Web 2.0的出现使信息构建(IA)的内容发生了深刻变化,IA已进入"信息构建2.0"(IA2.0)阶段。在IA2.0阶段,IA作为一门学科、一种角色和一类社团的协调统一体而存在,它强调真正"以用户为中心"和"丰富的用户体验&qu...Web 2.0的出现使信息构建(IA)的内容发生了深刻变化,IA已进入"信息构建2.0"(IA2.0)阶段。在IA2.0阶段,IA作为一门学科、一种角色和一类社团的协调统一体而存在,它强调真正"以用户为中心"和"丰富的用户体验"的核心理念,以满足新环境下的用户需求。Web2.0网站的IA,是IA2.0的典型应用,也是IA2.0阶段研究的主要内容,本文将其称为网站IA2.0。文中设计了一个网站IA2.0模型,并进行了简单的实例分析。展开更多
Strained bridged rings bicyclo[3.2.1]octane and tricyclo[3.2.1.0^(2,7)]octane are prevalent in natural products known for their significant biological activities.However,strategies for efficiently synthesizing these c...Strained bridged rings bicyclo[3.2.1]octane and tricyclo[3.2.1.0^(2,7)]octane are prevalent in natural products known for their significant biological activities.However,strategies for efficiently synthesizing these complex frameworks from simple starting materials via de novo synthesis remain underexplored.This article presents an efficient strategy that combines phosphine catalysis and photocatalysis to execute a stepwise tandem reaction involving allenoates and α-cyano cinnamaldehydes,including[3+2]cyclization,[5+2]cyclization,acyl transfer,and decarboxylation reactions,synthesizing a series of functional bicyclo[3.2.1]octa-2,6-diene and tricyclo[3.2.1.0^(2,7)]oct-3-ene skeleton derivatives with excellent chemoselectivity demonstrated throughout the process.Meanwhile,the reaction can also be performed via a onepot,scalable phosphine/photocatalytic cascade process,efficiently yielding the bridged products which can serve as versatile intermediates for further applications.展开更多
系统探讨一点到多点连接(point to multi-point,P2MP)2.0技术在政企专线领域的全流程应用。通过构建分层架构设计,开发动态带宽分配模型,并在某市政务云专网开展实证验证。结果显示,带宽利用率达92.3%,传输延迟稳定在18.7 ms,故障恢复...系统探讨一点到多点连接(point to multi-point,P2MP)2.0技术在政企专线领域的全流程应用。通过构建分层架构设计,开发动态带宽分配模型,并在某市政务云专网开展实证验证。结果显示,带宽利用率达92.3%,传输延迟稳定在18.7 ms,故障恢复时间缩短至4.2 min,综合效能指数(Ec)达93.5。研究证实该技术可有效解决政企专线的高并发、低延迟与安全可靠传输需求,为数字化转型提供关键技术支撑。展开更多
细颗粒物浓度是评估空气质量的重要指标之一,精确预测PM2.5浓度仍是国内外研究的挑战,也是政府和学术界关注的重点。文章以2014年1月1日至2024年9月30日的乌鲁木齐市PM2.5日平均浓度为研究对象,对其线性回归模型应用两阶段自适应Lasso...细颗粒物浓度是评估空气质量的重要指标之一,精确预测PM2.5浓度仍是国内外研究的挑战,也是政府和学术界关注的重点。文章以2014年1月1日至2024年9月30日的乌鲁木齐市PM2.5日平均浓度为研究对象,对其线性回归模型应用两阶段自适应Lasso多变点检测与估计方法检测并估计回归系数的多变点,建立了更精准的分段线性回归模型来刻画乌鲁木齐市PM2.5日平均浓度。The concentration of fine particulate matter (PM2.5) is one of the key indicators for assessing air quality. Accurate prediction of PM2.5 concentration remains a challenge in both domestic and international research and is a major focus of attention for governments and scholars. This study takes the daily average PM2.5 concentrations in Urumqi City from January 1, 2014 to September 30, 2024 as the research object. A two-stage adaptive Lasso multiple change-point detection and estimation method is applied to detect and estimate multiple change points in the regression coefficients of the linear regression City daily average PM2.5 concentrations in Urumqi City.展开更多
基金financial support from National Natural Science Foundation of China(Nos.82374020 and 22401025)Science&Technology Department of Sichuan Province(No.2024NSFTD0023)Xinglin Scholar Research Promotion Project of Chengdu University of TCM。
文摘Strained bridged rings bicyclo[3.2.1]octane and tricyclo[3.2.1.0^(2,7)]octane are prevalent in natural products known for their significant biological activities.However,strategies for efficiently synthesizing these complex frameworks from simple starting materials via de novo synthesis remain underexplored.This article presents an efficient strategy that combines phosphine catalysis and photocatalysis to execute a stepwise tandem reaction involving allenoates and α-cyano cinnamaldehydes,including[3+2]cyclization,[5+2]cyclization,acyl transfer,and decarboxylation reactions,synthesizing a series of functional bicyclo[3.2.1]octa-2,6-diene and tricyclo[3.2.1.0^(2,7)]oct-3-ene skeleton derivatives with excellent chemoselectivity demonstrated throughout the process.Meanwhile,the reaction can also be performed via a onepot,scalable phosphine/photocatalytic cascade process,efficiently yielding the bridged products which can serve as versatile intermediates for further applications.
文摘系统探讨一点到多点连接(point to multi-point,P2MP)2.0技术在政企专线领域的全流程应用。通过构建分层架构设计,开发动态带宽分配模型,并在某市政务云专网开展实证验证。结果显示,带宽利用率达92.3%,传输延迟稳定在18.7 ms,故障恢复时间缩短至4.2 min,综合效能指数(Ec)达93.5。研究证实该技术可有效解决政企专线的高并发、低延迟与安全可靠传输需求,为数字化转型提供关键技术支撑。
文摘细颗粒物浓度是评估空气质量的重要指标之一,精确预测PM2.5浓度仍是国内外研究的挑战,也是政府和学术界关注的重点。文章以2014年1月1日至2024年9月30日的乌鲁木齐市PM2.5日平均浓度为研究对象,对其线性回归模型应用两阶段自适应Lasso多变点检测与估计方法检测并估计回归系数的多变点,建立了更精准的分段线性回归模型来刻画乌鲁木齐市PM2.5日平均浓度。The concentration of fine particulate matter (PM2.5) is one of the key indicators for assessing air quality. Accurate prediction of PM2.5 concentration remains a challenge in both domestic and international research and is a major focus of attention for governments and scholars. This study takes the daily average PM2.5 concentrations in Urumqi City from January 1, 2014 to September 30, 2024 as the research object. A two-stage adaptive Lasso multiple change-point detection and estimation method is applied to detect and estimate multiple change points in the regression coefficients of the linear regression City daily average PM2.5 concentrations in Urumqi City.
