The measurements of correlation times of molecules adsorbed on silica gel,alumina and charcoal using NOESY and MAS NMR

The correlation times (τ_c) and cross relaxation rates of toluene, dimethylformamide, tetrahydrofuran, water-acetone and water-dioxane adsorbed on silica gel, alumina and charcoal were obtained by measurements of the integrated intensities of cross and diagonal peaks in their NOESY spectra. The (τ_c) of the above mentioned systems is in the range of 10^?6?10^?9 s, much longer than that in the liquid (10^?12?10^?14 s). It was found that intramolecular rotation of toluene adsorbed on charcoal is slower than that on SiO₂, Al₂O₃ and the inversion of α and β protons in tetrahydrofuran is very fast (τ_c = 1.76×10^?9 s). The cross relaxation plays an important role in the relaxation of molecules adsorbed on solid surfaces with low electron densities.     

纳米二氧化锆制备过程的DSC、TGA和XRD研究

用ＤＳＣ、ＴＧＡ和ＸＲＤ技术研究了在沉淀法制备纳米ＺｒＯ２的过程中，残留ＮＨ４Ｃｌ、ｐＨ值、滴加方式、以及结构稳定剂Ｙ２Ｏ３的添加量对结晶过程的影响。结果表明，残留ＮＨ４Ｃｌ使结晶化温度降低，使放热过程变为吸热过程。而ｐＨ值、滴加方式和结构稳定剂的添加对结晶过程无明显影响。     

活性炭酸处理对CuO／C催化剂上NO还原反应的影响

４种国产活性炭被用于ＮＯ还原反应，其中，山楂核炭和山桃核炭具有较高的ＮＯ还原转化率。实验发现，表面含氧基团－ＣＯＯ－对活性炭自身的还原性和对ＮＯ的还原活性有很重要的影响。对表面富－ＣＯＯ－基团的活性炭，稀盐酸处理使表面－ＣＯＯ－显著分解。     

紫外光度法间接测定脱脂乳中的芽孢数量

为了有效控制乳制品生产过程、保证质量,克服芽孢杆菌传统计数方法周期长的缺点,本实验通过分光光度法检测芽孢中特异性物质2,6-吡啶二羧酸(DPA)。根据DPA浓度与芽孢数量的关系,建立了快速检测脱脂乳中芽孢数量的方法。本研究对脱脂乳及其芽孢处理、DPA释放及采用紫外分光光度法检测做了研究。通过准确度和加标回收率检验,建立DPA含量与芽孢数的线性关系,回归方程为y=0.2084x-0.9363,r=0.6998,经验证可有效估测脱脂乳中芽孢数量(P<0.05)。     

螺桨烷

本文综述了螺桨烷的最新进展,详细叙述了螺桨烷的合成、结构与性质,特別是小螺桨烷的张力能及桥头-桥头碳-碳单键的价键状态。     

Crystal Structure and Characterization of a Large Polyoxotungstate (NH4)21{La(H2O)5[Ni(H2O)]2As4W40O140}·53H2O

The heteropolytungstate (NH4)₂₁{La(H₂O)₅[Ni(H₂O)]₂As₄W₄₀O₁₄₀}·53H₂O is obtained by the reaction of Na₂₇[NaAs₄W₄₀O₁₄₀]· 60H₂O with NiCl₂·6H₂O, La(NO₃)₃·6H₂O and NH₄Cl at pH‐4.5. The structure and chemical composition are determined by X‐ray diffraction analysis and elemental analysis. The crystal data and main structure refinement are a = 1.9551(3) nm, b = 2.4156(4) nm, c= 3.7068(6) nm, β = 91.505(3)°, V = 17.500 (5) nm³, monoclinic crystal system with space group P2₁/n, Z = 4, R₁ = 0.0573, wR₂ = 0.0717 [I >2<s?(I)], R₁, = 0.2463 and wR₂ = 0.1199 (all data). [La(H₂O)₅] {Ni(H₂O)}₂AS₄W₄₀O₁₄₀ has C₂, symmetry. IR spectra of the ligand [NaAs₄W₄₀O₁₄₀]^27‐ and its three complexes were discussed.     

A Novel Green Preparation of a, a''''-Bis (substituted benzylidene)-cycloalkanones Promoted by FeCl_3 6H-2O in Ionic Liquid

a, a'-Bis(substituted benzylidene)cycloalkanones were efficiently prepared from cycloalkanones and benzaldehydes in [bmim][BF4] by using iron(III) chloride hexahydrate as a catalyst. It is shown that [bmim][BF4] and iron(III) chloride hexahydrate can be quantitatively recovered and be reused effectively for many times. Compared with the known methods, this novel process has the advantage of being an envkonmentally benign process together with good yields and mild reaction conditions.     

互贯型螯合树脂的研究．Ⅱ．IPN型含偕胺肟基螯合树脂的合成与性能研究

以交联聚苯乙烯－聚丙烯腈树脂为骨架，经功能基化反应制备出含偕胺肟基团的互贯型螯合树脂。对功能基化反应条件和螯合树脂对金的吸着性能，吸着选择性和吸着机理进行了研究。互贯型螯合树脂的吸着性能与互贯树脂的结构有关，而螯合树脂的选择吸着性则与互贯网络无关．     

α-杂环硫代苯乙酮衍生物的合成

以5-氨基-3-巯基-(1H）-1，2，4-三唑和2-巯基苯并噻唑为主要原料在碱性条件下与α-氯代苯乙酮反应合成了10个新的标题化合物。其结构经元素分析、IR，^1H NMR和MS确证。