检索结果-南通市图书馆

Multi-stage ammonia production for sorption selective catalytic reduction of NO_(x)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers in Energy 2022年第5期16卷 840-851页

作者： Chen ZHANG Guoliang AN Liwei WANG shaofei wu Institute of Refrigeration and Cryogenics Key Laboratory of Power Machinery and Engineering of the Ministry of EducationShanghai Jiao Tong UniversityShanghai 200240China

Sorption selective catalytic reduction of nitrogen oxides(NO_(x))(sorption-SCR)has ever been proposed for replacing commercial urea selective catalytic reduction of NO_(x)(urea-SCR),while only the single-stage sorption cycle is hitherto adopted for sorption-SCR.Herein,various multi-stage ammonia production cycles is built to solve the problem of relative high starting temperature with ammonia transfer(AT)unit and help detect the remaining ammonia in ammonia storage and delivery system(ASDS)with ammonia warning(AW)unit.Except for the singlestage ammonia production cycle with MnCl2,other sorption-SCR strategies all present overwhelming advantages over urea-SCR considering the much higher NO_(x) conversion driven by the heat source lower than 100℃ and better matching characteristics with low-temperature catalysts.Furthermore,the required mass of sorbent for each type of sorption-SCR is less than half of the mass of AdBlue for urea-SCR.Therefore,the multifunctional multi-stage sorption-SCR can realize compact and renewable ammonia storage and delivery with low thermal energy consumption and high NO_(x) conversion,which brings a bright potential for efficient commercial de-NO_(x) technology.

关键词： selective catalytic reduction(SCR) nitrogen oxides(NO_(x)) ammonia composite sorbent chemisorption

Unveiling strain-enhanced moiréexciton localization in twisted van der Waals homostructures

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第4期17卷 3245-3252页

作者： Henry Rui He Haihong Zheng Biao wu shaofei Li Junnan Ding Zongwen Liu Jian-Tao Wang Anlian Pan Yanping Liu Institute of Quantum Physics School of PhysicsCentral South UniversityChangsha 410083China State Key Laboratory of Precision Manufacturing for Extreme Service Performance Central South UniversityChangsha 410083China School of Chemical and Biomolecular Engineering The University of SydneyNSW 2006Australia Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China College of Materials Science and Engineering Hunan UniversityChangsha 410082China State Key Laboratory of High-Performance Complex Manufacturing Central South UniversityChangsha 410083China Shenzhen Research Institute of Central South University Shenzhen 51800China

Moirésuperlattices,arising from the controlled twisting of van der Waals homostructures at specific angles,have emerged as a promising platform for quantum emission applications.Concurrently,the manipulation of strain provides a versatile strategy to finely adjust electronic band structures,enhance exciton luminescence efficiency,and establish a robust foundation for two-dimensional quantum light sources.However,the intricate interplay between strain and moirépotential remains partially unexplored.Here,we introduce a meticulously designed fusion of strain engineering and the twisted 2L-WSe_(2)/2L-WSe_(2) homobilayers,resulting in the precise localization of moiréexcitons.Employing low-temperature photoluminescence spectroscopy,we unveil the emergence of highly localized moiré-enhanced emission,characterized by the presence of multiple distinct emission lines.Furthermore,our investigation demonstrates the effective regulation of moirépotential depths through strain engineering,with the potential depths of strained and unstrained regions differing by 91%.By combining both experimental and theoretical approaches,our study elucidates the complex relationship between strain and moirépotential,thereby opening avenues for generating strain-induced moiréexciton single-photon sources.

关键词： moirésuperlattices strain engineering moiréexcitons moirépotential

Chemisorption solid materials for hydrogen storage near ambient temperature:A review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers in Energy 2023年第1期17卷 72-101页

作者： Yiheng ZHANG shaofei wu Liwei WANG Xuefeng ZHANG Institute of Refrigeration and Gryogenic Key Laboratory of Power Machinery and Engineering of the Ministry of EducationShanghai Jiao Tong UniversityShanghai 200240China

Solid chemisorption technologies for hydrogen storage,especially high-efficiency hydrogen storage of fuel cells in near ambient temperature zone defined from−20 to 100℃,have a great application potential for realizing the global goal of carbon dioxide emission reduction and vision of carbon neutrality.However,there are several challenges to be solved at near ambient temperature,i.e.,unclear hydrogen storage mechanism,low sorption capacity,poor sorption kinetics,and complicated synthetic procedures.In this review,the characteristics and modification methods of chemisorption hydrogen storage materials at near ambient temperature are discussed.The interaction between hydrogen and materials is analyzed,including the microscopic,thermodynamic,and mechanical properties.Based on the classification of hydrogen storage metals,the operation temperature zone and temperature shifting methods are discussed.A series of modification and reprocessing methods are summarized,including preparation,synthesis,simulation,and experimental analysis.Finally,perspectives on advanced solid chemisorption materials promising for efficient and scalable hydrogen storage systems are provided.

关键词： hydrogen storage capacity chemisorption near-ambient-temperature modification methods alloy hydrides

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

人机协同巡检下绝缘子分类及故障检测方法

华中科技大学学报（自然科学版） 2024年第1期52卷 91-98,111页

作者：王少飞吴琼水田猛王先培武汉大学电子信息学院湖北武汉430072

针对目前电网人机协同巡检过程中数据收集量、来源面和复杂度增加,导致绝缘子目标小、遮挡严重、背景复杂、故障难以识别等问题,提出一种基于Yolov5-TBT模型的绝缘子分类及故障检测算法.首先构建了多目标(3种类别+2种故障)的人机协同巡... 详细信息

针对目前电网人机协同巡检过程中数据收集量、来源面和复杂度增加,导致绝缘子目标小、遮挡严重、背景复杂、故障难以识别等问题,提出一种基于Yolov5-TBT模型的绝缘子分类及故障检测算法.首先构建了多目标(3种类别+2种故障)的人机协同巡检数据集,为模型训练提供充足的绝缘子图像,提高模型的鲁棒性和泛化能力.然后,以Yolov5模型为基础,增加Transformer编码器,减少复杂背景的干扰;使用加权双向特征金字塔网络(BiFPN)学习不同层级输入特征的重要性,进行更有效的特征聚合;增加小目标预测分支,提高对小目标的检测效果.实验结果表明:改进模型效果优于Yolov5模型,对伞裙破损故障的检测精度提高了19.4%,整体性能提高3.6%.

关键词：电网巡检绝缘子分类故障检测 Yolov5模型 Transformer编码器

维普期刊数据库

Benzo[1,2-c;4,5-c']bis[1,2,5]thiadiazole-porphyrin-based near-infrared dyes

在线全文

学校读者我要写书评

暂无评论

SmartMat 2021年第3期2卷 398-405页

作者： Yi Liu shaofei wu Tullimilli Y.Gopalakrishna Jishan wu Department of Chemistry National University of SingaporeSingaporeSingapore Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhouBinhai New CityChina

Benzo[1,2-c;4,5-cʹ]bis[1,2,5]thiadiazole(BBT)has intrinsic diradical character and herein it is used to construct organic near-infrared(NIR)dyes together with the aromatic porphyrin unit.Three BBT-porphyrin hybrid dyes 1-3 with different linkage modes are synthesized by Pd-catalyzed Sonogashira crosscoupling between meso-ethynylene porphyrin units and monobromo-/dibromo-BBT,or through unexpected homocoupling between the BBT units.They all possess small open-shell diradical character and display intense NIR absorption in the range of 800-1000 nm.They also exhibit amphoteric redox behavior.BBT-based diradicaloids are thus good candidates for organic NIR dyes.

关键词： benzo[1,2-c 4,5-c']bisthiadiazole diradical character near-infrared dye porphyrin

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

鄱阳湖流域水沙变化及出湖水沙模拟研究

人民长江 2024年第3期55卷 97-104页

作者：香天元孙思瑞王超吴绍飞长江水利委员会水文局湖北武汉430010 长江水利委员会水文局长江中游水文水资源勘测局湖北武汉430010 南昌工程学院江西南昌330099

自20世纪50年代以来,鄱阳湖流域气候发生显著变化,人类活动日益频繁,降水、产流能力和产沙能力都发生了明显变化。基于鄱阳湖流域“五河”入湖控制站以及湖口水文站数据,运用Mann-Kendall检验法和双累积曲线法确定了年输沙量突变时间点... 详细信息

自20世纪50年代以来,鄱阳湖流域气候发生显著变化,人类活动日益频繁,降水、产流能力和产沙能力都发生了明显变化。基于鄱阳湖流域“五河”入湖控制站以及湖口水文站数据,运用Mann-Kendall检验法和双累积曲线法确定了年输沙量突变时间点,再利用累积量斜率变化分析法量化降水、产流能力和产沙能力对鄱阳湖入湖沙量的影响;在此基础上,提出了变分模态分解、LSTM神经网络和完全逐步抽样技术等多方法耦合的水沙模拟模型及其评价方法,并建立了研究区域鄱阳湖湖口站水沙模拟模型。研究结果表明:不论是“五河”入湖沙量变化,还是湖区泥沙淤积量变化,以降水变化为代表的气候变化因素对其影响较小,主要影响还是来自人类活动因素;但在具体的变化规律上却存在差异,人类活动对入湖沙量的贡献率呈上升趋势,但对同期鄱阳湖湖区淤积沙量的影响贡献率则呈现先降后升的趋势。水沙模拟分析表明,湖口站出湖月径流量、出湖月输沙量的模拟过程与实测过程较为吻合,取得了较高模拟精度,湖口、星子站水位对模拟精度的提升贡献较小。

关键词：水沙变化水沙模拟归因分析鄱阳湖

维普期刊数据库

Changes in cesarean section rates and its indications among primiparous women during each implementation phase of Chinese two-child policy:a retrospective study

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2022年第18期135卷 2264-2266页

作者： Yumei Cheng shaofei Su Shaowen wu Department of Perinatal Medicine Beijing Obstetrics and Gynecology HospitalCapital Medical UniversityBeijing Maternal and Child Health Care HospitalBeijing 100026China Department of Central Laboratory Beijing Obstetrics and Gynecology HospitalCapital Medical UniversityBeijing Maternal and Child Health Care HospitalBeijing 100026China

To the Editor:Cesarean section(CS)is among the most important and safe procedures in obstetrics.When medically indicated,CS can be a life-saving intervention.During the Chinese one-child policy,couples tended to choose CS for various reasons.In 2010,the CS rate in China rose to among the world’s highest.^([1])Yet,CS can also have various adverse maternal and neonatal consequences.Maternal mortality and maternal and infant complications are higher with CS compared with vaginal delivery.[2]Over the past several decades,CS rates have increased sharply worldwide,and controlling these rates has become among the most prominent obstetric issues.

关键词： section policy among

维普期刊数据库

在线全文

学校读者我要写书评

暂无评论

我国南方镭污染区优势植物及根际微生物分析

核农学报 2024年第6期38卷 1146-1152页

作者：原寒乔新燕曹少飞吴仁杰李建国商照荣中国辐射防护研究院中核集团核环境模拟与评价技术重点实验室山西太原030006 中国原子能科学研究院北京102413 生态环境部核与辐射安全中心北京100082

为探索我国南方中低水平镭污染土壤环境中优势植物对226Ra的富集规律及其根际微生物特征,对属于中亚热带湿润型季风气候区的南方典型铀矿区进行了野外实地样方调查,采集该地区优势植物和土壤,分析物种优势度、土壤镭污染水平、植物对22... 详细信息

为探索我国南方中低水平镭污染土壤环境中优势植物对226Ra的富集规律及其根际微生物特征,对属于中亚热带湿润型季风气候区的南方典型铀矿区进行了野外实地样方调查,采集该地区优势植物和土壤,分析物种优势度、土壤镭污染水平、植物对226Ra的转移和富集特征、植物根际微生物特征。结果表明,现场共筛选出15种优势草本植物,以苏丹草(Sorghum sudanense)的生物量最大,富集系数和转运系数分别为0.17、0.45;采样区226Ra的平均浓度为211 Bq·kg^(-1);土壤中存在大量的变形菌门(Proteobacteria)、子囊菌门(Ascomycota)等微生物,且不同的植物根际有特定的微生物类群富集,在放射性环境治理和修复、形成植物-微生物联合修复组合方面具有应用潜力。本研究结果为后期筛选原位治理土壤放射性污染的植物-微生物联合修复技术提供了依据。

关键词：镭超富集植物转移参数根际微生物

维普期刊数据库博看期刊

Moiré-superlattice MXenes enabled ultra-stable K-ion storage in neutral electrolyte

在线全文

学校读者我要写书评

暂无评论

Nano Research 2023年第4期16卷 5006-5017页

作者： Qiong wu Yanhui Xue shaofei Chao Fufa wu Muhammad Sufyan Javed Lu Li Wei Zhang School of Materials Science and Engineering Liaoning University of TechnologyJinzhou 121001China School of Physical Science and Technology Lanzhou UniversityLanzhou 730000China Key Laboratory for Photonic and Electronic Bandgap Materials Ministry of EducationSchool of Physics and Electronic EngineeringHarbin Normal UniversityHarbin 150025China Key Laboratory of Automobile Materials MOE School of Materials Science&EngineeringJilin Provincial International Cooperation Key Laboratory of High-Efficiency Clean Energy MaterialsElectron Microscopy Centerand International Center of Future ScienceJilin UniversityChangchun 130012China

Ti_(3)C_(2)MXene is an auspicious energy storage material due to its metallic conductivity and layered assembly.However,in the real working condition of electrochemical energy storage with long cycle charging-discharging,a structural collapse is usually caused by the stacking of its layers creating a large attenuation of specific capacitance.Inspired by the superlattice effect of magic angle graphene,we conducted microscopical regulation of rotation mismatch on the Ti_(3)C_(2)lattice;consequently,a hexagonal fewlayered Ti_(3)C_(2)free-standing film constructed with Moiré-superlattices.Such finding not only solves the problem of Ti_(3)C_(2)structural collapse but also dramatically improves the specific capacitance of Ti_(3)C_(2)as a supercapacitor electrode under long cycle charging and discharging.The ultra-stable energy storage of this electrode material in a neutral aqueous electrolyte was realized.Moreover,the formation mechanism of rotating Moirépattern is revealed through microscopy and microanalysis of the produced Moirépattern,assisted with modeling and analyzing the underlying mechanism between the Moirépattern and the rotation angle.Our work provides experimental and theoretical support for future construction of Moiré-superlattice structure for a wide range of MXene phases and is undoubtedly promoting the development of MXene materials in the field of energy storage.

关键词： Ti_(3)C_(2)MXene Moiré-superlattice microwave-assisted etching specific capacitance