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Flexible and densified graphene/waterborne polyurethane composite film with thermal conducting property for high performance electromagnetic interference shielding

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Nano Research 2022年第11期15卷 9926-9935页

作者： wang Yang Hengxuan Bai Bo Jiang Chaonan wang Weimin Ye Zhengxuan Li Chong Xu xiaobai wang Yongfeng Li State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China Department of Materials Application Research AVIC Manufacturing Technology InstituteBeijing 100024China

High-performance electromagnetic interference(EMI)shielding materials with flexibility,excellent mechanical property,and thermal conductivity are highly desired for fifth-generation communications devices.Graphene exhibits tremendous potential due to its high electrical conductivity and unique lamellar structure.However,the construction of densified graphene structure in polymer matrix is still challenging.Herein,we develop a graphene/waterborne polyurethane(G/WPU)flexible film with densified and ordered layer-structure for using as an EMI shielding material.By virtue of the polyvinylpyrrolidone modified strategy and facile liquid phase ball-milling treatment,the graphene nanosheets can be efficiently dispersed into the WPU substrate and tightly connected between each other via internal interactions.Benefiting from the relatively low defects and densified structure of graphene,the resultant G/WPU film yields a high electrical conductivity of 1,004.5 S/m,and a tensile strength of around 48.5 MPa.As a consequence,it achieves an average EMI shielding effectiveness of over 30 dB in the X-band with a thickness of merely 0.15 mm and the value is further enhanced to 73.4 dB at 0.9 mm with a low density of 1.4 g/cm^(3),offering over 99.99999%shielding of incident electromagnetic waves.More importantly,this G/WPU film also exhibits a high cross-plane thermal conductivity of about 1.13 W/(m·K).Thus,this work develops a high-performance EMI shielding material with both good capacity of heat transmission,but also provides a facile strategy for designing next-generation advanced,lightweight,flexible,and multifunction shielding materials.

关键词： electromagnetic interference shielding graphene densification flexible thermal conductivity

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Multiscale structure and interface engineering of Fe/Fe_(3)C in situ encapsulated in nitrogen-doped carbon for stable and efficient multi-band electromagnetic wave absorption

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Journal of Materials Science & Technology 2023年第27期158卷 9-20页

作者： Bo Jiang wang Yang Hengxuan Bai Chen Zhang Siyuan Li Shaoxiong Du Ye wang Li Sun xiaobai wang Yongfeng Li State Key Laboratory of Heavy Oil Processing China University of Petroleum(Beijing)Changping 102249China Department of Materials Application Research AVIC Manufacturing Technology InstituteBeijing 100024China

Most reported electromagnetic wave absorption(EWA)materials show significant effective absorption in a certain frequency range,but their performances deteriorate dramatically as the frequency changes.As the range of working frequencies for electronic devices is gradually widening,it is of great interest to explore frequency-insensitive EWA materials that can achieve efficient absorption in every waveband by simply changing the absorption thickness.To this end,a multi-scale absorber(Fe/Fe_(3) C@NC)is rationally synthesized by chemical foaming and in-situ growth strategy.By controlling the growth of carbon nan-otubes,the Fe/Fe_(3) C@NC-2 exhibits a well-constructed 3D multi-scale architecture.Thanks to dipole po-larization,interface polarization and magnetic-dielectric energy conversion,the Fe/Fe_(3) C@NC-2 overcomes the frequency dispersion behavior and keeps a stable dielectric attenuation capability across the entire frequency range.Consequently,it delivers a superb full-band absorption of-50.1,-59.83,-55.87 and-51.91 dB in the S,C,X and Ku bands,respectively.The maximum radar cross-sectional reduction reaches 35.44 dB m^(-2) when the incidentθis 20°,testifying its impressive performance.Surprisingly,this EWA material also shows a remarkable resistance to oxidation and corrosion derived from the tightly coated carbon layers.This work provides new insight into the design of multi-band and stable EWA materials for practical application.

关键词： Multi-scale structure Heterogeneous interface Multiple bands Magnetic-dielectric composites Electromagnetic waves absorption

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Spin-orbit torque efficiency enhancement to tungsten-based SOT-MTJs by interface modification with an ultrathin MgO

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Science China(Information Sciences) 2024年第1期67卷 316-317页

作者： Shiyang LU xiaobai NING Hongchao ZHANG Sixi ZHEN Xiaofei FAN Danrong XIONG Dapeng ZHU Gefei wang Hong-Xi LIU Kaihua CAO Weisheng ZHAO Fert Beijing Institute School of Integrated Science and EngineeringBeihang University Truth Memory Corporation

Spin-orbital torque (SOT) based three-terminal magnetic tunnel junctions (MTJs) have attracted much interest as the next generation magnetic random-access memory (MRAM)key device both in the academy and the industry. This is because SOT-MTJs feature high endurance and fast switching speed, benefiting tremendously from the separation of read/write current paths and less incubation time during the write in contrast to the spin-transfer torque (STT) MTJs [1].

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Chemical synthesis and coercivity enhancement of Nd2Fe14B nanostructures mediated by non-magnetic layer

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Nano Research 2020年第4期13卷 1141-1148页

作者： Kai Zhu Junjie Xu xiaobai wang Wei Li Kesong Tian Yanglong Hou Beijing Key Laboratory for Magnetoelectric Materials and Devices(BKLMMD) Beijing Innovation Centre for Engineering Science and Advanced TechnologyDepartment of Materials Science and EngineeringCollege of EngineeringPeking UniversityBeijing 100871China Academy for Advanced Interdisciplinary Studies Peking UniversityBeijing 100871China

High-performance Nd2Fei4B magnets have been widely required in various fields recently due to the lightweight and miniaturization of devices.In this work,we synthesize Nd2Fei4B nanostructures with tunable magnetic properties through surfactant-assisted high energy ball milling(SAHEBM)process,achieving prominently enhanced coercivity by forming non-magnetic layers as grain boundary phase.When the reduction annealing process was carried out as pellet with Ca,the coercivity increased from 0.8 kOe to over 3 kOe as Nd2Fei4B powder,which is proved to be the contribution of the chemical diffusion of Nd elements and the formation of Nd-rich layer as magnetic insulating medium.In addition,two-dimensional graphene oxide(GO)was employed to build extra grain boundary,by which the coercivity of the core@dual-shell structure can achieve up to 8 kOe,tenfold of the original sample.The intrinsic mechanism indicated that the Nd-diffusion induced Nd-rich phase along with the reduced GO in the system could form non-magnetic layer as grain boundary and magnetically isolate the adjacent grains,significantly enhancing the exchange coupling effect.This work markedly opens up an effective approach for the chemical preparation of high-performance Nd2Fe14B nanostructured magnets,especially after post treatment,and gives an insight on the interactions at nanoscale.

关键词： Nd2Fei4B nanostructures chemical reduction diffusion process grain boundary graphene oxide coercivity enchantment

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蛋白质结构预测模型AlphaFold2的应用进展

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生物工程学报 2024年第5期40卷 1406-1420页

作者：张弘王慧洁鲁睿捷兰家靖陈林洁何小柏杭州医学院检验医学院与生物工程学院浙江杭州310053 检验诊断关键技术浙江省工程研究中心浙江杭州310053 浙江省生物标志物与体外诊断转化重点实验室浙江杭州310053

蛋白质结构预测是生命科学和医学的重要研究领域,也是人工智能在科学研究中的重要应用场景。AlphaFold2是由DeepMind开发的一种基于深度学习的蛋白质结构预测系统,可以从氨基酸序列中高效地生成原子级精度的蛋白质空间结构。由于AlphaFo... 详细信息

蛋白质结构预测是生命科学和医学的重要研究领域,也是人工智能在科学研究中的重要应用场景。AlphaFold2是由DeepMind开发的一种基于深度学习的蛋白质结构预测系统,可以从氨基酸序列中高效地生成原子级精度的蛋白质空间结构。由于AlphaFold2优越的性能,自问世以来对蛋白质结构预测方面的研究提供了前所未有的助力,因此备受关注和研究。本文介绍了AlphaFold2的模型架构、亮点、局限性和应用进展,列举了几种其他类型的蛋白质结构预测模型,并讨论了其能力、优势及局限性并思考该蛋白质结构预测模型的未来发展方向。

关键词： AlphaFold2 蛋白质结构蛋白质结构预测深度学习

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Lignin-derived dual-function red light carbon dots for hypochlorite detection and anti-counterfeiting

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Frontiers of Chemical Science and Engineering 2023年第7期17卷 966-975页

作者： Yixuan Chang Fanwei Kong Zihao Zhu Ziai wang Chunxia Chen xiaobai Li Hongwei Ma Key Laboratory of Forest Plant Ecology Ministry of EducationEngineering Research Center of Forest Bio-PreparationCollege of ChemistryChemical Engineering and Resource UtilizationNortheast Forestry UniversityHarbin 150040China State Engineering Laboratory of Bio-Resource Eco-Utilization Northeast Forestry UniversityHarbin 150040China Collaborative Innovation Center for Development and Utilization of Forest Resources Harbin 150040China

The efficient utilization of natural lignin,which is the main by-product of the cellulose industry,is crucial for enhancing its economic value,alleviating the environmental burden,and improving ecological security.By taking advantage of the large sp2 hybrid domain of lignin and introducing amino functional groups,new lignin-derived carbon dots(SPN-CDs)with red fluorescence were successfully synthesized.Compared with green and blue fluorescent materials,red SPN-CDs have desirable anti-interference properties of short-wave background and exhibit superior luminescence stability.The SPN-CDs obtained exhibited sensitive and distinctive visible color with fluorescence-dual responses toward hypochlorite.Considering this feature,a portable,low-cost,and sensitive fluorescence sensing paper with a low limit of detection of 0.249μmol∙L^(–1) was fabricated using the SPN-CDs for hypochlorite detection.Furthermore,a new type of visible-light and fluorescence dual-channel information encryption platform was constructed.Low-concentration hypochlorite can be employed as an accessible and efficient information encryption/decryption stimulus,as well as an information“eraser”,facilitating a safe and diversified transmission and convenient decryption of information.This work opens new avenues for high-value-added applications of lignin-based fluorescent materials.

关键词： alkali lignin red light carbon dots hypochlorite encryption and anti-counterfeiting

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全程化疼痛管理在晚期肺癌骨转移疼痛患者中的应用效果

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癌症进展 2024年第1期22卷 44-47,91页

作者：王炯琦李娟李雁韦小白复旦大学附属华山医院静安分院急诊科上海200040 复旦大学附属华山医院静安分院肿瘤科上海200040

目的探讨全程化疼痛管理在晚期肺癌骨转移疼痛患者中的应用效果。方法选取126例肺癌骨转移疼痛患者,将2020年1月至2021年6月接受常规疼痛管理的68例患者作为对照组,将2021年7月至2022年12月接受全程化疼痛管理的58例患者作为观察组。比... 详细信息

目的探讨全程化疼痛管理在晚期肺癌骨转移疼痛患者中的应用效果。方法选取126例肺癌骨转移疼痛患者,将2020年1月至2021年6月接受常规疼痛管理的68例患者作为对照组,将2021年7月至2022年12月接受全程化疼痛管理的58例患者作为观察组。比较两组患者的数字分级评分法(NRS)评分、爆发性疼痛发生情况、癌痛状况[美国疼痛学会病人结局问卷修订量表(APS-POQ-Medified)]、心理状态[抑郁自评量表(SDS)、焦虑自评量表(SAS)]、生活质量[欧洲癌症研究与治疗组织生命质量测定量表(EORTC QLQ-C30)]及护理满意度。结果干预后,两组患者NRS评分均低于本组干预前,观察组患者NRS评分低于对照组,对照组患者爆发性疼痛发生率为42.65%,高于观察组患者的13.79%,差异均有统计学意义(P﹤0.05)。干预后,两组患者疼痛控制满意度评分均高于本组干预前,疼痛程度、疼痛影响、疼痛信念评分均低于本组干预前,观察组患者疼痛控制满意度评分高于对照组,疼痛程度、疼痛影响、疼痛信念评分均低于对照组,差异均有统计学意义(P﹤0.05)。干预后,两组患者SDS、SAS评分均低于本组干预前,观察组患者SDS、SAS评分均低于对照组,差异均有统计学意义(P﹤0.05)。干预后,两组患者EORTC QLQ-C30量表各维度评分均高于本组干预前,观察组患者EORTC QLQ-C30量表各维度评分均高于对照组,差异均有统计学意义(P﹤0.05)。观察组患者的护理满意度为98.28%,明显高于对照组患者的80.88%,差异有统计学意义(P﹤0.01)。结论全程化疼痛管理应用于晚期肺癌骨转移疼痛患者中,能够明显改善疼痛程度和负性情绪,提高生活质量和护理满意度。

关键词：晚期肺癌骨转移全程化疼痛管理疼痛程度

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泸州市白酒生产企业安全生产风险防控体系研究报告

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酿酒 2024年第3期51卷 16-19页

作者：李小佰王泽伟张勇李果四川省酒业集团有限责任公司四川成都610000 泸州市酒业发展促进局四川泸州646099 泸州老窖股份有限公司四川泸州646000 四川省川酒集团自然香酒业有限公司四川泸州646104

通过对泸州市白酒生产企业现行安全生产风险防控体系的调查研究,分析现行安全生产风险防控体系的优点与不足。结合泸州市白酒生产企业的安全生产实际情况。发现,泸州市白酒生产企业从业人员安全素养参差不齐,对安全生产管理理解不全面... 详细信息

通过对泸州市白酒生产企业现行安全生产风险防控体系的调查研究,分析现行安全生产风险防控体系的优点与不足。结合泸州市白酒生产企业的安全生产实际情况。发现,泸州市白酒生产企业从业人员安全素养参差不齐,对安全生产管理理解不全面。同时存在多个安全生产风险管控体系,造成了安全管理难度大,安全责任不明确,安全管理理念混淆不清,产生内耗。

关键词：白酒生产企业安全生产风险防控

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Residues of organochlorine pesticides in surface soils from college school yards in Beijing, China

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Journal of Environmental Sciences 2008年第9期20卷 1090-1096页

作者： Xiaofei wang[a], Dianzhong wang[b], Xiaofei QIN[a] xiaobai XU[a] [a]State Key Laboratory of Environmental Chemistry Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China [b]State Key Laboratory of Remote Sensing Science Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing 100101 China

Organochlorine pesticides (OCPs) have been a major environmental issue, attracting much scientific concern because of their nature of toxicity, persistence, and endocrine disrupting effects. Soil samples were collected from ten college school yards in Beijing in 2006 and analyzed to determine fifteen OCPs. Dichlorodiphenyltrichloroethanes (DDTs) were found to be the main pollutants, accounting for 93.70% of total OCPs, followed by hexachlorohexanes (HCHs) (2.25%) and hexachlorobenzene (HCB) (1.82%). Content...

关键词： organochlorine pesticides （OCPs） pollution soil college school yards

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Progress in study on endocrine disrupting pesticides (EDPs) in aquatic environment

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Chinese Science Bulletin 2005年第20期50卷 2257-2266页

作者： XUE Nandong wang Hongbo XU xiaobai State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China Department of Environmental Sciences and Engineering Hunan Agricultural University Changsha 410128 China

Background on the generation of the problems of endocrine disrupting pesticides (EDPs) in aquatic environment, characteristics of EDPs, adverse effects and their effect mechanism of EDPs on human and wildlife, the transportation and degradation pathways of EDPs in water and analysis methods of EDPs in water were reviewed. The importance of EDPs in water should be attached to adverse effects on wildlife and human health. It was advised to estab- lish research programs on EDPs in aquatic environment es- pecially in water supply source.

关键词：水生环境内分泌紊乱杀虫剂 EDPs 人类健康化学物质

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