全文获取类型
收费全文 | 1235篇 |
免费 | 42篇 |
国内免费 | 29篇 |
专业分类
电工技术 | 42篇 |
技术理论 | 1篇 |
综合类 | 37篇 |
化学工业 | 97篇 |
金属工艺 | 26篇 |
机械仪表 | 125篇 |
建筑科学 | 159篇 |
矿业工程 | 25篇 |
能源动力 | 41篇 |
轻工业 | 23篇 |
水利工程 | 25篇 |
石油天然气 | 48篇 |
武器工业 | 7篇 |
无线电 | 76篇 |
一般工业技术 | 116篇 |
冶金工业 | 23篇 |
原子能技术 | 131篇 |
自动化技术 | 304篇 |
出版年
2024年 | 2篇 |
2023年 | 12篇 |
2022年 | 18篇 |
2021年 | 25篇 |
2020年 | 32篇 |
2019年 | 21篇 |
2018年 | 20篇 |
2017年 | 30篇 |
2016年 | 37篇 |
2015年 | 40篇 |
2014年 | 95篇 |
2013年 | 126篇 |
2012年 | 88篇 |
2011年 | 100篇 |
2010年 | 81篇 |
2009年 | 66篇 |
2008年 | 67篇 |
2007年 | 78篇 |
2006年 | 59篇 |
2005年 | 32篇 |
2004年 | 32篇 |
2003年 | 37篇 |
2002年 | 27篇 |
2001年 | 23篇 |
2000年 | 21篇 |
1999年 | 23篇 |
1998年 | 18篇 |
1997年 | 10篇 |
1996年 | 14篇 |
1995年 | 15篇 |
1994年 | 8篇 |
1993年 | 10篇 |
1992年 | 7篇 |
1991年 | 10篇 |
1990年 | 10篇 |
1989年 | 6篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 1篇 |
排序方式: 共有1306条查询结果,搜索用时 15 毫秒
1.
The effect of the emergency perception of bystanders of cyberbullying victims on helping behaviors is often neglected in research on cyberbullying. In this study, we explored the influence of this cognitive factor on cyber-bystanders’ helping tendencies as well as elucidated possible underlying processes. The results of two studies were reported. In Study 1, 150 undergraduates read a true case of a girl experiencing cyberbullying. The results indicated that when the participants perceived the victim’s situation to be more critical (i.e., higher emergency perception), their helping tendencies were stronger, partly through increased state empathy followed by feelings of responsibility to help. In Study 2, we randomly assigned 300 undergraduates to two groups. The low emergency group read the same cyberbullying case as Study 1, whereas the cyberbullying case read by the high emergency group contained additional emergency information of the victim. The results indicated that the high emergency group expressed stronger helping tendencies than did the low emergency group. This effect was caused by a stronger perception that the victim was in an emergency situation, which not only strengthened the participants’ helping tendencies directly but also indirectly through increasing their state empathy and feelings of responsibility to help. 相似文献
2.
3.
为确保特殊时期党政军指挥通信畅通,充分利用中国移动现网资源,将卫星通信与地面光缆、微波传榆。以及移动网络无缝衔接,共同构建中国移动天地一体应急通信平台。 相似文献
4.
5.
It has been well recognized that a diagnosis procedure that allows operators to successfully identify the nature of an on-going event is inevitable for an effective and appropriate recovery. Unfortunately, studies for a framework that can suggest a unified and consistent process in constructing a serviceable diagnosis procedure seem to be scant. Thus, Park et al. have suggested a systematic framework that can be used to construct a useful diagnosis procedure. In addition, the diagnosis procedure that is currently in use at the reference nuclear power plant (NPP) is reformed in order to demonstrate the appropriateness of the suggested framework. However, the necessity of a well-designed experiment is proposed to confirm the appropriateness of the suggested framework.In this regard, in this study, an experiment is conducted using a full-scope simulator of the reference NPP. From the experiment, two sets of operators' diagnosis performance data are collected, and then they are compared to investigate the change of an operator's diagnosis performance with respect to two types of diagnosis procedures.As a result, it is shown that an operator's diagnosis performance is improved when the revised diagnosis procedure is used. Therefore, it is reasonable to conclude that the suggested framework is useful in constructing an effective diagnosis procedure. 相似文献
6.
各国核电厂场外应急计划的比较 总被引:1,自引:0,他引:1
本文分析和比较了各国核电厂的应急计划,特别是场外应急的干予水平和应急计划区,讨论了我国干予水平、核电厂应急计划区和香港核应急计划几个实际问题。 相似文献
7.
核电厂应急计划中若干问题和概念的讨论 总被引:1,自引:0,他引:1
本文讨论了我国核电厂应急计划和应急准备中新所关心的若干问题,阐述了应急计划中一些基本概念;弄清这些问题和概念,对推动和恰当地进行应急准备可能是重要的。 相似文献
8.
Scheduling emergency medicine residents (EMRs) is a complex task, which considers a large number of rules (often conflicting) related to various aspects such as limits on the number of consecutive work hours, number of day and night shifts that should be worked by each resident, resident staffing requirements according to seniority levels for the day and night shifts, restrictions on the number of consecutive day and night shifts assigned, vacation periods, weekend off requests, and fair distribution of responsibilities among the residents. Emergency rooms (ERs) are stressful workplaces, and in addition shift work is well-known to be more demanding than regular daytime work. For this reason, preparing schedules that suit the working rules for EMRs is especially important for reducing the negative impact on shift workers physiologically, psychologically, and socially. In this paper, we present a goal programming (GP) model that accommodates both hard and soft constraints for a monthly planning horizon. The hard constraints should be adhered to strictly, whereas the soft constraints can be violated when necessary. The relative importance values of the soft constraints have been computed by the analytical hierarchy process (AHP), which are used as coefficients of the deviations from the soft constraints in the objective function. The model has been tested in the ER of a major local university hospital. The main conclusions of the study are that problems of realistic size can be solved quickly and the generated schedules have very high qualities compared to the manually prepared schedules, which require a lot of effort and time from the chief resident who is responsible for this duty. 相似文献
9.
Daniel Röhnert Fritz Phillipp Helfried Reuther Till Weber Egbert Wessel Michael Schütze 《Oxidation of Metals》2007,68(5-6):271-293
The initial stages of the metal-dusting process on Alloy 800 at 620 °C were investigated by light optical microscopy, RAMAN
spectroscopy, atomic-force microscopy, Auger electron spectroscopy, transmission-electron microscopy and electron back-scatter
diffraction. As it turned out the incubation period for metal-dusting is characterized by simultaneous formation of a heterogeneously
growing oxide scale and deposition of carbon. The material surface shows different tarnish colors depending on the substrate-grain
orientation with different susceptibility to the beginning of metal-dusting attack. “Low-index” grains were not attacked within
the times investigated while the other grain orientations showed pitting. Carbon is evidently incorporated into the oxide
scale from the very beginning of exposure with different intensities depending on the underlying substrate-grain orientation
leading to differences in the tarnish colors. As a consequence carbides are formed even underneath “dense” oxide layers. Evidently
metal-dusting attack starts at positions of the oxide scale where “higher carbon concentrations” are present. 相似文献
10.
在压水堆核电站应急计划和应急响应中,堆底熔穿事故占有重要位置。本文用法国核电厂事故源项S3(对应于堆底熔穿事故)计算了在典型气象条件下的场外放射学的后果,根据一般防护决策原则和我国颁布的干预水平,提出了保护公众的应急防护措施的建议。 相似文献