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   1571篇
  免费   80篇
  国内免费   8篇
电工技术   23篇
综合类   7篇
化学工业   545篇
金属工艺   34篇
机械仪表   31篇
建筑科学   100篇
矿业工程   4篇
能源动力   39篇
轻工业   94篇
水利工程   12篇
无线电   113篇
一般工业技术   294篇
冶金工业   153篇
原子能技术   2篇
自动化技术   208篇
  2023年   31篇
  2022年   32篇
  2021年   53篇
  2020年   34篇
  2019年   31篇
  2018年   42篇
  2017年   29篇
  2016年   61篇
  2015年   45篇
  2014年   64篇
  2013年   86篇
  2012年   85篇
  2011年   101篇
  2010年   64篇
  2009年   67篇
  2008年   78篇
  2007年   72篇
  2006年   63篇
  2005年   53篇
  2004年   40篇
  2003年   34篇
  2002年   45篇
  2001年   17篇
  2000年   33篇
  1999年   27篇
  1998年   25篇
  1997年   30篇
  1996年   18篇
  1995年   15篇
  1994年   22篇
  1993年   17篇
  1992年   15篇
  1991年   20篇
  1990年   14篇
  1989年   9篇
  1988年   9篇
  1987年   9篇
  1986年   7篇
  1985年   14篇
  1984年   16篇
  1983年   16篇
  1982年   11篇
  1981年   9篇
  1980年   6篇
  1979年   14篇
  1976年   11篇
  1975年   6篇
  1974年   14篇
  1973年   6篇
  1969年   8篇
排序方式: 共有1659条查询结果,搜索用时 15 毫秒
21.
The focus of this article is to review recent techniques in proteomic analysis of ocular fluids. These fluids include tears, aqueous humor, and vitreous, they will also be compared to serum analysis. Furthermore, we attempt to summarize some disease correlated biomarkers in ocular fluids that were discovered through different proteomic techniques in eye diseases like dry eye, glaucoma, age-related macular degeneration, uveitis, or diabetic retinopathy. This review is trying to point out the importance of these biomarkers for clinical applications.  相似文献   
22.
We introduce a novel transmission-line method for determining the penetration depth in thin high-temperature superconducting (HTS) films. The method is based on the accurate measurement of the inductance per unit length of a superconducting coplanar-waveguide (CPW) transmission line fabricated on the HTS sample. Using the experimentally obtained inductance per unit length, we interpolate the penetration depth from a table of numerically determined values of inductance (per unit length) as a function of penetration depth, calculated from a coupled transmission-line model. A novelty of our procedure is the utilization of the multiline thru-reflect-line (TRL) method and the calibration-comparison method to accurately determine the inductance per unit length of the superconducting transmission line. By measuring different CPW geometries patterned onto the same thin-film sample, we can verify our penetration depth values. We demonstrate this technique by extracting the penetration depth for several different HTS films at 76 K. Estimated uncertainties in the extracted penetration depth are also provided. Contribution of an agency of the US government not subject to copyright.  相似文献   
23.
24.
A new generation of beam deflection technique is the basis for the development of electron beam (EB) technologies, which are not realisable with conventional methods. A high frequency 3D‐beam deflection makes possible multi‐field, multi‐pool and multi‐process technologies for EB welding und EB surface treatment, which result in a clear higher productivity and new combinations of properties.  相似文献   
25.
26.
27.
By investigating the second-order statistics of Gabor wavelet responses derived from natural images, we show that collinearity and parallelism are conspicuous relations. We give a precise mathematical characterization of these Gestalt principles by the conditional probability of two responses. Essential for our investigations is a non-linear transformation, initially utilized within the object recognition system [5], which transforms continuous Gabor wavelet responses into a binary code indicating the presence or absence of local oriented line segments.  相似文献   
28.
Noise peaks are powerful distractors. This study focuses on the impact of noise peaks on surgical teams’ communication during 109 long abdominal surgeries. We related measured noise peaks during 5-min intervals to the amount of observed communication during the same interval. Results show that noise peaks are associated with less case-relevant communication; this effect is moderated by the level of surgical experience; case-relevant communications decrease under high noise peak conditions among junior, but not among senior surgeons. However, case-irrelevant communication did not decrease under high noise level conditions, rather there was a trend to more case-irrelevant communication under high noise peaks. The results support the hypothesis that noise peaks impair communication because they draw on attentional resources rather than impairing understanding of communication. As case-relevant communication is important for surgical performance, exposure to high noise peaks in the OR should be minimised especially for less experienced surgeons.

Practitioner Summary: This study investigated whether noise during surgeries influenced the communication within surgical teams. During abdominal surgeries, noise levels were measured and communication was observed. Results showed that high noise peaks reduced the frequency of patient-related communication, but did not reduce patient-irrelevant communication. Noise may negatively affect team coordination in surgeries.  相似文献   

29.
This paper presents a behavioral model that can be used to improve the manufacturability of systems based on MEMS convective sensors. This model permits to handle faults related to process scattering, taking into account not only the electrical and lateral geometrical parameters but also the influence of the cavity depth. Moreover correlations between conductive and convective phenomena are included. The model is validated with respect to FEM simulations and a very good agreement is obtained between the behavioral model and FEM results. The proposed model can then be used in system-level simulations, for instance to evaluate the impact of process scattering on the performances of the sensing part and/or to investigate different design and calibration strategies with respect to the system robustness.  相似文献   
30.
In the field of humidity quantities, the first CIPM key comparison, CCT-K6 is at its end. The corresponding European regional key comparison, EUROMET.T-K6, was completed in early 2008, about 4?years after the starting initial measurements in the project. In total, 24 NMIs from different countries took part in the comparison. This number includes 22 EURAMET countries, and Russia and South Africa. The comparison covered the dew-point temperature range from ?50?°C to +20?°C. It was carried out in three parallel loops, each with two chilled mirror hygrometers as transfer standards in each loop. The comparison scheme was designed to ensure high quality results with evenly spread workload for the participants. It is shown that the standard uncertainty due to the long-term instability was smaller than 0.008?°C in all loops. The standard uncertainties due to links between the loops were found to be smaller than 0.025?°C at ?50?°C and 0.010?°C elsewhere. Conclusions on the equivalence of the dew-point temperature standards are drawn on the basis of calculated bilateral degrees of equivalence and deviations from the EURAMET comparison reference values (ERV). Taking into account 16 different primary dew-point realizations and 8 secondary realizations, the results demonstrate the equivalence of a large number of laboratories at an uncertainty level that is better than achieved in other multilateral comparisons so far in the humidity field.  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