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Numerical research on adverse effect of muzzle flow formed by muzzle brake considering secondary combustion

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Defence Technology（防务技术） 2021年第4期17卷 1178-1189页

作者： Peng-fei Li xiao-bing zhang School of Energy and Power Engineering Nanjing University of Science and TechnologyNanjing210094PR China

The simulation of the artillery interior and intermediate ballistics problem is performed to investigate the influence of a gas dynamics device,muzzle brake,on the muzzle hazard phenomena,such as flash and blast *** correlation of the chemical reactions with the characteristics of the muzzle flow field is analyzed by the simulation for a further understanding of the secondary combustion phenomenon of the muzzle *** novel structure of muzzle flow caused by the muzzle brake is presented by the simultaneous solution of the interior ballistics model and multi-species Navier-Stokes equations in order to analyze the influence of the muzzle brake structure on the chemical *** secondary combustion of the muzzle flow due to the oxygen-supplement chemical reactions is obtained by the chemical reaction kinetic *** interaction of the blast waves released from the muzzle brake is illustrated in detail and the mechanism of the formation of muzzle flash is *** research provides a reference for the studies on the suppression of the muzzle flash.

关键词： Muzzle flow Muzzle brake Secondary combustion Chemical reaction

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近红外二区激活型小分子荧光探针研究进展

应用化学 2024年第1期41卷 39-59页

作者：赵欣雨秦作佳张晓兵袁林湖南大学化学化工学院化学生物传感与计量学国家重点实验室长沙410082

近红外二区(NIR-Ⅱ)荧光成像具有优良的组织穿透深度和空间分辨率,广泛应用于生物医学领域。与传统的常亮型荧光探针相比,激活型探针只有当特定的生物标志物存在情况下才会发生荧光信号变化,因此具有更高的信背比,会进一步提高区分病变... 详细信息

近红外二区(NIR-Ⅱ)荧光成像具有优良的组织穿透深度和空间分辨率,广泛应用于生物医学领域。与传统的常亮型荧光探针相比,激活型探针只有当特定的生物标志物存在情况下才会发生荧光信号变化,因此具有更高的信背比,会进一步提高区分病变与正常组织的准确度和可靠性。基于此,本文按照生物疾病模型进行分类,系统总结了近5年报道的近红外二区激活型小分子探针的结构、响应机理以及活体应用,并对目前激活型小分子探针面临的问题及发展方向进行简要介绍。

关键词：近红外二区成像小分子荧光探针激活型探针生物成像

Design optimization for a launching system with novel structure

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Defence Technology（防务技术） 2019年第5期15卷 680-689页

作者： Run-duo Cao xiao-bing zhang School of Energy and Power Engineering Nanjing University of Science and Technology

A launching system with novel structure using optimization method is investigated to improve the muzzle velocity of guns in this *** system has two tandem chambers of which the front one is ignited first and the other is ignited after a *** launching process of this novel system is modelled and a series of different schemes are simulated,to discover the interior ballistic performance of this novel launching *** order to obtain the optimal loading conditions,an optimization model combined with the combustion model is *** optimal schemes can improve the muzzle velocity by 20.6%without changing the parameters of *** means that this novel launch system could improve the interior ballistics performance significantly and it still has considerable potential to be ameliorated.

关键词： Interior ballistics Mobile chamber Design optimization

Influence of multiple structural parameters on interior ballistics based on orthogonal test methods

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Defence Technology（防务技术） 2019年第5期15卷 690-697页

作者： Chao-bin Hu xiao-bing zhang School of Energy and Power Engineering Nanjing University of Science and Technology

Influence of multiple structural parameters on the performance of a gun launch system driven by highpressure reactive gases is important for structural design and performance adjustment.A coupled lumped parameter model was utilized to predict the propellant combustion,and a dynamic finite element method was applied to approximate the mechanical interactions between the projectile and the *** combustion and the mechanical interactions were coupled through a user subroutine interface in *** correctness and the capability of the finite element approximations in capturing small structural changes were validated by comparing predicted resistance with *** on the coupled model,the influence of structural parameters of a medium-caliber gun on the system performance was *** order to reduce the research costs,orthogonal tests were designed to investigate the comprehensive effects of the *** to statistical analysis,the important order of the structural parameters on the launching process was *** results indicate that the influence of the width of the rotating band stands out among the studied parameters in the *** work provides a method to investigate the influence of multiple parameters on system performance and gives guidance for controlling the system performance.

关键词： Multiple parameters Coupled model Combustion Sensitivity analysis Orthogonal test

Machine learning and numerical investigation on drag reduction of underwater serial multi-projectiles

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Defence Technology（防务技术） 2022年第2期18卷 229-237页

作者： Xi Huang Cheng Cheng xiao-bing zhang School of Energy and Power Engineering Nanjing University of Science and TechnologyNanjing210094China

To increase launching frequency and decrease drag force of underwater projectiles,a serial multiprojectiles structure based on the principle of supercavitation is proposed in this *** drag reduction and supercavitation characteristics of the underwater serial multi-projectiles are studied with computational fluid dynamics(CFD)and machine ***,the numerical simulation model for the underwater supercavitating projectile is established and verified by experimental *** the evolution of the supercavitation for the serial multi-projectiles is *** addition,the effects of different cavitation numbers and different distances between projectiles are investigated to demonstrate the supercavitation and drag reduction ***,the artificial neural network(ANN)model is established to predict the evolution of drag coefficient based on the data obtained by CFD,and the results predicted by ANN are in good agreement with the data obtained by *** finding provides a useful guidance for the research of drag reduction characteristics of underwater serial projectiles.

关键词： Drag reduction Serial multi-projectiles Machine learning Artificial neural network(ANN) Numerical simulation

A NON-LINEAR MODEL FOR ESTIMATING THE COST OF ACHIEVING EMISSION REDUCTION TARGETS:THE CASE OF THE U.S.,CHINA AND INDIA

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Journal of Systems Science and Systems Engineering 2012年第3期21卷 297-315页

作者： Lei ZHU xiao-bing zhang Ying FAN Center for Energy & Environmental Policy Research Institute of Policy and Management Chinese Academy of Sciences Beijing 100190 China Department of Economics University of Gothenburg SE 40530 G teborg Sweden

With the world talking about climate change, the United States （U.S.）, China and India have announced their carbon emission reduction targets. For these three countries to achieve their targets, significant questions arise, shch as what will be the annual emission reduction efforts to achieve those targets, how much it would cost and what would be the economic effects. This paper puts the carbon intensity reduction targets of China and India together with the absolute emission reduction target of the U.S. into the same non-linear model to quantitatively study the optimal emission control strategies and associated total cost for achieving those targets by the year 2020, and estimate and compare the minimized total costs of the three countries to reach their targets. Our results show that the total cost for the U.S. to achieve its emission reduction target is greater than those of China and India in terms of absolute amount. However, in terms of proportion of total cost to GDP, China and India＇s ratios are significantly greater than that of the U.S., indicating that for the developing countries such as China and India, the achievement of emission reduction targets needs relatively greater effort.

关键词： Emission reduction cost analysis emission reduction strategy optimization model

Cellular Reprogramming of Human Peripheral Blood Cells

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Genomics, Proteomics & Bioinformatics 2013年第5期11卷 264-274页

作者： xiao-bing zhang Department of Medicine Loma Linda University

Breakthroughs in cell fate conversion have made it possible to generate large quantities of patient-specific cells for regenerative medicine. Due to multiple advantages of peripheral blood cells over fibroblasts from skin biopsy, the use of blood mononuclear cells （MNCs） instead of skin fibroblasts will expedite reprogramming research and broaden the application of reprogramming technology. This review discusses current progress and challenges of generating induced pluripotent stem cells （iPSCs） from peripheral blood MNCs and of in vitro and in vivo conversion of blood cells into cells of therapeutic value, such as mesenchymal stem cells, neural cells and hepatocytes. An optimized design of lentiviral vectors is necessary to achieve high reprogramming efficiency of peripheral blood cells. More recently, non-integrating vectors such as Sendai virus and episomal vectors have been successfully employed in generating integration-free iPSCs and somatic stem cells.

关键词： Reprogramming Peripheral blood Hematopoietic cells Induced pluripotent stemcells Cell fate conversion

An Algorithm of Voice Activity Detection Based on EMD and Wavelet Entropy Ratio

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Journal of Electronic Science and Technology 2017年第1期15卷 64-68页

作者： xiao-bing zhang Ting-Ting Sun Yan-Ping School of Electrical and Information Engineering Anhui University of TechnologyMaanshan 243000China

A new method was proposed to identify speech-segment endpoints based on the empirical mode decomposition（EMD） and a new wavelet entropy ratio with improving the accuracy of voice activity *** the EMD, the noise signals can be decomposed into several intrinsic mode functions（IMFs）. Then the proposed wavelet energy entropy ratio can be used to extract the desired feature for each IMFs component. In view of the question that the method of voice endpoint detection based on the original wavelet entropy ratio cannot adapt to the low signal-to-noise ratio（SNR）condition, an appropriate positive constant was introduced to the basic wavelet energy entropy ratio with effectively improved discriminability between the speech and noise. After comparing the traditional wavelet energy entropy ratio with the proposed wavelet energy entropy ratio, the experiment results show that the proposed method is simple and fast. The speech endpoints can be accurately detected in low SNR environments.

关键词： wavelet entropy decomposed Wavelet adapt environments Voice noisy empirical desired

Dynamics of a stochastic heroin epidemic model with bilinear incidence and varying population size

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International Journal of Biomathematics 2019年第1期12卷 93-113页

作者： Shitao Liu Liang zhang xiao-bing zhang Aibing Li College of Science Northwest A&F University YanglingShaanxi 712100P.R.China Department of Applied Mathematics Lanzhou University of Technology Lanzhou Gansu 730050P.R.China

We investigate a stochastic heroin epidemic model with bilinear incidence and varying population *** criteria for the extinction of the drug abusers and the existence of ergodic stationary distribution for the model are established by constructing suitable stochastic Lyapunov *** analyzing the sensitivity of the threshold of spread,we obtain that prevention is better than *** simulations are carried out to confirm the analytical results.

关键词： Stochastic heroin epidemic model Lyapunov function extinction stationary distribution sensitivity analysis