建筑施工过程中的环境管理

从噪声、粉尘、污水、大气污染物、固体废弃物等方面阐述了施工企业常见的环境污染因素,并提出了控制各种环境污染因素的措施,指出企业应在施工中进行合理的环境管理,解决好环境问题,从而提高企业形象,增强企业竞争能力。     

粘弹性阻尼器的计算模型模拟分析

介绍了粘弹性阻尼器的构造与力学性能,研究分析了用于分析粘弹性阻尼器的3种计算模型,并通过实例试验进行了试验结果与计算模型的对比分析,得出了相关结论。     

造纸固废处理专利技术分析

2008年至2018年专利数量基本呈线性增长。利用IPC分类号和关键词在中文专利数据库中进行检索,对我国造纸固废处理技术的申请量、主要申请区域、主要申请人、技术分布等情况进行分析。研究热点和重点为焚烧发电、生产纤维板、作为燃料回收利用等。     

硫酸法钛白粉酸解主反应对固相物溶解度的影响

在硫酸法钛白粉生产过程中,钛精矿酸解产生的固相物难以溶解是限制钛白粉产能的主要因素。为降低其影响,对酸解固相物进行了X射线衍射（XRD）分析;对钛精矿酸解主反应影响因素包括酸矿比、反应酸浓度和引发温度等对固相物溶解率的影响进行了对比实验。XRD分析表明,钛精矿酸解过程产生的钛的硫酸盐并没有形成晶体,固相物的溶解只是物理过程。钛精矿酸解主反应影响因素对比实验结果表明,影响钛精矿酸解固相物溶解难易程度的因素从大到小的顺序为反应酸浓度、引发温度,酸矿比没有影响。随着反应酸浓度升高,主反应速率加快,脱水率上升,钛的硫酸盐中结合水含量减少,溶解率降低,固相物越难溶解。酸解过程最优反应酸质量分数为82%~83%,引发温度为145 ℃。     

复合固体推进剂在石灰石矿山深孔爆破中的应用

通过前期对石灰石矿山露天深孔爆破技术的了解和考察,首次将复合固体推进剂余药应用于石灰石矿山爆破工程,基于原有使用炸药的设计方法,结合现场情况,针对复合固体推进剂设计了一套爆破方案,并不断优化爆破参数,爆破结果表明,复合固体推进剂能够很好的满足石灰石矿山露天深孔爆破的要求,解决了长期以来以焚烧方式进行复合固体推进剂余药的销毁工作,为复合固体推进剂余药的销毁提供了一条新途径。     

Induced p-type semiconductivity in yttria-stabilized zirconia

8 mol% yttria-stabilized zirconia (8YSZ) ceramic is an oxide ion conductor at atmospheric pressure but shows the onset of p-type semiconduction, in addition to the preexisting oxide ion conduction, on application of a dc bias in the range 4-66 Vcm⁻¹ and at temperatures in the range 150°C-750°C. The p-type behavior is attributed to the location and hopping of holes on oxygen. This contrasts with the commonly observed introduction of n-type conduction under reducing conditions and high fields. The hole conductivity increases with both dc bias and pO₂. Its occurrence may contribute to the early stages of flash phenomena in 8YSZ ceramics.     

One-step synthesis of coral-like high-entropy metal carbide powders

The synthesis of high-entropy metal carbide powders is critical for implementing their extensive applications. However, the one-step synthesis of high-entropy metal carbide powders is rarely studied. Herein, the synthesis possibility of high-entropy metal carbide powders, namely (Zr_0.25Ta_0.25Nb_0.25Ti_0.25)C (ZTNTC), via one-step carbothermal reduction was first investigated theoretically by analyzing chemical thermodynamics and lattice size difference based on the first-principle calculations, and then the ZTNTC powders with particle size of 0.5-2 μm were successfully synthesized experimentally. The as-synthesized powders not only had a single rock-salt crystal structure of metal carbides, but also possessed high-compositional uniformity from nanoscale to microscale. More interestingly, they exhibited the distinguished coral-like morphology with the hexagonal step surface, whose growth was governed by a classical screw dislocation growth mechanism.     

Synthesis and thermal stability of (Co,Ni)O solid solutions

(Co,Ni)O solid solutions are considered as promising protective materials of O₂-evolving anodes for Al production. In this context, two solid-state synthesis methods, namely high-energy ball milling (HEBM) and calcination, have been evaluated for the synthesis of (Co,Ni₎O solid solutions. In all cases, Co_xNi_1−xO solid solutions can be formed over the whole composition range. However, undesired WC contaminant is observed using the HEBM method due to the erosion of the milling tools. Their thermal stability in air has been analyzed by thermogravimetric analyzes (TGA) complemented by X-ray diffraction (XRD) analyses. It is shown that Co_xNi_1−xO solid solutions are stable at 1000°C over the whole composition range whereas they are only stable for x ≤ 46 and x ≤ 22 at 800°C and 700°C, respectively. For higher Co contents, the formation of Co₃O₄ is observed. This is a relevant information for their future use for Al production, which can be done at different temperatures (~700-1000°C) depending of the electrolyte composition.     

High temperature mechanical behavior of porous ceria and ceria-based solid-oxide fuel cells

Multiple environment mechanical testing of solid-oxide fuel cells (SOFCs) and SOFC materials is critical to ensure appropriate compressive sealing in stack designs. Establishing the effects of temperature, environment, and porosity on the flexural strength of ceria-based SOFCs is a significant step toward practical deployment of the technology. This article presents research into these properties by use of a temperature and atmosphere controlled 3-point bend fixture capable of reaching Intermediate Temperature (IT)-SOFC operating conditions (650°C). Gadolinium-doped ceria (GDC) samples with varying porosity and pore geometry were tested and it was determined that more spherical porosity contributed to improved flexural strength as compared with higher aspect ratio porosity. A linear strengthening effect was also observed with increasing temperature from ambient to 650°C for GDC-based anode support layers and half-cell samples. Scanning electron microscopy was performed on fracture surfaces to identify fracture modes and to examine internal pore structures. Directionality of the applied stress with respect to the layered microstructure was found to have no measurable impact on mechanical properties in air, but orientation had a significant impact on strength of cells with reduced anodes. Additionally, with the support of thermogravimetric analysis, it was determined that after reduction, exposure to oxygen below 100°C does not influence mechanical properties of the cells.     

液黏传动摩擦副流固耦合传热分析

为探求液黏传动在充满工作油的流体阶段摩擦副温度分布情况,建立薄盘结构摩擦副热流固耦合模型,采用计算机流体仿真软件FLUENT对径向槽摩擦副进行数值模拟,得到摩擦副的温度云图。通过搭建液黏传动装置试验台,测得径向油槽摩擦副间油膜温度分布数据。结果表明:在径向方向上,随半径的增加,摩擦副温度逐渐增加且沟槽处温度低于无沟槽处;在圆周方向上,相同半径处摩擦副的沟槽区比无沟槽区温度高,表明沟槽可以有效地降低工作油的升温;在纯油膜阶段摩擦片升温明显高于对偶片升温。有限元分析和实验研究结果趋势基本一致,验证了理论分析的可靠性。