On the vast plateau of Xizang,boa rd i ng education is a standardized and necessary modern schooling model.It provides centralized accommodation and higher quality teachi ng for school-age children and adolescents in ...On the vast plateau of Xizang,boa rd i ng education is a standardized and necessary modern schooling model.It provides centralized accommodation and higher quality teachi ng for school-age children and adolescents in geographically remote and sparsely populated areas where ordinary modern education is difficult to access.This special mode of public service delivery,tailored for populations living in specific geographical environments,ensures equitable development and common prosperity even in the remote border corners.展开更多
A new method,to our knowledge,in designing a metasurface with wideband and angularly stable radar cross section(RCS)reduction based on the coupling effect of orbital angular momentum(OAM)and focal shift(FS)is proposed...A new method,to our knowledge,in designing a metasurface with wideband and angularly stable radar cross section(RCS)reduction based on the coupling effect of orbital angular momentum(OAM)and focal shift(FS)is proposed.Through the analytical discussion of both an ideal scattering model and a practical array model,it is found that the effect of OAM-FS coupling can control the scattering wavefronts efficiently with an optimal arrangement in backward field and‘homogenization'reflected field,indicating RCS reduction in both monostatic and bistatic directions.To verify this method,by combining three phases(geometric phase,gradient phase,and divergent phase),the OAM-FS coupling metasurface is designed and its performance in RCS reduction is tested in simulation and experimentally.The unit cell of the metasurface,constructed with arcs and lines,can provide arbitrary phase compensation and polarization conversion performance within a fractional bandwidth of115.4%.Our results show that the proposed metasurface achieves a 10 d B reduction in both monostatic and bistatic RCSs over 8–32 GHz and has angular stability under 0°-30°oblique incidence of plane waves,and the measured results are in good agreement with the simulations.Our findings not only reveal a coupling effect in scattering waves of metasurfaces,but also offer a new perspective in manipulation of reflection and RCS reduction,which has potential applications in stealth technology.展开更多
Building-up and running a university-based research group is a multi-faceted undertaking.The visualization working group at TU Wien(vis-group)has been internationally active over more than 25 years.The group has been ...Building-up and running a university-based research group is a multi-faceted undertaking.The visualization working group at TU Wien(vis-group)has been internationally active over more than 25 years.The group has been acting in a competitive scientific setting where sometimes contradicting multiple objectives require trade-offs and optimizations.Research-wise the group has been performing basic and applied research in visualization and visual computing.Teaching-wise the group has been involved in undergraduate and graduate lecturing in(medical)visualization and computer graphics.To be scientifically competitive requires to constantly expose the group and its members to a strong international competition at the highest level.This necessitates to shield the members against the ensuing pressures and demands and provide(emotional)support and encouragement.Internally,the vis-group has developed a unique professional and social interaction culture:work and celebrate,hard and together.This has crystallized into a nested,recursive,and triangular organization model,which concretizes what it takes to make a research group successful.The key elements are the creative and competent vis-group members who collaboratively strive for(scientific)excellence in a socially enjoyable environment.展开更多
文摘On the vast plateau of Xizang,boa rd i ng education is a standardized and necessary modern schooling model.It provides centralized accommodation and higher quality teachi ng for school-age children and adolescents in geographically remote and sparsely populated areas where ordinary modern education is difficult to access.This special mode of public service delivery,tailored for populations living in specific geographical environments,ensures equitable development and common prosperity even in the remote border corners.
基金Fundamental Research Funds for the Central Universities(D5000240290)National Key Basic Research Program(NKBRP-25115X002)+2 种基金Key Research and Development Projects of Shaanxi Province(2024GXYBXM-080)National Natural Science Foundation of China(62401464)Sustainably Supported Foundation by the National Key Laboratory of Science and Technology on Space Microwave(HTKJ2024KL504003)。
文摘A new method,to our knowledge,in designing a metasurface with wideband and angularly stable radar cross section(RCS)reduction based on the coupling effect of orbital angular momentum(OAM)and focal shift(FS)is proposed.Through the analytical discussion of both an ideal scattering model and a practical array model,it is found that the effect of OAM-FS coupling can control the scattering wavefronts efficiently with an optimal arrangement in backward field and‘homogenization'reflected field,indicating RCS reduction in both monostatic and bistatic directions.To verify this method,by combining three phases(geometric phase,gradient phase,and divergent phase),the OAM-FS coupling metasurface is designed and its performance in RCS reduction is tested in simulation and experimentally.The unit cell of the metasurface,constructed with arcs and lines,can provide arbitrary phase compensation and polarization conversion performance within a fractional bandwidth of115.4%.Our results show that the proposed metasurface achieves a 10 d B reduction in both monostatic and bistatic RCSs over 8–32 GHz and has angular stability under 0°-30°oblique incidence of plane waves,and the measured results are in good agreement with the simulations.Our findings not only reveal a coupling effect in scattering waves of metasurfaces,but also offer a new perspective in manipulation of reflection and RCS reduction,which has potential applications in stealth technology.
文摘Building-up and running a university-based research group is a multi-faceted undertaking.The visualization working group at TU Wien(vis-group)has been internationally active over more than 25 years.The group has been acting in a competitive scientific setting where sometimes contradicting multiple objectives require trade-offs and optimizations.Research-wise the group has been performing basic and applied research in visualization and visual computing.Teaching-wise the group has been involved in undergraduate and graduate lecturing in(medical)visualization and computer graphics.To be scientifically competitive requires to constantly expose the group and its members to a strong international competition at the highest level.This necessitates to shield the members against the ensuing pressures and demands and provide(emotional)support and encouragement.Internally,the vis-group has developed a unique professional and social interaction culture:work and celebrate,hard and together.This has crystallized into a nested,recursive,and triangular organization model,which concretizes what it takes to make a research group successful.The key elements are the creative and competent vis-group members who collaboratively strive for(scientific)excellence in a socially enjoyable environment.
