Devonian integrative stratigraphy and timescale of China

The Global Boundary Stratotype Sections and Points(GSSPs) for the bases of all seven international Devonian stages have been formally defined and ratified by IUGS till 1996, and nowadays, the main tasks for Devonian stratigraphers include further subdivision of these standard stages, strictly constrained absolute ages for the boundaries, and precise neritic-pelagic and marine-terrestrial correlations using multidisciplinary stratigraphy methods. Establishment of high-resolution Devonian integrative stratigraphy framework and timescale of China would play an important role in improving regional and international correlation, facilitating the recognition of important stratigraphic levels in different paleogeographic settings, and understanding the evolution pattern of biota, paleoclimate and paleoenvironment during this critical interval. Based on well-studied bio-and chronostratigraphy of Devonian in South China and adjacent areas, in combination with recent achievements in carbon isotope stratigraphy, event stratigraphy and radioactive isotope ages, this paper briefly summarize the research history and current status of Devonian chronostratigraphy of China, and for the first time introduce Devonian integrative stratigraphy framework of China.Up to date, few studies have been conducted on the astronomical cyclostratigraphy and high-resolution radioactive isotope dating in Devonian of China, which should be our main focuses in the near future.     

考虑支座滑移及挡块破坏的中小跨径梁桥地震易损性研究

从板式橡胶支座及混凝土挡块抗震设计角度,以一座典型的3跨预应力混凝土连续梁桥为例,结合概率地震需求分析及桥墩、支座等抗震关键构件极限破坏状态,建立不同支座及挡块分析模型的中小跨径梁桥地震易损性曲线,研究考虑支座滑移效应及挡块破坏的中小跨径梁桥的易损性特征。研究结果表明:不考虑橡胶支座的滑移效应及混凝土挡块破坏,桥墩地震破坏概率明显增大,且会低估支座破坏概率;桥梁系统易损性受支座破坏状态的影响显著,需设置合理的限位装置;在中小跨径梁桥地震易损性分析中,考虑支座的滑移效应及混凝土挡块的破坏十分必要。     

曲靖非相干散射雷达电离层F区日间电子温度变化特征初步分析

利用曲靖非相干散射雷达2017-2018年春夏季观测数据首次分析了电离层日间150~450km电子温度的地方时与高度变化特征及其与电子密度的相关性.发现hmF2及以上的电子温度在日出日落时具有两个峰值,在11∶00-16∶00LT之间变化较小,高度越高午后上升的时间越早;从150km开始迅速增加,在约220km达到最大值,然后开始降低,在约300~350km达到最小值,最后单调上升;200km以下电子温度与电子密度成正相关(主要由热传导控制),200~450km之间存在明显的反相关(光电离过程占主导),电子-离子温度差与电子密度对数之间存在近似线性关系,电子温度逐日变化与光电离因子的变化趋势相似,这种相关性在中午与午后更明显;以上结果与其他非相干散射雷达观测和电离层模型计算结果基本一致,但也存在一些差别,需要结合更多数据深入分析.     

Spatio-temporal differentiation of spring phenology in China driven by temperatures and photoperiod from 1979 to 2018

Large amounts of data accumulated in ecology and related environmental sciences arouses urgent need to explore useful patterns and information in it. Here we propose coclustering-based methods and a temperatures-photoperiod driven phenological model to explore spatio-temporal differentiation in long-term spring phenology in China. First, we created the first bloom date(FBD) dataset in China from 1979 to 2018 using the extended spring indices and China Meteorological Forcing Dataset. Then we analyzed the dataset using Bregman block average co-clustering algorithm with I-divergence(BBAC_I) and kmeans algorithm. Such analysis delineated the spatially-continuous phenoregions in China for the first time. Results showed three spatial patterns of FBD in China and their temporal dynamics for 40 years(1979–2018). More specifically, overall late spring onsets occur in 1979–1996, in which areas located in Jiangxi, northern Xinjiang and middle Inner Mongolia experienced constant changing spring onsets. Overall increasingly earlier spring onsets occur in 1997–2012, in which areas located in Fujian,Hunan and eastern Heilongjiang experienced the most variable spring onsets. Stable early spring onsets over China occur after 2012. Results also showed 15 temporal patterns of spring phenology over the study period and their spatial delineation in China.More specifically, most areas in China have the same FBD category for 40 years while northern Guizhou, Hunan and southern Hubei have the same category in 1979–1997 and then fluctuate between different categories. Finally, our results have certain directive significance on the design of existing observational sites in Chinese Phenological Network.     

Spatio-temporal distribution of Konosirus punctatus spawning and nursing ground in the South Yellow Sea

In recent years, Konosirus punctatus has accounted for a large portion in catch composition and become important economic species in the South Yellow Sea. However, the distribution of K. punctatus early life stages is still poorly understood. In this study, generalized additive models with Tweedie distribution were used to analyze the relationships between K. punctatus ichthyoplankton and environmental factors(longitude and latitude, sea surface temperature(SST), sea surface salinity(SSS) and depth), and predict distribution K. punctatus spawning ground and nursing ground, based on samplings collected in 6 months during 2014–2017. The results showed that K. punctatus' spawning ground were mainly distributed in central and north study area(from 33.0°N to 37.0°N).By comparison, the nursing ground shifted southward, which were approximately located along central and south coast of study area(from 31.7°N to 35.5°N). The optimal models identified that suitable SST, SSS and depth for eggs were 19–26°C, 25–30 and 9–23 m, respectively. The suitable SSS for larvae were 29–31. The K. punctatus spawning habit might have changed in the past decades, which was a response to increasing SST and fishing pressure. That needs to be proved in further study. The study provides references of conservation and exploitation for K. punctatus.     

海洋聚球藻对不同硝酸盐浓度的响应特征

近年来,由于陆源污染的加重以及近海环境治理的推进,中国近海海域营养盐浓度发生明显变化,导致浮游植物生物量及群落结构发生改变。作为一种广泛分布且丰度较高的微微型蓝藻,聚球藻在中国近海生态系统中发挥着重要的角色,但其对不同硝酸盐浓度的响应尚待研究。本文分别从渤海和黄海采集聚球藻富集样本,在不同硝酸盐浓度下进行半连续培养,通过测定生长曲线、色素含量、光合生理参数以及碳氮含量,研究聚球藻对硝酸盐浓度的响应特征。当硝酸盐浓度为0.1、1.0、10.0μmol·L^–1时,聚球藻培养体系可支持的生物量较小,光能转化效率较低;当硝酸盐浓度为100.0μmol·L^–1时,聚球藻细胞生长得到促进,其培养体系可支持的生物量约提高5倍,同时培养体系整体的光能转化效率达到最高,但单位细胞的捕光能力受到抑制,氮和磷的转化率提高。研究表明海洋聚球藻能够适应不同的硝酸盐浓度维持生长,在较高的硝酸盐浓度下,聚球藻生物量显著提高,但释放至胞外的碳氮未出现相应的当量增加。研究结果为营养盐胁迫条件下浮游生态系统的响应提供了原核微藻方面的实验依据。     

1971-2010年三江源地区干湿状况变化的空间特征

 依据1971-2010年地面观测气象数据,计算了三江源地区湿润指数。利用经验正交函数分解（EOF）和偏相关系数,对近40 a三江源地区干湿状况变化的时空特征及其影响因素进行了分析。结果表明:三江源地区干湿状况的变化在其北部与南部、东部与西部间存在明显反相位变化特征。北部和东部的部分区域分别在20世纪90年代和21世纪后表现出气候湿润化趋势,其余大部地区的持续干旱化趋势始于20世纪80年代初,其中南部与西部变干趋势显著,其湿润指数线性趋势率达到-8%/10 a。虽然三江源地区干湿状况主要决定于降水量和相对湿度的变化,但20世纪90年代中期后气温的显著上升,使得气温也成为关键的影响因子之一,即使在降水明显增加的背景下,也引起三江源主体区域湿润指数的明显下降。气候变暖情景下,北部和东部地区在近十几年暖湿化趋势明显,其余大部地区表现为不同程度的暖干化趋势。     

气候系统预测:基础创新和集成应用

随着全球变暖,极端天气气候事件增强,天气气候灾害造成的损失也愈发严重。当前气候预测的准确性远远不能满足社会需要,气候系统预测理论和方法面临着众多挑战性问题。为提档气候预测科学水平和准确率,由南京信息工程大学和中山大学承担的“气候系统预测研究中心”获得国家自然科学基金基础科学中心项目支持(2021年1月—2025年12月)。在该项目执行的前三年,项目团队开展了大量深入系统的研究,并取得了若干重要进展:1)揭示了气候系统的若干关键变化、驱动力和机制;2)剖析了海-陆-冰-气相互作用对我国重大极端气候事件的影响;3)在气候系统数值模式研发和预测系统集成方面取得重要进展;4)发展了延伸期-S2S-年代际的气候系统预测理论和方法。本文对这些进展作了扼要介绍,并针对气候与环境变化归因、古今气候环境研究融合、跨时空气候系统变异和极端气候、人工智能与气候科学、年代际预测和风险应对体系等关键科学问题做了展望。     

基于JAVA技术的江苏气象物资供应管理系统

为了提高气象物资供应的管理效率、管理质量以及保障能力研制了本系统。系统采用JAVA语言进行开发,采用B/S架构,以成熟可靠的开源软件Tomcat作为软件服务器并采用安全性较高的DB2数据库,实现了采购、调拨、领用借用、资产管理、检定维修、设备管理、报废、项目等业务的流程化管理,从而使相关人员更高效、更规范地做好气象探测中心的气象装备保障工作。     

沙尘暴天气数值预报系统及其预报效果检验

沙尘暴天气数值预报系统包括区域大气模式、陆面过程模式、风沙模式(包括风蚀、输送和沉降模式)和地理信息系统。用该系统对2002年3月20日和4月7日2次沙尘天气进行了预报试验,利用地面观测资料和卫星观测资料对模式输出的主要沙尘天气预报产品进行了对比分析。分析结果认为,沙尘暴天气数值预报系统对沙通量、尘通量和垂直积分质量有很好的预报能力,但仍需改进陆面参数和沙尘气溶胶的初始值。