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京津冀城市群虚拟水流动格局变化对区域水资源压力的影响

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水利水电技术（中英文） 2024年第6期55卷 148-158页

作者：任江楠吕小瑜李伟峰陈利顶韩立建云南大学生态与环境学院云南昆明650031 中国科学院生态环境研究中心城市与区域生态国家重点实验室北京100085 中国科学院大学北京100049

【目的】合理的虚拟水调动是缓解水压力的重要途径,尤其在人口聚集的城市群地区,用水需求激增导致区域缺水问题严重。城市群内部不同地区间的紧密关联有助于促进虚拟水贸易,对优化城市群水资源配置、缓解水资源压力具有重要意义。【方... 详细信息

【目的】合理的虚拟水调动是缓解水压力的重要途径,尤其在人口聚集的城市群地区,用水需求激增导致区域缺水问题严重。城市群内部不同地区间的紧密关联有助于促进虚拟水贸易,对优化城市群水资源配置、缓解水资源压力具有重要意义。【方法】采用多区域投入产出法,解析极端缺水的京津冀城市群内外间及其内部的虚拟水流动格局与变化,并揭示其对缓解区域水压力的作用。【结果】结果表明:(1)2012—2017年京津冀城市群与外部地区的虚拟水贸易量先增加后减少,而城市群内部虚拟水自给量却先减少后增加,2015年后京津冀内部虚拟水贸易增强;(2)京津冀城市群内部虚拟水流动格局呈现明显的时空异质性,虚拟水主要由经济相对欠发达的周边城市流入经济相对发达的中心城市(北京市、天津市、石家庄市和廊坊市),且随时间的推移,流动强度和向中心城市的集中程度均不断加强;(3)虚拟水流动明显缓解了京津冀中心城市的水资源压力,其实际水压力指数比虚拟水流动后的假定水压力指数年均下降12.12%,且下降程度逐年增加,但却加重了周边城市的水资源压力。【结论】京津冀城市群虚拟水流动有效缓解了中心城市的缺水压力,但不同城市的产业结构调整、虚拟水流动格局优化仍有很大提升空间。

关键词：多区域投入产出法城市群不同城市虚拟水流动水压力指数水资源承载力

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Incorporation of intra-city human mobility into urban growth simulation:A case study in Beijing

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Journal of Geographical Sciences 2022年第5期32卷 892-912页

作者： WANG Siying FEI Teng li weifeng ZHANG Anqi GUO Huagui DU Yunyan School of Resource and Environmental Science Wuhan UniversityWuhan430079China Department of Urban Planning and Design The University of Hong KongHong KongChina Guangdong-Hong Kong-Macao Joint Laboratory for Smart Cities Hong KongChina Institute of Geographic Sciences and Natural Resources Research CASBeijing100101China School of Architecture and Urban-rural Planning Fuzhou UniversityFuzhou350108China

The effective modeling of urban growth is crucial for urban planning and analyzing the causes of land-use *** urbanization has slowed down in most megacities,improved urban growth modeling with minor changes has become a crucial open issue for these *** existing models are based on stationary factors and spatial proximity,which are unlikely to depict spatial connectivity between *** research attempts to leverage the power of real-world human mobility and consider intra-city spatial interaction as an imperative driver in the context of urban growth ***,the gravity model,which considers both the scale and distance effects of geographical locations within cities,is employed to characterize the connection between land areas using individual trajectory data from a macro *** then becomes possible to integrate human mobility factors into a neural-network-based cellular automata(ANN-CA)for urban growth modeling in Beijing from 2013 to *** results indicate that the proposed model outperforms traditional models in terms of the overall accuracy with a 0.60%improvement in Cohen’s Kappa coefficient and a 0.41%improvement in the figure of *** addition,the improvements are even more significant in districts with strong relationships with the central area of *** example,we find that the Kappa coefficients in three districts(Chaoyang,Daxing,and Shunyi)are considerably higher by more than 2.00%,suggesting the possible existence of a positive link between intense human interaction and urban *** paper provides valuable insights into how fine-grained human mobility data can be integrated into urban growth simulation,helping us to better understand the human-land relationship.

关键词： cellular automata urban growth simulation human mobility massive trajectories

Beyond city expansion:multi-scale environmental impacts of urban megaregion formation in China

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National Science Review 2022年第1期9卷 79-91页

作者： Weiqi Zhou Wenjuan Yu Yuguo Qian lijian Han Steward T.A.Pickett Jing Wang weifeng li Zhiyun Ouyang State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences College of Resources and Environment University of Chinese Academy of Sciences Cary Institute of Ecosystem Studies Beijing Urban Ecosystem Research Station Research Center for Eco-Environmental Sciences Chinese Academy of Sciences

Environmental degradation caused by rapid urbanization is a pressing global ***,little is known about how urban changes operate and affect environments across multiple *** on China,we found urbanization was indeed massive from 2000 to 2015,but it was also very uneven,exhibiting high internal city *** areas in China as a whole became less green,warmer,and had exacerbated PM2.5 ***,environmental impacts differed in newly developed versus older areas of *** impacts were prominent in newly urbanized areas,while old urban areas generally showed improved environmental *** addition,regional environmental issues are emerging as cities expand,connect and interact to form urban *** turn urbanization into an opportunity for,rather than an obstacle to,sustainable development,we must move beyond documenting urban expansion to understand the environmental consequences of both internal city dynamics and the formation of urban megaregions.

关键词： urbanization urban and regional sustainability landscape change air pollution urban heat island

Neural networks-based iterative learning control consensus for periodically time-varying multi-agent systems

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Science China(Technological Sciences) 2024年第2期67卷 464-474页

作者： CHEN JiaXi li JunMin CHEN WeiSheng GAO weifeng School of Mathematics and Statistics Xidian UniversityXi'an 710071China School of Aerospace Science and Technology Xidian UniversityXi'an 710071China

In this paper,the problem of adaptive iterative learning based consensus control for periodically time-varying multi-agent systems is studied,in which the dynamics of each follower are driven by nonlinearly parameterized terms with periodic *** networks and Fourier base expansions are introduced to describe the periodically time-varying dynamic *** this basis,an adaptive learning parameter with a positively convergent series term is constructed,and a distributed control protocol based on local signals between agents is designed to ensure accurate consensus of the closed-loop ***,consensus algorithm is generalized to solve the formation control ***,simulation experiments are implemented through MATLAB to demonstrate the effectiveness of the method used.

关键词： multi-agent systems adaptive iterative learning control nonlinearly parameterized dynamics Fourier series expansion neural networks

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寻常型鱼鳞病中西医诊治研究进展

医学综述 2024年第16期30卷 1976-1983页

作者：徐宁章印红李伟峰张哲川李飞罗光云张星贺云南中医药大学第二临床医学院昆明650500 云南中医药大学基础医学院昆明650500 云南省第一人民医院医学遗传科国家卫生健康委西部优生与出生缺陷防控重点实验室昆明650032

寻常型鱼鳞病(IV)是鱼鳞病最常见的类型,临床治疗难度大,治疗后极易复发。近年来,人们对IV的认识已达到基因层面,但将其转化为实际治疗仍有障碍。现代医学通过基因检测进一步确诊IV后,多采用口服维A酸或外拭尿素、甘油、乳酸等软膏治疗... 详细信息

寻常型鱼鳞病(IV)是鱼鳞病最常见的类型,临床治疗难度大,治疗后极易复发。近年来,人们对IV的认识已达到基因层面,但将其转化为实际治疗仍有障碍。现代医学通过基因检测进一步确诊IV后,多采用口服维A酸或外拭尿素、甘油、乳酸等软膏治疗。中医认为,IV属先天不足,治以扶正御邪,可采用中药内服、外拭、熏蒸、药浴、针刺等方式辨证论治。遗传机制和阻断方式的进一步明确可能有助于阻断家族遗传性IV。未来,应加强针对IV病因的研究,同时进一步开拓相关基因治疗。

关键词：寻常型鱼鳞病中西医遗传

The effects of medical insurance and patients’ preference on manufacturer encroachment in a pharmaceutical supply chain

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Journal of Management Science and Engineering 2022年第2期7卷 243-265页

作者： Yanfei Lan Pingping Lu Chen Pan Sarmajit Kar weifeng li College of Management&Economics Tianjin UniversityTianjin300072China College of Stastics and Mathematics Huanggang Normal UniversityHuanggang438000China Department of Mathematics National Institute of TechnologyDurgapurWest BengalIndia Academy of Medical Engineering&Translation Medicine Tianjin UniversityTianjin300072China

With the development of e-commerce,manufacturers have opportunities to sell products to consumers through direct channels in addition to independent *** manufacturers’encroachment upon the retailing market of traditional goods has been extensively studied,there is a lack of research on manufacturers’encroachment in a pharmaceutical supply *** paper analyzes a pharmaceutical manufacturer encroachment strategy by taking into account the distinctive features of drugs,in which drug expenses are covered by medical insurance only in the physical channel and patients'channel preference is also *** find that under certain circumstances,the manufacturer encroachment may lead to a win-win outcome for both the manufacturer and the retailer,contradicting the conventional wisdom that the manufacturer's encroachment into retail space is detrimental to the independent ***,the manufacturer is more likely to encroach when the incurred extra cost is sufficiently small,the perceived quality of the drug selling through the direct channel is sufficiently high and the out-of-pocket percentage cost of the drug selling in the physical channel is *** further study the impact of manufacturer encroachment on social welfare and find that the introduction of encroachment decreases the social welfare when patients'perceived quality of the drug obtained through the online store is low and improves the social welfare when the perceived quality exceeds a certain threshold.

关键词： Manufacturer encroachment Drug supply chain Patients preference Game theory

太阳能-余热联合驱动吸收过冷CO_(2)制冷-淡水联产系统性能分析

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流体机械 2024年第2期52卷 32-39页

作者：代宝民赵佳仪刘圣春杨海宁李伟锋章立标陈月天津大学医学工程与转化医学研究院天津300072 天津商业大学天津市制冷技术重点实验室天津300134 浙江国祥股份有限公司浙江上虞3123001

为了同时满足制冷和淡水的共同需求,提出了太阳能-余热联合驱动吸收过冷CO_(2)制冷-淡水联产系统(AbsCWCS),在提高CO_(2)制冷系统能效的同时可生产淡水。建立系统的热力学模型,分析了环境温度和太阳辐射强度对系统能效(COP)的影响。此外... 详细信息

为了同时满足制冷和淡水的共同需求,提出了太阳能-余热联合驱动吸收过冷CO_(2)制冷-淡水联产系统(AbsCWCS),在提高CO_(2)制冷系统能效的同时可生产淡水。建立系统的热力学模型,分析了环境温度和太阳辐射强度对系统能效(COP)的影响。此外,为进一步分析气候条件的影响,选取5个典型缺水城市,对年度性能系数(APF)和年淡水产量进行了评估。结果表明:Abs-CWCS的COP和淡水产量均显著提升,与基础CO_(2)增压制冷-淡水联产系统(Base-CWCS)相比,COP提高了1.95%~41.02%,淡水产量增加了0.8~28.6倍,Abs-CWCS的CO_(2)制冷系统排气压力可降低7.86%;AbsCWCS可有效提高系统的APF,5个典型缺水城市的APF可提升3.66%,年淡水产量的提升率可达9.54%~64.62%。研究结果为同时解决制冷和淡水需求提供了可靠的解决方案。

关键词：吸收式过冷 CO_(2)制冷系统太阳能制冷-淡水联产余热

Reheat effect on the improvement in efficiency of the turbine driven by pulse detonation

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Defence Technology（防务技术） 2024年第1期31卷 200-210页

作者： Junyu liu Zhiwu Wang Zixu Zhang Junlin li weifeng Qin Jingjing Huang School of Power and Energy Northwestern Polytechnical UniversityXi’an 710072China Shenzhen Research Institute of Northwestern Polytechnical University Shenzhen 518057China Mechanical Engineering College Xi’an Shiyou UniversityXi’an 710065China

Due to the strong unsteadiness of pulse detonation,large flow losses are generated when the detonation wave interacts with the turbine blades,resulting in low turbine *** that the flow losses are dissipated into the gas as heat energy,some of them can be recycled during the expansion process in subsequent stages by the reheat effect,which should be helpful to improve the detonationdriven turbine *** this into account,this paper developed a numerical model of the detonation chamber coupled with a two-stage axial turbine,and a stoichiometric hydrogen-air mixture was *** improvement in turbine efficiency attributable to the reheat effect was calculated by comparing the average efficiency of the stages with the efficiency of the two-stage *** research indicated that the first stage was critical in suppressing the flow unsteadiness caused by pulse detonation,which stabilized the intake condition of the second stage and consequently allowed much of the flow losses from the first stage to be recycled,so that the efficiency of the two-stage turbine was *** a 95%confidence level,the efficiency improvement was stable at 4.5%—5.3%,demonstrating that the reheat effect is significant in improving the efficiency of the detonation-driven turbine.

关键词： Pulse detonation turbine engine Hydrogen detonation Turbine efficiency Reheat effect Multi-cycle detonation

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陇东地区深井钻井循环温度预测及应用分析

非常规油气 2024年第4期11卷 135-143页

作者：王瑞陈子豪李录科李伟峰袁晨雨张瑞超周毅西安石油大学石油工程学院西安710065 油气藏地质及开发工程全国重点实验室(西南石油大学) 成都610500 中国石油集团川庆钻探工程有限公司长庆钻井总公司西安710018 陕西延长石油(集团)有限责任公司研究院西安710065

长庆油田陇东地区部分天然气井深度约为5000 m,相应的地层温度会超过130℃。然而随着该地区对深层油气、非常规油气以及页岩气等资源的不断开发,高温已成为钻井作业的重要制约因素。为了防范井下高温可能引发的工程事故,构建了一个二维... 详细信息

长庆油田陇东地区部分天然气井深度约为5000 m,相应的地层温度会超过130℃。然而随着该地区对深层油气、非常规油气以及页岩气等资源的不断开发,高温已成为钻井作业的重要制约因素。为了防范井下高温可能引发的工程事故,构建了一个二维钻井循环温度预测模型,对井筒温度特性进行了分析,并为钻井液和钻井工具的选择提供了理论支持。研究结果表明:1)在开始泵送循环的初期,井口温度迅速升高,井底温度迅速下降,之后的1.5 h内,井口和井底温度变化逐渐趋缓;2)在相同的井深下,随着循环时间的增加,井筒内的钻柱内钻井液温度和环空内钻井液温度逐渐下降,同时相应位置的环空内钻井液温度和钻柱内钻井液温度也下降;3)在预测的温度范围内,对该井的3种钻井液体系进行了表观黏度和塑性黏度实验,结果显示黏度的变化受温度影响较大;4)在预测的温度范围内,以三元乙橡胶为研究对象,随着老化时间的增加以及温度的升高,橡胶密封圈的厚度逐渐减小,硬度逐渐增加,压缩永久变化率也逐渐增加。该预测模型的预测结果与实际生产相符,为设计和选型提供了有价值的指导,具有重要的研究意义。

关键词：陇东地区深井钻井温度预测钻井温度