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21.
22.
Treatment of [Ti(O-i-Pr)(2)Cl(2)] with NaL(OEt) (L(OEt)(-) = [CpCo[P(O)(OEt)(2)](3)](-), Cp = eta(5)-C(5)H(5)) afforded [L(OEt)Ti(O-i-Pr)(2)Cl] that reacted with HCl in ether to give [L(OEt)TiCl(3)] (1). The average Ti-O and Ti-Cl distances in 1 are 1.975 and 2.293 A, respectively. Reaction of titanyl sulfate with NaL(OEt) in water followed by addition of HBF(4) afforded [L(OEt)TiF(3)] (2), the Ti-O and Ti-F distances of which are 2.020(2) and 1.792(2) A, respectively. The Zr(IV) analogue [L(OEt)ZrF(3)] (3) was prepared similarly from zirconyl nitrate, NaL(Oet), and HBF(4) in water. The Zr-O and average Zr-F distances in 3 are 2.139(2) and 1.938(2) A, respectively. Treatment of 1 with tetrachlorocatechol (H(2)Cl(4)cat) afforded [L(OEt)Ti(Cl(4)cat)Cl] (4). The average Ti-O(P), Ti-O(C), and Ti-Cl distances in 4 are 1.972, 1.926, and 2.334 A, respectively. Hydrolysis of 4 in the presence of Et(3)N yielded the mu-oxo dimer [(L(OEt))(2)Ti(2)(Cl(4)cat)(2)(mu-O)] (5). The average Ti-O(P), Ti-O(C), and Ti-O(Ti) distances in 5 are 2.027, 1.926, and 1.7977(9) A. Treatment of 1 with 1,1'-binaphthol (BINOLH(2)) in the presence of Et(3)N afforded [(L(OEt))(2)Ti(2)(mu-O)(2)(mu-BINOL)] x 2BINOLH(2) (6.2BINOLH(2)). Complex 1 is capable of catalyzing ring opening of epoxides with Me(3)SiN(3) under solvent-free conditions presumably via a Ti-azide intermediate. 相似文献
23.
The first successful attempt to construct supramolecular entities via incorporation of bifunctional exodentate ligands into the silver acetylide system is reported. Coordination assembly with nitrogen-donor spacers led to the formation of five distinct supramolecular complexes, namely [(Ag(2)C(2))(AgCF(3)CO(2))(4)(pyz)(2)](n) (1), [(Ag(2)C(2))(2)(AgCF(3)CO(2))(10)(CF(3)CO(2))(4)(DabcoH)(4)(H(2)O)(1.5)].H(2)O (2), [(Ag(2)C(2))(AgCF(3)CO(2))(4)(CF(3)CO(2))(bpaH)](n)() (3), [(Ag(2)C(2))(AgCF(3)CO(2))(8)(bpa)(4)](n) (4), and [(Ag(2)C(2))(2)(AgCF(3)CO(2))(10)(bppz)(2)(H(2)O)](n) (5) (pyz = pyrazine; Dabco = 1,4-diazabicyclo[2.2.2]octane; bpa = 1,2-bis(4-pyridyl)ethane; bppz = 2,3-bis(2-pyridyl)pyrazine). Complex 1 is a three-dimensional framework composed of silver columns cross-linked by pyrazine bridges, whereas 2 contains a discrete supermolecule whose core is a Ag(14) double cage that is completely surrounded by trifluoroacetate, aqua, and terminal monoprotonated Dabco ligands. Complex 3 has a branched-tree architecture with one terminal of the bpa ligand attached to the silver backbone and the other exposed and protonated. In 4, neutral decanuclear [(Ag(2)C(2))(AgCF(3)CO(2))(8)] units are interlinked by bpa spacers adopting both gauche and anti conformations to generate a layer structure. Another two-dimensional network was formed with bppz serving as an angular bridging ligand in 5, in which the building unit is a silver quadruple cage containing 24 silver atoms. 相似文献
24.
Huatian Shi Jianhui Xie William W. Y. Lam Wai-Lun Man Chi-Keung Mak Shek-Man Yiu Hung Kay Lee Tai-Chu Lau 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(56):12895-12899
The synthesis and X-ray structure of a new manganese(V) mesitylimido complex with a tetraamido macrocyclic ligand (TAML), [MnV(TAML)(N-Mes)]− ( 1 ), are reported. Compound 1 is oxidized by [(p-BrC6H4)3N ]+.[SbCl6]− and the resulting MnVI species readily undergoes H-atom transfer and nitrene transfer reactions. 相似文献
25.
Ag2C4, the second silver carbide to be fully characterized, has been synthesized as a light-gray powder (contaminated with metallic silver) that is explosive at high temperature (130 degrees C) and sensitive to mechanical shock, rather like the well-known prototype Ag2C2. In the pair of hydrated double salts Ag2C4.6AgNO3.nH2O (n = 2, 3), the nearly linear, centrosymmetric 1,3-butadiyne-1,4-diyl dianion C42-exhibits an unprecedented mu8-coordination mode, each terminal being capped by four sigma-bonded silver(I) atoms with pi-interaction to one of them. 相似文献
26.
A simple and efficient preparation of gramicidin S and its analogues is described. It involves solid-phase peptide synthesis and on-resin macrolactamization without side chain protection, affording cyclic products in high yield and high purity. The high specificity of the cyclization reaction was shown to originate in the formation of a pre-organized conformation of the linear biosynthetic precursor of gramicidin S. This facile method will provide convenient access to the analogues of the natural product for functional optimization to counter microbial resistance. 相似文献
27.
Dr. Sam C. K. Hau Prof. Dr. Thomas C. W. Mak 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(17):5387-5400
Single‐crystal X‐ray diffraction of a series of ten crystalline silver(I)–trifluoroacetate complexes that contained designed ligands, each of which was composed of an aromatic system that was functionalized with terminal and internal ethynyl groups and a vinyl substituent, provided detailed information on the influence of ligand disposition and orientation, coordination preferences, and the co‐existence of different types of silver(I)–carbon bonding interactions (silver–ethynide, silver–ethynyl, silver–ethenyl, and silver–aromatic) on the construction of coordination networks that were consolidated by argentophilic and weak inter/intramolecular interactions. The complex Ag L10? 6 AgCF3CO2 ? H2O ? MeOH ( HL10 =1‐{[4‐(prop‐2‐ynyloxy)‐3‐vinylphenyl]ethynyl}naphthalene) is the first reported example that exhibits all four kinds of silver(I)–carbon bonding interactions in the solid state. 相似文献
28.
29.
30.
Zou Jianzhong Hu Xiaodong Duan Chenying Xu Zheng You Xiaozeng Mak Thomas C. W. 《Transition Metal Chemistry》1998,23(4):477-480
Reaction of either K3[Fe(CN)6] or K4[Fe(CN)6] with a macrocyclic CuII complex, [Cu(teta)](ClO4)2 (teta = 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacylotetradecane), in aqueous solution gave the same product as shown by spectroscopic and physicochemical characterisation. The crystal structure of the complex shows that it is a one-dimensional linear chain type heterobinuclear FeIII–CuII polymer. The unit is composed of a [Cu(teta)(H2O)2]2+ cationic complex, a FeIII–CuII alternate linear chain unit, a ClO
4
–
ion and four water molecules. The Cu atom is coordinated in a distorted octahedral arrangement by four nitrogen atoms from one teta ligand and two nitrogen atoms of the bridging cyanide groups. The Cu—N bond distances involving the cyanide bridges, 2.522(7) and 2.608(7)Å, respectively, indicate weak antiferromagnetic interactions between the FeIII and CuII atoms. 相似文献