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   108篇
  免费   6篇
电工技术   8篇
化学工业   31篇
金属工艺   1篇
机械仪表   1篇
建筑科学   2篇
能源动力   3篇
轻工业   13篇
石油天然气   1篇
一般工业技术   31篇
冶金工业   13篇
原子能技术   1篇
自动化技术   9篇
  2022年   4篇
  2021年   5篇
  2020年   3篇
  2019年   4篇
  2018年   4篇
  2017年   4篇
  2016年   3篇
  2015年   4篇
  2014年   3篇
  2013年   11篇
  2012年   8篇
  2011年   8篇
  2010年   5篇
  2009年   3篇
  2008年   6篇
  2007年   5篇
  2006年   3篇
  2005年   3篇
  2004年   1篇
  2003年   3篇
  2002年   3篇
  1999年   1篇
  1998年   5篇
  1997年   5篇
  1995年   3篇
  1994年   1篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
  1985年   1篇
  1975年   1篇
排序方式: 共有114条查询结果,搜索用时 15 毫秒
81.
Some prior reports have suggested that guided tissue regeneration (GTR) procedures achieve only partial regeneration and induces the ankylosis rather than true attachment. Accordingly, others have developed an alternative procedure employing gelatine membrane compounded with bovine cementum particles (CGM) which has proven effective in stimulating a more physiologic form of attachment. This study was undertaken to perform a direct comparison of histological results when CGM and GTR membrane were used at comparable sites in the same monkey. Three monkeys with no periodontal disease were used. Following flap surgery, recession type defects were created on the buccal side of the maxillary lateral incisors and second premolars, and the cementum was removed from the root surface at an area corresponding to the bone crest. The right and left lateral incisors and second premolars were covered with CGM and GTR membrane, respectively. The GTR membranes were removed after 4 weeks. At 6 wks, the animals were sacrificed, and specimens were prepared for histological examination. More coronally placed true new attachment was observed following application of CGM to the planed root surfaces. Application of the GTR membrane resulted in formation of bone-like cementum and ankylosis, whereas CGM established true periodontal regeneration.  相似文献   
82.
We evaluated the microbiological safety of bottled mineral water products commercially available in Japan. Of 10 bottled mineral water products manufactured in Japan, no bacteria or fungi were detected in 9 (90%), but 1 (10%) contained 1.8x10(3) colony-forming units (cfu)/mL. Of 12 bottled mineral water products manufactured in the EU, 11 (91.7%) contained 23-3.5x10(4) cfu/mL. On the other hand, of 5 bottled mineral water products manufactured in North America, 2 (40%) contained 2.3x10(2)-2.5x10(3) cfu/mL. The detected microorganisms were glucose-nonfermentative Gram-negative bacilli such as Brevundimonas vesicularis, Moraxella spp., and Burkholderia cepacia, but Pseudomonas aeruginosa was not detected in any product. For immunocompromised host patients being managed in ultra-clean rooms, the examined bottled mineral water products manufactured in Japan, except 1, were microbiologically safe.  相似文献   
83.
An efficient boundary element method to calculate crack weight functions is developed. The weight function method is applied to bridging effect analysis in a single-edge notched composite specimen by using a bridging law which includes both interfacial debonding and sliding properties between fiber and matrix in ceramic matrix composites. A numerical method to solve the distributed spring model treating bridging fibers as stress distribution to close the crack surface is provided to determine the bridging stress, debond length, crack opening displacement and stress intensity factor.  相似文献   
84.
Fracture mechanics can be regarded as a methodology to characterize the actual crack by using the parameters given by the analysis of a simple mathematical crack model. Therefore, the selection of these crack models has very significant meanings. In recent years, several precise crack models have been proposed.In this paper, we paid attention to the influences of the two-dimensional crack geometry and presented the numerical value of the elastic analytical solutions for the non-linear shaped cracks, those are, the bent, the curved and the branched crack. On the basis of these results, the characteristics of these cracks were discussed and the methods of approximate replacement to a simple straight crack were proposed.We examined a zig-zag growth of crack and the crack branching observed in actual fracture processes.  相似文献   
85.
To prevent infectious diseases induced by the adhesion of microorganisms and their metabolic products to dental implants, saliva protein adsorption, which induces the plaque deposition to the intraoral substrates should be inhibited. We used a water-soluble 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer to modify the surface of hydroxyapatite (HAp) substrate, the main component of dental implant surface. The MPC polymer containing a catechol group at the terminal of polymer chain and amino groups in the side chain was synthesized by mimicking the mussel adhesive protein. The MPC polymer containing 2% of the primary amino groups showed effective adhesion to the HAp substrate. Mucin, the dental plaque protein, adsorbs on the HAp surface; however, the MPC polymer modification could reduce this adsorption amount by more than 98% compared to the original HAp substrate surface. Thus, the treatment of the MPC polymer has potential to reduce oral infection due to plaque deposition.  相似文献   
86.
Abstract— To estimate the qualified viewing spaces for two‐ and multi‐view autostereoscopic displays, the relationship between image quality (image comfort, annoying ghost image, depth perception) and various pairings between 3‐D cross‐talk in the left and right views are studied subjectively using a two‐view autostereoscopic display and test charts for the left and right views with ghost images due to artificial 3‐D cross‐talk. The artificial 3‐D cross‐talk was tuned to simulate the view in the intermediate zone of the viewing spaces. It was shown that the stereoscopic images on a two‐view autostereoscopic display cause discomfort when they are observed by the eye in the intermediate zone between the viewing spaces. This is because the ghost image due to large 3‐D cross‐talk in the intermediate zone elicits different depth perception from the depth induced by the original images for the left and right views, so the observer's depth perception is confused. Image comfort is also shown to be better for multi‐views, especially the width of the viewing space, which is narrower than the interpupillary distance, where the parallax of the cross‐talking image is small.  相似文献   
87.
We evaluate laser-pumped magnetic-field-modulation (LP-MFM), continuous laser-irradiated magnetic-field-modulation, andlight-intensity-modulation recording in magneto-optical disks, usingtemperature calculations and experiments. LP-MFM is useful forrecording short marks: One can record magnetic domains as small as 0.15-mum marks with LP-MFM by using a spin-polarized scanningelectron microscope. LP-MFM is also useful for reducing the trackpitch. Experiments showed that no cross write occurred at a 0.6-mum track pitch, and calculation showed that the heatdistribution is narrow. We confirmed the advantages of LP-MFM forrecording magnetically induced superresolution disks by investigatingthe difference in the shapes of the recorded domains.  相似文献   
88.
An evanescent-field-coupled waveguide-mode sensor with a multilayer structure consisting of a dielectric waveguide, a thin reflecting layer, and a glass substrate illuminated under the Kretschmann configuration operates as a sensor that is capable of detecting modifications in the dielectric environment near the waveguide surface with superior sensitivity by measuring the change in reflectivity. The sensitivity of the sensor is strongly dependent on the optical constants of the reflecting layer. Numerical simulations show that a sensor having a reflecting layer with a small value of the real part of the complex refractive index shows a good sensitivity for both S-?and P-polarized light. Materials with values of the real and imaginary parts of the complex refractive index of >4 and ~0.5, respectively, are suitable for use as reflecting layers when S-polarized light excites only the lowest order waveguide mode. The simulations were experimentally confirmed using sensors with Au, Cu, Cr, W, a-Si, or Ge reflecting layers deposited by radiofrequency magnetron sputtering by observation of specific adsorption of streptavidin on biotinyl groups using an S-polarized laser beam with a wavelength of 632.8?nm. From the results, guidelines are given for the fabrication of preferred sensor configurations.  相似文献   
89.
Metallurgical and Materials Transactions B - The optimal conditions for preparing composites, in which tar-derived carbonaceous materials completely fill the pores in Indonesian limonite(IL), were...  相似文献   
90.
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