Free vibrations of beam-mass-spring systems:analytical analysis with numerical confirmation

Free vibrations of a beam-mass-spring system with different boundary conditions are analyzed both analyt- ically and numerically. In the analytical analysis, the system is divided into three subsystems and the effects of the spring and the point mass are considered as internal boundary con- ditions between any two neighboring subsystems. The par- tial differential equations governing the motion of the sub- systems and internal boundary conditions are then solved us- ing the method of separation of variables. In the numerical analysis, the whole system is considered as a single system and the effects of the spring and point mass are introduced using the Dirac delta function. The Galerkin method is then employed to discretize the equation of motion and the result- ing set of ordinary differential equations are solved via eigen- value analysis. Analytical and numerical results are shown to be in very good agreement.

Hydrodynamic characteristics of a typical karst spring system based on time series analysis in northern China

In order to study the hydrodynamic characteristics of the karst aquifers in northern China,time series analyses(correlation and spectral analysis in addition with hydrograph recession analysis)are applied on Baotu Spring and Heihu Spring in Jinan karst spring system,a typical karst spring system in northern China.Results show that the auto-correlation coefficient of spring water level reaches the value of 0.2 after 123 days and 117 days for Baotu Spring and Heihu Spring,respectively.The regulation time obtained from the simple spectral density function in the same period is 187 days and 175 days for Baotu Spring and Heihu Spring.The auto-correlation coefficient of spring water level reaches the value of 0.2 in 34-82 days,and regulation time ranges among 40-59 days for every single hydrological year.The delay time between precipitation and spring water level obtained from cross correlation function is around 56 days for the period of 2012-2019,and varies among 30-79 days for every single hydrological year.In addition,the spectral bands in cross amplitude functions and gain functions are small with 0.02,and the values in the coherence functions are small.All these behaviors illustrate that Jinan karst spring system has a strong memory effect,large storage capacity,noticeable regulation effect,and time series analysis is a useful tool for studying the hydrodynamic characteristics of karst spring system in northern China.

Mathematical Model of the Geothermal Water Resources in the South Hot Spring System in Chongqing

The geothermal waters of south hot spring, small hot spring and Qiaokouba in Chongqing, are all part of the south hot spring geothermal water system. Exploitation has caused a decline in the water levels of the south and small hot springs, which have not flowed naturally for 15 years. Now, bores pump geothermal water to the springs. If the water level drops below the elevation of the rivers, river-water will replenish the geothermal water, destroying this resource. It is therefore an urgent task to model the geothermal water system, to enable sustainable development and continued use of the geothermal water in Qiaokouba. A numerical simulation of the geothermal water system was adopted and a quantitative study on the planning scheme was carried out. A mathematical model was set up to simulate the whole geothermal water system, based on data from the research sites. The model determined the maximum sustainable water yield in Qiaokouba and the two hot springs, and the south hot spring and small hot spring sustainable yields are 1 100 m^3/d and 700 m^3/d from 2006 to 2010, 1 300 m^3/d and 1 000 m^3/d from 2011 to 2015, and 1 500 m^3/d and 1 200 m^3/d from 2016 to 2036. The maximum exploitable yield is 3 300 m^3/d from 2006 to 2036 in Qiaokouba. The model supplies a basis to adequately exploit and effectively protect the geothermal water resources, and to continue to develop the geothermal water as a tourist attraction in Chongqing.

基于Spring Boot的产教联合体信息平台设计

该文设计基于B/S架构的联合体信息平台,利用Spring Boot、MyBatis Plus、Vue等优秀框架实现高效的开发,集成Spring Security和JWT令牌机制,完成认证和权限控制。同时整合Redis缓存,将热点资源缓存至内存中,以实现快速查询操作,从而减轻MySQL数据库的负载压力。该系统稳定、兼容性强,能使联合体成员沟通更方便、信息的发布和维护的效率更高,实现人才共育共享。

基于SpringBoot框架的智慧校园管理系统设计与实现

随着国家《智慧校园总体框架》的提出,各职业院校纷纷启动了智慧校园的建设,因学校发展实际情况、重视程度、资金投入等不同,智慧校园建设的步伐也不一致。文章分析了智慧校园管理系统需求,提出基于Spring Boot框架,整合MyBatis数据持久化框架,数据库选择高性能的MySQL,内存数据库采用Redis缓存技术,采用前后端分离模式设计,前端采用Vue.js、Element-UI、Axios来实现前后端数据交互的系统设计方案和实现过程,为智慧校园的建设提供一种可行的方案参考。

基于Spring Boot+Vue框架的羊场综合 管理系统软件的设计与应用

本研究旨在辅助羊场生产数据规范化管理及良种繁育智能科学化应用,采用MySQL数据库及Java、R编程语言,基于Spring Boot+Vue框架设计了一套羊场综合管理系统软件。该系统优化了羊只信息管理、羊场配种方案,实现生产数据可视化,设置预警功能帮助羊场及时掌握羊只产羔时间与生产性能情况;系统设计羊只基本信息管理、生产信息、疫病信息、繁殖信息、药品管理、饲料管理、统计报表与预警、科学育种八个模块。其中,在科学育种管理子模块中,根据羊场育种需求,构建了三种育种值计算模型(BLUP模型、GLMM模型、平均表现型模型),结合种公母羊实际表现,实现种公母羊的等级排序并自动生成近交系数,得到科学合理的配种方案。本系统在陕北某集约化肉羊场、横山区某绒山羊养殖联合育种户、富平县某奶山羊养殖场进行为期半年的实际生产应用,通过跟踪核心群体,完善与优化系统各项功能,为羊场智慧化、数字化育种管理提供了数据平台,同时也为实现智慧羊场的发展增添了新版本1.0。

基于Spring Cloud的分布式医疗数据平台建设

为解决互联网时代医疗大数据的可靠存储问题,探索异构数据的有效处理方案,加强医疗数据检索能力。提出一种基于Spring Cloud的分布式医疗数据平台建设方案,该方案通过Spring Cloud技术构建分布式架构,选取MongoDB非关系型数据库作为分布式存储,同时对数据进行标准化、分词等操作,从而实现一个异构数据可存储、系统高可用、规模易扩展、检索高效率的医疗数据平台。

Dynamic frequency response characteristics of a compound regulative quasi-zero stiffness air spring system

Quasi-zero stiffness(QZS) device is widely studied for their better performance in low-frequency and micro-vibration isolation due to the high-static and low-dynamic(HSLD) stiffness characteristics.The previous QZS isolator with determined parameters is not suitable for variable isolated mass.In this study,a novel compound regulative quasi-zero stiffness air spring(CRQSAS)has been proposed and designed by introducing a bidirectional regulator for the horizontal air springs.The CRQSAS could change the quasi-zero region depending on the payload.To identify the parameters of the convoluted air spring(CAS) and novel rubber air spring(NRAS),the air spring testing system is established.The stiffness functions of air springs are obtained by the multi-parameter fitting method.According to the structure of the CRQSAS,the dynamic model of the system is analyzed and simplified by Taylor Expansion.The harmonic balance method(HBM) is applied to calculate the frequency response and absolute displacement transmissibility.An experimental prototype has been set up to verify the theoretical model and simulation.Compared with the single NRAS,CRQSAS performs better in low-frequency and micro-amplitude vibration.The research proves that CRQSAS is a passive device widely applied for improving isolation precision under low-frequency vibration.

基于SpringBoot和Vue框架的高校统战工作服务信息管理系统的设计与实现

针对高校统战工作较为传统化、宣传力度不够、工作成果展示不够全面等问题,采用当前主流框架技术,包括SpringBoot、Vue和Uni-App等前后端框架,MySQL、Redis和ElasticSearch等数据库技术以及Echarts开源可视化图表库、WebSocket全双工通信协议和Nginx反向代理等前沿技术,设计与实现了一个高校统战工作服务信息管理系统。该系统分为PC端后台管理子系统、PC端可视化展示子系统和移动App端三大子系统,其中移动App端包括业绩管理、新闻管理、互动交流管理等功能模块。本系统具有较好的可扩展性和可维护性,可提高高校统战工作的管理效率和用户体验满意度,可为统战工作的信息化建设提供有力支持。

基于Spring Cloud微服务架构的非物质文化遗产展示与学习系统的设计与实现

针对目前人民群众对非物质文化遗产认识不够全面,以及市面上利用系统软件来有效保护和传承非物质文化遗产的软件很缺乏等问题,结合相应软件开发技术和数字可视化技术,设计和实现了一款非物质文化遗产展示与学习系统以实现对非物质文化遗产项目的传承和保护创新。本系统以江西省范围内的主要非物质文化遗产项目为例,设置有移动App端和PC端,采用前后端分离的开发模式,以当前主流的Spring Cloud微服务架构技术为基础,结合SpringBoot框架,在华为云服务器上搭建起弹性可伸缩的后端服务。使用Uni-App开发移动端,以解决无法在Android、IOS及各大小程序平台运行的问题。经测试,本系统具有操作简单,易于使用、维护和扩展,高并发性等优点。

基于SpringBoot在线教育网站设计

随着互联网技术的发展,以“互联网+”为主要形式的新型在线教育模式逐渐展开,在疫情原因导致学校不能线下授课的时期尤其突出。文章采用前后端分离模式设计了在线教育网站系统:后端选择SpringBoot作为开发框架,并通过Spring Cloud完成分布式部署等功能;前端则采用Vue框架,力求UI界面操作简单。系统选用微服务架构来分担高并发的压力,在数据存储方面选择了MySQL,通过阿里云OSS进行云端存储。在该平台上视频在线播放流畅,多模块划分清晰,用户可以自由选择学习资源,同时满足灵活、稳定、易扩展的现代开发需求。

Changes in Spring Snow Cover over the Eastern and Western Tibetan Plateau and Their Associated Mechanism

The spring snow cover(SC)over the western Tibetan Plateau(TP)(TPSC)(W_TPSC)and eastern TPSC(E_TPSC)have displayed remarkable decreasing and increasing trends,respectively,during 1985–2020.The current work investigates the possible mechanisms accounting for these distinct TPSC changes.Our results indicate that the decrease in W_TPSC is primarily attributed to rising temperatures,while the increase in E_TPSC is closely linked to enhanced precipitation.Local circulation analysis shows that the essential system responsible for the TPSC changes is a significant anticyclonic system centered over the northwestern TP.The anomalous descending motion and adiabatic heating linked to this anticyclone leads to warmer temperatures and consequent snowmelt over the western TP.Conversely,anomalous easterly winds along the southern flank of this anticyclone serve to transport additional moisture from the North Pacific,leading to an increase in snowfall over the eastern TP.Further analysis reveals that the anomalous anticyclone is associated with an atmospheric wave pattern that originates from upstream regions.Springtime warming of the subtropical North Atlantic(NA)sea surface temperature(SST)induces an atmospheric pattern resembling a wave train that travels eastward across the Eurasian continent before reaching the TP.Furthermore,the decline in winter sea ice(SIC)over the Barents Sea exerts a persistent warming influence on the atmosphere,inducing an anomalous atmospheric circulation that propagates southeastward and strengthens the northwest TP anticyclone in spring.Additionally,an enhancement of subtropical stationary waves has resulted in significant increases in easterly moisture fluxes over the coastal areas of East Asia,which further promotes more snowfall over eastern TP.

Leading Pattern of Spring Drought Variability over East Asia and Associated Drivers

Drought events have become more frequent and intense over East Asia in recent decades,leading to huge socioeconomic impacts.Although the droughts have been studied extensively by cases or for individual regions,their leading variability and associated causes remain unclear.Based on the Standardized Precipitation Evapotranspiration Index(SPEI)and ERA5 reanalysis product from 1979 to 2020,this study evealuates the severity of spring droughts in East Asia and investigates their variations and associated drivers.The results indicate that North China and Mongolia have experienced remarkable trends toward dryness during spring in recent decades,while southwestern China has witnessed an opposite trend toward wetness.The first Empirical Orthogonal Function mode of SPEI variability reveals a similar seesawing pattern,with more severe dryness in northwestern China,Mongolia,North China,South Korea,and Japan but increased wetness in Southwestern China and southeast Asia.Further investigation reveals that the anomalously dry(wet)surface in North(Southwestern)China is significantly associated with anomalously high(low)temperature,less(more)precipitation,and reduced(increased)soil moisture during the previous winter and early spring,regulated by an anomalous anticyclone(cyclone)and thus reduced(increased)water vapor convergence.The spring dry-wet pattern in East Asia is also linked to cold sea surface temperature anomalies in the central-eastern Pacific.The findings of this study have important implications for improving the prediction of spring drought events in East Asia.

SPRING FESTIVAL CELEBRATIONS BUILD A GLOBAL CULTURAL COMMUNITY

As the Year of the Dragon draws close,the Chinese worldwide,as well as the countries and groups sharing the festival,are gearing up to celebrate the most important social event in the Chinese lunar calendar.For the Chinese,the Spring Festival,or the Chinese New Year,is far more than an occasion for merrymaking.It’s a time for family reunion and the beginning of a new start filled with hope.So the celebrations are also a prayer for peace,prosperity,health,longevity,good luck,and even a bumper harvest.

Spring Festival Boom Propels Concerted Consumption

The 474 million trips-raking in RMB 632.69 billion of tourism-related revenue-during the eight-day Spring Festival holiday indisputably signifies both the vitality of China’s economy and the huge potential of the country’s domestic consumption.The figures respectively represent a 19 percent increase and a 7.7 percent growth over those for the same holiday period,prior to the COVID-19 pandemic,in 2019,according to data released by the country’s Ministry of Culture and Tourism on February 18.

Spring Festival offers window on China’s economic vibrancy

A Chinese foreign ministry spokesperson on February 19 said the Spring Festival of the Year of the Dragon offers the world a window on China’s economic vibrancy,during which China sees its inbound and outbound travels soar,with more Chinese tourists going abroad and more foreign travelers visiting China.

Spring Festival Celebrations Fire Maltese Fascination with Chinese Culture--An Exclusive Interview with Director of the China Cultural Center in Malta Yuan Yuan

THRONGS of shoppers,in a department store adorned with colorful Spring Festival posters,vying to try their hand either at Chinese calligraphy or traditional Chinese lantern-making,might seem incongruous in a European setting.The background to this vibrant scenario was The Point,Malta’s largest shopping mall,as part of the island country’s 2023 Chinese New Year celebrations,courtesy of the China Cultural Center in Malta.

The Roots and Fruits of Chinese Spring Festival

The Chinese New Year-the most important holiday in the country-offers a window into China’s past and present.T RADITIONAL festivals forge a nation’s cultural identity and solidarity.Through opulent customs and celebratory activities,they convey the collective psyche,emotions,and aspirations of a nation.As a key part of Chinese culture,traditional Chinese festivals reinforce the bond among Chinese people and preserve our cultural roots.

Spring Scenery

Tourists enjoy the spring scenery in the wetland area of Xixinan Village,Huizhou District,Huangshan City,Anhui Province,on April 7,2024.

THE ROOTS AND FRUITS OF CHINESE SPRING FESTIVAL

Traditional festivals forge a nation’s cultural identity and solidarity.Through opulent customs and celebratory activities,they convey the collective psyche,emotions,and aspirations of a nation.As a key part of Chinese culture,traditional Chinese festivals reinforce the bond among Chinese people and preserve our cultural roots.Of all Chinese festivals,the Spring Festival is the most important,both culturally and historically.