全文获取类型
收费全文 | 813篇 |
免费 | 7篇 |
国内免费 | 9篇 |
专业分类
化学 | 538篇 |
晶体学 | 14篇 |
力学 | 7篇 |
数学 | 26篇 |
物理学 | 244篇 |
出版年
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 5篇 |
2019年 | 7篇 |
2018年 | 4篇 |
2016年 | 6篇 |
2015年 | 7篇 |
2014年 | 11篇 |
2013年 | 31篇 |
2012年 | 35篇 |
2011年 | 45篇 |
2010年 | 20篇 |
2009年 | 21篇 |
2008年 | 44篇 |
2007年 | 68篇 |
2006年 | 58篇 |
2005年 | 67篇 |
2004年 | 60篇 |
2003年 | 47篇 |
2002年 | 49篇 |
2001年 | 11篇 |
2000年 | 9篇 |
1999年 | 9篇 |
1998年 | 9篇 |
1997年 | 13篇 |
1996年 | 5篇 |
1995年 | 6篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1991年 | 10篇 |
1990年 | 6篇 |
1989年 | 11篇 |
1988年 | 5篇 |
1987年 | 10篇 |
1986年 | 5篇 |
1985年 | 10篇 |
1984年 | 12篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1981年 | 4篇 |
1980年 | 8篇 |
1979年 | 8篇 |
1978年 | 13篇 |
1977年 | 6篇 |
1976年 | 3篇 |
1975年 | 5篇 |
1974年 | 6篇 |
1973年 | 12篇 |
1969年 | 3篇 |
1968年 | 3篇 |
排序方式: 共有829条查询结果,搜索用时 519 毫秒
81.
Asako Shimada Tomoko Haraga Akiko Hoshi Yutaka Kameo Mikio Nakashima Kuniaki Takahashi 《Journal of Radioanalytical and Nuclear Chemistry》2010,286(3):765-770
In order to analyze actinide elements in radioactive metal waste, the dissolution and chemical separation conditions were optimized. The surfaces of a type 304 stainless steel plate and of pipe waste sampled from the prototype advanced thermal reactor (Fugen) were dissolved in mixed acid solution (HNO3:HCl:H2O = 1:1:4). The resulting solution was evaporated to dryness and dissolved with 2 mol/dm3 of HNO3 to prepare sample solutions. In order to analyze trivalent actinide elements in the sample solution containing a large amount of Fe(III) (>0.1 g) using TRU resin, the effect of Fe(III) concentration on the recovery of Am(III) and reduction effect of Fe(III) to Fe(II) with ascorbic acid were studied. On the basis of results of this study, chemical separation scheme was constructed and Pu and Am in the sample solutions were separated. Thorium and U in the sample solutions were separated with UTEVA resin. High recoveries for all experimented elements were obtained from the analysis of spiked sample solutions, the effectiveness of the method was confirmed. 相似文献
82.
Vossen A Seidl R Adachi I Aihara H Aushev T Balagura V Bartel W Bischofberger M Bondar A Bračko M Browder TE Chang MC Chen A Chen P Cheon BG Cho K Choi Y Eidelman S Feindt M Gaur V Gabyshev N Garmash A Golob B Perdekamp MG Haba J Hayasaka K Horii Y Hoshi Y Hou WS Hyun HJ Inami K Ishikawa A Iwabuchi M Iwasaki Y Iwashita T Joshi NJ Kichimi H Kim HO Kim MJ Ko BR Kumita T Lange JS Lee MJ Lee SH Leitgab M Li Y Liu C Liventsev D Louvot R McOnie S Miyata H Miyazaki Y Mizuk R Mohanty GB Nakano E 《Physical review letters》2011,107(7):072004
The interference fragmentation function translates the fragmentation of a quark with a transverse projection of the spin into an azimuthal asymmetry of two final-state hadrons. In e(+)e(-) annihilation the product of two interference fragmentation functions is measured. We report nonzero asymmetries for pairs of charge-ordered π(+)π(-) pairs, which indicate a significant interference fragmentation function in this channel. The results are obtained from a 672 fb(-1) data sample that contains 711 × 10(6) π(+)π(-) pairs and was collected at and near the Υ(4S) resonance, with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. 相似文献
83.
84.
Toshihiko Ueki Matsumi Doe Yoshiki Morimoto Takamasa Kinoshita Rika Tanaka Kazuo Yoshihara 《Journal of heterocyclic chemistry》2001,38(1):165-172
Hyperolactones A ( 1 ) and C ( 3 ) have been synthesized starting from (S)‐malic acid by a straightforward route. The unique spirolactone skeleton was efficiently constructed by one‐pot reaction as a key step. The absolute stereochemistry of hyperolactones was unambiguously established by this synthesis. 相似文献
85.
H. Hoshi Y. -Z. Wei M. Kumagai T. Asakura Y. Morita 《Journal of Radioanalytical and Nuclear Chemistry》2005,262(3):601-605
Electroreduction of Tc(VII) was studied in nitric acid solution using glassy carbon electrode. The electroreduction was conducted at a constant potential –300 mV (vs. Ag/AgCl) with a potentiostat. It was found that the difference of the Tc concentration in the solutions before and after the electrolysis was negligibly small. This means that there were almost no TcO2 or Tc deposited on the carbon fiber electrode during the electroreduction. Absorption spectra and distribution coefficients obtained by ion-exchange analysis indicated that Tc(VII) was reduced to Tc(IV).This work was financed by the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT) under the framework of The Development of Innovative Nuclear Technologies. 相似文献
86.
Tomohiko Sato Toshihiko Nakaoka Makoto Kudo Yasuhiko Arakawa 《Physica E: Low-dimensional Systems and Nanostructures》2006,32(1-2):152
We have investigated magneto-optical properties of GaSb/GaAs self-assemble type II quantum dots by single dot spectroscopy in magnetic field. We have observed clear Zeeman splitting and diamagnetic shift of GaSb/GaAs quantum dots. The diamagnetic coefficient ranges from 5 to 30 μeV/T2. The large coefficient and their large distribution are attributed to the size inhomogeneity and electron localization outside the dot. The g-factor of GaSb/GaAs quantum dots is slightly larger than that of similar type I InGaAs/GaAs quantum dots. In addition, we find almost linear relationship between the diamagnetic coefficient and the g-factor. The linear increase of g-factor with diamagnetic coefficient is due to an increase of spin-orbit interaction with dot size. 相似文献
87.
Daisuke Adachi Kohei Takei Toshihiko Toyama Hiroaki Okamoto 《Applied Surface Science》2007,254(1):299-302
Effects of ZnS:Mn/AlN multilayer structure on luminescent properties of nanostructured (NS) thin-film electroluminescent (TFEL) device of which emission layer is a multilayer composed with ZnS:Mn layers and 0.7-nm-thick AlN interlayers were studied. The bandgap widening and the increased PL efficiency of Mn2+ 3d-3d transitions with a decrease in the ZnS:Mn single-layer thickness down to 5 nm were observed, which is ascribed to quantum confinement effects. Meanwhile, the multilayer with 2-nm-thick ZnS:Mn single-layers shows a drop of PL efficiency, indicating the presence of defective region just on AlN. The tendency of the luminous efficiency of the NS-TFEL device against the ZnS:Mn single-layer thickness is similar to the tendency found in the PL efficiency, indicating the importance of the ZnS:Mn/AlN interface for the device performance. 相似文献
88.
Yu Ding Ruggero Micheletto Hiroaki Hanada Toshihiko Nagamura Satoshi Okazaki Koji Otsuka 《Optical Review》2002,9(6):277-281
This work describes a groundbreaking process that provides a direct highly localized measurement of the atomic mass on surfaces at room temperature. Employing an original system that joins a scanning tunneling microscopy (STM) device and a time of flight (TOF) mass analyzer, we could previously ionize surface atoms by the combination of an optical laser pulse and an electric pulse at the STM tip. Desorbed ions from a localized area were accelerated and detected by a TOF chamber. We will demonstrate in this paper that high localization and mass discrimination can be obtained even without the aid of an electric pulse from the tip. We reduced the angle of incidence of the laser beam to zero (laser beam parallel to the sample surface). In this condition we were able to demonstrate for the first time ionic desorption at a confinement level of the order of 5-10nm, an order of magnitude better than previous configurations.This paper was originally presented at the 11th Optical Near Field Workshop, which was held on June 28, 2002 at Tokyo Institute of Technology, Yokohama, organized by the Optical Near Field Group of the Optical Society of Japan, an affiliate of the Japan Society of Applied Physics. 相似文献
89.
90.
Toshihiko Sakurai Maki Horikawa Makoto Takafuji Atsushi Kubo Hirotaka Ihara 《Applied Surface Science》2006,253(2):869-873
An l-glutamic acid-derived lipid with a terminal thiol has been synthesized and its corresponding self-assembled structure on Au(1 1 1) surfaces described. The surface morphology of the lipid self-assembled monolayer (SAM) exhibits nano-order patterning, where the height of the monolayer (approximately 1.5 nm) could be interpreted as due to the monolayer structure estimated from molecular models. The molecular orientation in the monolayer is almost perpendicular to the Au(1 1 1) surface depending on the three-point hydrogen-bonding sites in the molecule. 相似文献