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101.
Katerina N. Lazarou Iordanis Chadjistamatis Aris Terzis Spyros P. Perlepes Catherine P. Raptopoulou 《Polyhedron》2010
The use of succinamic acid (H2sucm)/N,N′-chelate (2,2′-bipyridine, bpy; 4,4′-dimethyl-2,2′-bipyridine, dmbpy; 1,10-phenanthroline, phen) ‘ligand blends’ in CuX2·yH2O (X = NO3, y = 3; X = Cl, y = 0) chemistry has yielded the new complexes [Cu2(Hsucm)3(bpy)2](NO3)·0.5MeOH (1·0.5MeOH), [Cu2(Hsucm)(OH)Cl(bpy)2](OH)·3.6H2O (5·3.6H2O) and [Cu2(Hsucm)2Cl2(phen)2] (6). The succinamate(−1) ion behaves as a carboxylate ligand and exists in two different coordination modes in the structures of the above complexes, i.e., the common syn, syn μ2-κO:κO′ in 1, 5 and 6, and the μ2-κ2O:κO′ in 1. The primary amide group of Hsucm− remains uncoordinated and participates in intermolecular hydrogen bonding interactions leading to 1D, 2D and 3D networks. Characteristic IR bands of the complexes are discussed in terms of the known structures and the coordination modes of the Hsucm− ligands. 相似文献
102.
Papatriantafyllopoulou C Stamatatos TC Efthymiou CG Cunha-Silva L Paz FA Perlepes SP Christou G 《Inorganic chemistry》2010,49(21):9743-9745
The initial employment of 2-pyridinealdoxime in 3d/4f chemistry has led to a Ni(II)(8)Dy(III)(8) cluster with an unprecedented metal topology; the compound has an unusual structure, is the highest-nuclearity metal oxime cluster to date, and exhibits slow magnetization relaxation. 相似文献
103.
Demetris P. Papahatjis Dr. Victoria R. Nahmias Spyros P. Nikas Dr. Marion Schimpgen Alexandros Makriyannis 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(13):4091-4099
Two novel methyl‐substituted arachidonic acid derivatives were prepared in an enantioselective manner from commercially available chiral building blocks, and were found to be excellent templates for the development of (13S)‐methyl‐substituted anandamide analogues. One of the compounds synthesized, namely, (13S,5Z,8Z,11Z,14Z)‐13‐methyl‐eicosa‐5,8,11,14‐tetraenoic acid N‐(2‐hydroxyethyl)amide, is an endocannabinoid analogue with remarkably high affinity for the CB1 cannabinoid receptor. 相似文献
104.
Spyros Drivelos Marilena E. Dasenaki Nikolaos S. Thomaidis 《Analytical and bioanalytical chemistry》2010,397(6):2199-2210
A new hydrophilic interaction liquid chromatographic (HILIC) method for the simultaneous determination of isoascorbic (IAA)
and ascorbic acid (AA) was developed. The separation of IAA and AA was studied in various HILIC stationary phases and the
influence of the composition of the mobile phase, the ionic strength and the column temperature to the chromatographic characteristics
is presented. The final method used an aminopropyl column under isocratic elution with acetonitrile–100 mM ammonium acetate
solution (90:10, v/v) at a flow rate of 0.4 mL/min and a detection wavelength of 240 nm. This method was validated and the calibration curves
were found to be linear in the range of 1.0–65 μg/mL for both IAA and AA. The method limit of detection for IAA determination
in fish tissue was 2.3 μg/g. Inter-day precision (as %RSDR) was ranged between 0.56% and 8.3% at three concentration levels, whereas the respected recoveries ranged between 82% and
98%. This method was applied to the determination of IAA (as additive E315) in frozen redfish samples. The hyphenation of
the HILIC separation with a tandem mass spectrometer was also studied and the problems encountered with negative electrospray
ionization under HILIC separation conditions are discussed. 相似文献
105.
The copper-catalyzed asymmetric conjugate addition of dialkyl zinc leads to homochiral zinc enolates. These intermediates were trapped in situ with activated allylic electrophiles, without the need of additional palladium catalysis. High trans selectivity (85/15 to 100/0) and excellent enantioselectivities (up to 99%) could be attained. The functionalized nature of the electrophiles makes the new synthons potential candidates for further elaboration. 相似文献
106.
Godlewski G Alapafuja SO Bátkai S Nikas SP Cinar R Offertáler L Osei-Hyiaman D Liu J Mukhopadhyay B Harvey-White J Tam J Pacak K Blankman JL Cravatt BF Makriyannis A Kunos G 《Chemistry & biology》2010,17(11):1256-1266
The enzyme fatty acid amide hydrolase (FAAH) catalyzes the in vivo degradation of the endocannabinoid anandamide, thus controlling its action at receptors. A novel FAAH inhibitor, AM3506, normalizes the elevated blood pressure and cardiac contractility of spontaneously hypertensive rats (SHR) without affecting these parameters in normotensive rats. These effects are due to blockade of FAAH and a corresponding rise in brain anandamide levels, resulting in CB? receptor-mediated decrease in sympathetic tone. The supersensitivity of SHR to CB? receptor-mediated cardiovascular depression is related to increased G protein coupling of CB? receptors. Importantly, AM3506 does not elicit hyperglycemia and insulin resistance seen with other FAAH inhibitors or in FAAH?/? mice, which is related to its inability to inhibit FAAH in the liver due to rapid hepatic uptake and metabolism. This unique activity profile offers improved therapeutic value in hypertension. 相似文献
107.
Chatziefthimiou SD Lazarou YG Hadjoudis E Dziembowska T Mavridis IM 《The journal of physical chemistry. B》2006,110(47):23701-23709
Twelve Schiff bases of methoxy-substituted salicylaldehyde have been examined by crystallographic and spectroscopic methods, as well as by DFT theoretical calculations in order to investigate the effect of the substituent's position on the keto-enol equilibrium in the crystalline state. Four out of the 10 structurally characterized compounds with methoxy substitution on the para and/or ortho positions with respect to the aldimine bridge and deriving from aliphatic amines or alkylarylamines are found as cis-keto tautomers and form dimers. In contrast, the five pure enol tautomers derive either from aliphatic or alkylarylamines and are meta substituted or from aniline or benzylamine and are para and/or ortho methoxy substituted. The DFT calculations support the crystallographic results and, moreover, they have shown that keto and enol tautomers are affected differently by the relative arrangement of the monomers. Overall, the DFT calculations point to a plausible hypothesis for the stabilization of the keto form in the crystalline state: In cases with a sufficiently low enol-keto energy difference of the isolated monomers, as when the methoxy group is at ortho and/or para positions with respect to the aldimino group, extra stabilization of the keto form is derived from molecular association, thus leading to its crystallization. 相似文献
108.
109.
We develop the notion of t-homogeneous, G-semiregular large sets of t-designs, show that there are infinitely many 3-homogeneous PSL(2, q)-semiregular large sets when q 3 mod 4, two sporadic 3-homogeneous AL(1,32)-semiregular large sets, and no other interesting t-homogeneous G-semiregular large sets for t 3. 相似文献
110.
Phosphoramidite ligands, based on ortho-substituted biphenols and a chiral amine, induce high enantioselectivities (ee's up to 99%) in the copper-catalyzed conjugate addition of dialkylzinc reagents to a variety of Michael acceptors. Particularly, the best reported ee's were obtained for acyclic nitroolefins. 相似文献