伴随对流层中低层气温持续下降的雪转雨过程分析

利用欧洲中期天气预报中心（ECMWF）0.25°×0.25°分辨率细网格模式产品、探空观测资料和风廓线雷达等资料,对2014年2月18日浙江嘉兴雨雪天气过程中降水相态先由雨转雪、再由雪转雨的变化条件进行了分析,并对ECMWF细网格模式产品进行了预报性能检验,结果表明：模式形势预报准确,但未能预报出雪转雨过程。在对流层中低层气温持续降低的情况下,水汽凝结高度不同是造成两次相态转换的主要原因。上午垂直运动加强,水汽充沛,降水粒子的凝结高度高,足以形成大的雪花,在较低的零度层高度以下降落时不至于融化;下午垂直运动减弱,水汽集中在低层,尽管这一高度层的气温在-3～-2 ℃,但是不足以凝结成固态降水,同时地面气温受海上暖平流影响而回升,因此降水相态由雪转雨。     

一种长英黝帘石玉的岩石矿物学研究

采用X射线粉晶衍射、电子探针、化学分析法和傅立叶变换红外光谱等方法,对近来在北京珠宝市场上出现的一种粉白相间的玉石新品种进行了测试,全面分析了这种玉石的结构和成分,并根据硅酸盐体系的物质平衡原理,利用相混合计算(PMC)方法,估算了玉石中主要矿物的含量。结果表明,这种玉石中黝帘石含量占51.9%,钠长石占33.3%,石英14.4%,并含有少量的褐帘石、单斜辉石等矿物。样品中粉红色矿物的红外光谱最强峰位于1110～900cm-1范围内,为快速、方便地鉴定此种玉石提供了参考依据。     

相位相关速度分析方法研究及效果比较

利用统计假设原理及地震信号瞬时相位的相关特性,计算了叠加速度谱。理论模型的试算和实际资料的处理结果表明:与常规速度分析方法相比,该方法具有较高的时间分辨率和速度分辨率,而且抗噪性非常好。该方法不仅不受时窗边界奇异性的影响,还可以有效地避免边缘效应,反映更多反射波信息。该方法对于层速度的精确计算很关键,同时也表明了统计方法用在多道信号估计上是有效的。     

大通河盆地二叠系沉积相及铜矿化特征

大通河盆地为一上古生代—中新生代断陷盆地,沉积持续时间长,后期构造作用强烈。通过对盆地内二叠系沉积相及铜矿化特征分析,认为铜矿化物质来源于北祁连古陆核,经剥蚀—沉积形成了含铜二叠系陆相杂色砂岩,后期断裂构造及热液活动更加强化了铜矿化的作用。     

低温平衡ZnS-PbS-FeS-H_2S四组分体系的热力学分析

本文介绍了热力学相图在浅成低温热液硫化物矿床中的应用,并以三江地区金顶铅锌矿床中的矿物含量为例进行定量分析。一方面在相同温度下,浓度与矿物(组合)之间存在对应关系,并且一些矿物(组合)对应特定的酸碱条件,例如在400K和105Pa条件下,黄铁矿与方铅矿的组合在碱性环境下稳定,而方铅矿与闪锌矿的组合在酸性环境中稳定,且酸性条件下当lg[Pb2+]≥-11.29时,才开始出现方铅矿;另一方面对比了298.15K和400K条件下矿物共生组合的及介质pH值的变化情况,并得到400K条件下形成矿物或矿物组合所需离子的浓度更高。     

铁山湾内天文潮对风暴潮水位的影响研究

作为半封闭狭长海湾,铁山湾受风暴潮灾害的影响较为严重。根据多年观测资料和数值模型对铁山湾内的风暴潮水位特征进行了研究。观测资料表明海湾内风暴潮峰值水位受天文潮相位影响较为显著,然后基于ADCIRC风暴潮模型和1409号“威马逊”台风参数,定量评估了天文潮对风暴潮水位的影响。模拟结果表明当考虑天文潮作用时,会显著提高模拟结果精度,然后通过数值实验研究了风暴潮与不同相位天文潮相互作用时的水位变化特征。数值实验结果表明天文潮-风暴潮相互作用引起的非线性水位在涨潮阶段不明显,在高潮位时非线性水位达到负值最大;在落潮时达到正值最大。风暴潮增水峰值由于受到这种非线性效应的影响,在高潮位时数值最小。海湾内非线性作用要远大于外部,非线性效应越强,总水位峰值相对于天文潮高潮位的延迟时间也就越长。     

利用生产动态及地震资料分析井间河流相砂体连通性

渤海PL油田是位于渤海湾盆地的大型河流相油田,在其注水开发过程中,亟需准确认识注水井与生产井之间的砂体连通性,以便优化和调整注采井网,提高采收率.针对油田砂体横向变化快,纵向上薄砂体发育的特点,利用丰富的压力、水淹等生产动态资料及相位转换后赋予地质意义的地震资料综合分析砂体的连通性,进一步完善和修正了早期以地质及测井资料确定的砂体连通性分析成果,并引入注采连通率概念,用来定量表示井组范围内注水井与生产井之间的砂体的连通性.该套方法在PL油田注水优化及井网调整研究中得到了充分的体现,对其它河流相注水开发油田井组范围内井间砂体连通性研究具有一定的借鉴作用.     

海洋地震资料相位控制处理——东海研究实例

为了满足定量解释的需要,地震资料处理必须是高分辨率、振幅保持和相位控制的.面向海洋地震资料的相位控制处理技术包括利用远场信号进行确定性零相位化、Q补偿、预测反褶积及剩余相位校正等.利用模拟远场信号求取确定性去气泡及零相位化算子.此文基于相位控制处理,讨论了海洋地震资料的相位和极性判别方法,探讨了大于24 ms算子长度的预测反褶积对于保持信号形状的必要性,介绍了东海三维地震资料相位控制流程.     

Optimal Forward-Scattering Angles of Atmospheric Aerosols in North China

The accurate understanding of atmospheric aerosol extinction coefficients is very important for at- mospheric science research. To achieve a fast and simple method for determining the parameters, the selection of optimal forward-scattering angles of atmospheric aerosols is required. In this paper, the authors introduce the detec- tion basis of forward-scattering of atmospheric aerosols, and the authors verify the sensitivity of the phase function to the real part of the complex refractive index. The au- thors use the Jaenicke urban aerosol model to determine that forward-scattering angles near 33° are suitable. However, the optimal forward-scattering angles in North China are between 37° and 40°. Numerical simulation shows that certain types of particle size distribution of newly generated particles and pollution have limited in- fluences on the selection of forward-scattering angles. But the ranges of these insensitive angles shift - 10 degrees for dust intrusion, and the relative deviations of the phase function are less than 5.0% within extra angles of 0° to 3°. This study can serve as a reference for the selection of optimal forward-scattering angles for visibility meters and Present Weather Identifiers （PWIs） in addition to the de- tection of forward-scattering optical properties.     

Stationary Wave Activity Associated with the East Asian Winter Monsoon Pathway

The pathway of the East Asian winter monsoon(EAWM) that usually leads to the out-of-phase pattern of surface air temperature between northern and southern East Asia is an important feature in the variability of the EAWM besides its strength.Using the European Centre for Medium-Range Weather Forecasts 40-year(ERA40) reanalysis dataset,this study investigates the pathway-related stationary wave activity to explore the mechanism of the interannual variations in the EAWM pathway.It reveals that when the southern pathway of the EAWM is strong,the phase of the climatological stationary wave tends to be shifted westward significantly in both the horizontal and vertical directions by an anomalous wavenumber 2 pattern at mid-latitudes,whereas the changes are relatively small in the subtropics.The horizontal changes in the stationary wave phase facilitate a north-south-oriented East Asian trough in the middle troposphere that eventually produces the strong southern pathway of the EAWM.The vertical changes in the stationary wave,in contrast,feature a westward-tilted phase line with height over the North Pacific,indicating enhanced upward propagation of waves into the stratosphere.This result suggests that the phase of stationary waves at mid-latitudes dominate the interannual variations in the EAWM pathway.Moreover,it supports our previous interpretation of the possible role of the North Pacific sea surface temperature(SST) in the EAWM pathway variability.It also implies that the excitation of anomalous mid-latitude stationary waves may be the key in the response of the EAWM pathway to the North Pacific SST.