全文获取类型
收费全文 | 15121篇 |
免费 | 2808篇 |
国内免费 | 2178篇 |
专业分类
化学 | 12252篇 |
晶体学 | 142篇 |
力学 | 771篇 |
综合类 | 168篇 |
数学 | 1763篇 |
物理学 | 5011篇 |
出版年
2024年 | 15篇 |
2023年 | 320篇 |
2022年 | 328篇 |
2021年 | 454篇 |
2020年 | 710篇 |
2019年 | 761篇 |
2018年 | 549篇 |
2017年 | 462篇 |
2016年 | 790篇 |
2015年 | 803篇 |
2014年 | 926篇 |
2013年 | 1119篇 |
2012年 | 1361篇 |
2011年 | 1369篇 |
2010年 | 1006篇 |
2009年 | 928篇 |
2008年 | 1025篇 |
2007年 | 897篇 |
2006年 | 808篇 |
2005年 | 731篇 |
2004年 | 623篇 |
2003年 | 621篇 |
2002年 | 727篇 |
2001年 | 682篇 |
2000年 | 410篇 |
1999年 | 353篇 |
1998年 | 217篇 |
1997年 | 177篇 |
1996年 | 142篇 |
1995年 | 136篇 |
1994年 | 94篇 |
1993年 | 86篇 |
1992年 | 89篇 |
1991年 | 96篇 |
1990年 | 73篇 |
1989年 | 40篇 |
1988年 | 35篇 |
1987年 | 21篇 |
1986年 | 23篇 |
1985年 | 22篇 |
1984年 | 16篇 |
1983年 | 6篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1973年 | 4篇 |
1969年 | 4篇 |
1968年 | 7篇 |
1967年 | 3篇 |
1966年 | 5篇 |
1936年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 201 毫秒
1.
Journal of Algebraic Combinatorics - APR tilts for path algebra kQ can be realized as the mutation of the quiver Q in $${\mathbb Z}Q$$ with respect to the translation. In this paper, we show that... 相似文献
2.
Hu Duo-Duo Gao Qian Dai Jing-Cheng Cui Ru Li Yuan-Bo Li Yuan-Ming Zhou Xiao-Guo Bian Kang-Jie Wu Bing-Bing Zhang Kai-Fan Wang Xi-Sheng Li Yan 《中国科学:化学(英文版)》2022,65(4):753-761
Science China Chemistry - A light-induced, nickel-catalyzed three-component arylsulfonation of 1,3-enynes in the absence of photocatalyst is reported. This methodology exhibited mild conditions,... 相似文献
3.
Given a graph sequence denote by T3(Gn) the number of monochromatic triangles in a uniformly random coloring of the vertices of Gn with colors. In this paper we prove a central limit theorem (CLT) for T3(Gn) with explicit error rates, using a quantitative version of the martingale CLT. We then relate this error term to the well-known fourth-moment phenomenon, which, interestingly, holds only when the number of colors satisfies . We also show that the convergence of the fourth moment is necessary to obtain a Gaussian limit for any , which, together with the above result, implies that the fourth-moment condition characterizes the limiting normal distribution of T3(Gn), whenever . Finally, to illustrate the promise of our approach, we include an alternative proof of the CLT for the number of monochromatic edges, which provides quantitative rates for the results obtained in [7]. 相似文献
4.
Xinghuo Xiao Wenyan Wang Jiali Wang Prof. Can Yang Prof. Guigang Zhang Prof. Xianjun Lang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(52):e202201244
Conjugated polymers feature promising structure and properties for photocatalytic water splitting. Herein, a hydrolysis strategy was demonstrated to rationally modulate the surface hydrophilicity and band structures of conjugated poly-benzothiadiazoles. High hydrophilicity not only enhances the dispersions of polymeric solids in an aqueous solution but also reduces the absorption energy of water molecules. Besides, both theoretical and experimental results reveal that a more positive valence band potential is generated, which contributes to enhancing the photocatalytic water oxidation performance. Accordingly, the surface-modified conjugated polymers show largely promoted photocatalytic water oxidation activities by deposition of cobalt oxides as cocatalysts. 相似文献
5.
The carbon composite materials have been a research hotspot in the fields of catalysis, energy conversion and so on, because of their features of large structure and morphology variety, good chemical and electrochemical stability, and high electronic conductivity, large specific surface area and rich active sites. This paper summarizes some research progress of carbon composite materials, including assembly methodologies, their structure regulation, properties, and related applications. Moreover, the current challenges and the prospects of these materials are also discussed. 相似文献
6.
7.
8.
Bioelectrochemical dioxygen reduction reaction (ORR) catalyzed by multi-copper oxidases (MCOs) is a process of paramount importance occurring at the cathode of enzymatic biofuel cells (EBFCs), which is an energy harvester that holds promise of self-sustained implantable and wearable medical devices. The MCO biocathode is, however, frequently the limiting factor of a working EBFC. Besides the operational stability issue, enzymatic biocathodes are largely constrained by the relatively low solubility of dioxygen in aqueous solution. As an emerging topic, we here review the introduction of dioxygen-enriching materials to the cathodic bioelectrode for overcoming the dioxygen supply limitation, leading to improved ORR performance. 相似文献
9.
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
10.
Journal of Global Optimization - In this paper, we propose a novel algorithm that is based on quadratic-piecewise-linear approximations of DC functions to solve nonnegative sparsity-constrained... 相似文献