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Polymeric nanocomposites for electrocaloric refrigeration

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能源前沿:英文版 2023年第4期17卷 450-462页

作者： Yu CAI Qiang LI feihong du Jiawang FENG Donglin HAN Shanyu ZHENG Shihao YANG Yingjing ZHANG Binbin YU Junye SHI Xiaoshi QIAN State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai200240China Interdisciplinary Research Center Institute of Refrigeration and CryogenicsSchool of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai200240China Shanghai Jiao Tong University Zhongguancun Research Institute Liyang213300China

Electrocaloric refrigeration represents an alternative solid-state cooling technology that has the potential to reach the ultimate goal of achieving zero-global-warming potential,highly efficient refrigeration,and heat pumps.To date,both polymeric and inorganic oxides have demonstrated giant electrocaloric effect as well as respective cooling devices.Although both polymeric and inorganic oxides have been identified as promising cooling methods that are distinguishable from the traditional ones,they still pose many challenges to more practical applications.From an electrocaloric material point of view,electrocaloric nanocomposites may provide a solution to combine the beneficial effects of both organic and inorganic electrocaloric materials.This article reviews the recent advancements in polymer-based electrocaloric composites and the state-of-the-art cooling devices operating these nanocomposites.From a device point of view,it discusses the existing challenges and potential opportunities of electrocaloric nanocomposites.

关键词： nanocomposites electrocaloric refrigeration polymer

Isotopic characteristics and source analysis of atmospheric ammonia during agricultural periods in the Xichuan area of the Danjiangkou Reservoir

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Journal of Environmental Sciences 2024年第2期136卷 460-469页

作者： Xiaoshu Chen Tongqian Zhao Chunyan Xiao Xiaoming Guo feihong Chen Institute of Resources and Environment Henan Polytechnic UniversityJiaozuo 454000China

Nitrogen deposition is an important means of exogenous nitrogen input in reservoir water.Agricultural activities around the reservoir lead to a sharp increase in the concentration of ammonia in the atmosphere,which poses a threat to the reservoir water body.Clarifying the contribution of agricultural ammonia release to atmospheric NH_(x)(gaseous NH_(3)and particulate NH_(4)^(+)),in the reservoir area can provide a theoretical foundation for local reactive nitrogen control.We collected atmospheric NH_(3)and NH_(4)^(+)samples during the agricultural periods and analyzed the isotopic characteristics of atmospheric NH_(x)and the contribution rates of different ammonia sources in the Xichuan area of the Danjiangkou Reservoir.The results showed that the initialδ~(15)N values of NH_(3)(-30.0‰to–7.2‰)and particulate NH_(4)^(+)(–33‰to+4.9‰for finer and coarser particles,respectively)are different,and their contribution ratios from dissimilar ammonia sources are also different,among which NH_(4)^(+)is more susceptible to meteorological factors.However,since the atmospheric NH_(x)in the Xichuan area is mainly gaseous NH_(3),the final sources of atmospheric ammonia nitrogen source depend on gaseous NH_(3).Agricultural sources(59%-74%)were the main NH_(3)sources in this area.Among them,the fertilizer use emission was dominant;it had the highest contribution rate in summer during the agricultural period and a more prominent impact in areas with less human interference.Reasonable regulation of the application of high-ammonia releasing fertilizer,especially during the agricultural period in summer,is an effective way to reduce the threat of atmospheric ammonia to water health.

关键词： Danjiangkou reservoir Atmospheric ammonia nitrogen Isotope Ammonia source analysis Agricultural sources

A low-profile metamaterial absorber with ultrawideband reflectionless and wide-angular stability

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Defence Technology（防务技术） 2024年第4期34卷 258-268页

作者： feihong Lin Zhongming Yan Ping Wang Yu Wang Hongcheng Zhou Haoran Lu School of Electrical Engineering Southwest Jiaotong UniversityChengdu 611756China Key Laboratory of Magnetic Suspension Technology and Maglev Vehicle Ministry of EducationChengdu 610031China China Academy of Launch Vehicle Technology Beijing 100076China

An ultrawideband reflectionless metamaterial absorber(MA)is proposed by replacing the metallic ground with the complementary split-ring resonator(CSRR)structure.The proposed MA exhibits-10 d B reflectivity spectrum from 1 GHz to 20 GHz,which maintains more than 90%absorption from 1.5 GHz to20 GHz.Furthermore,it achieves angle stability for TE and TM polarization at oblique incident angles up to 40°and 65°,respectively.To achieve broadband absorption spectrum,we have adopted a single-layer high-impedance surface(HIS)loaded with a double-layer magnetic material(MM)structure.To further realize the RCS reduction into a lower frequency range,we have employed the scattering cancellation technology into the traditional metallic ground.Finally,we have fabricated a sample exhibiting the 10 d B RCS reduction from 1 GHz to 20 GHz with a thickness of 10 mm.Measurement and simulation results confirm that the proposed MA exhibits excellent comprehensive performance,making it suitable for many practical applications.

关键词： Metamaterial absorber(MA) Magnetic material(MM) High-impedance surface(HIS) Scattering cancellation technology Ultrawideband Wide-angular stable

Traceless photodegradable polymer cocoons for universal protein delivery and light-controlled gene editing

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Science China Chemistry 2024年第2期67卷 664-676页

作者： Huaibin Yu Meron Tsegay Kifle Lili Chen feihong Xiong Yan Zhang Shangbang Gao Wei Hou Shuliang Chen Weining Zhao Yuzhou Wu Hubei Engineering Research Center for Biomaterials and Medical Protective Materials Hubei Key Laboratory of Bioinorganic Chemistry&Materia MedicaKey Laboratory of Material Chemistry for Energy Conversion and StorageMinistry of EducationSchool of Chemistry and Chemical EngineeringHuazhong University of Science and Technology(HUST)Wuhan430074China Zhengzhou Research Institute Harbin Institute of TechnologyZhengzhou450000China College of Life Science and Technology Huazhong University of Science and Technology(HUST)Wuhan430074China Institute of Medical Virology School of Basic Medical SciencesWuhan UniversityWuhan430071China College of Pharmacy Shenzhen Technology UniversityShenzhen518118China

Polymer conjugation was found highly valuable in clinic to improve the bioavailability of protein therapeutics.However,it is still a tremendous challenge to achieve a complete release of original proteins from the conjugated hybrid under external stimulus to recover active proteins in the targeted tissue.Herein,we report a general light-controlled protein delivery methodology by weaving a photodegradable polymer cocoon around proteins,which could reliably protect them from degradation in the dark while efficiently releasing them under illumination without any residual atoms.The surface charge of the polymer shell is easily tunable to facilitate efficient cell uptake.The versatility of this strategy is demonstrated by the delivery of the Cas9/sg RNA complex that realized light-controlled gene editing both in vitro and in vivo,and such repertoire is of particular value in regard to minimizing the off-target toxicity of CRISPR-Cas9-based gene therapy.

关键词： photodegradable polymer-protein conjugate protein delivery light control gene editing

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智能化环境治理的内在悖论与矛盾纾解

中国人口·资源与环境 2024年第1期34卷 97-105页

作者：程飞鸿上海社会科学院法学研究所上海200020

智能技术代表了以数据与算法主导的、一元性与多元性并存的、虚拟与现实交互的生产关系。智能技术对环境治理的重塑,主要体现在技术治理和社会治理两个维度,并凝结成“数据与算法”“一元性与多元性”“虚拟与现实”三组关键词。智能化... 详细信息

智能技术代表了以数据与算法主导的、一元性与多元性并存的、虚拟与现实交互的生产关系。智能技术对环境治理的重塑,主要体现在技术治理和社会治理两个维度,并凝结成“数据与算法”“一元性与多元性”“虚拟与现实”三组关键词。智能化环境治理可以分为感知型、服务型和互联型3种治理类型,以此为基础,其内在悖论分别表现为:在感知型智能化环境治理中,环境数据所有权的专属性与开展环境数据行为的便宜性之间存在张力;在服务型智能化环境治理中,平台发展、治理服务和决策形成存在一元性与多元性矛盾;在互联型智能化环境治理中,网络空间的交互性和传统公共空间的被支配性之间相互掣肘。纾解这3对矛盾,对智能化环境治理的健康发展至关重要。于感知型智能化环境治理而言,需要明确环境数据行为的主体、限制环境数据行为的目的以及厘定环境数据行为的后果,最终消解环境数据行为的便宜性。对服务型智能化环境治理来说,则要尽可能把握平衡一元性与多元性的“度”的客观标准,即平台有序发展的客观标准、环境治理服务的弱势标准以及环境决策形成的底线标准。互联型智能化环境治理的矛盾纾解之策最终指向了政府在智能社会的公共空间中如何调适方能言之为“妥当”。申言之,在支持层面,转变政府对民间环境治理力量的投入模式;在引导层面,健全政府对民间环境治理力量的引导机制;在管理层面,实现政府对民间环境治理力量的法治管理。

关键词：智能技术智能化环境治理环境数据智能平台虚拟空间

论两湖地区隋唐墓葬出土盟器神煞的构成与变迁

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南方文物 2024年第2期 154-169页

作者：徐斐宏上海大学文化遗产与信息管理学院

盟器神煞是两湖隋唐墓中的重要随葬品,主要包含镇墓兽、生肖俑、人首有翼俑、连体俑、镇墓武士、门吏俑等种类;它们各自的出现时间与演变轨迹不尽相同,整体面貌经历了“层累”的形成过程,是新因素不断融入、地区丧葬礼俗逐步丰满的产物... 详细信息

盟器神煞是两湖隋唐墓中的重要随葬品,主要包含镇墓兽、生肖俑、人首有翼俑、连体俑、镇墓武士、门吏俑等种类;它们各自的出现时间与演变轨迹不尽相同,整体面貌经历了“层累”的形成过程,是新因素不断融入、地区丧葬礼俗逐步丰满的产物。两湖隋唐墓葬中大部分盟器神煞被安放于甬道,生肖俑则于墓葬后部拱卫逝者,此种格局与《大汉原陵秘葬经》“盟器神煞篇”的记载有较高相似性,二者可能存在部分共同文化渊源,而两湖隋唐墓葬文化的历史影响或需重新评估。

关键词：两湖隋唐墓葬盟器神煞《大汉原陵秘葬经》

基于HDMI数码显微相机的自动曝光优化方法

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激光与光电子学进展 2024年第6期61卷 315-321页

作者：翟梦伟余飞鸿浙江大学光电科学与工程学院浙江杭州310027

针对HDMI数码显微相机在观测时由于不同目标反光水平不一致而出现过曝、曝光收敛速度慢、不稳定的问题,提出一种自动曝光优化方法。相较于传统的HDMI显微相机中的自动曝光控制方法,所提方法实现了基于感兴趣区域的曝光控制,可对RAW图像... 详细信息

针对HDMI数码显微相机在观测时由于不同目标反光水平不一致而出现过曝、曝光收敛速度慢、不稳定的问题,提出一种自动曝光优化方法。相较于传统的HDMI显微相机中的自动曝光控制方法,所提方法实现了基于感兴趣区域的曝光控制,可对RAW图像中的任意区域进行测光和亮度统计,拓展亮度统计的动态范围并实现基于不同目标的曝光控制,提升亮度统计的准确性,解决因目标过亮或者过暗而出现的过曝现象。同时设计了可变的曝光调节步长,该功能能够根据当前亮度水平动态调整曝光步长,实现曝光的粗调和细调,以平衡曝光收敛速度和曝光精确度。最终结合实际的相机进行实验,所提曝光控制优化方法相较于原有的自动曝光法曝光偏离度降低了一半,曝光收敛时间缩短了一半以上,最快能在4帧图像内完成曝光收敛。

关键词：自动曝光过曝 RAW图像数码显微相机

教育强国建设背景下综合高中发展的行动逻辑、历史镜鉴与推进路径

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中国职业技术教育 2024年第16期 20-25,36页

作者：郭静何飞红国家教育行政学院“中国职业教育改革与发展”智库国家教育行政学院人事处湖南石油化工职业技术学院经管信息学院

建设教育强国背景下,综合高中是增强教育多样性和选择性,以适配学生个性发展推动教育公平的重要举措;是推动职普融通,建设高质量教育体系的重要路径;是奠基发展新质生产力的高素质人才,打牢学生多维知识结构和技能基础的重要载体。我国... 详细信息

建设教育强国背景下,综合高中是增强教育多样性和选择性,以适配学生个性发展推动教育公平的重要举措;是推动职普融通,建设高质量教育体系的重要路径;是奠基发展新质生产力的高素质人才,打牢学生多维知识结构和技能基础的重要载体。我国曾开展过两次综合高中试点改革,均未取得理想成效。新时期发展综合高中要以史为鉴,遵循服务建设教育强国的行动逻辑,推动高中阶段教育的系统性重构、整体性重塑和机制性重建,从加强顶层设计、设置核心课程、建立独立课程体系、地市为主优化资源配置、完善配套制度保障等方面系统推进。

关键词：综合高中教育强国职普融通高中阶段教育多样化

Three-Dimensional Conjugate Tooth Surface Design and Contact Analysis of Harmonic Drive with Double-Circular-Arc Tooth Profle

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Chinese Journal of Mechanical Engineering 2023年第5期36卷 248-265页

作者： Chaosheng Song feihong Zhu Xinzi Li Xuesong du State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing 400030China

A three-dimensional conjugate tooth surface design method for Harmonic Drive with a double-circular-arc tooth profle is proposed. The radial deformation function of the fexspline (FS), obtained through Finite Element (FE) analysis, is incorporated into the kinematics model. By analyzing the FS tooth enveloping process, the optimization of the overlapping conjugate tooth profle is achieved. By utilizing the hobbing process, the three-dimensional machinable tooth surface of FS can be acquired. Utilizing the coning deformation of the FS, simulations are conducted to analyze the multi-section assembly and meshing motion of the machinable tooth surface. The FE method is utilized to analyze and compare the loaded contact characteristics. Results demonstrate that the proposed design method can achieve an internal gear pair consisting of a circular spline with a spur gear tooth surface and the FS with a machinable tooth surface. With the rated torque, approximately 24% of the FS teeth are engaged in meshing, and more than 4/5 of the tooth surface in the axial direction carries the load. The contact patterns, maximum contact pressure, and transmission error of the machinable tooth surface are 227.2%, 40.67%, and 71.24% of those on the spur gear tooth surface, respectively. It clearly demonstrates exceptional transmission performance.

关键词： Three-dimensional conjugate tooth surface Coning deformation Double-circular-arc tooth profle Harmonic Drive Contact characteristics