中国航天:现实与改革的断想

用高新技术产业的10个条件,对中国航天的现状进行分析对比,找出差距;从经济学关于资本与劳动两种要素合理投人的角度出发,提出关于中国航天改革设想的一家之言.     

在高职高专基础上构建应用型本科会计专业实践教学体系的探索

如何做好从高职高专教育到应用型本科教育的衔接,是大多数刚刚“升本”的高校所要面临的重要课题.从会计专业实践教学来看,这一课题就是要在高职高专教育实践教学的不足基础之上,建立适合应用型本科的会计专业实践教学体系.     

对我国征收遗产税的法理分析

在一个健康有序的财税制度中，遗产税必不可少。但我国建国以来一直未开征遗产税，目前我国已在一定程度上具备了开征遗产税的条件，但仍然存在很多有待解决的问题。在分析我国开征遗产税现实条件的基础上，借鉴国外的相关税收制度，结合我国实际情况，给出了构建我国的遗产税框架的一种模式。     

Effect of Water Absorption on the Impact Properties of Carbon Fiber/Epoxy Composites

In this paper, the effects of test temperatures and time on the impact damage behavior of unidirectional carbon fiber reinforced epoxy resin composites, immersed in pure water, on a pendulum impact tester, was studied. The results show that immersion in liquids has a significant effect on the impact resistance of the unidirectional composite material. It is obvious that after immersion, the mass of the material increases. The fracture initiation forces as well as the fracture initiation energy decrease as the immersion time lengthens. Moreover, the higher the temperature and the longer the time are, the more the crack propagation energy and the ductility index will be. Immersion makes the fracture mode change from the dominant fiber fracture into dominant delamination. All in all, immersion decreases the impact resistance of the composites and causes the fracture mode to change.     

Preparation and Properties of Organically Modified Sepiolite/High-performance Epoxy Nanocomposites

Fibrous organic sepiolites (OSEP) and novel epoxy/OSEP nanocomposites were prepared, and different methods were investigated to produce an intercalated/exfoliated structure of OSEP. Experimental results show that the modifier molecules can be easily adsorbed by the sepiolite, but the layer space (d001) of the sepiolite, linked by means of covalent bond, remains unchanged. A proper method to solve this problem appears to exert large shearing force on the original sepiolite followed by its organic modification (OSEP2). The morphol-ogy observation shows that there are formed an even dispersion of nano-sized OSEP2 fibers in epoxy resin and a structure intercalated by epoxy molecules, which lead to significantly improved mechanical properties. Impact strength of the epoxy/OSEP2 nanocomposite increases from 32.1 kJ/m2 to 44.4 kJ/m2, 38.3% higher than that of pristine matrix with 3 wt% OSEP2 content. It is also noted that the flexural strength of the OSEP/epoxy composites has risen by about 3% higher than that of the pure epoxy resin.     

Mechanical Properties and Microstructure of In Situ TiB_2-7055 Composites

In order to fabricate a kind of high strength particulate reinforced aluminum-matrix composites, the high strength aluminum alloy 7055 was selected as a matrix. Composites reinforced with varying amounts of TiB2 particles were synthesized using the in situ method, and their mechanical properties and microstructure were analyzed. It is found that the in situ TiB2 particles sized from 50 to 400 nm uniformly disperse in the matrix. With the weight fraction of TiB2 particles increasing, the elastic modulus as well as the yield strength and the ultimate tensile strength increase, while the ductility decrease. The improvement of strength could be attributed to good bonding between TiB2 and the matrix, and also the TiB2 particles act as a barrier to dislocation.     

Preparation and Microstructure of Highly-Oriented LaNiO_3 Thin Films by RF Sputtering Method

In an attempt of being used as buffer layers and electrodes for the textured BaTiO3 (BTO) ferroelectric thin films, highly (100)-oriented LaNiO3 (LNO) thin films of different thicknesses were deposited directly on Si (100) substrate with radio-frequency (RF) magnetron sputtering method. It is observed that the substrate temperatures and the film thicknesses bring main influences on the micro-structures and orientation of the thin film. The effects of the thicknesses and substrate temperatures on the orientation of the films were studied on the LNO films of different thicknesses. The highly (100)-oriented LNO thin films were obtained at the substrate temperature of 600 ℃. The existence of epitaxially grown BTO films indicates that the oriented LNO thin films obtained in this work could be used as a buffer layer for epitaxial growth.     

衬层料浆无桨混合工艺

已定型LN106衬层手工混合工艺质量一致性差、料浆粘度高、使用量少,一般的机械搅拌设备难以满足要求。为提高产品质量可靠性,通过调研相关混合方法,结合产品特点,拟针对声共振工艺替代现用的手工混合工艺的可行性进行研究。通过对投料量、加料顺序、混合加速度、混合时间等工艺参数进行单因素实验,借助元素分析与胶片力学性能测试结果比对。实验结果表明,声共振混合工艺可有效地混匀衬层料浆,力学性能亦满足指标要求,混合工艺的边界条件为投料量100～1000 g,加速度为80g～90g,混合时间8～12 min。确定的工艺参数为:手工预混60～80 s(与原工艺相同),混合时间10 min,混合加速度80g。     

公务员素质与依法行政

依法治国是我国的一项基本治国方略，党的十六大报告中确立的全面建设小康社会的目标，其中就包括“社会主义民主更加完善，社会主义法治更加完备，依法治国方略得到全面落实人民的政治、经济、文化权益得到切实尊重和保障”可见，依法治国不仅是我国步入现代化的必由之路，也是全面建设小康社会的标志之一，江泽民在党十六大报告中指出：“宪法和法律是党的主张和人民意志相统一的体现，必须严格依法办事，任何组织和个人都不允许有超越宪法和法律的特权。”而依法行政是实施依法治国方略的核心，公务员的素质则是实现依法行政的关键和根本。     

英语习语中的饮食民俗文化

英语饮食习语积淀了深厚的民族文化特色,充分认识英语国家的饮食习惯,研究英语习语的来源和饮食民俗文化,有助于我们体会其深层含义.论文分析了英语国家的日常饮食习惯与节日饮食文化,说明了探讨英语饮食习语的学习,必须从其饮食文化方面入手.