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   664篇
  免费   31篇
  国内免费   8篇
电工技术   37篇
综合类   14篇
化学工业   73篇
金属工艺   13篇
机械仪表   22篇
建筑科学   99篇
矿业工程   5篇
能源动力   95篇
轻工业   81篇
水利工程   25篇
石油天然气   15篇
无线电   41篇
一般工业技术   93篇
冶金工业   15篇
原子能技术   8篇
自动化技术   67篇
  2024年   2篇
  2023年   7篇
  2022年   9篇
  2021年   13篇
  2020年   15篇
  2019年   19篇
  2018年   14篇
  2017年   21篇
  2016年   35篇
  2015年   23篇
  2014年   44篇
  2013年   52篇
  2012年   41篇
  2011年   59篇
  2010年   64篇
  2009年   54篇
  2008年   41篇
  2007年   46篇
  2006年   31篇
  2005年   31篇
  2004年   26篇
  2003年   16篇
  2002年   13篇
  2001年   5篇
  2000年   1篇
  1999年   1篇
  1998年   3篇
  1997年   1篇
  1996年   2篇
  1995年   5篇
  1994年   2篇
  1993年   1篇
  1991年   2篇
  1989年   1篇
  1979年   1篇
  1955年   1篇
  1954年   1篇
排序方式: 共有703条查询结果,搜索用时 812 毫秒
1.
The use of computer models offers a general and flexible framework that can help to deal with some of the complexities and difficulties associated with the development of water management plans as prescribed by the Water Framework Directive. However, despite the advantages modelling presents, the integration of information derived from models into policy is far away from being trivial or the norm. Part of the difficulties of this integration is rooted in the lack of confidence policy makers have on the incorporation of modelling information into policy formulation. In this paper we examine the reasons for this apparent lack of confidence and explore how some tools, presently in use, address this problem. We conclude that public confidence in models is highly dependent on the way uncertainties are addressed and suggest possible directions of action to improve the current situation. Four real case studies illustrate how computer models have been used in The Netherlands for carrying out management plans at regional and national scale. We suggest that the solution to integrate modelling information into policy formulation lies on both the modelling and the policy-making communities.  相似文献   
2.
This paper focuses on the harmonization of feed-in laws in the European Union as a support mechanism for the promotion of renewable electricity. In particular, it proposes a methodology for harmonization based on a feed-in law with a modular and transparent premium for renewable electricity producers. This premium considers technology costs, some grid services, political incentives and national priorities. The proposed approach includes flexibility mechanisms to update and revise premiums, to avoid windfall profits for producers, and to share technology innovation benefits with electricity consumers while maintaining incentives for innovation. Our approach is based on the review of the main features of the German and Spanish feed-in laws, and takes into account other necessary considerations for harmonization, such as grid access, funding, definitions and standards, ownership of rights derived from renewables, and exceptions for small non-commercial producers and energy-intensive industries.  相似文献   
3.
In the Industry 4.0 era, manufacturers strive to remain competitive by using advanced technologies such as collaborative robots, automated guided vehicles, augmented reality support and smart devices. However, only if these technological advancements are integrated into their system context in a seamless way, they can deliver their full potential to a manufacturing organization. This integration requires a system architecture as a blueprint for positioning and interconnection of the technologies. For this purpose, the HORSE framework, resulting from the HORSE EU H2020 project, has been developed to act as a reference architecture of a cyber-physical system to integrate various Industry 4.0 technologies and support hybrid manufacturing processes, i.e., processes in which human and robotic workers collaborate. The architecture has been created using design science research, based on well-known software engineering frameworks, established manufacturing domain standards and practical industry requirements. The value of a reference architecture is mainly established by application in practice. For this purpose, this paper presents the application and evaluation of the HORSE framework in 10 manufacturing plants across Europe, each with its own characteristics. Through the physical deployment and demonstration, the framework proved its goal to be basis for the well-structured design of an operational smart manufacturing cyber-physical system that provides horizontal, cross-functional management of manufacturing processes and vertical control of heterogeneous technologies in work cells. We report on valuable insights on the difficulties to realize such systems in specific situations. The experiences form the basis for improved adoption, further improvement and extension of the framework. In sum, this paper shows how a reference architecture framework supports the structured application of Industry 4.0 technologies in manufacturing environments that so far have relied on more traditional digital technology.  相似文献   
4.
牙舟泥哨     
牙舟泥哨作为民间陶制玩具在数百年的发展中逐渐形成了自己的风格和个性,在造型、审美上带有独特黔南地方特色。本文从造型和审美的角度对牙舟泥哨进行了分析。  相似文献   
5.
European authorities consider that N2O emissions from nitric acid plants can be reduced to a large extent at a relatively low cost. Two regulation approaches can have major implications for the fertilizer industry in Europe. The EU integrated pollution prevention and control (IPPC) directive will be effective from October 2007 for existing plants. In this, emission permits will be based on best available techniques (BAT). Additionally, the EU commission will shortly consider whether the emission trading directive should be applicable to cover other greenhouse gases besides CO2. This paper discusses advantages and drawbacks of these approaches, with emphasis on how emission trading with N2O can be turned into a win–win situation both for European governments and for the fertilizer industry.  相似文献   
6.
欧盟对农药的重新评定与我国除草剂品种发展   总被引:1,自引:0,他引:1  
苏少泉  滕春红  王春林 《农药》2004,43(9):385-388
评述了欧盟评定的农药名单中禁用的除草剂品种及我国今后除草剂的开发与使用。  相似文献   
7.
Recent European Directives promoted the development of biofuels, requesting mandatory limits to their emissions ot greenhouse gases (GHG). Second-generation biofuels based on lignocellulosic biomass are prime candidates but their GHG emissions are variable and uncertain. Agro-ecosystem modeling can capture them and the performance of biofuel feedstocks.This study aimed at optimizing feedstock supply for a bioethanol unit in France, from agricultural residues, annual and perennial crops. Their productivity and environmental impacts were modelled on a regional scale using geo-referenced data on soil properties, crop management, land-use and future weather data. Several supply scenarios were tested. Cereal straw was the most efficient feedstock but had a low availability, and only miscanthus could meet the bioethanol plant's demand. Sorghum combined poor yields and high GHG emissions compared by miscanthus and triticale. A mix of three biomass sources used less than 3% of the regional agricultural land while abating GHG emissions by 60%.  相似文献   
8.
玩具是儿童的天使,在儿童成长中起到教育、益智等重要作用,儿童玩具的安全性也就更加的令人关注。儿童玩具安全设计应遵循三大原则:人性化设计原则、科学性设计原则、绿色设计原则。根据这三大原则进行儿童玩具的安全性设计,有利于儿童身心的健康发展,加速现代玩具企业的产业升级,打造具有国际影响力的民族品牌。  相似文献   
9.
The European Directive on computer work (VDU 90/270/EEC) is implemented in the Finnish Government Decree. The aim of the present study was to evaluate the effects of the legislation and its applications in practice. The quantitative method used an online questionnaire. The respondents were employers (N = 934), employees (N = 1872) and occupational health care (OHC) units (N = 289). The majority of all these three groups considered the provisions clear and easy to understand, comprehensive, and easy to comply with. The provisions had a great impact on preventing mental overloading, arranging sight tests at the employer's cost, and on the refunding of eyeglasses for computer work. Most employers felt they did not need any more specific provisions, whereas half of the employees and OHC professionals would have liked the provisions to be more detailed. More explicit and specific regulations were also needed for practice applications in particular, as well as for the refunding of the costs of special eyeglasses for computer work. A total of 59% of the employers reported that costs of glasses are refunded, whereas the figure for employees was clearly lower (37%). OHC professionals reported that the costs of glasses were refunded in 82% of their customer workplaces. The practical conclusion is that employees' sight examinations and compensation for eyeglasses should be promoted in computer work. Moreover, ergonomic applications are best carried out in co-operation with OHC personnel.  相似文献   
10.
文章探讨了体验经济时代下积木式产品因何受到消费者青睐,以及在积木式产品生产、使用过程中设计师与用户角色的转变,并从设计角度提出对积木式产品开发的思考。  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