全文获取类型
收费全文 | 67403篇 |
免费 | 10045篇 |
国内免费 | 6574篇 |
专业分类
化学 | 45279篇 |
晶体学 | 639篇 |
力学 | 4548篇 |
综合类 | 518篇 |
数学 | 8426篇 |
物理学 | 24612篇 |
出版年
2024年 | 59篇 |
2023年 | 1357篇 |
2022年 | 1352篇 |
2021年 | 1981篇 |
2020年 | 2504篇 |
2019年 | 2390篇 |
2018年 | 2135篇 |
2017年 | 1882篇 |
2016年 | 2892篇 |
2015年 | 2953篇 |
2014年 | 3510篇 |
2013年 | 4709篇 |
2012年 | 5805篇 |
2011年 | 6023篇 |
2010年 | 4087篇 |
2009年 | 4022篇 |
2008年 | 4192篇 |
2007年 | 3794篇 |
2006年 | 3575篇 |
2005年 | 3097篇 |
2004年 | 2475篇 |
2003年 | 1874篇 |
2002年 | 1575篇 |
2001年 | 1457篇 |
2000年 | 1330篇 |
1999年 | 1484篇 |
1998年 | 1281篇 |
1997年 | 1118篇 |
1996年 | 1173篇 |
1995年 | 1064篇 |
1994年 | 1000篇 |
1993年 | 860篇 |
1992年 | 758篇 |
1991年 | 662篇 |
1990年 | 549篇 |
1989年 | 483篇 |
1988年 | 364篇 |
1987年 | 347篇 |
1986年 | 295篇 |
1985年 | 301篇 |
1984年 | 202篇 |
1983年 | 174篇 |
1982年 | 145篇 |
1981年 | 112篇 |
1980年 | 82篇 |
1978年 | 56篇 |
1977年 | 52篇 |
1976年 | 50篇 |
1975年 | 57篇 |
1973年 | 57篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Crystallography Reports - A coordination polymer, [CuL]n (HL = 1H-benzimidazole-2-methanol), has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction.... 相似文献
62.
63.
Recent advances in photocatalysis focus on the development of materials with hierarchical structure and on the surface plasmon resonance (SPR) phenomenon exhibited by metal nanoparticles (NPs). In this work, both are combined in a material where size‐controllable Ag‐NPs are uniformly loaded onto the hierarchical microporous and mesoporous and nanocolumnar structures of ZnO, resulting in Ag‐NP/ZnO nanocomposites. The embedded Ag‐NPs slightly decrease the hydrophobicity of fibrous ZnO, improve its wettability, and increase the absorption of formaldehyde (H2CO) onto the photocatalyst, all of this resulting in excellent photodegradation of formaldehyde in aqueous solution. Besides, we found that Ag‐NPs with optimal size not only accelerate the charge transfer to the surface of ZnO, but also strengthen the SPR effect in the intercolumnar channels of fibrous ZnO particles combining with high concentration of photo‐generated radical species. The micro‐to‐mesoporous ZnO is like a nanoarray packed Ag‐NPs. With Ag‐NPs of diameter 2.5 < ? < 6.5 nm, ZnO exhibits the most superior photodegradation rate constant value of 0.0239 min?1 with total formaldehyde removal of 97%. This work presents a new feasible approach involving highly sophisticated Ag‐NP/ZnO architecture combining the SPR effect and hierarchically ordered structures, which results in high photocatalytic activity for formaldehyde photodegradation. 相似文献
64.
65.
Chang Mingning Wang He Zheng Yonglei Li Ningning Chen Siheng Wan Yong Yuan Feng Shao Weiquan Xu Sheng 《Journal of Solid State Electrochemistry》2019,23(2):607-613
Journal of Solid State Electrochemistry - Li1.2Ni1/3Co1/3Mn1/3O2 was synthesized as a cathode material for lithium-ion batteries and coated with various amounts of CoAl2O4 (0–5 wt%)... 相似文献
66.
Chen Qinlei Xia Zhengbin Zhang Yanhong Wang Shumin 《Journal of Solid State Electrochemistry》2019,23(12):3399-3408
Journal of Solid State Electrochemistry - Polyaniline/diazonium salt/TiO2 nanotube arrays (PANI/DZ/TiO2 NAs), as a supercapacitor electrode material, are fabricated by two-step anodic oxidation of... 相似文献
67.
68.
Tenghao Yin Lei Wu Tonghao Wu Guoyong Mao Guodong Nian Zhe Chen Xiaocheng Hu Peng Wang Yuhai Xiang Honghui Yu Shaoxing Qu Wei Yang 《Journal of Polymer Science.Polymer Physics》2019,57(5):272-280
Conductive hydrogels with ionic compounds possess great potential for the development of soft smart devices. A dielectric scarfskin is typically required for these devices to prevent short circuiting, leading to devices with lower stretchability than the hydrogel. Henceforth, commonly used dielectric materials, such as PDMS and Ecoflex, cannot be largely stretched. Hydrogel devices with ultrastretchability are required to accommodate hostile application environments. Herein, we propose a hydrogel fiber coated with a dielectric layer that can be stretched to over 2000% of its initial length. The fiber remains conductive when stretched to ~1300%. In addition, the core/sheath hydrogel fiber can be endowed with a variety of functional properties, such as electroluminescence (EL), photoluminescence (PL), and magnetic‐responsiveness, demonstrating scalability of the resultant fiber. The present work can pave the way for numerous next‐generation soft devices, such as smart textiles and wearable electronics. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 272–280 相似文献
69.
Meng-Meng Zhao Lin Zhou Ping-Ping Shi Xuan Zheng Xiao-Gang Chen Ji-Xing Gao Lei He Prof. Dr. Qiong Ye Prof. Dr. Cai-Ming Liu Prof. Dr. Da-Wei Fu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(25):6447-6454
Organic–inorganic hybrid perovskite-type multiferroics have attracted considerable research interest owing to their fundamental scientific significance and promising technological applications in sensors and multiple-state memories. The recent achievements with divalent metal dicyanamide compounds revealed such malleable frameworks as a unique platform for developing novel functional materials. Herein, two 3D organic–inorganic hybrid perovskites [Et3P(CH2)2F][Mn(dca)3] ( 1 ) and [Et3P(CH2)2Cl][Mn(dca)3] ( 2 ) (dca=dicyanamide, N(CN)2−) are presented. Accompanying the sequential phase transitions, they display a broad range of intriguing physical properties, including above room temperature ferroelastic behavior, switchable dielectricity, and low-temperature antiferromagnetic ordering (Tc=2.4 K for both 1 and 2 ). It is also worth noting that the spontaneous strain value of 1 is far beyond that of 2 in the first ferroelastic phase, as a result of the precise halogen substitution. From the point view of molecular design, this work should inspire further exploration of multifunctional molecular materials with desirable properties. 相似文献
70.