Evaluation of the integrated multi-satellite retrievals for global precipitation measurement over the Tibetan Plateau

The availability of high-resolution satellite precipitation measurement products provides an opportunity to monitor precipitation over large and complex terrain and thus accurately evaluate the climatic, hydrological and ecological conditions in those regions. The Global Precipitation Measurement(GPM) mission is an important new program designed for global satellite precipitation estimation, but little information has been reported on the applicability of the GPM’s products for the Tibetan Plateau(TP). The object of this study is to evaluate the accuracy of the Integrated Multi-Satellite Retrievals for GPM(IMERG) Final Run product under different terrain and climate conditions over the TP by using 78 ground gauges from April 2014 to December 2017. The results showed the following:(1) the 3-year average daily precipitation estimation in the IMERG agrees well with the rain gauge observations(R~2=0.58, P0.01), and IMERG also has a considerable ability to detect precipitation, as indicated by a high probability of detection(78%-98%) and critical success index(65%-85%);(2) IMERG performed better at altitudes from 3000 m to 4000 m with a small relative bias(RB) of 6.4%. Precipitation change was not significantly affected by local relief;(3) the climate system of the TP was divided into four climate groups with a total of 12 climate types based on the K?ppen climate classification system, and IMERG performed well in all climate types with the exception of the arid-desert-cold climate(Bwk) type. Furthermore, although IMERG showed the potential to detect snowfall, it still exhibits deficiencies in identifying light and moderate snow. These results indicate that IMERG could provide more accurate precipitation data if its retrieval algorithm was improved for complex terrain and arid regions.     

深反射地震成像揭示的班公湖 怒江缝合带中段Moho断阶及其大地构造意义

揭示班公湖- 怒江(班怒)缝合带Moho(莫霍面)结构对于认识中特提斯洋壳俯冲和南羌塘坳陷成因具有重要地球动力学意义。基于横跨班怒缝合带的深反射地震数据(88°30′E),本文采用了中长波长静校正、噪声压制、优化叠加和叠前深度偏移(PSDM)等地震处理技术,获得了深度域地震反射偏移剖面、层速度场和高分辨率Moho结构。由深度域剖面显示,班怒缝合带Moho位于地表以下65～80 km,呈不连续北向抬升趋势,指示在拉萨地块与南羌塘地块之间存在岩石圈上地幔断阶,最大阶步可达15 km。综合分析缝合带两侧的Moho形态认为,这些断阶受南侧拉萨地体的岩石圈上地幔以19. 5°北倾俯冲与北侧南羌塘地块的上地壳抬升驱动,可能与深部存在局部熔融相关。班怒缝合带下的Moho结构表明,随着晚侏罗世—早白垩世中特提斯洋闭合,南羌塘地体由边缘海沉积向前陆盆地转换,形成南羌塘坳陷。     

Chemical constituents of marine medicinal mangrove plant Sonneratia caseolaris

Twenty-four compounds including eight steroids (1-8), nine triterpenoids (9-16, 24), three flavonoids (20-22), and four benzenecarboxylic derivatives (17-19, 23) were isolated and identified from stems and twigs of medicinal mangrove plant Sonneratia caseolaris. The structures of the isolated compounds were determined by extensive analysis of their spectroscopic data. Among these metabolites, compounds 1, 4-20 and 22-24 were isolated and identified for the f'urst time from S. caseolaris. In the in vitro cytotoxic assay against SMMC-7721 human hepatoma cells, compound 21 (3',4',5,7-tetrahydroxyflavone)exhibited significant activity with IC50 2.8 μg/mL, while oleanolic acid (14), 3,3'-di-O-methyl ether ellagic acid (18), and 3,3',4-O-tri-O-methyl ether ellagic acid (19) showed weak activity. None of these compounds displayed significant antibacterial activites.     

岩石圈热-流变结构的研究方法和发展动向

岩石圈并不是经典板块理论认为的整体的刚性圈层,而是在不同大地构造位置及不同深度具有不同的流变性质。在介绍岩石圈热一流变结构的计算方法以及不同大地构造位置的岩石圈流变学分层特征的基础上,阐述了岩石圈热一流变结构所反映的地球动力学信息,并对我国在该领域的研究进展做出总结,认为未来需要加强深部结构和地热学的研究,尤其是我国海域此方面的研究。     

西施舌外套膜蛋白质组双向电泳体系的构建

建立了西施舌(Coelomactra antiquata)外套膜蛋白质组的双向凝胶电泳体系,比较分析了不同pH梯度胶条、水化条件的优化及不同染色方法对双向电泳结果的影响.结果表明:用pH 4～7的非线性胶条,水化时加上除盐步骤,采用硝酸银染色,即可获得高分辨率、高重现性的双向电泳图谱,为进一步研究西施舌外套膜蛋白质的组成奠定了基础.     

Characteristics of dissolved organic matter in lakes with different eutrophic levels in southeastern Hubei Province,China

Dissolved organic matter (DOM) plays a crucial role in both the carbon cycle and geochemical cycles of other nutrient elements, which is of importance to the ma...     

三个牙鲆育种群体亲本效应及遗传参数估计

针对牙鲆(Paralichthys olivaceus)养殖品种生长速度变慢、抗病力降低这一问题。近年来构建了牙鲆抗病群体(RS)、日本群体(JS)和黄海群体(YS)3个育种群体,开展牙鲆选择育种,建立了63个家系,收集了所有家系5 328尾鱼苗的体长和体重数据。借助线形混合模型(Linear mixedmodel)、"加性-显性"模型、约束极大似然法(REML)及最佳线性无偏预测(BLUP)分别估计亲本效应值、体重和体长遗传力和遗传相关、父母本效应和杂交效应。预测结果显示,其中父本130,141,146,170,218,229,303和308随机效应达到了极显著效应水平(P<0.01),父本112,122,141,190,212达到显著水平(P<0.05),所有母本体重随机效应达到了极显著水平(P<0.01);体长和体重两性状的加性、显性、表型和基因型相关分量都达到极显著水平(P<0.01),体长和体重的加性方差比率均大于显性方差比率,可见两性状的遗传效应主要取决于基因的加性效应。体长的总遗传效应率为31.20%,体重的总遗传效应率为33.58%,体长和体重的随机方差比率分别达到68.80%和66.41%,说明养殖环境等因素对牙鲆体长和体重的影响较大,同时说明在牙鲆选择育种中消除环境影响极为重要。体长和体重的狭义遗传率分别为0.199和0.256(P<0.01),广义遗传率分别为0.312和0.336(P<0.01),牙鲆在以上两性状上属于中等遗传力,通过选择育种可取得较大的遗传进展。对3个牙鲆育种群体杂交随机效应估计结果显示,抗病群体和黄海群体在体长和体重两性状上加性随机效应显著(P<0.05);抗病群体分别与日本群体、黄海群体杂交,其后代表现出显性随机效应达到0.10的水平(P<0.10),黄海群体自交、日本群体和黄海群体杂交随机效应不显著(P>0.05),因此在杂交组配中选择抗病群体与其他两个群体交配可取得较好的效果。     

凤爪沟边坡稳定性评价

主要研究了一个边坡在施加冷却塔荷载前后的稳定性问题。采用有限元法和摩尔-库仑屈服准则计算和分析了冷却塔荷载对边坡稳定性的影响,得到较理想的结果。结果表明,边坡的整体稳定性问题,主要是变形稳定性问题;玄武岩柱状节理的存在对边坡稳定性产生了不利的影响;冷却塔的修建对边坡稳定性是有影响的;边坡的变形破坏随时间的增长而增加;边坡的破坏形式以倾倒破坏为主。     

考虑裂尖塑性区影响的水力压裂缝高计算模型

储层可压性的准确评价是储层压裂设计和压后产能评估的重要前提。目前,采用岩石力学参数进行页岩可压裂性评价取得了较好的现场应用效果。因此,如何准确获取岩石力学参数成为至关重要的问题。通过建立一种基于物理信息约束的神经网络模型,该模型采用物理和数据双驱动,仅使用少量数据就能够实现岩石力学参数的准确预测。为验证模型性能的优异性,采用人工神经网络、随机森林和XGBoost模型与之进行对比。结果表明,物理信息约束的神经网络在少量数据下预测岩石力学参数的平均准确率高于95%,性能远优于其他模型。采用物理信息约束的神经网络预测得到弹性模量、泊松比、抗拉强度和断裂韧性4种岩石力学参数,基于岩石力学参数对储层可压性的影响,建立了基于脆性指数和力学参数的可压性评价方法。最后,以渤海湾盆地沧东凹陷K2段不同储层可压性为例进行验证。结果表明：研究区整体可压性较好,其中,纹层状混合质页岩可压裂指数高于0.7,可压性良好;纹层状长英质页岩、厚层状灰云质页岩和薄层灰云质页岩可压裂指数均处在0.4~0.7,可压性中等。评价结果与实际施工现场各储层日采油量进行对比,证实了可压性智能评价方法的可靠性,该方法可以推广至页岩储层可压性评价工作中。

     

川西坳陷中段新场地区天然气研究及气源对比

经过大量学者多年的研究总结,川西坳陷中段新场地区具备良好的生、储、盖等成藏组合。结合地质背景及碳同位素、轻烃的研究,认为新场地区天然气主要是Ⅲ型干酪根的煤型气,气藏主要分布在上三叠系的须二段和须四段,以及中侏罗系、上侏罗系地层中。