全文获取类型
收费全文 | 95篇 |
免费 | 4篇 |
专业分类
化学 | 70篇 |
数学 | 3篇 |
物理学 | 26篇 |
出版年
2019年 | 3篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2013年 | 6篇 |
2012年 | 2篇 |
2011年 | 2篇 |
2010年 | 2篇 |
2009年 | 5篇 |
2008年 | 2篇 |
2007年 | 6篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2002年 | 1篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1999年 | 9篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1967年 | 1篇 |
1931年 | 2篇 |
排序方式: 共有99条查询结果,搜索用时 593 毫秒
1.
Apparent molar volumes of aqueous solutions of argon and xenon have been calculated using a previously developed comprehensive equation of state for nonelectrolyte systems. The equation consists of a virial expansion truncated after the fourth virial coefficient and a closed-form term approximating higher coefficients. Mixing rules are based on the composition dependence of virial coefficients, which is known from statistical mechanics. The equation accurately represents vapor-liquid and gas-gas equilibria for the Ar+H2O and Xe+H2O systems over wide ranges of pressure and temperature using two binary parameters. With the binary parameters determined from phase equilibrium data, the equation accurately predicts apparent molar volumes V in the near-critical and far-from-critical regions. Apart from reproducing experimental V data, the equation reveals remarkable maxima of V as a function of pressure and temperature in the near-critical region. The implications of this equation with respect to the Ar–H2O potential are discussed via the second virial coefficient. 相似文献
2.
3.
4.
Boris S. Krumgalz Rita Pogorelsky Kenneth S. Pitzer 《Journal of solution chemistry》1995,24(10):1025-1038
The ion interaction approach developed by Pitzer was used for the prediction of volumetric properties of mixed electrolyte solutions at 25°C based on parameters calculated from experimental data for single-solute electrolyte solutions. Such an approach was shown to be especially effective for application to the calculation of volumetric properties of natural hypersaline brines and of industrial electrolyte solutions of large complexity. The use of the latest recommended sets of volumetric ion interaction parameters for single electrolyte solutions and symmetrical mixing parameters for Na–K–Cl ion combinations considerably improved the precision of the density calculations of highly concentrated mixed electrolyte solutions and of various natural waters. 相似文献
5.
6.
Subbiah Meenakshisundaram RM. Sockalingam 《Journal of molecular catalysis. A, Chemical》2000,160(2):269-275
Catalytic activity of Os(VIII) in the oxidation of some twenty organic sulfides with sodium salt of N-chlorobenzenesulfonamide (CAB) has been investigated in alkaline (pH8.7) t-butanol–water (1:1 v/v) medium. Significant retarding influence of [OH−] on the reactivity is exhibited. The catalysed reaction is strongly accelerated in the presence of Hg(II). Imperfections are observed in the linear Hammett relationship in the case of –NO2 substituents. 相似文献
7.
R. F. Le Guyon R. M. May W. M. Mc Nabb A. v. Endrédy H. H. Willard A. W. Boldyreff G. E. F. Lundell J. I. Hoffman W. Blum C. M. Johnson O. Kuhnt R. Ariano R. P. Hudson F. Graziani L. Losana H. Burton-Smith W. F. Pond L. E. Pitzer B. Salkin K. Hinsberg D. Laszlo und G. Schikorr 《Fresenius' Journal of Analytical Chemistry》1931,85(7-8):286-303
Ohne Zusammenfassung 相似文献
8.
Michael Teders Dr. Adrián Gómez-Suárez Lena Pitzer Prof. Dr. Matthew N. Hopkinson Prof. Dr. Frank Glorius 《Angewandte Chemie (International ed. in English)》2017,56(3):902-906
Three new visible-light-promoted functionalizations of benzotriazole substrates were discovered using a mechanism-based screening method. ortho-Thiolated, borylated, and alkylated N-arylbenzamide products were obtained under mild reaction conditions in a new denitrogenative synthetic approach to functionalized aniline derivatives. The functional group tolerance of the borylation reaction was further analyzed in the first application of an additive-based robustness screen in a photocatalytic transformation. All the functionalizations proceed via photocatalytically initiated chain mechanisms as indicated by determination of the reaction quantum yields and Stern–Volmer analyses. 相似文献
9.
Nano titanium dioxide (nTiO2), generally considered to be toxicologically inert, is manufactured in large quantities and extensively applied in consumer products. The small size and large surface area endow them with an active group or intrinsic toxicity. Advances in instrumentation are making Raman spectroscopy the tool of choice for an increasing number of (bio) chemical applications. One of the great advantages of this technique is its ability to provide information on the concentration, structure and interaction of biochemical molecules in their microenvironments within intact cells and tissues, non-destructively. Zebrafish (Danio rerio), one of the most important vertebrate model organisms used in developmental biology, are increasingly used in biomedical research, particularly as a model of human disease. In the present work, an attempt is made to study the effect of titanium dioxide, both nano and bulk, on the microenvironment of the liver tissues of Zebrafish using FT-Raman spectroscopy. The results of the present study suggest that TiO2 exposure demonstrate a marked influence on the microenvironments of the liver tissues of Zebrafish. A shift to a higher wavenumber and an increase in the intensity of the band at ∼1087 cm−1 in the TiO2 exposed tissues suggest that some of the conformational changes resulting from the alkali recovery process takes place due to TiO2 exposure. The decreased intensity ratio (I3220/I3400) observed in the titanium-exposed tissues suggests a decreased water domain size, which could be interpreted in terms of weaker hydrogen-bonded molecular species of water in the TiO2 exposed tissues. The observed shift of COO− bands to higher frequencies shows the disruption of salt bridges as a result of a change in the oppositely charged partners and due to the enhanced random coil conformation. The variation in the intensity ratio of the tyrosyl doublet (I858/I825) indicates variation in the hydrogen bonding of the phenolic hydroxyl group due to TiO2 exposure. The results further suggest that the microenvironments are greatly altered due to titanium nano exposure when compared to titanium bulk. In conclusion, the results indicate that FT-Raman spectroscopy might be a useful tool for rapid assessment of nano particle biological interactions. 相似文献
10.
Kenneth S. Pitzer 《Journal of solution chemistry》1975,4(3):249-265
The contribution of higher-order electrostatic terms (beyond the Debye-Hückel approximation) to the thermodynamic properties of mixed and pure electrolytes is investigated. It is found that these effects are important for cases of unsymmetrical mixing, especially when one ion has a charge of three units or more. The appropriate correction can be made by a purely electrostatic function since the mutual repulsion of ions of the same sign keeps them far enough apart that short-range forces have little effect. This function is evaluated, and several convenient approximations are also given. Application is made to systems mixing ions of the type 1–2 and 1–3. Higher-order limiting laws exist for symmetrical mixtures and for pure, unsymmetrical solutes, but these effects were not found to be significant in relationship to existing activity or osmotic-coefficient data. 相似文献