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   125篇
  免费   0篇
电工技术   5篇
化学工业   10篇
建筑科学   6篇
能源动力   5篇
轻工业   10篇
水利工程   1篇
无线电   16篇
一般工业技术   17篇
冶金工业   29篇
原子能技术   1篇
自动化技术   25篇
  2022年   1篇
  2021年   4篇
  2020年   1篇
  2018年   1篇
  2017年   2篇
  2016年   2篇
  2015年   3篇
  2014年   2篇
  2013年   3篇
  2012年   2篇
  2011年   6篇
  2010年   2篇
  2009年   2篇
  2008年   4篇
  2007年   2篇
  2006年   3篇
  2005年   10篇
  2004年   4篇
  2003年   4篇
  2002年   3篇
  2001年   1篇
  2000年   1篇
  1999年   2篇
  1998年   10篇
  1997年   6篇
  1996年   6篇
  1995年   5篇
  1994年   3篇
  1993年   2篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
  1988年   4篇
  1987年   1篇
  1986年   1篇
  1985年   3篇
  1984年   3篇
  1983年   1篇
  1982年   1篇
  1981年   3篇
  1980年   1篇
  1978年   2篇
  1977年   1篇
  1976年   2篇
  1974年   1篇
排序方式: 共有125条查询结果,搜索用时 15 毫秒
1.
We assessed the use of 15N-labeled dietary proteins as a possible tool for the determination of the true ileal amino acid (AA) digestibility in pigs. The first experiment was designed to study the dietary N excretion pattern at the ileum subsequent to the ingestion of a single 15N-labeled meal. In a second experiment, we compared ileal endogenous AA outputs and true AA digestibility estimates obtained in pigs ingesting 15N-labeled dietary proteins in a single meal vs. intravenous infusion of [15N]leucine for 10 d during the ingestion of a pea-based diet and a protein-free starch diet. The proportion of endogenous N found in the ileal digesta differed when the label was delivered orally (50%) vs. intravenously (72%) and changed with time. As a consequence, the true ileal AA digestibilities measured with labeled diets were lower. A third experiment demonstrated that this was due to the rapid recycling of labeled dietary N in endogenous moieties, because 15N was found in blood within 10 min of consuming the labeled meal, within 50 min of consumption in pancreatic enzymes, 90 min in bile and 4 h in ileal mucins. We conclude that the use of 15N-labeled meals for determination of true ileal AA digestibilities is limited by the fast recycling of dietary N in endogenous secretions following a single 15N-labeled meal. The accuracy of results will depend on meaningful estimates of AA flow during a limited period and accurate estimates of 15N in AA.  相似文献   
2.
A quantitative model for fitting infrared spectra of polyethyleneterephthalate samples over the region from 1100 to 720 cm?1 has been evaluated. The absorbance was described as the sum of a linear base line and a set of symmetrical bell-shaped Pearson VII curves. Using this model, experimental transmission spectra of yarns, measured with the electric vector parallel and perpendicular to the fiber axis, were fitted. It was found that each of the trans bands near 972 and 845 cm?1 consists of two components, a narrow and a broad one. These two components represent the crystalline and amorphous phases respectively. The band due to the out of plane benzene ring C? H deformation vibration at about 875 cm?1 appeared also to be composed of two contributions. In this case, the narrow component was found to be due to molecules having interactions with direct neighbors. So this narrow component not only contains the molecules in the crystalline phase but also those forming part of bundles which are too small to be detected by x-ray diffraction. For a detailed insight into the molecular arrangement of the amorphous regions, the infrared detection of trans-guache transitions, fold content, detection of bundlelike structures, and molecular stress on tie molecules turned out to be of great practical importance. The structural details, which can be revealed by the infrared technique, cannot be obtained by other means. The potential of the method is illustrated with some practical examples.  相似文献   
3.
International Journal on Software Tools for Technology Transfer - A commonly used approach to develop deterministic parallel programs is to augment a sequential program with compiler directives...  相似文献   
4.
VerifyThis 2015     
VerifyThis 2015 was a one-day program verification competition which took place on April 12th, 2015 in London, UK, as part of the European Joint Conferences on Theory and Practice of Software (ETAPS 2015). It was the fourth instalment in the VerifyThis competition series. This article provides an overview of the VerifyThis 2015 event, the challenges that were posed during the competition, and a high-level overview of the solutions to these challenges. It concludes with the results of the competition and some ideas and thoughts for future instalments of VerifyThis.  相似文献   
5.
The traditional Dutch rental contract is permanent (i.e. time unlimited), but there are indications that in recent years the number of temporary rental contracts has increased considerably. Dutch housing policy appears to be responding to this by pursuing deregulation of the conditions under which temporary rent is permitted. It is in this regard startling that there is no reliable data available about the size or character of the temporary sector, and it has thus far not attracted any scholarly attention. Given that temporary rent can be viewed as a form of precarisation, a transfer of risk to citizens, with corresponding negative effects on the lives of those involved, it is imperative to close this knowledge gap. This paper is a first attempt to do this. Firstly, I systematically review the scarce evidence that is currently available, and secondly, I explore why the rise of temporary rent has thus far failed to stimulate any social debate; it appears to constitute a silent precarisation that contrasts with the politically sensitive issue of labour precarisation. In doing so, I will identify the research questions that must be answered if the significance of this process for both tenants and wider welfare-state restructuring is to be fully understood.  相似文献   
6.
A desktop study has been performed to analyse the performance of biomass-to-fuel plants producing methanol, dimethylether (DME) or hydrogen. Two different designs have been made. One design based on the technology of today and one design based on the technology of tomorrow. Mass and energy balances are presented for both designs producing all three fuels. Biomass-to-fuel conversion efficiencies (LHV) of the plants range between 45 and 56% for hydrogen and DME production respectively in the present-day design and between 56 and 69% for hydrogen and methanol production respectively for the near-future design. Biomass-to-fuel conversion efficiency to DME is only marginally smaller than biomass-to-fuel conversion efficiency of methanol. Expression of efficiency of the biomass-to-fuel plant in biomass-to-fuel conversion efficiency does not include electrical power consumption and district heat generation. Exergy also includes the quality of the energy that is consumed or generated. Therefore exergetic efficiency should be used to express process efficiency. Methanol production using the technology of tomorrow is most efficient with exergetic efficiency of 55%. The least efficient is hydrogen production with exergetic efficiency of 40% and 45%, for present-day and near-future design, respectively. This is caused by the large purge stream in the plant design. The use of new technologies developed within the CHRISGAS project give an increase of 5–8% points in exergetic efficiency.  相似文献   
7.
At present, flexible displays are an important focus of research. Further development of large, flexible displays requires a cost-effective manufacturing process for the active-matrix backplane, which contains one transistor per pixel. One way to further reduce costs is to integrate (part of) the display drive circuitry, such as row shift registers, directly on the display substrate. Here, we demonstrate flexible active-matrix monochrome electrophoretic displays based on solution-processed organic transistors on 25-microm-thick polyimide substrates. The displays can be bent to a radius of 1 cm without significant loss in performance. Using the same process flow we prepared row shift registers. With 1,888 transistors, these are the largest organic integrated circuits reported to date. More importantly, the operating frequency of 5 kHz is sufficiently high to allow integration with the display operating at video speed. This work therefore represents a major step towards 'system-on-plastic'.  相似文献   
8.
Rosemary (dried leaves ofRosmarinus officinalis L.) added to cooked meat balls (minced pork) was found to retard the formation of warmed over flavour (WOF) during chill storage. The spice was added to pork meat (Longissimus dorsi) balls in an amount acceptable for the product, as evaluated by a sensory panel (0.05% of total weight). After cooking (water bath, internal temperature 80°C), the meat balls were packed using five atmosphere packaging conditions: (i) air; (ii) 5% O2/95% N2; (iii) 3% O2/97% N2; (iv) 1% O2/99% N2; and (v) 100% N2. During chill storage (5°C), the sensory quality of the reheated meat balls was evaluated by a trained sensory panel, and lipid oxidation was followed by measurement of thiobarbituric acid reactive substances (TBARS). The combination of decreased O2 atmosphere in the packages and addition of rosemary resulted in a significantly (p<0.05) lower amount of TBARS and a significantly (p<0.05) better sensory score.
Gemeinsamer Effekt von Rosmarin (Rosmarinus officinalis L.) und Verpackung in modifizierter Atmosphäre auf den Aufwärmegeschmack (WOF) von wärmebehandeltem, gehacktem Schweinefleisch
Zusammenfassung Rosmarin (getrocknete Blätter vonRosmarinus officinalis L.), erwärmten Fleischklößen (gehacktes Schweinefleisch) zugesetzt, hinderte die Entwicklung des Aufwärmgeschmacks (warmed over flavour) während der Kühllagerung. Das Gewürz wurde den aus Schweinefleisch (Longissimus dorsi) hergestellten Fleischklößen in einer für das Produkt akzeptablen Menge zugegeben, beurteilt von einem sensorischen Panel (0.05% des Totalgewichtes). Nach der Wärmebehandlung (Wasserbad, Zentrum-Temperatur 80°C) wurden die Fleischklöße in fünf unterschiedlichen und kontrollierten Atmosphären wie folgt verpackt: (i) Luft; (ii) 5% O2/95% N2; (iii) 3% O2/97% N2; (iv) 1% O2/99% N2 und (v) 100% N2. Während der Kühllagerung (5°C) wurde die sensorische Qualität der wiedererwärmten Fleischklöße von einem geschulten Panel beurteilt und die Lipid-Oxidation durch Messung der Thiobarbitursäure-reaktiven Substanzen (TBARS) beobachtet. Die Kombination von ermäßigtem Sauerstoffgehalt in den Verpackungen mit der Zugabe von Rosmarin ergab eine signifikant (p<0.05) niedrigere Menge TBARS wie auch signifikant (p<0.05) bessere Punkte in der sensorischen Beurteilung.
  相似文献   
9.
10.
A key question in setting up take-back systems for discarded consumer electronics is how much environmental improvement can be realized per amount of money invested. With the eco-efficiency concept developed, the environmental and economic performance of single products within various end-of-life scenarios can be quantified as well as the contribution of individual materials and material fractions to this performance. Also analysis the effectiveness and efficiency of optimization and changes in the take-back system like, glass recycling and plastic recycling, and Design for End-of-Life activities is determined. Moreover, the environmental effectiveness and cost-efficiency effects of the European Waste of Electrical and Electronic Equipment (WEEE) Directive is reviewed. Based on the eco-efficiency analyses, an implementation roadmap for this legislation is proposed in order to further improve environmental performance on one hand and to minimize costs on the other hand.  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