混合高温菌浸出黄铜矿及浸出过程中微生物群落的演替

研究3株极端嗜热古菌(金属硫叶菌,Sulfolobus metallicus JCM 9184;瑟杜生金属球菌,Metallosphaera sedula JCM 9185和万座酸菌,Acidianus manzaensis YN25)在不同起始pH值和不同温度条件下对黄铜矿的混合浸出,并对浸矿过程中混合菌群落的动态演替进行分析.结果表明:在起始pH 1.5时的铜浸出率明显高于在起始pH 2.5时的铜浸出率,而65 ℃条件下的铜浸出率高于75 ℃时的铜浸出率.利用限制性长度多态性(RFLP)分析65 ℃、起始pH 1.5条件下的微生物群落演替,结果显示:在黄铜矿的浸出前期Sulfolobus metallicus是占据优势的菌种,而到后期Acidianus manzaensis的比例则会上升,并最后取代Sulfolobus metallicus成为优势种.     

尾矿库无土植被护坡工程技术研究

尾矿库坝坡无土植被护坡在国内是一项新兴的技术.文中系统地介绍了无土植被技术在尾矿库坝坡的试验研究和实践,并阐明了无土植被护坡对于尾矿库的实际效果.该项技术有着良好的经济效益和巨大的社会效益,具有广阔的推广使用前景.     

海州露天矿排土场植被重建技术研究

由于农业用地对环境要求相对较高,且需要大量的人力、物力进行管理,多数矿山企业在土地复垦时一般不将种植作物作为其土地用途,而是以管理工作及费用相对较少的林、草种植为主.林草种植在矿山复垦种植中占有相当重要的地位,着重探讨海州露天矿排土场牧草种植的技术途径.     

光电非接触式表面流速测量

针对水工物理模型试验中尚无简单易行的表面流速测量方法,提出了一种新型光电非接触式表面流速直接测量法。在对光束入射水体后散射光强度公式进行推导的基础上,根据水体浅层泥沙浓度的统计继承效应,得出了经上下游浅层泥沙调制的散射光强成相关特性的结论。根据上下游散射光的相关特性,推导了流速测量公式,并分析了上下游测量间距、水流流速、采样率对测量结果的影响。搭建了实验系统,在6种不同标定流速下,分析了不同含沙量对测量精度的影响。实验结果表明,在0～50kg/m36种不同含沙量情况下,实测流速与标定流速的一致性均较好,但水体在10～50kg/m3适量含沙情况下,测量精度较不含沙情况有所提高,测量绝对误差均小于0.1m/s,相对误差能控制在8%以内。     

Species richness, structural diversity and species composition in meadows created by visitors of a botanical garden in Switzerland

Biodiversity is an increasingly important criterion in designing ecological compensation areas and urban green areas. However, little is known about how important biodiversity is to the general public. This paper presents the results of two complementary studies investigating the meadow preferences of visitors to a botanical garden in Switzerland. In the first study, 152 people were asked to create their own favourite meadow patch by selecting 25 out of 779 local wild plants (54 species) that were displayed in flowerpots. In the second study, 143 people were asked with the help of a written questionnaire to imagine a bare piece of land the size of 100 m × 100 m close to their place of living and mentally create the meadow of their dreams. In both cases, study participants assembled meadows that were species-rich and rich in structural diversity (expressed by plant height and leaf forms). Moreover, they explicitly stated diversity as their main assemblage criterion. Although study participants favoured plants with large or colourful flowers, only a third of all plants in the meadows created with real plants were flowering and in people's imagined meadows grasses were frequently included, indicating that people like diverse meadows consisting of a green matrix with some colourful flowers.     

Atmospheric deposition of nitrogen at five subtropical forested sites in South China

Elevated concentrations of reactive nitrogen (N) in precipitation have been reported for many cities in China. Due to increased use of fossil fuels and expansion in agriculture, further increases in deposition of ammonia (NHx) and reactive N oxides (NOy) are predicted. Increased deposition of reactive N is likely to affect N dynamics and N runoff in forest ecosystems. Yet, in China little work has been done to quantify the levels of atmospheric N deposition in such systems. Here, we assess the deposition of inorganic N (ammonium, NH4+ and nitrate, NO3-) for five subtropical forest ecosystems in remote and urban areas of South China. Annual volume-weighted concentrations in bulk precipitation range from 0.18 to 1.55 mg NH4+ -N L(-1) and from 0.12 to 0.74 mg NO3- -N L(-1). These values are large and several times greater than those reported for remote sites of the world. The fluxes of total inorganic N (TIN) in wet-only deposition range from 0.8 to 2.3 g N m(-2) yr(-1), with NH4+ -N contributing 54% to 77%. Both the tree canopy and the ground vegetation layer are important in determining the net N flux reaching the forest floor, but the net effect varies from site to site. At TieShanPing (TSP), close to Chongqing city, and at CaiJiaTang (CJT), near Shaoshan (Hunan province), the canopy represents a net source of N, probably due to dry deposition. At the other three sites (LiuChongGuan (LCG), LeiGongShan (LGS), both in Guizhou province, and LiuXiHe (LXH) in Guangdong), a net loss of reactive N from precipitation water occurs in the canopy, probably due to uptake processes. The total annual atmospheric TIN load is estimated to range from at least 0.8 g N m(-2) yr(-1) to 4.0 g N m(-2) yr(-1), with a considerable contribution from dry deposition. Concentrations and fluxes of inorganic N in tree canopy throughfall are greater than those in North America. Also the contribution of NH4+ -N to TIN fluxes in throughfall (40% to 70%) is greater than in North America. Our sites have N deposition levels and NH4+ -N contributions similar to those found in Northwest and central Europe. The TIN loads at TSP and CJT far exceed 2.5 g N m(-2) yr(-1), which is the N deposition load above which NO3- leaching is expected in temperate and boreal forests.