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Experimental and numerical investigation of the impacts of rotor tip-rake on excitation forces of pump-jet propulsors

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Journal of Hydrodynamics 2024年第1期36卷 142-157页

作者： Xue-qin Ji Xiao-song zhang Chen-jun Yang Xiao-qian Dong State Key Laboratory of Ocean Engineering Marine Numerical Experiment CentreSchool of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China CSSC Shanghai Marine Energy Saving Technology Co. Ltd.Shanghai200011China China Ship Scientific Research Center Shanghai Branch Shanghai200011China

The tip-clearance flow in a pump-jet propulsor exerts great impacts on the fluctuating pressures and resultant unsteady forces,which are important sources of structural vibrations and radiated noise underwater.The blade geometry close to the tip is an important factor determining the vortex strength in the tip-clearance flow.In the open-water condition,the effects of raking the rotor tips on the duct-surface fluctuating pressures and the resultant unsteady forces acting on different components of the propulsor are investigated via physical model experiments and the numerical solution of Reynolds-averaged Navier-Stokes(RANS)equations coupled with the SST k-ωturbulence model.The measured and simulated results of hydrodynamic pressures are consistent to each other,and the simulated flows help better understand why the fluctuating pressures change with the tip geometry.The strong fluctuations of duct-surface pressures are caused by intensive tip separation vortices.The duct-surface pressure fluctuations are effectively reduced by using the rake distribution near the tip towards blade back side and,for the combination of the five-bladed rotor and the seven-bladed stator,the resultant unsteady horizontal(and vertical)forces acting on the duct and stator are also reduced;while increasing rake leads to negative effect on pressure fluctuations and unsteady horizontal(and vertical)forces acting on all the components of the propulsor.

关键词： Pump-jet tip-clearance tip-rake fluctuating pressures excitation forces

Low-density polyethylene microplastics partially alleviate the ecotoxicological effects induced by cadmium exposure on the earthworm Eisenia fetida

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Soil Ecology Letters 2024年第1期6卷 47-60页

作者： song zhang Yating Du Guangshen Shang Kejiao Hu Xing Wang College of Resources and Environmental Sciences China Agricultural UniversityBeijing 100193China Beijing Key Laboratory of Biodiversity and Organic Farming Beijing 100193China Organic Cycle Research Institute(Suzhou) China Agricultural UniversitySuzhou 215100China Key Laboratory of Plant-Soil Interactions Ministry of EducationBeijing 100193China

LDPE had no effect on the mortality,growth,and reproduction of earthworms.LDPE did not alter the mortality,growth,and reproduction of earth-worm caused by Cd.LDPE alleviated histopathological damage to earthworms caused by Cd.LDPE alleviated DNA damage in earthworm coelomocytes caused by Cd.LDPE did not affect the accumulation of Cd in earthworms.Cadmium(Cd)can accumulate in the food chain,with serious impacts on human health and safety.Microplastics(MPs)such as low-density polyethylene(LDPE)should be considered not only as a single pollutant but also as a carrier of other pollutants.In this study,we investigated the joint effects of 30%LDPE and 313 mg kg-1 Cd on mortality,growth,reproduction,microstructure,DNA damage,oxidative stress,and mRNA levels in the earthworm Eisenia fetida.We found that 313 mg kg-1 Cd inhibited growth and reproduction and damaged the microstructures of the skin and intestine.Meanwhile,LDPE had no effect on the mortality,growth,or cocoon production of earthworms.Moreover,it did not increase the mortality,growth,or inhibition of cocoon production caused by Cd and instead alleviated the DNA damage in coelomocytes caused by Cd treatment.Finally,it did not alter the accumulation of Cd in the worms.These indicators can be used for toxicity safety assessment and soil ecological risk assessment of LDPE and Cd cooccurrence in soil.

关键词： microplastics Eisenia fetida DNA damage histopathological damage heavy metals

A neuromorphic device mimicking synaptic plasticity under different body fluid K^(+) homeostasis for artificial reflex path construction and pattern recognition

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Fundamental Research 2024年第2期4卷 353-361页

作者： Lu Yang Yao Ni Chengpeng Jiang Lu Liu song zhang Jiaqi Liu Lin Sun Wentao Xu Institute of Photoelectronic Thin Film Devices and Technology Key Laboratory of Optoelectronic Thin Film Devices and Technology of TianjinEngineering Research Center of Thin Film Photoelectronic TechnologyMinistry of EducationNankai UniversityTianjin 300350China Shenzhen Research Institute of Nankai University Shenzhen 518000China

The ionic environment of body fluids influences nervous functions for maintaining homeostasis in organisms and ensures normal perceptual abilities and reflex activities.Neural reflex activities,such as limb movements,are closely associated with potassium ions(K+).In this study,we developed artificial synaptic devices based on ion concentration-adjustable gels for emulating various synaptic plasticities under different K+concentrations in body fluids.In addition to performing essential synaptic functions,potential applications in information processing and associative learning using short-and long-term plasticity realized using ion concentration-adjustable gels are presented.Artificial synaptic devices can be used for constructing an artificial neural pathway that controls artificial muscle reflex activities and can be used for image pattern recognition.All tests show a strong relationship with ion homeostasis.These devices could be applied to neuromorphic robots and human-machine interfaces.

关键词： Nervous regulation Artificial synaptic device Ion gel Ion homeostasis Artificial reflex pathway

面向工业化种植的光热管理农膜——机遇与挑战

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Engineering 2024年第4期35卷 191-200页

作者： song zhang zhang Chen Chuanxiang Cao Yuanyuan Cui Yanfeng Gao School of Materials Science and Engineering Shanghai UniversityShanghai 200444China

As indispensable parts of greenhouses and plant factories,agricultural covering films play a prominent role in regulating microclimate environments.Polyethylene covering films directly transmit the full solar spectrum.However,this high level of sunlight transmission may be inappropriate or even harmful for crops with specific photothermal requirements.Modern greenhouses are integrated with agricultural covering materials,heating,ventilation,and air conditioning(HVAC)systems,and smart irrigation and communication technologies to maximize planting efficiency.This review provides insight into the photothermal requirements of crops and ways to meet these requirements,including new materials based on passive radiative cooling and light scattering,simulations to evaluate the energy consumption and environmental conditions in a greenhouse,and data mining to identify key biological growth factors and thereby improve new covering films.Finally,future challenges and directions for photothermalmanagement agricultural films are elaborated on to bridge the gap between lab-scale research and large-scale practical applications.

关键词： Greenhouse Photothermal management Passive radiative cooling Light scattering

Ecological Networks of Allometric Growth,Feeding Behavior and Gut Microbiota in Chinese Alligator Hatchlings

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Asian Herpetological Research 2024年第2期15卷 104-114页

作者： Ke SUN Wengang LI Guangwei FAN Liuyang YANG Huabin zhang Yilin SHU Yongkang ZHOU Genjun TU song zhang Pingsi YI Maliha AYUB Xiaobing WU Tao PAN College of Life Sciences Anhui Normal UniversityWuhu 241000AnhuiChina The Anhui Provincial Key Laboratory of Biodiversity Conservation and Ecological Security in the Yangtze River Basin Wuhu 241000AnhuiChina School of Wetland Yancheng Teachers UniversityYancheng 224007JiangsuChina National Long-term Scientific Research Base for Chinese Alligator Artificial Breeding and Protection in Anhui Anhui Research Center for Chinese Alligator ReproductionXuancheng 242034AnhuiChina

Chinese alligator hatchlings in captivity are fragile and have a high mortality rate within first year.The body mass gain of reptile animals is closely related to their feeding behavior and gut microbiota.This study analyzed the intrinsic factors influencing the allometric growth of Chinese alligator hatchlings based on their body mass gain,feeding behavior,and gut microbiota.This information would enhance the health management of Chinese alligator hatchlings.There was a significant correlation between the total distance moved,the average number of conspecifics nearby,and body mass gain.Chinese alligator hatchlings with a greater growth rate showed greater activity and more independent behavior during feeding than those with a lower growth rate.Moreover,after feeding started,some functions of the gut microbiota showed significant relationships with growth rate and feeding activity.Chinese alligator hatchlings with a greater growth rate showed greater levels of heme biosynthesis than those with a lower growth rate,and feeding activity was inhibited by long-chain fatty acid biosynthesis.These results elucidate the relationships between health,feeding behavior,and the gut microbiota of Chinese alligator hatchlings.Understanding the intrinsic factors of their health and feeding behavior can improve the health management of Chinese alligator hatchlings in captivity for conservation.

关键词： allometric growth behavior Chinese alligator hatchlings gut microbiota

A Modified Principal Component Analysis Method for Honeycomb Sandwich Panel Debonding Recognition Based on Distributed Optical Fiber Sensing Signals

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Structural Durability & Health Monitoring 2024年第2期18卷 125-141页

作者： Shuai Chen Yinwei Ma Zhongshu Wang Zongmei Xu song zhang Jianle Li Hao Xu Zhanjun Wu State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of TechnologyDalian116024China Beijing Aerospace Technology Institution Beijing116024China College of Water-Conservancy and Civil Engineering Shandong Agricultural UniversityTaian271000China

The safety and integrity requirements of aerospace composite structures necessitate real-time health monitoring throughout their service life.To this end,distributed optical fiber sensors utilizing back Rayleigh scattering have been extensively deployed in structural health monitoring due to their advantages,such as lightweight and ease of embedding.However,identifying the precise location of damage from the optical fiber signals remains a critical challenge.In this paper,a novel approach which namely Modified Sliding Window Principal Component Analysis(MSWPCA)was proposed to facilitate automatic damage identification and localization via distributed optical fiber sensors.The proposed method is able to extract signal characteristics interfered by measurement noise to improve the accuracy of damage detection.Specifically,we applied the MSWPCA method to monitor and analyze the debonding propagation process in honeycomb sandwich panel structures.Our findings demonstrate that the training model exhibits high precision in detecting the location and size of honeycomb debonding,thereby facilitating reliable and efficient online assessment of the structural health state.

关键词： Structural health monitoring distributed opticalﬁber sensor damage identiﬁcation honeycomb sandwich panel principal component analysis

Effect of transcranial direct current stimulation on postoperative sleep disturbance in older patients undergoing lower limb major arthroplasty:a prospective,double-blind,pilot,randomised controlled trial

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General Psychiatry 2024年第2期37卷 224-233页

作者： Jie Yang Mingshu Tao Rongguang Liu Jiaxing Fang Chunyan Li Dexian Chen Qi Wei Xingyu Xiong Wenxin Zhao Wen Tan Yuan Han Hongxing zhang He Liu song zhang Junli Cao Department of Anesthesiology The Affiliated Hospital of Xuzhou Medical UniversityXuzhouJiangsuChina Department of Anesthesiology Hospital of Chengdu University of Traditional Chinese Medicine&Traditional Chinese Medicine Hospital of Sichuan ProvinceChengduSichuanChina NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs&Jiangsu Province Key Laboratory of Anesthesiology&Jiangsu Key Laboratory of Applied Technology of Anesthesia and Analgesia Xuzhou Medical UniversityXuzhouJiangsuChina Department of Anesthesiology Eye&ENT Hospital of Fudan UniversityShanghaiChina Department of Anesthesiology&Clinical Research Center for Anesthesia and Perioperative Medicine&Huzhou Key Laboratory of Basic Research and Clinical Translation for Neuromodulation The Fifth School of Clinical Medicine of Zhejiang Chinese Medical University||Huzhou Central Hospital||The Affiliated Huzhou HospitalZhejiang University School of Medicine||Affiliated Central Hospital Huzhou UniversityHuzhouZhejiangChina Department of Anesthesiology Renji Hospital School of MedicineShanghai Jiao Tong UniversityShanghaiChina

Background Postoperative sleep disturbance(PSD)is a common and serious postoperative complication and is associated with poor postoperative outcomes.Aims This study aimed to investigate the effect of transcranial direct current stimulation(tDCS)on PSD in older patients undergoing lower limb major arthroplasty.Methods In this prospective,double-blind,pilot,randomised,sham-controlled trial,patients 65 years and over undergoing lower limb major arthroplasty were randomly assigned to receive active tDCS(a-tDCS)or sham tDCS(s-tDCS).The primary outcomes were the objective sleep measures on postoperative nights(N)1 and N2.Results 116 inpatients were assessed for eligibility,and a total of 92 patients were enrolled;47 received a-tDCS and 45 received s-tDCS.tDCS improved PSD by altering the following sleep measures in the a-tDCS and s-tDCS groups;the respective comparisons were as follows:the promotion of rapid eye movement(REM)sleep time on N1(64.5(33.5-105.5)vs 19.0(0.0,45.0)min,F=20.10,p<0.001)and N2(75.0(36.0-120.8)vs 30.0(1.3-59.3)min,F=12.55,p<0.001);the total sleep time on N1(506.0(408.0-561.0)vs 392.0(243.0-483.5)min,F=14.13,p<0.001)and N2(488.5(455.5-548.5)vs 346.0(286.5-517.5)min,F=7.36,p=0.007);the deep sleep time on N1(130.0(103.3-177.0)vs 42.5(9.8-100.8)min,F=24.4,p<0.001)and N2(103.5(46.0-154.8)vs 57.5(23.3-106.5)min,F=8.4,p=0.004);and the percentages of light sleep and REM sleep on N1 and N2(p<0.05 for each).The postoperative depression and anxiety scores did not differ significantly between the two groups.No significant adverse events were reported.Conclusion In older patients undergoing lower limb major arthroplasty,a single session of anodal tDCS over the left dorsolateral prefrontal cortex showed a potentially prophylactic effect in improving postoperative short-term objective sleep measures.However,this benefit was temporary and was not maintained over time.

关键词： sleep stimulation postoperative

Compliant Iontronic Triboelectric Gels with Phase-Locked Structure Enabled by Competitive Hydrogen Bonding

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Nano-Micro Letters 2024年第9期16卷 180-194页

作者： Guoli Du Yuzheng Shao Bin Luo Tao Liu Jiamin Zhao Ying Qin Jinlong Wang song zhang Mingchao Chi Cong Gao Yanhua Liu Chenchen Cai Shuangfei Wang Shuangxi Nie School of Light Industry and Food Engineering Guangxi UniversityNanning 530004People’s Republic of China

Rapid advancements in flexible electronics technology propel soft tactile sensing devices toward high-level biointegration,even attaining tactile perception capabilities surpassing human skin.However,the inherent mechanical mismatch resulting from deficient biomimetic mechanical properties of sensing materials poses a challenge to the application of wearable tactile sensing devices in human-machine interaction.Inspired by the innate biphasic structure of human subcutaneous tissue,this study discloses a skin-compliant wearable iontronic triboelectric gel via phase separation induced by competitive hydrogen bonding.Solvent-nonsolvent interactions are used to construct competitive hydrogen bonding systems to trigger phase separation,and the resulting soft-hard alternating phase-locked structure confers the iontronic triboelectric gel with Young’s modulus(6.8-281.9 kPa)and high tensile properties(880%)compatible with human skin.The abundance of reactive hydroxyl groups gives the gel excellent tribopositive and self-adhesive properties(peel strength>70 N m^(−1)).The self-powered tactile sensing skin based on this gel maintains favorable interface and mechanical stability with the working object,which greatly ensures the high fidelity and reliability of soft tactile sensing signals.This strategy,enabling skin-compliant design and broad dynamic tunability of the mechanical properties of sensing materials,presents a universal platform for broad applications from soft robots to wearable electronics.

关键词： Triboelectric nanogenerator Cellulose Triboelectric gel Self-powered sensor Energy harvesting

Geophysical prediction of organic matter abundance in source rocks based on geochemical analysis:A case study of southwestern Bozhong Sag,Bohai Sea,China

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Petroleum Science 2024年第1期21卷 31-53页

作者： Xiang Wang Guang-Di Liu Xiao-Lin Wang Jin-Feng Ma Zhen-Liang Wang Fei-Long Wang Ze-zhang song Chang-Yu Fan State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China College of Geosciences China University of Petroleum(Beijing)Beijing102249China State Key Laboratory of Continental Dynamics Northwest UniversityXi'an710069ShaanxiChina Department of Geology Northwest UniversityXi'an710069ShaanxiChina CNOOC Tianjin Branch Company Tianjin300459China

The Bozhong Sag is the largest petroliferous sag in the Bohai Bay Basin,and the source rocks of Paleogene Dongying and Shahejie Formations were buried deeply.Most of the drillings were located at the structural high,and there were few wells that met good quality source rocks,so it is difficult to evaluate the source rocks in the study area precisely by geochemical analysis only.Based on the Rock-Eval pyrolysis,total organic carbon(TOC)testing,the organic matter(OM)abundance of Paleogene source rocks in the southwestern Bozhong Sag were evaluated,including the lower of second member of Dongying Formation(E_(3)d2L),the third member of Dongying Formation(E_(3)d_(3)),the first and second members of Shahejie Formation(E_(2)s_(1+2)),the third member of Shahejie Formation(E_(2)s_(3)).The results indicate that the E_(2)s_(1+2)and E_(2)s_(3)have better hydrocarbon generative potentials with the highest OM abundance,the E_(3)d_(3)are of the second good quality,and the E_(3)d2L have poor to fair hydrocarbon generative potential.Furthermore,the well logs were applied to predict TOC and residual hydrocarbon generation potential(S_(2))based on the sedimentary facies classification,usingΔlogR,generalizedΔlogR,logging multiple linear regression and BP neural network methods.The various methods were compared,and the BP neural network method have relatively better prediction accuracy.Based on the pre-stack simultaneous inversion(P-wave impedance,P-wave velocity and density inversion results)and the post-stack seismic attributes,the three-dimensional(3D)seismic prediction of TOC and S_(2)was carried out.The results show that the seismic near well prediction results of TOC and S_(2)based on seismic multi-attributes analysis correspond well with the results of well logging methods,and the plane prediction results are identical with the sedimentary facies map in the study area.The TOC and S_(2)values of E_(2)s_(1+2)and E_(2)s_(3)are higher than those in E_(3)d_(3)and E_(3)d_(2)L,basically consistent with the geochemical analysis resul

关键词： Total organic carbon(TOC) Residual hydrocarbon generation potential(S_(2)) Geophysical prediction Seismic attribute Bozhong Sag Bohai Bay Basin