Age and spatial distribution of the world's oldest trees

Extremely old trees have important roles in providing insights about historical climatic events and supporting cultural values, yet there has been limited work on their global distribution and conservation. We extracted information on 197,855 tree cores from 4854 sites and combined it with other tree age (e.g., the OLDLIST) data from a further 156 sites to determine the age of the world's oldest trees and quantify the factors influencing their global distribution. We found that extremely old trees >1000 years were rare. Among 30 individual trees that exceeded 2000 years old, 27 occurred in high mountains. We modeled maximum tree age with climatic, soil topographic, and anthropogenic variables, and our regression models demonstrated that elevation, human population density, soil carbon content, and mean annual temperature were key determinants of the distribution of the world's oldest trees. Specifically, our model predicted that many of the oldest trees will occur in high-elevation, cold, and arid mountains with limited human disturbance. This pattern was markedly different from that of the tallest trees, which were more likely to occur in relatively more mesic and productive locations. Global warming and expansion of human activities may induce rapid population declines of extremely old trees. New strategies, including targeted establishment of conservation reserves in remote regions, especially those in western parts of China and the United States, are required to protect these trees.     

有机磷农药废水处理技术

久效磷和亚磷酸三甲酯生产过程中产生的废水经碱解沉淀和超声气浮预处理,可降低其ＣＯＤ和毒性,提高其可生化性,再经以光合细菌为主的生化处理,可使其ＣＯＤ降至２００ｍｇ／Ｌ。     

六六六热解废渣提取物对家兔皮肤的毒性

使用六六六热解废渣提取物对家兔进行了皮肤毒性试验。家兔皮肤经涂布提取物后,在涂布处及其他部位引起常有丘疹和小脓疱特征的痤疮型皮炎,与六六六热解生产多氯苯时暴露于其废渣烟尘中的工人所患氯疮相似。分析证明废渣中含有大量PCDDs和PCDFs,显然这是家兔皮肤反应和工人皮肤疾患的原因。引起家兔皮肤反应的最小涂布剂量为55μg混合物质,其中含2,3,7,8-TCDD约0.003μg。     

N-methylcarbamate pesticides and their phenolic degradation products: hydrolytic decay,sequestration and metal complexation studies

We report on the rates of decomposition of a group of N-methylcarbamate (NMC) pesticides (carbaryl, carbofuran and propoxur) under pre-determined tropical field conditions. Rates of decomposition for three NMCs were determined at pH 7.08 and T?=?20?°C and pH 7.70 and T = 33?°C respectively, as follows: carbaryl (78?days and 69?days); carbofuran (143?days and 83?days) and propoxur (116?days and 79?days). Investigation on methods for removal of NMCs and their phenolic decomposition products shows that activated charcoal outperforms zeolite, alumina, diatomaceous earth, cellulose and montmorillonite clay in the removal of both NMCs and phenols from aqueous solution. Furthermore, metal complexation studies on the NMCs and phenols showed that Fe (III) forms a complex with isopropoxyphenol (IPP) within which the Fe:IPP ratio is 1:3, indicative of the formation of a metal chelate complex with the formula Fe(IPP)₃.     

不同氮磷浓度下2种无毒微藻的生长特性和脱氮除磷效能

根据城市二级出水水质特性,选择4 种不同氮磷水平的二级出水作为培养基,研究纯培养与共培养下,椭圆小球藻(Chlorella ellipsoidea)和斜生栅藻(Scenedesmus obliquus)在不同初始氮磷浓度下的生长状况及脱氮除磷的能力。结果表明,纯培养条件下,椭圆小球藻在2#(TN=15.00 mg/L,TP=1.00 mg/L)实验组中生物量最高,斜生栅藻在4#(TN=10.00 mg/L,TP=0.20 mg/L)实验组中收获最大生物量,椭圆小球藻与斜生栅藻对TP均具有70%以上去除率。共培养下,3#(TN=15.00 mg/L,TP=0.50 mg/L)实验组收获最高生物量,斜生栅藻生物量均高于椭圆小球藻,表明斜生栅藻在共培养条件下更具有生长优势,培养基中TN、TP含量分别降至5.00 mg/L和0.05 mg/L以下。2种培养模式均可达到对二级出水的深度脱氮除磷。     

燃煤电厂烟气脱硫主要工艺

简要介绍燃煤电厂烟气脱硫（FGD）的湿法，半干法，干法，可回收工艺和联合SO2／NOx工艺等五类主要工艺，并对我国烟气脱硫技术的进展进行了探讨，指出我国烟气脱硫技术的发展应走国产化的道路。     

百色油田含油污水混凝法除油试验

通过室内和现场试验表明，自然除油。混凝除油－压力过滤流程是适合百色油田含油污水处理的，通过投加混凝剂ＰＡＣ－４（加入量为３０～５０ｍｇ／Ｌ时），污水处理即可达到石油开发工业污水排放标准（ＣＯＤ除外），从而减轻和防止了对周围环境的污染，同时进一步处理后可作为油田回注地层水。     

Experts' perspective on the performance of Chinese technical guidelines for Plan Environmental Impact Assessment

This research was to evaluate the Technical Guideline (HJ/T130-2003) effectiveness based on data resource from a questionnaire survey and interviews on EIA experts. The result demonstrated that the guideline served mainly as a quality control measure for PEIA products, and only a small proportion of experts considered it effective due to its inconsistency with the newly released Chinese PEIA Regulation (2009) and poor practicability. Current status of SEA implementation in China was also studied in terms of application fields, effectiveness evaluation, and major issues to affect SEA, to conclude that SEA implementation in China is premature, and with limited effectiveness. The major problem was the lack of effective methodologies and technical tools. Recommendations for revising the PEIA Guideline and advices to improving SEA implementation in China were accordingly proposed.     

微生物絮凝剂在水处理中的应用

系统介绍了微生物絮凝剂的特性、絮凝机理及影响絮凝效果的因素,列举并分析了微生物絮凝剂的应用实例。微生物絮凝剂具有安全、高效、不污染环境等特点。产生絮凝剂的微生物种类多,生长快,易于实现产业化,因而微生物絮凝剂正日益受到人们的重视。