Train post‑derailment behaviours and containment methods:a review

Railway accidents,particularly serious derailments,can lead to catastrophic consequences.Therefore,it is essential to prevent derailment escalation to reduce the likelihood of severe derailments.Train post-derailment behaviours and containment methods play a critical role in preventing derailment escalation and providing passive safety protection and accident prevention in the event of a derailment.However,despite the increasing attention on this field from academia and industry in recent years,there is a lack of systematic exploration and summarization of emerging applications and containment methods in train post-derailment research.For this reason,this paper presents a comprehensive review of existing studies on train post-derailment behaviours,encompassing various topics such as post-derailment contact-impact models,dynamic modelling and simulation techniques,and the primary factors influencing post-derailment behaviours.Significantly,this review introduces and elucidates substitute guidance mechanisms(SGMs),which serve as railway-specific passive safety protection and accident prevention measures.The various types of SGMs are depicted,and their ongoing developments and applications are explored in depth.The review additionally points out several unresolved challenges including the adverse effects of SGMs,and proposes future research directions to advance the theoretical understanding and practical application of train post-derailment behaviours and containment methods.This review seeks to be a valuable reference for railway industry professionals in preventing catastrophic derailment consequences through post-derailment containment methods.

Geochemistry, zircon U–Pb geochronology, and Hf isotopes of S-type granite in the Baoshan block, constraints on the age and evolution of the Proto-Tethys

Geochemistry, zircon U–Pb geochronology, and Hf isotope data for the Early Paleozoic granites in the Baoshan Block reveal the Early Paleozoic tectonic evolution of the Proto-Tethys. The samples are high-K, calcalkaline, strongly peraluminous rocks with A/CNK values of 1.37–1.46, are enriched in SiO2, K2O, and Rb, and are depleted in Nb, P, Ti, Eu, and heavy rare earth elements,which indicates the crystallization fractionation of the granitic magma. Zircon U–Pb dating indicates that they formed in ca. 480 Ma. The Nansa granites have εHf(t) values ranging from-16.04 to 4.36 with corresponding TC DMages of 2.10–0.81 Ga, which suggests the magmas derived from the partial melting of ancient metasedimentary with minor involvement of mantle-derived components. A synthesis of data for the Early Paleozoic igneous rocks in the Baoshan block and adjacent(Tengchong,Qiangtang, Sibumasu, Himalaya, etc.) blocks indicates that these blocks were all aligned along the proto-Tethyan margin of East Gondwana in the Early Paleozoic. The Early Paleozoic S-type granites from Nansa were generated in a high-temperature and low-pressure(HTLP) extensional tectonic setting, which resulted from Andean-type orogeny instead of the final assembly of Gondwana or crustal extension in a non-arc environment. In certain places, an expanding environment may exist in opposition to the tectonic backdrop of the lithosphere’s thickening and shortening, leading the crust to melt and decompress,mantle-derived materials to mix, and a small quantity of peraluminous granite to emerge.

Continuous synthesis of N,N-dicyanoethylaniline in microreactors:Reaction kinetics and process intensification

Cyanoethylation of phenylamine is one of the important steps for the production of dicyanoethyl-based disperse dyes.However,the exothermic nature of this reaction and the inherent instability of intermittent dynamic operation pose challenges in achieving both high safety and reaction efficiency.In this study,a continuous cyanoethylation of phenylamine for synthesizing N,N-dicyanoethylaniline in a microreactor system has been developed.By optimizing the reaction conditions,the reaction time was significantly reduced from over 2 h in batch operation to approximately 14 min in the microreactor,while high conversion and selectivity were maintained.Based on the reaction network constructed,the reaction kinetics was established,and the kinetic parameters were then determined.These findings provide valuable insights into a controllable cyanoethylation reaction,which would be helpful for the design of efficient processes and optimization of reactors.

Activating d^(10)electronic configuration to regulate p-band centers as efficient active sites for solar energy conversion into H_(2)by surface atomic arrangement

Relationship between the activity for photocatalytic H_(2)O overall splitting(HOS)and the electron occupancy on d orbits of the active component in photocatalysts shows volcanic diagram,and specially the d^(10)electronic configuration in valley bottom exhibits inert activity,which seriously fetters the development of catalytic materials with great potentials.Herein,In d^(10)electronic configuration of In_(2)O_(3)was activated by phosphorus atoms replacing its lattice oxygen to regulate the collocation of the ascended In 5p-band(Inɛ5p)and descended O 2p-band(Oɛ2p)centers as efficient active sites for chemisorption to*OH and*H during forward HOS,respectively,along with a declined In 4d-band center(Inɛ4d)to inhibit its backward reaction.A stable STH efficiency of 2.23%under AM 1.5 G irradiation at 65°C has been obtained over the activated d^(10)electronic configuration with a lowered activation energy for H_(2)evolution,verified by femtosecond transient absorption spectroscopy,in situ diffuse reflectance infrared Fourier transform spectroscopy and theoretical calculations of dynamics.These findings devote to activating d^(10)electronic configuration for resolving the reaction energy barrier and dynamical bottleneck of forward HOS,which expands the exploration of high-efficiency catalytic materials.

Investigating the charge transfer mechanism of ZnSe QD/COF S-scheme photocatalyst for H_(2)O_(2) production by using femtosecond transient absorption spectroscopy

Hydrogen peroxide(H_(2)O_(2))has gained widespread attention as a versatile oxidant and a mild disin-fectant.Here,an electrostatic self-assembly method is applied to couple ZnSe quantum dots(QDs)with a flower-like covalent organic framework(COF)to form a step-scheme(S-scheme)photocata-lyst for H_(2)O_(2)production.The as-prepared S-scheme photocatalyst exhibits a broad light absorption range with an edge at 810 nm owing to the synergistic effect between the ZnSe QDs and COF.The S-scheme charge-carrier transfer mechanism is validated by performing Fermi level calculations and in-situ X-ray photoelectron and femtosecond transient absorption spectroscopies.Photolumi-nescence,time-resolved photoluminescence,photocurrent response,electrochemical impedance spectroscopy,and electron paramagnetic resonance results show that the S-scheme heterojunction not only promotes charge carrier separation but also boosts the redox ability,resulting in enhanced photocatalytic performance.Remarkably,a 10%-ZnSe QD/COF has excellent photocatalytic H_(2)O_(2)-production activity,and the optimal S-scheme composite with ethanol as the hole scavenger yields a H_(2)O_(2)-production rate of 1895 mol g^(-1)h^(-1).This study presents an example of a high-performance organic/inorganic S-scheme photocatalyst for H_(2)O_(2)production.

Configuration and Kinematics of a 3-DOF Generalized Spherical Parallel Mechanism for Ankle Rehabilitation

The kinematic equivalent model of an existing ankle-rehabilitation robot is inconsistent with the anatomical structure of the human ankle,which influences the rehabilitation effect.Therefore,this study equates the human ankle to the UR model and proposes a novel three degrees of freedom(3-DOF)generalized spherical parallel mechanism for ankle rehabilitation.The parallel mechanism has two spherical centers corresponding to the rotation centers of tibiotalar and subtalar joints.Using screw theory,the mobility of the parallel mechanism,which meets the requirements of the human ankle,is analyzed.The inverse kinematics are presented,and singularities are identified based on the Jacobian matrix.The workspaces of the parallel mechanism are obtained through the search method and compared with the motion range of the human ankle,which shows that the parallel mechanism can meet the motion demand of ankle rehabilitation.Additionally,based on the motion-force transmissibility,the performance atlases are plotted in the parameter optimal design space,and the optimum parameter is obtained according to the demands of practical applications.The results show that the parallel mechanism can meet the motion requirements of ankle rehabilitation and has excellent kinematic performance in its rehabilitation range,which provides a theoretical basis for the prototype design and experimental verification.

Albizzia chinensis(Osbeck)Merr extract YS ameliorates ethanol-induced acute gastric ulcer injury in rats by regulating NRF2 signaling pathway

Background:Around the world,there is a high incidence of gastric ulcers.YS,an extract from the Chinese herb Albizzia chinensis(Osbeck)Merr,has potential therapeutic applications for gastrointestinal diseases.Here we elucidated the protective effect and underlying mechanism of action of YS on gastric ulcer in rats injured by ethanol.Methods:The ethanol-i nduced gastric ulcer rat model was used to assess the protective effect of YS.A pathological examination of gastric tissue was performed by H&E staining.GES-1 cells damaged by hydrogen peroxide were used to simulate oxidative damage in gastric mucosal epithelial cells.Endogenous NRF2 was knocked down using small interfering RNA.Immunoprecipitation was used to detect ubiquitination of NRF2.Co-i mmunoprecipitation was used to detect the NRF2-Keap1 interaction.Results:YS(10 and 30 mg/kg,i.g.)significantly reduced the ulcer index,decreased MDA level,and increased SOD and GSH levels in gastric tissues damaged by ethanol.YS promoted NRF2 translocation from cytoplasm to nucleus and enhanced the NQO1 and HO-1 expression levels in injured rat gastric tissue.In addition,YS regulated NQO1 and HO-1 via NRF2 in H_(2)O_(2)-i nduced oxidative injured GES-1 cells.Further studies on the underlying mechanism indicated that YS reduced the interaction between NRF2 and Keap1 and decreased ubiquitylation of NRF2,thereby increasing its stability and expression of downstream factors.NRF2 knockdown abolished the effect of YS on MDA and SOD in GES-1 cells treated with H_(2)O_(2).Conclusion:YS reduced the NRF2-Keap1 interaction,promoting NRF2 translocation into the nucleus,which increasing the transcription and translation of NQO1 and HO-1 and improved the antioxidant capacity of rat stomach.

Regional Brand and High-quality Development of Fruits in Ethnic Areas of the Yangtze River Economic Belt under the Greater Food Approach

Establishing the Greater Food Approach and promoting the Yangtze River Economic Belt s national major regional development strategy can better support and serve the agricultural power and Chinese-style modernization.This paper introduces the characteristics of fruit industry in 16 autonomous prefectures and 47 autonomous counties under the jurisdiction of the Yangtze River Economic Belt.It studies the intellectual property resources of brand marks from the aspects of geographical indications,collective trademarks,certification trademarks,well-known trademarks in China and national design patents,and analyzes the main problems of brand and high-quality development of fruit industry in these ethnic autonomous areas.Finally,it puts forward some strategies,such as improving the protection of intellectual property rights of geographical indications,using intellectual property rights of brand signs,building modern seed industry upgrading project,drawing lessons from the experience of thousand villages demonstration project,ensuring that large-scale poverty does not occur,and building a diversified food supply system.

Promoting High-quality Development of Grain and Oil in Ethnic Areas of the Yangtze River Economic Belt from the Perspective of Agricultural Power

Accelerating the construction of agricultural power,further promoting the high-quality development of the Yangtze River Economic Belt,and better supporting and serving Chinese-style modernization are the key issues at present.This paper first introduces the Yangtze River Economic Belt and its ethnic areas,and studies the characteristics of the grain and oil industry in the ethnic autonomous areas of the economic belt,as well as the current situation of various types of intellectual property resources,such as industrial cultural heritage,scientific and tech-nological innovation,and brand marking intellectual property.Besides,it analyzes the main problems in the high-quality development of grain and oil in the Yangtze River Economic Belt ethnic areas.Finally,it comes up with recommendations,including protecting the intellectual prop-erty rights of cultural heritage in the field of grain and oil,leading the inheritance and development of excellent traditional Chinese culture,use scientific and technological innovation intellectual property rights to promote the innovation-driven development strategy of the grain and oil in-dustry,and providing counterpart assistance to ethnic autonomous areas in the Yangtze River Economic Belt to further promote the high-quality development of the Yangtze River Economic Belt.

MOF/CdS梯型光催化剂同时进行苯甲醇氧化和析氢反应及其机理研究

太阳能驱动的光催化水分解制氢是一种清洁、可持续的技术,可以减少碳排放.一般来说,光催化全解水的析氧半反应过程需要消耗四个空穴,且迟缓的反应动力学会抑制整体反应,因此光催化全解水极具挑战性.在光催化制氢中通常利用空穴牺牲剂来提升产氢半反应的效率.然而,这些过程会产生无用的氧化产物,造成光生空穴氧化能力的浪费,且增加了系统成本.因此,构建一个由光催化产氢和选择性有机合成相结合的双功能氧化还原体系,可同时利用光生电子和空穴,并且产物中氢气和高附加值的有机产品容易分离,因此具有较高的可持续经济效应.利用梯型异质结将两种带隙适合且能带结构匹配的光催化剂复合在一起,可以最大程度地利用两种光催化剂的氧化还原能力,为解决上述问题提供了一条理想途径.本文采用化学浴法将CdS纳米颗粒原位生长在锆基金属有机框架UiO-66-NH_(2)(U6N)上.在光照条件下,梯型异质结催化苯甲醇选择性氧化生成苯甲醛和氢气的性能大幅度提升,UC0.75(U6N/CdS理论质量比为0.75)复合物光照3 h产氢速率为630μmol·g^(-1)h^(-1),同时苯甲醇氧化为苯甲醛的选择性达到99%.原位辐照X射线光电子能谱结果表明,UC0.75梯型异质结界面的电子转移路径,在暗态下电子由CdS转移到U6N,在光照下电子由U6N转移到CdS.利用飞秒瞬态吸收(fs-TA)光谱进一步研究了异质结的载流子迁移的动力学信息,结果表明,复合样品中基态漂白信号衰减时间减少,梯型异质结界面处电子转移效率较高.此外,通过原位漫反射红外傅里叶变换光谱、电子顺磁共振和同位素实验揭示了苯甲醇的氧化机理,光照下,位于U6N的光生空穴与苯甲醇相互作用,先氧化苯甲醇上的α-C产生·CH(OH)Ph,然后进一步氧化产生苯甲醛,同时,CdS上的光生电子与水中产生的H+结合产生氢气.综上,本文通过飞秒瞬态吸收光谱(fs-TAS)光谱来阐述梯型异质结的电子转移机制,并为金属有机框架/无机物复合光催化剂的设计提供了借鉴.

Trade-offs between ion-conducting and mechanical properties: The case of polyacrylate electrolytes

Polymer electrolytes(PEs)have been long recognized as the key materials to enable energy-dense batteries and render flexible energy devices practically viable,owing to their chemical and mechanical reliability.However,much of their promise is yet to be realized.The roomtemperature ion conductivity of existing PEs still falls short of the implementation criterion of 10^(-4) S cm^(-1) on the promise of acceptable mechanical properties,thereby precluding their practical application.The twin but inversely related duties of polymers,that is,functioning as both an ion-conducting medium and a structural backbone,underlie this issue but are less elucidated systematically.The polyacrylate(PA)family is among promising polymer matrices on account of ester polarity,electrode compatibility,chemical tunability,and mechanical durability.The extensive applicability of PA in plasticized gels,dry solids,and emerging composites makes PA-based PEs representative to illustrate the trade-off between ion conduction and mechanical strength.We herein seek to outline the stated long-standing conflict exemplified by PA-based PEs,focusing on crucial strategies toward balancing and reconciling the two mutually exclusive properties,with the intention of offering designing guidelines for next-generation PEs.

Inheritance,Innovation and High-quality Development of Herbaceous Edible Oils in Hubei Province under the Strategy of Strengthening the Country with Intellectual Property

Only by improving the production capacity of domestic herbal edible oil can China ensure the safety of the supply chain of the important industrial chain of vegetable edible oil in China and practice the big food concept.In addition to rice,maize,and soybean for using as grain and oil,there are eight kinds of herbaceous edible oil crops in Hubei Province,including rape,peanut,sesame,sunflower,perilla(perilla seed),cotton,linen and tiger nut(Cyperus esculentus).This paper studies the main industries of herbaceous edible oil crops and their intellectual property resources in Hubei Province,and analyzes the main problems of its inheritance,innovation and high-quality development under the strategy of strengthening the country with intellectual property.Finally,it proposes the countermeasures of carrying forward and inheriting traditional knowledge and traditional culture,maintaining the biodiversity of crops,strengthening the creation of new plant varieties and breeding patents,and opening up the whole chain of intellectual property rights.

Intellectual Property Protection,Inheritance,Innovation and Development of Woody Edible Oilseeds in Hubei Province

Only by developing woody edible oilseeds industry can we ensure the safety of the important industrial chain and supply chain of vegetable edible oil in China.There are 13 kinds of woody edible oil plants in Hubei,including Camellia oleifera Abel(oil tea),Juglans regia L.(walnut),Olea europaea L.(olive)and Paeonia suffruticosa(oil peony).This paper studies the main industries of woody edible oilseeds in Hubei Province and their intellectual property resources,and analyzes the main problems in their intellectual property protection,inheritance,innovation and development.Finally,it proposes some strategies,including carrying forward the traditional knowledge related to woody edible oilseeds,innovating the"agricultural chip",creating key counties of national woody edible oil seeds,and developing industrial clusters with national advantages and characteristics.

The Role and Mechanism of LncRNA-p21 in Regulating Gastric Cancer Metastasis by Mediating Wnt/β-Catenin Signaling Pathway

Objective:To study the mechanism of lncRNA p21 inhibiting the growth and metastasis of human gastric cancer SGC7901/GES-1 cells by mediating the Wnt/β-catenin signaling pathway.Methods:Lentiviral overexpression of lncRNA-p21 in human gastric cancer SGC7901/GES-1 cell transfections was observed and analyzed for in vitro migration,invasion,cell morphology and proliferation.Besides.Wnt/β-catenin signaling pathway was tested for direct involvement in lncRNA-p21-mediated inhibition of gastric cancer cell growth and proliferation.Wnt/β-catenin signaling pathway was validated using Li-C1.Results:Gastric cancer SGC7901/GES-1 cells in the overexpression of lncRNA-p21 showed changes in stellate morphology,low invasion,or spindle-shaped morphology.LncRNA-p21 inhibited the growth and proliferation of gastric cancer SGC7901/GES-1 cells both in vivo and in vitro,and Wnt/β-catenin signaling pathway mediated the proliferation,invasion,and migration of lncRNA-p21 on gastric cancer SGC7901/GES-1 cells.Conclusion:LncRNA-p21 can inhibit the growth and metastasis of gastric cancer SGC7901/GES-1 cells in vitro and in vivo,and the inhibition of lncRNA p21 is mainly mediated by inhibiting the Wnt/β-catenin signaling pathway.

Configuration Design and Kinematic Performance Analysis of a Novel 4-DOF Parallel Ankle Rehabilitation Mechanism with Two Virtual Motion Centers

Aiming at the problem that the existing ankle rehabilitation robot is difficult to fully fit the complex motion of human ankle joint and has poor human-machine motion compatibility,an equivalent series mechanism model that is highly matched with the actual bone structure of the human ankle joint is proposed and mapped into a parallel rehabilita-tion mechanism.The parallel rehabilitation mechanism has two virtual motion centers(VMCs),which can simulate the complex motion of the ankle joint,adapt to the individual differences of various patients,and can meet the reha-bilitation needs of both left and right feet of patients.Firstly,based on the motion properties and physiological structure of the human ankle joint,the mapping relationship between the rehabilitation mechanism and ankle joint is determined,and the series equivalent model of the ankle joint is established.According to the kinematic and con-straint properties of the ankle equivalent model,the configuration design of the parallel ankle rehabilitation robot is carried out.Secondly,according to the intersecting motion planes theory,the full-cycle mobility of the mechanism is proved,and the continuous axis of the mechanism is judged based on the constraint power and its derivative.Then,the kinematics of the parallel ankle rehabilitation robot is analyzed.Finally,based on the OpenSim biomechanical soft-ware,a human-machine coupling rehabilitation simulation model is established to evaluate the rehabilitation effect,which lays the foundation for the formulation of a rehabilitation strategy for the later prototype.

Application of Time Serial Model in Water Quality Predicting

Water resources are an indispensable and valuable resource for human survival and development.Water quality predicting plays an important role in the protection and development of water resources.It is difficult to predictwater quality due to its random and trend changes.Therefore,amethod of predicting water quality which combines Auto Regressive Integrated Moving Average(ARIMA)and clusteringmodelwas proposed in this paper.By taking thewater qualitymonitoring data of a certain river basin as a sample,thewater quality Total Phosphorus(TP)index was selected as the prediction object.Firstly,the sample data was cleaned,stationary analyzed,and white noise analyzed.Secondly,the appropriate parameters were selected according to the Bayesian Information Criterion(BIC)principle,and the trend component characteristics were obtained by using ARIMA to conduct water quality predicting.Thirdly,the relationship between the precipitation and the TP index in themonitoring water field was analyzed by the K-means clusteringmethod,and the random incremental characteristics of precipitation on water quality changes were calculated.Finally,by combining with the trend component characteristics and the random incremental characteristics,the water quality prediction results were calculated.Compared with the ARIMA water quality prediction method,experiments showed that the proposed method has higher accuracy,and its Mean Absolute Error(MAE),Mean Square Error(MSE),and Mean Absolute Percentage Error(MAPE)were respectively reduced by 44.6%,56.8%,and 45.8%.

Correlation Analysis of Turbidity and Total Phosphorus in Water Quality Monitoring Data

At present,water pollution has become an important factor affecting and restricting national and regional economic development.Total phosphorus is one of the main sources of water pollution and eutrophication,so the prediction of total phosphorus in water quality has good research significance.This paper selects the total phosphorus and turbidity data for analysis by crawling the data of the water quality monitoring platform.By constructing the attribute object mapping relationship,the correlation between the two indicators was analyzed and used to predict the future data.Firstly,the monthly mean and daily mean concentrations of total phosphorus and turbidity outliers were calculated after cleaning,and the correlation between them was analyzed.Secondly,the correlation coefficients of different times and frequencies were used to predict the values for the next five days,and the data trend was predicted by python visualization.Finally,the real value was compared with the predicted value data,and the results showed that the correlation between total phosphorus and turbidity was useful in predicting the water quality.

Role of CST1 in Promoting Gastric Cancer Metastasis and Analysis of Its Mechanism

Objective:To elucidate the role and mechanism of cysteine protease inhibitor SN(CST1)in promoting the metastasis of gastric cancer.Methods:(1)Firstly,6 pairs of cancer and paracancer tissue samples from gastric cancer patients without distant metastasis and 5 pairs of cancer and paracancer tissue samples from gastric cancer patients with peritoneal metastasis were collected for transcriptome sequencing.Statistical analysis was performed on the sequencing results to identify significantly upregulated differential genes.(2)Another 75 pairs of cancer and paracancer tissue samples were collected from gastric cancer patients,and the protein and total RNA of gastric cancer tissue samples were extracted.Western blot and quantitative reverse transcription polymerase chain reaction(qRT-PCR)were used to detect the expression of CST1 protein and messenger RNA(mRNA)in gastric cancer and adjacent tissues.(3)The total protein and total RNA of AGS,BGC823,HGC-27,MGC803,MKN45,SGC7901,and SNU-1 gastric cancer cells and normal gastric mucosal epithelial cells GES-1 were extracted.Western blot and qRT-PCR were used to detect CST1 protein and mRNA expression.Results:(1)The significantly upregulated differential gene CST1 was screened,and the expression of CST1 in gastric cancer tissues was significantly higher than that in adjacent tissues.(2)Compared with normal gastric mucosal epithelial cells GES-1,the expression of CST1 in gastric cancer cell lines was upregulated,and the expression of CST1 in HGC-27 and SNU-1 was relatively low,while the expression of CST1 in AGS and MKN45 was relatively high.At the same time,a stable cell line of HGC-27 overexpressing CST1 and MKN45 knocking down CST1 was successfully constructed.(3)Overexpression or knockdown of CST1 did not significantly change the proliferation ability of gastric cancer cells,but can promote the migration and invasion of gastric cancer cells.(4)CST1 may promote the metastasis of gastric cancer cells by activating the epithelial-mesenchymal transition(EMT)signaling pathway.Conclusion:CST1 gene promotes the migration of gastric cancer cells,and we found through animal experiments that CST1 can affect the metastasis and invasion function of gastric cancer and is negatively correlated with the level of E-cadherin.

基于超声波联用技术的中药材党参绿色养护的可行性

绿色养护中药材党参的迫切而必要,超声清洗和果蔬、食品的绿色防腐保鲜技术和方法,应用于党参药材贮藏养护科学、可行。超声波联用技术养护党参后评价养护效果的待检药效成分和质量标准成分及其测定方法,分别选定为HPLC法测定党参炔苷、苍术内酯Ⅲ,UV-Vis法测定党参多糖,选定的测定成分代表性强,测定方法经典科学,简捷高效,重现性好,稳定性高,应用广泛。将超声波及其联用技术应用于党参药材绿色养护中,研究和应用前景光明广阔。

考虑经济成本和环境影响的城市物流枢纽布局研究

在中国城市高速发展扩张的背景下,经济发展依旧是城市发展的重要目标,然而近年来城市环境受到越来越多的关注,对追求可持续的城市发展提出更高的要求。本文从城市物流整体角度,考虑城市物流的多层次、多类商品和多种运输工具,基于具体指标量化了经济和环境等目标,分别建立城市物流枢纽布局模型,以上海市为实证研究对象,实例求解,验证模型的有效性。研究表明,经济成本与环境影响是相悖的,经济成本小,二氧化碳排放量大,反之亦然。