Rational scale of urban rail transit network based on system dynamics

Optimization design and experimental research for space intelligent structurecapacity, high efficiency and low pollution. Estimating URT network scale is the key to ensure the scientificity and feasibility of its construction. The existing studies on rational scale of URT network have not dealt with the interaction of supply and demand. This paper describes the establishment of a system dynamics model of rational URT network scale determination, considering the interaction between URT construction and city social economic development as well as the dynamic equilibrium of capital supply and traffic demand, and the verification of the model validity by applying it to the case of Wuhan City’s URT construction.     

计算流体力学软件在汽车气动问题研究中的应用

汽车在行驶过程中受到空气的作用力,会对汽车运动产生影响。汽车气动特性的研究是汽车设计研发的重要内容,随着计算机技术与数值计算方法的发展,计算流体力学（CFD）在汽车气动特性的研究中得到日益广泛的应用,特别是各类计算流体力学商业软件使其参与工程设计成为可能。文章在介绍计算流体力学的基础上,结合实例对计算流体力学软件在汽车气动问题研究中的应用进行了探究。     

绪论课的地位作用与讲授策略

论述了绪论课的地位、作用与讲授策略,指出绪论课的教学目的。强调绪论课就是要回答为什么学、学什么、怎么学三个基本问题,概述了机电系统动力学绪论课的教学实践成果。     

杏仁油提取的各种工艺方法与研究

杏仁油是一种应用广泛的植物基础油,基础油和精油一起应用于芳香疗法中。大多数的植物精油具有强烈的刺激性,无法直接被人体吸收,只有在基础油中稀释后才能使用。基础油是在低温条件下制取的,温度不高于60℃,这就使得油脂中的矿物质、维生素以及脂肪酸等保存良好,具有优越的滋润滋养特质。本文利用杏仁提取杏仁油,主要综述了水代法、水酶法、冷压榨法、浸出法、超临界萃取法、超声波提取法等主要提取方法。     

垃圾焚烧发电厂燃烧控制及环保排放的研究

我国垃圾水分大、热值低、灰分大、成分复杂,焚烧炉燃烧控制不可控因素多,结合TIF-CFB特点,从垃圾品质、助燃煤成分、过量空气系数、负荷变化等参数分析影响垃圾燃烧稳定性的因素,对垃圾焚烧中产生的二恶英、重金属、酸性气体、固体废物等进行解析利于有针对性地防治,可实现垃圾发电最大的环境效益。     

Exploring CO2 mitigation pathway of local industries using a regional-based system dynamics model

Low-carbon development based on low energy consumption, low pollution and low emissions has become an important strategic choice for worldwide governments to achieve sustainable development. In order to support smart government in decision making, information systems have been developed to monitor and predict CO₂ emissions. Most of the existing studies investigate CO₂ emission amounts, identify influencing factors of CO₂ emission and discuss potential suggestions to mitigate CO₂ emission for different industries. They often focus on CO₂ emission research of industries in a region or country, while the integration of carbon flow in the neighboring regions is not well studied. Therefore, this paper proposes a system dynamics model to explore an optimal carbon emission reduction path of a regional industry by integrating regional differences, i.e., industrial comparative advantages, technology advantages and the inter-regional context between the neighboring regions. In the case study, we use a key industry in a typical industrial region of Western China, the cement industry in Chongqing, as a scenario to simulate the CO₂ emission, possible energy demand and cement production of the cement industry in this region for recent years. Simulation results show that by leveraging the regional differences, especially the collaboration of the industrial chain and production capacity among regions, the cement industry in Chongqing can achieve the low-carbon target. In addition, through the analysis and discussions about the features of our model and Chongqing’s cement industry, it reflects that our model using regional differences is applicable to industries with a common demand market at the regional level such as energy, chemical and steel industries.     

基于油气藏渗流力学课程的创新创业深度研究融合

"油气藏渗流力学"作为石油工程专业主干课程,在日常教学中,多为理论知识教学,缺少实践教学活动。本文通过问卷调查,得出创新创业教育实际情况的相关数据。根据实际情况,以创新创业为方向,将其思想与内涵同"油气藏渗流力学"的教学计划及活动相结合。从课上到课下,从学校到学生,全方位、深层次、多方向地提出了模块教学、合理规划科技创新竞赛及跨专业联合教学模式三种教学改革方式。     

Dynamics and manipulation of ferroelectric domain walls in bismuth ferrite thin films

Ferroelectric domain walls differ from domains not only in their crystalline and discrete symmetry, but also in their electronic, magnetic, and mechanical properties. Although domain walls provide a degree of freedom to regulate the physical properties at the nanoscale, the relatively lower controllability prevents their practical applications in nano-devices. In this work, with the advantages of 3D domain configuration detection based on piezoresponse force microscopy, we find that the mobility of three types of domain walls (tail-to-tail, head-to-tail, head-to-head) in (001) BiFeO₃ films varies with the applied electrical field. Under low voltages, head-to-tail domain walls are more mobile than other domain walls, while, under high voltages, tail-to-tail domain walls become rather active and possess relatively long average lengths. This is due to the high nucleation energy and relatively low growth energy for charged domain walls. Finally, we demonstrate the manipulation of domain walls through successive electric writings, resulting in well-aligned conduction paths as designed, paving the way for their application in advanced spintronic, memory and communication nano-devices.     

Diagnosis of CO2 dynamics and fluxes in global coastal oceans

Global coastal oceans as a whole represent an important carbon sink but, due to high spatial–temporal variability, a mechanistic conceptualization of the coastal carbon cycle is still under development, hindering the modelling and inclusion of coastal carbon in Earth System Models. Although temperature is considered an important control of sea surface pCO₂, we show that the latitudinal distribution of global coastal surface pCO₂ does not match that of temperature, and its inter-seasonal changes are substantially regulated by non-thermal factors such as water mass mixing and net primary production. These processes operate in both ocean-dominated and river-dominated margins, with carbon and nutrients sourced from the open ocean and land, respectively. These can be conceptualized by a semi-analytical framework that assesses the consumption of dissolved inorganic carbon relative to nutrients, to determine how a coastal system is a CO₂ source or sink. The framework also finds utility in accounting for additional nutrients in organic forms and testing hypotheses such as using Redfield stoichiometry, and is therefore an essential step toward comprehensively understanding and modelling the role of the coastal ocean in the global carbon cycle.     

大连物流的系统动力学分析

引入系统动力学概念,简述对大连物流进行系统动力学分析的必要性,应用系统动力学理论说明物流及相关因素之间的制约关系,并结合大连现状进行系统动力学分析。