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   276篇
  免费   2篇
电工技术   12篇
化学工业   41篇
金属工艺   3篇
机械仪表   2篇
建筑科学   6篇
能源动力   2篇
轻工业   28篇
水利工程   1篇
无线电   27篇
一般工业技术   20篇
冶金工业   110篇
原子能技术   7篇
自动化技术   19篇
  2023年   1篇
  2022年   6篇
  2021年   5篇
  2020年   2篇
  2018年   3篇
  2017年   1篇
  2016年   2篇
  2015年   2篇
  2014年   3篇
  2013年   5篇
  2012年   7篇
  2011年   5篇
  2010年   5篇
  2009年   5篇
  2008年   7篇
  2007年   12篇
  2006年   6篇
  2005年   9篇
  2004年   6篇
  2003年   5篇
  2002年   8篇
  2001年   1篇
  2000年   6篇
  1999年   8篇
  1998年   49篇
  1997年   27篇
  1996年   16篇
  1995年   8篇
  1994年   8篇
  1993年   13篇
  1992年   4篇
  1991年   3篇
  1990年   2篇
  1989年   1篇
  1987年   4篇
  1986年   2篇
  1984年   3篇
  1983年   1篇
  1982年   4篇
  1981年   1篇
  1980年   3篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
  1976年   2篇
  1975年   1篇
  1974年   2篇
  1971年   1篇
排序方式: 共有278条查询结果,搜索用时 15 毫秒
71.
The fabrication of cellulose nanofiber-reinforced composites has been so far problematic due to difficulties in obtaining good dispersion of hydrophilic cellulose fibers in a hydrophobic polymer matrix. A new manufacturing process similar to papermaking, which enables the production of thin sheets made of uniformly dispersed microfibrillated cellulose (MFC) with polylactic acid (PLA) fibers was devised, and the composites were obtained by compression molding of the stacked sheets. The process is suitable for adoption at an industrial scale owing to the high yields and fast dewatering times. The measurement of tensile properties revealed that the modulus, strength, and strain at fracture increased linearly with the MFC content. The improvement in toughness was considered one of the key benefits brought by MFC reinforcement.  相似文献   
72.
73.
The capability and reliability are crucial characteristics of mobile robots while navigating in complex environments. These robots are expected to perform many useful tasks which can improve the quality of life greatly. Robot localization and decision-making are the most important cognitive processes during navigation. However, most of these algorithms are not efficient and are challenging tasks while robots navigate through complex environments. In this paper, we propose a biologically inspired method for robot decision-making, based on rat’s brain signals. Rodents accurately and rapidly navigate in complex spaces by localizing themselves in reference to the surrounding environmental landmarks. Firstly, we analyzed the rats’ strategies while navigating in the complex Y-maze, and recorded local field potentials (LFPs), simultaneously. The recorded LFPs were processed and different features were extracted which were used as the input in the artificial neural network (ANN) to predict the rat’s decision-making in each junction. The ANN performance was tested in a real robot and good performance is achieved. The implementation of our method on a real robot, demonstrates its abilities to imitate the rat’s decision-making and integrate the internal states with external sensors, in order to perform reliable navigation in complex maze.  相似文献   
74.
In low-density polyethylene containing the additive propylfluorancene, radiation energy received by polyethylene is transferred to propylfluorancence, and the production of radicals at 77 K in polyethylene is suppressed. Propylfluoranncene also increases the rate of the decay of radicals of polyethylene at room temperature. The depression of radical production and accelaration of radical decay at room temperature results in the depression of gas production and crosslinks at room temperature in low-density polyethylene containing propylfluorancene. Similar results were obtained in ethylen–propylene copolymer containing the same additive.  相似文献   
75.
YMnO3 thin films with Y/Mn ratios from 1.00/1.05 to 1.00/0.90 were prepared by dip-coating from solution, in which starting materials were refluxed, and the effects of the Y/Mn ratio on the structure and dielectric properties of YMnO3 thin films were investigated. XRD measurements indicated that the films with the Y/Mn ratios in this study were a single phase of polycrystalline YMnO3. The lattice constants along the a -axis and c -axis lengthened with an increase in the Y/Mn ratio. FE-SEM micrographs of the films showed that the surface of the films became smoother and denser with an increase in the Y/Mn ratio. YMnO3 thin films with good dielectric properties were obtained with an Y/Mn ratio of 1.00/0.90, which gave the smoothest and densest microstructure and the smallest leakage current.  相似文献   
76.
This paper addresses the manufacturability, yield, and reliability aspects of X Architecture interconnects (diagonal lines) in a very large scale integrated (VLSI) design that enables integrated circuit (IC) chips to become faster and smaller (area) compared to the same design in Manhattan routing. Test chips that consist of comb/serpentine, maze, via chain, as well as resistance and capacitance structures are designed and fabricated using both 130- and 90-nm copper processes. A new technique to characterize interconnect physical parameters (top and bottom line widths, metal line, and dielectric thickness) is developed that requires capacitance measurement on sets of special test structures. An excellent agreement is found between the extracted process parameters, for both diagonal and Manhattan lines, using this technique and those of SEM/FIB data. Measurements of the line resistance, capacitance, and SEM/FIB data on different types of test structures show that 1:1 design rule ratio (Manhattan versus X Architecture) is manufacturable, and the uniformity and fidelity of the diagonal lines are as good as Manhattan lines. The current generation of mask, lithography, wafer processing techniques are applicable to X Architecture designs.  相似文献   
77.
In-situ experiments on the Ni/SiC interface reaction were carried out with a high temperature X-ray diffractometer capable of measuring the X-ray diffraction pattern in 1–2 s using an imaging plate. The kinetic formation processes of the interface reaction layer were measured in short-period exposure experiments with the apparatus. The time-temperature phase diagram of Ni/SiC in N2 was determined. -Ni2Si and -Ni2Si (high temperature phase of -Ni2Si) were formed at the Ni/SiC interface between 1072 K and 1418 K in N2. The formation of -Ni2Si obeyed the parabolic rate law. The value of the activation energy suggests that the diffusion of Ni through -Ni2Si controls the rate of formation. The results of thermal expansion coefficient measurements suggest that when a sample is cooled to room temperature, compression caused by -Ni2Si occurs on SiC.  相似文献   
78.
A single nucleotide polymorphism (SNP) typing method using color-coded beads is promising because it is easy to use and inexpensive. However, the present protocols are not suitable for clinical and diagnostic applications because they need centrifugation for bead-washing. Here, we developed a simplified protocol without a bead-washing procedure that enables SNP typing of PCR amplified fragments in only 30 min.  相似文献   
79.
Quality on Time     
How is it that a group of talented, highly motivated, hard working software engineers consistently produce low-quality software, late? It is the author's view that schedule management and quality management go hand in hand. This paper discusses the notion that schedules are probability distributions, and presents several practical quality and schedule management techniques.  相似文献   
80.
Our research has focused on the molecular design of immunotherapeutic vaccines and the advancement of mite-allergy diagnosis. Here, we describe the research history of the major group 1 and group 2 allergens, immunoelectrophoretic analyses covering the complete spectrum of mite allergens, our results on allergens with distinctive characteristics (a conjunctival congestion-eliciting antigen [LM2], an immunotherapeutic antigen [HM2] with high efficacy and without definite adverse reactions, and a potent T-cell stimulatory antigen [HM1] with secretion of IFN-gamma), the full spectrum and immunochemical properties of the major and other important mite allergens (including our newly described allergens: a pan-allergen [tropomyosin, group 10], a potent T-cell stimulatory allergen [M-177, apolipophorin, group 14] and its peptide fragments Mag1 and Mag3, a moderate IgE-binding allergen [gelsolin/villin, group 16], an EF-hand Ca2+-binding allergen [group 17], and a less IgE-binding allergen [heat shock protein 70]), and prospects for the development of immunotherapeutic and diagnostic agents.  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