褐藻多酚合成的模拟研究

褐藻多酚是间苯三酚的聚合物,结构复杂,有关生物合成途径方面的研究报道甚少。近年发现,褐藻多酚具有多种生物活性和医药价值(Ragan & Glombitza,1986),因此，研究褐藻多酚的人工合成不仅可模似研究褐藻多酚的生物合成过程,而且为寻找替代自然资源打下了基础。 作者在实验中观察到配制的间苯三酚溶液放置一段时间后会逐渐发黄,因此认为间苯三酚在放置过程中发生了氧化聚合,并对此作了进一步研究。     

广东信宜井水位异常分析

针对信宜井水位2018年8月中旬快速下降后又转折上升的异常变化特征,通过实地异常调查和以往的震例总结,建立水位与降雨量关系的多元回归方程,综合分析该井水位异常原因.初步判定水位快速下降后又大幅回升有多个影响因素,一是附近工地抽水与施工爆破可能导致了水位下降;二是水位大幅度回升并不只是由降雨造成,还有别的干扰因素.通过此次信宜井水位异常变化的调查,形成的分析过程和方法,有助于今后此类水位异常的判别.     

怀4井气体取样对水位观测干扰的解决措施

怀4井水位观测一直存在取气样所造成的干扰,其表现为水位分钟值曲线每天出现有规律的向上脉冲式突跳且持续时间较长,这使得数据连续率及完整率降低。为改变怀4井长期存在的取气样影响水位观测的现状,减少水位观测数据突跳次数,提高观测质量精度,针对取气样方式进行改进,采用球胆排水真空脱气法进行溶解气样品的采集与脱气,避开直接在泄流口采样时的压力效应,从而解决了水位观测中遇到的实际问题。     

High-energy afterglow emission from gamma-ray bursts

We calculate the very high-energy (sub-GeV to TeV) inverse Compton emission of GRB afterglows. We argue that this emission provides a powerful test of the currently accepted afterglow model. We focus on two processes: synchrotron self-Compton emission within the afterglow blast wave, and external inverse Compton emission which occurs when flare photons (produced by an internal process) pass through the blast wave. We show that if our current interpretations of the Swift X-ray telescope (XRT) data are correct, there should be a canonical high-energy afterglow emission light curve. Our predictions can be tested with high-energy observatories such as GLAST , Whipple, HESS and MAGIC. Under favourable conditions we expect afterglow detections in all these detectors.     

XUV Photometer System (XPS): Improved Solar Irradiance Algorithm Using CHIANTI Spectral Models

Solar soft X-ray (XUV) radiation is highly variable on all time scales and strongly affects Earth’s ionosphere and upper atmosphere; consequently, the solar XUV irradiance is important for atmospheric studies and for space weather applications. Although there have been several recent measurements of the solar XUV irradiance, detailed understanding of the solar XUV irradiance, especially its variability during flares, has been hampered by the broad bands measured in the XUV range. In particular, the simple conversion of the XUV photometer signal into irradiance, in which a static solar spectrum is assumed, overestimates the flare variations by more than a factor of two as compared to the atmospheric response to the flares. To address this deficiency in the simple conversion, an improved algorithm using CHIANTI spectral models has been developed to process the XUV Photometer System (XPS) measurements with its broadband photometers. Model spectra representative of quiet Sun, active region, and flares are combined to match the signals from the XPS and produce spectra from 0.1 to 40 nm in 0.1-nm intervals for the XPS Level 4 data product. The two XPS instruments are aboard NASA’s Solar Radiation and Climate Experiment (SORCE) and Thermosphere, Ionosphere, Mesosphere, Energetics, and Dynamics (TIMED) satellites. In addition, the XPS responsivities have been updated for the latest XPS data processing version. The new XPS results are consistent with daily variations from the previous simple conversion technique used for XPS and are also consistent with spectral measurements made at wavelengths longer than 27 nm. Most importantly, the XPS flare variations are reduced by factors of 2 – 4 at wavelengths shorter than 14 nm and are more consistent, for the first time, with atmospheric response to solar flares. Along with the details of the new XPS algorithm, several comparisons to dayglow and photoelectron measurements and model results are also presented to help verify the accuracy of the new XUV irradiance spectra.     

内蒙古敖汉旗早三叠世正长花岗岩锆石U-Pb年代学、地球化学特征

正近些年研究显示华北地台北缘存在一条近东西向展布的早三叠世后造山的花岗岩带,在吉林东部,内蒙古中部及西部地区具有发现,但在赤峰敖汉旗地区还未见报道。本次工作在敖汉旗区域地质调查过程中,从原来侏罗纪岩体中重新厘定出一套正长花岗岩,本文对其年代学及地球化学进行介绍,以探讨华北地台北缘中段-东段过渡带的古亚洲洋闭合时限。     

小尺度断层定量预测及对注水开发的影响——以渤中34油田为例

大尺度断层往往控制了沉积盆地的形成和油气成藏,而小尺度断层则影响着注水开发效果和剩余油分布.大尺度断层可以通过二维或三维地震资料识别,而小尺度断层的识别则特别困难.本文提出了一种基于断层分形生长模式和三维地质力学模拟相结合来确定小尺度断层的数量、发育位置和方位的方法,并根据油田开发动态资料来确定小尺度断层对注水开发和剩余油分布的影响.将地震上识别的大尺度断层引入到三维数值力学模型中,模拟大尺度断层形成时期断裂带附近的应力扰动作用,然后结合破裂准则来建立最易发生破裂的方位和最大库伦剪切应力网格,以这两套网格和断层尺度的幂律分布确定的小尺度断层数量为约束条件来确定随机模型,对小尺度断层的密度、产状和发育位置进行定量预测.研究表明:利用分形理论和三维地质力学模拟可以对大尺度断层伴生小尺度断层进行有效预测;小尺度断层对注水开发效果和剩余油分布的影响取决于小尺度断层的规模(断距)以及小尺度断层方位和注采方向的关系.     

A study on the effects of soil moisture,air humidity,and air temperature on wind speed threshold for dust emissions in the Taklimakan Desert

Natural Hazards - Soil and the atmospheric conditions are important factors that affect wind speed threshold of surface dust emissions. Based on the observed data of surface dust emissions in the...     

膨胀式尾管悬挂器的研究

为了解决常规尾管悬挂器过流面积小、密封性能差的缺点,研究了膨胀式尾管悬挂器。主要对膨胀式尾管悬挂器的工作原理,结构原理,关键技术包括替浆技术、固井技术、膨胀悬挂技术、丢手技术进行了研究;解决了膨胀管悬挂的一系列技术难题;对膨胀管受力进行了有限元分析,并将结果与室内试验进行了对比,两者结果基本一致。通过野外试验进一步证明了膨胀式尾管悬挂器能够提供足够的悬挂力,满足悬挂要求。