全文获取类型
收费全文 | 383篇 |
免费 | 9篇 |
国内免费 | 2篇 |
专业分类
化学 | 132篇 |
晶体学 | 5篇 |
力学 | 28篇 |
数学 | 98篇 |
物理学 | 131篇 |
出版年
2023年 | 2篇 |
2022年 | 4篇 |
2021年 | 6篇 |
2020年 | 6篇 |
2019年 | 8篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 6篇 |
2015年 | 10篇 |
2014年 | 9篇 |
2013年 | 13篇 |
2012年 | 14篇 |
2011年 | 28篇 |
2010年 | 17篇 |
2009年 | 16篇 |
2008年 | 20篇 |
2007年 | 23篇 |
2006年 | 16篇 |
2005年 | 11篇 |
2004年 | 9篇 |
2003年 | 17篇 |
2002年 | 11篇 |
2001年 | 9篇 |
2000年 | 18篇 |
1999年 | 2篇 |
1998年 | 6篇 |
1997年 | 7篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1994年 | 4篇 |
1992年 | 5篇 |
1990年 | 2篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1985年 | 2篇 |
1984年 | 5篇 |
1982年 | 6篇 |
1981年 | 4篇 |
1980年 | 6篇 |
1978年 | 3篇 |
1976年 | 2篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1972年 | 3篇 |
1968年 | 2篇 |
1967年 | 3篇 |
1966年 | 3篇 |
1956年 | 2篇 |
1911年 | 2篇 |
排序方式: 共有394条查询结果,搜索用时 31 毫秒
41.
S. Bollanti R. Cotton P. Di Lazzaro F. Flora T. Letardi N. Lisi D. Batani A. Conti A. Mauri L. Palladino A. Reale M. Belli F. Ianzini A. Scafati L. Reale M. A. Tabocchini P. Albertano A. Ya. Faenov T. Pikuz A. Oesterheld 《Il Nuovo Cimento D》1996,18(11):1241-1255
Summary A large-aperture, long-pulse XeCl excimer laser has been used to generate a soft-X-ray plasma source. Several laser optical
configurations have been employed to optimise X-ray emission, including positive-branch unstable resonators and injection
by seeding the gain region of the laser with a small commercial excimer laser, resulting in power densities in the range 1012–1014 W cm−2. The characteristics of the plasma source for each different laser configuration and for different target materials are investigated.
The most suitable source conditions (spectral energy distribution, time duration, etc.) for specific applications are discussed.
Supported by the Royal Society, UK.
Supported by INFM, Italy. 相似文献
42.
D. Batani A. Conti A. Masini M. Milani M. Costato A. Pozzi E. Turcu R. Allot N. Lisi F. Musumeci A. Triglia 《Il Nuovo Cimento D》1996,18(5):657-662
Summary Soft-X-rays irradiation of yeast cells allows selective interference with different cellular structures. The monitoring of
different physical parameters leads to substantial variations in the response to X-rays showing that monotonicity should not
be taken for granted.
Also at INFM (Istituto Nazionale di Fisica della Materia). 相似文献
43.
44.
C. Bellecci A. Bonanno M. Camarca M. Conti L. La Rotonda R. Visentin 《Il Nuovo Cimento C》1984,7(2):169-178
Summary A model has been solved to evaluate the influence of different control options on the performances of a linear-collector solar
power plant. The results represent a basis for the choice between the different options.
This work has been performed in the framework of activities of the „Progetto Finalizzato Energetica” supported by the C.N.R. 相似文献
45.
Giuseppina Conti Giuseppe Minoni Giuseppe Zerbi 《Journal of Molecular Structure》1984,118(3-4):237-243
Contrary to previous literature reports, crystallisation of behenic and lignoceric acids from warm acetone is found to give the crystalline modification E. The phase transition from E to the more stable C form was studied with Fourier Transform Infrared Spectroscopy. The structural evolution with temperature through the phase transition is discussed. 相似文献
46.
R. Conti 《Journal of Optimization Theory and Applications》1974,14(5):497-503
Control processes of the form \(\dot x - A(t) x = B(t) u(t)\) , which are normal with respect to the unit ballB p′, r′ of the control spaceL p′([τ, T]),l m r ′ are characterized in terms ofH(t)=X(T)X ?1(t),B(t),X(t) any fundamental matrix solution of \(\dot x - A(t)x = 0\) , and directly in terms ofA, B, when bothA andB are independent oft. 相似文献
47.
We discuss order of convergence for subdivision algorithms, in the scalar-valued and the vector-valued case. In order to find the generic order, the usual definition of convergence order is extended, refering to a proper quasi interpolant operator whose representation on polynomial spaces can be constructively determined with recourse to properties of the subdivision mask. Assuming stability and smoothness of the limit functions, the approximation order of the quasi interpolant operator determines the order of convergence of subdivision. 相似文献
48.
Summary The classical Stefan problem assumes a fixed melting temperature. However, when the solid phase is the one with lower density
(e.g., water) the solidification of the system causes an overall volume increase that is often contrasted by the container walls.
In that case the growing pressure determines a continuous lowering of the freezing point, and the temperature field as well
as the interface motion are strongly affected. This paper is concerned with these aspects of the problem; the planar solidification
of a slab of finite thickness, contrasted by an opposing elastic force, is numerically simulated. The effects of two different
boundary conditions are analysed. When the solidification is driven by convective cooling, the continuous advancement of the
melting front is replaced by an asymptotic behaviour, until thermal equilibrium is attained. When the boundary condition is
specified in terms of a prescribed heat flow, the melting front velocity is slowed down by a growing adverse temperature gradient.
The influence of various parameters on the process is presented and discussed. 相似文献
49.
M.I. Adamivich Y.A. Alexandrov J.M. Bolta L. Bravo A.M. Cartacci M.M. Chernyavski A. Conti G. Crosetti M.G. Dagliana M. Dameri G. Diambrini-Palazzi G. Di Caporiacco A. Forino R. Gessaroli E. Higon S.P. Kharlamov V.G. Larionova R. Llosa A.P. Waite 《Physics letters. [Part B]》1981,99(3):271-276
Preliminary results of an experiment using nuclear emulsions exposed to a tagged photon beam at the CERN SPS (experiment WA58) are presented. Six events showing pairs of charmed particles have been found. One of these has been interpreted as an associated production of Λc+ and 0. The mean lifetime of the neutral D meson based on three events is τ0 = (0.58?0.2+0.8 × 10?13 s,, whereas a statistical analysis of eight charged charmed particles, assumed to be D mesons, leads to an estimate of the mean lifetime of τ± ≈ 4.4 × 10?13 s. 相似文献
50.
In this paper we discuss methods for investigating the convergence of multivariate vector subdivision schemes and the regularity of the associated limit functions. Specifically, we consider difference vector subdivision schemes whose restricted contractivity determines the convergence of the original scheme and describes the connection between the regularity of the limit functions of the difference subdivision scheme and the original subdivision scheme. 相似文献