The Effect of Tb80Fe20/Al Co-adding on Coercivity and Thermal Stability in Sintered Nd–Fe–B Magnets

Journal of Superconductivity and Novel Magnetism - The influence of Tb80Fe20/Al co-adding on coercivity and temperature stability of sintered Nd–Fe–B magnets was studied. Compared with...     

多晶硅锭中硬质点分析及控制研究

以多晶硅锭中硬质点为研究对象,通过实验研究和数值模拟的方法,对多晶硅锭中硬质点进行形貌和成分分析,并提出改善控制方法。研究结果表明硅锭中部的硬质点较细小,主要由SiC组成;硅锭头部的硬质点较粗大,主要由SiC和Si3N4组成,还有少量O的存在。进一步研究发现多晶硅定向凝固铸锭炉的热场结构对于多晶硅锭硬质点形成有直接影响,通过改进热场结构,优化晶体生长界面,显著减少了铸锭中硬质点的数量。     

A Two-Stage Genetic Algorithm for Molding Parameters Optimization for Minimized Residual Stresses in Composite Laminates During Curing

The residual stress generated during the curing process of composite structures will seriously reduce the material performance. This paper presents a two-stage genetic algorithm (GA) procedure to inversely determine the optimal molding parameters that minimize residual stresses. In our proposed two-stage GA procedure, a finite element model for Multiphysics simulation is first created to compute the residual stresses of the composite laminated plate for a given temperature curve. The FEM model is then modulated by an improved GA with the residual stresses of the plate as the objective function. The improved GA is called in two-stages: the first stage determines a set of likelihoods of the modeling parameters around which the "optimal" parameters may reside. The 2^nd stage zooms-in the areas centered by these likelihoods, which finds molding parameters that minimize the residual stresses. The results show that the proposed two-stage genetic algorithm is more efficient than the traditional genetic algorithm.

     

Bioengineered magnetoferritin nanozymes for pathological identification of high-risk and ruptured atherosclerotic plaques in humans

Atherosclerotic plaque rupture results in thrombus formation and vessel occlusion, and is the leading cause of death worldwide. There is a pressing need to identify plaque vulnerability for the treatment of carotid and coronary artery diseases. Nanomaterials with enzyme-like properties have attracted significant interest by providing biological, diagnostic and prognostic information about the diseases. Here we showed that bioengineered magnetoferritin nanoparticles (M-HFn NPs) functionally mimic peroxidase enzyme and can intrinsically recognize plaque-infiltrated active macrophages, which drive atherosclerotic plaque progression and rupture and are significantly associated with the plaque vulnerability. The M-HFn nanozymes catalyze the oxidation of colorimetric substrates to give a color reaction that visualizes the recognized active macrophages for one-step pathological identification of plaque vulnerability. We examined 50 carotid endarterectomy specimens from patients with symptomatic carotid disease and demonstrated that the M-HFn nanozymes could distinguish active macrophage infiltration in ruptured and high-risk plaque tissues, and M-HFn staining displayed a significant correlation with plaque vulnerability (r = 0.89, P < 0.0001).

     

Inclusion Capture Probability Prediction Model for Bubble Floatation in Turbulent Steel Flow

Metallurgical and Materials Transactions B - The turbulent flow around bubbles is simulated for the fixed turbulent kinetic energy. Inclusion motion through the flow field is studied by considering...     

蒸压加气混凝土砌块生产线升级改造技术简析

目前,在加气混凝土行业中有很多的企业都在寻求扩大生产规模,以自动化、规模化生产寻求发展。目前行业中企业最大规模达200多万m3/a,近年来新上生产线行业平均规模25万m3/a以上,年生产规模50万m3的企业数明显增加。在原有生产线基础上改扩建年产40万m3加气混凝土砌块及板材生产线已成为加气混凝土企业的普遍现象,这样的项目建设既可使电厂排放的粉煤灰及脱硫石膏等资源得到充分利用,又可以缓解周边新型墙材市场供求紧张局面,且兼顾适应未来装配式建筑构件的发展,同时还可以改善当地环境状况,取得较好的企业经济效益。     

认知结构理论指导下的高校应用电化学课程双语教学实践

应用电化学是一门讲述基本电极过程、电化学分析技术及能量储存与转换等知识的专业基础课程。太原理工大学化学化工学院在认知结构教学理论的指导下,以英文原版教材为基础,以中英文结合的教学语言为媒介,采用讲授为主、翻转课堂为辅的教学方法,实施了应用电化学课程双语教学,并同步进行了实验教学和评价方式的改革。教学充分激发了学生的学习兴趣,获得了良好的效果。     

Transformation between nanosheets and nanowires structure in MnO2 upon providing Co2+ ions and applications for microwave absorption

The phase transition process of the MnO₂ phase with increases in Co²⁺ doping can be described by the Ouroboros symbol. The undoped sample is pure δ-MnO₂ with nanosheets structures. Then a small amount of Co²⁺ ions changes the final products and generates α-MnO₂ nanofibres in the δ-MnO₂ matrix. The products become pure α-MnO₂ with an appropriate amount of Co added. However, when the Co amount continues to increase, the amount of α-MnO₂ decreases in the products and turns back to form pure δ-MnO₂ in the end. Analysing the electromagnetic absorption performance, the relationship between the properties and the proportion of δ-MnO₂/α-MnO₂ in the powders adjusted by Co²⁺ doping has been explored, and the composites of δ-/α-MnO₂ show better absorption ability than the single-phase samples. As a result, the optimal reflection loss (RL) is −54.8 dB, and the effective absorption bandwidth can cover the Ku band at a thickness of 2.2 mm and the X band at a thickness of 3.1 mm with 50 wt.% filler loading ratios. This research might shed new light on the improvement of novel microwave absorption materials.