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大直径盾构始发端头加固区域隧道变形差异特征实测研究

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城市轨道交通研究 2024年第7期27卷 113-119,126页

作者：杨光高俊华甘彬霖黄忠凯张吾渝张冬梅中交隧道工程局有限公司上海机场联络线项目部南京211106 同济大学上海自主智能无人系统科学中心上海200092 同济大学土木工程学院上海200092 青海大学土木水利学院西宁810016

[目的]为保证盾构顺利始发,通常对始发工作井周围区域进行局部地层加固,导致加固区域两侧隧道变形存在差异,影响隧道结构安全,但目前变形差异特征及其规律尚不明确,因此有必要对大直径盾构始发端头加固区域隧道变形的差异特征进行实测... 详细信息

[目的]为保证盾构顺利始发,通常对始发工作井周围区域进行局部地层加固,导致加固区域两侧隧道变形存在差异,影响隧道结构安全,但目前变形差异特征及其规律尚不明确,因此有必要对大直径盾构始发端头加固区域隧道变形的差异特征进行实测研究。[方法]以上海市域铁路机场联络线大直径盾构隧道工程为例,基于现场实测数据,分析了始发工作井加固区域盾构掘进施工地面竖向变形、隧道竖向变形、隧道横向收敛的差异特征,分析了地层局部加固对软土地层大直径盾构隧道掘进差异变形的影响规律。[结果及结论]地层局部加固导致盾构隧道变形响应差异显著;地面竖向变形发展由非加固区的扰动沉降、卸荷隆起、固结沉降和相对稳定4个阶段,转变为加固区的扰动沉降、卸荷隆起和相对稳定3个阶段;对于隧道竖向变形,非加固区一侧以波动上浮为主,加固区以沉降为主,导致临界区域差异沉降达到0.022%L s(L s为隧道轴线两个监测点间距),超过管片结构差异沉降预警值;对于隧道横向收敛,加固区隧道结构呈竖鸭蛋变形特征,非加固区呈横鸭蛋变形特征;施工中,应重点防范临界区域管片结构差异沉降和差异收敛造成的环缝螺栓剪切破坏和螺栓孔混凝土损伤。

关键词：盾构隧道端头加固区域隧道变形差异现场监测

Atomically dispersed materials:Ideal catalysts in atomic era

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Nano Research 2024年第1期17卷 18-38页

作者： Tao gan Dingsheng Wang Department of Chemistry Tsinghua UniversityBeijing 100084China

Catalysts can accelerate the chemical reaction rate and effectively promote the molecules transformation,which is of great significance in the research of chemical industry and material *** extreme utilization of reactive sites has led to the emergence and development of atomically dispersed materials(ADMs).The highly active coordination unsaturated metal sites and fully utilized metal atoms make ADMs show great potential in catalytic *** adjustment of coordination environment and electronic structure provides more possibilities for constructing reactive centers with different *** review summarized the application and research progress of ADMs in different *** design strategy and structure–activity relationship of ADMs for specific reactions were summarized and ***,we also provided advices for the challenges and opportunities faced by ADMs in catalytic reactions.

关键词： atomically dispersed materials catalysis organic synthesis battery sensor enzyme

Progress Report on ASO-S: 2022–2024

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空间科学学报 2024年第4期44卷 687-689页

作者： gan Weiqun Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023

The Advanced Space-based Solar Observatory(ASO-S)marked China's first comprehensive solar mission in *** upon the previous reports covering 2018-2020 and 2020-2022,we present here an update on the ASO-S made from 2022 to *** August 2022,ASO-S completed its Phase D study and was successfully launched on October 9,*** commissioning phase was carried out and concluded within the first nine months following the *** data and associated analysis software have been opened to the community and the research on the early ASO-S data has been well *** anticipate also the achievements in data research pertaining to ASO-S in the near future.

关键词： Space astronomy Solar physics Spacecraft

Distributed Least Squares Algorithm of Continuous-Time Stochastic Regression Model Based on Sampled Data

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Journal of Systems Science & Complexity 2024年第2期37卷 609-628页

作者： ZHU Xinghua gan Die LIU Zhixin The Key Laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of Sciencesand School of Mathematical SciencesUniversity of Chinese Academy of SciencesBeijing 100190China Zhongguancun Laboratory Beijing 100094China

In this paper,the authors consider the distributed adaptive identification problem over sensor networks using sampled data,where the dynamics of each sensor is described by a stochastic differential *** minimizing a local objective function at sampling time instants,the authors propose an online distributed least squares algorithm based on sampled data.A cooperative non-persistent excitation condition is introduced,under which the convergence results of the proposed algorithm are established by properly choosing the sampling time *** upper bound on the accumulative regret of the adaptive predictor can also be ***,the authors demonstrate the cooperative effect of multiple sensors in the estimation of unknown parameters by computer simulations.

关键词： Cooperative excitation condition distributed least squares regret sampled data stochastic differential equation

N-Heterocyclic carbene-catalyzed enantioselective(dynamic) kinetic resolutions and desymmetrizations

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Science China Chemistry 2024年第2期67卷 482-511页

作者： Yi Zhang Hui Cai Xiuhai gan Zhichao Jin National Key Laboratory of Green Pesticide Key Laboratory of Green Pesticide and Agricultural BioengineeringMinistry of EducationGuizhou UniversityHuaxi DistrictGuiyang550025China

N-heterocyclic carbene-catalyzed enantioselective kinetic resolutions,dynamic kinetic resolutions,and desymmetrization reactions are systematically *** content is organized according to the activation modes involved i... 详细信息

关键词： N-heterocyclic carbene kinetic resolution dynamic kinetic resolution desymmetrization organocatalysis

A Sustainable Dual Cross‑Linked Cellulose Hydrogel Electrolyte for High‑Performance Zinc‑Metal Batteries

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Nano-Micro Letters 2024年第6期16卷 63-75页

作者： Haodong Zhang Xiaotang gan Yuyang Yan Jinping Zhou Hubei Engineering Center of Natural Polymers‑Based Medical Materials Key Laboratory of Biomedical Polymers of Ministry of EducationCollege of Chemistry and Molecular SciencesWuhan UniversityWuhan 430072People’s Republic of China Zhongnan Hospital of Wuhan University Institute of Hepatobiliary Diseases of Wuhan UniversityTransplant Center of Wuhan UniversityWuhan 430072People’s Republic of China

Aqueous rechargeable Zn-metal batteries(ARZBs)are considered one of the most promising candidates for grid-scale energy ***,their widespread commercial application is largely plagued by three major challenges:The uncontrollable Zn dendrites,notorious parasitic side reactions,and sluggish Zn^(2+) ion *** address these issues,we design a sustainable dual crosslinked cellulose hydrogel electrolyte,which has excellent mechanical strength to inhibit dendrite formation,high Zn^(2+) ions binding capacity to suppress side reaction,and abundant porous structure to facilitate Zn^(2+) ions ***,the Zn||Zn cell with the hydrogel electrolyte can cycle stably for more than 400 h under a high current density of 10 mA cm^(−2).Moreover,the hydrogel electrolyte also enables the Zn||polyaniline cell to achieve high-rate and long-term cycling performance(>2000 cycles at 2000 mA g^(−1)).Remarkably,the hydrogel electrolyte is easily accessible and biodegradable,making the ARZBs attractive in terms of scalability and sustainability.

关键词： Cellulose Dual cross-linked Aqueous rechargeable Zn-metal batteries Hydrogel electrolyte

Blast waveform tailoring using controlled venting in blast simulators and shock tubes

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Defence Technology（防务技术） 2024年第7期37卷 14-26页

作者： Edward Chern Jinn gan Alex Remennikov David Ritzel Faculty of Engineering and Information Sciences University of WollongongWollongongNSW2522Australia Dyn-FX Consulting Ltd 19 Laird Ave NorthAmherstburgONN9V 2T5Canada

A critical challenge of any blast simulation facility is in producing the widest possible pressure-impulse range for matching against equivalent high-explosive *** tubes and blast simulators are often constrained with the lack of effective ways to control blast wave profiles and as a result have a limited performance *** wave shaping techniques employed in some facilities are reviewed but often necessitate extensive geometric modifications,inadvertently cause flow anomalies,and/or are only applicable under very specific *** paper investigates controlled venting as an expedient way for waveforms to be tuned without requiring extensive modifications to the driver or existing geometry and could be widely applied by existing and future blast simulation and shock tube *** use of controlled venting is demonstrated experimentally using the Advanced Blast Simulator(shock tube)at the Australian National Facility of Physical Blast Simulation and via numerical flow simulations with Computational Fluid *** venting is determined as an effective method for mitigating the impact of re-reflected waves within the blast *** control method also allows for the adjustment of parameters such as tuning the peak overpressure,the positive phase duration,and modifying the magnitude of the negative phase and the secondary shock of the blast *** paper is concluded with an illustration of the potential expanded performance range of the Australian blast simulation facility when controlled venting for blast waveform tailoring as presented in this paper is applied.

关键词： Advanced blast simulator Shock wave propagation Far-field explosion Blast loads Blast waves Computational fluid dynamics

WEAK APPROXIMATIONS OF STOCHASTIC PARTIAL DIFFERENTIAL EQUATIONS WITH FRACTIONAL NOISE

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Journal of Computational Mathematics 2024年第3期42卷 735-754页

作者： Meng Cai Siqing gan Xiaojie Wang School of Mathematics and Statistics HNP-LAMACentral South UniversityChangshaChina

This paper aims to analyze the weak approximation error of a fully discrete scheme for a class of semi-linear parabolic stochastic partial differential equations(SPDEs)driven by additive fractional Brownian motions with the Hurst parameter H∈(1/2,1).The spatial approximation is performed by a spectral Galerkin method and the temporal discretization by an exponential Euler *** far as we know,the weak error analysis for approximations of fractional noise driven SPDEs is absent in the literature.A key difficulty in the analysis is caused by the lack of the associated Kolmogorov *** the present work,a novel and efficient approach is presented to carry out the weak error analysis for the approximations,which does not rely on the associated Kolmogorov equations but relies on the Malliavin *** the best of our knowledge,the rates of weak convergence,shown to be higher than the strong convergence rates,are revealed in the fractional noise driven SPDE setting for the first *** examples corroborate the claimed weak orders of convergence.

关键词： Parabolic SPDEs Fractional Brownian motion Weak convergence rates Spec-tral Galerkin method Exponential Euler method Malliavin calculus

Production of linear alkylbenzene over Ce containing Beta zeolites

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Chinese Journal of Chemical Engineering 2024年第3期67卷 220-227页

作者： Shiqi Zhang Shengzhi gan Baoyu Liu Jinxiang Dong School of Chemical Engineering and Light Industry Guangdong Provincial Key Laboratory of Plant Resources BiorefineryGuangzhou Key Laboratory of Clean Transportation Energy ChemistryGuangdong University of TechnologyGuangzhou 510006China Jieyang Branch of Chemistry and Chemical Engineering Guangdong Laboratory(Rongjiang Laboratory) Jieyang 515200China

Ce-encapsulated Beta zeolite was synthesized by a one-pot hydrothermal method with citric acid complexing Ce in the absence of Na *** citric acid can effectively prevent the deposition of Ce species during the hydrothermal synthesis of zeolites,leading to uniform distribution of Ce cluster in the framework of Beta ***,the sodium-free synthesis system resulted that the Brønsted acid sites were mainly located on the straight channels and external surface of Beta zeolites,improving the utilization of Brønsted acid *** addition,Ce encapsulated Beta zeolites showed enhanced activity and robust stability in the alkylation of benzene with 1-dodecene based on the synergistic effect between Ce species and Brønsted acid sites,which pave the way for its practical application in the production of alkylbenzene.

关键词： Beta zeolites Catalysis Alkylation Long-chain olefins