中国四大林区固碳效率:测算、驱动因素及收敛性

论文将林业碳汇纳入到林业经济核算体系之中,构建含有正外部性产出的DEAMalmquist效率分析模型,在系统测算林业固碳量的基础上,对1988—2013年中国四大林区的林业固碳效率变动及驱动因素进行了分析,并进一步对其效率收敛性进行了检验。研究结果表明:1)全国四大林区间的固碳量及固碳价值差异较大,固碳总价值从高到低依次为西南(1 870.69×108元)、东北(1 335.41×108元)、南方(842.73×108元)、北方林区(407.35×108元)。2)1988—2013年不含碳汇产出的林业生产Malmquist指数较低,为0.958;而把碳汇纳入林业产出进行考量,全国林业Malmquist指数整体有所提升,主要源于技术效率推动,年均增长速度为0.6%;其中南方、东北林区固碳效率处于提升状态,而西南林区和北方林区呈下降趋势。3)西南和南方林区固碳效率随时间变动呈现倒"U"型态势;四大林区中南方林区效率均值最高,为1.036,其次是东北林区,为1.020。4)我国四大林区地区间固碳Malmquist指数没有出现σ收敛,相反,还存在绝对β发散现象,即四大林区地区内的林业固碳效率绝对值和增长率差异并没有随着时间而缩减。     

When and where do we see the proximity effect of a new park? –A case study of the Dream Forest in Seoul,Korea

This study aimed to unpack the dynamic proximity effects of a park on residential values in the urban regeneration context: first by the development phase of the park, and second, by specific characteristics of the residential units. The study site is the Dream Forest in Seoul, South Korea, and the study period is from 2006 to 2015. The two-fold multilevel regression analysis suggests that the Dream Forest began exerting proximity effects from the time of site acquisition by the city, which peaked at a 3.7% price increment per 100-meter distance to the park from a prototypical housing unit, soon after the public announcement of the park procurement plan. During construction, inauguration and stabilization, the effect has remained at around 3.0%. The analysis also suggests that the proximity effect applies unevenly to housing units: apartment type or older housing units are more sensitive to the externality effects than their counterparts – multifamily type or newer housing units.     

Modeling of variations in nitrogen trichloride concentration over time in swimming pool water

In water, chlorine reacts with nitrogen-containing compounds to produce disinfection by-products such as nitrogen trichloride which induces ocular and respiratory irritations in swimming pool workers. This study proposes a model to predict variations in NCl₃ concentration over time in a traditional indoor swimming pool as a function of its operating parameters and attendance. The model was developed taking into consideration the reaction mechanisms, thermodynamic equilibria, physico-chemical properties, and transfer mechanisms occurring at the pool's surface. This model was validated through a robust series of experiments over two days and two nights in a real swimming pool. The model was found to satisfactorily predict variations over time in the concentrations of the chemical species investigated, including nitrogen trichloride. The work presented constitutes a first step to extend the model at different swimming pools. This approach may also be used to study the influence of the main operating parameters and to evaluate the impact of setting up water treatment systems on nitrogen trichloride concentration.     

特长TBM施工隧道环境粉尘安全控制研究

采用双洞单线设计方案的中天山隧道长约22.5 km,施工通风采用独头通风方案,其进口TBM施工段的长度达到13.8 km,创下国内TBM独头施工通风长度新高。此外,TBM的掘进中将产生大量的粉尘对隧道的安全施工造成重大影响,超长距离的施工通风能否提供足够的风量来净化作业环境中的粉尘相关的研究非常必要。于是对中天山隧道施工环境中的粉尘含量进行了数值模拟和现场测试,期望得出施工环境中粉尘的分布规律以更好地指导隧道安全、高效的施工。     

声学环境影响评价——大剧院设计声学案例分析

大剧院观众厅是音乐家最后的乐器,音乐效果是由观众厅声学反应出来的。前面演奏者要把声音传播给观众席,再从观众席后排反声回给演奏者,这样的互动是最完美的剧院设计。     

Forest clearing and sex ratio in forest-dwelling wood ant <Emphasis Type="Italic">Formica aquilonia</Emphasis>

Sex ratios of ants have been shown to vary with food resource levels in several studies, but it is not known whether forest clear-cutting has any effect on sex ratio of aphid-tending forest-dwelling ants. We investigated whether the offspring sex ratio of the forest dwelling ant Formica aquilonia varied as a response to clear-cutting. We found that the proportion of males was smaller in clear-cuts than in adjacent forests. Our results are among the first showing that anthropogenic changes in forest structures may have a potential to modify sex ratios of social insects and other forest-dwelling animals.     

Health hazards from exposure to cobalt with special reference to carcinogenic,mutagenic and teratogenic effects†

Occupational exposure to cobalt‐containing dust may cause a severe type of pneumoconiosis as well as obstructive lung disease. Peroral exposure to cobalt chloride may under certain circumstances precipitate cardiomyopathy.

There are only a limited number of experimental studies available which deal with the carcinogenic, mutagenic and teratogenic effects of cobalt and its salts. Single or repeated injections of cobalt powder or cobalt chloride have been shown to induce malignant tumours at the site of injection in rats, but not in mice. In vitro studies have shown that cobalt chloride has mutagenic and teratogenic properties. There are no data available on cancer incidence among workers occupationally exposed to cobalt. Thus the possible role of cobalt in human carcinogenesis is still an open question.     

In utero therapy for fetal thoracic abnormalities

Fetal thoracic lung anomalies are rare. The specific diagnosis can be made by utilizing ultrasound, magnetic resonance imaging (MRI), and Doppler studies. Perinatal surveillance is required for large lesions and mediastinal shift regardless of the pathological diagnosis. These can cause physiological changes in the cardiovascular system with resulting hydrops. In utero therapies are variable but with no large randomized trials to compare risks and benefits. In most cases of fetal lung lesions, continued observation with postnatal therapy is the outcome. When fetal hydrops is present or impending, in utero fetal therapy is required to try to reverse that pathological course associated with fetal or neonatal death. Maternal morbidity is increased with the development of MIRROR syndrome following the presence of long-standing fetal hydrops and possible surgical procedures. Copyright © 2008 John Wiley & Sons, Ltd.     

A bioeconomic model of afforestation in Southern Ontario: Integration of fiber,carbon and municipal biosolids values

This study explores the economic attractiveness of afforestation as a strategy for the joint production of fibre, carbon storage and biosolids (treated municipal sewage sludge) disposal for municipalities in Southern and Central Ontario, Canada. We use a spatial, stochastic model, the Canadian Forest Service Afforestation Feasibility Model (CFS-AFM), to simulate a range of spatial biosolids application scenarios in hybrid poplar afforestation projects. Results suggest that such joint afforestation strategies could be financially attractive. Significant cost savings can be expected through decreases in transportation distances and avoided waste disposal fees. Sensitivity analysis is used to examine the effects of variations in critical model parameters on net present values. Our findings indicate that waste disposal savings from application of biosolids on hybrid poplar plantations combined with incentives for landowners to sequester carbon can easily compete with agricultural land rental values in some regions of Ontario. Social acceptance of this kind of activity, however, may be an impediment to adoption.     

改性PES膜在MBR中膜阻力分析及膜污染机理研究

以聚醚砜(PES)、醋酸纤维素(CA)和纳米二氧化钛(TiO2)为膜材料,采用L-S相转化法制备共混改性PES膜。在24℃、0.2 MPa的操作条件下,制得的PES膜纯水通量为300 L/(m2.h)左右,CA改性PES膜为660 L/(m2.h)左右,TiO2改性PES膜为840 L/(m2.h)左右。通过膜生物反应器中膜阻力的测定,表明膜污染主要由浓差极化层及凝胶层引起的;通过活性污泥对膜污染机理的研究,判断出污泥的过滤过程基本符合沉积过滤定律。在MBR中运行时,改性PES膜稳定通量高于未改性膜,总阻力低于未改性膜;TiO2改性膜稳定通量高于CA改性膜,总阻力低于CA改性膜;通过扫描电镜分析,改性PES膜沉积层的厚度均比未改性膜薄,TiO2改性膜沉积层厚度小于CA改性膜,表明改性膜的抗污染性能提高了,TiO改性膜抗污染性能更优。