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We introduce an impartial combinatorial game on Steiner triple systems called Next One to Fill Is the Loser (Nofil ). Players move alternately, choosing points of the triple system. If a player is forced to fill a block on their turn, they lose. By computing nim-values, we determine optimal strategies for Nofil on all Steiner triple systems up to order 15 and a sampling for orders 19, 21 and 25. The game Nofil can be thought of in terms of play on a corresponding hypergraph which will become a graph during play. At that point Nofil is equivalent to playing the game Node Kayles on the graph. We prove necessary conditions and sufficient conditions for a graph to reached playing Nofil. We conclude that the complexity of determining the outcome of the game Nofil on Steiner triple systems is PSPACE-complete for randomized reductions. 相似文献
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Kudoh T Fukuoka M Ichikawa S Murayama T Ogawa Y Hashii M Higashida H Kunerth S Weber K Guse AH Potter BV Matsuda A Shuto S 《Journal of the American Chemical Society》2005,127(24):8846-8855
We previously developed cyclic ADP-carbocyclic ribose (cADPcR, 2) as a stable mimic of cyclic ADP-ribose (cADPR, 1), a Ca(2+)-mobilizing second messenger. A series of the N1-ribose modified cADPcR analogues, designed as novel stable mimics of cADPR, which were the 2"-deoxy analogue 3, the 3"-deoxy analogue 4, the 3"-deoxy-2"-O-(methoxymethyl) analogue 5, the 3"-O-methyl analogue 6, the 2",3"-dideoxy analogue 7, and the 2",3"-dideoxydidehydro analogue 8, were successfully synthesized using the key intramolecular condensation reaction with phenylthiophosphate-type substrates. We investigated the conformations of these analogues and of cADPR and found that steric repulsion between both the adenine and N9-ribose moieties and between the adenine and N1-ribose moieties was a determinant of the conformation. The Ca(2+)-mobilizing effects were evaluated systematically using three different biological systems, i.e., sea urchin eggs, NG108-15 neuronal cells, and Jurkat T-lymphocytes. The relative potency of Ca(2+)-mobilization by these cADPR analogues varies depending on the cell-type used: e.g., 3"-deoxy-cADPcR (4) > cADPcR (2) > cADPR (1) in sea urchin eggs; cADPR (1) > cADPcR (2) approximately 3"-deoxy-cADPcR (4) in T-cells; and cADPcR (2) > cADPR (1) > 3"-deoxy-cADPcR (4) in neuronal cells, respectively. These indicated that the target proteins and/or the mechanism of action of cADPR in sea urchin eggs, T-cells, and neuronal cells are different. Thus, this study represents an entry to cell-type selective cADPR analogues, which can be used as biological tools and/or novel drug leads. 相似文献
4.
N. Rösch P. Sandl P. Knappe A. Görling B. I. Dunlap 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1989,12(1-4):547-550
LCGTO Xα model cluster calculations have been carried out to rationalize the shape of the CO 1π band of the chemisorption system CO/Ni(111) observed in angular resolved photoemission. The splitting induced by substrate interaction at twofold bridging sites (0.4 eV) is much smaller than the value deduced from experiment (1.2 eV). From calculations on (CO) n clusters lateral adsorbate interaction is estimated to cause a sizable broadening of the 1π band (1.2eV, in satisfactory agreement with experiment), but essentially no splitting (?0.1 eV). Therefore, rehybridisation due to local interaction does not seem to suffice as an explanation for the observed shape of the CO 1π band. 相似文献
5.
E. Knappe und I. Rohdewald 《Fresenius' Journal of Analytical Chemistry》1965,210(3):183-193
Zusammenfassung Zur Untersuchung umfassender Gemische von Di- und einigen anderen Oligocarbonsäuren wurden fünf dünnschichtchromatographische Anordnungen ausgearbeitet, die in geeigneter Weise miteinander kombiniert werden können. Im einzelnen wurde die Chromatographie an Polyäthylenglykol—Kieselgur (0,31,0) mit Diisopropyläther—Ameisensäure—Wasser (9073), an Polyamid mit Diisopropyläther—Petroläther—Kohlenstofftetrachlorid—Ameisensäure—Wasser (50202081), Acetonitril—Essigsäureäthylester—Ameisensäure (901010) bzw. Ameisensäurebutylester—Essigsäureäthylester—Ameisensäure (9010 10) und an Kieselgel mit Diisopropyläther—Ameisensäure—Wasser (9073) durchgeführt. Die für dreißig Säuren in diesen Anordnungen ermittelten Rf-Werte zeigten zum Teil erhebliche Unterschiede sowohl in ihrer Größe als auch in ihrer Reihenfolge, so daß — gegebenenfalls im Verein mit der Hydrierung von ungesättigten aliphatischen Säuren — sichere Identifizierungen möglich wurden. Fünfzehn der untersuchten dreißig Säuren traten zumindest in einer der genannten fünf Anordnungen als Einzelläufer auf.
Frau M. Ellermeier und vor allem Frau J.-I. Stuck danken wir für ihre gewissenhafte und geduldige Mitarbeit an den umfangreichen Versuchsserien.
III. Mitteilung: Knappe, E., u. D. Peteri: diese Z. 190, 380 (1962). 相似文献
Summary For the examination of mixtures of dicarboxylic acids and some oligocarboxylic acids by thin-layer chromatography five systems have been developed, which can be utilized as required. These systems are: polyethylene glycokieselguhr (0.31.0) with diisopropyl ether—formic acid—water (9073), polyamide with diisopropyl ether—petroleum ether—carbon tetrachloride—formic acid—water (50202081), polyamide with acetonitrile—ethylacetate—formic acid (901010), polyamide with butyl formate—ethyl acetate—formic acid (901010) and silicagel with diisopropyl ether—formic acid—water (9073). The resulting Rf values may show remarkable differences in magnitude as well as in sequence, thus making possible reliable identification, if necessary employing the additional hydrogenation of unsaturated aliphatic acids. Fifteen of the thirty acids studied appear as isolated entities in at least one of the five thin-layer systems cited, thus permitting direct identification.
Frau M. Ellermeier und vor allem Frau J.-I. Stuck danken wir für ihre gewissenhafte und geduldige Mitarbeit an den umfangreichen Versuchsserien.
III. Mitteilung: Knappe, E., u. D. Peteri: diese Z. 190, 380 (1962). 相似文献
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J. Kirchhof S. Unger B. Knappe P. Kleinert A. Funke 《Crystal Research and Technology》1987,22(4):495-501
Fluorine incorporation during the deposition of silica layers is studied under MCVD conditions using C2F3Cl3 as fluorine source. The experimental results are compared with known models of the incorporation mechanism. It is found that a gas/solid equilibrium during the consolidation step determines the final fluorine content of the layers. 相似文献