三峡水库浮游植物群落特征及水体富营养化评价

基于2003—2017年三峡水库浮游植物群落结构、优势种群的变化和2017年水库干支流水质数据,全面分析浮游植物群落结构和演替特征,并运用综合营养状态指数法对水体富营养化程度进行评价。结果表明,三峡水库浮游植物种类丰富,监测期间共鉴定出浮游植物7门62属,细胞密度在7.5×10~4~2.8×10~7cell/L之间变化,Shannon-Wiener多样性指数为1.0~3.0,在α-中污带和β-中污带之间,说明三峡水库水生态环境健康状况相对较好;三峡水库浮游植物季节性演替特征呈硅藻和甲藻向蓝藻和绿藻演替的趋势,年际变化特征分析发现浮游植物密度在2008年175 m实验蓄水后大量增长,且优势藻类由河道型藻类向湖泊型藻类转化。通过监测数据分析,得出三峡水库干流处于中营养状态,支流在春季主要处于轻度富营养状态,秋季支流比春季支流的富营养化程度低,主要处于中营养状态,总氮(total nitrogen,TN)、总磷(total phosphorus,TP)和透明度(transparency,SD)为水质主要影响因子。     

Evaluation of a population mobility,mortality, and birth surveillance system in South Kivu,Democratic Republic of the Congo

Prospective, community-based surveillance systems for measuring birth, death, and population movement rates may have advantages over the ‘gold-standard’ retrospective household survey in humanitarian contexts. A community-based, monthly surveillance system was established in South Kivu, Democratic Republic of the Congo, in partnership with a local implementing partner and the national ministry of health. Data were collected on the occurrence of births, deaths, arrivals, and departures over the course of one year, and a retrospective survey was conducted at the end of the period to validate the information. Discrepancies between the two approaches were resolved by a third visit to the households with discordant records. The study found that the surveillance system was superior in terms of its specificity and sensitivity in measuring crude mortality and birth rates as compared to the survey, demonstrating the method's potential to measure accurately important population-level health metrics in an insecure setting in a timely, community-acceptable manner.     

Formulaic Expert Method to Integrate Evaluation and Valuation of Heritage Trees in Compact City

Urban trees serve important environmental, social and economic functions, but similar to other natural endowments they are not customarily depicted in monetary terms. The needs to augment protection, funding and community support for urban greening call for proper valuation. Heritage trees (HTs), the cream of urban-tree stock, deserve special attention. Existing assessment methods do not give justice to outstanding trees in compact cities deficient in high-caliber greenery, and to their social-cultural-historical importance. They artificially separate evaluation from valuation, which should be a natural progression from the former. Review of tree valuation methods suggested the formula approach to be more suitable than contingent valuation and hedonic pricing, and provided hints on their strengths and weaknesses. This study develops an alternative formulaic expert method (FEM) that integrates evaluation and valuation, maximizes objectivity, broadly encompasses the key tree, tree-environment and tree-human traits, and accords realistic monetary value to HTs. Six primary criteria (dimension, species, tree, condition, location, and outstanding consideration) branched into 45 secondary criteria, each allocated numerical marks. Each primary criterion was standardized to carry equal weight, and a tree's maximum aggregate score is capped at 100. A Monetary Assignment Factor (MAF) to consign dollar value to each score unit was derived from three-year average per m² sale price of medium-sized residential flats. The applicability of FEM was tested on selected HTs in compact Hong Kong. The aggregate score of a tree multiplied by MAF yielded monetary value, which was on average 66 times higher than the result from the commonly-adopted Council of Tree and Landscape Appraisers method. The computed tree values could be publicized together with multiple tree benefits to raise understanding and awareness and rally support to protect HTs. The property-linked FEM could be flexibly applied to other cities, especially to assess HTs in compact developing cities.     

Variation in posture quality across musical instruments and its impact during performances

Objective. Bad posture increases the risk that a musician may suffer from musculoskeletal disorders. This study compared posture quality required by different instruments or families of instruments. Methods. Using an ad-hoc postural observation instrument embracing 11 postural variables, four experts evaluated the postures of 100 students attending a Spanish higher conservatory of music. Results. The agreement of the experts’ evaluations was statistically confirmed by a Cohen's κ value between 0.855 and 1.000 and a Kendall value between 0.709 and 1.000 (p?χ² tests revealed significant association between instrument families and seated posture with respect to pelvic attitude, dorsal curvature and head alignment in both sagittal and frontal planes. This analysis also showed an association between instrument families and standing posture with respect to the frontal plane of the axis of gravity, pelvic attitude, head alignment in the frontal plane, the sagittal plane of the shoulders and overall posture. Conclusions. While certain postural defects appear to be common to all families of instruments, others are more characteristic of some families than others. The instrument associated with the best posture quality was the bagpipe, followed by percussion and strings.     

工作场所职业工效相关因素及其管理初探

为了探讨工作场所职业工效管理的基本策略和方法,在概述职业工效相关因素类别、相互关联及评价方法等基础上,提出基于职业病危害防治要求、风险管理理念和管理体系建设模式的职业工效不良因素干预管理的初步策略及实施要点。研究结果表明:工作场所职业工效相关因素包括个体特征、工艺设备及其布局、工作系统设计、作业环境、作业管理和社会心理因素等,不同因素间存在直接或间接的相互影响,并最终影响到微观层面劳动者职业活动的工效特点及宏观层面工作场所整体的职业工效特征;实施有效的职业工效管理,在于科学辨识、评估不良职业工效因素的基础上,进一步在职业病危害预防控制的不同阶段采取合理可行的管理方法进行干预,并持续改进。     

基于平衡计分卡的大气环境监测数据共享网站绩效评估研究

基于平衡计分卡原理,结合网站特点,建立了大气环境监测数据共享网站绩效评估模型。以共享网站的战略愿景为模型框架的中心,以财务、顾客、内部程序、学习与成长等4个基本维度为一级指标,构建了绩效评估指标体系,并采用层次分析法确定了各指标的权重。利用该模型对长三角区域空气质量预测预报系统和宁波市空气质量预报预警平台的大气数据共享模块进行实证研究,绩效评估结果均为良好。     

基于因子分析法优选河流水体中氮浓度预测方法的研究

定量的河流水体中氮浓度预测方法有很多种,如何优选出预测精度较高的方法一直是学术界多年来致力于研究的重点。本研究采用因子分析法对预测方法的精度评价指标进行分析,并建立了预测方法精度的评价模型,对回归分析法、神经网络法、灰色系统法和增长率统计法4种水体氮浓度预测方法进行综合评估,优选出精度较高的河流水体氮浓度预测模型——BP神经网络预测模型。结果表明,此评估模型对类似研究具有一定的参考价值,能为选择出合适的河流水体氮浓度预测方法提供依据。     

利用城市污泥堆肥及建筑弃土种植麦冬研究

将污泥堆肥产品分别与建筑弃土按0%、10%、20%、30%、40%和50%(湿重)的比例配制营养土,以麦冬为例进行180 d的栽培实验,分析了营养土对麦冬生长特性、植物体内及栽培土壤中营养学指标和重金属含量的变化规律,并通过模糊综合评价方法选择营养土较佳配制方案。实验结果表明:堆肥比例在50%时麦冬生物量增加率、新生芽数及地表部分比重为最大值,在30%时纺锤体肉质数减少率为最大值;随着营养土中堆肥比例增加,麦冬体内养分含量、重金属积累量随之增加,均在50%时达到最大值;栽培土壤养分越多损失量越多,各指残留率越低,同时全磷、全氮及K含量降低率较有效磷、碱解氮小得多,Cr降低率在5.20%～8.34%之间,Zn降低率在3.27%～17.35%之间;堆肥比例在40%以上的营养土对麦冬生长效果好,但较佳配制方案为堆肥产品占20%。     

国内外可持续发展评价方法对比分析

国际、国内很多组织都对可持续性评价方法进行过研究分析,但大多是特定的案例研究.目前国内外对可持续发展评价方法没有一个全面系统的分析比较,使得不同地区比较起来很困难.本文对各种评价方法如环境可持续性指数法、生态足迹法、能值分析法和指标综合评价法的来源、理论和应用作了介绍.得出各方法适用范围:可持续性指数法适合于国家间的综合评价;生态足迹和能值分析法适合于各种范围,包括国家、区域、地区和小系统;指标体系综合评价法对于小范围更合适.同时对各种方法的优势和缺陷进行了分析讨论,得出:可持续性指数法信息量大,但是计算复杂;生态足迹法计算过程简单,但是缺失一些可持续性信息;能值分析法考虑问题全面,但是其原理涉及热力学知识,很难被一些学者认同;指标体系评价法变通性较大,可随着评价系统的变化而进行调整,但是主观性较强.通过分析指出不同方法适用范围并指出每种分析方法的优势和不足,为以后选择合适的分析方法评价对象的可持续性提供依据.     

采油用油田化学剂对鱼类的急性毒性实验研究

以白鲢鱼为实验生物,采用半静态实验方法,研究了几种油田化学剂的半致死浓度和安全浓度。研究表明:防膨剂、杀菌剂K、杀菌剂L、清蜡剂、四氟硼酸、酸化缓蚀剂、阻垢剂、阻垢缓蚀剂、缓蚀阻垢剂和破乳剂的96h半致死浓度LC50值分别为0.68、1.6、9.3、25、123、510、620、3240、4570、7410mg/L。根据化学物质对鱼类毒性物质分级标准,防膨剂属于剧毒物质;杀菌剂K、杀菌剂L和清蜡剂属于高毒物质;四氟硼酸、酸化缓蚀剂和阻垢剂属于中毒物质;阻垢缓蚀剂、缓蚀阻垢剂和破乳剂属于低毒物质。这几种油田化学剂的安全浓度为0.068～741mg/L。此研究可为评价油田化学剂对水生生物的影响,制定废水排放浓度标准提供依据。