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   422篇
  免费   64篇
  国内免费   56篇
电工技术   9篇
综合类   55篇
化学工业   19篇
金属工艺   1篇
机械仪表   10篇
建筑科学   12篇
矿业工程   1篇
能源动力   6篇
轻工业   47篇
水利工程   3篇
武器工业   4篇
无线电   19篇
一般工业技术   39篇
冶金工业   101篇
自动化技术   216篇
  2023年   7篇
  2022年   5篇
  2021年   9篇
  2020年   12篇
  2019年   14篇
  2018年   20篇
  2017年   24篇
  2016年   18篇
  2015年   21篇
  2014年   34篇
  2013年   24篇
  2012年   30篇
  2011年   36篇
  2010年   34篇
  2009年   30篇
  2008年   33篇
  2007年   30篇
  2006年   19篇
  2005年   23篇
  2004年   13篇
  2003年   15篇
  2002年   12篇
  2001年   3篇
  2000年   3篇
  1999年   4篇
  1998年   2篇
  1997年   6篇
  1996年   3篇
  1995年   2篇
  1994年   5篇
  1993年   4篇
  1992年   7篇
  1991年   3篇
  1990年   6篇
  1989年   2篇
  1986年   2篇
  1983年   1篇
  1982年   4篇
  1981年   2篇
  1979年   1篇
  1967年   1篇
  1964年   3篇
  1963年   1篇
  1961年   3篇
  1960年   1篇
  1959年   1篇
  1957年   1篇
  1956年   2篇
  1955年   2篇
  1954年   1篇
排序方式: 共有542条查询结果,搜索用时 15 毫秒
71.
Reviews the book, Experimental techniques in human neuropsychology by H. J. Hannay (1986). With the growth of the field of neuropsychology during the last few decades, research related to the varied aspects of human neuropsychology has progressed with insufficient attention to the quality of the methods employed. Certainly, the need for this type of book is unquestionable. This edited volume is designed to present a variety of procedures and current technologies at a level which can be beneficial to both the novice and the expert researcher in various areas of neuropsychology. It is, for the most part, successful in explaining techniques in sufficient detail for the new researcher while also presenting recent advances of interest to the more experienced researcher. The volume contains chapters approximately equally divided between behavioral and physiological measures, written by authors who have established reputations in the research areas which they discuss. Although this book addressed a broad range of experimental topics in neuropsychology, it should provide particular appeal to those interested in methods of investigating cerebral dominance and asymmetry. The research populations discussed represent a diverse mix of neurologically impaired adult groups, with a brief mention of child populations in two chapters. The strength of this book lies on the questions raised about the status of current neuropsychological research techniques. The chapters are well written and are structured in a clearly organized manner that provides ready assessment of the advantages and disadvantages of each technique. Researchers in almost every area of neuropsychology should find this book a valuable aid in designing studies by avoiding the pitfalls which have beset other projects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
72.
This study presents evidence on the validity and limits of applicability of the MMPI portion of the responsibility scale and the dominance scale. "25 Minneapolis fire captains did not differ significantly from 262 Minneapolis firemen in mean scores obtained on the MMPI items of the social responsibility and dominance scales. If the attainment of a captaincy is granted as an appropriate criterion, the data appear to constitute evidence against the validity of at least the MMPI portion of the responsibility scale. The criterion may be less appropriate with respect to Dominance." (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
73.
In examining the prediction that left cerebral dominance, as indexed by hand and sighting preference, should be a positive accompaniment of speech learning in individuals whose cerebral speech areas are likely to be in the left hemisphere, it was found that over a 10-12 year period of formal education right-handed-right-sighting deaf students consistently earned higher speech grades than their right-handed-left sighting and right-handed-mixed-sighting counterparts matched on the basis of hearing loss. This finding supports the hypothesis that the cerebral mechanisms relevant to speech acquisition are simplified, facilitated, and/or less prone to interference when control of speech, hand, and eye is localized primarily in 1 hemisphere of the brain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
74.
Finding link‐disjoint or node‐disjoint paths under multiple constraints is an effective way to improve network QoS ability, reliability, and so on. However, existing algorithms for such scheme cannot ensure a feasible solution for arbitrary networks. We propose design principles of an algorithm to fill this gap, which we arrive at by analyzing the properties of optimal solutions for the multi‐constrained link‐disjoint path pair problem. Based on this, we propose the link‐disjoint optimal multi‐constrained paths algorithm (LIDOMPA), to find the shortest link‐disjoint path pair for any network. Three concepts, namely, the candidate optimal solution, the contractive constraint vector, and structure‐aware non‐dominance, are introduced to reduce its search space without loss of exactness. Extensive simulations show that LIDOMPA outperforms existing schemes and achieves acceptable complexity. Moreover, LIDOMPA is extended to the node‐disjoint optimal multi‐constrained paths algorithm (NODOMPA) for the multi‐constrained node‐disjoint path pair problem.  相似文献   
75.
The main objective was to assess the consistency in competitive success across 3 common resources available to dairy cows housed in free-stall barns. Specifically, we determined if those cows that displaced other cows most often at the feed bunk (high-ranking) had priority of access to free-stalls or a mechanical brush. Our secondary objective was to determine if the displacements at each resource were a function of usage of that resource. These objectives were tested using 6 groups of 12 lactating dairy cows housed in pens with 0.6 m of bunk space per cow, 1 free-stall per cow, and 1 mechanical brush per pen. Time-lapse video was used to quantify the time spent feeding, in the stalls, and using the mechanical brush. The incidence of displacements at the feed alley and lying area was measured for 3 d consecutively. Usage was lower for the brush, so displacements were monitored for 14 d consecutively. The individual measures of competitive success were not highly correlated between resources indicating a cow that frequently displaced other cows for access to one particular resource did not always do so when accessing the other resources. Competition at the feeder was responsible for 87.6 ± 1.4% of displacements observed throughout the experiment, indicating that gaining access to feed was a high priority for cows. These results suggest that competitive success by dairy cows may vary according to each cow's motivation to access the resource.  相似文献   
76.
Heterosis is the beneficial deviation of crossbred progeny from the average of parental lines for a particular trait. Heterosis is due to nonadditive genetic effects with dominance and epistatic components. Recent advances in genotyping technology have encouraged researchers to estimate and scan heterosis components for a range of traits in crossbred populations, applying various definitions of such components. In this study, we defined the intralocus (dominance) component of heterosis using local genetic ancestry and performed genome-wide association analysis for admixed Swiss Fleckvieh bulls and their parental populations, Red Holstein Friesian and Swiss Simmental, for semen traits. A linear mixed model for 41,824 SNP, including SNP additive genetic, breed additive, and breed dominance effects on 1,178 bulls (148 Red Holstein Friesian, 213 Swiss Simmental, and 817 Swiss Fleckvieh) with a total of 43,782 measurements was performed. In total, 19 significant regions for breed dominance were identified for volume (2 regions on Bos taurus autosome 10 and 22) and percentage of live spermatozoa (17 regions on Bos taurus autosome 3, 4, 5, 7, 13, 14, and 17), and genes associated with spermatogenesis, sperm motility, and male fertility traits were located there. No significant region for breed dominance was detected for total number of spermatozoa. The signals for breed dominance were relatively wide, most likely due to limited numbers of recombination events in a small number of generations (10–15 generations) of crossbreeding in the recent Swiss Fleckvieh composite.  相似文献   
77.
The temporal dominance of sensations (TDS) method measures dynamic changes of panelists’ attention to the sensory attributes of products. The temporal check-all-that-apply (TCATA) method measures all sensory attributes perceived at each moment of an evaluation. However, unlike in TDS, significant levels cannot be calculated in TCATA. This study proposes the use of dominance-highlighted TCATA (dTCATA) curves, which are highlighted TCATA curves that show significant time periods for the TDS data of different panels. Twelve R&D panelists evaluated five commercial corn soups using the TCATA method. Then, 125 consumer panelists evaluated the same products using the TDS method. The dTCATA curves showed TCATA curves for all attributes for each product evaluated by the R&D panel highlighted with the dominance rates identified by the consumer panel in the TDS evaluation. For example, for product 1, some attributes (sweet, viscosity) showed relatively high citation proportions in the TCATA evaluations of the R&D panel and significant dominance rates in the TDS evaluations of the consumer panel. In contrast, consommé flavor showed relatively low citation proportions in TCATA but significant dominance rates in TDS. By merging TDS and TCATA data, we could compare consumers’ dominant sensations with the evaluations of R&D panelists. This comparison could provide useful insights to product developers. In some cases, we observed attributes with significant dominance rates that were under-identified by the R&D panel in TCATA. This could suggest that most of the R&D panel may not have perceived these attributes; therefore, during product development, these attributes should be carefully considered.  相似文献   
78.
In this paper, we try to fill in the gap between theory and practice in production scheduling by defining a new term as “rejection” and treating the corresponding scheduling problem with multi-objective optimization approach. We study a bi-objective single machine scheduling problem with rejection. At the beginning of scheduling time horizon, scheduler needs to decide which job shall be rejected due to the resource constraints regarding two objective functions: minimization of total weighted completion time of accepted jobs and total rejection penalty of rejected jobs. We develop different algorithms to find the best estimation of Pareto-optimal front for this problem. In order to improve the quality of the solutions, on the one hand, and facilitate the process of selecting best solution for the final decision maker, on the other hand, we integrate various dominance criteria into our proposed algorithms. Finally we compare the performance of those methods by testing on a large set of instances and highlight the advantages and weak points of each one.  相似文献   
79.
针对MOEA/D算法中差分进化操作收敛精度不高且速度较慢的不足,提出了一种综合基于可控支配域的向量差生成策略和基于主成分的动态缩放因子的新型差分进化模型,均衡显性与隐性搜索引导;并实现了一种基于新型差分进化模型的MOEA/D改进算法(MOEA/D-iDE)。新型差分进化是借助基于可控支配域的非支配排序对邻域进行分层,根据分层信息生成与不同进化阶段相匹配的向量差,实现对种群收敛速度的显性引导;同时对决策空间进行主成分分析,动态调整差分进化缩放因子,实现对种群收敛精度的隐性引导。实验选取ZDT、DTLZ和WFG等为测试问题,以IGD+,ER作为评价指标,将MOEA/D-iDE算法与6个同类算法进行对比实验,结果表明新算法在保证多样性的同时具有更好的收敛速度与精度,从而验证了新型差分进化模型的有效性。  相似文献   
80.
This paper proposes a new and low complexity technique for the simultaneous achievement of open and closed loop diagonal dominance for uncertain plants. The method is based on the introduction of a static high gain inner feedback which modifies the plant to attain a diagonal dominant open loop compensated plant. The sufficient, easy to use, conditions derived for the open loop diagonal dominance also assure the simultaneous achievement of closed loop diagonal dominance under soft assumptions on the diagonal elements of the decoupled controller robustly stabilizing the plant. These assumptions agree with the usual closed‐loop performance specifications, so that closed‐loop diagonal dominance is achieved without any extra complication on the controller design procedure. The main merits of the present method are: applicability to uncertain plants, ease of implementation and low computational cost. Three examples taken from the relevant literature, are given to show the effectiveness of the proposed approach.  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