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   553篇
  免费   8篇
  国内免费   1篇
电工技术   1篇
化学工业   107篇
金属工艺   19篇
机械仪表   10篇
建筑科学   15篇
能源动力   21篇
轻工业   20篇
水利工程   2篇
无线电   67篇
一般工业技术   104篇
冶金工业   97篇
原子能技术   11篇
自动化技术   88篇
  2023年   2篇
  2022年   2篇
  2021年   17篇
  2020年   4篇
  2019年   6篇
  2018年   2篇
  2017年   9篇
  2016年   14篇
  2015年   5篇
  2014年   11篇
  2013年   23篇
  2012年   20篇
  2011年   45篇
  2010年   25篇
  2009年   30篇
  2008年   32篇
  2007年   20篇
  2006年   23篇
  2005年   13篇
  2004年   10篇
  2003年   15篇
  2002年   9篇
  2001年   6篇
  2000年   4篇
  1999年   5篇
  1998年   40篇
  1997年   30篇
  1996年   12篇
  1995年   12篇
  1994年   8篇
  1993年   12篇
  1992年   6篇
  1991年   11篇
  1990年   4篇
  1989年   6篇
  1987年   6篇
  1986年   3篇
  1985年   7篇
  1984年   3篇
  1983年   5篇
  1982年   8篇
  1981年   3篇
  1980年   4篇
  1979年   7篇
  1977年   3篇
  1976年   7篇
  1970年   4篇
  1967年   1篇
  1963年   2篇
  1960年   1篇
排序方式: 共有562条查询结果,搜索用时 15 毫秒
1.
The respective contributions of taste (saltiness and sweetness) and texture (the hardness dimension) to sensory-specific satiety (SSS) were compared. Sixteen male and 16 female, young, normal-weight adults rated the pleasantness of taste, pleasantness of texture and desire to eat on visual analog scales for eight test foods, were then given one of the foods to eat ad libitum for lunch, and re-rated the same parameters for the eight foods 2 and 20 min after the end of the meal. The experimental sets of eight test foods and four lunch foods were balanced for taste quality (salty vs. sweet) and texture quality (hard vs. soft). Lunch foods were the hard and soft versions of a salty food (ham and cheese sandwich on baguette vs. white bread) or of a sweet food (apples vs. applesauce). Sensory-specific satiety was observed for both saltiness and sweetness (e.g. pleasantness of the taste of, and desire to eat sweet test foods decreased significantly after eating a sweet lunch food and similarly for salty foods), and to a lesser extent for texture (e.g. pleasantness of the texture of, and desire to eat hard test foods decreased after eating a hard lunch food and similarly for one of the soft foods). The authors conclude texture-specific satiety may be a significant component of satiety.  相似文献   
2.
Bioactive glasses are used as coating biomaterials to facilitate anchorage of metallic prostheses implanted into the body. The aim of this work is to study the behavior of gel formed in contact with alloys and BVA and BVH bioactive glasses implanted. Cylinders of metallic implants composed by Ti, Al and V, are coated with bioactive glass. Three sheep were implanted for different time length: 3, 6 and 12 months in the femoral epiphysis. Results obtained with particle induced X-ray emission and scanning electron microscopy show that BVA coating induces a better contact between the metallic implant and bone. On the other hand, BVH coating prevents corrosion from the metallic implant.  相似文献   
3.
Fourier-transform-limited pulses ( Delta tau . Delta nu approximately=0.35) have been obtained from a microwave-modulated DBR laser at 1.56 mu m. The chirp of the gain-switched pulse is compensated for by applying a fraction of the microwave signal to the phase section, thereby creating an instantaneous frequency shift of opposite sign. The generation of short coherent pulses from such a monolithic source can be of great interest for long haul soliton transmission.<>  相似文献   
4.
The variability of optical frequency modulation with electric field in an electro-optical phase section is analysed. When configured for maximum sensitivity, the electro-optical phase section was used to compensate for the chirp of the gain section: 48 ps and 8.5 GHz wide transform-limited pulses were obtained at 5 GHz  相似文献   
5.
6.
7.

Announcements

Preliminary course programme international centre for mechanical Sciences  相似文献   
8.
In this work a new optical technology, ASII, is presented, for the study of film formation from all kinds of dispersed systems, such as latexes, emulsions or solvent-borne suspensions. Various film-forming products have been investigated, including water-borne coatings, on various types of substrates. A wide range of information can be extracted such as objective drying times (dust-free, dry-hard times, etc) or mechanism taking place, thereby offering new possibilities to analyse film formation from complex colloidal systems.  相似文献   
9.
A hierarchical structure of thermally stable macroporous zirconium phosphate solid acids with supermicroporous walls was prepared by a simple self-assembly process from the precursors of zirconium propoxide and orthophosphoric acid solution. The macroporous structures are uniform with the diameters ranging from 300 to 800 nm, one-dimensional channel-like. The effect of surfactant Brij 56 on the formation of macroporous structures has been studied. The frameworks of the synthesized hierarchical zirconium phosphates are amorphous with Zr–O–P bonding, exhibiting remarkably high thermal stability (at least 800 °C), on the basis of the X-ray diffraction (XRD), N2 adsorption, X-ray photoelectron spectroscopy (XPS) analysis, Fourier transform infrared (FT-IR) and 31P nuclear magnetic resonance (NMR) spectra. Larger quantities of Zr–OH and P–OH groups are observed besides surface hydroxyl groups, suggesting the presence of acidity and the possibility of surface functionalization for practical applications including catalysis. The macroporous zirconium phosphates with hierarchical structures could also be the potential and efficient catalyst supports for the design of the structured catalysts and reactors.  相似文献   
10.
There is a rich variety of physics underlying the fundamental gating operations for quantum information processing (QIP). A key aspect of a QIP system is how noise may enter during quantum operations and how suppressing or correcting its effects can best be addressed. Quantum control techniques have been developed to specifically address this effort, although a detailed classification of the compatibility of controls schemes with noise sources found in common quantum systems has not yet been performed. This work numerically examines the performance of modern control methods for suppressing decoherence in the presence of noise forms found in viable quantum systems. The noise-averaged process matrix for controlled one-qubit and two-qubit operations are calculated across noise found in systems driven by Markovian open quantum dynamics. Rather than aiming to describe the absolute best control scheme for a given physical circumstance, this work serves instead to classify quantum control behavior across a large class of noise forms so that opportunities for improving QIP performance may be identified.  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