全文获取类型
收费全文 | 280篇 |
免费 | 5篇 |
国内免费 | 3篇 |
专业分类
化学 | 216篇 |
晶体学 | 3篇 |
力学 | 1篇 |
数学 | 14篇 |
物理学 | 54篇 |
出版年
2023年 | 1篇 |
2021年 | 5篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 1篇 |
2016年 | 5篇 |
2015年 | 3篇 |
2014年 | 6篇 |
2013年 | 11篇 |
2012年 | 18篇 |
2011年 | 20篇 |
2010年 | 12篇 |
2009年 | 5篇 |
2008年 | 16篇 |
2007年 | 15篇 |
2006年 | 24篇 |
2005年 | 18篇 |
2004年 | 10篇 |
2003年 | 11篇 |
2002年 | 16篇 |
2001年 | 12篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 6篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 7篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1973年 | 1篇 |
1961年 | 1篇 |
排序方式: 共有288条查询结果,搜索用时 46 毫秒
101.
Ikeda K Ikawa K Kozumi T Yokoshige S Horikawa S Morikawa N 《Analytical and bioanalytical chemistry》2012,403(7):1823-1830
A simple and sensitive GC-EI-MS method using solvent extraction and evaporation was developed for the determination of olanzapine concentrations in plasma samples. Because olanzapine and promazine, which was used as the internal standard (IS), are nitrogenous bases, they can adsorb to the weakly acidic silanol groups on the surfaces of glass centrifuge tubes during solvent extraction and evaporation. Silylation of the glass tubes, addition of triethylamine (TEA), and use of a sample solution with a basic pH could prevent adsorption loss. The extraction method involved mixing plasma (500 μL) in a silylated glass tube with a promazine solution (2 μg/mL, 25 μL) in methanol containing 1% TEA. After addition of aqueous sodium carbonate (0.5 mol/L, pH 11.1, 1 mL) and extraction into 3 mL of dichloromethane/n-hexane (1:1, v/v) containing 1% TEA, the organic phase was evaporated to dryness in a silylated glass tube. The residue was dissolved in ethyl acetate containing 1% TEA (50 μL). For GC-EI-MS analysis, the calibration curves of olanzapine in human plasma were linear from 0.5 to 100 ng/mL. Intra- and interday precisions in plasma were both less than 7.36% (coefficient of variation), and the accuracy was between 94.6 and 110% for solutions with concentrations greater than 0.5 ng/mL. The limit of quantification was 0.5 ng/mL in plasma. The assay was applied to therapeutic drug monitoring in samples from three schizophrenic patients. 相似文献
102.
Yutaka Fujimoto Hiroaki Tanno Shigetomo Yoshida Masanobu Shirai Kouichirou Tanaka Yutaka Kawabe Eiichi Hanamura 《Journal of luminescence》2008,128(3):282-286
Spinel MgAl2O4 crystals doped with transition metals show charge-transfer transitions for Ti:MgAl2O4 on one hand and multiplet transitions of (3d)-electrons for Mn:, Fe:, and Co:MgAl2O4 on the other hand. We will show that optical responses of V:MgAl2O4 are closer to those of Ti:MgAl2O4 and also that white emission spectrum is observed. The microscopic process of the white emission is also proposed. 相似文献
103.
104.
Radial distribution of electron temperature as well as that of plasma current has been measured in the skin phase in turbulent heating of a high-density plasma (n ? 2 × 1014m?3). Anomalously rapid disappearance of the current skin is observed, while the skin profile of the electron temperature remains longer near the plasma core, indicating that the plasma current is redistributed without electron heat transfer across the magnetic field. 相似文献
105.
Omori A Ichinose S Kitajima S Shimotohno KW Murashima YL Shimotohno K Seto-Ohshima A 《Electrophoresis》2002,23(24):4167-4174
The distribution of proteins in the cerebral cortex of a seizure-sensitive (SS) strain of gerbil and its seizure-resistant (SR) counterpart was profiled using two-dimensional gel electrophoresis. A series of proteins of similar molecular weight (around 83 kDa) showed small but consistent differences in their isoelectric point (pI) with indistinguishable profiles of distribution between the two strains. Amino acid sequences of peptides produced by limited proteolysis of each protein in the spots from the strains were identical or highly homologous to those of mitofilin, a mitochondrial inner membrane protein (IMMT) in humans. Analysis of cDNA sequences revealed the proteins of these spots to be gerbil mitofilin-like proteins (gIMMT), with a few base substitutions between SS and SR strains, in particular within a region near a putative transmembrane domain that is highly conserved in humans and gerbils. The amino acid at the site was acidic, Glu in humans and Asp in the strain SR of gerbil and a neutral, Asn in strain SS. In addition to these base substitutions, production of multiple species of mRNA for gIMMT by alternative splicing was observed. 相似文献
106.
Haru Ogawa Hiroshi Morita Satoko Suemura Taiji Imoto Yasuyoshi Nogami Toshitaka Koga Yujiro Sakuragi Izumi Miyamoto Hidefumi Kato Yōichi Taniguchi 《Tetrahedron letters》1985,26(45):5567-5570
The titled annulenone 1 could be converted into new annulenones 3 and 8 by carbonyl transposition reactions. Compound 8 can be regarded as the first 14π hydroxy-enone as a higher homolog of tropolone (6π) and hydroxy[11]annulenones (10π), and was proved to be aromatic. 相似文献
107.
Kenji Tabata Takashi Kawabe Yoichi Yamaguchi Yousuke Nagasawa 《Catalysis Surveys from Asia》2003,7(4):251-259
The electronic states of chemisorbed oxygen species on the (110) face of SnO2 and their variations caused by heat treatments and/or O2 exposure have been investigated. The reactivities of the chemisorbed oxygen species for methane oxidations were also examined.Four different chemisorbed oxygen species (O2
2-, O2-, O-, Ob) were observed, in addition to the lattice oxygen (O2-), on the surface of the stabilized (110) surface of SnO2 after O2 exposure. The Ob species was assumed to be the bridging oxygen at the topmost layer of the SnO2 (110) surface having no neighboring oxygen vacancies. The electronic state of Ob was converted to O- upon CH4 exposure at 473 K by coupling with newly produced vacancies at the bridging site of the SnO2 (110) surface. 相似文献
108.
Satoko Akashi Kazuyoshi Noguchi Reiko Yuji Uno Tagami Kazuo Hirayama Koichi Kato HaHyung Kim Kazuhiro Tokioka Ichio Shimada Yoji Arata 《Journal of the American Society for Mass Spectrometry》1996,7(8):707-721
The amino acid sequences of mouse monoclonal antibodies have been characterized completely by mass spectrometry. Antibodies used in the present study were derived from mouse switch variant cell lines that produce four kinds of immunoglobulin Gs (IgGs). The amino acid sequences of these antibodies had not been estimated from the corresponding DNA sequence, so the sequences of IgGs derived from other strains were used as references in this study. Intra- and interchain disulfide bonds of the IgGs were reduced and carboxymethylated and the products were subjected to proteolytic digestion. The existence of N-linked oligosaccharides also was taken into account. The capabilities and limitations of matrix-assisted laser desorption ionization-time-of-flight mass spectrometry and capillary liquid chromatography-electrospray ionization mass spectrometry are discussed in the structural characterization of the antibodies. Based on our results, allotypes of the antibodies examined are discussed. This study shows that amino acid sequences of proteins, such as IgG, can be investigated without information about the corresponding DNA sequence if appropriate reference sequences derived from other strains can be used. 相似文献
109.
T Dohji M Fushimi T Kawabe F Kamiyama M Mori N Sugita O Tanizawa 《Journal of chromatography. A》1984,311(2):249-255
A fluorometric liquid chromatographic method was developed for measurements of unconjugated oestradiol and oestriol in the serum of pregnant women. The serum samples are injected directly into the apparatus and pass to a pretreatment column, where oestrogens are adsorbed while hydrophilic components such as proteins and carbohydrates are not. The oestrogens then pass into a separation column containing a new type of polymer gel. The mobile phase consists of an acetonitrile-water mixture, and separation is achieved by a reversed-phase mechanism. The eluent is monitored for fluorescence. Data on the reproducibility and recovery by this method and the correlation of values with those obtained by radioimmunoassay are reported. Results on the increases of oestradiol and oestriol in the serum during pregnancy are also reported. 相似文献
110.
Total energies of small molecules were calculated with a local density functional (LDF) approximation within the LCAO MO SCF scheme. The local spin density functional (LSD) of Gunnarsson and Lundqvist was used. The basis sets used are of contracted gaussian type which allow comparison of LSD with Hartree-Fock (HF) results. The program for calculation of the LSD term was incorporated into the standard ab initio package. The LSD binding energies were in better agreement with experiment than those from HF. 相似文献