低碳城市建设的社会成本研究

目前把社会成本（Social Cost）概念引入到低碳城市的碳排放控制指标与政策手段中的研究相对比较少低碳经济和低碳城市的概念也只是在过去10多年来,特别是在1997年〈京都议定书〉签订后才受到政府和社会的广泛、高度重视。政府在城市发展领域推动低碳城市的政策和行动都有其相对的社会成本和效益．因此这直接影响着社会整体的资源配置效率。社会成本分析就是要将客观而科学的工具引入到城市规划建设政策制定过程中．把有关的社会成本量化为经济价值．为决策者提供参考,以实现社会整体资源的最优化。     

Low-Angle Grain-Boundary Macrostructure in Large-Diameter Czochralski White Sapphire

Large-diameter Czochralski sapphire crystals grown in several orientations were occasionally found to contain complex networks of low-angle grain boundaries. The subboundaries lie in major low-index crystallographic planes which are uniquely determined by the gowth orientation. The major subboundary planes were the (11¯00) and (011¯0) for crystals gro_wn_in the direction normal to the ( r )-(1¯012) plane and the (1¯21¯0) and (21¯1¯0) planes for crystals grown in the 90°-[1120] direction. The formation of the subboundary macrostructure was attributed to an excessive temperature gradient during seeding and is not related to growth rate, impurity content, or annealing.     

月下独步水竹园

2008年11月15日,北京798的尤伦斯当代艺术中心开始呈献一场名为"迪奥与中国艺术家"的大型展览,此次展览是两块大陆之间与两种不同表达方式——当代艺术与时尚之间的对话,叶锦添、张大力、张洹、马岩松等20名中国艺术家应邀彰显创意,以其特有方式诠释迪奥(Dior)内涵,再现传统艺术与奢华时尚的完美结合。叶锦添先生的"水竹园"极富中国庭院的神韵,将众多中国当代艺术品与迪奥历年经典服装完美协调地呈现在展馆中,本刊特邀其撰文阐述创作理念,以飨读者。     

《城乡规划法》:落实区域循环经济的机遇

提出要把循环经济整合到城市规划决策过程中,可以与《城乡规划法》确立的不同层次的法定规划编制接轨,通过城市空间规划从宏观、中观、微观层次着手进行落实。     

Fast-sweeping Langmuir probes:what happens to the Ⅰ-Ⅴ trace when sweeping frequency is higher than the ion plasma frequency?

Limited particle transit time is one of several limiting factors which determine the maximum temporal resolution of a Langmuir probe.In this work,we have revisi...     

国外城市区域温室气体清单编制对我国城乡规划的启示

城乡规划作为应对气候变化的政策平台,城市规划决策者需要有能力明确指出相关的基本排放数据:包括不同规划方案产生的温室气体排放量、规划范围的主要排放源头,排放结构等,编制减少温室气体排放的指标,作为行动计划实施的依据.要科学地建设低碳城市,以城乡规划建设政策控制温室气体排放,温室气体清单编制是十分重要的基础规划要求.但目前我国以地方城市区域为空间单元进行温室气体排放清单研究的工作都还不够,影响了城乡规划和建设领域应对气候变化的政策体系的发展和推进.本文对近年来国外城市或地区温室气体排放清单编制的理论和实践经验进行回顾,以英国的莱斯特市和伦敦市,美国的纽约州和纽约市、及加拿大温哥华市5个尺度规模不同的地方区域近年编制的温室气体清单为例,总结其对我国城市温室气体清单编制工作的参考作用.最后指出对我国城乡规划建设领域温室气体清单编制工作的启示,并提出三个基本方法和原则:(1)城乡规划建设政策职能匹配;(2)明确解释城乡空间边界的影响;(3)减排目标与进度成果数据公开.     

Measurement of bearing reactions in small-scale bridge slabs

An experimental technique is described for the measurement of bearing reactions in small-scale bridge slabs. The reactions are determined implicitly by direct measurement of the frictional forces between the slab and its supporting abutment, using thin pull-out steel strips     

Integer sinusoidal transforms for image processing

The sine and cosine transforms, which are popular transforms for image coding, are members of a sinusoidal transform family. Each member of the family is the optimal KLT of a Markov process. This paper derives the conditions under which the order-8 sinusoidal transforms can be approximated by orthogonal integer transforms which can be implemented using integer arithmetic. Some integer transforms are derived as examples. The results show that for the popular even sine-1, even sine-2 and the cosine transforms, there is an infinite number of integer transforms and some have their transform component magnitudes less than eight. In LSI implementation, if low implementation cost and fast computation speed are paramount, then an integer transform of small component magnitudes can be chosen. If better performance is desired, integer transforms whose elements have larger magnitudes can be used. The availability of many integer transforms provides a design engineer the freedom to trade-off performance against simple implementation and speed.     

生态城市:从概念到规划管理实施——上海崇明岛东滩和北京丰台长辛店

"生态城市"规划近年来被城市规划决策者关注,无论是发展商或是地方政府,都对此概念及如何去编制和实施产生兴趣。然而,要规划和实施生态城市,无论在理念、手段、方法和决策过程等方面都与当前国内的城市规划管理方法不完全相同。本文以两个案例去讨论从生态城市规划概念实施到城乡规划管理制度面对的机遇和挑战。     

Compression Deformation Mechanisms at the Nanoscale in Magnesium Single Crystal

The dominant deformation mode at low temperatures for magnesium and its alloys is generally regarded to be twinning because of the hcp crystal structure. More recently, the phenomenon of a "loss" of the twins has been reported in microcompression experiments of the magnesium single crystals. Molecular dynamics simulation of compression deformation shows that the pyramidal slip dominates compression behavior at the nanoscale. No compression twins are observed at different temperatures at different loadings and boundary conditions. This is explained by the analyses, that is, the {102} and {101} twins can be activated under c-axis tension, while compression twins will not occur when the c/a ratio of the hcp metal is below √3. Our theoretical and simulation results are consistent with recent microcompression experiments of the magnesium (0001) single crystals.