全文获取类型
收费全文 | 127篇 |
免费 | 1篇 |
专业分类
化学 | 58篇 |
力学 | 14篇 |
数学 | 44篇 |
物理学 | 12篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2018年 | 5篇 |
2016年 | 4篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 7篇 |
2012年 | 8篇 |
2011年 | 10篇 |
2010年 | 5篇 |
2009年 | 3篇 |
2008年 | 6篇 |
2007年 | 4篇 |
2006年 | 7篇 |
2005年 | 5篇 |
2004年 | 6篇 |
2003年 | 6篇 |
2001年 | 4篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1976年 | 2篇 |
1974年 | 1篇 |
1969年 | 1篇 |
1967年 | 1篇 |
1941年 | 2篇 |
排序方式: 共有128条查询结果,搜索用时 15 毫秒
31.
This paper gives a pathwise construction of Jackson-type queueing networks allowing the derivation of stability and convergence theorems under general probabilistic assumptions on the driving sequences; namely, it is only assumed that the input process, the service sequences and the routing mechanism are jointly stationary and ergodic in a sense that is made precise in the paper. The main tools for these results are the subadditive ergodic theorem, which is used to derive a strong law of large numbers, and basic theorems on monotone stochastic recursive sequences. The techniques which are proposed here apply to other and more general classes of discrete event systems, like Petri nets or GSMPs. The paper also provides new results on the Jackson-type networks with i.i.d. driving sequences which were studied in the past.The work of this author was supported in part by a grant from the European Commission DG XIII, under the BRA Qmips contract.The work of this author was supported by a sabbatical grant from INRIA Sophia Antipolis. 相似文献
32.
Applied Biochemistry and Biotechnology - 相似文献
33.
M. Foss 《Annali di Matematica Pura ed Applicata》2008,187(2):263-321
We prove some global, up to the boundary of a domain $\Omega \subset {\mathbb{R}}^{n}We prove some global, up to the boundary of a domain , continuity and Lipschitz regularity results for almost minimizers of functionals of the form
The main assumption for g is that it be asymptotically convex with respect its third argument. For the continuity results, the integrand is allowed
to have some discontinuous behavior with respect to its first and second arguments. For the global Lipschitz regularity result,
we require g to be H?lder continuous with respect to its first two arguments.
相似文献
34.
35.
This paper provides an overview of results, concerning longest or heaviest paths, in the area of random directed graphs on the integers along with some extensions. We study first-order asymptotics of heaviest paths allowing weights both on edges and vertices and assuming that weights on edges are signed. We aim at an exposition that summarizes, simplifies, and extends proof ideas. We also study sparse graph asymptotics, showing convergence of the weighted random graphs to a certain weighted graph that can be constructed in terms of Poisson processes. We are motivated by numerous applications, ranging from ecology to parallel computing models. It is the latter set of applications that necessitates the introduction of vertex weights. Finally, we discuss some open problems and research directions. 相似文献
36.
Aiga?MackevicaEmail author Mikael?Emil?Olsson Steffen?Foss?Hansen 《Journal of nanoparticle research》2018,20(1):6
TiO2 is ubiquitously present in a wide range of everyday items, both as an intentionally incorporated additive and naturally occurring constituent. It can be found in a wide range of consumer products, including personal care products, food contact materials, and textiles. Normal use of these products may lead to consumer and/or environmental exposure to TiO2, possibly in form of nanoparticles. The aim of this study is to perform a leaching test and apply state-of-the-art methods to investigate nano-TiO2 and total Ti release from five types of commercially available conventional textiles: table placemats, wet wipes, microfiber cloths, and two types of baby bodysuits, with Ti contents ranging from 2.63 to 1448 μg/g. Released particle analysis was performed using conventional and single particle inductively coupled plasma mass spectrometry (ICP-MS and spICP-MS), in conjunction with transmission electron microscopy (TEM), to measure total and particulate TiO2 release by mass and particle number, as well as size distribution. Less than 1% of the initial Ti content was released over 24 h of leaching, with the highest releases reaching 3.13 μg/g. The fraction of nano-TiO2 released varied among fabric types and represented 0–80% of total TiO2 release. Particle mode sizes were 50–75 nm, and TEM imaging revealed particles in sizes of 80–200 nm. This study highlights the importance of using a multi-method approach to obtain quantitative release data that is able to provide an indication regarding particle number, size distribution, and mass concentration, all of which can help in understanding the fate and exposure of nanoparticles. 相似文献
37.
Yu. A. Veits E. G. Neganova A. A. Rorisenko V. L. Foss I. F. Lutsenko 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract Addition of variousnucleophiles to phosphaalkenes is considered to be irreversible. As an example, the quantitative formation of iminodiphosphine III from phosphinous amide and phosphaalkene was recently reported (1). 相似文献
38.
L. E. Foss Yu. K. Voronina P. I. Gryaznov A. T. Gubaidullin P. S. Fakhretdinov I. A. Litvinov G. V. Romanov 《Journal of Structural Chemistry》2010,51(2):392-394
2-(2-p-Tolyloxyethoxy)ethylchloroacetate is synthesized and its single crystal X-ray diffraction analysis is performed. 相似文献
39.
Steffen Foss Hansen 《Journal of nanoparticle research》2010,12(6):1959-1970
In order to facilitate stakeholder discussions on how to regulate nanotechnology, the opensource program multicriteria mapping (MCM) was used to structure 26 interviews with stakeholders in the USA. MCM offers a systematic part quantitative, part qualitative approach to clarify why some regulatory options (bans, moratoriums, voluntary measures, etc.) were deemed to be acceptable/unacceptable by various stakeholders and which criteria stakeholders used to evaluate the different regulatory options. Adopting an incremental approach and implementing a new regulatory framework was evaluated as the best options whereas a complete ban and no additional regulation of nanotechnology were found to be the least favorable. Criteria applied differed substantially among stakeholders and included social, ethical, regulatory, environmental, and health issues. Opinions on future regulation seem far less polarized than expected and it seems that stakeholders would welcome a combination of voluntary measures, an incremental approach and forming of a new regulatory framework. 相似文献
40.
Attila Kormányos Mohammad S. Hossain Ghazaleh Ghadimkhani Joe J. Johnson Prof. Csaba Janáky Prof. Norma R. de Tacconi Prof. Frank W. Foss Jr. Prof. Yaron Paz Prof. Krishnan Rajeshwar 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(27):9209-9217
This study establishes structure–property relationships for four synthetic flavin molecules as bioinspired redox mediators in electro‐ and photocatalysis applications. The studied flavin compounds were disubstituted with polar substituents at the N1 and N3 positions (alloxazine) or at the N3 and N10 positions (isoalloxazines). The electrochemical behavior of one such synthetic flavin analogue was examined in detail in aqueous solutions of varying pH in the range from 1 to 10. Cyclic voltammetry, used in conjunction with hydrodynamic (rotating disk electrode) voltammetry, showed quasi‐reversible behavior consistent with freely diffusing molecules and an overall global 2e?, 2H+ proton‐coupled electron transfer scheme. UV/Vis spectroelectrochemical data was also employed to study the pH‐dependent electrochemical behavior of this derivative. Substituent effects on the redox behavior were compared and contrasted for all the four compounds, and visualized within a scatter plot framework to afford comparison with prior knowledge on mostly natural flavins in aqueous media. Finally, a preliminary assessment of one of the synthetic flavins was performed of its electrocatalytic activity toward dioxygen reduction as a prelude to further (quantitative) studies of both freely diffusing and tethered molecules on various electrode surfaces. 相似文献