福建省机动车尾气污染情况分析与点燃式发动机轻型汽车尾气排放检测方法

随着我省经济的发展,机动车的数量急剧攀升。随之而来的是交通拥堵、停车难等众多的的社会问题,与此同时人们却往往忽视了机动车尾气污染带来的严峻的环境问题和健康问题。本文在近年福建省机动车数据和国内外各类机动车尾气检测办法的基础上,对福建省近年机动车尾气排放所带来的环境问题和针对小轿车(点燃式发动机轻型汽车)尾气排放检测办法的分析,旨在能进一步引起对机动车尾气所带来的环境问题的重视,进而希望能找到有效控制并减少城市道路空气污染的程度。     

福建省机动车尾气污染情况分析与点燃式发动机轻型汽车尾气排放检测方法

随着我省经济的发展,机动车的数量急剧攀升。随之而来的是交通拥堵、停车难等众多的的社会问题,与此同时人们却往往忽视了机动车尾气污染带来的严峻的环境问题和健康问题。本文在近年福建省机动车数据和国内外各类机动车尾气检测办法的基础上,对福建省近年机动车尾气排放所带来的环境问题和针对小轿车(点燃式发动机轻型汽车)尾气排放检测办法的分析,旨在能进一步引起对机动车尾气所带来的环境问题的重视,进而希望能找到有效控制并减少城市道路空气污染的程度。     

炸药的加速金属能力与分子结构关系的探讨

根据炸药分子结构的特点,应用量子力学原理和化学动力学的观点,探讨了炸药的分子结构与其在爆轰过程中能量释放速率之间的关系及炸药的分子结构与其加速金属能力之间的关系,发现共轭炸药具有能量释放快的特点,非共轭炸药具有持续加速金属的特性,高能量和能量释放快是炸药具有优越加速能力的必要条件,高能量、高密度共轭炸药是值得探索的一类炸药。     

烷基聚氧乙烯醚磺基甜菜碱的构效关系研究

为了研究非-两性离子混合型表面活性剂的构效关系,以乙氧基(EO)长度n分别为1,2,3和4的N,N-二甲基-N-十二烷基聚氧乙烯醚磺基甜菜碱(C_(12)EO_nSBe)为研究对象,利用滴体积法、时间分辨荧光法等获得C_(12)EO_nSBe的临界胶束浓度(cmc)、胶束聚集数(Nm)等性质参数。实验结果表明:与分子结构相近的传统十二烷基磺基甜菜碱(C_(12)SBe)相比,C_(12)EO_nSBe的cmc更低;随着n增大,C_(12)EO_nSBe的cmc降低,饱和吸附量(Γ_m)增大,分子占据面积(A_(min))减小,临界胶束聚集数(N_(m,c))减小。     

Catalyst design and development for upgrading aromatic hydrocarbons

Background and strategy of catalyst development for upgrading aromatic hydrocarbons are intensively discussed. Originally prepared catalysts (hydrogenation and hydrocracking catalysts) were used for accelerated aging tests. Though each catalyst showed superior catalytic performance as compared to commercially available catalysts, a severe deactivation was observed on the hydrocracking (HC) catalysts. A new type of HC catalyst was designed and prepared, based on the understanding of catalyst deactivation. High silica NaY zeolites were synthesized using crown-ether. USY zeolites were then prepared by ion exchange, steaming and calcining. Surface properties and catalytic functions of well-crystallized USY zeolites were investigated to develop practical HC catalysts. The Ni–W catalyst prepared using the newly prepared USY zeolite showed a considerable improvement in the HC activity.     

Interface adhesion properties of syndiotactic polypropylene/cellulose group composite: Relationship between chemical structure of coupling agent and reactivity for cellulose group

Reinforcement of interfacial adhesion between syndiotactic polypropylene (SPP) and fibrous pure cellulose (FC) was performed by the FC silanizations with 3‐aminopropyltrimethoxysilane (APTMS), with hexyltrimethoxysilane (HTMS) and by an addition of a SPP grafted with dimethyl itaconate (SPP‐g‐DMI: number‐average molecular weight = 3.3 × 10⁴, DMI cont. = 0.11 wt %), respectively. The adhesion and the morphology were improved by them, respectively. However, their behavior was considerably different. The hexyl group in the HTMS converted the FC surface into hydrophobicity, leading to the hindrance of the interhydrogen bonding in the FC. The silanized FC was embrittled with the increase of the degree of the silanization. In the case of the APTMS, the inter hydrogen bonding was kept because of the existence of the amino group. Whereas, the SPP‐g‐DMI was unable to penetrate into the cellulose because of its higher molecules, and the interhydrogen bonding was not hindered. The keeping the inter hydrogen bonding was important for the reinforcement of the tensile properties such as Young's modulus and tensile strength in the composite. Furthermore, the interfacial adhesion between the SPP and holocellulose (HC) was studied as well as the SPP/FC. Although the tensile properties were slightly improved by the APTMS silanization and by the addition of the SPP‐g‐DMI, respectively, the reactivity of the HC was much less than that of the FC. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Processes during the Hypergolic Ignition between Monomethylhydrazine (MMH) and Dinitrogen Tetroxide (N2O4) in Rocket Engines

Two potential sources for engine complications with methylhydrazine/nitrogen tetroxide rocket engines were examined. The products formed during a cold pre‐reaction before the actual ignition of the rocket engine and their later behavior were investigated with Car‐Parrinello molecular dynamics simulations. It was found that methyldiazene is the main product of the cold pre‐reaction. As a side product, especially in the presence of an excess of methylhydrazine, dimethyltetrazanes are formed. These may be responsible for violent side reactions.     

Relationship between breakthrough curve and adsorption isotherm of Ca(Ⅱ) imprinted chitosan microspheres for metal adsorption

In this work, an equilibrium-dispersion model was successfully established to describe the breakthrough performance of Ca(II) imprinted chitosan (Ca(II)-CS) microspheres packed column for metal adsorption, and the assumptions of Langmuir isotherms and axial dispersion controlled mass transfer process were confirmed. The axial dispersion coefficient in Ca(II)-CS microspheres packed column was found to be almost proportional to the linear velocity and fit for prediction through single breakthrough test. Sensitivity analysis for breakthrough curve indicated the axial dispersion coefficient as well as Langmuir coefficient was sensitive variable for deep removal requirement. The retrieval of the adsorption isotherms of Ca(II)-CS microspheres from breakthrough curve was fulfilled by model ing calibration. A strategy based on the correlation between adsorption isotherms and breakthrough performance was further proposed to simplify the column adsorption design using absorbents with smal/uniform size and fast adsorption kinetics like Ca(II)-CS microspheres to cut down the gap between lab and industry.     

Residual Stress Assessment for Thin 8YSZ Electrolytes Using Focused Ion Beam Milling and Digital Image Correlation

With respect to solid oxide fuel cell power density it has been verified that 1–2 μm thick 8YSZ electrolytes have significant advantages, offering the potential to operate stacks at temperatures of 600 °C. However, reliability of the component depends on integrity and hence residual stress state. In this work, an advanced method is used to determine the electrolyte residual stress locally using stress relaxation tests by a combination of focused ion beam milling and digital image correlation.     

A dual-chamber microbial fuel cell with conductive film-modified anode and cathode and its application for the neutral electro-Fenton process

This study reports on the modification of the anode and the cathode in a dual-chamber microbial fuel cell (MFC) with a polypyrrole (PPy)/anthraquinone-2,6-disulfonate (AQDS) conductive film to boost its performance and the application of the MFC to drive neutral electron-Fenton reactions occurring in the cathode chamber. The MFC equipped with the conductive film-coated anode and cathode delivered the maximum power density of 823 mW cm⁻² that was one order of magnitude larger than that obtained in the MFC with the unmodified electrodes. This was resulted from the enhanced activities of microbial metabolism in the anode and oxygen reduction in the cathode owing to the decoration of both electrodes with the PPy/AQDS composite. The MFC with the modified electrodes resulted in the largest rate of H₂O₂ generation in the cathode chamber by the two-electron reduction of O₂. The increase in the concentration of H₂O₂ was beneficial for the enhancement in the amount of hydroxyl radicals produced by the reaction of H₂O₂ with Fe²⁺, thus allowing an increased oxidative ability of the electro-Fenton process towards the decolorization and mineralization of an azo dye (i.e., Orange II) at pH 7.0.     

Comparison of tris(dimethylphenylsilyl)methyllithium and tris(trimethylsilyl)methyllithium reactions with carbon disulfide: a new route for the synthesis of some 1,1-bis(benzylthio)- and bis(allylthio)-2,2-bis(dimethylphenylsilyl)ethenes

A series of bis(benzylthio)- and bis(allylthio)-2,2-bis(dimethylphenylsilyl) ethenes has been obtained by the reaction of (PhMe₂Si)₃CLi and CS₂ with benzyl and allyl bromides. A plausible mechanism for the formation of these compounds has been proposed. The reactivity of (PhMe₂Si)₃CLi toward CS₂ has been compared with that of (Me₃Si)₃CLi. The reaction of (PhMe₂Si)₃CLi with CS₂ and 2-methyloxirane gave a cyclic thiocarbonate.     

新型IT-SOFC阴极材料的合成和表征

以La（NO3）3·6142O、Ni（N03）2·6H2O和Co（NO3）2·6H2O为原料,尿素为燃料,采用凝胶低温燃烧技术合成L％Ni0．7C00．304粉体,利用各种分析方法粉体进行研究。X射线衍射分析表明：适当提高尿索在凝胶中的含量,燃烧后得到的粉体晶粒尺寸显著减小,未经燃烧的粉体中除含有La2Ni0.7Co0．3O4外,还有h2O3、CoO、La2cO5等杂质相。扫描电镜观察发现,随着锻烧温度的提高,La2NiO．7C00．304粉体的粒径有所增大,且远小于在相同锻烧条件下用固相反应法制备的La2Ni0.7Co0．304。采用低温燃烧法能够合成具有单一相结构的La2Ni0．7Co0．3O4粉体。