Solid-state cooling technologies have been considered as potential alternatives for vapor compression cooling systems.The search for refrigeration materials displaying a unique combination of pronounced caloric effect...Solid-state cooling technologies have been considered as potential alternatives for vapor compression cooling systems.The search for refrigeration materials displaying a unique combination of pronounced caloric effect,low hysteresis,and high reversibility on phase transformation was very active in recent years.Here,we achieved increase in the elastocaloric reversibility and decrease in the friction dissipation of martensite transformations in the superelastic nano-grained NiTi alloys obtained by cold rolling and annealing treatment,with very low stress hysteresis(6.3 MPa)under a large applied strain(5%).Large adiabatic temperature changes(△T_(max)=16.3 K atε=5%)and moderate COP_(mater)values(maximum COP_(mater)=11.8 atε=2%)were achieved.The present nano-grained NiTi alloys exhibited great potential for applications as a highly efficient elastocaloric material.展开更多
近年来,中央银行数字货币(CBDC)受到全球多个国家和地区的高度关注.双离线交易作为CBDC的可选属性,在无网络连接的情况下进行支付,被认为具有较大的实用价值.面向CBDC的双离线匿名支付场景,基于可信执行环境(TEE)和安全单元(SE)技术,提...近年来,中央银行数字货币(CBDC)受到全球多个国家和地区的高度关注.双离线交易作为CBDC的可选属性,在无网络连接的情况下进行支付,被认为具有较大的实用价值.面向CBDC的双离线匿名支付场景,基于可信执行环境(TEE)和安全单元(SE)技术,提出了一种专为移动平台设计的高效双离线匿名支付方案(dual offline anonymous E-payment for mobile devices,OAPM).OAPM适用于资源受限的移动设备,允许移动付款者在不联网状态下安全地向收款者支付数字货币,且不向收款者及商业银行泄露个人隐私信息,付款者的支付行为也不会被链接,同时允许收款者设备处于离线状态,监管机构(如中央银行)在必要情况下能够识别匿名付款者的真实身份.该方案满足数字货币交易的多项重要属性,包括正确性、不可链接性、可追踪性、不可陷害性、机密性、真实性、防双花性以及可控匿名性等.实现了原型系统,并对可能的参数进行了评估.安全性分析和实验结果表明,该方案从安全性和效率两方面均能满足移动用户CBDC双离线交易的实际需求.展开更多
根据蓝印花布纹样的风格特征,文章提出一种端到端的蓝印花布纹样自动生成方法,实现简笔画图像向蓝印花布单纹样的自动迁移。针对蓝印花布的抽象风格和小数据集问题,重新构造CycleGAN生成网络中的编码器和解码器,使用SE(squeeze and exci...根据蓝印花布纹样的风格特征,文章提出一种端到端的蓝印花布纹样自动生成方法,实现简笔画图像向蓝印花布单纹样的自动迁移。针对蓝印花布的抽象风格和小数据集问题,重新构造CycleGAN生成网络中的编码器和解码器,使用SE(squeeze and excitation)注意力模块和残差模块与原始的卷积模块串联,提高特征提取能力和网络学习能力。同时减少生成网络中转换器的残差块层数,降低过拟合。实验结果表明,基于SE注意力CycleGAN网络方法自动生成的蓝印花布新纹样主观性上更贴合原始风格,与原图更加接近,有助于蓝印花布的数字化传承和创新。展开更多
With the advantage of fast charge transfer,heterojunction engineering is identified as a viable method to reinforce the anodes'sodium storage performance.Also,vacancies can effectively strengthen the Na+adsorption...With the advantage of fast charge transfer,heterojunction engineering is identified as a viable method to reinforce the anodes'sodium storage performance.Also,vacancies can effectively strengthen the Na+adsorption ability and provide extra active sites for Na+adsorption.However,their synchronous engineering is rarely reported.Herein,a hybrid of Co_(0.85)Se/WSe_(2) heterostructure with Se vacancies and N-doped carbon polyhedron(CoWSe/NCP)has been fabricated for the first time via a hydrothermal and subsequent selenization strategy.Spherical aberration-corrected transmission electron microscopy confirms the phase interface of the Co_(0.85)Se/WSe_(2) heterostructure and the existence of Se vacancies.Density functional theory simulations reveal the accelerated charge transfer and enhanced Na+adsorption ability,which are contributed by the Co_(0.85)Se/WSe_(2) heterostructure and Se vacancies,respectively.As expected,the CoWSe/NCP anode in sodium-ion battery achieves outstanding rate capability(339.6 mAh g^(−1) at 20 A g^(−1)),outperforming almost all Co/W-based selenides.展开更多
基金Project supported by the Science Fund of the Key Laboratory of Cryogenic Science and Technology(Grant Nos.CRYO20230203 and CRYO202106)the National Natural Science Foundation of China(Grant Nos.51872299 and 52071223)the National Key Research and Development Program of China(Grant No.2019YFA0704904)。
文摘Solid-state cooling technologies have been considered as potential alternatives for vapor compression cooling systems.The search for refrigeration materials displaying a unique combination of pronounced caloric effect,low hysteresis,and high reversibility on phase transformation was very active in recent years.Here,we achieved increase in the elastocaloric reversibility and decrease in the friction dissipation of martensite transformations in the superelastic nano-grained NiTi alloys obtained by cold rolling and annealing treatment,with very low stress hysteresis(6.3 MPa)under a large applied strain(5%).Large adiabatic temperature changes(△T_(max)=16.3 K atε=5%)and moderate COP_(mater)values(maximum COP_(mater)=11.8 atε=2%)were achieved.The present nano-grained NiTi alloys exhibited great potential for applications as a highly efficient elastocaloric material.
文摘近年来,中央银行数字货币(CBDC)受到全球多个国家和地区的高度关注.双离线交易作为CBDC的可选属性,在无网络连接的情况下进行支付,被认为具有较大的实用价值.面向CBDC的双离线匿名支付场景,基于可信执行环境(TEE)和安全单元(SE)技术,提出了一种专为移动平台设计的高效双离线匿名支付方案(dual offline anonymous E-payment for mobile devices,OAPM).OAPM适用于资源受限的移动设备,允许移动付款者在不联网状态下安全地向收款者支付数字货币,且不向收款者及商业银行泄露个人隐私信息,付款者的支付行为也不会被链接,同时允许收款者设备处于离线状态,监管机构(如中央银行)在必要情况下能够识别匿名付款者的真实身份.该方案满足数字货币交易的多项重要属性,包括正确性、不可链接性、可追踪性、不可陷害性、机密性、真实性、防双花性以及可控匿名性等.实现了原型系统,并对可能的参数进行了评估.安全性分析和实验结果表明,该方案从安全性和效率两方面均能满足移动用户CBDC双离线交易的实际需求.
文摘根据蓝印花布纹样的风格特征,文章提出一种端到端的蓝印花布纹样自动生成方法,实现简笔画图像向蓝印花布单纹样的自动迁移。针对蓝印花布的抽象风格和小数据集问题,重新构造CycleGAN生成网络中的编码器和解码器,使用SE(squeeze and excitation)注意力模块和残差模块与原始的卷积模块串联,提高特征提取能力和网络学习能力。同时减少生成网络中转换器的残差块层数,降低过拟合。实验结果表明,基于SE注意力CycleGAN网络方法自动生成的蓝印花布新纹样主观性上更贴合原始风格,与原图更加接近,有助于蓝印花布的数字化传承和创新。
基金support from the Natural Science Foundation of Jilin Province(Grant No.20200201073JC)the National Natural Science Foundation of China(Grant No.52130101)+1 种基金Interdisciplinary Integration and Innovation Project of JLU(Grant No.JLUXKJC2021ZY01)the Fundamental Research Funds for the Central Universities.
文摘With the advantage of fast charge transfer,heterojunction engineering is identified as a viable method to reinforce the anodes'sodium storage performance.Also,vacancies can effectively strengthen the Na+adsorption ability and provide extra active sites for Na+adsorption.However,their synchronous engineering is rarely reported.Herein,a hybrid of Co_(0.85)Se/WSe_(2) heterostructure with Se vacancies and N-doped carbon polyhedron(CoWSe/NCP)has been fabricated for the first time via a hydrothermal and subsequent selenization strategy.Spherical aberration-corrected transmission electron microscopy confirms the phase interface of the Co_(0.85)Se/WSe_(2) heterostructure and the existence of Se vacancies.Density functional theory simulations reveal the accelerated charge transfer and enhanced Na+adsorption ability,which are contributed by the Co_(0.85)Se/WSe_(2) heterostructure and Se vacancies,respectively.As expected,the CoWSe/NCP anode in sodium-ion battery achieves outstanding rate capability(339.6 mAh g^(−1) at 20 A g^(−1)),outperforming almost all Co/W-based selenides.
