期刊文献+
共找到3,108篇文章
< 1 2 156 >
每页显示 20 50 100
EAST中央安全联锁系统安全完整性等级验证研究
1
作者 黄子涵 张祖超 +2 位作者 田腾飞 张杰 徐国顺 《核电子学与探测技术》 北大核心 2026年第1期93-99,共7页
为验证EAST中央安全联锁系统在采用国产化安全仪表系统(SIS)升级优化后是否满足功能安全要求,并确保装置运行的安全性与可靠性,依据功能安全标准GB/T 20438,从架构约束和随机失效两方面开展安全完整性等级(SIL)验证。针对初步方案中各... 为验证EAST中央安全联锁系统在采用国产化安全仪表系统(SIS)升级优化后是否满足功能安全要求,并确保装置运行的安全性与可靠性,依据功能安全标准GB/T 20438,从架构约束和随机失效两方面开展安全完整性等级(SIL)验证。针对初步方案中各安全仪表功能(SIF)回路的SIL等级因架构约束仅能达到SIL2的瓶颈问题,提出优化方案并实施系统改造。研究结果表明,优化后的EAST中央安全联锁系统的SIL等级提升至SIL3,充分验证了国产化系统的安全性与可靠性。该研究成果为后续各子系统的验证计算提供了重要参考,可为未来系统优化改造及聚变堆建设的方案设计与器件选型提供技术指导。 展开更多
关键词 安全仪表系统 安全完整性等级 安全仪表功能 EAST
在线阅读 下载PDF
Machinery Meets Demand
2
作者 SHADRACK KAVILU 《ChinAfrica》 2026年第3期38-39,共2页
East Africa’s construction boom draws Chinese heavy machinery manufacturers and distributors The booming construction of new housing and commercial units has led to unprecedented demand for heavy construction equipme... East Africa’s construction boom draws Chinese heavy machinery manufacturers and distributors The booming construction of new housing and commercial units has led to unprecedented demand for heavy construction equipment in Nairobi,Kenya. 展开更多
关键词 HOUSING east africa DEMAND chinese manufacturers distributors heavy machinery CONSTRUCTION construction equipment
原文传递
Mechanisms of ENSO's cross-seasonal modulation of winter–spring atmospheric river activity over East Asia
3
作者 Yuliang Zhou Wentao Jia +1 位作者 Weimin Zhang Huizan Wang 《Atmospheric and Oceanic Science Letters》 2026年第1期66-71,共6页
In this study,based on MERRA-2 reanalysis data and a multi-algorithm integrated atmospheric river(AR)iden-tification method,the authors reveal the cross-seasonal regulation mechanism of El Niño-Southern Oscillati... In this study,based on MERRA-2 reanalysis data and a multi-algorithm integrated atmospheric river(AR)iden-tification method,the authors reveal the cross-seasonal regulation mechanism of El Niño-Southern Oscillation(ENSO)on winter-spring AR activities in East Asia.The results show that ENSO asymmetrically modulates AR ac-tivity through teleconnection and hysteresis effects,and has significant enhancement/inhibition effects on ARs in different regions.At the onset of El Niño,enhanced southwesterly flow at the western edge of the western Pacific subtropical high(WPSH)leads to enhanced AR activity in the western Pacific,and anomalous southerly winds in the Indian Ocean promote northward transport of water vapor in the Arabian Sea and Bay of Bengal.With a three-month lag,the weakening and eastward retreat of the WPSH weakens the low-latitude AR activity,but persistent southerly winds in the Bay of Bengal maintain the AR activity over Southwest China.The mid-to high-latitude AR response exhibits delayed dynamics,initially dominated by the synergistic effect of the southward deviation of the upper-air rapids and the low-level convergence(double-rapid-flow effect)and later modulated by the Pacific-North American teleconnection(PNA)-triggered East Asian ridge,which enhances the precipitation efficiency through prolonged frontal activity and enhanced cold-warm airmass convergence.Overall,El Niño promotes the development of low-and midlatitude AR activity in East Asia,while La Niña promotes(maritime continental)AR activity in the tropics.This study establishes the“ENSO teleconnection→circulation adjust-ment→East Asian AR response”chain,revealing a cross-seasonal lagged response mechanisms of East Asian AR activity,and provides a theoretical basis for winter and spring climate prediction and extreme precipitation forecasting. 展开更多
关键词 ENSO Atmospheric river Western Pacific subtropical high East Asia Lagged response
在线阅读 下载PDF
Metamorphic P-T-t Evolution and Tectonic Implications of High-pressure Granulites in the Qushan Islands,East China Sea
4
作者 CAO Yiwen ZHOU Xiwen +1 位作者 DONG Jie DENG Xuanyu 《Acta Geologica Sinica(English Edition)》 2026年第1期69-81,共13页
Debate has persisted over whether the metamorphic basement of the Zhoushan Islands,easternmost Cathaysia Block,is Precambrian.Here,representative metamorphic rocks from the Qushan Islands were investigated using petro... Debate has persisted over whether the metamorphic basement of the Zhoushan Islands,easternmost Cathaysia Block,is Precambrian.Here,representative metamorphic rocks from the Qushan Islands were investigated using petrography,mineral chemistry,phase equilibria modeling and SHRIMP zircon U-Pb dating to constrain their metamorphic evolution and tectonic significance.Both the pelitic granulites(garnet-kyanite-perthite-biotite-quartz)and the mafic granulites(garnet-clinopyroxene-amphibole-plagioclase-quartz)reached high-pressure granulite-facies conditions of 1.2-1.4 GPa/820-900℃,and recorded three metamorphic stages along a clockwise P-T path with post-peak isothermal decompression.This trajectory indicated rapid exhumation of thickened continental crust during collisional orogeny.Metamorphic ages of 254±3 Ma,262±4 Ma and 259±3 Ma were obtained for mafic granulite,pelitic granulite and marble,respectively,and were consistent with the emplacement age of 259±4 Ma for a pegmatite vein.Detrital zircons in metasediments spanned 2706-330 Ma,which constrained the latest deposition to~330 Ma;thus represented mid-Paleozoic sediment metamorphosed during the late Paleozoic rather than Precambrian basement.We conclude that the Indosinian tectonothermal event in the Cathaysia Block had originated from late Paleozoic-early Mesozoic collisional orogeny between the South China Plate to the north and the Indochina Block to the south. 展开更多
关键词 METAMORPHISM high-pressure granulite zircon U-Pb dating Qushan Islands East China Sea Cathaysia Block
在线阅读 下载PDF
A Nexus for East Africa--China-supported projects help East Africans to boost energy, water and food security
5
作者 RICHARD WETAYA 《ChinAfrica》 2026年第1期44-45,共2页
Andrew Wangota,a 48-year-old Ugandan farmer,has been using agrivoltaics technology,a solar technology that uses agricultural land for both food production and solar power generation,on his farm in Bunashimolo Parish,B... Andrew Wangota,a 48-year-old Ugandan farmer,has been using agrivoltaics technology,a solar technology that uses agricultural land for both food production and solar power generation,on his farm in Bunashimolo Parish,Bukyiende Subcounty in Uganda where he has been cultivating plantain,coffee and Irish potatoes for the past 16 years. 展开更多
关键词 water security solar technology NEXUS irish potatoes East Africa energy security China supported projects agrivoltaics technologya
原文传递
From Pigsties to Pitchers:Xujiadai Village turns baseball into a driver of economic growth,cultural vitality,and community pride
6
作者 LIU TING 《ChinAfrica》 2026年第2期25-27,共3页
In the countryside of east Zhejiang Province,a quiet village has hit a home run.Xujiadai,once a place known for pig farming and environmental pollution,is drawing visitors from across China with a sport still uncommon... In the countryside of east Zhejiang Province,a quiet village has hit a home run.Xujiadai,once a place known for pig farming and environmental pollution,is drawing visitors from across China with a sport still uncommon in the country:baseball. 展开更多
关键词 Xujiadai village economic growth environmental pollution environmental pollutionis BASEBALL East Zhejiang province community pride pig farming
原文传递
Why record-breaking gale and nationwide dust in China in April 2025
7
作者 Zhicong Yin Qianyi Huo +2 位作者 Dingzhu Hu Yanyan Huang Hujian Wang 《Science Bulletin》 2026年第3期463-465,共3页
An unprecedented extreme gale and dust event struck East Asia during 10-14 April2025.A record-breaking gale swept across most regions of China.It carried large amounts of dust from northern deserts,resulting in nation... An unprecedented extreme gale and dust event struck East Asia during 10-14 April2025.A record-breaking gale swept across most regions of China.It carried large amounts of dust from northern deserts,resulting in nationwide dust weather.Gales affected more than 3.5 million km^(2),and the windspeeds in North China were the strongest in April since 1940(Fig.1a,b). 展开更多
关键词 east asia windspeeds northern deserts record breaking gale unprecedented extreme gale dust event nationwide dust
原文传递
Geological characteristics and genesis of the Mailong gold deposit in the East Kunlun Orogen,Qinghai
8
作者 Jia Bowen Zhang Shunbin +6 位作者 Li Xiaoliang Yang De Yu Xiaoliang Li Hua Zhang Jian Qian Ye Sun Fengyue 《Global Geology》 2026年第1期49-67,共19页
The Mailong gold deposit is located in the eastern section of the East Kunlun orogenic belt and is one of the recently discovered important gold polymetallic deposits in the Qinhai Gouli region.The primary host rocks ... The Mailong gold deposit is located in the eastern section of the East Kunlun orogenic belt and is one of the recently discovered important gold polymetallic deposits in the Qinhai Gouli region.The primary host rocks of the Mailong gold deposit consist of intermediate-acid intrusive rocks from the Varisian and Indosinian periods,as well as the Precambrian Jinshuikou Group,with mineralization controlled by northeast and northwest faults.The alteration of the host rocks is mainly characterized by silicification,sericitization,chloritization,and carbonatization.Based on the cross-cutting relationships of the veins,the hydrothermal mineralization of the gold deposit can be categorized into three stages:the quartz-pyrite stage,the quartzpolymetallic sulfide stage,and the quartz-carbonate stage.Microthermometry of fluid inclusions indicates that the Mailong gold deposit belongs to a low-density(0.73–0.86 g/cm3),medium-temperature(240–340℃),and medium-salinity(4.01–10.74 wt%NaCl)NaCl-CO2-H2O fluid system.The C-H-O isotopic analysis suggests that the mineralizing fluids is derived from magmatic water,with later contributions from atmospheric precipitation.In-situ S isotopic results indicate that the mineralizing materials mainly derive from igneous rocks.A comprehensive analysis concludes that the Mailong gold deposit is a mesothermal hydrothermal vein-type gold deposit controlled by structural factors. 展开更多
关键词 East Kunlun Orogen Mailong gold deposit fluid characteristics C-H-O-S isotopes mediumtemperature hydrothermal vein-type gold deposit
在线阅读 下载PDF
全超导托卡马克核聚变发电装置快控电源的改进灰色预测滑模电流控制
9
作者 黄海宏 陈昭 王海欣 《电工技术学报》 北大核心 2025年第16期5317-5329,共13页
全超导托卡马克核聚变发电装置(EAST)快控电源是实现可控核聚变中等离子体垂直位移控制的重要装置。EAST快控电源采用多个H桥逆变支路并联工作模式,电源的总输出电流对参考电流的快速跟踪控制直接影响等离子体的平衡控制,而各个并联支... 全超导托卡马克核聚变发电装置(EAST)快控电源是实现可控核聚变中等离子体垂直位移控制的重要装置。EAST快控电源采用多个H桥逆变支路并联工作模式,电源的总输出电流对参考电流的快速跟踪控制直接影响等离子体的平衡控制,而各个并联支路的输出电流一致性对支路稳定工作十分重要。为加快EAST快控电源输出电流动态响应速度和保证各个支路电流平衡,该文提出一种改进灰色预测新型快速变幂次趋近率滑模控制方法,实现EAST快控电源输出电流的良好控制。为加快输出电流响应速度,在总输出电流反馈环节加入改进灰色预测,根据输出电流的凹凸性和积分思想对灰色预测背景值进行重构,将预测值加入到原始序列替换旧信息以实现滚动预测,可以有效提高输出电流的预测精度。设计以总电流跟踪参考电流和支路电流均衡为控制目的滑模面,提出一种新型快速变幂次趋近率以加快滑模系统的收敛速度。仿真和实验验证了提出的控制方法对比其他传统控制方法具有更好的支路电流一致性和更快的输出电流响应速度。 展开更多
关键词 全超导托卡马克核聚变发电装置(EAST)快控电源 输出电流 灰色预测 滑模控制
在线阅读 下载PDF
EAST鱼尾偏滤器线圈电源频率反馈控制策略的优化研究
10
作者 周宇 孙浩章 +1 位作者 郭斐 黄懿赟 《核聚变与等离子体物理》 北大核心 2025年第4期396-403,共8页
EAST装置中鱼尾偏滤器磁体线圈电源采用多频率谐振技术方案以实现3.5 kHz/5000 A的正弦电流输出。而在实验中,环境磁场的变化会引起鱼尾偏滤器负载磁体的电流趋肤效应的变化,从而引起谐振网络频率的偏移和谐振电流的衰减。为了保证谐振... EAST装置中鱼尾偏滤器磁体线圈电源采用多频率谐振技术方案以实现3.5 kHz/5000 A的正弦电流输出。而在实验中,环境磁场的变化会引起鱼尾偏滤器负载磁体的电流趋肤效应的变化,从而引起谐振网络频率的偏移和谐振电流的衰减。为了保证谐振电流的输出幅值,采用了基于谐振频率辨识的反馈控制策略。由于高频工作点的谐振品质因数Q要大于低频工作点,高频点谐振频率偏移引起的电流幅值衰减远大于低频点。当工作点频率值增加时,采用固定扫描间隔和扫描次数的谐振频率辨识控制导致的谐振电流误差会大大增加。因此,为了提高输出电流反馈控制精度,提出了一种基于多种间隔的频率扫描策略。根据工作点的频率高低,该控制策略优化了频率反馈范围和频率反馈间隔,可以有效提高反馈控制精度。通过建模和仿真,验证了该频率反馈优化控制策略的效果。 展开更多
关键词 EAST 偏滤器 谐振 频率反馈
在线阅读 下载PDF
中青年高血压患者控盐行为干预方案的构建
11
作者 葛澜 官雪薇 +6 位作者 汤磊雯 钟瑜镁 朱倩寅 王莺 吴小燕 宋国港 兰美娟 《中国护理管理》 北大核心 2025年第8期1264-1269,共6页
目的:基于简化、吸引力、社会性、及时性行为干预原则和助推理论构建中青年高血压患者控盐行为干预方案,为进一步改善中青年高血压患者控盐行为提供参考。方法:在文献研究和质性访谈的基础上形成中青年高血压患者控盐行为干预方案初稿,... 目的:基于简化、吸引力、社会性、及时性行为干预原则和助推理论构建中青年高血压患者控盐行为干预方案,为进一步改善中青年高血压患者控盐行为提供参考。方法:在文献研究和质性访谈的基础上形成中青年高血压患者控盐行为干预方案初稿,于2024年7月—11月采用德尔菲专家函询法对12名专家进行2轮函询,形成干预方案终稿。结果:两轮专家函询问卷的有效回收率分别为92%和100%,专家权威系数分别为0.850、0.884,两轮函询条目重要性和可行性的肯德尔和谐系数分别为0.267、0.204和0.275、0.210(均P<0.05),重要性、可行性变异系数分别为0.06~0.40、0.10~0.45和0~0.22、0~0.20。最终形成的干预方案包含简化、吸引力、社会性和及时性4个一级条目和11个二级条目、15个三级条目。结论:构建的中青年高血压患者控盐行为干预方案具有科学性和针对性,可为中青年高血压患者控盐行为管理的相关护理措施提供借鉴依据。 展开更多
关键词 助推 EAST 高血压 控盐 方案构建
原文传递
EAST上锂粉流量动态注入对燃料再循环影响研究
12
作者 汪哲 吴凯 +8 位作者 黄耀 徐伟 孙震 黄明 周之泰 管艳红 陈跃 左桂忠 胡建生 《核聚变与等离子体物理》 北大核心 2025年第4期459-466,共8页
磁约束聚变装置等离子体放电中燃料粒子再循环的控制对于长脉冲高参数等离子体的稳定运行至关重要。为探索不同流量的锂粉注入对燃料粒子再循环的控制效果,升级了锂粉控制系统以实现单次等离子体放电中锂粉流量大小的实时主动调节。台... 磁约束聚变装置等离子体放电中燃料粒子再循环的控制对于长脉冲高参数等离子体的稳定运行至关重要。为探索不同流量的锂粉注入对燃料粒子再循环的控制效果,升级了锂粉控制系统以实现单次等离子体放电中锂粉流量大小的实时主动调节。台面测试结果表明,锂粉流量与控制电压满足线性关系。在此基础上,在EAST装置开展了锂粉流量动态变化注入对燃料再循环的控制实验,结果表明,该系统在单次等离子体放电过程中实时改变了锂粉注入流量大小。随着锂粉流量增大,偏滤器位置中性气压及Dɑ线辐射强度进一步降低,验证了锂粉注入速率的增加可以增强对燃料再循环的控制。该研究为EAST未来长脉冲高参数等离子体放电中燃料再循环的反馈控制实验的开展提供了支持。 展开更多
关键词 锂粉 壁处理 燃料再循环 EAST
在线阅读 下载PDF
EAST装置上新型离子回旋天线法拉第屏蔽的设计及应用
13
作者 梁启超 张伟 +3 位作者 刘鲁南 秦成明 毛玉周 杨桦 《核聚变与等离子体物理》 北大核心 2025年第1期1-6,共6页
为达到全超导托卡马克核聚变实验装置(EAST)长脉冲高功率目标,提高离子回旋波与等离子体的耦合效率,并降低离子回旋共振加热(ICRH)天线法拉第屏蔽的热负载,需对ICRH天线中的法拉第屏蔽进行优化设计。通过RAPLICASOL ICRH天线计算模型对... 为达到全超导托卡马克核聚变实验装置(EAST)长脉冲高功率目标,提高离子回旋波与等离子体的耦合效率,并降低离子回旋共振加热(ICRH)天线法拉第屏蔽的热负载,需对ICRH天线中的法拉第屏蔽进行优化设计。通过RAPLICASOL ICRH天线计算模型对法拉第屏蔽结构进行计算分析,综合考虑最大电场强度、耦合阻抗以及离子回旋天线有限的内部空间,最终确定了法拉第屏蔽的结构尺寸。然后对法拉第屏蔽的流热分布进行了优化和分析。经过仿真优化设计,在300s运行条件下,法拉第屏蔽最高温度为300℃,满足法拉第屏蔽热设计要求。该天线于2021年成功应用于EAST实验。实验结果表明,新ICRH天线的耦合及加热效率明显提高,已完成1.5MW/30s和0.5MW/300s的长脉冲实验,并且法拉第屏蔽最高温度为330℃,满足ICRH天线的设计要求。 展开更多
关键词 EAST 离子回旋共振加热天线 耦合效率 法拉第屏蔽
在线阅读 下载PDF
EAST装置技术诊断系统数据高效归档方案设计与实现
14
作者 侯长申 奚维斌 +1 位作者 杜庆庆 刘唤唤 《计算机科学与应用》 2025年第11期60-67,共8页
EAST技术诊断系统需长期监测装置运行状态,采集的数据类型复杂,涵盖来自磁体、支撑结构、馈线等多个关键部件的温度、流量、电位等物理信号。每一轮EAST实验运行周期长达5~8个月,涉及300多个通道、数十种信号源,采集数据规模可达数10 T... EAST技术诊断系统需长期监测装置运行状态,采集的数据类型复杂,涵盖来自磁体、支撑结构、馈线等多个关键部件的温度、流量、电位等物理信号。每一轮EAST实验运行周期长达5~8个月,涉及300多个通道、数十种信号源,采集数据规模可达数10 TB。庞大且持续增长的数据量对系统的归档性能、数据一致性、检索效率以及存储空间管理提出了严峻挑战。研究基于EPICS通过应用Archive Appliance与RDB Archive Engine构建归档系统。实现了对数据的统一管理,增强了历史数据的多用户并发访问能力与系统整体可扩展性。对Archive Appliance和RDB Archive Engine关于PV最高归档速率、PV检索速度、多客户端同时访问历史数据等方面进行性能测试,实验结果表明Archive Appliance相较于RDB Archive Engine更适配EAST主机诊断数据的存储需求。 展开更多
关键词 EAST技术诊断 EPICS Archive Appliance RDB Archive Engine
在线阅读 下载PDF
Speciation,classification and phylogeny of the longi lineage(Pleistocene humans) 被引量:3
15
作者 Ji Qiang Ji Yannan +2 位作者 Liu Aoran Chen Shaokun Han Kaibo 《地质学刊》 2025年第1期1-10,共10页
Based on the study of two Early Pleistocene human skulls found in Yunxian County,Hubei Province,China,Ji et al.(2024)suggested that Homo orientalis was the common ancestor of the sapiens lineage and the longi lineage,... Based on the study of two Early Pleistocene human skulls found in Yunxian County,Hubei Province,China,Ji et al.(2024)suggested that Homo orientalis was the common ancestor of the sapiens lineage and the longi lineage,and proposed that both the two lineages originated from East Asia.We further proposed that Genus Homo should be divided into two subgenera:Subgenus Homo and Subgenus Parahomo.All members of the sapiens lineage would be assigned to Subgenus Homo,and all members of the longi lineage would be grouped into Subgenus Parahomo.Homo(Parahomo)heidelbergensis and Homo(Parahomo)neanderthalensis also were the members of the longi lineage,an evolutionary branch spreaded from East Asia to Africa and Europe more than 600,000 years ago.This paper mainly makes an introduction to the speciation,classification and phylogeny of the longi lineage.The longi lineage and the sapiens lineage are″sister group″relationship,but the longi lineage is an extinct lineage,having nothing to do with our modern people. 展开更多
关键词 Genus Homo Subgenus Parahomo the longi lineage China East Asia
在线阅读 下载PDF
Economic and Social Impacts of Hydrogen Energy:East Asia Summit Region Case Study 被引量:2
16
作者 LI Yanfei SHI Xunpeng SHIGERU Kimura 《南方能源建设》 2025年第3期1-19,共19页
[Objective]As hydrogen energy has gained new momentum recently,analyzing the economic and social impacts of developing a hydrogen energy sector can inform further policy formation and investment decision making in thi... [Objective]As hydrogen energy has gained new momentum recently,analyzing the economic and social impacts of developing a hydrogen energy sector can inform further policy formation and investment decision making in this regard.[Method]Considering the increasingly important role of East Asia Summit(EAS)region in both economic growth and green energy transition,this paper developed a demand-driven model for the hydrogen energy supply chains to comprehensively and quantitatively evaluate the economic and social impacts hydrogen energy development in the EAS region.[Result]This model provides estimates of the capital investment required,the number of new jobs created,the potential carbon emissions reduction,the subsidies needed in the early stages of development,and the impacts on key energy security indicators.[Conclusion]This study find that hydrogen energy development has a significant job creation effect,and that the total investment and the fiscal burden appear to be manageable for countries in the EAS region.In addition to substantial carbon emissions reduction,positive social impacts also include general improvements in energy security indicators. 展开更多
关键词 hydrogen energy economic impact social impact ASEAN East Asia Summit
在线阅读 下载PDF
Geochronology and Geochemistry of Paleozoic S-type Granites in the Western Segment of the East Kunlun Orogen and its Implications for Tectonic Evolution 被引量:1
17
作者 REN Haidong PAN Tong +5 位作者 WANG Tao WANG Bingzhang WANG Xiaoxia ZHANG Jianjun WANG Jianguo ZHAO Wentao 《Acta Geologica Sinica(English Edition)》 2025年第3期743-760,共18页
In the western segment of the East Kunlun Orogen(WEKO),muscovite granite and garnet granite from the Hureguole intrusion exhibit zircon U-Pb ages of 435-442 Ma.Geochemically,these rocks contain high concentrations of ... In the western segment of the East Kunlun Orogen(WEKO),muscovite granite and garnet granite from the Hureguole intrusion exhibit zircon U-Pb ages of 435-442 Ma.Geochemically,these rocks contain high concentrations of SiO_(2),K_(2)O and Al_(2)O_(3),with low concentrations of TiO_(2)and MgO,indicating a peraluminous high-K calc-alkaline affinity.They are enriched in Rb,Th,U and LREE,depleted in Eu,Ba,Sr and Ti,being classified as S-type granites.Negative whole-rockε_(Nd)(t)values(-9.8 to-9.1)and zirconε_(Hf)(t)values(-11.6 to-8.2)for those granites indicate that they were derived from partial melting of pelitic rocks in the Paleoproterozoic Baishahe Formation of the Jinshuikou Group.Based on the collected zircon ages,Cambrian-Devonian magmatic activity in the WEKO was divided into three stages:early(446-520 Ma),middle(427-441 Ma)and late(372-424 Ma)stages.Statistically,whole-rock Nd and zircon Hf isotope data(ε_(Nd)(t)/T_(DM)^(Nd),ε_(Hf)(t)/T_(DMC)^(Hf))from Paleozoic igneous rocks in the WEKO reveal a magma source that was initially dominated by depleted mantle components in the northward subduction stage of the Proto-Tethy an Ocean plate(446-520 Ma),shifting to predominantly crustal sources during the closure period of the North Qimantagh back-arc basin(427-441 Ma),then to crust-mantle mixed sources in the post-collision stage(372-424 Ma). 展开更多
关键词 Nd-Hf isotopes S-type granite magmatic activity SILURIAN East Kunlun Orogen
在线阅读 下载PDF
The strongest early-summer drought–flood abrupt alternation event over the Huang–Huai–Hai River Basin in 2024 since the 1980s:Perspective of anomalous subseasonal circulation evolution 被引量:1
18
作者 Zhiheng Chen Zhihai Zheng 《Atmospheric and Oceanic Science Letters》 2025年第5期65-72,共8页
Since the 21st century,the Huang–Huai–Hai River Basin(HHHRB)in China has experienced increased frequency and severity of drought–flood abrupt alternation(DFAA)events during early summer,characterized by droughts in... Since the 21st century,the Huang–Huai–Hai River Basin(HHHRB)in China has experienced increased frequency and severity of drought–flood abrupt alternation(DFAA)events during early summer,characterized by droughts in June followed by floods in July.The 2024 event was the most severe since 1981.This study demonstrates that such compound extreme events are closely linked to anomalous subseasonal evolution of large-scale atmospheric circulation.During the drought phase,the East Asian subtropical westerly jet(EAJ)shifts southward,and the western Pacific subtropical high(WPSH)exhibits anomalous strengthening with its western ridge line displaced southward.The flood phase is characterized by acceleration of the EAJ,westward extension of the WPSH,and enhanced southwestern moisture transport from the western Pacific.Beyond these typical features,the 2024 early summer circulation exhibited unique characteristics:Anomalous northeastward intensification of the WPSH facilitated merged moisture influx from both the Indian Ocean and the western Pacific along the southeast pathway into the HHHRB in July,resulting in the highest net moisture inflow at the southern boundary of the HHHRB since 1981.The synergistic effects of multiple factors primarily explain the exceptionally intense DFAA event in 2024. 展开更多
关键词 Drought-flood abrupt alternation Anomalous subseasonal circulation evolution East Asian subtropical westerly jet Western Pacific subtropical high Water vapor transportation
在线阅读 下载PDF
Characterization of novel highly pathogenic avian influenza A(H5N6)clade 2.3.4.4b virus in wild birds,East China,2024 被引量:1
19
作者 Renjie Sun Xiaoxiao Feng +9 位作者 Jing Huang Fangyu Zheng Ronghui Xie Chuanliang Zhang Hongli Zhang Yin Xue Aijun Liu Xiaobing Huang Lin Yuan Lingyan Zhao 《Virologica Sinica》 2025年第2期284-287,共4页
Dear Editor,The highly pathogenic avian influenza viruses(HPAIVs)are important epizootic and zoonotic pathogens that cause significant economic losses to the poultry industry and pose a serious risk to veterinary and ... Dear Editor,The highly pathogenic avian influenza viruses(HPAIVs)are important epizootic and zoonotic pathogens that cause significant economic losses to the poultry industry and pose a serious risk to veterinary and public health.Wild birds have been recognized as the primary reservoirs for influenza A virus,and some species show little sign of clinical disease or even can be asymptomatic during long distance carriers of the virus(Lycett et al.,2019).Since it was first discovered in 1959,the H5Nx HPAIVs have spread globally and cause outbreaks in wild birds,poultry and sporadic human and other mammalian infections(Lycett et al.,2019).Due to the reassortant events of diverse strains facilitated by migratory waterfowl,the clade 2.3.4.4 of H5Nx viruses acquiring neuraminidase(NA)gene from other low pathogenicity avian influenza viruses(LPAIVs)emerged in 2014 and gradually became the dominant sub-clade(Lee et al.,2017). 展开更多
关键词 wild birds highly pathogenic avian influenza East China EPIZOOTIC highly pathogenic avian influenza viruses hpaivs avian influenza H N ZOONOTIC h nx hpaivs
原文传递
上一页 1 2 156 下一页 到第
使用帮助 返回顶部