Entity

Time filter

Source Type

Beijing, China

Song L.,Xian Shiyou University | Song L.,Northwest University, China | Liu C.,Northwest University, China | Guo Z.,Peiking University | And 5 more authors.
Scientia Geologica Sinica | Year: 2013

Sangshutai fractures belt is in the western magin faul of Lishu fault depression, which consists of Sunjiatun fault, Xidingjia linkage fault, Sangshutai fault, Laosonglinzi linkage fault, north Jinshan fault and south Jinshan fault. In Huoshiling stage of Early Cretaceous, under the extensive environment of NW-SE, Sangshutai fault, north Jinshan fault and south Jinshan fault stretched intensely, and Sujiatun fault wasn't still active. In Shahezi stage of Early Cretaceous, Sangshutai fault, north Jinshan fault and south Jinshan fault stretched strongly, Laosonglinzi linkage fault between the above the faults was active, and Sujiatun fault also began to act, under the sinisterly strike-slip environment. Under the dextral strike-slip environment, Sujiatun fault and the northern part of Sangshutai fault were all extending strongly, the south Jinshan fault and Laosonglinzi linkage fault were in highly compression in Yingcheng stage of Early Cretaceous. From Denglouku stage to early Quantou stage, Sujiatun fault, Sangshutai fault, Jinshan fault and Laosonglinzi linkage fault were in transtensional strike-slip. This movement became weaker apparently and almost stopped in early Quntou stage of Early Cretaceous. So, it was covered by the thick upper Quantou Formation and Upper Cretaceous. From late Nenjiang stage to Mingshui stage, Laosonglinzi linkage fault slipped strongly and upperly cutted the Upper Cretaceous, under the NW-SE compression environment. Source


Hayes W.I.,University of Ulster | Lubarsky G.,University of Ulster | Li M.,Peiking University | Papakonstantinou P.,University of Ulster
Journal of Power Sources | Year: 2014

A novel production method for graphene nanoplatelets (GPs) with enhanced electrocatalytic behaviour is presented. GPs show improvement in their oxygen reduction reaction (ORR) catalysis after prolonging the grinding of graphite in 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF6). Nitrogen doping of the GPs has inferred a further increase in ORR. The ORR onset potential, cathodic current magnitude and electron transfer efficiency have all improved as a direct consequence of increasing the graphite grinding duration from 30 min to 4 h. Atomic force microscopy has confirmed a decrease in the GP diameter and height as the grinding increases. Raman spectroscopy indicates a higher level of defects present after prolonging the graphite grinding in BMIM-PF6, most likely a result of the increased edge plane exposure. This increased edge plane appears to promote a higher level of nitrogen incorporation as the graphite grinding duration increases, as confirmed by X-ray photoelectron spectroscopy analysis. The stability of the cathodic current assessed by chronoamperometry analysis is higher for the GP and nitrogen doped graphene nanoplatelet (N-GP) samples than the platinum on carbon black (Pt/C). This study presents a novel process for the production of nitrogen doped graphene nanoplatelets, constituting a strategy for the up-scaled production of electrocatalysts. © 2014 Elsevier B.V. All rights reserved. Source


Liu W.,Tsinghua University | Ding H.,Tsinghua University | Zhu Z.,Tsinghua University | Wang G.,Tsinghua University | Zhou Y.,Peiking University
Proceedings - 2011 4th International Conference on Biomedical Engineering and Informatics, BMEI 2011 | Year: 2011

Surgical navigation system has been widely used by surgeons to improve alignment accuracy during Total Knee Arthroplasty (TKA). In this article, we present an image-free surgical navigation system for TKA with a more interactive and robust in-house developed Graphical User Interface (GUI). The navigation system has a more intuitive view and can trace surgical steps easily by saving surgery information data. System steps, feature of the interactive GUI, coordinate definition and osteotomy value/angle calculation method have been introduced. The stability and accuracy test are performed. © 2011 IEEE. Source


Zhu Z.,Tsinghua University | Ji S.,Peiking University | Yang M.,Tsinghua University | Ding H.,Tsinghua University | Wang G.,Tsinghua University
IFMBE Proceedings | Year: 2013

There is an increasing need of the accurate comparison of the in-vivo joint kinematics before and after the knee replacement, which is still a challenging issue in technique. In this paper, we applied an automatic 2D-3D image matching technique to study the knee joint of a Chinese patient before and after a traditional posterior-stabilized TKA. An imaging system of Shimadzu's fluoroscopy was used to acquire the 2D images, which were recorded in sagittal view during a dynamic activity of knee flexion. The algorithm of automatic procedure was tested 20 times for a single pose to examine the repeatability. The result shew that the in-plane repeatability was within 0.5 mm and 1.5°, and the out-of-plane repeatability was within 5.4 mm and 1.7°. The dynamic kinematics was calculated based on the series of reproduced spatial positions of the knee joint. The result of the pre and postoperative patellar flexion in patellofemoral joint was similar. In sagittal view, less sinking of the patella and variation of the angle of patellar tendon were observed in TKA knee after 30° of knee flexion. This technique will be applied to study more knees of the healthy, abnormal and TKA patients in China. © 2013 Springer-Verlag. Source


Zhu Z.,Tsinghua University | Zhang Y.,Tsinghua University | Shao H.,Peiking University | Ding H.,Tsinghua University | Wang G.,Tsinghua University
IFMBE Proceedings | Year: 2013

The quadriceps (Q) angle between the rectus femoris and the patella tendon, measured in laying or standing, is an important reference to value a healthy or abnormal knee joint. The purpose of the present study was to measure a dynamic Q angle, which was defined as the Q angles during the flexion of the knee joint. Skin maker-based motion tracking technique was applied. The dynamic Q angle was calculated based on the cluster of markers attached to the skin. 30 normal subjects (15 male, 15 female) participated in the test. The results indicated that the Q angle was similar between the male and female during the knee flexion from 0° to 100°, but significant difference was observed from 105° to 120°. We observed this new phenomenon and reported the data in order to help understand the knee joint mechanism and the function of the patella. As a reference, our results proved more information for the diagnosis of an abnormal knee joint. © 2013 Springer-Verlag. Source

Discover hidden collaborations