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排序方式: 共有496条查询结果,搜索用时 15 毫秒
101.
We discuss the scenario with TeV-scale right-handed neutrinos, which are accessible at future colliders, while holding down tiny seesaw-induced masses and sizable couplings to the standard-model particles. The signal with tri-lepton final states and large missing transverse energy is appropriate for studying collider signatures of the scenario with extra spatial dimensions. We show that the LHC experiment generally has a potential to discover the signs of extra dimensions and the origin of small neutrino masses. 相似文献
102.
Tomohito Kameda Hidenori Takeuchi Toshiaki Yoshioka 《Journal of Physics and Chemistry of Solids》2009,70(7):1104-1083
New layered magnesium hydroxides whose brucite layers had been bridged with malate2− and tartrate2− were prepared by dropwise addition of Mg(NO3)2 to malate and tartrate solutions at a constant pH of 10.5. Malate2− and tartrate2− may have been also absorbed on the surfaces of hydroxides. In the case of using citrate solution, Mg(OH)2 absorbed with citrate3− was produced. These materials were found to take up Cu2+ rapidly from an aqueous solution at pH 5.0. Copper uptake by precipitates is attributed to the formation of chelate complexes of Cu2+ with citrate3−, malate2−, and tartrate2−. 相似文献
103.
Tomohito Kameda Katsuaki Imai Guido Grause Tadaaki Mizoguchi Toshiaki Yoshioka 《Polymer Degradation and Stability》2009,94(9):1595-1597
The dehydrochlorination of PVC in the presence of NaOH was investigated in different diols. Diethylene glycol (DEG), triethylene glycol (TEG), and propylene glycol (PG) were found to be effective in accelerating the dechlorination of PVC. The dehydrochlorination was promoted in the order TEG > DEG > PG, which was in agreement with the compatibility between PET and the diol. Compatibility resulted in an improved penetration of the PVC particle by the solvent, leading to the acceleration of the dehydrochlorination. The dehydrochlorination of PVC in NaOH/diol followed first-order kinetics, confirming the progress of the reaction under chemical reaction control. The apparent activation energies were 82 kJ mol−1, 109 kJ mol−1, and 151 kJ mol−1 for TEG, DEG, and PG, respectively. The lower the activation energy became the faster the dehydrochlorination of PVC proceeded. 相似文献
104.
We report the basis set dependencies and the basis set superposition errors for the hydrated complexes of K+ and Na+ ions in relation to the recent studies of the KcsA potassium channel. The basis set superposition errors are estimated by the geometry optimizations at the counterpoise-corrected B3LYP level. The counterpoise optimizations alter the hydration distances by about 0.02–0.03 Å. The enthalpies and free energies for K+ + n(H2O) → [K(H2O)n]+ and Na+ + n(H2O) → [Na(H2O)n]+ (n = 1–6) are compared between the theoretical and experimental values. The results show that the addition of diffuse functions to K, Na, and O species are effective. However, it is also found that the counterpoise corrections using diffuse functions work so as to underestimate the free energies for the complexes with increasing the hydration number. The stabilization energies in aqueous solution are larger for a Na+ ion than for a K+ ion, suggesting the contributions of their dehydration processes to the ion selectivity of the KcsA potassium channel. The changes in coordination distance between the isolated [K(H2O)8]+ and the [K(H2O)8]+ in the KcsA potassium channel indicate the importance of hydrogen bondings between the first hydration shell and the outer hydration shells. 相似文献
105.
Crystallization rates of drug-polymer solid dispersions prepared with acetaminophen (ACA) and p-aminoacetanilide (AAA) as model drugs, and polyvinylpyrrolidone and polyacrylic acid (PAA) as model polymers were measured in order to further examine the significance of drug-polymer interactions. The crystallization of AAA and ACA was inhibited by mixing those polymers. The most effective inhibition was observed with solid dispersions of AAA and PAA. The combination of AAA and PAA showed a markedly longer enthalpy relaxation time relative to drug alone as well as a higher T(g) than predicted by the Gordon-Taylor equation, indicating the existence of a strong interaction between the two components. These observations suggest that crystallization is effectively inhibited by combinations of drug and polymer that show a strong intermolecular interaction due to proton transfer between acidic and basic functional groups. 相似文献
106.
Petrykin V Kakihana M Yoshioka K Sasaki S Ueda Y Tomita K Nakamura Y Shiro M Kudo A 《Inorganic chemistry》2006,45(23):9251-9256
The stable water-soluble tantalum complex with lactic acid (ammonium tetralactatodiperoxo-mu-oxo-ditantalate(V)), (NH4)4[Ta2(C3H4O3)4(O2)2O].3H2O, was prepared in the crystalline form. According to the single-crystal X-ray diffraction data, this compound forms a monoclinic cell with a = 13.85(2) A, b = 9.06(1) A, c = 12.32(2) A, and beta = 116.30 degrees , space group C2 (No. 2), and has Z = 2 molecules per unit cell. The solid-state 13C NMR data and low flack parameter are consistent with the determined structure. Appearance of the same vibration modes in Raman and IR spectra supports the choice of the space group without inversion symmetry. The solution of the tantalum complex was successfully applied for the synthesis of two photocatalytic materials, NaTaO3 and Sr2Ta2O7. 相似文献
107.
In the preceding study, we reported an application of the double exponential formula to the radial quadrature grid for numerical
integration of the radial electron distribution function. Three-type new radial grids with the double exponential transformation
were introduced. The performance of radial grids was compared between the double exponential grids and the grids proposed
in earlier studies by applying to the electron-counting integrals of noble gas atoms and diatomic molecules including alkali
metals, halogens, and transition metals. It was confirmed that the change in accuracy of the quadrature approximation depending
on atomic or molecular species is not significant for the double exponential integration schemes rather than the other integration
schemes. In the present study, we further investigate the accuracy of the double exponential formula for the electron-counting
integrals of all the atoms from H to Kr in the periodic table to elucidate the stable performance of the double exponential
radial grids. The electron densities of the atoms are calculated with the Gauss-type orbital basis functions at the B3LYP
level. The quadrature accuracy and convergence behavior of numerical integration are compared among the double exponential
formula and the formulas proposed by Treutler et al. and by Mura et al. The results reveal that the double exponential radial
grids remarkably improve the convergence rate toward high accuracy compared with the previous radial grids, particularly for
heavy elements in the 4th period, without fine tuning of the radial grids for each atom. 相似文献
108.
Tomohito Kameda Yuki Fubasami Toshiaki Yoshioka 《Journal of Thermal Analysis and Calorimetry》2012,110(2):641-646
The thermal properties of SO4 2?-intercalated Mg?CAl layered double hydroxide (SO4·Mg?CAl LDH) were investigated using simultaneous thermogravimetry?Cmass spectrometry (TG?CMS), and the elimination behavior of sulfur oxides from this double hydroxide was examined. The TG?CMS results showed that SO4·Mg?CAl LDH decomposed in five stages. The first stage involved evaporation of surface-adsorbed water and interlayer water in SO4·Mg?CAl LDH. In the second, third, and fourth stages, dehydroxylation of the brucite-like octahedral layers in SO4·Mg?CAl LDH occurred. The fifth stage corresponded to the elimination of SO4 2? intercalated in the interlayer of Mg?CAl LDH, producing SO2 and SO3. The thermal decomposition of SO4·Mg?CAl LDH resulted in the formation of SO2 and SO3 at 900?C1000?°C, which then reacted with H2O to form H2SO3 and H2SO4. The elimination of sulfur oxides increased with the decomposition time and temperature. Almost all of the intercalated SO4 2? was desulfurized from SO4·Mg?CAl LDH at 1000?°C; however, Mg?CAl oxide was not formed due to the production of MgO and MgAl2O4. 相似文献
109.
Kōta Yoshioka 《Mathematische Annalen》2001,321(4):817-884
In this paper, we consider basic problems on moduli spaces of stable sheaves on abelian surfaces. Our main assumption is
the primitivity of the associated Mukai vector. We determine the deformation types, albanese maps, Bogomolov factors and their
weight 2 Hodge structures. We also discuss the deformation types of moduli spaces of stable sheaves on K3 surfaces.
Received: 28 February 2000 / Revised version: 15 September 2000 / Published online: 24 September 2001 相似文献
110.
Masahiro Mikuriya Yuko Naka Ayumi Inaoka Mika Okayama Daisuke Yoshioka Hiroshi Sakiyama Makoto Handa Motohiro Tsuboi 《Molecules (Basel, Switzerland)》2022,27(13)
A mixed-valent trinuclear complex with 1,3-bis(5-chlorosalicylideneamino)-2-propanol (H3clsalpr) was synthesized, and the crystal structure was determined by the single-crystal X-ray diffraction method at 90 K. The molecule is a trinuclear CoIII-CoII-CoIII complex with octahedral geometries, having a tetradentate chelate of the Schiff-base ligand, bridging acetate, monodentate acetate coordination to each terminal Co3+ ion and four bridging phenoxido-oxygen of two Schiff-base ligands, and two bridging acetate-oxygen atoms for the central Co2+ ion. The electronic spectral feature is consistent with the mixed valent CoIII-CoII-CoIII. Variable-temperature magnetic susceptibility data could be analyzed by consideration of the axial distortion of the central Co2+ ion with the parameters Δ = –254 cm−1, λ = –58 cm−1, κ = 0.93, tip = 0.00436 cm3 mol−1, θ = –0.469 K, gz = 6.90, and gx = 2.64, in accordance with a large anisotropy. The cyclic voltammogram showed an irreversible reduction wave at approximately −1.2 V·vs. Fc/Fc+, assignable to the reduction of the terminal Co3+ ions. 相似文献