Analysis of acquisition parameters and geometry quality

High-quality seismic geometry is the key to obtain high-quality seismic data, and can affect the accuracy of data processing and imaging. Based on the analysis of the relationship between the quality of the geometry and the four acquisition parameters(the number of traces, shot line spacing, and the space and number of receiver lines), a quality evaluation method of the geometry based on comprehensive quality factor(CQF) is proposed, and the relationship between the geometry quality and the four parameters is given. We use field data collected in an oil field in Western China with complex geology: First we use a wide azimuth geometry. Then, we calculate the relationship curve between geometry and data quality by varying each parameter while keeping the rest fixed. and the analysis results are given by using the CQF evaluation method. The results show that the shot-line spacing has the greatest effect on the quality of the geometry, and the increase of the receiver line spacing can appropriately improve the quality of the geometry, and the increase of the number of receiving traces can improve the geometry quality. The different acquisition parameters have different effects on the imaging quality of shallow and deep events. The model forward and prestack depth migration are used to generate prestack depth migration profiles with different acquisition parameters. The imaging results are consistent with the above calculated results. According to the depth of the target layer, the quality factor evaluation method is applied to guide the design of the geometry and optimize the acquisition parameters to improve the imaging accuracy of seismic data.

广东省江门地区2015-2017年白纹伊蚊密度监测及抗药性调查

目的了解2015-2017年广东省江门地区白纹伊蚊季节消长规律及抗药性水平,为白纹伊蚊防制提供科学依据。方法采用布雷图指数(BI)法和诱蚊诱卵器法,于2015-2017年在江门市的7个市(区)的城市居民区逐月开展白纹伊蚊种群密度监测;采用WHO推荐的幼虫浸渍法开展幼虫抗药性测定。用SPSS 19.0软件进行生物测定数据统计,获得半数致死浓度(LC_(50)),根据抗性水平判定标准用Epi Info 3.5.3软件做抗性分布图。结果江门地区白纹伊蚊BI和诱蚊诱卵器指数(MOI)季节消长多数呈单峰趋势,5、7-9月为密度高峰期。2015-2017年BI最高分别为14.23、12.85和7.36;MOI最高分别为11.39、20.41和14.86。7个市(区)平均BI、MOI显示,大部分地区白纹伊蚊密度呈低密度状态。7个白纹伊蚊幼蚊种群对氯菊酯均呈敏感,对高效氯氰菊酯、残杀威、溴氰菊酯、双硫磷、Es-生物烯丙菊酯呈低抗或敏感。新会区种群对四氟甲醚菊酯呈现中抗,其他均为低抗。结论应加强对白纹伊蚊密度及抗药性监测,合理使用杀虫剂,延缓抗性产生,并将监测结果与蚊媒传染病进行关联分析,为城市蚊虫控制及蚊媒病的预防提供指导意见。

基于地震正交各向异性的裂缝介质岩石力学建模研究

岩石力学模型是描述地层原地应力状态的基础,而常规各向同性模型难以刻画地层本征横观各向同性(VTI)和天然高角度裂缝的耦合作用,建立更为准确的正交各向异性模型变得尤为重要.本文利用VTI介质中发育单组垂直缝的Schoenberg裂缝等效模型,简化了一般正交各向异性介质的表征参数,推导了由背景VTI介质弹性参数和裂缝参数的各向异性杨氏模量、泊松比和水平地应力的精确方程.借鉴Thomsen弱各向异性近似思路,舍去裂缝弱度参数高阶扰动项,推导了正交各向异性介质岩石力学近似方程,由裂缝弱度表示的近似方程更为直观地反映了裂缝对背景介质力学性质的影响,杨氏模量和泊松比值随裂缝法向弱度的增大而显著减小.选取页岩实验数据进行数值实验,结果表明本文方程与实际物理规律相吻合,随裂缝弱度的增加,形成相同应变所需的水平地应力值降低,且近似方程与模拟结果相对误差小于5%,有助于提高岩石力学参数估算和地应力预测精度.

鞘氨醇激酶2在肿瘤中的作用及其抑制剂研究进展

近年来,鞘脂通路中的关键靶点鞘氨醇激酶2(sphingosine kinase 2,SphK2)在肿瘤发生发展过程中的作用逐渐被阐明。SphK2抑制剂既可单独作为抗癌药物,还可以与现有药物联合用药,以增加耐药肿瘤的治疗敏感性。其中SphK2选择性抑制剂ABC294640具有出色的口服生物利用度和体内分布,目前已进入临床Ⅱ期研究。基于该靶点进行创新药物开发具有很大的发展空间和应用前景,本文对近年来SphK2参与肿瘤发生发展的机制及SphK2抑制剂的开发现状进行综述。