全文获取类型
收费全文 | 115篇 |
免费 | 4篇 |
专业分类
化学 | 46篇 |
晶体学 | 1篇 |
力学 | 3篇 |
数学 | 12篇 |
物理学 | 57篇 |
出版年
2024年 | 1篇 |
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 5篇 |
2016年 | 6篇 |
2015年 | 5篇 |
2014年 | 2篇 |
2013年 | 10篇 |
2012年 | 7篇 |
2011年 | 7篇 |
2010年 | 6篇 |
2009年 | 7篇 |
2008年 | 11篇 |
2007年 | 8篇 |
2006年 | 8篇 |
2005年 | 5篇 |
2004年 | 2篇 |
2003年 | 3篇 |
1998年 | 3篇 |
1996年 | 1篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1976年 | 2篇 |
1971年 | 2篇 |
1965年 | 1篇 |
排序方式: 共有119条查询结果,搜索用时 0 毫秒
51.
U. K. Ghoshal S. Bhattacharyya Partha P. Gopmandal Simanta De 《Transport in Porous Media》2018,121(1):121-133
A numerical study is made on the electrophoresis of a core-shell soft particle based on the first principle of electrophoresis. The soft particle consists of a charged rigid core coated with a polymer shell. Numerical computations for the electrophoretic velocity are obtained and compared with the existing analytical solution. The analytical solutions, based on the Boltzmann distribution of ions and the Debye–Huckel approximation, are valid for lower range of charge density, weak applied electric field and thin double layer. Discrepancy from the existing analytical solution is found when the Debye layer extends beyond the porous shell. This discrepancy becomes larger for higher values of the rigid core surface potential, fixed charge density of the soft shell and stronger imposed electric field. The double-layer polarization is found to have a strong impact when the shell thickness is lower than the Debye length. The electrophoretic velocity is found to vary nonlinearly with the imposed electric field when the imposed field strength is large enough to create a potential drop across the particle bigger than the thermal potential. We have also analyzed the mechanism of sustained solute release from the soft particle. Our results show that the rate of solute release is large compared to a pure diffusion dominated process. 相似文献
52.
Structural, optical and magnetic studies of Co-doped ZnO have been carried out for bulk as well as thin films. The magnetic studies revealed the superparamagnetic nature for low-temperature synthesized samples, indicating the presence of cobalt metallic clusters, and this is supported by the optical studies. For the high-temperature sintered samples one obtains paramagnetism. The optical studies reveal the presence of Co2+ ions in the tetrahedral sites indicating proper doping. Interestingly, the films deposited by laser ablation from the paramagnetic target showed room temperature ferromagnetism. It appears that the magnetic nature of this system is process dependent. 相似文献
53.
54.
The intensities of the forbidden Δk = ±6 and ±4 transitions in symmetric top molecules arising from rotational intensity borrowing are reported. A perturbation theoretical approach has been used to study the mixing of wavefunctions produced by the additional splitting term in the rotational Hamiltonian of C3v or C4v-type molecules. Numerical values are presented for PH3, PD3, and BrF5 molecules. The importance of these results in structural analysis and astrophysical studies is discussed. 相似文献
55.
Arijit Halder Dr. Biswajit Bhattacharya Fazle Haque Susanta Dinda Dr. Debajyoti Ghoshal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(52):12196-12205
A pair of supramolecular isomers of CdII-based MOF have been synthesized by utilizing a flexible N,N′-donor linker and a dicarboxylate with ESIPT (excited-state intramolecular proton transfer) fluorophore by varying the reaction media. One of the MOFs has a 3D four-fold interpenetrating framework with guest solvent in the structure that undergoes a solvent-dependent crystalline-to-crystalline structural transformation, which has been extensively studied by powder XRD and IR spectroscopy. The other MOF is structurally rigid in nature and has a two-fold interpenetrating structure without any guest molecules. Both the compounds show moderate CO2 adsorption and one of them, the MOF with the four-fold interpenetrating structure, also shows moderately high H2 adsorption. Furthermore, both the compounds show interesting luminescence behavior. In the solid state, the two compounds show single-peak spectra, whereas upon suspension of these compounds in polar solvents, the maxima split into two peaks with a large Stokes shift. On the other hand, in nonpolar solvents, only one emission maximum is observed. This solvatochromic dual-emission phenomenon is due to ESIPT, which has been extensively studied. 相似文献
56.
Srinivas Lavanya Kumar Manda Shashank Tripathi Anirban Ghoshal Mayur D. Ambule Dr. Ajay Kumar Srivastava Dr. Gautam Panda 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(23):5131-5156
Macrocyclic alkaloids (macrolides) and cyclopeptides have an immense range of applications in drug discovery research because of their natural abundance and potential biological and physicochemical properties. Presently, more than 100 approved drugs or clinical drug candidates contain macrocyclic scaffolds as the biologically active component. This review provides an interesting perspective about the use of amino acid-derived chiral pools versus other methods derived from miscellaneous synthons towards the total synthesis of non-peptidic macrolides. The synthetic routes and the key strategies involved in the total syntheses of ten natural macrolides have been discussed. Both the amino acid-derived and non-amino acid-derived synthetic routes have been illustrated to present a comparative study between the two approaches. 相似文献
57.
58.
Methylindium(III) dithiolate complexes of the general formulae [Me2In(S∩S)] ( 1 ) and [MeIn(S∩S)2] ( 2 ) [S∩S = (EtO)2PS2?, (PriO)2PS2?, Et2NCS2?, , O(CH2CH2)2NCS2?, EtOCS2? and PriOCS2?] have been isolated conveniently by the reaction of Me3In·OEt2 with In(S∩S)3 ( 3 ) in an appropriate stoichiometry. Both 1 and 2 have been characterized by indium analysis, IR, NMR (1H, 13C{1H} and 31P{H}) and mass spectral data. NMR data of 3 are also included for comparison. The Me–In and S∩S resonances are sensitive to the number of methyl groups attached to indium metal. The mass spectral data indicate that these complexes are monomeric in nature. The thermal behavior of a few complexes has been investigated. The xanthate and dithiocarbamate complexes on pyrolysis under dynamic vacuum or flowing nitrogen atmosphere gave either In2S3 or a mixture of InS, In2S3 and In6S7, which were characterized using EDAX and powder XRD. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
59.
Sharma VK Saharo PD Sharma N Rastogi RC Ghoshal SK Mohan D 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2003,59(6):1161-1170
Absorption and fluorescence emission of 4 and 7 substituted coumarins viz. C 440, C 490, C 485 and C 311 have been studied in various polar and non-polar organic solvents. These coumarin dyes are substituted with alkyl, amine and fluorine groups at 4- and 7-positions. They give different absorption and emission spectra in different solvents. The study leads to a possible assignment of energy level scheme for such coumarins including the effect on ground state and excited state dipole moments due to substitutions. Excited state dipole moments of these dyes are calculated by solvetochromic data experimentally and theoretically these are calculated by PM 3 method. The dipole moments in excited state, for all molecules investigated here, are higher than the corresponding values in the ground state. The increase in dipole moment has been explained in terms of the nature of excited state and resonance structure. 相似文献