Primary logistics planning of oil products under the imbalance of supply and demand

This paper intends to complete the primary logistics planning of oil products under the imbalance of supply and demand. An integrated mathematical programming model is developed to simultaneously find the balance between supply and demand, and optimize the logistics scheme. The model takes minimum logistics cost and resource adjustment cost as the objective function, and takes supply and demand capacity, transportation capacity, mass balance, and resource adjustment rules as constraints.Three adjustment rules are considered in the model, including resource adjustment within oil suppliers,within oil consumers, and between oil consumers. The model is tested on a large-scale primary logistics of a state-owned petroleum enterprise, involving 37 affiliated refineries, 31 procurement departments,286 market depots and dedicated consumers. After the unified optimization, the supply and demand imbalance is eased by 97% and the total cost is saved by 7%, which proves the effectiveness and applicability of the proposed model.

Farmer's Perception on Supply-Demand Matching of New Variety and Its Influence Factors

Using disordered multinomial logistic regression and multiple linear regression method,385 copies of questionnaires on farmer are analyzed to explore the relationship between peasant's psychological traits,peasant's cognition on seed technology and perception on supplydemand matching of new variety.Research results show that the vast majority of farmers think that current new variety is at high-level supplydemand balance and the oversupply status,and updating speed of new variety on the market is faster;the farmers preferring risk,seeking innovation and having strong learning and cognition ability may select high-level supply-demand matching state,and the farmers understanding the importance and difference of seed technology tend to choose high-level supply-demand matching situation;the farmers with strong learning and cognition ability can acknowledge the importance and difference of seed technology,while the farmers preferring risk can perceive the difference of seed technology;psychology seeking the innovation and learning and cognition ability affect the farmer's perception on supplydemand matching status of new variety via affecting the farmer's cognition on technical difference.

Research on two-part revenue-sharing contract under demand disruption

Assuming that the realized demand is determined by the inventory level,a two-part revenue sharing contract of one supplier and one retailer is analyzed under the circumstance of demand disruption(the disruption cost occurs at the supplier).Based on the centralized optimization,the profits of the two members are maximized in sequential optimization though a two-part revenue-sharing contract.The result shows that when the demand disruption occurs,if the degree of disruption is within some range,the ordering and manufacturing plans need not be changed,while only the revenue sharing fraction for the retailer should be diminished;if not,both the plan and the revenue sharing fraction should be changed for the possible coordination of the supply chain.Finally,numerical illustrations of the contract for various scenarios are given.

Impacts of Climate Change on Water and Agricultural Production in Ten Large River Basins in China

The overall goal of this paper is to examine impacts of climate change on water supply and demand balance and their consequences on agricultural production in ten river basins in China. To realize this goal, China Water Simulation Model （CWSM） is used to analyze three alternative climate scenarios （A1B, A2 and B2）. The results show that the impacts of climate change on water supply and demand balance differ largely among alternative scenarios. While significant impacts of climate change on water balance will occur under the A1B scenario, the impacts of climate change under the A2 and B2 scenarios will be marginal. Under the A1B scenario, the water shortage in the river basins located in the northern China will become more serious, particularly in Liaohe and Haihe river basins, but the other river basins in the southern China will improve their water balance situations. Despite larger impacts of climate change on water balance in the northern China, its impacts on total crops＇ production will be moderate if farmers would be able to reallocate water among crops and adjust irrigated and rainfed land. The paper concludes with some policy implications.

Modeling some long-term implications of CO_2 fertilization for global forests and forest industries

Background： This paper explored the long-term, ceteris-paribus effects of potential CO2 fertilization on the global forest sector. Based on the findings of Norby et al. （PNAS 2005, 102（50）） about forest response to elevated [CO2]. Methods： Forest productivity was increased in the Global Forest Products Model （GFPM） in proportion to the rising [CO2] projected in the IPCC scenario A1B, A2, and 132. Projections of the forest area and forest stock and of the production, consumption, prices, and trade of products ranging from fuelwood to paper and paperboard were obtained with the GFPM for each scenario, with and without CO2 fertilization beginning in 2011 and up to 2065. Results： CO2 fertilization increased wood supply, leading to lower wood prices which in turn induced modest lower prices of end products and higher global consumption. However, production and value added in industries decreased in some regions due to the relative competitive advantages and to the varying regional effects of CO2 fertilization. Conclusion： The main effect of CO2 fertilization was to raise the level of the world forest stock in 2065 by 9 to 10 % for scenarios A2 and B2 and by 20 % for scenario A1B. The rise in forest stock induced by fertilization was in part counteracted by its stimulation of the wood supply which resulted in lower wood prices and increased harvests.

Supply and Demand Levels for Livestock and Poultry Products in the Chinese Mainland and the Potential Demand for Feed Grains

The widening gap between the supply and demand levels for livestock and poultry products in the Chinese mainland poses a significant challenge to the secure supply of feed grains. Therefore, the accurate prediction of the demand potential for feed grains represents a key scientific issue for ensuring food security in the Chinese mainland. This study is based on an analysis of several factors, such as the Chinese mainland’s output, trade volume, apparent consumption of livestock and poultry products, and two different scenarios for predicting the future demand for feed grains are assessed. The results indicate that output and consumption of livestock and poultry products, as well as the country’s trade deficit and the pressure of the supply and demand balance with respect to these products, have been increasing in recent years. The analysis predicts that the demand for feed grains in the Chinese mainland will reach 425.5 or 389.6 million tons in 2030 based on the two scenarios. This finding indicates that with the increasing demand for livestock and poultry products in the Chinese mainland, the demand for feed grains will continue to increase, and the shortfall in feed grains and raw materials will expand further, especially dependence on external sources of protein-rich feed grains will remain high.

Integrated assessment of the supply-demand relationship of ecosystem services in the Loess Plateau during 1992-2015

Landscape alterations and ecosystem services(ES)are crucial elements that affect the socioecological development of ecologically fragile regions.To provide scientific support for the land-use planning and regional ecological restoration to achieve sustainable development goals(SDGs)in the Loess Plateau from 1992 to 2015,this study proposes an integrated assessment framework for assessing the supply-demand match and equilibrium of ES combining potential relationships between landscape alterations,ES,and sustainable development at the county and regional scales.Results show that more than 85%of local counties have a supply-demand mismatch in terms of ecosystem services.Supply-demand distributions for provisioning and supporting services were relatively balanced compared to cultural services,which were imbalanced.Although the overall supply-demand relationship is relatively balanced because of the significant influence of ecological restoration,it shows an increasing trend toward imbalance as human-land conflict is prominent in some regions.SDGs emphasize on specific ES information such as ecosystem conservation,sustainable agriculture,and urban construction.Furtherly,positive impacts from landscape dynamics can improve the supply capacity of the ES and contribute to regional sustainability.

Analog simulation of urban construction land supply and demand in Chang-Zhu-Tan Urban Agglomeration based on land intensive use

Urban land intensive use is an important indicator in harmonizing the relationship between land supply and demand. The system dynamics(SD) can be used to construct the feedback loop between urban construction land supply and demand and index variable function. Based on this, this study built a supply and demand system dynamic model of urban construction land for Chang-Zhu-Tan urban agglomeration. This model can simulate the change trends of supply and demand of construction land, industrial land, and residential land in 2016–2030 by three scenarios of low, medium, and high intensity modes. The results showed that the scale of construction land of urban agglomeration is expanding, with a rapid increase rate for the urban construction land. The scale and speed of land use based on the three intensity modes existed differences. The large scale and supply of construction land in the low intensity mode caused easily the waste of land resources. In high intensity mode, the scale and supply of construction land were reduced against the healthy development of new-type urbanization. In the medium intensity mode, the scale and supply of land use adapted to the socio-economic development and at the same time reflected the concept of modern urban development. In addition, the results of this study found that the proportion of industrial land in construction land ranged from 15% to 21%, which increased year by year in the low intensity mode, and decreased slowly and stabilized in medium and high intensity modes. The proportion of residential land in construction land ranged from 27% to 35%, which decreased in the low and the medium intensity modes, and maintained a high level in the higher intensity mode. This study contributes to provide scientific reference for decision-making optimization of land supply and demand, urban planning, and land supply-side reform.

Optimization research on supply and demand system for water resources in the Chang-Zhu-Tan urban agglomeration

Using system analysis theory and methods, a dynamic model of a water resource supply and demand system was built to simulate trends in the supply and demand of water in the Changsha-Zhuzhou-Xiangtan （Chang-Zhu-Tan） urban agglomeration for the period 2012 to 2030. Four scenarios were examined; namely, a traditional development model, an economic development model, a water-saving model, and a coordinated development model. （i） The problem of balancing water resource supply and demand is becoming increasingly conspicuous with a growing population and a rapidly developing economy. （ii） By 2030, water demand is set to reach a total of 105.1 × 10^8 m^3, with a water supply of 5.4 × 10^8 m^3. A coordinated development model for water resource supply could meet the growing demands of socio-economic development, and generate huge comprehensive benefits. This will be the best solution for the development and utilization of a water resource supply and demand system in the Chang-Zhu-Tan urban agglomeration. （iii） We should accelerate the construction of water conservation projects, strengthen the management of water conservation, optimize economic structures, enhance our awareness of the importance of protecting water resources, hasten the recycling of waste water and environmental improvement, and promote utilization efficiency, and support the capabilities of water resources to meet our expectations.

我国重要农产品供需变化趋势与供给保障能力提升策略

基于对我国重要农产品生产、消费和进口历史变化情况的分析,以及对2035年前变化趋势的预测,认为我国重要农产品供给保障面临国内增产边际效应递减和利用国际市场风险增大的双重挑战,应从统筹国内和国际两个大局、发展和安全两件大事出发,谋划好现代化新征程重要农产品供给保障思路。一方面,应从供需两侧入手扩产能、控消费,构建农业综合生产能力内在增长机制,针对农民务农种粮和地方重农抓粮逻辑采取差异化扶持政策,推进节粮减损、倡导节约消费;另一方面,应实施农产品进口多元化战略,提高海外供应链稳定性可靠性;此外,还应推动建立统一、联动的全国农产品大市场,完善农产品储备调节制度。

全社会物流成本的影响因素及下降空间测算

为了给有效降低全社会物流成本提供理论支持,支撑政府精准施策,首先,在深入剖析物流成本核算方法和衡量指标的基础上,系统分析了产业结构、产品价值、供需分布、流通速率、运输效能等因素的影响作用和影响趋势。然后,针对社会物流总费用与国内生产总值(GDP)的比率这一衡量指标,基于关联产业占比、工业增加值率、平均运距、存货周转天数、公路货物周转量占比5个关键参数建立了回归预测模型,对2024—2030年各影响因素贡献度开展预测分析。结果显示:2030年物流总费用与GDP的比率将降至12.36%;2024—2030年,关联产业占比贡献度将从20.9%波动降低至-0.48%;工业增加值率贡献度将从47.91%持续上升至78.39%;存货周转天数贡献度将从9.86%小幅上升至11.17%左右;平均运距贡献度将从33.49%持续下降至7.59%;公路货物周转量占比贡献度将从-12.15%稳定上升至3.33%。最后,基于测算成果,针对交通物流领域的降本工作提出推动交通物流融入现代化产业体系、推进新质生产力赋能、优化交通基础设施及重大生产力布局、引领构建现代流通体系、优化调整运输结构和促进多式联运发展等建议,为我国交通物流业的持续健康发展提供支撑。

基于土地利用变化的长江中游地区生态系统服务供需平衡研究

[目的]揭示生态系统服务供需平衡的时空特征,并进一步探究土地利用变化对生态系统服务供需平衡的双重效应及其影响机理。[方法]选取长江中游地区作为研究对象,引入生态系统服务供需量化矩阵分析生态系统供需平衡的时空格局,并运用土地利用变化生态贡献率模型分析土地利用变化对生态系统服务供需平衡的双重影响。[结果](1)研究期间,长江中游地区生态系统服务供需平衡状况持续恶化,主要是由建设用地大规模扩张和耕地、林地大面积缩减带来的生态系统服务供给能力减少和消费需求增加造成的。(2)长江中游地区不同类型生态系统服务供给间的关系在时间尺度上由权衡转为协同,需求和供给平衡间的协同关系在时间尺度上进一步增强,但不同类型生态系统服务供给、需求和供需平衡间的权衡或协同性质及其程度在空间尺度上却存在高度异质。(3)长江中游地区土地利用变化对生态系统服务供需平衡存在改善和恶化双重效应,且恶化效应显著大于改善效应,但引起生态系统服务及其分项服务供需改善和恶化的土地利用变化类型具有时序异质性。[结论]应促进具有协同改善生态系统服务供需平衡的土地利用变化类型,提升与区域主体生态系统服务功能一致的土地利用类型,以及遏制具有协同恶化生态系统服务供需平衡的土地利用变化类型,以实现区域生态系统服务供需改善。

新疆农产品物流价格波动的影响研究

目前,有关农产品价格的研究文献有很多,发现关于农产品物流价格波动造成农户收入波动问题的研究已经在行业内处于发展阶段,研究的理论主要有农产品物流价格波动的短周期的周期性、季节性、随机性、异常性,货币关系的超调性、工业化演进的阶段性等对农产品物流价格波动产生显著影响,结果偏向于农产品物流价格波动对运输成本、物流配送中心网点设定、运输体系构建、配送价格和物流效率对农民种植作物的积极性影响呈显著正相关,为今后农民规避风险、减少农产品和生鲜冷链物流运输成本提供建议。

基于供需匹配的应用型物流管理人才培养研究

目前,物流业正向数字化、全球化、多元化及服务一体化转型升级,如何满足新发展形势对人才的要求,是应用型物流管理人才培养面临的挑战。从“需求—供给”视角,以武汉轻工大学为调研对象,通过剖析高校应用型物流管理人才培养现状以及用人单位的人才需求,深入探讨应用型物流管理人才培养存在的问题并提出相应建议。

2022年夏季川渝高温干旱事件对电力供需影响分析

在气候变化背景下,极端天气气候事件的多发对电力系统的影响加剧。利用川渝地区1961—2022年的气温、降水和气象干旱指数,2022年7—9月泸定、立洲和瓦屋山水电站的日入库流量和发电量,及2022年6—9月成都市和四川省的日用电量和日高峰负荷等数据,分析2022年盛夏川渝地区高温干旱事件及其对水电和电力需求的影响。结果表明,1961—2022年川渝地区气温及高温日数显著增加,高温干旱灾害风险增大。2022年盛夏(7—8月),川渝地区气温偏高幅度、降水偏少程度、高温日数、最大干旱影响范围均为1961年以来之最。降雨量和入库流量是影响水电的重要因素,水电出力对入库流量的响应呈非线性;夏季气温与用电量具有显著的正相关,日用电量和高峰负荷对日平均气温的敏感性最高。

基于联网收费数据的湖南省高速公路物流通道供需适应性研究

公路运输是现代物流体系中的重要组成部分,高速公路是公路运输中最重要的载体,研究高速公路货运特征,分析物流通道供给和物流需求之间的适应性,有利于推进物流行业持续向好发展,推动交通运输与现代物流深度融合。基于高速公路联网收费数据,可有效识别高速公路物流通道,并通过流量饱和度指标来评估物流通道的供需适应性。首先将高速公路货车联网收费数据基于路径识别点处打断,降低货车运行轨迹还原的计算复杂度;其次利用广度优先搜索算法、朴素贝叶斯分类理论精准还原货车运行轨迹,然后根据货车运行轨迹,计算高速公路路段货运车流量、货运量、饱和度,从物流的角度分析研究交通设施供给的适应性。以湖南省为研究对象的实例表明,湖南省高速公路物流主通道成“三纵三横”的格局分布,京港澳高速公路等路段拥堵日益严重,许广高速公路与长沙绕城高速、江干高速与浏洪高速等衔接仍有不畅。基于联网收费数据的研究方法,可以高效精准地分析与物流强相关的高速公路供需适应性情况,为物流通道规划及交通基础设施布局的理论研究和实践应用提供参考借鉴。

COORDINATING PRODUCTION AND RECYCLING DECISIONS WITH STOCHASTIC DEMAND AND RETUR

In this paper, the joint production and recycling problem is investigated for a hybrid manufacturing and remanufacturing system where brand-new products are produced in the manufacturing plant and recycled products are remanufactured into as-new products in the remanufacturing facility. Both the brand-new products and remanufactured products are used to satisfy customer demands. Returns of used products that are recycled from customers are assumed to be stochastic and nonlinearly price-dependent. A mathematical model is proposed to maximize the overall profit of the system through simultaneously optimizing the production and recycling decisions, subject to two capacity constraints ？ the manufacturing capacity and the remanufacturing capacity. Based on Lagrangian relaxation method, subgradient algorithm and heuristic algorithm, a solution approach is developed to solve the problem. A representative example is presented to illustrate the system, and managerial analysis indicates that the uncertainties in demand and return have much influence on the production and recycling policy. In addition, twenty randomly produced examples are solved, and computational results show that the solution approach can obtain very good solutions for all examples in reasonable time.

物流业智慧化发展对经济韧性的影响:效应及机制

科学评估物流业智慧化发展对经济韧性的影响具有重要现实意义。基于2006—2021年我国286个城市的面板数据,构建物流业智慧化与经济韧性指标,探究物流业智慧化对经济韧性的影响及作用机制。结果表明,物流业智慧化显著提升了经济韧性,且这一结论具有较强的稳健性。机制检验发现,物流业智慧化主要通过降低外部扰动风险、实现供需两端协调及激发经济活跃程度增强了经济韧性。拓展分析表明,物流业智慧化有助于促进市场一体化发展和市场潜力的释放,且在市场分割程度高的地区和低市场化地区,物流业智慧化对经济韧性的促进作用更强。物流业智慧化对经济韧性的促进作用还存在网络效应,物流网络越完善,物流业智慧化促进经济韧性的效应越强。因而应推动新一代信息技术与物流技术的深度融合,加强数字基础和交通基础设施建设,优化运输结构,完善地区间的物流体系,以更好地畅通国民经济循环、增强经济韧性。

考虑低碳政策和不确定需求的物流网络鲁棒优化

为应对全球气候变暖,将政府调控政策融入供应链网络设计是物流业低碳转型面临的一项挑战。为此,本文研究考虑低碳政策和不确定需求的物流网络设计问题。首先,运用分布式模糊集刻画产品需求的不确定性,并构建供应链物流网络的两阶段鲁棒优化模型。该模型在经典的三级网络规划基础上,综合考虑分销中心建设成本、运输成本、产品短缺成本以及碳排放交易的负效用以实现总成本最小化。其次,针对提出模型的两阶段特点,对其进行拆分为主问题和子问题并定制迭代分解算法。最后,结合案例验证所提出的模型及分解算法的有效性。数值结果表明:提出的分布式鲁棒优化方法在提高决策方案鲁棒性的同时可有效减少其所需投资;低碳政策虽然会促进物流企业调整运输结构、降低碳排放总量,但仍然会增加企业的总成本,建议政府部门可适当考虑补贴。

基于粮食安全视角的喀什地区耕地“非粮化”影响因素及监管对策研究

[目的]基于粮食安全的视角,分析喀什地区的耕地“非粮化”特征、耕地供需盈亏情况以及耕地“非粮化”的影响因素,并提出耕地“非粮化”的监管对策建议。[方法]基于实地调查及统计数据,分析喀什地区1995—2020年耕地“非粮化”时空演变特征,运用粮食供需平衡法分析喀什地区的耕地供需盈亏情况以及耕地“非粮化”的安全区间,构建耕地“非粮化”影响因素指标体系,使用二元Logistic回归模型分析各影响因素对耕地“非粮化”的影响程度。[结果](1)1995—2020年,喀什地区的耕地“非粮化”率及“非粮化”面积的时空演变趋势基本一致,在1995—2014年呈波动中上升的趋势,2014年后呈波动中下降的趋势,空间演变特征呈现东北高,西南西北低的分布格局。(2)在研究期内,只有喀什市长期处于耕地供给赤字状态,塔县于2010年处于耕地供给赤字状态,其余县市均处于耕地供给盈余状态;喀什市的耕地“非粮化”率已严重超过安全区间,喀什地区的其余区域均处于安全区间范围内。(3)家庭农业劳动力、农户兼业化程度、农资价格变化、种粮补贴政策效果对耕地“非粮化”的影响显著,其余影响因素对耕地“非粮化”的影响不显著。[结论]喀什地区耕地“非粮化”水平较高,耕地供给不平衡,应完善区域耕地保护政策,制定差别化的管理策略,遏制耕地“非粮化”现象继续蔓延,实现粮食安全与耕地安全的可持续发展目标。