全文获取类型
收费全文 | 86篇 |
免费 | 3篇 |
国内免费 | 2篇 |
专业分类
化学 | 30篇 |
力学 | 8篇 |
数学 | 36篇 |
物理学 | 17篇 |
出版年
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 9篇 |
2012年 | 7篇 |
2011年 | 6篇 |
2010年 | 6篇 |
2009年 | 3篇 |
2008年 | 6篇 |
2007年 | 6篇 |
2006年 | 6篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2003年 | 1篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 3篇 |
排序方式: 共有91条查询结果,搜索用时 0 毫秒
1.
Michael Giudici 《Designs, Codes and Cryptography》2006,39(2):163-172
We determine all linear codes C containing the constant code E, for which there is a weight-preserving group of semilinear automorphisms which acts transitively on the set of nontrivial
cosets of E in C.
Michael Giudici - The author holds an Australian Postdoctoral Fellowship. 相似文献
2.
Oliveira SC Paiva TC Visconti AE Giudici R 《Applied biochemistry and biotechnology》1998,74(3):161-172
Discrimination between different rival models for describing the inhibitory effect of ethanol both on yeast growth and on
fermentation was studied for a continuous process of alcoholic fermentation in a tower reactor with recycling of flocculating
cells. Models tested include linear, parabolic, hyperbolic, exponential, and generalized nonlinear power-law types. The best
expressions were identified under the criteria that all the kinetic parameters should assume acceptable values in a feasible
range and should result in the best fit of the experimental data. The kinetic parameters were estimated from steady-state
data of several sugar concentrations in feeding stream (S0 = 160, 170, 180, 190, 200 g/L), constant dilution rate (D = 0.2 h-1), recycle ratio (α = 13.6), and temperature (T = 30°C). The best model for the yeast growth was of power-law type, whereas
for the product formation the best model was of linear type. These models were able to reproduce the trends of the process
variables satisfactorily. 相似文献
3.
HARUN REŞIT YAZAR 《Pramana》2013,81(4):579-585
The sd-interacting boson approximation (sd-IBA) and the df-interacting boson approximation (df-IBA) can be related to each other and the states of the interacting boson approximation model can be identified with the fully symmetric states in the sdf interacting boson approximation model. A systematic study of the sdf-IBA model showed that the constructed Hamiltonian can successfully describe the strong octupole correlations in the deformed nuclei. We showed that the interacting boson approximation may account for many of these K π ?=?0+ states. It was found that the calculated energy spectra of the gadolinium isotopes agree quite well with the experimental data. The observed B(E2) values were also calculated and compared with the experimental data. 相似文献
4.
5.
The management of Operational Risk has been a difficult task due to the lack of data and the high number of variables. In
this project, we treat operational risks as multivariate variables. In order to model them, copula functions are employed,
which are a widely used tool in finance and engineering for building flexible joint distributions. The purpose of this research
is to propose a new methodology for modelling Operational Risks and estimating the required capital. It combines the use of
graphical models and the use of copula functions along with hyper-Markov law. Historical loss data of an Italian bank is used,
in order to explore the methodology’s behaviour and its potential benefits.
相似文献
6.
7.
In this paper we extend the plane blow-up results of Grundy& McLaughlin (1997) to the three-dimensional Navier-Stokes equations.Using a solution structure originally due to Lin we first providenumerical evidence for the existence of blow-up solutions on- < x, z < , 0 y 1 with boundary conditions on y = 0and y = 1 involving derivatives of the velocity components.The formulation enables us to consider plane and radial flowas special cases. Various features of the computations are isolatedand are used to construct a formal asymptotic solution closeto blow-up. We show that the numerical and asymptotic analysesprovide a mutually consistent global picture which supportsthe conclusion that, for the family of problems we considerhere, blow-up in fact can take place in three dimensions butat an inverse linear rate rather than the faster inverse squareof the plane case. 相似文献
8.
Ice nucleating-active Pseudomonas fluorescens F264C was fed to Colorado potato beetles to determine bacterial retentioin in the beetle gut and its effect on the cold hardiness of this insect pest. The bacrterium was present in beetles recovered after overwintering in the field, seven months after their exposure to P. fluorescens. Retention was evident not only in the detection of the P. fluorescens ice nucleating gene, inaW, in bacterial cultures from beetle guts but also in the elevated supercooling points of some treated beetles. 相似文献
9.
M. Giudici M. Menziani S. Pugnaghi M. R. Rivasi R. Santangelo 《Il Nuovo Cimento C》1989,12(6):781-786
Summary Analytical expressions of conductivity and diffusivity have been obtained for an unsaturated sandy soil in the whole range
of admissible values of volumetric water content. Besides fitting experimental values they satisfy a set of relations which
guarantee that unphysical situations cannot be reached. The matric potential has been obtained by the numerical integration
of a known relation which connects conductivity, diffusivity and matric potential.
Riassunto Per un suolo sabbioso non saturo sono state ottenute delle espressioni analitiche della conducibilità idraulica e della diffusività per tutto l'intervallo di valori che il contenuto di acqua può assumere. Oltre ad approssimare i valori sperimentali, queste espressioni soddisfano alle condizioni imposte per garantire che non vengano raggiunte situazioni non fisiche. Il potenziale di matrice è stato ottenuto dalla integrazione numerica di una nota espressione analitica che lega tra loro conducibilità, diffusività e potenziale di matrice.
Резюме Получаются аналитические выражения для проводимости и температуропроводности для ненасьщенных песчаных почв во всей области допустимых значений обьемных концентраций воды. Эти выражения аппроксимируют экспериментальные данные, а также удовлетворяют системе соотношений, которые гарантируют, что нефизические ситуации не могут возникать. Получается матричный потенциал с помощью численного интегрирования известного соотношения, которое связывает проводимость, температуропроводность и матричный потенциал.相似文献
10.
F. Pedaci M. Giudici J.R. Tredicce G. Giacomelli 《Applied physics. B, Lasers and optics》2005,81(7):993-1000
In this work we experimentally study mode-hopping in bulk semiconductor lasers. This stochastic process is ruled by Kramers
statistics with a decay rate depending on the laser parameters of the temperature of the substrate and the pumping current.
For a general combination of these parameters the average residence times in the two active modes are not equal, resulting
in an asymmetric probability distribution for the modal intensities. We show that, by choosing an appropriate path in the
parameter space, we can vary the residence times of the two modes while holding their ratio constant. Along this path, the
shape of modal intensities distributions are constant up to a scaling factor which is a function of the laser parameters.
Then, the system can be described by a single Langevin equation. The effect of adding noise to the pumping current is also
investigated.
PACS 42.65.Sf; 42.55.Sa; 42.50.-p 相似文献