全文获取类型
收费全文 | 1035篇 |
免费 | 50篇 |
国内免费 | 52篇 |
专业分类
电工技术 | 46篇 |
技术理论 | 2篇 |
综合类 | 158篇 |
化学工业 | 42篇 |
金属工艺 | 9篇 |
机械仪表 | 35篇 |
建筑科学 | 103篇 |
矿业工程 | 42篇 |
能源动力 | 21篇 |
轻工业 | 36篇 |
水利工程 | 27篇 |
石油天然气 | 8篇 |
武器工业 | 3篇 |
无线电 | 30篇 |
一般工业技术 | 94篇 |
冶金工业 | 267篇 |
原子能技术 | 7篇 |
自动化技术 | 207篇 |
出版年
2024年 | 5篇 |
2023年 | 9篇 |
2022年 | 13篇 |
2021年 | 13篇 |
2020年 | 13篇 |
2019年 | 11篇 |
2018年 | 15篇 |
2017年 | 18篇 |
2016年 | 23篇 |
2015年 | 17篇 |
2014年 | 52篇 |
2013年 | 83篇 |
2012年 | 51篇 |
2011年 | 79篇 |
2010年 | 66篇 |
2009年 | 80篇 |
2008年 | 79篇 |
2007年 | 85篇 |
2006年 | 62篇 |
2005年 | 65篇 |
2004年 | 57篇 |
2003年 | 51篇 |
2002年 | 37篇 |
2001年 | 31篇 |
2000年 | 20篇 |
1999年 | 15篇 |
1998年 | 14篇 |
1997年 | 8篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 8篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1978年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1966年 | 1篇 |
1963年 | 2篇 |
1961年 | 3篇 |
1960年 | 2篇 |
1959年 | 1篇 |
1958年 | 3篇 |
1957年 | 2篇 |
1956年 | 3篇 |
1955年 | 1篇 |
排序方式: 共有1137条查询结果,搜索用时 203 毫秒
91.
92.
依据goal-scenario coupling方法提出了一种基于概念属性的结构化目标描述与识别方法.根据上述方法获得的目标模型,在Le Metayer提出的基于图形语法的体系结构建模理论和原则基础之上,提出了一种新的、目标驱动的软件体系结构建模方法. 相似文献
93.
基于AHP-GP的物流中心选址方法 总被引:2,自引:0,他引:2
采用了一种改进的无需一致性检验的AHP来解决物流中心的选址问题.针对AHP方法无法解决有限资源的约束问题,将AHP与目标规划(GP)方法相结合,提出了一种基于AHP-GP的物流中心选址模型.该模型主要适用于在有限资源约束下,进行多个物流中心选址方案的优化组合,而当资源的约束条件较大时,模型的准确性和合理性均有所降低. 相似文献
94.
随着我国房地产市场的不断发展,房地产企业的数量和规模也都在急剧扩大,房地产企业的投资目标也日趋多元化,对其投资目标的正确认识也显得尤为重要。文中主要针对当前高额利润诱惑下的房地产企业的投资目标的缺失现象进行分析,探讨了这种缺失将产生的严重后果,给出了房地产企业应如何正确认识投资目标的次序,以求能对房地产企业制定可持续发展战略有所裨益。 相似文献
95.
郑州煤业集团公司采煤工作面采用走向长壁的采煤方法,跳采。接替工作面留窄小煤柱沿空送巷时,临近采空侧回风顺槽受探放水影响,掘进被迫中断时间较长,为此,裴沟煤矿通过留设防水煤柱施工改造回风顺槽,绕过老空积水区,提前施工回风顺槽里段,使回风顺槽如期贯通,保证了采面的正常接替。 相似文献
96.
Six studies explore the role of goal shielding in self-regulation by examining how activation of focal goals to which the individual is committed inhibits the accessibility of alternative goals. Consistent evidence was found for such goal shielding, and a number of its moderators were identified: Individuals' level of commitment to the focal goal, their degree of anxiety and depression, their need for cognitive closure, and differences in their goal-related tenacity. Moreover, inhibition of alternative goals was found to be more pronounced when they serve the same overarching purpose as the focal goal, but lessened when the alternative goals facilitate focal goal attainment. Finally, goal shielding was shown to have beneficial consequences for goal pursuit and attainment. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
97.
安全案例提供清晰、全面和可靠的论据,说明系统在特定环境下的操作满足可接受的安全性.在受监管的安全攸关领域,如汽车、航空和核能等领域,认证机构通常要求系统经过严格的安全评估程序,以确保其符合一个或多个安全标准.在系统开发中应用安全案例是一种新兴的技术手段,以结构化和全面的方式表达安全攸关系统的安全属性.我们对安全案例的四个基本构建步骤—确定目标、收集证据、构建论证和评估安全案例—进行简要介绍.然后聚焦于构建论证这一关键步骤,详细介绍现有的8种安全案例表达形式,包括目标结构符号(GSN)、声明-论点-证据(CAE)、结构化安全案例元模型(SACM)等,并分析了它们的优缺点.由于安全案例所需材料的显著复杂性,软件工具通常被用作构建和评估安全案例的实用方法.我们比较7种用于安全案例开发和评估的工具,包括Astah System Safety、gsn2x、NOR-STA、Socrates、ASCE、D-Case Editor和AdvoCATE.此外,本文还深入探讨了安全案例构建中所面临的多重挑战,这些挑战包括数据的可靠性和完整性、复杂性和不确定性的管理、监管和标准的不一致、人因工程、技术的快速发展以及团队和跨学科合作6个方面.最后,我们展望安全案例的未来研究方向,揭示其潜在应用和研究问题. 相似文献
98.
Weary Gifford; Jacobson Jill A.; Edwards John A.; Tobin Stephanie J. 《Canadian Metallurgical Quarterly》2001,81(2):206
In 3 studies, we examined the hypothesis that the effects of stereotype usage on target judgments are moderated by causal uncertainty beliefs and related accuracy goal structures. In Study 1, we focused on the role of chronically accessible causal uncertainty beliefs as predictors of a target's level of guilt for an alleged academic misconduct offense. In Study 2, we examined the role of chronic causal uncertainty reduction goals and a manipulated accuracy goal; in Study 3, we investigated the role of primed causal uncertainty beliefs on guilt judgments. In all 3 studies, we found that activation of causal uncertainty beliefs and accuracy concerns was related to a reduced usage of stereotypes. Moreover, this reduction was not associated with participants' levels of perceived control, depression, state affect, need for cognition, or personal need for structure. Results are discussed in terms of their implications for the model of causal uncertainty and, more generally, in terms of the motivational processes underlying stereotype usage. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
99.
Reports a retraction of "Hierarchical encoding of behavior: Translating perception into action" by Bridgette Martin Hard, Sandra C. Lozano and Barbara Tversky (Journal of Experimental Psychology: General, 2006[Nov], Vol 135[4], 588-608). All authors retract this article. Co-author Tversky and co-author Hard believe that the research results cannot be relied upon; Sandra C. Lozano takes full responsibility for the need to retract this article. (The following abstract of the original article appeared in record 2006-20327-007.) People encode goal-directed behaviors, such as assembling an object, by segmenting them into discrete actions, organized as goal-subgoal hierarchies. Does hierarchical encoding contribute to observational learning? Participants in 3 experiments segmented an object assembly task into coarse and fine units of action and later performed it themselves. Hierarchical encoding, measured by segmentation patterns, correlated with more accurate and more hierarchically structured performance of the later assembly task. Furthermore, hierarchical encoding increased when participants (a) segmented coarse units first, (b) explicitly looked for hierarchical structure, and (c) described actions while segmenting them. Improving hierarchical encoding always led to improvements in learning, as well as a surprising shift toward encoding and executing actions from the actor's spatial perspective instead of the participants' own. Hierarchical encoding facilitates observational learning by organizing perceived actions into a representation that can serve as an action plan. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
100.
Turner Julianne C.; Midgley Carol; Meyer Debra K.; Gheen Margaret; Anderman Eric M.; Kang Yongjin; Patrick Helen 《Canadian Metallurgical Quarterly》2002,94(1):88
The relation between the learning environment (e.g., students' perceptions of the classroom goal structure and teachers' instructional discourse) and students' reported use of avoidance strategies (self-handicapping, avoidance of help seeking) and preference to avoid novelty in mathematics was examined. Quantitative analyses indicated that students' reports of avoidance behaviors varied significantly among classrooms. A perceived emphasis on mastery goals in the classroom was positively related to lower reports of avoidance. Qualitative analyses revealed that teachers in high-mastery/low-avoidance and low-mastery/high-avoidance classrooms used distinctively different patterns of instructional and motivational discourse. High incidence of motivational support was uniquely characteristic of high-mastery/ low-avoidance classrooms, suggesting that mastery goals may include an affective component. Implications of the results for both theory and practice are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献