Ocean Tide Models Developed by Assimilating TOPEX/POSEIDON Altimeter Data into Hydrodynamical Model: A Global Model and a Regional Model around Japan

A global ocean tide model (NAO.99b model) representing major 16 constituents with a spatial resolution of 0.5° has been estimated by assimilating about 5 years of TOPEX/POSEIDON altimeter data into barotropic hydrodynamical model. The new solution is characterized by reduced errors in shallow waters compared to the other two models recently developed; CSR4.0 model (improved version of Eanes and Bettadpur, 1994) and GOT99.2b model (Ray, 1999), which are demonstrated in comparison with tide gauge data and collinear residual reduction test. This property mainly benefits from fine-scale along-track tidal analysis of TOPEX/POSEIDON data. A high-resolution (1/12°) regional ocean tide model around Japan (NAO.99Jb model) by assimilating both TOPEX/POSEIDON data and 219 coastal tide gauge data is also developed. A comparison with 80 independent coastal tide gauge data shows the better performance of NAO.99Jb model in the coastal region compared with the other global models. Tidal dissipation around Japan has been investigated for M₂ and K₁ constituents by using NAO.99Jb model. The result suggests that the tidal energy is mainly dissipated by bottom friction in localized area in shallow seas; the M₂ ocean tidal energy is mainly dissipated in the Yellow Sea and the East China Sea at the mean rate of 155 GW, while the K₁ energy is mainly dissipated in the Sea of Okhotsk at the mean rate of 89 GW. TOPEX/POSEIDON data, however, detects broadly distributed surface manifestation of M₂ internal tide, which observationally suggests that the tidal energy is also dissipated by the energy conversion into baroclinic tide.     

几种消暖云（雾）催化剂性能的实验研究

本文选取了十一种吸湿性物质,对它们的吸湿特性进行了实验研究,对其中一些吸湿性能较好的催化剂开展了云室消雾试验,结果表明,这些物质的吸湿能力及其随相对湿度变化的分布有较大的区别,其饱和状态下的平衡增长率也有较大差异,水泥类物质中,矿渣水泥及普通４２５＾＃Ｋ水泥的吸湿特性与氯化钠类似,氯化钠、氯化铵及矿潭水泥的云室消雾效果较好,但其作用机理可能有所不同。     

非齐次复合 Poisson地震发生概率模型研究

依据现有地震发生概率模型合理性与局限性以及地震估计的基本思想提出五类非齐次复合 Poisson 地震发生概率模型,阐述各模型的基本特点及可能实用的前提。 以华北地区的地震序列为例大致模拟了不同阶段的地震发生概率水平,分析表明非齐次复合 Poisson 地震发生概率模型更能反映地震发生的时间不均匀性。     

农业生态系统的水热耗散过程与节水调控

华北平原广大的干旱、半干旱甚至半湿润区 ,水资源形势严峻 ,威胁农业持续发展。本文从近年来迅速发展的土壤—植物—大气连续体理论出发 ,论述了 SPAC过程与生态过程的联系与区分 ;在两个过程的联结点上衍生出水分利用率概念。讨论了界面的梯度驱动力 ,分析了水势驱动及其阻力 ,作物水分胁迫及反冲机制的诱导和增益 ,界面过程的高度非线性及其耦合。在此基础上提出水热传输界面调控与生态过程的机制调控相结合的理论与措施 ,以缓解水资源匮乏 ,提高持续生产力和水分利用效益 ;为实现农业持续发展 ,提供理论依据的实践途径。     

轴压和围压对循环冲击下砂岩能量耗散的影响

利用动静组合加载试验装置,对具有不同轴压和围压的砂岩进行循环冲击试验,研究循环冲击过程中砂岩单位体积吸收能的变化特性、单位体积吸收能与平均应变率的关系以及轴压和围压对循环冲击作用下岩石能量耗散的影响。围压分别设置为4、8、10、12 MPa等4个系列,轴向静载荷分别设置为49、84、105、125 MPa等4个系列,入射杆上的入射波峰值大小近似相等,入射能大小为230 J。研究结果表明,砂岩单位体积吸收能随循环冲击次数的增加而增加。平均应变率和单位体积吸收能具有良好的正线性关系,围压从低到高增加过程中,二者间拟合直线的斜率K随轴压增加的变化关系为“增加-基本不变-减小”。当轴压较小时,K随围压的增加先增加后降低,轴压越小K由上升到下降转折点处的围压越大;当轴压增加到125 MPa时,K随围压的增加始终降低。研究结果为具有不同地应力条件下工程岩体爆破设计提供理论依据。     

基于能量的新型消能摇摆结构体系抗震性能研究

利用能量法分析新型消能摇摆结构体系在地震动过程中的耗能机制,并对其抗震性能进行系统研究。以某已建成的6层框架结构为研究对象,建立新型消能摇摆结构体系的计算模型,利用Opensees软件获得新型消能摇摆结构体系在不同地震动激励下的动力响应,分析其各子结构的耗能部位及所占比例。结果表明:新型消能摇摆结构体系的耗能机制更为合理,其抗震性能优于传统结构体系,为工程设计和研究提供一些参考。     

脉动孔隙水压下三轴加压对煤岩损伤变形的影响

为研究脉动孔隙水压作用下低透性松软煤岩在不同三轴加压条件下的损伤变形规律,采用RLW-2000M煤岩流变仪进行了不同轴压和围压系列下的试验研究。结果表明：煤岩破坏的应变曲线具有先疏后密再疏的变化规律,且累积应变和残余应变随着围压的增加而减小,而随着轴压的增加而增大;平均单次耗散能随着围压的增加而减小,随着轴压的增加而增加,其关系符合指数函数变化特征;采用累积耗散能计算了煤岩破坏过程中的损伤变化特征,并采用Logistic方程逆函数对其进行了拟合分析,得到了煤岩损伤演化模型,为预测煤岩破坏周期提供了依据。研究结果为具有不同地应力条件下的低透气性松软煤层施工脉动水力压裂提供了一定的理论依据。     

Development of elasto-plastic viscous damper finite element model for reinforced concrete frames

By advancing the technologies regarding seismic control of structures and development of earthquake resistance systems in the past decades application of different types of earthquake energy dissipation system has incredibly increased. Viscous damper device as a famous and the simplest earthquake energy dissipation system is implemented in many new structures and numerous number of researches have been done on the performance of viscous dampers in structures subjected to earthquake. The experience of recent severe earthquakes indicates that sometimes the earthquake energy dissipation devices are damaged during earthquakes and there is no function for structural control system. So, damage of earthquake energy dissipation systems such as viscous damper device must be considered during design of earthquake resistance structures.This paper demonstrates the development of three-dimensional elasto-plastic viscous damper element consisting of elastic damper in the middle part and two plastic hinges at both ends of the element which are compatible with the constitutive model to reinforce concrete structures and are capable to detect failure and damage in viscous damper device connections during earthquake excitation. The finite element model consists of reinforced concrete frame element and viscous damper element is developed and special finite element algorithm using Newmark׳s direct step-by-step integration is developed for inelastic dynamic analysis of structure with supplementary elasto-plastic viscous damper element. So based on all the developed components an especial finite computer program has been codified for “Nonlinear Analysis of Reinforced Concrete Buildings with Earthquake Energy Dissipation System”. The evaluation of seismic response of structure and damage detection in structural members and damper device was carried out by 3D modeling, of 3 story reinforced concrete frame building under earthquake multi-support excitation.     

塔克拉玛干沙漠腹地湍流能量耗散率和结构函数参数特征

利用塔中气象站垂直探测系统的湍流观测资料,计算并分析了塔克拉玛干沙漠腹地不同稳定层结条件的湍涡特征长度尺度、能量耗散率及湍流结构函数参数特征。结果表明：湍涡特征长度尺度在弱不稳定或近中性条件时最大,随不稳定程度的增强有明显减小的趋势,随着稳定程度的增加有先迅速减小后又缓慢增加的趋势,且热量特征长度尺度比动量特征长度尺度总体要大一个数量级;无因次湍流热量耗散率的拟合函数形式与其他试验一致,但经验系数略有差异;利用Kaimal公式和湍流谱方法间接计算的稳定条件湍流能量耗散率及湍流结构函数参数具有较好的一致性。     

地震作用下煤矿开采损伤建筑的能量耗散演化致灾分析

基于耗散结构理论,从能量理论角度对煤矿开采区建筑物的动力破坏过程进行了系统的定量分析。提出了建筑物能量耗散的理论判据,研究了地震作用下煤矿开采区建筑的损伤演化灾变过程。根据结构动力学理论,建立了煤矿开采区建筑物在地震作用下的能量演化平衡方程,定量分析了地震作用下煤矿开采区建筑物系统中耗散能量的变化过程。结果表明:在开采沉陷和地震联合作用下,建筑物与外界产生更多的有害的能量交换,进而产生更多的塑性损伤变形,结构阻尼耗能降低;根据建筑物能量耗散演化趋势应建立合适的抗开采沉陷变形隔震保护新体系,为我国矿区建筑物保护提供借鉴意义。