建设用地二三产业增长贡献及空间相关性研究

在土地资源总量有限和耕地保护压力巨大背景下,将建设用地纳入经济增长内生模型,研究土地要素对二三产业增长贡献,探寻省际建设用地产出弹性在空间上是否存在相关性与集聚性具有一定的理论与现实意义.已有关于建设用地经济增长贡献研究大多假设技术水平单调上升,或直接把固定资产投资当资本存量,且很少研究增长贡献的空间相关性.本文首先测算1999 - 2008年全国与各省技术水平及二三产业资本存量,以准确测度建设用地经济增长贡献,其次对C-D生产函数进行回归以计算建设用地产出弹性,最后用空间相关分析法分析产出弹性在空间上的相关性与集聚区域.结果表明:技术水平变化并非像以往假设一样——随时间单调上升,而是在某些年份进步迅速,某些年份进步缓慢,甚至有些年份停滞不前;资本存量对经济增长弹性最大,劳动力次之,建设用地最小,其值是0.1027;中国省际建设用地二三产业产出弹性存在全局自相关现象,自身及相邻省份的建设用地二三产业贡献水平高于平均数(HH)的区域主要分布在长江三角洲地区,与此相反(LL)的区域则主要分布在西北内陆地区.     

循环经济视角下原生和再生资源消费的动态分析

从循环经济视角出发,聚焦这种新经济模式下原生资源和再生资源的动态关系,以世界铅资源为实证对象,利用1974-2006年世界铅资源的相关时间序列数据组织样本,基于协整关系分析构建VAR模型,在VAR模型框架下研究原生铅产量和再生铅产量对来自不同冲击的脉冲响应函数和方差分解。研究结果表明:原生铅产量、再生铅产量与铅消费总量之间存在着一个协整关系。这意味着在当前经济系统中,对铅资源是刚性需求,没有有效替代品,其供给的途径只有原生铅和再生铅两种。另外,对于来自市场消费规模、原生和再生铅产量的变动冲击,再生铅所做出的响应比原生铅更富有弹性,这一结论可以很好的阐释为什么再生资源市场比原生资源市场波动大的现象。     

间接制冷换热器除霜方案研究

目的对以载冷剂为冷媒,用于极端低温气候环境实验室的换热器的除霜问题进行研究,获得可行的除霜设计方案。方法从抑霜和融霜两个方面出发,设计包含变片距结霜换热器的内融霜和外融霜两种除霜方案,并搭建实验台对除霜方案进行实验研究。结果变片距结霜换热器迎风面结霜严重,背风面轻度结霜,内融霜可在3.5 min完成,而外融霜需要2倍的时间。内融霜结束后继续加热换热器,并配合新风置换可在20 min内除去化霜后的附着水。结论变片距结霜换热器能够有效对来流空气进行预除湿,抑制主换热器结霜,内融霜效果最好且目前以蒸汽为热源、内融霜为主、新风吹扫为辅的除霜系统已应用于大型气候环境实验室。     

次生铁矿物及其与环境中锑的相互作用研究进展

我国锑矿资源丰富,锑矿资源开发利用过程导致锑进入表生环境并富集。锑作为人体非必需重金属,具有高化学毒性,是国际公认优先控制金属污染物。次生铁矿物在形成过程中和成矿后能以共沉淀、吸附等方式固定有害金属,但又易受环境因子变化的影响,重新释放被固定的有害金属,对有害金属的环境行为和归宿有着重要影响。本文面向我国锑污染现状,立足于常见次生铁矿物的基本结构和表面过程,以次生铁矿物相转变为切入点,论述了次生铁矿物与锑的相互作用机理,总结了环境pH、溶解性有机物、Fe(II)、微生物及环境温度等外界因素作用下次生铁矿物对锑环境行为的作用规律,以期从矿物学角度厘清环境因素-次生铁矿物-锑之间的微观作用机制,为表生环境锑污染的环境风险评价和修复治理提供理论指导。     

上向流好气滤池冬季挂膜启动及运行参数探讨

好气滤池同时具有普通滤池和曝气生物滤池的优点,能对二级出水中的COD、氨氮和浊度等指标进一步去除,提高再生水水质。试验探讨了冬季好气滤池的挂膜启动方法和运行参数,提出采用逐渐增加流量到设计流量的自然挂膜法,同时提出运行采用上向流;滤速1 m/h;气水比采用（1～3）∶1;填料填充高度与滤料直径有关;出水水头损失增加到1 m作为过滤周期的终点;适宜的冲洗强度冲洗滤池后,4 h内能恢复到滤池反冲洗前的处理状态。冬季低温条件延长了好气滤池的挂膜启动时间,但不影响挂膜质量;为保证出水质量,对好气滤池的运行滤速要通过试验确定。     

滤布滤池强化处理城市二级出水中试研究

采用滤布滤池对南方某城市污水处理厂二级出水进行强化处理中试研究,以达到中水回用的目的。实验选用氯化铁(FeCl₃)、聚合氯化铝铁（PAFC）和聚合氯化铝（PAC）作为强化滤布滤池除磷效果的混凝剂。当不投加混凝剂时,滤布滤池对TP和COD的平均去除率为28.76%和8%,其中TP的去除效果受进水水质影响较大;当投加氯化铁、聚合氯化铝铁与聚合氯化铝强化滤布滤池时,滤布滤池对TP的平均去除率分别为63.58%、60.13%和66.94%,TP去除效果受进水水质影响较小;对SS的平均去除率分别为70.7%、64.3%和49.1%;对COD平均去除率分别为17.7%、26.3%和27.7%。滤布滤池对TN和NH₃-N去除效果不稳定。     

Conservation of Epiphyte Diversity in an Andean Landscape Transformed by Human Land Use

Abstract: Epiphytes are diverse and important elements of tropical forests, but as canopy‐dwelling organisms, they are highly vulnerable to deforestation. To assess the effect of deforestation on epiphyte diversity and the potential for epiphyte conservation in anthropogenically transformed habitats, we surveyed the epiphytic vegetation of an Ecuadorian cloud forest reserve and its surroundings. Our study was located on the western slopes of the Andes, a global center of biodiversity. We sampled vascular epiphytes of 110 study plots in a continuous primary forest; 14 primary forest fragments; isolated remnant trees in young, middle‐aged, and old pastures; and young and old secondary forests. It is the first study to include all relevant types of habitat transformation at a single study site and to compare epiphyte diversity at different temporal stages of fragmentation. Epiphyte diversity was highest in continuous primary forest, followed by forest fragments and isolated remnant trees, and lowest in young secondary forests. Spatial parameters of habitat transformation, such as fragment area, distance to the continuous primary forest, or distance to the forest edge from inside the forest, had no significant effect on epiphyte diversity. Hence, the influence of dispersal limitations appeared to be negligible or appeared to operate only over very short distances, whereas microclimatic edge effects acted only in the case of completely isolated trees, but not in larger forest fragments. Epiphyte diversity increased considerably with age of secondary forests, but species assemblages on isolated remnant trees were impoverished distinctly with time since isolation. Thus, isolated trees may serve for recolonization of secondary forests, but only for a relatively short time. We therefore suggest that the conservation of even small patches of primary forest within agricultural landscape matrices is essential for the long‐term maintenance of the high epiphyte diversity in tropical cloud forests.     

Mineral materials as feasible amendments to stabilize heavy metals in polluted urban soils

Four minerals, agricultural limestone (AL), rock phosphate (RP), palygorskite (PG), and calcium magnesium phosphate (CMP), were evaluated by means of chemical fractions of heavy metals in soils and concentrations of heavy metals in leachates from columns to determine their ability to stabilize heavy metals in polluted urban soils. Two urban soils (calcareous soil and acidic soil) polluted with cadmium, copper, zinc and lead were selected and amended in the laboratory with the mineral materials) for 12 months. Results indicated that application of the mineral materials reduced exchangeable metals in the sequence of Pb, Cd > Cu > Zn. The reduction of exchangeable fraction of heavy metals in the soils amended with di erent mineral materials followed the sequence of CMP, PG > AL > RP. Reductions of heavy metals leached were based on comparison with cumulative totals of heavy metals eluted through 12 pore volumes from an untreated soil. The reductions of the metals eluted from the calcareous soil amended with the RP, AL, PG and CMP were 1.98%, 38.89%, 64.81% and 75.93% for Cd, 8.51%, 40.42%, 60.64% and 55.32% for Cu, 1.76%, 52.94%, 70.00% and 74.12% for Pb, and 28.42%, 52.74%, 64.38% and 49.66% for Zn. Those from the acidic soil amended with the CMP, PG, AL, and RP were 25.65%, 68.06%, 78.01% and 79.06% for Cd, 26.56%, 49.64%, 43.40% and 34.68% for Cu, 44.44%, 33.32%, 61.11% and 69.44% for Pb, and 18.46%, 43.77%, 41.98% and 40.68% for Zn. The CMP and PG treatments were superior to the AL and RP for stabilizing heavy metals in the polluted urban soils.     

Beijing Ministerial Declaration on Environment and Development

Abstract

As the main organic pollutant in municipal living waste, kitchen waste causes secondary pollution in the course of its being gathered and transported to the landfill by mixing with other refuse and by decomposition. This makes pollution prevention more difficult and raises the cost of landfill engineering. However, the amount of solid waste to be treated can be decreased and such pollution burden lessened by disposing of the solid waste in local municipal areas. The program in Beijing also shows that this works well with our situation in China and can accelerate marketization and public participation.     

Contribution of small-scale mining to employment,development and sustainability – an Indian scenario

Small-scale mining is more prevalent in India. The maximum production capacity of 50,000 tonnes/year has been accepted as a criterion to Indian small-scale mine. Such mines constitute about 90% of total number of mines, 42% of the total non-fuel minerals and metals, 5% of the fuel minerals. Some 3000 small scale mines account for a work force of about 0.5 million people. Yet this sector is a neglected sector in Indian economy and still considered as an unorganized sector. This paper examines the contribution of small-scale mines to employment and national mineral production, practices, and Indian policy on small-scale mining. It identifies the drawbacks in the existing Government policy and discusses the role of Government for up gradation in this sector. It focuses the need for technical up gradation and to ensure the economic and social infrastructure. It also discusses how the pursuit of sustainable livelihoods, poverty alleviation and indigenous peoples right in artisanal and small-scale mining be more effective when these communities are disadvantaged or neglected by Government policies. This paper concludes that this sector can make significant contribution to Indian economy and employment generation. It recommends that by establishing mining centre consist of shared mining and processing facilities, educating and training related initiatives it can be achieved.