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   885篇
  免费   22篇
  国内免费   3篇
电工技术   48篇
综合类   1篇
化学工业   166篇
金属工艺   20篇
机械仪表   20篇
建筑科学   21篇
能源动力   16篇
轻工业   79篇
水利工程   5篇
无线电   113篇
一般工业技术   128篇
冶金工业   233篇
原子能技术   13篇
自动化技术   47篇
  2023年   4篇
  2022年   8篇
  2021年   22篇
  2020年   8篇
  2019年   5篇
  2018年   10篇
  2017年   15篇
  2016年   16篇
  2015年   9篇
  2014年   15篇
  2013年   27篇
  2012年   37篇
  2011年   33篇
  2010年   47篇
  2009年   23篇
  2008年   28篇
  2007年   35篇
  2006年   28篇
  2005年   31篇
  2004年   25篇
  2003年   20篇
  2002年   11篇
  2001年   18篇
  2000年   15篇
  1999年   19篇
  1998年   84篇
  1997年   64篇
  1996年   43篇
  1995年   24篇
  1994年   24篇
  1993年   20篇
  1992年   11篇
  1991年   12篇
  1990年   10篇
  1989年   16篇
  1988年   7篇
  1987年   7篇
  1986年   6篇
  1985年   11篇
  1984年   6篇
  1983年   9篇
  1982年   3篇
  1981年   6篇
  1980年   3篇
  1979年   4篇
  1978年   3篇
  1977年   5篇
  1976年   6篇
  1974年   5篇
  1966年   2篇
排序方式: 共有910条查询结果,搜索用时 401 毫秒
61.
Kawakami M  Ward L  Doi H 《Lipids》2000,35(2):205-211
The interaction of lipid peroxides with cellular proteins has been postulated to contribute to cellular aging. A potential target for such effects is tubulin, the building block of microtubules. We examined the concentration-dependent effects of phosphatidylcholine hydroperoxides on the ability of tubulin to polymerize into microtubules. The results demonstrated that even very low concentrations of peroxides were sufficient to interfere with the tubulin and, therefore, the microtubule function. Decreased tubulin activity (as measured by tubulin GTPase activity) showed correlation with the modification of methionine and cysteine in tubulin and a change in the tubulin conformational state as indicated by fluorescence and ultraviolet spectroscopic measurements. As no effect on electric conductivity was observed, indicating that modulation of ionic binding was not involved, the interaction mechanism may be a hydrophobic one.  相似文献   
62.
In 4 studies, the authors examined the effect of approaching Blacks on implicit racial attitudes and immediacy behaviors. In Studies 1-3, participants were trained to pull a joystick toward themselves or to push it away from themselves when presented with photographs of Blacks, Whites, or Asians before completing an Implicit Association Test to measure racial bias. In Study 4, the effect of this training procedure on nonverbal behavior in an interracial contact situation was investigated. Results from the studies demonstrated that approaching Blacks decreased participants' implicit racial prejudice and increased immediacy when interacting with a Black confederate. The implications of these findings for current theories on approach, avoidance, and intergroup relations are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
63.
Optical absorption images of the tissue mimic phantom including gold nanoparticles were obtained by detecting the ultrasonic velocity-change caused by light irradiation. A series of experimental results showed the possibility as a nanoparticle distribution monitor for the drug delivery system.  相似文献   
64.
In previous studies, various stabilizing control methods for humanoids during the stance phase while hopping and running were proposed. Although these methods contribute to stability while hopping and running, it is possibility that the control during the flight phase could also affect the stability. In this study, we investigated whether the control during the flight phase can affect the stability of a humanoid while running. To achieve stable hopping, we developed a control system that accounts for the angular momentum of the whole body during the flight phase. In this system, the angular momentum generated by the motion of the lower body in each time interval is calculated during the flight phase, and the trunk joints are controlled to generate the angular momentum necessary to compensate for the deviation of the waist posture, which is used as the reference point for the motion coordinate system of the robot. Once the proposed control system was developed and simulated, we found that the hopping duration in the unconstrained state was extended.  相似文献   
65.
A new single-chip microprocessor for speech recognition, the SRP, has been developed, utilizing a multiprocessor architecture and a pipelined structure. It can recognize up to 340 isolated words or 40 connected words in real time. The SRP contains a vector distance calculator, a DP-equation calculator, and an I/O controller operating in a pipelined manner. Algorithm variations and operation parameters are user programmable, and the total size of the SRP program for a typical speech recognition system is about 700 words. The device has been fabricated with n-channel Si-gate E/D MOS technology with 2.5 μm design rules and employs 7296 three-transistor dynamic RAM cells for a total of more than 40 000 transistors.  相似文献   
66.
Although several kinds of computational associative memory models and emotion models have been proposed since the last century, the interaction between memory and emotion is almost always neglected in these conventional models. This study constructs a dynamic memory system, named the amygdala-hippocampus model, which intends to realize dynamic auto-association and the mutual association of time-series patterns more naturally by adopting an emotional factor, i.e., the functional model of the amygdala given by Morén and Balkenius. The output of the amygdala is designed to control the recollection state of multiple chaotic neural networks (MCNN) in CA3 of the hippocampus-neocortex model proposed in our early work. The efficiency of the proposed association system is verified by computer simulation using several benchmark time-series patterns. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008  相似文献   
67.
68.
The present research examined how implicit racial associations and explicit racial attitudes of Whites relate to behaviors and impressions in interracial interactions. Specifically, the authors examined how response latency and self-report measures predicted bias and perceptions of bias in verbal and nonverbal behavior exhibited by Whites while they interacted with a Black partner. As predicted, Whites' self-reported racial attitudes significantly predicted bias in their verbal behavior to Black relative to White confederates. Furthermore, these explicit attitudes predicted how much friendlier Whites felt that they behaved toward White than Black partners. In contrast, the response latency measure significantly predicted Whites' nonverbal friendliness and the extent to which the confederates and observers perceived bias in the participants' friendliness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
69.
Abstracts are not published in this journal This revised version was published online in November 2006 with corrections to the Cover Date.  相似文献   
70.
PURPOSE: To determine whether infiltrative lung, airway, or vascular disease can be differentiated as the cause of mosaic attenuation on thin-section computed tomographic (CT) scans of the lung. MATERIALS AND METHODS: Thin-section CT scans were reviewed in 70 patients examined at three institutions. A mosaic attenuation pattern and pathologic or clinical proof of a specific type of disease were demonstrated. Causes of the mosaic pattern included infiltrative lung disease (n = 37), airway disease (n = 22), and vascular disease (n = 11). Thin-section CT findings were assessed independently by two observers blinded to clinical findings. RESULTS: The type of disease was identified correctly at CT in 58 (83%) of 70 patients by observer 1 and 57 (81%) of 70 patients by observer 2. Infiltrative lung disease was diagnosed correctly by both observers in 34 (92%) of 37 cases. Observer 1 identified 21 (95%) of 22 cases of airway disease and three (27%) of 11 cases of vascular disease. Observer 2 identified 19 (86%) of 22 cases of airway disease and four (36%) of 11 cases of vascular disease. CONCLUSION: Infiltrative lung disease and airway disease may be differentiated reliably as the cause of mosaic attenuation on lung CT scans, whereas vascular disease is often misinterpreted as infiltrative lung disease or airway disease.  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