转基因动物应用的巨大潜力

转移基因技术是近年来发展起来的一门新技术。它通过显微注射、电转移、病毒传染、胚胎干细胞移植等方法，能将外源基因导入动物细胞中，使之与动物细胞中的染色体发生重组，形成转基因动物。目前已获得转基因猪、转基因牛、转基因羊、转基因兔等多种转基因动物。它们在生产性能、抗病性、生产生物医学产品诸方面发挥了巨大作用，并为研究和征服人类遗传疾病提供模型。     

化学法改变聚苯胺的氧化状态及其性能的研究

本文通过化学氧化与还原的方法改变聚苯胺的氧化状态,并借助元素分析,FT—IR、ESR和X射线衍射分析等对所得产物的结构和性能进行了研究。发现聚苯胺的氧化状态对其导电性和结晶性的影响很大,用化学氧化剂和还原剂可使不同氧化状态的聚苯胺相互转化,而且转化过程具有良好的可逆性。     

硬盘多种DOS版本的实现

本通过对MS－DOS3．3启动及扩展分区的论述与研究，实现了硬盘多种DOS版本的运行。     

Interfacial interaction between polyurethane/poly (methacrylateco-styrene) coating and the regenerated cellulose film

Water-resistant films were prepared by coating the surface of regenerated cellulose films with castor oil-based polyurethane (PU)/ poly-(methacrylate-co-styrene) [P (MA-St)]. The effects of the ratio of PU to P (MA-St) copolymer on tensile strength (dry and wet states), vapor permeability, size stability, and water resistivity of the coated films were studied. The interfacial interaction between cellulose and the PU/P (MA-St) coating was analyzed using infrared (IR), ultraviolet (UV), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential thermal analysis (DTA), and electron probe microanalysis (EPMA). The results indicated that the mechanical properties and water resistivity of the coated films significantly enhanced, and the biodegradability was displayed, when the ratio of PU to P (MA-St) was 8∶2 by weight. The chemical bonds and hydrogen bonds between the cellulose, PU, and the copolymer exist in the coated films. It is regarded that PU/P (MA-St) semi-interpenetrating polymer networks (IPNs) were formed, and a shared network of PU with both the cellulose and the coating in the coated film occurred simultaneously resulting in a strong bonding between the coating layer and the film. Supported by the State Economy and Trade Commission of China Gong Ping: born in 1963, Ph. D candidate     

毛泽东邓小平江泽民社会主义价值观比较研究

效率和平等是社会主义的两大价值,二者在社会主义价值结构中有着科学的排列秩序和辩证关系。对其进行正确的认识和把握是成功进行社会主义建设的关键所在。毛泽东、邓小平、江泽民都充分肯定并努力实现着社会主义的效率价值和平等价值,但在不同的时代背景下,他们围绕着效率与平等在社会主义价值体系中的地位及其相互关系问题进行了不尽相同的实践和探索,为中国最终能够完整地实现社会主义价值做出了重大贡献。     

102G层析仪的改装及其与微型反应器的联用

本工作将102G层析仪成功地改装成毛细管柱及填充柱两用仪。装上自制的高效毛细管色谱柱,并与微型反应器联用,在分析邻氯甲苯催化异构化反应尾气中难分离的氯甲苯异构体等含量时,获得了很好的效果。     

非等温空腔法确定固体材料的比辐射率

本文讨论一种确定固体材料比辐射率的方法。在被测材料的表面开一个圆柱形空腔,并在其背面均匀加热。联立求解腔壁的辐射换热和体内的热传导方程,求得温度场分布和腔底的有效辐射。结果表明,腔底的有效辐射是比辐射率、腔深和半径之比以及一个表示温度梯度的参数的函数。文中讨论了能量辐射和光子辐射两种情况。在实验中,用热象仪测量材料表面和腔底的有效辐射。由理论分析结果和实验测定的有效辐射,求得材料的比辐射率。     

Optimal Taxation in an Endogenous Growth Model with Multiple Levels of Governments

This paper presents a framework with federal income tax, federal transfer, and local taxes in an dynamic growth model with multiple levels of governments and public capital formation. It derives the rate of endogenous growth and, with both simulations and special examples, examines how the rate of endogenous growth changes with respect to federal income tax, local taxes, and federal transfers.     

Formation of highly crystalline maghemite nanoparticles from ferrihydrite in the liquid phase

Fe₅O₇(OH)·4H₂O ferrihydrite is a low-crystallinity antiferromagnetic material. γ-Fe₂O₃ (maghemite) magnetic nanoparticles were prepared from a ferrihydrite precursor, by chemically induced transformation in FeCl₂/NaOH solution. The magnetization, morphology, crystal structure and chemical composition of the products were determined by vibrating sample magnetometry, transmission electron microscopy, X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy (XPS). Ferrihydrite underwent aggregation growth and transformed into α-FeO(OH) (goethite) particles, which subsequently transformed into γ-Fe₂O₃ nanoparticles, that became coated with NaCl. The γ-Fe₂O₃ particles had a flake-like morphology, when prepared from 0.01 mol/L FeCl₂ and a FeCl₂:NaOH molar ratio of 0.4. The γ-Fe₂O₃ particles were more spherical, when prepared from a FeCl₂:NaOH molar ratio of 0.6. The Fe content of the flake-like particles was lower than that of the spherical particles. Their magnetizations were similar, and the coercivity of the flake-like particles was larger. The differences in morphology and magnetization were attributed to the surface effect, and the difference in coercivity to the shape effect.     

The influence of molar ratios of Ce/Zr on the selective catalytic reduction of NOx with NH3 over Fe2O3-WO3/CexZrl-xO2 （0 〈 x 〈 1） monolith catalyst

A series of CexZrl_xO2 （0 ≤ x ≤ 1） with dif- ferent molar ratios of Ce/Zr were syhthesized via coprecip- itation method, and Fe2O3-WO3/CexZrl-xO2 monolithic catalysts were prepared, for selective catalytic reduction of nitrogen oxides by ammonia （NH3-SCR）. The structural properties and redox behavior of the catalysts were com- prehensively characterized by N2 physisorption, X-ray diffraction （XRD）, X-ray photoelectron spectra （XPS）, H2-temperature programmed reduction （H2-TPR） and activity measurement for NH3-SCR. The results showed that the NH3-SCR activities of the catalysts were gradually enhanced by increasing the molar ratios of Ce/Zr, especially the low- temperature catalytic activity and the reaction temperature window. Fe2O3-WO3/Ceo.68Zro.3202 monolithic catalyst presented the best NH3-SCR activity among the investigated catalysts, more than 90 % NOx could be removed in the temperature range of 247-454 ℃ on the catalyst under the gas hourly space velocities of 30,000 h- 1. And it always held more than 99 % N2 selectivity and less than 20 ppm （1 ppm =10-6 L/L ） N20 generation concentration between 200 and 500 ℃, the catalyst also displayed its strong resistance of H20 and SO2. Good textural and structural properties, more surface Fe, Ce and active oxygen were together contributed to the excellent NH3-SCR performance of Fe2O3-WO3/ Ce0.68Zr0.32O2 catalyst.