全文获取类型
收费全文 | 43篇 |
免费 | 0篇 |
专业分类
化学 | 19篇 |
力学 | 2篇 |
数学 | 8篇 |
物理学 | 12篇 |
无线电 | 2篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2016年 | 3篇 |
2013年 | 1篇 |
2012年 | 4篇 |
2011年 | 2篇 |
2008年 | 2篇 |
2006年 | 1篇 |
2004年 | 2篇 |
2003年 | 2篇 |
2000年 | 2篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
排序方式: 共有43条查询结果,搜索用时 15 毫秒
1.
Barthez J.M. Molino F. Marignan J. Ayral A. Guizard C. Jullien R. 《Journal of Sol-Gel Science and Technology》1997,8(1-3):83-88
We present here an experimental and numerical study of the chemical and aggregative mechanisms for titanium alkoxide in a
reverse micellar medium. NMR experiments were done to study the first step of the sol-gel process: hydrolysis of titanium
isopropoxide. Light and X-ray scattering experiments were then conducted to characterize the clustering of aggregates and
aggregation kinetics. Fractal dimension, measured by U.S.A.X.S., varies with the hydrolysis ratio and the hydration of the
surfactant. This evolution was explained by polydispersity of the hydrolysis which depends on the surfactant concentration.
This hypothesis was tested through a numerical simulation of irreversible aggregation using a chemically limited aggregation
model. The hydrolyzed sites are distributed among the monomers by a random procedure governed by a polydispersity parameterp, varying from 0 to 1. The total number of hydrolyzed sites is governed by a parameterq belonging to the interval [0, 1]. Thep-q evolution of the fractal dimension coincides rather well with the experimental data in all the region of the two dimensional
phase space. 相似文献
2.
Molino A. Vacca F. Masera G. Nguyen T.Q. 《Vision, Image and Signal Processing, IEE Proceedings -》2006,153(6):860-868
To efficiently compute the phase difference (PD) between two complex numbers, two novel approaches are described. The problem of fast PD computation is central in many applications. As a case study, the main focus is on the phase correlation technique that is used for motion estimation. Starting from the problem statement, the system requirements are dealt with showing how PD requires a remarkable amount of computational resources. Reduced complexity techniques are then proposed and specifically tailored to suit the application needs. Each solution is completely implemented both in 0.25 mum as well as 0.13 mum CMOS. The so-called LUT-ROT exhibits noteworthy figures in terms of area occupation, delay and power dissipation, saving nearly 50% in terms of area and power when compared to recent work on this subject 相似文献
3.
Summary Ceramic and metallic materials were alloyed and cladded on a C40 steel by means of a CO2 laser heat source. The main objectives of the research were to obtain a surface modification of the C40 steel in order to
increase its wear resistance and to develop a repeatable coating process of potential industrial application. In the following
sections, the laser coating process (including experimental equipment and working parameters) and the most important metallurgical
results are described. 相似文献
4.
In this paper, we study the existence of positive solutions for the quasilinear elliptic singular problemwhere \({c,\lambda >0}\), \({\gamma \in (0,1)}\), f is strictly increasing and derivable in \({[0,\infty)}\) with \({f(0)>0}\). We show that there exists \({\lambda^*>0}\) such that \({(0,\lambda^*]}\) is the maximal set of values such there exists solution. In addition, we prove that for \({\lambda<\lambda^*}\) there exists minimal and bounded solutions. Moreover, we give sufficient conditions for existence and regularity of solutions for \({\lambda=\lambda^*}\).
相似文献
$$\left\{\begin{array}{ll}-\Delta u + c\,\frac{|\nabla u|^2}{u^\gamma} = \lambda\,f(u), \quad \quad \mbox{in $\Omega$},\\ u=0, \quad \qquad \qquad \qquad \quad \, \, \, \, \, \mbox{on $\partial$$\Omega$},\end{array}\right.$$
5.
F.R. Molino J.-F. Berret G. Porte O. Diat P. Lindner 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,3(1):59-72
We study the behavior under flow of soft spherical micelles forming a fcc phase at high volume fraction. Due to the size (300 ?) of the elementary objects, the structure can be investigated through
X-rays and neutron scattering, at rest and under flow in a Couette cell. Using scattering in two perpendicular directions,
different mechanisms of flow are identified. At intermediate shear (around 100 s-1) the system exhibits the so called layer sliding mechanism where two dimensional hexagonal compact planes of spheres align
themselves with the Couette cell walls. At lower shear rate, the fcc structure is locally preserved, and the flow is mediated by defects between crystallites. At high shear rate, we observe
the melting of the structure and a liquid-like structure factor. Moreover, we were able to use the existence of the layer
sliding regime to generate a fcc monocrystal by annealing the satcking faults between the decorrelated planes created by the layer sliding.
Received: 7 July 1997 / Received in final form: 16 January 1998 / Accepted: 5 March 1998 相似文献
6.
The aldehyde (
) reacts with ylid (
) to give (
) as 4:1 Z/E mixture which, upon methanolysis under catalysis by pyridinium
-toluenesulfonate (PPTS), affords the bispyranoside (
) as single anomer. 相似文献
7.
8.
9.
Starting from the symmetry groupG × SU(2) for the special case of negligible spin-orbit coupling, a general character formula is derived for them-tuplet representation, which is realized in the space of state functions ofn-electron systems in fields with symmetryG. Apart from the characters of the initial representation for the single electron space function, the formula only contains the number of particlesn and the multiplicitym.
Herrn Professor Dr. Hermann Hartmann zu seinem 60. Geburtstag gewidmet. 相似文献
10.