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711.
712.
用量子化学密度泛函(DFT)方法, 在B3LYP/LanL2DZ的水平上, 研究了一系列异构配合物α-, β-, γ-, δ-, ε-[Ru(azpy)2Cl2](azpy = 2-phenylazopyridine)(1~5)的电子结构与几何构型, 并着重研究了已报道具有优良抗癌活性的1~3的构效关系(SAR). 计算结果表明, 配合物3的两个共轭配体(azpy)的主体部分几乎处于同一平面上, 有利于插入到DNA碱基对之间. 而配合物1和2的两个共轭配体(azpy)的主体部分几乎相互垂直, 对配合物的DNA插入键合空间位阻较大. 计算结果还进一步显示了该系列异构体配合物的电子结构特征及相关性质. 作为配合物在亲电反应中起主要作用的最低未占据分子轨道(LUMO)的能量顺序为εL(2)>εL(1)>εL(3); 与反应活性密切相关的LUMO与最高占据分子轨道(HOMO)之间的能量差(ΔεL-H)顺序为ΔεL-H(3)<ΔεL-H(1)<ΔεL-H(2); 反映配合物疏水性的偶极矩顺序为µ(2)>µ(1)>µ(3); 此外, 与亲电反应有关的配合物共轭配体azpy上正电荷(QL)顺序为QL(3)>QL(1)>QL(2). 同时, 对迄今尚未见抗癌活性报道的同系列其它两个异构配合物(4和5)进行了活性预测. 相似文献
713.
《Electrochemistry communications》2007,9(9):2291-2298
Chemical vapor deposition (CVD) was firstly used to simultaneously codope fluorine and boron into TiO2 nanotubes anodized Ti in C2H2O4 · 2H2O + NH4F electrolyte. F–B-codoping was successfully carried out by annealing the anodized TiO2 nanotubes through CVD, as evidenced from XPS analysis. SEM images showed that the higher the annealing temperature, the greater structure damage of F–B-codoped sample. XRD results confirmed that annealing temperature had an influence on the phase structure and boron and fluorine impurities could retard anatase–rutile phase transition. F–B-codoped samples displayed remarkably strong absorption in both UV and visible range. Under visible-light irradiation, F–B-codoped samples showed the higher Iph and catalytic activity in methyl orange photoelectrodegradation than F-doped sample and B-doped sample. This showed a convincing evidence of F–B-codoping of TiO2 had an obvious synergistic effect on the enhancement of photocurrents and photoelectrocatalytic activity. 相似文献
714.
Z. V. Belyakova M. G. Pomerantseva E. A. Chernyshev P. A. Storozhenko 《Russian Journal of General Chemistry》2009,79(12):2634-2636
Hydrosilylation of allyl esters of fluoro acids and ethers of fluoro alcohols with hydrochlorosilanes in the presence of the
Speier’s catalyst was studied. Yields of adducts with ethers reach 62–68%, and with esters, 27–45%. By etherification of the
adduts with ethers the respective ethoxysilanes were obtained in 41–43% yield. The latter reaction even in very mild conditions
is complicated by the formation of a large amount of siloxanes. Yield of siloxanes is 22–32%. 相似文献
715.
716.
717.
XU Qing-jun ZHANG De-zhi DANG Li-juan LI Kun-ping College of Pharmacy Guangdong Pharmaceutical University Guangzhou P. R. China 《高等学校化学研究》2009,25(3)
Cynoglossum amabile Stapf et Drumm is widely distributed in southern China, which has been used as an anti-inflammatory, antihepatitis, anticystitis agent in Chinese folk medicine[1]. However, only a few phytochemical researches have been performed[2]. 相似文献
718.
Prof. Dr. Ajmal Khan Heng Zhao Meina Zhang Shahid Khan Prof. Dr. Depeng Zhao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(3):1356-1361
Chiral sulfones are of great importance in medicinal chemistry and chemical synthesis. Efficient methods for preparing enantiomerically enriched sulfone-containing molecules can therefore be of significant value; such methods, however, are uncommon. Herein, we report the first general palladium-catalyzed sulfonylation of vinyl cyclic carbonates with sodium sulfinates. A series of enantiomerically enriched tertiary allylic sulfones were synthesized in good yields with excellent enantiomeric ratios. Both aliphatic- and aryl-substituted vinyl cyclic carbonates are suitable reactants with excellent results. This reaction features broad substrates scope, readily available starting materials, excellent regio- and enantioselectivity, and synthesis of sulfone-bearing quaternary carbon stereocenters. Through the sulfonylation of geranyl derived cyclic carbonate 1 h , we achieve the formal total synthesis of (+)-agelasidine A. 相似文献
719.
Dr. Junxian Yang Dr. Zheng Wang Zeyuan He Dr. Guofeng Li Prof. Dr. Liang Hong Prof. Dr. Wangsheng Sun Prof. Dr. Rui Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(2):652-657
The first asymmetric synthesis of tetrasubstituted α-amino allenoates by a chiral phosphoric acid catalyzed dearomative γ-addition reaction of 2,3-disubstituted indoles to β,γ-alkynyl-α-imino esters is reported. This method provides access to a series of highly functionalized tetrasubstituted allenes featuring quaternary stereocenters in high yields, and with excellent regio-, diastereo-, and enantioselectivities under mild conditions without by-product formation. Representative large-scale reactions and diverse transformations of the products into various scaffolds with potential biological activities render are also disclosed. The mechanism of the reaction was elucidated by control reactions and DFT calculations. 相似文献
720.
H. Y. Liu G. W. Li Z. L. Li J. Y. Wu Y. C. Cai 《Russian Journal of Coordination Chemistry》2011,37(9):668-673
Two new zinc(II) complexes, [ZnBr2L1] (I) and [ZnBr2L2] (II), where L1 is 2-[(2-isopropylaminoethylimino)methyl]-5-methoxyphenol and L2 is N,N-dimethyl-N′-(1-pyridin-2-yl-ethylidene)ethane-1,2-diamine, were prepared and characterized using elemental analysis,
FT-IR spectroscopy, and X-ray single-crystal diffraction. In complex I, the Zn(II) atom is coordinated by one phenolic O and
one imino N atoms of L1 and two Br atoms, forming a tetrahedral coordination geometry. In complex II, the Zn(II) atom is in a trigonal bipyramidal coordination geometry with the equatorial plane formed by the imino N atom
of L2 and two Br atoms and with the two axial positions occupied by one pyridine N and one amino N atoms of L2. In the crystal structure of I, the mononuclear zinc complex molecules are linked through intermolecular N-H…O and N-H…Br
hydrogen bonds, forming chains running along the y axis. The chains are further linked via intermolecular C-H…Br hydrogen bonds. In the crystal structure of II, the mononuclear zinc complex molecules are linked through intermolecular C-H…Br hydrogen bonds, forming a 3D network. 相似文献