全文获取类型
收费全文 | 142276篇 |
免费 | 33687篇 |
国内免费 | 10087篇 |
专业分类
化学 | 119677篇 |
晶体学 | 1264篇 |
力学 | 8838篇 |
综合类 | 534篇 |
数学 | 14531篇 |
物理学 | 41206篇 |
出版年
2024年 | 359篇 |
2023年 | 5290篇 |
2022年 | 4297篇 |
2021年 | 5892篇 |
2020年 | 8123篇 |
2019年 | 6136篇 |
2018年 | 5325篇 |
2017年 | 3661篇 |
2016年 | 9969篇 |
2015年 | 9658篇 |
2014年 | 10230篇 |
2013年 | 12167篇 |
2012年 | 12115篇 |
2011年 | 10691篇 |
2010年 | 9566篇 |
2009年 | 9304篇 |
2008年 | 7492篇 |
2007年 | 6703篇 |
2006年 | 5568篇 |
2005年 | 4658篇 |
2004年 | 3446篇 |
2003年 | 2706篇 |
2002年 | 2446篇 |
2001年 | 2018篇 |
2000年 | 1781篇 |
1999年 | 2097篇 |
1998年 | 1868篇 |
1997年 | 1802篇 |
1996年 | 1964篇 |
1995年 | 1635篇 |
1994年 | 1542篇 |
1993年 | 1374篇 |
1992年 | 1166篇 |
1991年 | 1050篇 |
1990年 | 846篇 |
1989年 | 638篇 |
1988年 | 577篇 |
1987年 | 480篇 |
1986年 | 453篇 |
1985年 | 414篇 |
1984年 | 346篇 |
1977年 | 337篇 |
1976年 | 397篇 |
1975年 | 488篇 |
1974年 | 516篇 |
1972年 | 387篇 |
1971年 | 375篇 |
1970年 | 554篇 |
1969年 | 437篇 |
1968年 | 466篇 |
排序方式: 共有10000条查询结果,搜索用时 250 毫秒
141.
Jia Tian-Cong Guo Jin-Tao Wang Zhen Zhu Xiao-Shan Zhang Qian-Xin Chen Ping Yao Kun Lv Wen-Ying Liu Guo-Guang 《Journal of Radioanalytical and Nuclear Chemistry》2019,321(3):823-829
Journal of Radioanalytical and Nuclear Chemistry - In the present work the final products of coumarin radiation chemical transformation are investigated by chromatography. During radiolysis of... 相似文献
142.
Particularly-shaped silver nanostructures are successfully applied in many scientific fields, such as nanotechnology, catalysis, (nano)engineering, optoelectronics, and sensing. In recent years, the production of shape-controlled silver-based nanostructures and the knowledge around this topic has grown significantly. Hence, on the basis of the most recent results reported in the literature, a critical analysis around the driving forces behind the synthesis of such nanostructures are proposed herein, pointing out the important role of surface-regulating agents in driving crystalline growth by favoring (or opposing) development along specific directions. Additionally, growth mechanisms of the different morphologies considered here are discussed in depth, and critical points highlighted. 相似文献
143.
Journal of Thermal Analysis and Calorimetry - The fire behavior of one flame-retardant PVC cable used as building wire is investigated in this work. Bench scale tests were performed using a cone... 相似文献
144.
145.
Back Cover: Reactions of Group 4 Metallocenes with Monosubstituted Acetonitriles: Keteniminate Formation versus CC Coupling (Chem. Eur. J. 8/2015)
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)
146.
147.
148.
Prof. Dr. Francisco Melo Leonardo Caballero Esteban Zamorano Natalia Ventura Camilo Navarro Irving Doll Prof. Dr. Pedro Zamorano Prof. Dr. Alberto Cornejo 《Chemphyschem》2021,22(6):526-532
Parkinson's disease is a neurodegenerative disorder involving a functional protein, α-synuclein, whose primary function is related to vesicle trafficking. However, α-synuclein is prone to form aggregates, and these inclusions, known as Lewy bodies, are the hallmark of Parkinson's disease. α-synuclein can alter its conformation and acquire aggregating capacity, forming aggregates containing β-sheets. This protein's pathogenic importance is based on its ability to form oligomers that impair synaptic transmission and neuronal function by increasing membrane permeability and altering homeostasis, generating a deleterious effect over cells. First, we establish that oligomers interfere with the mechanical properties of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) membrane, as demonstrated by nanoindentation curves. In contrast, nanoindentation revealed that the α-synuclein monomer's presence leads to a much more resistant lipid bilayer. Moreover, the oligomers’ interaction with cell membranes can promote lactate dehydrogenase (LDH) release, suggesting the activation of cytotoxic events. 相似文献
149.
Dr. Carla Carrera Dr. Eleonora Cavallari Dr. Giuseppe Digilio Dr. Oksana Bondar Prof. Silvio Aime Dr. Francesca Reineri 《Chemphyschem》2021,22(11):1042-1048
An efficient synthesis of vinyl-[1-13C]pyruvate has been reported, from which 13C hyperpolarized (HP) ethyl-[1-13C]pyruvate has been obtained by means of ParaHydrogen Induced Polarization (PHIP). Due to the intrinsic lability of pyruvate, which leads quickly to degradation of the reaction mixture even under mild reaction conditions, the vinyl-ester has been synthesized through the intermediacy of a more stable ketal derivative. 13C and 1H hyperpolarizations of ethyl-[1-13C]pyruvate, hydrogenated using ParaHydrogen, have been compared to those observed on the more widely used allyl-derivative. It has been demonstrated that the spin order transfer from ParaHydrogen protons to 13C, is more efficient on the ethyl than on the allyl-esterdue to the larger J-couplings involved. The main requirements needed for the biological application of this HP product have been met, i. e. an aqueous solution of the product at high concentration (40 mM) with a good 13C polarization level (4.8 %) has been obtained. The in vitro metabolic transformation of the HP ethyl-[1-13C]pyruvate, catalyzed by an esterase, has been observed. This substrate appears to be a good candidate for in vivo metabolic investigations using PHIP hyperpolarized probes. 相似文献
150.
Wang Yingying Wang Donghui Shu Weiqing Sha Jingquan Zhang Haifeng 《Transition Metal Chemistry》2020,45(4):245-251
Transition Metal Chemistry - Two cubane-like complexes, namely [Ni4L4(HOEt)4] (1), [Co4L4(HOEt)4] (2) (H2L?=?(E)-2-((3-hydroxypropylimino)methyl)-6-methoxyphenol), were prepared under... 相似文献