A comparison of chemical mechanisms based on TRAMP-2006 field data

A comparison of a model using five widely known mechanisms (RACM, CB05, LaRC, SAPRC-99, SAPRC-07, and MCMv3.1) has been conducted based on the TexAQS II Radical and Aerosol Measurement Project (TRAMP-2006) field data in 2006. The concentrations of hydroxyl (OH) and hydroperoxy (HO₂) radicals were calculated by a zero-dimensional box model with each mechanism and then compared with the OH and HO₂ measurements. The OH and HO₂ calculated by the model with different mechanisms show similarities and differences with each other and with the measurements. First, measured OH and HO₂ are generally greater than modeled for all mechanisms, with the median modeled-to-measured ratios ranging from about 0.8 (CB05) to about 0.6 (SAPRC-99). These differences indicate that either measurement errors, the effects of unmeasured species or chemistry errors in the model or the mechanisms, with some errors being independent of the mechanism used. Second, the modeled and measured ratios of HO₂/OH agree when NO is about 1 ppbv, but the modeled ratio is too high when NO was less and too low when NO is more, as seen in previous studies. Third, mechanism–mechanism HO_x differences are sensitive to the environmental conditions – in more polluted conditions, the mechanism–mechanism differences are less. This result suggests that, in polluted conditions, the mechanistic details are less important than in cleaner conditions, probably because of the dominance of reactive nitrogen chemistry under polluted conditions.     

Effect of urbanization on the structure and functional traits of remnant subtropical evergreen broad-leaved forests in South China

We investigated the effects of major environmental drivers associated with urbanization on species diversity and plant functional traits (PFTs) in the remnant subtropical evergreen broad-leaved forests in Metropolitan Guangzhou (Guangdong, China). Twenty environmental factors including topography, light, and soil properties were used to quantify the effects of urbanization. Vegetation data and soil properties were collected from 30 400-m² plots at 6 study sites in urban and rural areas. The difference of plant species diversity and PFTs of remnant forests between urban and rural areas were analyzed. To discern the complex relationships, multivariate statistical analyses (e.g., canonical correspondence analysis and regression analysis) were employed. Pioneer species and stress-tolerant species can survive and vigorously establish their population dominance in the urban environment. The native herb diversity was lower in urban forests than in rural forests. Urban forests tend to prefer the species with Mesophanerophyte life form. In contrast, species in rural forests possessed Chamaephyte and Nanophanerophyte life forms and gravity/clonal growth dispersal mode. Soil pH and soil nutrients (K, Na, and TN) were positively related to herb diversity, while soil heavy metal concentrations (Cu) were negatively correlated with herb diversity. The herb plant species diversity declines and the species in the remnant forests usually have stress-tolerant functional traits in response to urbanization. The factors related to urbanization such as soil acidification, nutrient leaching, and heavy metal pollution were important in controlling the plant diversity in the forests along the urban–rural gradients. Urbanization affects the structure and functional traits of remnant subtropical evergreen broad-leaved forests.     

Rewriting the Plot: sustaining allotments in the UK and Japan

In the search for a model form of allotment garden in the late 1980s, capable of absorbing surplus farmland while sustaining the capacity of the land to support agriculture, Japanese experts rejected the UK allotment, which was perceived to be of low status and in decline, in favour of the German Kleingarten. This paper suggests that it may be time to reconsider the UK experience, in the light of subsequent moves to rewrite the image and practice of allotment gardening in the UK within the local sustainable development agenda, and the problems which the Japanese version of the Kleingarten model has encountered in the changed economic circumstances of the 1990s.     

转型时期中国城市化水平变动及动力分析

收集各省区近20年有关城市化方面的资料，分析了我国在转型时期城市化水平的时空变化规律。分析结果表明我国转型时期城市化水平在时间变化上具有水平起点低，发展速度快的特点；在空间变化上存在着较大的东中西区际和省际差异。在些基础上，利用多元统计方法，定量研究影响我国城市化发展的主动力因子，结果表明：工农业发展推拉因子、产业结构转换因子和出口替代外向因子是影响我国城市化发展的三大主动力因子。但表现在东中西城市化发展的主作用力是不同的。进一步研究表明：东部省区城市化水平与第三产业发展水平、产业结构转换能力和经济外向化密切相关，其中与第三产业发展水平表现最为显著；中部省区城市化水平与大中型工业企业的分面、工农业发展产相关性强；西部省区城市化水平与工业发展水平最为相关。     

Impact of Regional Economy on Internal Migration in Yangtze Delta： Based on Panel Data

Metropolitan Shanghai, in Yangtze River Delta （YRD）, plays undoubtedly the leading role in the economic development in China, and becomes one of the most important population congregation areas. It is also widely regarded as the sixth uprising urban agglomeration in the world. Based on the quantitative studies on basic socioeconomic and demographic profile on the number and transition of population, this paper concluded that the migration is the key factor for population dynamics in YRD. Then, what are the regional economic factors affecting the migration of different cities in YRD？ The panel data show that the different wage level is the most important factor that affects the immigration in YRD. Moreover, the ratio of industry sector and service sector has an impact on attracting immigration. However, per-capital GDP and the share of foreign direct investment （FDI） to GDP have dual-side impact： not high per-capital GDP and FDI bring the high immigration.     

以天然气为原料生产亚氨基二乙腈的污染物产生及治理措施

以天然气-氢氰酸-羟基乙腈-亚胺基二乙腈-亚胺基二乙酸-双甘膦-草甘膦工艺路线正以其良好的经济性得到推广和发展，而其中的关键中间原料亚氨基二乙腈（IDAN）由于规模化生产装置较少，污染物的产生情况及治理措施尚有待于探讨，结合四川省拟建的和已有部分同类项目及装置的经验，在进行污染物源点、源强调查的基础上，分析、归纳和总结了已有治理技术，提出了较为完整亚氨基二乙腈生产的污染治理措施。本研究对草甘膦产业的污染物有效治理具有一定的指导意义。     

2005年世界各国风电发展回顾

全球风能事业发展在2005年再创新高.根据全球风能委员会（Global Wind Energy Council,GWEC）日前发布的数据,2005年世界风电装机容量净增11769 MW（兆瓦）,与前一年8207 MW的新增装机容量相比,全球市场年增长提高43.4%,新增发电设备总价值逾120亿欧元（140亿美元）.现在,全世界风电装机容量达到59322 MW,比2004年增加了25%.