全文获取类型
收费全文 | 159篇 |
免费 | 11篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 30篇 |
金属工艺 | 1篇 |
机械仪表 | 2篇 |
建筑科学 | 13篇 |
能源动力 | 3篇 |
轻工业 | 21篇 |
水利工程 | 1篇 |
无线电 | 17篇 |
一般工业技术 | 36篇 |
冶金工业 | 20篇 |
自动化技术 | 28篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2020年 | 8篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2017年 | 3篇 |
2016年 | 9篇 |
2015年 | 6篇 |
2014年 | 6篇 |
2013年 | 12篇 |
2012年 | 11篇 |
2011年 | 10篇 |
2010年 | 15篇 |
2009年 | 10篇 |
2008年 | 6篇 |
2007年 | 5篇 |
2006年 | 11篇 |
2005年 | 5篇 |
2004年 | 4篇 |
2003年 | 5篇 |
2002年 | 8篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 5篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 2篇 |
排序方式: 共有173条查询结果,搜索用时 31 毫秒
151.
Lily Wang 《China Chemical Reporter》2010,(19)
<正> With the awful whether like drought,extremelylow temperature and flood in China,the domestic demand for pesticides fell inthe first half of 2010.Furthermore,the globalpesticide market was still sluggish due tothe economic turmoil.As a result,almost allof China's pesticide firms experienced a bothersomeperiod in the first half of 2010 fortheir unsatisfactory performances. 相似文献
152.
Loo Chalsa M.; Fairbank John A.; Scurfield Raymond M.; Ruch Libby O.; King Daniel W.; Adams Lily J.; Chemtob Claude M. 《Canadian Metallurgical Quarterly》2001,13(4):503
This article describes the development and validation of the Race-Related Stressor Scale (RRSS), a questionnaire that assesses exposure to race-related stressors in the military and war zone. Validated on a sample of 300 Asian American Vietnam veterans, the RRSS has high internal consistency and adequate temporal stability. Hierarchical regression analyses revealed that exposure to race-related stressors accounted for a significant proportion of the variance in posttraumatic stress disorder (PTSD) symptoms and general psychiatric symptoms, over and above (by 20% and 19%, respectively) that accounted for by combat exposure and military rank. The RRSS appears to be a psychometrically sound measure of exposure to race-related stressors for this population. Race-related stressors as measured by the RRSS appear to contribute uniquely and substantially to PTSD symptoms and generalized psychiatric distress. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
153.
In field experiments, which started several years ago to investigate the means of chemical communication of the Maladera matrida beetle, we found that the ratio of males to females attracted to the bait (live females with food) was 3 : 2–5 : 4 60 : 40–55 : 45). These findings suggested that an aggregation pheromone is involved in the chemical communication, but the constant small preference for attracted males raised the question whether the active compound(s) is indeed an aggregation pheromone or whether it is a sex pheromone released by the female to attract the male. Since the traps used in our field studies were made of yellow plastic, we had to consider the possibility that the yellow color could have influenced the trapping of the flying beetles and biased the findings for the behavior and mode of attraction toward the source of the chemical communication. To clarify this point, we set out, in this study, to conduct field experiments in which we compared the standard yellow traps with black traps. We found that the bright yellow color did indeed affect the results for chemical communication: The total catch in the yellow traps was double that in black traps, and the male–female ratio in the black traps increased to 4 : 1(80 : 20). This result hints that a sex pheromone, and probably not an aggregation pheromone, as previously thought, is involved in the chemical communication of the M. maladera beetle. 相似文献
154.
To address the charge that research findings are obvious, this study examined the perceived obviousness of 12 findings of process–product research on teaching. 1,215 volunteers in Singapore and in the San Francisco Bay Area rated the degree of obviousness of each finding after (1) attempting to select the actual finding from 2 possible opposite outcomes, (2) reading a single outcome that was either the actual or the direct opposite of the actual finding, or (3) reading a single outcome plus an explanation for the outcome. The selections of actual findings and the ratings of obviousness of actual or opposite-of-actual findings indicated that respondents could not always distinguish the true findings from their opposites. Explanations tended to increase the rated obviousness of the findings. Differences in gender, knowledge about teaching, and cultural background had inconsistent effects on the judgments of obviousness. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
155.
科技的发展引发了学习空间的巨大转变。本文通过分析若干美国大学校园建设实例,阐释了反映综合科技趋势的设计理念。 相似文献
156.
Carter James A.; McNair Lily D.; Corbin William R.; Black David H. 《Canadian Metallurgical Quarterly》1998,6(4):399
Studied the effects of priming positive and negative expectancy outcomes on the drinking responses of college students. Men and women (N?=?64; mean age 19.5 yrs) were randomly assigned to 1 of 3 priming conditions: a positive expectancy outcome condition, a negative expectancy outcome condition, and a neutral (control) condition. Participants were exposed to a series of semantic primes corresponding to their condition and then asked to complete a beer taste-rating task. Planned comparisons revealed that the average ratio of beer consumed to body weight in the positive condition was significantly greater than the average ratio in the neutral condition, and the average ratio of beer consumed to body weight was significantly less in the negative condition than the average ratio in the neutral condition. These findings are discussed as they relate to cognitive models of alcohol use. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
157.
A vertex-colored graph is rainbow vertex-connected if any two vertices are connected by a path whose internal vertices have distinct colors, which was introduced by Krivelevich and Yuster. The rainbow vertex-connection of a connected graph G, denoted by rvc(G), is the smallest number of colors that are needed in order to make G rainbow vertex-connected. In this paper, we study the complexity of determining the rainbow vertex-connection of a graph and prove that computing rvc(G) is NP-Hard. Moreover, we show that it is already NP-Complete to decide whether rvc(G)=2. We also prove that the following problem is NP-Complete: given a vertex-colored graph G, check whether the given coloring makes G rainbow vertex-connected. 相似文献
158.
This communication demonstrates the role of cyclic compressive loads in inducing mode I fatigue crack growth at room temperature in Si3 N4 matrix–SiC whisker composite materials containing stress concentrations. The characteristics of stable, cyclic fracture are examined for several volume fractions of the SiC whisker and are compared with those of the matrix material. It is found that the composites with higher volume fractions of SiC whiskers exhibit an inferior resistance to fracture under cyclic compressive loads despite improvements in fracture toughness values. 相似文献
159.
160.
Lily Yang Hui Mao Y. Andrew Wang Zehong Cao Xianghong Peng Xiaoxia Wang Hongwei Duan Chunchun Ni Qingan Yuan Gregory Adams Mark Q. Smith William C. Wood Xiaohu Gao Shuming Nie 《Small (Weinheim an der Bergstrasse, Germany)》2009,5(2):235-243
Epidermal growth factor receptor (EGFR) targeted nanoparticle are developed by conjugating a single‐chain anti‐EGFR antibody (ScFvEGFR) to surface functionalized quantum dots (QDs) or magnetic iron oxide (IO) nanoparticles. The results show that ScFvEGFR can be successfully conjugated to the nanoparticles, resulting in compact ScFvEGFR nanoparticles that specifically bind to and are internalized by EGFR‐expressing cancer cells, thereby producing a fluorescent signal or magnetic resonance imaging (MRI) contrast. In vivo tumor targeting and uptake of the nanoparticles in human cancer cells is demonstrated after systemic delivery of ScFvEGFR‐QDs or ScFvEGFR‐IO nanoparticles into an orthotopic pancreatic cancer model. Therefore, ScFvEGFR nanoparticles have potential to be used as a molecular‐targeted in vivo tumor imaging agent. Efficient internalization of ScFvEGFR nanoparticles into tumor cells after systemic delivery suggests that the EGFR‐targeted nanoparticles can also be used for the targeted delivery of therapeutic agents. 相似文献