Processes of initial collision and suturing between India and Asia

The initial collision between Indian and Asian continents marked the starting point for transformation of land-sea thermal contrast, uplift of the Tibet-Himalaya orogen, and climate change in Asia. In this paper, we review the published literatures from the past 30 years in order to draw consensus on the processes of initial collision and suturing that took place between the Indian and Asian plates. Following a comparison of the different methods that have been used to constrain the initial timing of collision, we propose that the tectono-sedimentary response in the peripheral foreland basin provides the most sensitive index of this event, and that paleomagnetism presents independent evidence as an alternative, reliable, and quantitative research method. In contrast to previous studies that have suggested collision between India and Asia started in Pakistan between ca. 55 Ma and 50 Ma and progressively closed eastwards, more recent researches have indicated that this major event first occurred in the center of the Yarlung Tsangpo suture zone (YTSZ) between ca. 65 Ma and 63 Ma and then spreading both eastwards and westwards. While continental collision is a complicated process, including the processes of deformation, sedimentation, metamorphism, and magmatism, different researchers have tended to define the nature of this event based on their own understanding, an intuitive bias that has meant that its initial timing has remained controversial for decades. Here, we recommend the use of reconstructions of each geological event within the orogenic evolution sequence as this will allow interpretation of collision timing on the basis of multidisciplinary methods.     

大地电场观测深埋铅电极测量系统试验

为使用铅电极替代不极化电极,以解决滨海地区大地电场观测系统稳定性差的问题,先后开展了浅埋的铅电极与不极化电极的大地电场对比观测,以及深埋铅电极与浅埋铅电极的对比观测试验。结果表明:铅电极与固体不极化电极的观测数据在短期内有较好的一致性;深埋铅电极的大地电场观测资料在长期稳定性上优于固体不极化电极;而观测数据的内在观测质量也高于浅埋铅电极。     

南海夏季风爆发日期和强度的短期气候预测方法研究

利用合成及相关统计方法，研究冬季南海季风指数与850hPa风场、500hPa高度、海表温度、OLR等环境场的相互关系及其影响南海夏季风活动的可能机制。指出冬季南海季风指数及环境场的异常特征可以作为预测南海夏季风活动的前兆信号。在此基础上建立了预测南海夏季风爆发日期和强度的概念模型，1998－2001年的预测试验取得了较好成绩。     

上高县紫皮大蒜种植气候适宜性区划

基于紫皮大蒜生长周期和当地农业气象条件,得到上高县紫皮大蒜气候适宜性指标：10—11月的最低气温、10月至次年4月的平均气温和平均降水量以及2—4月的累计日照时数。利用1970—2020年宜春市和新余市辖区内共12个地面观测站的气象资料,采用GIS建立上高县紫皮大蒜种植区划因子地理空间分析模型。依据分区等级指标,将上高县划分为最适宜、一般适宜和不适宜3个紫皮大蒜气候种植区。     

热球菌HJ21高温α-淀粉酶基因克隆、表达及性质研究

通过简并引物扩增热球菌(Thermococcus siculi)HJ21高温α-淀粉酶保守区域之间的序列,再利用Site-finding技术获得两端未知序列.构建了在N端添加了His6标签的表达载体pEt-28a-His6-THJA后转化E.coli,在IPTG诱导下表达.进一步纯化后SDS-PAGE电泳检测达到电泳纯...     

二维小波变换与中值滤波联合去噪方法研究

由于随机噪声是一种频带较宽的干扰波,因此依靠单一的去噪处理方式往往难以获得清晰反映目标体的地震信息。小波变换能够较好的去除高斯噪声,保留有效波中、高频成分,提高记录的信噪比,但去除脉冲噪声的效果却并不理想;中值滤波具有良好的边缘保持特性,虽低频去噪声效果有限,但去除脉冲噪声效果明显。因此可利用二维小波变换与中值滤波优势互补的方法,进行叠前去噪处理,达到去除宽频随机噪声的目的。首先运用二维小波变换的理论,采用自适应门限阀值方法进行去噪,同时结合中值滤波方法联合去噪。模型与实际数据的应用效果表明,联合去噪方法可有效压制噪声能量、保留高频有效信号、提高地震记录信噪比与分辨率。     

A bio-optical inversion model to retrieve absorption contributions and phytoplankton size structure from total minus water spectral absorption using genetic algorithm

We propose a bio-optical inversion model that retrieves the absorption contributions of phytoplankton and colored detrital matter(CDM),as well as the phytoplankton size classes(PSCs),from total minus water absorption spectra.The model is based on three-component separation of phytoplankton size structure and a genetic algorithm.The model performance was tested on two independent datasets(the NASA bio-Optical Marine Algorithm Dataset(NOMAD) and the northern South China Sea(NSCS) dataset).The relationships between the estimated and measured values were strongly linear,especially for aCDM(412),and the Root Mean Square Error(RMSE) of the CDM exponential slope(SCDM) was relatively low.Next,the inversion model was directly applied to in-situ total minus water absorption spectra determined by an underwater meter during a cruise in September 2008,to retrieve the phytoplankton size structure in the seawater.By comparing the measured and retrieved chlorophyll a concentrations,we demonstrated that total and size-specific chlorophyll a concentrations could be retrieved by the model with relatively high accuracy.Finally,we applied the bio-optical inversion model to investigate changes in phytoplankton size structure induced by an anti-cyclonic eddy in the NSCS.     

V-3θ图的结构与"98.6"暴雨过程预测分析

V-3θ图是成都气象学院欧阳首承教授设计出来的运用图像结构来预测天气的结构预测方法。主要利用大气中的压、湿、湿、风的垂直分布,判断大气滚流对天气演变的影响来预报天气转折性变化。利用V-3θ图对桂林站1998年6月份的暴雨过程作一个综合分析。结果几次特强的降水都在V-3θ图上有较好的反映。该方法对无明显降水的天气也能作定性的判断。     

扬子地块北缘武当山岩群与耀岭河岩群不整合接触关系的地质意义

鄂西北南化塘地区中元古界武当山岩群由三个岩段组成，其原岩分别以火山角砾岩、岩屑凝灰岩及晶屑凝灰岩为主。它们的空间展布与上覆上元古界耀岭河岩群高角度相交，三岩段所显示出早期褶皱也只限于武当山岩群内部，与上覆岩群的构造轮廓极不谐调，耀岭河岩群没有经历过这一期变形。因此，武当山岩群与耀岭河岩群之间最初存在着明显的角度不整合接触。该区域不整合面的厘定和早晋宁运动的确认将改变以往关于扬子地块北缘构造层的划分及构造演化历史的认识，对研究秦岭造山带的造山过程具有重要意义。