在线教材慕特(MOOT)何以在美国持续升温

本文以Pearson(培生集团)提供的My Math Lab平台的中学代数课程为例,简要介绍了美国目前流行的教育信息化教材模式及其特点。作者在美国慕特式教学的实践表明,如此融庞大信息量为一体的模式,深刻改变了大中学校基于课堂基础课程的教与学,慕特将是适合中国国情的大中学校教育信息化课程教材建设最佳的选择方向。

2015年教育信息化新趋势——美国年轻人对教育信息化的探索

当前教育正处于信息化创新与变革的大数据时代,我们学习和教授的内容及方式都在发生显著改变。如果你是从事中小学教育或高等教育领域的专业人士,那意味着你会时时感受到数字教育的革命性变革,这些变革的缔造者正在轻摇和撼动我们已知的教育体系,并且涉及到从小学到高等教育的方方面面。而带来这些变化的大多是年轻人,有生命、活力的教育产品很多都是年轻人做的,也是做给年轻人的。在这场革命中,美国教育界的几十位30岁以下俊杰在2015年走在了最前列,因为他们的创新型数字平台以学校、学区和教师为主要客户,或者直接面向学生本人。本文选取一些他们对于未来信息化教育、课堂和技术作用的探索。

美国校园威胁的临床评估及心理教育

校园威胁是在校园场所发生的危险。威胁评估是对个体明确的或潜在的威胁行为进行的一种风险评估。本文主要针对大学校园威胁的临床评估,阐述对个体进行评估时涉及的背景、评估时考虑的因素,以及评估后心理教育方面的应对措施,以消除安全威胁。

中国流域水质管理:生态补偿还是污染赔偿?——基于美国跨界流域水质管理的教训

针对我国的流域水质管理问题,上下游有明显的不同利益诉求,究竟应当是生态补偿还是污染赔偿并无定论。本文从制度经济学的角度,对目前的流域水质管理进行了梳理,分析了美国流域水质管理的教训及对我国流域水质管理的启示,明确提出了我国流域水质管理生态补偿与污染赔偿的界限。究竟是上游该得到生态补偿,还是下游该得到污染赔偿,这完全取决于该流域的规划以及规划的实施情况。上游政府水质规划实施得好,应得到下游政府的生态补偿;上游政府水质规划实施得差,下游政府该得到污染赔偿。

美国化学纤维和纺织工业:综述和展望

回顾了1995—2005年美国化学纤维和纺织工业的发展。化学纤维工业正在发生连续不断的变化。除了这里强调的观点，其他重要的趋势将继续发展：稳定的生产率和质量改进；批发价和零售价不断降低；创新的新纤维带来新的用途和新的用户；稳定增长的北美和全球经济构建不断扩大的消费品市场。北美化学纤维工业正在期待这些挑战和机遇。

中国家具对美国出口现状及前景

美国的家具生产和市场美国是一个森林资源丰富、木材加工工业发达的国家。据调查,美国拥有森林面积19500万公顷,年采伐量30800万立方米,年出口原木1443.5万立方米,年木材加工量7500万立方米(不包括胶合板、纤维板等),其中水曲柳(Ash)、栎木(Oak)占相当数量。加之,美国机械化程度高,故其所用家具历来以国内生产为主,约占销售量的70—80％。据统计,

“要把在美国的事做大！”

“要把在美国的事做大！”戴顺智“要把在美国的事做大！”这是总公司领导对中石化（美国）有限公司的期望与嘱咐。中石化（美国）有限公司的同志们也正在为此而做出最大的努力。中石化（美国）有限公司（原名实华（美国）有限公司）设在纽约世贸中心１号楼４６５５号，成...

中国大厨环球淘金记(5) 美国篇

"自由"、"随性"常常成为美国生活状态的代名词,而选择了在美国从厨,这些词汇也同样适用。高兴的时候,你可以一天换三个地儿,不高兴的时候,你可以在家避暑,如果不愿意打工,几年攒起的钱开个餐馆,也不是什么难事,在美国从厨,就是这么轻松?!这次我们特邀了在美国从厨10多年,现已取得美国国籍的邵红卫先生亲述其美国从厨经历,给我们展示美国从厨者的真实生活。

城市地下空间盾构隧道穿越工程研究综述

对盾构隧道穿越既有地铁线、各类建筑物桩基、地下管线等穿越工程研究动态进行归纳总结,讨论有待解决的主要问题及未来重点研究方向。首先,深入探讨盾构隧道穿越工程在复杂城市地下环境中面临的地质条件多样性、地下结构物复杂性及施工过程中可能引起的地层变形和结构损伤等问题。其次,阐述关于盾构隧道穿越复杂地下环境的研究成果,总结不同研究方法和监测手段在解决盾构隧道施工引起地下结构变形和安全问题中的应用情况,并讨论其优缺点。最后,归纳盾构隧道穿越工程引起结构变形问题的控制难点,从盾构隧道掘进参数和注浆控制、既有建筑物加固措施、监控量测等方面提出控制结构变形的可行方案。

阿尔茨海默病居家筛查专家共识

老年人痴呆或认知障碍多由一种以上年龄相关的常见脑部疾病所致。阿尔茨海默病(Alzheimer's disease,AD)是其中最常见的神经变性疾病,且是全球前10位死因中唯一无法治愈或缺乏长期对症疗效的疾病,给个人、家庭和全球经济都带来了巨大的负担。早期及时发现和干预是对抗AD的最佳策略。在过去的30年中,许多研究都提出了降低痴呆风险的方法,2020年《柳叶刀》杂志的痴呆预防报告已阐明通过应对风险因素可以预防或延缓超过40%的痴呆。然而,目前全球医疗体系尚未具备早期或及时发现AD的足够能力。最近的一项研究发现,只有不到10%的轻度认知障碍(mild cognitive impairment,MCI)是在初级医疗机构中诊断出来的。近来,抗淀粉样蛋白β(Amyloid beta,Aβ)抗体药物lecanemab和donanemab被批准上市用于早期AD治疗,以及30年的随访研究证明改善风险因素显著减少AD痴呆的发病率并延长了寿命,使得人们对AD早期识别的关注迅速增加。阿尔茨海默病防治协会(China Association for Alzheimer's Disease,CAAD)认识到居家早期和及时发现AD的重要性,并成立了一个由协会成员、临床医生和研究人员组成的全球AD多领域专家团队,就以下目标达成共识:①为个人、家庭、社区、协会和组织提供专家指导意见;②介绍用于认知障碍和痴呆居家筛查的数字工具和可用资源,并为AD高危人群或疑似患者制定下一步应对策略;③讨论现有可用或将来可能的居家筛查适宜AD生物标志物;④为未来的改进和全球应用建立可行性框架。专家组对于当前可用的证据、工具和资源进行综述,并进一步考量其在AD居家筛查中的价值。

中国阿尔茨海默病早期预防指南(2024)

阿尔茨海默病是一种病因复杂的严重智力致残疾病,目前尚无有效的治疗方法。我国是世界上老年人口最多、增长最快的国家之一,也是阿尔茨海默病发病率较高的国家。因此,如何早期预防阿尔茨海默病的发生,是现今健康领域最重要的课题之一。我们在国内外相关研究的基础上,通过文献循证、干预研究实践、案例分析、经验总结和专家咨询,结合中国老年健康和社会文化特点,体现中国传统医学、武术、养生以及社区组织优势,制订出具有中国特色的阿尔茨海默病早期预防指南,涵盖了个人、家庭和社会三个层面的预防策略,从积极生活态度、社会活动参与、认知训练、体育锻炼、戒烟限酒、营养、睡眠,血压、血糖、血脂管理,体重和其他慢病管理以及中医开展针对阿尔茨海默病的一级预防。本指南仅供个人、家庭和社会开展阿尔茨海默病预防时参考。

中国可以终止结核病

尽管中国每年发现并成功治疗70%以上的结核病病例,但按照目前结核病疫情下降的速度,中国无法实现《2030年可持续发展目标》中结核病相关目标。根据最新的科学知识和证据,如果结核病控制方法从单纯的“被动发现”转变为包括大规模的“主动筛查”,就有可能实现这些目标。中国有一个前所未有的机遇来扩大“主动筛查”,因为主动筛查的诊断技术和基础设施日臻成熟,包括基于舌拭子标本的分子检测技术和人工智能辅助的数字X线摄影和CT影像检查。抓住这一契机,中国有望在2030年成为首个将结核病发病率降低80%并消除结核病这一重大公共卫生问题的结核病高负担国家。

Optimality of Group Testing with Differential Misclassification

Group testing is a method that can be used to estimate the prevalence of rare infectious diseases,which can effectively save time and reduce costs compared to the method of random sampling.However,previous literature only demonstrated the optimality of group testing strategy while estimating prevalence under some strong assumptions.This article weakens the assumption of misclassification rate in the previous literature,considers the misclassification rate of the infected samples as a differentiable function of the pool size,and explores some optimal properties of group testing for estimating prevalence in the presence of differential misclassification conforming to this assumption.This article theoretically demonstrates that the group testing strategy performs better than the sample by sample procedure in estimating disease prevalence when the total number of sample pools is given or the size of the test population is determined.Numerical simulation experiments were conducted to evaluate the performance of group tests in estimating prevalence in the presence of dilution effect.

Trade credit contracting in a risk-averse supply chain under adverse selection and moral hazard

Trade credit,as an effective tool for integrating and coordinating material,information,and financial flows in supply chain management,is becoming increasingly widespread.We explore how a manufacturer can design optimal trade credit contracts when a risk-averse retailer hides its sales cost information(adverse selection)and selling effort level(moral hazard).We develop incentive models for a risk-averse supply chain when adverse selection and moral hazard coexist,which are then compared with the results under single information asymmetry(moral hazard).Moreover,we analyze the effects of private information and risk-aversion coefficient on contract parameters,selling effort level and the profit or utility of the supply chain.The study shows that when the degree of retailer’s risk aversion is within a certain range,reasonable trade credit contracts designed by the manufacturer can effectively induce the retailer to report its real sales cost and encourage it to exert appropriate effort.Furthermore,we find that the optimal trade credit period,optimal transfer payment,and retailer’s optimal sales effort level under dual information asymmetry are less than those under single information asymmetry.Numerical analysis are conducted to demonstrate the effects of the parameters on decisions and profits.

Solution of idle LBO problem for high FAR aero combustor

The paper sheds light on the idle lean blow off(LBO)problem for high fuel air ratio(FAR)com⁃bustor,which is impossible to be addressed with traditional aero combustor design.A significant improvement in aero combustor design is required to resolve the idle LBO issue.The authors detailed a practical and efficient solu⁃tion,which not only solved the idle LBO issue but also defined the aero-thermal design for high-FAR combustor.The design will usher in a new era of aero combustor.

Attitudes Toward People Who Stutter in the Chinese Context: An Exploratory Study on the Impact of Knowledge Sources

The public’s attitudes can affect the experience of stuttering of people who stutter.This study investigated the attitudes held by the public about people who stutter in China.A web-based written survey with closed and open-ended questions was implemented to develop a rich understanding.One hundred and two respondents in 26 provinces and 3 municipalities provided comments on people who stutter in their life aspects such as personality,speech,social life,work,life participation,education,dating and marriage,capability,and communication skills.The predominantly negative attitudes towards the overall domains were identified.Attitudes to people who stutter varied according to the different sources of knowledge.Familiarity with people who stutter might reduce stereotypes.However,knowledge from the media might aggravate stereotypes.Implications and future research orientation were also discussed.

Polar residual network model for assisting evaluation on rat myocardial infarction segment in myocardial contrast echocardiography

Objective To investigate the value of polar residual network(PResNet)model for assisting evaluation on rat myocardial infarction(MI)segment in myocardial contrast echocardiography(MCE).Methods Twenty-five male SD rats were randomly divided into MI group(n=15)and sham operation group(n=10).MI models were established in MI group through ligation of the left anterior descending coronary artery using atraumatic suture,while no intervention was given to those in sham operation group after thoracotomy.MCE images of both basal and papillary muscle levels on the short axis section of left ventricles were acquired after 1 week,which were assessed independently by 2 junior and 2 senior ultrasound physicians.The evaluating efficacy of MI segment,the mean interpretation time and the consistency were compared whether under the assistance of PResNet model or not.Results No significant difference of efficacy of evaluation on MI segment was found for senior physicians with or without assistance of PResNet model(both P>0.05).Under the assistance of PResNet model,the efficacy of junior physicians for diagnosing MI segment was significantly improved compared with that without the assistance of PResNet model(both P<0.01),and was comparable to that of senior physicians.Under the assistance of PResNet model,the mean interpretation time of each physician was significantly shorter than that without assistance(all P<0.001),and the consistency between junior physicians and among junior and senior physicians were both moderate(Kappa=0.692,0.542),which became better under the assistance(Kappa=0.763,0.749).Conclusion PResNet could improve the efficacy of junior physicians for evaluation on rat MI segment in MCE images,shorten interpretation time with different aptitudes,also improve the consistency to some extent.

Analysis of Smooth Cepstral Peak Prominence in Hypokinetic Dysarthria Associated With Parkinson’s Disease

Smoothed cepstral peak prominence(CPPs)is a measurement of the distance from the prominent cepstral peak to the linear regression line directly beneath it.Variations of CPPs data acquisition and analysis lead to the complexity of the clinical cut-off values,and there are no agreeable values for a specific voice disorder,such as hypokinetic dysarthria associated with Parkinson’s disease(PD).This study examined the CPPs in people with hypokinetic dysarthria associated with PD compared with healthy participants.Results demonstrated significant differences in speech tasks of sustained vowel and connected speech,with CPPs of connected speech more sensitive to dysphonia and gender difference in PD participants.Males in PD participants presented higher CPPs for sustained vowels and lower CPPs for connected speech than females.It is implied that a consistent clinical application protocol is necessary,and multiple acoustic measures are needed to ensure the accuracy of clinical decisions.

推动塑料重复使用:政策梳理与国际公约展望

在过去50年间,全球塑料消耗量增长了20多倍。据估计,如果不采取行动,到2034年,全球的塑料消耗量将再翻一番。中国已于2019年成为全球塑料产量最大的国家,塑料消费量更是与日俱增。一次性塑料包装在全周期内,从生产到回收,都在以不同形式对环境产生各种负面效应,特别是在生产和回收阶段,它们会排放大量的碳,加剧气候变化。