全文获取类型
收费全文 | 327篇 |
免费 | 9篇 |
国内免费 | 2篇 |
专业分类
化学 | 274篇 |
晶体学 | 2篇 |
力学 | 2篇 |
数学 | 11篇 |
物理学 | 40篇 |
无线电 | 9篇 |
出版年
2023年 | 2篇 |
2022年 | 6篇 |
2021年 | 10篇 |
2020年 | 5篇 |
2019年 | 9篇 |
2018年 | 6篇 |
2017年 | 2篇 |
2016年 | 5篇 |
2015年 | 3篇 |
2014年 | 8篇 |
2013年 | 16篇 |
2012年 | 15篇 |
2011年 | 27篇 |
2010年 | 11篇 |
2009年 | 6篇 |
2008年 | 17篇 |
2007年 | 26篇 |
2006年 | 29篇 |
2005年 | 30篇 |
2004年 | 24篇 |
2003年 | 22篇 |
2002年 | 6篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1994年 | 5篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1975年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1960年 | 1篇 |
1959年 | 1篇 |
1958年 | 2篇 |
排序方式: 共有338条查询结果,搜索用时 10 毫秒
201.
202.
A FORMULA FOR THE FUNDAMENTAL SOLUTION OF ANISOTROPIC ELASTICITY 总被引:1,自引:0,他引:1
NAKAMURA G.; TANUMA K. 《The Quarterly Journal of Mechanics and Applied Mathematics》1997,50(2):179-194
203.
Jiro Motoyoshiya Kazuya Yokota Takuro Fukami Shoji Konno Aya Yamamoto Masanori Hotta Ryu Koike Sachiko Yoshioka Yoshinori Nishi Hiromu Aoyama 《Journal of heterocyclic chemistry》2005,42(6):1063-1068
A series of 4‐styrylphthalhydrazides were synthesized and their chemiluminescence reactions were investigated. The chemiluminescence quantum yields as well as the emitters were variable depending on the electronic nature of the terminal substituents attached on the styryl groups. It was revealed that the excited phtha‐late ions were the emitters when they were highly fluorescent, while the energy transfer chemiluminescence from the excited phthalate ions to the phthalhydrazide anions took place when the fluorescence of the corresponding phthalate ions were very weakly fluorescent. 相似文献
204.
205.
206.
Jie Xu Shunichi Miyamoto Sachiko Tojo Prof. Dr. Kiyohiko Kawai 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(22):5075-5084
Controlling the conformation and function of biomolecules through photoregulators holds great promise as a spatiotemporally controllable tool for disease control. In addition, introducing photoregulators into biomolecules has also found applications in constructing smart nanomaterials. In spite of the astonishing advances that have been made in the past few years, realizing highly controllable and efficient regulation over the conformation and function of biomolecules under physiological conditions is still challenging. Herein, sulfonated pyrene SPy was synthesized and used as a photoregulator to control the looping of single-stranded DNAs (ssDNAs) in aqueous solution. Due to its water solubility, SPy merits use in the study of biomolecules in aqueous solution. The looping of the doubly SPy -modified ssDNAs is stimulated by irradiation and regulated by SPy . Photoionization generates the radical cation of SPy ( SPy .+). The association of SPy . + with its neutral counterpart, SPy , gives rise to the dimer radical cation of SPy ( SPy2 . + ). During the association process, the stabilization energy released to form SPy2 . + provides a driving force for the looping of ssDNAs. Conversely, the formed loop conformations were trapped by the formation of SPy2 . + , and this allowed the looping dynamics to be investigated. The results reported herein suggest potential of SPy as a photoregulator for controlling the conformation and function of biomolecules under physiological conditions. 相似文献
207.
Kisho Mori Mitsuhiro Hirase Takahiro Morishige Eri Takano Hirobumi Sunayama Yukiya Kitayama Sachiko Inubushi Ryohei Sasaki Masakazu Yashiro Toshifumi Takeuchi 《Angewandte Chemie (International ed. in English)》2019,58(6):1612-1615
Exosomes are small (30–100 nm) membrane vesicles that serve as regulatory agents for intercellular communication in cancers. Currently, exosomes are detected by immuno‐based assays with appropriate pretreatments like ultracentrifugation and are time consuming (>12 h). We present a novel pretreatment‐free fluorescence‐based sensing platform for intact exosomes, wherein exchangeable antibodies and fluorescent reporter molecules were aligned inside exosome‐binding cavities. Such antibody‐containing fluorescent reporter‐grafted nanocavities were prepared on a substrate by well‐designed molecular imprinting and post‐imprinting modifications to introduce antibodies and fluorescent reporter molecules only inside the binding nanocavities, enabling sufficiently high sensitivity to detect intact exosomes without pretreatment. The effectiveness of the system was demonstrated by using it to discriminate between normal exosomes and those originating from prostate cancer and analyze exosomes in tear drops. 相似文献
208.
Yamashita M Inaba T Nagahama M Shimizu T Kosaka S Kawasaki I Ohta S 《Organic & biomolecular chemistry》2005,3(12):2296-2304
1,2a-Disubstituted 1,2,2a,8b-tetrahydro-3H-benzo[b]cyclobuta[d]pyran-3-ones bearing an electron-withdrawing group at the 2a-position were treated with two equivalents of dimethylsulfoxonium methylide to give r-1,t-4a,t-9b-1,3-disubstituted 1,2,4a,9b-tetrahydrodibenzofuran-4-ols stereoconvergently regardless of the stereochemistry of the 1-position on the benzocyclobutapyran ring. This methodology was applied to the second-generation synthesis of (+/-)-linderol A, a melanin biosynthesis inhibitory natural product. 相似文献
209.
Tachikawa T Tojo S Fujitsuka M Majima T 《The journal of physical chemistry. B》2005,109(37):17460-17466
The influence of hydroxypropyl-beta-cyclodextrin (HP-beta-CD) on the one-electron oxidation reaction of aromatic sulfides (S) with Br2*- and the decay process of the S radical cation (S*+) was investigated by pulse radiolysis. The dissociation kinetics of S*+ from the CD cavity was examined in terms of the apparent equilibrium constants (Kapp) for the formation and decay processes of S*+. Inhibition of the one-electron oxidation reaction of S by Br2*- was clearly observed in the presence of HP-beta-CD. On the basis of a comparison between the determined Kapp values, it was found that the binding ability of S*+ with HP-beta-CD is much lower than that of S, because of the hydrophobic nature of the cavity. The formation process of the dimer radical cation of 4-(methylthio)phenylmethanol ((MTPM)2*+), which is generated between MTPM(*+) and neutral MTPM in solution, was also inhibited by the addition of HP-beta-CD. 相似文献
210.
Kabashima S Tanaka S Kageyama M Yoshikawa I Araki K 《Langmuir : the ACS journal of surfaces and colloids》2011,27(14):8950-8955
Sulfamide derivatives showed high ability to form hydrogen-bond-directed two-dimensional (2-D) sheet assemblies of nanometer thickness. Further, fine-tuning of the side chain structures and preparation conditions allowed for the formation of micrometer-sized giant vesicles of 4b in water by the simple injection method. IR and XRD studies indicated that 4b having tetradecyl and oxyethylene-terminated alkyl side chains formed hydrogen-bond-directed 2-D nanosheet pairs. SEM, AFM, and TEM observation of the dried vesicles revealed that the vesicle membrane was composed of several lamellar-stacked layers of 2-D nanosheets and showed a characteristic patchwork-like pattern on the surface. 相似文献