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Silicon dioxide-protection boosting the peroxidase-like activity of Fe single-atom catalyst for combining chemo-photothermal therapy

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Nano Research 2024年第6期17卷 4924-4933页

作者： yu fan yu Yi Hongpan Rong Jiatao zhang Beijing Key Laboratory of Construction-Tailorable Advanced Functional Materials and Green Applications School of Materials Science&EngineeringBeijing Institute of TechnologyBeijing 100081China CAS Center for Excellence in Nanoscience CAS KeyLaboratory for Biomedical Effects of Nanomaterials and NanosafetyNational Center for Nanoscience and Technology(NCNST)Beijing 100190China Key Laboratory of Medical Molecule Science and Pharmaceutics Engineering Ministry of Industry and Information TechnologySchool of Chemistry&Chemical EngineeringBeijing Key Laboratory of Construction-Tailorable Advanced Functional Materials and Green ApplicationsSchool of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China

Carbon-based single-atom catalysts(SACs)have been widely studied in the field of biomedicine due to their excellent catalytic ***,carbon-based SACs usually aggregate during pyrolysis,which leads to the reduction of catalytic ***,we describe a method to improve the monodispersion of SACs using silicon dioxide as a protective *** decoration of silicon dioxide serves as a buffer layer for individual nanoparticles,which is not destroyed during the pyrolysis process,ensuring the single-particle dispersion of the nanoparticles after *** approach increased the hydroxyl groups on the surface of Fe-SAC(Fe-SAC-SE)and improved its water solubility,resulting in a four times enhancement of the peroxidase(POD)-like activity of Fe-SAC-SE(58.4 U/mg)than that of non-protected SACs(13.9 U/mg).The SiO_(2)-protection approach could also improve the catalytic activities of SACs with other metals such as Mn,Co,Ni,and Cu,indicating its generality for SACs *** advantage of the high POD-like activity,photothermal properties,and large specific surface area of Fe-SAC-SE,we constructed a synergistic therapeutic system(Fe-SAC-SE@DOX@PEG)for combining the photothermal therapy,catalytic therapy,and *** was verified that the photothermal properties of Fe-SAC-SE@DOX@PEG could effectively improve its POD-like activity,exhibiting excellent tumor-killing performance at the cellular *** work may provide a general approach to improve the performances of SACs for disease therapy and diagnosis.

关键词： single-atom catalysts peroxidase-like activity SiO2-protection photothermal therapy catalytic therapy chemotherapy

A probabilistic generative model for tracking multi-knowledge concept mastery probability

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Frontiers of Computer Science 2024年第3期18卷 155-170页

作者： Hengyu LIU Tiancheng zhang fan LI Minghe yu Ge yu School of Computer Science and Engineering Northeastern UniversityShenyang 110169China Software College Northeastern UniversityShenyang 110169China

Knowledge tracing aims to track students’knowledge status over time to predict students’future performance *** a real environment,teachers expect knowledge tracing models to provide the interpretable result of knowledge *** chain-based knowledge tracing(MCKT)models,such as Bayesian Knowledge Tracing,can track knowledge concept mastery probability over ***,as the number of tracked knowledge concepts increases,the time complexity of MCKT predicting student performance increases exponentially(also called explaining away problem).When the number of tracked knowledge concepts is large,we cannot utilize MCKT to track knowledge concept mastery probability over *** addition,the existing MCKT models only consider the relationship between students’knowledge status and problems when modeling students’responses but ignore the relationship between knowledge concepts in the same *** address these challenges,we propose an inTerpretable pRobAbilistiC gEnerative moDel(TRACED),which can track students’numerous knowledge concepts mastery probabilities over *** solve explain away problem,we design long and short-term memory(LSTM)-based networks to approximate the posterior distribution,predict students’future performance,and propose a heuristic algorithm to train LSTMs and probabilistic graphical model *** better model students’exercise responses,we proposed a logarithmic linear model with three interactive strategies,which models students’exercise responses by considering the relationship among students’knowledge status,knowledge concept,and *** conduct experiments with four real-world datasets in three knowledge-driven *** experimental results show that TRACED outperforms existing knowledge tracing methods in predicting students’future performance and can learn the relationship among students,knowledge concepts,and problems from students’exercise *** also conduct several case *** case studies show that

关键词： probabilistic graphical model deep learning knowledge tracing learner modeling

Entangled photons enabled ultrafast stimulated Raman spectroscopy for molecular dynamics

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Light(Science & Applications) 2024年第8期13卷 1615-1622页

作者： Jiahao Joel fan Zhe-yu Ou Zhedong zhang Department of Physics City University of Hong KongKowloonHong Kong SARChina City University of Hong Kong Shenzhen Research InstituteShenzhenGuangdongChina

Quantum entanglement has emerged as a great resource for studying the interactions between molecules and *** propose a new scheme of stimulated Raman scattering with entangled photons.A quantum ultrafast Raman spectroscopy is developed for condensed-phase molecules,to monitor the exciton populations and *** results are obtained,showing an entanglement-enabled time-frequency scale not attainable by classical *** Raman signal presents an unprecedented selectivity of molecular correlation functions,as a result of the Hong-Ou-Mandel *** work suggests a new paradigm of using an unconventional interferometer as part of spectroscopy,with the potential to unveil advanced information about complex materials.

关键词： materials spectroscopy selectivity

Investigation of electrostatically tunable adhesion and instability of flying head slider

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Friction 2024年第3期12卷 462-473页

作者： fan zhang yu WANG yueqiang HU Mingquan zhang Baotong LI School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an 710049China National Engineering Research Center for High Efficiency Grinding College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China

The interfacial adhesion between microstructures is inevitable in a micro-electro-mechanical system(e.g.,hard disk drive(HDD)),which may lead to complicated microtribodynamics *** research has investigated the effect of surface potential on the interfacial adhesion and microtribodynamics of the head–disk interface(HDI)in an HDD.A dynamic continuum surface force model,where the electrowetting is considered,is proposed to evaluate the interfacial interaction,and then employed into a two-degree-of-freedom(2DOF)model to theoretically analyze the potential influence mechanism on the *** results confirm that the elimination of potential can effectively repress the adhesion retention,which is further proved by the measured slider response with a laser Doppler vibrometer(LDV).Moreover,the effect of the potential on the adhesion-induced instability is also analyzed through the phase *** tells that the critical stable flying height can be lowered with the elimination of potential.

关键词： electric field(EF) retention instability adhesion

Committed-programming reductions: formalizations,implications and relations

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Science China(Information Sciences) 2024年第10期67卷 151-171页

作者： Jiang zhang yu yu Dengguo FENG Shuqin fan Zhenfeng zhang State Key Laboratory of Cryptology Department of Computer Science and Engineering Shanghai Jiao Tong University Trusted Computing and Information Assurance Laboratory Institute of SoftwareChinese Academy of Sciences

In this work, we introduce a class of black-box(BB) reductions called committed-programming reduction(CPRed) in the random oracle model(ROM) and obtain the following interesting results:(1) we demonstrate that some well-known schemes, including the full-domain hash(FDH) signature(Eurocrypt1996) and the Boneh-Franklin identity-based encryption(IBE) scheme(Crypto 2001), are provably secure under CPReds;(2) we prove that a CPRed associated with an instance-extraction algorithm implies a reduction in the quantum ROM(QROM). This unifies several recent results, including the security of the Gentry-Peikert-Vaikuntanathan IBE scheme by Zhandry(Crypto 2012) and the key encapsulation mechanism(KEM) variants using the Fujisaki-Okamoto transform by Jiang et al.(Crypto 2018) in the ***, we show that CPReds are incomparable to non-programming reductions(NPReds) and randomly-programming reductions(RPReds) formalized by Fischlin et al.(Asiacrypt 2010).

关键词： provable security random oracle model quantum random oracle model black-box reduction/separation programmability

VARIABLE STEP-SIZE BDF3 METHOD FOR ALLEN-CAHN EQUATION

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Journal of Computational Mathematics 2024年第5期42卷 1380-1406页

作者： Minghua Chen fan yu Qingdong zhang Zhimin zhang School of Mathematics and Statistics Gansu Key Laboratory of Applied Mathematics and Complex SystemsLanzhou UniversityLanzhou 730000China Department of Mathematics Wayne State UniversityDetroitMI 48202USA

In this work,we analyze the three-step backward differentiation formula(BDF3)method for solving the Allen-Cahn equation on variable *** BDF2 method,the discrete orthogonal convolution(DOC)kernels are positive,the stability and convergence analysis are well established in[Liao and zhang,***.,90(2021),1207–1226]and[Chen,yu,and zhang,arXiv:2108.02910,2021].However,the numerical analysis for BDF3 method with variable steps seems to be highly nontrivial due to the additional degrees of freedom and the non-positivity of DOC *** developing a novel spectral norm inequality,the unconditional stability and convergence are rigorously proved under the updated step ratio restriction rk:=τk/τk−1≤1.405 for BDF3 ***,numerical experiments are performed to illustrate the theoretical *** the best of our knowledge,this is the first theoretical analysis of variable steps BDF3 method for the Allen-Cahn equation.

关键词： Variable step-size BDF3 method Allen-Cahn equation Spectral norm inequality Stability and convergence analysis

Plant RNA-binding proteins:Phase separation dynamics and functional mechanisms underlying plant development and stress responses

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Molecular Plant 2024年第4期17卷 531-551页

作者： Sheng fan yu zhang Shaobo Zhu Lisha Shen Temasek Life Sciences Laboratory 1 Research LinkNational University of Singapore1 Research LinkSingapore 117604Singapore Department of Biological Sciences National University of Singapore14 Science Drive 4Singapore 117543Singapore

RNA-binding proteins(RBPs)accompany RNA from synthesis to decay,mediating every aspect of RNA metabolism and impacting diverse cellular and developmental processes in *** RBPs undergo phase separation along with their bound RNA to form and function in dynamic membraneless biomolecular condensates for spatiotemporal coordination or regulation of RNA *** evidence suggests that phase-separating RBPs with RNA-binding domains and intrinsically disordered regions play important roles in plant development and stress ***,we summarize the current knowledge about how dynamic partitioning of RBPs into condensates controls plant development and enables sensing of experimental changes to confer growth plasticity under stress conditions,with a focus on the dynamics and functional mechanisms of RBP-rich nuclear condensates and cytoplasmic granules in mediating RNA *** also discuss roles of multiple factors,such as environmental signals,protein modifications,and N6-methyladenosine RNA methylation,in modulating the phase separation behaviors of RBPs,and highlight the prospects and challenges for future research on phase-separating RBPs in crops.

关键词： RNA-binding proteins phase separation biomolecular condensates RNA metabolism development stress resilience

Vibration Control of the Rail Grinding Vehicle with Abrasive Belt Based on Structural Optimization and Lightweight Design

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Chinese Journal of Mechanical Engineering 2024年第3期37卷 311-337页

作者： Wengang fan Shuai zhang Zhiwei Wu Yi Liu Jiangnan yu School of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China Key Laboratory of Vehicle Advanced Manufacturing Measuring and Control TechnologyMinistry of EducationBeijing 100044China China Railway Materials Operation and Maintenance Technology Co. LtdBeijing 100036China

As a new grinding and maintenance technology,rail belt grinding shows significant advantages in many applications The dynamic characteristics of the rail belt grinding vehicle largely determines its grinding performance and service *** order to explore the vibration control method of the rail grinding vehicle with abrasive belt,the vibration response changes in structural optimization and lightweight design are respectively analyzed through transient response and random vibration simulations in this ***,the transient response simulation analysis of the rail grinding vehicle with abrasive belt is carried out under operating conditions and non-operating ***,the vibration control of the grinding vehicle is implemented by setting vibration isolation elements,optimizing the structure,and increasing ***,in order to further explore the dynamic characteristics of the rail grinding vehicle,the random vibration simulation analysis of the grinding vehicle is carried out under the condition of the horizontal irregularity of the American AAR6 ***,by replacing the Q235 steel frame material with 7075 aluminum alloy and LA43M magnesium alloy,both vibration control and lightweight design can be achieved *** results of transient dynamic response analysis show that the acceleration of most positions in the two working conditions exceeds the standard value in GB/T 17426-1998 *** optimizing the structure of the grinding vehicle in three ways,the average vibration acceleration of the whole car is reduced by about 55.1%from 15.6 m/s^(2) to 7.0 m/s^(2).The results of random vibration analysis show that the grinding vehicle with Q235 steel frame does not meet the safety conditions of 3σ.By changing frame material,the maximum vibration stress of the vehicle can be reduced from 240.7 MPa to 160.0 MPa and the weight of the grinding vehicle is reduced by about 21.7%from 1500 kg to 1175 *** modal analysis results indic

关键词： Vibration control Dynamic characteristics Structural optimization Lightweight design Modal analysis

Cyclodextrin nanofilms with hydrophobic and hydrophilic channels for solvent permeation and molecular sieving

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Nano Research 2024年第7期17卷 6638-6644页

作者： Kai zhang yu Dai Yongli Shi Zhaoxin zhang Linji Li Xiaojin zhang fan Xia Faculty of Materials Science and Chemistry China University of GeosciencesWuhan 430074China Henan Academy of Geology Zhengzhou 450052China

Nanofilms that can fast permeate solvents and accurately sieve molecules are of significant importance for separation.A promising strategy is to align the inner cavities of macrocycles into the channels within nanofilms,and control the channel size by selecting the ***,the channels outside the macrocycles are ***,we prepare nanofilms with hydrophobic channels(cyclodextrin inner cavity)and hydrophilic channels(cyclodextrin outer space)through interfacial polymerization of azobenzene-4,4’-dicarbonyl dichloride and amino-functionalizedβ-*** utilizing the significant geometric changes caused by the photoisomerization of azobenzene,nanofilms with adjustable hydrophilic channel sizes were *** nanofilms have high permeability to polar and non-polar solvents,and can distinguish molecules with almost the same molecular weight but different *** work expands the development of next-generation nanofilms generated through interfacial polymerization by incorporating rational molecular design.

关键词： nanofilm β-cyclodextrin azobenzene interfacial polymerization solvent permeation molecular sieving