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   226篇
  免费   7篇
电工技术   1篇
化学工业   33篇
金属工艺   1篇
机械仪表   1篇
建筑科学   25篇
能源动力   8篇
轻工业   33篇
水利工程   4篇
无线电   24篇
一般工业技术   26篇
冶金工业   27篇
自动化技术   50篇
  2023年   1篇
  2022年   1篇
  2021年   1篇
  2020年   5篇
  2019年   4篇
  2018年   4篇
  2017年   4篇
  2016年   3篇
  2015年   5篇
  2014年   7篇
  2013年   13篇
  2012年   9篇
  2011年   25篇
  2010年   12篇
  2009年   7篇
  2008年   20篇
  2007年   11篇
  2006年   10篇
  2005年   12篇
  2004年   14篇
  2003年   8篇
  2002年   12篇
  2001年   8篇
  2000年   3篇
  1999年   8篇
  1998年   4篇
  1997年   4篇
  1996年   4篇
  1994年   1篇
  1993年   3篇
  1991年   2篇
  1989年   2篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1982年   2篇
  1978年   1篇
排序方式: 共有233条查询结果,搜索用时 15 毫秒
31.
Previous research showed that decisions to act (i.e., actions) produce more regret than decisions not to act (i.e., inactions). This previous research focused on decisions made in isolation and ignored that decisions are often made in response to earlier outcomes. The authors show in 4 experiments that these prior outcomes may promote action and hence make inaction more abnormal. They manipulated information about a prior outcome. As hypothesized, when prior outcomes were positive or absent, people attributed more regret to action than to inaction. However, as predicted and counter to previous research, following negative prior outcomes, more regret was attributed to inaction, a finding that the authors label the inaction effect. Experiment 4, showing differential effects for regret and disappointment, demonstrates the need for emotion-specific predictions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
32.
In this paper we present a software programmable design flow that facilitates the implementation and integration of efficient digital pre-distortion (DPD) solutions on the leading-edge field programmable gate arrays, combining industry-standard embedded processors and programmable logic fabric into one chip. In addition to software programmability, another key contribution of this design flow is the flexible partitioning of functionality among the hardware and software components, depending on the complexity of the DPD parameter estimation algorithm in use. We have applied processor-specific optimizations to the software implementation and used Vivado high-level synthesis (HLS) tool as the design tool for the programmable logic. Furthermore, we have compared two different techniques for the integration of hardware and software components, where we have chosen the one with better area/latency trade-off. We present a comprehensive study reporting the DPD parameter update times when exploring the partitioning of the functionality among hardware and software. For low-complexity algorithms, we show that a software-only solution is applicable after carrying out the processor-specific software optimizations. For higher-complexity algorithms, we use Vivado HLS to accelerate the time-consuming blocks in the programmable logic, leading to a speed-up factor of up to 7× in the overall algorithm execution time. We present the performance results for two target devices. We also show that our accelerators use only a small portion of the programmable logic fabric on these devices and that a significant reduction of the system’s energy consumption can be obtained by leveraging the FPGA fabric.  相似文献   
33.
The aim of this investigation was to determine whether the regioselectivity found for lipoxygenases in the formation of fatty acid hydroperoxides from linoleic acid is reflected in the formation of dimeric products in secondary reactions involving linoleic acid, product hydroperoxide and lipoxygenase. A method was therefore developed for the separation and identification of dimers formed by fusion of two linoleic acid radicals or a linoleic acid radical and linoleate. The method includes solid-phase extraction, preparative separation of products by thin-layer chromatography, derivatization to the corresponding fully hydrogenated methyl esters and capillary gas chromatography (GC) coupled with electron impact mass spectrometry. We present evidence that the formation of octadecadienoate dimers, during the secondary reaction of soybean lipoxygenase-1 or lipoxygenase-3, is a nonenzymic process that can be envisaged by nonspecific association of intermediate fatty acid radicals (L*) that have dissociated from the enzyme. We could show that the relative amounts of different octadecadienoate dimers formed remain unaltered, regard-less of pH and type of soybean isoenzyme used. Quantitative analysis by GC showed that under the reaction conditions used, the formation of dimers branching at the 13-position is preferred.  相似文献   
34.
Open access for new broadcasting organizations "has led not to an increase, but a decrease in diversity" and a greater dependence on group membership.  相似文献   
35.
浪漫茅屋记     
坐落在荷兰海利近郊zoetermeer,覆盖了一层厚厚稻草的这座现代住宅,让我不禁想起了旧时的茅草屋。在那个建造技术有限、物质匮乏的年代,由夯土、木头、麦秆建成的房子,是当时人们赖以生  相似文献   
36.
37.
Significant interest has emerged in the introduction of food packaging materials manufactured from biodegradable polymers that have the potential to reduce the environmental impacts associated with conventional packaging materials. Current technologies in active packaging enable effective antimicrobial (AM) packaging films to be prepared from biodegradable materials that have been modified and/or blended with different compatible materials and/or plasticisers. A wide range of AM films prepared from modified biodegradable materials have the potential to be used for packaging of various food products. This review examines biodegradable polymers derived from polysaccharides and protein-based materials for their potential use in packaging systems designed for the protection of food products from microbial contamination. A comprehensive table that systematically analyses and categorizes much of the current literature in this area is included in the review.  相似文献   
38.
<正>该建筑坐落在海牙市中心,邻近海牙森林,矗立在Bezuidenhoutseweg大街——一条连接皇家宫殿Huisten Bosch和荷兰国会建筑Het Binnenhof的历史性轴线。这个具有强烈而独特风格的雄伟建筑始建于1917年,由当时的政府首席建筑师DanielE.C. Knuttel设计,为财政紧缩时期的外交部办公所用,1994年由Hans  相似文献   
39.
In order to estimate the spatial variation within well-defined study areas, nitrogen dioxide was measured with diffusion samplers (Palmes tube) in 40-42 sites each in Germany (Munich), the Netherlands and Sweden (Stockholm County). Each site was measured over four 2-week periods during 1 year (spring 1999 to summer 2000). In each country, one reference site was measured during all periods and the results were used to adjust for seasonal variability, to improve the estimates of the annual average. Comparisons between the chemiluminescence method (European reference method) and Palmes tube measurement indicated a good agreement in Germany (with a ratio of 1.0 for Palmes tube/chemiluminescence) but underestimation for Palmes tube measurement in the Netherlands and Sweden (0.8 for both countries). The r2 values were between 0.86 and 0.90 for all three countries. The annual average values for NO2 for different sampling sites were between 15.9 and 50.6 (mean 28.8 microg/m3) in Germany, between 12.1 and 50.8 (mean 28.9 microg/m3) in the Netherlands and between 6.1 and 44.7 (mean 18.5 microg/m3) in Sweden. Comparing spatial variation between similar sites in the three countries, we did not find any significant differences between annual average levels for urban traffic sites. In Sweden, annual average levels in urban background and suburban backgrounds sites were about 8 microg/m3 lower than comparable sites in Germany and the Netherlands. Comparing site types within each country only urban traffic sites and suburban background sites differed in Germany. In the Netherlands and Sweden, the urban traffic sites differed from all other sites and in Sweden also the urban background sites differed from the other background sites. The observed contribution from local traffic was similar in the Netherlands and Sweden (10 and 8 microg/m3, corresponding to 26-27% of the NO2 concentration found in the urban traffic sites). In Germany, the contribution from local traffic was only 3 microg/m3, corresponding to 9% of the NO2 concentration found in the urban traffic sites. The spatial variation was substantially larger for NO2 than the variation for PM2.5 and similar to PM2.5 absorbance, measured in the same locations.  相似文献   
40.
Housing choice and tenure choice have beenstudied from many different theoreticalperspectives and with a great variety ofmethodological approaches. In explaininghousing choice, researchers have shown theinfluence of both macrolevel (housing market,economic situation) and microlevel (age,income) factors. Relatively little attentionhas been given to motivational microlevelfactors such as goals and values. In thisarticle, the focus is on values and goals asdeterminants of housing choice. Therelationships between these motivationalfactors, other microlevel factors, and housingchoice are specified in an extended means-endmodel which is based on means-end theory. Theempirical validity of this extended model hasbeen partly assessed by using it to predictintended tenure choice. In the article,previous research on the motivations forhousing choice is discussed and the extendedmeans-end model is described. The empiricalresults of applying the model to intendedtenure choice are presented and discussed,while the assessment of the reliability of thevalue scales is also described.  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