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Tracking the maneuvering spacecraft propelled by swing propulsion of constant magnitude

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Journal of Systems Engineering and Electronics 2020年第2期31卷 370-382页

作者： ZHAI Guang WANG Yanxin zhao qi School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Systems Engineering Research Institute Beijing 100094China

This paper proposes partially norm-preserving filtering for a class of spacecraft in the presence of time-varying, but constant-magnitude maneuver. The augmented state Kalman filter(ASKF) is commonly used to track the maneuvering spacecraft with unknown constant propulsion;however, if the maneuver varies via time, the estimation performance will be degraded. To promote the tracking performance of the ASKF in case of time-invariant,constant-magnitude disturbance, the partially norm-preserving ASKF is developed by applying the norm constraint on the unknown maneuver. The proposed estimator, which is decomposed into two partial estimators and iteratively propagated in turns,projects the unconstrained maneuver estimation onto the Euclidian surface spanned by the norm constraint. The illustrative numerical example is provided to show the efficiency of the proposed method.

关键词： maneuvering spacecraft tracking augmented state norm-preserving Kalman filter

Integration of GPS and low cost INS for pedestrian navigation aided by building layout

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Chinese Journal of Aeronautics 2013年第5期26卷 1283-1289页

作者： Feng Wenquan zhao Hongbo zhao qi Li Jingwen School of Electronics and Information Engineering Beihang University

In outdoor environments, GPS is often used for pedestrian navigation by utilizing its signals for position computation, but in indoor or semi-obstructed environments, GPS signals are often unavailable. Therefore, pedestrian navigation for these environments should be realized by the integration of GPS and inertial navigation system （INS）. However, the lowcost INS could induce errors that may result in a large position drift. The problem can be minimized by mounting the sensors on the pedestrian＇s foot, using zero velocity update （ZUPT） method with the standard navigation algorithm to restrict the error growth. However, heading drift still remains despite using ZUPT measurements since the heading error is unobservable. Also, tbot mounted INS suffers from the initialization ambiguity of position and heading from GPS. In this paper, a novel algorithm is developed to mitigate the heading drift problem when using ZUPT. The method uses building lay- out to aid the heading measurement in Kalman filter, and it could also be combined for the initial- ization. The algorithm has been investigated with real field trials using the low cost Microstrain 3DM-GX3-25 inertial sensor, a Leica GS10 GPS receiver and a uBlox EVK-6T GPS receiver. It could be concluded that the proposed method offers a significant improvement in position accuracy for the long period, allowing pedestrian navigation for nearly40 min with mean position error less than 2.8 m. This method also has a considerable effect on the accuracy of the initialization.

关键词： Heading drift Initialization Integrated navigation Pedestrian navigation Satellite navigation Zero velocity update

2,3,7,8-Tetrachlorodibenzo-p-dioxin Promotes Proliferation of Astrocyte Cells via the Akt/STAT3/Cyclin D1 Pathway

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Biomedical and Environmental Sciences 2019年第4期32卷 281-290页

作者： WU Chang Yue YIN kai Zhi ZHANG Yan JIAO Man zhao Xin Yuan WU qi Yun Medical Colledge Nantong University Department of Nutrition and Food Hygiene School of Public HealthNantong University Xishan District Center for Disease Control and Preventive Department of Occupational Medicine and Environmental Toxicology School of Public HealthNantong University

Objective The compound 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD), a persistent organic pollutant, is harmful to the nervous system, but its effects on the brain are still unclear. This study aimed to investigate the effects of TCDD on astrocytes proliferation and underlying molecular mechanism. Methods The cell proliferation was measured by EdU-based proliferation assay and PI staining by flow cytometry. Protein expression levels were detected by Western blotting. Immunofluorescence, cytoplasmic and nuclear fractions separation were used to assess the distribution of signal transducer and activator of transcription 3(STAT3). Results C6 cells treated with 10 and 50 nmol/L TCDD for 24 h showed significant promotion of the proliferation of. The exposure to TCDD resulted in the upregulation in the expression levels of phosphorylated protein kinase B(p-Akt), phosphorylated STAT3, and cyclin D1 in a dose-and time-dependent manner. The inhibition of Akt expression with LY294002 or STAT3 expression with AG490 abolished the TCDD-induced cyclin D1 upregulation and cell proliferation. Furthermore, LY294002 suppressed the activation of STAT3. Finally, TCDD promoted the translocation of STAT3 from the cytoplasm to the nucleus, and LY294002 treatment blocked this effect. Conclusion TCDD exposure promotes the proliferation of astrocyte cells via the Akt/STAT3/cyclin D1 pathway, leading to astrogliosis.

关键词： 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) Akt STAT3 Cyclin D1 Proliferation Astrocytes

A climate-resilient R gene in rice traps two pathogen effectors for broad and durable resistance to bacterial blight

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Molecular Plant 2021年第3期14卷 366-368页

作者： kaijun zhao qi Zhang National Key Facility for Crop Gene Resources and Genetic Improvement Institute of Crop ScienceChinese Academy of Agricultural SciencesBeijing 100081China

The fast-and ever-growing human population and rapid climate change are threatening the global food *** a staple food crop,rice(Oryza sativa)feeds nearly half of the world's ***,bacterial blight(BB),the most devastating bacterial disease of rice(Mew et al.,1993),caused by Xanthomonas oryzae ***(Xoo),affects millions of hectares of cultivated rice plants annually,with an estimated crop loss of as high as 75%.

关键词： sativa blight Oryza

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膝骨关节炎疼痛领域热点与前沿的可视化分析

中国组织工程研究 2025年第15期29卷 3280-3289页

作者：赵盾祁令臣徐金凡邵敏广州中医药大学广东省广州市510000 广州中医药大学顺德医院广东省广州市510000

背景:疼痛是膝骨关节炎的主要症状,严重影响老年患者的生活质量。膝骨关节炎疼痛机制复杂,涉及多组织、多学科,需要可视化分析了解其主要内容与研究热点。目的:运用文献计量学可视化软件分析归纳膝骨关节炎疼痛领域的前沿内容和研究热... 详细信息

背景:疼痛是膝骨关节炎的主要症状,严重影响老年患者的生活质量。膝骨关节炎疼痛机制复杂,涉及多组织、多学科,需要可视化分析了解其主要内容与研究热点。目的:运用文献计量学可视化软件分析归纳膝骨关节炎疼痛领域的前沿内容和研究热点。方法:从Web of Science核心合集(Web of Science Core Collection,WoSCC)中检索2014-2024年膝骨关节炎疼痛领域的相关文献,运用Citespace、VOSviewer和Bibliometrix R-package三个可视化软件进行文献计量与可视化分析。结果与结论:①膝骨关节炎疼痛研究的发文量呈现逐年递增的趋势;②美国、中国、澳大利亚是该领域10年内发文量排名前三的国家;波士顿大学、悉尼大学、弗洛里达大学是发文量前三的科研机构;《OSTEOARTHRITIS AND CARTILAGE》是出版该领域文献最多的期刊,《PAIN》则是该领域被引次数最多的期刊;发文量最多的作者是Fillingim Roger B,该领域的核心作者之间已经建立了一些稳定的团队,但国际性合作尚有欠缺;③膝骨关节炎疼痛患者的日常管理(运动、心理、智能管理)、疼痛的炎症机制、蛋白组学、联合用药、中枢敏化和疼痛调节是膝骨关节炎疼痛研究的重点内容;人工智能辅助、体外冲击波疗法、射频消融术、神经冷冻术、关节腔内注射血液或细胞制剂可能是该领域的研究前沿。

关键词： VOSviewer软件 Citespace软件 Bibliometrix R-package 文献计量学炎症因子体外冲击波疗法疼痛管理神经阻滞蛋白组学

Wet flue gas desulfurization performance of 330 MW coal-fired power unit based on computational fluid dynamics region identification of flow pattern and transfer process

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Chinese Journal of Chemical Engineering 2021年第1期34卷 13-26页

作者： Jiangyuan Qu Nana qi kai Zhang Lifeng Li PengchengWang Beijing Key Laboratory of Emission Surveillance and Control for Thermal Power Generation North China Electric Power UniversityBeijing 102206China Key Laboratory of Power Station Energy Transfer Conversion and System(North China Electric Power University) Ministry of EducationBeijing 102206China Shanxi Hepo Power Generation Company Limited Yangquan 045011China

Wet Flue Gas Desulfurization(WFGD)unit based upon spray scrubber has beenwidely employed to control SO_(2) emissions from flue gas in coal-fired power *** clarify the dependence of desulfurization performance on inter-phase transfer behaviors with non-ideal contacting patterns of flue gas and slurry droplets,three regions in spray scrubber are distinguished in terms of gas-slurry flow structures using CFD method in the Eulerian-Lagrangian framework.A comprehensive model is established by involving the transfer process between two phases and chemical reactions in aqueous phase,which is validatedwith the measured data froma WFGD scrubber of 330 MW coal-fired power *** results show that the overall uniformity degree of flue gas in whole scrubber is largely determined by the force-balanced droplets in the middle part of scrubber,which is dominated by counter-current *** momentum transfer behavior and SO_(2) chemical absorption process present the synchronicity with the evolution of gas-slurry flow pattern,whilst the heat transfer together with H_(2)O evaporation has little effect on overall absorption *** regions are firstly defined as Gas Inlet Region(GIR),Dominant Absorption Region(DAR)and Slurry Dispersed Region(SDR)from the bottom to top of ***_(2) is mainly scrubbed in DAR,which provides much more intensive interaction between two phases compared to GIR or SDR.A better understanding of the desulfurization process is obtained from the fundamental relationship between transport phenomena and chemical reactions based upon the complicated hydrodynamics of gas-slurry two-phase flow,which should be useful for designing and optimizing the scrubber in coal-fired power unit.

关键词： Wet flue gas desulfurization Gas-liquid flow Eulerian-Lagrangian model Flow pattern Transport processes Absorption

Aeroelastic analysis and structural parametric design of composite rotor blade

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Chinese Journal of Aeronautics 2021年第1期34卷 336-349页

作者： Li MA qijun zhao kai ZHANG Xiayang ZHANG Mengmeng zhao National Key Laboratory of Science and Technology on Rotorcraft Aeromechanics Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Based on FEM theory,a method of dynamic analysis for hingeless rotors considering anisotropic composite materials is established.A parametric modeling method of composite blade with typical profile and high simulation degree for design is *** the finite element method,the profile characteristics of rotor blade can be obtained efficiently and accurately,and the synchronization of parametric design and finite element analysis of structural characteristics can be *** a 23-degrees of freedom non-linear beam element is used to simulate the extended one-dimensional beam,thereby a nonlinear differential equation describing the elastic motion of the rotor is *** obtain the crosssectional target characteristics of the blades,an inverse design method is proposed for cross-section components based on combinatorial optimization *** calculation and validation work show that the proposed model can effectively analyze the aeroelastic characteristics of general composite ***,the influence of cross-sectional parameters on the aeroelastic stability and hub loads of hingeless rotor is analyzed and some remarkable conclusions are obtained.

关键词： Aeroelastic stability Composite material Cross-section analysis Hub loads Inverse design Rotor

Protective effect of multi-row HDPE board sand fences:A wind tunnel study

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International Soil and Water Conservation Research 2021年第1期9卷 103-115页

作者： kai Zhang Peiwen zhao Jianchang zhao Xingxin Zhang College of Civil Engineering Lanzhou Jiaotong UniversityLanzhou730000China School of Economics and Management Lanzhou Jiaotong UniversityLanzhou730000China

Recently,sand fences,made of high density polyethylene(HDPE)board,which is resistant against harsh plateau environmental conditions,could possibly be used to control the wind-blown sand along the qinghai section of the Golmud-Korla *** this paper,wind tunnel simulation was performed on the protective effect of multiple rows of HDPE board sand fences on wind-blown *** parameters have been used to reflect the protective effect of sand fences,that is,windproof efficiency and sand control efficiency,referring to the reduction rates of wind speed at a height of 0.04 m and sand flux in a run of test with the fence compared those in the control run of test without it,*** test results showed that when the porosity was 30%,the single-row sand fence had the best wind proof and sand control efficiency with respective values of 46%and 65.3%.The windproof efficiencies of double-row and triple-row sand fences at 20H were 59%and 62%,*** with the windproof effi-ciency of the single-row sand fence,those of the two-row and three-row fences increased by 13%and 16%,respectively:The maximum sand control efficiency of the double-row and triple-row sand fences were 92.1%and 96.5%,increased by 26.8%and 31.2%,respectively,compared with that of the single-row sand *** study indicates that the sand control efficiency after adding one or two rows was not double or triple that of the single-row fence,while the first-row sand fence played a major protective *** with the double-row sand fences,the effect of the third row sand fence in triple-row sand fences is limited,and thus double-row HDPE board sand fences with the porosity of 30%are rec-ommended to control wind-blown sand along the qinghai section of the Golmud-Korla Railway.

关键词： HDPE board sand fences Windproof efficiency Sand control efficiency Reasonable spacing Porosity

Topography of InP Surface Bombarded by O_(2)^(+) Ion Beam

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Chinese Physics Letters 1997年第10期14卷 760-763页

作者： SUN zhao-qi Department of Physics Anhui UniversityHefei 230039

The topography of InP surface bombarded by O_(2)^(+) ion beam was *** topographies were observed for bombarded samples,and the data show that the ripple formation starts from a sputtering depth of about 0.4μ*** wavelength and the disorder of the ripples both increase as the sputtering depth *** wavelength of the ripples appears to be sputtering depth dependent rather than sputtering rate *** is confirmed that the ion-beam-induced surface rippling can be effectively suppressed by sample rotation during bombardment.

关键词： InP beam sputtering