城市草坪温室气体排放特征及影响因素

草坪作为城市绿地的重要组成部分，其温室气体的吸收或排放不容忽视.然而当前对亚热带城市草坪温室气体通量的研究相对匮乏.采用静态箱-气相色谱法，对杭州市城区典型城市草坪的多种温室气体（CO₂、CH₄、N₂O和CO）地气交换通量进行了连续观测研究.结果表明，城市草坪的温室气体月平均通量变化明显，而其日变化特征并不明显.城市草地和土壤（无植被生长的裸土）是大气N₂O的源，平均通量分别为（0.66±0.17）μg·（m²·min）^-1和（0.58±0.20）μg·（m²·min）^-1；是CH₄和CO的汇，其中CH₄平均通量分别为（-0.21±0.078）μg·（m²·min）^-1和（-0.26±0.10）μg·（m²·min）^-1，CO分别为（-6.36±1.28）μg·（m²·min）^-1和（-6.55±1.69）μg·（m²·min）^-1.城市草地和土壤CO₂平均通量分别为（5.28±0.75） mg·（m²·min）^-1和（4.83±0.91） mg·（m²·min）^-1.基于相关性分析研究发现，草地和土壤的CO₂和N₂O通量均与降水量呈显著的负相关，而CH₄和CO通量与降水量呈显著的正相关；除草地CH₄通量与土壤温度无显著相关、草地N₂O通量与土壤温度呈显著负相关外，其余各温室气体通量与土壤温度均呈显著正相关.另外，城市草坪的草地和土壤CO₂（R²为0.371和0.314）和N₂O （R²为0.371和0.284）通量季节变化受降水量的影响要大于其它温室气体，而土壤温度对CO通量的影响（R²为0.290和0.234）要显著于其它温室气体.     

模拟降雨条件下沉积物对磷的富集机理

通过模拟降雨径流实验，在７２ｍｍ／ｈ的大暴雨备件下，研究侵蚀性颗粒从土壤中的径流流失过程及其对磷的富集作用和机理。结果表明，深积物中不同粒长团聚体的组成和原来土壤中的组成有很大差异。径流流失的沉积物主要以０．２５ｍｍ以下的团聚体为主，径流中８０％以上的磷以颗粒态形式流失，而颗粒态磷的６０％－９０％随０．１ｍｍ以下的团聚体流失。不同粒径团聚体对磷的富集作用和富集系数不同。模拟实验建立了沉积物富集系数     

几种重金属对紫背萍过氧化氢酶活性的影响

通过测定被暴露植物分解过氧化氢后放出氧气的体积，确定紫背萍过氧化氢酶（ＣＡＴ）的活性。结果表明，紫背萍暴露在Ｈｇ、Ｐｂ、Ｃｒ、Ｎｉ、Ｆｅ的溶液中，其ＣＡＴ活性除在Ｐｂ作用下明显降低外，在其它４种重金属的作用下都有不同程度的升高。这表明Ｐｂ对紫背萍 ＣＡＴ活性有抑制作用，而其它４种重金属对紫背萍ＣＡＴ均有刺激作用。紫背萍对５种重金属所表现出来的这种生态效应，是重金属水污染的植物潜在效应，植物的ＣＡＴ     

县级生态农业建设的人工神经网络模型

引入人工神经网络的评价识别方法，建立了ＢＰ模型，以前人建立的县级生态农业建设评价指标体系评价标准，和某县生态农业综合评价指标数据为实例，比较ＢＰ模型的有效性，得到的评价分类结果和指标优先发展顺序决策与实际情况相吻合。     

First-trimester prenatal diagnosis of aspartylglucosaminuria

Fetal aspartylglucosaminuria (AGU) was studied during the first trimester of pregnancy in six at-risk pregnancies using chorionic villus samples. The activity of aspartylglucosaminidase (AGA) was high in five cases, indicating an unaffected fetus. This was confirmed through delivery of healthy newborns with a normal pattern of urinary oligosaccharides. Low enzyme activity in an uncultured biopsy specimen and in cultured amniotic fluid cells in one case demonstrated that the fetus was affected. The pregnancy was terminated and the prenatal diagnosis was confirmed by showing reduced AGA activity in cultured fibroblasts of the fetus.     

改进灰色系统模型在城市噪声预测中的应用

把城市噪声作为一个灰色系统,分别通过GM(1,1)模型和改进灰色系统模型GM'(1,1),对城市噪声进行预测,并进行精度检验.改进的灰色系统模型GM'(1,1)在精度上均优于GM(1,1)模型,但是GM'(1,1)在计算上比较复杂,需要通过计算机迭代来实现.     

固相微萃取-毛细管气相色谱法测定水中有机污染物

固相微萃取是一种快速、简便、集萃取浓缩于一体的样品前处理技术,具有分析快速、灵敏度高、无需有机溶剂的优点。用固相微萃取-毛细管气相色谱分析水中甲醇、丙酮、异丙醇、乙醇、乙腈、丙烯腈,检出限可达0.003～0.03mg/L。     

Sex‐specific and dose‐response relationships of urinary cobalt and molybdenum levels with glucose levels and insulin resistance in U.S. adults

Growing studies have linked metal exposure to diabetes risk. However, these studies had inconsistent results. We used a multiple linear regression model to investigate the sex-specific and dose-response associations between urinary metals (cobalt (Co) and molybdenum (Mo)) and diabetes-related indicators (fasting plasma glucose (FPG), hemoglobin A1c (HbA1c), homeostasis model assessment for insulin resistance (HOMA-IR), and insulin) in a cross-sectional study based on the United States National Health and Nutrition Examination Survey. The urinary metal concentrations of 1423 eligible individuals were stratified on the basis of the quartile distribution. Our results showed that the urinary Co level in males at the fourth quartile (Q4) was strongly correlated with increased FPG (β = 0.61, 95% CI: 0.17–1.04), HbA1c (β = 0.31, 95% CI: 0.09–0.54), insulin (β = 8.18, 95% CI: 2.84–13.52), and HOMA–IR (β = 3.42, 95% CI: 1.40–5.44) when compared with first quartile (Q1). High urinary Mo levels (Q4 vs. Q1) were associated with elevated FPG (β = 0.46, 95% CI: 0.17–0.75) and HbA1c (β = 0.27, 95% CI: 0.11–0.42) in the overall population. Positive linear dose-response associations were observed between urinary Co and insulin (P_nonlinear = 0.513) and HOMA–IR (P_nonlinear = 0.736) in males, as well as a positive linear dose-response relationship between urinary Mo and FPG (P_nonlinear = 0.826) and HbA1c (P_nonlinear = 0.376) in the overall population. Significant sex-specific and dose-response relationships were observed between urinary metals (Co and Mo) and diabetes-related indicators, and the potential mechanisms should be further investigated.     

污水生物处理过程中的同步硝化反硝化研究概况

在好氧生物氧化过程中通过控制反应器内 DO浓度、C/N比、污泥负荷的条件下 ,观察到较明显的同步硝化反硝化现象 ,通过控制反应条件 ,可使硝化、反硝化速率都得以同步提高。     

聚合氯化铝与有机高分子复合絮凝剂的形态分布研究——AlFerron和~(27)AlNMR相结合

主要研究了Ａｌ－Ｆｅｒｒｏｎ逐时络合比色法和＾２７Ａｌ－ＮＭＲ法应用于聚合铝与有机高分子复合絮凝剂形态分布的测定，结果表明，两种方法分别测定的Ａｌｂ和Ａｌ１３的结果具有一定的相关性；聚合铝与有机高分子复合后其形态分布发生了一定的变化，Ａｌｂ（或Ａｌ１３）的含量有所降低，但仍是优势形态，Ａｌａ（或Ａｌ单）的含量基本保持不变。