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Heterologous Expression,Biosynthetic Studies,and Ecological Function of the Selective Gq‐Signaling Inhibitor FR900359 下载免费PDF全文
Dr. Max Crüsemann Raphael Reher Isabella Schamari Dr. Alexander O. Brachmann Dr. Tsubasa Ohbayashi Markus Kuschak Dr. Davide Malfacini Alexander Seidinger Marta Pinto‐Carbó René Richarz Tatjana Reuter Dr. Stefan Kehraus Dr. Asis Hallab Misty Attwood Prof. Dr. Helgi B. Schiöth Dr. Peter Mergaert Dr. Yoshitomo Kikuchi Prof. Dr. Till F. Schäberle Prof. Dr. Evi Kostenis Prof. Dr. Daniela Wenzel Prof. Dr. Christa E. Müller Prof. Dr. Jörn Piel Prof. Dr. Aurélien Carlier Prof. Dr. Leo Eberl Prof. Dr. Gabriele M. König 《Angewandte Chemie (International ed. in English)》2018,57(3):836-840
The cyclic depsipeptide FR900359 (FR), isolated from the tropical plant Ardisia crenata, is a strong and selective inhibitor of Gq proteins, making it an indispensable pharmacological tool to study Gq‐related processes, as well as a promising drug candidate. Gq inhibition is a novel mode of action for defense chemicals and crucial for the ecological function of FR, as shown by in vivo experiments in mice, its affinity to insect Gq proteins, and insect toxicity studies. The uncultured endosymbiont of A. crenata was sequenced, revealing the FR nonribosomal peptide synthetase (frs) gene cluster. We here provide a detailed model of FR biosynthesis, supported by in vitro enzymatic and bioinformatic studies, and the novel analogue AC‐1, which demonstrates the flexibility of the FR starter condensation domains. Finally, expression of the frs genes in E. coli led to heterologous FR production in a cultivable, bacterial host for the first time. 相似文献
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Definitive evidence is presented for the favourable electrochemical properties of carbon nanotube modified electrodes arising from the ends of SWNTs due to oxygenated carbon species in general, and carboxylic acid moieties in particular, produced during acid purification. 相似文献
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ESCA has been used to characterize films deposited from perfluorobenzene and perfluorobenzene/benzene vapors during plasma polymerization and irradiation with vacuum ultraviolet light. The films deposited by both methods are shown to be essentially the same. This indicates that similar electronically excited states are involved in the formation of the precursors to deposition in both methods and that reaction mechanisms involving ions do not need to be considered for the plasma polymerization of the monomers investigated. 相似文献
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Zusammenfassung Durch thermodilatometrische und DTA-Untersuchungen wurde das thermische Verhalten von C-Typ-PrO1.50, A-Typ-PrO1.50 und PrO1.833 im Temperaturintervall von Raumtemperatur bis 1200 °C in Luft und Wasserstoff-Atmosphäre untersucht. Die Temperatur des Phasenüberganges C-PrO1.50 A-PrO1.50 wurde zu 790±10 °C gefunden. C-PrO1.50 ist nur unterhalb der Umwandlungstemperatur beständig, A-PrO1.50 im gesamten untersuchten Temperaturbereich. PrO1.833 geht oberhalb von 400 °C, in Luft erhitzt, über mehrere definierte oxidische Zwischenphasen in A-PrO1.50 über.
The thermal behaviour of C-type PrO1.50, A-type PrO1.50 and PrO1.833 was investigated by thermodilatometric and DTA measurements in the temperature range from 20 to 1200 °C in air and in a hydrogen atmosphere. The phase transition C-type PrO1.50 A-type PrO1.50 proceeds at 790±10 °C; C-type PrO1.50 is stable only below this temperature, but A-type PrO1.50 in the whole range. Pro1.833 is stable up to 400 °C at atmospheric pressure. When heated further it decomposes stepwise forming several defined intermediate oxide phases.
Résumé On a étudié par thermodilatométrie et ATD le comportement thermique de PrO1.50-type C, PrO1.50-type A, et PrO1.833, dans le domaine de température allant jusqu'à 1200 °C, dans l'air et en atmosphère d'hydrogène. On a trouvé 790±10° comme température de la transition de phase C-PrO1.50/A-PrO1.50. C-PrO1.50 n'est stable qu'au-dessous de la température de conversion, alors que A-PrO1.50 l'est dans tout le domaine de température examiné. PrO1.833 chauffé dans l'air se transforme au-dessus de 400 °C en donnant plusieurs phases intermédiaires d'oxydes définis avant A-PrO1.50.
PrO1.50, PrO1.50 PrO1.833, 20–1200° . PrO1.50 PrO1.50 790±10°; PrO1.50 ; PrO1.50 PrO1.833 400° . , , .相似文献
86.
Till Einig Gerhard Görlitz B. Neidhart 《Fresenius' Journal of Analytical Chemistry》1996,355(1):71-77
The suitability of two in vitro oxidation systems as chemical models for the biological degradation of plant protecting agents has been investigated. As representative herbicides diclofop, fenoxaprop, isoproturon, linuron and monolinuron have been oxidised by two systems, the Fentons reagent and the ascorbic acid oxidation system (AAOS) and the results compared to those of the known metabolic pathways of these compounds. The herbicides have been oxidised by Fentons reagent (hydroxy radicals). The main products were isolated by preparative scale HPLC and identified with 1H-NMR and MS. Some of the products have been identified by comparing their retention times and UV/Vis-spectra to those of standard compounds. Several products known from biological degradation are also found after chemical oxidation, however, notable differences between the two pathways have been observed, for instance in the case of diclofop. Oxidation by the AAOS leads to comparable results. Reaction rates for the oxidation with the AAOS have been studied and compared with data known from degradation studies of the herbicides in soil. Compounds which are slowly degraded in soil are oxidised more slowly in the biomimetic process than those with a fast degradation in soil. 相似文献
87.
Sebastian Preiß Ayla Päpcke Lukas Burkhardt Luca Großmann Prof. Dr. Stefan Lochbrunner Prof. Dr. Matthias Bauer Prof. Dr. Till Opatz Prof. Dr. Katja Heinze 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(23):5940-5949
In the context of solar-to-chemical energy conversion, inspired by natural photosynthesis, the synthesis, electrochemical properties and photoinduced electron-transfer processes of three novel zinc(II)-gold(III) bis(porphyrin) dyads [ZnII(P)–AuIII(P)]+ are presented (P: tetraaryl porphyrin). Time-resolved spectroscopic studies indicated ultrafast dynamics (k >1010 s−1) after visible-light excitation, which finally yielded a charge-shifted state [ZnII(P ⋅ +)–AuII(P)]+ featuring a gold(II) center. The lifetime of this excited state is quite long due to a comparably slow charge recombination (k ≈3×108 s−1). The [ZnII(P ⋅ +)–AuII(P)]+ charge-shifted state is reductively quenched by amines in bimolecular reactions, yielding the neutral zinc(II)–gold(II) bis(porphyrin) ZnII(P)–AuII(P). The electronic nature of this key gold(II) intermediate, prepared by chemical or photochemical reduction, is elucidated by UV/Vis, X-band EPR, gold L3-edge X-ray absorption near edge structure (XANES) and paramagnetic 1H NMR spectroscopy as well as by quantum chemical calculations. Finally, the gold(II) site in ZnII(P)–AuII(P) is thermodynamically and kinetically competent to reduce an aryl azide to the corresponding aryl amine, paving the way to catalytic applications of gold(III) porphyrins in photoredox catalysis involving the gold(III/II) redox couple. 相似文献
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