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51.
Fluorinated Vinylsilanes from the Copper‐Catalyzed Defluorosilylation of Fluoroalkene Feedstocks 下载免费PDF全文
Hironobu Sakaguchi Prof. Dr. Masato Ohashi Prof. Dr. Sensuke Ogoshi 《Angewandte Chemie (International ed. in English)》2018,57(1):328-332
Herein, a copper‐catalyzed C?F bond defluorosilylation reaction of tetrafluoroethylene and other polyfluoroalkenes is described. Mechanistic studies, based on a series of stoichiometric reactions with copper complexes, revealed that the key steps of this defluorosilylation reaction are 1) the 1,2‐addition of a silylcopper intermediate to the polyfluoroalkene and 2) a subsequent selective β‐fluorine elimination, which generates a Cu?F species. The β‐fluorine elimination is facilitated by Lewis acidic F?Bpin, which is generated in situ during the defluorosilylation. 相似文献
52.
We utilize the classical hypercircle method and the lowest-order Raviart–Thomas H(div) element to obtain a posteriori error estimates of the P1 finite element solutions for 2D Poisson's equation. A few other estimation methods are also discussed for comparison. We give some theoretical and numerical results to see the effectiveness of the methods. 相似文献
53.
金孙均 王友宝 苏俊 颜胜权 李云居 郭冰 李志宏 曾晟 连钢 白希祥 柳卫平 山口英齐 久保野茂 胡钧 D.Kahl 郑孝顺 文俊永 寺西高 王宏伟 石山博信 岩佐直人 小松原哲郎 李二涛 张健 《原子核物理评论》2015,32(3):274-279
在日本东京大学CRIB 次级束装置上,用长气体靶开展了22Na+ α共振散射的厚靶实验研究。针对长气体靶实验中的两体运动学重构问题,提出了一套包括构建空间复杂几何关系、计算能量损失以及反应运动学的逐事件分析方法;对22Na+α共振散射的实验数据进行了重构分析,得到了Ec.m. = 4.2 ~ 5.4 MeV 区间22Na( α,α ) 的激发函数,从实验的激发函数中观测到了复合核26Al 5 个较为明显的共振峰。鉴于26Al 共振态的衰变模式比较复杂,本工作发现的26Al新共振态的能级性质有待进一步的理论分析。The 22Na+α resonant scattering is studied via a conventional thick target inverse kinematic method with an extended gas target. A data analysis method is proposed for the two-body reaction kinematic reconstruction, in which the spatial geometry, the reaction kinematics and the energy losses are considered. The experimental data of 22Na+ αresonant scattering have been thus reconstructed, and the excitation function is obtained in the energy interval of Ec.m. =4.2~5.4 MeV. Five resonant states in 26Al are observed in the experimental excitation function. Since several decay modes coexist for the observed 26Al resonant states, multi-channel theoretical analysis is thus needed to reveal their structure and decay features. 相似文献
54.
Hironobu Sakagawa 《Journal of statistical physics》2009,135(3):467-481
We consider the d+1-dimensional effective interface model of gradient type with a quadratic interaction potential and a self-potential. Without
the self-potential, the model coincides with the d-dimensional massless Gaussian field. We show that for an arbitrary repulsive self-potential which can be thought as interaction
of the interface with a “soft wall”, the field is pushed up at least to the same level when the original Gaussian field is
conditioned to be positive everywhere, namely the “hard wall” condition is imposed. 相似文献
55.
Matsuura S Yokoyama T Ishii R Itoh T Tomon E Hamakawa S Tsunoda T Mizukami F Nanbu H Hanaoka TA 《Chemical communications (Cambridge, England)》2012,48(56):7058-7060
A flow-type microreactor containing glutaminase-mesoporous silica composites with 10.6 nm pore diameter (TMPS10.6) was developed for the continuous synthesis of theanine, a unique amino acid. High enzymatic activity was exhibited by the local control of the reaction temperature. 相似文献
56.
Hironobu Kunieda Hamidul Kabir Kenji Aramaki Kazuki Shigeta 《Journal of Molecular Liquids》2001,90(1-3):157-166
Cloud temperatures, phase behavior, and the structures of liquid crystals were investigated in the aqueous systems of homogenous hexaethylene glycol dodecyl ether(C12EO6) and mixed C12EO4-C12EO8, C12EO2-EO8, C12EO2-C12EO8, and C12EO0-C12EO8 In the mixed surfactant systems, the average polyoxyethylene- (EO-) chain lengths are kept constants, the same as C12EO6. The change in cloud temperatures is small in all the systems, whereas the phase behavior is successively changed with increasing the difference in EO-chain length in the mixture. Lamellar liquid crystal is developed in the phase diagrams and it intrudes in the two-phase region above the cloud temperature. Hence, the phase pattern of the present mixed surfactant systems resembles that of C12EO5 system, but both cloud point and W+L region appear at much higher temperature. Hence, the Hydrophile-Lipophile Balance of the surfactant is not largely changed by mixing the surfactants but the SAXS results show that the surfactant molecules are more tightly packed in the hexagonal and lamellar phases by mixing. It is considered that when surfactants of different EO-chain lengths are mixed, the considerable reduction in repulsion between the hydrophilic moieties takes place and the surfactant molecules are more tightly packed. 相似文献
57.
Hironobu Kimura 《Annali di Matematica Pura ed Applicata》1989,155(1):25-74
Summary
We study the theory of isomonodromic deformation for the second order linear differential equations on the Riemann sphere and show that the deformation equations are written in the form of Hamiltonian system completely integrable in the sense of Frobenius. We also obtain from them the Hamiltonian systems with the polynomials Hamiltonians. 相似文献
58.
Hironobu Sakagawa 《Journal of statistical physics》2004,114(1-2):37-49
We consider two dimensional lattice free fields (harmonic crystals) and study the asymptotic behavior of the fields under the constraint that each field lies above a hard-wall and is forced to be piled on top of another. This problem is the so-called entropic repulsion and our result extends that of ref. 2 which studied the higher dimensional case. 相似文献
59.
Hojo H Matsumoto Y Nakahara Y Ito E Suzuki Y Suzuki M Suzuki A Nakahara Y 《Journal of the American Chemical Society》2005,127(39):13720-13725
Peptide thioester corresponding to a MUC2 tandem repeat unit, which retains seven GalNAc moieties, was prepared by the Fmoc method followed by the low TfOH treatment to remove benzyl groups at the carbohydrate portions. The glycosylated peptide thioester was then consecutively joined by the activation of a thioester group by silver ions to obtain a MUC2 tandem repeat model composed of 141 amino acids with 42 GalNAc moieties. 相似文献
60.
Catalytic effect of nanoparticle 3d-transition metals on hydrogen storage properties in magnesium hydride MgH2 prepared by mechanical milling 总被引:1,自引:0,他引:1
We examined the catalytic effect of nanoparticle 3d-transition metals on hydrogen desorption (HD) properties of MgH(2) prepared by mechanical ball milling method. All the MgH(2) composites prepared by adding a small amount of nanoparticle Fe(nano), Co(nano), Ni(nano), and Cu(nano) metals and by ball milling for 2 h showed much better HD properties than the pure ball-milled MgH(2) itself. In particular, the 2 mol % Ni(nano)-doped MgH(2) composite prepared by soft milling for a short milling time of 15 min under a slow milling revolution speed of 200 rpm shows the most superior hydrogen storage properties: A large amount of hydrogen ( approximately 6.5 wt %) is desorbed in the temperature range from 150 to 250 degrees C at a heating rate of 5 degrees C/min under He gas flow with no partial pressure of hydrogen. The EDX micrographs corresponding to Mg and Ni elemental profiles indicated that nanoparticle Ni metals as catalyst homogeneously dispersed on the surface of MgH(2). In addition, it was confirmed that the product revealed good reversible hydriding/dehydriding cycles even at 150 degrees C. The hydrogen desorption kinetics of catalyzed and noncatalyzed MgH(2) could be understood by a modified first-order reaction model, in which the surface condition was taken into account. 相似文献