全文获取类型
收费全文 | 543篇 |
免费 | 16篇 |
国内免费 | 2篇 |
专业分类
化学 | 261篇 |
晶体学 | 10篇 |
力学 | 8篇 |
数学 | 27篇 |
物理学 | 255篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 4篇 |
2020年 | 8篇 |
2019年 | 15篇 |
2018年 | 14篇 |
2017年 | 7篇 |
2016年 | 13篇 |
2015年 | 9篇 |
2014年 | 18篇 |
2013年 | 48篇 |
2012年 | 23篇 |
2011年 | 35篇 |
2010年 | 16篇 |
2009年 | 24篇 |
2008年 | 24篇 |
2007年 | 23篇 |
2006年 | 20篇 |
2005年 | 22篇 |
2004年 | 12篇 |
2003年 | 8篇 |
2002年 | 18篇 |
2001年 | 11篇 |
2000年 | 8篇 |
1999年 | 7篇 |
1998年 | 9篇 |
1997年 | 4篇 |
1996年 | 17篇 |
1995年 | 17篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 13篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1988年 | 3篇 |
1986年 | 5篇 |
1985年 | 7篇 |
1984年 | 9篇 |
1983年 | 14篇 |
1982年 | 6篇 |
1981年 | 3篇 |
1980年 | 8篇 |
1979年 | 6篇 |
1978年 | 7篇 |
1977年 | 2篇 |
1975年 | 4篇 |
1960年 | 1篇 |
1958年 | 1篇 |
1938年 | 2篇 |
排序方式: 共有561条查询结果,搜索用时 15 毫秒
91.
Nirmal Kumar Sarkar Joydeep Choudhury Srinivasa Rao Karumuri Ramendu Bhattacharjee 《Molecular physics》2013,111(5):693-702
Using the Lie algebraic method the vibrational energy levels of HCCF and HCCD are calculated for 102 and 110 vibrational bands, respectively, using the local Hamiltonian. A comparative study is made between the two. Better results are obtained than those published earlier from local mode analysis. 相似文献
92.
R.R. Bhattacharjee S.S.M. Lau-Chapdelaine G. Maines L. Maley M.I. Radulescu 《Proceedings of the Combustion Institute》2013,34(2):1893-1901
This experimental study addresses the re-initiation mechanism of detonation waves following the Mach reflection of a shock–flame complex. The detonation diffraction around a cylinder is used to reproducibly generate the shock–flame complex of interest. The experiments are performed in methane–oxygen. We use a novel experimental technique of coupling a two-in-line-spark flash system with a double-frame camera in order to obtain microsecond time resolution permitting accurate schlieren velocimetry. The first series of experiments compares the non-reactive sequence of shock reflections with the reflection over a rough wall under identical conditions. It was found that the hot reaction products generated along the rough wall are entrained by the wall jet into a large vortex structure behind the Mach stem. The second series of experiments performed in more sensitive mixtures addressed the sequence of events leading to the detonation establishment along the Mach and transverse waves. Following ignition and jet entrainment, a detonation first appears along the Mach stem while the transverse wave remains non-reactive. The structure of the unburned tongue however indicates local instabilities and hot spot formation, leading to the rapid reaction of this gas. Numerical simulations are also reported, confirming the sequence of ignition events obtained experimentally. 相似文献
93.
94.
We employ a layer-by-layer adsorption technique for deposition on solid substrates of polyionic films of Chicago Sky Blue. Film growth was significant with the increasing number of layers. Photochemical properties of these films are investigated for different ionic concentrations. A significant blue shift is observed with the increasing ionic strength of the solution, suggesting the formation of aggregation. Temperature effect studies show some preferable reorientation of molecules in the film during cooling process. Most remarkable observation is that the absorption intensity is the highest for a particular degree of inclination. Deposition time is fixed at 15rain because adsorption kinetics results show saturation after 15 min. 相似文献
95.
Self-assembling behaviour of block copolymers and their ability to evade the immune system through polyethylene oxide stealth
makes it an attractive candidate for drug encapsulation. Micelles formed by polyethylene oxide-polypropylene oxide- polyethylene
oxide triblock copolymers (PEO-PPO-PEO), pluronic P123, have been employed for encapsulating the anti-cancer drug doxorubicin
hydrochloride. The binding affinity of doxorubicin within the micelle carrier is enhanced through complex formation of drug
and anionic surfactant, aerosol OT (AOT). Electrostatic binding of doxorubicin with negatively charged surfactants leads to
the formation of hydrophobic drug-surfactant complexes. Surfactant-induced partitioning of the anti-cancer drug into nonpolar
solvents such as chloroform is investigated. SANS measurements were performed on pluronic P123 micelles in the presence of
drug-surfactant complex. No significant changes in the structure of the micelles are observed upon drug encapsulation. This
demonstrates that surfactant- drug complexes can be encapsulated in block copolymer micelles without disrupting the structure
of aggregates.
相似文献
96.
Angshuman Ghosh Soumen Kumar Dubey Dr. Maxcimilan Patra Jishu Mandal Narendra Nath Ghosh Priyanka Das Arpita Bhowmick Dr. Keka Sarkar Dr. Suprabhat Mukherjee Rajat Saha Dr. Subham Bhattacharjee 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(63):e202201621
We have shown solvent- and substrate-dependent chiral inversion of a few glycoconjugate supramolecules. (Z)-F-Gluco, in which d -glucosamine has been attached chemically to Cbz-protected l -phenylalanine at the C terminus, forms a self-healing hydrogel through intertwining of the nanofibers wherein the gelators undergo lamellar packing in the β-sheet secondary structures with a single chiral handedness. Dihybrid (Z)-F-gluco nanocomposite gel was prepared by in-situ formation of silver nanoparticles AgNPs in the gel; this enhances the mechanical properties of the composite gel through physical crosslinking without altering the packing pattern. In contrast, (Z)-L-gluco bearing an l -leucine moiety does not form a hydrogel but an organogel. Interestingly, the chiral handedness of the aggregates of (Z)-L-gluco can be reversed by choosing suitable solvents. In addition to self-healing behavior, (Z)-L-gluco gel revealed shape persistency. Further, (Z)-F-gluco hydrogel is benign, nontoxic, non-immunogenic, and non-allergenic in animal cells. AgNP-loaded (Z)-F-gluco hydrogel showed antibacterial activity against both Gram-positive and Gram-negative bacteria. 相似文献
97.
Dey Chaudhuri S. Banerjee D. Bhattacharjee T. Wasim Raja Sk Acharya R. Pujari P. K. 《Journal of Radioanalytical and Nuclear Chemistry》2020,324(2):829-835
Journal of Radioanalytical and Nuclear Chemistry - Performance of 1″?×?1″ LaBr3 (5% Ce) scintillator coupled to Hamamatsu R2083 PM Tube has been investigated for the... 相似文献
98.
99.
100.
Ramanuj Mishra Ayon Bhattacharjee Debanjan Bhattacharjee Keisham Nanao Singh Binod Gogoi 《Liquid crystals》2018,45(9):1333-1341
Raman spectra of pure and 2 wt.% gold nanoparticles (GNPs) dispersed liquid crystalline compound 4-n-Hexyloxy-4?- cyanobiphenyls (6OCB) has been recorded as a function of temperature from room temperature (solid crystal) to 80°C (isotropic liquid) in the spectral region of 500–2500 cm?1. The variation of Raman spectral parameters (peak positions and line width) with temperature is used to explain the changes in molecular alignment and its effect on inter-/intra-molecular interactions at crystal-Nematic (K-N) transition. To understand the change in molecular structure during phase transition and on account of dispersion of gold nanoparticles in pure liquid crystal more precisely, two spectral regions 1000–1500 cm?1 and 1500–2400 cm?1 have been selected separately. From the detailed study, it is concluded that increased orientational/vibrational freedom of the molecules as well as delocalisation of electron clouds results in the spectral anomalies at K-N transition. The geometrical structure of 6OCB was optimised using density functional theory (DFT) and theoretical Raman spectra have been obtained for comparison with experimental spectra. The tentative assignment of vibrational modes observed in our region of study was calculated based on potential energy distribution (PED) using vibrational energy distribution analysis (VEDA) calculation. 相似文献