RESEARCH ON THE CONSTRAINT MAPPING FROM FUNCTION TO ASSEMBLY

Assembly sketch is not only the visualization of abstract function, but also the template of detail design. Two kinds of information are needed to create assembly sketch: structure and assembly constraint. Most researches are aimed at how to obtain structures from function, but the problem of how to obtain assembly constraint from function is ignored. Following the definition of assembly unit and the classification of function, a hierarchical mapping method from function to assembly constraint is put forward, and the mapping method includes two steps. The first step is the mapping from function to assembly semantics which is assembly expression and accordant with engineer's design habit. The second one is the mapping from assembly semantics to basic assembly constraints that are convenient for computer to handle. The mapping method is applied to DDMS (design, drafting and management system) successfully.     

Large scale synthesis of nickel oxide/multiwalled carbon nanotube composites by direct thermal decomposition and their lithium storage properties

A large scale direct thermal decomposition method has been developed to prepare NiO/MWCNT nanocomposites. The as-prepared NiO nanoparticles are uniformly coated onto the surface of MWCNTs. The well crystallized NiO/MWCNT composites show superior electrochemical performance in Li ion batteries. The lithium storage capacity maintains at ∼800 mAh g⁻¹ after 50 discharge/charge cycles, which is much larger than those reported for NiO and its composites. Therefore, the NiO/MWCNT composites have significant potentials for application in energy storage devices. The direct thermal decomposition method is a versatile route for preparing carbon nanotube-inorganic hybrid electrode materials for lithium ion batteries.     

A novel fading-resistant Al-3Ti-3B grain refiner for Al-Si alloys

Al-Ti-B refiners with excess-Ti perform adequately for wrought aluminum alloys but inefficiently in the case of foundry alloys. The high content of silicon in the latter, which forms silicides with Ti and severely impairs the refining potency of the nuclei, is known to be responsible for the poor performance. Hence, new grain refiners, such as Al-3B and Al-3Ti-3B master alloys with excess-B have been developed with well documented advantages for Al-Si alloys. It is very desirable to involve TiAl₃ particles in the Al-3Ti-3B master alloy to maximize its grain refining efficiency. However, fading phenomenon is a key drawback for application of the TiAl₃-containing refiners in aluminum foundry. In the present work, new Al-3Ti-3B grain refiners, containing TiB₂, AlB₁₂ and TiAl₃ particles were developed with an aim to prolong the acting time after inoculation. The results showed that inoculation of Al-7Si alloy with thus meliorated Al-3Ti-3B grain refiner has produced a fine grain structure which was approximately maintained up to 30 min.     

探析CRO机制下我国企业的风险管理体系

伴随着企业风险范围的日益宽广、风险管理角色的变化以及法律制度的改革,传统的零散式风险管理方法越来越难以满足企业持续发展需求.为此,世界不同国家的各类企业均试图努力寻求一种更为科学的风险管理机制.其中,CRO(首席风险官)便是这种实践的产物.本文从风险管理的发展历程谈起.进一步介绍CRO实践效果以及对我国公司治理产生的借鉴作用,并就我国企业如何构建CRO机制,从企业风险控制环境、风险评估、风险控制活动、信息与沟通、监督和项目管理五个部分着手予以探讨.     

Grain boundary microstructure in DyF3-diffusion processed Nd-Fe-B sintered magnets

The effect of post-sinter tempering on the DyF₃-diffusion processed Nd-Fe-B was investigated using two kinds of starting magnets. The increase of coercivity after diffusion process using as-sintered magnet was higher than that using two-stage tempered magnet. The grain boundary phase of the tempered magnet became discontinuous upon further annealing at the temperature of diffusion process. This clearly indicates that a continuous grain boundary phase is helpful to the DyF₃-diffusion process. When sufficiently diffused, there is no enrichment of Dy in the grain boundary phase. The excess Nd as a result of Dy substitution in the Nd₂Fe₁₄B matrix phase forms Nd-O phase at grain boundary and on the surface of the magnet. The increase of coercivity can be related to the (Nd,Dy)₂Fe₁₄B grains as well as to the improved decoupling by the grain boundary phase.     

CASE-BASED PRODUCT CONFIGURATION AND REUSE IN MASS CUSTOMIZATION

The increasing complexity and size of configuration knowledge bases requres the provisionof advanced methods supporting the development of the actual configuration process and design reuse.A new framework to find a feasible and practical product configuration method is presented in masscustomization. The basic idea of the appoach is to integrate case-based reasoning (CBR) with a con-straint satisfaction problem(CSP). The similarity measure between a crisp and range is also given,which is common in case retrieves. Based on the configuration model, a product platform and customerneeds, case adaptation is carried out with the repair-based algorithm. Lastly, the methodology in theelevator configuration design domain is tested.     

The impact of solvent and modifier on ZnO thin-film transistors fabricated by sol-gel process

Techniques for fabricating solution-processed zinc oxide(ZnO)-based thin-film transistors(TFTs)are feasible with solution using various routes.Here,ZnO TFTs were fabricated via sol-gel method using zinc acetate as the starting reagent with different modifiers and solvents.The ZnO thin-film semiconductors with well-controlled,preferential crystal orientation and densely packed ZnO crystals can be prepared with the optimized fabrication conditions,exhibiting excellent field-effect far exceeding those of hydrogenated amorphous silicon(a-Si:H).However,the field-effect characteristics of ZnO TFTs were different for different precursor systems which were constituted by zinc acetate,modifiers and solvents.The co-modification of acetoin and monoethanolamine for the precursor system exhibited higher extent of crystal orientation and field-effect.The maximum mobility of 7.65 cm2V-1s-1 and current on-to-off ratio of~105–106 have been obtained.     

“油气运移动态富集”概念及其在塔里木台盆区油气勘探中的应用

"油气运移动态富集"概念,用初次富集、二次富集和再次富集描述动态充注条件,分4个层次研究.塔里木台盆区(塔中隆起、塔北隆起和巴楚隆起)特殊石油地质问题要点是:①控制古生界烃源岩品质、生烃母质丰度的因素是有利沉积相带分布;②存在古隆起发育事件、深埋事件和热事件,导致寒武系-奥陶系有效烃源岩局限于一些特定地区,须从烃源岩动态演化的角度分析油源条件.③沉积、构造多旋回规律性迁移造成多含油气系统叠合.塔中地区可划分4个运聚成藏阶段:①中奥陶世-早志留世下构造层形成自生自储内幕原生油气藏与破坏散失并存阶段,油气动态富集明显受古隆起控制;②中志留世-二叠纪再次运移形成沥青砂为主阶段,隆起西部倾没端是有利运聚成藏区带;③二叠纪-第三纪运聚充注成藏为主阶段,塔中10构造带和塔中1号断裂构造带是有利运聚成藏区带,主分隔槽(北翼鼻隆与中央断垒交汇带)以南因无油源条件而无成藏条件;④晚第三纪以来油气藏调整为主阶段.塔中地区下构造层关键评价要素是古油气藏保存条件和有无晚期油气补充条件,特别应注意位于有利油气汇聚区的岩性圈闭.提出塔中地区勘探部署建议,认为要建立以"动态"思想贯穿始终的研究体系及勘探模式.     

论旅游规划中的平衡关系

旅游规划应平衡旅游开发过程中的一系列关系:区域发展与阶段开发的关系;经济发展与环境保护的关系;本土习俗与外来文化的关系;旅游开发用地空间需求与原住居民、村寨的去留关系。