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Research on optimal guaranteed cost control of flexible spacecraft

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Journal of Systems Engineering and Electronics 2008年第5期19卷 988-995页

作者： wang qingchao Cai Peng School of Astronautics Harbin Inst. of Technology Harbin 150001 P. R. China

This article is concerned with the modeling and control problems of the flexible spacecraft. First, the state observer is designed to estimate the vibration mode on the basis of free vibration models, Then, an optimal guaranteed cost controller is proposed to stabilize system attitude and damp the vibration of the flexible beam at the same time. Numerical simulation examples show the feasibility and validity of the proposed method.

关键词： spacecraft attitude control Euler-Bernoulli beam optimal guaranteed cost control.

Arginine metabolism and its functions in growth, nutrient utilization, and immunonutrition of fish

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Animal Nutrition 2021年第3期7卷 716-727页

作者： qingchao wang Zhen Xu Qinghui Ai Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt Ministry of EducationCollege of FisheriesHuazhong Agricultural UniversityWuhanChina Laboratory for Marine Fisheries Science and Food Production Processes Qingdao National Laboratory for Marine Science and TechnologyQingdaoChina Key Laboratory of Aquaculture Nutrition and Feed(Ministry of Agriculture) Ocean University of ChinaQingdaoChina

Fish have limited ability in endogenous biosynthesis of *** is an indispensable amino acid for fish,and the arginine requirement varies with fish species and fish *** studies on fish have demonstrated that arginine influences nutrient metabolism,stimulates insulin release,is involved in nonspecific immune responses and antioxidant responses,and elevates disease ***,arginine can regulate energy homeostasis via modulating the adenosine 5'-monophosphate(AMP)-activated protein kinase(AMPK)pathway,and also regulate protein synthesis via activating the target of rapamycin(TOR)signaling *** present article reviews pertinent knowledge of arginine in fish,including dietary quantitative requirements,endogenous anabolism and catabolism,regulation of the endocrine and metabolic systems,and immune-regulatory functions under pathogenic *** findings showed that further data about the distribution of arginine after intake into specific cells,its sub-cellular sensor to initiate downstream signaling pathways,and its effects on fish mucosal immunity,especially the adaptive immune response against pathogenic infection in different species,are urgently needed.

关键词： Arginine metabolism Arginase Immunonutrition Nitric oxide Target of rapamycin signaling

Numerical Study of Combining Steady Vortex Generator Jets and Deflected Trailing Edge to Reduce the Blade Numbers of Low Pressure Turbine Stage

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Journal of Thermal Science 2016年第6期25卷 511-517页

作者： Li Chao YAN Peigang wang Xiangfeng HAN Wanjin wang qingchao School of Energy Science and Engineering Harbin Institute of Technology

A flow control system that combined steady Vortex Generator Jets and Deflected Trailing-edge(VGJs-DT) to decrease the low pressure turbine(LPT) blade numbers was *** effects of VGJs-DT on energy loss and flow of low solidity low pressure turbine(LSLPT) cascades were ***-DT was found to decrease the energy loss of LSLPT cascade and increase the flow turning ***-DT decreased the solidity by 12.5%without a significant increase in energy ***-DT was more effective than steady ***-DT decreased the energy loss and increased the flow angle of the LSLPT cascade with steady ***-DT can use 50%less mass flow than steady VGJs to inhibit the flow separation in the LSLPT *** deflected trailing edge enhanced the ability of steady VGJs to resist flow ***,VGJs-DT can be used to control flow separation in LPT cascade and reduce the blade numbers of low pressure turbine stage.

关键词： Vortex cascade turbine resist blade Turbine Numbers turbulence projection pitch

Numerical Study of Improving Aerodynamic Performance of Low Solidity LPT Cascade through Increasing Trailing Edge Thickness

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Journal of Thermal Science 2016年第4期25卷 342-348页

作者： LI Chao YAN Peigang wang Xiangfeng HAN Wanjin wang qingchao School of Energy science and engineering Harbin Institute of Technology

This paper presents a new idea to reduce the solidity of low-pressure turbine(LPT) blade cascades,while remain the structural integrity of LPT *** performance of a low solidity LPT cascade was improved by increasing blade trailing edge thickness(TET).The solidity of the LPT cascade blade can be reduced by about12.5% through increasing the TET of the blade without a significant drop in energy *** the low solidity LPT cascade,increasing the TET can decrease energy loss by 23.30% and increase the flow turning angle by1.86% for Reynolds number(Re) of 25,000 and freestream turbulence intensities(FSTT) of 2.35%.The flow control mechanism governing behavior around the trailing edge of an LPT cascade is also *** results show that appropriate TET is important for the optimal design of high-lift load LPT blade cascades.

关键词： Aircraft engine low pressure turbine trailing edge thickness profile loss flow control

Rotation Effect on Flow and Heat Transfer for High-Temperature Rotor Blade in a Heavy Gas Turbine

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Journal of Thermal Science 2021年第2期30卷 707-715页

作者： DONG Aihua YAN Peigang QIAN Xiaoru HAN Wanjin wang qingchao School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China Harbin Turbine Company Limited Harbin 150046China

In this paper,the composite inner cooling structures of the rotating blade in the first stage heavy gas turbine were modeled and simulated by coupling heat transfer (CHT).The flow characteristics and heat transfer performances were comparatively analyzed under two operations of the stationary and the rotational *** results show that the turbulence intensity,the flow resistance and the heat transfer level of the rotating coolant are significantly increased compared with the stationary state,which is considered to be obtained by the combined effects of the Coriolis force,the centrifugal force and their derived buoyancy *** is pointed out that the rotation leads to the non-uniform flow of film holes at the leading edge of the pressure surface along blade *** addition,it increases the slope of the limiting streamline,which has a decisive influence on the heat transfer of both the pressure and suction *** paper provides guidance for the design of a rotating composite cooling structure based on the relations between the stationary and rotational conditions.

关键词： heavy gas turbine composite cooling structure coupled heat transfer rotation effect simulation

Polysaccharides in Sipunculus nudus: Extraction Condition Optimization and Antioxidant Activities

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Journal of Ocean University of China 2017年第1期16卷 74-80页

作者： ZHANG Qin DONG Lanfang TONG Tong wang qingchao XU Mingzhu Key Laboratory of Marine Biotechnology of Guangxi Guangxi Institute of Oceanology Key Laboratory of Aquaculture Nutrition and Feed (Ministry of Agriculture) & Key Laboratory of Mariculture (Ministry of Education) Ocean University of China

Marine organisms constitute unlimited resource of bioactive substances due to their high biodiversity and represent a valuable source of new compounds. This study optimized the alkali-extraction conditions and antioxidant activities of soluble polysaccharides from the body wall of Sipunculus nudus. The effects of solid-liquid ratio, extraction duration, extraction temperature, and alkali concentration on the yield of S. nudus polysaccharides(SNP) were examined, according to which the optimal combination of extraction parameters was obtained by an orthogonal test. The relative influencing importance of different extraction parameters on the yield of SNP followed the order as solid-liquid ratio > extraction temperature > alkali concentration > extraction duration. The highest extraction yield, 1.98%, was achieved under an optimal extraction condition: temperature 60℃, solid-liquid ratio 1:6 g mL^(-1), duration 5 h, and alkali(Na OH) mass fraction 6%. The in vitro antioxidant activities examination showed that extracted SNP under this optimized condition had strong power in reducing certain hydroxyl and superoxide radical scavenging abilities. The promising results showed that extracted SNP could be a potent natural antioxidant.

关键词： Sipunculus nudus polysaccharide extraction condition antioxidant activities

Direct Lyapunov-based control law design for spacecraft attitude maneuvers

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Progress in Natural Science:Materials International 2006年第11期16卷 1188-1192页

作者： HU Likun** and wang qingchao (School of Astronautics, Harbin Institute of Technology, Harbin 150001, China) School of Astronautics Harbin Institute of Technology Harbin 150001 China

A direct Lyapunov-based control law is presented to perform on-orbit stability for spacecraft attitude maneuvers. Spacecraft attitude kinematic equations and dynamic equations are coupled, nonlinear, multi-input multi-output(MIMO), which baffles controller design. Orbit angular rates are taken into account in kinematic equations and influence of gravity gradient moments and disturbance moments on the spacecraft attitude in dynamic equations is considered to approach the practical environment, which enhance the problem complexity to some extent. Based on attitude tracking errors and angular rates, a Lyapunov function is constructed, through which the stabilizing feedback control law is deduced via Lie derivation of the Lyapunov function. The proposed method can deal with the case that the spacecraft is subjected to mass property variations or centroidal inertia matrix variations due to fuel assumption or flexibility, and disturbance moments, which shows the proposed controller is robust for spacecraft attitude maneuvers. The unlimited controller and the limited controller are taken into account respectively in simulations. Simulation results are demonstrated to validate effectiveness and feasibility of the proposed method.

关键词： spacecraft attitude control direct Lyapunov function nonlinear control Lie derivative.

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基于UART的可靠通信与性能分析

计算机工程 2006年第10期32卷 15-17,21页

作者：胡立坤王庆超哈尔滨工业大学航天学院哈尔滨150001

分析了基于UART总线型拓扑的可靠性连接和单主多从、令牌、多主对等系统的实现方案。从3个方面研究了通信性能,UART的接口与传输线特性决定了系统的最高通信速率;基于UART位串时槽研究了重新校准波特率的最大时间;基本UART的协议相关分... 详细信息

分析了基于UART总线型拓扑的可靠性连接和单主多从、令牌、多主对等系统的实现方案。从3个方面研究了通信性能,UART的接口与传输线特性决定了系统的最高通信速率;基于UART位串时槽研究了重新校准波特率的最大时间;基本UART的协议相关分析表明,衡量通信效果应从协议的效率、传输线的“忙闲”程度、数据理解率和时态特性几个方面分析。

关键词： UART 可靠通信通信性能

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涡轮转子起动温升曲线优化及试验研究

机械工程学报 2016年第2期52卷 189-194页

作者：徐宁王庆超刘占生哈尔滨工业大学能源科学与工程学院哈尔滨150001 中国船舶重工集团公司第703研究所哈尔滨150078

涡轮转子在快速起动的过程中会产生较大的热应力,影响转子的热疲劳寿命。结合遗传算法与转子结构热分析,提出发动机起动温升控制曲线非单调参数化,对涡轮转子快速起动过程中的温升控制曲线进行优化设计。优化过程以转子最大热应力为目... 详细信息

涡轮转子在快速起动的过程中会产生较大的热应力,影响转子的热疲劳寿命。结合遗传算法与转子结构热分析,提出发动机起动温升控制曲线非单调参数化,对涡轮转子快速起动过程中的温升控制曲线进行优化设计。优化过程以转子最大热应力为目标函数,计算搜索最优解,并研究温升控制曲线对转子最大热应力的影响。结果显示,优化后的发动机快速起动温升控制曲线可以有效地降低转子的最大热应力和缩短快速起动时间。同时,为了验证提出的涡轮转子快速起动温升曲线优化设计方法的有效性,搭建转子热冲击应力测试试验台,通过对比优化前后温升曲线下的转子最大热应力,验证了理论分析结果。提出的优化设计方法可以为发动机设计初期的快速起动控制方案设计提供一定借鉴。

关键词：涡轮转子快速起动温升控制曲线热应力优化