论河流保护与修复的生态目标

分析了国内外河流保护与修复的相关理论研究和实践进展,指出开展河流保护与修复工作必须首先明确河流生态修复目标。为能够实际指导河流修复和管理,生态保护目标需要量化。介绍了国外以水流情势为核心的河流生态目标量化新方法（DRIFT法）,以及对河流生态保护等级的标准划分。结合我国的具体国情,建议应用“生态支持配置”概念,尽快规划我国河流生态功能分区,设定不同区位的生态保护目标和等级,确定相应的保护水平,分区、分类、分级实施河流保护与修复。     

Fish consumption reduces transfer of BDE47 from dam to murine offspring

Fish and seafood are important contributions to a healthy diet, but also contain persistent organic pollutants (POPs) like polybrominated diphenylethers (PBDEs) and polychlorinated biphenyls (PCBs). Discrepancies have been found between intake and accumulated levels of POPs, where fish consumers have had similar levels of POPs to the general population. Similarly fish oil consumption has been found to reduce accumulation of POPs. This study examined the accumulation of BDE47 or PCB153 in mice fed diets with different nutritional composition, using female mice with pre-weanling pups exposed through gestation and lactation. A fish-based diet was compared to a standard casein-based rodent diet. All diets had low background levels of environmental contaminants and were spiked with BDE47 or PCB153 to levels representing a realistic (∼0.004 μmol kgbw⁻¹ d) or a high dietary exposure (∼1.3 μmol kgbw⁻¹ d). Accumulation of BDE47 or PCB153 in offspring tissues after 18 d lactation reflected the maternal exposure levels. However, the pups of dams fed a fish-based diet had consistently lower BDE47 accumulation in liver, fat and stomach than pups from casein-fed dams. Similarly the pups of dams fed a high dose of PCB153 in a fish diet also accumulated less PCB153 than pups of the dams fed a casein diet, although not significant. In conclusion, the fish based diets seemed to reduce transfer of BDE47 and PCB153 from dams to pups. The study highlights that in-depth knowledge about nutritional impact on toxicokinetics is of great interest to vulnerable consumers.     

Nature of the field-to-field distribution of pesticide residues

The supervised trial datasets (1950), consisting of a minimum of five residue values and selected by the experts of FAO/WHO Joint Meeting on Pesticide Residues for recommending maximum residue levels between 1997 and 2011, were evaluated to obtain information on the typical spread of residue values in individual datasets. The typical relative standard deviation, CV, of field-to-field variation of pesticide residues was about 80%. The spread of residues in datasets is independent from the chemical structure of pesticides, residue level, pre-harvest interval and number of values in the datasets. The CV ranges within the Codex commodity groups and between groups overlapped and their difference were not statistically significant. The number of residues below the limit of quantification (LOQ) affects the CV at various extents depending on the ratio of LOQ/R _mean. The combined uncertainty of the highest residue in a dataset significantly affects the CV of the dataset. The lowest and intermediate ones have less influence. The residues in different fields receiving the same treatment vary within large range: 55%, 72%, 78%, 86% and 89% of the 25,766 residues values were, respectively, within 3, 4, 5, 6 and 7 times the median value of the corresponding dataset.     

旅游者安全价值及其评价

笔者提出旅游者安全价值概念,并从安全效用与旅游者价值观角度入手,通过研究旅游者为保障自身安全所愿意支付的货币代价,构建旅游者安全价值的量化概念、评价体系与测算公式。从而获得旅游者为保障自身的旅游安全所愿意支付的货币代价,形成对旅游者的安全保障需求的整体认识,使旅游经营管理者对旅游安全保障工作的市场潜在效益形成定量化认识,树立"安全出效益"的观念。     

Dissolution of beryllium in artificial lung alveolar macrophage phagolysosomal fluid

Dissolution of a lung burden of poorly soluble beryllium particles is hypothesized to be necessary for development of chronic beryllium lung disease (CBD) in humans. As such, particle dissolution rate must be sufficient to activate the lung immune response and dissolution lifetime sufficient to maintain chronic inflammation for months to years to support development of disease. The purpose of this research was to investigate the hypothesis that poorly soluble beryllium compounds release ions via dissolution in lung fluid. Dissolution kinetics of 17 poorly soluble particulate beryllium materials that span extraction through ceramics machining (ores, hydroxide, metal, copper-beryllium [CuBe] fume, oxides) and three CuBe alloy reference materials (chips, solid block) were measured over 31 d using artificial lung alveolar macrophage phagolysosomal fluid (pH 4.5). Differences in beryllium-containing particle physicochemical properties translated into differences in dissolution rates and lifetimes in artificial phagolysosomal fluid. Among all materials, dissolution rate constant values ranged from 10⁻⁵ to 10⁻¹⁰ g cm⁻² d⁻¹ and half-times ranged from tens to thousands of days. The presence of magnesium trisilicate in some beryllium oxide materials may have slowed dissolution rates. Materials associated with elevated prevalence of CBD had faster beryllium dissolution rates [10⁻⁷-10⁻⁸ g cm⁻² d⁻¹] than materials not associated with elevated prevalence (p < 0.05).     

What have we known so far for fluorescence staining and quantification of microplastics: A tutorial review

• Fluorescence staining provides a fast and easy method to quantify microplastics. • Factors that influence staining are summarized to obtain an optimum staining effect. • Natural organic matter can be stained by dye and interfere with quantification. • Fluorescence staining is applied in both field and laboratory studies. • Future work involves developing new dyes and automated image-analysis methods. Understanding the fate and toxicity of microplastics (MPs,<5 mm plastic particles) is limited by quantification methods. This paper summarizes the methods in use and presents new ones. First, sampling and pretreatment processes of MPs, including sample collection, digestion, density separation, and quality control are reviewed. Then the promising and convenient staining procedures and quantification methods for MPs using fluorescence dyes are reviewed. The factors that influence the staining of MPs, including their physicochemical properties, are summarized to provide an optimal operation procedure. In general, the digestion step is crucial to eliminate natural organic matter (NOM) to avoid interference in quantification. Chloroform was reported to be the most appropriate solvent, and 10–20 μg/mL are recommended as optimal dye concentrations. In addition, a heating and cooling procedure is recommended to maintain the fluorescence intensity of MPs for two months. After staining, a fluorescence microscope is usually used to characterize the morphology, mass, or number of MPs, but compositional analysis cannot be determined with it. These fluorescence staining methods have been implemented to study MP abundance, transport, and toxicity and have been combined with other chemical characterization techniques, such as Fourier transform infrared spectroscopy and Raman spectroscopy. More studies are needed to focus on the synthesis of novel dyes to avoid NOM’s interference. They need to be combined with other spectroscopic techniques to characterize plastic composition and to develop image-analysis methods. The stability of stained MPs needs to be improved.     

向性能化防火规范转变应注意的几个问题

介绍了性能化建筑防火规范产生的背景以及国内外的发展概况。在对国外一些性能化经验进行总结的基础上,重点从建筑物防火安全水平的量化、性能化设计的不确定性、性能化设计方案的验证以及性能化文件的编制和性能化建筑设计、施工到使用各个环节的连续性等方面,讨论了从处方式防火规范向性能化防火规范转变时应该注意的几个问题。结合中国的具体情况,指出其在发展性能化规范中应着力解决的几个问题:正确处理处方式规范和性能化规范两者的关系;积极推动消防相关产品的发展;解决资金来源,加大经费投入;制定工程惯例或设计导则等。     

HFL模型在海上压裂工艺过程风险评估中的应用

为有效降低海上压裂工艺过程事故发生的可能性,建立将危险与可操作性研究(HAZOP)、事故树分析(FTA)和保护层分析(LOPA)集成的量化风险评估模型(HFL模型)。阐述HFL模型的集成机理和分析流程。以海上压裂工艺过程高压管线危险性分析为实例,开展该模型的研究与应用。在运用HAZOP方法对危险源初步辨识基础上,构建高压管线超压的蝴蝶结模型(BTM),确定导致事故发生的9种风险因素和5种事故后果,并估算高压管线断裂事故场景的初始事件概率和剩余事故风险。结果表明,现有的独立保护层(IPL)即超压电子保护装置无法使事故风险达到可接受水平,需要通过增加新的IPL,即安装井口保护装置和泄压装置,提高压裂过程高压管线运行的可靠性,确保剩余事故风险处于可接受水平。     

土壤湿度与风速对沙尘暴发生的贡献程度分析

在沙尘暴研究中，大风和下垫面的土壤湿度是影响沙尘暴发生的两个重要因子，它们分别以数值形式定量记录，但这种定量因子与沙尘暴发生的定性特征之间难以建立联系，从而影响了沙尘暴的定量研究。利用内蒙古中西部地区二连浩特、乌拉特中旗和乌海等3个观测站点2001年4月至2004年4月的土壤湿度、风速及相应的沙尘暴记录资料，采用数量化理论Ⅱ这种可以将定性分析与定量分析相结合的方法，研究了沙尘暴发生时风速和土壤湿度对沙尘暴的贡献程度。结果表明：在不同地区、不同地貌的自然条件下，风速和土壤湿度对沙尘暴发生的贡献程度相差甚远，乌拉特中旗和二连浩特地区风速的贡献大于土壤湿度的影响，而对乌海地区来说，土壤湿度对沙尘暴的贡献要大于风速的影响。     

关于安全减灾业的基础性研究及量化模式探讨

本文重点论证加强安全减灾业基础性研究的必要性,并从建立安全减灾量化模式及数学体系作出探讨。