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   260篇
  免费   11篇
电工技术   2篇
化学工业   48篇
金属工艺   1篇
机械仪表   2篇
建筑科学   5篇
能源动力   2篇
轻工业   15篇
无线电   50篇
一般工业技术   55篇
冶金工业   31篇
原子能技术   1篇
自动化技术   59篇
  2022年   3篇
  2021年   4篇
  2020年   2篇
  2019年   5篇
  2018年   5篇
  2017年   2篇
  2016年   7篇
  2015年   3篇
  2014年   9篇
  2013年   16篇
  2012年   14篇
  2011年   23篇
  2010年   22篇
  2009年   11篇
  2008年   17篇
  2007年   16篇
  2006年   12篇
  2005年   6篇
  2004年   12篇
  2003年   6篇
  2002年   6篇
  2001年   8篇
  2000年   4篇
  1999年   4篇
  1998年   6篇
  1997年   8篇
  1996年   7篇
  1995年   1篇
  1994年   4篇
  1993年   3篇
  1992年   6篇
  1991年   2篇
  1990年   3篇
  1989年   2篇
  1988年   1篇
  1987年   1篇
  1983年   1篇
  1982年   3篇
  1980年   1篇
  1978年   1篇
  1976年   2篇
  1975年   1篇
  1963年   1篇
排序方式: 共有271条查询结果,搜索用时 46 毫秒
51.
52.
The language FCP(:,?) is the outcome of attempts to integrate the best of several flat concurrent logic programming languages, including Flat GHC, FCP (↓, |) and Flat Concurrent Prolog, in a single consistent framework. FCP(:) is a subset of FCP(:, ?), which is a variant of FPP(↓, |) and employs concepts of the concurrent constraint framework of cc(↓, |). FCP(:, ?) is a language which is strong enough to accommodate all useful concurrent logic programming techniques, including those which rely on atomic test unification and read-only variables, yet incorporates the weaker languages mentioned as subsets. This allows the programmer to remain within a simple subset of the language such as Flat GHC when the full power of atomic unification or read-only variables is not needed.  相似文献   
53.
Industrial robots have proved to be a key technology for promoting flexible automation in manufacturing. However, integrating robots into a flexible manufacturing cell (FMC) is still facing a few obstacles. In this paper a research project on the development of a robot and its integration into an FMC is presented. The main research areas of the project were the development of the robot control, the mechanical system, the establishment of an off-line and online programming system, and the links between the cell modules.  相似文献   
54.
The assumption that the thermal effect (heating) is the sole factor that should be considered when a microwave source is applied has been debated by many reports, often claiming that athermal (non-thermal) effects exist as well. Such effects are claimed to change the chemical, biochemical, or the physical behaviour of some systems while the temperature and all other parameters remain unaltered. The possibility of an athermal effect was tested in a number of chemical, biological and physical systems in a very well controlled, high radiation intensity system (2.45 GHz, up to 1000 W/kg, with continuous radiation up to 48 h). The systems that were tested included: Maillard reaction, protein denaturation and polymer solubility, mutagenesis of bacteria, mutarotation equilibrium of α/β-d-glucose, and saturation solubility of NaCl. All data failed to show any significant athermal effects. The results of this study are in contrast to what has been previously reported for some of the tested systems.  相似文献   
55.
We report results of torsional oscillator (TO) experiments on solid 4He at temperatures above 1?K. We have previously found that single crystals, once disordered, show some mobility (decoupled mass) even at these rather high temperatures. The decoupled mass fraction with single crystals is typically 20–30%. In the present work we performed similar measurements on polycrystalline solid samples. The decoupled mass with polycrystals is much smaller, ~1%, similar to what is observed by other groups. In particular, we compared the properties of samples grown with the TO’s rotation axis at different orientations with respect to gravity. We found that the decoupled mass fraction of bcc samples is independent of the angle between the rotation axis and gravity. In contrast, hcp samples showed a significant difference in the fraction of decoupled mass as the angle between the rotation axis and gravity was varied between zero and 85 degrees. Dislocation dynamics in the solid offers one possible explanation of this anisotropy.  相似文献   
56.
Location-Based Services   总被引:1,自引:0,他引:1  
Today, location information is in the hands of the masses. The success of location in pervasive computing has exposed new challenges and opportunities for researchers including making location sensing more robust, accurate, deployable, secure, and developer-friendly. This special issue showcases papers that describe recent research that addresses these challenges.  相似文献   
57.
This study evaluates the implementation of a new process: spray freeze drying (SFD), to produce dry micro-capsules of Lactobacillus paracasei with high viability. The study concentrated on determining the survival of the cells, encapsulated in a matrix of maltodextrin and trehalose. SFD was compared with the conventional bulk freeze drying (BFD). Overall it was shown that SFD is a successful method to generate dry micro-capsules of probiotic cells with high viability (>60%). The spraying stage did not affect the viability of the bacteria. In the freezing stage, high osmotic pressures originated by elevated trehalose concentrations, helped preserving the cells viability. It was also found that the lower the maltodextrin molecular weight, the larger the beads volume and solids concentration, the higher is the bacteria survival during the freezing and drying stages. In the drying stage, trehalose concentration was also the critical factor that increased final probiotic viability.  相似文献   
58.
Micron‐sized fibers of UHMWPE reinforced with CNT were fabricated by the electrospinning process. Conditions for a metastable mutual solution of UHMWPE and CNTs were found at elevated temperature. These solutions were used for electrospining using a device having controlled temperature and gaseous environment around the electrospun liquid jet. The fabricated micron‐sized fibers exhibited the reinforcing CNTs as self‐organized nano‐ropes embedded within them. A post‐spinning drawing process enhanced the mechanical properties of the composite fibers to the level of 6.6 GPa strength and elongation at break of 6%. The CNT nano‐ropes form spontaneously in the liquid jet during electrospinning, and provide the reinforcement framework which is amenable for post‐drawing of the fibers for subsequent utilization as composite nanofibers. The experimental results exhibit the highest strength value reported to date for electrospun fibers.

  相似文献   

59.
We present a self-assembly method to construct CdSe/ZnS quantum dot-gold nanoparticle complexes. This method allows us to form complexes with relatively good control of the composition and structure that can be used for detailed study of the exciton-plasmon interactions. We determine the contribution of the polarization-dependent near-field enhancement, which may enhance the absorption by nearly two orders of magnitude and that of the exciton coupling to plasmon modes, which modifies the exciton decay rate.  相似文献   
60.
Amylose molecular inclusion complexes, or V-amylose, have been studied as a possible nano-sized delivery system for unsaturated fatty acids. This study aimed to study three different structural levels of V-amylose produced via an acidification method. Molecular attributes were studied using XRD, DSC and 13C CP/MAS NMR, nanostructures using SAXS and AFM, and the microscopic level by SEM and AFM. 13C labeled fatty acids revealed head groups were entrapped in both COO- and COOH forms. SAXS data, showed that conjugated linoleic acid yield particles with the highest values for parameters like average crystalline lamellar thickness (φ = 0.46) and characteristic particle dimension (Rg = 1011). AFM revealed surface roughness increases from 7.72 ± 4.34 nm to 11.54 ± 6.05 nm during the formation of V-amylose. The insights described contribute to the understanding of V-amylose structure and help establish a model for V-amylose structure which may prospectively be used in the fabrication of a novel delivery system.  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