Thermal expander metadevices can yield a large uniform temperature field powered by a linear heat source.Previous design of thermal expander metadevices can be regarded as a combination of achieved thermal cloaks and ...Thermal expander metadevices can yield a large uniform temperature field powered by a linear heat source.Previous design of thermal expander metadevices can be regarded as a combination of achieved thermal cloaks and their background materials.However,these thermal-cloak-inspired expander metadevices have an inherent flaw,i.e.,their thermal functionality will be lost when the background material is changed,thus limiting their practical applications.To solve this problem,the multiscale topology optimization(MTO)method is employed to design thermal expander metadevices that can maintain their expander functionality under different background materials.In MTO,transformation thermotic technology is used to determine the anisotropic thermal conductiv-ities inside a thermal expander metadevice and topology optimization is performed to generate the topological configuration of each microstructure with the target effective thermal conductivity.Subsequently,the thermal functionalities of thermal double and triple expander metadevices with different background materials are nu-merically verified via simulations.Finally,the thermal double expander metadevice is fabricated via additive manufacturing and experimentally tested for its thermal functionality.The findings of this study address the challenge of designing thermal expander metadevices with background material-independent functionality.展开更多
The China Dark Matter Experiment （CDEX） is located at the China Jinping Underground Laboratory （CJPL） and aims to directly detect the weakly interacting massive particles （WIMP） flux with high sensitivity in the...The China Dark Matter Experiment （CDEX） is located at the China Jinping Underground Laboratory （CJPL） and aims to directly detect the weakly interacting massive particles （WIMP） flux with high sensitivity in the low mass region. Here we present a study of tile predicted photon and electron backgrounds including the background contribution of the structure materials of the germanium detector, the passive shielding materials, and the intrinsic radioactivity of the liquid argon that serves as an anti-Compton active shielding detector. A detailed geometry is modeled and the background contribution has been simulated based on the measured radioactivities of all possible components within tile GEANT4 program. Then the photon and electron background level in the energy region of interest （〈10-2events-kg1·day 1·keV-1 （cpkkd）） is predicted based on Monte Carlo simulations. The simulated result is consistent with the design goal of the CDEX-10 experiment, 0.1cpkkd, which shows that the active and passive shield design of CDEX-10 is effective and feasible.展开更多
基金supported by National Natural Science Foundation of China(Grant No.52305259)National Postdoctoral Program for In-novative Talents of China(Grant No.BX20230135)+5 种基金China Postdoctoral Science Foundation(Grant No.2023M741261)the New Cornerstone Science Foundation through the XPLORER PRIZEthe Young Top-notch Talent Cultivation Program of Hubei Provincethe Knowledge Innova-tion Program of Wuhan-Shuguangthe Fundamental Research Funds for the Central Universities(Grant No.HUST:2024BRB005)the Taihu Lake Innovation Fund for Future Technology(Grant No.HUST:2023-B-7).
文摘Thermal expander metadevices can yield a large uniform temperature field powered by a linear heat source.Previous design of thermal expander metadevices can be regarded as a combination of achieved thermal cloaks and their background materials.However,these thermal-cloak-inspired expander metadevices have an inherent flaw,i.e.,their thermal functionality will be lost when the background material is changed,thus limiting their practical applications.To solve this problem,the multiscale topology optimization(MTO)method is employed to design thermal expander metadevices that can maintain their expander functionality under different background materials.In MTO,transformation thermotic technology is used to determine the anisotropic thermal conductiv-ities inside a thermal expander metadevice and topology optimization is performed to generate the topological configuration of each microstructure with the target effective thermal conductivity.Subsequently,the thermal functionalities of thermal double and triple expander metadevices with different background materials are nu-merically verified via simulations.Finally,the thermal double expander metadevice is fabricated via additive manufacturing and experimentally tested for its thermal functionality.The findings of this study address the challenge of designing thermal expander metadevices with background material-independent functionality.
基金Supported by National Natural Science Foundation of China(11175099,10935005,10945002,11275107,11105076)State Key Development Program of Basic Research of China(2010CB833006)
文摘The China Dark Matter Experiment （CDEX） is located at the China Jinping Underground Laboratory （CJPL） and aims to directly detect the weakly interacting massive particles （WIMP） flux with high sensitivity in the low mass region. Here we present a study of tile predicted photon and electron backgrounds including the background contribution of the structure materials of the germanium detector, the passive shielding materials, and the intrinsic radioactivity of the liquid argon that serves as an anti-Compton active shielding detector. A detailed geometry is modeled and the background contribution has been simulated based on the measured radioactivities of all possible components within tile GEANT4 program. Then the photon and electron background level in the energy region of interest （〈10-2events-kg1·day 1·keV-1 （cpkkd）） is predicted based on Monte Carlo simulations. The simulated result is consistent with the design goal of the CDEX-10 experiment, 0.1cpkkd, which shows that the active and passive shield design of CDEX-10 is effective and feasible.
