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Effects of the nozzle structure and fluidized gas composition on the gas-particle two-phase jet characteristic in a powder fuel scramjet

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Particuology 2024年第9期92卷 166-179页

作者： Changfei Zhuo Hongming Ding Xiaobin Ren Hanyu Deng Xiong Chen School of Mechanical and Engineering Key Laboratory of Special Engine TechnologyMinistry of EducationNanjing University of Science and TechnologyNanjing210094China department of Mechanical Engineering National University of Singapore9 Engineering Drive 1Singapore117576 Shanxi North Xing'an Chemical Industry Co. Ltd.Taiyuan030008China

The interaction between nozzle design and fluidization gas composition significantly influences the dynamics within a powder fuel scramjet's combustion *** investigate this relationship,an experimental study utilized high-speed shadow imaging technology to explore the macroscopic aspects of powder fuel *** investigation examined various convergence angles,nozzle throat lengths,and fluidized gas *** findings include:During jet development,powder fuel initially concentrates near the axis,with non-convergence angle nozzles exhibiting longer concentrated distribution periods than convergence angle *** nozzle convergence angles lead to increased penetration distance,frontal velocity,and radial diffusion distance during the initial stages of jet ***,stable jet shapes show larger divergence angles as nozzle convergence angle decreases,with the largest divergence angle observed atα=60°.In the initial 0-7 ms of jet development,the powder fuel jet demonstrates greater penetration distance and frontal velocity under certain ***,penetration distance and frontal velocity increase with throat length from 7 to 20 ms,accompanied by changes in divergence ***,at a throat length(l)of 2 mm,the near-field divergence angle measures 46.50°,and the far-field divergence angle is 22.25°.Conversely,at l=8mm,the near-field divergence angle is 33.49°,and the far-field divergence angle is 23.21°.The fluidization gas composition minimally affects jet penetration distance and frontal velocity during the initial 0-3 ***,due to hydrogen's low density,hydrogen/powder fuel jets exhibit shorter distances and velocities compared to nitrogen/powder fuel *** fluidization also results in larger divergence angles,particularly in the near *** findings underscore the importance of nozzle design and fluidization gas composition in optimizing scramjet performance and efficiency.

关键词： Multiphase flows Gas-particle two-phase jet Nozzle contraction angle Powder fuel scramjet

Net effect of air pollution controls on health risk in the Beijing-Tianjin-Hebei region during the 2022 winter Olympics and Paralympics

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Journal of Environmental Sciences 2024年第1期135卷 560-569页

作者： Changqing Lin Peter K.K.Louie Alexis K.H.Lau Jimmy C.H.Fung Zibing Yuan Minghui Tao Xuguo Zhang Md.Shakhaoat Hossain Chengcai Li Xiang Qian Lao Division of Environment and Sustainability The Hong Kong University of Science and TechnologyHong KongChina Environmental Protection department Hong Kong Government SARHong KongChina department of Civil and Environmental Engineering The Hong Kong University of Science and TechnologyHong KongChina Guangdong-Hongkong-Macao Joint Laboratory of Collaborative Innovation for Environmental Quality The Hong Kong University of Science and TechnologyHong KongChina department of Mathematics The Hong Kong University of Science and TechnologyHong KongChina School of Environment and Energy South China University of TechnologyGuangzhou 510006China Hubei Key Laboratory of Critical Zone Evolution School of Geography and Information EngineeringChina University of GeosciencesWuhan 430074China department of Public health and Informatics Jahangirnagar UniversityDhaka 1342Bangladesh department of Atmospheric and Oceanic Sciences School of PhysicsPeking UniversityBeijing 100871China Jockey Club School of Public health and Primary care The Chinese University of Hong KongHong KongChina

Due to the non-linearity in ozone(O_(3))formation,reducing the emission of nitrogen oxides(NO_(x))may increase O_(3) *** the counteractive O_(3) response to NO_(x) reduction,overall impact of air pollution controls can be ambiguous when the assessments focus on the changes in pollutant *** this study,a risk-based method was used to gauge the net effect of air pollution controls on mortality risk in the Beijing–Tianjin–Hebei(BTH)region during the 2022 Winter Olympics and Paralympics(WOP).This mega-event presents a unique opportunity to investigate the efficacy of deep cuts in pollutant *** show that O_(3) concentrations greatly increased as nitrogen dioxide(NO_(2))concentrations decreased in the *** to the active photochemical formations,O_(3) became the dominant pollutant that affected human health during the *** the substantial O_(3) increases,the health benefits of NO_(2) reductions overwhelmed the adverse health effects of O_(3) increases in most regions of the BTH(at 81 out of 112 stations).After considering the impacts of particulate matter,the integrated health risk of air pollution mixtures declined almost everywhere in the *** results underscore the great necessity of changing the assessment paradigm of pollution control from using concentration-based methods to using risk-based *** with the carbon neutrality policy,stringent control of NO_(x)emission from combustion sources is a promising way to achieve synergistic control solutions for air pollution and climate change.

关键词： Ozone Nitrogen dioxide health risk Carbon neutrality Mega-events

Electrical stimulation for brighter persistent luminescence

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Light(Science & Applications) 2024年第8期13卷 1590-1601页

作者： Xilin Ma Yuhua Wang Takatoshi Seto Key Laboratory for special Function Materials and Structural Design of the Ministry of Education National&Local Joint Engineering Laboratory for Optical Conversion Materials and Technology of National Development and Reform CommissionDepartment of Materials ScienceSchool of Materials and EnergyLanzhou UniversityNo.222South Tianshui RoadLanzhouGansu 730000China

An immature understanding of the mechanisms of persistent luminescence(PersL)has hindered the development of new persistent luminescent materials(PersLMs)with increased *** this regard,in-situ direct current(DC)electric field measurements were conducted on a layered structure composed of the SrAl_(2)O_(4):Eu^(2+),Dy^(3+)phosphor,and an *** this study,the photoluminescence(PL)and afterglow properties were investigated with respect to voltage by analyzing the current signal and thermoluminescence(TL)*** intensity of PersL increased due to a novel phenomenon known as“external electric field stimulated enhancement of initial brightness of afterglow”.This dynamic process was illustrated via the use of a rate equation approach,where the electrons trapped by the ultra-shallow trap at 0.022 eV could be transferred through the conduction band during long *** afterglow intensity could reach 0.538 cdm^(-2)at a 6 V electric *** design of an electric field stimulation technique enables the enhancement of the intensity of PersLMs and provides a new perspective for exploring the fundamental mechanics of certain established PersLMs.

关键词： spectroscopy luminescence conduction

Effects of Different Culture Conditions and Growth States on the Structure and Hemostatic Properties of Coscinodiscus sp.

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Journal of Ocean University of China 2024年第4期23卷 1121-1134页

作者： HE Zheng LI Qinfeng LIU Jinfeng HUI Guangyan FENG Chao CHENG Xiaojie CHEN Xiguang College of Marine Life Science Sanya Oceanographic InstitutionOcean University of ChinaQingdao 266003China Laboratory for Marine Drugs and Bioproducts Qingdao Marine Science and Technology CenterQingdao 266237China department of Stomatology Qingdao Women and Children’s HospitalQingdao 266034China department of Stomatology Qingdao Special Servicemen Recuperation Center of PLA NavyQingdao 266071China

As a renewable marine inorganic material,Coscinodiscus *** significant potential in the field of rapid ***,the low yield of Coscinodiscus *** limits the *** this study,two new culture modes were adopted to increase the production of Coscinodiscus sp.,the effect of changes in culture conditions and growth status on the hemostatic activity of diatoms was *** prevent Coscinodiscus *** sinking in culture,the suspension culture mode was realized by adding0.5%*** semi-continuous high nutrient concentration culture mode increased the cell density of Coscinodiscus *** 11000cells mL^(-1)and shorten the culture cycle to 5 *** terms of coagulation activity,the addition of frustules reduced the in vitro coagulation time by half and the activation time of coagulation by 70%.The hemolysis rate and cytotoxicity of frustules harvested in the two culture modes did not change *** results showed that suspension culture mode and high nutrient concentration culture mode only changed the growth state of Coscinodiscus sp.,while the hemostatic performance remained stable.

关键词： diatom culture Coscinodiscus sp frustule hemostatic material hemorrhage control

Leisure-time physical activity and all-cause mortality and cardiovascular disease in adults with type 2 diabetes:Cross-country comparison of cohort studies

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Journal of Sport and health Science 2024年第2期13卷 212-221页

作者： Jakob Tarp Mengyun Luo Miguel Adriano Sanchez-Lastra Knut Eirik Dalene Borja del Pozo Cruz Mathias Ried-Larsen Reimar Wernich Thomsen Ulf Ekelund Ding Ding department of Clinical Epidemiology Aarhus University&Aarhus University HospitalAarhus 8200Denmark Prevention Research Collaboration Sydney School of Public HealthThe University of SydneyCamperdownNSW 2006Australia Charles Perkins Centre the University of SydneyCamperdownNSW 2050Australia department of Sports Medicine Norwegian School of Sports SciencesOslo 0806Norway department of special Didactics Faculty of Education and Sports SciencesUniversity of VigoPontevedra 36005Spain Well-Move Research Group Galicia Sur Health Research Institute(IIS Galicia Sur)SERGAS-UVIGOVigo 36213Spain department of Chronic Diseases Norwegian Institute of Public HealthOslo 0473Norway Centre for Active and healthy Ageing Department of Sports Science and Clinical BiomechanicsUniversity of Southern DenmarkOdense 5230Denmark Faculty of Education University of CadizCadiz 11519Spain Biomedical Research and Innovation Institute of Cadiz(INiBICA)Research Unit Puerta del Mar University HospitalUniversity of CadizCadiz 11009Spain The Centre of Inflammation and Metabolism&the Centre for Physical Activity Research RigshospitaletUniversity of CopenhagenCopenhagen 2100Denmark department of Sports Science and Clinical Biomechanics University of Southern DenmarkOdense 5230Denmark

Purpose:This study aimed to quantify the dose-response association and the minimal effective dose of leisure-time physical activity(PA)to prevent mortality and cardiovascular disease in adults with type 2 ***:Cross-country comparison of 2 prospective cohort studies including 14,913 and 17,457 population-based adults with type 2 diabetes from the UK and *** leisure-time PA was self-reported and categorized by metabolic equivalent hours per week(MET-h/week)according to World health Organization recommendations:none,below recommendation(>0-7.49 MET-h/week);at recommended level(7.5-14.9 MET-h/week);above recommendation(>15 MET-h/week).Mortality and cardiovascular disease data were obtained from national ***:During a median follow-up of 12.4 and 9.7 years,in the UK and China cohorts,repectively,higher levels of leisure-time PA were inversely associated with all-cause(1571 and 2351 events)and cardiovascular mortality(392 and 1060 events),mostly consistent with a linear dose-response *** below,at,and above recommendations,compared with no activity,yielded all-cause mortality hazard ratios of0.94(95%confidence interval(95%CI):0.79-1.12),0.90(95%CI:0.74-1.10),and 0.85(95%CI:0.70-1.02)in British adults and 0.87(95%CI:0.68-1.10),0.88(95%CI:0.74-1.03),and 0.77(95%CI:0.70-0.85)in Chinese *** with cardiovascular mortality were more pronounced in British adults(0.80(95%CI:0.58-1.11),0.75(95%CI:0.52-1.09),and 0.69(95%CI:0.48-0.97))but less pronounced in Chinese adults(1.06(95%CI:0.76-1.47),1.01(95%CI:0.80-1.28),and 0.79(95%CI:0.69-0.92)).PA at recommended levels was not associated with lower rates of major adverse cardiovascular events(2345 and 4458 events).Conclusion:Leisure-time PA at the recommended levels was not convincingly associated with lower mortality and had no association with risk of major adverse cardiovascular events in British or Chinese adults with type 2 ***-time PA above current recom

关键词： Complications Epidemiology Exercise Prevention

Cardiac remodeling in patients with atrial fibrillation reversing bradycardia-induced cardiomyopathy:A case report

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World Journal of Clinical Cases 2024年第7期12卷 1339-1345页

作者： De-Kui Gao Xiang-Lin Ye Zhen Duan Hong-Yang Zhang Tao Xiong Zheng-Hong Li Hai-Feng Pei department of Cardiology Jiangyou Second People's HospitalJiangyou 621701Sichuan ProvinceChina department of Cardiology The General Hospital of Western Theater CommandChengdu 610083Sichuan ProvinceChina department of Clinical Medicine Southwest Medical UniversityLuzhou 646000Sichuan ProvinceChina department of special Inspection Jiangyou Second People's HospitalJiangyou 621701Sichuan ProvinceChina

BACKGROUND Bradycardia-induced cardiomyopathy(BIC),which is a disease resulting from bradycardia,is characterized by cardiac chamber enlargement and diminished cardiac *** correction of bradycardia can allow for significant improvements in both cardiac function and structure;however,this disease has been infrequently *** this case,we conducted a longitudinal followup of a patient who had been enduring BIC for more than 40 years to heighten awareness and prompt timely diagnosis and rational *** SUMMARY A woman who presented with postactivity fatigue and dyspnea was diagnosed with bradycardia at the age of *** she had no obvious symptoms,she did not receive any treatment to improve her bradycardia during the 42-year follow-up,except for the implantation of a temporary pacemaker during labor induction *** time progressed,the patient's heart gradually expanded due to her low ventricular rate,and she was diagnosed with *** 2014,the patient developed atrial fibrillation,her ventricular rate gradually increased,and her heart shape gradually returned to *** report describes the cardiac morphological changes caused by the heart rate changes in BIC patients older than 40 years,introduces another possible outcome of BIC,and emphasizes the importance of early intervention in treating *** BIC can induce atrial fibrillation,causing an increased ventricular rate and leading to positive cardiac remodeling.

关键词： Bradycardia cardiomyopathy Heart rate Atrial fibrillation Cardiac dilatation Case report

Dietary Lipid Intervention in the Prevention of Brain Aging

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Engineering 2024年第6期37卷 128-137页

作者： Wei Xiong Bing Fang Xiaoyu Wang Ming Zhang Min Du Jiazeng Sun Juan Chen Yixuan Li Changhao Sun Xingen Lei Xue Zhang Fazheng Ren Key Laboratory of Precision Nutrition and Food Quality Department of Nutrition and HealthChina Agricultural UniversityBeijing 100083China Key Laboratory of Functional Dairy Co-Constructed by the Ministry of Education and Beijing MunicipalityCollege of Food Science and Nutritional EngineeringChina Agricultural UniversityBeijing 100083China School of Food Science and Chemical Engineering Beijing Technology and Business UniversityBeijing 100048China department of Animal Science Washington State UniversityPullmanWA 99164USA department of Nutrition and Food Hygiene School of Public HealthHarbin Medical UniversityHarbin 150028China department of Animal Science Cornell UniversityIthacaNY 14853USA National health Commission(NHC)and Chinese Academy of Medical Sciences(CAMS)Key Laboratory of Molecular Probe and Targeted Theranostics Harbin Medical UniversityHarbin 150028China

As people live longer,the burden of aging-related brain diseases,especially dementia,is *** aging increases the risk of cognitive impairment,which manifests as a progressive loss of neuron function caused by the impairment of synaptic plasticity via disrupting lipid ***,supplemental dietary lipids have the potential to prevent brain *** review summarizes the important roles of dietary lipids in brain function from both structure and mechanism *** and animal studies have provided evidence of the functions of polyunsaturated fatty acids(PUFAs)in brain *** results of interventions indicate that phospholipids—including phosphatidylcholine,phosphatidylserine,and plasmalogen—are efficient in alleviating cognitive impairment during aging,with plasmalogen exhibiting higher efficacy than *** is a recognized nutrient used in clinical trials due to its special vinyl ether bonds and abundance in the postsynaptic membrane of *** research should determine the dose-dependent effects of plasmalogen in alleviating brain-aging diseases and should develop extraction and storage procedures for its clinical application.

关键词： Brain aging Nutritional intervention Phospholipids Phosphatidylcholine Phosphatidylserine Plasmalogen

Sex-biased single-cell genetic landscape in mice with autism spectrum disorder

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Journal of Genetics and Genomics 2024年第3期51卷 338-351页

作者： Qian Zhang Yongjie Wang Jie Tao Ruixue Xia Yijie Zhang Zhirui Liu Jiwei Cheng department of Neurology and Central Laboratory Putuo HospitalShanghai University of Traditional Chinese MedicineShanghai 200062China School of Pharmacy Hangzhou Normal UniversityHangzhouZhejiang 311121China department of Respiratory and Critical care Medicine Henan University Huaihe HospitalKaifengHenan 475099China

Autistic spectrum disorder(ASD)is a male-biased,heterogeneous neurodevelopmental disorder that affects approximately 1%e2%of the *** exposure to valproic acid(VPA)is a recognized risk factor for ASD,but the cellular and molecular basis of VPA-induced ASD at the single-cell resolution is ***,we aim to compare the cellular and molecular differences in the hippocampus between male and female prenatal mice with ASD at the single-cell transcriptomic *** transcriptomes of more than 45,000 cells are assigned to 12 major cell types,including neurons,glial cells,vascular cells,and immune *** type-specific genes with altered expression after prenatal VPA exposure are analyzed,and the largest number of differentially expressed genes(DEGs)are found in neurons,choroid plexus epithelial cells,and *** microglia,several pathways related to inflammation are found in both males and females,including the tumor necrosis factor(TNF),nuclear factor kappa B(NF-kB),toll-like receptor(TLR),and mitogen-activated protein kinase(MAPK)signaling pathways,which are important for the induction of autistic-like ***,we note that several X-linked genes,including Bex1,Bex3,and Gria3,were among the male-specific DEGs of *** pioneering study describes the landscape of the transcriptome in the hippocampus of autistic *** elucidation of sexual differences could provide innovative strategies for the prevention and treatment of ASD.

关键词： Autistic spectrum disorder(ASD) Sex Single cell Neurons Microglia

Comprehensive study on fail-safe topological design method for 3D structures

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Acta Mechanica Sinica 2024年第6期40卷 87-99页

作者： Hongxin Wang Yujun Liao Guilin Wen Liangliang Chen Jie Liu Center for Research on Leading Technology of special Equipment School of Mechanical and Electric EngineeringGuangzhou UniversityGuangzhou510006China department of Rehabilitation Medicine The Fifth Affiliated Hospital of Guangzhou Medical UniversityGuangzhou510735China Hebei Innovation Center for Equipment Lightweight Design and Manufacturing School of Mechanical EngineeringYanshan UniversityQinhuangdao066004China

Fail-safe topology optimization is valuable for ensuring that optimized structures remain operable even under damaged *** selectively removing material stiffness in patches with a fixed shape,the complex phenomenon of local failure is modeled in fail-safe topology *** this work,we first conduct a comprehensive study to explore the impact of patch size,shape,and distribution on the robustness of fail-safe *** findings suggest that larger sizes and finer distribution of material patches can yield more robust fail-safe ***,a finer patch distribution can significantly increase computational costs,particularly for 3D *** keep computational efforts tractable,an efficient fail-safe topology optimization approach is established based on the framework of multi-resolution topology optimization(MTOP).Within the MTOP framework,the extended finite element method is introduced to establish a decoupling connection between the analysis mesh and the topology description *** examples demonstrate that the developed methodology is 2 times faster for 2D problems and over 25 times faster for 3D problems than traditional fail-safe topology optimization while maintaining similar levels of robustness.

关键词： Robust design Fail-safe structures Multi-resolution topology optimization Computational efficiency XFEM