成团泛菌(Pantoea agglomerans)对镉胁迫下蒌蒿耐受性的影响

为探讨功能微生物对镉(Cd)胁迫下蒌蒿耐受性的影响,以成团泛菌(Pantoea agglomerans)J2为对象,通过盆栽试验,研究不同Cd处理水平下J2菌对蒌蒿生长、生理、Cd富集转运与根际微生态的影响。结果表明:J2菌可显著促进蒌蒿株高、地上部干重、地下部干重、总生物量及根冠比的增加。在J2菌的作用下,蒌蒿叶绿素a、叶绿素b和总叶绿素含量以及超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性均显著增加,丙二醛(MDA)含量明显减少。J2菌可显著促进蒌蒿对Cd的富集转运,蒌蒿地上部、地下部与总Cd含量均显著增加,地上部生物富集系数(BCF)明显大于地下部,转运系数(TF)相比于对照增加了7.5%~37.4%。J2菌可显著增加蒌蒿根际土壤细菌、放线菌数量及微生物总量,明显减少真菌数量。研究表明成团泛菌J2对蒌蒿生长、生理、Cd富集转运与根际微生态可产生积极影响,在一定程度上可提高蒌蒿植株对Cd的耐受性。     

Size-resolved aerosol ionic composition and secondary formation at Mount Heng in South Central China

To understand the size-resolved aerosol ionic composition and the factors influencing secondary aerosol formation in the upper boundary layer in South Central China, size-segregated aerosol samples were collected using a micro-orifice uniform deposit irnpactor （MOUDI） in spring 2009 at the summit of Mount Heng （1269 m asl）, followed by subsequent laboratory analyses of 13 inorganic and organic water-soluble ions. During non- dust-storm periods, the average PM1.8 concentration was 41.8 μg·m^-3, contributing to 55% of the PM10. Sulfates, nitrates, and ammonium, the dominant ions in the fine particles, amounted to 46.8% of the PM1.8. Compared with Mount Tai in the North China Plain, the concentrations of both fine and coarse particles and the ions contained therein were substantially lower. When the air masses from Southeast Asia prevailed, intensive biomass burning there led to elevated concentrations of sulfates, nitrates, ammonium, potassium, and chloride in the fine particles at Mount Heng. The air masses originating from the north Gobi brought heavy dust storms that resulted in the remarkable production of sulfates, ammonium, methane sulfonic acid, and oxalates in the coarse particles. Generally, the sulfates were primarily produced in the form of （NH4）2SO4 in the droplet mode via heterogeneous aqueous reactions. Only approximately one-third of the nitrates were distributed in the fine mode, and high humidity facilitated the secondary formation of fine nitrates. The heterogeneous formation of coarse nitrates and ammonium on dry alkaline dust surfaces was found to be less efficient than that on the coarse particles during non-dust-storm periods.     

基于鱼类生物完整性指数的拒马河北京段河流健康评价

拒马河是北京周边具有独特生物多样性的河流,目前面临很多水生态环境问题.鱼类生物完整性指数(F-IBI)是评价河流生态健康的重要方法.本研究于2018年5月和10月,在拒马河北京段设置9个采样点,利用地笼和刺网进行调查,共获得鱼类样本2001尾,隶属于4目9科.根据采样情况,初步设置了5大类21个初选指标,经过对指标完整性、相关性和取值范围分析,筛选得出6个评价指标:鱼类总物种数(M1)、鲤科占总种数的百分比(M3)、中上层鱼种类数百分比(M9)、杂食性鱼类种类数百分比(M13)、产粘性卵鱼类种类数百分比(M19)和鱼类总个体数(M20),构建了适用于拒马河的F-IBI指标体系,运用该体系对拒马河北京段的河流健康状况进行了评价,并将F-IBI与几个主要水环境参数和拦河坝相关数据进行了相关性分析.研究结果表明,拒马河北京段河流健康整体处于较差水平,F-IBI与水质理化因子无显著相关性,与参数"采样点与上游最近拦河坝的距离"呈显著相关.结果表明,拒马河北京段河流健康指数的关键影响因素不是水质理化因子,可能与拦河坝导致的河流片段化有关.     

Carbon storage in northeast China as estimated from vegetation and soil inventories

We have estimated the stocks of carbon in vegetation and soil in northeast China based on data for 122 plots from the fourth national forest inventory, and for 388 soil profiles from the second national soil survey. The techniques of Geographic Information System (GIS) have been used to extrapolate site-specific estimates of vegetation and soil organic carbon to the entire area of northeast China. Our estimate indicates that the amount of carbon in vegetation and soil for the region are 2.81 PgC (10(15) g C) and 26.43 PgC, respectively, and that the area weighted average density of vegetation and soil organic carbon are 22.7 MgC/ha and 212.7 MgC/ha, respectively. The eastern and northern parts of the region show much higher carbon storage than the rest of the region. Substantial spatial variations in vegetation and soil organic carbon across northeast China suggest that regional estimates on carbon stocks and fluxes should take into account these spatial variations. We suggest that the methodology developed can be used for the entire nation of China as well as other regions of the world.     

重庆市崩塌和滑坡的危险性评价

根据大量的勘查和社会经济统计资料,建立数学模型,对重庆市崩塌和滑坡的危险性指数进行了计算并划分出危险度．在此基础上,绘出区域灾害危险性分布图并对其危险性进行了评价。     

房地产开发项目环境影响评价

房地产开发项目环境影响评价可以从源头控制和预防可能发生的环境污染和环境纠纷。介绍了房地产开发项目环境影响评价的分类和施工期和运营期产生的废气、废水、噪声及固废等对环境造成不利影响,并且提出了公众参与在房地产开发项目的重要性,为环境影响评价工作者正确评价房地产开发项目的环境影响提供参考。     

四种金属离子对CHBr_3和小牛胸腺DNA间结合作用的影响

采用紫外光谱和荧光光谱法研究了CHBr3与离体小牛胸腺DNA(ctDNA)间的相互作用,以及Cu2+、Co2+、Cd2+、Mg2+4种金属离子单独或共存时对CHBr3与ctDNA结合的影响.结果表明:4种金属离子与CHBr3、ctDNA均能发生基态络合反应,络合物的生成导致体系的紫外吸收峰强度和形状改变,使ctDNA-溴化乙锭体系的荧光发生了不同程度的猝灭;向CHBr3-ctDNA-溴化乙锭体系中分别或同时加入4种金属离子后,Cu2+、Co2+、Cd2+可减弱两者之间的结合,减弱顺序为Cu2+Co2+Cd2+,Mg2+可加强两者之间的结合,4种金属离子同时加入后出现不同于4种金属离子单独加入时的中间类型.据此推断,CHBr3可能主要是通过嵌插作用与ctDNA碱基结合,金属离子对CHBr3与ctDNA结合的影响主要取决于金属离子与DNA的碱基和磷酸基团间结合的相对亲和比.     

超声萃取—高效液相色谱法测定土壤中多环芳烃

多环芳烃（简称PAHs）是一类具有致癌、致畸及致突变的持久性污染物。可靠的PAHs检测方法是研究其环境行为的重要保证。实验采用超声萃取、用固相萃取柱（SPE-C18）进行净化处理土壤样品,用液相色谱-荧光检测技术对美国环保署（USEAP）优先监测的15种多环芳烃污染物进行定量分析。实验结果表明,该方法对15种PAHs的最低检出限为0.231μg/kg-3.846μg/kg,回收率为51.48%-69.84%,相对标准偏差为6.84%-11.92%。     

基于排列熵重构的EEMD-RVM短期光伏功率预测

针对光伏功率序列周期性非平稳特性,难以准确预测的问题,提出一种基于排列熵重构原则的集合经验模态分解(ensemble empirical mode decomposition, EEMD)和相关向量机(relevance vector machine,RVM)的短期光伏功率预测新方法。仿真结果表明:该方法不仅能够有效提高短期光伏功率预测的准确性,而且缩短了预测时间,提高了光伏功率预测效率,适用于光伏功率短期在线预测。