We successfully employ an automatic centroid moment tensor(CMT) inversion system to infer the CMT solutions of the February 12,2014 MS7.3 Yutian,Xinjiang earthquake using near-field seismic waveforms(4° < △ &...We successfully employ an automatic centroid moment tensor(CMT) inversion system to infer the CMT solutions of the February 12,2014 MS7.3 Yutian,Xinjiang earthquake using near-field seismic waveforms(4° < △ < 12°) observed by the virtual China seismic networks,which have been recently set up.The results indicate that this event occurred on a rupture plane(strike 243°,dip 70°,and rake-18°),showing left-lateral strike-slip faulting with a minor normal-faulting component.The centroid in the horizontal direction is located nearly 13 km east of the epicenter(36.123° N,82.499° E),and the best-fitting centroid depth is around 10 km.The total scalar moment,M0,is retrieved with an average value of 3.05 × 1019N·m,corresponding to moment magnitude MW6.92.Most of the energy is released within about 14 s.Moreover,we discuss about the potential application of this system in earthquake disaster decision.展开更多
The synthesis of large area, homogenous, single layer graphene on cobalt (Co) and nickel (Ni) is reported. The process involves vacuum annealing of sputtered amorphous carbon (a-C) deposited on Co/sapphire or Ni...The synthesis of large area, homogenous, single layer graphene on cobalt (Co) and nickel (Ni) is reported. The process involves vacuum annealing of sputtered amorphous carbon (a-C) deposited on Co/sapphire or Ni/sapphire substrates. The improved crystallinity of the metal film, assisted by the sapphire substrate, proves to be the key to the quality of as-grown graphene film. The crystallinity of the Co and Ni metal films was improved by sputtering the metal at elevated temperature as was verified by X-ray diffraction (XRD). After sputtering of a-C and annealing, large area, single layer graphene that occupies almost the entire area of the substrate was produced. With this method, 100 mm2-area single layer graphene can be synthesized and is limited only by the substrate and vacuum chamber size. The homogeneity of the graphene film is not dependent on the cooling rate, in contrast to syntheses using polycrystalline metal films and conventional chemical vapor deposition (CVD) growth. Our facile method of producing single layer graphene on Co and Ni metal films should lead to large scale graphene-based applications.展开更多
A mass-conservative average flow model based on the finite element method(FEM) is introduced to predict the performances of textured surfaces applied in mechanical seals or thrust bearings.In this model,the Jakobsson-...A mass-conservative average flow model based on the finite element method(FEM) is introduced to predict the performances of textured surfaces applied in mechanical seals or thrust bearings.In this model,the Jakobsson-Floberg-Olsson(JFO) boundary conditions are applied to the average flow model for ensuring the mass-conservative law.Moreover,the non-uniform triangular grid is utilized,which can deal with the problem of complex geometric shapes.By adopting the modeling techniques,the model proposed here is capable of dealing with complex textured surfaces.The algorithm is proved correct by the numerical experiment.In addition,the model is employed to gain further insight into the influences of the dimples with different shapes and orientations on smooth and rough surfaces on the load-carrying capacity.展开更多
基金funded by Special Oceanic Scientific Research Program(201405026)Science for Earthquake Resilience Program(XH12060Y)Special Seismological Industry Research Program(201208003)
文摘We successfully employ an automatic centroid moment tensor(CMT) inversion system to infer the CMT solutions of the February 12,2014 MS7.3 Yutian,Xinjiang earthquake using near-field seismic waveforms(4° < △ < 12°) observed by the virtual China seismic networks,which have been recently set up.The results indicate that this event occurred on a rupture plane(strike 243°,dip 70°,and rake-18°),showing left-lateral strike-slip faulting with a minor normal-faulting component.The centroid in the horizontal direction is located nearly 13 km east of the epicenter(36.123° N,82.499° E),and the best-fitting centroid depth is around 10 km.The total scalar moment,M0,is retrieved with an average value of 3.05 × 1019N·m,corresponding to moment magnitude MW6.92.Most of the energy is released within about 14 s.Moreover,we discuss about the potential application of this system in earthquake disaster decision.
文摘The synthesis of large area, homogenous, single layer graphene on cobalt (Co) and nickel (Ni) is reported. The process involves vacuum annealing of sputtered amorphous carbon (a-C) deposited on Co/sapphire or Ni/sapphire substrates. The improved crystallinity of the metal film, assisted by the sapphire substrate, proves to be the key to the quality of as-grown graphene film. The crystallinity of the Co and Ni metal films was improved by sputtering the metal at elevated temperature as was verified by X-ray diffraction (XRD). After sputtering of a-C and annealing, large area, single layer graphene that occupies almost the entire area of the substrate was produced. With this method, 100 mm2-area single layer graphene can be synthesized and is limited only by the substrate and vacuum chamber size. The homogeneity of the graphene film is not dependent on the cooling rate, in contrast to syntheses using polycrystalline metal films and conventional chemical vapor deposition (CVD) growth. Our facile method of producing single layer graphene on Co and Ni metal films should lead to large scale graphene-based applications.
基金supported by the National Basic Research Program of China(Grant No.2009CB724304)the National Key Technology R&D Program(Grant No.2011BAF09B05)+1 种基金the National Natural Science Foundation of China(Grant No.50975157)the Key Research Program of the State Key Laboratory of Tribology of Tsinghua University(Grant No.SKLT08A06)
文摘A mass-conservative average flow model based on the finite element method(FEM) is introduced to predict the performances of textured surfaces applied in mechanical seals or thrust bearings.In this model,the Jakobsson-Floberg-Olsson(JFO) boundary conditions are applied to the average flow model for ensuring the mass-conservative law.Moreover,the non-uniform triangular grid is utilized,which can deal with the problem of complex geometric shapes.By adopting the modeling techniques,the model proposed here is capable of dealing with complex textured surfaces.The algorithm is proved correct by the numerical experiment.In addition,the model is employed to gain further insight into the influences of the dimples with different shapes and orientations on smooth and rough surfaces on the load-carrying capacity.