The Earth's inner core deviation to plate movement

Under the premise of the Earth’s layer structure and mass distribution, the solid inner core cannot be stable in the center of the sphere. Thus, the deviation of the inner core is towards the sphere’s center and the liquid outer core must have asymmetrical thermal convection. Based on the two suggestions, a concise and self-consistent global motion model can be built. The model consists of the following cycle: an asymmetrical thermal convection structure in the outer core led by the dislocation of the inner core→the plume is in special upwell position because of differential activation→the formation and split of lithosphere→the split plates drift and assemble in a new location, the mass of which causes the inner core to deviate towards this direction again→the new asymmetry is formed. As this circulation continues, a definite and periodical motion emerges/forms. Its nonlinear features result in the Earth’s motion with simple mechanisms but complex behavior. Ultraterrestrial events may disturb or

Localized temporal variation of Earth's inner-core boundary from high-quality waveform doublets

The topography of the inner core is crucial to understand its growth process and interaction with the geodynamo. With the accuracy of teleseismic waveform doublets in determining the travel-time shifts between PKPcd and PKPdf inner-core phases, we examined the temporal change of the inner-core boundary sampled by new earthquake doublets that occurred in the Western Pacific and those previously found from the South Sandwich Islands. The receiver stations are those within the distance range of 128°–142° from the hypocenters of the waveform doublets. Our results suggest that temporal changes in PKPcd-PKPdf differential times are very subtle except some isolated regions under central America and Africa. The observations may indicate localized topography of the inner core and/or the inner-core boundary as transient slurry in isolated regions.

THE COMPONENT OF 29.8 YEARS IN POLAR MOTION AND △ l. o.d. AND OSCILLATION OF EARTH'S INNER CORE

This paper deals with the components of pcriod of 29.8 yr in polar motion and △ I. o. d. The oscillation of inner core (OIC), as a most possible cause of them, is proposed. Parameters of oscillation are found and its effects on Earth’s mass center (EMC), distance of observatories to EMC, gravity and latitude are estimated.

PRELIMINARY RESEARCH ON THE RELATIONSHIPS BETWEEN THE INNER CORE SIZE AND OUTER SIZE OF TROPICAL CYCLONES AND THEIR INTENSITY

Based on the Regional Spectral Model(RSM) re-analysis data from Japan Meteorological Agency(JMA) with a horizontal resolution of 20 km and a time interval of 6 h,this study works on the outer and inner core size of 2174 samples of tropical cyclones(TCs) occurring over the western North Pacific between 2001 and 2007.Some conclusions have been drawn on the basis of preliminary analysis of the TC inner core size and outer size and their relationship with TC intensity.First,the outer size increase(decrease) helps TCs intensify(weaken).Second,the enlargement(shrinking) of the inner core size helps TCs intensify(weaken) if TCs have a large inner core(with radius of maximum winds larger than 120 km).Contrarily,when TCs have small inner core(with radius of maximum winds smaller than 120 km),the enlargement(shrinking) of the inner core is good for weakening(intensifying) of TCs.

The Akp-Btk value method and the resultsfor the retrieval of the parameters of the Earth's free core nutation

The rotation of the Earth's liquid core creates the Nearly Diurnal Free Wobble (NDFW). It is one of the problems of researching the Earth's liquid core for us to retrieve the parameters of the Earth's Free Core Nutation (FCN),from the Earth's liquid core resonance of gravity tide waves on the diurnal frequency band. Since 1987, some scientists in many different countries have come to calculate the parameters of FCN by using the observational data of gravity tide waves on the diumal frequency band. They basically followed the Stacking method, which needed five diurnal waves for the resolution. In this paper, authors introduced the Aky-Btk value method with clearly geometrical meaning as a new method, which only requires three very high signal-noise-ratio waves o1, K1 and P1 for the resolution. Authors chose the observational data of the three superconducting gravimeter stations respectively located in Cantley of Canada, Wuhan of China and Brussels of Belgium, to compute the parameters of FCN. It was the first time that the observational results of the parameters of FCN obtained from gravitational tide were in accord with the parameters of FCN gained from VLBI since 1987.

Sensitivity of Tropical Cyclone Intensification to Inner-Core Structure

In this study, the dependence of tropical cyclone （TC） development on the inner-core structure of the parent vortex is examined using a pair of idealized numerical simulations. It is found that the radial profile of inner-core relative vorticity may have a great impact on its subsequent development. For a system with a larger inner-core relative vorticity/inertial stability, the conversion ratio of the diabatic heating to kinetic energy is greater. Furthermore, the behavior of the convective vorticity eddies is likely modulated by the system-scale circulation. For a parent vortex with a relatively higher inner-core vorticity and larger negative radial vorticity gradient, convective eddy formation and radially inward propagation is promoted through vorticity segregation. This provides a greater potential for these small-scale convective cells to self-organize into a mesoscale inner-core structure in the TC. In turn, convectively induced diabatic heating that is close to the center, along with higher inertial stability, efficiently enhances system-scale secondary circulation. This study provides a solid basis for further research into how the initial structure of a TC influences storm dynamics and thermodynamics.

The effect of the differential rotation of the earth inner core on the free core nutation

Seismic observations shows that the inner core rotates faster than the mantle and the rotation axis of the inner core may not align with the rotation axis of the mantle. Free core nutation reflects core's information. We discuss the effect of the inner core's differential rotation on free core nutation from two aspects: rotation speed and deflection angle. Our result shows it is in accordance with the observations when the inner core's rotation speed doesn't exceed 10° faster than mantle's per year, and the deflection angle is less than 1°,if the rotation speed and the deflection angle are respectively considered separately.

The anisotropy of hexagonal close-packed iron under inner core conditions: the effect of light elements

In recent decades,global seismic observations have identified increasingly complex anisotropy of the Earth’s inner core.Numerous seismic studies have confirmed hemispherical variations in the inner core’s anisotropy.Here,based on ab initio molecular dynamics calculations,we report how the anisotropy of hexagonal close-packed(hcp)-iron,under inner core conditions,could be altered when alloyed with light elements.We find that light elements in binary allows with iron-hcp-Fe-X(X=C,O,Si,and S)-could have significant effects on density,sound velocities,and anisotropy,compared with the behavior of pure hcp-iron;the anisotropy of these binary alloys depends on combined effects of temperature and the particular alloying light element.Furthermore,the change in anisotropy strength with increasing temperature can be charted for each alloy.Alloying pure iron with some light elements such as C or O actually does not increase but decreases core anisotropy at high temperatures.But the light element S can significantly enhance the elastic anisotropy strength of hcp-Fe.

Notes on the variability of reflected inner core phases

Recent events beneath Central America have produced excellent sets of inner core reflection （PKiKP phase） at high frequency recorded by USArray ranging from 18° to 30°. However, the amplitude of this phase displays considerable scatter with a factor of six or more. Such scatter has been attributed to upper-mantle scattering and the Inner Core Boundary （ICB） in combination. Here, we show that neighboring events share upper-mantle scatterers beneath the receivers, and their ratio allows a clearer image of deep earth structure. Alter confirming some of the measured variation is indeed due to deep structure, we stacked nearby traces to reduce fine scale variations which are mostly due to shallow structure. Then, the remaining relatively large scale variation pattern of PKiKP phase is caused by the inner core boundary, as demonstrated by numerical experiments. After migration of data to the 1CB, we observe a consistent image. We find such a pattern can be explained by a patch of mushy material of a few kilometers high where the material changes gradually from that of the outer core to that of the inner core.

Determination of the Effect of Initial Inner-Core Structure on Tropical Cyclone Intensification and Track on a Beta Plane

The sensitivity of TC intensification and track to the initial inner-core structure on a β plane is investigated using a numerical model. The results show that the vortex with large inner-core winds（CVEX-EXP） experiences an earlier intensification than that with small inner-core winds（CCAVE-EXP）, but they have nearly the same intensification rate after spin-up. In the early stage, the convective cells associated with surface heat flux are mainly confined within the inner-core region in CVEXEXP, whereas the vortex in CCAVE-EXP exhibits a considerably asymmetric structure with most of the convective vortices being initiated to the northeast in the outer-core region due to the β effect. The large inner-core inertial stability in CVEX-EXP can prompt a high efficiency in the conversion from convective heating to kinetic energy. In addition, much stronger straining deformation and PBL imbalance in the inner-core region outside the primary eyewall ensue during the initial development stage in CVEX-EXP than in CCAVE-EXP, which is conducive to the rapid axisymmetrization and early intensification in CVEX-EXP. The TC track in CVEX-EXP sustains a northwestward displacement throughout the integration, whereas the TC in CCAVE-EXP undergoes a northeastward recurvature when the asymmetric structure is dominant. Due to the enhanced asymmetric convection to the northeast of the TC center in CCAVE-EXP, a pair of secondary gyres embedded within the large-scale primary β gyres forms, which modulates the ventilation flow and thus steers the TC to move northeastward.

超强台风“舒力基”(2021)的尺度可预报性

台风尺度表征了台风低层风场特定风速半径大小,是台风灾害影响范围的重要度量.针对超强台风“舒力基”(2021),对其尺度可预报性进行初步探讨.结果表明,模式可以模拟出台风发展初期台风尺度(内核尺度RMW、外围尺度R17)的演变趋势.基于集合预报的模拟试验,具体分析了内核尺度RMW、外围尺度R17演变及其误差增长特征.台风预报总体误差主要出现在对流层下层850 h Pa,距离台风中心50~150 km.从初始环境场看,初始相对湿度是影响台风尺度误差增长的重要因子,初始高湿环境有利于台风发展阶段的台风尺度高离散度,从而限制了台风尺度的可预报性.在一定程度上,外围风圈半径的可预报性要高于内核风圈半径.

地球内核超离子态铁合金及其效应

超离子态介于固态与液态之间,被认为广泛存在于地球和行星内部。计算研究发现,在地球内核温度压力条件下,铁-氢、铁-碳、铁-氧合金处于超离子态,表现为氢、碳、氧等元素在固态铁合金中像液体一样快速流动。流动的轻元素导致铁合金软化及地震波速降低,与地球物理观测到的内核密度亏损和低剪切波速的特征一致。内核超离子态铁-氢合金可以与地磁场发生相互作用,在偶极地磁场的驱动下形成定向排列组构,从而解释了内核的各向异性结构成因。内核超离子态铁-轻元素合金的发现更新了人们对内核物态的认知,对掌握地球内核的结构、组成和演化以及内核结构与地球磁场的关系等具有重要意义。

汽车发动机缸体内腔质量影响因素分析及工艺控制

随着汽车轻量化的发展,发动机缸体壁厚要求越来越薄。针对水套内腔质量的影响因素进行了分析和工艺改善;介绍了烧结陶瓷砂、纤维素和铬尖晶石用于硅砂制芯添加对砂芯高温和常温特性以及产品质量的影响;指出涂料的热暴、热膨胀和烧结性对产品内腔质量影响以及涂料粉料的作用机理;运用射砂模拟技术对砂芯致密性进行了分析和质量改善。

细长形装饰条注射模设计

根据装饰条的结构特点,设计了1模4腔的模具结构,为使模具零件运动过程中保持平衡,且同时成型左、右装饰条,分型面采用斜面过渡。针对塑件特征分别采用内抽芯机构脱模、斜推机构脱模、滑块结构脱模,为了消除普通流道的注射缺陷,采用热流道+普通流道的混合浇注系统。模具经实际生产验证:成型的塑件符合要求,对类似塑件的模具设计具有一定的参考作用。

Detection and interpretation of the Earth's free oscillations excited by the great Sumatra-Andaman earthquake with GGP station data

The mode serials of the Earth’s free oscillation provide some important information on the Earth’s deep structure and superconducting gravimeters （SG） can investigate the phenomena of the Earth’s free oscillations with high accuracy. The great Sumatra-Andaman earthquake fully excited the Earth’s free oscillations and these signals were perfectly recorded by five superconducting gravimeters in the globe. After the pre-treatment and spectral analysis on the SG observation data, we obtained the experimented mode serials of the Earth’s free oscillations consisting of 147 modes with GGP station data. These observed modes were themselves some new important data for the study of the Earth’s deep structure. On the basis of the discussions on some checked inner-core-sensitive modes, we distinguished three layers from the inner core, and the boundary of the upper layer was compatible with the formerly known transition zone in the inner core based on seismic body waves and supported that there were the hemispherical variation and very lower shear velocity zone in the lower inner core.

High-Resolution Geochemical Records in the Inner Shelf Mud Wedge of the East China Sea and Their Indication to the Holocene Monsoon Climatic Changes and Events

The inner shelf mud wedge(ISMW)located in the East China Sea(ECS)is the fine-grained sedimentary area with high sedimentation rate and has provided an ideal study area for understanding the East Asian Summer Monsoon(EASM)evolution during the Holocene.In this paper,we presented the high-resolution geochemical data of the sediments from the core MD06-3040 in the ISMW of the ECS determined by X-ray fluorescence core scanning(XRF-CS)analysis,a high-resolution,continuous,and multielement method.Geochemical and factor analysis results reveal that the variations of elemental compositions(Al,Si,K,Ti,Fe),the elemental ratios of Al/Zr,Ca/Ti and Rb/Sr,and the factor scores(F1 are correlated with the changes of the EASM during the period of 6000–1300 cal yr BP.The higher values of geochemical compositions indicating the terrigenous inputs implied the intensification of anthropogenic activities after 1300 cal yr BP.Meanwhile,the significant decrease of most geochemical compositions and the F1 factor scores during 4500–3500 cal yr BP and 1700–1500 cal yr BP,within the dating errors,coincided with the weak EASM events(presumably drought and cold events).The spectral analysis results of K concentrations,Al/Zr ratios and F1 factor scores show the millennial and centennial climatic fluctuations,which are consistent with other marine sedimentary records in the adjacent areas.All the findings show that the geochemical compositions of sediments from core MD06-3040 are influenced by the EASM evolution,the variable El Niño/Southern Oscillation(ENSO)and the local oceanic thermohaline circulation(e.g.,Kuroshio Current).These results are greatly helpful in uncovering the forcing mechanism of the monsoonal climate in the east China over the Holocene and also contribute to the understanding of EASM variability.

Study and Analysis of a Landing Gear Actuating Cylinder Inner-lock

Three kinds of landing gear actuating cylinder inner-locks of an aircrafi ： block ring lock, steel ball lock, finger lock are taken as the study object based on the mechanics, geometry, materials, technology etc and some aircrafi typical inner-lock practical applications. The working principle of the three typical actuating cylinder innerlocks are expounded and the stress and workmanship requirements of the three inner-lock core components are analyzed. The advantages and disadvantages of different kinds are compared and the characteristics and applications of the three inner-locks investigated. The research and analysis results provide valuable information for the actuating cylinder inner-lock of the aircraft landing gear design.

中华传统节日文化融入高校思想政治教育的路径研究

新时代高校思想政治教育面临许多新要求,中华传统节日文化融入高校思想政治教育工作中,不仅有利于促进中华优秀传统文化的传承和国家认同,培育深厚的民族情感,而且能为高校思想政治教育提供新的传播载体。通过科学提炼中华传统节日文化的内核,深入研究中华传统节日中所蕴含的爱国主义、价值观及传统美德等教育资源,探讨中华传统节日融入高校思想政治教育的原则和路径。

孔隙结构对水冷燃烧器燃烧换热特性的影响

针对天然气等高热值气体燃烧时氮氧化物排放高和多孔介质烧蚀问题,设计开发了变孔隙多孔介质燃烧试验系统,研究了燃烧室内沿横向孔密度变化的孔隙结构对多孔介质中燃烧换热的影响.结果表明:燃烧室内平均孔密度相同条件下,孔密度沿横向由内而外先阶跃增加再阶跃减小的孔隙结构有利于燃烧放热沿冷却边界方向的传递,该燃烧室内整体温度低,从燃烧室中心截面处沿冷却边界方向的温差最大达568℃,多孔介质燃烧器的温升速率最小为16.2℃/min,平均传热系数最大为656.6 W/(m^(2)·℃);横向孔密度变化的6种燃烧室内芯结构采用水冷方式降低了燃烧室温度,NO排放都可以达到20 mg/m^(3)以下,而CO最高也仅有60 mg/m^(3).