Water plays a central role in sustaining a thriving human society. Given its immense importance, safeguarding the related water infrastructure such as dams and reservoirs, which ensures the proper functioning of water...Water plays a central role in sustaining a thriving human society. Given its immense importance, safeguarding the related water infrastructure such as dams and reservoirs, which ensures the proper functioning of water ecosystem, becomes crucial.展开更多
Recently,Mach–Zehnder modulators based on thin-film lithium niobate have attracted broad interest for their potential for high modulation bandwidth,low insertion loss,high extinction ratio,and high modulation efficie...Recently,Mach–Zehnder modulators based on thin-film lithium niobate have attracted broad interest for their potential for high modulation bandwidth,low insertion loss,high extinction ratio,and high modulation efficiency.The periodic capacitively loaded traveling-wave electrode is optimally adopted for ultimate high-performances in this type of modulator.However,such an electrode structure on a silicon substrate still suffers from the velocity mismatch and substrate leakage loss for microwave signals.Here,we introduce a thin-film lithium niobate modulator structure using this periodic capacitively loaded electrode on a silicon substrate.Backside holes in the silicon substrate are prepared to solve robustly the above difficulties.The fabricated device exhibits an insertion loss of 0.9 dB,a halfwave-voltage–length product of 2.18 V·cm,and an ultra-wide bandwidth well exceeding 67 GHz for a 10-mm-long device.Data transmissions with rates up to 112 Gb/s are demonstrated.The proposed structure and fabrication strategy are compatible for other types of monolithic and heterogeneous integrated thin-film lithium niobate modulators on a silicon substrate.展开更多
Flexible pressure sensors with high sensitivity and linearity are highly desirable for robot sensing and human physiological signal detection.However,the current strategies for stabilizing axial microstructures(e.g.,m...Flexible pressure sensors with high sensitivity and linearity are highly desirable for robot sensing and human physiological signal detection.However,the current strategies for stabilizing axial microstructures(e.g.,micro-pyramids)are mainly susceptible to structural stiffening during compression,thereby limiting the realization of high sensitivity and linearity.Here,we report a bending-induced nonequilibrium compression process that effectively enhances the compressibility of microstructures,thereby crucially improving the efficiency of interfacial area growth of electric double layer(EDL).Based on this principle,we fabricate an iontronic flexible pressure sensor with vertical graphene(VG)array electrodes.Ultra-high sensitivity(185.09 kPa^(-1))and linearity(R^(2)=0.9999)are realized over a wide pressure range(0.49 Pa–66.67 k Pa).It also exhibits remarkable mechanical stability during compression and bending.The sensor is successfully employed in a robotic gripping task to recognize the targets of different materials and shapes based on a multilayer perception(MLP)neural network.It opens the door to realizing haptic sensing capabilities for robotic hands and prosthetic limbs.展开更多
This paper is concerned with the minimizers of L^(2)-subcritical constraint variar tional problems with spatially decaying nonlinearities in a bounded domain Ω of R~N(N≥1).We prove that the problem admits minimizers...This paper is concerned with the minimizers of L^(2)-subcritical constraint variar tional problems with spatially decaying nonlinearities in a bounded domain Ω of R~N(N≥1).We prove that the problem admits minimizers for any M> 0.Moreover,the limiting behavior of minimizers as M→∞ is also analyzed rigorously.展开更多
Intercalated transition metal dichalcogenides(TMDCs)attract much attention due to their rich properties and potential applications.In this article,we grew successfully high-quality V_(1/3)TaS_(2) crystals by a vapor t...Intercalated transition metal dichalcogenides(TMDCs)attract much attention due to their rich properties and potential applications.In this article,we grew successfully high-quality V_(1/3)TaS_(2) crystals by a vapor transport method.We measured the magnetization,longitudinal resistivityρxx(T,H),Hall resistivityρxy(T,H),as well as performed calculations of the electronic band structure.It was found that V_(1/3)TaS_(2) is an A-type antiferromagnet with the Neel temperature T_(N)=6.20 K,and exhibits a negative magnetoresistance(MR)near T_(N).Both band structure calculations and Hall resistivity measurements demonstrated it is a magnetic semimetal.展开更多
Using micromagnetic simulations, we demonstrate the tilted perpendicular anisotropy-induced spin-orbit ratchet effect. In spin-orbit torque(SOT)-induced magnetization switching, the critical currents required to switc...Using micromagnetic simulations, we demonstrate the tilted perpendicular anisotropy-induced spin-orbit ratchet effect. In spin-orbit torque(SOT)-induced magnetization switching, the critical currents required to switch between the two magnetization states(upward and downward magnetization) are asymmetric. In addition, in the nanowire structure, tilted anisotropy induces formation of tilted domain walls(DWs). The tilted DWs exhibit a ratchet behavior during motion. The ratchet effect during switching and DW motions can be tuned by changing the current direction with respect to the tilting direction of anisotropy. The ratchet motion of the DWs can be used to mimic the leaky-integrate-fire function of a biological neuron, especially the asymmetric property of the “potential” and “reset” processes. Our results provide a full understanding of the influence of tilted perpendicular anisotropy on SOT-induced magnetization switching and DW motion, and are beneficial for designs of further SOT-based devices.展开更多
基金supported by the National Natural Science Foundation of China (42090015,42071400,42371339)the International Research Center of Big Data for Sustainable Development Goals (CBAS2022GSP04)+3 种基金the Croucher Foundation (CAS22902/ CAS22HU01)The University of Hong Kong Faculty of Business and Economics and Shenzhen Research Institutes (SZRI2023-CRF04)The University of Hong Kong HKU-100 Scholars Fundthe Seed Fund for Strategic Interdisciplinary Research Scheme Fund。
文摘Water plays a central role in sustaining a thriving human society. Given its immense importance, safeguarding the related water infrastructure such as dams and reservoirs, which ensures the proper functioning of water ecosystem, becomes crucial.
基金This work was partially supported by the National Natural Science Foundation of China(NSFC)(Nos.62135012,62105107,and 61961146003)Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(No.2021R01001)。
文摘Recently,Mach–Zehnder modulators based on thin-film lithium niobate have attracted broad interest for their potential for high modulation bandwidth,low insertion loss,high extinction ratio,and high modulation efficiency.The periodic capacitively loaded traveling-wave electrode is optimally adopted for ultimate high-performances in this type of modulator.However,such an electrode structure on a silicon substrate still suffers from the velocity mismatch and substrate leakage loss for microwave signals.Here,we introduce a thin-film lithium niobate modulator structure using this periodic capacitively loaded electrode on a silicon substrate.Backside holes in the silicon substrate are prepared to solve robustly the above difficulties.The fabricated device exhibits an insertion loss of 0.9 dB,a halfwave-voltage–length product of 2.18 V·cm,and an ultra-wide bandwidth well exceeding 67 GHz for a 10-mm-long device.Data transmissions with rates up to 112 Gb/s are demonstrated.The proposed structure and fabrication strategy are compatible for other types of monolithic and heterogeneous integrated thin-film lithium niobate modulators on a silicon substrate.
基金supported by Guangdong Major Talent Project(2019CX01X014,and 2019QN01C177)。
文摘Flexible pressure sensors with high sensitivity and linearity are highly desirable for robot sensing and human physiological signal detection.However,the current strategies for stabilizing axial microstructures(e.g.,micro-pyramids)are mainly susceptible to structural stiffening during compression,thereby limiting the realization of high sensitivity and linearity.Here,we report a bending-induced nonequilibrium compression process that effectively enhances the compressibility of microstructures,thereby crucially improving the efficiency of interfacial area growth of electric double layer(EDL).Based on this principle,we fabricate an iontronic flexible pressure sensor with vertical graphene(VG)array electrodes.Ultra-high sensitivity(185.09 kPa^(-1))and linearity(R^(2)=0.9999)are realized over a wide pressure range(0.49 Pa–66.67 k Pa).It also exhibits remarkable mechanical stability during compression and bending.The sensor is successfully employed in a robotic gripping task to recognize the targets of different materials and shapes based on a multilayer perception(MLP)neural network.It opens the door to realizing haptic sensing capabilities for robotic hands and prosthetic limbs.
基金supported by the Graduate Education Innovation Funds(2022CXZZ088)at Central China Normal University in Chinasupported by the NSFC(12225106,11931012)the Fundamental Research Funds(CCNU22LJ002)for the Central Universities in China。
文摘This paper is concerned with the minimizers of L^(2)-subcritical constraint variar tional problems with spatially decaying nonlinearities in a bounded domain Ω of R~N(N≥1).We prove that the problem admits minimizers for any M> 0.Moreover,the limiting behavior of minimizers as M→∞ is also analyzed rigorously.
基金Project supported by the National Key Research and Development Program of China(Grant No.2022YFA1403202)the National Natural Science Foundation of China(Grant Nos.NSFC-12074335,11974095,5177115,11974095,and 12188101)the Natural Science Foundation of Shaanxi Province of China(Grant No.2022JM-028).
文摘Intercalated transition metal dichalcogenides(TMDCs)attract much attention due to their rich properties and potential applications.In this article,we grew successfully high-quality V_(1/3)TaS_(2) crystals by a vapor transport method.We measured the magnetization,longitudinal resistivityρxx(T,H),Hall resistivityρxy(T,H),as well as performed calculations of the electronic band structure.It was found that V_(1/3)TaS_(2) is an A-type antiferromagnet with the Neel temperature T_(N)=6.20 K,and exhibits a negative magnetoresistance(MR)near T_(N).Both band structure calculations and Hall resistivity measurements demonstrated it is a magnetic semimetal.
基金supported by the National Natural Science Foundation of China (Grant No.12274108)the Natural Science Foundation of Zhejiang Province (Grant Nos.LY23A040008 and LY23A040008)the Basic Scientific Research Project of Wenzhou (Grant No.G20220025)。
文摘Using micromagnetic simulations, we demonstrate the tilted perpendicular anisotropy-induced spin-orbit ratchet effect. In spin-orbit torque(SOT)-induced magnetization switching, the critical currents required to switch between the two magnetization states(upward and downward magnetization) are asymmetric. In addition, in the nanowire structure, tilted anisotropy induces formation of tilted domain walls(DWs). The tilted DWs exhibit a ratchet behavior during motion. The ratchet effect during switching and DW motions can be tuned by changing the current direction with respect to the tilting direction of anisotropy. The ratchet motion of the DWs can be used to mimic the leaky-integrate-fire function of a biological neuron, especially the asymmetric property of the “potential” and “reset” processes. Our results provide a full understanding of the influence of tilted perpendicular anisotropy on SOT-induced magnetization switching and DW motion, and are beneficial for designs of further SOT-based devices.
