全文获取类型
收费全文 | 227篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
化学 | 161篇 |
晶体学 | 6篇 |
力学 | 8篇 |
数学 | 4篇 |
物理学 | 51篇 |
出版年
2022年 | 5篇 |
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 6篇 |
2018年 | 4篇 |
2017年 | 2篇 |
2016年 | 9篇 |
2014年 | 6篇 |
2013年 | 8篇 |
2012年 | 9篇 |
2011年 | 13篇 |
2010年 | 10篇 |
2009年 | 12篇 |
2008年 | 9篇 |
2007年 | 7篇 |
2006年 | 9篇 |
2005年 | 7篇 |
2004年 | 4篇 |
2003年 | 5篇 |
2002年 | 11篇 |
2001年 | 8篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 6篇 |
1989年 | 5篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 3篇 |
1984年 | 5篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 7篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1970年 | 2篇 |
1968年 | 2篇 |
1966年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有230条查询结果,搜索用时 421 毫秒
21.
Russian Physics Journal - The paper describes the problem of finding the likelihood ratio for specific problem of stochastic system recognition in continuous time to member functions within... 相似文献
22.
. Barta I. M. Silvestrova Ju. V. Pisarevskij N. A. Moiseeva L. M. Beljaew 《Crystal Research and Technology》1977,12(9):987-996
Velocities of propagation of elastic waves along principal crystallographic directions in Hg2Br2 and Hg2J2 single crystals were measured using the pulse and phase-pulse techniques. The values obtained were used to calculate the components of the elastic tensors cik and sik, as well as the phase and group velocities of propagation of longitudinal and transverse waves in the (100) and (001) planes, and the angular deviation of acoustic energy flux from the direction of the corresponding wave normal. Knowledge of the anisotropy of the elastic properties of Hg2X2 crystals and of their change with the anion (X = Cl, Br, J) leads to deeper understanding of the character of bonds in the crystal lattice and points the way to a better utilization of technical properties of the crystals. — Minimum velocity of propagation of an elastic wave falls in the case of Hg2J2 to a value v [100] [11 10] = 0,25 · 105 cm/s, what is the lowest value known among all crystals. Maximum angular deviation of acoustic energy flux — nearly 50° — is exhibited by the quasi-longitudinal wave in Hg2J2 crystals. On substituting the Cl− ions with Br− and J− ions, the anisotropy of elastic moduli C33/C11 increases by nearly 80%. Different mechanisms contribute to vectorial dependence of the elastic properties along different crystallographic directions. 相似文献
23.
G. P. Moiseeva I. M. Yusupova Sh. Z. Kasymov M. I. Yusupov 《Chemistry of Natural Compounds》1982,18(3):295-297
The circular dichroism method has been used to study the products of the amination of sesquiterpene lactones containing α-methylene-γ-lactone groupings. Analysis of the results obtained has shown that in all the lactones considered the amination reaction takes place with the predominant formation of one of the possible stereochemical forms of the product of the addition of the amine to the exomethylene group of the lactone ring, namely, that having the 11S configuration. 相似文献
24.
25.
Gekhman A. E. Moiseeva N. I. Minin V. V. Larin G. M. Kovalev Yu. V. Ustynyuk Yu. A. Rosniatovskii V. A. Timokhina E. N. Bozhenko K. V. Moiseev I. I. 《Kinetics and Catalysis》2003,44(1):40-53
In the Mo(VI)/H2O2/H2O system, the relaxation time (T
1) of protons in a water molecule and in a CH3 group decreases 10 to 30 times under conditions of dismutation of H2O2 with the formation of 1O2(1g). It is experimentally found that the overequilibrium concentration of triplet dioxygen cannot be the reason behind a decrease in T
1 in the 1H NMR spectra. Neither can it explain the anomalous line broadening in ESR spectra under conditions of 1O2(1g) formation in the systems V(V)/H2O2/AcOH and Mo(VI)/H2O2/H2O. Ab initio calculations showed that it is principle possible that the 3O4(3·-
g-1g) molecule exists in a snake-like form and is formed by the reaction between 3O2(3·-
g) and 1O2(1g), which is the product of H2O2 decomposition in the systems V(V)/H2O2/AcOH and Mo(IV)/H2O2/H2O. The interaction of 1O2 with the ·OOH radical is exothermic (Q = 2.30 kcal/mol) and leads to the formation of ·OOOOH. It is assumed that the paramagnetic species of type ·OOOOH or 3O4(3
A
1) that is formed in the reaction might be responsible for the spectral effects observed. 相似文献
26.
27.
AA Yan LI Kai CAO ZhongHua & HU WenRui Key Laboratory of Microgravity 《中国科学:物理学 力学 天文学(英文版)》2011,(2)
The dependency of the critical Marangoni number on the geometrical aspect ratio of the floating half zone is essential to predict the onset of oscillatory thermocapillary convection.The experimental studies in the microgravity conditions on floating half zones of several centimeters in diameter have predicted that the critical Marangoni number increases with the increasing aspect ratio,and the terrestrial experimental studies have predicted the contradictory conclusion for floating half zones of several mil... 相似文献
28.
29.
30.
Non-Gravitational Effects with Density-Matching in Evaluating the Influence of Sedimentation on Colloidal Coagulation
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The method of density matching between the solid and liquid phases is often adopted to effectively eliminate the effect of sedimentation of suspensions in studies on dynamic behaviour of a colloidal system. However, the associated changes in the solvent composition may bring side effects to the properties investigated and therefore might lead to a faulty conclusion if the relevant correction is not made. To illustrate the importance of this side effect, we present an example of the sedimentation influence on the coagulation rate of suspensions of 2μm (diameter) polystyrene. The liquid mixtures, in the proper proportions of water (H2O), deuterium oxide (D2O) and methanol (MeOH) as the liquid phase, density-matched and unmatched experiments are performed. Besides the influence of viscosity, the presence of methanol in solvent media, used to enhance the sedimentation effect, causes significant changes (reduction) in rapid coagulation rates compared to that in pure water. Without the relevant corrections for those non-gravitational factors it seems that gravitational sedimentation would retard the coagulation. The magnitude of the contribution from the non-gravitational factor is quantitatively determined, making the relevant correction possible. After necessary the influence of the sedimentation on coagulation rates at corrections for all factors, our experiments show that the initial stage of the coagulation is not observable. 相似文献