全文获取类型
收费全文 | 20640篇 |
免费 | 3647篇 |
国内免费 | 3092篇 |
专业分类
化学 | 15717篇 |
晶体学 | 310篇 |
力学 | 1236篇 |
综合类 | 215篇 |
数学 | 2433篇 |
物理学 | 7468篇 |
出版年
2024年 | 18篇 |
2023年 | 342篇 |
2022年 | 494篇 |
2021年 | 663篇 |
2020年 | 726篇 |
2019年 | 846篇 |
2018年 | 683篇 |
2017年 | 679篇 |
2016年 | 997篇 |
2015年 | 1049篇 |
2014年 | 1249篇 |
2013年 | 1553篇 |
2012年 | 1929篇 |
2011年 | 1908篇 |
2010年 | 1461篇 |
2009年 | 1411篇 |
2008年 | 1495篇 |
2007年 | 1303篇 |
2006年 | 1233篇 |
2005年 | 1151篇 |
2004年 | 884篇 |
2003年 | 692篇 |
2002年 | 742篇 |
2001年 | 588篇 |
2000年 | 480篇 |
1999年 | 389篇 |
1998年 | 325篇 |
1997年 | 321篇 |
1996年 | 277篇 |
1995年 | 235篇 |
1994年 | 219篇 |
1993年 | 152篇 |
1992年 | 138篇 |
1991年 | 125篇 |
1990年 | 124篇 |
1989年 | 96篇 |
1988年 | 85篇 |
1987年 | 44篇 |
1986年 | 61篇 |
1985年 | 46篇 |
1984年 | 24篇 |
1983年 | 21篇 |
1982年 | 19篇 |
1981年 | 10篇 |
1980年 | 11篇 |
1975年 | 8篇 |
1972年 | 7篇 |
1965年 | 6篇 |
1964年 | 5篇 |
1936年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 366 毫秒
1.
Liu Wenbin Huang Yiwei Huang Guolin Fan Lijiao Xie Yuming Shi Jeffery 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(5):2055-2068
Journal of Radioanalytical and Nuclear Chemistry - Eco-friendly and low-cost composite, amidoxime-functionalized microcrystalline cellulose/mesoporous silica (MCC/MS-AO), were synthesized by... 相似文献
2.
Qianqian Fan Zirui Liu Feng Qiu Prof. Yong Mao Prof. Qingju Liu Prof. Longzhou Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(63):e202202700
The artificially accurate design of nonmetal electrocatalysts’ active site has been a huge challenge because no pure active species with the specific structure could be strictly controlled by traditional synthetic methods. Species with a multiconfiguration in the catalyst hinder identification of the active site and the subsequent comprehension of the reaction mechanism. We have developed a novel electro-assisted molecular assembly strategy to obtain a pure pentagon ring on perfect graphene avoiding other reconstructed structures. More importantly, the active atom was confirmed by the subtle passivation process as the topmost carbon atom. Recognition of the carbon-defect electrocatalysis reaction mechanism was first downsized to the single-atom scale from the experimental perspective. It is expected that this innovative electro-assisted molecular assembly strategy could be extensively applied in the active structure-controlled synthesis of nonmetal electrocatalysts and verification of the exact active atom. 相似文献
3.
High Energy Chemistry - Modification of Polyvinylidene fluoride (PVDF) by radiation grafting is a research hotspot in recent years. In this study, the monomer 2-Hydroxyethyl methacrylate (HEMA) was... 相似文献
4.
Hua Saixiang Zhu Huichao Wang Xiao Wu Mingyuan Wu Qingyun Liu Jiuyi Yang Jianjun Zhang Jianan 《Cellulose (London, England)》2022,29(13):7465-7475
Cellulose - Ultraviolet (UV) protective cotton fabric is a convenient and reliable way to protect human body from sunlight. Herein, a polymerizable UV-absorber,... 相似文献
5.
Journal of Algebraic Combinatorics - A dessin is called circular if the boundary of each face is a circuit (a simple cycle). In this paper, we address the problem of characterizing edge-transitive... 相似文献
6.
Li Quanxin Li Zheng He Cheng Sun Huilin Tan Shengheng Zhang Hua 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(5):2105-2115
Journal of Radioanalytical and Nuclear Chemistry - The simplified 8-oxide system (SiO2-B2O3-Na2O-Al2O3-CaO-TiO2-MoO3-La2O3) has been prepared under two types of cooling methods, and analyzed with... 相似文献
7.
In this article,we study the initial boundary value problem of coupled semi-linear degenerate parabolic equations with a singular potential term on manifolds with corner singularities.Firstly,we introduce the corner type weighted p-Sobolev spaces and the weighted corner type Sobolev inequality,the Poincare′inequality,and the Hardy inequality.Then,by using the potential well method and the inequality mentioned above,we obtain an existence theorem of global solutions with exponential decay and show the blow-up in finite time of solutions for both cases with low initial energy and critical initial energy.Significantly,the relation between the above two phenomena is derived as a sharp condition.Moreover,we show that the global existence also holds for the case of a potential well family. 相似文献
8.
Nonlinear Dynamics - Epilepsy is the second largest neurological disease which seriously threatens human life and health. The one important reason of inducing epileptic seizures is ischemic stroke... 相似文献
9.
10.
Richiro Ushimaru Zhang Chen Houyuan Zhao Po-hsun Fan Prof. Dr. Hung-wen Liu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(9):3586-3590
Albomycin δ2 is a sulfur-containing sideromycin natural product that shows potent antibacterial activity against clinically important pathogens. The l -serine-thioheptose dipeptide partial structure, known as SB-217452, has been found to be the active seryl-tRNA synthetase inhibitor component of albomycin δ2. Herein, it is demonstrated that AbmF catalyzes condensation between the 6′-amino-4′-thionucleoside with the d -ribo configuration and seryl-adenylate supplied by the serine adenylation activity of AbmK. Formation of the dipeptide is followed by C3′-epimerization to produce SB-217452 with the d -xylo configuration, which is catalyzed by the radical S-adenosyl-l -methionine enzyme AbmJ. Gene deletion suggests that AbmC is involved in peptide assembly linking SB-217452 with the siderophore moiety. This study establishes how the albomycin biosynthetic machinery generates its antimicrobial component SB-217452. 相似文献