Time-Dependent Tsunami Source Following the 2018 Anak Krakatau Volcano Eruption Inferred from Nearby Tsunami Recordings

The eruption of the Anak Krakatau volcano,Indonesia,on 22 December 2018 induced a destructive tsunami(the Sunda Strait tsunami),which was recorded by four nearby tidal gauges.In this study we invert the tsunami records and recover the tsunami generation process.Two tsunami sources are obtained,a static one of instant initial water elevation and a time-dependent one accounting for the continuous evolution of water height.The time-dependent results are found to reproduce the tsunami recordings more satisfactorily.The complete tsunami generation process lasts approximately 9 min and features a two-stage evolution with similar intensity.Each stage lasts about 3.5 min and elevates a water volume of about 0.13 km3.The time,duration and volume of the volcano eruption in general agree with seismic records and geomorphological interpretations.We also test different sizes of the potential source region,which lead to different maximum wave height in the source area,but all the results of time-dependent tsunami sources show the robust feature of two stages of wave generation.Our results imply a time-dependent and complex process of tsunami generation during the volcano eruption.     

中国居民食物消费碳排放时空演变趋势及其驱动机制分析

食物生产是影响温室效应气体排放的重要方面,由于食物类型不同其碳排强度存在较大的差异,因此当前中国居民食物消费快速演替必然会对生态碳环境产生重要影响。论文利用洛伦兹曲线和基尼系数,研究1997—2016年中国城乡居民食物消费在生产过程中碳排放时空演变及其主要驱动因子。主要结论如下：① 在数量上,中国居民食物消费碳排放总量和人均量整体都呈现逐渐的增长刚性,但仍属于低碳消费模式;② 在结构上,各类型食物碳排放演变呈现显著的分异态势,整体上动物性食物碳排放增长速度快于植物性食物碳排放减少速度;③ 在城乡差异上,城镇和乡村居民食物消费碳排放在数量、结构和趋势上表现出显著的城乡二元属性,但近年城乡差异表现出减缓趋势;④ 在空间上,各地食物消费碳排放呈现较显著的民族性、地域性、集聚性和中心“塌陷”的特征,碳排放密度高值主要分布在直辖市和沿海经济相对发达地区;⑤ 在驱动力上,结构演替是全国居民食物消费碳排放总量整体变化的主要驱动因素,而人口数量是各地地域空间差异分布的主要驱动因子。     

Base cation concentrations in forest litter and topsoil have different responses to climate and tree species along elevational gradients

The forest litter is an essential reservoir of nutrients in forests, supplying a large part of absorbable base cations(BC) to topsoil, and facilitating plant growth within litter-soil system. To characterize elevational patterns of base cation concentrations in the forest litter and topsoil, and explore the effects of climate and tree species, we measured microclimate and collected the forest litter and topsoil(0-10 cm) samples across an elevational range of more than 2000 m(1243 ～ 3316 m a.s.l.),and analyzed the concentrations of BC in laboratory. Results showed that: 1) litter Ca concentration displayed a hump-shaped pattern along the elevational gradients, but litter K and Mg showed saddle-shaped patterns. Soil Ca concentration increased with elevation, while soil K and Mg had no significant changes. 2) Ca concentration in the forest litter under aspen(Populus davidiana) was significantly higher than that in all other species, but in topsoil, Ca concentration was higher under coniferous larch and fir(Larix chinensis and Abies fargesii). Litter K and Mg concentrations was higher under coniferous larch and fir, whereas there were nosignificant differences among tree species in the concentrations of K and Mg in topsoil. 3) Climatic factors including mean annual temperature(MAT), growing season precipitation(GSP) and non-growing season precipitation(NGSP) determined BC concentrations in the forest litter and topsoil. Soil C/N and C/P also influenced BC cycling between litter and soil. Observation along elevations within different tree species implies that above-ground tree species can redistribute below-ground cations, and this process is profoundly impacted by climate. Litter and soil Ca, K and Mg with different responses to environmental variables depend on their soluble capacity and mobile ability.     

Rift structures and its related unconformities on and adjacent the Dongsha Rise: insights into the nature of the high-velocity layer in the northern South China Sea

Marine Geophysical Research - It is curious that the typical feature of high-velocity layer (HVL) underneath the crust for the magma-rich margin was found in the magma-poor margin of the South...     

Selective feeding of bay scallop Argopecten irradians on phytoplankton community revealed by HPLC analysis of phytopigments in Bohai Sea,China

Understanding the feeding selectivity on phytoplankton by shellfish is currently a big challenge.In order to investigate the feeding behavior of bay scallop(Argopecten irradians)on phytoplankton,we compared its compositions of phytopigments in digestive glands with those in the surrounding seawater,and conducted five consecutive investigations between July and November 2016 in a bay scallop culture area along coast of Qinghuangdao City,northwest of the Bohai Sea,China.Phytopigments in four-size fractionated phytoplankton of seawater(micro-(20-200 μm);nano(L)-[10-20 μm];nano(S)-[2.7-10 μm],and pico-[2.7 μm])and digestive glands of A.irradians were examined to investigate the selective feeding of A.irradians.Results show that fucoxanthin and peridinin constituted the major part of taxonomically diagnostic carotenoids(TDCs)in the micro-and nano(L)-phytoplankton in seawater.Compared with total phytoplankton biomass of seawater(TPB,sum of the four sizes),a substantial decrease of fucoxanthin proportion to total DCs in digestive glands was observed while that of peridinin,19'-butanoyloxyfucoxanthin,alloxanthin and 19'-hexanoyloxy-fucoxanthin showed an obvious increase when those pigments were mainly confined to micro-sized phytoplankton(20-200 μm).However,zeaxanthin and prasinoxanthin were mainly confined to nano(s)-and pico-phytoplankton,of which the proportions in digestive glands were usually lower in TPB.The contribution of lutein to total DCs in digestive glands(with an average of 7.23%)increased compared with TPB of seawater(with an average of 0.63%)during all five sampling times.     

三门峡断陷盆地及邻区深部结构及成因——来自深地震反射与大地电磁测深的证据

近年来,围绕三门峡断陷盆地中的油气、地热资源做了大量的工作,成因机制研究较少,严重制约了矿产资源的勘探开发。本文在前人研究工作基础上,结合野外地质调查并利用高精度深反射地震剖面、大地电磁（MT）、重磁等地球物理探测技术,对三门峡盆地进行综合研究。发现三门峡盆地主要由东、西2个负花状构造构成,西花状构造体大于东花状构造体;盆地东部边缘以观音堂隆起与洛阳凹陷相邻,观音堂隆起发育有壳内透镜状低速体,其东、西两侧均发育有规模较大的隐伏逆断层。研究区内莫霍面为大约5 km厚度滑脱层,在深反射地震剖面上表现为蚯蚓状反射特征,指示滑脱层为西向运动。莫霍面滑脱层上部与下部新发现多条弧形断层。地质与地球物理资料综合研究表明,莫霍面滑脱层的解耦作用是三门峡断陷盆地花状构造形成的主因;在不同时空构造力系作用下,形成研究区新生代全地壳旋转花状构造盆地。     

上海青浦CINRAD/SAD雷达和南汇WSR-88D雷达数据对比分析

上海青浦CINRAD/SAD雷达和南汇WSR 88D雷达型号不同,并且采用不同的双偏振技术升级方案,实际业务运行中2部雷达存在一定的数据偏差。为了对雷达的探测性能进行定量评估,在共同探测区域遴选2022年7—9月及2023年6月共30个过程3933个时次数据,以稳定性降水与对流性降水分类并按强度分级进行对比,评估了反射率因子ZH,差分反射率ZDR,相关系数CC和差分传播相移ΦDP的水平分布特征及随方位变化趋势,雷达灵敏度随仰角变化趋势以及ZH和ZDR偏差的定量统计。结果表明：2部雷达ZH的观测结果接近,青浦CINRAD/SAD雷达的ZH,CC和ΦDP受地物及避雷针影响较大,随方位变化不稳定,青浦CINRAD/SAD雷达在低层的非气象回波滤除效果较南汇WSR 88D雷达差。2部雷达ZH和ZDR的偏差在ZH大于40 dBz的区域较大,ZH平均偏差为0.9 dB,ZDR为-0.14 dB。本文基于台风、冰雹、短时强降水和梅雨降水数据,定量化评估了上海2部S波段双偏振天气雷达数据之间的差异,为后续算法改进以及数据订正提供参考。     

Detection of the end point temperature of thermal denatured protein in fish and chicken meat through SDS-PAGE electrophoresis

Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was applied in the detection of the end point temperature (EPT) of thermal denatured protein in fish and meat in this study. It was also used in studying the thermal denatured temperature range of proteins in salmon and chicken meat. The results show that the temperature ranges of denatured proteins were from 65 ℃ to 75 ℃ , and these temperature ranges were influenced by the processing methods. Through SDS-PAGE, the features of repeated he...     

基于海量海底地形数据的存储和可视化研究

针对海量海底地形数据的存储和可视化的技术难点,提出一种基于细节层次模型的处理技术。使用这种技术,可以对海底地形模型进行有效的管理。通过实验证明,使用细节层次模型技术可以对海底地形模型进行高效绘制。