27.3-day and 13.6-day Atmospheric Tide and Lunar Forcing on Atmospheric Circulation

An analysis of time variations of the earth’s length of day (LOD) versus atmospheric geopotential height fields and lunar phase is presented. A strong correlation is found between LOD and geopotential height from which a close relationship is inferred and found between atmospheric circulation and the lunar cycle around the earth. It is found that there is a 27.3-day and 13.6-day east-west oscillation in the atmospheric circulation following the lunar phase change. The lunar revolution around the earth strongly influences the atmospheric circulation. During each lunar cycle around the earth there is, on average, an alternating change of 6.8-day-decrease, 6.8-day-increase, 6.8-day-decrease and 6.8-day-increase in atmospheric zonal wind, atmospheric angular momentum and LOD. The dominant factor producing such an oscillation in atmospheric circulation is the periodic change of lunar declination during the lunar revolution around the earth. The 27.3- day and 13.6-day atmospheric oscillatory phenomenon is akin

Quantifi cation of the Atmospheric Corrosion of 304 and 2205 Stainless Steels Using Electrochemical Probes Based on Thevenin Electrochemical Equivalent Circuit Model

Stainless steel(SS)is one of the most widely used engineering materials in marine engineering.However,its corrosion in the marine atmospheric environment due to the high concentration of Cl-is a problem.The SS corrosion is a threat to the development and security of marine industry;therefore,evaluating the corrosion resistance of SSs is necessary.In this work,atmospheric corrosion detection probes based on a symmetrical electrode system were used to study the corrosion behaviors of 304 SS and 2205 duplex stainless steel(DSS)in a simulated marine atmosphere.A theoretical model for electrochemical noise(EN)data analysis based on the Thevenin electrochemical equivalent circuit(EEC)model was established.The relationship between the EN characteristic parameters and the corrosion rate was obtained.The Thevenin EEC model analysis showed that the relationship between the noise resistance(Rn),the noise impedance[Rsn(f)],and the impedance modulus(|Z(f)|)was Rn≈Rsn=■.Thus,Rn and Rsn can be used as indicators for quantitative corrosion evaluation.The results of EN detection for the 304 SS and 2205 DSS showed that in a simulated marine atmospheric environment,the passive fi lms on the two SSs were relatively intact at the initial exposure stage,and their dissolution rates were slow.The corrosion resistance of the 2205 DSS was higher than that of the 304 SS.With the deposition of Cl-on the SS surface,pitting was initiated and the dissolution rate increased.The pitting initiation process on the SS surface was random,and part of the active pores could be repassivated.

Numerical simulation of influence of the anomalies of theCentral-eastern Equatorial Pacific SST and Arctic seaice cover in summer on the atmospheric circulation

A series of numerical experiments have been conducted with a perpetual July, nine-level general circulation spectral model to determine the effect of variation of the Arctic sea ice cover extent and the joint effect of anomalies of both the Arctic sea ice cover and the Central-eastern Equatorial Pacific sea surface temperature on the summer general circulation. Results show that the two factors,anomalously large extent of the Arctic sea ice cover and anomalously warm sea surface temperature over the Central-eastern Equatorial Pacific Ocean, play substantially the equal role in the effect on the summer general circulation, and either of them can notably induce the atmospheric anomalies. The main dynamical processes determining the effect of the Arctic sea ice and the equatorial SST anomalies are associated with two leading teleconnection patterns, i. e. the Asia North/American and Eurasian patterns observed in atmosphere. The results presented in this paper again prove that the general circulation is fundamentally motivated by the non-uniform heating between the equator and the pole on the rotating earth.

External Influence to Geochemical Assessment of the Land Quality—Atmospheric Dry and Wet Deposition

The heavy metals in the atmosphere mainly come from the gas and dust which involved by the energy costs,transport,metallurgy and building materials production.Other than the element of Hg,the heavy metals come into the atmosphere in the form of aerosol basically and go into the soil through

STRUCTURES AND CONDITIONS OF EXISTENCE FORA KIND OF ATMOSPHERIC MOTIONS

With the method of phase plane, the ρ-coordinated equation sets have been derived that include no friction without the introduction of the kdv equation and the structure of atmospheric motions, conditions for existence and movement are studied for all individual solutions. The result shows that a weak high or low pressure system isjointly affected by the atmospheric static stability, latent heating due to condensation and sensible heating for the conditions for existence, state of movement, structural features.

Preliminary Study on Vertical Velocity Caused by Katabatic Wind in Antarctica and Its Influence on Atmospheric Circulation

The vertical velocity at the top of Ekman layer caused by katabatic winds is proposed and deduced. By computing actual data we get a distribution of the velocities over Antarctica. The distribution plays a positive role in maintaining the cyclone and anticyclone over Antarctica.

Influence of Continental Atmospheric Forcing on the Decadal Variability of the West African Monsoon

The West African Monsoon (WAM) is characterized by strong decadal and multi-decadal variability and the impacts can be catastrophic for the local populations. One of the factors put forward to explain this variability involves the role of atmospheric dynamics, linked in particular to the Saharan Heat Low (SHL). This article addresses this question by comparing the sets of preindustrial control and historical simulation data from climate models carried out in the framework of the CMIP5 project and observations data over the 20th century. Through multivariate statistical analyses, it was established that decadal modes of ocean variability and decadal variability of Saharan atmospheric dynamics significantly influence decadal variability of monsoon precipitation. These results also suggest the existence of external anthropogenic forcing, which is superimposed on the decadal natural variability inducing an intensification of the signal in the historical simulations compared to preindustrial control simulations. We have also shown that decadal rainfall variability in the Sahel, once the influence of oceanic modes has been eliminated, appears to be driven mainly by the activity of the Arabian Heat Low (AHL) in the central Sahel, and by the structure of the meridional temperature gradient over the inter-tropical Atlantic in the western Sahel.

A new probe for atmospheric electric field mill

A new probe for atmospheric electric field mill is introduced.It consists of three parts：signal acquisition circuit for atmospheric electric field,preamplifier circuit and phase sensitive detection circuit.The signal acquisition circuit adopts the double-stator structure to form differential input circuit,thus double-precision is obtained.Preamplifier circuit is made of current-to-voltage （I-V） conversion circuit,differential amplifier circtuit and secondary amplifying circuit.The polarity of electric field is obtained via phase sensitive detection circuit.Simulation results are obtained using Multisim,and the feasibility of the designed probe is verified.

Influence of Tilted Angle on Effective Linear Energy Transfer in Single Event Effect Tests for Integrated Circuits at 130 nm Technology Node

A heavy-ion irradiation experiment is studied in digital storage cells with different design approaches in 130？nm CMOS bulk Si and silicon-on-insulator （SOI） technologies. The effectiveness of linear energy transfer （LET） with a tilted ion beam at the 130？nm technology node is obtained. Tests of tilted angles θ=0 ° , 30 ° and 60 ° with respect to the normal direction are performed under heavy-ion Kr with certain power whose LET is about 40？MeVcm 2 /mg at normal incidence. Error numbers in D flip-flop chains are used to determine their upset sensitivity at different incidence angles. It is indicated that the effective LETs for SOI and bulk Si are not exactly in inverse proportion to cosθ , furthermore the effective LET for SOI is more closely in inverse proportion to cosθ compared to bulk Si, which are also the well known behavior. It is interesting that, if we design the sample in the dual interlocked storage cell approach, the effective LET in bulk Si will look like inversely proportional to cosθ very well, which is also specifically explained.

Analysis and comparison of the tidal gravity observations obtained with LCR-ET20 spring gravimeter

Based on the tide gravity observations recorded with LCR-ET20 spring gravimeter at Wuhan international fundamental tidal gravity station, the characteristics of ET20 and atmospheric and oceanic gravity signals are studied systematically by using international standard data pre-processing and analysis methods and by comparing the results with those obtained by superconducting gravimeter (SG) at the same station. The numerical results indicate that the identical tidal gravity parameters are the same as those with the SG, the instrument can be effectively used to record temporal change of the gravity field, though the ET20 accuracy is one order lower than that of the SG, and has the large drift induced by the spring creep character.

新冠疫情期间西安市空气质量时空特征研究

2019年和2021年新冠疫情期间西安市政府均采取了强有力的管控措施,为此对比研究了不同程度减排措施对空气质量的影响。采用特征雷达图、空间插值和HYPLIST轨迹模型等方法对西安市疫情期间(2019年12月—2020年2月、2021年12月—2022年2月)和正常生产期(2020年12月—2021年2月)冬季空气质量变化特征进行了对比分析,并探讨了人为减排情景下空气质量变化潜在原因。结果表明:(1)西安市环境空气质量指数(AQI)空间分布整体呈现“西北劣东南优”特征。2020年疫情严控期空气质量得到明显改善,优良率达到53%;2022年疫情严控期空气质量未受管控措施明显影响。(2)2020年疫情严控期除O_(3)外污染物浓度均明显下降,降幅分别为PM2.5(42.90%)>NO_(2)(42.13%)>CO(35.37%)>PM10(32.58%)>SO_(2)(17.40%);2022年仅有SO_(2)和NO_(2)浓度下降,降幅为NO_(2)(31.86%)>SO_(2)(18.31%)。疫情期间污染类型属于偏二次型。(3)疫情期间,污染天气是在高湿静风天气条件和盆地地形的基础上,受人为源排放和区域污染物传输引起的,因此促进污染物协同减排和关中地区联防联控是改善空气质量的关键举措。

甲醇燃料船加注泄漏模拟及影响因素分析

为研究甲醇燃料船加注作业泄漏事故对人员安全和环境污染的影响,指导甲醇加注作业安全开展,基于有害大气空中定位(ALOHA)模型模拟分析甲醇泄漏事故的影响范围和影响因素。根据点火条件、泄漏源位置和消防系统响应等因素构建甲醇泄漏事件树,在此基础上对泄漏导致的毒性扩散、闪火和蒸气云爆炸等3类典型场景进行模拟计算,并分析不同环境条件对甲醇泄漏后果的影响。结果表明,在设定场景下,毒性扩散最大距离为1450 m,闪火伤害最大距离为225 m,蒸气云爆炸最大直径为65 m;大气温度和风速对甲醇泄漏后果有重要影响,甲醇蒸气云爆炸最大直径、毒性扩散和闪火伤害最大距离随大气温度的升高而增大,随风速的增加而减小;相对湿度和云层覆盖率对甲醇泄漏的后果基本无影响。研究成果可供甲醇燃料加注作业的开展参考。

集成电路产业集群韧性测度及影响因素研究

培育世界级先进制造业集群,是新时代国家实施制造强国战略的一项重要举措,也是提升产业链供应链韧性和安全水平的有效途径。以南京江北新区集成电路产业集群为研究对象,通过文献梳理,分析产业集群韧性的影响因素,并从抵抗力、恢复力、复原力、再生力等4个维度建立集群韧性评价指标体系。研究发现:龙头企业、公共政策、创新网络和市场等对集成电路产业集群韧性具有显著正向影响;而企业联动不具有显著影响。因此,培优扶强龙头企业、完善相关产业政策、打造产学研用联盟和培育集群市场竞争力是集成电路产业集群提升韧性的重要途径。

中国夏季边界层高度及其主要影响因子的分区研究

中国区域下垫面复杂且边界层热力和动力影响因子众多,目前缺乏对全国范围内边界层高度及其影响因子的综合分析。本文基于2012~2016年L波段高分辨率探空资料,采用K-prototypes算法结合12个可能影响因子将中国夏季边界层高度进行了聚类分析,以探讨中国夏季边界层高度的区域性特征和主要影响因子。结果表明,中国区域100个站点08、14、20时(北京时,下同)的边界层高度均可划分为东北、东南、西北和西南4个区域。在此基础上,分析了三个不同时次不同区域边界层高度的主要影响因子,并探究这些因子影响不同热力状态下边界层发展的可能机理。结果表明:稳定边界层早(08时)、晚(20时)的发展主要受风速湍流动力作用的影响,而中午14时的发展与间歇性湍流作用密切相关。中性和对流边界层的发展在早上也主要受风速的驱动,而在中午则主要受较高地表温度和较大地表净辐射通量所引起的湍流热力作用驱动。此外,东北地区的云量和比湿、东南地区的潜热通量、西北地区的感热通量和比湿、西南地区的感热通量和土壤湿度也会通过对热力湍流的直接或间接影响,从而影响该区域中性和对流边界层的发展。晚上,由于东西时差的影响,在东部地区,风速开始成为中性和对流边界层高度的主要影响因子,而西部地区边界层高度的主要影响因子仍为热力因子。值得注意的是,北部地区的叶面积指数可以通过植被蒸腾作用改变比湿,从而影响边界层的发展;东北地区地表气压的变化可以通过影响气流的上升和下沉运动从而影响边界层的发展。

塑封集成电路HAST影响因素探讨

随着塑封集成电路在人工智能、移动互联网、物联网、云计算和大数据等领域的广泛应用,其面临长时间加电连续工作的需求,因此需要对其长期可靠性进行研究。结合试验实例,分别从设备、试验硬件和导线材质等方面对塑封集成电路高加速应力试验(HAST)的影响因素进行了分析。分析结果表明采用高纯水、优化温湿度控制程序可避免凝露引发的集成电路试验过程失效;导电性阳极丝(CAF)和电化学迁移(ECM)是HAST中常见失效问题,试验硬件与工艺需做好CAF和ECM防控;试验线材会影响HAST,线材绝缘层与线芯材质要定期监测,适时更换。

环境对大型激光陀螺仪的影响研究综述

基于萨格纳克效应的大型激光陀螺仪被认为是精确监测地球自转的合适传感器,可用于潜在的地面科学研究和重大工程应用,如世界时UT1精密测量,地球固体潮观测、旋转地震波探测、广义相对论预言引力磁效应等领域。激光陀螺的灵敏度随环形腔尺寸增大而提高,其运行的长期稳定性受环境变化的影响。本文从激光陀螺仪工作原理出发,梳理了温度、倾斜、气压和风等环境变化对大型激光陀螺仪灵敏度和稳定度的影响,分析说明监测环境因素变化对其输出的萨格纳克频差修正和处置方法,为提高大型激光陀螺仪应用性能提供相关指导。

基于CESM模式的4至6月热带西南印度洋海表异常增暖对印太气候影响的研究

热带西南印度洋温跃层深度较浅,该海域温跃层的变化与海表温度具有密切的联系,具有独特的海气相互作用。文章基于观测资料和模式资料分析了4至6月热带西南印度洋海表增暖对热带印度洋-西太平洋的气候影响。结果表明, 4至6月热带西南印度洋海表增暖增强了当地的对流活动,导致热带西南印度洋降水的增加;热带印度洋的低空出现了关于赤道反对称的“C型”风场异常,即赤道以北为异常的东北风,赤道以南为异常的西北风;5月至6月北印度洋低空异常的东北风会减弱亚洲夏季风,北印度洋海表潜热释放减少,北印度洋海表增暖。热带西南印度洋海表增暖的气候影响并不局限在热带印度洋地区,其增暖能加热对流层大气,激发东传的大气开尔文波,热带西北太平洋低层的东风响应在信风的背景下也能触发局地的海气正反馈,两者共同有利于热带西北太平洋地区低空反气旋式风场的维持。反气旋式风场异常在5、6月能增强季风水汽输送,使得我国长江流域的降雨显著增多。该研究结果揭示了热带西南印度洋加热异常可引起横跨北印度洋-热带西太平洋的海气相互作用,为我国东部地区夏季降水预报提供了有益参考。

金沙江下游流域大气降水氢氧稳定同位素特征及水汽来源

金沙江下游流域地处干热河谷气候影响区,大气降水对该区域水文循环至关重要。分析了金沙江下游流域降水稳定同位素组成的季节变化特征及其影响因素,结合同位素示踪和HYSPLIT模型探讨了流域大气降水水汽来源。结果表明:金沙江下游流域降水δ^(2) H和δ^(18) O雨季偏负而旱季偏正,气温和降水量对同位素组成影响较大而高程效应不显著;流域大气降水线斜率和截距均低于全球和我国大气降水线,主要受到非平衡蒸发作用影响;流域大气降水水汽来源和昆明地区类似,雨季降水主要受到西南与南亚季风影响,旱季降水潜在来源为西风带或极地大陆气团。研究成果对金沙江下游区域水文循环具有重要指导意义。

五运六气理论历法学探析

探讨运气历法对于深入把握五运六气理论具有重要意义。文章从运气历法概述、运气历法研究中存在的问题、运气历法在中医临床中的体现及运气历法的不足这四个方面对五运六气理论进行了历法学分析。结果认为:运气历法属于干支太阳历;易混淆的干支太阳历和干支农历实是两种历法体系;此外,在《黄帝内经》运气篇章的记载中存在干支太阳历纪时系统不全面的缺点。

Fluid-chemical modeling of the near-cathode sheath formation process in a high current broken in DC air circuit breaker

When the contacts of a medium-voltage DC air circuit breaker(DCCB) are separated, the energy distribution of the arc is determined by the formation process of the near-electrode sheath. Therefore, the voltage drop through the near-electrode sheath is an important means to build up the arc voltage, which directly determines the current-limiting performance of the DCCB. A numerical model to describe the near-electrode sheath formation process can provide insight into the physical mechanism of the arc formation, and thus provide a method for arc energy regulation. In this work, we establish a two-dimensional axisymmetric time-varying model of a medium-voltage DCCB arc when interrupted by high current based on a fluid-chemical model involving 16 kinds of species and 46 collision reactions. The transient distributions of electron number density, positive and negative ion number density, net space charge density, axial electric field, axial potential between electrodes, and near-cathode sheath are obtained from the numerical model. The computational results show that the electron density in the arc column increases, then decreases, and then stabilizes during the near-cathode sheath formation process, and the arc column's diameter gradually becomes wider. The 11.14 V–12.33 V drops along the17 μm space charge layer away from the cathode(65.5 k V/m–72.5 k V/m) when the current varies from 20 k A–80 k A.The homogeneous external magnetic field has little effect on the distribution of particles in the near-cathode sheath core,but the electron number density at the near-cathode sheath periphery can increase as the magnetic field increases and the homogeneous external magnetic field will lead to arc diffusion. The validity of the numerical model can be proven by comparison with the experiment.