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   159篇
  免费   3篇
综合类   2篇
化学工业   25篇
金属工艺   1篇
建筑科学   6篇
矿业工程   6篇
能源动力   20篇
轻工业   5篇
水利工程   1篇
无线电   10篇
一般工业技术   10篇
冶金工业   47篇
原子能技术   11篇
自动化技术   18篇
  2023年   1篇
  2022年   1篇
  2021年   2篇
  2020年   1篇
  2019年   1篇
  2018年   3篇
  2017年   1篇
  2016年   3篇
  2015年   4篇
  2014年   2篇
  2013年   7篇
  2012年   5篇
  2011年   4篇
  2010年   14篇
  2009年   12篇
  2008年   10篇
  2007年   6篇
  2006年   10篇
  2005年   8篇
  2004年   5篇
  2003年   2篇
  2002年   5篇
  2001年   2篇
  2000年   1篇
  1999年   4篇
  1998年   8篇
  1997年   15篇
  1996年   5篇
  1995年   3篇
  1994年   4篇
  1993年   4篇
  1992年   1篇
  1991年   1篇
  1989年   1篇
  1988年   1篇
  1986年   1篇
  1984年   2篇
  1975年   1篇
  1971年   1篇
排序方式: 共有162条查询结果,搜索用时 15 毫秒
11.
The acid-sensing ion channels ASIC1 and ASIC2, as well as the transient receptor potential vanilloid channels TRPV1 and TRPV4, are proton-gated cation channels that can be activated by low extracellular pH (pHe), which is a hallmark of the tumor microenvironment in solid tumors. However, the role of these channels in the development of skin tumors is still unclear. In this study, we investigated the expression profiles of ASIC1, ASIC2, TRPV1 and TRPV4 in malignant melanoma (MM), squamous cell carcinoma (SCC), basal cell carcinoma (BCC) and in nevus cell nevi (NCN). We conducted immunohistochemistry using paraffin-embedded tissue samples from patients and found that most skin tumors express ASIC1/2 and TRPV1/4. Striking results were that BCCs are often negative for ASIC2, while nearly all SCCs express this marker. Epidermal MM sometimes seem to lack ASIC1 in contrast to NCN. Dermal portions of MM show strong expression of TRPV1 more frequently than dermal NCN portions. Some NCN show a decreasing ASIC1/2 expression in deeper dermal tumor tissue, while MM seem to not lose ASIC1/2 in deeper dermal portions. ASIC1, ASIC2, TRPV1 and TRPV4 in skin tumors might be involved in tumor progression, thus being potential diagnostic and therapeutic targets.  相似文献   
12.
Raman spectroscopy and optical light microscopy were applied to analyze the morphology within the bulk and on the surface of wax modified topcoats. To vary the processing conditions resin formulations were coated on primed steel sheets and cured at peak metal temperatures of 230, 240 and 250 °C. By Raman spectroscopy dispersed, spherical wax domains within the bulk and on the surface were detected. These features revealed residues of the polyester based resin and the TiO2 pigment. While the size of the identified lubricant features showed only a slight shift to smaller diameters with increasing peak metal temperature, a significant effect of the curing conditions on the overall number of wax domains and the relative area covered by wax was ascertained. A direct linear correlation between peak metal temperature and relative area covered by wax within the bulk and on the surface of the topcoats was established.  相似文献   
13.
The most widely used equation, V = pL2/R, is developed for the computation of ventricular volume from catheter based impedance measurements. The assumptions implicit in this derivation are examined and found to be generally invalid. An empirical discrete resistor model is described which includes the impedance of the myocardial tissue and the adjoining ventricular blood volume. Once the parameters of this model are determined for individual canine hearts, the model predicts stroke volume from measured impedances. Due to the difficulty involved in determining the parameters of the empirical model, a numerical model is developed which solves the equation V ?a V U + F = 0 in a three-dimensional volume. This model is then used to determine the effect of parallel tissue resistance, catheter position, and contraction of the other ventricle on volumes computed by intracardiac impedance. Parallel tissue resistance is found to have the greatest impact on absolute volume measurements. However, stroke volume computations are relatively unaffected by any of the three factors.  相似文献   
14.
Polypropylene homopolymers and ethylene/propylene‐random‐copolymers formulated with and without anti‐blocking additives were extruded to cast films with an industrial scale extruder equipped with a soft box, a specific air knife that expels a higher volume of air at lower velocity. The films were analyzed as to their optical properties haze and clarity. A comprehensive topographical characterization was performed using atomic force microscopy (AFM) and confocal microscopy. To obtain morphological information on a nanometer scale AFM phase imaging, micro‐thermal analysis and small angle X‐ray scattering (SAXS) were done. A significant effect of additives and processing conditions on the film topography and the optical properties was revealed. The films without anti‐blocking and antacid aids showed the best optical properties and lowest vertical roughness fluctuations. In contrast, the addition of anti‐blocking and antacid aids reduced the optical properties associated with an increase in surface roughness. While for films without anti‐blocking aids an enhanced soft box condition resulted in lower vertical fluctuations of roughness and better optical properties, the behavior was in reverse for films with anti‐blocking aid. By means of SAXS crystalline lamellae with a thickness of about 2.5 nm were detected. High‐resolution phase imaging AFM yielded thicker crystal lamellae on the film surface. POLYM. ENG. SCI., 46:520–531, 2006. © 2006 Society of Plastics Engineers.  相似文献   
15.
Wallner  Bernard  Fieder  Martin  Iber  Karoline 《Scientometrics》2003,58(1):143-153
This study analyzes the age profile of scientific employees and its relation to personnel costs and scientific productivity within eight faculties at the University of Vienna. The age demography can overall be divided into two main categories: Category one faculties represent an increased number of younger aged researchers (Catholic-, Protestant Theology, Law, Economics, Information Sciences, and Medicine), category two faculties show an increased number of older aged researchers (Social Sciences, Humanities, and Science). In addition, it can be demonstrated that the personnel costs for full professors are higher within four faculties (Catholic-, Protestant Theology, Law, and Economics and Information Sciences). Inevitably, this leads to savings for habilitated and non- habilitated researchers at these faculties. The faculty of Medicine represents a well-balanced use of personnel costs. Three faculties (Social Sciences, Humanities, and Sciences) have to pay dramatically more for their older aged habilitated and non-habilitated personnel. For the entire university and two faculties, Medicine and Humanities, a positive and significant relationship between age and the average weekly teaching performance is shown. This study suggests that institutions with a high percentage of older researchers, mainly in the categories of habilitated and non- habilitated personnel, must change their policy to become more flexible and attractive for new talented young people. Due to the fact, that this cannot only be realized through the introduction of new laws, each faculty must establish a scientific plan combined with reorganizations of the personnel structure and personnel costs. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
16.
17.
18.
19.
This paper presents a study with the aim of evaluating the relative efficacy of an alliance-focused treatment, brief relational therapy, in comparison to a short-term dynamic therapy and a cognitive-behavioral therapy on a sample of highly comorbid personality disordered patients. Results indicated that the three treatments were equally effective on standard statistical analyses of change, including those conducted on repeated measures and residual gain scores. Some significant differences were indicated regarding clinically significant change and reliable change, favoring the brief relational and cognitive-behavioral models. There was also a significant difference regarding dropout rates, favoring brief relational therapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
20.
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