全文获取类型
收费全文 | 187篇 |
免费 | 10篇 |
专业分类
化学 | 142篇 |
力学 | 2篇 |
数学 | 21篇 |
物理学 | 32篇 |
出版年
2023年 | 1篇 |
2022年 | 9篇 |
2021年 | 9篇 |
2020年 | 5篇 |
2019年 | 3篇 |
2018年 | 5篇 |
2017年 | 4篇 |
2016年 | 7篇 |
2015年 | 8篇 |
2014年 | 5篇 |
2013年 | 9篇 |
2012年 | 19篇 |
2011年 | 14篇 |
2010年 | 8篇 |
2009年 | 8篇 |
2008年 | 9篇 |
2007年 | 11篇 |
2006年 | 6篇 |
2005年 | 8篇 |
2004年 | 12篇 |
2003年 | 4篇 |
2002年 | 1篇 |
2001年 | 1篇 |
1999年 | 1篇 |
1996年 | 3篇 |
1994年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1972年 | 1篇 |
1971年 | 3篇 |
1961年 | 1篇 |
1935年 | 4篇 |
1914年 | 1篇 |
1910年 | 2篇 |
1905年 | 1篇 |
排序方式: 共有197条查询结果,搜索用时 46 毫秒
31.
Experimental study on the retention of silica particles in gravitational field-flow fractionation effects of the mobile phase composition 总被引:3,自引:0,他引:3
Pierluigi Reschiglian Dora Melucci Giancarlo Torsi 《Journal of chromatography. A》1996,740(2):245-252
Effects of mobile phase composition can play an effective role in modulating the retention of particles in gravitational field-flow fractionation (GFFF), the simplest and cheapest among field-flow fractionation (FFF) techniques. In the framework of an optimized procedure for the GFFF characterization of particulate systems, an experimental approach to the effects of the mobile phase composition on the retention of silica particles retention is presented. The role of the ionic strength and the presence of surfactant are emphasized, with special regards to the shape of the particles. Moreover, the first experimental evidence of potential-barrier GFFF is reported. 相似文献
32.
The decays Higgs → Higgs + V (V = W, Z) are studied in the Weinberg-Salam model with two Higgs doublets and are shown to exceed the usual fermion decay mode with known fermions and the mode V in a large region of Higgs masses and mixing angles. Higgs-Higgs final states and the role of the heavy Higgs decays are briefly discussed. 相似文献
33.
34.
An approximate analytical approach for revealing bandgap information for photonic band gap fibers with depressed index cladding rods is presented. The method considers isolated rods in cladding, with three layers structure: higher index in the core, lower-index depressed layer and silica cladding. Good consistency is found between the results of the approximate analytical method and those from accurate numerical simulations. 相似文献
35.
We consider the problem , , in a smooth bounded domain Ω in , under zero Dirichlet boundary conditions. We obtain solutions to this problem exhibiting multiple bubbling behavior at k different points of the domain as λ tends to a special positive value , which we characterize in terms of the Green function of . 相似文献
36.
We treat the stochastic Dirichlet problem \(L\lozenge u = h+\nabla f\) in the framework of white noise analysis combined with Sobolev space methods. The input data and the boundary condition are generalized stochastic processes regarded as linear continuous mappings from the Sobolev space \(W_0^{1,2}\) into the Kondratiev space (S)???1. The operator L is assumed to be strictly elliptic in divergence form \(L\lozenge u=\nabla(A\lozenge\nabla u+b\lozenge u)+c\lozenge\nabla u+d\lozenge u\). Its coefficients: the elements of the matrix A and of the vectors b, c and d are assumed to be generalized random processes, and the product of two generalized processes, denoted by \(\lozenge\), is interpreted as the Wick product. In this paper we prove the weak maximum principle for the operator L, which will imply the uniqueness of the solution to \(L\lozenge u = h+\nabla f\). 相似文献
37.
In this paper we consider the stochastic Dirichlet problem \(L\lozenge u=h+\nabla f\) in the framework of white noise analysis combined with Sobolev space and Colombeau algebra methods. The operator L is assumed to be strictly elliptic in divergence form \(L\lozenge u=\nabla(A\lozenge\nabla u+b\lozenge u)+c\lozenge\nabla u+d\lozenge u\). Its coefficients: the elements of the matrix A and of the vectors b, c and d are assumed to be generalized random processes, and the product of two generalized processes is interpreted as the Wick product. Generalized random processes are considered as linear bounded mappings from the Sobolev space \(W_0^{1,2}\) into the Kondratiev space (S)???1. In this paper we prove existence and uniqueness of the problem of this form in the case when the operator L generates a coercive bilinear form, and then extend this result to the general case. We also consider the case when the coefficients of L, the input data and the boundary condition are Colombeau-type generalized stochastic processes. 相似文献
38.
Nayak Debasis Dora J. K. Ghosh Sudipto Adyam Venimadhav 《Journal of Solid State Electrochemistry》2022,26(5):1231-1239
Journal of Solid State Electrochemistry - Sodium-ion batteries have emerged as an exciting alternative to commercially dominant lithium-ion batteries for electric vehicles and other applications.... 相似文献
39.
Prof. Dr. Petra Schwille Prof. Dr. Joachim Spatz Prof. Dr. Katharina Landfester Prof. Dr. Eberhard Bodenschatz Prof. Dr. Stephan Herminghaus Prof. Dr. Victor Sourjik Dr. Tobias J. Erb Prof. Dr. Philippe Bastiaens Prof. Dr. Reinhard Lipowsky Prof. Dr. Anthony Hyman Prof. Dr. Peter Dabrock Dr. Jean‐Christophe Baret Dr. Tanja Vidakovic‐Koch Dr. Peter Bieling Dr. Rumiana Dimova Dr. Hannes Mutschler Dr. Tom Robinson Dr. T.‐Y. Dora Tang Dr. Seraphine Wegner Prof. Dr. Kai Sundmacher 《Angewandte Chemie (International ed. in English)》2018,57(41):13382-13392
A large German research consortium mainly within the Max Planck Society (“MaxSynBio”) was formed to investigate living systems from a fundamental perspective. The research program of MaxSynBio relies solely on the bottom‐up approach to synthetic biology. MaxSynBio focuses on the detailed analysis and understanding of essential processes of life through modular reconstitution in minimal synthetic systems. The ultimate goal is to construct a basic living unit entirely from non‐living components. The fundamental insights gained from the activities in MaxSynBio could eventually be utilized for establishing a new generation of biotechnological processes, which would be based on synthetic cell constructs that replace the natural cells currently used in conventional biotechnology. 相似文献
40.
Zusammenfassung Es wurde festgestellt, da? beim Mischen von Quecksilbersol und Schwefelsol kolloides Sulfid entsteht. Und zwar konnte dies
dadurch nachgewiesen werden, da? überschüssiger Schwefel aus dem Gemisch der ausgeflockten Kolloide durch Ausziehen mit Natriumsulfitl?sung
entfernt wurde, worauf der Rückstand als Merkurisulfid identifiziert werden konnte.
In analoger Weise wie früher bei Kupfer- und Schwefelsol konnte gezeigt werden, da? auch hier die kolloiden Stoffe die Reaktionstr?ger
sind.
Die Umsetzung zwischen kolloidem Quecksilber und Schwefel verlief wesentlich weniger schnell als zwischen Kupfer und Schwefel.
So konnte noch eine gewisse Zeit nach dem Zusammengeben der Sole trotz Anwendung eines überschusses an kolloidem Schwefel
nicht gebundenes Quecksilber bzw. umgekehrt bei überschüssigem Quecksilber freier Schwefel nachgewiesen werden. 相似文献