艾比湖盐尘对周边地区土壤盐分及景观变化的影响

通过对准噶尔盆地西部艾比湖地区盐尘的扩散和堆积进行观测和取样分析,鉴别出粉尘中可溶盐的化学成分、pH和盐尘堆积强度,分析研究了盐尘的形成、分布特征和灾害强度以及盐尘暴与温度、降水、风等气候因子之间的相关关系.结果表明:近50 a来艾比湖的沉积环境总体是比较稳定的,但由于气候波动与人类活动引起艾比湖水位、水域面积曾发生较明显的变化,并产生了盐尘暴的发生、湖泊和土壤盐度以及湖周景观的变化.根据艾比湖周边盐漠区盐尘的时空分布规律、活动特点和危害强度分析,盐尘对准噶尔盆地西部土壤盐分及景观变化的影响强度范围和影响程度划分为3级区.     

基于GRACE-FO的微波与激光星间测距数据的重力场模型对比分析

为分析GRACE-FO微波测距系统KBR及激光干涉测距系统LRI对时变重力场结果的影响,以动力学方法为基础,分别采用KBR数据和LRI数据反演2019-01~2021-08的90阶无约束时变重力场模型APM_KBR和APM_LRI,并进行对比分析。 从重力场模型阶方差和等效水柱高的空间分布来看,在两类测距数据完整且质量较好的前提下,两者精度处于同一水平,而当发生较多月卫星机动或其他卫星事件时会使LRI数据缺失,从而导致APM_LRI模型在该月得到的等效水柱高时间序列信噪比略低。由后验残差结果可知,APM_LRI后验残差RMS比APM_KBR减少约50%,且在高频处(大于等于60 CPR)LRI的后验残差显著低于KBR。总体来说,在现有条件下,由于背景场模型等其他因素影响,两类测距数据反演重力场的阶方差和等效水柱高结果基本一致,但后验残差上LRI测距具有更低的噪声。因此,未来可直接使用LRI测距数据探测、分析较弱的地球物理信号。     

Phospholipid Compositions in Portunus trituberculatus Larvae at Different Developmental Stages

Phospholipids are used to improve the growth and survival of Portunus trituberculatus,a widely cultured crab species in China.However,only total phospholipids or several classes are applied in crab diets.In this study,we employed a targeted lipidomic method to investigate the comprehensive phospholipid composition in P.trituberculatus larvae and reveal the changing phospholipid profile over the larval development.Results showed that P.trituberculatus larvae contain 112 phospholipid species belonging to 10 phospholipid classes,in which phosphatidylcholine(PC)and phosphatidylethanolamine(PE)species are the most abundant,and PC,PE,phosphatidic acid,and phosphatidylserine(PS)are with high concentrations.The levels of all phospholipids significantly changed with larval development,which was highlighted by the downward parabolic changes in PE,phosphatidylglycerol,phosphatidylino-sitol,PS,lysophosphatidic acid,and sphingomyelin levels.In addition,nearly all phospholipid species were depleted at the M stage,which probably contributed to the mass mortality of crab larvae.These findings on the composition and alterations of phospholipids in P.trituberculatus larvae provide novel perspectives for the targeted supplementation of phospholipids in crab diets.Our work also highlights the use of targeted UHPLC-MS lipidomics in understanding the changes of phospholipids during crab development.     

Effect of Long-Term Low-Salinity Culture on the Survival,Growth, and Nutrient Composition of Mud Crab Scylla paramamosain

This study investigated the effects of long-term low-salinity on the growth performance,proximate composition,amino acid and fatty acid profiles of Scylla paramamosain.The salinity of the low-salinity-culture group(LC)and maintained-salinity-cul-ture group(MC)were set at 5 and 25 respectively.After rearing for 30 d,the survival rate(SR)of the LC group was significantly lower,whereas the average daily molting frequency(ADMF)was significantly higher than those in MC group(P<0.05).There were no significant difference for weight gain rate(WGR)and specific growth rate(SGR)between the two groups.The moisture content of the LC group was slightly higher than the MC group without significant difference.The contents of ash,crude lipid and crude pro-tein in the LC group were lower than those in the MC group,but no significant differences were found except for ash content.A total of 17 free amino acids and 23 fatty acids were identified from the muscle of S.paramamosain.The total amino acids(TAA),essen-tial amino acids(EAA)and essential amino acid index(EAAI)had no significant difference between the two groups.The crabs from LC group had a significantly higher HUFA,including EPA,DHA,ARA.The percentage of n-3 PUFA and the ratio of n-3/n-6 PUFA were significantly higher in the LC group.These results indicated that S.paramamosain rearing at low salinity had significantly de-creased SR;however,the low-salinity environment significantly promoted the accumulation of unsaturated fatty acids(UFAs),espe-cially the n-3 PUFA,which might be related to the osmoregulation mechanism.     

The IAMAS-CNC Early Career Scientists Nobel Prize Online Interpretation Workshop

1.Overview The 2021 Nobel Prize for Physics was awarded to three scientists for their contribution to the physical understanding of complex systems(The Nobel Committee for Physics,2021).Two of the laureates,Dr.Syukuro MANABE and Dr.Klaus HASSELMANN,are climate scientists.This is the first time a climate scientist has won a Nobel Prize for physics and is thus a great encouragement to the entire climate science community,especially young scientists.Because the two winners'groundbreaking contributions that led to their award were achieved decades ago,young people may not be very familiar with these works.Therefore,to help young scientists better understand the scientific merit of the fundamental works and to inspire them in their future research careers,on 20 October 2021,the young scientist working group of The China National Committee of the International Association of Meteorology and Atmospheric Sciences(IAMAS-CNC)organized an online Nobel Prize interpretation workshop.Over 400 participants attended the online workshop,and more than 120000 parti-cipants watched the replay.     

考虑流固耦合效应的单桩式海上风电机组结构响应模拟

针对海上风电整机系统,建立了一体化流固耦合分析方法。在模拟过程中,采用浸入边界法解决风机叶片旋转引起的静动干涉问题,利用改进的守恒式 level set（简称 ICLS）方法捕捉海浪自由面,并使用交错迭代法求解流固耦合方程。通过构建 “风机—塔架—基础”一体化流固耦合数值模拟方法,能够在一次仿真计算中实现海上风电整机系统的全过程数值模拟,准确求解多荷载耦合作用下“风机—塔架—基础”的整体结构动力响应。以某单桩式海上风电工程为例,验证了本方法能够实现对海上风电整体系统的一体化分析。     

略图调制系统的设计与实现

介绍了应用Visual C 6.0开发工具开发的略图调制系统,内容主要包括：开发背景、系统总体构成、主要功能和应用实例,并对一些技术要点作了原理性阐述,最后简单展望了进一步的工作。     

油气勘探中的碳酸盐岩古岩溶研究方法综述

检索了国内外相关文献,重新阐述了古岩溶的概念,同时介绍了岩溶研究进展情况。在此基础上,对国内外学者关于古岩溶研究的方法和技术手段进行总结,分析了几种主要方法的优点和不足之处,并对今后岩溶研究思路和方法提出建议。      

基于GRACE的空间约束方法监测华北平原地下水储量变化

华北平原作为我国重要的工农业基地和政治经济中心,面临着严重的水资源危机.因此,开展对华北平原地下水储量变化的监测工作具有重要现实意义与科学价值.本文基于GRACE重力卫星的空间约束方法,研究了华北平原地下水储量变化的时空分布规律,并与地面水井实测与地下水模型结果进行了综合比较和分析.结果表明:2002-2014年,华北平原地下水存在明显的长期亏损,GRACE估计的亏损速率为-7.4±0.9 km~3·a~(-1),而地面水井资料估计的浅层地下水亏损速率为-1.2 km~3·a~1,对比两者之间的差异可以发现,华北平原的地下水亏损以深层地下水为主.2002-2008年,GRACE估计的华北平原地下水亏损速率为-5.3±2.2 km~3·a~(-1),这与华北平原两个地下水模型得到的平均亏损速率-5.4 km~3·a~(-1)十分吻合.通过华北平原区域地下水模型的独立验证,说明GRACE可以有效评估华北平原的地下水储量变化趋势.除了长期亏损的趋势项之外,华北平原地下水还存在明显的年际变化特征,并与该地区年降雨量变化特征一致.在降雨偏少的2002年、2005-2009年和2014年,华北平原地下水储量显著减少.在空间分布上,GRACE结果表明,华北平原的地下水储量减少主要发生在山前平原和中部平原区,这也与水井实测资料和区域地下水模型结果较为吻合.与GRACE和区域地下水模型相比,目前的全球水文模型仍无法准确估计华北平原地下水变化的空间分布和亏损速率.上述研究表明,GRACE提供了评估华北平原地下水储量变化的重要监测手段.     

基于OLCI数据的洱海叶绿素a浓度估算

海陆颜色仪(OLCI)是搭载在Sentinel-3上的新型水色遥感传感器,其对于内陆清洁水体水质遥感监测的适用性有待验证.本研究以评价水体富营养化程度的重要参数叶绿素a(Chl.a)浓度为指标,以高原湖泊洱海为研究区,基于2017年4月19日共20个星地同步实验数据,建立了3种可应用于OLCI数据的Chl.a浓度遥感估算模型(波段比值模型、三波段模型以及FLH模型),并估算了当日洱海Chl.a浓度的空间分布.结果表明:(1)选用波段Oa8(665 nm)、Oa11(708.75 nm)和Oa12(753.75 nm)构建的三波段模型最适用于洱海水域的Chl.a浓度估算,其平均绝对误差百分比为12.37%,低于波段比值模型的16.04%和FLH模型的13.50%;(2)对OLCI使用的大气校正方法中,基于去瑞利散射的暗像元法对估算模型的适用性要优于6S、FLAASH以及QUAC方法;(3)洱海OLCI影像中近岸水体受邻近效应影响严重,近红外波段Oa12(753.75 nm)受陆地邻近效应影响的距离为1~2个像元,而Oa8(665 nm)、Oa10(681.25 nm)和Oa11(708.75 nm)波段为1个像元;(4)2017年4月19日全湖Chl.a浓度均值为12.15±5.72μg/L,洱海中部水域Chl.a浓度最低(9.00~12.00μg/L),北部水域浓度最高(12.00~22.76μg/L),南部水域浓度稍高(12.00~14.00μg/L),阳南溪与波罗江入湖口受降雨径流的影响出现"羽流现象",导致Chl.a浓度偏低,约为8.33μg/L.