般工业技术   3篇
自动化技术   43篇
  2022年   1篇
  2021年   2篇
  2020年   2篇
  2019年   1篇
  2018年   1篇
  2017年   3篇
  2016年   8篇
  2015年   1篇
  2014年   5篇
  2013年   2篇
  2012年   5篇
  2011年   4篇
  2010年   1篇
  2009年   8篇
  2008年   4篇
  2007年   2篇
  2006年   3篇
  2005年   3篇
  2004年   4篇
  2003年   2篇
  2002年   2篇
  1981年   1篇
排序方式: 共有65条查询结果,搜索用时 15 毫秒
41.
The glial cells in the central nervous system express diverse inward rectifying potassium channels (Kir). They express multiple Kir channel subtypes that are likely to have distinct functional roles related to their differences in conductance, and sensitivity to intracellular and extracellular factors. Dysfunction in a major astrocyte potassium channel, Kir4.1, appears as an early pathological event underlying neuronal phenotypes in several neurological diseases. The autoimmune effects on the potassium channel have not yet been fully described in the literature. However, several research groups have reported that the potassium channels are an immune target in patients with various neurological disorders. In 2012, Srivastava et al. reported about Kir4.1, a new immune target for autoantibodies in patients with multiple sclerosis (MS). Follow-up studies have been conducted by several research groups, but no clear conclusion has been reached. Most follow-up studies, including ours, have reported that the prevalence of Kir4.1-seropositive patients with MS was lower than that in the initial study. Therefore, we extensively review studies on the method of antibody testing, seroprevalence of MS, and other neurological diseases in patients with MS. Finally, based on the role of Kir4.1 in MS, we consider whether it could be an immune target in this disease.  相似文献   
42.
晴空大气太阳短波辐射观测与模式比较   总被引:3,自引:0,他引:3  
利用大气物理研究所香河观测站12d晴空条件下地表太阳直接和散射辐射观测资料、太阳光度计观测资料反演获得的气溶胶特性参数和水汽柱含量以及Dobson仪观测的臭氧柱总量资料,运用3个辐射传输模式,对地表太阳直接和散射辐射观测和模拟进行了对比分析。结果表明:直接辐射观测和模拟能较好吻合,但散射辐射的观测和模拟之间的差相对较大,模拟与观测的平均偏差为3%~5%,且80%~90%的模拟值高于观测量。与文献结果不同的是我们的模拟偏高量相对较低,而且有10%~20%的模拟低于观测。提高气溶胶特性以及其他输入参数估计精度将提高散射辐射观测和模拟的吻合程度。  相似文献   
43.
Acquisition, Synthesis, and Rendering of Bidirectional Texture Functions   总被引:1,自引:1,他引:0  
One of the main challenges in computer graphics is still the realistic rendering of complex materials such as fabric or skin. The difficulty arises from the complex meso structure and reflectance behavior defining the unique look‐and‐feel of a material. A wide class of such realistic materials can be described as 2D‐texture under varying light‐ and view direction, namely, the Bidirectional Texture Function (BTF). Since an easy and general method for modeling BTFs is not available, current research concentrates on image‐based methods, which rely on measured BTFs (acquired real‐world data) in combination with appropriate synthesis methods. Recent results have shown that this approach greatly improves the visual quality of rendered surfaces and therefore the quality of applications such as virtual prototyping. This state‐of‐the‐art report (STAR) will present the techniques for the main tasks involved in producing photo‐realistic renderings using measured BTFs in details.  相似文献   
44.
孙维峰 《机电技术》2009,32(1):25-27
阐述了PRO/E模块中的Moldesign的设计理念和功能以及扩展模块EMX4.1的设计流程,以实例讲述了这两个模块在注塑模设计当中的应用,探讨了在现代模具工程设计中,先进设计工具的运用在产品开发中的作用,在企业缩短生产周期及保证产品质量上的优越性、先进性和高效性。  相似文献   
45.
46.
《Displays》1981,2(5):222-223
  相似文献   
47.
In this paper, we present a physical validation of global illumination algorithms based on measurements from a simple experimental setup. The validation methodology emphasizes tractability and error minimization. To this end, we discuss issues such as the acquisition and accurate simulation of material bidirectional reflection distribution functions (BRDFs) and the light source distribution, as well as error analysis. In addition, we present a nearest‐neighbor resampling technique for BRDFs and a simple method for extracting the light source distribution from digitized high dynamic range (HDR) images. Finally, we compare the measurements to a forward and backward raytracing solution (photon map and RADIANCE, respectively) in a set of case studies.  相似文献   
48.
This paper presents methods for photo‐realistic rendering using strongly spatially variant illumination captured from real scenes. The illumination is captured along arbitrary paths in space using a high dynamic range, HDR, video camera system with position tracking. Light samples are rearranged into 4‐D incident light fields (ILF) suitable for direct use as illumination in renderings. Analysis of the captured data allows for estimation of the shape, position and spatial and angular properties of light sources in the scene. The estimated light sources can be extracted from the large 4D data set and handled separately to render scenes more efficiently and with higher quality. The ILF lighting can also be edited for detailed artistic control.  相似文献   
49.
This work concerns a novel study in the field of image‐to‐geometry registration. Our approach takes inspiration from medical imaging, in particular from multi‐modal image registration. Most of the algorithms developed in this domain, where the images to register come from different sensors (CT, X‐ray, PET), are based on Mutual Information, a statistical measure of non‐linear correlation between two data sources. The main idea is to use mutual information as a similarity measure between the image to be registered and renderings of the model geometry, in order to drive the registration in an iterative optimization framework. We demonstrate that some illumination‐related geometric properties, such as surface normals, ambient occlusion and reflection directions can be used for this purpose. After a comprehensive analysis of such properties we propose a way to combine these sources of information in order to improve the performance of our automatic registration algorithm. The proposed approach can robustly cover a wide range of real cases and can be easily extended.  相似文献   
50.
The accurate measurement of the light transport characteristics of a complex scene is an important goal in computer graphics and has applications in relighting and dual photography. However, since the light transport data sets are typically very large, much of the previous research has focused on adaptive algorithms that capture them efficiently. In this work, we propose a novel, non-adaptive algorithm that takes advantage of the compressibility of the light transport signal in a transform domain to capture it with less acquisitions than with standard approaches. To do this, we leverage recent work in the area of compressed sensing, where a signal is reconstructed from a few samples assuming that it is sparse in a transform domain. We demonstrate our approach by performing dual photography and relighting by using a much smaller number of acquisitions than would normally be needed. Because our algorithm is not adaptive, it is also simpler to implement than many of the current approaches.  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