全文获取类型
收费全文 | 15334篇 |
免费 | 684篇 |
国内免费 | 115篇 |
专业分类
化学 | 10319篇 |
晶体学 | 142篇 |
力学 | 439篇 |
数学 | 1674篇 |
物理学 | 3559篇 |
出版年
2023年 | 68篇 |
2022年 | 63篇 |
2021年 | 323篇 |
2020年 | 264篇 |
2019年 | 273篇 |
2018年 | 312篇 |
2017年 | 270篇 |
2016年 | 526篇 |
2015年 | 432篇 |
2014年 | 578篇 |
2013年 | 991篇 |
2012年 | 1150篇 |
2011年 | 1310篇 |
2010年 | 809篇 |
2009年 | 671篇 |
2008年 | 1030篇 |
2007年 | 955篇 |
2006年 | 874篇 |
2005年 | 766篇 |
2004年 | 677篇 |
2003年 | 558篇 |
2002年 | 522篇 |
2001年 | 326篇 |
2000年 | 303篇 |
1999年 | 211篇 |
1998年 | 134篇 |
1997年 | 135篇 |
1996年 | 131篇 |
1995年 | 122篇 |
1994年 | 126篇 |
1993年 | 90篇 |
1992年 | 92篇 |
1991年 | 74篇 |
1990年 | 81篇 |
1989年 | 70篇 |
1988年 | 51篇 |
1987年 | 35篇 |
1986年 | 29篇 |
1985年 | 68篇 |
1984年 | 48篇 |
1983年 | 39篇 |
1982年 | 45篇 |
1981年 | 42篇 |
1980年 | 29篇 |
1979年 | 43篇 |
1978年 | 34篇 |
1977年 | 35篇 |
1976年 | 36篇 |
1975年 | 28篇 |
1973年 | 35篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Jong‐Dae Lee Il‐Hwan Suh Sang Ook Kang 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(5):o151-o153
The title compound, C38H48NOP, isolated from the reaction of (2‐diphenylphosphanyl‐4,6‐di‐tert‐butyl)phenol with 2,6‐diisopropylphenyl azide at 273 K, can act as an N,O‐bidentate ligand. Crystal structure analysis shows a deviation from ideal tetrahedral symmetry around the P atom. The molecule exists as a monomer in the solid state, whose conformation is stabilized via multiple intramolecular hydrogen bonds. Geometric parameters from both experimental and theoretical calculations are compared. 相似文献
992.
993.
994.
Readily Accessible and Predictable Naphthalene‐Based Two‐Photon Fluorophore with Full Visible‐Color Coverage 下载免费PDF全文
Ja Young Koo Cheol Ho Heo Dr. Young‐Hee Shin Dahahm Kim Dr. Chang Su Lim Prof. Dr. Bong Rae Cho Prof. Dr. Hwan Myung Kim Prof. Dr. Seung Bum Park 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(40):14166-14170
Herein we report 22 acedan‐derived, two‐photon fluorophores with synthetic feasibility and full coverage of visible wavelength emission. The emission wavelengths were predicted by computational analysis, which enabled us to visualize multicolor images by two‐photon excitation with single wavelength, and to design a turn‐on, two‐photon fluorescence sensor for endogenous H2O2 in Raw 264.7 macrophage and rat brain hippocampus ex vivo. 相似文献
995.
Chul‐Soon Lee Zhengfei Dai Seong‐Yong Jeong Chang‐Hoon Kwak Bo‐Young Kim Do Hong Kim Prof. Ho Won Jang Joon‐Shik Park Prof. Jong‐Heun Lee 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(21):7102-7107
Monolayers of periodic porous Co3O4 inverse opal (IO) thin films for gas‐sensor applications were prepared by transferring cobalt‐solution‐dipped polystyrene (PS) monolayers onto sensor substrates and subsequent removal of the PS template by heat treatment. Monolayer Co3O4 IO thin films having periodic pores (d≈500 nm) showed a high response of 112.9 to 5 ppm C2H5OH at 200 °C with low cross‐responses to other interfering gases. Moreover, the selective detection of xylene and methyl benzenes (xylene+toluene) could be achieved simply by tuning the sensor temperature to 250 and 275 °C, respectively, so that multiple gases can be detected with a single chemiresistor. Unprecedentedly high ethanol response and temperature‐modulated control of selectivity with respect to ethanol, xylene, and methyl benzenes were attributed to the highly chemiresistive IO nanoarchitecture and to the tuned catalytic promotion of different gas‐sensing reactions, respectively. These well‐ordered porous nanostructures could have potential in the field of high‐performance gas sensors based on p‐type oxide semiconductors. 相似文献
996.
Detoxification of Chemical Warfare Agents Using a Zr6‐Based Metal–Organic Framework/Polymer Mixture 下载免费PDF全文
Dr. Su‐Young Moon Emmanuel Proussaloglou Gregory W. Peterson Dr. Jared B. DeCoste Morgan G. Hall Dr. Ashlee J. Howarth Prof. Joseph T. Hupp Prof. Omar K. Farha 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(42):14864-14868
Owing to their high surface area, periodic distribution of metal sites, and water stability, zirconium‐based metal–organic frameworks (Zr6‐MOFs) have shown promising activity for the hydrolysis of nerve agents GD and VX, as well as the simulant, dimethyl 4‐nitrophenylphosphate (DMNP), in buffered solutions. A hurdle to using MOFs for this application is the current need for a buffer solution. Here the destruction of the simulant DMNP, as well as the chemical warfare agents (GD and VX) through hydrolysis using a MOF catalyst mixed with a non‐volatile, water‐insoluble, heterogeneous buffer is reported. The hydrolysis of the simulant and nerve agents in the presence of the heterogeneous buffer was fast and effective. 相似文献
997.
Young Bok Ryu Ji Sun Kim Kyeong Ho Kim Yangdo Kim Man Sig Lee 《Research on Chemical Intermediates》2016,42(1):83-93
Zn/Al mixed oxide was prepared by the coprecipitation or the hydrothermal method under different conditions and used as catalyst for synthesis of glycerol carbonate by carbonylation of glycerol with urea. The physical properties of the prepared Zn/Al mixed oxide particles were investigated, as well as their activity as catalyst in the mentioned synthesis. The dried Zn/Al mixed-oxide particles prepared by the coprecipitation method showed higher activity in synthesis of glycerol carbonate than those prepared by the hydrothermal method. The Zn/Al mixed oxide prepared by the coprecipitation method without NaNO3 showed the highest catalytic activity in synthesis of glycerol carbonate. 相似文献
998.
999.
Valentina Simonetti Jason Y. Park Nicholas J. Panaro Larry J. Kricka 《Journal of nanoparticle research》2008,10(2):365-368
Nylon nanorods and nanotubes (200 nm diameter) were fabricated by the membrane wetting technique (solvent and melt wetting)
from a range of nylons (6; 6,6; 6,9; 6,10; 6,12; 11; 12, 6(3)T) and nylon blended with different dyes (Nylon Cast Blue, Nylon
6/6 Black) or with molybdenum disulfide (Nylon cast MDS). The 65-μm long nylon nanotubes and nanorods were characterized by
scanning electron microscopy. The nanoscale nylon 6,6 served as an effective high surface area alternative to a nylon membrane
as a solid support in a chemiluminescent assay for nylon-bound biotinylated nucleic acids based on streptavidin- alkaline
phosphatase and chemiluminescent detection of the bound alkaline phosphatase label with the dioxetane substrate, CDP-Star.
Layer-by-layer deposition of the cationic polymer (Sapphire-II™; Tropix) onto the nylon 6,6 nanostructures prior to UV-cross-linking
with biotinylated DNA resulted in further enhancement of binding and detection of biotinylated DNA. 相似文献
1000.
Tae Jin Park Sung Jin Park Dae Hyun Kim In Soo Kim Soo Kyung Kim Se Young Choi 《Current Applied Physics》2008,8(6):716-719
Optical switching and structural transformation of GeTe–Sb2Te3 pseudobinary alloys, Ge2Sb2Te5, Ge1Sb2Te4, and Ge1Sb4Te7, were studied for data storage application. As-deposited Ge2Sb2Te5, Ge1Sb2Te4, and Ge1Sb4Te7 thin films were amorphous and they crystallized to FCC and HCP upon heat treatment. Crystallization was accelerated by increasing the proportion of Sb2Te3 rather than GeTe in Ge–Sb–Te compounds; this was observed by reflectivity changes under nanosecond laser irradiation in static tester. The different crystallization kinetics according to composition might be affected by the structural incompatibility of GeTe under the ‘Umbrella Flip’ theory. 相似文献