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Probing the Gamma-Ray Emission Region of Five TeV Flat Spectrum Radio Quasars

Research in Astronomy and Astrophysics 2024年第6期24卷 156-169页

作者： Hu-Bing Xiao hai-Tao Cao Rui Xue Jin-Ting Cai Ge-Ge Wang marina manganaro Shao-Hua Zhang Zhi-Hao Ouyang Li-Ping Fu jun-hui Fan Shanghai Key Lab for Astrophysics Shanghai Normal UniversityShanghai 200234China School of Information Engineering Guangzhou Panyu PolytechnicGuangzhou 511483China Department of Physics Zhejiang Normal UniversityJinhua 321004China College of mathematics and Physics Guangxi Minzu UniversityNanning 530006China Key Laboratory of Cosmology and Astrophysics(Liaoning) College of SciencesNortheastern UniversityShenyang 110819China Department of Physics University of RijekaRijeka 51000Croatia Center for Astrophysics Guangzhou UniversityGuangzhou 510006China Key Laboratory for Astronomical Observation and Technology of Guangzhou Guangzhou 510006China Astronomy Science and Technology Research Laboratory of Department of Education of Guangdong Province Guangzhou 510006China

The location ofγ-ray emission of blazars remains a contested topic,inspiring the development of numerous investigative techniques to address this *** this work,we analyzed Fermiγ-ray light curves in the GeV and MeV bands,employing the discrete cross-correlation function method to discern time lags between the two *** 4C+21.35,Ton 599,B21420+32,and PKS 1510-089,we identified a time lag spanning several days,while for PKS 1441+25,the time lag was not statistically *** results imply that the soft photons necessary for inverse Compton scattering predominantly originate from the dusty torus in the first four sources,whereas for PKS1441+25,they seem to be sourced mainly from the broad-line *** analysis of the opacity(τγγ)and the GeV spectra study supports the conclusion that the location of the dissipation region must be beyond the BLR to avoid significant ***,for PKS 1441+25,the emission region is also posited to lie outside yet proximate to the *** parameters of describing the emission region were obtained by fitting broadband spectral energy distribution with contemporaneous observation *** findings suggest that for the five TeV FSRQs,during Te V flaring events,the jet appears to maintain an equilibrium between the energy density of the magnetic field and that of the particles for all investigated sources,with the exceptions of 4C+21.35 and PKS1441+*** terms of the overall jet power,particle energy is the dominant contributor,and the observed blazar radiation cannot be solely attributed to the magnetic field,except in the case of 4C+***,magnetic reconnection is unlikely to be the primary mechanism behind particle acceleration in these systems.

关键词： galaxies:active gamma-rays:galaxies galaxies:jets

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Developing a diagnostic model for predicting prostate cancer: a retrospective study based on Chinese multicenter clinical data

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Asian Journal of Andrology 2024年第1期26卷 34-40页

作者： Chang-Ming Wang Lei yuan Xue-Han Liu Shu-Qiu Chen hai-Feng Wang Qi-Fei Dong Bin Zhang Ming-Shuo Huang Zhi-Yong Zhang jun Xiao Tao Tao Department of Urology The First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei 230001China Department of Radiology The First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei 230001China Core Facility Center for Medical Sciences The First Affiliated Hospital of USTcDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei 230001China Department of Urology Affiliated Zhongda Hospital of Southeast UniversityNanjing 210009China Department of Urology Shanghai East HospitalTongji University School of MedicineShanghai 200120China Department of Urology Shanghai Changhai HospitalSecond Military Medical UniversityShanghai 200000China Department of Urology Affiliated Anhui Provincial Hospital of Anhui Medical UniversityHefei 230001China

The overdiagnosis of prostate cancer(PCa)caused by nonspecific elevation serum prostate-specific antigen(PSA)and the overtreatment of indolent PCa have become a global problem that needs to be solved *** aimed to construct a prediction model and provide a risk stratification system to reduce unnecessary *** this retrospective study,clinical data of 1807 patients from three Chinese hospitals were *** final model was built using stepwise logistic regression *** apparent performance of the model was assessed by receiver operating characteristic curves,calibration plots,and decision curve ***,a risk stratification system of clinically significant prostate cancer(csPCa)was created,and diagnosis-free survival analyses were *** multivariable screening and evaluation of the diagnostic performances,a final diagnostic model comprised of the PSA density and Prostate Imaging-Reporting and Data System(PI-RADS)score was *** validation in the development cohort and two external cohorts showed excellent discrimination and ***,we created a risk stratification system using risk thresholds of 0.05 and 0.60 as the cut-off *** follow-up results indicated that the diagnosis-free survival rate for csPCa at 12 months and 24 months postoperatively was 99.7%and 99.4%,respectively,for patients with a risk threshold below O.05 after the initial negative prostate biopsy,which was significantly better than patients with higher *** diagnostic model and risk stratification system can achieve a personalized risk calculation of *** provides a standardized tool for Chinese patients and physicians when considering thenecessity of prostatebiopsy.

关键词： nomogram prostate biopsy prostate cancer Prostate Imaging-Reporting and Data System prostate-specific antigen density

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Simultaneously Improved Curing,Mechanical,Antioxidative Properties and Reduced ZnO Loading of Silica Filled NR Composites by Incorporation of Low-cost Crude Carbon Dots via Conventional Melt-milling Method

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Chinese Journal of Polymer Science 2024年第6期42卷 815-825页

作者： Chao-Ying Sun hai-jun Ji Li-Wei Li hui Yang Xiao-Peng An Yi-Ping Chen Ming-Jian Han Can Jiang Li-Qun Zhang Peng Yu Run-Guo Wang State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing100029China School of materials Science and Engineering Wuhan Institute of TechnologyWuhan430205China

Rubbers or elastomers play an important role in hi-tech technology and civilian daily life because of their unique and strategical ***,the rubber additives are essential components for rubbers’practical ***,developing novel multifunctional additives has attracted increasing research *** this work,low-cost crude carbon dots(CCDs)were used as multifunctional additives for natural rubber/silica system(without any additional modification)through industrial compatible melt-mixing *** results revealed that the CCDs could disperse well in the NR/silica system,and they could not only endow the rubber compound with excellent anti-aging capability due to CCDs’radical scavenging activity because of their plenty of nitrogen-containing species,but also improve the curing rate and mechanical performance of the rubber ***,the CCDs could reduce the rolling resistance of the rubber composites(tanδvalue at 7%strain of the rubber composite could be decreased by 34%),which is promising for the application of energy-saving tire ***,the addition of CCDs could effectively reduce the ZnO dosage by at least 40%in the rubber composite without deteriorating its ***,this work provides valuable guidance to develop novel cheap yet effective additives for the elastomer.

关键词： Natural rubber Crude carbon dots Antioxidant ZnO reduction Vulcanization

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Experimental study of the damage characteristics of rocks containing non-penetrating cracks under cyclic loading

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International Journal of Mining Science and Technology 2024年第2期34卷 197-210页

作者： jun Xu Xiaochun Xiao Lu ma Sen Luo Jiaxu Jin Baijian Wu School of Mechanics and Engineering Liaoning Technical UniversityFuxin 123000China School of Civil Engineering Liaoning Technical UniversityFuxin 123000China Department of Engineering Mechanics Southeast UniversityNanjing 211189China

The damage evolution process of non-penetrating cracks often causes some unexpected engineering *** specimens containing non-penetrating crack(s)are used to study the damage evolution and characteristics under cyclic *** results show that under cyclic loading,the relationship between the number of non-penetrating crack(s)and the characteristic parameters(cyclic number,peak stress,peak strain,failure stress,and failure strain)of the pre-cracked specimens can be represented by a decreasing linear *** damage evolution equation is fitted by calibrating the accumulative plastic strain for each cycle,and the damage constitutive equation is proposed by the concept of effective ***,non-penetrating cracks are more likely to cause uneven stress distribution,damage accumulation,and local failure of *** local failure can change the stress distribution and relieve the inhibition of non-penetrating crack extension and eventually cause a dramatic destruction of the ***,the evolution process caused by non-penetrating cracks can be regarded as one of the important reasons for inducing *** results are expected to improve the understanding of the process of spalling formation and rockburst and can be used to analyze the stability of rocks or rock structures.

关键词： Damage characteristics Constitutive model Fissured rocks Non-penetrating crack Cyclic loading

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Transient state analysis of a rub-impact rotor system during maneuvering flight

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Chinese Journal of Aeronautics 2024年第7期37卷 236-251页

作者： jun WANG Yunfei LIU Zhaoye QIN Liang ma Fulei CHU Beijing Key Laboratory of Health Monitoring and Self-Recovery for High-End machinery Equipment Beijing University of Chemical TechnologyBeijing 100029China State Key Laboratory of Tribology Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China College of Aeronautical Engineering Civil Aviation University of ChinaTianjin 300300China

maneuvering flight substantially affects the dynamic behavior of rotors;particularly,such flight may cause rubbing between a rotor and stator,which is one of the most serious damages in aircraft *** this paper,a nonlinear dynamic model for describing the dynamic characteristics of a rub-impact rotor system during maneuvering flight is established based on the Lagrange ***,numerical simulations employing the Newmark method are performed,delving into the detailed discussion of the influence of parameters such as rotational speed and maneuvering flight on the transient and steady-state responses of the rotor *** effect mechanism of maneuver load and its coupling with rub impact is *** results show that the impact response induced by maneuvering flight is more obvious in the subcritical state than in the supercritical *** additional stiffness and damping are also induced;in particular,the additional damping has a coupling ***,the rub impact imposes an additional constraint on the rotor system,thereby weakening the influence of the maneuver load and becoming the major factor that determines the dynamic behavior of the rotor system at high speeds.

关键词： maneuvering flight Rub impact Rotor system Dynamic response Impact response

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Preparation of tungsten-particle-reinforced Zr-based bulk metallic glass composites by two-step spark plasma sintering:microstructure evolution,densification mechanism and mechanical properties

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Rare Metals 2024年第4期43卷 1793-1808页

作者： Yun-Fei ma Pan Gong mao Zhang hui-EHu Zhen Peng Xiao Xu Xin Wang Mehdi malekan Xue-Feng Tang Lei Deng jun-Song Jin Xin-Yun Wang State Key Laboratory of materials Processing and Die and Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan430074China Research Institute of Huazhong University of Science and Technology in Shenzhen Shenzhen518057China Department of Chemistry and materials Naval University of EngineeringWuhan430032China School of materials Science and Engineering Jiangsu UniversityZhenjiang212013China College of machine Shanghai Dianji UniversityShanghai201306China School of Metallurgy and materials Engineering College of EngineeringUniversity of TehranTehran 11155-4563Iran

A new two-step spark plasma sintering(TSS)process with low-temperature pre-sintering and high-temperature final sintering has been successfully applied to prepare the tungsten-particle(Wp)-reinforced bulk metallic glass composites(Wp/BMGCs).Compared to normal spark plasma sintering(NS),the densification rate and relative density of Wp/BMGCs can be improved by selecting TSS with appropriate sintering pressure in the low temperature pre-sintering ***,the compressive strength and plastic strain of 30%Wp/BMGCs prepared by TSS are both higher than those of the samples prepared by *** TSS process can significantly enhance the compressive strength of 30%Wp/BMGCs by 12%and remarkably increase the plastic strain by 50%,while the trend is completely opposite for 50%Wp/***-in situ experiments and finite element simulations reveal that uneven temperature distribution among particles during low-temperature pre-sintering causes local overheating at contact points between particles,accelerating formation of sintering neck between particles and plastic deformation of *** the volume fraction of Wp is low,TSS can improve the interface bonding between particles by increasing the number of sintering *** makes the fracture mode of Wp/BMGCs being predominantly transgranular ***,as the volume fraction of Wp increases,the adverse effects of Wp plastic deformation are becoming more and more *** aggregated Wp tends to form a solid"cage structure"that hinders the bonding between particles at the interface;correspondingly,the fracture behavior of Wp/BMGCs is mainly dominated by intergranular ***,reducing the sintering pressure during the low-temperature pre-sintering stage of TSS has been shown to effectively decrease plastic deformation in Wp,resulting in a higher degree of densification and better mechanical properties.

关键词： Bulk metallic glass composites Tungsten particle Two-step spark plasma sintering Densification mechanism Mechanical properties

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Sensing matrix Optimization for Random Stepped-Frequency Signal Based on Two-Dimensional Ambiguity Function

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Chinese Journal of Electronics 2024年第1期33卷 161-174页

作者： Mingjiu LYU Hao CHEN jun YANG Xia WU Ming ZHOU Xiaoyan ma Radar NCO School Air Force Early Warning Academy Department of Early Warning Technology Air Force Early Warning Academy

Compressive sensing technique has been widely applied to achieve range-Doppler reconstruction of high frequency radar by utilizing sparse random stepped-frequency(SRSF) signal, which can suppress the complex electromagnetic interference and greatly reduce the coherent processing interval. An important way to improve the performance of sparse signal reconstruction is to optimize the sensing matrix(SM). However, the existing research on the SM optimization needs to design a measurement matrix with superior performance, which needs a large amount of computation and does not consider the influence of the waveform parameters design. In order to improve the superior reconstruction performance, a novel SM optimization approach for SRSF signal is proposed by using two-dimensional ambiguity function(TDAF) in this paper. Firstly, based on the two-dimensional sparse reconstruction model of the SRSFs, the internal relationship between the waveform parameters and the SM was derived. Secondly, the SM optimization problem was directly transformed into the waveform design of SRSFs. Furthermore, on the basis of analyzing the relationship between the mutual coherence matrix of SM and the TDAF matrix of SRSFs, the purpose of optimizing the SM can be achieved by designing the TDAF of the SRSFs. Based on this analysis, a sparse waveform optimization method with joint constraints of maximum and mean sidelobes of the TDAF by using the genetic algorithm was derived. Compared with the traditional SM optimization method, our method not only avoids generating a new measurement matrix, but also further reduces the complexity of the waveform optimization. Simulation experiments verified the effectiveness of the proposed method.

关键词： Correlation Computational modeling Electromagnetic interference Optimization methods Signal reconstruction High frequency radar Sensors

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Potentiation of the lateral habenula-ventral tegmental area pathway underlines the susceptibility to depression in mice with chronic pain

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Science China(Life Sciences) 2024年第1期67卷 67-82页

作者： Chun-Kui Zhang Pan Wang yuan-yuan Ji Jian-Shuai Zhao jun-Xiang Gu Xian-Xia Yan Hong-Wei Fan Ming-Ming Zhang Yu Qiao Xiao-Die Liu Bao-Juan Li Ming-hui Wang hai-Long Dong Hao-Hong Li Peng-Cheng Huang Yun-Qing Li Wu-Gang Hou Jin-Lian Li Tao Chen Department of Anatomy and K.K.Leung Brain Research Centre Fourth Military Medical UniversityXi’an 710032China Beijing Institute of Basic Medical Sciences Beijing 100850China Key Laboratory of Ministry of Public Health for Forensic Science Xi’an Jiaotong UniversityXi’an 710061China Department of Anesthesiology Xijing HospitalFourth Military Medical UniversityXi’an 710032China Department of Neurosurgery the Second Affiliated Hospital of Xian Jiaotong UniversityXi’an 710004China School of Biomedical Engineering Fourth Military Medical UniversityXi’an 710032China Affiliated Mental Health Centre and Hangzhou Seventh People’s Hospital Zhejiang University School of MedicineHangzhou 310013China The MOE Frontier Research Center of Brain&Brain-machine Integration Zhejiang University School of Brain Science and Brain MedicineHangzhou 310058China Department of Neurology The First Affiliated Hospital of Nanchang UniversityNanchang 330006China Department of Anatomy School of MedicineNorthwest UniversityXi’an 710069China

Chronic pain often develops severe mood changes such as ***,how chronic pain leads to depression remains elusive and the mechanisms determining individuals’responses to depression are largely *** we found that depression-like behaviors could only be observed in 67.9%of mice with chronic neuropathic pain,leaving 32.1%of mice with depression *** determined that the spike discharges of the ventral tegmental area(VTA)-projecting lateral habenula(LHb)glutamatergic(Glu)neurons were sequentially increased in sham,resilient and susceptible mice,which consequently inhibited VTA dopaminergic(DA)neurons through a LHbGlu-VTAGABA-VTADA ***,the LHbGlu-VTADA excitatory inputs were dampened via GABAB receptors in a pre-synaptic *** of LHb-VTA pathway largely affected the development of depressive symptoms caused by chronic *** study thus identifies a pivotal role of the LHb-VTA pathway in coupling chronic pain with depression and highlights the activity-dependent contribution of LHbGlu-to-VTADA inhibition in depressive behavioral regulation.

关键词： chronic pain depression lateral habenula ventral tegmental area dopamine susceptibility

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Catalyst-free and Reprocessable Aromatic Polydithiourethanes

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Chinese Journal of Polymer Science 2024年第10期42卷 1435-1441页

作者： Bo Yang hai-jun Feng Tian-Tian Ni Xiao-Rui Zhou Tao Xie Ning Zheng State Key Laboratory of Chemical Engineering College of Chemical and Biological Engineering Zhejiang University Department of Colorectal Surgery and Oncology Key Laboratory of Cancer Prevention and Intervention Ministry of Education The Second Affiliated HospitalZhejiang University School of Medicine

The incorporation of dynamic covalent bonds into thermosets facilitates the reprocessing of polymer networks, thereby meeting the sustainable requirements for polymer recycling. However, the mechanical properties of many materials often decline significantly upon reprocessing due to side reactions caused by harsh processing conditions. In this work, we find that the aromatic dithiocarbamate bond can undergo dissociation under mild conditions without the need for a catalyst, enabling the efficient reprocessing of the corresponding *** a consequence, the mechanical properties of the polydithiourethane can be largely preserved after reprocessing. The discovery of this dynamic chemistry is anticipated to broaden the potential for material design in dynamic covalent polymer networks.

关键词： Dynamic covalent bond Polydithiourethane Reprocessing

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Research progress of slippage characteristic and gas film stability enhancement methods on biomimetic hydrophobic surfaces

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Journal of Hydrodynamics 2024年第1期36卷 87-101页

作者： Meng-zhuo Zhang hai-bao Hu Liu-zhen Ren Lu-yao Bao jun Wen Luo Xie School of marine Science and Technology Northwestern Polytechnical UniversityXi’an710072China Research and Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen518063China

The biomimetic hydrophobic surface is a potentially efficient underwater drag reduction method and the drag reduction mechanism of this kind of surface comes from the interfacial *** now,it is a hotspot to grasp the slippage characteristic and explore slippage enhancement *** paper not only summarizes our numerical simulation and experimental results of slippage characteristic at the solid-liquid interface(SLI)of hydrophobic surfaces(HS)and the gas-liquid interface(GLI)of superhydrophobic surfaces(SHS)in recent years,but also introduces some innovative methods that can effectively improve the gas film stability and drag reduction effect of ***,we used the molecular dynamics(MD)simulation method to figure out the effect of the solid-liquid interaction strength,the system temperature and the shear rate on the slippage of SLI,and expound their action mechanism from molecular ***,by MD and multibody dissipative particle dynamics(MDPD)method,the slippage behavior at the GLI was studied under the influence of the microstructure size and the flow driving *** proposed a new kind of hybrid slip boundary condition model to describe the slippage characteristic on *** addition,we found through experiment that a three-dimensional backflow will appear on the GLI under the interfacial adsorption of surfactants,and the backflow direction will reverse with the change of GLI ***,we put forward the wettability step structure and gas injection method to enhance the stability and drag reduction effect of the gas film on SHS.

关键词： Hydrophobic surface superhydrophobic surface interfacial slip underwater drag reduction

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