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   184篇
  免费   0篇
电工技术   2篇
化学工业   39篇
金属工艺   3篇
机械仪表   1篇
建筑科学   12篇
轻工业   77篇
无线电   1篇
一般工业技术   3篇
冶金工业   8篇
自动化技术   38篇
  2018年   1篇
  2014年   1篇
  2013年   43篇
  2012年   1篇
  2008年   2篇
  2007年   2篇
  2006年   1篇
  2004年   1篇
  2002年   1篇
  2001年   2篇
  1999年   1篇
  1998年   3篇
  1997年   5篇
  1996年   3篇
  1995年   4篇
  1994年   8篇
  1993年   4篇
  1992年   2篇
  1991年   8篇
  1990年   2篇
  1989年   5篇
  1988年   3篇
  1987年   2篇
  1986年   4篇
  1985年   1篇
  1984年   1篇
  1983年   3篇
  1982年   10篇
  1980年   4篇
  1979年   1篇
  1978年   6篇
  1977年   4篇
  1976年   5篇
  1975年   5篇
  1974年   7篇
  1973年   3篇
  1972年   3篇
  1971年   2篇
  1970年   1篇
  1968年   4篇
  1967年   7篇
  1966年   3篇
  1965年   1篇
  1963年   2篇
  1960年   2篇
排序方式: 共有184条查询结果,搜索用时 15 毫秒
1.
Distinguishable patterns of mass homeownership have emerged across industrialised societies in recent decades, and have become increasingly central in comparative analyses of housing systems. This paper examines the nature of differences and similarities within and between two particular groups of societies where owner occupation dominates housing demand and policy systems, one constituted of English-speaking, Anglo-Saxon societies, and another of East Asian societies. The paper considers the potential of forming loose models based on core divergences in terms of systems, regimes and socio-ideological relationships. The aim is to further illustrate interactions between housing systems and welfare regimes in international contexts. Comparisons of housing and welfare elements are broadly related between societies, rather than quantitatively isolated, as systems are substantially variegated across the East Asian region. However, a loose system-model provides considerable insight into convergence within the group in regards to how housing systems have served a minimal social-welfare regime type.  相似文献   
2.
We introduce a new probabilistic approach to dealing with uncertainty, based on the observation that probability theory does not require that every event be assigned a probability. For a nonmeasurable event (one to which we do not assign a probability), we can talk about only the inner measure and outer measure of the event. In addition to removing the requirement that every event be assigned a probability, our approach circumvents other criticisms of probability-based approaches to uncertainty. For example, the measure of belief in an event turns out to be represented by an interval (defined by the inner and outer measures), rather than by a single number. Further, this approach allows us to assign a belief (inner measure) to an event E without committing to a belief about its negation -E (since the inner measure of an event plus the inner measure of its negation is not necessarily one). Interestingly enough, inner measures induced by probability measures turn out to correspond in a precise sense to Dempster-Shafer belief functions. Hence, in addition to providing promising new conceptual tools for dealing with uncertainty, our approach shows that a key part of the important Dempster-Shafer theory of evidence is firmly rooted in classical probability theory. Cet article présente une nouvelle approche probabiliste en ce qui concerne le traitement de l'incertitude; celle-ci est basée sur l'observation que la théorie des probabilityés n'exige pas qu'une probabilityé soit assignée à chaque événement. Dans le cas d'un événement non mesurable (un événement pour lequel on n'assigne aucune probabilityé), nous ne pouvons discuter que de la mesure intérieure et de la mesure extérieure de l'évenément. En plus d'éliminer la nécessité d'assigner une probabilityéà l'événement, cette nouvelle approche apporte une réponse aux autres critiques des approches à l'incertitude basées sur des probabilityés. Par exemple, la mesure de croyance dans un événement est représentée par un intervalle (défini par la mesure intérieure et extérieure) plutǒt que par un nombre unique. De plus, cette approche nous permet d'assigner une croyance (mesure intérieure) à un événement E sans se compromettre vers une croyance à propos de sa négation -E (puisque la mesure intérieure d'un événement et la mesure intérieure de sa négation ne sont pas nécessairement une seule et unique mesure). II est intéressant de noter que les mesures intérieures qui résultent des mesures de probabilityé correspondent d'une manière précise aux fonctions de croyance de Dempster-Shafer. En plus de constituer un nouvel outil conceptuel prometteur dans le traitement de l'incertitude, cette approche démontre qu'une partie importante de la théorie de l'évidence de Dempster-Shafer est fermement ancrée dans la theorie classique des probabilityés.  相似文献   
3.
A screening procedure utilizing boysenberry juice as a substrate, which combined HPLC and spectrophotometric analyses, was used to measure β-glucosidase activity of enzyme preparations used for juice processing. Enzyme preparations (n = 26) were evaluated at two dosage rates. At the mean recommended dosage, one preparation produced a decrease in total monomeric anthocyanin and cyanidin-3-glucoside, relative to a control, indicating β-glucosidase activity. At 0.1% dosage, 4 enzymes produced a significant decrease in cyanidin-3-sophoroside and 2 enzymes caused an increase in cyanidin-3-rutinoside, indicating β-1,2-glucosidase activity. Such activity in juice processing enzymes was much lower and less prevalent than found previously for β-galactosidase. Botrytis cinerea also degraded anthocyanins in boysenberry juice.  相似文献   
4.
Investigation of the effects of varying air velocity, slice thickness, and pre-treatment with sodium chloride solutions and surface active agents on drying potato slices indicated that the drying occurred entirely in the falling rate period and was controlled by the mechanism of liquid diffusion. The rate of drying, and therefore the diffusion coefficients, increased with the addition of sodium chloride and surface active agents. Diffusion coefficients were also influenced by air velocity and slice thickness, suggesting that the rate of drying of potato slices is controlled by a combination of internal and external resistances.  相似文献   
5.
ABSTRACT: In the first three decades after the Second World War in Europe millions of dwellings were built, in most cases on large estates in or near cities. At that time, many people in various kinds of household found these estates attractive and were happy to live on them. But, in the last two decades, in many parts of Europe social, economic, and physical problems have emerged and the reputation of the estates has suffered a deep decline. That is not to say that they have lost their function in the housing market: some groups might still be drawn to them—low‐income households who cannot find a decent, affordable place elsewhere, for example. In this article, we describe the current position of these estates in the housing careers of specific groups. Are there some groups who find them attractive places in which to live? Or do most people want to get away as soon as they can? Are some people “trapped”? We show that the situation differs substantially between parts of Europe, but even per estate and per household category. Our findings imply that intervention strategies with regard to these estates will have to become much more differentiated than they currently are.  相似文献   
6.
We investigate the meaning of the concept of fuzziness. It is suggested that fuzziness can be related to the lack of distinction between a set and its negation. Using fuzzy subsets with grades of membership in the unit interval, measures of fuzziness are suggested. First, a class of measures based on metric distances is used to derive numeric measures of fuzziness of a fuzzy set. Finally, the concept of compatibility is used to develop linguistic measures of fuzziness.  相似文献   
7.
We provide a set theoretic framework for looking at the classical logical inference problem. We then introduce within this framework a new class of propositions, called second order propositions, which provide a prototypical characterization of nonmonotonic type default knowledge. We study the properties of this new class of propositions.  相似文献   
8.
Abstract

We review Shafer's theory of evidence. We then introduce the concepts pf entropy and specificity in the framework of Shafer's theory. These become complementary aspects in the indication of the quality of evidence.  相似文献   
9.
In this current paper the following problems are addressed: (1) extending the knowledge of a partially known probability distribution function to any point of a continuous sample space, (2) constructing an imprecise probability distribution based on the knowledge of a set of credible or confidence intervals, and (3) computing the lower and upper expected values of a random continuous variable. An example is provided.  相似文献   
10.
The antioxidant efficacy of ground clove, ginger, oregano, rosemary, sage, and thyme was investigated in comminuted pork systems. Spices at 200–2000 ppm levels of addition inhibited the formation of the 2-thiobarbituric acid (TBA) reactive substances (TBARS) by 12–96% over 21-days of storage at 4C. The anti-oxidative effect of spices was concentration-dependent; but close followed by sage and then rosemary was most effective. Ginger and thyme exerted the least effect in prevention of oxidation of meat lipids.  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