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Dynamic symmetry breaking and structure-preserving analysis on thelongitudinal wave in an elastic rod with a variable cross-section

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Applied Mathematics and Mechanics(English Edition) 2022年第1期43卷 81-92页

作者： jingjing HU Mengbo XU Weipeng HU Ruisong JIANG Zichen DENG School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’an710072China School of Civil Engineering and Architecture Xi’an University of TechnologyXi’an710048China State Key Laboratory of Eco-Hydraulics in Northwest Arid Region of China Xi’an University of TechnologyXi’an710048China School of Aeronautics and Astronautics Sichuan UniversityChengdu610065China

The longitudinal wave propagating in an elastic rod with a variable cross-section owns wide engineering background,in which the longitudinal wave dissipation determines some important performances of the slender *** reproduce the longitudinal wave dissipation effects on an elastic rod with a variable cross-section,a structure-preserving approach is developed based on the dynamic symmetry breaking *** the dynamic model controlling the longitudinal wave propagating in the elastic rod with the variable cross-section,the approximate multi-symplectic form is deduced based on the multi-symplectic method,and the expression of the local energy dissipation for the longitudinal wave propagating in the rod is presented,referring to the dynamic symmetry breaking theory.A structure-preserving method focusing on the residual of the multi-symplectic structure and the local energy dissipation of the dynamic model is constructed by using the midpoint difference discrete *** longitudinal wave propagating in an elastic rod fixed at one end is simulated,and the local/total energy dissipations of the longitudinal wave are investigated by the constructed structure-preserving scheme in two typical cases in detail.

关键词： dynamic symmetry breaking longitudinal wave variable cross-section structure-preserving Hamiltonian

Aberrant elevation of FTO levels promotes liver steatosis by decreasing the m^(6)A methylation and increasing the stability of SREBF1 and ChREBP mRNAs

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Journal of Molecular Cell Biology 2022年第9期14卷 40-53页

作者： Zhili Tang Chao Sun Ying Yan Zhoumin Niu Yuying Li xi Xu Jing Zhang Yuting Wu Yan Li Li Wang Cheng Hu Zhuoyang Li jingjing Jiang Hao Ying CAS Key Laboratory of Nutrition Metabolism and Food SafetyShanghai Institute of Nutrition and HealthUniversity of Chinese Academy of SciencesChinese Academy of Sciencesand Shanghai Jiao Tong University Affiliated Sixth People's HospitalShanghai 200031China Innovation Center for Intervention of Chronic Disease and Promotion of Health Shanghai 200031China Department of Endocrinology and Metabolism Zhongshan HospitalFudan UniversityShanghai 200031China State Key Laboratory of Food Science and Technology School of Food Science and TechnologyJiangnan UniversityWuxi 214122China Shanghai Diabetes Institute Shanghai Key Laboratoryof Diabetes MelitusShanghai Clinical Centre for DiabetesShanghai jiao Tong University Affiliated Sixth People's HospitalShanghai 200233China Key Laboratory of Food Safety Risk Assessment Ministry of HealthBeijing 100021China

Previous studies have indicated an association of fat mass and obesity-associated(FTO)with nonalcoholic fatty liver disease(NAFLD),the most common chronic liver disease *** study aimed to decipher the complex role of FTO in hepatic lipid *** found that a decrease in N^(6)-methyladenosine(m^(6)A)RNA methylation in the liver of mice fed with a high-fat diet(HFD)was accompanied by an increase in FTO *** of FTO in the liver promoted triglyceride accumulation by upregulating the expression of lipogenic *** studies revealed that FTO could stabilize the mRNAs of sterol regulatory element binding transcription factor 1(SREBF1)and carbohydrate responsive element binding protein(ChREBP),two master lipogenic transcription factors,by demethylating m^(6)A *** ofeither SREBF1 or ChREBP attenuated the lipogenic effect of FTO,suggesting that they are bona fide effectors for FTO in regulating *** could stimulate FTO transcription through a mechanism involving the action of intranuclear insulin receptor beta,while knockdown of FTO abrogated the lipogenic effect of *** ofFTo by entacapone decreased the expression of SREBF1,ChREBP,and downstream lipogenic genes,ameliorating liver steatosis in HFD-fed ***,our study established a critical role of FTO in both the insulin-regulated hepatic lipogenesis and the pathogenesis of NAFLD and provided a potential strategyfor treating NAFLD.

关键词： FTO m^(6)A SREBF1 ChREBP lipogenesis NAFLD

Flexible Nanocomposite Conductors for Electromagnetic Interference Shielding

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Nano-Micro Letters 2023年第10期15卷 210-259页

作者： Ze Nan Wei Wei Zhenhua Lin jingjing Chang Yue Hao State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology School of MicroelectronicsXidian University2 South Taibai RoadXi’an 710071People’s Republic of China Advanced Interdisciplinary Research Center for Flexible Electronics Xidian University2 South Taibai RoadXi’an 710071People’s Republic of China

With the extensive use of electronic communication technology in integrated circuit systems and wearable devices, electromagnetic interference(EMI) has increased dramatically. The shortcomings of conventional rigid EMI shielding materials include high brittleness, poor comfort, and unsuitability for conforming and deformable applications. Hitherto, flexible(particularly elastic) nanocomposites have attracted enormous interest due to their excellent deformability. However, the current flexible shielding nanocomposites present low mechanical stability and resilience, relatively poor EMI shielding performance, and limited multifunctionality. Herein, the advances in low-dimensional EMI shielding nanomaterials-based elastomers are outlined and a selection of the most remarkable examples is discussed. And the corresponding modification strategies and deformability performance are summarized. Finally, expectations for this quickly increasing sector are discussed, as well as future challenges.

关键词： Electromagnetic interference shielding Intrinsically stretchable nanocomposites Compressible monolith Low-dimensional materials Flexible devices

我国陆地接壤国家新冠病毒病疫情及输入风险评估

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疾病监测 2020年第4期35卷 283-287页

作者：杨昕娉庞明樊梁作如董小平吕柯施国庆施小明席晶晶冯录召戚晓鹏李新华中国疾病预防防控制中心北京102206

目的对与我国陆地接壤的14个国家进行综合分析,评估其新冠病毒病疫情及输入风险,为进一步做好防输入工作提供依据。方法通过搜集各国政府网站、主流媒体、相关专业门户网站的公开信息、正式发表的参考文献,运用传染病SEIR(易感者–暴露... 详细信息

目的对与我国陆地接壤的14个国家进行综合分析,评估其新冠病毒病疫情及输入风险,为进一步做好防输入工作提供依据。方法通过搜集各国政府网站、主流媒体、相关专业门户网站的公开信息、正式发表的参考文献,运用传染病SEIR(易感者–暴露者–感染者–移出者)数学模型和牛津大学发布的"防控措施严格性指数",对接壤国家的新冠病毒病发病和检测、华人华侨、人口和卫生资源、防控措施进行梳理和分析。结果总体上,我国陆地接壤国家人群检测比例偏低,可能存在大量病例未被诊断和报告的情况。俄罗斯目前病例最多,防控措施严格性指数不高,老龄人口比例高,未来潜在的重症医疗需求大。印度和巴基斯坦的病例数量仅次于俄罗斯,其人口基数大且医护人员数量少,未来可能面临医疗资源紧缺的情况。结论陆地接壤国家对我国输入风险增高,陆路口岸城市需持续关注。建议尽快开展口岸城市输入风险应对的能力梳理和预案制定,建立和加强入境健康筛查和患者转运机制。

关键词：新冠病毒病陆地接壤国家输入风险评估

Identification of impacts of climate change and direct human activities on streamflow in Weihe River Basin in Northwest China

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International Journal of Agricultural and Biological Engineering 2017年第4期10卷 119-129页

作者： Fan jingjing Huang Qiang Liu Dengfeng Hebei University of Engineering Handan 056038China State Key Laboratory Base of Eco-Hydraulic Engineering in Arid Area Xi’an University of TechnologyXi’an 710048China

Climate change and human activities make major influences on hydrology,which are known to have important impacts on streamflow ***,it is critically important to identify how climate change and human activities will impact streamflow ***,the goal of this study is to identify the impacts of climate change and direct human activities on annual streamflow at four hydrologic stations in the Weihe River basin of China,with the estimation of evaporation based on the Budyko *** Mann-Kendall test was employed to detect the break points of the four *** to the occurrence time of break points,the data series were divided into two periods:pre-change period(1960-1984)and post-change(1985-2010)*** parameter of one-parameter Budyko-type model was calibrated with observed data during the pre-change period,with the R^(2) values ranged from 0.95 to 0.97 and the NSE values ranged from 0.80 to 0.94,and the high R^(2) and Nash-Sutcliffe Efficiency coefficient shows the model has good *** contribution ratios of climate change impacts on decreasing streamflow were 37%,23%,57%and 43%,and those of the impacts of direct human activities were 63%,77%,43%and 57%for the Linjiacun,xianyang,Lintong and Huaxian station,*** the climate change and direct human activities have positive impacts on streamflow decrease at all of the four stations,and the direct human activities are the main factor causing the decrease of annual streamflow.

关键词： streamflow,climate change human activities evaporation,hydrological cycle,watershed,Budyko hypothesis,Weihe River basin

Removal of arsenate with hydrous ferric oxide coprecipitation: Effect of humic acid

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Journal of Environmental Sciences 2014年第2期26卷 240-247页

作者： jingjing Du Chuanyong Jing Jinming Duan Yongli Zhang Shan Hu State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of Sciences School of Environmental and Municipal Engineering Xi’an University of Architecture and Technology College of Architecture and Environment Sichuan University

Insights from the adverse effect of humic acid （HA） on arsenate removal with hydrous ferric oxide （HFO） coprecipitation can further our understanding of the fate of As（V） in water treatment process. The motivation of our study is to explore the competitive adsorption mechanisms of humic acid and As（V） on HFO on the molecular scale. Multiple complementary techniques were used including macroscopic adsorption experiments, surface enhanced Raman scattering （SERS）, extended X-ray absorption fine structure （EXAFS） spectroscopy, flow-cell attenuated total reflectance Fourier transform infrared （ATR-FTIR） measurement, and charge distribution multisite complexation （CD- MUSIC） modeling. The As（V） removal efficiency was reduced from over 95% to about 10% with the increasing HA concentration to 25 times of As（V） mass concentration. The SERS analysis excluded the HA-As（V） complex formation. The EXAFS results indicate that As（V） formed bidentate binuclear surface complexes in the presence of HA as evidenced by an As-Fe distance of 3.26--3.31 ,~. The in situ ATR-FTIR measurements show that As（V） replaces surface hydroxyl groups and forms inner- sphere complex. High concentrations of HA may physically block the surface sites and inhibit the As（V） access. The adsorption of As（V） and HA decreased the point of zero charge of HFO from 7.8 to 5.8 and 6.3, respectively. The CD-MUSIC model described the zeta potential curves and adsorption edges of As（V） and HA reasonably well.

关键词： arsenate humic acid HFO adsorption multiple spectroscopic techniques

Sparse reconstruction for fluorescence molecular tomography via a fast iterative algorithm

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Journal of Innovative Optical Health Sciences 2014年第3期7卷 50-58页

作者： jingjing Yu Jingxing Cheng Yuqing Hou xiaowei He School of Physics and Information Technology Shaanai Normal University Xian 710062P.R.China School of Information Sciences and Technology Northwest University Xi'an 710069P.R.China

Fluorescence molecular tomography(FMT)is a fast-developing optical imaging modalitythat has great potential in early diagnosis of disease and drugs ***,recon-struction algorithms have to address a highly ill-posed problem to fulfll 3D reconstruction *** this contribution,we propose an efficient iterative algorithm to solve the large-scalereconstruction problem,in which the sparsity of fluorescent targets is taken as useful a prioriinformation in designing the reconstruction *** the implementation,a fast sparseapproximation scheme combined with a stage-wise learning strategy enable the algorithm to dealwith the ill-posed inverse problem at reduced computational *** validate the proposed fastiterative method with numerical simulation on a digital mouse *** results demonstrate that our method is robust for different finite element meshes and different Poissonnoise levels.

关键词： Fluorescence molecular tomography sparse regularization reconstruction algorithm least absolute shrinkage and selection operator.

Recycling strategies for vitrimers

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International Journal of Smart and Nano Materials 2022年第3期13卷 367-390页

作者： Haochuan Zhang jingjing Cui Guang Hu Biao Zhang Frontiers Science Center for Flexible Electronics(FSCFE) Ningbo Institute of Northwestern Polytechnical UniversityNorthwestern Polytechnical UniversityXi’anShaanxiChina Queen Mary University of London Engineering School Northwestern Polytechnical University(NPU)Xi’anP.R.China

Vitrimer is a new type of material that combine the advantages of thermoplastic and thermoset *** rapid dynamic exchange reactions at high temperature allow the topology of cross-linked networks to change and rearrange while keeping material structures and properties *** concept of vitrimer has emerged to provide a viable strategy for the recycling of highperformance polymer materials,and lots of research works have been carried out for the development of various types of *** addition,the recycling strategies for vitrimers are particularly important to determine the performance and potential applications of the recovered ***,it is an innovative and valu-able perspective to discuss vitrimer materials according to their different recycling *** this review,we start with a brief overview of vitrimers,and then,focus on recycling strategies for ***,we highlight the advantages and disadvan-tages of the two different recycling strategies:physical and chemi-cal recycling methods,and then explore the feasibility of upcycling vitrimers using 3D printing ***,the impact of recy-cling strategies on vitrimer materials and the prospects for max-imizing the use of vitrimer materials are discussed.

关键词： Vitrimers chemical recycling physical recycling 3D printing

Modelling the iron ore price index:A new perspective from a hybrid data reconstructed EEMD-GORU model

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Journal of Management Science and Engineering 2020年第3期5卷 212-225页

作者： jingjing Tuo Fan Zhang International Business School Shaanxi Normal UniversityXi'an710061China

As iron ore is the fundamental steel production resource,predicting its price is strategically important for risk management at related enterprises and *** on a signal decomposition technology and an artificial neural network,this paper proposes a hybrid EEMD-GORU model and a novel data reconstruction method to explore the price risk and fluctuation correlations between China's iron ore futures and spot markets,and to forecast the price index series of China's and international iron ore spot markets from the futures *** analysis found that the iron ore futures market in China better reflected the price fluctuations and risk factors in the imported and international iron ore spot ***,the forward price in China's iron ore futures market was unable to adequately reflect the changes in the domestic iron ore market,and was therefore unable to fully disseminate domestic iron ore market *** proposed model was found to provide better market risk perceptions and predictions through its combinations of the different volatility information in futures and spot *** results are valuable ref-erences for the early-warning and management of the related enterprise project risks.

关键词： Iron ore market Neural networks Price forecasting Project risk management Series decomposition