全文获取类型
收费全文 | 10526篇 |
免费 | 422篇 |
国内免费 | 321篇 |
专业分类
电工技术 | 325篇 |
综合类 | 854篇 |
化学工业 | 225篇 |
金属工艺 | 167篇 |
机械仪表 | 1018篇 |
建筑科学 | 2735篇 |
矿业工程 | 428篇 |
能源动力 | 190篇 |
轻工业 | 214篇 |
水利工程 | 111篇 |
石油天然气 | 265篇 |
武器工业 | 24篇 |
无线电 | 704篇 |
一般工业技术 | 327篇 |
冶金工业 | 427篇 |
原子能技术 | 20篇 |
自动化技术 | 3235篇 |
出版年
2024年 | 9篇 |
2023年 | 52篇 |
2022年 | 94篇 |
2021年 | 136篇 |
2020年 | 177篇 |
2019年 | 116篇 |
2018年 | 132篇 |
2017年 | 130篇 |
2016年 | 231篇 |
2015年 | 293篇 |
2014年 | 583篇 |
2013年 | 615篇 |
2012年 | 591篇 |
2011年 | 762篇 |
2010年 | 613篇 |
2009年 | 634篇 |
2008年 | 622篇 |
2007年 | 850篇 |
2006年 | 898篇 |
2005年 | 754篇 |
2004年 | 659篇 |
2003年 | 653篇 |
2002年 | 423篇 |
2001年 | 308篇 |
2000年 | 235篇 |
1999年 | 175篇 |
1998年 | 134篇 |
1997年 | 78篇 |
1996年 | 57篇 |
1995年 | 49篇 |
1994年 | 31篇 |
1993年 | 23篇 |
1992年 | 13篇 |
1991年 | 17篇 |
1990年 | 12篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1987年 | 5篇 |
1986年 | 10篇 |
1985年 | 11篇 |
1984年 | 14篇 |
1983年 | 10篇 |
1982年 | 10篇 |
1981年 | 5篇 |
1980年 | 2篇 |
1979年 | 5篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 5篇 |
1968年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
81.
82.
针对现有的汽车衡计量方式存在利用遥控信号作弊的问题,提出了一种ERP环境下的汽车衡GPRS计量监控系统的设计方案,详细介绍了该系统的硬件、软件设计及功能。该系统采用分段计算、列表筛选的方法进行数据处理,在没有红外定位系统时仍可以自动检测车辆信息,并可将准确的计量数据发给企业监管部门,使系统突破了使用场所的限制,可以很方便地适应一些不适合安装红外定位系统的汽车衡现场;利用无线识别技术实时判断出作弊吨位数据,并把这些数据信息和报警信号通过GPRS网络传送给企业监管部门并进行报警。实际应用表明,该系统操作简单、实用、方便,与企业ERP系统相结合有效地预防了人为作弊,提高了工作效率。 相似文献
83.
84.
丁贤 《数字社区&智能家居》2011,(13)
作为企业级数据仓库的路径图,元数据在企业级数据仓库的建设中起着重要的作用。设计一个描述能力强、内容完善的元数据,是有效实现企业级数据仓库功能的重要环节。该文通过对双向体系元数据管理系统的研究,给出了一个企业级数据仓库的元数据管理的解决方案。该方案能够支持从企业级数据仓库子系统抽取元数据存储到元数据管理系统,同时也支持向数据仓库子系统提供其所需的元数据信息,解决诸多企业级数据仓库的运行管理问题,大大减少了企业级数据仓库的管理难度、保证了元数据的准确性、使得各子系统能高效地通信和稳定运行。 相似文献
85.
通过基于SOA技术的高校管理工作一体化信息系统软件的设计,综合性地量化学校各项重要信息,使信息一体化程度更为集中,帮助管理工作者、校务管理人员做出动态的管理决策调整,对于URP流程改造提供具体的实践模型参考。同时研究出一种能够应用于各类普通高校管理工作的无线与网络相结合的软件系统设计模型,提供一种可量化的工作数据系统样本,以比较低廉的代价解决校园信息化过程中的信息孤岛问题,进一步提升校园信息一体化程度。 相似文献
86.
Robert Lagerström Author Vitae Pontus Johnson Author VitaeAuthor Vitae 《Journal of Systems and Software》2010,83(8):1387-1403
Enterprise architecture (EA) models can be used in order to increase the general understanding of enterprise systems and to perform various kinds of analysis. This paper presents instantiated architectural models based on a metamodel for enterprise systems modifiability analysis, i.e. for assessing the cost of making changes to enterprise-wide systems. The instantiated architectural models detailed are based on 21 software change projects conducted at four large Nordic companies. Probabilistic relational models (PRMs) are used for formalizing the EA analysis approach. PRMs enable the combination of regular entity-relationship modeling aspects with means to perform enterprise architecture analysis under uncertainty. The modifiability metamodel employed in the analysis is validated with survey and workshop data (in total 110 experts were surveyed) and with the data collected in the 21 software change projects. Validation indicates that the modifiability metamodel contains the appropriate set of elements. It also indicates that the metamodel produces estimates within a 75% accuracy in 87% of the time and has a mean accuracy of 88% (when considering projects of 2000 man-hours or more). 相似文献
87.
Bas van der Raadt Author Vitae Marc Bonnet Author Vitae 《Journal of Systems and Software》2010,83(10):1954-1969
Enterprise Architecture (EA) is increasingly being used by large organizations to get a grip on the complexity of their business processes, information systems and technical infrastructure. Although seen as an important instrument to help solve major organizational problems, effectively applying EA seems no easy task. Active participation of EA stakeholders is one of the main critical success factors for EA. This participation depends on the degree in which EA helps stakeholders achieve their individual goals. A highly related topic is effectiveness of EA, the degree in which EA helps to achieve the collective goals of the organization. In this article we present our work regarding EA stakeholder satisfaction and EA effectiveness, and compare these two topics. We found that, regarding EA, the individual goals of stakeholders map quite well onto the collective goals of the organization. In a case study we conducted, we found that the organization is primarily concerned with the final results of EA, while individual stakeholders also worry about the way the architects operate. 相似文献
88.
Semantic Web computing in industry 总被引:1,自引:0,他引:1
John G. Breslin Author Vitae David O'Sullivan Author VitaeAuthor Vitae Laurentiu Vasiliu Author Vitae 《Computers in Industry》2010,61(8):729-741
The Semantic Web has attracted significant attention during the last decade. On the one hand, many research groups have changed their focus towards Semantic Web research and research funding agencies particularly in Europe have explicitly mentioned Semantic Web in their calls for proposals. On the other hand, industry has also begun to watch developments with interest and a number of large companies have started to experiment with Semantic Web technologies to ascertain if these new technologies can be leveraged to add more value for their customers or internally within the company, while there are already several offers of vendors of Semantic Web solutions on the market. The essence of the Semantic Web is to structure Web-based information to make it more interoperable, machine-readable and thereafter to provide a means to relate various information concepts more easily and in a reusable way. The Semantic Web acts as an additional layer on the top of the Web, and is built around explicit representations of information concepts and their relationships such as ontologies and taxonomies. Furthermore, Semantic Web technologies are not only valuable on an open environment like the Web, but also in closed systems such as in industrial settings. Hence, these technologies can be efficiently deployed for domains including Web Services, Enterprise Application Integration, Knowledge Management and E-Commerce, fulfilling existing gaps in current applications. This paper focuses on this synthesis between Semantic Web technologies and systems problems within industrial applications. There will be a short review of Semantic Web standards, languages and technologies followed by a more detailed review of applications of Semantic Web computing in industry. The paper covers theoretical considerations as well as use cases and experience reports on the topic, and we also present some current challenges and opportunities in the domain. 相似文献
89.
In this paper, we study two interesting variants of the classical bin packing problem, called Lazy Bin Covering (LBC) and Cardinality Constrained Maximum Resource Bin Packing (CCMRBP) problems. For the offline LBC problem, we first prove the approximation ratio of the First-Fit-Decreasing and First-Fit-Increasing algorithms, then present an APTAS. For the online LBC problem, we give a competitive analysis for the algorithms of Next-Fit, Worst-Fit, First-Fit, and a modified HARMONICM algorithm. The CCMRBP problem is a generalization of the Maximum Resource Bin Packing (MRBP) problem Boyar et al. (2006) [1]. For this problem, we prove that its offline version is no harder to approximate than the offline MRBP problem. 相似文献
90.
Modeling organizational performance indicators 总被引:1,自引:0,他引:1
Performance measurement and analysis is crucial for steering the organization to realize its strategic and operational goals. Relevant performance indicators and their relationships to goals and activities need to be determined and analyzed. Current organization modeling approaches do not reflect this in an adequate way. This paper attempts to fill the gap by presenting a framework for modeling performance indicators within a general organization modeling framework. 相似文献