全文获取类型
收费全文 | 505篇 |
免费 | 7篇 |
国内免费 | 1篇 |
专业分类
化学 | 358篇 |
晶体学 | 4篇 |
力学 | 13篇 |
数学 | 100篇 |
物理学 | 38篇 |
出版年
2023年 | 6篇 |
2022年 | 11篇 |
2021年 | 12篇 |
2020年 | 13篇 |
2019年 | 7篇 |
2018年 | 8篇 |
2017年 | 6篇 |
2016年 | 8篇 |
2015年 | 3篇 |
2014年 | 17篇 |
2013年 | 26篇 |
2012年 | 33篇 |
2011年 | 35篇 |
2010年 | 24篇 |
2009年 | 13篇 |
2008年 | 36篇 |
2007年 | 26篇 |
2006年 | 27篇 |
2005年 | 23篇 |
2004年 | 16篇 |
2003年 | 25篇 |
2002年 | 20篇 |
2001年 | 9篇 |
2000年 | 7篇 |
1999年 | 11篇 |
1998年 | 10篇 |
1997年 | 6篇 |
1996年 | 9篇 |
1995年 | 2篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1989年 | 2篇 |
1985年 | 2篇 |
1984年 | 5篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1968年 | 3篇 |
1912年 | 2篇 |
1903年 | 1篇 |
1899年 | 1篇 |
1897年 | 2篇 |
1894年 | 1篇 |
1892年 | 1篇 |
1889年 | 2篇 |
1888年 | 1篇 |
1882年 | 1篇 |
排序方式: 共有513条查询结果,搜索用时 31 毫秒
141.
David Kenning Iztok Golobič Huijuan Xing Matej Bašelj Vito Lojk Jost von Hardenberg 《Heat and Mass Transfer》2006,42(6):511-527
Correlations for nucleate boiling heat transfer should be improved, or in the long term possibly be replaced, by the development
of mechanistic simulations that include the non-uniform spacing and variable characteristics of the nucleation sites and non-linear
interactions between the sites. This paper discusses the interactions that should be included in simulations and some lessons
from a first attempt to validate a particular simulation against experimental spatio-temporal data for wall temperature. Input
data for nucleation site positions and characteristics are a particular problem and the prospects for obtaining this data
from measurements that are independent of boiling are discussed. 相似文献
142.
Héctor Rosas Leidy Erika Sarmiento Vito Lubes María Goncalves Mary Lorena Araujo Felipe Brito 《Journal of solution chemistry》2008,37(5):701-711
The complex species formed between vanadium(III) cysteine and small blood serum bioligands: lactic, oxalic, citric and phosphoric
acids were studied in aqueous solution by means of electromotive force measurements, Emf(H), at 25 °C and 3.0 mol⋅dm−3 KCl as the ionic medium. The ternary complexes were studied by potentiometric measurements and the data analyzed using the
least-squares computational program LETAGROP to obtain the respective stability constants and stoichiometric coefficients.
The UV-Vis spectrophotometric measurements were done in order to make a qualitative characterization of the complexes formed
in aqueous solution. 相似文献
143.
Capriati V Florio S Luisi R Perna FM Barluenga J 《The Journal of organic chemistry》2005,70(15):5852-5858
A diastereo- and enantiospecific formation of tetrasubstituted cyclopropane carbene complexes and cyclopropanecarboxylates from lithiated aryloxiranes and alpha,beta-unsaturated Fischer carbene complexes is described. 相似文献
144.
It is probably redundant to stress how extensive are nowadays the attempts to reduce the diesel particulate emissions from automotive and stationary sources. The present paper looks into a technology relied on a catalytic trap based on a SiC wall-flow monolith lined with suitable catalysts for the sake of promoting a more complete and faster regeneration after particulate capture. All the major steps of the catalytic filter preparation are dealt with, including: the synthesis and choice of the proper catalyst and trap materials, the development of an in situ catalyst deposition technique, the bench testing of the derived catalytic wall-flow. The best catalyst selected was the perovskite La0.9K0.1Cr0.9O3-delta. The filtration efficiency and the pressure drop of the catalytic and non-catalytic monoliths were evaluated on a diesel engine bench under various operating conditions. 相似文献
145.
Starting from 3-bromo-, 1-iodo- and 4-iodo-9-oxo-fluorene three symmetrical bifluorenonyls and the corresponding hydrocarbons 3,3′-, 1,1′- and 4,4′-bifluorenyls are prepared. An attempt to obtain the non-symmetrical 1,2′-bifluorenyl is also described. 相似文献
146.
Guido Barone Giuseppina Castronuovo Vittorio Elia Vito Savino 《Journal of solution chemistry》1984,13(3):209-219
The excess Gibbs free energies of four -methyl-D-aldopyranosides in water were determined at 25°C from isopiestic measurements. The excess entropies were obtained by subtracting the free energy values from the enthalpy data. The results show a remarkable enthalpy-entropy compensation. The positive sign of the excess free energies is interpreted as due to the favorable solute-solvent interactions that prevent the favorable solute-solute interaction. The signs and magnitudes of the pair interaction coefficients are attributed to the release of water from the hydration cospheres during the concentration process. The excess properties seem to depend, however, on the stereochemistry of the solutes. This effect is discussed and attributed to the different specific stabilities of the hydration shells. 相似文献
147.
148.
Vito?FragnelliEmail author Anna?Iandolino 《Mathematical Methods of Operations Research》2004,59(3):447-463
In this paper we consider a cost allocation problem arising in a consortium for urban solid wastes collection and disposal. A classical allocation rule is the proportional division according to the volume of wastes collected; here we propose a different allocation method, rooted in game theory, based on a model developed by Fragnelli et al. [3], using the Shapley Value and the Owen Value as allocation rules. The model was applied to the data of the consortium Ovadese – Valle Scrivia, comparing our results and the actual ones. 相似文献
149.
Aragoni MC Arca M Demartin F Devillanova FA Garau A Isaia F Lippolis V Verani G 《Journal of the American Chemical Society》2002,124(17):4538-4539
Interaction of methimazole (MMI, 1-methyl-imidazole-2-thione) with I2 in solvents having different polarity gives two new stable compounds containing a dication disulfide and a monocation disulfide arranged in dimers, respectively. These two species could represent effective intermediates in the reaction of MMI with an active iodine species in the thyroid gland and therefore shed more light on the mechanism of action of MMI as an antithyroid drug. 相似文献
150.
Vito Fragnelli Ignacio García-Jurado Luciano Méndez-Naya 《Mathematical Methods of Operations Research》2000,52(2):251-264
A class of cooperative TU-games arising from shortest path problems is introduced and analyzed. Some conditions under which
a shortest path game is balanced are obtained. Also an axiomatic characterization of the Shapley value for this class of games
is provided. 相似文献