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21.
Ryota Seto Kozo Matsumoto Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2014,52(13):1832-1842
Reactivity of isothiocynate moieties in the side chain of polymethacrylate with amine, alcohol, or thiol was investigated, and the reactions were applied to preparation of networked polymers. Isothiocyanate of polymer side chain rapidly reacted with amines without a catalyst, to give the corresponding thioureas. However, it did not react with alcohols or thiols under the same conditions. Using 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) as a catalyst, addition of alcohols or thiols to the isothiocyanate proceeded smoothly. Addition of amines, alcohols, and thiols to isothiocyanates moiety contained in the side chain of polymethacrylate also proceeded readily with or without the catalyst, respectively, to effectively give the corresponding side chain modified polymers. Occurrence of these additions was confirmed by 1H NMR and IR measurements. Glass transition temperatures and thermal decomposition temperatures of the obtained polymers were investigated by differential scanning calorimetry and thermogravimetric analysis. Networked polymers were easily prepared by addition of 1,6‐hexamethylenediamine or hexamethylene glycol to the polymethacrylate having isothiocyanato groups. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1832–1842 相似文献
22.
Shigeo Iwayanagi Ikuko Sakurai Tosio Sakurai Tsuneo Seto 《Journal of Macromolecular Science: Physics》2013,52(2):163-177
The crystal structure of trans-1,4-polybutadiene has been reported by Natta et al. to be pseudo-hexagonal below its solid-phase transition temperature. In the present X-ray structure analysis, it is revealed that the crystal belongs to the monoclinic system with the space group P21/a. The unit cell, with the lattice constants a = 8.63 Å, b = 9.11 Å, c = 4.83 Å, and β = 114°, includes four molecular segments. 相似文献
23.
24.
Misawa Kensuke Yamaotsu Noriyuki Hirono Shuichi 《Journal of computer-aided molecular design》2021,35(5):601-611
Journal of Computer-Aided Molecular Design - Enhancer of zeste homolog 2 (EZH2) is a histone lysine methyltransferase that is overexpressed in many cancers. Numerous EZH2 inhibitors have been... 相似文献
25.
Yuji Kikukawa Kensuke Seto Daiki Watanabe Hiromasa Kitajima Misaki Katayama Shohei Yamashita Yasuhiro Inada Yoshihito Hayashi 《Angewandte Chemie (International ed. in English)》2020,59(34):14399-14403
Dodecavanadate, [V12O32]4? (V12), possesses a 4.4 Å cavity entrance, and the cavity shows unique electrophilicity. Owing to the high polarizability, Br2 was inserted into V12, inducing the inversion of one of the VO5 square pyramids to form [V12O32(Br2)]4? (V12(Br2)). The inserted Br2 molecule was polarized and showed a peak at 185 cm?1 in the IR spectrum. The reaction of V12(Br2) and toluene yielded bromination of toluene at the ring, showing the electrophilicity of the inserted Br2 molecule. Compound V12(Br2) also reacted with propane, n‐butane, and n‐pentane to give brominated alkanes. Bromination with V12(Br2) showed high selectivity for 3‐bromopentane (64 %) among the monobromopentane products and preferred threo isomer among 2‐,3‐dibromobutane and 2,3‐dibromopenane. The unique inorganic cavity traps Br2 leading the polarization of the diatomic molecule. Owing to its new reaction field, the trapped Br2 shows selective functionalization of alkanes. 相似文献
26.
Tolerance bioaccumulation and biotransformation of arsenic compounds by a freshwater prawn (Macrobrachium rosenbergii) were investigated. M. rosenbergii was exposed to 10, 20, 30 and 35 μg As cm−3 of disodium arsenate [abbreviated as As(V)], 25, 50, 100 and 120 μg As cm−3 of methylarsonic acid (MMAA), or 100,200, 300 and 350 μg As cm−3 of dimethylarsinic acid (DMAA). Tolerances (50% lethal concentration: LC50) of the prawn against As(V), MMAA, and DMAA were 30, 100, and 300 μg As cm−3, respectively. The prawn accumulated arsenic compounds directly from aqueous phase and biotransformed them in part. Both methylation and demethylation of the arsenicals were observed in vivo. Highly methylated and less toxic arsenicals were less accumulated in M. rosenbergii. 相似文献
27.
Prof. Makoto Tadokoro Masaki Itoh Ryota Nishimura Kensuke Sekiguchi Dr. Norihisa Hoshino Dr. Hajime Kamebuchi Prof. Jun Miyazaki Dr. Fumiya Kobayashi Prof. Motohiro Mizuno Prof. Tomoyuki Akutagawa 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(47):e202201397
A new H-bonded crystal [RuIII(Him)3(Im)3] with three imidazole (Him) and three imidazolate (Im−) groups was prepared to obtain a higher-temperature proton conductor than a Nafion membrane with water driving. The crystal is constructed by complementary N−H⋅⋅⋅N H-bonds between the RuIII complexes and has a rare Icy-c* cubic network topology with a twofold interpenetration without crystal anisotropy. The crystals show a proton conductivity of 3.08×10−5 S cm−1 at 450 K and a faster conductivity than those formed by only HIms. The high proton conductivity is attributed to not only molecular rotations and hopping motions of HIm frameworks that are activated at ∼113 K, but also isotropic whole-molecule rotation of [RuIII(Him)3(Im)3] at temperatures greater than 420 K. The latter rotation was confirmed by solid-state 2H NMR spectroscopy; probable proton conduction routes were predicted and theoretically considered. 相似文献
28.
We introduce a new formalism to describe the polarization signal of galaxy clusters on the whole sky. We show that a sparsely sampled, half-sky map of the cluster polarization at z approximately 1 would allow us to better characterize the very large scale density fluctuations. While the horizon length is smaller in the past, two other competing effects significantly remove the contribution of the small scale fluctuations from the quadrupole polarization pattern at z approximately 1. For the standard LambdaCDM universe with vanishing tensor mode, the quadrupole moment of the temperature anisotropy at z = 0 is expected to have an approximately 32% contribution from fluctuations on scales below 6.3 h(-1) Gpc. This percentage would be reduced to approximately 2% level for the quadrupole moment of polarization pattern at z approximately 1. A cluster polarization would shed light on the potentially anomalous features of the largest scale fluctuations. 相似文献
29.
S. Nasu T. Shibatani Y. Maeda M. Seto H. Dohnomae N. Mima T. Shinjo 《Hyperfine Interactions》1992,71(1-4):1359-1362
197Au Mössbauer measurements have been performed at 16 K on the Au/Ni artificial multilayers having three different thickness of the layers those are 10Å Au/10Å Ni, 30Å Au/30Å Ni and 53Å Au/53Å Ni on a 250Å pure Au buffer layer. Mössbauer spectra obtained can be decomposed into mainly two components. One is an unperturbed component having an identical isomer shift value to the bulk Au metal. The other is the component perturbed strongly by the Ni layer indicating a broad contribution at positive velocity side and its intensity depends on the thickness of the Au layer. The spectrum from 10Å Au/10Å Ni multilayer is an entirely perturbed one and its area ratio to the component rising from pure Au buffer layer indicates the large Debye-Waller-factor suggesting the supermodulus effect in this multilayer. 相似文献
30.
Kensuke Aishima Takayasu Matsuo Kazuo Murota Masaaki Sugihara 《Journal of Computational and Applied Mathematics》2010,234(4):1179-1187
DLASQ is a routine in LAPACK for computing the singular values of a real upper bidiagonal matrix with high accuracy. The basic algorithm, the so-called dqds algorithm, was first presented by Fernando-Parlett, and implemented as the DLASQ routine by Parlett-Marques. DLASQ is now recognized as one of the most efficient routines for computing singular values. In this paper, we prove the asymptotic superquadratic convergence of DLASQ in exact arithmetic. 相似文献