检索结果-南通市图书馆

Reflection behavior of insensitive explosive detonation propagating around a cylinder

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2024年第7期40卷 55-65页

作者： Zixuan Zhang Yuan Wang Xiaomian Hu Haitao Chen Institute of Applied Physics and Computational Mathematics Beijing 100094China graduate school of china Academy of Engineering Physics Beijing 100088China

Insensitive explosive detonation has wide applications in compressing and driving inert materials,and thereby the interaction between detonation and inert materials has received more *** this paper,a two-dimensional numerical simulation based on the Euler multiphase flow framework is used to investigate the reflection behavior of the insensitive explosive detonation propagating around a *** results show that there is a critical incident angle,defined as transition angle for detonation propagating around the cylinder,below which the regular reflection(RR)on the cylinder surface is *** the incident angle is greater than the transition angle,RR changes to Mach *** transition angle is larger than that obtained by polar curve theory and the change of incident angle is used to interpret above *** addition,the influence of cylindrical radius and detonation reaction zone width on the reflection behavior is *** the cylindrical radius increases,the height of Mach stem increases while the transition angle decreases and gradually approaches the value in pole curve *** Neumann reflection is observed when the reaction zone width is relatively *** is because the energy release rate in the reaction zone is high for small reaction zone width,resulting in the formation of a series of compression waves near the cylindrical interface.

关键词： Insensitive explosive detonation Cylindrical inert material Reflection behavior

Xuebijing improves intestinal microcirculation dysfunction in septic rats by regulating the VEGF-A/PI3K/Akt signaling pathway

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Emergency Medicine 2024年第3期15卷 206-213页

作者： A-ling Tang Yan Li Li-chao Sun Xiao-yu Liu Nan Gao Sheng-tao Yan Guo-qiang Zhang Department of Emergency China-Japan Friendship HospitalBeijing 100029China graduate school Beijing University of Chinese MedicineBeijing 100105China

BACKGROUND:This study aims to explore whether Xuebijing(XBJ) can improve intestinal microcirculation dysfunction in sepsis and its ***:A rat model of sepsis was established by cecal ligation and puncture(CLP).A total of 30 male SD rats were divided into four groups:sham group,CLP group,XBJ + axitinib group,and XBJ *** was intraperitoneally injected 2 h before *** data(blood pressure and heart rate) were *** intestinal microcirculation data of the rats were analyzed via microcirculation ***-linked immunosorbent assay(ELISA) kits were used to detect the serum levels of interleukin-6(IL-6),C-reactive protein(CRP),and tumor necrosis factor-α(TNF-α) in the *** analysis and transmission electron microscopy were used to analyze the injury of small intestinal microvascular endothelial cells and small intestinal mucosa in *** expression of vascular endothelial growth factor A(VEGF-A),phosphoinositide 3-kinase(PI3K),phosphorylated PI3K(p-PI3K),protein kinase B(Akt),and phosphorylated Akt(p-Akt) in the small intestine was analyzed via Western ***:XBJ improved intestinal microcirculation dysfunction in septic rats,alleviated the injury of small intestinal microvascular endothelial cells and small intestinal mucosa,and reduced the systemic inflammatory ***,XBJ upregulated the expression of VEGF-A,p-PI3K/total PI3K,and p-Akt/total Akt in the rat small ***:XBJ may improve intestinal microcirculation dysfunction in septic rats possibly through the VEGF-A/PI3K/Akt signaling pathway.

关键词： Sepsis Xuebijing Vascular endothelial growth factor A Microcirculation Rat Phosphoinositide 3-kinase Protein kinase B

Few-shot incremental radar target recognition framework based on scattering-topology properties

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第8期37卷 246-260页

作者： Chenxuan LI Weigang ZHU Bakun ZHU Yonggang LI graduate school Space Engineering UniversityBeijing 101400China Department of Electronic and Optical Engineering Space Engineering UniversityBeijing 101400China

The continuous emergence of new targets in open scenarios leads to a substantial decrease in the performance of Inverse Synthetic Aperture Radar(ISAR)recognition ***,data scarcity further exacerbates the challenge of identifying new classes of ISAR *** this paper,a few-shot incremental target recognition framework based on Scattering-Topology Properties(STPIL)is ***,STPIL extracts scattering-topology properties of ISAR targets as recognition ***,the pseudo-incremental training strategy effectively alleviates the algorithm’s forgetting of old knowledge,and improves compatibility with new ***,a feature embedding network,with few parameters,is designed based on the graph neural *** embedding network is highly adaptable to changes in data ***,STPIL fully considers the joint distribution and marginal distribution in scattering features,and uses the Brownian distance metric module to make the scattering-topology features more *** results on both the simulation dataset and the public measured data indicate that STPIL can effectively balance new classes with old classes,and has superior performance to other advanced methods in the incremental recognition of targets.

关键词： Brownian distance metric Graph neural networks Incremental learning Inverse Synthetic Aperture Radar(ISAR) Scattering

Numerical insight into heat transfer enhancement by granules inner-migration in a moving bed:A performance comparison between slanted-stick and plow-shaped agitator

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第6期89卷 109-116页

作者： Binfan Jiang Hao Pei Dehong Xia Haiyang Wang school of Energy and Environmental Engineering University of Science and Technology BeijingBeijing 100083China Shunde graduate school of University of Science and Technology beijing Guangdong 528399China Jianlong Group&USTB Joint Laboratory Beijing 100083China

Waste heat recovery of high-temperature granules is one of the most promising sustainable energy supply and carbon reduction ways for industry.A moving bed indirect heat exchanger(MBIHE)with inner-migration was proposed for granular heat *** migration and the enhanced heat transfer induced by two types of agitators(i.e.,agitator with slanted stick A_(s)and with plow-shaped surface A_(p))in the MBIHE are analyzed based on DEM coupled with *** to the effective agitation,the average heat transfer coefficient in the granule side is enhanced to∼3 times compared to that without *** heat recovery efficiency in the moving bed reached more than 70%with the agitations of either A_(s)or A_(p).The heat efficiency of A_(s)is∼7%higher than that of A_(p),but with at least 60%greater rotational *** ensure reliable agitation,the A_(p)is suggested to be adopted in the MBIHE to induce granule migration.

关键词： Waste heat recovery High-temperature granule Granule migration Heat transfer enhancement Industry energy saving

Deformation and mutual influence of two cylindrical water columns in tandem subjected to shock wave

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第8期33卷 316-327页

作者：洪振宇宋洋王睿马宗强马东军王裴 Institute of Applied Physics and Computational Mathematics Beijing 100094China graduate school of china Academy of Engineering Physics Beijing 100088China Center for Applied Physics and Technology Peking UniversityBeijing 100871China

The interaction between shock waves and multiple cylinders,referred to as shock–cylinder interaction(SCI),is an important phenomenon in science and ***,its underlying physical mechanisms remain *** study entailed the numerical simulation of the aerobreakup of two tandem water columns subjected to a high-speed gas flow by using an adaptive mesh refinement(AMR)-based diffusion-interface *** objective was to elucidate the changes in water–column deformation patterns over a wide range of Weber *** analysis was performed to examine the deformation of the water columns in vertical *** reveal distinct deformation patterns between the two columns as the Weber number ***,an extended exponential stretching law model was devised,and its improved capability to predict the deformation patterns was demonstrated.

关键词： shock-cylinder interaction(SCI) Weber number effect aerobreakup multiphase flow

Laparoscopic versus open surgery in treating patients with gallbladder cancer: a systematic review and meta-analysis

在线全文

学校读者我要写书评

暂无评论

Hepatobiliary Surgery and Nutrition 2024年第3期13卷 444-459,I0012-I0014页

作者： Duo Li Li Xu Xiangling Deng Yongliang Sun Zihuan Zhang Tianxiao Wang Ruili Wei Yingjixing Luo Wenquan Niu Zhiying Yang graduate school Peking Union Medical College and Chinese Academy of Medical SciencesBeijingChina Department of General Surgery China-Japan Friendship HospitalBeijingChina graduate school Beijing University of Chinese MedicineBeijingChina Department of Pediatrics China-Japan Friendship HospitalBeijingChina graduate school Peking University Health Science CenterBeijingChina graduate school Capital Medical UniversityBeijingChina Center for Evidence-Based Medicine Capital Institute of PediatricsBeijingChina

Background:Concerns over the security of laparoscopic radical operation for gallbladder cancer(GBC)*** systematic review and meta-analysis attempted to compare the safety and efficacy of laparoscopic surgery(LS)versus open surgery(OS)in the treatment of ***:The PubMed,EMBASE,and Web of Science were searched from inception to July 18,*** search,quality assessment,and data extraction were completed independently and in ***-size estimates expressed as weighted mean difference(WMD)or odds ratio(OR)with 95%confidence interval(CI)were derived under the random-effects ***:A total of 27 independent studies including 2,868 participants were *** was noted for intraoperative blood loss(WMD:−117.194,95%CI:−170.188 to 64.201,P<0.001),harvested lymph nodes(WMD:−1.023,95%CI:−1.776 to−0.269,P=0.008),postoperative hospital stay(WMD:−3.555,95%CI:−4.509 to−2.601,P<0.001),postoperative morbidity(OR:0.596,95%CI:0.407 to 0.871,P=0.008),overall survival rate at 2-year(OR:1.524,95%CI:1.143 to 2.031,P=0.004),T2 survival at 1-year(OR:1.799,95%CI:1.777 to 2.749,P<0.01)and 2-year(OR:2.026,95%CI:1.392 to 2.949,P<0.001),as well as T3 survival at 1-year(OR:2.669,95%CI:1.564 to 4.555,P<0.001)and 2-year(OR:2.300,95%CI:1.308 to 4.046,P=0.004).Subgroup analyses revealed that ethnicity,incidental GBC,sample size,and follow-up period were possible sources of *** was a low probability of publication bias for all outcomes except postoperative ***:Our findings indicated that LS statistically had better 2-year survival rates,less intraoperative bleeding,shorter hospitalization times,and lower rates of complications than ***,the superiority and even the safety of LS still remain an open question due to the impact of incidental GBC,unaccounted heterogeneity,publication bias,lymph node dissection,and port-site metastasis.

关键词： Systematic review and meta-analysis gallbladder cancer(GBC) laparoscopic surgery(LS) open surgery survival

A combined evaluation of the characteristics and antibiotic resistance induction potential of antibiotic wastewater during the treatment process

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第4期138卷 626-636页

作者： Sun Miao Yanyan Zhang Cong Men Yiou Mao Jiane Zuo State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China school of Energy and Environmental Engineering Beijing Key Laboratory of Resource-Oriented Treatment of Industrial PollutantsUniversity of Science and Technology BeijingBeijing 100083China High school Affiliated to Renmin University of china Beijing 100080China Tsinghua Shenzhen International graduate school Shenzhen 518055China

Antibiotic wastewater contains a variety of pollutant stressors that can induce and promote antibiotic resistance(AR)when released into the *** these substances are mostly in concentrations lower than those known to induce AR individually,it is possible that antibiotic wastewater discharge might still promote the AR transmission risk via additive or synergistic ***,the comprehensive effect of antibiotic wastewater on AR development has rarely been evaluated,and its treatment efficiency remains ***,samples were collected from different stages of a cephalosporin production wastewater treatment plant,and the potential AR induction effect of their chemical mixtures was explored through the exposure of the antibiotic-sensitive Escherichia coli K12 *** with raw cephalosporin production wastewater significantly promoted mutation rates(3.6×10^(3)-9.3×10^(3)-fold)and minimum inhibition concentrations(6.0-6.7-fold)of *** against ampicillin and *** may be attributed to the inhibition effect and oxidative stress of cephalosporin wastewater on *** AR induction effect of cephalosporin wastewater decreased after the coagulation sedimentation treatment and was completely removed after the full treatment process.A Pearson correlation analysis revealed that the reduction in the AR induction effect had a strong positive correlation with the removal of organics and biological *** indicates that the antibiotic wastewater treatment had a collaborative processing effect of conventional pollutants,toxicity,and the AR induction *** study illustrates the potential AR transmission risk of antibiotic wastewater and highlights the need for its adequate treatment.

关键词： Antibiotic wastewater treatment plant Antibiotic resistance Antibiotic resistance induction effect Correlation analysis Biological toxicity

Design and validation of a variable camber wing structure

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第2期37卷 1-11页

作者： Xiasheng SUN Jingfeng XUE Jin ZHOU Zhigang WANG Wenjuan WANG Mengjie ZHANG Chinese Aeronautical Establishment Beijing 100012China school of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China Aircraft Strength Research Institute of china Xi’an 710065China graduate school of Chinese Aeronautical Establishment Yangzhou 225002China

Variable camber wing technology is one of the important development trends of green aviation at *** smooth,seamless,continuous and adaptive change of wing camber,the aerodynamic performance is improved in achieving increase in lift and reduction in resistance and *** on the aerodynamic validation model CAE-AVM,Chinese Aeronautical Establishment(CAE)has carried out the design and validation of a variable camber wing,proposed an aerodynamic deformation matrix for the leading and trailing edges of aircraft wings in takeoff,landing and cruise *** structures and driving schemes are compared,and several key technology problems of leading and trailing edge deformation are solved.A full-size leading edge wind tunnel test piece with a span of 2.7 m and a trailing edge ground function test piece are *** deformation and shape maintenance capabilities of the leading edge is verified under real wind load conditions,and the load bearing and deformation capabilities of the trailing edge is verified under simulated follow-on *** results indicate that the leading and trailing edges of the variable camber wing can achieve the required deformation angle and have a certain load-bearing *** study can provide some insights into the application of variable camber wing technology for civil aircraft.

关键词： Variable camber wing Leading edge Trailing edge Structure Measurement and control Test

Density-based ship detection in SAR images:Extension to a self-similarity perspective

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第3期37卷 168-180页

作者： Xueqian WANG Gang LI Zhizhuo JIANG Yu LIU You HE Department of Electronic Engineering Tsinghua UniversityBeijing 100084China Shenzhen International graduate school Tsinghua UniversityShenzhen 518055China

Nonlocal self-similarity is an important property of Synthetic Aperture Radar(SAR)images to characterize the repetitiveness of features embodied by SAR images within nonlocal areas and has been used for enhancement of SAR *** SAR ship detectors often independently handle small sub-images cropped from a large marine SAR image and do not exploit the nonlocal self-similarity *** this paper,we propose a new ship detector from the perspective of nonlocal self-similarity in SAR images to improve the ship detection performance,basically including three stages:prescreening,intra-cue calculation,and inter-cue *** the prescreening stage,we design a new Histogram-based Density(HD)feature to rapidly select candidate sub-images potentially containing ship targets from a large SAR *** the intra-cue calculation stage,target cues within a single candidate sub-image are *** the inter-cue calculation stage,thanks to the nonlocal self-similarity among different candidate sub-images in terms of density features,we innovatively extract a weighted superpixel-HD map to obtain accumulated intracues across all the candidate ***,for each candidate sub-image,we fuse its inter-cue and intra-cue to obtain final detection *** results based on real SAR images show that our newly proposed method provides a better target-to-clutter contrast and ship detection performance than those of other state-of-the-art detection approaches.

关键词： Ship detection Synthetic aperture radar(SAR) Density Self-similarity Histogram