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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第2期25卷 161-182页

作者： shen LIU Xieping HUANG Xiangzhen KONG Qin fang Center for Hypergravity Experiment and Interdisciplinary Research Zhejiang UniversityHangzhou310058China Institute of Geotechnical Engineering Zhejiang UniversityHangzhou310058China State Key Laboratory of Disaster Prevention&Mitigation of Explosion&Impact Army Engineering University of PLANanjing210007China

This paper presents a numerical study to improve the understanding of the complex subject of penetration and perforation of concrete targets impacted by low-velocity projectiles.The main focus is on the damage mechanisms and the major factors that account for the target resistance of the concrete.An improved continuous surface cap model recently proposed was employed.The model was first equipped with element erosion criteria and was adequately validated by comparisons with ballistic experiments.Comprehensive numerical simulations were carried out where the individual influence of tensile,shear,and volumetric behaviors(pore collapse)of a concrete target on its ballistic performance was investigated.Results demonstrated that cratering on the front face and scabbing on the rear face of the concrete target were mainly dominated by its tensile behavior.The major target resistance came from the second tunneling stage which was primarily governed by the shear and volumetric behaviors of the concrete.Particularly,this study captured the pore collapse-induced damage phenomenon during the high-pressure tunneling stage,which has been extensively reported in experiments but has usually been neglected in previous numerical investigations.

关键词： Penetration Perforation Damage mechanism Target resistance Projectile impact Pore collapse

Stability Investigation and Improvement for DC Cascade Systems with Simplified Impedance-based Stability Criterion

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1044-1052页

作者： Junbin fang Zhikang Shuai Yang Li Zhibing Wang Xiangyang Wu Xia shen Z.John shen College of Electrical and Information Engineering Hunan UniversityChangsha 410082China Renewable Energy Department of China Electric Power Research Institute Beijing 100192China Department of Electrical and Computer Engineering Illinois Institute of TechnologyChicagoIL 60616USA IEEE

In DC distributed power systems(DPSs),the complex impedance interactions possibly lead to DC bus voltage oscillation or collapse.In previous research,the stability analysis of DPSs is implemented based on mathematical analysis in control theory.The specific mechanisms of the instability of the cascade system have not been intuitively clarified.In this paper,the stability analysis of DPSs based on the traditional Nyquist criterion is simplified to the resonance analysis of the seriesconnected port impedance(Z=R+jX)of source and load converters.It reveals that the essential reason for impedance instability of a DC cascade system is that the negative damping characteristic(R<0)of the port the overall impedance amplifies the internal resonance source at reactance zero-crossing frequency.The simplified stability criterion for DC cascade systems can be concluded as:in the negative damping frequency ranges(R<0),there exists no zero-crossing point of the reactance component(i.e.,X=0).According to the proposed stability criterion,the oscillation modes of cascade systems are classified.A typical one is the internal impedance instability excited by the negative damping,and the other one is that the external disturbance amplified by negativity in a low stability margin.Thus,the impedance reshaping method for stability improvement of the system can be further specified.The validity of the simplified criterion is verified theoretically and experimentally by a positive damping reshaping method.

关键词： DC cascaded system,impedance model impedance reconstruction stability criterion

Flexible, efficient, and accurate tests for epidemics

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Science China Mathematics 2024年第8期67卷 1881-1898页

作者： Linjiajie fang Bing-Yi Jing shen Ling Qiyue Wang Qing Yang Data Science and Analytics Thrust The Hong Kong University of Science and Technology Department of Statistics and Data Science Southern University of Science and Technology Department of Mathematics and Statistics Dalhousie University Department of Mathematics The Hong Kong University of Science and Technology

Group testing involves discovering a small subset of distinguished subjects from a large population while efficiently reducing the total number of tests. It has been widely used for industrial testing, information technology, and biology, especially epidemic screening. Tests, in reality, are noisy for the presence of false outcomes. Some tests are accurate but time-consuming, while others are cheaper but less accurate. Exactly which test to use is constrained by various considerations, such as availability, cost, accuracy, and efficiency.In this paper, we propose flexible, efficient, and accurate tests(FEATs). FEATs are based on group testing with simple but careful designs by incorporating ideas such as close contact cliques and repeated tests. FEATs could dramatically improve the efficiency or accuracy of existing tests. For example, for accurate but slow tests, the FEAT can improve efficiency multiple times without compromising accuracy. On the other hand,for fast but inaccurate tests, the FEAT can sharply reduce the false-negative rate(FNR) and significantly increase efficiency. Theoretical justifications are provided. We point out some scenarios where the FEAT can be effectively employed.

关键词： epidemiology control blood testing testing efficiency testing accuracy

A Low Cost, Green Sustainable and Biodegradable Biomass-based Fluorine-free Water and Oil Repellent

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Chinese Journal of Polymer Science 2024年第4期42卷 480-491页

作者： Zhi-Wei shen Shu-Feng Hu Chen Zeng Wei-Qing Kong Mei-fang Zhu State Key Laboratory for Modification of Chemical Fibers&Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai201620China State Key Laboratory of Pulp and Paper Engineering School of Light Industry and EngineeringSouth China University of TechnologyGuangzhou510630China

With the global ban on plastics intensifying, the substitution of plastic with paper has garnered increasing attention. However, the inadequate water and oil repellency of pulp molding hinders its practical applications. Currently, the common method to enhance the oil and water repellency of pulp molding is by adding fluorinated water and oil repellents. Nevertheless, fluorinated compounds are environmentally and physiologically harmful. Therefore, the development of fluorine-free, water and oil repellent alternatives is crucial. In this study, chitosan and stearic acid were utilized as the first and second layers of the oil and water repellent coatings, respectively. The coated samples exhibited favorable water repellency, with a water contact angle of 116.4°, and excellent oil repellency, achieving a 12/12 rating on the kit scale. Importantly, the samples did not exhibit any leakage after being soaked in hot water and hot oil at 95±5℃ for 30 min, demonstrating remarkable performance as a barrier against hot water and oil. Moreover, the coated samples displayed outstanding mechanical properties, thermal stability, biodegradability, and recyclability. The approach presented in this study is simple, cost-effective, environmentally friendly, and represents a promising technique for producing fluoride-free, oil-and water-resistant pulp molding products.

关键词： Biomass Fluoride-free Oil-andwater-resistant Plasticfree

Re-delocalization of localized d-electrons in VO2（R）-VS4 hetero-structure enables high performance of rechargeable Mg-ion batteries

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Journal of Magnesium and Alloys 2024年第5期12卷 1830-1840页

作者： Lijiao Zhou Chao shen Xueyang Hou Zhao fang Ting Jin Keyu Xie School of Materials Science and Engineering Northwestern Polytechnical University School of Metallurgical Engineering Xi'an University of Architecture and Technology

Rechargeable Mg-ion batteries（MIBs） have attracted much more attentions by virtue of the high capacity from the two electrons chemistry.However, the reversible Mg2+diffusion in cathode materials is restricted by the strong interactions between the high-polarized bivalent Mg2+ions and anionic lattice. Herein, we design and propose a hetero-structural VO2（R）-VS4cathode, in which the re-delocalized d-electrons can effectively shield the polarity of Mg2+ions. Theoretically, the electrons should spontaneously transfer from VS4to VO2（R） through the interfaces of hetero-structure due to the lower work function value of VS4. Furthermore, the internal electrons transfer lead to the electronic injection into VO2（R） from VS4and the partially broken V-V dimers, indicating the presence of lone pair electrons and charge re-delocalization. Benefiting from the shield effect of re-delocalized electrons, and the weakened attraction between cations and O/S anions enables more S2--S22-redox groups to participate the electrochemical reactions and compensate the double charge of Mg2+ions. Accordingly,VO2（R）-VS4hetero-structure exhibits a high specific capacity of 554 mA h g-1at 50 mA g-1. It is believed that the charge re-delocalization of cathode extremely boost the Mg2+ions migration for the high-capacity of MIBs.

关键词： Mg-ion batteries Cathode Charge delocalization Electronic structure Heterostructure

Energy Harvesting in the Wake of An Inverted C-Shaped Bluff Body

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China Ocean Engineering 2024年第1期38卷 68-80页

作者： WANG Jun-lei LI shen-fang Md.Mahbub ALAM ZHU Hong-jun HU Guo-biao School of Mechanical and Power Engineering Zhengzhou UniversityZhengzhou 450000China Center for Turbulence Control Harbin Institute of Technology(Shenzhen)Shenzhen 518055China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu 610500China Internet of Things Thrust The Hong Kong University of Science and Technology(Guangzhou)Guangzhou 511400China

This paper proposes a novel wake-induced vibration(WIV)-based energy harvesting system consisting of two bluff bodies.An inverted C-shaped bluff body is stationary installed at the upstream position to generate an interference wake street,and a cylinder bluff body equipped with a transducer is elastically suspended at the downstream position to harness WIV energy.The hydrodynamics and energy harvesting(EH)performance of the proposed system are investigated via experimental studies.The reduced velocity(U*)ranging from 2 to 14(the corresponding Reynolds number ranging from 15100 to 106200)is considered in the present study.It is found that the wake generated by the inverted C-shaped bluff body significantly affects the EH performance.Enlarging the opening angle(α)of the C-shaped bluff body increases the vibration amplitude of the downstream cylinder,thereby increasing the harvested power.When the spacing(L)between two bluff bodies is two times the cylinder diameter(D),the wake-induced vibration(WIV)mode is observed,while the combined WIV and wake galloping(WG)mode occurs whenαis 150°,and L equals 3D or 4D.The average drag coefficient becomes negative when L is 2D,3D,or 4D.By carefully configuring a C-shaped bluff body,the wake generated by it can bring an augmenting effect on the vibration of the downstream EH cylinder.For example,the RMS power output of the proposed EH system reaches a maximum of 0.31 W at U*=8 and L=4D,which is 300%greater than that of its traditional counterpart.Furthermore,after a number of case stud-ies,it is identified that the proposed EH system can achieve the best performance whenαis 150°and L=2D.

关键词： wake-induced vibration vortex-induced vibration galloping energy harvesting bluff body

Analysis of strength characteristics of loess before and after freezing using a hollow cylinder torsional shear apparatus

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Research in Cold and Arid Regions 2024年第2期16卷 63-72页

作者： Peng shen QingZhi Wang JianHong fang ChenWei Wang Kui Zhang School of Civil Engineering and Water Resources Qinghai University Qinghai Scientific Research Observation Base Key Laboratory of Highway Construction and Maintenance Technology in Permafrost RegionsMinistry of Transport

This paper aims to comprehensively analyze the influence of the principal stress angle rotation and intermediate principal stress on loess's strength and deformation characteristics. A hollow cylinder torsional shear apparatus was utilized to conduct tests on remolded samples under both normal and frozen conditions to investigate the mechanical properties and deformation behavior of loess under complex stress conditions. The results indicate significant differences in the internal changes of soil particles, unfrozen water, and relative positions in soil samples under normal and frozen conditions, leading to noticeable variations in strength and strain development.In frozen state, loess experiences primarily compressive failure with a slow growth of cracks, while at normal temperature, it predominantly exhibits shear failure. With the increase in the principal stress angle, the deformation patterns of the soil samples under different conditions become essentially consistent, gradually transitioning from compression to extension, accompanied by a reduction in axial strength. The gradual increase in the principal stress axis angle(α) reduces the strength of the generalized shear stress and shear strain curves.Under an increasing α, frozen soil exhibits strain-hardening characteristics, with the maximum shear strength occurring at α = 45°. The intermediate principal stress coefficient(b) also significantly impacts the strength of frozen soil, with an increasing b resulting in a gradual decrease in generalized shear stress strength. This study provides a reference for comprehensively exploring the mechanical properties of soil under traffic load and a reliable theoretical basis for the design and maintenance of roadbeds.

关键词： Loess Hollow cylinder torsional shear apparatus Major principal stress angle Intermediate principal stress coefficient

Growth,optical dispersion and magnetic behavior of Dy^(3+) doped yttrium iron garnet crystals

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Journal of Rare Earths 2024年第6期42卷 1110-1117,I0004页

作者： Yating fang Hui shen Yudie Ma Shijie Liao Shuang Xia Tian Tian Ding Zhou Yunfeng Ma Jiayue Xu Institute of Crystal Growth School of Materials Science and EngineeringShanghai Institute of Technology National Engineering Center of Electromagnetic Radiation Control Materials School of Electronic Science and EngineeringUniversity of Electronic Science and Technology of China

Y_(3)Fe_(5)O_(12)(YIG)crystals are highly desirable for the fabrication of mid-infrared isolators with the rapid growth of optical communications,although it is rather challenging to grow large size and high-quality single crystals.Dy^(3+)doping is expected to improve the optical and magneto-optical prope rties.However,high quality Dy:YIG crystals and the adjustment of Dy^(3+)on the structure and optical behavior of YIG crystal remain unclear,impeding its practical applications.Herein,a series of Y_(3-x)Dy_(x)Fe_(5)O_(12)(x=0,0.5,1.0,1.5,3)solid solution crystals was grown by the flux-Bridgman method and single crystals up to 25 mm were obtained.With the introduction of Dy^(3+),lattice parameters are gradually enlarged from 1.2379 nm(YIG)to 1.2420 nm(DyIG).Typical Dy^(3+)absorption peaks are observed around 1070,1265 and 1670 nm.The refractive index decreases from 2.37(500 nm)to 2.10(2500 nm)for YIG crystal,and it reduces from 2.47(500 nm)to 2.16(2500 nm)for DyIG crystal.The optical bandgaps remain almost unchanged for Dy:YIG crystals.The optical dispersion of the refractive indices was finely fitted by the Wemple and DiDomenico(WDD)and the Sellmeier models,respectively.With the increase of Dy^(3+)content,the saturation magnetization(Ms)decreases significantly from 23.62 emu/g(YIG)to 5.33 emu/g(DyIG).Small coercive field is persisted for this system,endowing small external magnetic field.These results provide valuable references for the manipulation of rare earths on the properties of magnetooptical crystals,which is beneficial to the design of high-performance garnet crystals for the application of optical switching and non-reciprocal related devices.

关键词： Magneto-optical crystal Yttrium iron garnet Dy^(3+)doping Crystal growth Optical dispersion Rare earths

Efficacy and safety of Yiqi Peiyuan granules for improving the short-term prognosis of patients with acute kidney injury:A multicenter,double-blind,placebo-controlled,randomized trial

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Journal of Integrative Medicine 2024年第3期22卷 279-285页

作者： Jia-jia Wu Tian-yi Zhang Ying-hui Qi Min-yan Zhu Yan fang Chao-jun Qi Li-ou Cao Ji-fang Lu Bo-han Lu Lu-min Tang Jian-xiao shen Shan Mou Department of Nephrology Molecular Cell Lab for Kidney DiseaseShanghai Peritoneal Dialysis Research CenterUremia Diagnosis and Treatment CenterRenji Hospital Affiliated to Shanghai Jiaotong University School of MedicineShanghai 200127China Department of Nephrology Shanghai Pudong New Area Punan HospitalShanghai 200125China Department of Nephrology Ningbo Hangzhou Bay HospitalNingbo 315336Zhejiang ProvinceChina

Background:Yiqi Peiyuan(YQPY)prescription,a composite prescription of traditional Chinese medicine,has been used to prevent or delay the continued deterioration of renal function after acute kidney injury(AKI)in some institutions and has shown considerable efficacy.Objective:This is the first randomized controlled trial to assess efficacy and safety of YQPY for improving short-term prognosis in adult patients with AKI.Design,setting,participants and interventions:This is a prospective,double-blind,multicenter,randomized,and placebo-controlled clinical trial.A total of 144 enrolled participants were randomly allocated to two groups according to a randomization schedule.Participants,caregivers and investigators assessing the outcomes were blinded to group assignment.Patients in the YQPY group received 36 g YQPY granules twice a day for 28 days.Patients in the placebo group received a placebo in the same dose as the YQPY granules.Main outcome measures:The primary outcome was the change in the estimated glomerular filtration rate(eGFR)between baseline and after 4 and 24 weeks of treatment.The secondary outcomes were the change of serum creatinine(Scr)level between baseline and after treatment,and the incidence of endpoint events,defined as eGFR increasing by more than 25%above baseline,eGFR>75 mL/min per1.73 m2or the composite endpoint,which was defined as the sum of patients meeting either of the above criteria.Results:Data from a total of 114 patients(59 in the YQPY group and 55 in the control group)were analyzed.The mean changes in eGFR and Scr in weeks 4 and 24 had no difference between the two groups.In further subgroup analysis(22 in the YQPY group and 31 in the control group),the mean change in eGFR after treatment for 4 weeks was 27.39 mL/min per 1.73 m2in the YQPY group and 5.78 mL/min per1.73 m2in the placebo group,and the mean difference between groups was 21.61 mL/min per 1.73 m2(P<0.001).Thirteen(59.1%)patients in the YQPY group and 5(16.1%)in the placebo group reached the composite endpoints(P=0.002).Du

关键词： Chinese herbal medicine Randomized controlled trial Acute kidney injury Renal function

MicroRNA-298 determines the radio-resistance of colorectal cancer cells by directly targeting human dual-specificity tyrosine(Y)-regulated kinase 1A

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World Journal of Gastrointestinal Oncology 2024年第4期16卷 1453-1464页

作者： Mei-Zhu shen Yong Zhang fang Wu Mei-Zhen shen Jun-Lin Liang Xiao-Long Zhang Xiao-Jian Liu Xin-Shu Li Ren-sheng Wang Department of Radiotherapy The First Affiliated Hospital of Guangxi Medical UniversityNanning 530021Guangxi Zhuang Autonomous RegionChina Department of Radiotherapy People’s Hospital of Guangxi Zhuang Autonomous RegionNanning 530021Guangxi Zhuang Autonomous RegionChina Department of Colorectal Anal Surgery The First Affiliated Hospital of Guangxi Medical UniversityNanning 530021Guangxi Zhuang Autonomous RegionChina Department of Clinical Medicine Guangxi Medical UniversityNanning 530021Guangxi Zhuang Autonomous RegionChina

BACKGROUND Radiotherapy stands as a promising therapeutic modality for colorectal cancer(CRC);yet,the formidable challenge posed by radio-resistance significantly undermines its efficacy in achieving CRC remission.AIM To elucidate the role played by microRNA-298(miR-298)in CRC radio-resistance.METHODS To establish a radio-resistant CRC cell line,HT-29 cells underwent exposure to 5 gray ionizing radiation that was followed by a 7-d recovery period.The quantification of miR-298 levels within CRC cells was conducted through quantitative RT-PCR,and protein expression determination was realized through Western blotting.Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and proliferation by clonogenic assay.Radio-induced apoptosis was discerned through flow cytometry analysis.RESULTS We observed a marked upregulation of miR-298 in radio-resistant CRC cells.MiR-298 emerged as a key determinant of cell survival following radiation exposure,as its overexpression led to a notable reduction in radiation-induced apoptosis.Intriguingly,miR-298 expression exhibited a strong correlation with CRC cell viability.Further investigation unveiled human dual-specificity tyrosine(Y)-regulated kinase 1A(DYRK1A)as miR-298’s direct target.CONCLUSION Taken together,our findings underline the role played by miR-298 in bolstering radio-resistance in CRC cells by means of DYRK1A downregulation,thereby positioning miR-298 as a promising candidate for mitigating radioresistance in CRC.

关键词： MicroRNA-298 Human dual-specificity tyrosine(Y)-regulated kinase 1A Colorectal cancer Radio-resistance p53 binding protein 1