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Sequence Hiberarchy Evolution Measurement Method and its Application
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作者 Jian Ding QIU Ru Ping LIANG +1 位作者 Jin Yuan MO Xiao Yong ZOU 《Chinese Chemical Letters》 SCIE CAS CSCD 2005年第12期1645-1648,共4页
A novel method based on discrete wavelet transform (DWT) and cross-covariance for revealing the evolution of species at different spatial resolutions is presented. The trypsin proteins of different species are chose... A novel method based on discrete wavelet transform (DWT) and cross-covariance for revealing the evolution of species at different spatial resolutions is presented. The trypsin proteins of different species are chosen as an example to describe the evolution relationship according to the evolution vectors by using this method. The results indicated that this method is a promising approach to reveal species evolution at different spatial resolutions. 展开更多
关键词 sequence hiberarchy evolution measurement protein evolution hydrophobicity
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Characteristics of geological structures in Shiling and Zhuanshanhu areas of Yehe Uplift,NE China
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作者 GUAN Yue YU Yinghua +1 位作者 ZHANG Yaxiong YUAN Hongqi 《Global Geology》 2024年第2期105-120,共16页
The basin marginal fault system is the key to understand the formation and evolution of Songliao Basin.In order to investigate the influence of marginal fault system on the structural evolution of Songliao Basin,a com... The basin marginal fault system is the key to understand the formation and evolution of Songliao Basin.In order to investigate the influence of marginal fault system on the structural evolution of Songliao Basin,a comprehensive study was conducted on Shiling Town and Zhuanshanhu area of Yehe Town in Siping City of Jilin Province,where is the southeastern margin of the Songliao Basin and there are a series of well-exposed fault,fold and intrusive bodies belonging to the main marginal fault system of the Songliao Basin known as the Jiamusi-Yitong(Jia-Yi)fault zone.Through profile measurement and field investigation,samples with various lithologies and distinctive features were collected.Detailed field and laboratory works include component and microstructure analysis of these samples,rock-rock contact analysis,main strike measurement and statistics analysis.These data reveal the structural characteristics of the fold,fault and intrusive bodies in the study area.The research results show that the folds are distributed in the Mesozoic strata near the main fault of the eastern branch of the Jia-Yi fault zone,and the folded strata involve the Cretaceous Denglouku and Quantou formations.In addition,the section is dominated by high-angle strikeslip thrust faults.Light-colored veins and dark-colored veins are extensively distributed in the exposed granites.Statistical analysis of joint and fault attitudes in the study area reveals a right-lateral strike-sliping along the main fault.The large-scale right-lateral strike-slip and thrust fault system in Shiling Town occurred in right-lateral transpressive stage in Late Cretaceous.Based on the results above,tectonic evolution sequence in Shiling section of the Jia-Yi fault zone during the Mesozoic can be divided into five stages:Middle Jurassic left-lateral ductile strike-slip stage,Late Jurassic compression stage,Early Cretaceous tension stage,Early Cretaceous extension stage and Late Cretaceous right-lateral transpressive stage.These may have important constraint on understanding the Mesozoic evolution of the Songliao Basin. 展开更多
关键词 Jia-Yi fault structural characteristics evolution sequence Shiling Zhuanshanhu northern segment Tanlu fault
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Study on Carbonate Sequence Stratigraphy of Ordovician in Northern Ordos Basin
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作者 Wei Kuisheng Xu Huaida Ye Shufen (Department of Geology and Energy Resources, China University of Geoscience, Beijing 100083) 《Journal of Earth Science》 SCIE CAS CSCD 1996年第1期63-71,138-139,共11页
The formation of carbonates is different from that of siliciclastics. The controlling factors, such as the in-situ production of carbonates the transport, local variation in depositional processes and the way of dis... The formation of carbonates is different from that of siliciclastics. The controlling factors, such as the in-situ production of carbonates the transport, local variation in depositional processes and the way of dispersal are unique to carbonates systems, and have resulted in the formation of a wide variety of stratal patterns. The authors believe that all the factors influencing the formation of carbonates, such as the evolution of carbonate platform, transgression and regression, drowning and exposing of the platform, should be taken into consideration during the study of carbonate sequence stratigraphy.This paper attempts to summarize the study procedure in outcrop sequence stratigraphy and to describe the integrated identification of condensed section, first flooding surface and maximum flooding surface, so that the framework of high-resolution sequence stratigraphy can be constructed. During the Sandokan in early Ordovician, a carbonate-siliciclastic ramp was developed in northern Ordos, which changed into a carbonate rimmed shelf or a distally steepened ramp during the Zhuozishan and Kelimoli. It was the break in the Wulalike and Middle Ordovician,changing the sedimentary setting into an aulacogen According to the basin evolution, the authors have established some different idealized models for depositional sequences and systems tracts. 展开更多
关键词 carbonate origin sequence stratigraphic framework basin evolution model.
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The medium- and short-term prediction methods of strong earthquakes based on neural network
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作者 韩志强 王碧泉 《Acta Seismologica Sinica(English Edition)》 CSCD 1997年第4期35-43,共9页
The field of neural network has found solid application in the past ten years and the field itself is still developing rapidly. Neural network is composed of many simple elements operating in parallel. A neural netwo... The field of neural network has found solid application in the past ten years and the field itself is still developing rapidly. Neural network is composed of many simple elements operating in parallel. A neural network can be trained to perform a particular mapping and this is the basis of its application to practical problems. In this paper, new methods for predicting the strong earthquakes are presented based on neural network. Neural network learns from existing earthquake sequences or earthquake precursors how to make medium and short term prediction of strong earthquakes. This paper describes two neural network prediction models. One is the model based on earthquake evolution sequences, which is applied to the modeling of the magnitude evolution sequences in the Mainland of China, the other is based on earthquake precursors, which is applied to the modeling of the occurrence time of strong earthquakes in North China. Test results show that the prediction methods based on neural networks are efficient, and convenient. They would find more application in the future. 展开更多
关键词 earthquake prediction neural network modeling earthquake evolution sequence earthquake precursor
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Conservative Evolution of Hepatitis B Virus Precore and Core Gene During Immune Tolerant Phase in Intrafamilial Transmission
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作者 Yuqian Luo Le Zhang +3 位作者 Yimin Dai Yali Hu Biyun Xu Yi-Hua Zhou 《Virologica Sinica》 SCIE CAS CSCD 2020年第4期388-397,共10页
Hepatitis B virus(HBV)is characterized with high mutations,which is attributed to the lack of proof-reading of the viral reverse transcriptase and host immune pressure.In this study,31 HBV chronic carriers from 14 fam... Hepatitis B virus(HBV)is characterized with high mutations,which is attributed to the lack of proof-reading of the viral reverse transcriptase and host immune pressure.In this study,31 HBV chronic carriers from 14 families were enrolled to investigate the evolution of the same original HBV sources in different hosts.Sequences of pre-C and C(pre-C/C)genes were analyzed in eight pairs of HBV-infected mothers with longitudinal sera(at an interval of 6.0–7.2 years)and their children(5.5–6.7 years old),and in 15 adults(21–78 years old)from six families with known intrafamilial HBV infection.The pre-C/C sequences had almost no change in eight mothers during 6.0–7.2 years and their children who were in immune tolerant phase.The pre-C/C sequences from the 15 adults of six families,mostly in the immune-clearance phase or the low replicative phase,showed various diversified mutations between individuals from each family.Compared to a reference stain(GQ205441)isolated nearby,the pre-C/C in individuals in immune tolerant phase showed 98.56%–99.52%homology at nucleotide level and 99.5%–100%homology at amino acid level.In contrast,multiple mutations were developed in the immune-clearance phase or the low replicative phase,affecting immune epitopes in core gene and G1896 in pre-C gene.The results indicate that the evolution of new HBV variants is not mainly resulted from the spontaneous error rate of viral reverse transcription,but from the host immune pressure. 展开更多
关键词 Hepatitis B virus(HBV) Pre-C/C gene sequence evolution
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