全文获取类型
收费全文 | 64篇 |
免费 | 2篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 28篇 |
金属工艺 | 2篇 |
建筑科学 | 1篇 |
轻工业 | 11篇 |
无线电 | 5篇 |
一般工业技术 | 5篇 |
冶金工业 | 1篇 |
原子能技术 | 1篇 |
自动化技术 | 11篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 4篇 |
2012年 | 4篇 |
2011年 | 8篇 |
2010年 | 5篇 |
2009年 | 1篇 |
2008年 | 4篇 |
2007年 | 3篇 |
2006年 | 2篇 |
2004年 | 1篇 |
2002年 | 1篇 |
2001年 | 1篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1976年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有66条查询结果,搜索用时 46 毫秒
1.
2.
We deal with a complex game between Alice and Bob where each contender’s probability of victory grows monotonically by unknown amounts with the resources employed. For a fixed effort on Alice’s part, Bob increases his resources on the basis of the results for each round (victory, tie or defeat) with the aim of reducing the probability of defeat to below a given threshold. We read this goal in terms of computing a confidence interval for the probability of losing and realize that the moves in some contests may bring in an indeterminacy trap: in certain games Bob cannot simultaneously have both a low probability-of-defeat measure and a narrow confidence interval. We use the inferential mechanism called twisting argument to compute the above interval on the basis of two joint statistics. Careful use of such statistics allows us to avoid indeterminacy. 相似文献
3.
Italo Odone Mazali Luiz Carlos Barbosa Oswaldo Luiz Alves 《Journal of Materials Science》2004,39(6):1987-1995
In the present work we describe the synthesis, spectroscopy, thermal and chemical durability properties of the vitreous system Li2O-Nb2O5-CaO-P2O5 (LNCP). Investigations of the short-range order by Fourier transform infrared, Raman, UV-VIS and 31P MAS-NMR spectroscopies suggest that the network former glass consists of Nb octahedra linked to pyro/orthophosphate units through Nb—O—P bonds. The presence of modifier cations (Li+ and Ca2+) promotes depolymerization of the P—O—P chains, yielding pyro/orthophosphate units. The presence of this kind of structure accounts for the improvement of the chemical durability at low pH when the Nb content in the LNCP glass composition is high. The density and linear refractive indices of LNCP glasses increased linearly as the Nb2O5/P2O5 molar ratio increased, as a consequence of P2O5 substitution by Nb2O5 as the glassformer. The dependence of the glass transition temperature, the softening temperature and the crystallization temperature on the Nb2O5/P2O5 ratio exhibits the same behavior. On the other hand, the thermal expansion coefficient decreases with the increased Nb2O5/P2O5 ratio. 相似文献
4.
Marco Antoniotti Marco Carreras Antonella Farinaccio Giancario Mauri Daniele Merico Italo Zoppis 《Computers & Operations Research》2010,37(8):1361-1368
The application of various clustering techniques for large-scale gene-expression measurement experiments is a well-established method in bioinformatics. Clustering is also usually accompanied by functional characterization of gene sets by assessing statistical enrichments of structured vocabularies, such as the gene ontology (GO) [Gene Ontology Consortium. The gene ontology (GO) project in 2006. Nucleic Acids Research (Database issue), vol. 34; 2006. p. D322–6]. If different clusters are generated for correlated experiments, a machine learning step termed cluster meta-analysis may be performed, in order to discover relations among the components of such sets. Several approaches have been proposed: in particular, kernel methods may be used to exploit the graphical structure of typical ontologies such as GO. Following up the formulation of such approach [Merico D, Zoppis I, Antoniotti M, Mauri G. Evaluating graph kernel methods for relation discovery in GO-annotated clusters. In: KES-2007/WIRN-2007, Part IV, Lecture notes in artificial intelligence, vol. 4694. Berlin: Springer; 2007. p. 892–900; Zoppis I, Merico D, Antoniotti M, Mishra B, Mauri G. Discovering relations among GO-annotated clusters by graph kernel methods. In: Proceedings of the 2007 international symposium on bioinformatics research and applications. Lecture notes in computer science, vol. 4463. Berlin: Springer; 2007], in this paper we discuss, from an information-theoretic point of view, further results about its applicability and its performance. 相似文献
5.
<正>Italo Rota,1953年出生在米兰,是近年来活跃在意大利建筑与室内设计领域的中坚设计师。他从学生时代起就对设计表现出极高的热情,曾经在多位知名设计师麾下工作过,并且对出版业、杂志、展览,以及建筑项目都有所涉及。早在上个世纪 相似文献
6.
Higher Alcohol Synthesis 总被引:5,自引:0,他引:5
It has been known for many years that it is possible to produce mixtures of methanol and higher alcohols from synthesis gas by alkali promotion of the methanol synthesis catalysts and by appropriate modification of the reaction conditions [l]. From 1927 to 1945 plants were in operation in the United States and Germany, that were dismantled with the coming of different feedstocks and the necessity of obtaining pure alcohols for chemical use. In the last decade the chemical and petroleum industry has shown a renewed and growing interest in the use of mixtures of methanol and higher aliphatic alcohols. The original goal in the late '70s was mainly to reduce oil dependence by producing synthetic components for gasoline blends. More recently the trend to lead phase-down due to environmental protection has focused the attention on the product performances of such alcohol mixtures as high octane blending stock for gasoline. It has been shown that the addition of higher alcohols to methanol increases the water tolerance in respect to phase separation, reduces the fuel volatility and the vapor lock tendency, and also results in higher volumetric heating values. 相似文献
7.
In this work oxidation of benzene and ethenylbenzene (IUPAC name for styrene) as single compounds and in binary mixtures over a Pt honeycomb catalyst were investigated. Both aromatic compounds showed zero-order kinetics over a wide concentration range. The ethenylbenzene reaction rate was affected weakly by the presence of benzene, whereas benzene oxidation was inhibited strongly by ethenylbenzene. The Mars-van Krevelen mechanism (which is generally accepted for single aromatic compound oxidation kinetics) gave rise to inconsistencies in describing mixture behaviour. A different kinetic model is proposed, where benzene reacts from the gas phase and ethenylbenzene is adsorbed on the catalyst competing with oxygen for active sites. This model was able to interpret the oxidation of mixtures quite satisfactorily. 相似文献
8.
9.
An approximation is given for the case of simultaneous steady state diffusion and chemical reaction in a liquid—liquid system under such conditions that diffusion and chemical reaction are of the same order of magnitude in the two phases. The two-film model was adopted to represent the system, and results were plotted as variations of the enhancement factor with the diverse parameters affecting it. Comparison was made with an exact numerical solution, and the results show that the proposed approximation leads to small errors for low reaction rates, and gives a first approximation for the mass transfer rate for very rapid chemical reactions. 相似文献
10.
借助虚拟化实现安全性 虚拟技术已从企业计算空间转向嵌入式世界.虚拟技术包括在虚拟计算机监控器的控制下提取系统资源,有时称为系统管理程序.系统管理程序使运行同时执行环境具有可能性,每个环境孤立存在,分别运行在基础硬件平台的一个虚拟代表上. 相似文献