Evaluation of acidity in late Permian outcrop coals and its association with endemic fluorosis in the border area of Yunnan,Guizhou, and Sichuan in China

The junction area of Yunnan, Guizhou, and Sichuan provinces is the heaviest coal-burning endemic fluorosis zones in China. To better understand the pathogenicity of endemic fluorosis in this area, 87 coal samples from the late Permian outcrop or semi-outcrop coal seams were collected in eight counties of the junction area of Yunnan, Guizhou, and Sichuan provinces. The total fluorine and sulfate content, etc. in the coal was determined using combustion-hydrolysis/fluoride-ion-selective electrode method and ion chromatography, respectively. The results show that the total fluorine concentrations in the samples ranged from 44 to 382 µg g^?1, with an average of 127 µg g^?1. The average pH of the coals is 5.03 (1.86–8.62), and the sulfate content varied from 249 to 64,706 µg g^?1 (average 7127 µg g^?1). In addition, the coals were medium- and high-sulfur coals, with sulfur mass fraction ranging from 0.08 to 13.41%. By heating the outcrop coals, HF release from the coal was verified quantitatively without exception, while simulated combustion directly confirmed the release of sulfuric acid (H₂SO₄). The acid in coal may be in the form of acidic sulfate (\({\text{HSO}}_{4}^{ - }\)/H₂SO₄) because of a positive relationship between pH and \(p\left( {{\text{SO}}_{4}^{2 - } } \right)\) in the acidic coal. The possible reaction mechanism would be that a chemical reaction between the acid (H₂SO₄ or \({\text{HSO}}_{4}^{ - }\)) and fluorine in the coal occurred, thereby producing hydrogen fluoride (HF), which would be the chemical form of fluorine released from coal under relatively mild conditions. The unique chemical and physical property of HF may bring new insight into the pathogenic mechanism of coal-burning endemic fluorosis. The phenomenon of coal-burning fluorosis is not limited to the study area, but is common in southwest China and elsewhere. Further investigation is needed to determine whether other endemic fluorosis areas are affected by this phenomenon.     

Effects of different endogenous fungi on the mass loss and nutrient content of leaf litter of Cunninghamia lanceolata北大核心CSCD

To explore the role of endophytic fungi in the decomposition of litter, the endophytic fungi Penicillium sp. strain CG2 (A), Fusarium flavum strain AY13 (B), and Talaromyces strain AJ14 (C) of Cunninghamia lanceolata were added to experimental pots in different forms (mycelium, sterilized fermentation broth, single fungus, and mixed fungi), and a control treatment (CK) was set up (no fungi added). At 10, 30, 60, 90, and 120 days after litter decomposition, a study on the decomposition dynamics of C. lanceolata litter under different treatments was performed. The results showed that the rate of leaf mass loss was the highest in the sterilized fermentation broth treatment A after 120 days, and that there was a significant difference (P < 0.05) between the mycelium treatment AC and the control treatment after 60 days (23.97% higher than the control group). On day 60, the litter carbon content from the mycelium treatment A was significantly different from that of the control (P < 0.05), showing a 16.74% lower value, whereas the litter carbon content of the mycelium treatment B was 21.13% lower than that of the control after 90 days. The nitrogen content of the litters of most mycelium and sterilized fermentation broth treatments was increased compared to that of the control group; there was significant difference (P < 0.05) between the sterilized fermentation broth treatment A and the control (P < 0.05), with a 17.05% higher value than that of the control. Similar to nitrogen, the litter phosphorus content also increased; there was a statistically significant difference between the mycelium treatment A and the control group, with treatment A showing a 46.67% higher value than the control group. The potassium content was 28% lower than that of the control group under the sterilized fermentation broth treatment C, a result that was significantly different from that of the control group (P < 0.05). After treatment for 90 days, the ratio of carbon to nitrogen was the lowest under the treatments with the mycelium A and the mycelium B, with values 25.54% and 25.11% lower than that of the control group, respectively, and a statistically significant difference from that of the control group (P < 0.05). The ratio of carbon to phosphorus was the lowest under the treatment with mycelium A after 60 days, and the result was significantly different from that of the control (P < 0.05), with a 43.05% lower value than the control. Thus, the three endophytic fungi had different effects on the mass loss rate and nutrient content of the litter. The Penicillium sp. strain CG2 (A) had statistically significant effects on the mass loss and nutrient content of leaf litter, which was within the range of fungi fertilizer reference values for the breeding of C. lanceolata. © 2018 Science Press. All rights reserved.     

沈阳市大气PM2.5中水溶性离子的季节变化特征

为研究沈阳市大气中PM2.5及其水溶性离子的污染特征、季节差异和来源情况,使用URG-9000D在线监测系统对沈阳市2019年大气颗粒物进行连续的采样分析,并利用正交矩阵因子分析法(PMF)进行污染物的来源解析.结果 表明,2019年沈阳市秋冬季节PM2.5质量浓度变化受相对湿度影响较大,冬季PM2.5平均质量浓度达到85.76 μg·m-3,细粒子污染较为严重.沈阳市大气PM2.5中SNA(SO42-、NO3和NH4+)所占比重表现为春季最高秋季最低;夏季SO42-和NH4+浓度较高,而NO3-浓度较低.SO42-在夏季呈单峰型日变化,与NO3-变化趋势相反.春夏秋三季NH4+与SO42-、NO3-主要结合为(NH4)2SO4和NH4NO3,冬季NH4+主要以(NH4)2SO4和NH4HSO4的形式存在.沈阳市存在较强的SO2和NOx二次转化现象,且各季节中SO2的转化率均高于NO2.PMF源解析结果表明,二次源对沈阳市大气污染贡献最大,夏秋季生物质燃烧和冬季燃煤源贡献同样不可忽视.     

计及多类约束的安控系统在线校核技术

通过对安控装置运行状态进行实时监视与识别,准确获取安控系统运行状态,对分散的安控系统策略进行结构化统一建模,实现了安控当值策略的快速识别,为离线策略在线校核提供基础数据,并进行了安控系统的静态安全、暂态安全和动态稳定的全面校核。研究结果表明一种计及多类安全稳定约束的安控系统在线校核技术对防止安控系统离线策略控制量不足或者不匹配等情况有很好的指导意义。     

香溪河流域水生态系统健康评价

随着人们环境保护意识的增强,河湖生态保护与修复成为社会关注的热点问题,科学的生态健康诊断则是有效进行河湖治理的前提.香溪河作为三峡水库典型支流,探究其水生态系统健康对于长江生态保护具有十分重要的意义.通过收集整理香溪河干支流的生物与生境数据,构建了涵盖水环境、水生生物、物理栖息地三方面共16项指标的水生态系统健康评价指标体系,综合运用专家判断法和熵权法确定评价因子权重,采用河流健康指数（RHI）表征香溪河流域水生态系统健康状况.结果表明:①2017年三峡水库蓄水期香溪河流域水生态系统整体健康水平为良好,优和良等级占比分别为12.5%和79.2%.②健康状况呈现出支流优于干流、非回水区优于回水区的空间分布特点,具体表现为支流南阳河>支流古夫河>支流高岚河>香溪河干流.干流水环境问题相对突出,而支流的河流连通性相对较差.③库湾健康状况的年内变化特征为冬季最好,春秋季次之,夏季最差.研究显示,该评价体系能准确地评估香溪河流域水生态健康状况,同时需重视三峡水库支流库湾的水环境治理.      

实物型水资源资产负债表表式结构设计

论文在阐述资产负债表基本概念和原理的基础上,遵循会计恒等式、复式记账规则和权责发生制的记账基础,结合我国水资源管理的实际,提出了基于会计学的水权益实体水资源资产负债表表式结构和基于统计学、经济学的国家（地区）水资源资产负债表表式结构,从而实现能够反映水权益实体之间和经济体与环境之间关于水资源资产的债务债权关系的水资源资产核算,实现国家和行政区层面的水资源资产负债核算,为生态文明体系建设、自然资源资产核算、领导干部离任审计考核等提供必要的基础信息,也为进一步完善水资源资产负债表账户体系奠定基础。     

黄河流域生态补偿研究进展与展望

黄河流域是我国重要的生态功能区,在全国经济社会发展格局中具有重要作用。生态补偿作为保护流域生态环境、促进人与自然和谐的重要手段,在推动黄河流域高质量发展过程中具有重要作用。本文从流域区段、评价方法、影响效应、优化思路、保障机制等方面对黄河流域生态补偿的理论和实践成果进行了综述,同时提出加强多学科协同攻关、构建具有区域特征的生态补偿模式、加快建立以海定陆的生态补偿机制、注重生态损害形成机制和程度评估、加强构建多元化生态补偿保障体系等未来研究中需要深化和完善的几点建议,以期为中国经济高质量发展阶段黄河流域生态补偿的理论与实践研究提供启示和借鉴。     

Cu2+和Cd2+对斑马鱼胚胎早期发育的联合毒性

采用斑马鱼胚胎早期发育技术,测定Cu2+和Cd2+ 2种重金属对胚胎发育的毒性效应. 以24 h致死和72 h胚胎孵化抑制为毒性终点,2种重金属的剂量-效应曲线可用Weibull函数或Logit函数有效描述,由最佳拟合函数计算得出半数致死浓度(LC₅₀)或半数效应浓度(EC₅₀)为毒性效应的评价标准,2个毒性终点的重金属毒性大小顺序均为Cu2+>Cd2+. 应用浓度加和(CA)与独立作用(IA)2种模型,对72 h孵化抑制率的无观测效应浓度(NOEC)配比混合物的联合毒性作用进行了预测,通过混合物试验观测数据的95%置信区间与CA模型和IA模型预测的剂量-效应曲线进行比较分析表明,2种模型都可以有效预测斑马鱼胚胎孵化的联合毒性.      

豫北平原近25年来生态服务价值研究

运用3S技术,分析和探讨了豫北平原的内黄县1979—2003年的生态系统服务价值变化. 土地利用变化直接影响生态服务价值,该区25年间的生态系统服务价值变化显著,呈增长趋势.耕地和林地生态系统服务功能约占总服务价值的80%～90%. 结果表明:25年来内黄县研究区域的生态环境质量呈不断上升的态势,生态系统服务价值增加逾2.6×108元. 研究区内的林地、园地面积不断增加,增加的面积部分主要源自未利用地,而另一部分则是由耕地转变而来. 这一方面反映了人口增长和经济建设需求对生态环境变化的积极影响,另一方面也反映了研究区人民和相关部门重视生态环境,环保意识增强.      

论流域环境经济学

流域系统具有整体性、地域分异性、污染的跨界单向外部性,面临着上下游和不同利益群体之间的利益冲突,使得传统环境经济学的理论和方法遇到了障碍.基于环境经济学在流域这一特殊研究对象的理论拓展和实践探索要求,提出了流域环境经济学发展的必要性,阐述了流域环境经济学的概念、内涵和理论基础,并初步构建了流域环境经济学框架和主要内容.研究认为,流域环境经济学是随着流域环境问题不断演化而产生的新研究领域,通过借鉴空间经济学、信息经济学、行为经济学和制度经济学等相关理论和方法,研究流域经济发展与环境保护之间的相互关系及其引发的人与人之间的关系,探索流域环境管理的机制设计和合理的环境经济政策手段,优化流域环境资源配置,实现流域经济增长与环境保护协调发展.