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991.
Roy L. Beddoes Jonathan R. Hinchliffe David Moorcroft Mark W. Whiteley 《Journal of organometallic chemistry》1998,560(1-2)
Reaction of [MX(CO)2(η7-C7H7)] (M=Mo, X=Br; M=W, X=I) with two equivalents of CNBut in toluene affords the trihapto-bonded cycloheptatrienyl complexes [MX(CO)2(CNBut)2(η3-C7H7)] (1, M=Mo, X=Br; 2, M=W, X=I). The X-ray crystal structure of 2 reveals a pseudo-octahedral molecular geometry with an asymmetric ligand arrangement at tungsten in which one CNBut is located trans to the η3-C7H7 ring. Treatment of 2 with tetracyanoethene results in 1,4-cycloaddition at the η3-C7H7 ring to give [WI(CO)2(CNBut)2{η3-C9H7(CN)4}], 3. The principal reaction type of the molybdenum complex 1 is loss of carbonyl and bromide ligands to afford substituted products [MoBr(CNBut)2(η7-C7H7)] 4 or [Mo(CO)(CNBut)2(η7-C7H7)]Br. Reaction of [MoBr(CO)2(η7-C7H7)] with one equivalent of CNBut in toluene at 60°C affords [MoBr(CO)(CNBut)(η7-C7H7)], 5, which is a precursor to [Mo(CO)(CNBut)(NCMe)(η7-C7H7)][BF4], 6, by reaction with Ag[BF4] in acetonitrile. In contrast with the parent dicarbonyl systems [MoX(CO)2(η7-C7H7)], complexes of the Mo(CO)(CNBut)(η7-C7H7) auxiliary, 5 and 6, do not afford observable η3-C7H7 products by ligand addition at the molybdenum centre. 相似文献
992.
《印度化学会志》2022,99(11):100759
Synthesis of binuclear dioxidomolybdate chloranilate complex of general formula [(MoO2X2)2(C6O4X2)] (where X = Cl, Br) were synthesized by dropwise addition of dichloromethane solution of chloranil (tetrachloro-1, 4-benzoquinone) with dichloro/dibromo dioxidobis(dimethylformamide) molybdenum(VI) in 1:2 M ratio by conventional, as well as, microwave irradiation (solvent free and solid support) methods. In [(MoO2X2)2(C6O4X2)] the environment around each molybdenum atom can be assign as the anticipated distorted octahedral coordination for the metal consisting of one terminal and one bridging oxygen along with chlorine atoms of the chloranil ligand. The binuclear dihalodioxidomolybdate(VI) complexes were characterized by elemental analysis, FT-IR, 13C NMR, UV–Vis and Mass Spectrometry to determine the complex formation. The synthesized binuclear dihalodioxidomolybdate(VI) complexes with plurality of uses as micro biocides and insecticide for controlling undesirable micro-organisms and pests in crop protection, protection of materials, household and veterinary pests apart from being cytotoxic. The synthesized complexes were also screened for their anti-inflammatory, antiulcer and antitumor activity using standard methods. 相似文献
993.
一维(1D)材料与二维(2D)材料的结合可形成独特的混合维度异质结,其在继承2D/2D范德瓦尔斯异质结的独特物性之外,还具有丰富的堆叠构型,为进一步调控异质结的结构及性能提供了新的可操控自由度。p型1D单壁碳纳米管(SWCNT)与n型2D二硫化钼(MoS2)的结合,为调控异质结的能带结构及器件性能提供了丰富的选择。本文直接在高密度、手性窄分布的SWCNT定向阵列及无序薄膜表面原位生长MoS2,制备出高质量1D SWCNT/2D MoS2混合维度异质结。深入分析形核点的表面形貌与结构,提出了“吸附-扩散-吸附”生长机制,用于解释混合维度异质结的生长。利用拉曼光谱分析,证实SWCNT与MoS2间存在显著的电荷转移作用,载流子可在界面处快速传输,为后续基于此类1D/2D异质结的新型电子及光电器件的设计与制备提供了新思路。 相似文献
994.
Since to the best of our knowledge, there is no potentiometric sensors based on carbon paste electrodes were proposed for the potentiometric determination of molybdenum(VI) ion. In this study, 2,2′-(propane-1,3-diylbis(oxy))dibenzoic acid (PBODBA) was synthesized and used as modifier in the fabrication of carbon paste electrode (CPE) for the quantification of molybdenum(VI). The developed electrodes I and II showed hexavalent Nernstian response of 9.80±0.05 and 9.90±0.08 mV decade−1 over the concentration ranges of 1.0×10−7–1.0×10−3 and 1.0×10−8–1.0×10−3 mol L−1, respectively. The electrodes showed good selectivity for Mo(VI). The modified electrodes were applied for the determination of Mo(VI) concentration in masscuaje agricultural fertilizer and spiked juice extractions containing several metals. 相似文献
995.
Phosphanediyl Transfer from Inversely Polarized Phosphaalkenes R1P=C(NMe2)2 (R1 = tBu, Cy, Ph, H) onto Phosphenium Complexes [(η5‐C5H5)(CO)2M=P(R2)R3] (R2 = R3 = Ph; R2 = tBu, R3 = H; R2 = Ph, R3 = N(SiMe3)2) Reaction of the freshly prepared phosphenium tungsten complex [(η5‐C5H5)(CO)2W=PPh2] ( 3 ) with the inversely polarized phosphaalkenes RP=C(NMe2)2 ( 1 ) ( a : R = tBu; b : Cy; c : Ph) led to the η2‐diphosphanyl complexes ( 9a‐c ) which were isolated by column chromatography as yellow crystals in 24‐30 % yield. Similarly, phosphenium complexes [(η5‐C5H5)(CO)2M=P(H)tBu] (M = W ( 6 ); Mo ( 8 )) were converted into (M = W ( 11 ); Mo ( 12 )) by the formal abstraction of the phosphanediyl [PtBu] from 1a . Treatment of [(η5‐C5H5)(CO)2W=P(Ph)N(SiMe3)2] ( 4 ) with HP=C(NMe2)2 ( 1d ) gave rise to the formation of yellow crystalline ( 10 ). The products were characterized by elemental analyses and spectra (IR, 1H, 13C‐, 31P‐NMR, MS). The molecular structure of compound 10 was elucidated by an X‐ray diffraction analysis. 相似文献
996.
We report on self-assembly of polymer and molybdenum oxide chains into a new class of lamellar hybrid materials. Aqueous ammonium molybdate and polyvinyl alcohol (PVA) or carboxymethyl cellulose (CMC) were used as the starting materials. Ammonium molybdate was hydrolyzed into layered molybdenum oxide under acidified conditions. The organic polymer chains and the inorganic molybdenum oxide layers self-assemble and pack into new hybrid composites. Scanning electron microscope (SEM) images and polarized microscopy show that these two new materials have typical lamellar structure. Transmission electron microscope (TEM) images show that the layer thickness is about 100 nm. X-ray diffraction (XRD) data confirm the formation of inorganic molybdenum oxide. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) data gave thermal behavior of these composites. The mechanism of this hybrid reaction and the templating function of polymers were discussed in this paper. A special entropy effect was discovered when polymer was used as guest species. This entropy effect makes polymers preferential candidates as guest species rather than small molecules when fabricating organic/inorganic layered hybrid materials. We believe that this opens a new way to create organic/inorganic hybrid superstructures. 相似文献
997.
Harry Adams 《Journal of organometallic chemistry》2008,693(4):709-716
Treatment of the metal carbonylate anions [CpMo(CO)2(L)]− (Cp = η-C5H5; L = PPh2Me, PPh2Et) with the electrophilic alkynes methyl propiolate or DMAD (RCCCO2Me, where R = H or CO2Me, respectively) followed by protonation affords the η3-acryloyl (1-oxoallyl) complexes [CpMo(η3-COCRCHCO2Me)(CO)(L)] (3a-d) as the major products, together with the isomeric vinyl complexes trans-[CpMo(CRCHCO2Me)(CO)2(L)] (4a-d). On the basis of the regioselectivity of the reaction, it is proposed that nucleophilic attack of the carbonylate anion occurs at the alkyne carbon bearing R; migration of the anionic vinyl ligand to a CO followed by protonation gives 3, whereas protonation without insertion gives 4. The X-ray structures of the acryloyl complex [CpMo(η3-COCHCHCO2Me)(CO)(PPh2Me)] (3b) and its vinyl isomer [CpMo(σ-CHCHCO2Me)(CO)2(PPh2Me)] (4b) have been determined. 相似文献
998.
The reactivities of a series of ternary and binary molybdenum nitrides have been compared. Data have been obtained for the catalytic synthesis of ammonia at 400 °C and ambient pressure using a 3:1 H2:N2 mixture. Amongst the ternary nitrides, the mass normalised activity is in the order Co3Mo3N>Fe3Mo3N?Ni2Mo3N. For the binary molybdenum nitrides, the ammonia synthesis activity is significantly lower than that of Co3Mo3N and Fe3Mo3N and varies in the order γ-Mo2N∼β-Mo2N0.78?δ-MoN. Nanorod forms of β-Mo2N0.78 and γ-Mo2N exhibit generally similar activities to conventional polycrystalline samples, demonstrating that the influence of catalyst morphology is limited for these two materials. In order to characterise the reactivity of the lattice nitrogen species of the nitrides, temperature programmed reactions with a 3:1 H2:Ar mixture at temperatures up to 700 °C have been performed. For all materials studied, the predominant form of nitrogen lost was N2, with smaller amounts of NH3 being formed. Post-reaction powder diffraction analyses demonstrated lattice shifts in the case of Co3Mo3N and Ni2Mo3N upon temperature programmed reaction with H2/Ar. Incomplete decomposition yielding mixtures of Mo metal and the original phase were observed for Fe3Mo3N and γ-Mo2N, whilst β-Mo2N0.78 transforms completely to Mo metal and δ-MoN is converted to γ-Mo2N. 相似文献
999.
Swarup K. Maiti 《Tetrahedron letters》2008,49(43):6205-6208
A great variety of olefinic substrates having aromatic, carbocyclic and aliphatic olefins are effectively and selectively oxidized with oxygen-rich molybdenum(VI) complexes, namely [MoO(O2)2·2QOH] 1, [MoO(O2)(QO)2] 2, [Mo(O)2(QO)2] 3, [PPh4][MoO(O2)2(QO)] 4, [PPh4][Mo(O)2(O2)(QO)] 5 and [PPh4][Mo(O)3(QO)] 6 (QOH = 8-quinolinol) as catalyst, NaHCO3 as co-catalyst and H2O2 as the terminal oxidant, at room temperature. Catalysts 1 and 4 show unmatched yield, turnover number (TON) and turnover frequency (TOF), and hence shortest reaction time. 相似文献
1000.
Addition of Cationic Lewis Acids [M′Ln]+ (M′Ln = Fe(CO)2Cp, Fe(CO)(PPh3)Cp, Ru(PPh3)2Cp, Re(CO)5, Pt(PPh3)2, W(CO)3Cp to the Anionic Thiocarbonyl Complexes [HB(pz)3(OC)2M(CS)]− (M = Mo, W; pz = 3,5‐dimethylpyrazol‐1‐yl) Adducts from Organometallic Lewis Acids [Fe(CO)2Cp]+, [Fe(CO)(PPh3)Cp]+, [Ru(PPh3)2Cp]+, [Re(CO)5]+, [ Pt(PPh3)2]+, [W(CO)3Cp]+ and the anionic thiocarbonyl complexes [HB(pz)3(OC)2M(CS)]− (M = Mo, W) have been prepared. Their spectroscopic data indicate that the addition of the cations occurs at the sulphur atom to give end‐to‐end thiocarbonyl bridged complexes [HB(pz)3(OC)2MCSM′Ln]. 相似文献