全文获取类型
收费全文 | 1209篇 |
免费 | 44篇 |
国内免费 | 6篇 |
专业分类
化学 | 958篇 |
晶体学 | 14篇 |
力学 | 9篇 |
数学 | 74篇 |
物理学 | 204篇 |
出版年
2023年 | 6篇 |
2021年 | 7篇 |
2020年 | 21篇 |
2019年 | 26篇 |
2018年 | 13篇 |
2017年 | 5篇 |
2016年 | 20篇 |
2015年 | 22篇 |
2014年 | 33篇 |
2013年 | 53篇 |
2012年 | 62篇 |
2011年 | 70篇 |
2010年 | 40篇 |
2009年 | 50篇 |
2008年 | 98篇 |
2007年 | 61篇 |
2006年 | 71篇 |
2005年 | 74篇 |
2004年 | 82篇 |
2003年 | 57篇 |
2002年 | 54篇 |
2001年 | 32篇 |
2000年 | 25篇 |
1999年 | 7篇 |
1998年 | 14篇 |
1997年 | 8篇 |
1996年 | 14篇 |
1995年 | 13篇 |
1994年 | 14篇 |
1993年 | 9篇 |
1992年 | 17篇 |
1991年 | 11篇 |
1990年 | 8篇 |
1989年 | 10篇 |
1988年 | 8篇 |
1987年 | 7篇 |
1986年 | 16篇 |
1985年 | 13篇 |
1984年 | 9篇 |
1982年 | 9篇 |
1981年 | 7篇 |
1980年 | 4篇 |
1979年 | 10篇 |
1978年 | 5篇 |
1977年 | 8篇 |
1976年 | 8篇 |
1975年 | 7篇 |
1974年 | 6篇 |
1973年 | 4篇 |
1927年 | 7篇 |
排序方式: 共有1259条查询结果,搜索用时 15 毫秒
991.
Dr. Naohiro Kameta Dr. Haruhisa Akiyama Dr. Mitsutoshi Masuda Dr. Toshimi Shimizu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(21):7198-7205
Self‐assembly of azobenzene‐modified amphiphiles (GlynAzo, n=1–3) in water at room temperature in the presence of a protein produced nanotubes with the protein encapsulated in the channels. The Gly2Azo nanotubes (7 nm internal diameter [i.d.]) promoted refolding of some encapsulated proteins, whereas the Gly3Azo nanotubes (13 nm i.d.) promoted protein aggregation. Although the 20 nm i.d. channels of the Gly1Azo nanotubes were too large to influence the encapsulated proteins, narrowing of the i.d. to 1 nm by trans‐to‐cis photoisomerization of the azobenzene units of the Gly1Azo monomers packed in the solid bilayer membranes led to a squeezing out of the proteins into the bulk solution and simultaneously enhanced their refolding ratios. In contrast, photoinduced transformation of the Gly2Azo nanotubes to short nanorings (<40 nm) with a large i.d. (28 nm) provided no further refolding assistance. We thus demonstrate that pertubation by the solid bilayer membrane wall of the nanotubes is important to accelerate refolding of the denatured proteins during their transport in the narrow nanotube channels. 相似文献
992.
Takayoshi Tsuzuki Natsumi Sakaguchi Takashi Kudoh Satoshi Takano Masato Uehara Takashi Murayama Takashi Sakurai Minako Hashii Haruhiro Higashida Karin Weber Andreas H. Guse Tomoshi Kameda Takatsugu Hirokawa Yasuhiro Kumaki Barry V. L. Potter Hayato Fukuda Mitsuhiro Arisawa Satoshi Shuto 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2013,125(26):6765-6769
993.
Daisuke Ogasawara Dr. Yukihiro Itoh Dr. Hiroki Tsumoto Dr. Taeko Kakizawa Dr. Koshiki Mino Dr. Kiyoshi Fukuhara Prof. Hidehiko Nakagawa Dr. Makoto Hasegawa Dr. Ryuzo Sasaki Prof. Tamio Mizukami Prof. Naoki Miyata Prof. Takayoshi Suzuki 《Angewandte Chemie (International ed. in English)》2013,52(33):8620-8624
994.
Yoshihiro Hayashiuchi Takeshi Hagihara Yusuke Kojima Takayoshi Yamamoto Sigehiro Owaki Toichi Okada 《辐射效应与固体损伤》2013,168(2):645-650
Abstract Deformation Luminescence(DL) is studied on KCl crystal colored by γ-irradiation. The spectra analysis of DL and thermoluminescence reveals that F-center plays a role as electron donor through the interaction with moving dislocation and V2-center is a probable luminescence center. A theory is presented for understanding the deformation rate and temperature dependences of DL intensity. 相似文献
995.
Ryoji Mitsuhashi Yuya Imai Takayoshi Suzuki Yoshihito Hayashi 《Molecules (Basel, Switzerland)》2022,27(7)
Three palladium(II) complexes with amino-amidato-phenolato-type tridentate ligands were synthesized and characterized by 1H NMR spectroscopy and X-ray crystallography. The strategic arrangement of a hydrogen-bond donor and acceptor adjacent to the substitution site of the PdII complex allowed the selective coordination of nucleosides. Among two pyrimidine-nucleosides, cytidine and 5-methyluridine, cytidine was successfully coordinated to the PdII complex while 5-methyluridne was not. On the other hand, both purine-nucleosides, adenosine and guanosine, were coordinated to the PdII complex. As purines have several coordination sites, adenosine afforded three kinds of coordination isomers expected from the three different donors. However, guanosine afforded a sole product according to the ligand design such that the formation of double intramolecular hydrogen-bond strongly induced the specific coordination by N1-position of guanine moiety. Furthermore, the preference of the nucleosides was evaluated by scrambling reactions. It was found that the preference of guanosine is nearly twice as high as adenosine and cytidine, owing to the three-point interaction of a coordination bond and two hydrogen bonds. These results show that the combination of a coordination and hydrogen bonds, which is reminiscent of the Watson–Crick base pairing, is an effective tool for the precise recognition of nucleosides. 相似文献
996.
In the polyomino puzzle, the aim is to fill a finite space using several polyomino pieces with no overlaps or blanks. Because it is an NP-complete combinatorial optimization problem, various probabilistic and approximated approaches have been applied to find solutions. Several previous studies embedded the polyomino puzzle in a QUBO problem, where the original objective function and constraints are transformed into the Hamiltonian function of the simulated Ising model. A solution to the puzzle is obtained by searching for a ground state of Hamiltonian by simulating the dynamics of the multiple-spin system. However, previous methods could solve only tiny polyomino puzzles considering a few combinations because their Hamiltonian designs were not efficient. We propose an improved Hamiltonian design that introduces new constraints and guiding terms to weakly encourage favorable spins and pairs in the early stages of computation. The proposed model solves the pentomino puzzle represented by approximately 2000 spins with >90% probability. Additionally, we extended the method to a generalized problem where each polyomino piece could be used zero or more times and solved it with approximately 100% probability. The proposed method also appeared to be effective for the 3D polycube puzzle, which is similar to applications in fragment-based drug discovery. 相似文献
997.
Ken Sakai Mai Kurashima Norinobu Akiyama Naoki Satoh Takashi Kajiwara Tasuku Ito 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(9):m345-m349
In the title compound, [Pt2(C5H10NO)2(C12H8N2)2](NO3)2·2H2O, the intradimer Pt—Pt distance is relatively short [2.8489 (17) Å], which must be due to the strong intramolecular π–π‐stacking interactions between the phenanthroline moieties. The dimers stack along the c axis, forming one‐dimensional columns in which very intriguing d–d, π–π and d–π interactions exist. Although the dimer–dimer Pt...Pt distances are very long [4.340 (2) and 4.231 (2) Å], some short interdimer Pt...C contacts leading to strong interdimer associations are found [3.325 (19) and 3.402 (19) Å]. 相似文献
998.
Keisuke Seto Hiromu Yamada Takayoshi Kobayashi Eiji Tokunaga 《Annalen der Physik》2020,532(9):2000241
Absorption spectroscopy, coupled with photothermal super-resolution microscopy, is enabled by the frequency division multiplexing of the pump-light (Pu) wavelength whose spectral component is discriminated by the modulation frequency. This demonstrates a great advantage in availing multicolor image information. However, the response gain of the thermal lens signal to the spectral components is not uniform because of the limited relaxation rate of the thermal lens, i.e., the gains of the components assigned to the high-frequency modulations are diminished, thus resulting in a distorted absorption spectrum. In this study, white-pump light (Pu) is multiplexed by pseudonoise sequences (PNSs) to avoid the distortion. The frequency bandwidth of the PNSs is equalized, and the gains of the thermal lens generation to the respective wavelength components are balanced. The obtained results indicate that the modulation-waveform deformation due to the slow responses of the sample can also distort spectra. To mitigate the problem, the countermeasures required to compensate for this distortion are also discussed. 相似文献
999.
1000.
The interesterification of olive oil with palmitic acid catalyzed by Rhizopus delemar lipase was investigated in phospholipid microemulsion systems. Soybean lecithin was used as the amphiphilic component. The maximal reaction rate was obtained at a buffer pH of 5.5–6.0. The reaction rate was also dependent on the WL (= [H2O]/[lecithin]) value and attained a maximum at WL = 5. The reaction rate reached a maximum at a palmitic acid concentration of 350 mM. The molar fraction of the interesterified product 1,3-dipalmitoyl-3-oleoyl glycerol (POP) in the olive oil was enhanced from 2.8 to 65.6 mol% after 24 h of the reaction. 相似文献