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Positions and Widths of Anticrossings for Potassium Rydberg Stark States

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Communications in Theoretical Physics 2007年第1期47卷 119-126页

The B-spline expansion technique is applied to study the anticrossings for potassium Rydberg states in a static electric field. The results of our calculation indicate that the antierossings are caused mainly by the core interaction or by the fine structure interaction. Our results for the positions and the widths of the anticrossings are in good agreement with experimental data.

关键词： B-splines model potential anticrossing Rydberg atom Stark state

Anonymous authentication scheme of trusted mobile terminal under mobile Internet

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The Journal of China Universities of Posts and Telecommunications 2013年第1期20卷 58-65页

作者： ZHANG De-dong MA zhao-feng NIU xin-xin Peng Yong Information Security Center Beijing University of Posts and Telecommunications National Engineering Laboratory for Disaster Backup and Recovery Beijing University of Posts and Telecommunications China Information Technology Security Evaluation Center

In order to solve the contradictions between user privacy protection and identity authentication, an anonymous authentication scheme under mobile Internet is proposed, which is based on the direct anonymous attestation of trusted computing and uses the encrypting transfer and signature validation for its implementation. Aiming at two access mode of trusted mobile terminal under mobile Internet, self access and cross-domain access, the authentication process of each mode is described in details. The analysis shows that the scheme implements anonymous authentication on mobile Internet and is correct, controllable and unforgeable.

关键词： trusted platform module anonymous authentication strong RSA assumption remote attestation

Gradient maturation experiment on hairs implies taphonomic changes in fossil hairs

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Science China Earth Sciences 2025年第1期 62-73页

作者： xin LI Yibo ZHOU Tao zhao xingjian HE Yanhong PAN State Key Laboratory for Mineral Deposits Research Center for Critical Earth Material Cycling Centre for Research and Education on Biological Evolution and Environment and Frontiers Science School of Earth Sciences and Engineering Nanjing University Institute of Palaeontology Yunnan Key Laboratory of Earth System Science Yunnan Key Laboratory for PalaeobiologyYunnan University

Mammalian hair, as a key feature related to endothermy, physical protection, and camouflage, has a long geohistorical record that dates back even to the Mesozoic. However, the limited information on the taphonomy of hair hinders the understanding of its evolutionary significance in deep time. To address this, we conducted taphonomic experiments to simulate the transformation process of black hair. The changes in the morphological structure, microscopic characteristics, and chemical composition of hair during the simulated fossilization process were documented by scanning electron microscopy, Fourier transform infrared(FTIR) spectroscopy, and Raman spectroscopy. Our results revealed that damage to the morphology of hair began at a mild temperature(150–175°C), and hair transformed into a fluid-like mass at a relatively high temperature(200°C). In addition, the morphological structure of melanosomes had relatively greater preservation potential than keratins did, and the microscopic features of melanosomes were persistently stable. The Raman and FTIR spectra indicated that the characteristic melanin and keratin peaks changed as the temperature increased. Although the chemical signals were not lost completely, the variations in the characteristic amide bands in the FTIR spectra indicate that the keratins severely degraded at high temperatures(>200°C), whereas the characteristic melanin bands in the Raman spectra suggested that melanin signals were still recognizable, even at high temperatures(>200°C). These results were confirmed by principal component analysis(PCA) and principal component analysis linear discriminant analysis(PCA–LDA). In addition, the Raman signals of all the samples in the simulated experiments were distinguished from the signals of common geological carbonaceous materials(humic acid), which suggested that Raman spectroscopy can be used to detect melanin in fossils.

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Surface effects on cylindrical indentation of a soft layer on a rigid substrate

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Acta Mechanica Sinica 2020年第2期36卷 422-429页

作者： Min Li Huan-xin Zhang Zi-Long zhao Xi-Qiao feng Institute of Biomechanics and Medical Engineering AMLDepartment of Engineering MechanicsTsinghua UniversityBeijing 100084China

In this paper,theoretical and numerical methods are combined to investigate the two-dimensional,cylindrical indentation of an elastic soft layer bonded on a rigid *** incorporating the Gurtin-Murdoch’s theory of surface elasticity into the Kerr model,we account for surface effects on the indentation behavior of a soft *** governing differential relation between the surface pressure and displacement of the film-substrate system is *** an incompressible thin layer,the explicit solutions are derived,which are simple and *** element simulations are performed using an explicit restart algorithm to study the indentation properties of the layer-substrate system and to examine the validity and accuracy of the theoretical *** work holds promise for applications in mechanical characterization of soft materials,such as biological tissues and cells.

关键词： Soft materials Indentation Surface effect Contact Kerr model

Conditional Random Field Tracking Model Based on a Visual Long Short Term Memory Network

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Journal of Electronic Science and Technology 2020年第4期18卷 308-319页

作者： Pei-xin Liu zhao-Sheng Zhu Xiao-feng Ye Xiao-feng Li School of Information and Communication Engineering University of Electronic Science and Technology of ChinaChengdu 611731

In dense pedestrian tracking,frequent object occlusions and close distances between objects cause difficulty when accurately estimating object *** this study,a conditional random field tracking model is established by using a visual long short term memory network in the three-dimensional(3D)space and the motion estimations jointly performed on object trajectory *** visual field information is added to the long short term memory network to improve the accuracy of the motion related object pair selection and motion *** address the uncertainty of the length and interval of trajectory segments,a multimode long short term memory network is proposed for the object motion *** tracking performance is evaluated using the PETS2009 *** experimental results show that the proposed method achieves better performance than the tracking methods based on the independent motion estimation.

关键词： Conditional random field(CRF) long short term memory network(LSTM) motion estimation multiple object tracking(MOT)

Clinical Experience of zhao＇s Artificial Trachea

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Chinese Medical Journal 2016年第1期129卷 95-97页

作者： Wei zhao Li-xin Tian Xiao-Rui Zhou feng-Rui zhao Department of Anesthesia China-Japan Friendship Hospital Beijing 100029 China Department of Thoracic Surgery Beijing Jiangong Hospital Beijing 100054 China Department of Anesthesia First Hospital of Tsinghua University Beijing 100016 China

The practice of artificial tracheal prosthesis has been a major challenge to the entire surgical field worldwide until now. The previously applied prosthesis is ＂inner stent＂ type, which is unable to heal biologically with native trachea, The newly developed design, the zhao＇s artificial trachea, uses a memory alloy mesh combined with traditional operation procedures. Following a 2-year experimental period, the device has been applied to seven patients with satisfying results.

关键词： Reconstruction Trachea Resection zhao's Artificial Trachea

Gray Cast Iron With Directional Graphite Flakes Produced by Cylinder Covered Compression Process

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Journal of Iron and Steel Research International 2007年第5期14卷 52-55页

作者： zhao xin WANG Jin-feng JING Tian-fu The Sixth Department Zhengzhou Institute of Aeronautics Zhengzhou 450015 Henan China State Key Lab of Metastable Materials Science and Technology Yanshan University Qinhuangdao 066004 Hebei China

A new plastic deformation process for gray cast iron named cylinder covered compression （CCC） was developed. By CCC process, gray cast iron （GCI） specimens, which are embedded in steel cylinders, were hot compressed up to 80% reduction in height without the cracking problem. It was clearly observed that the uniform distribution of directional graphite flakes appeared after more than 45 % reduction hot compression. The strength, ductility, and microhardness of GCI after 80% reduction deformation were significantly enhanced： the tensile strength varied from 117 MPa to 249 MPa, while the total elongation varied from 0 to 5.2%, and the microhardness varied from 153 HV to 217 HV. It was shown that the tensile fracture surface presented ductility characters after more than 45% reduction hot deformation.

关键词： gray cast iron hot working tensile strength elongation hardness

Secure and efficient anonymous proxy signature scheme in the random oracle model

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The Journal of China Universities of Posts and Telecommunications 2013年第4期20卷 87-92页

作者： ZHANG De-dong MA zhao-feng NIU xin-xin LI Guo-you Information Security Center Beijing University of Posts and Telecommunications Institute of Computing Technology China Academy of Railway Sciences

Anonymous proxy signature scheme can provide the privacy protection for the proxy signer. Recently, Yu et al. proposed an anonymous proxy signature, which can be viewed as the organic combination of proxy signature and ring signature. However, the efficiency is low. In this paper, we propose an efficient and secure proxy signature with the properties of anonymity and traceability, and it is provably secure in the random oracle model. Compared with Yu et al.＇s scheme, the scheme has higher efficiency.

关键词： anonymous proxy signature bilinear pairings random oracle model

Reduction of die roll height in duplex gears through a sheet-bulk metal forming method

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Advances in Manufacturing 2019年第1期7卷 42-51页

作者： Xiao-Long Sun xin-Cun Zhuang feng-Chun Yang Zhen zhao Institute of Forming Technology and Equipment School of Materials Science and Engineering Shanghai Jiao Tong University Shanghai 200030 People's Republic of China National Engineering Research Center of Die & Mold CAD Shanghai Jiao Tong University Shanghai 200030 People's Republic of China

In the existing shearing processes for fabricating parts such as duplex gears, die roll is difficult to avoid. Accordingly, a method based on sheet-bulk metal forming for fabricating a duplex gear with extremely small die roll in one stroke is proposed in the current work. The process could be divided into three stages according to the forming features: upsetting and shearing stage, lateral extrusion stage, and local filling stage. The die roll appeared in the shearing stage, which could be reduced in the subsequent extrusion and local filling stages. To reveal the underground mechanism, material flows under two situations, as a key factor to influence the forming quality, were compared and investigated. The results revealed that by controlling material flow, one could avoid the defects and reduce the die roll.

关键词： Die roll Duplex gear part Sheet-bulk metal forming Lateral extrusion Material flow