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   371篇
  免费   32篇
电工技术   2篇
化学工业   57篇
机械仪表   5篇
建筑科学   7篇
矿业工程   3篇
能源动力   1篇
轻工业   23篇
水利工程   4篇
石油天然气   1篇
无线电   41篇
一般工业技术   140篇
冶金工业   99篇
原子能技术   7篇
自动化技术   13篇
  2024年   1篇
  2023年   3篇
  2022年   17篇
  2021年   13篇
  2020年   7篇
  2019年   6篇
  2018年   3篇
  2017年   5篇
  2016年   13篇
  2015年   14篇
  2014年   18篇
  2013年   19篇
  2012年   14篇
  2011年   19篇
  2010年   16篇
  2009年   21篇
  2008年   11篇
  2007年   10篇
  2006年   12篇
  2005年   12篇
  2004年   8篇
  2003年   17篇
  2002年   12篇
  2001年   14篇
  2000年   5篇
  1999年   6篇
  1998年   27篇
  1997年   27篇
  1996年   10篇
  1995年   5篇
  1994年   5篇
  1993年   4篇
  1992年   1篇
  1991年   3篇
  1988年   4篇
  1987年   1篇
  1986年   2篇
  1985年   2篇
  1984年   2篇
  1983年   1篇
  1982年   1篇
  1980年   1篇
  1979年   1篇
  1977年   5篇
  1976年   3篇
  1973年   2篇
排序方式: 共有403条查询结果,搜索用时 15 毫秒
1.
Recent, as well as past, studies of reactor trip frequencies and other types of operating experience have shown that relatively high frequencies are likely in new plants with little accumulated operating time. In order to better understand all the factors which contribute to high frequencies in new plants, the authors have made a comparison of reactor trip frequencies between plants which went into operation in the 1960's and the early 1970's and those which have gone into operation more recently. Trip frequency versus accumulated operating time for two plant groups are compared to see the extent to which design differences (e.g., capacity, thermal margin) affect trip frequency.This paper also presents a review of some recent events in which plant age has played a major role. The events which are reviewed have been identified through the normal systematic event analysis program conducted by the NRC. Information regarding these events was obtained through followup by reviews conducted by NRC Resident Inspectors as well as event reports submitted by licensees.  相似文献   
2.
This study evaluated newly proposed Human–Machine Interface (HMI) design concepts for improving the ergonomics of hydraulic excavators. The design concepts were based on an augmented interaction technique which involved the use of heads-up display (HUD) and coordinated control as HMI elements. Two alternative HMI designs were elaborated in order to separately evaluate the ergonomic impacts of the head-up display and the coordinated control by comparing them to the standard HMI design. The effectiveness of these three HMI designs in terms of the reduction of the operators' mental and physical workload were assessed by conducting experiments utilizing human subjects, ages 23–35 years. The National Aeronautics and Space Administration's Task Load Index (NASA TLX) method was used for collecting subjective workload scores based on a weighted average of ratings of six factors: Mental Demand, Physical Demand, Temporal Demand, Own Performance, Effort, and Frustration Level. The results showed that the type of HMI design affects different aspects of the operator's workload. Indeed, it showed how the proposed augmented interaction is an effective solution for reducing the ergonomic gaps in terms of mental workload, and to a lesser extent the physical workload, subjected by the standard HMI design.  相似文献   
3.
4.
Replies to comments made by G. E. Gignac (see record 2005-06671-010) on the current authors' original article (see record 2003-02341-015). Gignac reanalyzed the factor structure of the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) and found results that differed from those the authors obtained initially. The authors tracked down the surprising sources of those discrepancies. G. E. Gignac's hierarchical model of emotional intelligence appears promising, and the authors anticipate that further investigations of the MSCEIT factor structure may yield additional information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
5.
6.
The stability and activity of electrocatalysts are fundamental in energy-related applications (e.g., hydrogen generation and energy storage). Electrocatalysts degrade over time when the active centers are not strongly anchored to the support. However, if the active centers are too strongly anchored, the activity of the electrocatalysts decreases due to reduced accessibility to reactants. Herein, a strategy is presented to balance the stability and activity of different active materials using a natural and flexible support material that can be woven and carbonized. Lotus fibers, which have surface hydroxyl and phenolic groups, high mechanical strength, and a mesoscale porosity post-pyrolysis, are used to load diverse functional metal-containing materials such as metal–organic frameworks, 2D materials, metal sulfide nanoparticles, metal ions, and high-entropy alloys. After pyrolysis, the electrocatalysts display flexibility, high catalytic performance, and long-term stability, outperforming commercial benchmarks (e.g., Pt/C) in specific scenarios for water splitting, liquid batteries, and flexible electronics.  相似文献   
7.
The preparation of monodisperse polymer (polydopamine, PDA) capsules by a one‐step interfacial polymerization of dopamine onto dimethyldiethoxysilane (DMDES) emulsion droplets and removal of the DMDES templates with ethanol is reported. The diameters of the PDA capsules can be tailored from 400 nm to 2.4 µm by varying either the DMDES emulsion condensation time or the emulsion concentration used for templating. Further, capsules with defined nanometer‐scale shell thicknesses (ranging from ~10 to 30 nm) can be prepared by adjusting the emulsion concentration. This shell thickness can be increased by repeated interfacial polymerization of dopamine, with three cycles yielding capsules with a shell thickness of up to 140 nm (for a 0.6% v/v suspension). Functional substances, such as organically stabilized magnetic (Fe3O4) nanoparticles, quantum dots (CdSe/CdS), and hydrophobic drugs (thiocoraline), can be preloaded in the emulsion droplets, and following PDA coating and DMDES removal, these materials remain encapsulated in the polymer capsules. All of the unloaded and loaded PDA capsules are monodisperse and do not aggregate. This work provides new avenues for the preparation of polymer capsules with defined size and shell thickness and for the encapsulation of a range of hydrophobic substances.  相似文献   
8.
A very important issue in optical burst switching (OBS) networks is the excessive burst drop when no suitable network resources are found during path reservation. In this study, a network scenario is evaluated in which AWG-based optical nodes are used as burst router nodes within the optical network. The two classical solutions to solve the burst contentions on the channels outgoing from the node are considered, that is, either based on buffering within the node, or by exploiting deflection routing. A performance evaluation is carried out to evaluate and compare these solutions for different network topologies with different node and traffic parameters. Our main contribution is to set numerical tradeoffs between burst deflection through the network and buffering in the node, so that a guidance in optical network design is provided where node buffering is inherently technologically limited.  相似文献   
9.
Therapeutic artificial cells or organelles are nanoengineered vehicles that are expected to substitute for missing or lost cellular function. The creation of capsosomes, polymer carrier capsules containing liposomal subcompartments, is a promising approach towards constructing such therapeutic devices using the layer‐by‐layer assembly method. Herein, the assembly of intact, nonaggregated capsosomes containing multiple liposome layers is reported. It is also further demonstrated that thiocoraline, a hydrophobic model peptide with antitumor activity, can be efficiently loaded into the membrane of the liposomal subcompartments of the capsosomes. Cell viability assays verify the activity of the trapped antitumor cargo. It is also shown that pristine capsosomes do not display inherent cytotoxic effects. The ability to tune the number of liposome layers and hence the drug loading in capsosomes as well as their noncytotoxicity provide new opportunities for the creation of therapeutic artificial cells and organelles.  相似文献   
10.
The ability to reliably engineer surfaces with nanoscale precision is a rapidly developing field of research with applications ranging from biosensing and biomedical materials to antifouling and corrosion protection. The layer‐by‐layer (LbL) approach is a widely utilized method for engineering surfaces, in part because of the large array of polymeric materials that can be integrated and the diverse range of functionality that these materials afford. Herein, we discuss the LbL deposition of multicomponent ‘blend' solutions to form polyelectrolyte blend multilayer films and coatings. This approach is a versatile platform for enhancing film stability, incorporating a wide range of functional materials, controlling film morphology and material properties, and increasing biological response, thereby expanding the range of potential applications.  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