Sonochemical dissolution of cinnabar (alpha-HgS)

To investigate the sonochemical dissolution of cinnabar, sulfur oxidation products (S(ox)) and dissolved Hg(II) released into the aqueous solution were determined. Detected S(ox), in the presence of ultrasound suggests that dissolution of cinnabar occurred. Terephthalic acid (TA) used to scavenge *OH in bulk solution formed from sonication showed that oxidative dissolution occurred in both the bulk solution and the interfacial areas of cavitation bubbles. Dissolved S(-II) was not detected, and SO4(2-) was the main S(ox) indicating that the formation of S(-II) from cinnabar by physical and thermal effects of sonication was the rate-limiting step. Hg(Il) released was much lower than S species measured. Hg(II) adsorption isotherms indicated that dissolved Hg(II) adsorbed back onto the remaining cinnabar particles lowering Hg(II) release. Ultrasound significantly reduced cinnabar particle size and increased surface area, leading to higher Hg(ll) adsorption. In addition, the cinnabar surface isoelectric point (IEP) increased after sonication, indicating adsorption of Hg(II) and/ or mineral phase transformation from cinnabar to metacinnabar. The presence of humic acid (HA) and ultrasound enhanced cinnabar dissolution and greatly increased the dissolved Hg(ll) concentration due to the synergistic effects of ultrasound and HA.     

Stable Zinc Anodes Enabled by Zincophilic Cu Nanowire Networks

Zn-based electrochemical energy storage(EES)systems have received tremendous attention in recent years,but their zinc anodes are seriously plagued by the issues of zinc dendrite and side reactions(e.g.,corrosion and hydrogen evolution).Herein,we report a novel strategy of employing zincophilic Cu nanowire networks to stabilize zinc anodes from multiple aspects.According to experimental results,COMSOL simulation and density functional theory calculations,the Cu nanowire networks covering on zinc anode surface not only homogenize the surface electric field and Zn²⁺concentration field,but also inhibit side reactions through their hydrophobic feature.Meanwhile,facets and edge sites of the Cu nanowires,especially the latter ones,are revealed to be highly zincophilic to induce uniform zinc nucleation/deposition.Consequently,the Cu nanowire networks-protected zinc anodes exhibit an ultralong cycle life of over 2800 h and also can continuously operate for hundreds of hours even at very large charge/discharge currents and areal capacities(e.g.,10 mA cm^-2and 5 mAh cm^-2),remarkably superior to bare zinc anodes and most of currently reported zinc anodes,thereby enabling Zn-based EES devices to possess high capacity,16,000-cycle lifespan and rapid charge/discharge ability.This work provides new thoughts to realize long-life and high-rate zinc anodes.     

电力变压器关键尺寸视觉检测方法及其缩比模型验证

电力变压器的关键尺寸测量是其装配制造、运输安装过程中重要一环,现有测量方法操作繁琐且效率较低。为此,本文提出了一种适用于110 kV油浸式电力变压器关键尺寸视觉检测方法,该方法利用YOLO目标检测算法、Grabcut图像分割算法实现关键组部件的智能检测与分割,然后基于双目立体视觉原理实现套管相间距离及变压器最大截面外形尺寸等关键尺寸的测量。本文搭建了110 kV油浸式电力变压器外观缩比模型,试验分析了拍摄距离和角度等因素对电力变压器关键尺寸视觉检测的影响。结果表明,本文基于缩比模型试验实现了在不同拍摄距离与角度下变压器关键尺寸的视觉检测,验证了该方法的有效性。本文方法可以为110 kV油浸式电力变压器现场尺寸测量提供参考。     

浇注温度和细化剂对K4169高温合金铸态组织的影响

研究了K4169高温合金在不同浇注温度下向熔体中加入和不加入细化剂的晶粒尺寸和组织特征。结果表明:降低浇注温度或者添加细化剂都能减小晶粒尺寸和提高等轴晶比例。在浇注温度1520℃时,向熔体中加入细化剂,可使圆柱锭的晶粒尺寸由原来的10.56 mm细化至2.84 mm,断面等轴晶比例由原来的10%提高到81%。     

MoB-CoCr涂层耐锌液腐蚀性能研究

研究了超音速火焰喷涂制备的MoB-CoCr涂层在熔融锌液中的腐蚀情况,并分析锌液对MoB-CoCr涂层的腐蚀机理。结果表明,涂层中的缺陷孔隙成为裂纹源,而MoB-CoCr涂层的残余应力、淬火应力以及涂层与不锈钢热膨胀系数不匹配所产生的应力使涂层开裂,甚至涂层与基体发生剥离,锌渗入到涂层缺陷中使裂纹扩展,形成沿着裂纹的腐蚀,加速了涂层的失效。     

γ-Y2Si2O7, a Machinable Silicate Ceramic: Mechanical Properties and Machinability

In this paper, the mechanical properties of bulk single-phase γ-Y₂Si₂O₇ ceramic are reported. γ-Y₂Si₂O₇ exhibits low shear modulus, excellent damage tolerance, and thus has a good machinability ready for metal working tools. To understand the underlying mechanism of machinability, drilling test, Hertzian contact test, and density functional theory (DFT) calculation are employed. Hertzian contact test demonstrates that γ-Y₂Si₂O₇ is a "quasi-plastic" ceramic and the intrinsically weak interfaces contribute to its machinability. Crystal structure characteristics and DFT calculations of γ-Y₂Si₂O₇ suggest that some weakly bonded planes, which involve Y–O bonds that can be easily broken, are the sources of the low shear deformation resistance and good machinability.     

Theoretical prediction and experimental realization of transition metal doped rutiles as diluted magnetic semiconductors

1. Introduction The new research area of ‘spintronics’ seeks to extend the properties and applications of electronic devices by making use of the spin of electrons in ad- dition to their charge. The development of magnetic semiconductors would be compatible with standard semiconductor technology and open new opportuni- ties. The so-called diluted magnetic semiconductor (DMS) is used to denote the no magnetic semicon- ductor doped with magnetic ions, and there have been considerable progress…     

圩田景观视野下的宁波日月二湖传统风景营建研究

首先对宁波平原圩田景观的发展沿革进行论述.其次,剖析了鄞西圩区、宁波市与日月二湖在圩田水系整理方面的关系,并梳理了日月二湖的景观营建过程,指出日月二湖的布局结构体现了圩田水利系统和开垦方式,是该区域圩田景观的特定表达.并分析日月二湖与宁波平原中的众多聚落公共空间的发育具有相似性,两者很大程度上都源于圩田开垦机制.最后,...     

碳达峰路径与智力城镇化

研究显示碳达峰与城镇化成熟期时间上高度重合,碳达峰国家达峰时的城镇化率均值在74％左右,因此如何把握城镇化与碳达峰的精准关系极为重要.基于全球198个国家和地区1960-2018年社会经济及碳排数据,引入机器学习算法,探寻世界国家碳达峰路径与智力型、体力型城镇化路径分化的内在关系,找出智力型国家碳达峰的关键衡量指标,并进一步分析智力型国家的创新驱动因子对其达峰路径的影响机制,以此为中国智慧创新的碳达峰道路提供借鉴.提出碳达峰路径的五种橄榄曲线,并指出中国未来的碳达峰道路必须由双层智慧进行控制,即达峰曲线的智慧设计,以及曲线内部造成不同走向的智力关键要素含量的设计.在国家2030年碳达峰总目标下,需结合地方差异性设计各个城市和区域的特殊曲线,制定各自的智慧策略.     

基于计算机视觉的建筑外墙剥落和裂缝两阶段检测方法

地震灾害中,对建筑物外墙立面损伤状况进行快速检测有利于灾情评估与灾后重建。为实现建筑外墙立面剥落和裂缝的自动化非接触式检测,提出了一种结合深度学习与图像处理的外墙损伤定位与量化评估的两阶段检测方法。通过建立并标定北川老县城地震破坏房屋数据集,采用基于损失函数模型Focal Loss的目标检测网络定位破损区域目标框,并克服小尺度区域的正负样本不均衡问题。根据提取的目标破损区域单幅图像,提出图像滤波、阈值分割和形态学操作的组合处理流程,进行贴面砖墙面下剥落和裂缝的像素级别分割与提取。进一步结合像素尺度与物理尺度的映射关系,完成剥落面积、裂缝宽度等关键破损信息的计算与识别。结果表明,该方法可较好地对震后建筑物外墙立面的墙面剥落和裂缝进行定位和提取,对墙面损伤可实现像素级分割并准确地识别损伤关键物理参数,能实现对建筑物震后损伤的准确和快速检测。