古希伯来诗歌的特征

圣经诗歌几乎完全出现在希伯来圣经中。语义上的平行体是希伯来诗节的普遍特征。希伯来诗歌中有一种趋于强化的叙述发展势态,这种"水平"运动经常通过一系列诗行,甚至一首完整的诗,向下投映到某种"垂直"运动中。这意味着希伯来诗歌被关注的是一种向着某个终极目标运动的动态过程。希伯来诗歌有两种最常见的结构,一是意象、概念、主题借助于一系列诗句实现的不断强化的运动;二是一种叙述运动,最常见诸于隐喻性行为的发展过程中。希伯来诗歌不仅是一种手段,被圣经作者们用来强化或戏剧化其宗教感知,而且是一种有力的塑形工具,借助于它,那些感知中蕴含的内在真理得以被人发现。

Bioturbation Effects of Branchiura sowerbyi (Tubificidae) on the Vertical Transport of Sedimentary Particles in Paddy Field

[Objective] The research aimed to investigate the bioturbation effects of Branchiura sowerbyi （Tubificidae） on the vertical transport of sedimentary particles in paddy field,and explore the bioturbation effects and mechanism of benthic Annelida in coupling process of benthic-pelagic interface.[Method]Using chemically stable glass beads as tracers,the vertical transport of sedimentary particles in paddy field was analyzed comparatively with and without B.sowerbyi.[Result]After 10 days＇ bioturbation of B.sowerbyi,41.3% of the glass beads on the surface of sedimentary particles were transferred downward to the maximum depth of 9.4 cm,and the vertical transportation rate of sedimentary particles was 1.370×10-3/（g·cm2·d）. 25.8% and 17.3% of glass beads at a depth of 6 cm were transferred upwards and downwards respectively after bioturbation,to the maximum depth of 5.2 and 2.7 cm respectively,and the vertical transportation rates of sedimentary particles were 8.557×10-4 and 5.738×10-4/（g·cm2·d） respectively.[Conclusion]The sedimentary particles on the surface and deep layer of the paddy field were vertically shifted by the physical activities of B.sowerbyi,thus changed the sedimentary environment.

Variation in Principal Modes of Midsummer Precipitation over Northeast China and Its Associated Atmospheric Circulation

This study documents the first two principal modes of interannual variability of midsummer precipitation over Northeast China （NEC） and their associated atmospheric circulation anomalies. It is shown that the first principal mode exhibits the largest amount of variability in precipitation over the south of NEC （referred to as the south mode）, whereas the second principal mode behaves with the greatest precipitation anomaly over the north of NEC （referred to as the north mode）. Further findings reveal that, through modulating moisture transportation and upper- and lower-troposphere divergence circulation as well as vertical movement over NEC, the anomalous northwestern Pacific anticyclone and the anticyclone centered over northern NEC exert the dominant influence on the south and north modes, respectively. Additionally, it is quantitatively estimated that water vapor across the southern boundary of NEC dominates the moisture budget for the south mode, while the north mode has a close connection with moisture through NEC＇s northern and western boundal＇ies. Furthermore, the north （south） mode is strongly related to the intensity （meridional shift） of the East Asian westerly jet.

Investigating the initiation and propagation processes of convection in heavy precipitation over the western Sichuan Basin

Heavy precipitation events occur often over the western Sichuan Basin in summer, near the transition zone between the Sichuan Basin and the steep terrain of the Tibetan Plateau. One such event -- a heavy precipitation process that occurred on 18-20 August 2010, with clear nocturnal peaks -- is chosen as a case to tentatively explore how the convection associated with convectivescale precipitation is initiated and propagated. By utilizing the vertical momentum equation from the viewpoint of separating perturbation pressure into dynamic and thermal parts, it is demonstrated that the vertical momentum is induced by the imbalance of several forces, including the dynamic/buoyant part of the perturbation pressure gradient force and the buoyancy force, with the latter dominating during the nocturnal-peak period. Although a negative value of the dynamic perturbation pressure gradient force partly offsets the positive buoyant forcing inside the strong updraft, the pattern of vertical motion tendency is largely attributable to its buoyancy because of its larger magnitude. Relative to the buoyancy component, the dynamic part of the vertical perturbation pressure gradient is also examined, revealing a smaller order of magnitude. Thus, it is the thermal effect that should be responsible for the initiation and propagation of convection. As for the convective-scale precipitation, it always presents a trailing morphology relative to the strong leading-side updraft. Furthermore, overlapping strong signals of vertical motion and its tendency point towards strong precipitation in the future.

Diving control of underactuated unmanned undersea vehicle using integral-fast terminal sliding mode control

The problem of diving control for an underactuated unmanned undersea vehicle(UUV) considering the presence of parameters perturbations and wave disturbances was addressesed.The vertical motion of an UUV was divided into two noninteracting subsystems for surge velocity control and diving.To stabilize the vertical motion system,the surge velocity and the depth control controllers were proposed using backstepping technology and an integral-fast terminal sliding mode control(IFTSMC).It is proven that the proposed control scheme can guarantee that all the error signals in the whole closed-loop system globally converge to the sliding surface in finite time and asymptotically converge to the origin along the sliding surface.With a unified control parameters for different motion states,a series of numerical simulation results illustrate the effectiveness of the above designed control scheme,which also shows strong robustness against parameters perturbations and wave disturbances.

A NOVEL METHOD FOR CALCULATING VERTICAL VELOCITY:A RELATIONSHIP BETWEEN HORIZONTAL VORTICITY AND VERTICAL MOVEMENT

The present work provides a novel method for calculating vertical velocity based on continuity equations in a pressure coordinate system.The method overcomes the disadvantage of accumulation of calculating errors of horizontal divergence in current kinematics methods during the integration for calculating vertical velocity,and consequently avoids its subsequent correction.In addition,through modifications of the continuity equations,it shows that the vorticity of the vertical shear vector(VVSV) is proportional to-ω,the vertical velocity in p coordinates.Furthermore,if the change of ω in the horizontal direction is neglected,the vorticity of the horizontal vorticity vector is proportional to-ω.When ω is under a fluctuating state in the vertical direction,the updraft occurs when the vector of horizontal vorticity rotates counterclockwise;the downdraft occurs when rotating clockwise.The validation result indicates that the present method is generally better than the vertical velocity calculated by the ω equation using the wet Q-vector divergence as a forcing term,and the vertical velocity calculated by utilizing the kinematics method is followed by the O'Brien method for correction.The plus-minus sign of the vertical velocity obtained with this method is not correlated with the intensity of d BZ,but the absolute error increases when d BZ is >=40.This method demonstrates that it is a good reflection of the direction of the vertical velocity.

A Study of Extratropical Transition and Re-Intensification of Typhoon Mindulle(2004)

In this study,the fifth-generation Pennsylvania State University-National Center for Atmospheric Research (PSU-NCAR) Mesoscale Model (MM5) is used to simulate Typhoon Mindulle (2004) at high resolution (3-km grid size).The data from measurements show that in the upper atmosphere the existence of an upper jet is important to the transition cyclone.When Mindulle moved to the area of the upper jet entrance,where high-altitude divergence existed, the pumping of the high-altitude divergence would enhance the vertical motion and low-level cyclone convergence. The enhanced vertical motion was confirmed by the simulation results and indicated that the existence of upper divergence enhanced the vertical motion which was favorable for the maintenance of Typhoon Mindulle.The process of extratropical transition (ET) and re-intensification always accompanies the process of cold air invasion. This process enhances the baroclinicity of the atmosphere and the formation of front at high altitudes, which converts baroclinic potential energy into kinetic energy and strengthens the cyclone vortex.The distributions of equivalent potential temperature (θe) and temperature anomalies show that the warm-core of the typhoon at the tropopause aids the re-intensification of the system. As the typhoon reenters the ocean, latent heat flux (LHF) increases in the north and west and the strong reflectivity and vertical motion occur in the east and southeast,and the west.With the re-intensification of the typhoon the wind field evolves from an oval to a circle at the lower atmosphere, the area coverage by high winds increases, and the distribution of the tangential wind shows an asymmetric pattern.

Calculation model and mechanism analysis for rain-wind-induced vibration of stay cable

Rain-wind-induced vibration of cable was studied based on previous research achievements. According to the quasi-steady assumption, the governing equation of vertical motion of the cable was derived and the criterion for unstable motion and occurrence mechanism was studied. A comparison was performed between the oscillation responses of the stay cable obtained from calculated model and previous results. The results indicate that the analysis model can reflect the main characteristics of wind-rain-induced vibrationt of the cable which is amplitude- and velocity-restricted, and it is probably related with the periodic vortex shedding of wake flow. It is essential for the occurrence of rain-wind-induced or wind-induced vibration of cable that the derivative of lift coefficient with respect to transient angle of attack is less than zero. When rain-wind-induced vibration occurs, the aerodynamic force has a dual function for the vibration, and the maximum amplitude of stayed-cable is determined by the relative value of aerodynamic exciting force and aerodynamic damping force.

Potential vorticity analysis of quasi-biweekly rainfall events over the Yangtze Basin in summer 2014

A series of heavy rainfall events occurred over the Yangtze River Valley(YRV)in summer 2014,which were modulated by the 10-20-day quasi-biweekly oscillation(QBWO).Thus,the strongest QBWO cycle for the period 10-24 July was used as a representative case to reveal the dynamical mechanism for the QBWO of the YRV rainfall from the potential vorticity(PV)perspective and based on MERRA-2 reanalysis data.The quasi-biweekly YRV rainfall was found to depend closely on the QBWO of the upper-tropospheric South Asian high(SAH),with the SAH configuration modified by the southward-intruding midlatitude high PV stream along with southwestward-advected high PV,altering the divergent condition over the YRV.Quantitative diagnoses for the anomalous vertical motion demonstrated that,in the wet phase of the QBWO cycle,the upper-tropospheric southward-intruding high PV stream acted as a positive PV advection,while negative PV advection was generated due to the lower-tropospheric southerlies,thereby forming a positive vertical gradient of horizontal PV advection to induce evident isentropic-displacement ascending motion.On the other hand,the southward-intruding high PV stream extended downward to the middle troposphere,causing the isentropic surfaces to become more sloping,thus producing a strong isentropic-gliding ascending component.Subsequently,the stronger diabatic heating-related ascending motion was induced to generate positive rainfall anomalies over the YRV.The opposite situation arose in the dry phase,with weak descending motion in magnitude.

Numerical Prediction of Added Resistance and Vertical Ship Motions in Regular Head Waves

The numerical prediction of added resistance and vertical ship motions of one ITTC （Intemational Towing Tank Conference） S-175 containership in regular head waves by our own in-house unsteady RANS solver naoe-FOAM-SJTU is presented in this paper. The development of the solver naoe-FOAM-SJTU is based on the open source CFD tool, OpenFOAM. Numerical analysis is focused on the added resistance and vertical ship motions （heave and pitch motions） with four very different wavelengths （ 0.8Lpp 〈 2 〈 1.5L ） in regular head waves. Once the wavelength is near the length of the ship model, the responses of the resistance and ship motions become strongly influenced by nonlinear factors, as a result difficulties within simulations occur. In the paper, a comparison of the experimental results and the nonlinear strip theory was reviewed and based on the findings, the RANS simulations by the solver naoe-FOAM-SJTU were considered competent with the prediction of added resistance and vertical ship motions in a wide range of wave lengths.

Vibration Analysis of Continuous Maglev Guideway Considering the Magnetic Levitation System

The dynamic interaction between moving vehicles and two-span continuous guideway was discussed. With the consideration of the magnetic levitation system, the maglev vehicle/guideway dynamic interaction model was developed. Numerical simulation was performed to understand dynamic characteristics of the guideway used in practice. The results show that vehicle speed, span length and primary frequency of the guideway have an important influence on the dynamic responses of the guideway and there is no distinct trend towards resonance vibration when fl equals 1.0. The definite way is to control the impact coefficient and acceleration of the guideway. The conclusions can serve the design of high speed maglev guideway.

Analyses of Crustal Deformation, Strain Field and Risk of Moderate and Strong Earthquakes in the Shanxi Seismic Belt

Using the four phases (1996～1999) of re-surveying data from the GPS network along the Shanxi fault zone, the recent state of horizontal movement of the fault zone and its relation with the Datong-Yanggao M5.6 earthquake (November 1, 1999), which took place on the north end of the monitored area, are analyzed. In the focal region, three areas with relatively higher strain (1×10 -6) appeared in Xinzhou and to the northeast of Jiexiu. The Shanxi fault zone is mainly controlled by the WNW-ESE-trending compressive stress field and the NNE-SSW-trending tensile stress field, and it does not have strike-slip movement. When examined for long-term tendency, attention should be paid to the junctures between the three moving elements.

Investigation of Pitch Motion Portion in Vertical Response at Sides of a Tension-Leg Platform

Tendons vertically moor Tension-Leg Platforms （TLPs）, thus, a deep understanding of physical tendon stresses requires the determination of the total axial deformation of the tendons, which is a combination of the heave, pitch, and surging responses. The vertical motion of the lateral sides of the TLP is coupled with surge and constitutes a portion of the pitch motion. Tendons are connected to the sides of the TLP; hence, the total displacement of the lateral sides is related to the total deformation of the tendons and the total axial stress. Therefore, investigating the total vertical response at the sides of the TLP is essential. The coupling between various degrees of freedom is not considered in the Response Amplitude Operator （RAO）. Therefore, in frequency domain analysis, the estimated vertical RAO is incomplete. Also, in the time domain, only the heave motion at the center of TLP is typically studied; this problem needs to be addressed. In this paper, we investigate the portion of the pitch motion in the vertical response at the sides of the TLP in both the frequency and time domains. Numerical results demonstrate a significant effect of the pitch motion in the vertical motion of the edges of the TLP in some period ranges.

Study on the Dynamic Characteristics of an Eastward-offshore Mesoscale Vortex along the Meiyu-Baiu Front

The eastward-moving Meiyu-Baiu frontal mesoscale vortices (MBFMVs) appear frequently and often cause heavy rainfall events along their tracks. A move-off-shore MBFMV was selected to enhance our understanding of this type of vortex. Synoptic analyses indicate that the MBFMV is a type of meso-α vortex and mainly occurs in the lower troposphere. A short wave trough near the coastline is highly favorable for the formation, sustainment, and displacement of the MBFMV. Vorticity budgets indicate that at lower levels of the MBFMV, convergence is the dominant factor for the increase of positive vorticity, and at high levels of the MBFMV, the vertical transportation associated with convective activities is the most important factor. The hori-zontal transportation was the main factor decreasing the positive vorticity. The land and sea environments are crucial to the evolution of the MBFMV. The characteristics of the Meiyu-Baiu Front (MBF) are also vital to the variation of the vortex.

Budget analysis of mesoscale available potential energy in a heavy rainfall event over the eastern Tibetan Plateau

Using model simulated data,the distribution characteristics,genesis,and impacts on precipitation of available potential energy(APE)are analyzed for a heavy rainfall event that took place over the eastern Tibetan Plateau during 10–11 July 2018.Results show that APE was mainly distributed below 4 km and within 8–14 km.The APE distribution in the upper level had a better correspondence with precipitation.Northwestern cold advection and evaporation of falling raindrops were primary factors leading to positive anomalies of APE in the lower level,while positive anomalies of APE in the upper level were caused by a combination of thermal disturbances driven by latent heat and potential temperature perturbations resulting from the orography of the Tibetan Plateau.Budget analysis of APE indicated that APE fluxes and conversion between APE and kinetic energy(KE)were the main source and sink terms.Meridional fluxes of APE and conversion of KE to APE fed the dissipation of APE in the lower level.Vertical motion enhanced by conversion of APE to KE in the upper level was the major factor that promoted precipitation evolution.A positive feedback between APE and vertical motion in the upper level generated a powerful correlation between them.Conversion of KE to APE lasted longer in the lower level,which weakened vertical motion;whereas,northwestern cold advection brought an enhanced trend to the APE,resulting in a weak correlation between APE and vertical motion.

Optimization of Wigley Hull Form in order to Ensure the Objective Functions of the Seakeeping Performance

The research performed in this paper was carried out to investigate the computational procedure to design seakeeping optimized ship hull form. To reach the optimized hull form, four stages should be done, which consists of： generate alternative hull form, seakeeping calculations, objective functions and optimization techniques. There are many parameters that may be determined in ship hull form optimization. This paper deals with developed strip theory for determining the seakeeping performance, genetic algorithm （GA） as optimization method, high order equations for curve fitting of the hull form and finally reaching to the minimum bow vertical motion in regular head waves. The Wigley hull is selected as an initial hull and carried to be optimized. Two cases are considered. For the first case, the only form coefficients of the hull （CB, CM, Cw, Cp） are changed and main dimensions （L, B, 7） are fixed. In the second case both hull form and main dimensions are varied simultaneously. Finally, optimized hull form and its seakeeping performances are presented. The results of optimization procedure demonstrate that the optimized hull forms yield a reduction in vertical motion and acceleration.

Buoyancy of convective-scale updrafts in the outer cores of sheared tropical cyclones

In this paper,the authors present the statistical characteristics of the buoyancy of outer-core convective-scale updrafts in numerically simulated sheared tropical cyclones(TCs).The total buoyancy is predominantly positive in weak-to-strong ambient vertical shears,whereas much of the total buoyancy under an extreme shear environment becomes negative.Thermal buoyancy positively contributes to the total buoyancy value.For weakly and moderately sheared TCs,the updraft buoyancy is statistically significantly stronger downshear but smaller upshear.Such a downshear preference of strong buoyancy becomes less evident as the shear magnitude increases.The total buoyancy of updrafts shows a decreasing tendency with radius.Both thermal and dynamic buoyancy do not significantly correlate with vertically averaged vertical mass fluxes.This also leads to no significant correlation between the total buoyancy and vertical mass fluxes of outer-core updrafts.

Mechanism Design of Palletizing Robot Based on Translating Cam Principle

Palletizing robot technology has been applied more and more extensively in logistics automation field.But there are some limitations in the current single-arm palletizing robot that it cannot do effective work in the process of moving back to the taking-end and the mechanical arm has so many freedoms that its control system is relatively complex.Based on the translating cam principle,a novel palletizing robot is designed.The horizontal movement of the palletizing mechanical arm is controlled by changeable outer slides,and the vertical movement is controlled by partitioned up-and-down spindles.To improve palletizing efficiency,the single palletizing mechanical arm is changed into multi-arm.Moreover,to improve its kinematic properties,the acceleration operating performance,joint driving force and palletizing trajectory are optimized through the multi-objective delaminating sequence method.According to the optimization results,the 3D model of the multi-arm palletizing robot is built in Pro/E,and the kinematic simulation is made.The simulation results show that the novel mechanism and optimization parameters are rational and feasible.This novel palletizing robot has the advantages of cam mechanism,so it simplifies the driving mode of palletizing movement and can lower the requirements for controlling system.At the same time,it can increase palletizing efficiency further by adding mechanical arms.

Effect of different stretching strategies on the kinetics of vertical jumping in female volleyball athletes

Purpose： The present study aimed to examine the effect of static stretching （SS） and a sport-specific dynamic stretching （DS） session at two specific post-stretch time intervals in highly trained female athletes （age 19.90 ± 1.60 years; height 1.80 ±0.06 m; mass 76.87 ± 9.95 kg） on kinetic parameters of peak force, time-to-takeoff, and rate of force development. Methods： The data were collected over 3 days （randomized within subject design with control session）. Following each stretch session （SS vs. DS vs. control） of equal duration （7 min total： 30 s per targeted muscle group） participants performed countermovement jumping on a force platform at 1 and 15 rain after stretching. Results： The DS session significantly improved upon kinetic variables of rate of force development, peak force, and time-to-takeoffrelative to SS at 1 min after stretching. No significant effect was found at 15 min. Conclusion： Together these findings suggest that when training and competing to jump quickly and maximally the female athlete should incorporate DS instead of SS as part of their pre-competition warm-up, but conduct performance within 15 min of their warm-up to elicit maximal gains

Experimental detection of bubble-wall interactions in a vertical gas–liquid flow

Bubble motions and bubble-wall interactions in stagnant liquid were experimentally investigated by high-speed CCD and PIV technique with the main feature parameters such as E?tv?s numbers Eo = 0.98–1.10, Morton number Mo = 3.21 × 10^(-9)and Reynolds numbers Re = 180 ~ 190. The effect of bubble injecting frequency and the distance S between the gas injection nozzle and the wall on the statistical trajectory of bubbles, average velocity distribution of flow field and Reynolds shear stress were studied in detail. It was shown that the combination of bubble injecting frequency and the distance S caused different bubble motion forms and hydrodynamic characteristics.When the normalized initial distance was very little, like S*≈ 1.2(here S*= 2S/d_e, and deis the bubble equivalent diameter), bubbles ascended in a zigzag trajectory with alternant structure of high and low speed flow field around the bubbles, and the distribution of positive and negative Reynolds shear stress looked like a blob. With the increase of distance S*, bubbles' trajectory would tend to be smooth and straight from the zigzag curve. Meanwhile, with the increase of bubble injecting frequency, the camber of bubble trajectory at 20<y<60 mm had a slight increase due to the inhibitory effect from the vertical wall. Under larger spacing, such as S*≈ 3.6, the low-frequency bubbles gradually moved away from the vertical plane wall in a straight trajectory and the high-frequency bubbles gradually moved close to the vertical wall in a similar straight trajectory after an unstable camber motion. Under the circumstances, high-speed fluid was mainly distributed in the region between the wall and the bubbles, while the relative large Reynolds shear stress mainly existed in the region far away from the wall.