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A rupture blank zone in middle south part of Longmenshan Faults: Effect after Lushan M_s7.0 earthquake of 20 April 2013 in Sichuan, China

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Science China Earth Sciences 2014年第9期57卷 2036-2044页

作者： gao yuan WANG Qiong zhao bo shi yutao Institute of Earthquake Science China Earthquake Administration Institute of Geophysics China Earthquake Administration China Earthquake Networks Center China Earthquake Administration

On April 20, 2013, the Lushan M^7.0 earthquake struck at the southern part of the Longmenshan fault in the eastern Tibetan Plateau, China. The shear-wave splitting in the crust indicates a connection between the direction of the principal crustal com- pressive stress and the fault orientation in the Longmenshan fault zone. Our relocation analysis of the aftershocks of the Lushan earthquake shows a gap between the location of the rupture zone of the Lushan Ms7.0 earthquake and that of the rup- ture zone of the Wenchuan MsS.0 earthquake. We believe that stress levels in the crust at the rupture gap and its vicinity should be monitored in the immediate future. We suggest using controlled source borehole measurements for this purpose.

关键词： Lushan earthquake Longmenshan Fault rupture gap crustal seismic anisotropy double difference relocation borehole measurements of stress change

Seismic relocation,focal mechanism and crustal seismic anisotropy associated with the 2010 Yushu M_S7.1 earthquake and its aftershocks

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Earthquake Science 2012年第1期25卷 111-119页

作者： bo zhao yutao shi yuan gao China Earthquake Networks Center Beijing 100045China Institute of Earthquake Science China Earthquake AdministrationBeijing 100036China Institute of Geophysics China Earthquake AdministrationBeijing 100081China

The 2010 Yushu MsT.1 earthquake occurred in Ganzi-Yushu fault, which is the south boundary of Bayan Har block. In this study, by using double difference algorithm, the locations of mainshock （33.13°N, 96.59°E, focal depth 10.22 km） and more than 600 aftershocks were obtained. The focal mechanisms of the mainshock and some aftershocks with Ms〉3.5 were estimated by jointly using broadband velocity waveforms from Global Seismic Network （GSN） and Qinghai Seismic Network as well. The focal mechanisms and relocation show that the strike of the fault plane is about 125° （WNW-ESE）, and the mainshock is left-laterally strikeslip. The parameters of shear-wave splitting were obtained at seismic stations of YUS and L6304 by systematic analysis method of shear-wave splitting （SAM） method. Based on the parameters of shear-wave splitting and focal mechanism, the characteristics of stress field in seismic source zone were analyzed. The directions of polarization at stations YUS and L6304 are different. It is concluded that after the mainshock and the Ms6.3 aftershock on April 14, the stress-field was changed.

关键词： Yushu earthquake double difference algorithm focal mechanism shear-wave splitting stress

Influence of longitudinal-torsional ultrasonic-assisted vibration on micro-hole drilling Ti-6Al-4V

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Chinese Journal of Aeronautics 2021年第9期34卷 247-260页

作者： Guofu gao Ziwen XIA zhaojie yuan Daohui XIANG bo zhao School of Mechanical and Power Engineering Henan Polytechnic UniversityJiaozuo 454000China

As Ti-6 Al-4 V is a typical hard to machine material,especially in micro drilling aviation parts,chip breaking difficulty is of increasing interest to explore its further *** this study,Longitudinal-Torsional Ultrasonic Assisted Drilling(LTUAD)was employed to machine Ti-6 Al-4 V,and its feasibility was evaluated by comparing with Conventional Drilling(CD).By combining periodical characteristics and vibration models(the separated or the unseparated ultrasonic elliptical vibration),the influence of ultrasonic frequency on the intersection characteristics of trajectories were *** the intersection characteristics were divided into four categories:even periodicity,odd periodicity,non-odd and even periodicity and composite periodicity,indicating different capability for chip *** applying the longitudinal-torsional compound vibration horn,the micro-hole drilling experiment was carried out on machining *** chip morphology,the thrust force,and the burr height were *** results showed that the morphology of chips presented as smaller and more fragmentary ones in LTUAD compared with continuous helical conical ones and fold-shaped ones in *** with CD,the average values of the thrust force in LTUAD reduced by 1.98%to 24.9%.According to the burr around the hole exit in both LTUAD and CD,the height of the latter was greatly affected by the drilling *** the burr around the exit of the hole were distributed rather evenly with smaller extension in ***,the LTUAD employed in micro-hole drilling was effective.

关键词： Capability for chip breaking Longitudinal-torsional ultrasonic assisted drilling Micro-hole drilling Periodical characters Ti-6Al-4V

On Shear Wave Splitting in the Zhangjiakou-bohai Sea Seismic Belt

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Earthquake Research in China 2014年第2期28卷 200-209页

作者： Sun Jin shi yutao zhao bo gao yuan Institute of Earthquake Science CEA Institute of Geological & Mineral Resources Survey of Henan Prorince China Earthquake Networks Center

The Zhangjiakou-bohai Sea seismic belt is an important seismic zone in North China. The direction of principal compressive stress is near EW in this region. According to digital seismic data from the Capital Region from September 2005 to September 2010,and using the SAM method,the spatial distribution of the crust anisotropy characteristics are studied and discussed in the middle-eastern part of the Zhangjiakou-bohai Sea seismic belt. The principal polarization direction,which is near EW direction,is obvious in the middleeastern Zhangjiakou-bohai Sea seismic belt. The spatial distribution of polarization direction crossing the Zhangjiakou-bohai Sea seismic belt shows that there is little difference among the Yanshan uplift area,inside of the seismic zone and North China basin,and the principal polarization direction is near EW.

关键词： Crustal anisotropy Shear-wave splitting Polarization Time delay The Zhangjiakou-bohai Sea seismic belt

Experimental investigation on aerodynamic and noise characteristics of Fenestron

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Chinese Journal of Aeronautics 2023年第12期36卷 88-101页

作者： bo WANG Wei ZHANG Fei WANG Qijun zhao Chenkai CAO yuan gao National Key Laboratory of Rotorcraft Aeromechanics Nanjing University of Aeronautics and AstronauticsNanjing 210016China China Helicopter Research and Development Institute Jingdezhen 333001China

It is difficult to simulate the strong interference and serious flow separation of Fenestron by the CFD method based on the widely used RANS equation,and the detailed experimental data,which could be used to validate the aerodynamic and noise numerical methods,is *** experimental investigation on the aerodynamic and noise characteristics of Fenestron is carried *** view of the complex internal flow field in duct and the relative motion between the stationary duct and the rotating rotor,a comprehensive aerodynamics and pressure measurement scheme is designed based on the bottom support *** this measurement scheme,the thrust generated by the rotating rotor can be measured by the rotating shaft balance,the thrusts from Fenestron are measured by the external balance and the pressures on duct inner wall are monitored by a pressure measuring *** fully capture the noise directionality of Fenestron,a series of noise observers located at an arc array are *** terms of the Fenestron test models,the baseline model,the performance improvement model based on the high-performance tail rotor and the noise reduction model based on the non-uniform blade distribution are designed *** the designed measurement scheme,aerodynamic forces and pressure distributions and noise were measured for the three different Fenestron *** results show that the aerodynamic thrusts of the tail rotor and duct increase greatly and the noise increases slightly for the performance improvement model because of the larger *** rotor aerodynamic performance of the noise reduction model is reduced,but the modulation effect of the tail rotor improves the forces of the *** noise radiated by the noise reduction model is reduced and a good noise reduction result is obtained in frequency domain.

关键词： Helicopter Fenestron Aeroacoustic wind tunnel Noise reduction Non-uniform rotor

Responses of the circulation and water mass in the Beibu Gulf to the seasonal forcing regimes

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Acta Oceanologica Sinica 2014年第7期33卷 1-11页

作者： gao Jingsong shi Maochong CHEN bo GUO Peifang zhao Dongliang Ocean University of China Guangxi Key Laboratory of Marine Environmental Science Guangxi Academy of Sciences

In the past 20 a, the gulf-scale circulation in the Beibu Gulf has been commonly accepted to be driven by a wind stress or density gradient. However, using three sensitive experiments based on a three-dimensional baroclinic model that was verified by observations, the formation mechanisms were revealed： the circula- tion in the northern Beibu Gulf was triggered by the monsoon wind throughout a year; whereas the southern gulf circulation was driven by the monsoon wind and South China Sea （SCS） circulation in winter and sum- mer, respectively. The force of heat flux and tidal harmonics had a strong effect on the circulation strength and range, as well as the local circulation structures, but these factors did not influence the major circulation structure in the Beibu Gulf. On the other hand, the Beibu Gulf Cold Water Mass （BGCWM） would disappear without the force of heat flux because the seasonal thermocline layer was generated by the input of heat so that the vertical mixing between the upper hot water and lower cold water was blocked. In addition, the wind-induced cyclonic gyre in the northern gulf was favorable to the existence of the BGCWM. However, the coverage area of the BGCWM was increased slightly without the force of the tidal harmonics. When the model was driven by the monthly averaged surface forcing, the circulation structure was changed to some extent, and the coverage area of the BGCWM almost extended outwards 100%, implying the circulation and water mass in the Beibu Gulf had strong responses to the temporal resolution of the surface forces.

关键词： Princeton ocean model (POM) Beibu Gulf (Gulf of Tonkin) circulation cold water mass response

A Security-Improved Scheme for Virtual TPM Based on KVM

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Wuhan University Journal of Natural Sciences 2015年第6期20卷 505-511页

作者： shi yuan zhao bo YU zhao ZHANG Huanguo School of Computer Key Laboratory of Aerospace Information Security and Trusted Computing Ministry of EducationWuhan University

Virtual trusted platform module （vTPM） is an impor- tant part in building trusted cloud environment. Aiming at the remediation of lack of effective security assurances of vTPM in- stances in the existing virtual TPM architecture, this paper pre- sents a security-improved scheme for virtual TPM based on ker- nel-based virtual machine （KVM）. By realizing the TPM2.0 speci- fication in hardware and software, we add protection for vTPM＇s secrets using the asymmetric encryption algorithm of TPM. This scheme supports the safety migration of a TPM key during VM-vTPM migration and the security association for different virtual machines （VMs） with vTPM instances. We implement a virtual trusted platform with higher security based on KVM virtual infrastructure. The experiments show that the proposed scheme can enhance the security of virtual trusted platform and has fewer additional performance loss for the VM migration with vTPM.

关键词： trusted computing virtual trusted platform mod- ule(vTPM) TPM2.0 kernel-based virtual machine (KVM)

Enhanced anti-icing properties of branched PDMS coatings with self-regulated surface patterns

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Science China(Technological Sciences) 2020年第6期63卷 960-970页

作者： PENG Jie LIU bo gao ShuHui ZHU KongYing zhao YunHui LI Xiao Hui yuan XiaoYan School of Materials Science and Engineering Tianjin Key Laboratory of Composite and Functional MaterialsTianjin UniversityTianjin 300350China Analysis and Measurement Center Tianjin UniversityTianjin 300072China

Adverse impact of icing,on either infrastructures or facilities,is the great impulsion for seeking anti-icing coatings with high *** this work,durable icephobic coatings with self-regulated surface patterns were developed from branched polydimethylsiloxane(PDMS)co-crosslinked with fluorinated polyhedral oligomeric silsesquioxane(POSS)through a breath figure *** prepared coatings with patterned microstructures on the surfaces exhibited excellent anti-icing performance ascribed to micro-crack generation between ice and coating surface under a small external *** stable cross-linked network composed of branched PDMS and fluorinated POSS endowed the coatings with durability and abrasion *** ice shear strength was achieved at approximate 19.7±2.5 kPa on coating surface with self-regulated honeycomb *** experiencing 30 icing/deicing cycles,the ice shear strength of the coating varied ***,owing to dedication of fluorinated POSS,the coating showed merely a little increase in ice shear strength after more than 1600 abrasion cycles,which was still in the icephobic range below 50 ***,the prepared coatings with remarkably enhanced anti-icing performance and superior mechanical stability would be promising for the practical applications.

关键词： branched PDMS fluorinated POSS patterned surfaces icephobic coatings durability

Nomogram model for predicting oculomotor nerve palsy in patients with intracranial aneurysm

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International Journal of Ophthalmology(English edition) 2022年第8期15卷 1316-1321页

作者： yuan-Yue Cui Bin Wang bo Jiang shi-Hong zhao Department of Ophthalmology Shanghai Children’s Medical CenterSchool of MedicineShanghai Jiao Tong UniversityShanghai 200127China Department of Neurosurgery Peking University International HospitalBeijing 102206China Department of Ophthalmolohy Anhui No.2 Provincial People’s HospitalHefei 230041Anhui ProvinceChina Nanjing Aier Eye Hospital Aier School of OphthalmologyCentral South UniversityChangsha 410015Hunan PronvinceChina Department of Ophthalmology the First Affiliated HospitalNaval Military Medical UniversityShanghai 200433China

AIM:To explore the risk factors of oculomotor nerve palsy(ONP)in patients with intracranial aneurysm(IA)and develop a nomogram model for predicting ONP of IA ***:A total of 329 IA patients were *** regression analysis was applied to identify independent factors,which were then integrated into the nomogram *** performance of the nomogram model was evaluated by calibration cur ve,receiver operating curve(ROC),and decision curve ***:Univariate and multivariate logistic regression analysis indicated posterior communicating artery(PCo A)aneur ysm[hazard ratio(HR)=17.13,P<0.001]and aneurysm diameter(HR=1.31,P<0.001)were independent risk factors of ONP in IA *** on the results of logistic regression analysis,a nomogram model for predicting the ONP in IA patients was *** calibration curve indicated the nomogram had a good agreement between the predictions and *** nomogram showed a high predictive accuracy and discriminative ability with an area under the curve(AUC)of *** decision curve analysis showed that the nomogram was powerful in the clinical *** A aneurysm(HR=3.38,P=0.015)was identified to be the only independent risk factor for ONP ***:PCo A aneurysm and aneurysm diameter are independent risk factors of ONP in IA *** nomogram established is performed reliably and accurately for predicting *** A aneurysm is the only independent risk factor for ONP severity.

关键词： intracranial aneurysm oculomotor nerve palsy Logistic regression analysis posterior communicating artery nomogram