Metal Fe, Ni and Fe-Ni Fine Fibers Derived from the Organic Gel-Thermal Reduction Process

The organic gel-thermal reduction process was successfully used for the preparation of magnetic metal Ni, Fe, Fe-Ni fine fibers from raw materials of citric acid or lactic acid and metal salts. Ni, Fe and Fe-Ni fine fibers synthesized were featured with diameters of around 1 μm and lengths of as long as 2 m for Ni fibers, 0.5 m for iron fibers, 1 m for Fe-Ni fibers. The structure, thermal decomposition process and morphologies of the gel precursors and fibers derived from thermal reduction of these gel precursors were characterized by FTIR, XRD,TG/DSC and SEM, respectively. The gel spinnability largely depends on molecular structures of metal-carboxylate complexes formed in the gel. It is reasoned that these gels consist of linear-type structural molecules [（C6H6O7）Ni]n or [（C6H5O7）2Ni3] for the nickel citrate gel, [（C3H5O3）3Fe] for the ferric lactate gel, [（C6H5O7）5（NiFe）3] for the iron-nickel citrate gel respectively and the gels obtain showed a good spinning performance.     

金属有机沉积法制备SrTiO3薄膜

采用金属有机沉积（MOD）法制备了SrTiO3（STO）外延薄膜作为YBa2Cu3O7-δ涂层导体的缓冲层.以乙酸锶、钛酸丁酯为前驱物配制了Sr离子浓度为0.125 mol.L-1的SrTiO3前驱溶液.研究了950℃下不同烧结时间（90、120、150 min）对在双轴织构的Ni-W（200）金属基带上沉积STO外延薄膜晶体取向和微观形貌的影响.结果表明,在950℃氩氢混合气氛（Ar-4%H2）下适宜于STO薄膜外延生长的最佳烧结时间为120 min;STO缓冲层薄膜表面平整致密,无裂纹和孔洞,具有良好取向,可作为YBa2Cu3O7-δ涂层导体的缓冲层.     

Structures and magnetic properties of nanocomposite CoFe_2O_4-BaTiO_3 fibers by organic gel-thermal decomposition process

The nanocomposite xCoFe2O4-(1-x)BaTiO3(x=0.2,0.3,0.4,0.5,molar fraction) fibers with fine diameters and high aspect ratios(length to diameter ratios) were prepared by the organic gel-thermal decomposition process from citric acid and metal salts.The structures and morphologies of gel precursors and fibers derived from thermal decomposition of the gel precursors were characterized by Fourier transform infrared spectroscopy,X-ray diffractometry and scanning electron microscopy.The magnetic properties of the nanocomposite fibers were measured by vibrating sample magnetometer.The nanocomposite fibers consisting of ferrite(CoFe2O4) and perovskite(BaTiO3) are formed at the calcination temperature of 900 ℃ for 2 h.The average grain sizes of CoFe2O4 and BaTiO3 in the nanocomposite fibers increase from 25 to 65 nm with the calcination temperature from 900 to 1 180 ℃.The single fiber constructed from these nanograins of CoFe2O4 and BaTiO3 has a necklace-like morphology.The saturation magnetization of the nanocomposite 0.4CoFe2O4-0.6BaTiO3 fibers increases with the increase of CoFe2O4 grain size,while the coercivity reaches a maximum value when the average grain size of CoFe2O4 is around the critical single-domain size of 45 nm obtained at 1 000 ℃.The saturation magnetization and remanence of the nanocomposite xCoFe2O4-(1-x)BaTiO3(x=0.2,0.3,0.4,0.5) fibers almost exhibit a linear relationship with the molar fraction of CoFe2O4 in the nanocomposites.     

蓄热调温纤维的纺制及其性能研究

以正十九烷和正二十烷以及正十八烷微胶囊为原料，采用熔融复合和溶液纺丝工艺制备相变材料(微胶囊)质量分数20％以上的蓄热调温纤维，观察其可纺性，测试纤维的结构并研究纺丝工艺对其相变性能、热效率、物理力学性能和耐热性能的影响．结果表明，采用相变材料微胶囊和聚丙烯腈一偏氯乙烯共聚物混合后进行溶液纺丝制成的腈氯纶纤维具有较好的可纺性，热效率和热稳定性最高，但物理力学性能较差．     

碱金属对煤焦异相还原NO的催化机理：量子化学研究

针对碱金属催化煤焦异相还原NO的相关反应,采用密度泛函计算方法UB3LYP/6 31G(d)优化获得了反应通道上所有驻点的几何构型,得到了微观反应进程.采用高精度能量计算方法QCISD(T)/6 311G(d,p)计算得到了所研究反应的活化能,并结合经典过渡态理论,计算得到反应速率常数,拟合出阿仑尼乌斯表达式.通过比较各反应的活化能和反应速率常数发现,碱金属的存在使煤焦异相还原NO的活化能大大降低,提高了反应速率,起到催化作用;碱金属的活泼性越强,则其与NO反应的活化能越低,对煤焦异相还原NO的催化性能越好.     

聚醚砜纤维研制

采用国产聚醚砜熔融纺丝，并对牵伸丝的取向，力学性能和机械性能进行评价。结果表明，该聚合物在３５０℃具有良好的熔融可纺性；在３０－１００℃温度范围内，随温度升高，牵伸倍数有所增加；牵伸丝力学性能与取向程度线性相关；聚醚砜牵伸丝在８０℃左右开始发生收缩，在其玻璃化转变温度附近出现明显收缩，尽寸热稳定性不理想。     

Structures and magnetic properties of nanocomposite CoFe2O4-BaTiO3 fibers by organic gel-thermal decomposition process

The nanocomposite xCoFe₂O₄-(1−x)BaTiO₃ (x=0.2, 0.3, 0.4, 0.5, molar fraction) fibers with fine diameters and high aspect ratios (length to diameter ratios) were prepared by the organic gel-thermal decomposition process from citric acid and metal salts. The structures and morphologies of gel precursors and fibers derived from thermal decomposition of the gel precursors were characterized by Fourier transform infrared spectroscopy, X-ray diffractometry and scanning electron microscopy. The magnetic properties of the nanocomposite fibers were measured by vibrating sample magnetometer. The nanocomposite fibers consisting of ferrite (CoFe₂O₄) and perovskite (BaTiO₃) are formed at the calcination temperature of 900 °C for 2 h. The average grain sizes of CoFe₂O₄ and BaTiO₃ in the nanocomposite fibers increase from 25 to 65 nm with the calcination temperature from 900 to 1 180 °C. The single fiber constructed from these nanograins of CoFe₂O₄ and BaTiO₃ has a necklace-like morphology. The saturation magnetization of the nanocomposite 0.4CoFe₂O₄-0.6BaTiO₃ fibers increases with the increase of CoFe₂O₄ grain size, while the coercivity reaches a maximum value when the average grain size of CoFe₂O₄ is around the critical single-domain size of 45 nm obtained at 1 000 °C. The saturation magnetization and remanence of the nanocomposite xCoFe₂O₄-(1−x)BaTiO₃ (x=0.2, 0.3, 0.4, 0.5) fibers almost exhibit a linear relationship with the molar fraction of CoFe₂O₄ in the nanocomposites.     

Effect of Surface Modification on Microwave Absorbing Properties of Magnetic Metal Fibers

In order to avoid forming an electrical conductive network due to surface connections, the magnetic metal fibers were coated with SiO2, for surface modification by the sol-gel process. The microstructure, composition and electromagnetic characteristics of SiO2-coated and uncoated metal fibers were studied using SEM, EDAX, and a voter network analyzer. The reflectivity was simulated using the RAMCAD software. The electromagnetic parameters and absorption properties of SiO2-coated metal fibers were improved greatly due to optimal impendence matching and the electric conductivity decreased, compared to those of uncoated materials.     

有机物质对铁还原降解四氯化碳的影响

为探寻土壤和地下水中广泛存在的醌和表面活性剂等有机物质对铁用于环境中有机氯污染修复的影响,实验采用在零价铁还原体系中,加入增强电子转移的醌类物质和铁表面负载表面活性剂,以提高铁对四氯化碳的吸附来增强铁还原脱氯.结果表明：分别加入4.0×10^-3mol/L蒽醌-2,6-二磺酸钠和1,4-二羟基蒽醌,四氯化碳的降解速度提高70%和52%.用阳离子表面活性剂负载的零价铁对四氯化碳降解有很好的增强效果,最佳的增强效果在临界胶束浓度附近,十六烷基三甲基溴化铵和溴代十六烷基吡啶处理的铁比未处理的铁可提高四氯化碳的降解速率分别为81%和130%,2种阴离子表面活性剂没有协同增强效果.     

环境中金属离子与有机污染物复合污染研究进展

金属离子与有机污染物可通过多种方式同时存在于环境中,形成复合污染。由于金属离子与有机污染物的相互作用,二者的物理化学性质、迁移转化规律以及生态毒性效应都发生了变化,给污染物的水处理过程以及污染物的生态毒性评估带来极大的挑战。综述了环境中金属-有机物复合污染的来源、金属离子与有机污染物之间的相互作用、共存对二者去除效率的影响以及复合污染的生态毒性研究,以期为复合污染的防治与处理工艺研究提供参考。     

碳/金属复合纤维材料的制备及性能研究

通过磁控溅射法在碳纤维表面镀Cu薄膜和Fe薄膜,制得碳/铜复合纤维和碳/铁复合纤维,对其基本性能进行测试分析研究,测试其表面形态、力学性能和浸润性等,并分析不同的溅射工艺条件对纤维的影响,为其产品的进一步开发和应用提供了参考.     

Preparation and properties of alkali activated foam cement reinforced with polypropylene fibers

A new form of foam cement was produced by mixing alkali-activated slag,clay,a small amount of polypropylene fibers with prepared foam during stirring.The preparation of the material is quite different from the normal one,which is produced just at room temperature and without baking.The fabrication of this energy-saving and low-price material can be favorable for lowering carbon emission by using recycled industrial wastes.Thermal conductivity of 0.116 W/(m·k),compressive strength of 3.30 MPa,flexural strength of 0.8 MPa and density of 453 kg/m3 can be achieved after 28 days aging.The hydration product is C-S-H with less Ca(OH)2,calcium aluminum and zeolite,which was characterized by X-ray diffraction(XRD) measurement.This prospective foam cement may be expected to be an excellent economical energy-saving building material.     

均相还原法制备铜纳米粒子

以CuSO4·5H2O和次亚磷酸钠（NaH2PO2）为原料,采用控制反应温度的方法实现了均相体系内铜纳米粒子的还原制备,通过X射线衍射分析（XRD）、扫描电子显微镜（SEM）对产物物相和形貌进行了表征,实验结果表明,反应体系在70℃下反应20min可以得到的产物为粒径分布在70nm～150nm的球形铜纳米粒子。     

理想纱条的纤维排列与随机过程分析

在Rao给出的理想纱条定义的基础上,进一步提出了理想纱条纤维排列的新定义.新定义考虑了纤维的长度分布,从纤维头端排列的概率分布角度指出了理想纱条的形态,新的理想纱条定义完全满足Rao理想纱条的4个条件.使用随机过程对这个新定义的理想纱条进行了分析,证明了这个随机过程是一个弱平稳过程,进一步求出了这个平稳过程的期望、方差和相关函数表达式,为理解理想纱条的意义和拟合非理想纱条建立了理论基础,也给出了理想纱条仿真的数学方法和途径.     

TiO_2光催化还原CO_2技术的研究进展

介绍了TiO_2的结构和性质,以及其催化还原CO_2的反应机理。分析了非金属沉积、贵金属沉积、半导体复合和有机光敏剂改性等4类Ti基催化剂光催化还原CO_2的性能。     

高浓度有机废水处理领域温室气体减排计算

在高浓度有机废水的厌氧处理过程中会产生大量沼气,作为沼气的主要成分,CH4即是重要的温室气体,同时也是一种可再生清洁能源。通过采取CDM方法学AMS.Ⅲ.H,对河北省邯郸市清源酿酒厂高浓度有机废水处理过程中的项目减排量进行计算。结果表明:在清洁发展机制下,该项目的减排量为55 485 tCO2e,且可获得约12.05%的项目收益率。因此,在高浓度有机废水处理领域实施温室气体减排技术,具有比较显著的环境效益与经济效益。     

Growth and characterization of doped CeO2 buffers on Ni-W substrates for coated conductors using metal organic deposition method

CeO2 and Ce0.8M0.2O2-d films (M = Mn, Y, Gd, Sm, Nd and La) with (00l) preferred orientation have been prepared on biaxially textured Ni-W substrates by metal organic decomposition (MOD) method. The factors influencing the formation of cracks on the surface of these CeO2 and doped CeO2 films on Ni-W substrates were explored by X-ray diffraction (XRD), scanning electron microscopy (SEM) analysis, atomic force microscopy (AFM) and differential scanning calorimetry (DSC). The results indicate that many factors, such as the change of the ionic radii of doping cations, the transformation of crystal structure and the formation of oxygen vacancies in lattices at high annealing temperature, may be related to the formation of cracks on the surface of these films. However, the crack formation shows no dependence on the crystal lattice mismatch degree of the films with Ni-W substrates. Moreover, the suppression of surface cracks is related to the change of intrinsic elasticity of CeO2 film with doping of cations with a larger radius. SEM and AFM investigations of Ce0.8M0.2O2-d (M = Y, Gd, Sm, Nd and La) films reveal the dense, smooth and crack-free microstructure, and their lattice parameters match well with that of YBCO, illuminating that they are potentially suitable to be as buffer layer, especially as cap layer in multi-layer architecture of buffer layer for coated conductors.     

催化氧化法处理含难降解有机物废水研究进展

催化氧化法可加强传统化学法处理含有机物废水效果，目前已成为处理含难降解有机物废水的一种重要途径。本文介绍了光催化氧化法，均相氧化法，多相氧化法（包括电催化氧化法）以及超临界水氧化技术在有机废水中的研究及应用现状，并对其发展前景作了扼要评述。     

复配有机硅乳液消泡剂的研制

介绍了以有机硅为主要成分，并以适当乳化剂和助剂在水相中的复合乳化剂进行复配制备有机硅乳液消泡剂的方法。考察了有机硅的含量、乳化剂含量及配制温度等对消泡效果的影响，并对结果进行了讨论。复配有机硅乳液消泡剂稳定性高，成本相对较低，消泡效果较好。