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   167篇
  免费   1篇
  国内免费   2篇
电工技术   1篇
化学工业   24篇
金属工艺   12篇
机械仪表   10篇
建筑科学   3篇
能源动力   5篇
轻工业   9篇
水利工程   1篇
无线电   17篇
一般工业技术   54篇
冶金工业   12篇
原子能技术   1篇
自动化技术   21篇
  2024年   2篇
  2023年   3篇
  2022年   7篇
  2021年   2篇
  2020年   5篇
  2019年   3篇
  2018年   8篇
  2017年   3篇
  2016年   5篇
  2015年   3篇
  2014年   6篇
  2013年   13篇
  2012年   8篇
  2011年   9篇
  2010年   6篇
  2009年   3篇
  2008年   4篇
  2007年   4篇
  2006年   3篇
  2005年   8篇
  2004年   3篇
  2003年   10篇
  2001年   2篇
  2000年   1篇
  1999年   1篇
  1998年   2篇
  1997年   1篇
  1996年   1篇
  1995年   2篇
  1994年   5篇
  1993年   2篇
  1992年   1篇
  1991年   4篇
  1990年   4篇
  1989年   7篇
  1988年   1篇
  1987年   3篇
  1986年   2篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
  1980年   3篇
  1979年   2篇
  1978年   2篇
  1975年   2篇
  1974年   1篇
排序方式: 共有170条查询结果,搜索用时 15 毫秒
101.
Eight nely developed and to commonly gron chickpea (Cicer arietinum L) cultivars ere evaluated for their cooking quality by measuring cooking time, ater absorption and sensory properties. Nutritional aspects of cooked hole seed samples ere measured chemically (including amino acids and minerals) and biologically in nitrogen-balance experiments ith rats. Results indicated that kabuli (cream seed coat) may be generally preferred to desi (bron seed coat) cultivars in terms of cooking time and sensory properties. Calcium content as noticeably higher in desi than in kabuli cultivars, hereas magnesium, iron, copper and zinc shoed no definite trend. Levels of lysine, threonine, methionine and cystine of these genotypes ere ithin the range of FAO values. Desi and kabuli revealed no noticeable difference in protein and amino acids. Hoever, biological value as considerably higher for kabuli than for desi. Consequently, kabuli contained more utilisable protein and may be nutritionally better than desi. In general, cooking quality and nutritional aspects of both nely developed and control cultivars ere similar.  相似文献   
102.
Artificial bee colony (ABC) optimization algorithm is relatively a simple and recent population based probabilistic approach for global optimization. ABC has been outperformed over some Nature Inspired Algorithms (NIAs) when tested over benchmark as well as real world optimization problems. The solution search equation of ABC is significantly influenced by a random quantity which helps in exploration at the cost of exploitation of the search space. In the solution search equation of ABC, there is a enough chance to skip the true solution due to large step size. In order to balance between diversity and convergence capability of the ABC, a new local search phase is integrated with the basic ABC to exploit the search space identified by the best individual in the swarm. In the proposed phase, ABC works as a local search algorithm in which, the step size that is required to update the best solution, is controlled by Golden Section Search approach. The proposed strategy is named as Memetic ABC (MeABC). In MeABC, new solutions are generated around the best solution and it helps to enhance the exploitation capability of ABC. MeABC is established as a modified ABC algorithm through experiments over 20 test problems of different complexities and 4 well known engineering optimization problems.  相似文献   
103.
In this paper we have presented some geometric techniques to characterize and parametrize surfaces of industrial parts in range images. The surfaces are characterized to one of plane, sphere, cylinder and cone, because they form the majority of object surfaces in man-made industrial parts. The problem has been studied for two different situations. In the first case,a priori knowledge about the surface shape is assumed. In such a situation the problem of surface characterization reduces to that of surface parameter estimation. The standard deviations of the estimated parameters give a measure of uncertainty of characterizing a surface patch to one of the four surface types. In the second case, noa priori information regarding the shape of a surface is available. This includes partially visible surfaces also. To deal with such a situation, a fuzzy classifier is designed using the uncertainty values. The fuzzy classifier classifies the unknown surface patch (including partially visible surfaces) to one of the four surface types. Experimental results with synthetic range images are presented to highlight the distinctive features of our technique.  相似文献   
104.
A spontaneous Raman scattering optical fiber sensor was developed for a specific need of the National Aeronautics and Space Administration (NASA) for long-term detection and monitoring of the purity of liquid oxygen (LO(2)) in the oxidizer feed line during ground testing of rocket engines. The Raman peak intensity ratios for liquid nitrogen (LN(2)) and LO(2) with varied weight ratios (LN(2)/LO(2)) were analyzed for their applicability to impurity sensing. The study of the sensor performance with different excitation light sources has helped to design a miniaturized, cost-effective system for this application. The optimal system response time of this miniaturized sensor for LN(2)/LO(2) measurement was found to be in the range of a few seconds. It will need to be further reduced to the millisecond range for real-time, quantitative monitoring of the quality of cryogenic fluids in a harsh environment.  相似文献   
105.
Epoxy syntactic foams that are capable of withstanding use-temperatures in the range of 106 to 175°C were fabricated with DGEBA or novolac based epoxy resins and appropriate amine hardener materials. These foams were characterized for dynamic mechanical properties in single cantilever mode. The storage modulus, loss modulus and tan δ values were recorded over a wide temperature range. A typical density value of around 0.45 g/cm3 of the syntactic foams made respectively from a cycloaliphatic amine hardener, aromatic amine hardener-I, aromatic amine hardener-II recorded storage modulus (E′) values of 1354 MPa, 1500 MPa and 1530 MPa respectively and tan δ values of 0.0139, 0.0090, 0.01039 respectively at 30°C. The storage modulus values gradually decreased with increasing temperature while the loss modulus values showed corresponding gradual increase in the same temperature range. There is a steep variation in these values when the material softens in the vicinity of the glass transition temperature (T g) indicating the upper temperature limits to which they can be put in use. The reduction in the storage modulus values with increasing temperature and the glass transition temperature values are characteristic of the resin/hardener systems as well as the curing/post curing cycles employed.  相似文献   
106.
There is an urgent need for techniques to rapidly and periodically measure biodiversity and ecosystem services over large landscapes. Conventional vegetation classification and mapping approaches are based on discrete arbitrary classes which do not capture gradual changes in forest type (and corresponding biodiversity and ecosystem services values) from site to site. We developed a simple multi-date NDVI based Mahalanobis distance measure (called eco-climatic distance) that quantifies forest type variability across a moisture gradient for complex tropical forested landscapes on a single ecologically interpretable, continuous scale. This Mahalanobis distance, unlike other distance measures takes into account the variability in the reference class and shared information amongst bands as it is based on the covariance matrix, and therefore is most useful to summarize ecological distance of a pixel to a reference class in multi-band remotely sensed space In this study we successfully apply this measure as a surrogate for tree biodiversity and ecosystem services at two nested scales for the Western Ghats Bio-diversity hotspot. Data from over 500 tree-plots and forest type maps was used to test the ability of this remotely sensed distance to be a surrogate for abundance based tree-species compositional turn-over and as a continuous measure of forest type and ecosystem services. Our results suggest a strong but scale dependant relationship between the remotely-sensed distance measure and floristic distance between plots. The multi-date NDVI distance measure emerges as very good quantitative surrogate for forest type and is a useful complement to existing forest classification systems. This surrogate quantifies forest type variability on a single, continuous quantitative scale and has important applications in conservation planning and mapping and monitoring of hydrologic and carbon storage and sequestration services.  相似文献   
107.
108.
    
The differential evolution (DE) algorithm relies mainly on mutation strategy and control parameters’ selection. To take full advantage of top elite individuals in terms of fitness and success rates, a new mutation operator is proposed. The control parameters such as scale factor and crossover rate are tuned based on their success rates recorded over past evolutionary stages. The proposed DE variant, MIDE, performs the evolution in a piecewise manner, i.e., after every predefined evolutionary stages, MIDE adjusts its settings to enrich its diversity skills. The performance of the MIDE is validated on two different sets of benchmarks: CEC 2014 and CEC 2017 (special sessions & competitions on real-parameter single objective optimization) using different performance measures. In the end, MIDE is also applied to solve constrained engineering problems. The efficiency and effectiveness of the MIDE are further confirmed by a set of experiments.   相似文献   
109.
Mahajan  Sumit  Kumar  Jagdish  Chhibber  Rahul 《SILICON》2020,12(11):2741-2753
Silicon - This article is an attempt to examines high-temperature wettability properties of laboratory-developed electrode coatings for power plant applications. The properties include contact...  相似文献   
110.
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