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Experimental investigation of turbulent flows around high-rise structure foundations and implications on scour

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Water Science and Engineering 2022年第1期15卷 47-56页

作者： Dong-fang Liang Hao jia Yang xiao Sai-yu Yuan Department of Engineering University of CambridgeCambridge CB21PZUK State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai UniversityNanjing 210098China Yangtze Institute for Conservation and Development Hohai UniversityNanjing 210098China

Many studies have been undertaken to predict local scour around offshore high-rise structure foundations(HRSFs),which have been used in constructing the Donghai Wind Farm in China.However,there have been few works on the turbulent flow that drives the scour process.In this study,the characteristics of the turbulent flow fields around an HRSF were investigated using the particle image velocimetry technique.The mean flow,vorticity,and turbulence intensity were analyzed in detail.The relationship between the flow feature and scour development around an HRSF was elaborated.The results showed that the flow velocity increased to its maximum value near the third row of the pile group.The shear layer and wake vortices could not be fully developed downstream of the last row of the piles at small Reynolds numbers.The strong flow and turbulent fluctuation near the third piles explained the existence of a longtail scour pattern starting from the HRSF shoulders and a trapezoidal deposition region directly downstream of HRSF.This laboratory experiment gains insight into the mechanism of the turbulent flow around HRSFs and provides a rare dataset for numerical model verifications.

关键词： High-rise structure foundations(HRSFs) Turbulent flow fields Particle image velocimetry(PIV) Scour Sediment transport

Nonlinearity-enabled higher-order exceptional singularities with ultra-enhanced signal-to-noise ratio

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National Science Review 2023年第7期10卷 98-106页

作者： Kai Bai Liang fang Tian-Rui Liu jia-Zheng Li Duanduan Wan Meng xiao Key Laboratory of Artificial Micro-and Nano-structures of Ministry of Education and School of Physics and Technology Wuhan University Wuhan Institute of Quantum Technology

Higher-order exceptional points(HOEPs) with extraordinary responsivity are expected to exhibit a vastly improved performance in detection-related applications.However,over the past few years,such an approach has been questioned due to several potential drawbacks,including the stringent parameter re quirements,fundamental resolution limits and noise.Here,exploring the conse quence of nonlinear gain saturation in exceptional singularities of non-Hermitian systems,we offer a feasible scheme to overcome all the above difficulties.We provide a simple and intuitive example by demonstrating with both theory and circuit experiments an ’exceptional nexus’(’EX’),a HOEP with an ultra-enhanced signal-to-noise ratio(SNR),in only two coupled resonators with the aid of nonlinear gain.The tedious parameter tuning in a six-dimensional hyper-dimensional space is reduced to two dimensions.The feedback mechanism of nonlinear saturable gain can give a solution to the ongoing debate on the SNR of EPs in other linear systems.Our findings advance the fundamental understanding of the peculiar topology of nonlinear non-Hermitian systems,significantly reduce the practical difficulty in EP sensing and possibly open new avenues for applications.

关键词： higher-order exceptional point nonlinearity ultra-enhanced signal-to-noise ratio

No Incidence of Liver Cancer Was Observed in A Retrospective Studyof Patients with Aristolochic Acid Nephropathy

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Chinese Journal of Integrative Medicine 2024年第2期30卷 99-106页

作者： SU Tao fang Zhi-e GUO Yu-ming WANG Chun-yu WANG jia-bo JI Dong BAI Zhao-fang YANG Li xiao xiao-he Renal Division Department of MedicinePeking University First HospitalBeijing(100034)China Department of Pharmacy Chongqing Hospital of Traditional Chinese MedicineChongqing(400021)China Department of Hepatology Fifth Medical Center of Chinese PLA General HospitalBeijing(100039)China China Military Institute of Chinese Materia Fifth Medical Center of Chinese PLA General HospitalBeijing(100039)China Phase I Clinical Trials Unit Department of Medicine for Infectious DiseasesFifth Medical Center of Chinese PLA General HospitalBeijing(100039)China Department of Pharmacy Affiliated Hospital of Shandong University of Traditional Chinese MedicineJinan(250000)China National Key Laboratory of Kidney Diseases Beijing(100039)China

Objective:To assess the risk of aristolochic acid(AA)-associated cancer in patients with AA nephropathy(AAN).Methods:A retrospective study was conducted on patients diagnosed with AAN at Peking University First Hospital from January 1997 to December 2014.Long-term surveillance and follow-up data were analyzed to investigate the influence of different factors on the prevalence of cancer.The primary endpoint was the incidence of liver cancer,and the secondary endpoint was the incidence of urinary cancer during 1 year after taking AA-containing medication to 2014.Results:A total of 337 patients diagnosed with AAN were included in this study.From the initiation of taking AA to the termination of follow-up,39 patients were diagnosed with cancer.No cases of liver cancer were observed throughout the entire follow-up period,with urinary cancer being the predominant type(34/39,87.17%).Logistic regression analysis showed that age,follow-up period,and diabetes were potential risk factors,however,the dosage of the drug was not significantly associated with urinary cancer.Conclusions:No cases of liver cancer were observed at the end of follow-up.However,a high prevalence of urinary cancer was observed in AAN patients.Establishing a direct causality between AA and HCC is challenging.

关键词： aristolochic acid hepatocellular carcinoma urinary cancer drug safety retrospective study

Moving horizon based wavelet de-noising method of dual-observed geomagnetic signal for nonlinear high spin projectile roll positioning

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Defence Technology（防务技术） 2020年第2期16卷 417-424页

作者： Ting-ting Yin fang-xiu jia xiao-ming Wang ZNDY of Ministerial Key Laboratory Nanjing University of Science and TechnologyNanjing210094China

Phase-frequency characte ristics of approximate sinusoidal geomagnetic signals can be used fo r projectile roll positioning and other high-precision trajectory correction applications.The sinusoidal geomagnetic signal deforms in the exposed and magnetically contaminated environment.In order to preciously recognize the roll information and effectively separate the noise component from the original geomagnetic sequence,based on the error source analysis,we propose a moving horizon based wavelet de-noising method for the dual-observed geomagnetic signal filtering where the captured rough roll frequency value provides reasonable wavelet decomposition and reconstruction level selection basis for sampled sequence;a moving horizon window guarantees real-time performance and non-cumulative calculation amount.The complete geomagnetic data in full ballistic range and three intercepted paragraphs are used for performance assessment.The positioning performance of the moving horizon wavelet de-noising method is compared with the band-pass filter.The results show that both noise reduction techniques improve the positioning accuracy while the wavelet de-noising method is always better than the band-pass filter.These results suggest that the proposed moving horizon based wavelet de-noising method of the dual-observed geomagnetic signal is more applicable for various launch conditions with better positioning performance.

关键词： High-spin projectile roll positioning Dual-observed geomagnetic signal Wavelet de-noising Discrete wavelet transform

Experimental study of the bearing capacity of a drainage pipe pile under vacuum consolidation

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2022年第8期23卷 639-651页

作者： xiao-wu TANG Wei-kang LIN Yuan ZOU jia-xin LIANG Wen-fang ZHAO Research Center of Coastal and Urban Geotechnical Engineering Department of Civil EngineeringZhejiang UniversityHangzhou 310058China Engineering Research Center of Urban Underground Space Development of Zhejiang Province Hangzhou 310058China

In this study,we propose a drainage pipe pile under vacuum consolidation to integrate foundation treatment and pile foundation engineering in soft soil areas.To study its bearing capacity characteristics and foundation treatment performance,single pile static load tests,vane shear tests,and water content tests were carried out for ordinary piles,perforated piles,and drainage pipe piles under conditions of static and vacuum consolidation.Based on the results,the concept of strong and weak reinforcement areas was proposed and used for bearing capacity prediction.The results showed that the drainage pipe pile did not become silted under vacuum consolidation.The single pile bearing capacity was much higher than that of an ordinary pile,and the pile side friction was exerted mainly in the middle and lower parts.Good results were achieved using the shear strength at the junction of the strong and weak reinforcement areas to estimate the ultimate bearing capacity of a single pile.This study provided important insights into the design and construction of drainage pipe piles in a soft soil foundation.

关键词： Drainage pipe pile Soft soil Consolidation Bearing capacity Foundation treatment

Psychosis secondary to recurrent spinal meningioma

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Chinese Medical Journal 2019年第18期132卷 2261-2262页

作者： Min-jia xiao fang fang Ya-Jing Zhan Zhi-Jie xiao Zi-Wei Lan Department of Neurology Second Xiangya Hospital Central South University Changsha Hunan 410011 China

To the Editor:A 27-year-old man without psychiatric history presented with a 2-month history of apathy,decreased responsiveness,and malaise.The onset of these new behavioral changes was preceded by fatigue and insomnia.On physical examination,the patient's limbs had normal muscle tone and strength and no pathological reflexes were detected.Four years earlier,the patient underwent an operation for spinal meningioma resection.Before the operation,some analogous symptoms,like apathy and reduced responsiveness,appeared;the symptoms lasted for a month and remitted after the operation.Four days later,the patient developed mutism and irresponsiveness.He was diagnosed with organic psychosis and was admitted to a psychiatric unit.The patient began regular anti-psychotic treatment,including olanzapine,escitalopram,sertraline,and oxazepam,but there was no improvement in his mutism and irresponsiveness.

关键词： physical examination mutism organic psychosis

Enzyme-Induced Carbonate Precipitation for the Protection of Earthen Dikes and Embankments Under Surface Runoff: Laboratory Investigations

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Journal of Ocean University of China 2022年第2期21卷 306-314页

作者： HE jia fang Changhang MAO Xunyu QI Yongshuai ZHOU Yundong KOU Hailei xiao Liang Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNanjing 210098China College of Engineering Ocean University of ChinaQingdao 266100China Department of Finance and Audit Army Logistics UniversityChongqing 401331China

Earthen structures such as shore protection dikes and river embankments easily suffer from erosion under surface water runoff.This study made experimental efforts to explore the enzyme-induced carbonate precipitation(EICP)method for slope erosion control under surface runoff for earthen structures.The sandy soils were treated by the EICP method for various rounds.Surface characteristics were evaluated by the surface penetration resistance,calcium carbonate content,and surface hard crust thickness of EICP-treated soils.Slope runoff erosion experiments were carried out to evaluate the erosion control performances of the EICP treatment.The surface penetration resistance,calcium carbonate content,and surface hard crust thickness were found to significantly increase with the treatment rounds.In the erosion experiments,it was observed that the level of damages decreased and the water flow volume required to trigger the damage increased with more treatments.The increase in the soil slope angle led to more serious surface damages.The amount and rate that the soil particles were eroded from the slope surfaces declined with more EICP treatments,which was consistent with those of visual observations.The preliminary investigations presented in this study have shown the potential of the EICP method for slope erosion control under surface runoff for earthen structures.

关键词： enzyme-induced carbonate precipitation urease erosion soil slope

Site difference influence of anchored Ru in mesoporous carbon on electrocatalytic performance toward pH-universal hydrogen evolution reaction

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Rare Metals 2023年第12期42卷 4015-4028页

作者： xiao-fang Ma He xiao Yan-Ying Jing Yang Gao Ying-Luo He Man Zhao jian-Feng jia Hai-Shun Wu Key Laboratory of Magnetic Molecules and Magnetic Information Materials Ministry of Education School of Chemical and Material ScienceShanxi Normal UniversityTaiyuan 030032China Department of Applied Chemistry School of EngineeringUniversity of ToyamaToyama 930-8555Japan

Ru-based electrocatalysts have demonstrated excellent electrocatalytic performance toward hydrogen evolution reaction(HER).However,designing Ru nanoparticles/nanoclusters(Ru NPs/NCs)with abundant accessible active sites is challenging.Herein,a selective facile hydrothermal in situ polymerization strategy is described to accurately control the anchoring point of Ru in hollow mesoporous carbon spheres(HMCs)(outer surface,HMCs@Ru;cavity,Ru@HMCs;and pore channels,Ru/SHMCs).The HER mechanisms of the three catalysts over a wide pH range were revealed by analyzing the loading position,content,dispersion,particle size,and valence state of Ru.HMCs@Ru shows excellent area activity,with overpotentials of 64.3,2.8,and 78.1 mV at 10 mA·cm^(-2)in0.5 mol·L^(-1)H_(2)SO_(4),1 mol·L^(-1)KOH;and 0.5 mol·L^(-1)phosphate buffer saline(PBS)solutions,respectively.Ru/S-HMCs exhibit high mass activity,with values 43.3,2.9,and 12.7 times those of Pt/C in alkaline,acidic,and neutral media,respectively,at-50 mV(vs.reversible hydrogen electrode(RHE)).After 2000 cyclic voltammetry cycles,the performances of HMCs@Ru and Ru/S-HMCs hardly decrease,indicating good stability.The excellent electrocatalytic activity can be attributed to two main factors:(1)the confinement effect,which not only promotes high Ru dispersion but also prevents the leaching of active metal under harsh conditions,and(2)their excellent structural characteristics.The catalyst structure features a large hollow located in the center(~160 nm in diameter)and an ultrathin monolayer of mesopores(~6 nm)uniformly distributed on the hollow shells,ensuring fast mass diffusion and electron transfer kinetics,as well as complete accessibility of catalytic sites.

关键词： Confinement effect Ru Monolayer hollow mesoporous carbon(HMC) Hydrogen evolution reaction(HER)

Electroacupuncture Attenuates Ischemic Brain Injury and Cellular Apoptosis via Mitochondrial Translocation of Cofilin

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Chinese Journal of Integrative Medicine 2021年第9期27卷 705-712页

作者： CHEN Bin LIN Wan-qing LI Zuan-fang ZHONG xiao-yong WANG Jing YOU xiao-fang ZHAO Hong-jia QI Da-shi Department of Rehabilitation Medicine and National Clinical Research Base of Traditional Chinese Medicine the Affiliated People's Hospital of Fujian University of Traditional Chinese MedicineFuzhou(350004)China Academy of Integrative Medicine Fujian University of Traditional Chinese MedicineFuzhou(350108)China Shanghai Key Lab of Birth Defect Children's Hospital of Fudan UniversityShanghai(200032)China

Objective:To investigate the potential mechanisms of electroacupuncture(EA)to prevent ischemic stroke.Methods:The method of middle cerebral artery occlusion(MCAO)was employed to establish a rat model of ischemic stroke.Seventy-eight Sprague-Dawley rats were divided into the sham group,MCAO+EA control(EC)group,and MCAO+EA(EA)group according to a random number table(n=26 per group).EA was applied to the acupoints of Baihui(DU 20)and Shenting(DU 24)5 min and 6 h,respectively after the onset of MCAO for 30 min.Rats in the sham and EC groups received only light isoflurane anesthesia for 30 min after MCAO.The neuroprotective effects of EA were evaluated by rota-rod test,neurological deficit scores and infarct volumes.Additionally,Nissl staining and immunostaining were performed to examine brain damage,rod formation,cellular apoptosis,and neuronal loss induced by ischemia.The activities of caspase-3,and expression levels of cofilin and p-cofilin in mitochondria and cytoplasm after ischemic injury were determined by Western blot.Results:Compared with the EC group,EA significantly improved neuromotor function and cognitive ability after ischemic stroke(P<0.05 or P<0.01).Therapeutic use of EA also resulted in a significant decrease of cofilin rod formation and microtubule-associated protein-2(MAP2)degradation in the cortical penumbra area compared with the EC rats(P<0.01).Furthermore,Western blot analysis showed that EA stimulation significantly inhibited mitochondrial translocation of cofilin and caspase-3 cleavage(P<0.05 or P<0.01).Additionally,brain damage(infarct volume and neuropathy),cellular apoptosis and neuronal loss induced by ischemia were remarkably suppressed by EA in the cortical penumbra of rats(P<0.05 or P<0.01).Conclusion:EA treatment after ischemic stroke may attenuate ischemic brain injury and cellular apoptosis through the regulation of mitochondrial translocation of cofilin,a novel mechanism of EA therapy.

关键词： electroacupuncture cofilin apoptosis ischemic stroke mitochondrial translocation Chinese medicine