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Cross-layer design of LT codes and LDPC codes for satellite multimedia broadcast/multicast services

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Chinese Journal of Aeronautics 2013年第5期26卷 1269-1275页

作者： Wang zhenbang Wang Zhenyong Gu Xuemai Guo Qing School of Electronics and Information Engineering Harbin Institute of Technology

According to large coverage of satellites, there are various channel states in a satellite broadcasting network. In order to introduce an efficient rateless transmission method to satellite multimedia broadcasting/multicast services with finite-length packets, a cross-layer packet transmission method is proposed with Luby transform （LT） codes for efficiency in the network layer and low density parity check （LDPC） codes for reliability in the physical layer jointly. The codewords generated from an LT encoder are divided into finite-length packets, which are encoded by an LDPC encoder subsequently. Based on noise and fading effects of satellite channels, the LT packets received from an LDPC decoder either have no error or are marked as erased, which can be mod- eled as a binary erasure channels （BECs）. By theoretical analysis on LT parameters and LDPC parameters, the relationships between LDPC code rates in the physical layer and LT codes word lengths in the network layer are investigated. With tradeoffs between the LT codes word lengths and the LDPC code rates, optimized cross-layer solutions are achieved with a binary search algorithm. Verified by simulations, the proposed solution for cross-layer parameters design can provide the best transmission mode according to satellite states, so as to improve throughput performance for satellite multimedia transmission.

关键词： Broadcast/multicast Cross-layer LDPC codes LT codes Satellite multimedia

Propagation of chirped solitons on a cw background in a non-Kerr quintic medium with self-steepening effect

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Communications in Theoretical Physics 2023年第12期75卷 3-11页

作者： Abdesselam Bouguerra Houria Triki Chun Wei zhenbang Lu Qin Zhou Radiation and Matter Physics Laboratory Matter Sciences DepartmentMohamed-Cherif Messaadia UniversityP.O.Box 1553Souk-Ahras41000Algeria Radiation Physics Laboratory Department of PhysicsFaculty of SciencesBadji Mokhtar UniversityP.O.Box 1223000 AnnabaAlgeria School of Electronics and Information Engineering Wuhan Donghu UniversityWuhan 430212China School of Mathematical and Physical Sciences Wuhan Textile UniversityWuhan 430200China

We study the existence and stability of envelope solitons on a continuous-wave background in a non-Kerr quintic optical material exhibiting a self-steepening *** propagation in such a nonlinear medium is governed by the Gerdjikov-Ivanov *** find that the system supports a variety of localized waveforms exhibiting an important frequency chirping property which makes them potentially useful in many practical applications to optical *** frequency chirp is found to be crucially dependent on the intensity of the wave and its amplitude can be controlled by a suitable choice of self-steepening *** obtained nonlinearly chirped solitons include bright,gray and kink *** also discuss the stability of the chirped solitons numerically under finite initial *** results show that the main character of chirped localized structures is not influenced by finite initial perturbations such as white noise.

关键词： solitons non-Kerr nonlinearity self-steepening effect

CYCLIC DEFORMATION BEHAVIOR OF ZIRCALOY-4 AT DIFFERENT TEMPERATURES

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Acta Metallurgica Sinica(English Letters) 1995年第3期8卷 219-225页

作者： XIAO Lin GU Haicheng KUANG zhenbang(Xi’an Jiaotong University, China Xi'an Jiaotong Univ Xi'an China

Fatigue lifetime curves of Zircaloy-4 at different temperatures were measured, and the fatigued dislocation configurations were investigated using transmission electron microscopy. Ii was found that prismatic slip is the primary deformation mode. for Zircaloy-4fatigued at RT prismatic plus Pyramidal slip at 400℃,and prismatic plus (0001) basic slip at 600℃. The corresponding dislocation configurations are parallel dislocation lines al RT, elongated cells at 400℃ and two sets of mutually Perpendicular dislocation bands at 600℃.respectively. The relationship among. fatigue deformation mode, dislocation configuration and lifetime is discussed.

关键词： Zircaloy-4,.fatigue dislocation configuration slip system

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大豆品种宿豆182的选育及栽培技术要点

安徽农学通报 2024年第12期30卷 26-29页

作者：高亮赵振邦马梦茹宿州市农业科学院安徽宿州234000

宿豆182是以恒豆6号为父本,中涡29为母本,采用系谱法经多年选育而成的大豆新品种,该品种具有稳产、抗病、籽粒商品性好和高油高蛋白等优点,适宜在黄淮海南片区种植。为了进一步推广该品种,本研究对其品种来源和选育过程进行分析,从农艺... 详细信息

宿豆182是以恒豆6号为父本,中涡29为母本,采用系谱法经多年选育而成的大豆新品种,该品种具有稳产、抗病、籽粒商品性好和高油高蛋白等优点,适宜在黄淮海南片区种植。为了进一步推广该品种,本研究对其品种来源和选育过程进行分析,从农艺性状、产量表现和品质角度研究了其品种特性,从播前准备、水肥管理、选种拌种、播种时期与要求、防治病虫草害、苗期防渍、花期防旱和适时收获等多个方面探究了该品种的栽培技术要点,为宿豆182的示范推广提供参考。

关键词：大豆宿豆182 品种选育栽培技术

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Compact Sn/C composite realizes long-life sodium-ion batteries

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Nano Research 2023年第3期16卷 3804-3813页

作者： Mingdong Tan Shuanghui Han zhenbang Li Hao Cui Danni Lei Chengxin Wang State Key Laboratory of Optoelectronic Materials and Technologies School of Materials Science and EngineeringSun Yat-sen UniversityGuangzhou 510275China

Sodium-ion batteries are considered as a promising low-cost alternative to commercial lithium-ion ***,the harsh preparation conditions and unsatisfactory electrochemical performance of most sodium-ion batteries anode materials limit their commercial ***,we develop a new alloying/dealloying method for producing nano-scale tin from freezing point to room *** to the unique surface properties of tin particles,a tin/carbon composite with a compact structure is *** coupled with a diglyme-based electrolyte,tin/carbon composite(contains 60 wt.%tin)exhibits a reversible capacity of 334.8 mAh·g^(−1)after 1,000 cycles at 500 mA·g^(−1).An as-prepared tin/carbon anode||high-load vanadium phosphate sodium full cell(N/P ratio:1.07)shows a stable cycle life of 300 cycles at 1 A·g^(−1).The achievement of such an excellent performance can be ascribed to the carbon conductive network and robust solid electrolyte interphase film,which facilitates the fast transportation of electrons and Na *** work provides a new idea to prepare other alloyed anode materials for highperformance sodium-ion batteries.

关键词： sodium-ion batteries alloying/dealloying method compact tin/carbon composite

PATH FOLLOWING GPS-BASED CONTROL OF SMALL-SIZE ROBOTIC UNMANNED BLIMP

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Chinese Journal of Mechanical Engineering 2007年第2期20卷 60-63页

作者： LUO Jun XIE Shaorong GONG zhenbang RAO Jinjun School of Mechatronics Engineering and Automation Shanghai University Shanghai 200072 China

Robotic unmanned blimps own an enormous potential for applications in low-speed and low-altitude exploration, surveillance, and monitoring, as well as telecommunication relay platforms. To make lighter-than-air platform a robotic blimp with significant levels of autonomy, the decoupled longitude and latitude dynamic model is developed, and the hardware and software of the flight control system are designed and detailed. Flight control and navigation strategy and algorithms for waypoint flight problem are discussed. A result of flight experiment is also presented, which validates that the flight control system is applicable and initial machine intelligence of robotic blimp is achieved.

关键词： Dynamics modeling Flight control Navigation Robotic unmanned blimp

石斑鱼转录因子NR1D1和NR1D2在冷胁迫中的调控作用

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应用海洋学学报 2024年第1期43卷 147-159页

作者：苗奔奔林楚曹文科梁燕珊吴仁协牛素芳梁镇邦广东海洋大学水产学院广东湛江524088 南方海洋科学与工程广东省实验室(湛江) 广东湛江524025

NR1D1和NR1D2转录因子属于核受体转录因子家族,二者通过调控靶基因表达参与众多生物学过程,尤其在昼夜节律调节中发挥重要作用。本研究通过分析NR1D1和NR1D2的蛋白质分子特征以及在冷胁迫下珍珠龙胆石斑鱼(Epinephelus fuscoguttatus♀... 详细信息

NR1D1和NR1D2转录因子属于核受体转录因子家族,二者通过调控靶基因表达参与众多生物学过程,尤其在昼夜节律调节中发挥重要作用。本研究通过分析NR1D1和NR1D2的蛋白质分子特征以及在冷胁迫下珍珠龙胆石斑鱼(Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂)的基因调控关系以及它们所参与的通路,揭示它们在鱼类低温环境中的功能作用。生物信息学比较分析显示NR1D1和NR1D2基因序列均有23个开放阅读框,编码的蛋白质均属于不稳定的亲水性蛋白质。NR1D1和NR1D2蛋白质均含有ZF-C4类锌脂蛋白结构域和Hormone_Recep核激素受体的配体结合域,主要配体为含铁原卟啉IX。这两种蛋白主要在细胞核中发挥调控基因表达的作用,且与昼夜节律通路的多个关键基因有直接作用关系。结果表明,在冷胁迫下NR1D1和NR1D2作为转录因子可通过调控靶基因的表达,参与昼夜节律调节并促进糖脂代谢、线粒体氧化等过程,为珍珠龙胆石斑鱼提供必要的能量,有助于增强其耐寒性。

关键词：海洋生物学珍珠龙胆石斑鱼冷胁迫核受体转录因子家族昼夜节律调节

Targeted Adversarial Examples Generating Method Based on cVAE in Black Box Settings

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Chinese Journal of Electronics 2021年第5期30卷 866-875页

作者： YU Tingyue WANG Shen ZHANG Chunrui WANG zhenbang LI Yetian YU Xiangzhan School of Cyberspace Science Harbin Institute of Technology Institute of Computer Application China Academy of Engineering Physics State Grid Heilongjiang Power Co. Ltd.

In recent years, adversarial examples has become one of the most important security threats in deep learning applications. For testing the security of deep learning models in adversarial environment,many researches focus on generating adversarial examples quickly and efficiently. In order to solve the problems of existing generative adversarial networks based methods which can not effectively generate the targeted adversarial examples in black box settings, and to improve the temporal performance of gradient-based generating methods,an adversarial examples generating method based on conditional Variational autoencoder(cVAE) is proposed in this paper, where a cVAE is designed elaborately to generate adversarial examples without most of the detailed information about the attacked deep learning models, of which the output can be controlled arbitrarily by these crafted inputs, used to test the robustness of deep learning models against adversarial examples. The experimental results show that the proposed method can achieve a comparable attack success rate and a better temporal performance than the existing gradient-based generating methods in black box environment.

关键词： Data security Neural nets Deep learning Image recognition Adversarial examples Conditional variational autoencoder

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单缸发动机曲轴敲击声的分析

机械制造 2024年第8期62卷 101-104页

作者：钱勉白清祥黄振邦江门市大长江集团有限公司广东江门529000

在单缸发动机开发过程中,在怠速工况下发现存在有节奏的“哒哒”敲击声。分析敲击声产生的原因,通过声源定位、噪声及振动测试,确认声源为曲轴。通过试验,进一步锁定敲击声从连杆大端发出。针对单缸发动机曲轴敲击声,提出有效对策方案。

关键词：发动机曲轴声响分析