开放物理实验教学模式的探索与实践

在广泛调研和总结经验的基础上,对大学物理实验开放教学模式进行了深入研究,形成比较可行的大学物理实验课程开放教学模式.通过设立创新工作室、网络实验室以及教学内容分层次等措施,实现了实验室硬件资源,实验教学活动在时间、空间和实验内容的深入开放,基本弥补了传统实验教学模式的不足.     

探索高校实验室大型仪器设备管理新模式

高等学校大型仪器设备是从事教学、科研的重要条件和基本手段,是学校综合实力的体现。随着现代科学技术的迅猛发展,知识在经济发展中起到越来越重要的作用,使得高校大型仪器设备的管理显得尤为重要。结合工作实践,以及对目前高校实验室大型仪器设备管理及使用现状的分析,提出了加强高校大型仪器设备管理,提高大型仪器设备使用效率的若干措施。     

关于Mordell方程y^2=x^3＋k

设l,l1,l2,…,ls为任意整数,n为正整数,n1,n2,…,ns为任意非负整数．用初等数论方法证明了：如果k满足k=（4l＋2）^3-Пi=1^s（4li＋1）^2ni或k=（4l＋3）^3-2^2nПi=1^s（4li＋1）^2ni,则Mordell方程y^2=x^3＋k无整数解．     

Enabling Mg metal anodes rechargeable in conventional electrolytes by fast ionic transport interphase

Rechargeable magnesium batteries have received extensive attention as the Mg anodes possess twice the volumetric capacity of their lithium counterparts and are dendrite-free. However, Mg anodes suffer from surface passivation film in most glyme-based conventional electrolytes, leading to irreversible plating/stripping behavior of Mg. Here we report a facile and safe method to obtain a modified Mg metal anode with a Sn-based artificial layer via ion-exchange and alloying reactions. In the artificial coating layer, Mg₂Sn alloy composites offer a channel for fast ion transport and insulating MgCl₂/SnCl₂ bestows the necessary potential gradient to prevent deposition on the surface. Significant improved ion conductivity of the solid electrolyte interfaces and decreased overpotential of Mg symmetric cells in Mg(TFSI)₂/DME electrolyte are obtained. The coated Mg anodes can sustain a stable plating/stripping process over 4000 cycles at a high current density of 6 mA cm⁻². This finding provides an avenue to facilitate fast ion diffusion kinetics of Mg metal anodes in conventional electrolytes.     

发展中国电子商务的几点思考

“电子商务”这个名词在我国已经不在是陌生的名词了,它已经在中国越来越被人们所认可.什么是电子商务?所谓电子商务(ElectronicCommerce)是利用计算机技术、网络技术和远程通信技术,实现整个商务(买卖)过程中的电子化、数字化和网络化。人们不再是面对面的、看着实实在在的货物、靠纸介质单据(包括现金)进行买卖交易。而是通过网络,通过网上琳琅满目的商品信息、完善的物流配送系统和方便安全的资金结算系统进行交易(买卖)。     

基于数学实验的高等数学教学改革

文章分析了现行理工科高等数学教学中存在的主要问题,论述了数学实验的引入是解决这些问题的重要方法,是培养数学素质不可缺少的环节。在不断普及与迅速发展的计算机等先进科技的支持下,数学教育应改变传统的教学模式,走进实验室,并就如何更好地发挥数学实验教学的作用提出了一些具体管理措施。     

Genomic diversity and post-admixture adaptation in the Uyghurs

Population admixture results in genome-wide combinations of genetic variants derived from different ancestral populations of distinct ancestry, thus providing a unique opportunity for understanding the genetic determinants of phenotypic variation in humans. Here, we used whole-genome sequencing of 92 individuals with high coverage (30–60×) to systematically investigate genomic diversity in the Uyghurs living in Xinjiang, China (XJU), an admixed population of both European-like and East-Asian-like ancestry. The XJU population shows greater genetic diversity, especially a higher proportion of rare variants, compared with their ancestral source populations, corresponding to greater phenotypic diversity of XJU. Admixture-induced functional variants in EDAR were associated with the diversity of facial morphology in XJU. Interestingly, the interaction of functional variants between SLC24A5 and OCA2 likely influences the diversity of skin pigmentation. Notably, selection has seemingly been relaxed or canceled in several genes with significantly biased ancestry, such as HERC2–OCA2. Moreover, signatures of post-admixture adaptation in XJU were identified, including genes related to metabolism (e.g. CYP2D6), digestion (e.g. COL11A1), olfactory perception (e.g. ANO2) and immunity (e.g. HLA). Our results demonstrated population admixture as a driving force, locally or globally, in shaping human genetic and phenotypic diversity as well as in adaptive evolution.     

Replication,pathogenicity, and transmission of SARS-CoV-2 in minks

Minks are raised in many countries and have transmitted severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to humans. However, the biologic properties of SARS-CoV-2 in minks are largely unknown. Here, we investigated and found that SARS-CoV-2 replicates efficiently in both the upper and lower respiratory tracts, and transmits efficiently in minks via respiratory droplets; pulmonary lesions caused by SARS-CoV-2 in minks are similar to those seen in humans with COVID-19. We further found that a spike protein-based subunit vaccine largely prevented SARS-CoV-2 replication and lung damage caused by SARS-CoV-2 infection in minks. Our study indicates that minks are a useful animal model for evaluating the efficacy of drugs or vaccines against COVID-19 and that vaccination is a potential strategy to prevent minks from transmitting SARS-CoV-2.     

Static analysis of synchronism deployable antenna

INTRODUCTION Large antennas for space applications have some differences as compared to their counterparts de-signed and manufactured for ground usage. For a larger space antenna, the applied loads in space can be several orders of magnitude less than the gravity loading it is subjected to when being fabricated and assembled on the ground. Since the effect of gravity cannot be removed from any experimental verifica-tion performed on the ground, we must rely on the use of efficient and hig…     

汉英表量结构中隐喻的分类及认知解读

以＂合成空间理论＂为理论背景,研究汉英表量结构中隐喻的分类与认知解读问题。根据输入空间的不同,从认知角度将汉英表量结构中的隐喻分为两类：显性隐喻和隐性隐喻。显性隐喻是通过＂量词＂和＂名词＂两个输入空间之间的概念整合进行建构的,而隐性隐喻是通过量词所描述的＂原型名词＂和表量结构中的＂名词＂两个输入空间之间的概念整合进行建构的。