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Science China Chemistry 2021年第5期64卷 761-769页

作者： jia-le xie Zheng Xu Han-Qi Zhou Yi-Xue Nie jian Cao Guan-Wu Yin Jean-Philippe Bouillon Li-Wen Xu Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education Key Laboratory of Organosilicon Material Technology of Zhejiang ProvinceHangzhou Normal UniversityHangzhou 311121China State Key Laboratory for Oxo Synthesis and Selective Oxidation Suzhou Research Institute(SRI)Lanzhou Institute of Chemical Physics(LICP)University of the Chinese Academy of Sciences(UCAS)Lanzhou 730000China Normandie University INSA RouenUNIROUENCNRSCOBRA(UMR 6014)Rouen 76000France

Hydrosilylation is one of the most important reactions in synthetic chemistry and ranks as a fundamental method to access organosilicon compounds in industrial and academic ***,the enantioselective construction of chiral-at-silicon compounds via catalytic asymmetric hydrosilylation remained limited and *** we report a highly enantioselective hydrosilylation of ynones,a type of carbonyl-activated alkynes,using a palladium catalyst with a chiral binaphthyl phosphoramidite *** stereospecific hydrosilylation of ynones affords a series of silicon-stereogenic silylenones with up to 94%yield,>20:1 regioselectivity and 98:2 *** density functional theory(DFT)calculations were conducted to elucidate the reaction mechanism and origin of high degree of stereoselectivity,in which the powerful potential of aromatic interaction in this reaction is highlighted by the multiple C–H-πinteraction and aromatic cavity-oriented enantioselectivitydetermining step during desymmetric functionalization of Si–H bond.

关键词： asymmetric catalysis DFT calculations hydrosilylation silicon-stereogenic vinylsilanes aromatic interaction

Common mechanism of Citrus Grandis Exocarpium in treatment of chronic obstructive pulmonary disease and lung cancer

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Chinese Herbal Medicines 2021年第4期13卷 525-533页

作者： Wei Zhou Min Dong Hao Wu Hui-lin Li jia-le xie Ru-yun Ma Wei-wei Su jian-ye Dai School of Pharmacy Lanzhou UniversityLanzhou 730000China Department of Pulmonology Gansu Provincial Hospital of Traditional Chinese MedicineLanzhou 730000China Guangdong Engineering and Technology Research Center for Quality and Efficacy Re-evaluation of Post-marketed TCM Guangdong Key Laboratory of Plant ResourcesSchool of Life SciencesSun Yat-sen UniversityGuangzhou 510275China

Objective:"Same treatment for different diseases"is a unique treatment strategy in traditional Chinese *** kinds of malignant respiratory diseases endanger human health-chronic obstructive pulmonary disease(COPD)and lung *** Grandis Exocarpium(Huajuhong in Chinese,HJH),a famous herbal,is always applied by Chinese medicine practitioners to dispersion the lung to resolve phlegm based on"syndrome differentiation and treatment"***,the common mechanism for HJH’s treatment of COPD and lung cancer is not ***:In this study,based on network pharmacology and molecular docking technology,the common mechanism of HJH in the treatment of COPD and lung cancer was *** active ingredients and related targets of HJH were integrated from TCMSP,BATMAN-TAM,STP,and Pubchem *** standard names of these targets were united by Uni Prot *** of COPD and lung cancer were enriched through Gene Cards,NCBI(Gene),Therapeutic Target Database,and Dis Ge NET(v7.0)*** the intersection targets of HJH and diseases were *** STRING network and the Cytoscape 3.7.2 were used to construct PPI network,the DAVID database was used to perform GO and KEGG *** Cytoscape 3.6.1 was used to build"ingredient-target-signal pathway"***,Auto Dock 1.5.6 software was used to perform molecular docking of key proteins and ***:Eleven active ingredients in HJH were obtained by searching the database,corresponding to 184 HJH-COPD-lung cancer targets *** results of biological network analysis showed that naringenin,the active component in HJH,could mainly act on target proteins such as AKT1,*** through positive regulation of vasoconstriction and other biological processes,naringenin could regulate estrogen signaling pathway,VEGF signaling pathway,HIF-1 signaling pathway,Erb B signaling pathway,PI3K-Akt signaling pathway to play an important role in the treatment of both COPD and lung can

关键词： chronic obstructive pulmonary disease Citrus Grandis Exocarpium lung cancer mechanism molecular docking network pharmacology same treatment for different diseases

Understanding Surface Water-Groundwater Conversion Relationship and Associated Hydrogeochemistry Evolution in the Upper Reaches of Luan River Basin, North China

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Journal of Earth Science 2024年第3期35卷 1010-1023页

作者： le Zhao Chunli Su Wenbo Liu Xianjun xie School of Environmental Studies China University of GeosciencesWuhan 430078China State Environmental Protection Key Laboratory of Source Apportionment and Control of Aquatic Pollution Ministry of Ecology and EnvironmentWuhan 430078China China Geological Environmental Monitoring Institute Beijing 100081China

Luan River is the main water source in Beijing-Tianjin-Hebei region,northern China,where the groundwater system is vulnerable and pollution issue is *** is significant for regional groundwater resources protection to identify the hydrogeochemistry evolution and affecting factors along flow direction occurred in the upper reaches,especially the surface water-groundwater(SWGW)conversion *** this study,recharge,conversion and geochemistry evolution of SW and GW were elucidated based on physical-hydrochemical indicators and stable isotopes in 36 GW samples and 20 SW samples,which were collected in July 2019 and July *** factor analysis was further utilized to determine the main factors responsible for regional hydrogeochemical *** indicate that GW recharged SW in plateau area,and SW and GW recharged each other in typical Alpine valley *** hydrochemical types are HCO3-Ca·Mg and HCO3-Ca,and the hydrochemical evolution is dominated by weathering of silicate and carbonate *** cation exchange adsorption has minor impact on groundwater *** rise of SO42-and NO3-contents in groundwater is related to industrial and agricultural *** main controlling factors of SW hydrochemical components included recharge from groundwater,industrial and mining activities,explaining 90.04%of data ***,water-rock interaction,agricultural and domestic sewage are responsible for GW quality,accounting for 83.38%.

关键词： groundwater water sources conversion relationship hydrogeochemical characteristics evolutional processes water-rock interaction factor analysis Luan River Basin.

A condition-based maintenance policy for reconfigurable multi-device systems

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Advances in Manufacturing 2024年第2期12卷 252-269页

作者： Shu-Lian xie Feng Xue Wei-Min Zhang jia-Wei Zhu School of Mechanical Engineering Tongji UniversityShanghai201804People’s Republic of China

The exploration of component states for optimizing maintenance schedules in complex systems has garnered significant interest from ***,current literature usually overlooks the critical aspects of system flexibility and *** implementation of system reconfiguration can effectively mitigate system downtime and enhance production *** study proposes a dynamic condition-based maintenance policy considering reconfiguration for reconfigurable systems.A double-layer decision rule was constructed for the devices and *** achieve the best overall maintenance effect of the system,the remaining useful life probability distribution and recommended maintenance time of each device were used to optimize the concurrent maintenance time window of the devices and determine whether to reconfigure them.A comprehensive maintenance efficiency index was introduced that simultaneously considered the maintenance cost rate,reliability,and availability of the system to characterize the overall maintenance *** reconfiguration cost was included in the maintenance *** proposed policy was tested through numerical experiments and compared with different-level *** results show that the proposed policy can significantly reduce the downtime and maintenance costs and improve the overall system reliability and availability.

关键词： Condition-based maintenance(CBM) Reconfigurable system Remaining useful life Maintenance cost System reliability

Adaptive detection of range-spread targets in homogeneous and partially homogeneous clutter plus subspace interference

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Journal of Systems Engineering and Electronics 2024年第1期35卷 43-54页

作者： jiaN Tao HE jia WANG Bencai LIU Yu XU Congan xie Zikeng Research Institute of Information Fusion Naval Aviation UniversityYantai 264001China Air Force Early Warning Academy Wuhan 430019China

Adaptive detection of range-spread targets is considered in the presence of subspace interference plus Gaussian clutter with unknown covariance *** target signal and interference are supposed to lie in two linearly independent subspaces with deterministic but unknown *** on the two-step criteria,two adaptive detectors based on Gradient tests are proposed,in homogeneous and partially homogeneous clutter plus subspace interference,*** of the proposed detectors exhibit theoretically constant false alarm rate property against unknown clutter covariance matrix as well as the power *** results show that,the proposed detectors have better performance than their existing counterparts,especially for mismatches in the signal steering vectors.

关键词： adaptive detection subspace interference constant false alarm rate Gradient test partially homogeneous environment

Pore-pressure and stress-coupled creep behavior in deep coal:Insights from real-time NMR analysis

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International Journal of Mining Science and Technology 2024年第1期34卷 77-90页

作者： Wenhao jia Hongwei Zhou Senlin xie Yimeng Wang Xinfeng Hu lei Zhang School of Mechanics and Civil Engineering China University of Mining and Technology-BeijingBeijing 100083China School of Energy and Mining Engineering China University of Mining and Technology-BeijingBeijing 100083China State Key Laboratory of Coal Resources and Safe Mining China University of Mining and Technology-BeijingBeijing 100083China College of Safety and Emergency Management Engineering Taiyuan University of TechnologyTaiyuan 030024China

Understanding the variations in microscopic pore-fracture structures(MPFS) during coal creep under pore pressure and stress coupling is crucial for coal mining and effective gas treatment. In this manuscript, a triaxial creep test on deep coal at various pore pressures using a test system that combines in-situ mechanical loading with real-time nuclear magnetic resonance(NMR) detection was ***-scale quantitative characterization, online real-time detection, and visualization of MPFS during coal creep influenced by pore pressure and stress coupling were performed using NMR and NMR imaging(NMRI) techniques. The results revealed that seepage pores and microfractures(SPM) undergo the most significant changes during coal creep, with creep failure gradually expanding from dense primary pore fractures. Pore pressure presence promotes MPFS development primarily by inhibiting SPM compression and encouraging adsorption pores(AP) to evolve into SPM. Coal enters the accelerated creep stage earlier at lower stress levels, resulting in more pronounced creep deformation. The connection between the micro and macro values was established, demonstrating that increased porosity at different pore pressures leads to a negative exponential decay of the viscosity coefficient. The Newton dashpot in the ideal viscoplastic body and the Burgers model was improved using NMR experimental results, and a creep model that considers pore pressure and stress coupling using variable-order fractional operators was developed. The model’s reasonableness was confirmed using creep experimental data. The damagestate adjustment factors ω and β were identified through a parameter sensitivity analysis to characterize the effect of pore pressure and stress coupling on the creep damage characteristics(size and degree of difficulty) of coal.

关键词： Real-time monitoring Pore pressure-stress coupling Microscopic pore-fracture structure Variable-order fractional creep model Deep coal

Furan-derived Schiff base covalent adaptable thermosets with recyclability and anti-flammability

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Green Chemical Engineering 2024年第3期5卷 364-373页

作者： Ping Zhang Shuyu jia Ruishi xie Lin Chen Ying Xiong State Key Laboratory of Environment-friendly Energy Materials School of Materials Science and EngineeringSouthwest University of Science and TechnologyMianyang621010China

Conventional thermosetting polymers,mostly derived from nonrenewable petroleum resources,are not reprocessable and recyclable due to their highly cross-linked three-dimensional networks and face the disadvantage of high *** solve these issues,in this study,we synthesized a novel Schiff base covalent adaptable thermoset from a furan-derived tri-aldehyde monomer(TMFP)and a furan-derived di-amine monomer(DFDA).The as-prepared TMFP-DFDA-Vitrimer exhibited superior anti-flammability with a high limiting oxygen index(LOI)of 35.0%and a UL-94 V-0 rating,which was attributed to the excellent charring ***,TMFPDFDA-Vitrimer could also be conveniently recycled by chemical decomposition under a mixed hydrochloric acid/tetrahydrofuran(HCl/THF)*** recycling for 5 times,the thermal,mechanical,and flame retardant properties of the recycled TMFP-DFDA-Vitrimer retained almost unchanged compared to the original *** work provides a prime instance to develop advanced thermosetting polymers from abundant furan-based compounds.

关键词： Furan-based compounds Vitrimer Recyclability Flame retardancy

Evolution of microstructure and properties of a novel Ni-based superalloy during stress relief annealing

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International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1876-1889页

作者： lei jia Heng Cui Shufeng Yang Shaomin Lü Xingfei xie Jinglong Qu Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Beijing GAONA Materials&Technology Co. Ltd.Beijing 100081China High-Temperature Materials Institute Central Iron and Steel Research InstituteBeijing 100081China

We discussed the decrease in residual stress,precipitation evolution,and mechanical properties of GH4151 alloy in different annealing temperatures,which were studied by the scanning electron microscope(SEM),high-resolution transmission electron microscopy(HRTEM),and electron backscatter diffraction(EBSD).The findings reveal that annealing processing has a significant impact on diminishing residual *** the annealing temperature rose from 950 to 1150℃,the majority of the residual stresses were relieved from 60.1 MPa down to 10.9 ***,the stress relaxation mechanism transitioned from being mainly controlled by dislocation slip to a combination of dislocation slip and grain boundary ***,the annealing treatment promotes the decomposition of the Laves,accompanied by the precipitation ofμ-(Mo_(6)Co_(7))starting at 950℃ and reaching a maximum value at 1050℃.The tensile strength and plasticity of the annealing alloy at 1150℃ reached the maximum(1394 MPa,56.1%)which was 131%,200%fold than those of the as-cast alloy(1060 MPa,26.6%),but the oxidation process in the alloy was accelerated at 1150℃.The enhancement in durability and flexibility is primarily due to the dissolution of the brittle phase,along with the shape and dispersal of theγ′phase.

关键词： GH4151 alloy annealing treatment residual stress precipitation evolution strength mechanical properties

The pseudospectrum and spectrum(in)stability of quantum corrected Schwarzschild black hole

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Science China(Physics,Mechanics & Astronomy) 2024年第10期67卷 55-75页

作者： Li-Ming Cao jia-Ning Chen Liang-Bi Wu Libo xie Yu-Sen Zhou School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China Peng Huanwu Center for Fundamental Theory Hefei 230026China Interdisciplinary Center for Theoretical Study and Department of Modern Physics University of Science and Technology of ChinaHefei 230026China

In this study,we investigate the pseudospectrum and spectrum(in)stability of quantum corrected Schwarzschild black ***,we use the hyperboloidal framework to cast the quasinormal mode(QNM)problem into an eigenvalue problem associated with a non-selfadjoint operator,and then the spectrum and pseudospectrum are ***,the invariant subspace method is exploited to improve the computational efficiency for *** investigation into the spectrum(in)stability entails two main *** the one hand,we calculate the spectra of the quantum corrected black hole,then by the means of the migration ratio,the impact of the quantum correction effect on the Schwarzschild black hole has been *** results indicate that the so-called“migration ratio instability”will occur for small black holes with small angular momentum number *** the eikonal limit,the migration ratios remain the same for each *** the other hand,we study the spectrum(in)stability of the quantum corrected black hole by directly adding some particular perturbations into the effective potential,where perturbations are located at the event horizon and null infinity,*** are two interesting observations under the same perturbation energy ***,perturbations at infinity are more capable of generating spectrum instability than those at the event ***,we find that the peak distribution can lead to the instability of QNM spectrum more efficiently than the average distribution.

关键词： quasinormal modes pseudospectrum hyperboloidal coordinate

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Target Detection on Water Surfaces Using Fusion of Camera and LiDAR Based Information

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Computers, Materials & Continua 2024年第7期80卷 467-486页

作者： Yongguo Li Yuanrong Wang jia xie Caiyin Xu Kun Zhang College of Engineering Science and Technology Shanghai Ocean UniversityShanghai201306China

To address the challenges of missed detections in water surface target detection using solely visual algorithms in unmanned surface vehicle(USV)perception,this paper proposes a method based on the fusion of visual and LiDAR point-cloud projection for water surface target ***,the visual recognition component employs an improved YOLOv7 algorithmbased on a self-built dataset for the detection of water surface *** algorithm modifies the original YOLOv7 architecture to a Slim-Neck structure,addressing the problemof excessive redundant information during feature extraction in the original YOLOv7 network ***,this modification simplifies the computational burden of the detector,reduces inference time,and maintains ***,to tackle the issue of sample imbalance in the self-built dataset,slide loss function is ***,this paper replaces the original Complete Intersection over Union(CIoU)loss function with the Minimum Point Distance Intersection over Union(MPDIoU)loss function in the YOLOv7 algorithm,which accelerates model learning and enhances *** mitigate the problem of missed recognitions caused by complex water surface conditions in purely visual algorithms,this paper further adopts the fusion of LiDAR and camera data,projecting the threedimensional point-cloud data from LiDAR onto a two-dimensional pixel *** significantly reduces the rate of missed detections for water surface targets.

关键词： Water surface target detection YOLOv7 joint calibration sensor fusion point-cloud projection