原地宇宙成因核素(TCN)测年靶标制备

自20世纪80年代以来,得益于高能加速器质谱的发展及其分析精度的提高,TCN测年技术得到了快速发展,并被成功应用于解决诸多领域关键性的年代学问题研究中,对地学的发展也起到了革命性的推动作用。TCN测年由测年靶标制备、AMS测量及数据分析等步骤组成。其中测年靶标制备直接影响AMS的测量结果,进而影响可靠年代学框架的建立与古气候环境的重建。测年靶标制备首先是代表性样品的采集,继而是所用靶标矿物的提纯,再者是所测元素的分离提取,最后是靶标压制。此处以第四纪冰川研究中应用较为广泛的TCN放射性核素¹⁰Be与²⁶Al为例,结合冰川侵蚀与沉积地貌的分布及其特征,从样品采集、石英提纯、¹⁰Be与²⁶Al核素的分离提取及最后的靶标压制等方面展开论述,以期为初涉第四纪冰川研究的学者提供TCN测年靶标制备的理论指导,同时也为地学其他研究领域该测年技术的应用提供参考。     

2013年6月19—20日甘肃陇东南暖区暴雨多普勒雷达特征分析

应用天水多普勒雷达资料,分析了2013年6月19—20日甘肃陇东南地区大暴雨过程中暖区降水时段的雷达反射率因子、径向速度及PUP产品特征。结果表明,雷达反射率因子特征与我国东部、南部的暖区暴雨特征极为相似,局地强回波的列车效应明显,强回波一般低于45 dBz,且主要分布于0℃层以下;雷达径向速度反映出对流层中低层的暖平流、风场辐合结构和低空急流的维持有利于强回波及高频次列车效应的产生;γ中尺度涡旋的出现对强降水的临近预报具有明显的指示意义。     

雷达资料在高原东北侧雷电预警中的应用

利用LD II闪电定位仪资料和兰州CINRAD/CC雷达资料,对甘肃中部2011和2012年夏季对流性降水过程中雷达回波单体与雷电活动之间的对应关系进行分析,提取反映较好的雷达产品特征量,建立雷电预警方案。结果表明,35 dBz回波顶高（ET）突破-10℃层高度和40 dBz回波顶突破过-10℃层高度等2个指标的雷电预警效果较好,预警时间可分别平均提前23和16 min;垂直累积液态含水量（VIL）可作为判断雷电发生的充分条件,但其值应小于30 kg·m-3;ET大于10 km预警雷电发生,预警时间可提前平均为7 min。利用建立的雷电预警方案对2013年的个例进行效果检验分析,结果表明该方案在雷暴天气具有较好的预警效果。     

加筋软土海堤的稳定分析

本文对于淤泥质海岸上的路堤，采用竹筋土工布加固软基的处理方法，进行了三种作用机理的分析研究和不同方法的整体稳定性分析计算，提出了旋转式复合滑动和相应的稳定计算方法，同时还对竹筋格栅按弹性支承结构进行了力学分析与计算。结果表明，这种加筋效果既满足使用要求，又易于施工，比较经济，是一种较为理想的软土海堤的加固方法。     

Statistics of the <Emphasis Type="Italic">Z</Emphasis>–<Emphasis Type="Italic">R</Emphasis> Relationship for Strong Convective Weather over the Yangtze–Huaihe River Basin and Its Application to Radar Reflectivity Data Assimilation for a Heavy Rain Event

The relationship between the radar reflectivity factor (Z) and the rainfall rate (R) is recalculated based on radar observations from 10 Doppler radars and hourly rainfall measurements at 6529 automatic weather stations over the Yangtze–Huaihe River basin. The data were collected by the National 973 Project from June to July 2013 for severe convective weather events. The Z–R relationship is combined with an empirical q_r–R relationship to obtain a new Z–q_r relationship, which is then used to correct the observational operator for radar reflectivity in the three-dimensional variational (3DVar) data assimilation system of the Weather Research and Forecasting (WRF) model to improve the analysis and prediction of severe convective weather over the Yangtze–Huaihe River basin. The performance of the corrected reflectivity operator used in the WRF 3DVar data assimilation system is tested with a heavy rain event that occurred over Jiangsu and Anhui provinces and the surrounding regions on 23 June 2013. It is noted that the observations for this event are not included in the calculation of the Z–R relationship. Three experiments are conducted with the WRF model and its 3DVar system, including a control run without the assimilation of reflectivity data and two assimilation experiments with the original and corrected reflectivity operators. The experimental results show that the assimilation of radar reflectivity data has a positive impact on the rainfall forecast within a few hours with either the original or corrected reflectivity operators, but the corrected reflectivity operator achieves a better performance on the rainfall forecast than the original operator. The corrected reflectivity operator extends the effective time of radar data assimilation for the prediction of strong reflectivity. The physical variables analyzed with the corrected reflectivity operator present more reasonable mesoscale structures than those obtained with the original reflectivity operator. This suggests that the new statistical Z–R relationship is more suitable for predicting severe convective weather over the Yangtze–Huaihe River basin than the Z–R relationships currently in use.     

Statistics of the Z–R Relationship for Strong Convective Weather over the Yangtze–Huaihe River Basin and Its Application to Radar Reflectivity Data Assimilation for a Heavy Rain Event

The relationship between the radar reflectivity factor(Z) and the rainfall rate(R) is recalculated based on radar observations from 10 Doppler radars and hourly rainfall measurements at 6529 automatic weather stations over the Yangtze–Huaihe River basin. The data were collected by the National 973 Project from June to July 2013 for severe convective weather events. The Z–R relationship is combined with an empirical qr–R relationship to obtain a new Z–qr relationship, which is then used to correct the observational operator for radar reflectivity in the three-dimensional variational(3 DVar) data assimilation system of the Weather Research and Forecasting(WRF) model to improve the analysis and prediction of severe convective weather over the Yangtze–Huaihe River basin. The performance of the corrected reflectivity operator used in the WRF 3 DVar data assimilation system is tested with a heavy rain event that occurred over Jiangsu and Anhui provinces and the surrounding regions on 23 June 2013. It is noted that the observations for this event are not included in the calculation of the Z–R relationship. Three experiments are conducted with the WRF model and its 3 DVar system, including a control run without the assimilation of reflectivity data and two assimilation experiments with the original and corrected reflectivity operators. The experimental results show that the assimilation of radar reflectivity data has a positive impact on the rainfall forecast within a few hours with either the original or corrected reflectivity operators, but the corrected reflectivity operator achieves a better performance on the rainfall forecast than the original operator. The corrected reflectivity operator extends the effective time of radar data assimilation for the prediction of strong reflectivity. The physical variables analyzed with the corrected reflectivity operator present more reasonable mesoscale structures than those obtained with the original reflectivity operator. This suggests that the new statistical Z–R relationship is more suitable for predicting severe convective weather over the Yangtze–Huaihe River basin than the Z–R relationships currently in use.     

单基站CORS的建设与应用研究

结合工程实践,总结单基站CORS的建设和应用情况,在基站选择与设立、网络RTK模型建立后,需要进行系统作用距离、系统精度和接收机兼容性的检测,经过应用提出单基站COPS建设和应用中应注意的问题.     

陕西区域成矿规律及其与重大成矿地质事件之关系

陕西横跨三大地质构造单元,曾历经前板块构造、板块构造和陆内造山等三大构造-成矿演化阶段、8个构造-成矿期和8次重大成矿地质事件,形成能源、金属、非金属和水气等四大类135种矿产2000余处矿产地。本文在建立涵盖陕西固体及非固体矿产矿床类型划分方案的基础上,总结了矿产时、空分布规律:时间上具有明显的阶段性,由早到晚分出8个构造-成矿期;空间上具有明显的丛聚性,由北到南划出12个矿集区。矿集区与地质历史时期的重大成矿地质事件密切相关,根据二者的时空关系,划分出单一型、耦合型、叠加型和复合型4种类型矿集区。矿集区的矿产种类、规模大小,一般与其所发生的成矿地质事件的性质和频次有关。叠加型矿集区比单一型矿集区更具找矿潜力。     

High-resolution Givetian-Frasnian boundary recognition from conodont-chemo-stratigraphic correlation at Liujing, Guangxi, South China

The Givetian-Frasnian boundary at Liujing, Guangxi, South China is for the first time recognized and correlated in high resolution using characteristic chemocycles of element abundance fluctuation integrated with conodont biostratignphy. The first appearance of Ancyrodella rotundiloba early form is as a biomarker, and the boundary of lowering fluctuation of element abundance followed by a sequence of characteristic chemocycles with a sequence of cmodonts is as an abiotic auxiliary marker. The error is not more than 0.10 Ma. The study indicates that in a quiet interval, characteristic chemocycles integrated with biomarkers can be used for boundary recognition and regional cormlation in high resolution, and this method has potential for intercontinental correlation     

论三水地震的成因

１９９７年９月２３日和２６日,在广东省三水相继发生ＭＬ３．７和４．４地震,由于这两次地震震源浅,具有震级小,烈度高和地震面波发育的特征,因震中位于盐矿开采区,震源深度与盐矿开采注水－抽水深度接近,故震源机制解表明该震为一次沿Ｆ７断上滑错动的正倾滑型地震,显著,这与盐矿注水－抽水采盐有着成生联系。由于注水－抽水极盐使开采地段产生一定规模的采空区,注水沿Ｆ７断层的渗透所产生的孔隙压降低了有效正应力,加