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991.
Yasuyuki Hirakawa Masashi Suzutoh Hitoshi Ohnishi Tomoteru Shingaki Edward M Eyring Makio Tokunaga Tsutomu Masujima 《Analytical sciences》2002,18(12):1293-1294
The nano-kinetics movement of a single DNA molecule was visualized by a newly developed video-microscope system with an optical fiber, called a "pin-fiber video scope". The stretching and shrinking motion was clearly observed, and its kinetics was analyzed by numerical calculations. The new video-microscope system has a potential to analyze the nano-kinetics of a molecule. 相似文献
992.
993.
Two-electron reduction of [(eta5-C5H4Me)4Fe4(mu3-CH)2(mu3-CO)2](PF6)2 (1) results in the coupling of two methylidyne ligands to form (eta5-C5H4Me)4Fe4(HCCH)(mu3-CO)2 (2), the two-electron oxidation of which reproduces 1. Structures of 1 and 2 were determined by X-ray diffraction analysis. 相似文献
994.
8-METHOXYPSORALEN PLUS UVA INDUCES THE 72 kDa HEAT SHOCK PROTEIN IN ORGAN-CULTURED NORMAL HUMAN SKIN
T. Muramatsu Y. Yamashina H. Tada N. Kobayashi M. Yamaji H. Ohno T. Shirai A. Takahashi T. Ohnishi 《Photochemistry and photobiology》1993,58(6):809-812
Abstract The proteins induced by heat and other stressors, called heat shock proteins (HSP) or stress proteins, are considered to play a general role in protection from cellular injury. Exposure to UVA (320400 nm) following application of 8-methoxypsoralen (8-MOP), termed PUVA is commonly used in the field of dermatology. In order to understand the induction of HSP in PUVA-treated human skin, indirect immunofluorescence using a monoclonal antibody specific for the 72 kDa HSP (HSP 72) was carried out in organ-cultured normal human skin that was treated with PUVA. When the organ-cultured skin was treated at 37°C for 1 h with 8-MOP at a final concentration of 10 or 100 μg/mL and exposed to UVA (51.3 kJ/m2 ), nuclear immunofluorcscence of HSP 72 was detected in the epidermal cells 12 h after UVA irradiation. In contrast, the induction of HSP 72 was not detected either by UVA irradiation or 8-MOP treatment. These results suggest that PUVA treatment is one of the stressors for human skin, and DNA damage caused by PUVA induces HSP 72. 相似文献
995.
The effects of various metal oxides upon the thermal decomposition of poly(vinyl chloride) (PVC) were previously reported. In this work, 23 metal chlorides were investigated to determine their effects on the thermal decomposition of PVC by pyrolysis–gas chromatography at 500°C. Each metal chloride exhibits influences on the course of thermal decomposition of PVC almost similar to the corresponding metal oxide except for a few elements; the metal chlorides from acidic metal oxides accelerate the thermal decomposition of PVC, but the metal chlorides from basic metal oxides do not. On comparing the effects of metal oxides and metal chlorides on the thermal decomposition of PVC, most metal chlorides were found to accelerate the thermal decomposition of PVC more than the corresponding metal oxides, owing to ease of addition of the chlorine atoms released from metal chloride to the dehydrochlorinated chains. It is concluded from these results that the thermal decomposition of PVC containing metal salts is markedly influenced by the ease with which chlorine atoms are released from the corresponding metal chloride. 相似文献
996.
Soo-Gil Park Jong-Eun Park Eun-In Cho Jin-Hee Hwang Takeo Ohsaka 《Research on Chemical Intermediates》2006,32(5):595-601
The electrochemical oxidation of ascorbic acid (AA) and serotonin (5-HT) at a boron-doped diamond (BDD) electrode modified
with poly(N,N-dimethylaniline) (PDMA) has been studied. The oxidation potentials of 5-HT and AA overlapped after mixing of the two chemicals,
due to interference of AA at the bare BDD electrode. However, after modifying the BDD electrode with a cationic polymer (PDMA),
the oxidation peaks of 5-HT and AA were separated. PDMA-coated BDD electrodes can be used for simultaneous detection of these
species. 相似文献
997.
Takeo Araki Koichi Nagata Hiroshi Tsukube 《Journal of polymer science. Part A, Polymer chemistry》1979,17(3):731-746
In the presence of Et2SO4, (S)-1-(N-phenyl-carbamoyl)-2-methylaziridine gave an oligomer with a structure of [CH2? CHCH3? N(CONHPh)]n. The oligomer has optically active isotactic configuration and narrow molecular weight distribution (DP ca. 8). The net polymerization behavior of the monomer and chemical property, such as absorptivity of Et2SO4, of the oligomer are analogous to the case of 1-(N-phenyl-carbamoyl)-aziridine. The ring opening occurs with retention of the configuration at the asymmetric carbon atom and the oligomer can be crystallized at around 90°C. 相似文献
998.
Usui T Kazami S Dohmae N Mashimo Y Kondo H Tsuda M Terasaki AG Ohashi K Kobayashi J Osada H 《Chemistry & biology》2004,11(9):1269-1277
The actin-targeting toxins have not only proven to be invaluable tools in studies of actin cytoskeleton structure and function but they also served as a foundation for a new class of anticancer drugs. Here, we describe that amphidinolide H (AmpH) targets actin cytoskeleton. AmpH induced multinucleated cells by disrupting actin organization in the cells, and the hyperpolymerization of purified actin into filaments of apparently normal morphology in vitro. AmpH covalently binds on actin, and the AmpH binding site is determined as Tyr200 of actin subdomain 4 by mass spectrometry and halo assay using the yeast harboring site-directed mutagenized actins. Time-lapse analyses showed that AmpH stimulated the formation of small actin-patches, followed by F-actin rearrangement into aggregates via the retraction of actin fibers. These results indicate that AmpH is a novel actin inhibitor that covalently binds on actin. 相似文献
999.
The reaction between some aliphatic aldehydes (acetaldehyde, propionaldehyde and butyraldehyde) and the typical stereospecific polymerization catalyst R2AlOCR′NPh has been studied in an attempt to elucidate the initiation mechanism of the polymerization reaction. The monomer-catalyst (1/1) complexes obtained from these aldehydes and R2AlOCR′NPh possess excellent catalytic activity towards the stereospecific polymerization. The structure of the complex in solution has been determined by NMR and IR spectra and compared with the structure determined by X-ray structure analysis. The presence of pentacoordinate aluminum in the complex has been demonstrated, for the first time, by X-ray studies.The structure of the aromatic monoaldehyde complex has also been studied and shown to be identical with that of the aliphatic aldehyde complex mentioned above. The chemical behavior of these aldehyde complexes towards Lewis bases and Lewis acids has also been studied. The aldehyde moiety of the R2AlOCR′NPh - MeCHO complex is liberated by the action of a strong Lewis base such as trimethylamine oxide and hexamethylphosphoramide, and is easily exchanged for another kind of aldehyde. The trimethylaluminum complex, Me2AlOCPhNPh · MeCHO · AlMe3, which only leads to the formation of amorphous polyacetaldehyde in contrast to Me2AlOCPhNPh · MeCHO, has been isolated and its structure determined by IR, NMR and X-ray studies in order to establish the relationship between its structure and its chemical behavior. 相似文献
1000.
S. Muthukumaru Pillai R. Ohnishi M. Ichikawa 《Reaction Kinetics and Catalysis Letters》1992,48(1):247-254
On Pd/-Al2O3 toluene undergoes reforming reaction with CO2 to give benzene and syngas at 1 atm and 400–500 °C. Among the promoters cerium oxide shows improved selectivity and activity compared to other rare earth oxides. Based on the catalytic runs and TPR experiments, the mechanism of the reaction is proposed.
CO2 Pd/-Al2O3 1 400–500°C . . .相似文献