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101.
Monodisperse molecularly imprinted polymers (MIPs) for diphenyl phosphate (DPP) and 1-naphthyl phosphate (1-NapP) have been prepared by a multi-step swelling and polymerization method using 4-vinylpyridine as a functional monomer, glycerol dimethacrylate as a crosslinker and cyclohexanol or 1-hexanol as a porogen. The retention and molecular-recognition properties of these MIPs for organophosphorus compounds were evaluated by HPLC using a mixture of phosphate buffer and acetonitrile as an eluent. In addition to shape recognition, hydrogen bonding and hydrophobic interactions could play an important role in the retention and molecular recognition of DPP and 1-NapP. Furthermore, the MIPs were applied to the separation of adenosine and adenosine phosphates (AMP, ADP and ATP). These phosphates were retained on the MIPs according to the number of phosphate groups in the molecule and were well separated from one another. Hydrogen bonding and hydrophobic interactions seemed to affect the retention and recognition of adenosine phosphates in low acetonitrile content, while hydrophilic interactions affected these properties in high acetonitrile content. Finally, the MIPs were applied to the trapping of phosphopeptides. The MIPs non-selectively trapped phosphopeptides, which have phosphorylated tyrosine, serine or threonine in the sequences, and successfully trapped four phosphopeptides in tryptic digests of bovine α-casein. 相似文献
102.
Shigeru Yoshikawa Hiromi Tashiro Yumiko Sakamoto 《Journal of sound and vibration》2012,331(11):2558-2577
Aero-dynamical models of sound generation in an organ pipe driven by a thin jet are investigated through an experimental examination of the vortex-sound theory. An important measurement requirement (acoustic cross-flow as an irrotational potential flow reciprocating sinusoidally) from the vortex-sound theory is carefully realized when the pipe is driven with low blowing pressures of about 60 Pa (jet velocities of about 10 m/s). Particle image velocimetry (PIV) is applied to measure the jet velocity and the acoustic cross-flow velocity over the mouth area at the same phase by quickly switching the jet drive and the loudspeaker-horn drive. The vorticity of the jet flow field and the associated acoustic generation term are evaluated from the measurement data. It is recognized that the model of the “jet vortex-layer formation” is more relevant to the sound production than the vortex-shedding model. The acoustic power is dominantly generated by the flow–acoustic interaction near the edge, where the acoustic cross-flow velocity takes larger magnitudes. The acoustic generation formula on the vortex sound cannot deny the conventional acoustical volume-flow model because of the in-phase relation satisfied between the acoustic pressure at the mouth and the acoustic volume flow into the pipe. The vortex layers formed along both sides of the jet act as the source of an accelerating force (through the “acceleration unbalance”) with periodically alternating direction to oscillate the jet flow and to reinforce the acoustic cross-flow at the pipe mouth. 相似文献
103.
An accurate and efficient scheme for two-component relativistic calculations at the spin-free infinite-order Douglas-Kroll-Hess (IODKH) level is presented. The present scheme, termed local unitary transformation (LUT), is based on the locality of the relativistic effect. Numerical assessments of the LUT scheme were performed in diatomic molecules such as HX and X(2) (X = F, Cl, Br, I, and At) and hydrogen halide clusters, (HX)(n) (X = F, Cl, Br, and I). Total energies obtained by the LUT method agree well with conventional IODKH results. The computational costs of the LUT method are drastically lower than those of conventional methods since in the former there is linear-scaling with respect to the system size and a small prefactor. 相似文献
104.
Previously we have investigated the cosmic wiggly strings in (3 + 1)-dimensional Schwarzschild, Reissner–Nordström and Kerr black holes. As an extension the solutions in (3 + 1)-dimensional axially symmetric charged rotating black hole are investigated. The solutions for the wiggly string exhibit open strings lying in the radial direction in the equatorial plane outside the horizon. 相似文献
105.
Taisei Ueda Naoyoshi Yatsuzuka Shin‐Ichi Nagai Kumiko Okada Emi Takeichi Hiromi Segi Jinsaku Sakakibara 《Journal of heterocyclic chemistry》2001,38(1):141-145
Oxidation of 7,8‐diaminotheophylline (1) with lead tetraacetate in refluxing toluene gave a mixture of 3‐amino‐5,7‐dimethylpyrimido[4,5‐e][1,2,4]triazine‐6,8‐dione ( 2 ) and 6‐cyanoimino‐5‐diazo‐1,3‐dimethylpyrimidine‐2,4‐dione ( 4 ). The latter was transformed to 2 by the reaction with 1‐propanethiol in quantitative yield. The reaction of 4 with methanol, ethanol and 1‐propanol in the presence of rhodium ( II ) acetate gave 5‐alkoxy‐6‐(2‐alkyl‐3‐isoureido)‐1,3‐dimethylpyrimidine‐2,4‐diones ( 7a‐c ). A similar reaction of 4 with alkylamines such as n‐propylamine, n‐butylamine, isobutylamine and n‐hexylamine gave a mixture of 7‐alkyl‐8‐aminotheophyllines ( 8a‐d ) and (5‐alkylamino‐1,3‐dimethyl‐2,4‐dioxopyrimidin‐6‐yl)cyanamides ( 9a‐d ). 相似文献
106.
Noriyasu Hada Tokio Morita Takashi Ueda Kazuki Masuda Hiromi Nakane Mami Ogane Kimiaki Yamano Frank Schweizer Fumiyuki Kiuchi 《Molecules (Basel, Switzerland)》2021,26(18)
Stereocontrolled syntheses of biotin-labeled oligosaccharide portions containing the carbohydrate moiety of glycoprotein from Echinococcus granulosus have been accomplished. Trisaccharide Galβ1-3Galβ1-3GalNAcα1-R (A), tetrasaccharide Galα1-4Galβ1-3Galβ1-3GalNAcα1-R (B), and pentasaccharide Galα1-4Galβ1-3Galβ1-3Galβ1-3GalNAcα1-R (C), (R = biotinylated probe) were synthesized by stepwise condensation and/or block synthesis by the use of 5-(methoxycarbonyl)pentyl 2-azido-4,6-O-benzylidene-2-deoxy-α-d-galactopyranoside as a common glycosyl acceptor. The synthesis of the tetrasaccharide and the pentasaccharide was improved from the viewpoint of reducing the number of synthetic steps and increasing the total yield by changing from stepwise condensation to block synthesis. Moreover, hexasaccharide E, which contains the oligosaccharide sequence which occurs in E. granulosus, was synthesized from trisaccharide D. We examined the antigenicity of these five oligosaccharides by an enzyme-linked immunosorbent assay (ELISA). Although compounds of C–E did not exhibit antigenicity against cystic echinococcosis (CE) patient sera, compounds B, D, and E showed good serodiagnostic potential for alveolar echinococcosis (AE). 相似文献
107.
Hiromi Shinohara Hirokazu Shibata Dieter Whrle Hiroyuki Nishide 《Macromolecular rapid communications》2005,26(6):467-470
Summary: A membrane of a cobalt tetraazaporphyrin polymer complex was prepared with a nanometer thickness and used as an oxygen‐facilitated transport membrane. Rapid and reversible oxygen binding to the cobalt tetraazaporphyrin complex with a polymeric imidazole ligand was observed at low temperature. Oxygen transport through the membrane was facilitated and a high (oxygen/nitrogen) permselectivity of 28 was obtained.
108.
Wu Zibin Zhang Haitao Guo Cheng Zou Jing Qin Ke Ban Chunyan Nagaumi Hiromi 《Journal of Solid State Electrochemistry》2019,23(8):2483-2491
Journal of Solid State Electrochemistry - In this paper, the electrochemical performances of Al 0.5-Mg 0.1-Sn (wt%), Al 0.5-Mg 0.1-Sn 0.05 In (wt%), Al 0.5-Mg 0.1-Sn 0.05 Ga (wt%) and Al 0.5-Mg... 相似文献
109.
Dr. Hiromi Oshita Prof. Dr. Yuichi Shimazaki 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(38):8324-8340
The phenoxyl radical plays important roles in biological systems as cofactors in some metalloenzymes, such as galactose oxidase (GO) catalyzing oxidation of primary alcohols to give the corresponding aldehydes. Many metal(II)–phenoxyl radical complexes have hitherto been studied for understanding the detailed properties and reactivities of GO, and thus the nature of GO has gradually become clearer. However, the effects of the subtle geometric and electronic structural changes at the active site of GO, especially the structural change in the catalytic cycle and the effect of the second coordination sphere, have not been fully discussed yet. In this Review, we focus on further details of the model studies of GO and discuss the importance of the structural change at the active site of GO. 相似文献
110.
Takashi Suzuki Dr. Hiromi Oshita Prof. Dr. Tatsuo Yajima Prof. Dr. Fumito Tani Prof. Dr. Hitoshi Abe Prof. Dr. Yuichi Shimazaki 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(69):15805-15814
Reaction of Cu(ClO4)2 ⋅ 6 H2O with a tripodal 2N2O ligand, H2Me2NL, having a p-(dimethylamino)phenol moiety, in CH2Cl2/MeOH (1:1 v/v) under basic conditions under an inert gas atmosphere gave [Cu(Me2NL)(H2O)] ( 1 ). The same reaction carried out under aerobic conditions gave [Cu(Me2NL)(MeOH)]ClO4 ( 2 ), which could be obtained also from the isolated complex 1 by reaction with O2 in CH2Cl2/MeOH. The X-ray crystal structures of 1 and 2 revealed similar square-pyramidal structures, but 2 showed the (dimethylamino)phenoxyl radical features. Complex 1 exhibits characteristic CuII EPR signals of the d ground state in CH2Cl2/MeOH at 77 K, whereas 2 is EPR-silent. The EPR and X-ray absorption fine structure (XAFS) results suggest that 2 is assigned to the CuII–(dimethylamino)phenoxyl radical. However, complex 1 showed different features in the absence of MeOH. The EPR spectrum of the CH2Cl2 solution of 1 exhibits distortion from the d ground state and a temperature-dependent equilibrium between the CuII–(dimethylamino)phenolate and the CuI–(dimethylamino)phenoxyl radical. From these results, CuII–phenoxyl radical complex 2 is concluded to be formed by the reaction of 1 with O2 via the CuI–phenoxyl radical species. 相似文献