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Pillar effect induced by ultrahigh phosphorous/nitrogen doping enables graphene/MXene film with excellent cycling stability for alkali metal ion storage
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作者 Meng Qin Yiwei Yao +5 位作者 Junjie Mao chi chen Kai Zhu Guiling Wang Dianxue Cao Jun Yan 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第6期146-156,I0004,共12页
Graphene's large theoretical surface area and high conductivity make it an attractive anode material for potassium-ion batteries(PIBs).However,its practical application is hindered by small interlayer distance and... Graphene's large theoretical surface area and high conductivity make it an attractive anode material for potassium-ion batteries(PIBs).However,its practical application is hindered by small interlayer distance and long ion transfer distance.Herein,this paper aims to address the issue by introducing MXene through a simple and scalable method for assembling graphene and realizing ultrahigh P doping content.The findings reveal that MXene and P-C bonds have a "pillar effect" on the structure of graphene,and the P-C bond plays a primary role.In addition,N/P co-doping introduces abundant defects,providing more active sites for K^(+) storage and facilitating K^(+) adsorption.As expected,the developed ultrahigh phosphorous/nitrogen co-doped flexible reduced graphene oxide/MXene(NPrGM) electrode exhibits remarkable reversible discharge capacity(554 mA hg^(-1) at 0.05 A g^(-1)),impressive rate capability(178 mA h g^(-1) at 2 A g^(-1)),and robust cyclic stability(0.0005% decay per cycle after 10,000 cycles at 2 A g^(-1)).Furthermore,the assembled activated carbon‖NPrGM potassium-ion hybrid capacitor(PIHC) can deliver an impressive energy density of 131 W h kg^(-1) and stable cycling performance with 98.1% capacitance retention after5000 cycles at 1 A g^(-1).Such a new strategy will effectively promote the practical application of graphene materials in PIBs/PIHCs and open new avenues for the scalable development of flexible films based on two-dimensional materials for potential applications in energy storage,thermal interface,and electromagnetic shielding. 展开更多
关键词 GRAPHENE MXene Phosphorous doping Pillar effect Potassium-ion batteries
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水利工程运行精细化管理的理论与实践探索 被引量:3
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作者 张劲松 沈菊琴 +2 位作者 郭宁 池辰 简迎辉 《水利经济》 2023年第2期33-40,94,共9页
水利工程运行精细化管理模式对提高水利工程运行管理现代化水平,顺应新时期经济社会高质量发展要求具有重要的现实意义与实践价值。基于水利工程运行精细化管理要素的理论框架分析,系统梳理了江苏省水利工程运行管理的实施路径和推进措... 水利工程运行精细化管理模式对提高水利工程运行管理现代化水平,顺应新时期经济社会高质量发展要求具有重要的现实意义与实践价值。基于水利工程运行精细化管理要素的理论框架分析,系统梳理了江苏省水利工程运行管理的实施路径和推进措施,并对在经济、社会、生态和安全等方面取得的效益进行了评估。通过实施水利工程运行的精细化管理,江苏省水利工程的安全状况明显改善,运行管理更加规范,管理精品不断涌现,管理水平全面提升,工程效益充分发挥,取得了巨大的经济效益、社会效益、生态效益和安全效益。 展开更多
关键词 水利工程 精细化管理 实施路径 推进措施 江苏省
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水利工程精细化管理实施条件及推广策略研究 被引量:2
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作者 徐灿灿 黄昕 +2 位作者 池辰 简迎辉 沈菊琴 《江苏水利》 2023年第11期42-45,共4页
为安全高效发挥水利工程作用,提升水利工程管理现代化水平,以满足水利高质量发展与工程精细化管理要求,结合江苏省实践,从水利工程精细化管理顶层架构和技术支撑体系以及人、材、物保障3个方面梳理了水利工程精细化管理实施现状和推广效... 为安全高效发挥水利工程作用,提升水利工程管理现代化水平,以满足水利高质量发展与工程精细化管理要求,结合江苏省实践,从水利工程精细化管理顶层架构和技术支撑体系以及人、材、物保障3个方面梳理了水利工程精细化管理实施现状和推广效果,并且从行业支持、激励机制和优势展现3个方面提出水利工程精细化管理的推广策略,为推进水利行业精细管理转型提供参考和借鉴。 展开更多
关键词 水利工程 精细化管理 实施条件 推广策略
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The <i>in Vivo</i>Antioxidant Effects of (&minus;)-Epigallocatechin-3-Gallate Consumption in Healthy Postmenopausal Women Measured by Urinary Excretion of Secondary Lipid Peroxidation Products
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作者 Chelsey Fiecke Mindy Kurzer +1 位作者 chi chen A.Saari Csallany 《Food and Nutrition Sciences》 2019年第1期15-27,共13页
The present study was carried out to determine whether the consumption of epigallocatechin (EGCG), the major bioactive green tea catechin, exerts a positive effect on lowering in vivo lipid peroxidation, a measure of ... The present study was carried out to determine whether the consumption of epigallocatechin (EGCG), the major bioactive green tea catechin, exerts a positive effect on lowering in vivo lipid peroxidation, a measure of oxidative stress, in healthy postmenopausal women. Urinary excretion of secondary lipid peroxidation products, a measure of in vivo lipid peroxidation, was determined in 40 participants randomly assigned to consume a green tea catechin extract (843.0 ± 44.0 mg EGCG/d) or placebo capsules for 12 months. Urine samples were analyzed for individual polar and nonpolar lipophilic aldehydes and related carbonyl compounds by high-performance liquid chromatography (HPLC) at the beginning and at the end of the 12-month intervention period. Results show that two nonpolar aldehydes, nonanal and decatrienal, were both 48% lower (p in vivo antioxidant activity exists with long-term EGCG consumption, which could slightly limit oxidative damage associated with lipid peroxidation and the onset and progression of chronic diseases. 展开更多
关键词 Antioxidants Epigallocatechin-3-Gallate Green Tea Humans Lipid PEROXIDATION Urinary EXCRETION
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Editorial for the special issue“Machine learning and artificial intelligence for energy materials”
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作者 Ziheng Lu Francesco Ciucci chi chen 《Materials Reports(Energy)》 2021年第3期1-1,共1页
With the development of advanced methods in the area of machine learning(ML),artificial intelligence(AI)is rapidly revolutionizing many fields and is starting to change the landscapes of physics and chemistry.Over the... With the development of advanced methods in the area of machine learning(ML),artificial intelligence(AI)is rapidly revolutionizing many fields and is starting to change the landscapes of physics and chemistry.Over the past decade,AI-assisted designs of novel materials have been gradually reshaping how researchers explore new chemistries for energy conversion and storage.In addition,innovative data-driven techniques have led to unprecedented perspectives on the physics and chemistries of the reactions/processes involved.With this background in mind,this themed issue of“Machine Learning and Artificial Intelligence for Energy Materials”presents a collection of 5 highly selected papers in machine learning and artificial intelligence for energy materials.1–5 By including comprehensive reviews,and original research report,this issue aims at providing a broad overview of the theoretical advancements and applications of related methods in the areas of energy storage and conversion. 展开更多
关键词 LEARNING LANDSCAPE INTELLIGENCE
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Effects of rod radius and voltage on streamer discharge in a short air gap 被引量:2
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作者 付钰伟 贺梦莎 +2 位作者 陈驰 王闯 张在秦 《Plasma Science and Technology》 SCIE EI CAS CSCD 2023年第8期44-53,共10页
Streamer discharge is the inaugural stage of gas discharge,and the average electron energy directly determines the electron collision reaction rate,which is a key parameter for studying streamer discharge.Therefore,ta... Streamer discharge is the inaugural stage of gas discharge,and the average electron energy directly determines the electron collision reaction rate,which is a key parameter for studying streamer discharge.Therefore,taking into account the average electron energy,this work establishes a fluid chemical reaction model to simulate and study the course of evolution of a streamer discharge in a 5 mm rod–plate gap,considering 12 particles and 27 chemical reactions.It introduces the electron energy drift diffusion equation into the control equation,and analyzes the temporal and spatial changes of average electron energy,electric field intensity and electron density with change in rod radius and voltage.The effects of voltage and rod radius on the course of streamer discharge can be reflected more comprehensively by combining the average electron energies.Three different values of 0.3 mm,0.4 mm and 0.5 mm are set for the rod radius,and three different values of 5 k V,6 k V and 7 k V are set for the voltage.The influence of an excitation reaction on the streamer discharge is studied.The findings indicate that,as voltage raises,the streamer head’s electron density,electric field and average electron energy all rise,and the streamer develops more quickly.When the rod radius increases,the electron density,electric field and average electron energy of the streamer head all decrease,and the streamer’s evolution slows down.When an excitation reaction is added to the model,the average electron energy,the magnitude of the electric field and the density of electrons decrease,and the evolution of the streamer slows down.An increase in average electron energy will lead to an increase in electric field strength and electron density,and the development of the streamer will be faster. 展开更多
关键词 streamer discharge rod radius VOLTAGE fluid chemical reaction model
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医疗机构保洁公司服务能力综合评价指标体系构建
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作者 李菲 李伟 +1 位作者 池晨 刘婷 《中国医院》 北大核心 2023年第12期71-73,共3页
目的:构建医疗机构保洁公司服务能力综合评价指标体系。方法:通过相关制度、规范和文献资料归纳评价指标,运用专家咨询法筛选重要性高、可实现性好的指标并为每项指标设计配套的指标要求。结果:评价体系共包括基础运行、安全管理、人力... 目的:构建医疗机构保洁公司服务能力综合评价指标体系。方法:通过相关制度、规范和文献资料归纳评价指标,运用专家咨询法筛选重要性高、可实现性好的指标并为每项指标设计配套的指标要求。结果:评价体系共包括基础运行、安全管理、人力资源管理和服务质量4类共11项评价指标,每项指标包含1~4条具体的评价内容作为指标要求。专家问卷咨询的内部一致性信度Cronbach'sα系数为0.853,总体内容效度指数(S-CVI)为0.86,条目内容效度(I-CVI)范围为0.83~1。结论:本研究构建的保洁公司服务能力综合评价指标体系为医疗机构选择和评价保洁公司服务质量和能力提供了管理工具,可明确医疗机构保洁工作质量的考核重点和方向,有利于保洁公司综合服务能力的提升。 展开更多
关键词 医疗机构 保洁公司 服务能力综合评价 专家咨询法
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Replacement of leisure-time sedentary behavior with various physical activities and the risk of dementia incidence and mortality:A prospective cohort study
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作者 Ying Sun chi chen +6 位作者 Yuetian Yu Haojie Zhang Xiao Tan Jihui Zhang Lu Qi Yingli Lu Ningjian Wang 《Journal of Sport and Health Science》 SCIE CSCD 2023年第3期287-294,共8页
Background:Whether or not there is targeted pharmacotherapy for dementia,an active and healthy lifestyle that includes physical activity(PA)may be a better option than medication for preventing dementia.We examined th... Background:Whether or not there is targeted pharmacotherapy for dementia,an active and healthy lifestyle that includes physical activity(PA)may be a better option than medication for preventing dementia.We examined the association between leisure-time sedentary behavior(SB)and the risk of dementia incidence and mortality.We further quantified the effect on dementia risk of replacing sedentary time with an equal amount of time spent on different physical activities.Methods:In the UK Biobank,484,169 participants(mean age=56.5 years;45.2%men)free of dementia were followed from baseline(2006-2010)through July 30,2021.A standard questionnaire measured individual leisure-time SB(watching TV,computer use,and driving)and PA(walking for pleasure,light and heavy do-it-yourself activity,strenuous sports,and other exercise)frequency and duration in the 4 weeks prior to evaluation.Apolipoprotein E(APOE)genotype data were available for a subset of 397,519(82.1%)individuals.A Cox proportional hazard model and an isotemporal substitution model were used in this study.Results:During a median 12.4 years of follow-up,6904 all-cause dementia cases and 2115 deaths from dementia were recorded.In comparison to participants with leisure-time SB<5 h/day,the hazard ratio((HR),95%confidence interval(95%CI))of dementia incidence was 1.07(1.02-1.13)for 5-8 h/day and 1.25(1.13-1.38)for>8 h/day,and the HR of dementia mortality was 1.35(1.12-1.61)for>8 h/day.A 1 standard deviation increment of sedentary time(2.33 h/day)was strongly associated with a higher incidence of dementia and mortality(HR=1.06,95%CI:1.03-1.08 and HR=1.07,95%CI:1.03-1.12,respectively).The association between sedentary time and the risk of developing dementia was more profound in subjects<60 years than in those>60 years(HR=1.26,95%CI:1.00-1.58 vs.HR=1.21,95%CI:1.08-1.35 in>8 h/day,p for interaction=0.013).Replacing 30 min/day of leisure sedentary time with an equal time spent in total PA was associated with a6%decreased risk and 9%decreased mortality from dementia,with exercise(e.g.,swimming,cycling,aerobics,bowling)showing the strongest benefit(HR=0.82,95%CI:0.78-0.86 and HR=0.79,95%CI:0.72-0.86).Compared with APOEε4 noncarriers,APOEε4 carriers are more likely to see a decrease in Alzheimer’s disease incidence and mortality when PA is substituted for SB.Conclusion:Leisure-time SB was positively associated with the risk of dementia incidence and mortality.Replacing sedentary time with equal time spent doing PA may be associated with a significant reduction in dementia incidence and mortality risk. 展开更多
关键词 Alzheimer's disease Apolipoprotein E DEMENTIA Isotemporal substitution model Physical activity Sedentary behavior
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中国14家实验室基于同位素稀释质谱法检测人血清同型半胱氨酸水平的能力验证
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作者 黄冰 迟晨 +4 位作者 蒋玉新 洪沫 曹冉 崔丽 曹云峰 《现代检验医学杂志》 CAS 2023年第5期195-198,共4页
目的评价检测实验室基于同位素稀释液相色谱串联质谱法(isotope dilution-liquid chromatography/tandem mass spectrometry,ID-LC/MS/MS)检测人血清中同型半胱氨酸(homocysteine,Hcy)的能力。方法采用单因素方差分析法和t检验法分别对... 目的评价检测实验室基于同位素稀释液相色谱串联质谱法(isotope dilution-liquid chromatography/tandem mass spectrometry,ID-LC/MS/MS)检测人血清中同型半胱氨酸(homocysteine,Hcy)的能力。方法采用单因素方差分析法和t检验法分别对能力验证样品进行均匀性和稳定性评价;由参加实验室公议值确定指定值,采用稳健算法A对参加实验室的回报结果进行分析,Z’比分数法对实验室检测能力进行评定。参加实验室为分布在9个省份10个城市的14家质谱检测实验室。结果二种浓度的能力验证样品均满足均匀性和稳定性要求。14家实验室二种浓度的Z’比分数绝对值均在2以内,满意率为100%。结论14家实验室使用ID-LC/MS/MS法检测人血清中同型半胱氨酸的能力均为满意。 展开更多
关键词 同位素稀释质谱法 同型半胱氨酸 能力验证 比分数法
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Serum 25-hydroxyvitamin D,genetic susceptibility,and the risk of incident type 2 diabetes:A prospective cohort in East China
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作者 Ying Sun Haojie Zhang +5 位作者 Bin Wang Yuying Wang chi chen Yi chen Yingli Lu Ningjian Wang 《Chinese Medical Journal》 SCIE CAS CSCD 2024年第8期972-979,共8页
Background:The serum vitamin D level varies widely by population,and studies have linked vitamin D levels with the risk of type 2 diabetes mellitus(T2DM).However,the relationship is inconsistent and the impact of vita... Background:The serum vitamin D level varies widely by population,and studies have linked vitamin D levels with the risk of type 2 diabetes mellitus(T2DM).However,the relationship is inconsistent and the impact of vitamin D on T2DM among East Chinese adults is unclear.The study aimed to investigate the association between serum 25-hydroxyvitamin D(25[OH]D)levels and the risk of T2DM and evaluated whether the association is modified by genetic predisposition.Methods:In the Survey on Prevalence in East China for Metabolic Diseases and Risk Factors(SPECT-China)cohort,1862 participants free of T2DM at baseline were included.A weighted genetic risk score was calculated with 28 variants associated with T2DM.Hierarchical logistic models were used to examine the association of serum 25(OH)D and genetic risk with T2DM.Results:After a 5-year follow-up,132 cases of T2DM were documented.We observed no significant association between quartiles of serum 25(OH)D and T2DM risk after multivariable adjustment(χ^(2)=0.571,P_(for trend)=0.426).Compared to those in the lowest quartile of 25(OH)D,the odds ratios(ORs)(95%confidence interval[CI])for participants with increased quartiles were 1.29(0.74-2.25),1.35(0.77-2.36),and 1.27(0.72-2.24),respectively.We observed a positive association of glycated hemoglobin(HbA1c)with 25(OH)D at baseline(β=1.752,P=0.001)and after follow-up(β=1.385,P=0.003),and a negative association of ln conversion homeostasis model assessment(HOMA)-βwith 25(OH)D at baseline(β=-0.982,P=0.021).There was no significant interaction between 25(OH)D and diabetes genetic predisposition on the risk of T2DM(χ^(2)=2.710,P_(for interaction)=0.100).The lowest OR(95%CI)of T2DM was among participants with low genetic risk and the highest quartile of 25(OH)D(0.17[0.05-0.62]).Conclusion:Serum 25(OH)D may be irrelevant to the risk of incident T2DM among East Chinese adults regardless of genetic predisposition. 展开更多
关键词 Vitamin D Diabetes mellitus Type 2 Genetic predisposition to disease Prospective cohort Glycated hemoglobin SPECT-China
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基于迁移学习与数据增强实现计算机断层扫描图像器官自动分割的实验研究
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作者 张雨萌 康文迪 +2 位作者 席俊青 池琛 杨正强 《肝癌电子杂志》 2023年第3期52-57,共6页
目的:探讨在机器深度学习中迁移学习在图像软件对实验动物解剖结构的识别、提取和自动分割中的作用,以及数据增强算法对迁移学习能力的影响。方法:在HyVision Ablation Planning V1.0图像软件的平台上,以Efficient Net b1神经网络作为... 目的:探讨在机器深度学习中迁移学习在图像软件对实验动物解剖结构的识别、提取和自动分割中的作用,以及数据增强算法对迁移学习能力的影响。方法:在HyVision Ablation Planning V1.0图像软件的平台上,以Efficient Net b1神经网络作为深度学习的骨干网络。利用51套VX2兔肝癌模型的计算机断层扫描(computed tomography,CT)图像,以数据增强的方式进行迁移学习训练。将图像软件已经具备的人体腹部CT图像上器官的识别、提取与自动分割功能在动物模型上进行重现。比较不同的学习模型和算法模型的Dice系数、归一化表面Dice(normalized surface Dice,NSD)、三维重建的图像质量及与医师标注的动物模型训练集的差异。结果:从有数据增强无迁移学习型的模型到有数据增强有迁移学习型的模型,VX2兔CT图像的器官自动分割Dice系数从0.525提升到0.676,提高了28.76%,NSD从0.448提升到0.616,提高了37.50%。从无数据增强有迁移学习型的模型到有数据增强有迁移学习型的模型,VX2兔CT图像的器官自动分割Dice系数从0.502提升到0.676,提高了34.66%,NSD从0.459提升到0.616,提高了34.20%。表明在机器深度学习过程中迁移学习与数据增强对于研究新的解剖对象同等重要。结论:在机器深度学习过程中,迁移学习的功能可以借助数据增强算法,获得更好的图像识别、提取与自动分割的结果。 展开更多
关键词 迁移学习 数据增强 动物CT图像分割 神经网络
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医院耗占比控制方法探讨 被引量:12
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作者 杨琼 沈雄山 +1 位作者 池晨 徐艳 《医疗卫生装备》 CAS 2019年第1期85-87,共3页
目的 :有效控制医院耗材成本,合理使用耗材,切实减轻患者负担。方法 :充分利用医院信息系统(hospital information system,HIS),结合DRGs(diagnosis related groups)费用对比,对医用耗材管理进行整改。结果:高值耗材、试剂类耗材、手术... 目的 :有效控制医院耗材成本,合理使用耗材,切实减轻患者负担。方法 :充分利用医院信息系统(hospital information system,HIS),结合DRGs(diagnosis related groups)费用对比,对医用耗材管理进行整改。结果:高值耗材、试剂类耗材、手术室使用耗材等得到有效控制,在保证医疗供给的同时,耗占比逐步下降,切实减轻了患者负担。结论:通过精确数据分析、针对性量化指标、加强监督等手段可有效控制耗占比。 展开更多
关键词 耗占比 科学分析 精确控制 量化指标
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以CaCl_2为模板合成的高活性和高稳定性铁、氮、硫共掺杂多孔碳氧还原电催化剂(英文) 被引量:3
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作者 陈驰 周志有 +4 位作者 王宇成 张雪 杨晓冬 张新胜 孙世刚 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2017年第4期673-682,共10页
燃料电池是一种可将化学能通过电催化反应直接转化成电能的装置,具有能量密度高和清洁无污染等优点.燃料电池阴极氧还原反应(ORR)的动力学较迟缓,是电池能量效率损失的主要原因.目前ORR催化活性最高的是铂基催化剂,但由于贵金属铂价格昂... 燃料电池是一种可将化学能通过电催化反应直接转化成电能的装置,具有能量密度高和清洁无污染等优点.燃料电池阴极氧还原反应(ORR)的动力学较迟缓,是电池能量效率损失的主要原因.目前ORR催化活性最高的是铂基催化剂,但由于贵金属铂价格昂贵,储量稀少,且对燃料小分子渗透的抗性较差,严重制约了燃料电池的大规模应用.因此,高性能、低成本的非贵金属催化剂成为燃料电池领域的研究热点.本文选用含氮量高达45%的三聚氰胺-甲醛树脂为碳源和氮源,Fe(SCN)_3为铁源和硫源,以CaCl_2为模板,在高温和铁的催化作用下将树脂碳化,经酸洗和二次热处理工艺,制备出铁、氮、硫共掺杂的多孔碳(FeNS-PC).干燥后的CaCl_2颗粒可防止树脂在高温下交联形成块状碳颗粒,同时起到造孔模板的作用.CaCl_2颗粒在温和条件下即可除去,无需强腐蚀性条件,因此不会对催化活性中心造成破坏.在Fe/N/C催化剂中掺杂S可进一步提高催化活性,不添加碳载体可避免低活性的碳载体降低质量活性,多孔结构可促进传质,充分利用活性位点.我们优化了热处理温度,并对催化剂的结构、组分及催化性能等进行了表征分析.结果表明,热处理温度为900℃时,可将树脂完全转化成多孔碳,并获得较高的杂原子掺杂量,可达到最优活性.CaCl_2为模板剂可避免使用强腐蚀性试剂去除模板,有利于保留活性位,并得到多孔结构.FeNS-PC-900的比表面积可达775 m^2/g.得益于原位掺杂的合成工艺,各掺杂元素在多孔碳表面均匀分布.在酸性介质中,FeNS-PC-900的半波电位可达到0.811V,仅比商业Pt/C催化剂低78mV;在0.8V电位下的质量活性为10.2A/g,表现出优异的催化活性.经过10000圈加速衰减测试后,其半波电位仅下降了20mV,在0.75V电位下持续放电10000s后,其ORR电流仍保持初始电流的84.4%,具有比Pt/C更加优异的稳定性.以FeNS-PC-900为阴极催化剂的质子交换膜燃料电池的最大功率密度可达到0.49 W/cm^2,并在0.6 V电压下持续放电10h后,其电流仍可保持初始电流的65%,表现出良好的应用潜力.FeNS-PC-900具有高掺杂含量、高比表面积和多孔结构,并且杂原子在催化剂表面均匀分散,在半电池和燃料电池测试中都表现出优异的催化活性和稳定性,表明其是一种非常有潜力应用于燃料电池的非贵金属氧还原催化剂. 展开更多
关键词 非贵金属催化剂 氧还原反应 质子交换膜燃料电池 铁、氮、硫共掺杂多孔碳 三聚氰胺-甲醛树脂
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高精度小抖动脉冲延时发生器的研制 被引量:7
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作者 迟晨 伍伟 +1 位作者 方盛江 刘德林 《光电子技术》 CAS 北大核心 2020年第2期108-113,共6页
针对激光雷达中脉冲同步存在的抖动大和精度低问题开展分析,提出了数字计数和模拟延时相结合的总体方案,采用抖动补偿技术实现抖动消除,模拟电路实现延时的高精度。通过对研制的脉冲延时发生器实测,抖动和精度分别小于40 ps和3 ps,测试... 针对激光雷达中脉冲同步存在的抖动大和精度低问题开展分析,提出了数字计数和模拟延时相结合的总体方案,采用抖动补偿技术实现抖动消除,模拟电路实现延时的高精度。通过对研制的脉冲延时发生器实测,抖动和精度分别小于40 ps和3 ps,测试结果表明该脉冲延时发生器能够满足激光雷达高性能同步技术的要求。 展开更多
关键词 脉冲延时 抖动 同步技术
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重大突发公共卫生事件冲击下农户的生计水平突变研究 被引量:4
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作者 赵旭 池辰 赵菲菲 《统计与信息论坛》 CSSCI 北大核心 2022年第1期65-77,共13页
重大突发公共卫生事件给农户生计造成了全面且持久的冲击,一定程度上阻碍了脱贫攻坚与乡村振兴的衔接进程。以新冠肺炎疫情为重大突发公共卫生事件的典型案例,从随机突变论的全新视角,构建疫情前后的农户生计水平演变动力学模型,基于疫... 重大突发公共卫生事件给农户生计造成了全面且持久的冲击,一定程度上阻碍了脱贫攻坚与乡村振兴的衔接进程。以新冠肺炎疫情为重大突发公共卫生事件的典型案例,从随机突变论的全新视角,构建疫情前后的农户生计水平演变动力学模型,基于疫情核心区湖北省的465户农村居民调研数据,采用非线性实证分析方法,探寻农户生计脆弱性引致因素及恢复路径。研究发现:以新冠肺炎疫情为代表的突发公共卫生事件可能会诱发农户生计水平的突变,其程度由生计风险决定,且事件发展不同阶段的影响存在差异。疫情冲击下,农户自然资本具有显著的抗风险能力,人力资本与物质资本损失甚微,而金融与社会资本却遭遇重创。疫后农户生计水平的不同源于生计策略差异,务工主导型农户生计脆弱性较高,而农工互补型农户适应力最强。现行的惠农政策对复工复产虽然有效,但农户生计水平恢复具有时滞性。面对突发公共卫生事件,政府应以农户生计策略为导向,制定并完善农户生计风险应急机制,探索差异化、特色化支农助农惠农政策,拓展农户多元化增收渠道,提高农户生计韧性和稳定性,实现生计恢复和可持续发展,以促进脱贫攻坚与乡村振兴的有效衔接。 展开更多
关键词 重大突发公共卫生事件 生计水平突变 生计脆弱性 非线性实证
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A Diet with 3% of Energy from a Mixture of Omega-3 Fatty Acids Significantly Increases in Vivo Lipid Peroxidation in Postmenopausal Women
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作者 A. Saari Csallany Cheryl E. Ainslie-Waldman +3 位作者 Lindsay R. Young chi chen Mindy S. Kurzer Susan K. Raatz 《Food and Nutrition Sciences》 2016年第12期1099-1111,共13页
Dietary omega-3 (n - 3) polyunsaturated fatty acids (PUFA) are recommended by public health organizations to reduce the risk of cardiovascular disease, and several epidemiological studies have suggested there is an in... Dietary omega-3 (n - 3) polyunsaturated fatty acids (PUFA) are recommended by public health organizations to reduce the risk of cardiovascular disease, and several epidemiological studies have suggested there is an inverse association between n - 3 intake and human cancers. However, n - 3 are susceptible to an increase in lipid peroxidation in the human body. As part of a crossover dietary intervention study of a diet (20% of energy from fat) with or without an additional 3% of energy from a mixture of n - 3 (with 5.36 g α-linolenic acid and 1.45 g eicosapentaenoic acid and docosahexaenoic acid per 2000 kcal per day), we measured total in vivo lipid peroxidation in healthy postmenopausal women (n = 15). Our results indicated that the diet with 3% of energy from n - 3 significantly increased the urinary concentrations of total polar lipophilic aldehydes and related compounds produced via lipid peroxidation (p α, β-unsaturated hydroxy aldehydes 4-hydroxy-2-trans - hexenal (p trans -decenal (p < 0.05) compared to the diet with less than 1% of energy from n - 3. This is also the first study to document the presence of 4-hydroxy-2-trans -decenal in the urine of individuals consuming n - 3. These results demonstrate that an increase in 3% of energy from dietary n – 3 increases in vivo lipid peroxidation. 展开更多
关键词 Lipid Peroxidation n 3 Fatty Acids Human HHE 4-Hydroxyhexenal HDE 4-Hydroxydecenal α β-4-Hydroxyaldehydes HPLC MS
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新型冠状病毒肺炎疫情防控期间医用防护物资的筹集与管理 被引量:2
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作者 沈雄山 杨琼 +1 位作者 池晨 邱萌 《医疗装备》 2020年第23期51-52,共2页
在新型冠状病毒肺炎疫情防控期间,湖北省各定点医疗机构都面临着医用防护物资供应紧张的局面。基于此,医院迅速成立防护物资保障部,科学计算和掌握防护物资需求量,通过社会捐赠、医学装备科应急采购、指挥部统一调拨等方式有效保障防护... 在新型冠状病毒肺炎疫情防控期间,湖北省各定点医疗机构都面临着医用防护物资供应紧张的局面。基于此,医院迅速成立防护物资保障部,科学计算和掌握防护物资需求量,通过社会捐赠、医学装备科应急采购、指挥部统一调拨等方式有效保障防护物资供应。 展开更多
关键词 新型冠状病毒肺炎 医用防护物资 筹集 管理
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条纹管超高速探测器件和组件研究
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作者 唐家业 王葵 +3 位作者 迟晨 石吟馨 刘昌春 唐光华 《光电子技术》 CAS 北大核心 2019年第4期225-231,237,共8页
分别介绍了不同类型的条纹管超高速探测器件、组件的工作原理、结构组成和基本性能参数。详细论述了两种典型结构条纹管器件的结构特点,工作原理,空间分辨率和时间分辨率测试。此外,还介绍了两种条纹管组件的结构,工作原理和实际测试结... 分别介绍了不同类型的条纹管超高速探测器件、组件的工作原理、结构组成和基本性能参数。详细论述了两种典型结构条纹管器件的结构特点,工作原理,空间分辨率和时间分辨率测试。此外,还介绍了两种条纹管组件的结构,工作原理和实际测试结果。条纹管器件和组件采用独特的结构设计、实现超高速时空转换,获得了皮秒级乃至飞秒级的时间分辨率,是目前时间分辨率最高的光电探测器件。基于高时间分辨率性能的拓展,条纹管器件和组件在惯性约束、激光雷达和科学研究等超高速探测领域具有广泛的应用前景。 展开更多
关键词 条纹管 条纹相机 时间分辨率 高速信号探测 激光雷达
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门控型微通道板光电倍增管的研制和应用
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作者 杨杰 徐鹏霄 +1 位作者 迟晨 赵文锦 《光电子技术》 CAS 北大核心 2019年第1期34-38,共5页
门控型微通道板光电倍增管是一种具有门选通功能的光电倍增管,采用该器件构成的探测器组件可以从强背景光中选出所需的信号,消除强激光对探测器可能造成的损害,广泛应用于核物理探测、卫星激光测距、时间相关荧光余辉测试等领域。本单... 门控型微通道板光电倍增管是一种具有门选通功能的光电倍增管,采用该器件构成的探测器组件可以从强背景光中选出所需的信号,消除强激光对探测器可能造成的损害,广泛应用于核物理探测、卫星激光测距、时间相关荧光余辉测试等领域。本单位成功研制了外门控型微通道板光电倍增管组件,解决了最大脉冲线性电流的提升、门信号干扰的优化、高电子增益实现等关键技术问题。探测器组件初步应用于CSNS反角白光中子源测量,实现了门控测试功能。 展开更多
关键词 微通道板光电倍增管 外门控 最大脉冲线性电流 门信号干扰
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小型化高分辨率激光雷达条纹管探测器的研制
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作者 迟晨 唐家业 +2 位作者 王葵 董光焰 韩文杰 《光电子技术》 CAS 北大核心 2019年第2期79-84,共6页
基于条纹管激光雷达原理与组成,对条纹管探测器输入、输出光学系统进行了小型化和高传输效率设计;针对激光雷达特点,对条纹管峰值响应波长进行了优化,对电子光学系统、偏转系统进行了高分辨率设计,给出了整管的性能参数测试典型值;开发... 基于条纹管激光雷达原理与组成,对条纹管探测器输入、输出光学系统进行了小型化和高传输效率设计;针对激光雷达特点,对条纹管峰值响应波长进行了优化,对电子光学系统、偏转系统进行了高分辨率设计,给出了整管的性能参数测试典型值;开发了包括门控电源、扫描电源、高精度同步控制电路在内的电子控制系统,给出了测试典型值。对研制的整个条纹管探测器尺寸、性能参数、接口等作了介绍,并对探测器进行了外场激光雷达试验,获得了清晰的灰度像和三维距离像,证明了条纹管激光雷达体制的可行性和广泛应用前景。 展开更多
关键词 条纹管 激光雷达 三维成像
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