北极薄冰-煎饼冰区域中不同重力波驱动形成海流的敏感性分析

A coupled ocean-ice-wave model is used to study ice-edge jet and eddy genesis during surface gravity wave dissipation in a frazil-pancake ice zone. With observational data from the Beaufort Sea, possible wave dissipation processes are evaluated using sensitivity experiments. As wave energy dissipated, energy was transferred into ice floe through radiation stress. Later, energy was in turn transferred into current through ocean-ice interfacial stress. Since most of the wave energy is dissipated at the ice edge, ice-edge jets, which contained strong horizontal shear, appeared both in the ice zone and the ocean. Meanwhile, the wave propagation direction determines the velocity partition in the along-ice-edge and cross-ice-edge directions, which in turn determines the strength of the along-ice-edge jet and cross-ice-edge velocity. The momentum applied in the along-ice-edge(cross-ice-edge)direction increased(decreased) with larger incident angle, which is favorable condition for producing stronger mesoscale eddies, vice versa. The dissipation rate increases(decreases) with larger(smaller) wavenumber, which enhances(reduces) the jet strength and the strength of the mesoscale eddy. The strong along-ice-edge jet may extend to a deep layer(> 200 m). If the water depth is too shallow(e.g., 80 m), the jet may be largely dampened by bottom drag, and no visible mesoscale eddies are found. The results suggest that the bathymetry and incident wavenumber(magnitude and propagation direction) are important for wave-driven current and mesoscale eddy genesis.     

长江口表层沉积物中正构烷烃的高分辨分布特征及有机碳来源解析

于2014年3月对长江口及邻近海域的表层沉积物进行了高分辨率采样,分析了沉积物粒级组成、比表面积、总有机碳含量及其稳定碳同位素组成(δ¹³C)、正构烷烃及其相关分子指标,讨论了此区域沉积有机碳和正构烷烃的高分辨分布特征,并结合基于主成分分析-蒙特卡洛模拟的三端元混合模型,对沉积有机碳的来源进行了定量解析。结果表明,长江口及其邻近海域表层沉积物中总有机碳含量为0.45%±0.16%,近岸泥质区总有机碳含量较高,外海砂质区含量较低。总正构烷烃(C₁₄-C₃₅)的绝对含量和相对于总有机碳的含量分别为(1.42±0.73)μg/g和(0.34±0.21) mg/g。泥质区以长链正构烷烃占优势,具有较强的奇碳优势;砂质区以短链正构烷烃占优势,且具有一定的偶碳优势。长江输入、老黄河口输入、闽浙沿岸小型河流输入和水动力分选等因素制约了正构烷烃的输运和分布特征。模型结果显示此区域沉积有机碳来自海源、土壤和高等植物的混合输入,其中以海源为主,其贡献为42.70%±18.18%,由陆地向外海贡献逐渐升高,其次是土壤和高等植物,其贡献分别为2...     

Underwater Navigation Based on Real-Time Simultaneous Sound Speed Profile Correction

Precise sound speed profile (SSP) information is critical when using sonar for underwater terrain navigation. Nevertheless, acquiring SSP information in real-time is difficult, especially in underwater navigation environment. To account for this problem, this paper presents an underwater navigation method that applies real-time SSP correction to the terrain measurements. The method uses a probe to measure the surface sound speed simultaneously. Meanwhile, redundancy of topographic measurement data is exploited to derive the equivalent SSP information. The acquired equivalent SSP is updated continuously with particle filter algorithm. The terrain measurements can be corrected in real-time with the equivalent SSP to improve the performance of underwater terrain navigation. By removing the impact of inaccurate SSP from the terrain measurements, the proposed method can achieve precise and robust underwater navigation result without using an underway-profiling instrument. Simulated results confirm the good performance of the proposed method.     

普里兹湾陆缘水边界的变化

利用１９９８年１１月－１９９９年２月中国第１５次南极考察资料,讨论了普里兹湾附近陆缘水边界（ＣＷＢ）两侧的水团分布,以及ＣＷＢ的中心位置、锋面宽度、锋面强度、锋面的垂直深度和垂直厚度等物理特征的空间变化。并与１９９２年１２月－１９９３年２月中国第９次南极考察资料进行了比较,说明了ＣＷＢ的时间２变化。同时,还进一步分析了ＣＷＢ两侧海水运动的各向异性,以及动力高度场的形势,指出了动力高度槽,ＣＷＢ锋面     

InSAR detection of residual settlement of an ocean reclamation engineering project: a case study of Hong Kong International Airport

Man-made land or islands that are reclaimed from the sea are suitable for building airports, harbors, and industry parks for material transportation because of their broad air and land spaces. However, the reclaimed foundation settlement process is of public concern, including the continuous impact of ocean processes on its stability. The majority of the buildings and facilities of Hong Kong International Airport (HKIA) are built on a reclaimed foundation. The reclaimed foundation has been in residual settlement since completion of the filling project in 1994. In this study, we use persistent scatterer interferometry (PSI) and ENVISAT (European Satellite) advanced synthetic aperture radar (ASAR) data to detect the residual settlement rates from 19 April 2006 to 9 January 2008. We use ground truth data to develop empirical correction models for correcting systematic biases in the ASAR PSI-detected settlement rates. The corrected data follow the Lorentz distribution well, implying that the residual settlement process is dominated by two modes or categories of settlement rates. The first category represents a relatively stable state and the second category represents a continuous settlement state. A ground settlement rate map of HKIA shows that an area of the Passenger Terminal Building and an area of the Southern Runway are two relatively stable areas. There are two major continuous settlement areas. One covers the airport Midfield. Another is along the coastline, implying that attention should be paid to impacts of ocean processes on the stability of airport foundations.     

中心外缺陷对带隙型光子晶体光纤色散特性的影响

利用时域有限差分法(FDTD)模拟仿真了在中心缺陷外出现点缺陷、空气柱位错和内层空气柱发生形变三种缺陷形态对光子带隙型光子晶体光纤(PBG-PCF)色散特性的影响.发现一方面缺陷的出现会使色散曲线趋于平坦,另一方面点缺陷和位错缺陷的出现会使零色散点向长波移动,内层空气柱的形变使零色散点向短波长移动.这对PBG-PCF的实际生产实践会有指导意义.     

松南十屋断陷深层油气成藏条件与模式研究

十屋断陷是断坳叠置的复合盆地,充填了巨厚的断陷地层。其深部地层包括登娄库组、营城组、沙河子组以及火石岭组。在十屋断陷深部沉积了沙河子组-营城组和登娄库组两套烃源岩和良好的储盖层组合;由于断陷构造运动,形成大量的断裂构造和不整合面,构成了油气运移的有效通道,同时还形成有效断裂、断鼻构造圈闭以及不整合圈闭。综合分析认为,十屋断陷深部具有有利油气成藏生储盖组合。主要有下生上储式、自生自储式和上生下储式三种成藏模式。     

Teleportation and thermal entanglement in two-qubit Heisenberg XYZ spin chain with the Dzyaloshinski—Moriya interaction and the inhomogeneous magnetic field

This paper studies the average fidelity of teleportation and thermal entanglement for a two-qubit Heisenberg XYZ chain in the presence of both an inhomogeneous magnetic field and a Dzyaloshinski--Moriya interaction. It shows that for a fixed D_z, the increase of b_z will broaden the critical temperature at the cost of decreasing the thermal entanglement. And it can modulate the inhomogeneous magnetic field and the Dzyaloshinski--Moriya interaction for the average fidelity of teleportation to be optimal.     

Characteristics and origins of middle Miocene mounds and channels in the northern South China Sea

Numerous elongated mounds and channels were found at the top of the middle Miocene strata using 2D/3D seismic data in the Liwan Sag of Zhujiang River Mouth Basin(ZRMB) and the Beijiao Sag of Qiongdongnan Basin(QDNB). They occur at intervals and are rarely revealed by drilling wells in the deepwater areas. Origins of the mounds and channels are controversial and poorly understood. Based on an integrated analysis of the seismic attribute, palaeotectonics and palaeogeography, and drilling well enco...