全文获取类型
收费全文 | 1284篇 |
免费 | 276篇 |
国内免费 | 200篇 |
专业分类
电工技术 | 170篇 |
技术理论 | 2篇 |
综合类 | 132篇 |
化学工业 | 18篇 |
金属工艺 | 1篇 |
机械仪表 | 13篇 |
建筑科学 | 179篇 |
矿业工程 | 41篇 |
能源动力 | 37篇 |
轻工业 | 7篇 |
水利工程 | 146篇 |
石油天然气 | 4篇 |
武器工业 | 66篇 |
无线电 | 153篇 |
一般工业技术 | 84篇 |
冶金工业 | 89篇 |
原子能技术 | 3篇 |
自动化技术 | 615篇 |
出版年
2024年 | 16篇 |
2023年 | 34篇 |
2022年 | 72篇 |
2021年 | 69篇 |
2020年 | 83篇 |
2019年 | 76篇 |
2018年 | 73篇 |
2017年 | 70篇 |
2016年 | 86篇 |
2015年 | 61篇 |
2014年 | 124篇 |
2013年 | 119篇 |
2012年 | 117篇 |
2011年 | 138篇 |
2010年 | 97篇 |
2009年 | 85篇 |
2008年 | 79篇 |
2007年 | 90篇 |
2006年 | 73篇 |
2005年 | 53篇 |
2004年 | 53篇 |
2003年 | 22篇 |
2002年 | 20篇 |
2001年 | 13篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1988年 | 1篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1979年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有1760条查询结果,搜索用时 15 毫秒
1.
D. P. Phillips, T. E. Ruth, and L. M. Wagner (1993) reported that 1969-1990 California mortality data show that Chinese Americans are particularly vulnerable to diseases that Chinese astrology and traditional Chinese medicine associate with their birth years. For example, because fire is associated with the heart, a Chinese person born in a fire year (such as 1937) is more likely to die of heart disease than is a Chinese person born in a nonfire year. However, many diseases were excluded from this study, some diseases that were included have ambiguous links to birth years, and the statistical tests were indirect. A more complete statistical analysis and independent California mortality data for the years 1960-1968 and 1991-2002 did not replicate the original results. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
2.
Utilizing data from the Riggs-Yale Project, 45 male and 45 female 18-29-year-old treatment-resistant inpatients undergoing intensive psychoanalytically oriented treatment were studied. Twenty-seven mixed-type anaclitic-introjective inpatients were compared with 29 "pure" anaclitic and 34 "pure" introjective inpatients. At intake, mixed-type inpatients were more clinically impaired (i.e., were more symptomatic, cognitively impaired, and thought disordered) and more vulnerable (i.e., less accurate object representations and more frequently used maladaptive defense mechanisms) in comparison with clearly defined anaclitic and introjective patients. Mixed-type patients, however, improved significantly more in the course of psychoanalytically oriented treatment, in terms of clinical functioning (i.e., symptoms, cognitive functioning) and psychological vulnerability (i.e., utilization of more adaptive defense mechanisms). (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
3.
The toll in death, suffering, and displacement caused by conflicts engaging groups defined by ethnicity, nationality, religion, or other social identities has reached staggering proportions over the past decade. With expertise in research and intervention, psychologists have critical contributions to make to more fully understanding and more effectively confronting this distressing global phenomenon. The authors focus on the parallels between the core beliefs of individuals and the collective worldviews of groups that may operate to trigger or constrain violent struggles. On the basis of a review of relevant literatures, 5 belief domains--superiority, injustice, vulnerability, distrust, and helplessness--are identified as particularly important for further study. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
4.
旱灾是影响安徽省农业特别是粮食生产可持续发展的重要制约因素。在相同致灾强度下,灾情会随灾害脆弱性的增强而加重,因此,研究农业旱灾脆弱性对安徽省防灾减灾和农业可持续发展具有特别重要意义。根据影响旱灾脆弱性的因素和指标体系选取的原则,选择了旱灾面积比、森林覆盖率、农村人均收入等9个指标,采用加权综合评价方法对各市旱灾脆弱性进行分析,并利用聚类分析方法进行旱灾脆弱性区划。结果表明,除合肥市、阜阳市、池州市、宿州市和黄山市5个市需要采取措施降低旱灾脆弱度外,安徽省总体上农业旱灾脆弱性较弱,有较强的抗旱承灾能力。 相似文献
5.
《Expert systems with applications》2014,41(2):644-654
This study aims to improve the general flood vulnerability approach using fuzzy TOPSIS based on α-cut level sets which can reduce the uncertainty inherent in even fuzzy multi-criteria decision making process. Since fuzzy TOPSIS leads to a crisp closeness for each alternative, it is frequently argued that fuzzy weights and fuzzy ratings should be in fuzzy relative closeness. Therefore, this study used a modified α-cut level set based fuzzy TOPSIS to develop a spatial flood vulnerability approach for Han River in Korea, considering various uncertainties in weights derivation and crisp data aggregation. Two results from fuzzy TOPSIS and modified fuzzy TOPSIS were compared. Some regions which showed no or small ranking changes have their centro-symmetric distributions, while other regions whose rankings varied dynamically, have biased (anti-symmetric) distributions. It can be concluded that α-cut level set based fuzzy TOPSIS produce more robust prioritization since more uncertainties can be considered. This method can be applied to robust spatial vulnerability or decision making in water resources management. 相似文献
6.
鉴于基础设施系统对社会生产和人民生活的重要性,分析基础设施系统的脆弱性,提出相应的抗干扰措施和改进策略,提高基础设施系统的可靠性,成为了当前研究的一个热点课题。基于此,在对基础设施系统脆弱性分析成果的基础上,从方法论的角度探讨了关联基础设施系统的脆弱性,并以华中地区某城市电力—供水网络为例分析了网络在节点级联故障下的脆弱性,为控制基础设施系统的级联故障、增强系统的抗干扰能力提供决策支持。 相似文献
7.
地域通信网作为一种复杂网络系统,具有复杂性、模糊性和多变性等特性,对其脆弱性评估指标赋权时,如果主观性较强,就容易出现与实际数据不相符的现象。针对这一情况,提出将熵值模糊综合评判法应用于地域通信网脆弱性评估。依据地域通信网的实际情况,建立层次化的脆弱性指标体系,在此基础上建立模糊集合及隶属度矩阵。运用熵值法对评价指标进行赋权,依次得到各层指标模糊评价,求得评估结果的数值。该方法充分保证了评估指标权重的客观性,能够更准确、方便地描述地域通信网的脆弱性。 相似文献
8.
本文对目前针对Linux平台下的BackTrack5进行阐述,内容涵盖敏感信息收集,漏洞信息收集,漏洞工具测试,账户特权升级等,笔者对在虚拟机环境下运行,下载BackTrack5,加载运行BackTrack5后需要进行网络配置加以说明,同时针对各种工具的常用命令及基本应用,实践后对其优缺点加以说明。 相似文献
9.
软件安全性检测技术综述 总被引:1,自引:0,他引:1
该文阐述了网络软件安全检测的重要性,介绍了现有的主要检测方法,包括形式化安全测试、基于模型的安全功能测试、语法测试、基于故障注入的安全测试、基于属性的测试、模糊测试、基于风险的安全性测试、基于故障树的安全性测试以及基于渗透的安全性测试。 相似文献
10.
芯片作为信息存储、传输、应用处理的基础设备,其安全性是信息安全的一个重要组成部分。可编程逻辑器件安全性漏洞检测平台正是为了检测出逻辑芯片内可能存在的攻击后门和设计缺陷而研制的,从而确保电子设备中信息安全可靠。文章研究可编程逻辑器件漏洞检测平台的设计与实现,简要介绍了检测平台的总体结构和运行机制,给出了检测平台的总体设计思想、实现方案及系统组成,并深入研究了漏洞检测平台设计与实现所涉及的相关技术。 相似文献