检索结果-南通市图书馆

Novel high-safety aeroengine performance predictive control method based on adaptive tracking weight

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第7期37卷 352-374页

作者： qian CHEN Hanlin SHENG Jie ZHANG Jiacheng LI College of Energy and Power Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Increasing attention has been attracted to the dynamic performance and safety of advanced performance predictive control systems of the next-generation *** latest research demonstrates that Subspace-based Improved Model Predictive Control(SIMPC)can overcome the difficulty in solving the predictive model in MPC/NMPC ***,applying constant design parameters cannot maintain consistent control effects in all ***,the designed system relies too much on sensor-measured data,and thus it is difficult to thoroughly validate the safety of the system because of its high *** means that any potential hardware/software faults will endanger the ***,this paper first presents a novel nonlinear mapping relationship to adaptively tune the tracking weight online with the change of Power Lever Angle(PLA)and real-time relative tracking ***,without introducing additional design parameters,an Adaptive Tracking Weight-based SIMPC(ATW-SIMPC)controller is designed to improve the control performance in all operating states ***,a Primary/Backup Hybrid Control(PBHC)strategy with the ATW-SIMPC controller as the primary system and the traditional speed(Nf)controller as the backup system is proposed to ensure *** designed affiliated switching controller and the real-time monitor therein can be used to realize reasonable and smooth switching between primary/backup systems,so as to avoid bump *** PBHC system switches to the Nf controller when the ATW-SIMPC controller is wrong because of potential hardware/software faults;otherwise,the ATW-SIMPC controller keeps acting on the *** main results prove that the ATW-SIMPC controller with the optimal nonlinear mapping relationship,compared with the existing SIMPC controller,uplifts the dynamic control performance by 32%and reduces overshoots to an allowable limit,resulting in a better control effect in full *** comparison results consistently i

关键词： Aeroengine Model predictive control Hybrid system Adaptive weight Safety

Associations between residence and cognitive function among Chinese older adults: the mediating role of leisure activity

在线全文

学校读者我要写书评

暂无评论

Medical Data Mining 2024年第3期7卷 46-52页

作者： Xiao-Dong Leng Wen-Ping Zeng Mao-rui qian School of Public Health Chongqing Medical UniversityChongqing 401331China

Background:Cognitive function is a current research hotspot,residence may be related to differences in cognitive function,and the mediating role of leisure activities are limited in Chinese *** study used leisure activities as a mediating variable to investigate the mediating role of leisure activity between place of residence(city-town-rural)and cognitive function among Chinese older,this is where the innovation of the article comes ***:Using cross-sectional data from the 2018 Chinese Longitudinal Healthy Longevity Survey,Pearson correlation analyses were employed to examine the relationships among various *** analyses were conducted using the SPSS PROCESS macro program,version 3.5,written by Hayes,to explore the mediating effects of leisure activity between place of residence and cognitive function in older ***:A total of 10955 older adults were included in this study,with a mean age of(84.23±11.57)*** them,2739(24.8%)lived in the city,3627(33.1%)in town,and 4615(42.1%)in rural areas;their leisure activity score was(5.34±3.77),and their cognitive function score was(24.69±6.65).Place of residence,leisure activities,and cognitive function were significantly correlated(P<0.01).Using city as a reference,place of residence is negatively associated with cognitive function,and place of residence not only had a direct effect on cognitive function in older adults:town-cognitive function(effect=–0.399;95%confidence interval(CI)=(–0.685,–0.113));rural-cognitive function(effect=–0.42;95%CI=(–0.698,–0.141)).There were also indirect effects on cognitive function through the pathway of leisure activity:town-leisure activity-cognitive function(effect=–0.17;95%CI=(–0.246,–0.1)),rural-leisure activity-cognitive function(effect=–0.199;95%CI=(–0.272,–0.13)).Conclusion:Leisure activities play a partially mediating role between the impact of place of residence and cognitive function in Chinese older adults,and it is vital to pay atte

关键词： residence leisure activity cognitive function intermediary role older adults

Microstructure features induced by fatigue crack initiation up to very-high-cycle regime for an additively manufactured aluminium alloy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第6期173卷 247-260页

作者： Xiangnan Pan Leiming Du Guian qian Youshi Hong State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China

Fatigue failure can still occur beyond 107 cycles,***-high-cycle fatigue(VHCF),in many metallic materials,such as aluminium alloys and high-strength *** VHCF of high-strength steels,a fine granular area(FGA)surrounding an inclusion is commonly identified as the characteristic region of crack initiation on the fracture ***,no such FGA feature and related crack initiation behaviour were observed in VHCF of conventionally cast or wrought aluminium ***,we first reported the distinct mechanisms of crack initiation and early growth,namely the microstructure feature and the role of FGA in VHCF performance for an additively manufactured(AM)AlSi10Mg *** AM pores play a key role in fatigue crack initiation similar to that of the inclusions in high-strength steels,resulting in almost identical FGA behaviour for different materials under a range of mean stress with a stress ratio at R*** profile microstructure of FGA is identified as a nanograin layer with Si rearrangement and grain boundary *** process consumes a large amount of cyclic plastic energy making FGA undertake a vast majority of VHCF *** results will deepen the understanding of VHCF nature and shed light on crack initiation mechanism of other aluminium and AM alloys.

关键词： Aluminium alloy Additive manufacturing Nanograins Very-high-cycle fatigue(VHCF) Crack initiation Mean stress

Direct Conversion of Methane to Propylene

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research 2024年第2期2023卷 463-472页

作者： Yunpeng Hou Yuxiang Lan Chao qian Shaodong Zhou College of Chemical and Biological Engineering Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture TechnologyZhejiang University310027 HangzhouP.R.China Zhejiang Provincial Innovation Center of Advanced Chemicals Technology Institute of Zhejiang University-Quzhou324000 QuzhouP.R.China

Nonoxidative coupling of methane exhibits promising prospect in that it affords value-added hydrocarbons and hydrogen with high atom ***,challenge remains in direct,selective conversion of methane to more valuable hydrocarbons like *** current work presents a catalyst with well-dispersed Ta atoms anchored by graphitic C_(3)N_(4)-supported *** a catalyst is able to convert methane selectively to ethylene and propylene at a relatively low temperature(350℃).The conception of the active center and construction of the catalyst have been described,and the origins of the catalytic performance are discussed.

关键词： methane catalyst hydrocarbons

Guaranteed Cost Attitude Tracking Control for Uncertain Quadrotor Unmanned Aerial Vehicle Under Safety Constraints

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1447-1457页

作者： qian Ma Peng Jin Frank L.Lewis School of Automation Nanjing University of Science and TechnologyNanjing 210094China UTA Research Institute University of Texas at ArlingtonFort WorthTexas 76118 USA IEEE

In this paper,guaranteed cost attitude tracking con-trol for uncertain quadrotor unmanned aerial vehicle(QUAV)under safety constraints is ***,an augmented system is constructed by the tracking error system and reference *** transformation aims to convert the tracking control prob-lem into a stabilization control ***,control barrier function and disturbance attenuation function are designed to characterize the violations of safety constraints and tolerance of uncertain disturbances,and they are incorporated into the reward function as penalty *** on the modified reward function,the problem is simplified as the optimal regulation problem of the nominal augmented system,and a new Hamilton-Jacobi-Bellman equation is ***,critic-only rein-forcement learning algorithm with a concurrent learning tech-nique is employed to solve the Hamilton-Jacobi-Bellman equa-tion and obtain the optimal *** proposed algorithm can not only ensure the reward function within an upper bound in the presence of uncertain disturbances,but also enforce safety *** performance of the algorithm is evaluated by the numerical simulation.

关键词： Attitude tracking control quadrotor unmanned aerial vehicle(QUAV) reinforcement learning safety constraints uncertain disturbances.

Probabilistic seismic inversion based on physics-guided deep mixture density network

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第3期21卷 1611-1631页

作者： qian-Hao Sun Zhao-Yun Zong Xin Li National Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao266580ShandongChina Laoshan Laboratory Qingdao266580ShandongChina CNOOC Research Institute Ltd. Beijing100028China

Deterministic inversion based on deep learning has been widely utilized in model parameters *** by logging data,seismic data,wavelet and modeling operator,deterministic inversion based on deep learning can establish nonlinear relationships between seismic data and model ***,seismic data lacks low-frequency and contains noise,which increases the non-uniqueness of the *** conventional inversion method based on deep learning can only establish the deterministic relationship between seismic data and parameters,and cannot quantify the uncertainty of *** order to quickly quantify the uncertainty,a physics-guided deep mixture density network(PG-DMDN)is established by combining the mixture density network(MDN)with the deep neural network(DNN).Compared with Bayesian neural network(BNN)and network dropout,PG-DMDN has lower computing cost and shorter training time.A low-frequency model is introduced in the training process of the network to help the network learn the nonlinear relationship between narrowband seismic data and low-frequency *** addition,the block constraints are added to the PG-DMDN framework to improve the horizontal continuity of the inversion *** illustrate the benefits of proposed method,the PG-DMDN is compared with existing semi-supervised inversion *** synthetic data examples of Marmousi II model are utilized to quantify the influence of forward modeling part,low-frequency model,noise and the pseudo-wells number on inversion results,and prove the feasibility and stability of the proposed *** addition,the robustness and generality of the proposed method are verified by the field seismic data.

关键词： Deep learning Probabilistic inversion Physics-guided Deep mixture density network

Preparation of K-doped g-C_(3)N_(4) composite loaded on magnetic attapulgite and its degradation performance for malachite green

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第7期71卷 110-121页

作者： Aishun Ma Hanlin qian Hongxia Liu Sili Ren Jiangxi Key Laboratory of Mining&Metallurgy Environmental Pollution Control Jiangxi University of Science and TechnologyGanzhou 341000China Jiangxi Provincial Key Laboratory of Low-Carbon Processing and Utilization of Strategic Metal Mineral Resources Jiangxi University of Science and TechnologyGanzhou 341000China

Visible-light-driven photocatalysis is a promising technology for the treatment of dye *** this work,a novel photocatalyst of K-doped g-C_(3)N_(4) loaded on magnetic attapulgite(ATP)(Kω-g-C_(3)N_(4)@ATP-Fe_(3)O_(4))with excellent visible light photocatalytic properties and stability were successfully prepared and *** removal efficiency of Kω-g-C_(3)N_(4)@ATP-Fe_(3)O_(4) for malachite green(MG)was studied,and the degradation mechanism was analyzed and *** was found that the K_(5)-g-C_(3)N_(4)@ATP-Fe_(3)O_(4) photocatalyst possessed excellent degradation efficiency of over 98.0%for the MG dye wastewater under optimal ***,the K_(5)-g-C_(3)N_(4)@ATP-Fe_(3)O_(4) materials possessed good recyclability with a removal rate over 82%after 4 *** visible light condition,the K_(5)-g-C_(3)N_(4)@ATP-Fe_(3)O_(4) photocatalyst produce radicals of·OH and O_(2)^(-)to degrade the MG dyes,which was supported by electron paramagnetic resonance(EPR)and radical trapping *** addition,the LC-MS analysis interpreted the degradation pathways and intermediates of MG in the *** findings in this work indicate that the prepared photocatalytic material has excellent degradation efficiency for MG and can be applied in dye wastewater treatment.

关键词： Photocatalyst Malachite green K-doped g-C_(3)N_(4) Degradation

Rice AGL1 determines grain size and sterile lemma identity

在线全文

学校读者我要写书评

暂无评论

The Crop Journal 2024年第2期12卷 630-634页

作者： Haiping Yu An Wang Guangheng Zhang Guojun Dong Longbiao Guo qian qian Deyong Ren State Key Laboratory of Rice Biology and Breeding China National Rice Research InstituteHangzhou 310006ZhejiangChina Hainan Yazhou Bay Seed Laboratory Sanya 572024HainanChina National Nanfan Research Institute(Sanya) Chinese Academy of Agricultural SciencesSanya 572024HainanChina

The grass spikelet is a unique inflorescence structure that determines grain *** many genetic factors have been well characterized for grain size and glume development,the underlying molecular mechanisms in rice are far from ***,we isolated rice gene,AGL1 that controlled grain size and determines the fate of the sterile *** of function of AGL1 produced larger grains and reduced the size of the sterile *** grains in the agl1 mutant were caused by a larger number of cells that were longer and wider than in the wild *** sterile lemma in the mutant spikelet was converted to a rudimentary glume-like *** findings showed that the AGL1(also named LAX1)protein positively regulated G1 expression,and negatively regulated NSG1 expression,thereby affecting the fate of the sterile *** together,our results revealed that AGL1 played a key role in negative regulation of grain size by controlling cell proliferation and expansion,and supported the opinion that rudimentary glume and sterile lemma in rice are homologous organs.

关键词： Abnormal grain and sterile lemma 1 Oryza sativa Grain size Rudimentary glume

Calculus bovis inhibits M2 tumor-associated macrophage polarization via Wnt/β-catenin pathway modulation to suppress liver cancer

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2024年第29期30卷 3511-3533页

作者： Zhen Huang Fan-Ying Meng Lin-Zhu Lu qian-qian Guo Chang-Jun Lv Nian-Hua Tan Zhe Deng Jun-Yi Chen Zi-Shu Zhang Bo Zou Hong-Ping Long Qing Zhou Sha Tian Si mei Xue-Fei Tian College of Integrated Chinese and Western Medicine Hunan University of Chinese MedicineChangsha 410208Hunan ProvinceChina Hunan Key Laboratory of Translational Research in Formulas and Zheng of Traditional Chinese Medicine Hunan University of Chinese MedicineChangsha 410208Hunan ProvinceChina Key Laboratory of Traditional Chinese Medicine for Mechanism of Tumor Prevention and Treatment Hunan University of Chinese MedicineChangsha 410208Hunan ProvinceChina The First Clinical College of Traditional Chinese Medicine Hunan University of Traditional Chinese MedicineChangsha 410007Hunan ProvinceChina Department of Hepatology Hunan University of Chinese MedicineChangsha 410007Hunan ProvinceChina The First Hospital of Hunan University of Chinese Medicine Hunan University of Chinese MedicineChangsha 410007Hunan ProvinceChina Faculty of Medicine Hunan University of Chinese MedicineChangsha 410208Hunan ProvinceChina

BACKGROUND Calculus bovis(CB),used in traditional Chinese medicine,exhibits anti-tumor effects in various cancer *** also constitutes an integral component of a compound formulation known as Pien Tze Huang,which is indicated for the treatment of liver ***,its impact on the liver cancer tumor microenvironment,particularly on tumor-associated macrophages(TAMs),is not well *** To elucidate the anti-liver cancer effect of CB by inhibiting M2-TAM polarization via Wnt/β-catenin pathway *** This study identified the active components of CB using UPLC-Q-TOF-MS,evaluated its anti-neoplastic effects in a nude mouse model,and elucidated the underlying mechanisms via network pharmacology,transcriptomics,and molecular *** vitro assays were used to investigate the effects of CB-containing serum on HepG2 cells and M2-TAMs,and Wnt pathway modulation was validated by real-time reverse transcriptase-polymerase chain reaction and Western blot *** This study identified 22 active components in CB,11 of which were detected in the *** investigations have demonstrated the ability of CB to effectively inhibit liver tumor *** integrated approach employing network pharmacology,transcriptomics,and molecular docking implicated the Wnt signaling pathway as a target of the antineoplastic activity of CB by suppressing M2-TAM *** vitro and in vivo experiments further confirmed that CB significantly hinders M2-TAM polarization and suppresses Wnt/β-catenin pathway *** inhibitory effect of CB on M2-TAMs was reversed when treated with the Wnt agonist SKL2001,confirming its pathway *** This study demonstrated that CB mediates inhibition of M2-TAM polarization through the Wnt/β-catenin pathway,contributing to the suppression of liver cancer growth.

关键词： Calculus bovis M2 tumor-associated macrophage polarization Liver cancer Wnt/β-catenin pathway Tumor microenvironment