Correcting the TRMM rainfall product for hydrological modelling in sparsely-gauged mountainous basins

This study developed a correction approach to improve the rainfall field estimation using the TRMM rainfall product in a sparsely-gauged mountainous basin. First, Thiessen polygons were generated to define the measurement domain of each raingauge. Second, the rainfall of TRMM pixels in each Thiessen polygon was corrected using a benchmark method based on the difference between the monthly rainfall estimated by a raingauge and the TRMM pixel that possessed a gauge station (referred to as a gauged pixel). Third, the rainfall values in the gauged pixels were adjusted to the weighted average value of the gauge rainfall and corrected pixel rainfall. Finally, the rainfall in the non-gauged TRMM pixels was corrected as the sum of two terms. The first term is the adjusted rainfall in the corresponding gauged pixel in the same Thiessen polygon, and the second term is the rainfall (after benchmark correction) difference between the current pixel and the gauged pixel. Our results indicate that the corrected rainfall data outperforms the original TRMM product in the simulations of moderate and low flows and outperforms the sparse raingauges in the simulations of both peak and low flows.

EDITOR A. Castellarin; ASSOCIATE EDITOR S. Huang     

川藏铁路交通廊道地质调查工程主要进展与成果

川藏铁路是我国正在规划建设的重点工程,由于其位于地形地貌和地质构造都极为复杂的青藏高原东部,在铁路规划建设中面临一系列迫切需要解决的关键地质问题: 区域性活动断裂与断错影响、地质灾害、高地应力及其引起的岩爆和大变形、高温热害、断裂带高压水与涌水突泥、高陡边坡稳定性等。为满足技术支撑川藏铁路规划建设、精准服务国家重大战略实施的需要,中国地质调查局部署了“川藏铁路交通廊道地质调查工程”,聚焦制约川藏铁路规划建设的关键问题,充分发挥地质调查工作对国家重大工程规划建设的支撑作用。2019年主要完成铁路沿线1:5万区域地质调查1 350 km²、1:5万地质灾害调查5 000 km²,建设6口大地热流地质参数井、8个地温监测站,完成地应力测量20孔,编制完成11份地质调查专报,提出的大渡河大桥段、理塘车站段、毛垭坝盆地段等线路优化建议/防灾建议被采纳; 首次将1:5 000大比例尺航空物探技术引入复杂山地铁路工程勘察,创新形成千米级超长水平钻孔定向取心钻进技术,实现500 m深的水平孔地应力测量突破等。该工程通过2019年调查研究,全力提升了铁路沿线地质调查程度与精度,并创新了复杂艰险山区重大工程地质问题与探测技术、地质灾害风险防控理论与减灾关键技术,有效支撑服务了川藏铁路规划建设。     

黔南上司地区石炭系有孔虫:兼论华南维宪阶有孔虫生物地层序列

石炭纪时期有孔虫具有演化快、分布广、数量丰富、分异度高的特点,对于地层的划分对比具有极为重要的意义。与全球其他重要的石炭纪沉积区相比,华南有孔虫生物地层划分精度相对较低。本文首次较为系统地报道了华南石炭系代表性岩石地层单位旧司组和上司组下部丰富的有孔虫化石及其在剖面上的分布情况,并综合现有关于华南的有孔虫化石资料,将华南维宪阶划分为7个有孔虫化石带,自下而上分别为Eoparastaffella simplex带、Viseidiscus/Planoarchaediscus带、Paraarchaediscus带、Pojarkovella nibelis带、Koskinotextularia带、Bradyina带和Janischewskina带。这些有孔虫带可与全球其他典型的石炭纪沉积区进行很好的对比,从而为相关的研究提供一个较为精细的地层格架。通过对黔南上司地区有孔虫的研究,提议中国石炭系区域性年代地层单位上司阶底界可用有孔虫Bradyina的首现定义,并将上司阶与西欧的Warnantian亚阶中上部和俄罗斯的Aleksinian亚阶—Venevian亚阶对比,对应国际维宪阶上部,为全球石炭系年代地层对比提供了可靠的化石依据。     

地面气象资料质量控制方法研究概述

为了促进我国地面气象资料质量控制方法的研究,以几个有代表性的数据集,如GHCN、GDCN、ISH为例,概述了国外地面气象资料质量控制技术的进展及新动态。研究表明：传统的质量控制方法仍是主要工具。在计算机技术迅速发展的时代,可以有更好的条件,使用自动控制和人机交互、气候背景资料和统计检验相结合的技术,并适当应用空间检验方法,来设计我国自动站地面气象资料质量控制业务流程。     

文蛤亮氨酸氨肽酶LAP3的基因克隆及其在幼体不同发育时期、成体不同组织的表达分析

为探索贝类LAP3基因的结构和功能特征以及在生长发育过程中的作用,利用cDNA末端快速扩增（RACE）法获得文蛤LAP3（Mm-LAP3）基因的cDNA全长序列,并对其生物信息学、组织及发育时期表达特征进行了分析。结果显示,Mm-LAP3基因cDNA全长2 037 bp,ORF区1 254 bp,编码417个氨基酸;Mm-LAP3蛋白由Peptidase_M17超家族序列的N-端结构域和Peptidase_M17催化结构域组成。荧光实时定量PCR结果表明,Mm-LAP3基因在文蛤成体6个组织和幼体10个发育时期中均有表达,其中在斧足中的表达量显著高于其他组织（P<0.05）,这与斧足蛋白含量丰富、代谢旺盛相关;在幼体10个发育时期中的表达量呈现逐渐升高的趋势,在D形幼虫时期达到最高,随后又有所降低,推测Mm-LAP3基因在早期发育时期参与了某些组织器官的形成。     

Treatment on oil/water gel deposition behavior in non-heating gathering and transporting process with polymer flooding wells

Against a background of crude oil shortage and low-carbon economy, optimization and simplification of oil–gas gathering and transporting play an indispensable role in efficient development of oilfield. Profit from the high efficient utilization of the produced liquid self-energy, single-pipe non-heating gathering and transporting process has been recognized in polymer flooding wells of Daqing oilfield (China). However, it is also facing the challenges of deposition, partial blockage, high wellhead pressure, production fluctuation and environment management. A field investigation of the application for the non-heating process and the variation of polymer flooding wellhead pressure were recently carried out. The flow patterns of the oil, water and gas mixture in single-pipe process were identified, and the locations where the gel deposition was most likely to occur were estimated. Deposition inhibitions and removal processes were practiced, and the operation parameters under different working conditions were optimized. The results indicated that single-pipe non-heating process could reduce 20% of the investment and 30% of the running cost and could also make the wellhead pressure of some wells exceed the maximum allowable operating pressure of oil gathering pipelines. There appears to be a proportional relationship among water content, flow rate, residual polymer concentration and gel deposition behavior in a certain range of gathering radius. The gel deposition rate of the produced liquid with polymer concentration of higher than 600 mg/L and the water content of 90.5% reached 0.1154 mm/h in the coldest climate under the normal flow rate of 85 t/d, and the theoretical pigging period was <10 days. Gelation nucleation which was related to emulsification was induced by the transition and coexistence of separated flow and dispersed flow in non-heating gathering pipelines. The main deposition located on the beginning of pipelines, manifold, valve and elbow, and wellhead pressure of 350 psi was created in the test period of 20 days. Although using chemical inhibition method could still obtain a drag reduction rate of more than 25% under crude oil gelation temperature, the fact of the centralization disability of wellhead dosing facilities and the potential threat of chemical inhibitors to the environment could not be ignored. The noticeable energy consumption and potential risks of pipeline restarting may be encountered using facilities improvement and sphere pigging operation in gel deposition behavior treatment. A relation schema which could be used to predict deposition rate and extract thermal flush period according to the actual working condition was established. The successful application of the non-heating gathering and transporting process combated the traditional view that heat tracing is essential for maintaining the surface process in extremely cold area. Furthermore, the results contributed to the existing literature in establishing subsurface and surface parts integration idea for a green field development and accelerate further application of non-heating gathering and transporting process.     

地磁加卸载响应比方法最佳阈值研究

地磁加卸载响应比方法(LURR)是从测震学中移植过来的、用于地震中期分析预测的一种地磁学方法。笔者应用红山地震台地磁数字化观测数据进行了地磁加卸载响应比的计算分析,经过统计得出在阈值选择为3.0时对地震进行预测的效果比较好,其与地震的对应概率为42%。同时,笔者还认为可能受限于方法本身及外界因素,地磁加卸载响应比方法在进行地震预测时,其虚报率及漏报率较高。     

Coal price fluctuation mechanism in China based on system dynamics model

Natural Hazards - We analyze and identify the factors that influence coal price fluctuations and construct a system dynamics model of these factors. The simulation results show that the trend in...     

Lock-up装置在连续梁桥上的减震性能研究

以某客运专线上大跨连续梁桥为实际工程背景,研究了Lock-up装置对结构纵向抗震性能的影响。根据Lock-up装置在地震作用下具有反复锁止的受力特点,采用非线性时程分析方法,分析了锁止速度对结构减震性能的影响。结果表明:对于大跨连续梁桥,Lock-up装置能够充分发挥活动墩的抗震承载能力,有效地提高桥梁结构整体抗震性能。当锁止速度较小时,Lock-up装置可以采用大刚度连杆模拟,并假定其始终处于完全锁定状态。但当锁止速度较高时,应考虑Lock-up装置反复锁止的实际工作特点,否则应用上述计算方法所得的结果偏于不安全。