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991.
Tetsuya Ishiwata Chiho Ishijima Akira Ohashi Haruki Okada Kousaburo Ohashi 《Analytical sciences》2007,23(6):755-758
Phosphorus-containing amino acid-type herbicides (PAAHs) and their metabolites in human plasma and whole blood were extracted with titania and determined by capillary electrophoresis (CE). The recoveries of glyphosate (GLYP), aminomethylphosphonic acid (AMPA), gluphosinate (GLUF), and 3-methylphosphonico-propionic acid (MPPA) from human plasma were 84.6, 76.8, 90.4, and 89.6%, respectively. The recoveries of GLYP, AMPA, GLUF, and MPPA from whole blood were 79.6, 84.4, 36.9, and 31.8%, respectively. The low recoveries of GLUF and MPPA from whole blood were improved by the dilution of whole blood with water to 4-fold. 相似文献
992.
Panagiota Fragouli Hermis Iatrou Nikos Hadjichristidis Takuro Sakurai Yosuke Matsunaga Akira Hirao 《Journal of polymer science. Part A, Polymer chemistry》2006,44(22):6587-6599
A series of novel four‐arm A2B2 and A2BC and five‐arm A2B2C miktoarm star polymers, where A is poly(dimethylsiloxane) (PDMS), B is polystyrene (PS), and C is polyisoprene (PI), were successfully synthesized by the combination of chlorosilane and benzyl chloride linking chemistry. This new and general methodology is based on the linking reaction of in‐chain benzyl chloride functionalized poly(dimethylsiloxane) (icBnCl–PDMS) with the in‐chain diphenylalkyl (icD) living centers of PS‐DLi‐PS, PS‐DLi‐PI, or (PS)2‐DLi‐PI. icBnCl–PDMS was synthesized by the selective reaction of lithium PDMS enolate (PDMSOLi) with the chlorosilane groups of dichloro[2‐(chloromethylphenyl)ethyl]methylsilane, leaving the benzyl chloride group intact. The icD living polymers, characterized by the low basicity of DLi to avoid side reactions with PDMS, were prepared by the reaction of the corresponding living chains with the appropriate chloro/bromo derivatives of diphenylethylene, followed by a reaction with BuLi or the living polymer. The combined molecular characterization results of size exclusion chromatography, 1H NMR, and right‐angle laser light scattering revealed a high degree of structural and compositional homogeneity in all miktoarm stars prepared. The power of this general approach was demonstrated by the synthesis of a morphologically interesting complex miktoarm star polymer composed of two triblock terpolymer (PS‐b‐PI‐b‐PDMS) and two diblock copolymer (PS‐b‐PI) arms. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6587–6599, 2006 相似文献
993.
994.
Yoshihide Masuda Yoshiaki Sakurai Hisanori Sugiura Shiro Mí yake Shunsuke Takenaka Shigekazu Kusabayashi 《Liquid crystals》1991,10(5):623-634
The thermal properties of 4-cyanophenyl 4-(4-alkyloxybenzoyloxy)benzoates having a lateral substituent have been examined. Commencing with the nonyloxy homologue the hydrogen derivative shows a smectic A phase having a partially bilayered arrangement (SAAd). When the substituents are introduced at position X, the SAd phase commences from the octyloxy homologue, and the chlorine and bromine derivatives show an additional SAd phase in the low temperature region. When the substituents are introduced at position Y, the SAd phase commences either from the undecyloxy or the dodecyloxy homologue, and the nitro derivative shows two tilted phases in the low temperature region. Compounds having a methoxy group at position Z have difficulty in forming the SAd phase. The effect of the substituent on the thermal properties of the smectic phases has been discussed in terms of the electrostatic and structural properties of the substituents. A driving force for the formation of the partially bilayered arrangement is also discussed. 相似文献
995.
Kuniko Nasu Tetsuya Taketsugu Takashi Nakano Umpei Nagashima Haruo Hosoya 《Theoretical chemistry accounts》1995,90(2-3):75-86
Summary By semi-empirical molecular orbital calculations stability of fullerenes was analyzed in terms of topological parameters, such as the number of special fragments and the number of three types of abutting bonds between two 5-membered rings. Relative stability was compared by AM1 method for all spectrally distinct closed-shell isomers of C36 and C40 fullerenes, and for some closed-shell isomers of C60 fullerene. Molecular geometries of these fullerenes were also optimized. Their relative stabilities were well explained by the instability of abutting bonds. 相似文献
996.
Dr. Tetsuya Fukuda Dr. Hisako Hashimoto Prof. Dr. Shigeyoshi Sakaki Prof. Dr. Hiromi Tobita 《Angewandte Chemie (International ed. in English)》2016,55(1):188-192
Treatment of pyridine‐stabilized silylene complexes [(η5‐C5Me4R)(CO)2(H)W?SiH(py)(Tsi)] (R=Me, Et; py=pyridine; Tsi=C(SiMe3)3) with an N‐heterocyclic carbene MeIiPr (1,3‐diisopropyl‐4,5‐dimethylimidazol‐2‐ylidene) caused deprotonation to afford anionic silylene complexes [(η5‐C5Me4R)(CO)2W?SiH(Tsi)][HMeIiPr] (R=Me ( 1‐Me ); R=Et ( 1‐Et )). Subsequent oxidation of 1‐Me and 1‐Et with pyridine‐N‐oxide (1 equiv) gave anionic η2‐silaaldehydetungsten complexes [(η5‐C5Me4R)(CO)2W{η2‐O?SiH(Tsi)}][HMeIiPr] (R=Me ( 2‐Me ); R=Et ( 2‐Et )). The formation of an unprecedented W‐Si‐O three‐membered ring was confirmed by X‐ray crystal structure analysis. 相似文献
997.
Yu Harabuchi Yuriko Ono Satoshi Maeda Tetsuya Taketsugu Kristopher Keipert Mark S. Gordon 《Journal of computational chemistry》2016,37(5):487-493
A new type of reaction pathway which involves a nontotally symmetric trifurcation was found and investigated for a typical SN2‐type reaction, NC‐ + CH3X → NC? CH3 + X‐ (X = F, Cl). A nontotally symmetric valley‐ridge inflection (VRI) point was located along the C3v reaction path. For X = F, the minimum energy path (MEP) starting from the transition state (TS) leads to a second‐order saddle point with C3v symmetry, which connects three product minima of Cs symmetry. For X = Cl, four product minima have been observed, of which three belong to Cs symmetry and one to C3v symmetry. The branching path from the VRI point to the lower symmetry minima was determined by a linear interpolation technique. The branching mechanism is discussed based on the reaction path curvature and net atomic charges, and the possibility of a nonotally symmetric n‐furcation is discussed. © 2015 Wiley Periodicals, Inc. 相似文献
998.
Shungo Zen Tetsuya Abe Yoshiyuki Teramoto 《Plasma Chemistry and Plasma Processing》2018,38(2):347-354
The indirect synthesis of NH3 from N2 and H2O through plasma processing is proposed and demonstrated. NH3 is a promising hydrogen storage material because of its high hydrogen storage density. Mg3N2 is a key material for indirect NH3 synthesis, because the reaction of Mg3N2 with water easily generates NH3 at room temperature. In this paper, therefore, we focus on generating Mg3N2 by nitridation of MgO with nonthermal atmospheric-pressure dielectric barrier discharge (DBD) plasma in a N2 atmosphere. By intermittent DBD nitridation treatment while the reaction device was cooled in a water bath, a maximum Mg3N2 generation efficiency of 93 mg/kWh was estimated. Because NH3 is generated through a simple chemical reaction, our scheme does not cause NH3 decomposition by plasma, which is one of the greatest concerns associated with plasma synthesis. Contrary to the conventional NH3 generation process, which emits CO2 and requires high temperature and pressure, our scheme enables NH3 synthesis from N2 and H2O without CO2 emissions. This allows for an onsite small-scale NH3 synthesis system to be realized under mild conditions, which is necessary for a future low-carbon society. 相似文献
999.
A Water‐Soluble Warped Nanographene: Synthesis and Applications for Photoinduced Cell Death 下载免费PDF全文
Dr. Hsing‐An Lin Dr. Yoshikatsu Sato Prof. Dr. Yasutomo Segawa Dr. Taishi Nishihara Nagisa Sugimoto Prof. Dr. Lawrence T. Scott Prof. Dr. Tetsuya Higashiyama Prof. Dr. Kenichiro Itami 《Angewandte Chemie (International ed. in English)》2018,57(11):2874-2878
Nanographene, a small piece of graphene, has attracted unprecedented interest across diverse scientific disciplines particularly in organic electronics. The biological applications of nanographenes, such as bioimaging, cancer therapies and drug delivery, provide significant opportunities for breakthroughs in the field. However, the intrinsic aggregation behavior and low solubility of nanographenes, which stem from their flat structures, hamper their development for bioapplications. Herein, we report a water‐soluble warped nanographene (WNG) that can be easily synthesized by sequential regioselective C?H borylation and cross‐coupling reactions of the saddle‐shaped WNG core structure. The saddle‐shaped structure and hydrophilic tetraethylene glycol chains impart high water solubility to the WNG. The water‐soluble WNG possesses a range of promising properties including good photostability and low cytotoxicity. Moreover, the water‐soluble WNG was successfully internalized into HeLa cells and promoted photoinduced cell death. 相似文献
1000.
A Cocatalyst that Stabilizes a Hydride Intermediate during Photocatalytic Hydrogen Evolution over a Rhodium‐Doped TiO2 Nanosheet 下载免费PDF全文
Prof. Shintaro Ida Kenta Sato Tetsuya Nagata Prof. Hidehisa Hagiwara Prof. Motonori Watanabe Namhoon Kim Prof. Yoshihito Shiota Prof. Michio Koinuma Prof. Sakae Takenaka Prof. Takaaki Sakai Prof. Elif Ertekin Prof. Tatsumi Ishihara 《Angewandte Chemie (International ed. in English)》2018,57(29):9073-9077
The hydrogen evolution reaction using semiconductor photocatalysts has been significantly improved by cocatalyst loading. However, there are still many speculations regarding the actual role of the cocatalyst. Now a photocatalytic hydrogen evolution reaction pathway is reported on a cocatalyst site using TiO2 nanosheets doped with Rh at Ti sites as one‐atom cocatalysts. A hydride species adsorbed on the one‐atom Rh dopant cocatalyst site was confirmed experimentally as the intermediate state for hydrogen evolution, which was consistent with the results of density functional theory (DFT) calculations. In this system, the role of the cocatalyst in photocatalytic hydrogen evolution is related to the withdrawal of photo‐excited electrons and stabilization of the hydride intermediate species; the presence of oxygen vacancies induced by Rh facilitate the withdrawal of electrons and stabilization of the hydride. 相似文献