基于多阶段模糊规模效应量化的TMC模式下供应链调度优化研究

旅游大规模定制(Tourism Mass Customization, TMC)模式实施的关键是通过对旅游供应链的调度优化处理旅游活动的“规模效应”与游客“个性化需求”之间的矛盾问题。运用经济学及模糊数学的理论方法分析并实现了TMC模式下存在的多阶段模糊规模效应量化处理。构建了引入规模效应量化的服务成本最小化、引入模糊时间窗的顾客满意度最大化及供应链协同度最大化为优化目标的TMC模式下多目标供应链调度优化模型。最后,通过蚁群算法实现TMC模式下多调度优化目标的求解并对优化效果进行对比研究。研究结果表明,TMC模式下供应链调度中旅游活动存在多阶段模糊规模效应并且可以量化处理;TMC模式中的规模效应具有合理的区间范围,旅游企业应注重规模效应与其他目标的均衡;蚂蚁算法在求解TMC模式下多目标优化问题方面不仅收敛速度快,而且通过对多调度目标优化效果的对比检验表明,性能稳健优良。

我国生态用地的研究进展与展望

从分析生态环境安全和生态用地保护的重要性入手,在生态用地的界定与分类、规模量化与空间布局、生态服务价值估算与生态补偿机制等方面分析了我国生态用地的研究进展,总结了相关研究的成果和存在的不足,并探讨了进一步开展我国生态用地研究的思路和方向。今后应重点加强5个方面的研究:1定性与定量结合的生态用地界定和分类方法;2"生态最优"和"最少保护"合力下的生态用地规模量化;3刚性与弹性框架下的生态用地分类保护制度;4基于栅格数据格式的生态服务价值估算和生态补偿机制;5不同尺度下生态用地的空间规划与地图综合。

关于我国发行地方公债问题探讨

1.谨慎选择债务主体进行试点。我国地方政府包括省(自治区、直辖市)、市、县、乡(镇)。现阶段,确定发行公债的主体,应考虑以下几个因素:(1)公债是必须偿还的,它不同于转移支出。发债主体,必须具备偿债能力。所以,要综合考虑一个地区的国民生产总值、财政收入水平、经济发展速度及公债项目的具体情况等因素。(2)我国的具体国情。在财政管理体制上“一统就死、一放就乱”的局面,并没有彻底解决。综合以上两个因素,我国确定地方公债发行主体的范围不宜过宽。

Quantitative Simulation of Dynamic Changes in Cultivated Land in Areas of Reclamation and Returning Cultivated Land to Forest or Pastures under RCPs Climate Scenarios

Northeast China as one of important agricultural production bases is an area under reclamation and returning cultivated land to forests or pastures. Therefore, it is of great practical significance in guaranteeing the sustainable development and national food security to study the spatial and temporal variation of cultivated land in Northeast China under future climate scenarios. In this study, based on data of land use, natural environment and social-economy, dynamics of land system（DLS） model was used to to simulate the spatial distribution and changing trends of cultivated land in the typical areas of reclamation and returning cultivated land to forest or pastures in Northeast China during 2010-2030 under land use planning scenario and representative concentration pathways（RCPs） scenarios quantitatively.The results showed that the area of cultivated land had an overall decreasing trend under the land use planning scenario, but the area of upland field increased slightly from 2000 to 2010 and then declined greatly, while the area of paddy field continuously declined from 2000 to 2030. Under the Asia-Pacific Integrated model（AIM）scenario, the total area of cultivated land had a tendency to increase considerably,with the upland field expanding more obviously and the paddy field declining slightly.In addition, the cultivated land showed a greater decreasing trend under the model for energy supply strategy alternatives and their general environmental impact（MESSAGE） scenario compared to the land use planning scenario. Moreover, analysis on the conversion between different land use types indicated that the reclamation and returning cultivated land to forests or pastures was likely to continue under future scenarios, but the frequency of occurrence could decrease as the time goes by. The conclusions can provide significant decision-making information for the rational agricultural planning and cultivated land protection in Northeast China to adapt to the climate change.

Treatment of flotation wastewater using biological activated carbon

A laboratory scale up-flow biological activated carbon(BAC) reactor was constructed for the advanced treatment of synthetic flotation wastewater. Biodegradation of a common collector(i.e., ethyl xanthate) for non-ferrous metallic ore flotation was evaluated. The results show that the two stages of domestication can improve microbial degradation ability. The BAC reactor obtains a chemical oxygen demand(COD) reduction rate of 82.5% for ethyl xanthate and its effluent COD concentration lowers to below 20 mg/L. The kinetics equation of the BAC reactor proves that the activated carbon layers at the height of 0 mm to 70 mm play a key role in the removal of flotation reagents. Ultraviolet spectral analysis indicates that most of the ethyl xanthate are degraded by microorganisms after advanced treatment by the BAC reactor.

Development and Application of CDOS Series Catalysts for Bottoms Cracking

Development of CDOS catalyst for bottoms cracking is based on DOSY zeolite,which is characterized by high metal tolerance.The results of DOSY tests have shown that the catalyst has better activity retention at high metal content in the feed.The performance of catalyst tested in the bench scale was superior over that of the reference catalyst.The results of catalyst application have shown that the CDOS series catalysts have better bottoms cracking activity,high metal tolerance,excellent dry gas selectivity,and enhanced liquid yield.

量化数据库与历史研究

历史学在今日仍被视为传统学科之一,但非历史学者借助大规模历史量化数据库进行自然和社会科学研究并取得重要成果的现象却有不断增长之势。不同于传统计量史学和以经济学为代表的社会科学学科所注重的"解释型学术",量化数据库推动的是"求是型学术",即通过统计分析从大规模系统数据中挖掘新事实、产生新认识。中国历史中长期存在规模宏大的户籍登记、土地分配和科考记录等系统材料以及海量文字记录,很多已得到收集和整理,有利于构建大规模数据库并开展定量研究。这种新的研究范式不仅有助于历史学科自身发展,更能够促进跨学科、跨国界的学术交流与融合,并为全面深入认识中国社会历史特征、平衡东西方学术发展作出贡献。

Greywater Reuse Assessments on Different Soil Types in Baghdad City

he effects of greywater irrigation on four commonly used agricultural soils and models were studied. Sand, sandy loam, sandy clay and light clay soils were selected as common Iraq soils. Soil＇s chemical and physical properties under different irrigation regimes were daily measured during period extended from February 2011 to April 2012 in Baghdad city and plant growth was monitored. A lab scale models of four acrylic columns of 100 mm diameter and 750 mm height were designed and constructed in environmental hydraulic lab at Mustansiriya University and tests were run concurrently with the characterization study to assess the effect of soil depth and loading rate on treatment efficiency. Soil samples were carried out in a site that had been drained with greywater for over 14 months. Measurements of greywater and treated greywater had been achieved which contains BODs, COD, pH, EC, TDS, turbidity, CI＋1, 504＋2, NO3＋1, Na＋l, Ca＋2, Mg＋2, E coli and coliform.