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Parametric study on the flutter sensitivity of a wide-chord hollow fan blade

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Chinese Journal of Aeronautics 2022年第11期35卷 277-293页

作者： Xiaojie zhang Yanrong WANG weiyu CHEN Xianghua JIANG School of Energy and Power Engineering Beihang UniversityBejing 100083China Jiangxi Research Institute Beihang University Nanchang 330096China

In recent years, the hollow fan blades have been widely used to meet the demand for light weight and good performance of the aero-engine. However, the relationship between the hollow structure and the aeroelastic stability has not been studied yet in the open literature. In this paper,it has been investigated for an H-shaped hollow fan blade. Before studying the flutter behavior, the methods of parametric modeling and auto-generation of Finite Element Model(FEM) are presented. The influence of the feature parameters on the vibration frequency and mode shape(as the input of flutter calculation) of the first three modes are analyzed by the Orthogonal Experimental Design(OED) method. The results show that the parameters have a more remarkable impact on the first torsional mode and thus it is concerned in the flutter sensitivity analysis. Compared with the solid blade, the minimum aerodynamic damping of the hollow blade decreases, indicating that the hollow structure makes the aeroelastic stability worse. For the parameters describing the hollow section, the rib number N has the greatest influence on the minimum aerodynamic damping, followed by the wall thickness W5. For the parameters in the height of hollow segment, the aerodynamic damping increases with the increase of parameters M1 and M2. This means that reducing the height of the hollow segment is helpful to improve the aeroelastic stability. Compared with the impact of parameters in hollow section, the variation of aerodynamic damping caused by the height of the hollow segment is small.

关键词： Aerodynamic damping Flutter Hollow fan blade Hollow structure Orthogonal experimental design

Clinical efficacy of comprehensive therapy based on traditional Chinese medicine patterns on patients with pneumoconiosis: a pilot double-blind, randomized, and placebo-controlled study

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Frontiers of Medicine 2022年第5期16卷 736-744页

作者： Jiansheng Li Hulei Zhao Yang Xie Jieya Li Qingwei Li Xuexin Chen Weiyu Zhang Collaborative Innovation Center for Chinese Medicine and Respiratory Diseases Co-constructed by Henan Province&Education Ministry of China Henan University of Chinese MedicineZhengzhou 450046China Henan Key Laboratory of Chinese Medicine for Respiratory Disease Henan University of Chinese MedicineZhengzhou 450046China Department of Respiratory Diseases The First Affiliated Hospital of Henan University of Chinese MedicineZhengzhou 450000China Department of Pneumoconiosis Henan Hospital for Occupational DiseasesZhengzhou 450052China Department of Respiratory Diseases Jiaozuo Coal Industry Group Co.Ltd.Central HospitalJiaozuo 454000China Department of Pneumoconiosis Yima Coal Industry Group Co.Ltd.General HospitalYima 472300China

Effective therapy options for pneumoconiosis are lacking.Traditional Chinese medicine(TCM)presents a favorable prospect in the treatment of pneumoconiosis.A pilot study on TCM syndrome differentiation can evaluate the clinical efficacy and safety of TCM and lay a foundation for further clinical research.A double-blind,randomized,and placebo-controlled trial was conducted for 24 weeks,in which 96 patients with pneumoconiosis were randomly divided into the control and treatment groups.Symptomatic treatment was conducted for the two groups.The treatment group was treated with TCM syndrome differentiation,and the control group was treated with placebo.The primary outcomes were the six-minute walking distance(6MWD)and the St.George Respiratory Questionnaire(SGRQ)score.The secondary outcomes were the modified British Medical Research Council Dyspnea Scale(mMRC),Chronic Obstructive Pulmonary Disease Assessment Test(CAT),Hospital Anxiety and Depression Scale(HADS),and pulmonary function.Only 83 patients from the 96 patients with pneumoconiosis finished the study.For the primary outcome,compared with the control groups,the treatment group showed a significantly increased 6MWD(407.90 m vs.499.51 m;95%confidence interval(CI)47.25 to 135.97;P<0.001)and improved SGRQ total score(44.48 vs.25.67;95%CI 27.87 to 9.74;P<0.001).The treatment group also significantly improved compared with the control group on mMRC score(1.4 vs.0.74;95%CI 1.08 to 0.23;P=0.003),CAT score(18.40 vs.14.65;95%CI 7.07 to 0.43;P=0.027),and the total symptom score(7.90 vs.5.14;95%CI 4.40 to 1.12;P<0.001).No serious adverse events occurred.This study showed that TCM syndrome differentiation and treatment had a favorable impact on the exercise endurance and quality of life of patients with pneumoconiosis.

关键词： pneumoconiosis randomized controlled trials traditional Chinese medicine

Amorphous Ru nanoclusters onto Co‐doped 1D carbon nanocagesenables efficient hydrogen evolution catalysis

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Chinese Journal of Catalysis 2022年第1期43卷 110-116页

作者： Wenxiu Yang Weiyu Zhang Rui Liu Fan Lv Yuguang Chao Zichen Wang Shaojun Guo School of Materials Science & Engineering Peking University Beijing 100871 China Advanced Research Institute of Multidisciplinary Science Advanced Technology Research Institute (Jinan) Key Laboratory of Cluster Science School of Chemistry and Chemical Engineering Beijing Institute of Technology Beijing 100081 China

析氢反应是电解水产制氢的关键反应之一.在碱性条件下,由于催化剂表面与反应过程中产生的氧物种、氢物种与催化剂的吸附未处于最佳状态,析氢反应动力学往往比较缓慢,比在酸性条件下慢2–3个数量级.目前,铂基纳米催化剂被认为是最优的析... 详细信息

析氢反应是电解水产制氢的关键反应之一.在碱性条件下,由于催化剂表面与反应过程中产生的氧物种、氢物种与催化剂的吸附未处于最佳状态,析氢反应动力学往往比较缓慢,比在酸性条件下慢2–3个数量级.目前,铂基纳米催化剂被认为是最优的析氢催化剂,但因价格昂贵、稳定性较差,限制了其在电解水器件上的大规模应用.因此,设计一种价格较为低廉、活性高和稳定性好的碱性析氢催化剂尤为必要.钌作为铂族金属之一,其价格约为铂的三分之一,但其与氢的结合能却与铂类似.因此,钌基催化剂被认为是有望替代铂作为析氢催化剂.本文结合模板法、静电纺丝和碳化热解策略构筑了一种负载无定型钌纳米簇的原子级钴掺杂一维碳纳米笼催化剂,有效提升了碱性条件下析氢反应性能.该催化剂具有较高的比表面积,丰富的缺陷结构,原子级分散的金属Co掺杂以及无定型钌纳米簇结构,并在碱性条件下催化析氢反应时,表现出了低起始过电位,低Tafel斜率(62 mV dec–1)和高稳定性.X射线衍射(XRD)结果表明,该催化剂中钌和钴以无定型形式存在.选区电子衍射结果表明了无定型结构的存在,并且钌以纳米簇形式存在,其平均粒径为1.48 nm.X射线光电子能谱结果表明该催化剂含有较高的氮掺杂,拉曼光谱证明了其存在碳缺陷结构.进一步通过X射线近边吸收谱和扩展边精细结构谱研究了钌和钴的配位环境,结果发现,钌带轻微正电荷,并且存在Ru–Ru键;钴带正电荷,价态介于0与+2价之间,其主要与N配位.在1 mol/L氢氧化钾电解液中,该杂化催化剂的电催化活性明显高于没有钴掺杂的催化剂以及商业化铂/碳催化剂.在电流密度为10 mAcm–2时,过电位仅为40 mV,在过电位为100 mV时,该催化剂的质量催化活性达到了3.77 mAμgRu–1,远超商业化铂/碳(2.01 mAμgRu–1)和钌/碳(1.66 mAμgRu–1).该催化剂也表现出了优异的析氢催化稳定性, 5000圈循环后, 10 mAcm–2下的过电位仅增加了2 mV,在恒电流测试中, 10 h后电位仅下降了95 mV.

关键词：无定型钌纳米簇单原子富缺陷碳析氢反应电催化

An in-situ NH_(4)^(+)-etched strategy for anchoring atomic Mo site on ZnIn_(2)S_(4) hierarchical nanotubes for superior hydrogen photocatalysis

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Science China Chemistry 2021年第10期64卷 1716-1722页

作者： Yuguang Chao Weiyu Zhang Peng Zhou Hui Chen Shiyu Lu Menggang Li Qinghua zhang Lin Gu Shaojun Guo School of Materials Science and Engineering Peking UniversityBeijing 100871China Institute of Physics Chinese Academy of SciencesBeijing 100190China Beijing Innovation Center for Engineering Science and Advanced Technology(BIC-ESAT) College of EngineeringPeking UniversityBeijing 100871China

Atomic sites co-catalyst (ASC) on photocatalytic materials possesses an attractive prospect to promote charge carrier separation and tune surface reaction kinetics,yet the synthesis of earth-abundant ASC under low temperature remains a great challenge.Here,a novel in-situ NH_(4)^(+)-etched strategy to anchor atomic Mo sites on ZnIn_(2)S_(4)hierarchical nanotubes (HNTs) with abundant mesopores under mild conditions for promoting charge carrier separation and enhancing light multi-reflections is developed for efficient photocatalytic H_(2) evolution.Density functional theory calculations and linear sweep voltammetry demonstrate that the well-defined Mo-S_(2)O_(1) sites with distinctive coordination configuration and electronic property contribute to the enhanced separation of photo-generated charge carriers and reduced Gibbs free energy for H_(2) evolution.Consequently,the well-defined MoSA-ZIS HNTs present an excellent photocatalytic activity with a rate of 29.9μmol h^(-1)(5.98 mmol g^(-1)h^(-1)),which is 7.3 times higher than that of ZnIn_(2)S_(4)nanosheets (NSs),to be among the best ZnIn_(2)S_(4)-based photocatalysts.The present strategy breaks the high-temperature limitation of conventional top-down thermal dissociation/emitting approach for anchoring non-noble metal atomic sites on catalyst support.

关键词： in-situ NH_(4)^(+)-etched hierarchical nanotubes Mo single atoms photocatalytic H_(2)evolution

Increasing prevalence of antibiotic resistance genes in manured agricultural soils in northern China

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Frontiers of Environmental Science & Engineering 2020年第1期14卷 43-54页

作者： Nan Wu Weiyu Zhang Shiyu Xie Ming Zeng Haixue Liu Jinghui Yang Xinyuan Liu Fan Yang College of Engineering and Technology Tianjin Agricultural UniversityTianjin 300384China College of Marine and Environmental Sciences Tianjin University of Science&TechnologyTianjin 300457China Laboratory of Agricultural Analysis Tianjin Agricultural UniversityTianjin 300384China College of Horticulture and Landscape Tianjin Agricultural UniversityTianjin 300384China

Land application of manure tends to result in the dissemination of antibiotic resistance in the environment.In this study,the influence of long-term manure application on the enrichment of antibiotic resistance genes(ARGs)and mobile genetic elements(MGEs)in agricultural soils was investigated.All the analyzed eight ARGs(tetA,tetW,tetX,sull,sulll,ermF,aac(6')-Ib-cr and blaTEM)and two MGEs(intJJ and Tn916/1545)were detected in both the manured and control soils,with relative abundances ranging from 10^-6 to 10^-2 Compared with the control soil,the relative abundances of ARGs and MGEs in manured soils were enriched 1.0-18.1 fold and 0.6-69.1 fold,respectively.High-throughput sequencing analysis suggested that at the phylum level,the bacteria carrying intll and ermF might be mainly affiliated with Proteobacteria and Bacteroides,respectively.The dominant genera carrying intll and ermF cow\d be Pseudomonas and Bacteroides,independent of manure application.Correlation analysis revealed that ARGs had strong links with soil physicochemical properties(TC,TN,and OM),heavy metals(Cu,Zn and Pb)and MGEs,indicating that the profile and spread of ARGs might be driven by the combined impacts of multiple factors.In contrast,soil pH and C/N exhibited no significant relationships with ARGs.Our findings provide evidence that long-term manure application could enhance the prevalence and stimulate the propagation of antibiotic resistance in agricultural soils.

关键词： Antibiotic resistance Mobile genetic elements Soil Manure Heavy metals

Stability,encapsulation and large-area fabrication of organic photovoltaics

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Science China Chemistry 2021年第9期64卷 1441-1459页

作者： Shan Song Jiaorong Lu weiyu Ye Bei zhang Xuan Liu Guichuan Xing Shiming zhang Key Laboratory of Flexible Electronics(KLOFE)&Institute of Advanced Materials(IAM) Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM)Nanjing Tech UniversityNanjing211816China Institute of Applied Physics and Materials Engineering University of MacaoMacao SAR999078China Jiangsu Seenbom Flexible Electronics Institute Co. Ltd.Nanjing211032China

Organic photovoltaics(OPVs)have become a timely research topic for their advantages of light weight,low cost,low toxicity,environmental adaptability,flexibility,and large-area manufacture,especially after non-fullerene acceptor ITIC reported in 2015.The highest power conversion efficiency(PCE)is currently above 18%for OPV.However,there are still imparities in the efficiency of OPVs when compared with silicon-based photovoltaics,as well as in their shelf life.Compared with inorganicbased photovoltaics,the efficiency of large-area OPVs is lower and the life time of OPVs is shorter.Therefore,such inferior performance of large-area OPVs restricts the commercial development.Based on these constraints,this paper reviews the research work regarding OPVs into three aspects:stability,encapsulation technology,and recent large-area preparation technologies.

关键词： organic photovoltaics stability encapsulation large-area fabrication

Repair of a small and crooked vesicovaginal fistula using electrocauterization

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Asian Journal of Urology 2018年第3期5卷 182-183页

作者： Weiyu Zhang Kexin Xu Xiaopeng zhang Hao Hu Qi Wang Department of Urology Peking University People’s HospitalBeijingChina

Dear Editor,Vesicovaginal fistula(VVF)is an abnormal opening between the urinary bladder and the vagina.The condition has an immense psychological effect on patients due to the continuous leakage of urine or watery vaginal discharge.The wet feeling and foul smell associated with leakage of urine cause social outcasting of the patients.This leads to immense emotional trauma and makes life miserable for the patient.The most common etiology for VVF in developing countries is obstructed labour[1],and in developed countries,it is abdominal hysterectomy[2].VVF poses a challenging problem to the surgeon.The location and the size of the fistula determine the extent of the patients’symptoms.

关键词： fistula vaginal urine

Recent advances and prospects of asymmetric non-fullerene small molecule acceptors for polymer solar cells

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Journal of Semiconductors 2021年第10期42卷 128-147页

作者： Liu Ye weiyu Ye Shiming zhang Key Laboratory of Flexible Electronics(KLOFE)&Institute of Advanced Materials(IAM) Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM)Nanjing Tech UniversityNanjing 211816China Jiangsu Seenbom Flexible Electronics Institute Co.Ltd. Nanjing 210043China

Recently,polymer solar cells developed very fast due to the application of non-fullerence acceptors.Substituting asymmetric small molecules for symmetric small molecule acceptors in the photoactive layer is a strategy to improve the performance of polymer solar cells.The asymmetric design of the molecule is very beneficial for exciton dissociation and charge transport and will also fine-tune the molecular energy level to adjust the open-circuit voltage(Voc)further.The influence on the absorption range and absorption intensity will cause the short-circuit current density(Jsc)to change,resulting in higher device performance.The effect on molecular aggregation and molecular stacking of asymmetric structures can directly change the microscopic morphology,phase separation size,and the active layer's crystallinity.Very recently,thanks to the ingenious design of active layer materials and the optimization of devices,asymmetric non-fullerene polymer solar cells(A-NF-PSCs)have achieved remarkable development.In this review,we have summarized the latest developments in asymmetric small molecule acceptors(A-NF-SMAs)with the acceptor-donor-acceptor(A-D-A)and/or acceptor-donor-acceptor-donor-acceptor(A-D-A-D-A)structures,and the advantages of asymmetric small molecules are explored from the aspects of charge transport,molecular energy level and active layer accumulation morphology.

关键词： polymer solar cells non-fullerene acceptors small asymmetric molecules

Defect engineering synergistically modulates power factor and thermal conductivity of CuGaTe2 for ultra-high thermoelectric performance

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Journal of Materials Science & Technology 2022年第33期128卷 213-220页

作者： Zipei zhang Wenhao Li Lu Yu Sitong Wei Shikai Wei Zhen Ji weiyu Song Shuqi Zheng State Key Laboratory of Heavy Oil Processing College of New Energy and MaterialsChina University of PetroleumBeijing 102249China College of Science China University of PetroleumBeijing 102249China

The ternary chalcopyrite CuGaTe_(2)has emerged as a promising p-type thermoelectric material with its advantages of low cost,good stability,and non-toxic elements.However,its thermoelectric performance is limited by the intrinsic low electrical conductivity and high lattice thermal conductivity.In this work,A deficiency of Cu in Cu_(1–x)Ga Te_(2)semiconductors can be used to optimize the electrical properties by improving the carrier concentration and to reduce thermal conductivity through multi-scale phonon scattering,which is predicted and guided by the First-principles density functional theory calculations.The carrier concentration is increased to 1020,which compensates for the low electrical performance caused by the intrinsic low nHof CuGaTe_(2).The average power factor of Cu_(0.96)Ga Te_(2)reaches 106.3%higher than that of the original CuGaTe_(2).In addition,the lattice thermal conductivity of the defective samples is greatly reduced at high temperatures,which is mainly due to the reduction of sound speed and phonon scattering.All the above factors contribute to the highest dimensionless figure of merit(ZT)value of 1.23 at 823 K in Cu_(0.96)GaTe_(2),which is 114%higher than the pristine CuGaTe_(2),and the average ZT is 171.4%higher.

关键词： Thermoelectric CuGaTe_(2) Carrier concentration Thermal conductivity