检索结果-南通市图书馆

S-wave Q structure of the crust and upper mantle beneath Yunnan from surface waves

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2012年第5期55卷 858-868页

作者： CHEN Jia hu jiafu YANG HaiYan ZHANG XiaoMan WEN LiMin PENG HengChu Department of Geophysics Yunnan UniversityKunming 650091China

A phase-matched filtering technique is applied to extract fundamental mode signals from Rayleigh waves recorded at 62 digital seismic stations in the Yunnan and Sichuan *** use the fundamental mode of vibrations at two stations that are located on the same great circle as the focus to calculate an inter-station attenuation coefficient of the Rayleigh wave with periods between 0.40 and 80.64 s,and invert for the inter-station S-wave Q-factor (Qβ) at depths of 0-200 *** results indicate that Qβ in Yunnan is 20-140,presenting a low Qβ background with apparent lateral *** the Honghe Fault as the boundary,Qβ of the crust is only 20 on the west side,extending to a depth of 120 *** distribution of Qβ is consistent with large-scale Cenozoic volcanic and intrusive rocks in western Yunnan,implying that the crust and mantle are in the thermally active *** the eastern Yunnan Block,east of the Xiaojiang Fault,Qβ in the upper 120 km is 140 in the south but only 20 in the ***,around the Dukou-Chuxiong in the mid-Yunnan Block,Qβ in the lithosphere is relatively high at 60-100,corresponding to a stiff *** is because the suture between the Indian and Eurasian plates reversed the tension in the rifting stage into the compression of orogenesis,leading to the closure of a gap in the *** some time,interstitial fluids gradually disappeared,resulting in a high velocity layer in the crust and low heat flow on the *** Yunnan region consists of an obvious block of elevated Qβ,distributed within the low background,consistent with the distribution of heat-flow values on the *** Honghe and Xiaojiang faults are tectonic boundaries in addition to being boundaries between regions of high and low crustal Qβ.The low Qβ is probably the result of crustal rupture and disturbance caused by strong earthquakes and the upwelling of hot substances along the deep fault zones.

关键词： Yunnan region attenuation of surface wave phase-matched filtering S-wave Q-factor

Mating and reproductive characteristics of the pathogenic nematode Bursaphelenchus xylophilus

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2021年第3期32卷 1281-1286页

作者： Yongxia Li Mengge Gao Baojun Liu Xuan Wang jiafu hu Zhenyu Liu Xingyao Zhang Laboratory of Forest Pathogen Integrated Biology Research Institute of Forestry New TechnologyChinese Academy of ForestryBeijing 100091People’s Republic of China College of Forestry Zhejiang Agriculture and Forestry UniversityLin’an 311300ZhejiangPeople’s Republic of China College of Plant Protection Shandong Agricultural UniversityTai’an 271018ShandongPeople’s Republic of China Co-Innovation Center for Sustainable Forestry in Southern China Nanjing Forestry UniversityNanjing 210037JiangsuPeople’s Republic of China

Pine wood nematode(B ursaphelenchus xylophilus),one of the most destructive invasive species,has caused extremely serious economic,ecological and social losses in many countries throughout the *** the high reproductive rate of *** PWN is the main cause of rapid death of its pine hosts(Pinus spp.),understanding the reproductive and population biology and the ecology of this nmatode are of great *** study mainly focused on analyzing the mating process and population structure under different combinations of sex ratios for *** efficiency of *** peaked when the sex ratio(female to male)was 3.4:*** of the mating process for the different sex-ratio combinations indicated that *** had evolved alternative reproductive strategies to cope with complex copulating conditions to obtain a suitable population structure for further *** research provides fundamental information on the mechanism that is responsible for the rapid population growth of ***.

关键词： Reproductive strategy Reproductive efficiency Sex ratio Population structure Pine wood nematode

Molecular characterization and functional analysis of daf-8 in the pinewood nematode,Bursaphelenchus xylophilus

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2022年第2期33卷 689-698页

作者： Jinghan Wang huan Hong Rong Xie Jingjing Ji Kai Guo Liqun Bai Jia Tang Hongshi Yu Jianren Ye jiafu hu Nanjing Forestry University Nanjing 210037China Zhejiang Agricultural and Forestry University Hangzhou 311300China Yuhuan Natural Resources and Planning Bureau Taizhou 317600China School of BioSciences The University of MelbourneParkvilleVIC 3010Australia

Bursaphelenchus xylophilus,causal agent of pine wilt disease,causes extensive damage ***-gies are needed to inhibit population growth or block the spread of the invasive nematode to control pine wilt *** gene daf-8 plays crucial roles in larval develop-ment and dauer formation in Caenorhabditis elegans,but little is known about its orthologue in *** the present molecular characterization and functional analysis of daf-8 in ***(Bx-daf-8),RT-qPCR showed that the expression of Bx-daf-8 gradually increased during the embryonic stage,peaked in the second-stage juvenile(J2),then dramatically dropped in the J3,and remained at that low level for the rest of its ***-daf-8-transgenic *** was employed to mimic the spatiotemporal expression of Bx-daf-8,which was expressed close to the pharynx during early embryogenesis and weakly throughout the whole body during late *** was observed in head neurons and tail ganglions throughout all postembryonic *** embryos were severely abnormal,and hatching rate decreased sharply after Bx-daf-8 ***-16-1 and da-f16-2,downstream genes in the IIS pathway,also dropped sharply after Bx-daf-8 *** propose that TGFβmay crosstalk with the IIS pathway upstream of Bx-daf-16 and that daf-8 may act as a master regulator of daf-16 in ***,knockdown of Bx-daf-8 did not lead to constitutive developmental arrest at the dauer larval stage,indicating that dauer entry in *** might be controlled by several genes and is more complicated than in ***-daf-8 alone did not control the dauer entry in ***,but it was indispensable for embryogen-esis,providing a potential target for suppressing population growth of ***.

关键词： Daf-8 Expression pattern RNAi Embryogenesis Bursaphelenchus xylophilus

Rayleigh波在工程勘察中的解释方法探讨

在线全文

学校读者我要写书评

暂无评论

岩土工程学报 1999年第5期21卷 599-602页

作者：胡家富云南大学地球科学系昆明650091

介绍了Ｒａｙｌｅｉｇｈ波在工程勘察中的常用解释方法，分析了影响勘探精度的主要因素，并提出了一种简单的解释方法。利用两个不同模型的理论频散进行计算表明，即使模型中含明显的低速层，该方法所得剪切波速度结构与真实值也非常... 详细信息

介绍了Ｒａｙｌｅｉｇｈ波在工程勘察中的常用解释方法，分析了影响勘探精度的主要因素，并提出了一种简单的解释方法。利用两个不同模型的理论频散进行计算表明，即使模型中含明显的低速层，该方法所得剪切波速度结构与真实值也非常接近。对实测地震波处理所得结果与单孔测井所得结果也较为吻合。

关键词： Rayleigh波勘探解释

S-wave velocity and Poisson's ratio structure of crust in Yunnan and its implication

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2005年第2期48卷 210-218页

作者： hu jiafu, SU Youjin, Zhu Xiongguan & CHEN Yun Geophysical Department of Yunnan University, Kunming 650091, China Seismological Bureau of Yunnan Province, Kunming 650041, China Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100101, China 1. Geophysical Department of Yunnan University 650091 Kunming China 2. Seismological Bureau of Yunnan Province 650041 Kunming China 3. Institute of Geology and Geophysics Chinese Academy of Sciences 100101 Beijing China

Receiver function of body wave under the 23 stations in Yunnan was extracted from 3-component broadband digital recording of teleseismic event. Thus, the S-wave velocity structure and distribution characteristics of Poisson's ratio in crust of Yunnan are obtained by inversion. The results show that the crustal thickness is gradually thinned from north to south. The crustal thickness in Zhongdian of northwest reaches as many as 62.0 km and the one in Jinghong of further south end is only 30.2 km. What should be especially noted is that there exists a Moho upheaval running in NS in the Chuxiong region and a Moho concave is generally parallel to it in Dongchuan. In addition, there exists an obvious transversal inhomogeneity for the S-wave velocity structure in upper mantle and crust in the Yunnan region. The low velocity layer exists not only in 10.0-15.0 km in upper crust in some regions, but also in 30.0-40.0 km in lower crust. Generally, the Poisson's ratio is on the high side, however it has a better corresponding relation to the crustal velocity structure. An obvious block distribution feature is still shown on such a high background of Poisson's ratio. It is discovered by synthetically analyzing the velocity structure and Poisson's ratio distribution that there are high Poisson's ratio and complicated crust-mantle velocity structure feature in the Sichuan-Yunnan Diamond Block with Xiaojiang fault to be the east boundary and Yulong Snow Mountain fault to be the west boundary besides the frequent seismicity. This feature differs obviously from that of surrounding areas, which would provide geophysical evidence to deeply study the eastwardly flowage of lithospheric substances in the Qinghai-Tibet Plateau.

关键词： Yunnan, S-wave velocity, Poisson's ratio, Sichuan-Yunnan Diamond Block.

2007年宁洱M_S6.4地震的地面运动预测

在线全文

学校读者我要写书评

暂无评论

地震学报 2012年第3期34卷 339-349,425页

作者：毛燕胡家富昆明理工大学建筑工程学院中国昆明650224 云南省地震局中国昆明650224 云南大学资环学院中国昆明650091

根据普洱、西双版纳地区6个地震观测台站在2008—2009年获取的5级以上的地震资料,利用接收函数和面波衰减系数,反演得到了研究区域的S波速度结构和Qβ结构.基于该结构模型,采用随机振动理论方法,预测了2007年宁洱MS6.4地震发生后,在震... 详细信息

根据普洱、西双版纳地区6个地震观测台站在2008—2009年获取的5级以上的地震资料,利用接收函数和面波衰减系数,反演得到了研究区域的S波速度结构和Qβ结构.基于该结构模型,采用随机振动理论方法,预测了2007年宁洱MS6.4地震发生后,在震中距为10—300km范围内引起的地面运动,并借助获取的强震观测记录检验、评价了该预测结果.同时,将地面运动预测结果与利用回归衰减公式计算得到的结果进行对比,进而讨论该地震动预测方法在地面运动预测中的可行性.结果表明,该预测结果与实测结果吻合.

关键词：地面运动预测接收函数面波频散宁洱地震普洱西双版纳地区

在线全文

学校读者我要写书评

暂无评论

用面波估计浅土层的品质因子

地震学报 1999年第4期21卷 433-438页

作者：胡家富苏有锦云南大学地球科学系云南省地震局

根据一个５５ｍ测线记录到的瑞雷波，利用多通道记录处理方法得到５～４０Ｈｚ内的相、群速度频散，并由速度频散反演得到深度３５ｍ以上土层的剪切波速度结构；同时，计算出基阶瑞雷波振幅谱的空间分布，以线性回归方法得衰减系数频散... 详细信息

根据一个５５ｍ测线记录到的瑞雷波，利用多通道记录处理方法得到５～４０Ｈｚ内的相、群速度频散，并由速度频散反演得到深度３５ｍ以上土层的剪切波速度结构；同时，计算出基阶瑞雷波振幅谱的空间分布，以线性回归方法得衰减系数频散曲线；最后，反演得到各土层的Ｑβ结构．结果表明：在软沉积层里Ｑβ＜１０；

关键词：瑞雷波回归 Qβ结构土层品质因子地震波

在线全文

学校读者我要写书评

暂无评论

云南地区的地幔过渡带结构及其动力学意义

科学通报 2017年第16期62卷 1752-1765页

作者：薛明王苏徐晓雅胡家富云南大学地球物理系昆明650091 昆明南方地球物理技术开发有限公司昆明650091

计算云南及周边地区48个宽频地震台记录的8600个远震P波接收函数,并根据参考地球模型将接收函数从时间域转换到深度域.在转换深度550 km处,将1°×1°面元内的接收函数叠加成一道信号,共获得了沿纬度28°,27°,26°,25°,24°和23°N的... 详细信息

计算云南及周边地区48个宽频地震台记录的8600个远震P波接收函数,并根据参考地球模型将接收函数从时间域转换到深度域.在转换深度550 km处,将1°×1°面元内的接收函数叠加成一道信号,共获得了沿纬度28°,27°,26°,25°,24°和23°N的6个共转换面元叠加剖面,其叠加深度在0~800 km之间.结果表明:(1)在26°N以北的地区,410和660 km间断面的平均深度分别为407~408和663~667 km,地幔过渡带的平均厚度处于255~259 km之间,过渡带的厚度接近全球平均厚度250 km;(2)在26°N以南的地区,410和660 km间断面的平均深度分别为412~426和675~703 km,地幔过渡带的平均厚度处于262~279 km之间,明显大于全球平均厚度250 km.云南地区410和660km间断面的加深显然与印度板块在缅甸弧下方的俯冲有关,然而,从云南地区地幔过渡带的结构来分析,本文认为印度板块沿缅甸弧向东俯冲主要发生在26°N以南地区.

关键词： P波接收函数面元叠加地幔过渡带印度板块向东俯冲

在线全文

学校读者我要写书评

暂无评论

可验证外包解密的离线/在线属性基加密方案

电子与信息学报 2018年第12期40卷 2998-3006页

作者：赵志远孙磊户家富周时娥信息工程大学三院郑州450001

属性基加密可以为雾-云计算中的数据提供机密性保护和细粒度访问控制,但雾-云计算系统中的移动设备难以承担属性基加密的繁重计算负担。为解决该问题,该文提出一种可验证外包解密的离线/在线属性基加密方案。该方案能够实现离线/在线的... 详细信息

属性基加密可以为雾-云计算中的数据提供机密性保护和细粒度访问控制,但雾-云计算系统中的移动设备难以承担属性基加密的繁重计算负担。为解决该问题,该文提出一种可验证外包解密的离线/在线属性基加密方案。该方案能够实现离线/在线的密钥生成和数据加密,同时支持可验证外包解密。然后,给出方案的选择明文攻击的安全证明和可验证性的安全证明。之后,该文将转换阶段所需双线性对的计算量降为恒定常数。最后,从理论和实验两方面对所提方案进行性能分析,实验结果表明该方案是有效且实用的。

关键词：属性基加密离线/在线外包解密可验证性