Model Test Study on Ice-Induced Vibrations of Compliant Multi-Cone Structures

For the study on the ice-induced vibration of a compliant mono-cone structure,a series of model tests were performed from 2004 to 2006.In these tests,the ice sheet before the compliant conical structure was found to be failed in two-time breaking.Based on this important finding,model tests study of the ice force on a compliant multi-cone structure were performed from 2006 to 2007.in these tests,the ice sheet broke before each single cone non-simultaneously.The exciting energy of the total ice force was found to be in a wide range of frequencies,and the structure can be easily excited with nonlinear resonance.     

利用卫星云图资料制作热带气旋预报路径的一种算法

根据台风生成后在云场中移动的环境条件,引入一个环境作用于台风中心的热力梯度力方向,用该热力梯度力方向与当前台风的移动方向相结合,研究台风移动过程的变化规律,寻找一种简易可行的台风路径预报方法．经过多年实践,本文揭示出台风中心未来沿着当前移动方向与环境作用于台风中心的热力方向合成移动的基本规律：当前台风中心移向与前方晴空区中轴线相交时,台风沿着当前移向前进到与阻挡轴线相交点相距4个纬距的位置时便发生偏转,逐渐与阻挡轴线走向趋于一致;若当前台风中心距相交点的距离小于或等于4个纬距时,则从当前位置发生偏转．文中利用以上规律研制出台风移向变化方程和移动轨迹方程．     

夏季长江口南北支溶解有机质的比较

本文以2021年5月长江口南北支采集的表层水为研究对象,通过测定氢、氧同位素,溶解有机碳(DOC)浓度,有色溶解有机质(CDOM)的吸收光谱和荧光光谱参数,探讨了夏季长江口北支、南支(北港、北槽、南槽)水体溶解有机质的组成、分布及其影响因素。沿长江下游到河口近海,南、北支DOC浓度分别为1.68±0.16 mg/L和1.46±0.31mg/L,CDOM的吸光系数a350分别为2.37±0.61 m^-1和1.59±0.24 m^-1。南支整体具有“高类腐殖质、低类蛋白”的特征,北支则具有“低类腐殖质、低类蛋白”的特征,这可能与南北支的径流量差异有关。在南北支不同分汊河道(北支、南支北港、南支北槽和南支南槽)中,南槽和北支有类似的海水入侵特征,但南槽具有较强的类蛋白组分输入,而南支北港和北槽样品间无显著差异,均表现为河流有机质为主的特征。对比2011年长江南北支DOC和CDOM数据显示,作为长江主河道的南支在2021年无明显变化,而北支有显著的变化。这些结果综合表明长江口DOM的变化格局可能受水动力条件(径流量)、人类活动因素共同作用的影响。比较全...     

水牛蹄型深海集矿机履齿设计及牵引性能研究

作为深海采矿系统的重要组成部分,深海集矿机的技术研究和开发一直是许多国家的难题。为了提高深海集矿机在稀软沉积物上的牵引性能,基于水牛蹄的曲面结构特征和特殊几何结构,设计了一款仿水牛蹄蹄型履齿。以该款履齿的结构参数为研究对象,通过对朗肯被动土压力理论的优化,得到了仿水牛蹄蹄型履齿的牵引力解析解,建立了对应的履齿仿生参数对履齿牵引力的影响公式。结合正交试验方法进行了不同形式履齿在沉积物上运动的单、多履齿剪切试验,将仿水牛蹄蹄型履齿与直型履齿、仿水牛蹄轮廓履齿（另一种仿生履齿）进行对比试验,并通过模型车试验验证了该款履齿的可行性。结果表明：3种履齿中,仿水牛蹄蹄型履齿提供的最大牵引力最高。研究可为进一步优化仿水牛蹄蹄型履齿结构参数和提高深海稀软底质机械的牵引性能提供参考依据。     

An unusual zone of seismic coupling in the Bonin arc: The 1972 Hachijo-Oki earthquakes and related seismicity

The 1972 February and December Hachijo-Oki earthquakes (M _s=7.3 and 7.4), in the northernmost part of the Izu-Bonin subduction zone, are the only major events (M _s>7.0) in the Bonin arc for the past 80 years. Relocation of the hypocenters, using one smaller event having a wellconstrained focal depth as a master event, shows that the depth of the February event is 10 km shallower than that of the December event. We have determined the rupture process for both events by minimizing the error in waveform between observed and synthetic seismograms. Although the number of available stations are limited, the depth range of the major energy release for the December event extends deeper than for the February one. The rupture propagated up-dip for both events. It is likely that the rupture zone of the two events overlapped, and that the December event ruptured the deeper part. This suggestion is consistent with the observation that the aftershock zones of both events overlap with that of the December event shifted landward. The waveforms of the December event have a smaller high frequency component than those of the February event, suggesting that the stress at the thrust zone became more uniform or reduced after the February event.No thrust type smaller event occurred near the rupture zone. Instead, theP-axes of smaller events are parallel to the dip of the slab and theirT-axes dip to the southwest. Focal depths of these events estimated byP-wave forward modeling are generally between 40–50 km and located beneath the thrust zone. We thus interpret them as the events within the Pacific slab near the zone ruptured by the two major events. The stress concentration around the rupture zone of the major events is suggested to have triggered these slab events. After the occurrence of the large events, the slab events are concentrated near the deeper portion of the rupture zone. These events may have been caused by the loading of the down-dip compressional stress near the down-dip end of the rupture zone due to the rupture. The occurrence of the doublet of large earthquakes and a number of down-dip compressional events beneath their rupture zones in a shallow portion of the subducting slab indicates an unusual zone of seismic coupling in the Bonin arc, most of which is seismically quiescent.     

Active tectonics of the Himalaya

The Himalayan mountains are a product of the collision between India and Eurasia which began in the Eocene. In the early stage of continental collision the development of a suture zone between two colliding plates took place. The continued convergence is accommodated along the suture zone and in the back-arc region. Further convergence results in intracrustal megathrust within the leading edge of the advancing Indian plate. In the Himalaya this stage is characterized by the intense uplift of the High Himalaya, the development of the Tibetan Plateau and the breaking-up of the central and eastern Asian continent. Although numerous models for the evolution of the Himalaya have been proposed, the available geological and geophysical data are consistent with an underthrusting model in which the Indian continental lithosphere underthrusts beneath the Himalaya and southern Tibet. Reflection profiles across the entire Himalaya and Tibet are needed to prove the existence of such underthrusting. Geodetic surveys across the High Himalaya are needed to determine the present state of the MCT as well as the rate of uplift and shortening within the Himalaya. Paleoseismicity studies are necessary to resolve the temporal and spatial patterns of major earthquake faulting along the segmented Himalayan mountains.     

用王水分解含金矿物的机理探讨

本文从理论上对王水分解含金矿物的机理进行了探讨。在非标准状态下,温度、压力不变,改变体系中物质的浓度、酸度条件,用能斯特公式求解体系中HNO_3和Au的电极电位值,而后用EMF(电池电动势)根据规则判断反应是否可以进行。经理论计算,结论是可行的。另外由于Au~(3 )和Cl~-大量存在时,生成稳定的[AuCl_4]~-,经过络合作用,促使了HNO_3和Au的氧化还原反应,最终使含金矿物溶解完全。作者认为王水同含金矿物反应的机理是:氧化和络合的双重作用。     

临汾裂谷现代构造应力场特征及其数值模拟

根据断层错动资料和小地震的平均震源机制解结果,运用弹性力学的叠加原理,对临汾裂谷作三维有限元模拟,反演其构造应力场。结果表明,临汾裂谷现今主要受南东东-北西西向引张力作用,辅之以北东-南西方向的挤压,同时在裂谷的中心叠加有底层拖曳的深部作用。     

逆冲断层前锋带的构造样式

由于逆冲断层产出构造环境和规模的不同，其前缘可以有拆离型，褶皱型，前冲型，反冲型等多种样式；每种样式又可具不同特征。此外，逆冲前缘还常伴生一些重力构造，盆地构造和不同方向的反转构造。各种构造样式可以相互转化和过渡而共存于同一逆冲带，或发育于不同逆冲带中。它们是研究塑冲作用的动力状态，，扩展方式和发展阶段的重要依据。     

Structural Styles of the Longmenshan Thrust Belt and Evolution of the Foreland Basin in Western Sichuan Province, China

The Longmenshan thrust system consists of two major groups of structural styles according to the depth of their involvement: basement thrusts-compressional fault blocks; fold-thrust system in the cover. In cross-section, the Longmenshan structural belt is divided into 5 zones. The propagation of the Longmenshan thrust system is piggy-back due to pushing at the early stage and overstep due to gravity sliding at the late stage. Balanced cross-sections and palinspastic reconstruction reveal that the total sliding displacement of the thrust system amounts to 120 km. The tectonic evolution of the Tethys domain in western Sichuan has experienced 5 stages: continental break-up; ocean-continent subduction ; continent-arc collision; orogenic thrusting; uplift of western Sichuan.