基于“CDIO”工程教育模式的土木工程材料课程教学改革探索

文章探讨了“CDIO”工程教育模式在土木工程材料课程教学改革中的应用,主要是从理论知识体系模块化构建、实践技能项目驱动化构建、课程效果多功能化构建、课程考核互动后构建4个方面对土木工程材料课程教学进行改革探索,实践证明,“CDIO” 工程教育模式教学激发了学生的主动性和创造性,教学质量得到明显提高。     

Asymmetric alumina-based ultrathin composite ceramic membranes with interfacial modification of black talc nanosheets

In this work, ultrathin planar alumina-based ceramic membranes with asymmetric structure and thickness less than 0.85 mm were successfully prepared by one-step molding phase transformation/sintering method using low-cost black talc (BT) nanosheets for the first time. The microstructure, pore structure, mechanical strength and permeability of novel ceramic membranes were systematically investigated with different BT amount and sintering temperatures. The doping of BT nanosheets effectively modulated the interfacial bonding area and strength between the grains, achieving significant increase in flexural strength through the evolution of the dense layer structure. The asymmetric structural features formed by the phase transformation/sintering process in combination with polymer substrate significantly reduced the thickness of effective separation layer, thus weakening the loss of flux caused by the densification of the film layer due to the interfacial modification process. Moreover, the organic carbon layers between BT layers were oxidized during the sintering process, forming fine pores and increasing the porosity, which showed to be unique characteristic different from other clay mineral materials. The prepared composite membrane had the pure water flux up to 16335 L m⁻² h⁻¹/bar at 1350 °C sintering, which achieved stable permeation of ∼5200 L m⁻² h⁻¹/bar and high retention over 90% for O/W emulsions.     

空气/水双冷型PV/T一体化组件实验与模拟研究

提出一种空气/水双冷型PV/T一体化组件,搭建2套测试平台开展PV/T组件的空冷、水冷、空气-水复合冷却实验,研究不同工作模式下组件的性能表现。实验结果表明：3种工作模式均可对光伏组件进行有效冷却,空冷、水冷、复合冷却模式组件综合效率分别为76.05%、74.51%、84.83%,其吸热板温度较无工质冷却模块分别可降低19.08、27.58和35.16℃。为进一步分析设计参数对PV/T组件电热特性的影响,利用ANSYS构建组件的三维数值模型,并通过实验数据验证模型的准确性。模拟显示：采用双风道翅片式结构可有效提升组件电热性能;随着环境温度的升高（10～40℃）,组件的综合效率由61.85%增至80.31%。     

Upward vs downward injection of droplets for the optimization of a radiative shield

A numerical and experimental study of a spray has been carried out at the laboratory scale, focusing on the comparison between downward and upward injection situations. The simulation has been carried out thanks to a dedicated numerical code addressing the two-phase flow with an Eulerian–Lagrangian approach, and treating the radiative transfer with a Monte Carlo method. The experimental setup involves a FTIR spectrometer and an IR camera, both characterizing simultaneously the spectral attenuation through the spray when irradiated by a blackbody. Numerical results and experimental data both show a better ability of the spray to attenuate radiation when injected upward. The residence time of droplets is highly increased when they are injected upward. This results in an increased attenuation ability of the spray. A gain by a factor 3 or more is possible regarding the attenuation of radiation if water is injected upward. This observation has to be considered with care however because of a possible poor stability of the spray. The influence of an air flow affecting the spray dynamics has also been investigated numerically, tests being done with a 2 m/s air flow. The droplet motion is strongly altered and the radiation attenuation is affected. In the upward injection case the deformation of the spray may be so strong in its upper part that the attenuation tends to zero because droplets are carried away.     

A new structural model of effective thermal conductivity for heterogeneous materials with co-continuous phases

A new structural model for a heterogeneous material with multiple continuous phases is proposed. The corresponding equation for effective thermal conductivity was derived using three methods. The new model is substantially different from the conventional five fundamental structural models (Series, Parallel, two forms of Maxwell–Eucken, Effective Medium Theory). The model has two applications. First, as a new fundamental structural model to produce composite models using the combinatory rules previously proposed by J.F. Wang, J.K. Carson, M.F. North, D. J. Cleland, A new approach to modelling the effective thermal conductivity of heterogeneous materials, International Journal of Heat and Mass Transfer, 49 (17–18) (2006) 3075–3083. Second, to narrow the bounds of the effective thermal conductivity for heterogeneous materials where the physical structure can be characterised into general classes.     

阴角夹角构型对聚氨酯保温材料火蔓延影响试验探究

摘 要：通过开展小尺寸试验研究,分析了阴角夹角构型对聚氨酯保温材料向下火蔓延特性的影响,分析不同夹角构型对聚氨酯保温材料火蔓延典型特征参数的影响,主要包括火焰形态、质量损失速率、近域场温度和火蔓延速率。研究结果表明：在边墙的约束条件下,阴角夹角为30°时试样的燃烧程度明显大于150°;对于阴角夹角构型形成的受限空间,小角度夹角构型下聚氨酯试样燃烧程度大于较大夹角构型;受侧边墙体限制效应的影响,聚氨酯保温材料火蔓延过程中质量损失率和火蔓延速率均随阴角夹角的增大呈先减小后增大的趋势;由于烟囱效应的拉伸作用,火蔓延会形成两个温度峰值,且第一个温度峰值大于第二个温度峰值。     

地方应用性高校卓越人才培养实施路径研究——以安徽建筑大学为例

基于地方高校人才培养、科学研究、社会服务、文化传承创新四大功能间的互动关系,文章以安徽建筑大学为例,探索地方应用性高校卓越人才培养的实施路径。提出地方应用性高校应进一步准确定位,发挥比较优势,坚持错位发展,实现特色办学。以应用型人才培养为核心,加强特色领域的科学研究与社会服务,形成特色区域文化教育教学体系,全面提高卓越应用型人才培养质量。     

纳米材料的生态环境暴露与生态环境效应研究及其控制体制

总结了纳米材料的生态环境暴露途径,分析了纳米材料在环境中的迁移、转化和蓄积过程,选择几种典型纳米材料研究对陆生植物的影响、对水体及水生生物的影响和对土壤的影响,并且依据毒理学或健康效应数据,结合工人的接触评价,综合判定危害的程度,提出了纳米材料的控制体制,具体的控制流程包括:上市前的检测、工艺控制、个人防护装备、生物监测与环境监测。同时对纳米材料的生态环境暴露与生态环境效应下一步研究进行了展望。     

Magnetic properties of polyaniline doped with FeCl3

Magnetic properties of polyaniline (PANI) doped with FeCl₃ were investigated as a function of temperature and magnetic field. The temperature dependence of the magnetic susceptibility (χ) of PANI doped with FeCl₃ exhibits dominant paramagnetic component (well described by Curie–Weiss law with a negative Curie–Weiss temperature Θ) accompanied by a small temperature-independent paramagnetic contribution. Magnetization measured as the function of magnetic field shows smaller saturation effect than expected for non-interacting iron ions. These two observations suggest weak antiferromagnetic (AF) interactions between Fe ions.     

Impact of Pt bottom electrode on the properties of ferroelectric Bi3.25La0.75Ti3O12 capacitors

Lanthanum-modified bismuth titanate (Bi_3.25La_0.75Ti₃O₁₂) (BLT) films have been prepared on platinized silicon substrates using sol–gel method. Highly (001) or (111) oriented platinum layers are used as the bottom electrodes of ferroelectric BLT capacitors to study the effects of Pt orientation on the structural and physical properties of BLT films. X-ray diffraction (XRD) and atomic force microscopy (AFM) measurements demonstrate that the microstructure and morphology of BLT films are not strongly affected by the Pt films. BLT film on highly (111) oriented Pt possesses much higher remanent polarization (∼ 8 μC/cm²) than that on highly (001) oriented Pt although the coercive fields of the two kinds of Bi_3.25La_0.75Ti₃O₁₂ films are almost equal.