全文获取类型
收费全文 | 10597篇 |
免费 | 1085篇 |
国内免费 | 475篇 |
专业分类
电工技术 | 2047篇 |
技术理论 | 1篇 |
综合类 | 818篇 |
化学工业 | 938篇 |
金属工艺 | 183篇 |
机械仪表 | 394篇 |
建筑科学 | 873篇 |
矿业工程 | 321篇 |
能源动力 | 502篇 |
轻工业 | 720篇 |
水利工程 | 1421篇 |
石油天然气 | 155篇 |
武器工业 | 37篇 |
无线电 | 487篇 |
一般工业技术 | 496篇 |
冶金工业 | 1366篇 |
原子能技术 | 62篇 |
自动化技术 | 1336篇 |
出版年
2024年 | 96篇 |
2023年 | 291篇 |
2022年 | 520篇 |
2021年 | 561篇 |
2020年 | 397篇 |
2019年 | 332篇 |
2018年 | 317篇 |
2017年 | 347篇 |
2016年 | 348篇 |
2015年 | 362篇 |
2014年 | 593篇 |
2013年 | 501篇 |
2012年 | 625篇 |
2011年 | 826篇 |
2010年 | 655篇 |
2009年 | 666篇 |
2008年 | 590篇 |
2007年 | 699篇 |
2006年 | 603篇 |
2005年 | 483篇 |
2004年 | 431篇 |
2003年 | 349篇 |
2002年 | 283篇 |
2001年 | 288篇 |
2000年 | 174篇 |
1999年 | 154篇 |
1998年 | 109篇 |
1997年 | 106篇 |
1996年 | 79篇 |
1995年 | 79篇 |
1994年 | 75篇 |
1993年 | 42篇 |
1992年 | 36篇 |
1991年 | 29篇 |
1990年 | 30篇 |
1989年 | 27篇 |
1988年 | 15篇 |
1987年 | 10篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 5篇 |
1976年 | 2篇 |
1966年 | 1篇 |
1964年 | 1篇 |
1958年 | 2篇 |
1954年 | 1篇 |
1951年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
H. A. Ellenbein and N. Ambady's (2002) conclusions concerning a possible in-group advantage in judging emotions across cultures are unwarranted. The author discusses 2 methodological requirements for studies to test adequately the in-group advantage hypothesis and an additional requirement in reviewing multiple judgment studies and examining variance in judgment effects across those studies. The few studies that Elfenbein and Ambady reported that support the in-group advantage hypothesis need to be examined for whether they meet the criteria discussed; if they do not, their data cannot be used to support any contention of cultural differences in judgments, let alone the in-group advantage hypothesis. Furthermore, the role of signal clarity needs to be explored in possibly moderating effects across studies; however, this was not done. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
992.
Robin Spence 《Building Research & Information》2004,32(5):391-402
From an examination of national policies for risk mitigation, the paper asks what types of laws are successful and should be more widely adopted, and what does not work. Three types of regulations are considered: (1) regulations for constructing new buildings and code enforcement; (2) regulations for intervening in/upgrading the existing building stock; and (3) regulation of the insurance industry. When applied, improved codes can substantially reduce the impacts of natural disasters. However, unnecessary complexity is shown to compromise implementation and enforcement. The widespread destruction of buildings in the earthquakes of Kocaeli, Turkey, in 1999 and Gujarat, India, in 2001 was not due to inadequate codes. Destruction occurred because codes were not generally adopted. Improving the application and enforcement of codes in developing countries are necessary key measures. For the strengthening of existing substandard buildings, some regulations exist and some successful programmes of evaluation and strengthening are in progress. However, lessons from the US experience indicate legislation is needed to back such programmes, and further incentives for action are needed. Several national insurance schemes for natural catastrophe losses (US programmes for flood, New Zealand programmes for earthquake, and French programmes for all catastrophic natural hazards) have considerable potential to stimulate mitigation activity. Ultimately, coercion by government is only part of the answer. The success of any government action depends equally on the development in society of a 'safety culture' in which citizens both understand the risks they face and are prepared to participate in the management of them. 相似文献
993.
Flemming Nielson Hanne Riis Nielson Corrado Priami Debora Rosa 《Electronic Notes in Theoretical Computer Science》2007,180(3):65-79
This paper presents a static analysis for investigating properties of biological systems specified in BioAmbients. We exploit the control flow analysis to decode the bindings of variables induced by communications and to build a relation of the ambients that can interact with each other. We eventually apply our analysis to an example of gene regulation by positive feedback taken from the literature. 相似文献
994.
995.
三峡工程对洞庭湖典型洪水的防洪作用分析 总被引:3,自引:0,他引:3
根据三峡工程建成后对荆江和城陵矶地区补偿的调度方式,采用大湖演算模型对1996、1998、1999年洞庭湖区3种不同来水组合的典型洪水进行了分析计算.计算结果表明,三峡工程不同的实时调度方案,其作用相差大,且对于不同的来水组合类型的洪水,不同的调度方式其作用大小不一样,对于历时不长,长江干流洪水与湖南省"四水"恶劣遭遇的湖区洪水,作用较大;对于湖南省"四水"来水为主的典型洪水和长江干流与"四水"长历时复峰恶劣遭遇的湖区洪水其作用较小. 相似文献
996.
Children's emotional regulation (as indexed by vagal suppression) and children's emotional reactivity during an argument were examined as moderators and mediators of parental problem drinking and children's adjustment in a sample of 6- to 12-year-olds. Cardiac vagal tone was assessed during both a baseline condition and exposure to an audiotaped argument. Vagal suppression was calculated by subtracting vagal tone during the baseline from that recorded during the argument, with a higher number representing increased suppression of vagal tone during the argument. Emotional reactivity was based on both observations of overt behaviors of children and their reported feelings during the argument. A higher level of vagal suppression was a protective factor against children's externalizing, internalizing, and social problems associated with exposure to parental problem drinking. Emotional reactivity was a vulnerability factor, and children's increased anger and fear, and to a lesser degree sadness, each moderated and exacerbated the effects of parental problem drinking on child outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
997.
引子渡水电站引水系统关键技术 总被引:3,自引:1,他引:2
引子渡水电站采用长引水系统,在下游较宽敞的胡家大地平地布置发电厂房、以使发电厂房远离雾化区,从而保障良好的运行条件,同时也有利于施工、减少施工的相互干扰。引水系统线路总长1100m,采用一洞-三机供水方式,由岸塔式进水口、引水隧洞、阻抗式调压井、压力钢管等组成。该引水系统线路长、建筑物复杂、洞室围岩稳定性较差。经过对引水系统的水力过渡过程分析计算、调保计算和结构计算,满足了结构、大小波动稳定和运行的要求。 相似文献
998.
房地产的政治经济学——简析当前房地产业的高热现象 总被引:1,自引:0,他引:1
运用政治经济学的理论,从经济学最基本的概念入手,对当前房地产业及高房价现象进行分析,探讨一下房地产业发展的客观规律,试图找出房地产业高热和房价居高不下的深层原因,并对相关房地产调控政策提供个人观点。 相似文献
999.
介绍了加油站应用情感营销的特点和要求,指出在加油站实施情感营销应从两个方面入手,一是用情感凝聚员工,员工是企业的核心竞争力之一,是企业利润的直接创造者;二是用情感来赢得顾客,注重在加油过程中的情感投入,用真诚架起情感沟通的桥梁,用情感战胜对手,用情感提升加油站的核心竞争力。 相似文献
1000.
People regulate their affect either to feel good or to achieve instrumental success. The present experiments show that when driven by performance goals, people can be motivated to experience unpleasant affect when it is trait-consistent, because of its instrumental benefits (e.g., M. Tamir & M. D. Robinson, 2004). In 4 studies, individuals high in neuroticism were more likely than those low in neuroticism to choose to increase their level of worry, as indicated by self-reported preferences (Study 1) and by behavioral choices in experimental settings (Studies 2-4). As predicted, such preferences were evident when expecting to perform demanding tasks but not when expecting an undemanding task (Study 2). Study 4 suggests that such preferences for short-term unpleasant affect may be beneficial to performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献