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Ultra-high extinction ratio optical pulse generation with a thin film lithium niobate modulator for distributed acoustic sensing

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Photonics Research 2024年第1期12卷 40-50页

作者： yuAN shen XIAOQIAN SHU LINGMEI MA SHAOLIANG yu GENGXIN CHEN liu liu RENYOU GE BIGENG CHEN yuNJIANG RAO Research Center for Optical Fiber Sensing Zhejiang LaboratoryHangzhou 311100China Research Center for Intelligent Optoelectronic Computing Zhejiang LaboratoryHangzhou 311100China International Research Center for Advanced Photonics College of Optical Science and EngineeringZhejiang UniversityHangzhou 310058China Fiber Optics Research Center(FORC) Key Laboratory of Optical Fiber Sensing and CommunicationsUniversity of Electronic Science and Technology of ChinaChengdu 611731China

We experimentally demonstrate ultra-high extinction ratio(ER)optical pulse modulation with an electro-optical modulator(EOM)on thin film lithium niobate(TFLN)and its application for fiber optic distributed acoustic sensing(DAS).An interface carrier effect leading to a relaxation-tail response of TFLN EOM is discovered,which can be well addressed by a small compensation component following the main driving *** ultrahigh ER>50 dB is achieved by canceling out the tailed response during pulse modulation using the EOM based on a cascaded Mach–Zehnder interferometer(MZI)*** modulated optical_(√)pulses are then utilized as a probe light for a DAS system,showing a sensitivity up to-62.9 dB·rad∕Hz~2(7 pε/Hz)for 2-km single-mode sensing *** crosstalk suppression of 24.9 dB along the fiber is also obtained when the ER is improved from 20 dB to 50 dB,clearly revealing its importance to the sensing performance.

关键词： modulator pulse interferometer

SmartEagleEye:A Cloud-Oriented Webshell Detection System Based on Dynamic Gray-Box and Deep Learning

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Tsinghua Science and Technology 2024年第3期29卷 766-783页

作者： Xin liu Yingli Zhang Qingchen yu Jiajun Min Jun shen Rui Zhou Qingguo Zhou School of Information Science and Engineering Lanzhou UniversityLanzhou 730000China College of Computer Science and Technology Zhejiang UniversityHangzhou 310058China School of Computing and Information Technology University of WollongongWollongong 2500Australia

Compared with traditional environments,the cloud environment exposes online services to additional vulnerabilities and threats of cyber attacks,and the cyber security of cloud platforms is becoming increasingly prominent.A piece of code,known as a Webshell,is usually uploaded to the target servers to achieve multiple *** Webshell attacks has become a hot spot in current ***,the traditional Webshell detectors are not built for the cloud,making it highly difficult to play a defensive role in the cloud ***,a Webshell detection system based on deep learning that is successfully applied in various scenarios,is proposed in this *** system contains two important components:gray-box and neural network *** gray-box analyzer defines a series of rules and algorithms for extracting static and dynamic behaviors from the code to make the decision *** neural network analyzer transforms suspicious code into Operation Code(OPCODE)sequences,turning the detection task into a classification *** experiment results show that SmartEagleEye achieves an encouraging high detection rate and an acceptable false-positive rate,which indicate its capability to provide good protection for the cloud environment.

关键词： Webshell detection cloud web security deep learning

Global burden of vision loss attributable to household air pollution from 1990 to 2019:A trend analysis and 10-year prediction

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Chinese Medical Journal 2024年第10期137卷 1231-1233页

作者： Cong Li Zuoqian Jing Jianbo shen Shunming liu Lei liu Xiaohong Yang Honghua yu Department of Ophthalmology Guangdong Eye InstituteGuangdong Provincial People’s Hospital(Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhouGuangdong 510080China School of Medicine South China University of Technology Guangzhou 510006China Department of Ophthalmology The First Hospital of China Medical UniversityShenyangLiaoning 110001China Department of Neurosurgery Jincheng People’s HospitalJinchengShanxi 048026China Guangdong Provincial Key Laboratory of Artificial Intelligence in Medical Image Analysis and Application Guangzhou 510080China

To the Editor:Blindness and vision loss(BVL)constitute a growing concern affecting an ever-expanding global population.[1]Globally,approximately 40%of the population relies on burning solid fuels for both cooking and *** air pollution(HAP)predominantly arises from the incomplete combustion of solid fuels used for ***,the adverse effects of HAP on eye health in human have ascended as a salient concern for environmental,ophthalmic,and public health.[2]Gaining a comprehensive understanding of the burden and temporal trends of BVL due to HAP is the essential basis for health program planning.

关键词： pollution cooking prediction

Investigation of Ce/BEA as a passive NO_(x)adsorber:*** aging deactivation mechanism

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Journal of Rare Earths 2024年第8期42卷 1524-1530,I0004页

作者： Yiying Ding Minghui yu Xiaojie yu Meiqing shen Jianqiang Wang Jun Wang Gurong shen School of Chemical Engineering and Technology Tianjin UniversityTianjin300350China School of Materials Science and Engineering Tianjin UniversityTianjin300350China National Rare Earth Catalysis Research Institute Dongying257000China

Ce/BEA has the potential to be applied as a novel passive NO_(x)absorber(PNA)in the after-treatment of vehicles due to its considerable NO_(x)storage ***,as a vehicle exhaust after-treatment material,it must withstand the test of long-term hydrothermal *** work examined the deactivation mechanism of Ce/BEA during hydrothermal aging.3.0 wt%Ce/BEA was prepared using the ionexchange method,and then subjected to hydrothermal treatment at 650℃with 10%H_(2)O for 1-12 h to obtain samples with different aging *** comparison,the H-BEA support was aged under the same ***-Emmett-Teller(BET)method,X-ray diffraction(XRD),NH_(3)temperature programmed reduction(NH_(3)-TPD),^(27)Al MAS nuclear magnetic resonance(^(27)Al MAS NMR),H_(2)temperature programmed reduction(H_(2)-TPR),and high resolution-transmission electron microscopy(HR-TEM)were performed to characterize the changes in PNA performance,structure,Ce species,and *** HR-TEM and H_(2)-TPR results show that CeO_(x)particles appear after hydrothermal aging,which results from the detachment and aggregation of active Ce *** on the^(27)Al MAS NMR results,we conclude that BEA zeolite dealumination leads to the loss of acidic sites and the transformation of active Ce species on the acidic sites into the less active CeO_(x).This is the primary reason for the hydrothermal aging deactivation of Ce/BEA.

关键词： Passive NO_(x)adsorber Ce/BEA Hydrothermal aging CeO_(x) Dealumination Rare earths

Hydrophobic modification of polysaccharides and the construction and properties of their micelles:a review of applications in the field of biomedicine

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Science China Chemistry 2024年第6期67卷 1881-1903页

作者： Dayang Wang Xiaohua Li Huanchen Yao Xin liu Yan Gao Hailin Cong Bing yu Youqing shen College of Chemistry and Chemical Engineering College of Life SciencesCollege of Materials Science and EngineeringInstitute of Biomedical Materials and EngineeringQingdao UniversityQingdao266071China State Key Laboratory of Bio-Fibers and Eco-Textiles Qingdao UniversityQingdao266071China School of Materials Science and Engineering Shandong University of TechnologyZibo255000China Key Laboratory of Biomass Chemical Engineering of Ministry of Education Center for Bionanoengineeringand Department of Chemical and Biological EngineeringZhejiang UniversityHangzhou310027China

Nanomedicine delivery technology plays an important role in modern medicine and has shown good therapeutic effects in scientific *** have the characteristics of wide sources,excellent biocompatibility,and *** addition,there are multifunctional groups on the main chain of polysaccharides,which can be surface-modified or functionalized to have targeting ability through specific sugar *** polysaccharide micelles with good biocompatibility,degradability,high safety,easy structural modification,and special core-shell structure are regarded as ideal carriers for ***,this review is focused on the hydrophobic modification designs of polysaccharides,the preparation methods and characteristics of micelles,and the applications of amphiphilic polysaccharide micelles in the field of *** is expected to provide some ideas and inspiration for the design of polysaccharide drug carriers.

关键词： polysaccharide hydrophobic modification micelle drug delivery biomedicine

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Sequential reactant water management by complementary multisite catalysts for surpassing platinum hydrogen evolution activity

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Nano Research 2024年第3期17卷 1232-1241页

作者： yu Lin Defang Ding Shicheng Zhu Qunlei Wen Huangjingwei Li Zhen Li Youwen liu Yi shen China Engineering Research Center of Nano-Geomaterials of Ministry of Education Faculty of Materials Science and ChemistryChina University of GeosciencesWuhan 430078China State Key Laboratory of Materials Processing and Die&Mould Technology and School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

Alkaline hydrogen evolution reaction(HER)offers a near-zero-emission approach to advance hydrogen ***,the activity limited by the multiple reaction steps involving H_(2)O molecules transfer,absorption,and activation still unqualified the thresholds of economic ***,we proposed a multisite complementary strategy that incorporates hydrophilic Mo and electrophilic V into Ni-based catalysts to divide the distinct steps on atomically dispersive sites and thus realize sequential regulation of the HER *** Isotopic labeled in situ Raman spectroscopy describes 4-coordinated hydrogen bonded H_(2)O to be free H_(2)O passing the inner Helmholtz plane in the vicinity of the catalysts under the action of hydrophilic Mo ***,potential-dependent electrochemical impedance spectroscopy(EIS)reveals that electrophilic V sites with abundant 3d empty orbitals could activate the lone-pair electrons in the free H_(2)O molecules to produce more protic hydrogen,and dimerize into H_(2) at the Ni *** the sequential management of reactive H_(2)O molecules,NiMoV oxides multisite catalysts surpass Pt/C hydrogen evolution activity(49 mV@10 mA∙cm^(-2) over 140 h).Profoundly,this study provides a tangible model to deepen the comprehension of the catalyst–electrolyte interface and create efficient catalysts for diverse reactions.

关键词： hydrogen evolution activity complementary multisite catalysts sequential reactive water management interfacial water molecules

Improved Double Deep Q Network-Based Task Scheduling Algorithm in Edge Computing for Makespan Optimization

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Tsinghua Science and Technology 2024年第3期29卷 806-817页

作者： Lei Zeng Qi liu Shigen shen Xiaodong liu School of Computer Science Nanjing University of Information Science and TechnologyNanjing 210044China School of Software Nanjing University of Information Science and TechnologyNanjing 210044China School of Information Engineering Huzhou UniversityHuzhou 313000China School of Computing Edinburgh Napier UniversityEdinburghEH105DTUK

Edge computing nodes undertake an increasing number of tasks with the rise of business ***,how to efficiently allocate large-scale and dynamic workloads to edge computing resources has become a critical *** study proposes an edge task scheduling approach based on an improved Double Deep Q Network(DQN),which is adopted to separate the calculations of target Q values and the selection of the action in two networks.A new reward function is designed,and a control unit is added to the experience replay unit of the *** management of experience data are also modified to fully utilize its value and improve learning *** learning agents usually learn from an ignorant state,which is *** such,this study proposes a novel particle swarm optimization algorithm with an improved fitness function,which can generate optimal solutions for task *** optimized solutions are provided for the agent to pre-train network parameters to obtain a better cognition *** proposed algorithm is compared with six other methods in simulation *** show that the proposed algorithm outperforms other benchmark methods regarding makespan.

关键词： edge computing task scheduling reinforcement learning makespan Double Deep Q Network(DQN)

Investigation of Ce/BEA as a passive NO_(x)adsorber:*** occurrences of cerium and adsorption behavior

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Journal of Rare Earths 2024年第7期42卷 1265-1271,I0003页

作者： Minghui yu Yiying Ding Xiaojie yu Siwei Yan Meiqing shen Jianqiang Wang Jun Wang Gurong shen School of Materials Science and Engineering Tianjin UniversityTianjin300350China School of Chemical Engineering and Technology Tianjin UniversityTianjin300350China National Rare Earth Catalysis Research Institute Dongying257000China

Ce/BEA has great potential as a passive NO_(x)absorber(PNA)to reduce the NO_(x)emissions during the cold start phase especially in diesel engine for its high resistance to CO and suitable NO_(x)desorption temperature ***,as a novel material,its physical and chemical properties still remain *** this work,Ce/BEA was synthesized by ion-exchange method to identify the active species in NO_(x)adsorption,compared with aggregated Ce species in Ce/SiAlO_(x) prepared by impregnation method.X-ray diffraction(XRD),high resolution-transmission electron microscopy(HR-TEM)and aberration-corrected-scanning transmission electron microscopy(AC-STEM)were performed to confirm the isolated single atom formation of Ce species in Ce/***-vis diffraction reflection spectra(DRS)and X-ray photoelectron spectroscopy(XPS)were conducted to find the difference of chemical environment between the isolated Ce species and aggregated *** performance evaluation and temperature programmed reduction of hydrogen(H_(2)-TPR)results show the high NO_(x)storage capacity and active oxygen species quantity in Ce/*** is also found that the main NO_(x)adsorption species are Ce^(4+)-O^(∗)rather than Ce^(3+).NO_(x)-diffuse reflectance infrared Fourier transform spectroscopy(NO_(x)-DRIFTS)confirms that the bidentate nitrite species are the critical NO_(x)adsorption intermediates and the conception of NO_(x)adsorption and desorption processes is proposed.

关键词： Passive NO_(x)absorber Ce/BEA Isolated Ce species Rare earths

Phenylalanine deprivation inhibits multiple myeloma progression by perturbing endoplasmic reticulum homeostasis

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Acta Pharmaceutica Sinica B 2024年第8期14卷 3493-3512页

作者： Longhao Cheng Xiaoxue Wang Aijun liu Ying Zhu Hu Cheng Jiangling yu Lili Gong Honglin liu Guolin shen Lihong liu Institute of Clinical Medical Sciences ChinaeJapan Friendship HospitalCapital Medical UniversityBeijing 100029China Department of Pharmacy ChinaeJapan Friendship HospitalBeijing 100029China Beijing Chao-Yang Hospital Capital Medical UniversityBeijing 100020China Institute of Chemicals Safety Chinese Academy of Inspection and QuarantineBeijing 100020China

Amino acid metabolic remodeling is a hallmark of cancer,driving an increased nutritional demand for amino *** acids are pivotal for energetic regulation,biosynthetic support,and homeostatic maintenance to stimulate cancer ***,the role of phenylalanine in multiple myeloma(MM)remains ***,we demonstrate that phenylalanine levels in MM patients are decreased in plasma but elevated in bone marrow(BM)*** the treatment,phenylalanine levels increase in plasma and decrease in *** suggests that changes in phenylalanine have diagnostic value and that phenylalanine in the BM microenvironment is an essential source of nutrients for MM *** requirement for phenylalanine by MM cells exhibits a similar *** phenylalanine utilization suppresses MM cell growth and provides a synergistic effect with Bortezomib(BTZ)treatment in vitro and murine ***,phenylalanine deprivation induces excessive endoplasmic reticulum stress and leads to MM cell apoptosis through the ATF3eCHOPeDR5 *** with ATF3 significantly affects phenylalanine deprivation *** conclusion,we have identified phenylalanine metabolism as a characteristic feature of MM metabolic *** is necessary for MM proliferation,and its aberrant demand highlights the importance of lowphenylalanine diets as an adjuvant treatment for MM.

关键词： Multiple myeloma Phenylalanine Amino acid metabolism Nutrient deprivation Cancer therapy Endoplasmic reticulum stress ATF3 Apoptosis