全文获取类型
收费全文 | 1072篇 |
免费 | 56篇 |
国内免费 | 4篇 |
专业分类
化学 | 933篇 |
晶体学 | 5篇 |
力学 | 18篇 |
数学 | 84篇 |
物理学 | 92篇 |
出版年
2024年 | 1篇 |
2023年 | 15篇 |
2022年 | 18篇 |
2021年 | 22篇 |
2020年 | 34篇 |
2019年 | 24篇 |
2018年 | 29篇 |
2017年 | 11篇 |
2016年 | 32篇 |
2015年 | 42篇 |
2014年 | 38篇 |
2013年 | 58篇 |
2012年 | 83篇 |
2011年 | 109篇 |
2010年 | 53篇 |
2009年 | 38篇 |
2008年 | 82篇 |
2007年 | 72篇 |
2006年 | 64篇 |
2005年 | 53篇 |
2004年 | 61篇 |
2003年 | 41篇 |
2002年 | 42篇 |
2001年 | 15篇 |
2000年 | 15篇 |
1999年 | 5篇 |
1998年 | 9篇 |
1997年 | 7篇 |
1996年 | 6篇 |
1995年 | 14篇 |
1994年 | 3篇 |
1993年 | 6篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1986年 | 1篇 |
1985年 | 5篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 5篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1937年 | 1篇 |
排序方式: 共有1132条查询结果,搜索用时 46 毫秒
1.
2.
Probing the Catalytic Activity of Reduced Graphene Oxide Decorated with Au Nanoparticles Triggered by Visible Light
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Jiale Wang Dr. Fabiane J. Trindade Caroline B. de Aquino Joana C. Pieretti Prof. Dr. Sergio H. Domingues Prof. Dr. Romulo A. Ando Prof. Dr. Pedro H. C. Camargo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(27):9889-9894
Hybrid materials in which reduced graphene oxide (rGO) is decorated with Au nanoparticles (rGO–Au NPs) were obtained by the in situ reduction of GO and AuCl4?(aq) by ascorbic acid. On laser excitation, rGO could be oxidized as a result of the surface plasmon resonance (SPR) excitation in the Au NPs, which generates activated O2 through the transfer of SPR‐excited hot electrons to O2 molecules adsorbed from air. The SPR‐mediated catalytic oxidation of p‐aminothiophenol (PATP) to p,p′‐dimercaptoazobenzene (DMAB) was then employed as a model reaction to probe the effect of rGO as a support for Au NPs on their SPR‐mediated catalytic activities. The increased conversion of PATP to DMAB relative to individual Au NPs indicated that charge‐transfer processes from rGO to Au took place and contributed to improved SPR‐mediated activity. Since the transfer of electrons from Au to adsorbed O2 molecules is the crucial step for PATP oxidation, in addition to the SPR‐excited hot electrons of Au NPs, the transfer of electrons from rGO to Au contributed to increasing the electron density of Au above the Fermi level and thus the Au‐to‐O2 charge‐transfer process. 相似文献
3.
4.
5.
6.
Briggs CR Allen MJ O'Hagan D Tozer DJ Slawin AM Goeta AE Howard JA 《Organic & biomolecular chemistry》2004,2(5):732-740
The energies of the gauche and anti conformers of 2-fluoroethylamine, 2-fluoroethanol and their protonated analogues are calculated using density functional theory. Unlike the non protonated systems, the protonated systems show a strong gauche effect where the C-F and the C-(+)NH(3) or C-F and C-(+)OH(2) bonds are gauche rather than anti to each other. Single crystal X-ray diffraction studies of 2-fluoroethylammonium compounds identify the same conformational preference. 相似文献
7.
Potter CV Freshwater J Dean JL Kybett AP Kidd R James M Saxton H 《Chemical Society reviews》2004,33(9):567-572
In January 2003, the Royal Society of Chemistry launched Organic & Biomolecular Chemistry (OBC)--a journal promising to provide high quality research from all aspects of synthetic, physical and biomolecular organic chemistry. The journal was set to build upon the foundations laid down by its predecessor publications (J. Chem. Soc., Perkin Trans. 1 and J. Chem. Soc., Perkin Trans. 2) as well as complement the subject coverage already published in prestigious general chemistry journals such as Chemical Communications and Chemical Society Reviews. Nearly two years on, just how is the programme developing and what can the community expect to see from the Royal Society of Chemistry (RSC)? 相似文献
8.
Caroline Rhr 《无机化学与普通化学杂志》1995,621(9):1496-1500
Novel Suboxide Clusters [O5Ba18] in the Crystal Structures of Ba21M2O5 (M = Si, Ge) The compounds Ba21M2O5 (M = Si, Ge) crystallize in the cubic system with space group Fd3m, lattice constants 2 038.3(10) pm (Si), 2 039.8(9) pm (Ge) resp. and Z = 8. The crystal structure contains isolated Si/Ge atoms coordinated by barium atoms in an icosahedral arrangement. The oxygen atoms are situated in the centers of barium octahedra, four of which share common faces with an additional central octahedron. The novel clusters [O5Ba18] in principal are related to those in the crystal structures of the binary Cs/Rb suboxides. 相似文献
9.
Mohanty S Ylitalo C Woo OS 《Langmuir : the ACS journal of surfaces and colloids》2004,20(6):2277-2281
Surface contaminants are commonly found on films. They get transferred to the surface from incompletely cured silicone liners on the films or owing to migration of additives to the surface from within the film. During the process of ink jet printing (a noncontact printing process), surface contamination affects the shape of the drops (causing the formation of fingers and crescents) and hence image quality. This study uses modeling methods to examine how such surface contamination affects the drops shapes. Subsequently, it models the effect of surface structures (pits) on the drop shape. This study explores how image quality can be controlled in the presence of surface contamination and surface structures. 相似文献
10.
Development and validation of methods for the trace determination of phthalates in sludge and vegetables 总被引:1,自引:0,他引:1
Sablayrolles C Montréjaud-Vignoles M Benanou D Patria L Treilhou M 《Journal of chromatography. A》2005,1072(2):233-242
A routine method which is simple, quick and precise has been set up and validated for phthalate analysis in environmental samples (tomato plants and sewage sludges). Six phthalates have been studied simultaneously: dimethylphthalate, diethylphthalate, di-n-butylphthalate, n-butylbenzylphthalate, di-2-ethyl-hexyl phthalate (DEHP) and di-n-octylphthalate. Optimization of sample, solvent extraction uses a Soxtec apparatus and extract purification with an a solid-phase extraction cartridge allows between 90 and 110% recovery of phthalates. Precise, sensitive and selective identification and quantifying of analytes is by GC-MS in the single ion monitoring mode. This protocol allows analytes with concentrations as low as 10 microg/kg dry matter (DM) to be determined from small (1-2 g DM) samples. This analytical method has been applied to the phthalate transfer study for agricultural recycling of sludges, where phthalate bioavailability has been studied in aquiculture using two types of experiments. Tomatoes have been grown in containers where the trace organics have been directly introduced as pure substances, and in a second experiment under the same growth conditions, sewage sludge has replaced the pure substances. Transfer of these trace organics has been followed into the various parts of the tomato plant and in general only the DEHP is worthy of note although its percentage transfer remains very low even in an experiment designed to maximize this. 相似文献