Public reaction to wind development in California

Substantial controversy has been produced from the location of over 4000 wind turbines in San Gorgonio Pass, California. The principal point of controversy is the conflicting land use which results from developing wind power in a populated area. A public opinion survey was conducted which demonstrated that the vocal opposition to the wind turbines so commonly expressed is not borne out in fact. While there is indeed some opposition to the development of wind power at this site, particularly in terms of aesthetic degradation, the majority of respondents favoured the development. This level of approval will be of interest to those developing large wind projects elsewhere.     

Hydrodynamic characteristics of a new permeable pavement material produced from recycled concrete and organic matter

The aim of the present study was to evaluate the hydrodynamic characteristics of a new material to be used for permeable and purifying pavements in urban areas. The new material is a mixture of crushed concrete, to provide structural support, and a compost mix intended to retain and biologically treat stormwater pollutants. The first part of this study was to evaluate the hydraulic conductivity of the material at different mixing ratios to define the range of materials suitable for urban drainage applications. The second part of the study involved using tracing experiments to quantify the effects of the pollutant transport mechanisms occurring during the water infiltration process. These experiments were conducted under steady state flows condition using a conservative tracer (NaCl). The results demonstrate that while the addition of compost significantly reduced the permeability of the concrete mix, it was still suitable for use as a paving material in an urban environment. The increased residence time of the stormwater pollutants due to the addition of the compost mix was shown to have a positive effect on the biological treatment of the stormwater pollution.     

Water exchange effect on eutrophication in landscape water body supplemented by treated wastewater

Artificial landscape water bodies filled by treated wastewater pose a risk of developing algal blooms due to high nutrient levels of treated wastewater. In this study, water exchange experiments were conducted using treated wastewater in an artificial landscape pond, and a eutrophication model was calibrated and applied to evaluate the effects of water exchange on algae growth in the pond. The results indicate that the joint dilution process and nutrient supply process of water exchange initially cause the algae level to rise and then rapidly decline as the hydraulic resident time (HRT) decreases, and HRT has a critical point at which the pond faces the highest risk of algal bloom. The study also indicates that phosphorus (instead of nitrogen) is the primary limiting factor of algae growth. Therefore, the critical HRT should be avoided and phosphorus is the target pollutant to be controlled in landscape pond water management.     

空间意境再现——现代中式住宅庭院空间的解读

现代中式住宅的出现不仅使其具有丰富住宅空间、继承传统文化、弘扬中国特色等重要作用,而且促使人们开始重新认识传统建筑文化精神的价值a文章主要从庭院空间角度来解读传统空间意境,分别以低层和多、高层的现代中式住宅的水平庭院和垂直庭院为客观载体．探讨现代中式住宅对庭院空间所进行的重新演绎及全新的空间形式。通过分析指出中式住宅庭院空间设计的不足,为现代中式住宅的设计提供更多的可能性。     

关于住宅建设用地使用权续期的讨论

社会主义的土地公有制决定了不能够变相买卖土地所有权。建设用地使用权出让金具有地租的性质,是权利人获得土地使用权的对价,因此应该采取住宅建设用地使用权有偿续期的方式。无偿续期实际是补贴富有人群,加剧贫富不均。明确住宅房地产价值的时限性可以有效降低房地产投机行为,稳定房价。国家应该尽早从法律角度细化住宅用建设用地使用权续期的办法,减少商品房价值的不确定性。     

Experimental and numerical study of the airflow distribution in mixed-flow grain dryers

The aim of this study was to investigate the airflow distribution in a mixed-flow dryer (MFD) and to study the effect of different bed materials and air duct arrangements. The results were used to validate the numerical model developed in a previous work based on Computational Fluid Dynamics (CFD). A series of experiments have been conducted at a semi-technical MFD test dryer with horizontal and diagonal air duct arrangement. Wheat and rapeseed were used as bed materials. The experiments were performed under isothermal conditions. Two experimental methods were selected and adapted to the measuring problem—the measurement of the isobar distribution within the grain bed and the residence time analysis using the tracer gas pulse method. As could be shown, the isobar distributions measured for wheat and rapeseed agreed well with the model predictions. The numerical model could calculate the influence of the bed material with its different particle characteristics (e.g., particle shape, particle size, bed porosity). The results obtained from the residence time analysis confirmed the known quartering of the air stream flowing from one inlet air duct to the four surrounding outlet air ducts for the horizontal air duct arrangement; in the diagonal air duct arrangement, the air stream from one inlet air duct was nearly halved flowing to the two adjacent diagonal outlet air ducts. These results were confirmed by investigations of the air velocity distribution within the grain bulk. Further experiments are necessary to refine the model. The residence time and isobar measurements will be extended to study the influence of different air properties under real drying conditions, the effect of structural elements, and dryer designs.     

Spray drying with a two-fluid nozzle to produce fine particles: Atomization,scale-up,and modeling

This article presents experimental and modeling work to complete previously reported work on spray drying. Back-calculated droplet sizes have been verified by measurements with a laser imaging rig. Flow patterns in a cylindrical spray chamber have been simulated by computational fluid dynamics and demonstrated that droplet residence times are much shorter than expected. A droplet tracking population balance model has been implemented in gSOLIDS and shows how drying times vary with droplet diameter. Particle collection by cyclone and bag filter have also been compared experimentally.     

基于熵值法径向基神经网络的清扫车吸尘口垃圾颗粒驻留时间预测

针对清扫车吸尘口内垃圾颗粒驻留时间受到结构类、固相类及气相类因素多类型、非线性作用预测难的问题,提出了基于熵值法的径向基神经网络(RBFNN)的垃圾颗粒驻留时间预测方法,该方法考虑了吸尘负压、滚刷转速、颗粒质量、颗粒密度、颗粒流量和吸尘管直径6种因素,将采用熵值法求解的因素权重作为输入扰动变量,建立了垃圾颗粒驻留时间的预测模型。结果表明：与采用传统RBFNN的预测方法相比,所提方法具有预测精度高的优点,可较好地解决清扫车吸尘口垃圾颗粒驻留时间预测难的问题,有助于提升清扫车吸尘系统设计水平。     

关于国内生态住宅评价标准的指导性分析——从《中国生态住宅技术评估手册》到《绿色建筑评价标准》

《中国生态住宅技术评估手册》（以下简称《手册》）在出台后不仅被作为生态住宅的评价工具,它同时也被生态住宅的生产者使用以指导生态住宅的建设,而新实施的《绿色建筑评价标准》（以下简称《绿评》）也必将扮演指导的角色,从进年来以《手册》指导建设的生态住宅项目中可以看到,《手册》在指导性方面存在一定的不足,故此,本文将对此展开分析,并在此基础上去与新实施的《绿评》作比较,分析《绿评》在指导生态住宅建设方面存在的优缺。     

稀薄氨气的燃烧特性及动力学研究

文章通过稀薄氨气在固定床反应器中的燃烧,研究了反应温度、停留时间、氨气浓度和氧气浓度对低浓度氨气燃烧特性的影响,并描述了氨气在氧气过量条件下在陶瓷蜂窝蓄热体中燃烧的动力学过程。研究结果表明:提高反应温度、延长停留时间以及增大氧气浓度和氨气浓度均可以提高NH3转化率,氧气浓度过高会促进NO生成;当反应温度为740~770℃、氨气浓度为1%、氧气浓度为15%时,氨气在陶瓷蓄热体中燃烧的活化能为253.56 kJ/mol;与氨气在自由空间内的燃烧相比,氨气在陶瓷蜂窝蓄热体中主要发生表面燃烧反应。