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Reliability analysis of torpedo loading based on fractional-order optimization model

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Journal of Systems Engineering and Electronics 2023年第3期34卷 798-803页

作者： Yang Cheng LIANG Qingwei HAO Xinyu LIN Sheng College of Marine Northwest Polytechnic UniversityXi’an 710072China

A fractional-order cumulative optimization GM(1,2)model based on grey theory is proposed to study the relationship between torpedo loading and working reliabilities.In this model,the average relative error function related to order and background value is established.Taking the average relative error function as the objective function,the optimal value of the two parameters is obtained through the optimization method,and the minimum value of the average relative error is determined.The calculation example shows that this method can greatly improve the accuracy of the model and more accurately reflect the relationship between torpedo loading and working reliabilities compared with the traditional GM(1,2)model.

关键词： torpedo loading reliability working reliability grey theory fractional-order

Heading rate controller for unmanned helicopters based on modified ADRC

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Science China(Technological Sciences) 2023年第5期66卷 1255-1262页

作者： CHEN cheng yang HuiXin College of Aerospace Engineering Shenyang Aerospace UniversityShenyang 110136China

A modified heading rate active disturbance rejection controller(ADRC)for miniature unmanned helicopters is presented to improve the transient performance and adaptability of working conditions.First,a tail-locking mathematical model is introduced,and the amplification factor is defined.Second,a standard ADRC controller is presented.Because the amplification factor plays an important role in both parts of the content and is primarily influenced by the main rotor speed,an online forgetting factor recursive least square algorithm is used to identify it,and the identification result is condensed into a function of the main rotor speed,adapting to various working conditions.This function is also included in the proposed ADRC controller to supplement the standard scheme.Finally,experiments were conducted on a small electric helicopter.A reduction of approximately 40%in the transient time(compared with an off-the-shelf PID controller)was achieved in the experiment.The comparative results show that the proposed ADRC scheme outperforms the classic PID and standard ADRC schemes in terms of transient performance and adaptability to working conditions.

关键词： heading rate controller ADRC model identification forgetting factor

Influence of Wellbore Trajectory on Pressure Drop and Fluid Discharge

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Fluid Dynamics & Materials Processing 2023年第8期19卷 2053-2066页

作者： Ruidong Wu Guowei Wang Zhixing yang Ruiquan Liao Yang Cheng Shanghai Branch of CNOOC(China)Co. Ltd.Shanghai200335 CNPC Key Laboratory of Oil and Gas Productions on yangtze University Jingzhou434023China Petrochina Multiphase Flow Laboratory of Gas Lift Innovation Center Wuhan430100China Petroleum Engineering College of yangtze University Wuhan430100China

An experimental analysis has been conducted to study the process of fluid accumulation for different borehole trajectories.More specifically,five heel angles have been experimentally realized to simulate the borehole trajectory of the sloping section of the formation.The fluid-carrying capacity,pressure drop and fluid discharge volatility have been investigated for these conditions and,accordingly,the relationship between heel angle and wellbore pressure drop fluid-carrying capacity has been determined.The results show that while the reasonable roll angle can increase the pressure loss in the wellbore,it is beneficial to drainage.In terms of pressure loss and liquid-carrying capacity,when the heeling angle is 50°,the latter is increased while the former becomes very high,which indicates that when drilling and completing wells on site,a 50°roll angle should be avoided.It is found that the main reason for the increase of the total pressure drop in the wellbore is the increase of the local pressure loss in the inclined section.From the perspective of drainage stability,when there is heeling in the inclined section of the horizontal well,the fluctuation of the wellbore drainage tends to be enhanced.Through the comparison of the Beggs-Brill(B-B)and Mukherjee-Brill liquid holdup methods,it is found that B-B method better predicts liquid holdup.A new method for calculating the pressure drop in the inclined section in the presence of lateral inclination is obtained by taking into account the pressure drop in the curved section.Through comparison with experimental data,it is found that the error is within 20%,and the prediction accuracy is high.

关键词： Horizontal well slant section heel angle pressure drop drainage quantity

China's unique role in the field of global health

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Global Health Journal 2019年第4期3卷 98-101页

作者： Yang Cheng Feng cheng Laboratory of pathogen Infection and Immunity Department of Public Health and Preventive MedicineWuxi School of MedicineJiangnan UniversityWuxi 214122China Research Center for Public Health School of MedicineTsinghua UniversityBejing 100084China

China's participation in global governance,inspired by the 17 United Nations Sustainable Development Goals,is driven by the guiding principle of"Building a Community of Shared Future for Mankind".China has been promoting the Belt and Road Initiative and South-South Cooperation and has made significant contributions to the prosperity of human beings.Along with the opportunities that globalization brought about such as the World Health Organization and the boom in the economy,global health challenges also emerged.This resulted in certain obstacles for China when it sought to advocate the Belt and Road Initiative and when it attempted to carry out its strategy to address global health issues.What are the emerging challenges for global health?What can China do for global health?Why does global health need China?We tried to address these questions as China's global engagement continues to expand in the new era.This article makes the case for Chinese approaches,including getting involved in public health,being consistent in addressing local conditions,and sharing China's experience with handling health services and staying in the lead through government action while being guided by relative policies.China has a lot to offer in the promotion of global health and in overcoming the challenges and risks that this goal currently faces.Thus,China should be considered an inseparable part of global health governance and bilateral health development cooperation.

关键词： China Global health Africa Proposal Asia

Recent progress in functional modification and crosslinking of bioprosthetic heart valves

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Regenerative Biomaterials 2024年第1期3卷 1-16页

作者： cheng Zheng Li yang Yunbing Wang National Engineering Research Center for Biomaterials Sichuan UniversityChengdu 610064China

Valvular heart disease(VHD),clinically manifested as stenosis and regurgitation of native heart valve,is one of the most prevalent cardiovascular diseases with high mortality.Heart valve replacement surgery has been recognized as golden standard for the treatment of VHD.Owing to the clinical application of transcatheter heart valve replacement technic and the excellent hemodynamic performance of bioprosthetic heart valves(BHVs),implantation of BHVs has been increasing over recent years and gradually became the preferred choice for the treatment of VHD.However,BHVs might fail within 10-15 years due to structural valvular degeneration(SVD),which was greatly associated with drawbacks of glutaraldehyde crosslinked BHVs,including cytotoxicity,calcification,component degradation,mechanical failure,thrombosis and immune response.To prolong the service life of BHVs,much effort has been devoted to overcoming the drawbacks of BHVs and reducing the risk of SVD.In this review,we summarized and analyzed the research and progress on:(i)modification strategies based on glutaraldehyde crosslinked BHVs and(ii)nonglutaraldehyde crosslinking strategies for BHVs.

关键词： bioprosthetic heart valves modification crosslinking anticalcification antithrombosis

Deflagration and detonation induced by shock wave focusing at different Mach numbers

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Chinese Journal of Aeronautics 2024年第2期37卷 249-258页

作者： Zezhong yang Jun cheng Bo ZHANG School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200240China

Shock wave focusing is an effective way to create a hot spot or a high-pressure and hightemperature region at a certain place,showing its unique usage in detonation initiation,which is beneficial for the development of detonation-based engines.The flame propagation behavior after the autoignition induced by shock wave focusing is crucial to the formation and self-sustaining of the detonation wave.In this study,wedge reflectors with two different angles(60°and 90°)and a planar reflector are employed,and the Mach number of incident shock waves ranging from 2.0 to 2.8 is utilized to trigger different flame propagation modes.Dynamic pressure transducers and the high-speed schlieren imaging system are both employed to investigate the shock-shock collision and ignition procedure.The results reveal a total of four flame propagation modes:deflagration,DDT(Deflagration-to-Detonation Transition),unsteady detonation,and direct detonation.The detonation wave formed in the DDT and unsteady detonation mode is only approximately 75%-85%of the Chapman-Jouguet(C-J)speed;meanwhile,the directly induced detonation wave speed is close to the C-J speed.Transverse waves,which are strong evidence for the existence of detonation waves,are discovered in experiments.The usage of wedge reflectors significantly reduces the initial pressure difference ratio needed for direct detonation ignition.We also provide a practical method for differentiating between detonation and deflagration modes,which involves contrasting the speed of the reflected shock wave with the speed of the theoretically nonreactive reflected shock wave.These findings should serve as a reference for the detonation initiation technique in advanced detonation propulsion engines.

关键词： Deflagration Detonation Hydrogen Ignition Shock wave focusing

The ferroptosis activity is associated with neurological recovery following chronic compressive spinal cord injury

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Neural Regeneration Research 2023年第11期18卷 2482-2488页

作者： Zhengran Yu Xing cheng Wenxu Pan cheng Yu yang Duan Department of Spine Surgery Orthopedics Center of Guangdong Provincial People’s Hospital(Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhouGuangdong ProvinceChina Department of Spine Surgery The First Affiliated HospitalSun Yat-sen UniversityGuangzhouGuangdong ProvinceChina Department of Gastroenterology Guangzhou Women and Children’s Medical CenterJinan UniversityGuangzhouGuangdong ProvinceChina Department of Spine Surgery Zhujiang HospitalSouthern Medical UniversityGuangzhouGuangdong ProvinceChina

Chronic compressive spinal cord injury in compressive cervical myelopathy conditions can lead to rapid neurological deterioration in the early phase,followed by partial self-recovery,and ultimately an equilibrium state of neurological dysfunction.Ferroptosis is a crucial pathological process in many neurodegenerative diseases;however,its role in chro nic compressive spinal cord injury remains unclear.In this study,we established a chronic compressive spinal cord injury rat model,which displayed its most severe behavioral and electrophysiological dysfunction at 4 wee ks and partial recovery at 8 weeks after compression.Bulk RNA sequencing data identified enriched functional pathways,including ferroptosis,presynapse,and postsynaptic membrane activity at both 4 and 8 wee ks following chro nic compressive spinal co rd injury.Tra nsmission electron microscopy and malondialdehyde quantification assay confirmed that ferroptosis activity peaked at 4 weeks and was attenuated at 8 weeks after chronic compression.Ferro ptosis activity was negatively correlated with behavioral score.Immunofluorescence,quantitative polymerase chain reaction,and western blotting showed that expression of the anti-ferroptosis molecules,glutathione peroxidase 4(GPX4) and MAF BZIP transcription factor G(MafG),in neuro ns was suppressed at 4 weeks and upregulated at 8 weeks following spinal co rd compression.There was a positive correlation between the expression of these two molecules,suggesting that they may work together to contribute to functional recovery following chronic compressive spinal cord injury.In conclusion,our study determined the genome-wide expression profile and fe rroptosis activity of a consistently compressed spinal cord at different time points.The results showed that anti-fe rroptosis genes,specifically GPX4 and MafG,may be involved in spontaneous neurological recovery at 8 weeks of chronic compressive spinal cord injury.These findings contribute to a better understanding of the mechanisms underlying chronic compressive spi

关键词： chronic spinal cord compression compressive cervical myelopathy ferroptosis genome-wide transcriptome glutathione peroxidase 4(GPX4) MAF BZIP transcription factor G(MafG) neurological function

Analysis of multi-objective optimisation method for main insulation structure configuration scheme of valve-side winding of ultra-high voltage converter transformer considering multi-field coupling

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High Voltage 2024年第2期9卷 296-308页

作者： Lijun yang Zhidong cheng Li cheng Ruijin Liao State Key Laboratory of Power Transmission Equipment Technology School of Electrical EngineeringChongqing UniversityChongqingChina

Because DC conductivities of oil-paper materials can be easily affected by electric field and temperature,the electrical properties under electro-thermal coupling of oil-paper materials should be considered when optimising the insulation structure of valve-side winding of the converter transformer.Based on the finite element multi-physical field coupling simulation,the multi-objective optimisation of main insulation structure of valve-side winding is carried out.In view of the high time consuming of multi-physical field calculation and the actual needs of an insulation structure optimisation,the Kriging method and technique for order preference by similarity to the ideal solution(TOPSIS)method are introduced,and combines them with NSGA-II to obtain a joint algorithm that can be used for the optimisation of insulation structure of the converter transformer.By using the joint algorithm of multi-objective optimisation,the insulation structure configuration scheme of valve-side winding is optimised.It can be seen from the experiment result that,on the one hand,the joint algorithm adopted can obtain the insulation structure configuration scheme that meets the design requirements.On the other hand,when facing the configuration scheme optimisation under multi-field coupling,the computational time required by this method is only 0.15%of that required by original genetic algorithm.

关键词： converter insulation coupling

Uncovering the miRNA-mediated regulatory network involved in Ma bamboo(Dendrocalamus latiflorus)de novo shoot organogenesis

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Horticulture Research 2023年第12期10卷 1-13页

作者： Nannan Wang Wenjia Wang Yang Cheng Changyang Cai Qiang Zhu Basic Forestry and Proteomics Center(BFPC) College of ForestryHaiXia Institute for Science and TechnologyFujian Agriculture and Forestry UniversityFuzhou 350002China

Bamboo is an important non-timber forest product and is well-known for its reluctance to regenerate.Recently we have established a de novo shoot organogenesis(DNSO)protocol in Ma bamboo(Dendrocalamus latiflorus)and revealed the transcriptomic dynamics during Ma bamboo regeneration,which suggested the potential roles of Ma bamboo microRNAs(DlamiRNAs)in this process.However,how DlamiRNAs regulate bamboo DNSO is poorly understood.Here we performed integrated analysis with sRNAome,degradome,and transcriptome sequencing by using samples covering the four stages of the bamboo DNSO process.A total of 727 DlamiRNAs showed differential expression during the bamboo DNSO process,and the core DlamiRNA-DlamRNA-mediated regulatory networks for bamboo DNSO were constructed.Based on the results,DlamiR156 was selected for further functional characterization of its potential roles in bamboo DNSO.Transgenic bamboos with increased DlamiR156 levels exhibited an enhancement in their regeneration efficiency.Conversely,when DlamiR156 levels were downregulated,the regeneration efficiencies of transgenic bamboos decreased.Our findings show that the DlamiRNA-mediated regulatory pathways are significant in the process of bamboo regeneration and will contribute to our understanding of the molecular mechanisms governing plant organogenesis in a more comprehensive manner.

关键词： bamboo Bamboo covering