Water quality characteristics and assessment of Yongding New River by improved comprehensive water quality identification index based on game theory

The Yongding New River is essential for the water supplies of Tianjin. To date, there is no comprehensive report that assesses the year-round water quality of the Yongding New River Main stream. Moreover, little attention has been given to determining a combined weight for improving the traditional comprehensive water quality identification index (ICWQII) by the game theory. Seven water quality parameters were investigated monthly along the main stream of the Yongding New River from May 2018 to April 2019. Organic contaminants and nitrogen pollution were mainly caused by point sources pollution, and the total phosphorus mainly by non-point source pollution. Dramatic spatio-temporal variations of water quality parameters were jointly caused by different pollutant sources and hydrometeorological factors. In terms of this study, an improved comprehensive water quality identification index (ICWQII) based on entropy weight or variation coefficient and traditional CWQII underestimated the water qualities, and an ICWQII based on the superstandard multiple method overvalued the assessments. By contrast, water qualities assessments done with an ICWQII based on the game theory matched perfectly with the practical situation. The ICWQII based on game theory proposed in this study takes into account not only the degree of disorder and variation of water quality data, but also the influence of standard-exceeded pollution indicators, whose results are relatively reasonable. All findings and the ICWQII based on game theory can provide scientific support for decisions related to the water environment management of the Yongding New River and other waters.     

粮食产量预测理论、方法与应用Ⅱ.粮食生产潜力短期预测理论、模型及其应用

粮食生产潜力短期预测结果可以检验粮食中长期生产潜力预测的准确性和为国家提供制定粮食生产战略的科学依据。粮食生产潜力短期预测理论即“趋势-波动理论”,它建立在粮食或作物“现状生产潜力”概念和“天-人-地概念模型”基础上,预测模型为最佳移动步长条件下的多年单产移动平均趋势模型,实际预测时采用系统预测方法。11个研究案例预测的平均误差为0.77％,最大误差为2.99％,预测精度高。本研究初步结论是：粮食生产潜力短期预测理论和模型是科学和实用的。     

粮食产量预测理论、方法与应用Ⅳ.粮食估产理论、模型及其应用

粮食估产的“通道-概率”理论：把属于最近通道的历年来的产量划分为5个气候年型通道,即丰产年、偏丰年、平产年、偏欠年、欠产年;计算产量出现在5个气候年型中的频率作为概率使用,估产年的初始估产值等于预测年各通道内平均产量与概率之积的和;估产值等于初始估产值与气候年型修正参数之积,专家根据当年气候条件和作物长势实时确定修正参数。预报单元为全国、省和县。应用结果表明：国家尺度上不需要修正,省和县级尺度需要气候年型参数修正;预测误差在3％以内;所述估产理论严谨、方法简单,参数少,参数来自原始数据本身和专家经验,易于推广使用。     

滑坡灰色系统预测模型及其应用

本文在分析目前国内外滑坡灰色预测预报模型基础上，提出了一种新的滑坡灰色系统预测预报模型。该模型相对於过去常用的灰色模型考虑了更多的影响因素，有更高的可信度。它不仅可用作滑波的临滑预报，还可用于般监测信息的预测。     

Identifying motivations and barriers to minimising household food waste

The amount of food discarded by UK households is substantial and, to a large extent, avoidable. Furthermore, such food waste has serious environmental consequences. If household food waste reduction initiatives are to be successful they will need to be informed by people's motivations and barriers to minimising household food waste. This paper reports a qualitative study of the thoughts, feelings and experiences of 15 UK household food purchasers, based on semi-structured interviews. Two core categories of motives to minimise household food waste were identified: (1) waste concerns and (2) doing the ‘right’ thing. A third core category illustrated the importance of food management skills in empowering people to keep household food waste to a minimum. Four core categories of barriers to minimising food waste were also identified: (1) a ‘good’ provider identity; (2) minimising inconvenience; (3) lack of priority; and (4) exemption from responsibility. The wish to avoid experiencing negative emotions (such as guilt, frustration, annoyance, embarrassment or regret) underpinned both the motivations and the barriers to minimising food waste. Findings thus reveal potentially conflicting personal goals which may hinder existing food waste reduction attempts.     

纳米银与微塑料在模拟垃圾填埋柱中的共迁移特征

以模拟垃圾填埋柱和人工配制渗滤液,探讨了纳米银（AgNPs）和微塑料（MPs）在垃圾填埋场中的迁移行为.结果发现,无论是单体系还是二元体系,随着填埋时间增长,AgNPs和MPs颗粒在渗滤液中稳定性增强,在填埋场中迁移能力增大,可能导致填埋中晚期有更多的污染颗粒随渗滤液流出填埋场.当AgNPs和MPs共存时,相对于单体系促进了AgNPs的迁移而轻微地抑制了MPs的迁移.结合DLVO理论和胶体过滤理论分析,一方面是由于流动性更高的MPs可作为AgNPs的载体,同时与AgNPs竞争固相介质上的吸附位点,从而促进AgNPs的迁移.另一方面,共存的AgNPs降低了MPs颗粒的表面负电荷使其稳定性减弱,并通过预沉积在固相介质上提供额外的MPs沉积位点,从而抑制MPs的迁移.     

An extension of the fuzzy improved risk graph and fuzzy analytical hierarchy process for determination of chemical complex safety integrity levels

The risk graph (RG) is widely used to evaluate the safety integrity level (SIL) of safety instrument systems (SIS). However, subjective opinion-based conventional RGs cannot provide successful results for the problems of risk parameters, such as shortages or lack of data; hence, the output of a conventional approach lacks sufficient reliability. We introduced the fuzzy improved risk graph (FIRG), an extension of fuzzy set theory, to deal with possible ambiguities during SIL study and increase the reliability of conventional RGs. In the present study, the levels of consequences defined as linguistic terms were converted into qualitative intervals; therefore, by correlating the proposed approach with experts’ opinions and attributing weight factors, a desired SIL value was obtained. The output of this new approach can be compared directly with quantitative risk assessment techniques to improve the safety performance of industrial systems.     

基于多因素耦合的航空运输系统脆弱性分析*

为分析航空运输系统脆弱性，提升航空运输系统安全水平。基于脆弱性理论，针对航空运输系统运行特点，提出航空运输系统脆弱性概念，并归纳分析航空运输系统安全影响因素；采用触发器原理建立基于航空运输系统脆弱性影响因素耦合的事故形成机理模型，选取1973—2019年的120起全球重大航空事故为数据基础，构建可量化航空运输系统脆弱性影响因素耦合关系的N-K模型。结果表明:影响航空运输系统耦合关系的关键因素为管理因素，有针对性地加强航空运输系统安全脆弱性关键耦合因素的管控，能更好地提高航空运输系统安全水平。     

基于AHP-证据理论的综合管廊火灾安全评价

为了进行综合管廊火灾安全评价,提出了基于AHP-证据理论的评价模型。采用AHP法得出综合管廊火灾安全评价体系中各因素的权重,再引入D-S证据理论提高评价的可信度。从"人、机、环、管"四大方面归纳出影响综合管廊火灾安全的潜在影响因素并分级,建立综合管廊火灾安全评价指标体系;通过AHP法得出体系中各因素的权重,再通过信任函数和似然函数的计算得到量化评价结果;最后将多个评价结果进行融合以提高最终评价结果的可信度,并且评判火灾安全等级。对某综合管廊的实例分析表明,当不同专家给出的评价结果有差异时,依据证据理论将不同的证据进行融合,能有效提高综合管廊火灾安全评价的可信度,最终得到可靠的评价结果。通过分析得出设备因素对综合管廊火灾安全评价体系影响最大。     

Assessing the Potential to Restore Historic Grazing Ecosystems with Tortoise Ecological Replacements

The extinction of large herbivores, often keystone species, can dramatically modify plant communities and impose key biotic thresholds that may prevent an ecosystem returning to its previous state and threaten native biodiversity. A potentially innovative, yet controversial, landscape‐based long‐term restoration approach is to replace missing plant‐herbivore interactions with non‐native herbivores. Aldabran giant (Aldabrachelys gigantea) and Madagascan radiated (Astrochelys radiata) tortoises, taxonomically and functionally similar to the extinct Mauritian giant tortoises (Cylindraspis spp.), were introduced to Round Island, Mauritius, in 2007 to control the non‐native plants that were threatening persistence of native species. We monitored the response of the plant community to tortoise grazing for 11 months in enclosures before the tortoises were released and, compared the cost of using tortoises as weeders with the cost of using manual labor. At the end of this period, plant biomass; vegetation height and cover; and adult, seedling, flower, and seed abundance were 3–136 times greater in adjacent control plots than in the tortoise enclosures. After their release, the free‐roaming tortoises grazed on most non‐native plants and significantly reduced vegetation cover, height, and seed production, reflecting findings from the enclosure study. The tortoises generally did not eat native species, although they consumed those native species that increased in abundance following the eradication of mammalian herbivores. Our results suggest that introduced non‐native tortoises are a more cost‐effective approach to control non‐native vegetation than manual weeding. Numerous long‐term outcomes (e.g., change in species composition and soil seed bank) are possible following tortoise releases. Monitoring and adaptive management are needed to ensure that the replacement herbivores promote the recovery of native plants. Estudiando el Potencial para Restaurar Ecosistemas Históricos de Forrajeo con Reemplazos Ecológicos de Tortugas Terrestres