The magnification invariant of circularly-symmetric lens models

In the context of strong gravitational lensing, the magnification of an image is crucially important for constraining various lens models. For several commonly used quadruple lens models,the magnification invariants, defined as the sum of the signed magnifications of images, have been analytically derived when the image multiplicity is a maximum. In this paper, we further study the magnification of several disk lens models, including(a) exponential disk lens,(b) Gaussian disk lens,(c) modified Hubble profile lens, and another two of the popular three-dimensional symmetrical lens models,(d) NFW lens and(e) Einasto lens. We find that magnification invariant exists for each lens model. Moreover, our results show that magnification invariants can be significantly changed by the characteristic surface mass density κc.     

Enhancing driving safety: Discovering individualized hazardous driving scenes using GIS and mobile sensing

Traffic collisions have been well acknowledged as a significant threat to public health, closely related to human driving errors. This study introduces an innovative approach to investigate spatiotemporal distributions of individualized driving errors and to characterize hazardous driving scenes, in which drivers are more prone to make driving mistakes. We first create a multi‐feature‐fusion framework to extract driving errors using smartphone sensors. Then, the detected errors are geo‐statistically analyzed with road networks and driving trajectories to identify driving error hotspots. We next construct a “scenic tuple” for representing the occurrence of driving errors. Finally, the individualized hazardous driving scenes are extracted by mining a long‐term collection of scenic tuples. Results demonstrate that our proposed approach can effectively identify driving errors. Additionally, the spatiotemporal patterns of driving mistakes can be identified from the individualized hazardous driving scenes, which has the potential to aid in reducing driving risks.     

CBS-3型数字位移压力测量仪

本文叙述CBS-3型数字位移(压力)测量仪和测量系统的设计,特点及性能。     

封管法制备有机碳同位素质谱分析样

本文介绍了在分析有机质中稳定碳同位素时制备CO_2的一种简单方法。该方法可用于湖泊沉积物样品及各种物态的石油分馏物,并且对其它有机化合物有很好的潜力。有机物样品在高温中灼烧生成CO_2和H_2O,然后进行分离转移。该方法所需材料极其便宜,设备简单,并且在8h内可制备近30个样品,适合我国一些中小实验室。     

水汞含量随观测时间变化及与观测环境关系的实验研究

通过进行对比观测实验,对水汞观测中同一水样的汞含量随观测时间变化及与观测环境的关系进行分析,研究所取得的一些结果。该结果对台站监测工作中仪器发生故障时的样品分析处理,以及特殊条件下的短临跟踪监测工作具有一定的借鉴作用。     

A Coastal Air-Ocean Coupled System (CAOCS) Evaluated Using an Airborne Expendable Bathythermograph (AXBT) Data Set

A coastal atmosphere-ocean coupled system (CAOCS) is developed with Princeton Ocean Model (POM) as the oceanic component, and with National Center for Atmospheric Research (NCAR) regional climate model (RegCM2) as the atmospheric component. The model domain (98.84°–121.16°E, 3.06°S–25.07°N) covers the whole SCS and surrounding land and islands. The surface fluxes of water, heat (excluding solar radiation), and momentum are applied synchronously with opposite signs in the atmosphere and ocean. Flux adjustments are not used. The CAOCS model was verified using an intensive airborne expendable bathythermograph (AXBT) survey between 14–25 May 1995 over the majority of the SCS down to about 300-m depth.     

带乘性噪声系统在加性噪声相关时的最优滤波

针对石油地震勘、通讯工程、语言处理等应用领域 ,该文研究一种在更弱的噪声限制条件下带乘性噪声系统的状态最优滤波 ,就动态噪声为有色噪声及动态噪声和量测噪声在有限时间段上相关的情形 ,给出了线性最小方差意义下的状态最优滤波算法 ,并对此算法作了仿真计算 ,获得满意的结果     

Analytical solution of water table fluctuations above an inclined leaky layer due to ditch recharge

Ditch recharge is a method used for raising a water table. However, if the aquifer lies above a leaky layer, then the leaky bed will have an effect on the height of the water table. This paper attempts to provide an analytical solution of the transient state to the linearized Boussinesq equation. The solution proposed in this paper is intended for a generalized form of the leaky layer, with the boundary condition of the water level moving according to an exponential form. The results of theoretical analysis and experimental studies can provide a much better explanation of ditch recharge on an inclined leaky layer. Copyright © 2006 John Wiley & Sons, Ltd.     

从断层擦痕反演的郯庐断裂带南段合肥盆地白垩纪构造应力场

本文通过断层擦痕应力场反演方法,对郯庐断裂带南段合肥盆地白垩纪伸展活动进行了详细研究,厘清了郯庐断裂带南段合肥盆地白垩纪拉伸方向的演变规律。研究结果显示：从早白垩世早-中期、晚期到晚白垩世,拉伸方向由NWW-SEE向、NW-SE向到近SN向转变,具顺时针旋转特征。与西太平洋区大洋板块运动方向对比分析认为：郯庐断裂带南段合肥盆地白垩纪伸展活动发生在弧后拉张的动力学背景下,拉伸方向的演变可能是西太平洋区大洋板块运动方向改变的结果。     

碳的化学地球动力学

本文简述了国际上在碳的化学地球动力学方面的研究进展。这包括对整个地球和地幔的碳丰度估计，对当代从大洋中脊、岛弧排出的ＣＯ２通量等估计，以及对涉及地球去气和深部碳循环等过程的一些有争议的化学地球动力学问题的探讨。