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   13298篇
  免费   2089篇
  国内免费   1508篇
电工技术   1511篇
综合类   1890篇
化学工业   291篇
金属工艺   151篇
机械仪表   916篇
建筑科学   693篇
矿业工程   287篇
能源动力   361篇
轻工业   175篇
水利工程   543篇
石油天然气   207篇
武器工业   238篇
无线电   1164篇
一般工业技术   1151篇
冶金工业   733篇
原子能技术   53篇
自动化技术   6531篇
  2024年   80篇
  2023年   247篇
  2022年   435篇
  2021年   510篇
  2020年   563篇
  2019年   506篇
  2018年   502篇
  2017年   547篇
  2016年   589篇
  2015年   631篇
  2014年   818篇
  2013年   1121篇
  2012年   924篇
  2011年   965篇
  2010年   823篇
  2009年   821篇
  2008年   859篇
  2007年   975篇
  2006年   791篇
  2005年   685篇
  2004年   604篇
  2003年   506篇
  2002年   466篇
  2001年   351篇
  2000年   253篇
  1999年   235篇
  1998年   179篇
  1997年   153篇
  1996年   116篇
  1995年   107篇
  1994年   119篇
  1993年   74篇
  1992年   50篇
  1991年   42篇
  1990年   49篇
  1989年   35篇
  1988年   24篇
  1987年   13篇
  1986年   9篇
  1985年   7篇
  1984年   13篇
  1983年   15篇
  1982年   14篇
  1981年   5篇
  1980年   8篇
  1979年   6篇
  1978年   6篇
  1966年   7篇
  1958年   4篇
  1955年   7篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Theorists have predicted that repetition blindness (RB) should be absent for nonwords because they do not activate preexisting mental types. The authors hypothesized that RB would be observed for nonwords because RB can occur at a sublexical level. Four experiments showed that RB is observed for word-nonword pairs (noon noof), orthographically similar nonwords (glome glame), and identical repetitions (plass plass). More RB was found for words than for nonwords. Prior researchers may have failed to find RB for nonwords because display conditions that allow 2 words to be reliably encoded are insufficient for nonwords, or because observers coped with low ability to encode nonwords by using guessing strategies that do not require creating a mental type or tokenizing it. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
82.
Lateralized readiness potentials (LRPs) were used to determine the stage(s) of reaction time (RT) responsible for speed-accuracy trade-offs (SATs). Speeded decisions based on several types of information were examined in 3 experiments, involving, respectively, a line discrimination task, lexical decisions, and an Erikson flanker task. Three levels of SAT were obtained in each experiment by adjusting response deadlines with an adaptive tracking algorithm. Speed stress affected the duration of RT stages both before and after the start of the LRP in all experiments. The latter effect cannot be explained by guessing strategies, by variations in response force, or as an indirect consequence of the pre-LRP effect. Contrary to most models, it suggests that SAT can occur at a late postdecisional stage. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
83.
At times the laws under which psychologists function may appear to contradict generally recognized ethical values and/or good clinical care. When these circumstances arise, psychologists must determine if a conflict really exists and, if so, seek solutions that reconcile respect for the law with their ethical values. At times, psychologists may decide to follow the law despite their ethical concerns. At other times, they may determine that a conscientious objection is warranted. The authors recommend options to consider when these situations arise and offer a decision-making process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
84.
Technical Note: Selecting a Classification Method by Cross-Validation   总被引:3,自引:0,他引:3  
Schaffer  Cullen 《Machine Learning》1993,13(1):135-143
If we lack relevant problem-specific knowledge, cross-validation methods may be used to select a classification method empirically. We examine this idea here to show in what senses cross-validation does and does not solve the selection problem. As illustrated empirically, cross-validation may lead to higher average performance than application of any single classification strategy, and it also cuts the risk of poor performance. On the other hand, cross-validation is no more or less a form of bias than simpler strategies, and applying it appropriately ultimately depends in the same way on prior knowledge. In fact, cross-validation may be seen as a way of applying partial information about the applicability of alternative classification strategies.  相似文献   
85.
针对我国工程索赔经验少、索赔专家稀缺的实际情况,提出了一种基于Web的工程索赔决策支持系统,首先综合了数据仓库,联机分析处理,数据挖掘技术于一体的综合决策支持系统,给出了数据仓库、模型库和知识库的具体设计,最后对系统的实现作了简要的介绍,该系统的应用旨在建立一个功能强大的在线工程索赔支持平台,共享索赔专家丰富的知识和经验,帮助承包商完成复杂的索赔工作。  相似文献   
86.
“To understand and protect our home planet, to explore the universe and search for life, and to inspire the next generation of explorers” is NASA's mission. The Systems Management Office at Johnson Space Center (JSC) is searching for methods to effectively manage the Center's resources to meet NASA's mission. D-Side is a group multi-criteria decision support system (GMDSS) developed to support facility decisions at JSC. D-Side uses a series of sequential and structured processes to plot facilities in a three-dimensional (3-D) graph on the basis of each facility's alignment with NASA's mission and goals, the extent to which other facilities are dependent on the facility, and the dollar value of capital investments that have been postponed at the facility relative to the facility's replacement value. A similarity factor rank orders facilities based on their Euclidean distance from Ideal and Nadir points. These similarity factors are then used to allocate capital improvement resources across facilities. We also present a parallel model that can be used to support decisions concerning allocation of human resources investments across workforce units. Finally, we present results from a pilot study where 12 experienced facility managers from NASA used D-Side and the organization's current approach to rank order and allocate funds for capital improvement across 20 facilities. Users evaluated D-Side favorably in terms of ease of use, the quality of the decision-making process, decision quality, and overall value-added. Their evaluations of D-Side were significantly more favorable than their evaluations of the current approach.  相似文献   
87.
预期回报对决策具有决定性的影响。基于行为经济模型,认为创业决策依赖于预期回报和欲望水平之间的相互作用,并通过计量分析验证了预期回报对创业决策的影响。  相似文献   
88.
The paper presents a case study of the development of an expert decision support system which uses simple heuristic methods for fast determination of routes for simultaneous signals in a transmission network of limited capacity. It illustrates how heuristic solutions can be embodied in a model-based DSS and how the standard decision support literature, although intuitively appealing, provides little practical assistance in system construction or classification  相似文献   
89.
现场地质预测与决策技术   总被引:1,自引:1,他引:0  
油气的生成、运移、分布、成藏、保存具有规律性,技术人员可以依据其规律性对地下地质情况进行推理、预测和决策。钻井过程的现场地质预测技术方法主要是外推法、因果法和直观法三大类。外推法是常用的预测方法,包含了岩性、沉积旋回、标志层、标准层、重矿物等岩石地层学对比方法和生物地层学方法及地球物理方法。现场地质预测与决策是通过确定预测目标、收集相关资料、进行对比分析、形成地质预测结果、拟定地质决策方案、方案优选、方案实施等环节来完成。该技术是现场地质监督的核心技术,在实践中取得显著成效。  相似文献   
90.
Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis does not provide an analytical means to determine the importance of the identified factors or the ability to assess decision alternatives according to these factors. Although the analysis successfully pinpoints the factors, individual factors are usually described briefly and very generally. For this reason, SWOT analysis possesses deficiencies in the measurement and evaluation steps. Although the analytic hierarchy process (AHP) technique removes these deficiencies, it does not allow for measurement of the possible dependencies among the factors. The AHP method assumes that the factors presented in the hierarchical structure are independent; however, this assumption may be inappropriate in light of certain internal and external environmental effects. Therefore, it is necessary to employ a form of SWOT analysis that measures and takes into account the possible dependency among the factors. This paper demonstrates a process for quantitative SWOT analysis that can be performed even when there is dependence among strategic factors. The proposed algorithm uses the analytic network process (ANP), which allows measurement of the dependency among the strategic factors, as well as AHP, which is based on the independence between the factors. Dependency among the SWOT factors is observed to effect the strategic and sub-factor weights, as well as to change the strategy priorities.  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