全文获取类型
收费全文 | 86篇 |
免费 | 1篇 |
专业分类
化学 | 53篇 |
晶体学 | 1篇 |
力学 | 1篇 |
数学 | 9篇 |
物理学 | 23篇 |
出版年
2021年 | 1篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2014年 | 2篇 |
2013年 | 7篇 |
2012年 | 3篇 |
2011年 | 1篇 |
2010年 | 4篇 |
2009年 | 1篇 |
2008年 | 8篇 |
2007年 | 6篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2002年 | 2篇 |
1999年 | 2篇 |
1996年 | 5篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 5篇 |
1984年 | 1篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1978年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有87条查询结果,搜索用时 93 毫秒
1.
The partition coefficient of strontium upon its extraction from the aqueous solutions of picric acid into chloroform containing DC-18-crown-6, B-15-crown-5 after their exposition to gamma radiation has been studied. A significant decrease of the partition coefficient in the studied range of doses 10–70 kGy was observed. This effect can be attributed to the radiolytic products of chloroform. The radiation destruction as well as dehydrogenation of crown ethers were not observed. 相似文献
2.
3.
The development of a rapid and reproducible method for the separation of plutonium from soil samples is described. Tetravalent plutonium is extracted from 8M HNO3 into 30% Aliquat-336/toluene mixture. Uranium and thorium are removed with nitric and hydrochloric acid washes. Plutonium is backextracted with HCl–H2C2O4 and HCl–HF solutions. Plutonium is coprecipitated with NdF3 and filtrated onto a 0.1–0.2 m membrane filter to prepare a source for -spectrometry. The chemical yields of separation are about 50–60%. 相似文献
4.
Isotherms and differential enthalpies of adsorption are obtained for nitrogen at ambient temperature on monovalent (Li(+), Na(+), K(+)) and divalent (Ca(2+), Ba(2+), Sr(2+), Mn(2+)) substituted X-faujasite systems by microcalorimetry measurements. These experimental data are compared with those obtained by combining grand canonical Monte Carlo simulations and newly derived force fields for describing the interactions between the extra-framework cations and the adsorbates obtained from a simple model based only on the intrinsic properties of the cations. It is the first time that such good qualitative agreement is reported between experiment and simulation for a series of both monovalent and divalent cations. 相似文献
5.
The radiation-induced oxidation of bis/1,2-dicarbollyl/cobalt/III/ acid to 8-monohydroxy-, and 8,8-dihydroxy-derivatives was observed in two-phase system of 4 to 96 vol. % of CCl4 and H2O. Carbon tetrachloride increases the radiation yields of the oxidation of the acid in the investigated dose region, nature of the radiolytic products being the same. The partial radiation yields in the system were ascertained. 相似文献
6.
The effect of vibration grinding on the DTA curves of montmorillonite isolated from the most important locality of bentonite in the Slovak Republic (Jel?ovy potok, Middle Slovakia) was studied in the temperature range 20–1500°C. Interpretation is offered for 6 endothermic and 3 exothermic peaks. vibration grinding modified the course of dehydration of the mineral, suppresses the “dehydroxylation’ peak at 700°C, enables the crystallization of high-temperature quartz, cristobalite and cordierite at lower temperatures in comparison with unground natural montmorillonite. Vibration griding slows down the crystallization of mullite which—unlike quartz, cristobalite and cordierite—does not belong to high-temperature phases of Cheto-montmorillonite. The order in which these high-temperature phases occur is not influenced by vibration grinding. 相似文献
7.
Ľ. Halušcarka Š. Baláž K. Dercová E. Benická J. Krupčík P. Bielek 《International journal of environmental analytical chemistry》2013,93(1-4):327-336
Abstract The anaerobic degradation of PCB in loamy and clayey soils containing indigeneous microflora was studied. The anaerobic conditions were created by an argon atmosphere in the flasks containing soil flooded by a liquid medium with glucose. GC-ECD analysis of soil extracts after 40 day incubation showed, in addition to the concentration changes of the less chlorinated PCB congeners, a significant decrease in the concentration of highly chlorinated congeners in both soils. The results indicate that in both soil types reductive dehalogenation of PCB congeners was encountered. 相似文献
8.
The results of Monte Carlo simulations of xenon monolayers deposited on graphite are presented. Systems of various surface densities and in a wide range of temperatures are investigated. The results are compared to the experimental data and to the previous results for nitrogen. The results of simulations are in good agreement with the experimental ones and confirm that melting in two dimensions is vacancy-driven. Typical real-space configurations of Xe atoms and calculated specific heat results are shown. 相似文献
9.
Mechanism of hydrogen adsorption in high surface area carbon-based porous materials has been studied. Influence of chemical modification of the adsorbing surface has been simulated using grand canonical Monte Carlo method. Special attention has been paid to the competition between increasing the surface of open carbon frameworks and heterogeneous distribution of the energy of adsorption. Additionally, it has been shown that the molecular mass of atoms which substitute carbon atoms is an important factor determining the final hydrogen uptake. 相似文献
10.
Jesenák K. Kuchta L'. Hudec P. Fajnor V. Š. 《Journal of Thermal Analysis and Calorimetry》1999,55(3):773-777
Differences in mass loss occurring in the course of dynamic and isothermal heating of SiO2-aerogel and changes of specific surface and hydrophylicity during calcination were studied by thermal analysis. SiO2-aerogel was prepared from tetramethoxysilane (TMOS) hydrolyzed by ammonia solution at 0°C with molar ratio TMOS: H2O:NH4OH 4:1:0.01. Differences are caused mainly by oxidation of organic matter and by diffusion of products of the oxidation. Heat
transfer has none or little effect on the differences. Samples calcined at temperatures about 300°C reach maximum hydrophilicity
though they still contain small amounts of residual organic matter.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献