南岳衡山悬钩子属植物种质资源的调查

调查发现，南岳衡山悬钩子属(Rubus L.)植物有19种，其中山莓(R．corchorifolius)、粉枝莓(R．biflorus)、大红泡(R.eustephonos)、山挂牌条(R．flosculosus)、木莓(R．swinhoei)、灰白毛莓(R．tephrodes)为优势种，Rubus属植物主要分布在海拔200～800m的范围内，该属植物的果实和叶片中都含有丰富的营养成分，既可食用也可药用，开发前景十分广阔．     

海洋假单胞杆菌QD80低温碱性蛋白酶的化学修饰

海洋假单胞杆菌QD80低温碱性蛋白酶(QDAPr)具有良好的低温适应性,且与常见的增稠剂及表面活性剂有良好的配伍性.因此该蛋白酶在日用化学领域,尤其是低温洗涤领域,具有广泛的应用价值.为研究其结构与功能之间的关系,用EDC、PMSF、N-AI、2,3-丁二酮等8种化学修饰剂修饰该低温碱性蛋白酶,然后检测残余酶活力,借以研究酶分子中氨基酸侧链基团与酶活性中心的关系.结果表明,羧基、丝氨酸、ε-氨基、巯基等残基与酶活性无关;而色氨酸、组氨酸、酪氨酸残基侧链的化学修饰引起酶活性的大幅度下降,说明色氨酸、组氨酸、酪氨酸残基是酶活力所必需的基团.精氨酸残基侧链的化学修饰引起酶活性的轻微下降,说明精氨酸对酶活性具有一定贡献,但不处于活性中心.图5表2参18     

富营养化湖区CH4排放特征及其影响因素

为明确富营养湖区CH_4排放特征及其影响因素,对太湖梅梁湾湖区和湖心区进行为期1a的观测,分析影响富营养化湖泊CH_4扩散通量时空格局的环境要素.结果表明,太湖不同湖区均表现为大气CH_4的源,但富营养化梅梁湾湖区的CH_4扩散排放量[年均值:0. 140 mmol·(m~2·d)~(-1))]要明显高于中营养化湖心区的排放量[年均值:0. 024 mmol·(m~2·d)~(-1)],并且在富营养化湖区中,湖岸区的CH_4排放量最高. CH_4通量表现出显著的季节变化:夏季排放量最高,冬季排放量最低,并且季节间的差异可达一个数量级大小.太湖CH_4通量的空间变化与水体DOC浓度显著正相关(R~2=0. 62,P 0. 01),富营养化湖区中较高DOC浓度导致其出现高CH_4排放量.太湖CH_4扩散通量的时间变化受风速和水温等气象因素的驱动,部分水质因子对此有间接影响作用.鉴于湖泊CH_4扩散通量强烈的时空变化以及环境因素巨大的影响,湖泊CH_4排放量准确的估算依赖于较大空间和较长时间的观测.     

公路施工中空气污染物净化成本对企业财务状况的影响研究

公路建设企业为了不违反施工中空气污染物排放标准,需要追加环保投入,购买先进的空气污染物净化设备,这种情况必然给企业财务状况带来一定的影响。传统的净化技术采用自然通风法来稀释公路施工中的空气污染物,通过空气的流通降低污染物浓度,用于施工段通风的能耗费用和建设费用过大,会给企业造成较大的财务负担。采用ESP技术达到了空气污染物高净化度指标,节省了企业空气污染物净化成本费用。由于企业整个施工项目收益会随着净化成本的降低而增加,所以该技术会对企业财务状况产生一定的影响,污染物净化负债的支付、净化收益费用、支出和产品成本随着净化成本的增加而减少。     

Multi-scale spatial determinants of dissolved oxygen and nutrients in Qiantang River, China

This study employed spatial regression to analyze the determinants of dissolved oxygen (DO) and nutrients in the Qiantang River, China. Determinants of their spatial patterns in 1996 and 2003 as well as their dynamics during this time period were characterized at sub-basin and 500-m riparian buffer scales. Results indicated that the determinants differed by variable and by scale. Built-ups, farmland, water body, population density and gross domestic product were positive indicators for nutrient pollution and hypoxia, while distance to river source and forest were negative indicators. Higher slope variability indicates more DO and nutrients. In addition, built-up increases that were accelerated by population growth and economic development accounted for DO and nutrients dynamics to a large extent. This study highlighted that incorporation of spatial autocorrelation into regression was not only a methodological advantage but also a promising management tool.     

Possible particulate nitrite formation and its atmospheric implications inferred from the observations in Seoul,Korea

Simultaneous measurements of gaseous species and fine-mode, particulate inorganic components were performed at the University of Seoul, Seoul in Korea. In the simultaneous measurements, a certain level of nitrous acid (HONO) was observed in the gas-phase, indicating possible heterogeneous HONO production on the surface of the ambient aerosols. On the other hand, high particulate nitrite (NO^2?) concentrations of 1.41(±2.26) μg/m³ were also measured, which sometimes reached 18.54 μg/m³. In contrast, low HONO-to-NO₂ ratios of 0.007(±0.006) were observed in Seoul. This indicates that a significant fraction of HONO is dissolved in atmospheric aerosols. Around the Seoul site, sufficient alkalinity may have been provided to the atmospheric aerosols from the excessive presence of NH₃ in the gas-phase. Due to the alkaline particulate conditions (defined in this study as a particle pH >～3.29), the HONO molecules produced at the surface of the atmospheric aerosols appeared to have been converted into particulate nitrite, thereby preventing their further participation in the atmospheric O₃/NO_y/HO_x photochemical cycles. It was estimated that a minimum average of 65% of HONO was captured by alkaline, anthropogenic, urban particles in the Seoul measurements.     

Comparison of inorganic and composite ferric oxide sorbents for arsenic removal

Three different sorbents based on hydrated ferric oxide (GEH, ArsenX^np and Lewatit FO 36) were compared from the viewpoints of their column operation. Particle size distribution, pressure drop across the column and ferric oxide content were measured. Sorption capacities under the presence of accompanying ions were measured in batch wise and column experiments.     

地铁动荷载作用下隧道-地裂缝-地层的三维动力响应

为了探明西安地裂缝场地地铁动荷载作用下的隧道-地层动力响应特征,提出了基于ABAQUS的地铁振动响应三维模拟方法,实现了地铁多轮对荷载的移动。通过有限元计算,得到了整体式隧道的振动响应特征和振动波在地裂缝场地的传播规律,并将有无地裂缝时的振动响应进行了对比,分析了地裂缝对振动响应的影响。计算表明:单节车辆诱发振动沿纵向的影响范围不超过75 m;地铁运行诱发的振动以竖向为主,振动沿横向传播时水平振动衰减较慢;在本次模拟工况下,地裂缝的存在对地裂缝邻近约12 m范围内土体的振动影响较大,对衬砌结构的影响不显著。     

Remediation of Ni2+-contaminated water using iron powder and steel manufacturing byproducts

Steel manufacturing byproducts and commercial iron powders were tested in the treatment of Ni^2＋-contaminated water. Ni^2＋ is a priority pollutant of some soils and groundwater. The use of zero-valent iron, which can reduce Ni^2＋ to its neural form appears to be an alternative approach for the remediation of Ni^2＋-contaminated sites. Our experimental data show that the removal efficiencies of Ni^2＋ were 95.15% and 94.68% at a metal to solution ratio of 20 g/L for commercial iron powders and the steel manufacturing byproducts in 60 min at room temperature, respectively. The removal efficiency reached 98.20% when the metal to solution ratio was 40 g/L for commercial iron powders. Furthermore, we found that the removal efficiency was also largely affected by other factors such as the pHs of the treated water, the length of time for the metal to be in contact with the Ni^2＋-contaminated water, initial concentrations of metal solutions, particle sizes and the amount of iron powders. Surprisingly, the reaction temperature appeared to have little effect on the removal efficiency. Our study opens the way to further optimize the reaction conditions of in situ remediation of Ni^2＋ or other heavy metals on contaminated sites.     

Fine dust filtration using a metal fiber bed

A bed-type filter composed of thin metal alloy fiber was closely examined with dust capturing in cold and hot runs. The investigation of an individual mechanism across the filter bed indicated that the aerated dust could be initially collected by depth filtration, and after a while, surface filtration dominated the overall dust collection. The present metal fiber bed was comparable to the conventional ceramic filters because of its good collection efficiency with low pressure drop. It also showed potential to be used as a prefilter in a diesel exhaust trapping system.