全文获取类型
收费全文 | 123篇 |
免费 | 2篇 |
国内免费 | 6篇 |
专业分类
化学 | 81篇 |
力学 | 3篇 |
综合类 | 4篇 |
数学 | 9篇 |
物理学 | 34篇 |
出版年
2021年 | 1篇 |
2020年 | 1篇 |
2015年 | 1篇 |
2013年 | 3篇 |
2012年 | 5篇 |
2011年 | 8篇 |
2010年 | 4篇 |
2009年 | 7篇 |
2008年 | 4篇 |
2007年 | 7篇 |
2006年 | 7篇 |
2005年 | 10篇 |
2004年 | 12篇 |
2003年 | 6篇 |
2002年 | 3篇 |
2000年 | 2篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 9篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1977年 | 1篇 |
1975年 | 2篇 |
1943年 | 2篇 |
排序方式: 共有131条查询结果,搜索用时 15 毫秒
21.
Molecular dynamics simulation of the cation motion upon adsorption of CO2 in Faujasite zeolite systems 总被引:2,自引:0,他引:2
Plant DF Maurin G Jobic H Llewellyn PL 《The journal of physical chemistry. B》2006,110(29):14372-14378
Molecular Dynamics simulations have been carried out in NaX and NaY Faujasite systems to deepen understanding of the cation rearrangement during the CO2 adsorption process suggested by our recent diffusivity measurements. This study is a major contribution since the rearrangement of the cations in Faujasite, the most promising adsorbent for CO2 storage, can represent a significant breakthrough in understanding the adsorption and diffusion processes at the mircroscopic scale. For NaY, it has been shown that at low and intermediate loadings, SII cations can migrate toward the center of the supercage due to strong interactions with the adsorbates, followed by a hopping of SI'cation from the sodalite cage into the supercage to fill the vacant SII site. The SI cations are only displaced at a higher loading, leading to cation de-trapping out of the double six rings into the vacant SI' sites. For NaX, the SIII' cations which occupy the most accessible adsorption sites move significantly upon coordination to the carbon dioxide molecules. The SI' and SII cations remain consistently located in their initial sites whatever the loading. Indeed, the most probable migration mechanism involves SIII' cation displacements into nearby vacant SIII' sites. 相似文献
22.
HARUN REŞIT YAZAR 《Pramana》2013,81(4):579-585
The sd-interacting boson approximation (sd-IBA) and the df-interacting boson approximation (df-IBA) can be related to each other and the states of the interacting boson approximation model can be identified with the fully symmetric states in the sdf interacting boson approximation model. A systematic study of the sdf-IBA model showed that the constructed Hamiltonian can successfully describe the strong octupole correlations in the deformed nuclei. We showed that the interacting boson approximation may account for many of these K π ?=?0+ states. It was found that the calculated energy spectra of the gadolinium isotopes agree quite well with the experimental data. The observed B(E2) values were also calculated and compared with the experimental data. 相似文献
23.
Moore AS Gumbrell ET Lazarus J Hohenberger M Robinson JS Smith RA Plant TJ Symes DR Dunne M 《Physical review letters》2008,100(5):055001
Experimental investigations into the dynamics of cylindrical, laser-driven, high-Mach-number shocks are used to study the thermal cooling instability predicted to occur in astrophysical radiative blast waves. A streaked Schlieren technique measures the full blast-wave trajectory on a single-shot basis, which is key for observing shock velocity oscillations. Electron density profiles and deceleration parameters associated with radiative blast waves were recorded, enabling the calculation of important blast-wave parameters including the fraction of radiated energy, epsilon, as a function of time for comparison with radiation-hydrodynamics simulations. 相似文献
24.
Stereoselective syntheses of both the natural (C5'- S) and unnatural (C5'- R) diastereoisomers of uracil polyoxin C methyl ester have been developed. The key stereocontrolled step involves nucleophilic addition of trimethylsilyl cyanide to the appropriate chiral sulfinimine derived from 2',3'-protected 5'-formyluridine and (S)-(-)-tert-butanesulfinamide or (R)-(+)-tert-butanesulfinamide, respectively. A variety of substrate mimics designed to function as inhibitors of chitin synthase have been synthesized by conjugation of the methyl ester of uracil polyoxin C (UPOC) with activated isoxazole carboxylic acids. Amide bond formation was accomplished via coupling of the amino functionality of UPOC methyl ester with a free isoxazole acid using HBTU or alternatively an isoxazole pentafluorophenyl ester. The substrate mimics incorporate features of the nucleoside-peptide antibiotics, the polyoxins and the nikkomycins, as well as features of the transition state structure expected during polymerization of the natural chitin synthase substrate uridine diphosphoryl-N-acetylglucosamine (UDP-GlcNAc), namely, a metal-binding site and glycosyl oxocarbenium ion mimic. 相似文献
25.
Ji Xia Zhang Yong Xue Wanga Zhi An Hea Fu Lin Yana Han Dong Sunb a Pharmaceutical Laboratory Xinxiang Medical University Xinxiang China b State Key Laboratory of Phytochemistry Plant Resources in West China Kunming Institute of Botany Chinese Academy of Sciences Kunming China 《中国化学快报》2009,20(2):201-203
Two new ent-kaurane diterpenoids taihangexcisoidesin A and B(1 and 2),were isolated from the EtOAc extract of the leaves of Isodon excisoides.Their structures were determined on the basis of spectroscopic methods. 相似文献
26.
HUANG HuoQiang PAN XuLin JI ChangJiu ZENG GuangZhi JIANG LiHua FU Xiang LIU JiKai HAO XiaoJiang ZHANG YingJun & TAN NingHua State Key Laboratory of Phytochemistry Plant Resources in West China Kunming Institute of Botany Chinese Academy of Sciences Kunming China Graduate University of the Chinese Academy of Sciences Beijing 《中国科学B辑(英文版)》2009,(3)
Carbonic anhydrase Ⅱ (CAⅡ) is an important enzyme complex with Zn2+,which is involved in many physiological and pathological processes, such as calcification, glaucoma and tumorigenicity. In order to search for novel inhibitors of CAⅡ, inhibition assay of carbonic anhydrase Ⅱ was performed, by which seven natural phenolic compounds, including four phenolics (grifolin, 4-O-methyl-grifolic acid, grifolic acid, and isovanillic acid) and three flavones (eriodictyol, quercetin and puerin A), showed in-hibitory a... 相似文献
27.
28.
29.
H. Heller H. Clever G. T. Piercy E. K. Plant M. C. Rogers S. Zweig A. Taub J. D. White F. W. Rose Jr. und K. S. Nitsche 《Fresenius' Journal of Analytical Chemistry》1943,125(1-2):66-68
Ohne Zusammenfassung 相似文献
30.
JianXinCAO GuoFangLAI YiFengWANG YuanFengHUANG ShiDeLUO 《中国化学快报》2004,15(7):791-793
A new sesquiterpenoid was obstained from the leaves of Magnolia delavayi. Its structure was determined as 8β-acetoxy-10α-ethyloxy-guaia-4α, 11-diol on the basis of spectral evidence. 相似文献