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青海省称多县(0~8)月龄婴儿喂养现状调查及改善应对策略
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作者 陈玲 德青文毛 +2 位作者 西然松毛 袁秀丽 欧玉兰 《高原医学杂志》 CAS 2024年第2期54-58,共5页
目的:调查青海省称多县(0~8)月龄婴儿喂养状况,为合理喂养提供科学依据,同时制定干预策略,促进青海省牧区儿童健康成长,以减少营养不良的发生。方法:收集2022年11月—2023年4月在青海省称多县人民医院、珍秦镇卫生院及清水河卫生院分娩... 目的:调查青海省称多县(0~8)月龄婴儿喂养状况,为合理喂养提供科学依据,同时制定干预策略,促进青海省牧区儿童健康成长,以减少营养不良的发生。方法:收集2022年11月—2023年4月在青海省称多县人民医院、珍秦镇卫生院及清水河卫生院分娩的孕妇家庭156例为调查对象,采用电话问卷形式调查(0~8)月龄婴儿喂养情况,了解现状并制定干预策略。结果:大部分家庭(0~8)月龄婴儿以母乳喂养为主,个别辅以配方奶,部分家庭以牛乳替代配方奶,作为母乳不足的补充。(0~8)月龄婴儿牛奶添加占18.54%,混合喂养率为17.88%,纯母乳喂养率为22.52%。最早者1月龄内即添加辅食,>3月~<6月龄添加辅食率为55.63%,8月龄尚未添加辅食者占9.27%。家庭整体对婴儿喂养相关问题知晓率较低。结论:青海省称多县(0~8)月龄婴儿纯母乳喂养率低,辅食添加时间、种类、引入顺序及速度存在较多问题,富铁食品添加少,维生素AD基本未补充是青海省称多县(0~8)月龄婴儿喂养的主要问题。高海拔偏远牧区家庭对婴儿喂养知识严重匮乏,知识获取渠道少,迫切需要一种适合当地推行的健康宣教管理模式,以促进牧区儿童健康成长,减少营养不良的发生。 展开更多
关键词 青海省称多县 高海拔地区 (0~8)月龄婴儿 科学喂养
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8-0聚丙烯缝线巩膜双联结缝合固定人工晶状体悬吊术在无晶状体眼中的应用
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作者 杜亚茹 陈佳娜 李维娜 《国际眼科杂志》 CAS 2024年第3期469-472,共4页
目的:观察8-0聚丙烯缝线巩膜双联结缝合固定人工晶状体悬吊术在无晶状体眼中的临床效果。方法:回顾性病例研究。收集2021-01/2022-11于我院行人工晶状体悬吊术的无晶状体患者30例31眼(其中男22例22眼)的临床资料,术中均采用8-0聚丙烯缝... 目的:观察8-0聚丙烯缝线巩膜双联结缝合固定人工晶状体悬吊术在无晶状体眼中的临床效果。方法:回顾性病例研究。收集2021-01/2022-11于我院行人工晶状体悬吊术的无晶状体患者30例31眼(其中男22例22眼)的临床资料,术中均采用8-0聚丙烯缝线巩膜双联结缝合法固定人工晶状体(AcrySof IQ或Tecnis ZCB00),术后至少随访6 mo,观察所有患者视力、眼压、术后人工晶状体位置和术中术后并发症发生情况。结果:术前术眼裸眼视力(UCVA,LogMAR)和最佳矫正视力(BCVA,LogMAR)分别为2.53±0.78和0.35±0.26,术后6 mo分别为0.58±0.26和0.36±0.27,手术前后UCVA比较有差异(t=15.408,P<0.01),BCVA比较无差异(t=-1.677,P=0.104)。术中未出现并发症。术后所有人工晶状体位置均居中,出现人工晶状体倾斜3眼,术后发生高眼压2眼、角膜水肿5眼、缝线外露1眼。术后未出现前房积血、玻璃体积血、黄斑水肿、角膜内皮失代偿、低眼压、脉络膜脱离、视网膜脱离、爆发性脉络膜上腔出血、眼内炎等并发症。结论:8-0聚丙烯缝线巩膜双联结缝合固定人工晶状体悬吊术早期可提高无晶状体患者的术后视力、并发症较少,可作为治疗无晶状体、晶状体脱位、悬韧带异常患者的一种手术方式选择。 展开更多
关键词 8-0聚丙烯缝线 人工晶状体悬吊术 无晶状体
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Co-seismic changes of Wenchuan Ms8.0 earthquake and six aftershocks recorded by four deformation instruments at Xuzhou seismostation
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作者 zhong Jiongrong Wang Jun Xu Ge Jiang Haolin 《Geodesy and Geodynamics》 2011年第2期58-65,共8页
Co-seismic changes of Wenchuan Ms8.0 earthquake and six strong aftershocks were recorded by 4 digital deformation instruments at Xuzhou seismostation at an cpicentral distance of 1392 km. The result shows that the str... Co-seismic changes of Wenchuan Ms8.0 earthquake and six strong aftershocks were recorded by 4 digital deformation instruments at Xuzhou seismostation at an cpicentral distance of 1392 km. The result shows that the straln-step changes and wave motions are caused by the arrival of the corresponding surface waves. The shape and size of the step changes and the response time were different for different instruments, even they were located in the same rock body only 7.65 m to 10.57 m apart. This difference is probably a reflection of different instrument properties, such as sensitivity and frequency response. The earthquake-caused stress changes, which were mainly compression in Xuzhou, had an important triggering effect on far-field strain changes 展开更多
关键词 Wenchuan msS. 0 earthquake earthquake motion deformation co-seismic response dynamic stress trigger Xuzhou seismostation
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汶川地震(Ms8.0)地表破裂及其同震右旋斜向逆冲作用 被引量:146
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作者 李海兵 付小方 +8 位作者 Jerome VAN DER WOERD 司家亮 王宗秀 侯立玮 邱祝礼 李宁 吴富晓 许志琴 Paul TAPPONNIER 《地质学报》 EI CAS CSCD 北大核心 2008年第12期1623-1643,共21页
2008年5月12日14时28分,青藏高原东缘龙门山地区发生了震惊世界的汶川地震(MS8.0),地震不仅造成巨大的人员伤亡和财产损失,并形成了迄今为止空间上分布最为复杂、长度最大的逆冲型同震地表破裂带。通过多次野外考查表明,汶川地震(MS8.0... 2008年5月12日14时28分,青藏高原东缘龙门山地区发生了震惊世界的汶川地震(MS8.0),地震不仅造成巨大的人员伤亡和财产损失,并形成了迄今为止空间上分布最为复杂、长度最大的逆冲型同震地表破裂带。通过多次野外考查表明,汶川地震(MS8.0)在龙门山断裂带上至少使两条NE走向、倾向NW的映秀-北川断裂和灌县-安县断裂同时发生地表破裂,并沿映秀-北川断裂产生的地表破裂带长度约275km,以逆冲运动伴随右旋走滑为其破裂特征,最大垂直位移量约11m,最大右旋走滑位移量至少约12m;沿灌县-安县断裂产生的地表破裂带长度约80km,表现为纯逆冲运动的破裂特征,最大垂直位移量约4m;另外发育一条长约6km呈NW走向连接于映秀-北川破裂带和汉旺破裂带的小鱼洞破裂带,以左旋走滑兼有逆冲运动为特征。地表破裂基本沿袭早先活动断裂带上,并使早先抬高的地貌更加抬高,表明龙门山地区地震在同一断裂带上重复发生过,并且无数次地震活动(包括类似汶川MS8.0地震的强震)的累积,逐渐形成了现今的龙门山。根据同震断裂面以及断裂面上的擦痕分析表明,汶川地震是由两次破裂事件叠加而成,初期破裂以逆冲运动为主,后期破裂以右旋走滑为主,这种破裂过程与地震波数据反演结果(陈运泰等,2008;Ji,2008;王为民等,2008)一致。在地表破裂带南段(映秀—清平段)叠加了两次不同性质的破裂过程,北段(北川—南坝段)只反映了第二次破裂事件的过程。利用长期滑移速率与汶川地震同震位移对比,估算出在龙门山断裂带上类似汶川地震(MS8.0)的强震复发周期为3000~6000a。通过对比研究,西昆仑山、阿尔金山和东昆仑山与龙门山具有很相似的转换挤压构造特征,斜向逆冲作用是青藏高原周缘山脉快速崛起的主要机制。 展开更多
关键词 汶川地震(ms 8.0) 地表破裂带 同震位移 斜向逆冲 快速崛起 青藏高原
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汶川Ms8.0地震前电离层TEC异常分析 被引量:45
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作者 祝芙英 吴云 +3 位作者 林剑 周义炎 熊晶 杨剑 《大地测量与地球动力学》 CSCD 北大核心 2008年第6期16-21,共6页
基于中国地壳运动观测网络的GPS观测数据,解算得到了汶川Ms8.0地震前中国区域上空电离层TEC分布图。用两种方法的研究显示,在相同时间和空间电离层TEC存在显著的异常扰动,即震前1~6天(除5月9日电离层TEC出现异常增加外)时间内多次出现... 基于中国地壳运动观测网络的GPS观测数据,解算得到了汶川Ms8.0地震前中国区域上空电离层TEC分布图。用两种方法的研究显示,在相同时间和空间电离层TEC存在显著的异常扰动,即震前1~6天(除5月9日电离层TEC出现异常增加外)时间内多次出现显著的TEC异常减少,而且电离层TEC的异常驼峰有向磁赤道漂移的趋势,由于距离发震时刻较近,排除其他因素后认为该异常可能源于汶川Ms8.0地震引起的电离层效应。 展开更多
关键词 GPS 总电子含量(TEC) 电离层异常 汶川地震 前兆
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Detection of a half-microgal coseismic gravity change after the Ms7. 0 Lushan earthquake 被引量:7
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作者 Wei Jin Zhao Bin +3 位作者 Tan Hongbo Yu Dan Shen Chongyang Li Hui 《Geodesy and Geodynamics》 2013年第3期7-11,共5页
Because only a small near-field coseismie gravity change signal remains after removal of noise from the accuracy of observations and the time and spatial resolution of the earth's surface gravity observation system, ... Because only a small near-field coseismie gravity change signal remains after removal of noise from the accuracy of observations and the time and spatial resolution of the earth's surface gravity observation system, it is difficult to verify simulations of dislocation theory. In this study, it is shown that the GS15 gravimeter, located 99.5 km from the epicenter of the Ms7.0 Lushan earthquake on April 20, 2013 at 08 : 04 UTC + 8, showed the influence of the earthquake from 2013-04-16 to 2013-04-26 after a time calibration, tide correc- tions, drift correction, period correction and relaxation correction were applied to its data. The post-seismic relaxation process of the spring in the gravimeter took approximately 430 minutes and showed a 2. 5 ×10^-8 ms^-2 gravity change. After correcting for the relaxation process, it is shown that a coseismic gravity change of approximately +0.59 +-0. 4 ~ 10-Sms-2 was observed by the GS15 gravimeter; this agrees with the simulated gravity change of approximately 0.31 ~ 10 -8 ms-2. The rate of the coseismie gravity change and the coseismic vertical displacement, as measured by one-second and one-day sampling interval GPS units, is also consistent with the theoretical rate of change. Therefore, the GS15 gravimeter at the Pixian Station observed a coseismic gravity change after the Ms7.0 Lushan earthquake. This and similar measurements could be applied to test and confirm the theory used for these simulations. 展开更多
关键词 GS15 gravimeter coseismic gravity change the ms7. 0 Lushan earthquake
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Surface rupture zone of the 1303 Hongtong M=8 earthquake, Shanxi Province 被引量:4
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作者 JIANG Wa-li(江娃利) +5 位作者 DENG Qi-dong(邓起东) XU Xi-wei(徐锡伟) XIE Xin-sheng(谢新生) 《Acta Seismologica Sinica(English Edition)》 CSCD 2004年第4期389-397,共9页
Based on the latest displacement of Huoshan piedmont fault, Mianshan west-side fault and Taigu fault obtained from the beginning of 1990s up to the present, the characteristics of distribution and displacement of surf... Based on the latest displacement of Huoshan piedmont fault, Mianshan west-side fault and Taigu fault obtained from the beginning of 1990s up to the present, the characteristics of distribution and displacement of surface rup-ture zone of the 1303 Hongtong M = 8 earthquake, Shanxi Province are synthesized and discussed in the paper. If Taigu fault, Mianshan west-side fault and Huoshan piedmont fault were contemporarily active during the 1303 Hongtong M = 8 earthquake, the surface rupture zone would be 160 km long and could be divided into 3 segments, that is, the 50-km-long Huoshan piedmont fault segment, 35-km-long Mianshan west-side fault segment and 70-km-long Taigu fault segment, respectively. Among them, there exist 4 km and 8 km step regions. The surface rupture zone exhibits right-lateral features. The displacements of northern and central segments are respectively 6~7 m and the southern segment has the maximum displacement of 10 m. The single basin-boundary fault of Shanxi fault-depression system usually corresponds to M 7 earthquake, while this great earthquake (M = 8) broke through the obstacle between two basins. It shows that the surface rupture scale of great earthquake is changeable. 展开更多
关键词 M = 8 earthquake surface rupture zone changeability of rupture scale
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基于改进YOLO v8的轻量化玉米害虫识别方法
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作者 李志良 李梦霞 +1 位作者 董勇 李龙 《江苏农业科学》 北大核心 2024年第14期196-206,共11页
针对目前玉米害虫识别领域中识别算法参数量大、计算量大导致玉米害虫识别算法不能部署在移动智慧农业设备中及玉米害虫识别算法检测精度低等问题,基于网络复杂程度最小的YOLO v8n,提出一种轻量化玉米害虫识别算法YOLO v8n-ERM。首先,... 针对目前玉米害虫识别领域中识别算法参数量大、计算量大导致玉米害虫识别算法不能部署在移动智慧农业设备中及玉米害虫识别算法检测精度低等问题,基于网络复杂程度最小的YOLO v8n,提出一种轻量化玉米害虫识别算法YOLO v8n-ERM。首先,在骨干特征提取网络引入EfficientNet-B0轻量化网络,通过对神经网络模型进行缩放,采用深度可分离卷积,有效降低了模型参数量、计算量;在颈部网络中引入RepVGG结构重参数化模块,融合多分支特征以提升模型的检测精度,同时有效降低模型的计算量;最后,用MPDIoU损失函数替换原损失函数,使最终预测框更接近真实框。用本研究算法处理数据增强后的IP102数据集,结果表明,相较于基线模型YOLO v8n,YOLO v8n-ERM算法的参数量为2.4 M,计算量为3.7 GFLOPs,二者分别下降了0.6 M、4.4 GFLOPs,而且YOLO v8n-ERM算法的mAP@0.5、mAP@0.5∶0.95分别为91.8%、62.0%,相较于基线模型分别提升了3.6、2.1百分点,表明使用更少的参数量、计算量得到了更高的精度。另外在黑暗、有遮挡、个体重叠及害虫与环境背景相似的复杂环境下的处理结果表明,YOLO v8n-ERM算法能够准确识别出玉米害虫个体,极大降低了复杂环境下的漏检率,具有一定的鲁棒性,可为玉米病虫害的数字智能防控提供技术支持。 展开更多
关键词 玉米害虫识别 YOLO v8 EfficientNet-B0 RepVGG MPDIoU
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The GIS and analysis of earthquake damage distribution of the 1303 Hongtong M=8 earthquake 被引量:1
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作者 GAO Meng-tan(高孟潭) +5 位作者 JIN Xue-shen(金学申) AN Wei-ping(安卫平) Xiao-jian(吕晓健) 《Acta Seismologica Sinica(English Edition)》 CSCD 2004年第4期398-404,共7页
The geography information system of the 1303 Hongtong M=8 earthquake has been established. Using the spatial analysis function of GIS, the spatial distribution characteristics of damage and isoseismal of the earthquak... The geography information system of the 1303 Hongtong M=8 earthquake has been established. Using the spatial analysis function of GIS, the spatial distribution characteristics of damage and isoseismal of the earthquake are studied. By comparing with the standard earthquake intensity attenuation relationship, the abnormal damage dis-tribution of the earthquake is found, so the relationship of the abnormal distribution with tectonics, site condition and basin are analyzed. In this paper, the influence on the ground motion generated by earthquake source and the underground structures near source also are studied. The influence on seismic zonation, anti-earthquake design, earthquake prediction and earthquake emergency responding produced by the abnormal density distribution are discussed. 展开更多
关键词 the 1303 Hongtong M=8 earthquake damage distribution Geography Information System strong ground motion near source
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Ionospheric total electron content disturbance associated with May 12, 2008,Wenchuan earthquake 被引量:3
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作者 Li Jianyong Meng Guojie +3 位作者 You Xinzhao Zhang Rui Shi Hongbo Han Yufei 《Geodesy and Geodynamics》 2015年第2期126-134,共9页
Possible ionospheric disturbances relating to the May 12, 2008, MsS.0 Wenchuan earthquake were identified by Global Positioning System (GPS)-derived total electron content (TEC), ion- osonde observations, the glob... Possible ionospheric disturbances relating to the May 12, 2008, MsS.0 Wenchuan earthquake were identified by Global Positioning System (GPS)-derived total electron content (TEC), ion- osonde observations, the global ionospheric map (GIM), and electron density profiles detected by the Constellation Observation System for Meteorology Ionosphere and Climate (COSMIC). We applied a statistical test to detect anomalous TEC signals and found that a unique enhancement in TEC, recorded at 16 GPS stations, appeared on May 9, 2008. The critical fre- quency at F2 peak (foF2), observed by the Chinese ionosondes, and maximal plasma frequency, derived from COSMIC data, revealed a characteristic similar to GPS TEC variations. The GIM showed that the anomalous variations of May 9 were located southeast of the epicenter. Using GPS data from 13 stations near the epicenter, we analyzed the TEC variations of satellite orbit traces during 04:00-11:00 UT. We found that TEC decreased to the east and increased to the southeast of the epicenter during this period. Results showed that the abnormal disturbance on May 9 was probably an ionosphenc precursor of the Wenchuan earthquake of May 12, 2008. 展开更多
关键词 Ionospheric disturbance Global positioning system (GPS) Total electron content (TEC) Wenchuan earthquake Global ionospheric map (GIM) COSMIC F0F2 Crustal Movement Observation Network of China (CMONOC)
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Variation of the Energy Field of Longmenshan Fault Zone before the Wenchuan M_S 8. 0 Earthquake
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作者 Yang Mingzhi Ma Heqing 《Earthquake Research in China》 2012年第3期355-364,共10页
During the process of preparation and occurrence of a large earthquake, the stress-strain state along the fault zone has close relation with the weak seismicity around the fault zone. The seismic energy release near t... During the process of preparation and occurrence of a large earthquake, the stress-strain state along the fault zone has close relation with the weak seismicity around the fault zone. The seismic energy release near the fault zone before an earthquake can better reflect the dynamic process of earthquake preparation. Thus, in this paper, the method of natural orthogonal function expansion has been adopted to discuss the time variation about the energy field of the seismic activity along the Longmenshan fault zone before the Wenchuan MsS. 0 earthquake, 2008. The results show that evident short-term rise changes appeared in the time factors of the typical field corresponding to several key eigenvalues of the energy field along the Longmenshan fault zone before the Wenchuan earthquake, probably being the short-term anomaly message for this earthquake. Through contrastive analysis of earthquake examples such as the 1976 Tangshan earthquake, the authors think that the study of time variation of energy field of seismicity along active fault zone will be helpful for conducting intentional and intensive earthquake monitoring and forecast in active fault regions with high seismic risk based on medium- and long-term earthquake trend judgment. 展开更多
关键词 Longmenshan fault zone Energy field Natural orthogonal function expansion Time factor anomaly Wenchuan ms8. 0 earthquake
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Preliminary Study on the Relationship between the M_s8.0 Wenchuan Earthquake of 2008 and the Anomalies of Earth Resistivity Observed at Qingdao Seismic Station
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作者 Zhang Jihong Zhao Guoze +2 位作者 Wang Jinsheng Tang Tingmei Qi Lijie 《Earthquake Research in China》 2011年第2期158-165,共8页
Near-surface earth resistivity and underground water level anomalies were recorded at Qingdao seismic observatory of Shandong Province before and after the MS8.0 Wenchuan Earthquake of May 12,2008.The observed data of... Near-surface earth resistivity and underground water level anomalies were recorded at Qingdao seismic observatory of Shandong Province before and after the MS8.0 Wenchuan Earthquake of May 12,2008.The observed data of earth resistivity at the observatory revealed that the underground water level dropped and the resistivity increased.It is postulated that in the special tectonic setting at Qingdao observatory,the variation of stress and strain caused the change of water level beneath the station,thus,leading to the variation of earth resistivity.The relationship between the variation of stress field and the change of earth resistivity before earthquake is analyzed. 展开更多
关键词 Wenchuan ms8. 0 earthquake Earth resistivity Underground water level Stress field
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Analysis on Tectonic Movement of the Longmenshan Fault Zone before the Wenchuan M_S 8. 0 Great Earthquake
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作者 Ping Jianjun Jiang Zaisen +3 位作者 Feng Xiangdong Ping Caipeng Shan Lianjun Wang Xia 《Earthquake Research in China》 2014年第3期299-310,共12页
On the basis of elastic rebound theory,using the horizontal velocity field of the Chinese mainland calculated from GPS data during three observation periods from 1999 to 2007,the velocity components that are parallel ... On the basis of elastic rebound theory,using the horizontal velocity field of the Chinese mainland calculated from GPS data during three observation periods from 1999 to 2007,the velocity components that are parallel and plumb to the fault zone are calculated respectively for different periods,and then relative ground movements of two sides of the fault zone are analyzed with power function fitting and graphics. The results show that the relative ground movement shows right-lateral shear deformation before the Wenchuan MS8. 0 earthquake,and at the same time the movement was hindered by the Longmenshan fault zone. Thus,this result has positive significance for distinguishing the elastic strain energy accumulation and deformation anomaly in an earthquake preparation process,and for conducting further research on earthquake prediction. 展开更多
关键词 LONGMENSHAN GPS Right-lateral shear Elastic strain The Wenchuanms8. 0 earthquake
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Analysis and Study on the Change of the Observed Geo-electric Field Data at Lhasa Geomagnetic Station before and after the Nepal MS8.1 Earthquake
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作者 Xi Jilou Guan Huaping +7 位作者 Liu Chao Zhuang Nan Guan Xinying Yang Xiaoming Zhang Zhiguo Ci Zhuoga Kelsang Drolma Ma Aiming 《Earthquake Research in China》 CSCD 2016年第4期526-541,共16页
In this paper,the main purpose is to analyze and research the characteristics of the geoelectric field observed data with a long time span and large amplitude abnormal change,at the Lhasa geomagnetic station( hereafte... In this paper,the main purpose is to analyze and research the characteristics of the geoelectric field observed data with a long time span and large amplitude abnormal change,at the Lhasa geomagnetic station( hereafter referred to as "Lhasa station "),before and after the Nepal M_S8. 1 strong earthquake,which occurred on April 25,2015. Based on the observation conditions,the observation system,and the observed data of Lhasa station preliminary discussed,the main characteristics of the abnormal change and evolution process are analyzed and studied,using the following two methods; the "synthesis energy accumulation"and the "power as MSA spectrum"analysis,from the two aspects of the"Time Domain"and"Frequency Domain. "The results show that the abnormal change of the geo-electric field observation of Lhasa station experienced a development stage following the process of "trend change- disturbance change- earthquake period-recovery period",and an evolution process of "low frequency change- high frequency change- smooth change- high frequency change ",before and after the Nepal M_S8. 1strong earthquake. Comprehensive analysis shows that the variation characteristics and evolution process of the geo-electric field at Lhasa station are basically consistent with the results of the relevant mechanism and phenomenon research. So far,this is valuable information with certain objectivity,which is typical and representative to reflect the whole process of the gestation, occurrence and complete development of such strongearthquakes. 展开更多
关键词 Geo-electric field Nepal ms8. 1 earthquake Lhasa geomagnetic station Abnormal change Synthesis energy accumulation Power as msA spectrum
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Field Investigation of the M_S6.8 Wuqia,Xinjiang Earthquake on October 5,2008
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作者 Chen Jianbo Tan Ming +8 位作者 Kou Dabing Gao Guoying Hu Weihua Du Chunqing Hou Jiansheng Li Zhiqiang Zhao Baozong Zhang Tiangang Ning Baokun 《Earthquake Research in China》 2010年第4期515-523,共9页
A Ms6. 8 earthquake occurred on October 5, 2008 in the Wuqia region in Xinjiang. The macroseismic epicenter is situated in the Nula village of the Kyrghyz Republic, 7km southwest of the Wuqia Yierkeshitan Port in Xinj... A Ms6. 8 earthquake occurred on October 5, 2008 in the Wuqia region in Xinjiang. The macroseismic epicenter is situated in the Nula village of the Kyrghyz Republic, 7km southwest of the Wuqia Yierkeshitan Port in Xinjiang. The epicenter intensity is VIII degrees (outside borders). The areas of intensity VII and VI are 7354km^2 and 1031km^2, respectively. This seismic event is related with movement of the NE-trending Kzikeaerkate fault belt. Buildings in the earthquake-stricken area were damaged or affected to a certain extent by this earthquake, accompanied with some phenomena of geological disaster. 展开更多
关键词 earthquake site investigation Wuqia earthquake with ms6. 8 Seismic intensity Seismogenic fault
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The Contrast Study of Precursor Anomalies before the M_S 8. 0 Wenchuan Earthquake
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作者 Chen Lide Fu Hong 《Earthquake Research in China》 2012年第3期365-376,共12页
The contrast research results show that the number of items and stations with imminent, short and medium term precursor anomalies for the Wenchuan M_S 8. 0 earthquake is less than that of the Menglian earthquake. The ... The contrast research results show that the number of items and stations with imminent, short and medium term precursor anomalies for the Wenchuan M_S 8. 0 earthquake is less than that of the Menglian earthquake. The number of anomalies and stations associated with the Wenchuan earthquake increased in the early stage of the short-term range,as opposed to the later period for the Menglian and Lijiang earthquakes. Most of the medium term anomalies occurred two to three years before the Wenchuan earthquake,when the number of anomaly stations and items was eleven,and a great change appeared in the observation values in about half of the stations ( items ) . However,for the Menglian earthquake,medium term anomalies happened one to two years before the earthquake, the number of abnormal stations and items reached 20,and a sharp change appeared in the observation values six months to one year before the earthquake in about 30 percent of the stations or items. In the epicenter and the nearby area,the macroscopic abnormalities started 3 years before the Wenchuan earthquake and lasted intermittently until 1 month before the earthquake. Within 2 percent of the total area of the province,the macroscopic abnormalities accounted for 30 to 50 percent of the total number of anomalies of the Province. For the Xingtai,Tangshan,Haicheng,Songpan earthquakes,the macroscopic anomalies started two to three months before,or on the very day of the earthquakes. The common feature of the precursors between the Wenchuan and other strong earthquakes is the appearance of tremendous changes in a certain number of observation values of anomalies in the mid and short terms before all these earthquakes. 展开更多
关键词 Wenehuan msS. 0 earthquake Precursor anomalies Contrast study
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Research on Stress Drops and the Focal Mechanisms of the Xinyuan- Hejing ML6.8 Earthquake Sequences
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作者 Liu Jianming Wang Qiong +4 位作者 Liu Jie Deng Fei Xiang Yuan Yang Wen Li Jin 《Earthquake Research in China》 CSCD 2017年第1期25-38,共14页
Based on the digital waveform data recorded by Xinjiang Digital Seismic Network for the Xinyuan-Hejing M_L6.8 earthquake sequences of June 30,2012,this paper analyzes the stress drops of earthquake sequences and the c... Based on the digital waveform data recorded by Xinjiang Digital Seismic Network for the Xinyuan-Hejing M_L6.8 earthquake sequences of June 30,2012,this paper analyzes the stress drops of earthquake sequences and the correlation coefficients of focal mechanisms significant for strong aftershocks.Firstly,the source parameters of the Xinyuan-Hejing M_L6.8 earthquake sequences are obtained by applying the spectrum analysis and the Brunes source model.Then,the correlation coefficients of spectral amplitudes are calculated using the low-frequency spectral amplitude recorded by the same station for the different events.Finally,based on the results of the correlation coefficients of spectral amplitudes,the events with similar focal mechanisms are grouped using the clustering method.The results show that:(1)The stress drop values show a steady trend in the aftershock sequence calm period and the stress drop values show a rise-fall in strong aftershocks.(2)The moving average correlation coefficient of amplitude spectrum begins to spread after the main shock.It shows that the correlation decreases between the main shock and the aftershocks in mechanisms.(3)The results of focal mechanism groups show that the earthquake sequences are mainly strike slips.The stress distribution of the main pressure axis is nearly NS,which is the same as the structural stress field.(4)The magnitude and mechanism show that there is an agreement before the strong aftershock,which shows that the regional stress field is enhanced. 展开更多
关键词 Xinyuan-Hejing ML6. 8 earthquake sequences Stress drop The correlationof the focal mechanism Body-wave spectral amplitude Clustering group
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The Co-seismic Response of Underground Fluid in Yunnan to the Nepal MS8.1 Earthquake
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作者 Zhang Li Su Youjin +2 位作者 Luo Ruijie Gao Wenfei Zhang Ping 《Earthquake Research in China》 CSCD 2017年第2期201-212,共12页
In this paper,statistics are taken on the co-seismic response of underground fluid in Yunnan to the Nepal M_S8. 1 earthquake,and the co-seismic response characteristics of the water level and water temperature are ana... In this paper,statistics are taken on the co-seismic response of underground fluid in Yunnan to the Nepal M_S8. 1 earthquake,and the co-seismic response characteristics of the water level and water temperature are analyzed and summarized with the digital data. The results show that the Nepal M_S8. 1 earthquake had greater impact on the Yunnan region,and the macro and micro dynamics of fluids showed significant co-seismic response. The earthquake recording capacity of water level and temperature measurement is significantly higher than that of water radon and water quality to this large earthquake; the maximum amplitude and duration of co-seismic response of water level and water temperature vary greatly in different wells. The changing forms are dominated by fluctuation and step rise in water level,and a rising or falling restoration in water temperature. From the records of the main shock and the maximum strong aftershock,we can see that the greater magnitude of earthquake,the higher ratio of the occurrence of co-seismic response,and in the same well,the larger the response amplitude,as well as the longer the duration. The amplitude and duration of co-seismic response recorded by different instruments in a same well are different. Water temperature co-seismic response almost occurred in wells with water level response,indicating that the well water level and water temperature are closely related in co-seismic response,and the well water temperature seismic response was caused mainly by well water level seismic response. 展开更多
关键词 Nepal ms8. 1 earthquake Underground fluid in Yunnan Co-seismic response Well water level Water temperature Digital observations Step change Fluctuation
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汶川8.0级地震前区域地壳运动与变形动态过程 被引量:122
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作者 江在森 方颖 +3 位作者 武艳强 王敏 杜方 平建军 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2009年第2期505-518,共14页
利用GPS等观测资料研究了2008年汶川8.0级地震前的区域地壳运动与构造变形、应变积累,以及大区域地壳运动微动态变化过程,结合同震位移场分布等分析、讨论了汶川地震前近10年区域地壳变形的表象所反映的大震孕震最后阶段的物理过程.结... 利用GPS等观测资料研究了2008年汶川8.0级地震前的区域地壳运动与构造变形、应变积累,以及大区域地壳运动微动态变化过程,结合同震位移场分布等分析、讨论了汶川地震前近10年区域地壳变形的表象所反映的大震孕震最后阶段的物理过程.结果表明,发生汶川8.0级地震的龙门山断裂带1999-2004年相对稳定的华南地块无明显的相对运动,2004-2007年有一定程度的相对运动显示,以右旋活动为主,年速率为1. 6mm/a.龙门山断裂带西北侧的巴颜喀拉地块东部为右旋剪切为主兼有推挤的大尺度缓慢变形状态,右旋扭动变形率为2.1±0.2(10^(-8)/a),地壳总体缩短变形率为-0.7±0.1(10^(-8)/a).由GPS基准站资料计算的基线时间序列显示,2005年以来大尺度北东向地壳缩短的相对运动明显增强,青藏块体相对华南地块的北东向运动明显增强.对汶川大地震前应变积累的特殊性等问题进行了初步讨论,分析认为,汶川大地震的发生是四川盆地西缘的龙门山断裂带受到其西侧巴颜喀拉地块推挤导致大尺度、长时期、缓慢的地壳应变积累的结果.在发震前不仅龙门山断裂带为显著闭锁状态,且孕震区域可能存在地壳弹性变形趋于极限后难以发生变形的相持阶段,大尺度地壳运动与动力环境的动态变化对汶川大地震的发生有促进影响. 展开更多
关键词 汶川ms8.0地震 GPS 地壳运动与变形 动态过程 孕震过程
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CeO_2表面修饰提高锂离子电池正极材料LiNi_(0.80)Co_(0.15)Al_(0.05)O_2的循环及存储性能 被引量:8
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作者 夏书标 张英杰 +2 位作者 董鹏 杨瑞明 张雁南 《无机化学学报》 SCIE CAS CSCD 北大核心 2014年第3期529-535,共7页
采用共沉淀法制备锂离子电池正极材料LiNi0.8Co0.15Al0.05O2。通过溶胶凝胶法对LiNi0.8Co0.15Al0.05O2材料进行表面修饰提高循环和存储性能,包覆后的材料经过600 ℃热处理4 h。测试结果显示,0.2C下,CeO2包覆量为0.02%(物质的量比)... 采用共沉淀法制备锂离子电池正极材料LiNi0.8Co0.15Al0.05O2。通过溶胶凝胶法对LiNi0.8Co0.15Al0.05O2材料进行表面修饰提高循环和存储性能,包覆后的材料经过600 ℃热处理4 h。测试结果显示,0.2C下,CeO2包覆量为0.02%(物质的量比)时首次放电比容量为182.44 mAh·g-1,与未包覆样品相比没有下降;同时包覆后拥有更优的容量保持率,在2.75~4.3 V,0.5C下,100次循环后容量保持达到85.96%。包覆CeO2不仅可以阻止电极与电解液之间的副反应,而且高氧化性CeO2包覆层可以提前与电解液反应,从而消耗电解液中痕量的水和HF,保护内部活性材料。 展开更多
关键词 LINI0 8Co0 15Al0 05O2正极 CeO2包覆 循环性能 电解液
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