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The Optical Variability Properties of TeV Blazars

Research in Astronomy and Astrophysics 2024年第9期24卷 66-75页

作者： zi-An Su Wen-Xin Yang Xiang-Tao Zeng Le-jian Ou Ze-lin li jiang-He Yang Jun-Hui Fan Department of Physics School of Physics and ElectronicsHunan Normal UniversityChangsha 410081China Center for Astrophysics Guangzhou UniversityGuangzhou 510006China Greater Bay Brand Center of the National Astronomical Data Center Guangzhou 510006China Astronomy Science and Technology Research Laboratory of Department of Education of Guangdong Province Guangzhou 510006China College of Microelectronics Feicuihu Campus of Hefei University of TechnologyHefei 230601China College of Mathematics and Physics Science Hunan University of Arts and ScienceChangde 415000China

Variability is one of the typical observational properties of blazars and the spectral changes are usually associated with variability,although this kind of association is unclear *** this work,we used data from the Steward Observatory blazar monitoring program to investigate the optical variability properties including the short-term timescale,the brightness-dependent spectral property,the correlation between the the brightness variation and the polarization,and then estimate the Doppler factors based on the obtained short timescale to study the polarization property for a sample of 20 TeV *** analyses arrive at the following results:(1)The largest variation amplitude in R-band,ΔR_(M),covers a range from ΔR_(M)=0.29 mag(1ES 2344+514)to ΔR_(M)=4.66 mag(3C 279).(2)Intra-day variability was found from five sources with timescales from 0.14 day for S50716+714 to 0.98 day for PKS *** sources show spectra that are bluer when they become brighter,suggesting a common bluer-when-brighter property.(3)The plot of the polarization versus estimated Doppler factor is consistent with the Doppler factor dependent formula of polarization.(4)The largest polarization is correlated with the largest optical variation,suggesting that the high polarization and high amplitude variation are both the indicator of beaming effect.

关键词： galaxies:active galaxies:jets radiation mechanisms:non-thermal

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Janus mesoporous nanoparticles enable building biological logic systems

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Science China Chemistry 2024年第1期67卷 316-318页

作者： Haitao li jian liu State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China College of Chemistry and Chemical Engineering Inner Mongolia UniversityHohhot 010021China

This highlight is inspired by a recent article in Nature Chemistry[1],in which Zhao and co-workers from Fudan University developed an innovative emulsion-orientated anisotropic assembly method for the controllable fabrication of MSN&mPDA(mesoporous silica nanoparticles=MSN,mesoporous polydopamine=mPDA)Janus mesoporous nanoparticles and used them to build biological logic *** reported Janus mesoporous nanoparticles have delicate structures and are well-controlled,and the authors also demonstrated the unique performance of this material at the application end.

关键词： enable emulsion silica

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Numerical simulation of aircraft arresting process with an efficient full-scale rigid-flexible coupling dynamic model

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Chinese Journal of Aeronautics 2024年第5期37卷 586-602页

作者： Haoyuan SHAO Daochun li zi KAN Lanxi BI Zhuoer YAO Jinwu XIANG School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China Tianmushan Laboratory Hangzhou 310023China

The arresting process of carrier-based aircraft is widely recognized as a challenging task,characterized by the highest accident rate among all carrier-based aircraft *** simulation plays a crucial role in assessing the intricate responses of the arresting process,favoring the design of carrier-based *** efficient and accurate rigid-flexible coupling model for analyzing the dynamic response of the arresting process is *** combining the dynamic characteristics of airframe,landing gear,arresting hook and arresting gear system,the rigid-flexible coupling dynamic model is established to reflect the relative motion of the coupling parts and arresting *** dynamic model is verified through simulations of landing gear landing drops and by comparing the arresting simulation results with corresponding data in the US military ***,simulations of the arresting process under different off-center distance and aircraft yaw angle are conducted to obtain the dynamic response of the aircraft during the arresting *** result indicates that the rigid-flexible coupling dynamic model proposed is effective for analyzing the arresting dynamics response of carrier-based *** axial force of the arresting cable on both sides of the hook engagement point,pitch and yaw angle of aircraft are inconsistent under yaw and off-center *** analysis method and obtained results provide valuable references for assessing the dynamic responses of carrier-based aircraft during arresting process and offer valuable in-sights in the design of carrier-based aircraft.

关键词： Carrier-based aircraft Deck landing Rigid-flexible coupling dynamic model Finite element method Dynamic analysis

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Chain Dynamics Heterogeneity in Plasticized Poly(vinyl butyral)(PVB) as Elucidated by Solid-State NMR

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Chinese Journal of Polymer Science 2024年第1期42卷 113-124,I0010页

作者： Jing Lv Xu Chen zi-Shuo Wu Ya-Hui li Wei Chen National Synchrotron Radiation Laboratory Anhui Provincial Engineering Laboratory of Advanced Functional Polymer FilmCAS Key Laboratory of Soft Matter ChemistryUniversity of Scienceand Technology of ChinaHefei 230026China

The chain dynamics heterogeneity of the poly(vinyl butyral)(PVB) plasticized by triethylene glycol bis(2-ethylhexa noate)(TEG-EH) was investigated by various solid-state NMR *** plasticized PVB shows two domains in distinct molecular dynamics differences,namely,rigid and soft domains,where the latter is the plasticizer-rich *** time domain low field NMR was first used to investigate the dynamics heterogeneity of the plasticized PVB,and the results show the decreasing activated energy of components in the soft domain of plasticized PVB(E_a=20.2 kJ/mol) as compared with that of the pristine one(E_a=24.3 kJ/mol).Detailed dynamics heterogeneity was obtained by high-field NMR with site-specific *** quadrupole-echo ~2H-NMR was adopted to elucidate the dynamics heterogeneity of the vinyl alcohol(VA) units,where only the hydroxyl group of VA is *** ~1H-^(13)C WISE NMR spectra show that there is not much difference in the mobility of the VB unit in PVB with and without plasticizer,whereas the glass transition temperature differed by approximately 53℃.This is further supported by Torchia's T_1 relaxation *** origin of such an unusual phenomenon is attributed to the critical role of the remaining VA(~22%) in the soft domain,where the VA units locally aggregate through hydrogen ***,the existence of a mobility gradient in the VB unit has been ***,the mobility difference for VB with different stereo-geometry(meso or racemic conformation) is observed for the first *** indicates the importance of modulating the ratio of meso over racemic VB for controlling the macroscopic perfo rmance of PVB.

关键词： Poly(vinyl butyral) Dynamics heterogeneity Plasticizer Solid state NMR

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Exploring changes of precipitation extremes under climate change through global variable-resolution modeling

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Science Bulletin 2024年第2期69卷 237-247页

作者： Wei Sun jian li Rucong Yu Nina li Yi Zhang State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China Institute of Tibetan Plateau Meteorology China Meteorological AdministrationChengdu 610072China Department of Atmospheric Science Yunnan UniversityKunming 650091China National Meteorological Center China Meteorological AdministrationBeijing 100081China 2035 Future Laboratory PIESAT Information Technology Co.Ltd.Beijing 100105China

Understanding the responses of precipitation extremes to global climate change remains limited owing to their poor representations in models and complicated interactions with multi-scale *** we take the record-breaking precipitation over China in 2021 as an example,and study its changes under three different climate scenarios through a developed pseudo-global-warming(PGW)experimental framework with 60-3 km variable-resolution global ensemble *** to the present climate,the precipitation extreme under a warmer(cooler)climate increased(decreased)in intensity,coverage,and total amount at a range of 24.3%-37.8%(18.7%-56.1%).With the help of the proposed PGW experimental framework,we further reveal the impacts of the multi-scale system interactions in climate change on the precipitation *** the warmer climate,large-scale water vapor transport converged from double typhoons and the subtropical high marched into central China,enhancing the convective energy and instability on the leading edge of the transport *** a result,the mesoscale convective system(Mcs)that directly contributed to the precipitation extreme became stronger than that in the present *** the contrary,the cooler climate displayed opposite changing characteristics relative to the warmer climate,ranging from the large-scale systems to local environments and to the *** summary,our study provides a promising approach to scientifically assess the response of precipitation extremes to climate change,making it feasible to perform ensemble simulations while investigating the multi-scale system interactions over the globe.

关键词： Precipitation extreme Climate change Pseudo-global-warming experiment Variable-resolution modeling Multi-scale system interaction

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Alignment efficient image-sentence retrieval considering transferable cross-modal representation learning

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Frontiers of Computer Science 2024年第1期18卷 77-91页

作者： Yang YANG Jinyi GUO Guangyu li Lanyu li Wenjie li jian YANG School of Computer Science and Engineering Nanjing University of Science and TechnologyNanjing 210094China Department of Computing Hong Kong Polytechnic UniversityHong Kong 100872China State Key Lab.for Novel Software Technology Nanjing UniversityNanjing 210094China 14th Research Institute of China Electronics Technology Group Corporation Nanjing 210094China guangyu.li2017@***

Traditional image-sentence cross-modal retrieval methods usually aim to learn consistent representations of heterogeneous modalities,thereby to search similar instances in one modality according to the query from another modality in *** basic assumption behind these methods is that parallel multi-modal data(i.e.,different modalities of the same example are aligned)can be obtained in *** other words,the image-sentence cross-modal retrieval task is a supervised task with the alignments as ***,in many real-world applications,it is difficult to realign a large amount of parallel data for new scenarios due to the substantial labor costs,leading the non-parallel multi-modal data and existing methods cannot be used *** the other hand,there actually exists auxiliary parallel multi-modal data with similar semantics,which can assist the non-parallel data to learn the consistent ***,in this paper,we aim at“Alignment Efficient Image-Sentence Retrieval”(AEIR),which recurs to the auxiliary parallel image-sentence data as the source domain data,and takes the non-parallel data as the target domain *** single-modal transfer learning,AEIR learns consistent image-sentence cross-modal representations of target domain by transferring the alignments of existing parallel ***,AEIR learns the image-sentence consistent representations in source domain with parallel data,while transferring the alignment knowledge across domains by jointly optimizing a novel designed cross-domain cross-modal metric learning based constraint with intra-modal domain adversarial ***,we can effectively learn the consistent representations for target domain considering both the structure and semantic ***,extensive experiments on different transfer scenarios validate that AEIR can achieve better retrieval results comparing with the baselines.

关键词： image-sentence retrieval transfer learning semantic transfer structure transfer

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Prevention and control strategies for antibiotic resistance:from species to community level

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Soil Ecology Letters 2024年第3期6卷 17-34页

作者： Yan-zi Wang Hu li Qing-lin Chen Ting Pan Yong-Guan Zhu Dirk Springael jian-Qiang Su Key Laboratory of Urban Environment and Health Ningbo Observation and Research StationInstitute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Division of Soil and Water Management KU LeuvenKasteelpark Arenberg 20 Box 24593001 HeverleeBelgium

Antibiotic resistance genes(ARGs)and antibiotic resistant bacteria(ARB)in the environment pose serious threats to environmental security and public *** is an urgent need for methods to specifically and effectively control environmental pollution or pathogen infection associated with ARGs and *** review aims to provide an overview of methods abating the prevalence and spread of ARGs and ARB from species to community *** the species level,species-specific technologies,such as nanoparticle-,photosensitizer-,CRISPR-Cas-,and phage-related technology can be utilized to clear a particular class of ARGs or ARB,and in combination with low-dose antibiotics,a higher removal efficiency can be ***,the combination of antibiotics can be used to reverse microbial resistance and treat recurrent antibiotic resistant pathogen *** the community level,community-specific strategies,such as biochar,hyperthermophilic compost,and fecal microbiota transplantation can eradicate most types of ARGs or ARB in one shot,reducing the probability of resistance *** some progress has been made to eliminate ARGs and ARB in disease treatment or decontamination scenarios,further research is still needed to elucidate their mechanisms of action and scopes of application,and efforts should be made to explore novel strategies to counter the prevalence of antibiotic resistance.

关键词： antibiotic resistance genes antibiotic resistant bacteria treatment strategy disinfection

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Microplastic exposure disturbs sleep structure,reduces lifespan,and decreases ovary size in Drosophila melanogaster

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Zoological Research 2024年第4期45卷 805-820页

作者： Wei Yan zi-Jie li zi-Yi lin Shu-Qin Ji William Ka Fai Tse Zhi-Qiang Meng Chang liu Lei li Shenzhen-Hong Kong Institute of Brain Science Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong 518000China CAS Key Laboratory of Brain Connectome and Manipulation the Brain Cognition and Brain Disease InstituteShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong 518000China Laboratory of Developmental Disorders and Toxicology Center for Promotion of International Education and ResearchFaculty of AgricultureKyushu UniversityFukuokaFukuoka 819-0395Japan Shenzhen Key Laboratory of Drug Addiction the Brain Cognition and Brain Disease InstituteShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong 518000China Guangdong Provincial Key Laboratory of Brain Connectome and Behavior Brain Cognition and Brain Disease InstituteShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong 518000China

The organ-specific toxicity resulting from microplastic(MP)exposure has been extensively explored,particularly concerning the gut,liver,testis,and ***,under natural conditions,these effects are not restricted to specific organs or *** whether MP exposure presents a systemic threat to an entire organism,impacting factors such as lifespan,sleep,and fecundity,is *** this study,we investigated the effects of dietary exposure to two different doses of MPs(1–5μm)using the terrestrial model organism Drosophila *** indicated that the particles caused gut damage and remained within the digestive *** MP exposure significantly shortened the lifespan of adult *** short-term exposure disrupted sleep patterns,increasing the length of daytime sleep ***,one week of MP exposure reduced ovary size,with a trend towards decreased egg-laying in mated *** MPs did not penetrate the brain or ovaries,transcriptome analysis revealed altered gene expression in these *** the ovary,Gene Ontology(GO)analysis indicated genotoxic effects impacting inflammation,circadian regulation,and metabolic processes,with significant impacts on extracellular structure-related *** the brain,GO analysis identified changes in pathways associated with proteolysis and carbohydrate ***,this study provides compelling evidence of the systemic negative effects of MP exposure,highlighting the urgent need to address and mitigate environmental MP pollution.

关键词： Microplastics Sleep lifespan Reproduction Risk assessment Drosophila melanogaster

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Experimental Study on Engineering Behavior of Solidified Soil for Scour Repair and Protection

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China Ocean Engineering 2024年第4期38卷 625-635页

作者： WU Xiao-ni li Ru-yu SHU jian TANG Chao CHEN Jin-jian WANG Hui-li jianG Hai-li WANG Xiao State Key Laboratory of Ocean Engineering Department of Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Shanghai Road and Bridge Group Co. Ltd.Shanghai 200433China Shanghai Engineering Research Center of Urban Infrastructure Renewal Shanghai 200032China jiangsu Kunze Technology Co. Ltd.Nanjing 210000China

A new scour countermeasure using solidified slurry for offshore foundation has been proposed *** solidified slurry is pumped to seabed area around foundation for scour protection or pumped into the developed scour holes for scour repair as the fluidized material solidifies *** the pumping operation and solidification,the engineering behaviors of solidified slurry require to be considered synthetically for the reliable application in scour repair and protection of ocean engineering such as the pumpability related flow value,flow diffusion behavior related rheological property,anti-scour performance related retention rate in solidification and bearing capacity related strength property after *** this study,a series of laboratory tests are conducted to investigate the effects of mix proportion(initial water content and binder content)on the flow value,rheological properties,density,retention rate of solidified slurry and unconfined compressive strength(UCS).The results reveal that the flow value increases with the water content and decreases with the binder *** the solidified slurry exhibits Bingham plastic behavior when the shear rate is larger than 5 s^(-1).The Bingham model has been employed to fit the rheology test results,and empirical formulas for obtaining the density,yield stress and viscosity are established,providing scientific support for the numerical assessment of flow and diffusion of solidified *** rate of solidified slurry decreases with the water flow velocity and flow value,which means the pumpability of solidified slurry is contrary to anti-scour *** unconfined compressive strength after solidification reduces as the water content increases and binder content decreases.A design and application procedure of solidified soil for scour repair and protection is also proposed for engineering reference.

关键词： scour repair and protection solidified soil pumpability strength flow properties anti-scour performance

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Computed tomography-based radiomics to predict early recurrence of hepatocellular carcinoma post-hepatectomy in patients background on cirrhosis

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World Journal of Gastroenterology 2024年第15期30卷 2128-2142页

作者： Gui-Xiang Qian zi-ling Xu Yong-Hai li jian-lin Lu Xiang-Yi Bu Ming-Tong Wei Wei-Dong Jia Department of Hepatic Surgery Anhui Provincial HospitalThe First Affiliated Hospital of USTCDivision of Life Science and MedicineUniversity of Science and Technology of ChinaHefei 230001Anhui ProvinceChina Department of Hepatic Surgery Anhui Provincial Hospital Affiliated to Anhui Medical UniversityAnhui Medical UniversityHefei 230001Anhui ProvinceChina Department of Anorectal Surgery the First People’s Hospital of HefeiHefei 230001Anhui ProvinceChina

BACKGROUND The prognosis for hepatocellular carcinoma(HCC)in the presence of cirrhosis is unfavourable,primarily attributable to the high incidence of *** To develop a machine learning model for predicting early recurrence(ER)of posthepatectomy HCC in patients with cirrhosis and to stratify patients’overall survival(OS)based on the predicted risk of *** In this retrospective study,214 HCC patients with cirrhosis who underwent curative hepatectomy were *** feature selection was conducted using the least absolute shrinkage and selection operator and recursive feature elimination ***-radiologic features were selected through univariate and multivariate logistic regression *** machine learning methods were used for model comparison,aiming to identify the optimal *** model’s performance was evaluated using the receiver operating characteristic curve[area under the curve(AUC)],calibration,and decision curve ***,the Kaplan-Meier(K-M)curve was used to evaluate the stratification effect of the model on patient *** Within this study,the most effective predictive performance for ER of post-hepatectomy HCC in the background of cirrhosis was demonstrated by a model that integrated radiomics features and clinical-radiologic *** the training cohort,this model attained an AUC of 0.844,while in the validation cohort,it achieved a value of *** K-M curves illustrated that the combined model not only facilitated risk stratification but also exhibited significant discriminatory ability concerning patients’*** The combined model,integrating both radiomics and clinical-radiologic characteristics,exhibited excellent performance in HCC with *** K-M curves assessing OS revealed statistically significant differences.

关键词： Machine learning Radiomics Hepatocellular carcinoma Cirrhosis Early recurrence Overall survival Computed tomography Prognosis Risk factor Delta-radiomics

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