中国“碳中和”目标的实现路径与模式选择

围绕中国碳中和目标的实现路径与模式选择问题，提出了一个中国应对气候变化整体治理模式，即多阶段混合主导型碳中和实现模式。这一模式是以国家为核心，在一定时期和内外环境约束下，通过减排和增汇路径，对中国境内由人类活动造成的CO2排放与人为CO2吸收量之间关系进行调整和平衡的过程；其内部由宏观、中观和微观三层结构组成，每层结构各不相同。多阶段混合主导型碳中和实现模式的提出，拓展和完善了气候变化整体治理理论，为气候变化治理提供了机制借鉴。     

Product partition latent variable model for multiple change-point detection in multivariate data

The product partition model (PPM) is a well-established efficient statistical method for detecting multiple change points in time-evolving univariate data. In this article, we refine the PPM for the purpose of detecting multiple change points in correlated multivariate time-evolving data. Our model detects distributional changes in both the mean and covariance structures of multivariate Gaussian data by exploiting a smaller dimensional representation of correlated multiple time series. The utility of the proposed method is demonstrated through experiments on simulated and real datasets.     

政府减排目标、产业结构与污染减排

政府是污染减排的重要主体,了解其行为对污染减排的作用对提升污染减排效果及实现中国绿色发展具有重要意义。创造性地将政府减排目标纳入研究框架,构建面板门槛模型,从工业污染排放总量的角度分析政府减排目标、产业结构、经济规模等因素对地方污染减排的影响,并用工业污染物强度进行稳健性检验。结果显示,政府减排目标对污染减排的作用存在阶段性不同:经济发展初级阶段,政府减排目标对污染排放总量的作用方向为正; 经济发展水平较高时,作用方向为负; 两者之间存在适应性调整阶段,作用方向具有不确定性,但总体由正向作用向负向作用转变。产业结构对工业污染排放总量的作用方向因污染物种类而异,经济规模对工业污染排放总量作用方向为正。     

焦炉煤气还原硫酸钠制硫化钠的研究

在固定床反应器内600～700℃的温度范围研究了焦炉煤气还原硫酸钠制硫化钠的反应速率和影响因素，在固定床内随着温度的提高，反应速率增大，并能达到较高的转化率．温度低于680℃，表现为催化反应，Fe2O3是活性较高的催化剂；在700℃以上表现为非催化反应。焦炉煤气中氢气的浓度和硫酸钠的颗粒直径对反应有一定的影响．在反应器内只要控制合适条件，往硫酸钠中加入脂肪酸的钠盐可以避免烧结，并能获得更高的反应速率。     

Uncertainty Analysis for Computer Model Projections of Hurricane Losses

Projecting losses associated with hurricanes is a complex and difficult undertaking that is wrought with uncertainties. Hurricane Charley, which struck southwest Florida on August 13, 2004, illustrates the uncertainty of forecasting damages from these storms. Due to shifts in the track and the rapid intensification of the storm, real-time estimates grew from 2 to 3 billion dollars in losses late on August 12 to a peak of 50 billion dollars for a brief time as the storm appeared to be headed for the Tampa Bay area. The storm hit the resort areas of Charlotte Harbor near Punta Gorda and then went on to Orlando in the central part of the state, with early poststorm estimates converging on a damage estimate in the 28 to 31 billion dollars range. Comparable damage to central Florida had not been seen since Hurricane Donna in 1960. The Florida Commission on Hurricane Loss Projection Methodology (FCHLPM) has recognized the role of computer models in projecting losses from hurricanes. The FCHLPM established a professional team to perform onsite (confidential) audits of computer models developed by several different companies in the United States that seek to have their models approved for use in insurance rate filings in Florida. The team's members represent the fields of actuarial science, computer science, meteorology, statistics, and wind and structural engineering. An important part of the auditing process requires uncertainty and sensitivity analyses to be performed with the applicant's proprietary model. To influence future such analyses, an uncertainty and sensitivity analysis has been completed for loss projections arising from use of a Holland B parameter hurricane wind field model. Uncertainty analysis quantifies the expected percentage reduction in the uncertainty of wind speed and loss that is attributable to each of the input variables.     

Will Swedish and Dutch drug policy converge? The role of theory

Sweden and The Netherlands are often referred to as the archetypes of prohibition and harm reduction, respectively. Both nations have, however, recently adopted political measures that fit well in the other country's model. But they have also taken steps that reflect traditional thinking. Are we witnessing the initial stages of convergence or are recent developments better interpreted as adjustments? This article addresses these questions by comparing Swedish and Dutch theoretical understandings of ‘the drug problem’. Goals and practices are illuminated in the context of underlying theory, raising the question: Can substantial convergence be achieved without significant prior changes in theoretical perceptions? It is found that the theoretical understandings of the two paradigms do not mix easily, complicating attempts at convergence. Moreover, both countries have invested a great deal of political prestige in their respective models, further exacerbating the problem. A conceivable way to circumvent these difficulties is suggested.     

Rainfall interception by Santa Monica's municipal urban forest

Effects of urban forests on rainfall interception and runoff reduction have been conceptualized, but not well quantified. In this study rainfall interception by street and park trees in Santa Monica, California is simulated. A mass and energy balance rainfall interception model is used to simulate rainfall interception processes (e.g., gross precipitation, free throughfall, canopy drip, stemflow, and evaporation). Annual rainfall interception by the 29,299 street and park trees was 193,168 m³ (6.6 m³/tree), or 1.6% of total precipitation. The annual value of avoided stormwater treatment and flood control costs associated with reduced runoff was $110,890 ($3.60/tree). Interception rate varied with tree species and sizes. Rainfall interception ranged from 15.3% (0.8 m³/tree) for a small Jacaranda mimosifolia (3.5 cm diameter at breast height) to 66.5% (20.8 m³/tree) for a mature Tristania conferta (38.1 cm). In a 25-year storm, interception by all street and park trees was 12,139.5 m³ (0.4%), each tree yielding $0.60 (0.4 m³/tree) in avoided flood control costs. Rainfall interception varied seasonally, averaging 14.8% during a 21.7 mm winter storm and 79.5% during a 20.3 mm summer storm for a large, deciduous Platanus acerifolia tree. Effects of differences in temporal precipitation patterns, tree population traits, and pruning practices on interception in Santa Monica, Modesto, and Sacramento, California are described.     

不同权力结构下碳税对供应链减排水平的影响

随着我国生态文明建设的不断推进,促进供应链协同减排成为生产和消费领域落实绿色发展理念的重要举措。在绿色供应链的管理实践中,不同类型的供应链核心企业在进行减排决策时会有不同的侧重点,因此供应链权力的结构成为影响供应链减排水平的关键因素。本文在一个由两个制造商和一个零售商组成的两级供应链中研究了不同权力结构下的供应链最优减排和定价决策问题,分别给出了零售商主导和制造商主导的Stackelberg-Nash博弈均衡解,并分析了产品的单位生产成本、单位批发价格、碳税税率等参数对供应链最优决策的影响。本文的研究结果表明：（1）在两种供应链权力结构下,当产品的单位批发价格固定时,降低产品的生产成本都可以促使制造商提高减排水平;但是当产品的单位生产成本固定时,提高产品的批发价格却不一定总是能够激励制造商提高减排水平;（2）在两种供应链权力结构下,对于低排放行业的制造商来说,提高碳税税率可以增加产品的减排水平,但是对于高排放行业的制造商来说,提高碳税税率反而会降低产品的减排水平;（3）一般来说,零售商占主导地位的供应链中产品减排水平和供应链总利润相对较高,供应链碳排放总量相对较低。最后,与供应链集中决策模式相比,随着产品批发价格的增加,两种分散决策模式下的供应链双重边际效应逐渐增强。数值实验结果显示：在碳税税率的一定取值范围内,这种双重边际效应会使得两种分散决策模式下的产品最优减排水平和供应链碳排放总量均优于集中决策模式。本文的研究可为碳税政策下供应链的协同减排提供有益的管理启示。     

考虑双重异质性的碳配额分配及交易机制研究

构建包含政府-企业-消费者三方的碳配额分配及交易减排供应链,其中消费者基于自身低碳偏好进行产品选购,政府基于行业社会福利最优进行企业配额分配和碳指导价设定,企业基于利润最优进行生产和销售。通过建立混合博弈模型,对比分析了考虑企业和消费者双重异质性的配额分配及交易机制对政府、企业最优决策行为的影响。研究结果表明：该减排机制能在保持社会福利最优的基础上更好地提升消费者和企业的参与积极性,实现对异质企业的双向和持续性减排激励。消费者低碳偏好和单位碳排差异度是影响减排机制实施方案和实施绩效的关键因素,其中,消费者低碳偏好决定了行业最优碳价和配额分配规则,且在主动和被动两个层面影响企业决策和产品价格;单位碳排差异度是影响企业利润、消费者主动支付倾向和减排绩效的重要因素,严格的差异度划分有利于形成正向激励;差异化的配额率易于形成减排激励,其与自主配额率间的差异是造成碳价波动的原因之一;研究也表明,过低的单位碳排差异度不适合进行企业异质性划分,在减排机制设计中应弱化“碳收益激励”目的。     

不同减排合同下企业间纵向持股对供应链决策的影响

本文针对节能服务公司融资难、回款难及其与用户之间缺乏信任等现象,结合实际中节能服务公司与制造企业采取的不同减排合同机制,分别构建了减排效益分享型合同和减排量保证型合同下企业间纵向持股的三级低碳供应链模型,并对比分析了不同减排合同下持股策略对供应链企业决策及利润的影响。通过模型分析并结合案例及数值算例发现,在减排效益分享型合同中,当制造商单独持股节能服务公司时,增加持股比例会使产品减排量和链条上其他成员利润增加,同时低碳产品市场价格增加;当零售商和制造商同时持股节能服务公司时,两公司增加持股比例同样会使企业决策和利润得到优化,实现真正意义上的供应链企业大联盟,但该种情形会加大持股比例与企业决策和利润的协调难度。此外,在减排效益分享型合同下,制造商对节能服务公司持股可使环保红利和企业效益均得到增加,建议此种减排模式下的供应链企业实施持股策略;但对于减排量保证型合同,持股策略对各企业决策及利润并无明显改善,因此该种减排合同下不建议企业间采取股权合作策略。