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1.
《Ergonomics》2012,55(3):269-281
The maximum voluntary range of motion (ROM) of the major joints of the upper body was studied in a seated position and compared between young and elderly subjects. A total of 41 subjects (22 young male and female subjects aged 25 to 35 years, 19 elderly male and female subjects aged 65 to 80 years) took part in the experiment. In total, 13 maximum voluntary joint motions were performed by each subject. Age was found to have a non-uniform effect on the ROM of the joints investigated in this study. Its effect on ROM was joint specific and motion specific. The highest loss in ROM was observed in the neck and trunk, especially for neck extension, lateral flexion and axial rotation as well as for trunk lateral flexion and axial rotation. No significant age differences were observed in the elbow and wrist joint ROMs. The effect of gender on joint ROM was much weaker than that of age. Only four among the 26 joint ROMs investigated in this study were significantly different between the two gender groups.  相似文献   
2.
Sixty-two samples were collected from the five formations at Um Bogma area, (Southwest Sinai, Egypt). Nine samples were collected from Sarabit El Khedim Formation, ten samples were collected from Abu Hamata Formation, eighteen samples were collected from Adedia Formation, eight samples were collected from Um Bogma Formation and eighteen samples were collected from Abu Thora Formation.The Paleozoic rocks at Um Bogma area, consist mainly of sandstones, siltstones, shales, limestone and dolostones, which are unconformably overlie igneous and metamorphic rocks (granite, diorite and gneiss) of Precambrian age.The petrographic studies were applied to identify different rock units, different facies and its diagenetic history and to reveal its effect on the storage capacity properties. Different types of porosity (oversized, intergranular, fracture and vuggy porosities) have been identified based on the petrographic investigation of the studied thin sections.The Paleozoic sandstone rock samples are characterized by porosity average about 19% for Facies 1 (quartz wack) and about 18%for Facies 2 (quartz arenite) and permeability average 420?mD for Facies 1 (quartz wack) and 690?mD for Facies 2 (quartz arenite), so these rocks can be considered as good reservoir rocks. The Paleozoic carbonate rock samples (Facies 3) are characterized by poor porosity (less than 7%) and very low permeability (less than 0.5?mD), which caused by matrix and diagenetic processes and refer to bad reservoir rocks.Porosity can be linked to the two derived electrical properties (formation resistivity factor and electrical tortuosity) of the studied Paleozoic rocks at Um Bogma area. The electrical tortuosity has significant effects on both permeability and formation resistivity factor. The permeability decreases with increasing electrical tortuosity and the relation between both of them is inverse relationship with good coefficient of correlation. The permeability decreases with increasing electrical tortuosity and the relations between both of them are inverse relationships with high coefficient of correlation. The formation resistivity factor increases with increasing electrical tortuosity and the relations between both of them are positive relationships with a fair to very high coefficient of correlation.  相似文献   
3.
基于Delphi的网络交通信号控制系统,上位机软件负责灯色方案表的数据形成,以及方案表和步伐时间数据的发送、信号机数据的接收与显示.交通控制客户端,采用组件Indy中的IdUDPClient组件读取信息.交通控制接收端由Delphi通过IdUDPServer组件的OnUDPRead事件,读取下位机数据.网络传输采用UDP通信协议.  相似文献   
4.
    
In this work, an analysis of the energy vanished by friction of thin-walled tube drawing processes in conical converging dies with a fixed conical inner plug has been conducted. The method used for analysis is the upper bound method (UBM), and the plastic deformation zone has been modelled by three triangular rigid zones (TRZ). The tube inner diameter is considered constant during the process, and therefore, a state of plane strain can be assumed. In addition, the existent friction between the external surface of the tube and the die (material-die), as well as that between the inner surface of the tube and the plug (material-plug) has been modeled by Coulomb friction (μ1 and μ2, respectively). Some significant findings emerged from this study are: the establishment of explicit expressions for evaluating the non-dimensional energy vanished by friction in the die and in the plug, the ability to select the plug that enables the process to be performed with a lower requirement of energy under defined conditions, and the detection of coupled effects between the friction coefficients define above.  相似文献   
5.
    
《Quality Engineering》2012,24(4):621-626

The desirability of a response that increases in a linear manner from the lower specification limit to the target value and decreases in a linear manner from the target value to the upper specification limit results in a breakpoint (nondifferentiable point) at the target value of its desirability function. Thus, modified desirability functions were proposed to solve this breakpoint problem so that the generalized reduced gradient can be applied. The modified desirability functions require the fitting of a quartic polynomial in the vicinity of the target. However, the fitting of the quartic polynomial needs to satisfy five conditions and involves numerous computations. Therefore, an approach with less computations and yet that is simple to implement is proposed in this article. This approach is applicable when the lower specification limit, the target value, and the upper specification limit of a response are available. In addition, this approach also allows practitioners to assign different degrees of importance to the responses. An example from the original paper of modified desirability functions is used to illustrate this approach.  相似文献   
6.
    
《Quality Engineering》2012,24(2):173-178

Runs rules are incorporated into the Shewhart control chart to increase its sensitivity in detecting small process shifts so that assignable causes can be detected more quickly. In this article, two improved runs rules are suggested. Average run length values for these new improved rules are computed and compared with that of the existing ones. The comparison shows that the new improved rules are superior in performance for large process average shifts, while maintaining the same sensitivity in the detection of small shifts.  相似文献   
7.
长江沙量变化和减沙途径探讨   总被引:2,自引:0,他引:2  
本文主要探讨长江上游输沙量、含沙量变化和减沙途径。在上游生态环境破坏程度日益加剧的情况下 ,1 95 0~ 1 985年长江输沙量、含沙量约每 1 2年以 4%的速率缓慢增长 ,1 992~1 997年大量减少。追根溯源系水库淤积的减沙作用。若无水库淤积拦沙 ,长江上游输沙量、含沙量年增长率将约达 1 % ,是相当可观的。根据水库拦沙效益 ,提出长江上游修建溪洛渡、亭子口、瀑布沟、构皮滩和白鹤滩等 5座大型水电站 ,与三峡枢纽共同进行水库泥沙联合调度 ,可使宜昌河段含沙量减少 1 / 2的年限延长达 1 5 0~ 2 0 0年 ;同时开展水土保持 ,可改变三峡下游河床冲刷后再淤积的不利局面。治水必治沙 ,通过“蓄水减沙 ,借水攻沙”的工程措施 ,和坚持不懈的水土保持 ,“标本兼治”,可使长江输沙量、含沙量长期减少 1 / 2 ,恢复到唐宋时代水平。  相似文献   
8.
李涟 《人民长江》1999,30(5):11-12
清江隔河岩溢流坝表孔采用液压启闭机对溢洪道闸门进行启闭操作,理对液压启闭机电控中所遇到的闭门到位,油缸行程检测的重复误差,闸门下滑时的自动提门以及油缸行程转 换成闸门开度等问题的产生原因进行分析,并就采用可编程序控制器的进行控制技术来解决这些问题的方法进行了阐述和探讨。  相似文献   
9.
在钢包炉中 (无氧枪设备条件下 ) ,首次采用吹氧 + VD(真空精炼 )法冶炼工艺 ,生产用于黄河万家寨电站水轮机铸件的超低碳不锈钢 (C≤ 0 .0 3% ,最低达到 0 .0 19% )。该方法的研究成功 ,为重机行业开拓大型不锈钢铸锻件市场奠定了基础  相似文献   
10.
This paper considers pre-impact vehicle maneuvers and analyzes the resulting driver motion from their comfort seating position. Part I of this work consists of analyzing the driver behavior during a crash. The study is conducted using the LAMIH driving simulator and involves 76 participants. The emergency situation is created by a truck emerging from behind a tractor on the opposite side of the road and tearing along the participant. The driver positioning throughout the simulation is recorded via five video cameras allowing view of the front scene, the driver face, feet and pedals, hands on the steering wheel and global lateral view. Data related to braking force, seat pressure, muscular activity for major groups of muscles and actions on the steering wheel are also collected.The typical response to this type of emergency event is to brace rearward into the seat and to straighten the arms against the steering wheel, or, to swerve to attempt to avoid the impacting vehicle. While turning the steering wheel, the forearm can be directly positioned on the airbag module at time of crash which represents a potential injurious situation.These positions are used in Part II to determine scenario of positions for numerical simulation of a frontal collision.  相似文献   
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