Stiffness Characteristics of a Basic Nonlinear Air Spring Model

This study predicts the characteristics of a compressible polytropic air spring model. A second-order nonlinear autonomous air spring model is presented. The proposed model is based on the assumption that polytropic processes occur. Isothermal and isentropic compression and expansion of the air within the spring chambers are the two scenarios that are taken into consideration. In these situations, the air inside the spring chambers compresses and expands, resulting in nonlinear spring restoring forces. The MATLAB/Simulink software environment is used to build a numerical simulation model for the dynamic behavior of the air spring. To quantify the values of the stiffnesses of the proposed models, a numerical solution is run over time for various values of the design parameters. The isentropic process case has a higher dynamic air spring stiffness than the isothermal process case, according to the results. The size of the air spring chamber and the area of the air spring piston influence the air spring stiffness in both situations. It is demonstrated that the stiffness of the air spring increases linearly with increasing piston area and decreases nonlinearly with increasing air chamber length. As long as the ratio of the vibration’s amplitude to the air spring’s chamber length is small, there is good agreement in both scenarios between the linearized model and the full nonlinear model. This implies that linear modeling is a reasonable approximation of the complete nonlinear model in this particular scenario.

Discussion on the Free Quenching Heat Treatment Process of Automotive Leaf Springs

Free quenching of automotive leaf springs is a new technology that has gradually started to be applied in the industry in China in recent years.Only a few manufacturers are applying it in the industry.Through more than half a year of on-site practice,the changes in the hot forming of spring plates before free quenching have been explored,and finally a heat treatment process that meets the production requirements of our company has been developed,achieving normal production.

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.

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.

The Shenzhen Experience:A Sequel to The Story of Spring

From almost nothing in the 1970s,Shenzhen today has emerged as a thriving trade and innovation hub,pioneering the country’s innovative development.IN the 1990s,one of the most popular songs in China was The story of spring,a tribute to the country’s reform and opening-up started in 1978 that ushered in a new“spring”of growth in China.One of the decisions taken at that time was to develop a county in southern China into a pilot for many of the reforms to be implemented.The county was the predecessor of today’s metropolis Shenzhen,a thriving industrial hub boasting many firsts.

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.

Upgrading jackets for spring

When the gentle breeze of spring starts to fill the air,it's often a time of transition,where the chill of winter gives way to the warmth of the coming season.However,for those who love the outdoors,spring can still present its own set of challenges,especially when it's time to choose the right jacket.Whether you're hiking in the hills,exploring the trails,or just taking a leisurely walk in the park,having a jacket that offers the perfect blend of warmth,comfort,and breathability is crucial.We'll delve into the various options available for jackets that are perfect for the outdoors in spring.

The mysterious Fosse Dionne spring

For centuries, people have been asking themselves what the source of the underground spring known as Fosse Dionne spring in France's Burgundy region might be, but they never got to the bottom of it, because they literally couldn't get to the bottom of it.

Product Development of High Strength and Toughness Spring Flat Steel

With the continuous development of mechanical industry,higher requirements are put forward for the comprehensive properties of spring steel.The chemical composition and production process of spring flat steel are designed to meet the requirements of high strength and high toughness of spring flat steel,through the test,the product surface quality and internal quality all meet the national standards,the performance indicators to meet user requirements.

Development of a Composite Suspension with a Coil and Hydro-Pneumatic Spring

A new composite suspension is developed, where a coil spring and a hydro-pneumatic spring are used in order to improve the poor reliability of off-road vehicle with pure hydro-pneumatic suspension. According to road conditions, the two springs play different roles. The method for matching the composite suspension stiffness and distributing the load is proposed. The working pressure of hydro-pneumatic spring as well as the load and stiffness characteristics of composite suspension is compared with a pure hydro-pneumatic suspension. In addition, the ISO weighted vehicle body acceleration, suspension travel and relative dynamic load of the wheels between two kinds of suspension are analyzed with a quarter vehicle mode. The simulation result shows that the developed composite suspension is more suitable for off-road vehicle than the one hydro-pneumatic suspension, because the composite suspension can reduce the working pressure, improve the reliability and keep a similar ride comfort with hydro-pneumatic suspension.

A discussion of up-flow springs

Based on their genesis, springs are commonly classified as depression spring, contact spring, overflow spring and fault spring, etc. In addition, a kind of springs, i.e., up-flow spring, can be found in the field. An aquifer is overlain by poorly-permeable unconsolidated sediments or relatively impervious formations. If the hydraulic head of the aquifer is higher than the land surface, groundwater may flow up to the ground surface through the local portion of the overlying aquicludes where the permeability is relatively good, and emerges as an up-flow spring. The common characteristics of an up-flow spring are discussed and summarized in this paper, and some examples of the up-flow springs are also given. Up-flow springs can flow up through local permeable zones in the overlying aquicludes rather than permeable faults. Although they cannot be found as frequently as depression springs, contact springs, overflow springs and fault springs etc., yet up-flow springs may occur in the form of normal-temperature springs, hot springs and salt springs.

少年儿童翻译文学的译本风格计量研究——以Silent Spring三译本为例

本研究基于自建Silent Spring(《寂静的春天》)英汉平行语料库,以教育部编义务教育语文教材中的科普文章为标准参照,从可读性、趣味性和具象性三个维度,探讨少年儿童文学翻译文本风格特征及其与目标读者认知水平和接受能力的契合度,希冀能拓宽少年儿童翻译文学风格计量研究视野,为少年儿童文学的翻译传播研究提供参考。

Evaluation of Pencil Lead Based Electrodes for Electrocardiogram Monitoring in Hot Spring

Electrocardiogram(ECG)electrodes are conductive pads applied to the skin to measure cardiac activity.Ag/AgCl electrodes are the commercial product which widely used to obtain ECGs.When monitoring the ECG in a hot spring,Ag/AgCl electrodes must be waterproofed;however,this is time-consuming,and the adhesive may tear the skin on removal.For solving the problem,we developed the carbon pencil lead(CPL)electrodes for use in hot springs.Both CPL and Ag/AgCl electrodes were connected to ECG100C’s cables.The Performance was evaluated in three conditions as following:hot spring water with and without bubble,and in cold water.In each environment,the procedure was followed by three different protocols that are recording from the dry condition,hot spring water immersion with and without movement,post hot spring water condition.Under dry and wet conditions,both electrodes can obtain the waveform of the ECG signal in which all PQRST waves were identifiable.Nevertheless,the signal quality of both types of electrodes was different in water immersion with and without movement.The overall morphology obtained by Ag/AgCl electrodes was unstable higher than that of CPL electrodes in immersion without movement condition.The CPL electrodes provided better ECG waveform quality compared to Ag/AgCl electrodes in which the ECG signal had high waveforms distortion in water immersion with movement condition.

Modeling and simulation of the static characteristics of diaphragm spring clutches

The diaphragm spring clutch static characteristics to improve the starting quality for cars equipped with automated mechanical transmission （AMT） were modeled and simulated. First, axial stiffness of clutch cushion spring and characteristic curves of diaphragm spring were theoretically and experimentally studied. Then, model of transfer characteristics of the normal force was built, with special conscen on the abrasion of friction discs and the influence of temperature to diaphragm spring. Finally, the model was tested in practical starting for cars equipped with AMT, which showed that the starting quality was significantly improved. The experimental results showed that the proposed model was precise enough to be implemented conveniently.

澳大利亚Alice Springs造山带北缘构造变形序列与伟晶岩成矿

澳大利亚北领地南部具有近平行展布的线性沉积盆地及隆起的变质地层相间排列的特征。这种独特构造格局的形成与新元古代晚期到古生代中期的两次板内造山事件有关。研究区主要受第二次板内造山事件,即Alice Springs造山活动影响。对研究区进行地质调查和填图工作后得到以下认识:1)区域经历了3个期次的构造活动,前两期活动伴随着花岗伟晶岩的侵位;2)变形深度逐渐变浅,主应力轴分别为前两期的近南北向和第三期的北西—南东向;3)研究区的花岗伟晶岩主要由常见的造岩矿物构成,呈平缓的席状侵位特征,并未发育与围岩相同的剪切面理,也没有出现由结晶分异导致的分带现象,因此推测其成矿潜力较小。

毛细管电泳检测血红蛋白Constant Spring

目的评价Capillarys 2型毛细管电泳仪在检测α非缺失型地中海贫血(地贫)Hb Constant Spring(Hb CS)中的应用价值。方法用Capillarys 2型毛细管电泳仪分别对确诊的67例Hb CS患者、50例非地贫患者和54例健康人进行血红蛋白电泳,提取全血基因组DNA进行PCR扩增及反向斑点杂交试验检测Hb CS。随机选取含量分别为0.1%、0.2%、1.5%、1.6%、2.7%和2.8%的6份Hb CS标本各重复测定5次,以评价仪器的重复性。结果以PCR加反向斑点杂交为金标准,Capillarys2型毛细管电泳仪测定Hb CS的敏感性和特异性分别为94.0%、98.1%,阳性预测值为96.9%,阴性预测值为96.2%,诊断效率为96.5%。Hb CS纯合子的Hb CS含量为(1.82±0.60)%,Hb CS杂合子为(0.55±0.26)%,二者差异有统计学意义(t=9.31,P<0.01)。重复性测定的6份标本值分别为(0.12±0.04)%、(0.18±0.04)%、(1.52±0.04)%、(1.6±0)%、(2.66±0.05)%、(2.8%±0.06)%。结论 Capillarys 2型毛细管电泳仪作为α非缺失型地贫血红蛋白CS的快速检测手段,有较高的敏感性、特异性和较好的重复性。

Effects of Super Absorbent Polymers on Yield and Water-saving and Drought-escaping Mechanism in Spring Maize

The effects of super absorbent polymers （SAP） on yield as well as water-saving and drought-escaping mechanism in spring maize in the seasonal drought region were studied. As shown by the results, during the seasonal drought in southern China, SAP treatment promoted the soil moisture, improved the capability of absorption and transportation of roots, promoted physiological and biochemical functions, increased the chlorophyll content, photosynthetic rate and intercellular CO2 concentration, and reduced the stomatal conductance and transplre.tion rate. As a result, the economic characters of spring maize were improved, and the yield was increased.

Analysis on Causes for "Late Spring Coldness" in Dalian in 2008

The NCEP data were applied to analyze causes of 'late spring coldness' occurring twice in Dalian in late April and mid May of 2008.The results showed that the 500 hPa Baikal ridge of high pressure maintained or strengthened in a stable manner.The delivery of accumulated cold air toward southeast was along the northwest airstream before the ridge.Therefore,the ridge of high pressure over Lake Baikal provided access for the cold air southward so that the cold air could continue to decline,resulting in the appearance of low temperature in late April and formation of 'late spring coldness'.The Northeast cold vortex(NECV) occurred frequently in mid May.There was a high possibility for low temperature and pluvial damages over Dalian.Thus the phenomenon of 'late spring coldness' appeared again.

Influences of Nitrogen Level on Carbon Metabolism of Spring Maize

[Objective]To study the effect of supplies of nitrogen level on spring maize leaf blade carbon metabolism.[Method]In this experiment,field trail and biochemistry analysis were used to study the effect of the diference-nitrogen level on the content of chlorophyl and carboxylase activity of RuBP and PEP in the leaf of spring maize during main growing period.[Result]Applying proper amount of N could keep relative higher content of chlorophyl and higher activity of carboxylase of RuBP and PEP in the leaf of spring maize,insufficient or excessive（N 400 kg/hm^2） of nitrogenous fertilizer has the adverse effect.[Conclusion]In this experiment,applying 300 kg/hm^2 amount of N could keep relative higher content of chlorophyl and higher activity of carboxylase of RuBP and PEP in the leaf of spring maize during main growing period.It was important to strengthens the leaf blade photosynthesis ability,promote the yield formation and postpone the decline of leaf blade.