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氮及氮磷比对附着藻类及浮游藻类的影响 总被引:5,自引:0,他引:5
2005年5月至11月,在河北省YH水库选取5个具有代表性的样点,进行了微囊藻毒素-LR的调查,同时,测定了相应各样点的TN,TP,NH4-N,NO3-N和PO4-P.结果显示,水库中微囊藻毒素-LR(MC-LR)随季节发生变化,其中,7-10月期间相对较高,且大部分超过了生活饮用水地表水标准限值(1 μg/L);MC-LR与水体中的N、P之间的相互关系表明,5-7月期间,水库MC-LR与TP呈正相关,与NH4-N和TN/TP呈负相关;8-9月期间,水库中TP逐渐降低,但其它降低速率低于TN,造成TN/TP明显降低,MC-LR与TP和TN/TP呈正相关,与NH4-N呈负相关;10-11月期间,大量藻细胞死亡,释放到水体中MC-LR也逐渐下降,这时,大量外源营养盐也进入水库,造成微囊藻毒素-LR的变化与TN、NH4-N、NO3-N呈显著或极显著负相关.这说明在不同季节下,微囊藻毒素-LR与营养盐的关系不同,必须视实际情况而定. 相似文献
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Weijie SUN Ryan MDEWEY Sae AIZAWA Jia HUANG James A.SLAVIN Suiyan FU Yong WEI Charles F.BOWERS 《中国科学:地球科学(英文版)》2022,65(1):25-74
This review paper summarizes the research of Mercury’s magnetosphere in the Post-MESSENGER era and compares its dynamics to those in other planetary magnetospheres,especially to those in Earth’s magnetosphere.This review starts by introducing the planet Mercury,including its interplanetary environment,magnetosphere,exosphere,and conducting core.The frequent and intense magnetic reconnection on the dayside magnetopause,which is represented by the flux transfer event"shower",is reviewed on how they depend on magnetosheath plasma β and magnetic shear angle across the magnetopause,followed by how it contributes to the flux circulation and magnetosphere-surface-exosphere coupling.In the next,Mercury’s magnetosphere under extreme solar events,including the core induction and the reconnection erosion on the dayside magnetosphere,as well as the responses of the nightside magnetosphere,are reviewed.Then,the dawn-dusk properties of the plasma sheet,including the features of the ions,the structure of the current sheet,and the dynamics of magnetic reconnection,are summarized.The last topic is devoted to the particle energization in Mercury’s magnetosphere,which includes the energization of the Kelvin-Helmholtz waves on the magnetopause boundaries,reconnection-generated magnetic structures,and the cross-tail electric field.In each chapter,the last section discusses the open questions related to each topic,which can be considered by the simulations and the future spacecraft mission.We end this paper by summarizing the future Bepi Colombo opportunities,which is a joint mission of ESA and JAXA and is en route to Mercury. 相似文献
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Fu Huishan Grigorenko Elena E. Gabrielse Christine Liu Chengming Lu San Hwang K. J. Zhou Xuzhi Wang Zhe Chen Fang 《中国科学:地球科学(英文版)》2020,63(2):235-256
In this paper, the particle acceleration processes around magnetotail dipolarization fronts(DFs) were reviewed. We summarize the spacecraft observations(including Cluster, THEMIS, MMS) and numerical simulations(including MHD, testparticle, hybrid, LSK, PIC) of these processes. Specifically, we(1) introduce the properties of DFs at MHD scale, ion scale, and electron scale,(2) review the properties of suprathermal electrons with particular focus on the pitch-angle distributions,(3)define the particle-acceleration process and distinguish it from the particle-heating process,(4) identify the particle-acceleration process from spacecraft measurements of energy fluxes, and(5) quantify the acceleration efficiency and compare it with other processes in the magnetosphere(e.g., magnetic reconnection and radiation-belt acceleration processes). We focus on both the acceleration of electrons and ions(including light ions and heavy ions). Regarding electron acceleration, we introduce Fermi,betatron, and non-adiabatic acceleration mechanisms;regarding ion acceleration, we present Fermi, betatron, reflection, resonance, and non-adiabatic acceleration mechanisms. We also discuss the unsolved problems and open questions relevant to this topic, and suggest directions for future studies. 相似文献
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吴子书,笔名"子书",字"虞心",号"双辑堂主人",别称"清心夫子"。吴子书自幼善书好写,研习书帖、碑刻、篆印。十七岁时正式学习书法,凭其天资聪慧,博众家之长,耕耘于执白守黑之间,挥洒于真草隶篆之中。吴子书的书法,绝名超美,灵姿秀俊。章法有制,狂中不燥。其超然之气度,天地合一之魂韵,令众人瞠目。欧阳先生说:大开大合者有,而当 相似文献
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正北京时间2013年4月20日8时02分,在四川,在雅安,在芦山,本来应该是一个有美好开始的早晨,也应该是一个安静的早晨,然而不应该动的却动了,天降灾难地动山摇,不应该毁的也毁了。一场灾难突然袭击,来不及逃脱,老天爷又跟四川开了个玩笑。雅安,不久的将来,你的世界,仍会春暖花开。8时02分四川省雅安市芦山县发生7.0级地震。震源深度13公里。截至4月27日8时,地震遇难人数升至 相似文献
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传统水资源信息管理模型采用GIS网络技术,对水资源信息进行优化配置,未对地震多发区域水资源管网进行综合规划,存在地震破坏后受污染水资源信息管理性能差的问题。设计考虑区域水资源地震破坏后污染的信息管理模型,模型包括受污染水资源信息规划设计模块、信息监测和采集模块、信息管理模块。3个模块分别实现对地震破坏后污染的水资源管网的合理规划、监测和采集以及污染信息的综合管理。实验结果表明,所设计模型对区域水资源地震破坏后污染的信息管理的平均时间达到1.38 s,且在管理过程中各项功能的评分都高于93.5分,具有较高的管理性能。 相似文献
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以广东省地震局现有技术系统为基础,开展地震应急信息的多渠道自动发布技术研究。研究面向对象型地震应急信息多渠道发布机制,研究如何综合现有的数据和资源更全面、更有效、更精准地向决策者、应急技术人员、媒体和公众提供更贴近实际需求的定向服务,从而提升地震应急信息的发布和展示能力。 相似文献
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针对黑龙江省地震监测中心工作任务和技术系统密集的特点,用Java开发一套基于Windows平台的区域台网智能管理软件系统,实现仪器自动化监控与故障分析、台网智能化运行与管理、综合信息智能化发布等功能,以自动化技术替代部分人力资源. 相似文献
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随着信息技术的飞速发展和信息化的推进,各个项目建设均要对硬件、网络、数据库、软件平台和系统进行重复的规划与建设,项目建设的系统越多,操作系统和应用服务的部署和运维就面临着越大的挑战,同时也造成了大量硬件资源的浪费,需要较高的成本进行维护。本文介绍了地震信息化项目中,利用云计算和大数据技术构建地震信息化共用服务平台,通过统一的基础设施建设和资源管理,提供一系列地震相关系统开发过程中需要的共用基础服务,使得开发人员能够在云平台提供的服务基础上,高效弹性地对系统进行开发、部署和运维,大大提高了资源利用率和时间效率。 相似文献
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The article presents a new information technology for the analysis of problems and the support of decision making regarding the availability of water resources for the users of the water management complex of the Lower Volga and the entire Volga–Kama chain of HPPs. A procedure is proposed to search for compromise decisions in water resources management in the interests of various water users (hydropower engineering, transport, ecology, agriculture, fishery, etc.). Modern methods of multicriteria analysis and the theory of compromises a used. The issues considered in the study include the determination of the potentially possible levels of meeting the requirements of the water users mentioned above and the effect produced on these levels by possible changes in the Management Rules of the Volga–Kama Chain of Reservoirs. 相似文献
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展望地震监测台网的发展与应用 总被引:4,自引:0,他引:4
随着国民经济的快速发展,我国地震监测台网的发展也日新月异,设备性能、技术系统、台网密度正逐步接近发达国家的水平,同时积累了大量的观测数据。如何利用这些监测资源,更好地为经济建设和社会公共安全服务,是值得研究的重要问题。本文认为提取有用的地震前兆信息、提升地震速报能力、扩展烈度速报功能是地震监测台网为地震预报和地震应急服务的重点;整合台网资源,构筑统一标准、多用途的地震监测网络是建设公共安全服务技术平台的前提;工程、海洋、气象、环保等是地震监测资源的主要服务领域。因此,开发监测资源,加强自主创新,构筑技术平台,拓展服务领域是未来地震监测台网为社会和公共安全服务的重要发展方向。 相似文献