管材压扁的回弹分析

应用材料力学中的单位力法求回弹值的新理论，对管材压扁工艺的回弹量进行了分析计算，理论得出的结果与实际相符，可用于管材压扁中回弹量的计算预报。     

以浮游植物评价太湖春季水质污染及富营养化

通过太湖浮游植物群落生态学的研究 ,对太湖春季水质污染及富营养化进行总评及分区评价。就太湖总体而论 ,藻量均值达 2 88× 1 0 6个细胞 /L ,硅藻指数 1 1 0 ,污染指示种占 58 8% ,各样点多以蓝藻 (微囊藻为主 )占优势 ,其分布频度达 1 0 0 % ,多度达 6 5 5% ,表明太湖受到中等程度的污染。与过去同期太湖浮游植物的调查资料对比表明人为富营养化进程有所减缓。     

白马泉风景区夏季大气PM2.5中二次有机物的初步研究

实验选择2010年7月于雅安市白马泉风景区常绿阔叶林内采集PM2.5样本,并对样本进行甲醇提取、三甲硅醚衍生化及GC/MS分析,探讨研究区域内气溶胶中异戊二烯氧化产物、α-/β-蒎烯氧化产物、小分子羧酸(苹果酸、2-羟基戊二酸)的浓度与昼夜变化趋势,并结合大气污染气体(SO2、NOx、O3)和环境气候条件(风速、温度、湿度等)对其浓度的影响进行讨论.结果表明,24 h PM2.5样本中,2-甲基丁四醇、异丁烯三醇、2-甲基甘油酸的浓度分别为63.3、45.0、4.4 ng.m-3;降蒎酸、3-羟基戊二酸、3-羟基-1,2,3-丁三酸的浓度分别为4.1、5.0、5.3 ng.m-3.除降蒎酸外,此次研究的其他二次有机气溶胶组分均呈现昼高夜低.白马泉风景区聚集了较高浓度的天然源二次有机物与当地亚热带繁茂的植被、湿热气候、沟谷型地貌及大气污染状况等诸多环境因素有关.     

Distribution and sources of solvent extractable organic compounds in PM2:5 during 2007 Chinese Spring Festival in Beijing

The solvent extractable organic compounds (SEOC), including n-alkanes, polycylic aromatic hydrocarbons, fatty acids, anddicarboxylic acids in PM2.5 during the 2007 Chinese Spring Festival in Beijing, were measured via gas chromatography-massspectrometry for determining the characteristics and sources of these organic pollutants. The concentrations of total n-alkanes, PAHs,and organic acids before Chinese Spring Festival Eve (1025.5, 95.9, and 543.3 ng/m3, respectively) were higher than those after (536.6,58...     

A population model for the peach fruit moth, Carposina sasakii Matsumura (Lepidoptera: Carposinidae), in a Korean orchard system

A population model for the peach fruit moth, Carposina sasakii Matsumura, was constructed to understand the population dynamics of this pest species and to develop an effective management strategy for various orchard (apple, peach, apple + peach) systems. The model was structured by the five developmental stages of C. sasakii: egg, larva, pupa, larval-cocoon (overwintering larva), and adult. The model consisted of a series of component models: (1) a bimodal spring adult emergence model, (2) an adult oviposition model, (3) stage emergence models of eggs, larvae, and pupae, (4) a larval survival rate model in fruits, (5) a larval-cocoon formation model, and (6) an insecticide effect model. Simulations using the model described the typical patterns of C. sasakii adult abundance in various orchard systems well, and was specific to the composition of host plants: three adult abundance peaks (first peak, mid-season peak, and last peak) a year with decreased peaks after the first peak in monoculture orchards of late apple, two adult peaks a year with a much higher last peak in monoculture orchards of early peach, and three adult peaks a year with much higher later peaks in mixed orchards of late apple and early peach. The average deviation between model outputs and actual records for first and second adult peak dates was 2.8 and 3.9 d, respectively, in simulations without an insecticide effect. The deviation decreased when insecticide effects were incorporated into the model. We also performed a sensitivity analysis of our model, and suggest possible applications of the model.     

春运对广州火车站周边环境噪声的影响研究

在广州火车站及其周边不同功能区设8个监测点,利用AWA6291+A型噪声频谱分析仪测量了春运期间和非春运期间不同功能区的环境噪声水平.结果表明,春运对广州火车站及周边环境噪声影响较大;远离主要交通干道及火车站的小区和公园噪声比较低;测点的噪声值与其所处位置的交通流量和人为活动有关.     

北京市春节期间大气污染分析

分析了北京市鞭炮燃放禁改限前禁放区和非禁放区除夕夜大气污染变化规律的明显差异,以及禁改限后,以上区域大气污染变化的趋同特点.同时评估了2000～2006年春节期间空气污染状况.结果表明,大量鞭炮的集中燃放造成了大气短时严重污染,但随鞭炮燃放的减少,污染状况迅速改善.燃放鞭炮对不同大气污染物的影响存在差异,PM₁₀污染最严重;SO₂、Nox浓度也有明显升高;CO则存在一定滞后,甚至没有明显响应.禁改限前非禁放区内存在明显的燃放污染高峰,禁放区则未出现.鞭炮燃放对大气颗粒物细粒子影响最显着,对粗粒子特别是粒径10～20μm之间的颗粒物影响不大.春节期间工业及交通污染排放的减少,导致空气质量好转,2000～2006年正月初一～正月十五PM₁₀浓度比冬季均值(12月～2月)低16%,比年均浓度低20%,但受一定气象条件影响.     

宁波市春节期间水溶性离子污染来源和特征分析

利用在线气体及气溶胶检测系统对宁波市春节期间痕量气体和水溶性离子组分进行观测,结合气象要素,分析研究细颗粒物中水溶性离子污染来源和组分特征.观测期间ρ(PM2.5)平均值为33.1 μg·m-3,存在轻度污染.水溶性离子浓度大小排序为:NO3-＞SO42-＞NH4+＞K+＞Cl-＞Na+＞Ca2+＞Mg2+,二次无机离...     

江苏省春季臭氧污染特征分析

对2018—2020年春季江苏省臭氧(O3)污染特征进行了分析.结果表明,江苏省ρ(O3)均超过二级标准限值,分别超出5.6％,11.3％和8.8％,沿江区域ρ(O3)略高于苏北区域;ρ(O3-1 h)日变化呈"单峰型",峰值呈逐年上升趋势,非污染日苏北区域ρ(O3-1 h)均高于沿江区域,主要时间段体现在夜间至次日早...     

春节烟花爆竹燃放期间苏州市区PM2.5中水溶性离子特征分析

使用在线离子色谱分析了苏州市区春节期间PM2.5中水溶性离子.结果表明：春节期间存在2个空气污染高峰时段（初一和初五）,其中初一凌晨PM2.5达到最高峰,小时质量浓度为571μg/m3;烟花爆竹集中燃放时段,PM2.5中K＋、Cl-、Mg2＋质量浓度明显上升,初-凌晨与腊月三十凌晨相比,K＋、Cl-、Mg2＋质量浓度分别增加了117倍、80.7倍、18.0倍;相关性分析表明,PM2.5中K＋、Mg2＋、Na＋、Ca2＋在烟花爆竹燃放时段可能具有相同的来源.