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991.
Dr. Hidetoshi Ohta Kanako Tobayashi Akihiro Kuroo Mao Nakatsuka Dr. Hirokazu Kobayashi Prof. Dr. Atsushi Fukuoka Dr. Go Hamasaka Prof. Dr. Yasuhiro Uozumi Dr. Haruno Murayama Prof. Dr. Makoto Tokunaga Dr. Minoru Hayashi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(65):14762-14766
The selective and efficient removal of oxygenated groups from lignin-derived phenols is a critical challenge to utilize lignin as a source for renewable aromatic chemicals. This report describes how surface modification of a zeolite-supported Pt catalyst using ionic liquids (ILs) remarkably increases selectivity for the hydrodeoxygenation (HDO) of phenols into arenes under mild reaction conditions using atmospheric pressure H2. Unmodified Pt/H-ZSM-5 converts phenols into aliphatic species as the major products along with a slight amount of arenes (10 % selectivity). In contrast, the catalyst modified with an IL, 1-butyl-3-methylimidazolium triflate, keeps up to 76 % selectivity for arenes even at a nearly complete conversion of phenols. The IL on the surface of Pt catalyst may offer the adsorption of phenols in an edge-to-face manner onto the surface, thus accelerating the HDO without the ring hydrogenation. 相似文献
992.
993.
Toshiya Ohtsuki Satoshi Tanimoto Makoto Sekiyama Akihiro Fujihara Hiroshi Yamamoto 《Physics letters. A》2018,382(22):1456-1459
Numerical simulations of multiplicatively interacting stochastic processes with weighted selections were conducted. A feedback mechanism to control the weight w of selections was proposed. It becomes evident that when w is moderately controlled around 0, such systems spontaneously exhibit the Pareto–Zipf distribution. The simulation results are universal in the sense that microscopic details, such as parameter values and the type of control and weight, are irrelevant. The central ingredient of the Pareto–Zipf law is argued to be the mild control of interactions. 相似文献
994.
Dr. Xiao Deng Dr. Naoshi Dohmae Dr. Anna H. Kaksonen Dr. Akihiro Okamoto 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(15):6051-6055
Microbes synthesize cell-associated nanoparticles (NPs) and utilize their physicochemical properties to produce energy under unfavorable metabolic conditions. Iron sulfide (FeS) NPs are ubiquitous and are predominantly biosynthesized by sulfate-reducing bacteria (SRB). However, the biological role of FeS NPs in SRB remains understudied. Now, conductive FeS NPs function is demonstrated as an electron conduit enabling Desulfovibrio vulgaris Hildenborough, an SRB strain, to utilize solid-state electron donors via direct electron uptake. After forming FeS NPs on the cell surface, D. vulgaris initiated current generation coupled with sulfate reduction on electrodes poised at −0.4 V versus standard hydrogen electrode. Single-cell activity analysis showed that the electron uptake and metabolic rate via FeS NPs in D. vulgaris were about sevenfold higher than those via native cell-surface proteins in other SRB. 相似文献
995.
996.
Takahiko Masuda Hideaki Hara Yuki Miyamoto Susumu Kuma Itsuo Nakano Chiaki Ohae Noboru Sasao Minoru Tanaka Satoshi Uetake Akihiro Yoshimi Koji Yoshimura Motohiko Yoshimura 《Hyperfine Interactions》2015,230(1-3):73-77
We recently reported an experiment which focused on demonstrating the macro-coherent amplification mechanism. This mechanism, which was proposed for neutrino mass measurements, indicates that a multi-particle emission rate should be amplified by coherence in a suitable medium. Using a para-hydrogen molecule gas target and the adiabatic Raman excitation method, we observed that the two photon emission rate was amplified by a factor of more than 1015 from the spontaneous emission rate. This paper briefly summarizes the previous experimental result and presents the current status and the future prospect. 相似文献
997.
998.
Yutaka Nanashima Rena Shibata Ryo Miyakoshi Akihiro Yokoyama Tsutomu Yokozawa 《Journal of polymer science. Part A, Polymer chemistry》2012,50(17):3628-3640
Kumada‐Tamao coupling polymerization of 6‐bromo‐3‐chloromagnesio‐2‐(3‐(2‐methoxyethoxy)propyl)pyridine 1 with a Ni catalyst and Suzuki‐Miyaura coupling polymerization of boronic ester monomer 2 , which has the same substituted pyridine structure, with tBu3PPd(o‐tolyl)Br were investigated for the synthesis of a well‐defined n‐type π‐conjugated polymer. We first carried out a model reaction of 2,5‐dibromopyridine with 0.5 equivalent of phenylmagnesium chloride in the presence of Ni(dppp)Cl2 and then observed exclusive formation of 2,5‐diphenylpyridine, indicating that successive coupling reaction took place via intramolecular transfer of Ni(0) catalyst on the pyridine ring. Then, we examined the Kumada‐Tamao polymerization of 1 and found that it proceeded homogeneously to afford soluble, regioregular head‐to‐tail poly(pyridine‐2,5‐diyl), poly(3‐(2‐(2‐(methoxyethoxy)propyl)pyridine) (PMEPPy). However, the molecular weight distribution of the polymers obtained with several Ni and Pd catalysts was very broad, and the matrix‐assisted laser desorption ionization time‐of‐flight mass spectra showed that the polymer had Br/Br and Br/H end groups, implying that the catalyst‐transfer polymerization is accompanied with disproportionation. Suzuki‐Miyaura polymerization of 2 with tBu3PPd(o‐tolyl)Br also afforded PMEPPy with a broad molecular weight distribution, and the tolyl/tolyl‐ended polymer was a major product, again indicating the occurrence of disproportionation. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
999.
Kentarou Fukumoto Kumi Adachi Akihiro Kajiyama Yuri Yamazaki Fumika Yakushiji Yoshio Hayashi 《Tetrahedron letters》2012,53(5):535-538
We report here the design and synthesis of a novel and selective SH-group biotinylating reagent, KSH-1 (1), for the biotinylation of small molecules using solid phase chemistry. The results demonstrate that 1 efficiently biotinylated a small molecule, captopril, and afforded the product in high yield and purity. 相似文献
1000.
Koji Nagahama Keiko Shimizu Shunsuke Ichimura Akihiro Takahashi Tatsuro Ouchi Yuichi Ohya 《Journal of polymer science. Part A, Polymer chemistry》2012,50(13):2669-2676
Water‐swellable biodegradable materials exhibiting mechanically tenacious and tough characters in the wet state were prepared by a simple blend of two enantiomeric polylactide‐grafted dextran copolymers (Dex‐g‐PLLA and Dex‐g‐PDLA). DSC and WAXD analyses demonstrated the formation of SC crystals in the copolymer blend films. SC blend films showed lamellar‐type microphase‐separated structures. When swollen with water, these blend films showed the same level of tensile strengths and Young's modulus as the films in the dry state. SC blend films degraded gradually over a month under physiological conditions with a degradation rate faster than the corresponding Dex‐g‐PLLA films. The SC‐forming enantiomeric mixture of polylactide‐grafted polysaccharides should be a good candidate for an implantable biocompatible material exhibiting favorable mechanical properties and degradation behavior. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献