江苏省8个沿海造林树种的耐盐性评价研究

以江苏省盐城市大丰区沿海地区为研究区域,选择中山杉（Taxodium 'Zhongshanshan'）、白榆（Ulmus pumila）、落羽杉（Taxodium distichum）、榔榆（Ulmus parvifolia）、乌桕（Triadica sebifera）、青皮柳（Salix ohsidare）、构树（Broussonetia papyrifera）和苦楝（Melia azedarach）8个造林树种,研究不同树种造林地土壤含盐量及其与树木成活率、胸径和树高生长量的关系,并对8个树种的耐盐性进行隶属函数法综合评价,以进一步研究江苏沿海地区典型树种的耐盐性。结果表明,48个调查样地土壤含盐量为0.4~11.9 mg/g;不同样地之间的土壤含盐量差异较大;土壤含盐量较高的样地具有典型的盐分表聚现象;8个树种的成活率、胸径和树高年生长量与土壤含盐量均呈负相关。8个造林树种的耐盐性评价结果显示,其耐盐能力表现为白榆>苦楝>落羽杉>乌桕>榔榆>中山杉>青皮柳>构树。其中,白榆和苦楝可耐受6 mg/g的土壤含盐量;落羽杉、乌桕、榔榆和中山杉可耐受4 mg/g的土壤含盐量;青皮柳和构树只能耐受3 mg/g的土壤含盐量。白榆和苦楝可在含盐量较高的沿海地区造林,落羽杉、乌桕、榔榆和中山杉可在含盐量中等的沿海地区造林,青皮柳和构树只能在含盐量较低的沿海地区造林。

     

Microbial community functional structure in response to micro-aerobic conditions in sulfate-reducing sulfur-producing bioreactor

Limited oxygen supply to anaerobic wastewater treatment systems had been demonstrated as an effective strategy to improve elemental sulfur(S0) recovery, coupling sulfate reduction and sulfide oxidation. However, little is known about the impact of dissolved oxygen(DO) on the microbial functional structures in these systems. We used a high throughput tool(GeoChip) to evaluate the microbial community structures in a biological desulfurization reactor under micro-aerobic conditions(DO: 0.02–0.33 mg/L). The results indicated that the microbial community functional compositions and structures were dramatically altered with elevated DO levels. The abundances of dsrA/B genes involved in sulfate reduction processes significantly decreased(p 0.05, LSD test) at relatively high DO concentration(DO: 0.33 mg/L). The abundances of sox and fccA/B genes involved in sulfur/sulfide oxidation processes significantly increased(p 0.05, LSD test) in low DO concentration conditions(DO: 0.09 mg/L) and then gradually decreased with continuously elevated DO levels. Their abundances coincided with the change of sulfate removal efficiencies and elemental sulfur(S0) conversion efficiencies in the bioreactor. In addition, the abundance of carbon degradation genes increased with the raising of DO levels, showing that the heterotrophic microorganisms(e.g., fermentative microorganisms) were thriving under micro-aerobic condition. This study provides new insights into the impacts of micro-aerobic conditions on the microbial functional structure of sulfatereducing sulfur-producing bioreactors, and revealed the potential linkage between functional microbial communities and reactor performance.     

温度、盐度、铜、氨对对虾仔虾(Penaues orientalis K)和光滑河兰蛤(Potamocorbula laevis)的影响

在室内模拟条件下,进行了热冲击及其与盐度、铜、氨联合对对虾仔虾和光滑河兰蛤的急性影响研究。结果表明,两种动物的起始致死温度(TL₅₀)和最高临界温度(CTM)随驯化温度的升高而增大;随盐度的降低,仔虾的耐高温能力明显降低,而兰蛤对盐度变化反应不明显;高温明显提高铜、氨对仔虾的毒性。也提高铜对兰蛤的毒性,但降低氨对兰蛤的毒性影响。仔虾对高温、低盐、铜离子及非离子氨反应敏感。     

Revealing the changes of bacterial community from water source to consumers tap: A full-scale investigation in eastern city of China

This study profiled the bacterial community variations of water from four water treatment systems,including coagulation,sedimentation,sand filtration,ozonation-biological activated carbon filtration(O₃-BAC),disinfection,and the tap water after the distribution process in eastern China.The results showed that different water treatment processes affected the bacterial community structure in different ways.The traditional treatment processes,including coagulation,sedimentation and sand f...     

Bioassay: A useful tool for evaluating reclaimed water safety

Wastewater reclamation and reuse has been proved to be an effective way to relieve the fresh water crisis.However, toxic contaminants remaining in reclaimed water could lead to potential risk for reuse, and the conventional water quality standards have difficulty guaranteeing the safety of reclaimed water.Bioassays can vividly reflect the integrated biological effects of multiple toxic substances in water as a whole, and could be a powerful tool for evaluating the safety of reclaimed water.There...     

Effect of NOx and SO2 on the photooxidation of methylglyoxal: Implications in secondary aerosol formation

Methylglyoxal(CH₃COCHO,MG),which is one of the most abundant α-dicarbonyl compounds in the atmosphere,has been reported as a major source of secondary organic aerosol(SOA).In this work,the reaction of MG with hydroxyl radicals was studied in a 500 L smog chamber at(293±3) K,atmospheric pressure,(18±2)% relative humidity,and under different NOx and SO₂.Particle size distribution was measured by using a scanning mobility particle sizer(SMPS) and the results showed that the ad...     

融合拓扑信息与气象信息的空气质量预测网络

通过空气质量监测数据对正在形成或即将到来的空气污染进行预测是一项具有重要意义的工作,而空气质量监测站只能检测其周围一定范围内的空气污染情况。为了衡量整个城市的空气污染情况,获取任意时间、任意位置的空气质量信息,结合交叉注意力机制,提出了一种融合拓扑信息与气象信息的空气质量预测网络(CGMIM)。将西安市空气质量监测数据与气象数据转换为图像拼接起来,作为输入信息。在高阶非线性时空动态神经网络(MIM)的基础上引入注意力机制,并增加拓扑图编码器模块,提高模型提取能力以及对空气质量监测数据中的空间特征的利用率。最后,使用时空损失函数替代传统的均方误差损失函数,提高模型对空间关系的关注。结果表明：CGMIM网络模型能够在准确预测的同时,对位置区域合理填充,能够有效提升空气质量监测数据的空间分辨率。     

皖南地区铜陵市大气颗粒物污染特征及潜在源研究

利用2018年3月—2021年2月环境和气象数据对皖南地区铜陵市大气颗粒物的污染特征和潜在贡献源进行了系统性研究.铜陵市大气颗粒物污染具有明显的季节变化特征,冬季污染物浓度最高,PM_2.5和PM₁₀平均为（60.3±31.0）μg·m^-3和（89.2±42.2）μg·m^-3.计算发现PM_2.5/PM₁₀超过0.5,铜陵市的大气颗粒物污染问题与细颗粒物关系密切.后向轨迹聚类分析表明铜陵市大气颗粒物的输送路径具有季节性差异.春季以西北、东北和西南方向气流为主,占比83.73%;夏季以东南和南部方向气流为主,占比82.90%;秋季以东北气流为主,占比51.00%;冬季则是以北方和西北气流为主,占比69.81%.其中,冬季气流轨迹所对应的PM_2.5和PM₁₀的浓度最高,平均为59.7和92.0μg·m^-3;夏季最低,平均为23.8和43.8μg·m^-3.潜在源贡献因子（WPSC...     

Temporal and spatial assessment of natural resource use in China using ecological footprint method

China has about 20% of the world's population. With rapid economic development and substantial population increase, China is now faced with severe conflicts between limited natural resources and increasing resource requirements. In this study, we used the ecological footprint method to assess the resource demand and supply conditions of each land use in China between 1978 and 2003. In order to provide insight into the spatial heterogeneity of resource demand and supply conditions, we also assessed the ecological footprint at provincial level in 2002. An ecological footprint curve method was introduced to compare differences in natural resource use, economic development and technological progress among different countries and provinces. The results showed that the ecological footprint, biocapacity and ecological deficit per capita for China have all been increasing during 1978–2003. The ecological footprints per person in northern and eastern China were larger than those in southern and western China. The ecological deficits per person in southern and eastern China were more severe than those in northern and western China. Though the resource use efficiency has increased considerably during 1978–2003, it was still much lower than those of the Netherlands, France, South Korea, Mexico, the Philippines and India.     

焦化苯初馏份蒸馏釜发生爆炸的原因探讨

通过对某企业的一起典型爆炸事故案例进行分析,找出其产生的原因,提出了预防措施。