二氧化钛柱撑层状氧化锰微孔材料的合成及表征

Na型层状锰氧化物于0.1 mol/L HCl 溶液中离子交换制得前驱体H型层状锰氧化物. H型层状锰氧化物在十二胺乙醇溶液中反应得到层间距为2.62 nm的中间产物——十二胺插入的层状锰氧化物, 该中间产物在异丙醇钛和乙醇的混合溶液中溶剂热处理得到层间距为1.24 nm的钛酸柱撑层状锰氧化物. 在300 ℃条件下经2 h焙烧得到二氧化钛铸型氧化锰微孔材料. 应用XRD, DSC-TGA, SEM, TEM, IR, 氮气吸附实验及元素分析进行了不同阶段所得试样的分析表征. 结果表明十二胺分子在锰氧层间的最大插入量为2.2 mmol/g, 异丙醇钛分子的置换插入生成了组成为Mn_7.00Ti_1.74O_23.3(C₁₂H₂₅NH₂)_0.52•1.93H₂O的铸型层状锰氧化物. 300 ℃焙烧处理所得二氧化钛铸型氧化锰微孔材料的比表面积为140 m²/g.     

高比表面CexZr1-xO2复合氧化物的制备及表征

分别采用共沉淀法和阴离子表面活性剂模板法制备了Ce_xZr_1-xO₂复合氧化物。采用XRD、AFM、FTIR以及N₂吸附-脱附等方法对样品进行了表征。结果表明，共沉淀法合成的样品在500 ℃煅烧2 h后，生成了立方相Ce_0.75Zr_0.25O₂和四方相Ce_0.5Zr_0.5O₂固溶体，比表面积为62.1 m²·g^-1，孔体积为0.097 cm³·g^-1；以阴离子表面活性剂十二烷基苯磺酸钠(SDBS)为模板剂，乙二胺为助模板剂合成的样品在500 ℃煅烧2 h后，生成了纯四方相Ce_0.5Zr_0.5O₂固溶体，比表面积为180 m²·g^-1，孔体积为0.182 cm³·g^-1。结果表明，以阴离子表面活性剂SDBS为模板剂，可以合成高比表面积且具有介孔结构的Ce_0.5Zr_0.5O₂复合氧化物；加入乙二胺作为助模板剂可明显的提高比表面积和孔体积。     

制备参数对高比表面积介孔催化剂La-Co-Zr-O结构与性能的影响

采用双表面活性剂模板(十六烷基三甲基溴化铵和聚乙二醇辛基苯基醚的混合物)分解法制备了不同原子比(n_La+n_Co)/(n_La+n_Co+n_Zr)和不同温度焙烧的系列介孔混合氧化物催化剂La-Co-Zr-O。运用XRD、N₂吸附/脱附、XPS和H₂-TPR等技术对催化剂进行了表征，并以CO和C₃H₈氧化为模型反应，考察了组分配比和焙烧温度等参数对催化剂催化性能的影响。比表面积和孔径测试结果表明，样品具有很高的比表面积(108～266 m²·g^-1)和分布集中的孔径(3.4～3.9 nm)，Zr含量较高的样品比表面积较大。XRD结果表明，样品中的活性组分钴物种主要以Co₃O₄形式存在；XPS和H₂-TPR结果表明，样品中可还原的晶格氧的数量、活动度以及表面钴原子浓度均与催化剂对CO和C₃H₈的氧化性能密切相关。原子比为0.5的样品中，较多的晶格氧易于在相对低温下还原；而原子比为0.7的样品表面钴原子浓度较高，这使得两样品均表现出较高的催化活性。经650 ℃焙烧的样品仍保持较高的比表面积(108 m²·g^-1)和分布集中的介孔孔径(最可几孔径约3.8 nm)，且催化活性下降幅度也很小，表明该系列介孔催化剂具有优良的抗烧结能力和介孔热稳定性。     

超细CeM(M=Mg,Sr)Ox复合氧化物的性能研究

采用聚合物前驱体法首次合成了超细粒子CeM(M=Mg，Sr)O_x复合氧化物粉体。通过XRD、TEM、BET等技术对合成的粉体进行了表征，结果表明CeO₂与碱土金属形成的CeM(M=Mg，Sr)O_x新粉体材料比表面积为66～69 m²·g^-1，经800 ℃、1 000 ℃焙烧2 h后，粉体平均晶粒仍保持在10～20 nm，基本不发生团聚现象，具有较好的抗烧结能力。用甲烷催化燃烧为模型反应，发现该粉体催化剂具有很高的催化活性，优于单组分CeO₂。     

溶胶插入法制备高比表面TiO2柱层状铌酸

采用溶胶插入法合成了氧化钛柱层状铌酸，并用XRD、IR、BET和TEM等技术进行了表征。所得层柱材料是多孔性的，包含大量的中孔，其BET比表面积高达131.3m²·g^-1(450℃)。另外，材料具有较好的热稳定性，经450℃焙烧后其层间距为1.26nm，经550℃焙烧2h后其层柱结构仍然保持。     

Co-Cu-Al水滑石的合成及对NO+CO反应性能的研究

本文研究了Co-Al水滑石中加入过渡金属(M)离子后对NO+CO反应的活性。结果表明Co-Al上引入Cu离子对NO+CO反应具有较高的催化活性；以Co-Cu-Al水滑石为研究对象，考察了Co和Cu含量的变化对NO+CO反应活性的影响，发现Co-Cu-Al对NO+CO反应存在一个最佳Co和Cu的含量配比；当n_Co∶n_Cu∶n_Al=5∶3∶1时，其催化活性为最佳，在反应温度120 ℃时，NO的转化率达100%；XRD结果表明Co-Cu-Al经450 ℃焙烧2 h后已有少量的尖晶石相形成，随焙烧温度的提高尖晶石相增多，尖晶石相的形成对催化还原NO有明显的影响；NO-TPD-MS结果表明NO吸附在Co-Cu-Al上的热脱附产物经质谱跟踪能检测到NO(m/e=30)、N₂O(m/e=44)、N₂(m/e=28)和O₂(m/e=32)等4种脱附物种，推测低温脱附物种为吸附在弱位上的NO，而高温脱附物种为吸附在强位上的NO，400 ℃焙烧的Co-Cu-Al水滑石上NO的脱附峰温略低于600 ℃焙烧的，NO在Co-Cu-Al表面的解离是NO+CO反应的速控步骤。     

高比表面TiO2光催化剂的制备及产氢性能研究

以钛酸四丁酯为前驱体，十六烷基三甲基溴化铵(CTAB)为模板剂合成了高比表面的TiO₂超细纳米粉体。采用XRD、TEM、BET分析方法对催化剂的物相、颗粒粒径及比表面积进行了表征，结果显示TiO₂的晶粒尺寸和比表面积与CTAB添加量和焙烧温度有关。重点考察了不同条件下制备的TiO₂系列光催化剂无氧条件下的光催化分解水产氢性能。实验结果表明，当CTAB与Ti的投料的物质的量之比为0.15，焙烧温度为450 ℃时，获得的晶粒尺寸为5.73 nm、比表面为150 m²·g^-1的TiO₂粉体具有最好的光催化产氢活性，测得的3 h内平均产氢速率为12.5 mL·h^-1。     

含Ce水滑石基复合氧化物对混合染料的光催化性能

将具有光催化活性的CeO₂和锌锡水滑石进行复合,经焙烧得到光催化性能较高的CeO₂/ZnO/SnO₂复合氧化物。通过X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和紫外-可见漫反射图谱(UV-Vis DRS)技术对样品的晶体结构、表面形貌和光学性能进行表征,并利用密度泛函理论(DFT)计算样品的态密度,分析其电子能态结构。以甲基橙(MO)和亚甲基蓝(MB)的混合溶液(C_MO:C_MB=1:1)模拟染料废水,研究CeO₂含量和焙烧温度对复合氧化物光催化降解混合染料的影响。结果表明:随着CeO₂含量和焙烧温度的增加,复合氧化物的结晶度及对MO和MB的光催化活性得到增强;同时,复合氧化物对混合染料中MO的降解率优于MB。其中CeO₂含量为20%,焙烧温度为700℃时的复合氧化物表现出最佳的光催化性能,对混合染料中MO和MB的降解率分别达到96.7%和95.0%。结合实验结果和理论计算,推测了混合染料中MO和MB的降解路径。     

CeZrYLaO对Fe基整体式稀薄甲烷催化燃烧性能的影响

采用共沉淀法制备了高性能低铈储氧材料Ce_0.35Zr_0.55Y_0.07La_0.03O_1.95(OSM,储氧材料)和胶溶法制备了耐高温、高比表面的La-Al₂O₃并以它们为载体,制备了一系列整体式铁基催化剂。考察了该系列催化剂对甲烷稀薄燃烧的催化性能,并用低温N₂吸附-脱附,储氧能力(oxygen storage capacity,OSC),XRD,XPS和H₂-TPR等测试手段对载体和催化剂进行了表征。活性测试结果表明所制得的整体式催化剂Fe/OSM+La-Al₂O₃可在50 000 h^-1的高空速条件下使含量为1%的甲烷在474 ℃起燃,565 ℃完全转化;低温氮吸附-脱附测试结果表明,所制得的Ce_0.35Zr_0.55Y_0.07La_0.03O_1.95经1 050 ℃焙烧5 h后的BET比表面积达33 m²·g^-1,孔容为0.14 mL·g^-1;La-Al₂O₃经1 050 ℃焙烧5 h后的BET比表面积达125 m²·g^-1,孔容为0.46 mL·g^-1,是优良的催化剂载体;OSC测试结果表明,加入储氧材料(oxygen storage material(OSM))能增加催化剂的储氧性能,有利于催化活性的提高;XRD测试结果表明,OSM以均一固溶体存在;XPS测试结果表明,Fe₂O₃与OSM载体之间的相互作用最强;H₂-TPR测试结果表明,加入OSM能增加催化剂的还原性能,从而提高了催化活性。     

纳米SO42-/ZrO2的合成及其在酯交换反应中的催化性能

采用两步晶化-后浸渍法合成了纳米SO₄^2-/ZrO₂固体酸催化剂,并考察了其在植物油与甲醇酯交换反应中的催化性能。XRD、N₂吸附-脱附和TEM等结果表明,经过600℃焙烧,催化剂仍保持单一四方相,粒径大小为5~10 nm,比表面积为137 m²·g^-1,孔径为3.6 nm。NH₃-TPD结果表明,随着焙烧温度升高,催化剂表面的酸含量和酸强度逐渐增加,超强酸含量的增加,更有利于反应在温和条件下进行。在酯交换反应中,当醇油物质的量之比为20：1,反应温度为135℃,反应时间为6 h,600℃焙烧后催化剂用量为5%（w/w）时,植物油能够完全转化为脂肪酸甲酯。与传统的SO₄^2-/ZrO₂催化剂相比,该催化剂在低温反应条件下具有更高的催化性能和良好的重复使用性。     

SYNTHESIS AND REACTIONS OF SOME 2-THIENYL- AND 2-THENOYL-DERIVATIVES OF THIAZOLE AND THIADIAZOLINE AND THEIR SELENIUM ANALOGS

Abstract

2-(Thiocyanatoacetyl)thiophene 2 and its selenium analog 3 couple with diazotized anilines and yield 3-aryl-2-imino-5-(2-thenoyl)-2,3-dihydro-1,3,4-thiadiazoles 6 and 3-aryl-2-imino-5-(2-thenoyl)-2,3-dihydro-1,3,4-selenadiazoles 7 respectively. The reactions of both 6 and 7 with nitrous acid, acetic anhydride and benzoyl chloride are described. Azo coupling of 2-amino-4-(2-thienyl)thiazole 17 and its selenazole analog 18 with diazotized anilines yielded the arylazo derivatives 19 and 20 respectively. Reaction of the hydrazidoyl bromide 16 with potassium thiocyanate, potassium selenocyanate, thiourea and selenourea yields 6, 7, 19, and 20 respectively.     

PHOTOLYSIS AND RADIOLYSIS OF NITROMETHANE AND NITROETHANE

Abstract— Prolonged photolysis of nitromethane and nitroethane in liquid and vapour phases, with simultaneous photolysis of the nitrogen dioxide formed, was studied in the absence and presence of cupric oxide. A high-pressure quartz immersion lamp providing the full range of visible and u.v. spectrum, with a high output of radiation at 366 and 313 mμ, was employed as source of light. The products of photolysis were detected by microanalytical methods, infrared-absorption spectrum analysis and gas chromatography. Photolysis of liquid nitro-alkanes resulted in formation of many compounds; saturated hydrocarbons, and in the case of nitroethane, ethylene, were submitted to detailed examination. Photolysis in the vapour phase was carried out in a specially designed glass apparatus. The main products were nitrogen dioxide, aldehydes and polyaldehydes; hydrocarbons were not estimated.
Liquid nitromethane and nitroethane were also irradiated with γ-rays from a ⁶⁰Co source. The radiolysis products were similiar to those obtained on photolysis. The mechanism of photolytic decomposition of nitroalkanes is proposed and discussed.     

CHLOROPHYLL a AND CAROTENOID AGGREGATES AND ENERGY MIGRATION IN MONOLAYERS AND THIN FILMS

Abstract— The spectra of absorption, fluorescence and excitation of monolayers and thin films containing chlorophyll a together with a carotenoid (cis-β-carotene, trans-β-carotene, fucoxanthin, or zeaxanthin), were measured at — 196°C. The concentration ratios used, (Chl)/(Car), were 6:1, 4:1, 3:1, 2:1, 1:1 and 1:3, and the area densities, 3·70, 2·55, 1·76, 0·71, 0·37 and 0·17 nm²/pigment molecule. In dilute monolayers, (3·70 nm²/molecule), with a constant concentration ratio (Chl)/(Car) = 3:1, evidence of three β-carotene forms, with absorption bands at 460, 500 and 520 nm (C₄₆₀, C₅₀₀ and C₅₂₀), and of a chlorophyll a form with an absorption band at 669–672 (Chl_669–672) was found. On increasing the density to 0·2–0·3 nm²/molecule, a conversion of C₄₆₀ and C₅₂₀ into C₅₀₀, was observed, and several more additional (probably more strongly aggregated) chlorophyll a forms appeared, with absorption bands at 672–733 nm. With excess carotene [(Chi)/(Car) = 1:3] the forms C₄₆₀, C₅₀₀, C₅₂₀ and Chl_669–672 were present even in the most dense films (0·2–0·3 nm²/molecule). The same was found with other carotenoids: if one of the pigments was in excess, aggregated forms of the other tended to disappear. In the transfer of energy from carotenoids to chlorophyll a, C₅₀₀ was found to be the main donor. In layers with a concentration ratio (Chl)/(Car) = 3:1, the efficiency of transfer was less than 10 per cent at the lowest density used (3·70 nm²/molecule); it increased to 50 per cent, as the density was increased to 0·20 nm²/molecule. When the relative concentration of the carotenoid was increased to (Chl)/(Car) = 1:1, the efficiency of energy transfer dropped to 25 per cent even at 0·20 nm²/molecule. It seems that the efficiency of energy transfer between carotene molecules (prior to its transfer to chlorophyll a) is low, and effective transfer occurs only between β-carotene and immediately adjacent chlorophyll a molecules.     

生物质热解、加氢热解及其与煤共热解的热重研究

在加压热天平上用非等温热重法进行生物质（锯末、稻壳）在Ｎ２气氛下的热解和加氢热解研究。考察了升温速率（５～２５℃／ｍｉｎ）和压力（０．１～７ＭＰａ）的影响，求取了热解动力学参数，并研究了生物质与煤在常压Ｎ２气下的共热解过程。研究结果表明：生物质在４００℃左右即完成热解反应，总失重率大于７０％（Ｗ％，ｄａｆ．），热解时仅一个峰位于３００℃左右；与煤热解行为相同，随升温速率及压力的升高，转化率下降，ＤＴＧ峰移向高温，但由于热解反应在较低温度下进行，氧气的存在对生物质热解ＴＧ和ＤＴＧ的影响远小于煤热解。证明生物质热解以其内部氢对自由基的饱和及分子重排反应为主。生物质热解可用一级反应动力学处理，主要热解阶段及表现活化能分别为：锯末，２６７～３１４℃，６９．６６ｋＪ／ｍｏｌ；稻壳，２８３～３１０℃，５３．４５ｋＪ／ｍｏｌ；生物质由于与煤的热分解温度相差很大，因而在其共热解过程中无协同作用。     

SURFACE ENTHALPY AND ENTROPY AND THE PHYSICO-CHEMICAL NATURE OF HYDROPHOBIC AND HYDROPHILIC INTERACTIONS

The attractive Interactions between typically hydrophobic molecules such as hexane or CCl₄, and the repulsive Interactions between extremely hydrophilic molecules such as poly(ethylene oxide) (PEO), when immersed in water, as well as the interactions between these molecules and water, have been examined from a surface thermodynamic viewpoint, taking the changes in surface free energy into account, as a function of temperature. It was found that attractive hydrophobic Interactions are not, as vas generally believed up to now, invariably entropic. Hydrophobic Interactions can be mainly enthalpic or mainly entropic, or more or less equal mixtures of both, depending on each individual case; however, all hydrophobic interactions are polar (in the sense of Lewis acid-base) in nature. Repulsive hydrophilic interactions are enthalpic, and also polar in nature. The interaction between hydrophobic solutes and water is mainly enthalpic, and is apolar in nature.     

聚壬酰胺的制备纺丝及结构与性能测定

9-氨基壬酸系从癸二酸经单酯化、氨化和Hofmann重排制得。该单体以10克规模在玻璃管中和以4公斤量在15升聚合釜中,于260℃聚合成聚壬酰胺。聚合物在288℃纺丝,120℃牵伸,得到尼龙-9纤维。测定了聚合物和纤维的结构和多种性能。     

温度及pH敏感N-异丙基丙烯酰胺/β-环糊精水凝胶的合成与性能研究

用顺丁烯二酸酐 (MAH)对具有分子包结能力的 β 环糊精 (β CD)进行化学改性 ,合成出了丁烯二酸单酯化 β CD单体 (MAH β CD) .通过氧化还原自由基引发MAH β CD与N 异丙基丙烯酰胺 (NIPA)聚合 ,合成出含 β CD结构单元的新型水凝胶 .用核磁共振、红外光谱及元素分析对MAH β CD单体及共聚物的结构和组成进行了表征 .溶胀研究结果表明 ,该水凝胶具有较好的pH、温度及离子强度敏感性 ;并且水凝胶在较高羧基(—COOH)含量和弱碱环境中 ,仍能表现出明显的温敏性     

MECHANICS AND THE EVOLUTION AND FUNCTIONAL MORPHOLOGY OF CONCHOSTRACAN CARAPACE MECHANICS AND THE EVOLUTION AND FUNCTIONAL MORPHOLOGY OF CONCHOSTRACAN CARAPACE

Conchostracans, with a laterally compressed body enclosed between two symmetric valves, live swimming in fresh or brackish water. The carapace valve has a number of growth bands with various sculptures. The general trend of sculptural evolution is from smooth to punctate-minute polygon-medium reticulation-large reticulation, while these punctate, polygonal and various reticulate patterns may separately develop into various radial ridges. The development of sculpture can be well explained by mechanical principle. Functional morphology of carapace is discussed in the light of mechanics in this paper.     

四个酰基硫脲衍生物及其配合物的合成与表征

本文报道了四个Ｎ－酰基硫脲衍生物及其Ｃｕ＾２＋，Ｎｉ＾２＋，Ｃｄ＾２＋，Ｓｎ＾４＋配合物的合成。用质谱、红外光谱、紫外光谱对它们进行了结构、性质表征。配体与金属离子配位主要是通过硫原子进行，配合物都是非离子型的。