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131.
In Schmitz (Aequ Math 91:373–389, 2017), the first author defines an “inverse ambiguous function” on a group G to be a bijective function \(f:G \rightarrow G\) satisfying the functional equation \(f^{-1}(x) = (f(x))^{-1}\) for all \(x \in G\). Using a simple criterion involving the number of elements in G not equal to their own inverse, the classification of finite abelian groups admitting inverse ambiguous functions is achieved. In this paper we aim to extend the results from (2017) to determine the existence of inverse ambiguous functions on members of certain families of non-abelian groups, namely the symmetric groups \(S_n\), the alternating groups \(A_n\), and the general linear groups GL(2, q) over a finite field \(\mathbb {F}_q\). 相似文献
132.
Cozzolino R Gallagher RT Drewello T 《European journal of mass spectrometry (Chichester, England)》2006,12(1):31-35
Salt-like cluster ions of the ([cation](n)[anion](n-1))(+) type are commonly composed of mono-atomic, inorganic components. Clusters containing organic ions are also known, with nitrogen-centred cations being particularly prominent. However, sulphur-centred analogues, such as organic sulphonium salts, represent a notable exception. Fast atom bombardment and liquid secondary ion mass spectrometry of such compounds show, in general, a low tendency towards the formation of clusters. The present study reveals that sputtering of cyclic sulphonium salts leads to the efficient formation of cluster ions beyond previous observations. Cluster ions are characterised by isotopic pattern analysis and collision-induced dissociation. 相似文献
133.
Lifetime of levels up to 22+, have been measured in 78Kr and an oblate shape is assigned to the ground state using the CSM and the configuration dependent shell correction calculations.
Calculations further show that 78Kr is highly γ-soft nucleus. The experimental Q
t values coupled with theoretical calculations indicate an oblate shape for 78Kr at low spins and triaxial shape at higher spins 相似文献
134.
John P. Sanders Patrick K. Gallagher 《Journal of Thermal Analysis and Calorimetry》2009,96(3):805-811
For complex decomposition reactions, traditional methods, such as TG and DSC cannot fully resolve all of the steps in the
reaction. Evolved gas analysis (EGA) offers another tool to provide more information about the decomposition mechanism. The
decomposition of sodium bicarbonate was studied by TG, DSC and EGA using a simultaneous thermal analysis unit coupled to a
FTIR. The decomposition of sodium bicarbonate involves two reaction products H2O and CO2, which are not evident from either TG or DSC measurements alone. A comparison of the reaction kinetics from TG, DTG and EGA
data were compared. 相似文献
135.
An allylstannane reagent on non-cross-linked polystyrene support 总被引:1,自引:0,他引:1
[reaction: see text] A new allylstannane reagent on non-cross-linked polystyrene was developed for the first time. This support differs markedly from standard cross-linked polymers because it is completely soluble in organic solvents; moreover, the reactions can be conveniently monitored directly by standard 1H NMR methods. The allylstannane underwent a free radical reaction with an alkyl halide to form a new allyl appendage. Tin byproducts can be easily recovered from cold methanol as white crystalline solids. 相似文献
136.
Sutherland A Gallagher T Sharples CG Wonnacott S 《The Journal of organic chemistry》2003,68(6):2475-2478
Two racemic fluoropyridine analogues 4 and 5 of the potent nicotinic agonist UB-165 have been synthesized. Halogenated pyridines 7 and 12 provided the organometallic reagents needed for the Negishi and Suzuki coupling reactions used for the preparation of 4 and 5, and the N-vinyloxycarbonyl protecting group of 8 and 15 was cleaved using a novel trifluoroacetic acid-mediated deprotection protocol. Analogue 4 retained high binding affinity at rat brain alpha4beta2 and alpha7 nicotinic receptors. 相似文献
137.
138.
A. Paul Krapcho Martin J. Maresch Cynthia E. Gallagher Miles P. Hacker Ernesto Menta Ambrogio Oliva Roberto Di Domenico Giovanni Da Re Silvano Spinelli 《Journal of heterocyclic chemistry》1995,32(6):1693-1702
Synthetic procedures have been developed which lead to 4-hydroxy-6,9-difluorobenz[g]isoquinoline-5,10-dione ( 4a ) and its 3-methyl analogue 4b . Attempts to displace the fluorides from 4a with N,N-dimethylethylenediamine were unsuccessful. Analogue 4a on treatment with N-(t-butoxycarbonyl)ethylene diamine led to 15 , formed from addition of the nucleophilic amine to C-3. On the other hand, analogue 4b , on treatment with N,N-dimethylethylenediamine led to the anticipated difluoride displacement product 3c . The protection of the hydroxy group of 4a by benzylation with phenyldiazomethane led to 4c which on treatment with N-(t-butoxycarbonyl)ethylene diamine or N,N-dimethylethylenediamine led to the corresponding 6,9-bis-substituted analogues 18a and 18b , respectively. Reductive debenzylations of 18a and 18b by hydrogenation over Pearlman's catalyst also effected partial reductions of the quinone. However, air oxidation of the over reduced products led to 3a and 3b , respectively. Treatment of 3a with hydrogen chloride gas led to the hydrochloride salt of 3d . Addition of O-p-Methoxybenzyl-N,N'-diisopropylurea to 4a led to the p-methoxybenzyl analogue 4d . Treatment of 4d with N,N-dimethylethylene diamine or N-(t-butoxycarbonyl)ethylene diamine led to displacements of the fluorides to yield 18c and 18d , respectively. Deprotection of 18c to 3b was accomplished using methanesulfonic acid. Treatment of 18d with trifluoroacetic acid followed by addition of maleic acid led to dimaleate salt of 3d . 相似文献
139.
140.
A. Paul Krapcho Cynthia E. Gallagher Abdelhakim Hammach Michael Ellis Ernesto Menta Ambrogio Oliva 《Journal of heterocyclic chemistry》1997,34(1):27-32
Treatment of difluoro or chloro fluoro-substituted benzyl bromides 5a-c with zinc dust in tetrahydro-furan leads to the corresponding benzylic zinc bromides 6a-c. These organometallics on treatment with chlorosubstituted heterocyclic esters 4A and 4B mediated by nickel catalysis undergo couplings to yield dihalobenzyl substituted heterocyclic esters 7Aa-c and 7Ba-c. Treatment of 4c with 6c under Pd catalysis leads to 7Cc. The acids 8, prepared by hydrolysis of these esters, with treatment of fuming sulfuric acid undergo cyclizations and oxidations to yield the desired regioisomeric dihalo-substituted heterocyclic quinones 2. 相似文献