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Defence Technology（防务技术） 2023年第6期24卷 122-128页

作者： xiao-xiao zheng Ting-ou Yan Lei Qian Hong-wei Yang Guang-bin Cheng School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing210094China

In this study,a new energetic hybrid skeleton was constructed through the integration of nitropyrazole and 1,3,4-oxadiazole skeletons in a molecule.Furthermore,the energetic precursor(2),the azo-bridged compound(3),the neutral nitramine(4)and the corresponding energetic salts(5-7)were synthesized.Their physicochemical and energetic properties we re experimentally and theo retically evaluated.Among the developed compounds,the azo-bridged compound(3)and dihydroxylammoinium(6)display high detonation performances(3,D_(v)=8904 m/s,P=34.47 GPa;6,D_(v)=9025 m/s,P=34.66 GPa),moderate sensitivities(3,IS=16 J,FS=120 N;6,IS=20 J,FS=312 N)and good densities(3,1.87 g/cm^(3);6,1.81 g/cm^(3)),which indicates that they have the potential to replace the traditional high-energy explosive RDX.The results show that the integration of different energetic skeletons can achieve a good balance between energy and sensitivity.

关键词： Heterocycle Azo-bridged Hybrid skeletons Energetic materials

Experimental research of the cavitation bubble dynamics during the second oscillation period near a spherical particle

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Journal of Hydrodynamics 2023年第4期35卷 700-711页

作者： xiao-yu Wang Hong-chen Su Shao-wei Li Guan-hao Wu xiao-xiao zheng Ya-xin Duan Yu-ning Zhang Key Laboratory of Power Station Energy Transfer Conversion and System(Ministry of Education) School of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBeijing102206China State Key Laboratory of Clean Energy Utilization Zhejiang UniversityHangzhou310027China

In this paper,the dynamic behaviors of the cavitation bubble near a fixed spherical particle during the second oscillation period are analyzed based on the high-speed photographic system.The deformation and motion of the bubble during the second period are investigated by changing the distance between the particle and the bubble and the maximum radius of the bubble.Meanwhile,the variation of the equivalent radius and the centroid motions are analyzed,and the dynamic behaviors of the bubble are categorized according to the bubble morphological characteristics during the second period.Through this research,it is found that(1)The dynamic behaviors of the bubble during the second oscillation period could be divided into three typical cases:For case 1,a bulge would exist on the bubble interface away from the particle,and for case 2,a bulge would appear on the bubble interface and evolve towards the particle,while for case 3,the bubble would be divided into two parts.(2)The larger the dimensionless distance between the particle and the bubble,the smaller the maximum bubble equivalent radius in the second period,and the shorter the second oscillation period.(3)When the bubble is close to the particle,a counter-jet appears at the bubble interface away from the particle during the rebound stage.

关键词： Cavitation bubble dynamics particle-bubble interaction second oscillation period high-speed photography

Theoretical investigation on the cavitation bubble dynamics near three spherical particles based on Weiss theorem

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Journal of Hydrodynamics 2023年第6期35卷 1119-1130页

作者： Yu-ning Zhang Zhi-ling Ding Jing-rong Hu xiao-xiao zheng Jia-xin Yu Jin-sen Hu College of Mechanical and Transportation Engineering China University of Petroleum-BeijingBeijing102249China Beijing Key Laboratory of Process Fluid Filtration and Separation China University of Petroleum-BeijingBeijing102249China China Fire and Rescue Institute Beijing102202China Key Laboratory of Power Station Energy Transfer Conversion and System(Ministry of Education) School of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBeijing102206China

To research the dynamics of the cavitation bubble under the interaction of particle clusters,the bubble morphological evolutionary characteristics near three equal-sized spherical particles are theoretically explored in the present study based on the Weiss theorem and the velocity potential superposition theory.The three particles are arranged symmetrically,and the fluid velocity field near the three particles and the cavitation bubble is obtained.Moreover,the effects of the bubble-particle distance and the maximum radius of the cavitation bubble on the fluid velocity are investigated,and the contribution mechanisms of the fluid velocity field constituents are compared.The analysis has found that:(1)The fluid velocity between the bubble and the particle is lower than that at the other locations in both the growth and collapse phases,thus the bubble cannot always maintain a standard spherical shape.(2)The bubble-particle distance and the maximum radius of the cavitation bubble are the key parameters affecting the circumferential inhomogeneity of the radial velocity of the fluid around the bubble.The larger the maximum radius or the smaller the bubble-particle distance is,the more visible the non-circularity of the bubble morphology.(3)The image bubbles and the linear sinks contribute oppositely to the fluid velocity field,and the presence of the image bubble reduces the fluid velocity.In the low velocity region,the image bubble is the main mechanism contributing to the effect of the particle on the fluid velocity.

关键词： Particles-bubble effects velocity potential fluid velocity bubble morphology Weiss theorem

Laser-induced cavitation bubble near boundaries

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Journal of Hydrodynamics 2023年第5期35卷 858-875页

作者： Jia-xin Yu xiao-yu Wang Jin-sen Hu Jun-wei Shen Xiang-qing Zhang xiao-xiao zheng Yu-ning Zhang Zhi-feng Yao Key Laboratory of Power Station Energy Transfer Conversion and System(Ministry of Education) School of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBeijing102206China China Fire and Rescue Institute Beijing102202China College of Water Resources and Civil Engineering China Agricultural UniversityBeijing100083China

Laser-induced cavitation bubble has been widely used to investigate the mechanisms of hydraulic machinery cavitation erosion and to explore applications in atomization, alloy strengthening, ultrasonic chemistry, biomedicine, surface cleaning and materials processing. This paper consolidates existing research findings on the cavitation bubble dynamics near different boundaries and provides insights for future research work. Firstly, the dynamics of a single cavitation bubble in an infinite field is presented. Subsequently, the focus shifts to the dynamics of cavitation bubble near a rigid wall, angular walls, particles and hydrofoil. Lastly, the paper delves into the dynamics of cavitation bubble within a droplet, revealing the microscopic mechanism of droplet breakup induced by cavitation bubble.

关键词： Laser-induced cavitation bubble bubble dynamics bubble-particle interactions droplet splash

Blow up of Solutions for a Nonlinear Petrovsky Type Equation with Time-dependent Coefficients

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Acta Mathematicae Applicatae Sinica 2020年第4期36卷 836-846页

作者： xiao-xiao zheng Ya-dong SHANG xiao-ming PENG School of Mathematical Sciences Qufu Normal UniversityQufu 273155China School of Mathematics and Information Science Guangzhou UniversityGuangzhou 510006China School of Statistics and Mathematics Guangdong University of Finance and EconomicsGuangzhou 510320China

4In this paper,we study a nonlinear Petrovsky type equation with nonlinear weak damping,a superlinear source and time-dependent coefficients utt+△^2u-ki(t)|ut|m^2ut=k2(t)|u|^p-2u,x∈Ω,t>0,whereΩis a bounded domain in R^n.Under certain conditions on k1(t),k2(t)and the initial-boundary data,the upper bound for blow-up time of the solution with negative initial energy function is given by means of an auxiliary functional and an energy estimate met hod if p>m.Also,a lower bound of blow-up time are obtained by using a Sobolev-type inequality and a first order differential inequality technique for n=2,3 and n>4.

关键词： nonlinear Petrovsky type equation time-dependent coefficients blow-up upper bound lower bound

Quantitative and qualitative analysis of common peaks in chemical fingerprint of Yuanhu Zhitong tablet by HPLC-DAD–MS/MS

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Journal of Pharmaceutical Analysis 2014年第2期4卷 96-106页

作者： Dao-Quan Tang xiao-xiao zheng Xu Chen Dong-Zhi Yang Qian Du Department of Pharmaceutical Analysis Xuzhou Medical College Key Laboratory of New Drug & Clinical Application Xuzhou Medical College Environmental Research Institute National University of Singapore

A quality control （QC） strategy for quantitative and qualitative analysis of “common peaks” in chemical fingerprint was proposed to analyze Yuanhu Zhitong tablet （YZT）, using high performance liquid chromatography with diode array detector and tandem mass spectrometry （HPLC-DAD-MS/MS）. The chromatographic separation was achieved on an Agilent Eclipse plus C18 column with a gradient elution using a mixture of 0.4‰ ammonium acetate aqueous （pH 6.0 adjusted with glacial acetic acid） and acetonitrile. In chemical fingerprint, 40 peaks were assigned as the “common peaks”. For quantification of “common peaks”, the detection wavelength was set at 254 nm, 270 nm, 280 nm and 345 nm, respectively. The method was validated and good results were obtained to simultaneously determine 10 analytes （protopine, jatrorrhizine, coptisine, palmatine, berberine, xanthotoxin, bergapten, tetrahydropalmatine, imperatorin and isoimperatorin）. For qualification of “common peaks”, 33 compounds including 10 quantitative analytes were identified or tentatively characterized using LC-MS/MS. These results demonstrated that the present approach may be a powerful and useful tool to tackle the complex quality issue of YZT.

关键词： Yuanhu Zhitong tablet Alkaloids Coumarins Quality control HPLC-DAD-MS/MS

Numerical investigation on dynamic response of the screen mesh in vibrating screening through DEM-FEM co-simulation

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Particuology 2024年第4期87卷 205-217页

作者： Huan Zhang xiao zheng Weimin Jing Key Laboratory of MetallurgicalEquipment and Control Technology Ministry of EducationWuhan University of Science and TechnologyWuhan430081 China Hubei Key Laboratory of Mechanical Transmssion and Manufacturing Engineering Wuhan University of Science and TechnologyWuhan430081China College of Mechanical and Vehicle Engineering Chongqing UniversityChongqing400044China

Dynamic response of the screen mesh is of great significance in the optimum vibrating screen design.In this paper,based on the DEM-FEM co-simulation method,the effect of screening parameters on the dynamic response of the screen mesh is explored and the mechanism is revealed on the particle level.Firstly,a virtual experiment on a linear vibrating screen was carried out to analyze the screening pa-rameters'effect with both impact load and sustained stress inflicted on the screen mesh.Then,the time-domain evolution regularity of the screen mesh LVA(Local Vibration Amplitude)under different particle plugging conditions was investigated based on the co-simulation.Finally,the influence of screening parameters on LVA and its distribution was discussed.The results show that the screening parameters can greatly affect the screen mesh LVA and its distribution by changing the movement of the granular material and the particle penetration probability,which provides an important basis for the optimal design of the screen mesh and its supporting structure.

关键词： Vibrating screen Dynamic response DEM-FEM Screening parameters Local vibration amplitude

A Trust Evaluation Mechanism Based on Autoencoder Clustering Algorithm for Edge Device Access of IoT

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Computers, Materials & Continua 2024年第2期78卷 1881-1895页

作者： xiao Feng zheng Yuan Cyber Security Academy Beijing University of Posts and TelecommunicationsBeijing100876China Department of Cyberspace Security Beijing Electronic Science and Technology InstituteBeijing100070China State Grid Info-Telecom Great Power Science and Technology Co. Ltd.Beijing102211China

First,we propose a cross-domain authentication architecture based on trust evaluation mechanism,including registration,certificate issuance,and cross-domain authentication processes.A direct trust evaluation mechanism based on the time decay factor is proposed,taking into account the influence of historical interaction records.We weight the time attenuation factor to each historical interaction record for updating and got the new historical record data.We refer to the beta distribution to enhance the flexibility and adaptability of the direct trust assessment model to better capture time trends in the historical record.Then we propose an autoencoder-based trust clustering algorithm.We perform feature extraction based on autoencoders.Kullback leibler(KL)divergence is used to calculate the reconstruction error.When constructing a convolutional autoencoder,we introduce convolutional neural networks to improve training efficiency and introduce sparse constraints into the hidden layer of the autoencoder.The sparse penalty term in the loss function measures the difference through the KL divergence.Trust clustering is performed based on the density based spatial clustering of applications with noise(DBSCAN)clustering algorithm.During the clustering process,edge nodes have a variety of trustworthy attribute characteristics.We assign different attribute weights according to the relative importance of each attribute in the clustering process,and a larger weight means that the attribute occupies a greater weight in the calculation of distance.Finally,we introduced adaptive weights to calculate comprehensive trust evaluation.Simulation experiments prove that our trust evaluation mechanism has excellent reliability and accuracy.

关键词： Cross-domain authentication trust evaluation autoencoder

Advances of biomarkers in nasopharyngeal carcinoma’s early detection

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Science Bulletin 2024年第2期69卷 141-145页

作者： xiao-Hui zheng Allan Hildesheim Wei-Hua Jia State Key Laboratory of Oncology in South China Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and TherapyGuangdong Provincial Clinical Research Center for CancerSun Yat-sen University Cancer CenterGuangzhou 510060China Costa Rican Agency for Biomedical Investigation INCIENSA FoundationSan Jose 10108Costa Rica

Nasopharyngeal carcinoma(NPC),a highly invasive and metastatic cancer,is widely prevalent in South China,Southeast Asia,and North Africa.NPC patients with stages I and II are often asymptomatic.Therefore,NPC patients are usually diagnosed with advanced-stage(stages III and IV)at their first visit.Detection of NPC at early stage is the key to improve the survival of patients.Epstein-Barr virus(EBV)plays an essential role in NPC occurrence in endemic areas.EBV-based biomarkers,including EBV antibody in serum and EBV DNA in plasma,have been specifically proposed for NPC early detection.Herein,we summarize recent advances in biomarkers for the early detection of NPC.

关键词： patients nasopharyngeal Nasopharyngeal

Efficacy of scraping therapy on blood pressure and sleep quality in stage Ⅰ and Ⅱ essential hypertension: A systematic review and meta-analysis

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Journal of Integrative Medicine 2024年第1期22卷 12-21页

作者： zheng-gang Zhu Jian-ru Wang xiao-yan Pan School of Nursing Hunan University of Chinese MedicineChangsha 410208Hunan ProvinceChina School of Health Sciences Universiti Sains MalaysiaKubang Kerian 16150KelantanMalaysia Department of Cardiovascular Medicine the First Affiliated Hospital of Henan University of Chinese MedicineZhengzhou 450000Henan ProvinceChina

Background Scraping therapy is widely used in treating stage I and II essential hypertension in China.However,there has been no systematic evaluation of the efficacy of scraping therapy on blood pressure and sleep quality in stage I and II essential hypertension.Search strategy Seven electronic databases(PubMed,Scopus,Cochrane Library,Web of Science,EBSCO,China National Knowledge Infrastructure and Wanfang Data electronic databases)were searched from inception to December 2022.Based on the principle of combining subject words with text words,the search strategy was constructed around search terms for“scraping therapy,”“scraping,”“Guasha,”“Gua sha,”“hypertension,”and“high blood pressure”during the database searches.Inclusion criteria Randomized controlled trials(RCTs)were included if they recruited patients with stage I and II essential hypertension and included a scraping therapy intervention.The intervention group received antihypertensive drugs and scraping therapy,while the control group only took antihypertensive drugs.Data extraction and analysis Review Manager 5.4.0 and STATA 15.1 were used to enter all the relevant outcome variables to conduct the meta-analysis.The quality of the selected RCTs was assessed using the PEDro scale.The sensitivity analysis was carried out by iteratively excluding individual studies and repeating the analysis to determine the stability of the findings and identify any studies with greater influence on the outcome.Subgroup analysis was performed to find the source of heterogeneity.Funnel plots were used to evaluate the publication bias of included studies.Results Nine RCTs including 765 participants were selected.Meta-analysis showed that scraping therapy combined with medication had an advantage over the use of medication alone in lowering systolic blood pressure(mean difference[MD]=?5.09,95%confidence interval[CI]=?6.50 to?3.67,P<0.001)and diastolic blood pressure(MD=?2.66,95%CI=?3.17 to?2.14,P<0.001).Subgroup analysis showed that scraping therapy improved sleep quality in mid

关键词： Scraping therapy Essential hypertension Efficacy Blood pressure Sleep quality Systematic review Meta-analysis