湖南衡山春季一次酸雨过程气象条件的数值模拟研究

采用MM5中尺度气象模式对湖南衡山2009年3月22~24日一次典型酸雨过程的气象条件进行了详细的数值模拟研究.模式模拟的降水场、流场、温度场、边界层结构与酸雨实测、实际天气图、地面站观测记录的对比表明,模式模拟的变化趋势与实况非常一致.研究表明,与广东春季典型的酸雨过程相比,衡山春季北面冷空气的入侵过程受地形作用明显,低层流场受北风影响较快,中高层较晚.广东、衡山两地春季酸雨发生前后整个边界层层结相对稳定,边界层高度较低,同时伴随有逆温过程,均不利于污染物的扩散输送,衡山春季酸雨发生前后的逆温和逆湿层都相对更低.     

新型波纹板导流墙氧化沟水力特性的数值模拟

提出新型波纹板导流墙氧化沟结构,并基于N-S方程和k-ε紊流模型,采用有限体积法,对新型波纹板导流墙氧化沟的水流流态和水流速度分布进行数值模拟。同时与无延长导流墙和平板导流墙的数值模拟进行比较,研究结果表明:新型波纹板导流墙对降低氧化沟隔墙背后的水流低速区范围和改善污泥沉积有促进作用。     

三八河河口潮滩有机碳、油类、硫化物及微生物分布特征

为了评价烟台市牟平区三八河河口潮滩中主要污染物的分布及土著微生物的修复潜力,研究了潮滩沉积物中w(TOC),w(油类),w(硫化物)和微生物的水平及垂直分布规律. 利用单因子污染指数法对污染状况进行了分析. 结果表明:各因子污染指数由大到小为有机碳(TOC)>硫化物>油类,河口区域w(TOC),w(油类)和w(硫化物)明显高于对照点,越靠近河口表层(0～≤20 cm)沉积物污染越重,说明潮滩污染主要由河流排污引起. 垂直深度上污染物主要集中在亚表层(5～≤20 cm),0～≤50 cm深度范围内w(TOC),w(油类)和w(硫化物)随深度的增加呈先增大后减小的趋势. 微生物分布规律显示,外源有机物的输入可提高沉积物中异养菌总数和呼吸强度,潮滩微生物可通过呼吸过程实现有机碳的矿化和输出,具有一定的修复潜力.      

辽河流域工业废水主要污染物排放强度单元差异分析

污染物排放强度反映了单位新创造经济价值的环境负荷大小,运用均方差赋权法对辽宁省辽河流域6个控制单元2006年度废水量、COD和氨氮等3种主要污染物排放强度的区域差异进行了评价,结果表明,当年3种主要污染物排放强度综合评价的平均水平为0.4411,低于和高于平均水平的单元各有3个,其中浑河中游单元的评价值最低,只有平均水平的11.74%;辽河上游单元的污染物排放强度综合评价值最高,是平均水平的1.8倍,更是浑河中游的15.6倍。然后,以流域污染物排放强度最低值作为流域污染物排放强度目标值,计算各单元污染物排放强度减排潜力,结果表明,各控制单元主要污染物排放强度减排潜力具有显著的区域间差异。最后,应用＂污染贡献率＂这一指标,分析了辽河流域COD和氨氮排放的重污染行业以及单元分布,指出了各单元控制的重点。     

高产田养分平衡及其环境风险特征研究

选择连续四年产量20000kg·hm-2以上的高产田为研究对象,并以当地常规农田为对照,分析了秸秆还田条件下冬小麦-夏玉米高产轮作体系中养分平衡及环境风险特征。结果表明,高产田和常规农田的氮、磷、钾素在冬小麦-夏玉米轮作体系中都有盈余,分别盈余130和202、122和162、315和119kg·hm-2。高产田氮素和磷素的盈余量小于常规农田,钾素盈余量高于常规农田。在冬小麦-夏玉米轮作体系的各生育期,高产田0～100cm土体硝态氮均存在大量累积,小麦季大于玉米季,高产田大于常规农田,存在较高的淋溶风险。土壤电导率均小于土壤盐渍化的临界值,尚未出现土壤盐渍化的现象。     

Sexual signalling and viability in a wolf spider (Hygrolycosa rubrofasciata): measurements under laboratory and field conditions

This study examined the crucial prediction of the conditional-handicap theory, the relationship between male sexual trait size and male viability, in the wolf spider Hygrolycosa rubrofasciata. In this species, males court females by drumming dry leaves with their abdomen, and males with the highest drumming rate enjoy highest mating success. We determined male drumming rate, body mass, and mobility, which reflects mate-searching activity, in relation to male survival. Because it is often difficult to know how results obtained from laboratory studies reflect the natural world, particularly when the measured variable is survival, we repeated our study in both laboratory and field conditions. Males drumming at the highest rate survived better than males drumming at a lower rate in both laboratory and field conditions. These results are in accordance with the predictions of conditional-handicap models of sexual selection. Survival was independent of male body mass and there was no significant correlation between male drumming activity and body mass. However, large males moved further than smaller males, and males moving longer distances lost less mass than those moving shorter distances. These results suggest that, moving, and consequently mate-searching activity, may be a condition-dependent trait and that there may be a advantage for large males in mate searching. Received: 22 October 1998 / Received in revised form: 28 January 1999 / Accepted: 14 February 1999     

合理开发坡地资源--以江西省吉水县为例

本文通过对江西省吉水县坡地资源现状、特点的分析,从未利用坡地、利用不充分坡地、利用不合理坡地３方面对吉水县坡地资源进行了潜力分析,并提出了开发利用坡地资源的途径     

LABORATORY TESTS OF EROSION DEPENDENCE ON PROPERTIES OF SOILS AND RAINFALL1

ABSTRACT: One hundred and sixty-two rainfall-induced soil erosion tests were conducted to assist in predicting soil loss and subsequent increase in total suspended solids leaving a highway construction site during a rainfall event. A rainfall simulator and a water flume were constructed for the tests. Soil shear strength, compressive strength, rainfall intensity, and soil bed slope were treated as variables during the experiments. The soil with a higher shear strength resisted soil erosion better than lower strength soils. Soil loss was nearly independent of shear strength at low rainfall intensity but at high intensities, the shear strength was more important in resisting soil loss. Lower soil loss can be expected for cohesive soils if the compressive strength is high.     

紊动对水体中有机物降解影响的实验

利用专门设计的紊动诱发装置,对不同紊动强度水体进行了紊动对有机物生物降解影响的实验研究．通过３种不同紊动强度的实验,发现紊动对有机物的降解有明显的影响紊动强度越大,有机物的降解率和降解速度越大．通过对较高紊动强度水体的降解实验数据分析发现,在水体有紊动时,有机物的降解反应并不遵循一级反应动力学。     

关于高层建筑中几个消防问题的探讨

根据目前国内高层建筑的状况,结合所发生的火灾特点,提出了在消防方面应引起重视的几个问题。还给出了处理这些问题的建议和防治方法,并指出在高层建筑中,若所有电梯都设计成消防电梯,同时少建裙房,必将有助于减少火灾造成的损失