Molecular Volume of Phosphates, Arsenates and Vanadates

The present paper discusses some characteristics of the molecular volumes of phosphates, arsenates and vanadates. In the salts, the volumes of per acid radical ((?)) quantitatively depend on the radii, charges, numbers of cations and anions. The functional relations between the (?) values of phosphates, arsenates, vanadates and the factors mentioned above are obtained. The molecular volumes of these salts are equal to the sum of the topological volumes of cations and anions. The authors have got a series of universally united topological volume values of cations and anions. It confirms that the topological molecular volume of the crystal water (H_2O) in the hydrates of the salts approximates to a constant, 244 (?)~3 with σ_(n-1)= 2.1. The topological volume of the hydroxide ion (OH~-) approximates to a constant too. The average value is 16.89 (?)~3 with σ_(n-1)=1.68.     

Study on the Dynamics of Blending of Glucomannan with Carrageenan and Guaran Gum

In order to prove up the interaction between konjac glucomannan (KGM) and other amyloses, by using KGM, guaran gum and carrageenan as materials, their blending in different external conditions was modeled by means of molecular dynamics (MD) method. The result showed that 323 K was a significant turning point for the formation of hydrogen bond, and KGM and guaran gum were just juxtaposed together via intermolecular hydrogen bond; but with the addition of carrageenan, KGM, guaran gum and carrageenan were spirally twisted together, and when their blending proportion is 3:2:9 the combination was the most compact. Moreover, the research result has provided the sequent studies afterwards on amyloses with some references.     

常温直接沉淀法制备ZnO纳米棒

在常温下, 以PEG-400(聚乙二醇400)为表面活性剂, 采用直接沉淀法合成了ZnO纳米棒. 产物用XRD, TEM, SAED和 HRTEM等进行了表征. 结果表明, 所得ZnO为一维的纳米棒, 属于六方纤维矿的单晶结构. ZnO纳米棒的直径在20~40 nm之间, 长度在300~800 nm范围. (0001)面为ZnO纳米棒的生长方向. 讨论了ZnO相的生成和ZnO纳米棒的形成机理以及PEG-400在其形成过程中的作用.     

Theoretical Study on Photoisomerization of 2-Methylfuran to 3-Methylfuran

1 INTRODUCTION 2-Methylfuran belongs to the basic heteroaromatic compounds relevant to many fields of modern che- mistry, ranging from the study of natural products and biologically active substances to the develop- ment of building blocks for organic synthesis and conducting polymers[1]. Since the photochemistry ofR-furan was gradually recognized in 1960s[2～7], lots of interest has been aroused. Herein we only study one branch of photoche- mistry of R-furan: the isomerization of 2-methy…     

柠檬酸溶胶-凝胶法制备的Ce1-xZrxO2: 结构及其氧移动性

采用 XRF、XRD、Raman、XPS、H₂-TPR 以及与氩离子刻蚀相结合的XPS等表征技术对柠檬酸溶胶-凝胶法制备的Ce_1-xZr_xO₂ (0≤x≤1)样品的结构及其氧移动性进行了研究. 结果表明, Ce_1-xZr_xO₂ 样品的晶型结构对其中氧的移动性有明显影响. 当x≤0.15 时, Ce_1-xZr_xO₂ 以立方CeO₂相 Ce-Zr-O 固溶体存在, 随着Zr含量的逐渐增加, CeO₂晶胞体积减小、氧空位浓度增加, 氧移动性逐渐增强; 当x＞0.15时, 形成四方ZrO₂相和立方CeO₂相Ce-Zr-O固溶体的混合物, 随着Zr含量的逐渐增加, 四方ZrO₂相的含量增加、氧空位浓度减小, 氧移动性逐渐减弱. 因此, Ce_0.852Zr_0.152O₂样品具有最高的氧移动性.     

THE EFFECT OF PHOTO-CROSSLINKING ON THE ORIENTATION STABILITY OF POLYVINYL ALCOHOL CONTAINING 4-NITRO-4′-ALKOXYSTILBENE AND CINNAMYL PENDENT GROUPS*

Crosslinking is one of the effective routes for improving the orientation stability of poledpolymer films. The derivative of polyvinyl alcohol containing 4-nitro-4'-alkoxystilbene andphoto-crosslinkable cinnamyl groups as side chains has been synthesized. The in-situ simul-taneous photo-crosslinking poling of synthesized polymer films has been performed. Thesecond order nonlinear optical coefficient d_(33) of poled film is 11 pm/V. The SHG mea-surements show that the break-over temperature of SHG signal is raised obviously afterirradiation, its orientation stability is doubled as compared with that of non-crosslinkingsamples.     

多壁碳纳米管-炭复合泡沫材料的制备和吸附性能

通过在聚氨酯泡沫模板中沉积多壁碳纳米管，用炭的预制体酚醛树酯将碳纳米管粘接固定在一起，经过高温碳化过程制备了碳纳米管-炭复合泡沫材料。红外光谱结果表明利用浓硫酸和浓硝酸的混合溶液处理可以使复合泡沫表面活化形成羧基和羟基，从而使复合泡沫具备较强的分子吸附能力。扫描电镜和氮吸附实验表明这种复合泡沫同时具备大孔和介孔，大孔能够满足流体自由流动的通畅性，介孔可以满足中分子的吸附需要。对标定物维生素B12的吸附实验证明这种复合泡沫对中分子量的生化分子具有有效的吸附能力。这种宏观尺寸的泡沫材料与传统的颗粒状活性炭相比具有简化工艺，提高吸附效率的应用潜力。     

1,4-双(二苯基膦)丁烷交联的季膦化聚芳醚酮阴离子交换膜

以1,4-双(二苯基膦)丁烷为交联剂,以具有四甲基联苯结构的聚芳醚酮为基体材料,分别制备了刚性三苯基膦和柔性三丁基膦修饰的阴离子交联膜材料.交联剂在交联结构形成的过程中转变成季膦盐,在提高膜材料机械稳定性的同时保持离子交换功能基团的含量.研究了2种阴离子交换膜的尺寸稳定性、电导率、机械性能及耐碱稳定性等.研究结果表明,当交联度为20%时,三苯基膦与三丁基膦修饰的阴离子交换膜的拉伸强度分别由未交联时的27和18 MPa提高到45和30 MPa;交联的膜材料在60℃的3 mol/L KOH溶液中浸泡120 h后,三苯基膦修饰的阴离子交换膜的电导率保留率为81%,三丁基膦修饰的阴离子交换膜的电导率保留率为69%,膜的耐碱稳定性均较未交联时有明显提高.交联度相同时,三苯基膦修饰的阴离子交换膜表现出更高的拉伸强度和更好的耐碱稳定性.     

4,5-二苯基-2-(9-苯基-9H-3-咔唑基)-1H-咪唑的合成及其性能

以联苯甲酰、对溴苯甲醛和乙酸铵为原料，经缩合反应制得2-(4-溴苯基)-4,5-二苯基咪唑(1); 1与N-苯基-3-咔唑硼酸经Suzuki偶联反应合成了一种具有D-π-A结构的新型咪唑衍生物4,5-苯基-2-(9-苯基-9H-3-咔唑基)-1H-咪唑(2），其结构经¹H NMR, ¹³C NMR, IR和MS(EI)表征。采用FL, UV-Vis，循环伏安法（CV）和理论计算对2的光电性能进行了研究。结果表明：2的最大吸收波长为302 nm和326 nm，荧光发射波长为395 nm和412 nm, HOMO和LUMO轨道能级分别为5.35 eV和2.14 eV。     

量子阱层和垒层具有不同Al组分的270/290/330nm AlGaN基深紫外LED光电性能

为了研究AlGaN量子阱层和垒层中Al组分不同对AlGaN基深紫外发光二极管(LED)光电性能的影响,本文利用MOCVD生长、光刻和干法刻蚀工艺制备了AlGaN量子阱层和垒层具有不同Al组分的270/290/330nm深紫外LED,通过实验和数值模拟计算方法发现,量子阱层和垒层中具有低Al组分紫外LED的AlGaN材料具有较低的位错密度、较高的光输出功率和外量子效率。通过电流-电压(I-V)曲线拟合出的较大的理想因子(3.5)和能带结构图表明,AlGaN深紫外LED的电流产生是隧穿机制占据主导作用,这是因为高Al组分AlGaN量子阱中强极化场造成了有源层区域较大的能带弯曲和电势降。