全文获取类型
收费全文 | 1142篇 |
免费 | 289篇 |
国内免费 | 55篇 |
专业分类
化学 | 1346篇 |
晶体学 | 1篇 |
力学 | 10篇 |
数学 | 1篇 |
物理学 | 128篇 |
出版年
2023年 | 11篇 |
2022年 | 25篇 |
2021年 | 58篇 |
2020年 | 136篇 |
2019年 | 77篇 |
2018年 | 55篇 |
2017年 | 51篇 |
2016年 | 92篇 |
2015年 | 91篇 |
2014年 | 99篇 |
2013年 | 89篇 |
2012年 | 86篇 |
2011年 | 88篇 |
2010年 | 81篇 |
2009年 | 72篇 |
2008年 | 73篇 |
2007年 | 54篇 |
2006年 | 45篇 |
2005年 | 39篇 |
2004年 | 38篇 |
2003年 | 29篇 |
2002年 | 15篇 |
2001年 | 11篇 |
2000年 | 7篇 |
1999年 | 1篇 |
1998年 | 6篇 |
1997年 | 9篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 7篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
排序方式: 共有1486条查询结果,搜索用时 15 毫秒
91.
92.
Wen Piao Satoru Tsuda Dr. Yuji Tanaka Dr. Satoshi Maeda Dr. Fengyi Liu Shodai Takahashi Yu Kushida Dr. Toru Komatsu Dr. Tasuku Ueno Dr. Takuya Terai Prof. Toru Nakazawa Prof. Masanobu Uchiyama Prof. Keiji Morokuma Prof. Tetsuo Nagano Dr. Kenjiro Hanaoka 《Angewandte Chemie (International ed. in English)》2013,52(49):13028-13032
93.
Dr. Vincenzo Grande Dr. Filippo Doria Prof. Dr. Mauro Freccero Prof. Dr. Frank Würthner 《Angewandte Chemie (International ed. in English)》2017,56(26):7520-7524
G-quadruplexes (G4s) are peculiar DNA or RNA tertiary structures that are involved in the regulation of many biological events within mammalian cells, bacteria, and viruses. Although their role as versatile therapeutic targets has been emphasized for 35 years, G4 selectivity over ubiquitous double-stranded DNA/RNA, as well as G4 differentiation by small molecules, still remains challenging. Here, a new amphiphilic dicyanovinyl-substituted squaraine, SQgl , is reported to act as an NIR fluorescent light-up probe discriminating an extensive panel of parallel G4s while it is non-fluorescent in the aggregated state. The squaraine can form an unconventional sandwich π-complex binding two quadruplexes, which leads to a strongly fluorescent (ΦF=0.61) supramolecular architecture. SQgl is highly selective against non-quadruplex and non-parallel G4 sequences without altering their topology, as desired for applications in selective in vivo high-resolution imaging and theranostics. 相似文献
94.
In this paper, a kind of β-amyloid peptide (Aβ1-16) conjugated gold nanoparticles (Aβ1-16@GNPs) are prepared and employed as colorimetric indicator for studying the interaction of β-amyloid peptide with metallic ions (e.g. Zn2+ and Ca2+). In the presence of Zn2+, mono-dispersing Aβ1-16@GNPs enable to form aggregates or attach on the SHG-44 (human glioma cell) cellular surface which results in significant color change of the solution. The experimental results indicate that Zn2+ can interact with Aβ1-16 and form Zn2+-β-amyloid peptide complexes. In particular, in the presence of Zn2+, a time-dependent interaction of cells with Aβ1-16@GNPs has been observed that may suggest different expression levels of β-amyloid peptide related proteins in various cell cycles. In addition, the aggregating/binding process can be easily reversed by adding EDTA, a good chelated ligand of Zn2+, which gives further proof of the interaction mechanism. 相似文献
95.
96.
Rational Design of an Ultrasensitive and Highly Selective Chemodosimeter by a Dual Quenching Mechanism for Cysteine Based on a Facile Michael‐Transcyclization Cascade Reaction 下载免费PDF全文
Xiangmin Li Yongjun Zheng Hongjuan Tong Rui Qian Dr. Lin Zhou Prof. Dr. Guixia Liu Prof. Dr. Yun Tang Prof. Dr. Hao Li Prof. Dr. Kaiyan Lou Prof. Dr. Wei Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(27):9247-9256
Differentiation of biologically important thiols, such as cysteine (Cys), homocysteine (Hcy), and glutathione (GSH) is still a challenging task. Herein, we present a novel fluorescent chemodosimeter capable of selectively detecting Cys over other biothiols including Hcy and GSH and other amino acids by a facile thiol‐Michael addition/transcyclization rearrangement cascade click process. The unique transcyclization step is critical for the selectivity as a result of the kinetically favorable formation of a six‐membered ring with the Cys Michael adduct. Moreover, the probe adopts a distinctive dual quenching mechanism—photoinduced electron transfer (PET) and photoinduced intramolecular charge transfer (ICT) to deliver a drastic turn‐on fluorescence response only at the Cys‐selective transcylization step. The judicious selection of strong electron‐withdrawing naphthalimide fluorophore with maleimide group enhances the electrophilicity and thus reactivity for the cascade process leading to fast detection and ultrasensitivity with a detection limit of 2.0 nm (S/N=3). The probe has demonstrated its practical utility potential in Cys imaging in live cells. 相似文献
97.
98.
99.
Novel probes represented connection of pyrene as chromophore and sterically hindered amine stabilizers (HAS) in the form of esters of 2-(1-pyrenyl)acrylic acid were synthesized. HAS was in the form of parent amine (PAP) as well as stable nitroxyl radical form (PAP-NO.). Photophysics of these probes were compared with their precursor as 2-(1-pyrenyl)acrylic acid (PAA) and its methyl ester (PAM). The fluorescence spectrum of PAA strongly depends on the acidity of the solution. The spectrum in neutral methanol indicates that it originates from the anionic form –COO−. Changes of acidity or basicity of methanol solution resulted in the changes of shape, position as well as the intensity of fluorescence band. This is due to the presence of protolytic equilibria, either in the ground state or in the singlet excited state, leading to the formation of molecular form –COOH and the cationic form –COOH2+. The ester analogues did not show any changes in various pH conditions. Fluorescence of all probes depends on the polarity of solvents and the presence of oxygen. Intermolecular quenching was studied with external quenchers TEMPO and oxygen and the data were compared with the intramolecular quenching using 1′-oxo-2′,2′,6′,6′-tetramethyl-4′-piperidinyl-2-(1-pyrenyl)acrylate (PAP-NO.). 相似文献
100.
Doezé RH Maltman BA Egan CL Ulijn RV Flitsch SL 《Angewandte Chemie (International ed. in English)》2004,43(24):3138-3141