用叠加谱比法研究新疆地区Lg尾波Q值的区域性变化

运用叠加谱比法,对分布于新疆地区的5个台站所记录的51个地震数据进行分析,得出与各射线路径相对应的Lg尾波Q0(Lg尾波在1Hz处的Q)值。结果表明:Q0值呈现出明显的区域性变化特点,与构造活动关系紧密。在较为稳定的塔里木地台,Q0呈现出高值,在350～450之间。在南部构造活动较为激烈的昆仑褶皱系,Q0呈现出较低的值,约为200～250。在构造活动最为激烈的帕米尔地区,Q0值在170～200之间。在北部的天山褶皱系,Q0值约为220～270。准葛尔褶皱系比天山褶皱系的Q0值略高,约为260～290。     

海带配子体无性繁殖(克隆)技术研究与应用进展

海带具有异型世代交替,其配子体在单独分离培养时可进行营养生长,形成无性繁殖系(克隆)。本文简要回顾了海带配子体克隆技术研究与应用的历程,综述海带配子体克隆在海带种质资源保存、海带生理和遗传学研究及海带育种和苗种繁育中的应用现状。     

西藏日土地区弗野岩体的成因——锆石U-Pb年龄及Hf同位素约束

班公湖—怒江成矿带西段日土—多龙地区为一条燕山期岩浆弧,已相续发现多处大、中型矿产,具有良好的成矿地质条件。弗野岩体位于该岩浆弧西侧,岩性以闪长岩和闪长玢岩为主,蚀变较强;微量元素原始地幔标准化后亏损Ba、Nb、Ta、Sr和Ti,富集Th、U和Pb;稀土元素球粒陨石标准化后表现出整体向右缓倾,显示负Eu异常;D1046和D1049两件样品的锆石LuHf同位素结果显示,εHf(t)主要集中在-5.2~-12.2区间,TDM1模式年龄介于0.98~1.28Ga之间;锆石206Pb/238U年龄加权平均值分别为119.06±0.48Ma和120.03±0.68Ma,均形成于早白垩世中期。结合岩石地球化学特征判断其属于I型花岗岩类,源区物质来源于幔源物质和下地壳物质。根据该岩浆弧带的岩体特征判断,班公湖—怒江特提斯洋至少在中侏罗世已经开始了向北的俯冲作用,且在早白垩世这种向北的俯冲作用仍在持续。     

城区内涝淹没模拟算法

针对城区内涝淹没范围和水深模拟问题,该文提出了一种基于约束Delaunay不规则三角网与三棱柱的城区内涝淹没模拟算法。该算法以沿地面三角形的顶点垂直向上引垂线形成的三棱柱为计算单元,通过"等体积"的方法,建立时间序列切片下的淹没水深和积水量的关系,据此实现淹没范围和水深模拟。以北京师范大学(简称"北师大")主校区为例,对单汇水区的水面高程上升模拟结果与实际观测值进行对比,基本吻合;并与传统栅格DEM的淹没效果进行了对比,表明该算法正确有效。     

三维符号构成及建模方法研究

随着计算机软硬件技术和三维可视化技术的快速发展,二维平面电子地图正在向直观、形象的三维电子地图方向过渡,而原来的二维地图符号已难以满足三维场景逼真性的要求,它必然要求与之配套的三维符号理论和技术的产生。由于三维符号如何构成及怎样标注尚无标准可遵循,在对三维符号的构成、分类及建模方法进行分析的基础上,提出了实体模型符号的两种建模方法,实验表明它们切实可行,能较好地表达三维实体模型。     

The Scientific Conceptual Framework for Ecological Quality of the Dryland Ecosystem: Concepts,Indicators, Monitoring and Assessment

The dryland ecosystem is the dominant component of the global terrestrial ecosystem since arid regions occupy 45% of the earth’s land area and feed 38% of the world's population. The stability and sustainable development of the dryland ecosystem are critical for achieving the millennium development goal (MDG) in the arid and semiarid areas. However, there is still no scientific guideline for measuring and conserving the health and productivity of dryland ecosystems. Therefore, the purpose of this study is to develop the scientific conceptual framework of defining, monitoring and evaluating the ecological quality of dryland ecosystems. The ecological quality of dryland ecosystems is represented by a system of comprehensive indicators that are each extracted from the ecological elements, and structural and functional indices of the ecosystem. These indicators can be monitored by integrating satellites and unmanned aerial vehicles with ground-based sensor networks at the scale of either observational sites or regional scales. Finally, the ecological quality can be evaluated by evaluation models based on the normalized index values and their thresholds. This paper presents a conceptual framework for monitoring and evaluating the ecological quality of drylands, which provides a way of advancing the monitoring, diagnosis, and evaluation of the ecological quality of the dryland ecosystems.     

人工冻土观测的冻点对应的土壤温度研究

基于2018年12月至2020年3月喀左、沈阳、辽阳、满洲里4个国家级地面气象站人工冻土器与测温式冻土自动观测仪观测的资料,对人工冻土观测获得的冻点与测温式冻土自动观测仪获得的相应深度的温度进行对比分析.结果表明:人工冻土器获取的冻点对应的土壤温度与0℃总体一致,又不完全重合;0—35 cm深度范围,冻点对应的温度变化...     

涌浪对风浪能量影响的实验研究

在实验室风浪水槽中进行纯风浪和混合浪波面位移观测,研究波长较长的规则波对风浪能量的影响.本文用混合浪和纯风浪中的风浪显著波的零阶谱矩之比代表混合浪中的风浪与纯风浪能量之比,并以此表征涌浪对风浪能量的影响.研究了该能量比随涌浪波陡S、风区x、波龄倒数u/C、涌浪频率与纯风浪谱峰频率之比fs/fwp的变化规律.结果表明,涌浪对风浪能量的抑制作用随涌浪波陡的增加、波龄倒数的增大及涌浪频率与纯风浪谱峰频率之比的增大而增强.发现该能量比依赖于无因次量R=(1+80(πS)2)1.9(fs/fwp)0.9(u/C)0.27,并拟合得到2者的经验关系.此外,本文实验还发现,在某些情况下,涌浪的存在使风浪能量增加.     

Rapid,specific and sensitive detection of Vibrio vulnificus by loop-mediated isothermal amplification targeted to vvhA gene

Vibrio vulnificus is an estuarine bacterial pathogen for human.The rapid,specific and sensitive detection of V.vulnificus is urgently needed for early disease diagnosis and timely treatment of V.vulnificus infection.In the study,a loop-mediated isothermal amplification(LAMP) technique was developed for V.vulnificus detection with a set of primers,composed of two out primers and two inner primers targeted to vvh A gene.The optimal amplification temperature was 63°C and the reaction only took 35 min.The amplification products could not only be detected by agarose gel electrophoresis with ladder-like pattern bands,but also could be visualized using calcein with naked eye directly.Forty-five strains were tested for the specificity of LAMP assay,and all the V.vulnificus strains were identified correctly while other strains were negative results.The sensitive of the new LAMP assay was 100-fold more sensitive than the conventional PCR.Meanwhile,all the V.vulnificus strains were detected correctly in spiked,clinical and environmental samples by the new LAMP assay.Compared with other well-known techniques,the new LAMP assay targeted to vvh A gene was extremely rapid,simple,sensitive and specific for V.vulnificus identification.