Short-Term Mindfulness Intervention on Adolescents’ Negative Emotion under Global Pandemic

Objective:In this research,we tried to explore how short-term mindfulness(STM)intervention affects adoles-cents’anxiety,depression,and negative and positive emotion during the COVID-19 pandemic.Design:10 classes were divided into experiment groups(5 classes;n=238)and control(5 classes;n=244)randomly.Hospital Anxi-ety and Depression Scale(HADS)and Positive and Negative Affect Schedule(PANAS)were used to measure par-ticipants’dependent variables.In the experiment group,we conducted STM practice interventions every morning in theirfirst class from March to November 2020.No interventions were conducted in the control group.Methods:Paired-sample t-tests were used to identify if a significant difference exists between every time point of the experimental and control groups.Repeated ANOVA and Growth Mixture Model(GMM)were used to analyze the tendency of positive and negative emotions,anxiety,and depression in the experimental group.Results and Conclusions:(1)With the intervention of STM,there was a significant decrease in negative emotions and an increase in positive emotions in the experimental group,whereas there were non-significant differences in the control group.(2)To explore the heterogeneity trajectories of dependent variables,we built a GMM and found there were two latent growth classes in the trajectories.(3)The results of the models showed their trajec-tories were downward,which meant that the levels of anxiety,depression,and negative emotions of participants decreased during the STM training period.Nonetheless,the score of positive affect showed upward in three loops of intervention,which indicated that the level of the participants’positive affect increased through the STM inter-vention.(4)This research indicated that STM should be given increasing consideration to enhance mental health during the worldwide outbreak of COVID-19.

基于学习通和钉钉直播的线上混合教学的探索与实践——以“配合物的价键理论”为例

基于新冠病毒感染肺炎疫情造成高校延期开学的背景,本文以无机化学课程中的“配合物的价键理论”为例,针对在线教学中存在的困难对混合教学模式进行重新设计和调整,通过学习通和钉钉直播实现线上混合教学。实践表明,这种线上混合教学设计在学生掌握知识的同时也培养了学生的自主学习能力,使学生获得了良好的学习体验,取得了良好的教学效果。

知识可视化在无机化学教学中的应用研究

知识可视化是一种有效促进知识学习、整理、创造和传播的技术。通过在无机化学教学中构建基于自我生成绘图策略和图形组织者策略的教学设计,将教学内容和教学方法与可视化表征高度融合,在实现显性知识高效传授的同时,能够培养学生思维能力和实现课程思政的有机融入。教学实践表明,知识视觉化呈现能够促进学生积极主动参与到教学过程中,激发学生积极思考,为学生创新能力和创造性思维的培养打下良好的基础。

基于深度学习的翻转课堂教学模式在“配合物的基本概念”中的教学设计与实践

翻转课堂是促进深度学习、提高教育质量的有效途径。我们将翻转课堂教学模式应用于“配合物的基本概念”的教学实践和探索。根据教学内容和学情分析,设计了层次化案例、分步和综合练习的教学策略以及结构化学习任务和元认知任务的学习策略。实践结果表明,基于深度学习的翻转课堂教学模式不仅能够帮助学生掌握核心概念,而且能够引导学生构建知识体系、自觉迁移知识、反思学习策略和方法,最终提升深度学习的能力。

Privacy Preserving Solution for the Asynchronous Localization of Underwater Sensor Networks

Location estimation of underwater sensor networks(USNs)has become a critical technology,due to its fundamental role in the sensing,communication and control of ocean volume.However,the asynchronous clock,security attack and mobility characteristics of underwater environment make localization much more challenging as compared with terrestrial sensor networks.This paper is concerned with a privacy-preserving asynchronous localization issue for USNs.Particularly,a hybrid network architecture that includes surface buoys,anchor nodes,active sensor nodes and ordinary sensor nodes is constructed.Then,an asynchronous localization protocol is provided,through which two privacy-preserving localization algorithms are designed to estimate the locations of active and ordinary sensor nodes.It is worth mentioning that,the proposed localization algorithms reveal disguised positions to the network,while they do not adopt any homomorphic encryption technique.More importantly,they can eliminate the effect of asynchronous clock,i.e.,clock skew and offset.The performance analyses for the privacy-preserving asynchronous localization algorithms are also presented.Finally,simulation and experiment results reveal that the proposed localization approach can avoid the leakage of position information,while the location accuracy can be significantly enhanced as compared with the other works.

Simultaneous determination of doxorubicin and its dipeptide prodrug in mice plasma by HPLC with fluorescence detection

A simple and sensitive high performance liquid chromatography with fluorescence detection （HPLC-FD） has been developed for simultaneous quantification of doxorubicin （DOX） and its dipeptide conjugate prodrug （PDOX） in mice plasma. The chromatographic separation was carried out on an Amethyst C18-H column with gradient mobile phase of 0.1% formic acid and 0.1% formic acid in acetonitrile at a flow rate of 1.0 mL/min. The excitation and emission wavelengths were set at 490 and 550 nm, respectively. The method was comprehensively validated. The limits of detection were low up to 5.0 ng/mL for DOX and 25.0 ng/mL for PDOX. And the limits of quantification were low up to 12.5 ng/mL for DOX and 50 ng/mL for PDOX, which were lower than those for most of the current methods. The calibration curves showed good linearity （R2 〉 0.999） over the concentration ranges. The extraction recoveries ranged from 84.0% to 88.2% for DOX and from 85.4% to 89.2% for PDOX. Satisfactory intra-day and inter-day precisions were achieved with RSDs less than 9.1%. The results show that the developed HPLC-FD method is accurate, reliable and will be helpful for preclinical pharmacokinetic study of DOX and PDOX.

Energy-Efficient Underwater Data Collection:A Q-Learning Based Approach

Underwater data collection is an importance part in the process of network monitoring,network management and intrusion detection.However,the limited-energy of nodes is a major challenge to collect underwater data.The solution of this problem are not only in the hands of network topology but in the hands of path of autonomous underwater vehicle(AUV).With the problem in hand,an energy-efficient data collection scheme is designed for mobile underwater network.Especially,the data collection scheme is divided into two phases,i.e.,routing algorithm design for sensor nodes and path planing for AUV.With consideration of limited-energy and network robustness,Q-learning based dynamic routing algorithm is designed in the first phase to optimize the routing selection of nodes,through which a potential-game based optimal rigid graph method is proposed to balance the trade-off between the energy consumption and the network robustness.With the collected data,Q-learning based path planning strategy is proposed for AUV in the second phase to find the desired path to gather the data from data collector,then a mode-free tracking controller is developed to track the desired path accurately.Finally,the performance analysis and simulation results reveal that the proposed approach can guarantee energy-efficient and improve network stability.

On Specificity of Politeness —— Contrastive Study of Western and Chinese Concepts of Politeness

Politeness is a social phenomenon, a means to achieve good interpersonal relationships, and a norm imposed by social conventions. Politeness is universal, that is, it can be observed as a phenomenon in all cultures. It is resorted to by speakers of different languages as a means to an end, and it is recognized as a norm in all societies. Despite its universality, the actual manifestations of politeness, the ways to realize politeness, and the standards differ in different cultures. Politeness is, to some extent, culture-specific.

Reform of Programming Fundamentals under the New Engineering Disciplines’ Background for Ethnic University

According to the requirement of New Engineering Disciplines initiated by the Ministry of Education of China,the course of Programming Fundamentals has been reformed in ethnic university to satisfy the standard of New Engineering Certification.The reform is implemented in teaching content,implementation in both theoretical and experimental classes,teaching assessment and teacher training.

角色扮演模式在神经内科医患沟通教学中的应用探索

医患沟通能力是医学生必须具备的基本素质之一,为了使住院医师更好地掌握医患沟通技巧,北京大学第三医院对神经内科的住院医师在教学中采用角色扮演的模式进行培训,对该培训模式做了初步的应用探索。由角色双方相互进行回馈指导,并由指导教师给予总结点评。该方法具有真实性、趣味性、方便性等特点。

Discussion on English-Language Films and College English Listening Teaching

The development of economic globalization has granted people more opportunities for crosscultural exchanges,and therefore,the demand for English language talents in the society has gradually increased and more requirements for English language talents have also been continuously set out.Therefore,high-quality English language talents who are capable of cultural exchanges and communication are very important.English language films are a very important carrier in English learning.It is a beloved tool for learning English language due to its nature.In addition,the vivid situations,interesting speeches and expressions,and intuitive auditory impacts in the English language films provide very effective materials for college English listening teaching,and have therefore been highly valued by the college English teachers and educators.In view of the above,this article discusses English language films and college English listening teaching.The main purpose is to improve the quality of English listening teaching and students’cross-cultural communication skills.

Blended College English Teaching Based on Online Live Classes During the COVID-19 Epidemic Period

This paper first makes an overview of blended teaching mode,and then analyzes the impact of the epidemic on college English teaching and the necessity of carrying out online live teaching.Finally,taking the current situation of online teaching in Universities in X city as an example,this paper puts forward some suggestions on blended college English teaching based on online live teaching during the epidemic period,hoping to contribute to the improvement of teaching quality with a modest effort.

Microbiome and metabolome dysbiosis analysis in impaired glucose tolerance for the prediction of progression to diabetes mellitus

Gut microbiota and circulating metabolite dysbiosis predate important pathological changes in glucose metabolic disorders;however,comprehensive studies on impaired glucose tolerance(IGT),a diabetes mellitus(DM)precursor,are lacking.Here,we perform metagenomic sequencing and metabolomics on 47 pairs of individuals with IGT and newly diagnosed DM and 46 controls with normal glucose tolerance(NGT);patients with IGT are followed up after 4 years for progression to DM.Analysis of baseline data reveals significant differences in gut microbiota and serum metabolites among the IGT,DM,and NGT groups.In addition,13 types of gut microbiota and 17 types of circulating metabolites showed significant differences at baseline before IGT progressed to DM,including higher levels of Eggerthella unclassified,Coprobacillus unclassified,Clostridium ramosum,L-valine,L-norleucine,and L-isoleucine,and lower levels of Eubacterium eligens,Bacteroides faecis,Lachnospiraceae bacterium 3_1_46FAA,Alistipes senegalensis,Megaspaera elsdenii,Clostridium perfringens,α-linolenic acid,10E,12Z-octadecadienoic acid,and dodecanoic acid.A random forest model based on differential intestinal microbiota and circulating metabolites can predict the progression from IGT to DM(AUC=0.87).These results suggest that microbiome and metabolome dysbiosis occur in individuals with IGT and have important predictive values and potential for intervention in preventing IGT from progressing to DM.

基于氧等离子体辐照处理的缺陷工程策略调控石墨烯性能

从石墨烯的制备到实际应用的整个过程中,缺陷的存在或引入不可避免.因此,阐明缺陷如何影响石墨烯的性能至关重要.本研究通过实验研究和理论计算的方法研究了石墨烯的结构变化、缺陷演变及性能调控.结果表明,当处于sp3缺陷状态时,石墨烯能够较好的保持其原始的机械性能,而随着缺陷数量迅速增加,石墨烯的机械性能显著下降,整体结构最终被破坏.此外,氧等离子体辐照引入的空位缺陷的散射效应增加了电子散射的概率,但掺杂效应有利于石墨烯的电传输;同时,石墨烯面内导电性与氧等离子体处理引起的石墨烯表面起伏程度呈负相关.本工作为基于缺陷工程的石墨烯和其它二维材料的改性研究提供了指导方向.

幕墙玻璃协同下索网结构自振特性分析

玻璃面板作为构成拉索式玻璃幕墙的重要组件之一,本文通过ANSYS软件对单层索网玻璃幕墙进行了自振特性分析,并参数化研究了拉索、玻璃对整体模型自振特性的影响,得到了对应振型与各阶自振频率。针对单榀拉索玻璃幕墙,考虑玻璃协同对拉索自振特性的影响,运用有限元方法对其单独展开研究。

Broadly neutralizing antibodies derived from the earliest COVID-19 convalescents protect mice from SARS-CoV-2 variants challenge

Coronavirus disease 2019(COviD-19)was first reported three years ago,when a group of individuals were infected with the original SARS-CoV-2 strain,based on which vaccines were developed.Here,we develop six human monoclonal antibodies(mAbs)from two elite convalescents in Wuhan and show that these mAbs recognize diverse epitopes on the receptor binding domain(RBD)and can inhibit the infection of SARS-CoV-2 original strain and variants of concern(VOCs)to varying degrees,including Omicron strains XBB and XBB.

High-fidelity Modeling of Multilayer Building Process in Electron Beam Powder Bed Fusion:Build-quality Prediction and Formation-Mechanism Investigation

High-fidelity simulations of powder bed fusion(PBF)additive manufacturing have made significant progress over the past decade.In this study,an efficient two-dimensional frame was developed for simulating the electron beam PBF process with hundreds of tracks for the direct prediction of the build quality.The applicable parameter range of the developed model was determined by comparing the heat transfer with that in three-dimensional cases.Subsequently,powder deposition and selective melting were coupled for a continuous simulation of the multilayer process.Three powder deposition models were utilized to generate random powder particles,and their effects on the packing structure and the resultant simulated build quality were investigated.The predicted build quality was validated using experimental results from independent studies.By reproducing the building process,the defect development mechanism in a multilayer process was revealed for the coalescence behaviors of randomly distributed powder particles,which also confirmed the importance of simulation at the high-fidelity powder scale.The effects of key process parameters during multilayer and multi-track processes on the build quality were systematically investigated.In particular,the formation statuses of all tracks during the simulated building process were recorded and analyzed statistically,which provided crucial information on the printing process for understanding the building mechanism or performing uncertainty analysis.

基于互联网群体智能的拼图问题求解

拼图游戏是一类复杂问题的典型代表.这类问题的复杂性体现在其无法通过自上而下、集中控制的方式进行有效求解.通常情况下,拼图游戏由一个玩家独立完成,或由几个玩家围坐在一起协同完成.本文提出一种基于互联网人类群体智能的拼图问题求解方法.该方法使用一种被称为“探索–融合–反馈”的回路用于支持人类玩家群体在互联网环境中进行并行、协同的拼图问题求解.其中,探索活动由玩家实施,融合与反馈活动由拼图环境自动实施.在探索活动中,每个玩家独立进行拼图问题的求解,不与其他玩家发生直接的交互.在任何时刻,一个玩家探索活动的结果是一个关于当前拼图问题的片段解,以及一组被该玩家判断为错误的图块邻接关系.在融合活动中,拼图环境实时地将所有玩家的当前探索结果融合在一起,形成一个不断演化的群体观点图.在反馈活动中,对于每一个玩家,拼图环境根据该玩家的当前探索结果和当前的群体观点图,向该玩家推荐特定的信息,以加速其拼图进程.我们实现了一个支持上述方法的多人在线拼图环境,并在2∼10人规模的玩家群体中进行了初步的实验.实验结果表明:(1)在这一多人拼图环境中,拼图求解时间大致正比于玩家数量的倒数,且以玩家群体中的最强个体为基准点,群体拼图效率能够实现31.36%∼64.57%的提升;(2)在该环境中,最快完成拼图的玩家获得的反馈信息平均具有86.34%的准确率,且随着群体规模的增加,反馈信息在最快玩家拼图结果中的平均占比逐渐从20%增加到45%左右;(3)相比于面对面协同的群体拼图求解方式,该环境展示出更好的群体规模可扩展性,且拼图结果总是具有100%的正确率,而拼图问题自动求解算法平均只具有52%的正确率.我们希望本文工作能够为探索群体智能在互联网环境下的更广泛应用提供一些有用的信息或观点.

Recent progress in the synthesis of graphene/CNT composites and the energy-related applications

Graphene and carbon nanotube(CNT) are representative carbon nanomaterials which have aroused numerous research interest due to their extraordinary material properties and promising application potentials,especially in the energy storage and conversion areas.However,the agglomeration happening in these materials has largely blocked their applications.Hybridization of CNT with graphene can,on one hand,prevent the agglomeration behavior,on the other hand,generate a synergistic effect between them with enhanced physical and chemical properties.There have been many studies conducted to find out the suitable approaches to synthesize graphene/CNT composites,and realize the application potentials of these structures.Based on the recent advances,this paper reviews the current research progress that has been achieved in synthesizing graphene/CNT composites,and the energy-related applications.Through this review,we aim at stimulating more significant research on this subject.

Bi Layer Formation at the Anode Interface in Cu/Sn-58Bi/Cu Solder Joints with High Current Density

Bi layer formation in Cu/Sn-58Bi/Cu solder joints was investigated with different current densities and solder thickness. Uniform and continuous Bi layers were formed at the anode interface which indicated that Bi was the main diffusing species migrating from the cathode to the anode. The electromigration force and Joule heating took on the main driving forces for Bi diffusion and migration. In addition, two appearance types of Bi layers, planar-type and groove-type, were found during current stressing. The morphology and thickness of Bi layers were affected by current density and current stressing time.