中国北部地区沙漠鸣沙对比研究

鸣沙发声机制是一个长期悬而未决的问题。中国北部地质公园内的沙漠鸣沙地质遗迹沿北方沙漠弧形带分布,但较少被报道和研究。本文选取位于内蒙古、甘肃和新疆的沙漠鸣沙及哑沙,对其地貌特征﹑粒度组分和矿物成分进行了对比研究。结果表明鸣沙一般发育在新月型沙丘链或新月型沙丘上,紧邻湖泊或泉水,背风坡和迎风坡上都会发育鸣沙,但主要集中在背风坡,研究结果与马玉明提出的"共鸣箱"理论中的"响沙都发育在背风坡"不符;哑沙粒度明显较鸣沙粗,哑沙的平均粒径分布峰值集中在0.5φ~1φ,鸣沙粒径频率分布峰值集中在2φ~3φ;主要差别在于细砂和粗砂的组分,所有鸣沙中的细砂含量所占比例均高于52.012%,哑沙中的细砂含量低于0.881%;响沙中粗砂的含量均小于1.221%,哑沙中粗砂的含量大于48.091%。鸣沙和哑沙主要矿物成分都以石英和长石为主;鸣沙中含有高岭石,钠长石,微斜长石及方解石等,而哑沙中几乎未含这些次要矿物。本文结果表明,地貌特征和物质组成是区别鸣沙和哑沙的重要特征,对于研究鸣沙的成因具有参考价值。     

东营凹陷页岩油储层特征

渤海湾盆地东营凹陷始新统—渐新统沙河街组第三段下亚段(E_(2-3)s~(3-x))和沙河街组第四段上亚段(E_(2-3)s~(4-s))泥页岩分布面积广、累计厚度大、有机质丰度高、有机质类型以Ⅰ型干酪根为主,具有良好的页岩油勘探潜力。泥页岩主要发育层状和纹层状构造,主要矿物组成为粘土矿物、碳酸盐矿物、石英和长石。宏观观察下,泥页岩发育的裂缝主要有成岩裂缝和构造裂缝,孔隙主要为溶蚀孔、结晶孔及生物孔隙。微观观察下,主要发育的孔隙有粒间孔、粒内孔、晶间孔和溶蚀孔等,在不同的有机质丰度、类型及热演化程度下孔隙发育特征差异明显。小角X射线散射能够得到样品介孔(2~50 nm)的分布特征,结合抽提实验,对比处理前后孔隙分布特征表明细介孔(2~10nm)是有效的页岩油储集空间,也是影响孔隙结构复杂化的主要贡献者。核磁共振冷孔计法(NMRC)能测量泥页岩纳米级(2~500 nm)开孔孔隙的分布特征,定量表征孔隙率,弥补其它表征方法的不足。东营凹陷地区泥页岩中广泛发育的纳米级粒间孔是页岩油主要的赋存空间。     

An analytical study on the second-order resonance system of tide in an ideal partially-enclosed bay

In the numerical studies of a real tide M4 resonance system, the Xiangshan Port which is a partially-closed bay, Dong et al. [1999. Acta Oceanologica Sinica, 21 （3）： 1-6] found the interesting phenomenon that the advection plays an important role in inhibiting the growth of the amplitude of the tidal second-order resonance response （M4）. This result is contrary to the general traditional ideas for a non-resonance system. How this phenomenon is interpreted and what internal mechanism is behind the phenomenon are the main focuses of this study. The followings are examined： （1） the dynamic features of a second-order resonance system of tide; （2） the dominating factors on the second-order resonance responses; （3） the effects of both the friction and the advection on the second-order resonance responses; and （4） their roles in dominating the second-order resonance response and internal mechanisms by using the analytical methods. The respective results show that： （1） Both the bottom friction and the advection play significant roles in dominating the magnitude of the amplitude of the second-order resonance responses; （2） the effect of the friction on the second-order resonance response depends on the distribution ratio of the work-done of the system to friction force exhausted into between the damping of the first-order system and the inner excitation of the second-order system; （3） the advection plays a positive role in increasing the amplitude of the second-order non-resonance response in the second order non-resonance of tide; （4） in a second-order resonance system of tide, the effect of the advection may be either to increase or to decrease the amplitudes of the second-order resonance responses of tide, which depends on the distribution ratio mentioned above.     

Non-Integrability and Structure of the Resonance Zones in a Class of Galactic Potentials

The structure of the resonance zone in nearly integrable Hamiltonian systems is studied by a more general method than the pendulum approximation. This method applies to the case of a non-degenerate integrable part in the Hamiltonian. This problem may be overcome in a class of galactic-type polynomial potentials, in the case where the higher-order term is by itself integrable. An illustrative example is worked out.     

Dissipative forces and external resonances

We analyze the process of resonance trapping due to Poynting–Robertson drag and Stokes drag in the frame of the restricted 3-body problem and in the case of external mean motion resonances. The numerical simulations presented are computed by using the 3-dimensional extended Schubart averaging (ESA) integrator developed by Moons (1994) for all mean motion resonances. We complete it by adding the contributions of the dissipative forces. To follow the philosophy of the initial integrator, we average the drag terms, but we do not make any expansion in series of eccentricity or inclination. We show our results, especially capture around asymmetric equilibria, and compare them to those found by Beaué and Ferraz-Mello (1993, 1994) and Liou et al. (1979).     

Symplectic Mapping for Trojan-Type Motion in the Elliptic Restricted Three-Body Problem

A symplectic mapping for Trojan-type motion has been developed in the secularly changing elliptic restricted three-body problem. The mapping describes well the characteristics of Trojan-type dynamics at small eccentricities. By using this mapping the boundary of the stability region has been studied for different values of the initial eccentricities of hypothetical Jupiter's Trojans. It has been found that in the secularly changing elliptic case the chaotic diffusion at the border of the stability region is stronger than simply in the elliptic case. An explanation of this observation might be the destruction of the chain of islands of the 13:1 secondary resonance between the short and long period component of the Trojan-like motion, caused possibly by the indirect perturbations of Saturn.     

Resonance Effect in Interaction Between South Asian Summer Monsoon and ENSO During 1958–2018

The study has shown that the shear component of the vertical integrated kinetic energy (Ks) over the box (40oE–100oE, 0o–20oN) can be used as a measure of the intensity of the South Asian summer monsoon (SASM). Based on its value averaged between June and August, the SASM can be divided into strong and weak monsoon episodes. Between 1958 and 2018, there existed 16 (16) strong (weak) monsoon episodes. Based on the calendar year, the relationship between the SASM and the ENSO episodes can be grouped into six patterns: weak monsoon - El Ni?o (WM-EN), normal monsoon - El Ni?o (NM-EN), weak monsoon - non ENSO (WM-NE), strong monsoon - La Ni?a (SM-LN), normal monsoon - La Ni?a (NM-LN) and strong monsoon - non ENSO (SM-NE). Previous studies have suggested that the WM-EN and SM-LN patterns reflect the correlated relationship between the SASM and El Ni?o/Southern Oscillation (ENSO) events. Therefore, we name these two strongly coupled categories WM-EN and SM-LN as the resonance effect. Two important circulations, Walker circulation (WC) and zonal Asian monsoon circulation (MC), in the vertical plane are found to be not always correlated. MC is controlled by thermal gradients between the Asian landmass and the tropical Indian Ocean, while the WC associated with the ENSO event is primarily the east-west thermal gradient between the tropical South Pacific and the tropical Indian Ocean. Furthermore, the gradient directions caused by different surface thermal conditions are different. The main factor for the resonance effect is the phenomenon that the symbols of SSTA in the tropical Indian Ocean and the equatorial eastern Pacific are the same, but are opposite to that of the SSTA near the maritime continent.     

刘长营环境科学钻探取样技术研究

针对环境取样的高取心率要求,利用SDR-100型全液压声频振动钻机结合压卡式钻具,完成了刘长营环境科学钻探取样。主要介绍了钻进工艺以及取样过程中遇到的问题,并给出了解决方案,最后对环境取样技术进行了展望。     

珠江河口对外海潮波响应的固有频率研究——采用系统控制论方法

采用受控的自回归滑动平均模型(CARMA)分别研究了珠江河口洪、枯季对外海潮波响应的固有频率.枯季采用单输入单输出模型,洪季采用双输入单输出模型,通过验证、检验表明,模型(CARMA)可用于寻求复杂网河对外海潮波响应的固有频率,方法可靠,易操作.通过频率增益响应分析,发现枯季珠江河口的固有频率以浅水分潮频段为主,对应周...     

GJ 876行星系统中潜在类地行星研究

用数值积分方法模拟探讨了GJ876行星系统中存在潜在类地行星的可能性．结果表明分别产生于内外两颗巨行星的长期共振v_1和v_2可激发类地行星(其轨道半长轴分布在0．21AU≤a＜0．50AU之间)的偏心率,并使它们在极短时间内被抛射出系统．然而,从动力学角度而言,类地行星潜在存在区域可分布在0．50 AU≤a≤1．00 AU之间,其能在系统中10~5年时间尺度上稳定地存在．