High-Chern-number and high-temperature quantum Hall effect without Landau levels

The quantum Hall effect (QHE) with quantized Hall resistance of h/νe² started the research on topological quantum states and laid the foundation of topology in physics. Since then, Haldane proposed the QHE without Landau levels, showing nonzero Chern number |C| = 1, which has been experimentally observed at relatively low temperatures. For emerging physics and low-power-consumption electronics, the key issues are how to increase the working temperature and realize high Chern numbers (C > 1). Here, we report the experimental discovery of high-Chern-number QHE (C = 2) without Landau levels and C = 1 Chern insulator state displaying a nearly quantized Hall resistance plateau above the Néel temperature in MnBi₂Te₄ devices. Our observations provide a new perspective on topological matter and open new avenues for exploration of exotic topological quantum states and topological phase transitions at higher temperatures.     

A2N工艺中有机物分子量分布及变化

本文利用超滤-纳滤膜法对改进A2N工艺中污水有机物分子量分布及变化进行测定试验研究。试验表明：原水中有机物近70%为颗粒性,且剩余溶解性有机物(DOC)在0.45μm~300分子量区间上呈现W型分布,其中在>10w、1w~5k、<1k的有机物分别占36.76%、8.36%、45.18%;经工艺处理,颗粒性有机物去除98.58%,其中80.42%在预缺氧池被吸附去除,总DOC去除80.49%,且出水在0.45μm~300区间上分布平缓,各区间出水TOC浓度明显减少,均小于1mg/L。由此可知,反硝化碳源不仅来源于溶解性小分子有机物,其中颗粒性大分子有机物也是主要贡献者,且厌氧处理是颗粒性有机物向溶解性转化的有效方法。     

“黑白文艺社”考述

黑白文艺社是20世纪三四十年代浙江大学最具影响力的学生社团之一。本文立足于档案史料,对黑白文艺社的发展脉络及主要活动进行考述,并指出其在思想启蒙、抗日救亡、营造文化、培养干部等方面的意义。     

再谈“让课程面向事情本身”——兼论课程的实践品质

从目的层面看,课程"面向事情本身"的根本目的在于提升学生的实践智慧,即让学生掌握"事情本身"显现的方式,让学生合乎理性地去生活,让学生以"以道观之"的方式认识世界;从内容层面看,课程所面向的"事情本身"具有明显的实践性",事情本身"归根到底是在实践中生成的,并在实践中显现自身;从方法层面看,课程"面向事情本身"的本体性方法是实践论方法,即以体验为中心,通过主体与世界的交互作用回到"事情本身"。     

太平宰相的平夷雅正——李昉的“白体诗”创作

李昉作为宋初＂白体诗＂的代表诗人,其诗歌创作体现出典型的＂白体诗＂特点：诗人心态上,居事常简,闲适清静;诗歌形式上,多属对工巧、＂吟玩性情＂的唱和之作,并以五言、七言律诗为主;语言风格上,闲适散淡、平夷雅正。     

郭沫若新诗中的白色——以《女神》为例

郭沫若最喜欢的色彩是白色,在《女神》中,白色的形象出现多达109次,这与郭沫若生活的环境、喜爱的诗人如李白、王维以及道家、基督教的影响有密切关联。白色使郭沫若的诗歌呈现出构图美,处处闪现着空白的意蕴,诗歌意境灵动轻盈。诗中的白色,在光的照耀下具有一种透明温热的感觉,而不像初期象征派诗中因为雾烟的遮挡,白色显得污浊和灰暗。郭沫若诗中的白色具有其独特的美感。     

随机Cahn-Hilliard方程的有限差分法

对随机Cahn-Hilliard方程建立六点Crank-Nicolson差分格式来求其数值解,以数值解来逼近方程的真解.最后,讨论了该格式的稳定性与收敛性.     

伊犁河谷新垦区土壤有机质、全氮、全磷特征

对伊犁河谷新垦区不同土地利用方式下土壤剖面有机质、全氮、全磷含量进行分析,结果表明:不同土地利用方式,土壤有机质、全氮含量明显不同,都是未开垦荒地最大,杨树林地、树上干杏林地次之,油葵地(耕地)最小,撂荒地因弃耕比油葵地稍大;土壤全磷则是树上干杏林地最大,油葵地最小。新垦区土壤有机质、全氮、全磷含量随着深度变大含量都有所减小,表现出的表聚的特征,并且有机质与全氮含量随深度增加差异也逐渐减小。研究区土壤有机质含量与全氮、全磷含量相关性较好,尤其是有机质与全氮具有更高的相关度。为了防止土地肥力逐渐退化,研究区应提倡以林草为主的土地利用方式,并且在耕作中适量增施有机肥。     

“顺万物之性，游变化之途”——从郭注、成疏《逍遥游》看庄子的思想

以如何在现实的人间世之中达到对人性的终极关怀,庄子将“逍遥”引入了人间世。同时,庄子的《逍遥游》也是一种给予重重束缚下人生以一种自由的希望,因此,本文即从郭注成玄英疏探讨庄子《逍遥游》的境界及意义,从“顺万物之性,游变化之途”阐述对庄子的思想世界更深入的理解。     

Investigation of Fogging on Glass Display Cases at the Royal Ontario Museum

ABSTRACT

Shortly after a major renovation at the Royal Ontario Museum, it was noticed that the glass panels in many of the new display cases exhibited fogging or hazing on the surface, sometimes in very specific patterns. Cleaning removed the fogging temporarily, but it began to reappear within 12 months. An investigation of fogged glass panels in display cases was undertaken to understand the source of the fogging and to develop an appropriate cleaning method. This included the analysis of residues from glass panels in several galleries, and surface imaging and compositional analysis of glass panels. The fogging residues on the glass panels consist mainly of sodium salts of organic acids and inorganic anions. Sources of the sodium in the residues include air particulate matter and the glass itself. The organic acids and inorganic anions that form salts with the sodium cations likely originate from volatile organic compounds (VOCs) and particulate matter in the air. Examination of the fogging patterns on the glass panels revealed that the sodium salts grow on marks made during cleaning attempts and the manufacturing process. These cleaning and manufacturing marks contain greasy residues that encourage crystal growth. Because of the variation in surface cleanliness, panels with more cleaning and manufacturing residues appear to be heavily fogged while those with less may appear to be unfogged in the museum display cases. A cleaning protocol was tested on two of the glass panels, and was found to remove all traces of grease and fogging residue.