Correlation of climatic events between East Asia and Norwegian Sea during last deglaciation

Using a high resolution¹⁴C chronology, β¹³C values and organic carbon content, from loess/paleosol and peat profiles in China, we can demonstrate century scale warm-cold East Asian monsoon paleoclimatic fluctuation events and significant precipitation variability within the last deglaciation. The major climatic events recognized are the Bolling (1 300-12 500 a B.P.), Older Dryas (12 500-11 750 a B. P.), Allerod (11 750-11 200 aB.P.) and Younger Dryas (11 200-10 000 aB.P.). The stratigraphic structure of the last deglaciation sediments is characterized by frequent changes in sedimentation phases reflecting climatic instability. These high frequency, rapid climatic events can correlate with fluctuations recorded by sea surface temperatures in the Norwegian Sea. This indicates a pale-oclimate teleconnection between polar, high latitude areas and East Asian monsoon areas through westerlies and the related atmospheric pressure system. Project supported by the National Natural Science Foundation of China, the Foundation of Chinese Academy of Sciences and the National Science Foundation of U.S.A.     

The paleosol complex S5 in the China Loess Plateau — A record of climatic optimum during the last 1.2 Ma

Having investigated the loess-paleosol sequence in various loess deposition basins in the China Loess Plateau, authors have found that the paleosol complex S₅ is of special significance in terms of Pleistocene paleoclimate. Paleopedological, micromorphological, palynological and paleomagnetic evidences indicate that this paleosol complex formed in the interval of 460,000 to at least 560,000 years BP, which was a climatic optimum.     

新沂台地电阻率整点值的远大震前驱波变化

介绍江苏新沂台地电阻率整点值观测资料中的一种新变化——远大震前驱波，并简单分析了产生这种变化的机理。这一变化对预测远大震具有前兆意义，值得进一步深入研究。     

芦潮港车客渡码头水域近期强势淤涨原因辨析

叙述了１９９３年前的芦潮港车客渡码头水域自然水深条件和１９９３年后强烈淤涨的态势,从诸事件的时间之窗及水下滩坡适应性调整、长丁坝促淤效应等方面讨论了该水域强势淤涨的原因,提供了一个海岸工程产生淤积响应的典型实例。海岸带（尤其在沉积环境响应敏感的区域）开发必须注重社会经济效益与环境效益的统一。     

Distribution of Rb and Sr in the Luochuan loess- paleosol sequence of China during the last 800 ka

The concentrations of Rb and Sr, and magnetic susceptibility in loess and paleosol samples from the Luochum profile have been measured. The loess units deposited in different geological periods display a very similar pattern of Rb and Sr distribution while paleosol units exhibit a dramatic increase in the Rb/Sr ratio, ranging from 20% to 120% in increase amplitude. Owing to different geochemical behavior of the two elements, Rb appears to be immobile while Sr appears to be mobile in the processes of weathering and pedogenesis. So variations of the Rb/Sr ratio in the loess-paleosol sequences could reflect intensities of weathering and pedogenesis, thus recording the relative wind strength of the East Asian summer monsoon circulation. This could be supported by the high degree of cornlation between the Rb/Sr ratio and the magnetic susceptibility. A continuous record of the Rb/Sr ratio in the Luochuan profile over the last 800 ka bears a striking resemblance to the δ¹⁸ O curve of the deep sea sediments and is in accordance with the SPECMAP chronology. Such similarity between the terrestrial and the deep sea records suggests that variability in global ice volume is a primary dynamic factor controlling long-term changes of the East Asian summer monsoon intensity. Project supported by the National Natural Science Foundation of China (Grant No. 49725307).     

Eolian evidence from the Chinese Loess Plateau: the onset of the Late Cenozoic Great Glaciation in the Northern Hemisphere and Qinghai-Xizang Plateau uplift forcing

On the basis of a newly-constructed record of magnetic susceptibility (SUS) and the depositional rate change of eolian loess-red clay sequences in the last 7.2 Ma BP from the hea Plateau, together with a cornperison of a record of °¹⁸O values from the equatorial East Pacific Ocean and eolian Quartz flux variations fmm the North Pacific Ocean, the evolutiomuy process of the Late Cenozoic Great Glaciation in the Northern Hemisphere can be divided into three stages: the arrival stage around 7.2–3.4 Ma BP, the initial stage at about 3.4—2.6 Ma BP, and the Great Ice Age since 2.6 Ma BP. The evolution of the East Asian monsoon is characterized by paid winter and summer monsoons, and it is basically composed of the initial stage of weak winter and summer monsoons, the transitional stage of simultaneous increase in intensity of winter and summer monsoons, and the prevailing stage of strong winter and week summer monsoons, or weak winter and strong summer monsoons. The Late Cenowic global tectonic uplift, paaicdarly the Qinghai-Xizang Plateau uplift and the associated CO₂ concentration variation, controls the dng processes of the onset of Great Glaciation and the long-term changes of East Asian monsoom climate in the Northern Hemisphere to a large extent. The accelerating uplift of the Qinghai-Xizang Plateau between 3.4 and 2.6 Ma BP provided an important driving force to global climiatic change. Project supported by the foundation of Chinese Academy of Sciences (Grant No. KZ951-A1-402), the State Science and Technology Committee (Grant No. 95-pre-40)and the Chinese Nature Science Foundation (Grant No. 49672140)     

Differential physiological responses of the coastal cyanobacterium Synechococcus sp. PCC7002 to elevated pCO_2 at lag,exponential,and stationary growth phases

We studied the effects of expected end-of-the-century p CO_2(1000 ppm)on the photosynthetic performance of a coastal marine cyanobacterium Synechococcus sp.PCC7002 during the lag,exponential,and stationary growth phases.Elevated p CO_2significantly stimulated growth,and enhanced the maximum cell density during the stationary phase.Under ambient p CO_2conditions,the lag phase lasted for 6 days,while elevated p CO_2shortened the lag phase to two days and extended the exponential phase by four days.The elevated p CO_2increased photosynthesis levels during the lag and exponential phases,but reduced them during the stationary phase.Moreover,the elevated p CO_2reduced the saturated growth light(Ik)and increased the light utilization efficiency(α)during the exponential and stationary phases,and elevated the phycobilisome:chlorophyll a(Chl a)ratio.Furthermore,the elevated p CO_2reduced the particulate organic carbon(POC):Chl a and particulate organic nitrogen(PON):Chl a ratios during the lag and stationary phases,but enhanced them during the exponential phase.Overall,Synechococcus showed differential physiological responses to elevated p CO_2during different growth phases,thus providing insight into previous studies that focused on only the exponential phase,which may have biased the results relative to the effects of elevated p CO_2in ecology or aquaculture.     

地震短期综合预测的一种思路

本文介绍了一种地震短期综合预测思路,即以虚报率较低的短期异常作为“引信”,在出现1个或数个“引信”异常后,再依据其它异常综合判定发震地点和震级,其优点是据此做出的综合预测意见的成功率较高。本文以2012年江苏高邮-宝应4.9级地震和2016年江苏射阳4.4级地震的震前实时跟踪过程为例,详细介绍了该思路的应用,该综合预测思路对指导今后震情跟踪工作有实际意义。     

基于地磁垂直分量反相位现象的地下畸变电流正演计算

基于毕奥萨伐尔定理正演模拟不同深度和强度的电流感应磁场空间分布及其随时间的变化,并根据甘东南地区大地电磁测深反演的电性结构成果,定量计算2013年岷县漳县MS6.6地震前的畸变电流强度,发现其感应磁场在Z分量上的叠加效果与实测数据差异较小。该模型在一定程度上解释了此次地震前出现的大范围地磁低点位移现象,可应用于出现低点位移现象且电性结构比较清楚的地区。     

几种海藻粗多糖的理化性质及结构特征分析

主要采用傅里叶红外光谱(fourier transform infrared spectroscopy, FTIR)、气相色谱(gas chromatography, GC)和凝胶渗透色谱(gel permeation chromatography, GPC)方法对5种海藻粗多糖的单糖组成、官能团、分子量进行了初步分析。结果显示5种海藻粗多糖均含有木糖和岩藻糖, 其中南方团扇藻多糖含有较为丰富的山梨糖, 属于大分子量均一性多糖, 而孔石莼多糖分子量分布较宽, 均一性较差。红外光谱分析结果表明, 5种粗多糖均为酸性多糖, 棒叶蕨藻、琼枝麒麟菜和匍枝马尾藻多糖具有明显的硫酸基团吸收峰, 琼枝麒麟菜多糖存在呋喃糖和吡喃糖, 并且吡喃糖苷键可能存在β和α两种类型。明胶氯化钡实验结果指出南方团扇藻多糖的硫酸基团含量为38.43%(±2.38%), 明显高于其他几种海藻多糖, 而棒叶蕨藻多糖的硫酸基团含量最低, 仅为8.92%(±1.04%)。