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51.
The first measurements of the enthalpies of combustion, sublimation, and fusion of an organo-phosphorus sulfide, triphenylphosphine sulfide, are reported: c
H
m
o
(C18H15PS, cr)=–(10752.58 ±2.90), sub
H
m
o
(C18H15PS, 403 K)=(136.80±6.09), and fus
H
m
o
(C18H15PS, Tm=435.92 K) =(30.53±0.21) kJ·mol–1. Correction of the phase change enthalpies toT=298.15K and po =0.1 MPa results in the standard phase change enthalpy values of sub
H
m
o
(298.15 K)=(142.8 ±6.8) and fus
H
m
o
(298.15 K)=(19.28±0.21) kj·mol–1. Accordingly, the enthalpies of formation of solid, liquid, and gaseous triphenylphosphine sulfide are derived: f
H
m
o
(C18H15PS, cr) =(63.20±2.56), fH
m
o
(C18H15PS, l)=(82.48±2.57), and fH
m
o
(C18H15PS, g)=(206.0±7.3) kJ·mol–1. From these ancillary data, the P=S double-bond enthalpy is 394 kJ-mol–1 and in good agreement with earlier reaction calorimetry results. These phosphorus sulfide values are compared with those for the arsenic sulfides. Plausibility arguments are given for our results. 相似文献
52.
The room temperature reaction of the complex cis,trans,cis-[Ir(H)2(PPh3)2(Solv)2]PF6 (Solv is a solvent) with the imine PhCH2N=CHPh in acetone generates (with loss of H2) the orthometallated complex [Ir(H){PhCH2N=CH(o-C6H4)}(PPh3)2(Me2CO)]PF6 (3) containing a five-membered cyclometallated imine moiety. In MeOH, the reaction at an imine : Ir ratio = 1 leads to the corresponding MeOH analog of 3, while with excess imine, the mixed orthometallated imine/bezylamine complex [Ir(H){PhCH2N=CH(o-C6H4)}(PPh3)2(PhCH2NH2)]PF2 (4) is formed; the source of the coordinated amine is an Ir-promoted hydrolysis of the imine, the water likely coming from imine. Complexes 3 and 4 are fully characterized by elemental analysis, 1H and 31P{1H} NMR spectroscopy, and X-ray crystal structure analysis. 相似文献
53.
含希土乙酰基丙酮配合物的均相催化体系催化丙烯齐聚反应的研究 Ⅰ.不同希土催化性能的比较和反应条件的影响 总被引:1,自引:0,他引:1
研究了十个希土元素(La、Ce、Pr、Nd、Sm、Gd、Dy,Ho、Er、Yb)的乙酰基丙酮配合物与三苯基膦、倍半氯乙基铝组成的均相体系对丙烯齐聚反应的催化性能,齐聚反应以二聚为主,二聚选择性一般在90%左右,二聚物的线性率均在32%左右。这三元体系的催化活性受PPh_3或Et_3Al_2Cl_3用量的影响很大,在最佳P/RE或Al_2/RE时,活性出现峰值。还考察了不同反应温度和不同反应时间下齐聚反应的结果。比较不同希土的乙酰基丙酮配合物,催化活性随希土元素的原子序数呈周期性的变化;前后两个周期的活性最高点分别出现在Pr和Dy处,最低点在Sm和Ho处。当反应条件为60℃,1.5h,Pr/RE=30,Dy/RE=25,P/RE=3.7时,Pr和Dy的二聚活性分别为1004和1261mol丙烯/(molRE·h)。 相似文献
54.
在NiCl2 (PPh3 ) 2 /NaH/Zn/PPh3 作用下 ,以 2 溴 3 ,4 次甲二氧基 5 甲氧基 苯甲酸甲酯为原料进行Ullmann type偶合 ,在温和条件下以较高的收率得到中间体 4,4′ 二甲氧基 5 ,6,5′ ,6′ 二次甲二氧基联苯 2 ,2′ 二甲酸二甲酯 ,经进一步的水解、环化成酸酐、开环酯化等反应得到 4,4′ 二甲氧基 5 ,6,5′ ,6′ 二次甲二氧基联苯 2 ,2′ 二甲酸单酯 .最后再与取代苄基哌嗪在DMAP及DCC催化下缩合 ,得到 12个新的不对称联苯甲酸酯甲酰哌嗪类化合物 ,并用1 HNMR ,IR ,ESI MS等手段进行了结构确认 相似文献
55.
AsymmetricTetrahedralCadmiumComplex:Bis[triphenylphosphine]cadmium(Ⅱ)DiiodideGouShao-Hua;LuJian-Ping;ZengQin-Dao;YouXiao-Zeng... 相似文献
56.
Mehdi Adib Esmaeil Sheibani Manizheh Mostofi Khadijeh Ghanbary Hamid Reza Bijanzadeh 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2701-2707
Crystalline phosphorus ylides are obtained in nearly quantitative yields from the addition reaction between triphenylphosphine, dialkyl acetylenedicarboxylates, and imidazolidine-2-thione. A dynamic NMR effect is observed in the 1 H NMR spectrum of the stabilized ylide obtained from dimethyl acetylenedicarboxylate (Δ G ≠ = 66.6 kJmol?1 ) and is attributed to restricted rotation around the carbon–carbon partial double bond resulting from the conjugation of the ylide moiety with the adjacent carbonyl group. 相似文献
57.
《Analytical letters》2012,45(11-12):2637-2651
Abstract An isocratic reversed phase high performance liquid chromatographic method is described for monitoring concentrations of triphenylphosphine (TPP) and other compounds involved in an oxygen-transfer reaction catalyzed by a molybdenum complex. Using an inexpensive octadecylsilane column and a mobile phase consisting of aqueous acetonitrile, good separations and linear chromatographic responses were achieved for solutions of TPP, pyridine and each of their oxides in the mobile phase with concentrations in the range of 0.0012 – 0.12 grams/100 mL. No evidence for TPP precipitation was observed during the analysis of supersaturated solutions containing TPP at concentrations as high as 0.27 grams/100 mL. Chromatograms of more concentrated TPP solutions exhibited a second peak corresponding in retention time to TPP-oxide. Contrary to the interpretation of a similar effect in a previous study, evidence is presented indicating that this second peak is not the result of decomposition of TPP to its oxide, but rather is caused by precipitation of TPP particles which coincidentally pass through the chromatographic system at the same rate as TPP-oxide. Thus in this interpretation, the correspondence of the retention time of the early eluting peak in the chromatograms of solutions containing high concentrations of TPP with that of the oxide of TPP is coincidental, and does not indicate the decomposition of TPP during its HPLC analysis. This is consistent with the data presented here and in earlier studies. 相似文献
58.
Aluminum phthalocyanine (AlPc) in the presence of Ph3PO acts as a highly effective catalyst for cyanosilylation of various aldehydes to the corresponding cyanohydrin trimethylsilyl ethers. The reaction proceeds smoothly with 5 mol% catalyst loading at room temperature, giving up to 96% yield. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
59.
α-Fluoro-α,β-unsaturated esters 2 were efficiently synthetized via diethylzinc-promoted Wittig reaction using a phosphonium-supported triphenylphosphine SCG-PPh31, which possesses similar reactivity as its parent analog triphenylphosphine. The main advantage of this system is the use of a novel low-molecular-weight support that is soluble in solvents of medium polarities for the attachment of reagents and insoluble in solvents of low polarities. 相似文献
60.