全文获取类型
收费全文 | 6178篇 |
免费 | 389篇 |
国内免费 | 464篇 |
专业分类
电工技术 | 664篇 |
综合类 | 480篇 |
化学工业 | 342篇 |
金属工艺 | 69篇 |
机械仪表 | 360篇 |
建筑科学 | 965篇 |
矿业工程 | 557篇 |
能源动力 | 161篇 |
轻工业 | 123篇 |
水利工程 | 160篇 |
石油天然气 | 266篇 |
武器工业 | 26篇 |
无线电 | 166篇 |
一般工业技术 | 525篇 |
冶金工业 | 215篇 |
原子能技术 | 960篇 |
自动化技术 | 992篇 |
出版年
2024年 | 14篇 |
2023年 | 29篇 |
2022年 | 124篇 |
2021年 | 194篇 |
2020年 | 172篇 |
2019年 | 114篇 |
2018年 | 115篇 |
2017年 | 169篇 |
2016年 | 227篇 |
2015年 | 181篇 |
2014年 | 498篇 |
2013年 | 503篇 |
2012年 | 565篇 |
2011年 | 501篇 |
2010年 | 367篇 |
2009年 | 398篇 |
2008年 | 319篇 |
2007年 | 412篇 |
2006年 | 368篇 |
2005年 | 305篇 |
2004年 | 256篇 |
2003年 | 241篇 |
2002年 | 166篇 |
2001年 | 147篇 |
2000年 | 144篇 |
1999年 | 92篇 |
1998年 | 73篇 |
1997年 | 66篇 |
1996年 | 49篇 |
1995年 | 30篇 |
1994年 | 31篇 |
1993年 | 20篇 |
1992年 | 23篇 |
1991年 | 9篇 |
1990年 | 17篇 |
1989年 | 13篇 |
1988年 | 10篇 |
1987年 | 7篇 |
1986年 | 10篇 |
1985年 | 3篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1977年 | 3篇 |
1975年 | 3篇 |
1971年 | 2篇 |
1959年 | 14篇 |
1954年 | 2篇 |
排序方式: 共有7031条查询结果,搜索用时 15 毫秒
31.
危险化学品突发泄漏事故应急决策系统研究 总被引:2,自引:0,他引:2
针对危险化学品突发泄漏事故需要应急反应,通过建立危险化学品及其特性数据库,利用GIS技术,实现地图数据的动态装载,实现一个面向危险化学品突发泄漏事故的应急决策系统.该系统可以向危险化学品相关行业人员提供相关化学品的理化性质,生产、运输所需的工具、操作方法和步骤,实现数据的双向更新,做到对危险化学品的实时监控,并在发生突发泄漏事故时软件能够及时自动生成紧急处置预案,包括处置方法、手段和标准.在突发泄漏事故发生时为领导决策层提供科学依据,实现快速反应,防止重大事故的发生. 相似文献
32.
朱程 《浙江水利水电专科学校学报》2010,22(4):98-101
建立大学生顶岗实习人身伤害事故校方责任评估体系,明确界定事故责任,有利于妥善地处理好学生伤害事故,维护学生合法权益和学校声誉;强化学校安全责任观念,增强学校预防意识,切实保护学生的人身安全;有利于进一步实施大学生素质教育.本文提出了制订评估体系应遵循的几项原则,分析了学校对事故所负责任大小的几种类型,构建了大学生顶岗实习期间发生人身伤害时学校承担责任的评估体系. 相似文献
33.
34.
35.
36.
根据港口集装箱码头装卸作业的实际情况,基于PLC,设计装卸模型所对应的下位机控制系统,并介绍设计过程中的技术要点、注意事项. 相似文献
37.
Knowledge management is crucial for construction safety management. Widely collected and well-organized safety-related documents are recognized to be significant in raising the workers' security awareness and then to prevent hazards and accidents. To improve document processing efficiency, automatic information extraction plays an important role. However, currently, automatic information extraction modeling requires large scale training datasets. It is a big challenge for the engineering industry, especially for the fields which heavily rely on the experts’ knowledge. Limited data sources, and high time and labor costs make it not practical to establish a large-scale dataset. This work proposed a natural language data augmentation-based small samples training framework for automatic information extraction modeling. With the designed cross combination-based text data augmentation algorithm, the deep neural network can be employed to build up automatic information extraction models without large-scale raw data and manual annotations. Characters semantic coding is employed to avoid word segmentation and make sure that the framework can be utilized in different writing language systems. The BiLSTM-CRF model is adopted as the detection core to conduct character classification. Through a case study of two independent accident news report datasets analysis, the proposed framework has been validated. A reliable and robust automatic information extraction model can be established, even though with small samples training. 相似文献
38.
Correlated color temperature (CCT) of the light source inside the road tunnel plays a crucial role in ensuring driving safety, which is demonstrated by previous studies that CCT influences not only visual effects but also non-visual effects. Although conventional laboratory experiments could simulate the CCT environment inside the tunnel to some extent, they fail to restore driving experience, let alone simulate driving behavior in the accident situation. It has largely remained unclear whether and how CCT would influence visual/non-visual performance of the subjects who are performing driving tasks, especially in the accident situation. Motivated by this gap, a virtual-reality-based framework for assessing the influence of CCT on the visual and non/visual performance in normal driving situation and in accident situation was proposed. In this study, tunnel models under seven different CCTs were created and a rear-end accident was designed in the tunnel. By integrating analog driving equipment, all participants were required to perform virtual driving tasks both in the normal situation and in the accident situation. The non-visual performance (driving fatigue) and the visual performance (reaction time) of the participants were collected and analyzed. Results show that the CCT of light source inside the tunnel was significant on the driving fatigue of the driver who was performing driving task, and it also had a significant impact on the visual performance when the driver was faced with a rear-end accident. Detailed experimental methodology, behavioral explanations underlying these findings, validity of results and practical implications are also discussed in the paper. 相似文献
39.
《矿业科学技术学报(英文版)》2017,27(1):37-41
In underground mining, machine design is predominantly dictated by mine conditions and individual customer desires. In partnership with Foresight Energy, J. H. Fletcher Company was tasked to design and manufacture a new roof bolting machine with six independent drilling apparatus on board capable of drilling and bolting the roof and ribs with material handling. The objective was to produce a machine capable of drilling and installing six bolts simultaneously with a limited number of operators. The goal of the mine is to decrease the time to bolt a cut to improve the safety level of the current roof bolting method, improve efficiency and to improve the bottom line cost of entry development. The customer wanted four drills at the front of the machine dedicated to installing roof bolts and then another two drills behind them dedicated to rib bolts. This dictated the requirement of latched controls, which would allow the operator to start drilling one hole and then latch the controls to be able to move on to the next.The result of the design is a machine with a single platform and six independent masts with drillheads:four masts strictly for drilling and installing roof bolts on the front of the platform and two masts on the back of the platform for rib bolts. The controls at each operator's station include a latch control for drilling. The six-head roof bolter allows fewer operators to drill and install roof and rib bolts, which in turn lowers the miners' roof exposure per cut. This design reduces the operator's exposure from the inherent pinch points and rotary hazards once he has engaged the latch drilling. Therefore, the machine will help to decrease the time to bolt a cut, improving productivity while enhancing the ability to operate the machine safely. 相似文献
40.
为分析月球与地球重力差异对驾驶员所带来的操纵影响,推导了载人月球车操纵动力学方程.基于径向基神经网络和间接逆模型的训练方法,建立以行驶轨迹为输入、驾驶员操纵转角为输出的载人月球车操纵动力学逆系统.采用两种不同类型的间接对比形式,包括地球重力条件下重复月面行驶的轨迹路线和月球重力条件下重复地面行驶的轨迹路线.将正弦函数和斜坡阶越函数作为驾驶员操纵输入,获得月球或地球重力条件下的行驶轨迹,并利用逆系统求解得到不同重力条件下行驶相同轨迹时驾驶员的操纵转角.结果表明,驾驶员在月球重力条件下需要做出更大的操纵转向角度、更快的操纵转向速度、更高的操纵转向变换频率,并且在月球重力条件下更不容易重复地球重力条件下的相同行驶轨迹.这说明载人月球车在月球重力条件下的操纵性能较差. 相似文献