Synthesis of nanodispersed oxides of vanadium, titanium, molybdenum, and tungsten on mesoporous silica using atomic layer deposition

The advantages of the atomic layer deposition (ALD) method for preparation of tungsten, vanadium, titanium, and molybdenum oxide catalyst supported on mesoporous silica are discussed, with emphasis on the importance of synthesis conditions on dispersion, structure and activity of the resulting materials. A suite of complementary techniques such as DRS-UV/Vis, BET, ¹H-NMR, XRD, and TEM were used to study the structural properties of the supported metal oxides, and probe reactions such as 2-butanol dehydration and ethanol partial oxidation were used to demonstrate the potential advantages of the ALD-prepared catalysts. Specifically, highly dispersed oxides of titanium, molybdenum, and tungsten oxide on mesoporous silica were synthesized using the ALD method. It is also demonstrated that attainment of high dispersions of vanadium oxide on mesoporous silica requires the presence of at least a single layer of titanium oxide due to the well-known poor interaction between vanadia and silica. The highly dispersed catalysts prepared here by ALD methods exhibited superior catalytic performance relative to those prepared using conventional incipient wetness impregnation.     

Synthesis and characterization of side‐chain liquid‐crystalline ionomers containing quaternary ammonium salt groups

A series of thermotropic side‐chain liquid‐crystalline ionomers (LCIs) containing 4‐(4‐alkoxybenzyloxy)‐4′‐allyloxybiphenyl (M) as mesogenic units and allyl triethylammonium bromide (ATAB) as nonmesogenic units were synthesized by graft copolymerization upon polymethylhydrosiloxane. The chemical structures of the polymers were confirmed by IR spectroscopy. DSC was used to measure the thermal properties of these polymers. The mesogenic properties were characterized by polarizing optical microscopy, DSC, and X‐ray diffraction. Homopolymers without ionic groups exhibit smectic and nematic mesophases. The nematic mesophases of the ionomers disappear and the mesomorphic temperature ranges decrease with increasing concentration of ionic units. The influence of the alkoxy chain length on clearing temperature (T_c) values of ionomers clearly shows an odd‐even effect, similar to that of other side‐chain liquid‐crystalline polymers. The mesomorphic temperature ranges increase with increasing alkoxy chain length when the number of alkoxy carbon is over 3. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2879–2886, 2003     

复合型絮凝剂PAFS的研制及性能

本文用钢厂废渣、浓硫酸及粉煤灰为原料制备了聚合硫酸铝铁（PAFS）。在合成中通过正交试验，从中探索了适宜的反应条件。产品经化学分析，鉴定了它的成分和性质。并以黄河水为原水，通过与市售聚铝（PAC）做絮凝对比试验取得了良好的絮凝效果。而且原水的pH值在4．5～9之间，去浊率达到99％以上．     

醋酸-水二元系25——75℃恒温汽液平衡的研究

建立了利用静态法测定溶液蒸气压的装置,它包括平衡器、零压计、水银压差计、脱气室以及高真空设备。在此装置中测定了醋酸-水二元系在25—75℃范围内的蒸气压。为了得到完整的恒温汽液数据,利用我们先前发展的一个直接热力学方法来计算平衡汽相组成,计算时考虑了汽相缔合。本文中用表格形式发表了所得的计算结果。 为了拟合实验数据,用了一个由热力学推导得到的关联活度系数与温度的多项式,多项式参数由最小二乘法求得。利用这些参数,并外推至常压,预测所得泡点和汽相组成与文献报导的恒压实验数据,具有良好地一致。这些参数,可在低压至常压的广阔范围内的实际汽液平衡计算中使用。     

大型陶瓷壁画电脑喷绘制作系统

简要阐述了电脑应用于大型陶瓷壁画制作的技术可行性。并对电脑瓷板画普遍存在的偏色技术难题,给出了解决问题的一种新方法,大大提高了大型陶瓷瓷板画的成色质量。对大型壁画的生产工艺给出了具有创造性的新思路。     

ER－892高分散松香胶的制备和应用研究

介绍了高浓度、高分散松香胶的制备和应用方法．研究结果表明：该胶游离松香含量高，乳液粒径细，施胶能力强，可减少松香和硫酸铝用量５０％～６０％，克服夏季施胶障碍，提高纸张理化性能．     

淹没前混合磨料射流的数值分析

利用CFD方法对淹没条件下前混合磨料射流流场进行了数值模拟,研究了喷嘴内外液固两相流的速度规律.仿真结果表明:磨料水射流在淹没条件下的耗散较大,磨料粒子速度最大值出现在一定喷距处;对于圆柱、圆锥、锥直型3种不同形式喷嘴,以锥直型喷嘴效果更优;仿真结果与实验结果基本一致.     

软岩击实试验结果影响因素分析

简述了土工试验中土样制备方法、击实标准对试验结果的影响,分析了制样过程中含水率随时间和温度变化的规律;提出了通过改变加土量和击实数,减小试样余土高度对结果的影响的结论。     

Mangrove forests as a nature-based solution for coastal flood protection: Biophysical and ecological considerations

Nature-based coastal protection is increasingly recognised as a potentially sustainable and cost-effective solution to reduce coastal flood risk. It uses coastal ecosystems such as mangrove forests to create resilient designs for coastal flood protection. However, to use mangroves effectively as a nature-based measure for flood risk reduction, we must understand the biophysical processes that govern risk reduction capacity through mangrove ecosystem size and structure. In this perspective, we evaluate the current state of knowledge on local physical drivers and ecological processes that determine mangrove functioning as part of a nature-based flood defence. We show that the forest properties that comprise coastal flood protection are well-known, but models cannot yet pinpoint how spatial heterogeneity of the forest structure affects the capacity for wave or surge attenuation. Overall, there is relatively good understanding of the ecological processes that drive forest structure and size, but there is a lack of knowledge on how daily bed-level dynamics link to long-term biogeomorphic forest dynamics, and on the role of combined stressors influencing forest retreat. Integrating simulation models of forest structure under changing physical (e.g. due to sea-level change) and ecological drivers with hydrodynamic attenuation models will allow for better projections of long-term natural coastal protection.     

非晶Fe—P合金的价电子结构

本文在“固体与分子经验电子理论”的基础上,通过推广的键距差分析,对非晶Fe-P合金的价电子结构进行了分析。结果表明,偏径向分布函数的峰位可视为实验健距,而偏径向分布函数第一峰下的面积可作为等同健距数目,所得结论在一级近似下是合理的。计算结果指出,Fe为B型双态杂化的13阶杂化,而P位于杂化态的第Ⅰ阶,Fe-P之间有很高的共价结合。