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   829篇
  免费   48篇
  国内免费   41篇
电工技术   22篇
综合类   51篇
化学工业   22篇
金属工艺   80篇
机械仪表   19篇
建筑科学   3篇
矿业工程   2篇
能源动力   47篇
轻工业   10篇
石油天然气   4篇
武器工业   3篇
无线电   89篇
一般工业技术   28篇
冶金工业   342篇
自动化技术   196篇
  2024年   2篇
  2023年   7篇
  2022年   21篇
  2021年   15篇
  2020年   22篇
  2019年   11篇
  2018年   11篇
  2017年   18篇
  2016年   12篇
  2015年   11篇
  2014年   28篇
  2013年   23篇
  2012年   51篇
  2011年   63篇
  2010年   78篇
  2009年   63篇
  2008年   55篇
  2007年   68篇
  2006年   84篇
  2005年   50篇
  2004年   68篇
  2003年   53篇
  2002年   29篇
  2001年   23篇
  2000年   14篇
  1999年   7篇
  1998年   3篇
  1997年   6篇
  1996年   4篇
  1995年   2篇
  1994年   1篇
  1993年   1篇
  1992年   4篇
  1991年   3篇
  1990年   2篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1985年   1篇
  1984年   1篇
排序方式: 共有918条查询结果,搜索用时 140 毫秒
1.
2.
马超  孙丽钢  张玮  关胜  贾贵君 《连铸》2020,39(4):54-59
为了研究薄板厂CSP产线热轧卷板纵裂缺陷产生原因,对连铸工艺及设备各运行参数进行了调查分析。结果表明,连铸机振动台振动精度差、结晶器铜板结垢是导致热轧卷纵裂缺陷的主要原因。采取调整振动参数、提升振动台对中精度以及控制铜板结垢等措施后,热轧卷板表面纵裂纹缺陷显著降低,纵裂率由最高的1.15%降至0.10%以下。针对CSP铸机,在保证结晶器铜板导热良好的前提下,需严格控制结晶器振动台四连杆机构的关节轴承间隙在0.02 mm以内,振动台台面标高偏差在0.05 mm之内。结晶器振动在水平方向的位移量在0.1 mm以内为宜。  相似文献   
3.
Global concern for depleting fossil fuel reserves have been compelling for evolving power generation options using renewable energy sources. The solar energy happens to be a potential source for running the power plants among renewable energy sources. Integrated Solar Combined Cycle(ISCC) power plants have gained popularity among the thermal power plants. Traditional ISCC power plants use Direct Steam Generation(DSG) approach. However, with the DSG method, the ISCC plant’s overall thermal efficiency does not increase significantly due to variations in the availability of solar energy. Thermal Energy Storage(TES) systems when integrated into the solar cycle can address such issues related to energy efficiency, process flexibility, reducing intermittency during non-solar hours. This review work focuses and discusses the developments in various components of the ISCC system including its major cycles and related parameters. The main focus is on CSP technologies, Heat Transfer Fluid(HTF), and Phase Change Material(PCM) used for thermal energy storage. Further, study includes heat enhancement methods with HTF and latent heat storage system. This study will be beneficial to the power plant professionals intending to modify the solar-based Combined Cycle Power Plant(CCPP) and to retrofit the existing Natural Gas Combined Cycle(NGCC) plant with the advanced solar cycle.  相似文献   
4.
In this study, two wind-solar-based polygeneration systems namely CES-1 and CES-2 are developed, modeled, and analyzed thermodynamically. CES-1 hybridizes a heliostat based CSP system with wind turbines while CES-2 integrates heliostat-based CPVT with wind turbines. This study aims to compare the production and thermodynamics performance of two heliostat based concentrated solar power technologies when hybridized with wind turbines. The systems have been modeled to produce, freshwater, hot water, electricity, hydrogen, and cooling with different cycles/subsystems. While the overall objective of the study is to model two polygeneration systems with improved energy and exergy performances, the performances of two solar technologies are compared. The wind turbine system integrated with the comprehensive energy systems will produce 1.14 MW of electricity and it has 72.2% energy and exergy efficiency. Also, based on the same solar energy input, the performance of the heliostat integrated CPVT system (CES-2) is found to be better than that of the CSP based system (CES-1). The polygeneration thermal and exergy efficiencies for the two systems respectively are 48.08% and 31.67% for CES-1; 59.7% and 43.91% for CES-2. Also, the electric power produced by CES-2 is 280 kW higher in comparison to CES-1.  相似文献   
5.
本文分析了一种群塔式太阳能光热发电系统的定日镜、吸热蓄热器、汽水管道等系统的基本仪表配置和仪表的主要功能。根据这些仪表配置的特点提出了无线仪表和无线网络的具体配置方案。本文还介绍了每种无线仪表的特点和在群塔式太阳能光热发电系统中的具体应用范围以及各种无线网络设备,如无线多功能节点、各类无线转接模块、手持设备、无线管理平台等的功能以及配置。  相似文献   
6.
In spite of the recent success on the implementation of Concentrating Solar Power (CSP), still this technology needs a substantial enhancement to achieve competitiveness. This paper provides thorough insight after previous analyses on an alternative concept for higher efficiency CSP systems based on the replacement of the power block by an electrochemical conversion system. Concentrating solar energy is herewith used to decompose methane into hydrogen and carbon, which are used in hydrogen and carbon fuel cells for electricity generation. This approach envisages modular, efficient and flexible generation plants. Dispatchability can be achieved by storing the solid carbon. Solar-to-electricity efficiency was calculated assuming thermodynamic equilibrium composition and experimental data available from literature, and compared with those of conventional power generation systems and commercial CSP plants. It is concluded that this new-generation CSP concept is potentially able to produce power more efficiently than the current state-of-the art solar thermal power plants.  相似文献   
7.
As one of the most promising architectural styles, REpresentational State Transfer (REST) was proposed to support a scalable and reliable design for large-scale distributed hypermedia systems such as the World Wide Web (WWW). However, the rapid development of RESTful systems brings the misunderstanding and misapplying of the REST architecture. As a consequence, considerable confusions about REST exist and many examples of supposedly RESTful applications violate key REST constraints. Thus, it is of significant importance to give a better and explicit understanding of REST architecture to guide the design and implementations of RESTful systems.In this paper, we give a formalization and analysis of the REST architecture from the perspective of Communicating Sequential Processes (CSP), which is one of the most famous process algebras. In particular, we present a formal model to capture essential features for the REST architecture, where components (together with one connector) of RESTful systems are modeled as CSP processes. Besides, resources are also abstracted as CSP processes. Furthermore, all the REST constraints, including Client–Server, Cacheable, Stateless, Uniform Interface, Layered and Code-On-Demand, are described in our framework and implemented in the model checker Process Analysis Toolkit (PAT) to check whether a system breaks REST constraints or not. It is difficult to ensure that a system is RESTful system, because many unRESTful systems may also contain unRESTful properties besides satisfying the six REST constraints. Thus, a complementary approach is proposed in this paper to check the system from a different perspective; that is, if a system breaks any specification of the REST constraints, then it is not a RESTful system. Finally, to show the feasibility of our approach, we illustrate a case study about an application scenario for environment monitoring. One feature of the proposed framework for the REST architecture is that it not only confines to HyperText Transport Protocol (HTTP) but can also be applied to other REST-compliant protocols, e.g., Constrained Application Protocol (CoAP). Consequently, through the general framework, a better understanding of the REST architecture can be achieved, and moreover, implementations and designs of RESTful systems can benefit from it.  相似文献   
8.
对比研究了武钢CSP厂和传统热轧工艺提供的冷轧基板的力学性能以及由其生产的冷轧普板的力学性能,并对CSP厂供冷轧基板的组织和第二相粒子进行了研究分析。CSP厂供冷轧基板的屈服强度和抗拉强度比传统热轧工艺生产供冷轧基板分别高30~40MPa、10~40MPa,其晶粒度为8级,比常规热轧供基板细。对该冷轧基板第二相粒子分析看出,有较多Ti(C,N)、CuS、MnS的复合相存在,故该冷轧基板有较高的力学性能。  相似文献   
9.
国内某钢厂CSP生产线生产2.0mm带钢时F3轧机出现异常振动.为查找振动原因,对其进行三维建模,并由此建立轧机整体有限元模型,通过节点耦合方式实现内部联接,得到轧机前15阶固有频率和振型.分析结果对轧机的设计与分析有一定的参考价值.  相似文献   
10.
为研究CSP工艺条件下钢的动态再结晶规律,利用Gleeble-1500热模拟实验机对CSP工艺生产的Q235B钢连铸坯进行了热模拟研究。研究结果表明,在较高变形温度和较低应变速率下Q235B钢容易发生动态再结晶,试验中Q235B钢发生动态再结晶的适宜条件为:变形温度970℃以上、应变速率在5/s以下。再结晶组织为铁素体和少量珠光体。通过热模拟数据的拟合分析,得出了其动态再结晶模型为Z=εexp(289.58/RT)。  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