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A flexible multiscale algorithm based on an improved smoothed particle hydrodynamics method for complex viscoelastic flows

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Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1387-1402页

作者： Jinlian REN Peirong LU Tao JIANG Jianfeng LIU Weigang LU College of Mathematical science Yangzhou UniversityYangzhou 225002Jiangsu ProvinceChina College of Hydraulic science and Engineering Yangzhou UniversityYangzhou 225002Jiangsu ProvinceChina

Viscoelastic flows play an important role in numerous engineering fields,and the multiscale algorithms for simulating viscoelastic flows have received significant attention in order to deepen our understanding of the nonlinear dynamic behaviors of viscoelastic ***,traditional grid-based multiscale methods are confined to simple viscoelastic flows with short relaxation time,and there is a lack of uniform multiscale scheme available for coupling different solvers in the simulations of viscoelastic *** this paper,a universal multiscale method coupling an improved smoothed particle hydrodynamics(SPH)and multiscale universal interface(MUI)library is presented for viscoelastic *** proposed multiscale method builds on an improved SPH method and leverages the MUI library to facilitate the exchange of information among different solvers in the overlapping *** test the capability and flexibility of the presented multiscale method to deal with complex viscoelastic flows by solving different multiscale problems of viscoelastic *** the first example,the simulation of a viscoelastic Poiseuille flow is carried out by two coupled improved SPH methods with different spatial *** effects of exchanging different physical quantities on the numerical results in both the upper and lower domains are also investigated as well as the absolute errors in the overlapping *** the second example,the complex Wannier flow with different Weissenberg numbers is further simulated by two improved SPH methods and coupling the improved SPH method and the dissipative particle dynamics(DPD)*** numerical results show that the physical quantities for viscoelastic flows obtained by the presented multiscale method are in consistence with those obtained by a single solver in the overlapping ***,transferring different physical quantities has an important effect on the numerical results.

关键词： multiscale method improved smoothed particle hydrodynamics(SPH) dissipative particle dynamics(DPD) multiscale universal interface(MUI) complex viscoelastic flow

Promotion effects of salt-alkali on ammonia volatilization in a coastal soil

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Pedosphere 2024年第1期34卷 191-199页

作者： Zhenqi SHI Dongli SHE Yongchun PAN Yongqiu XIA College of Agricultural science and Engineering Hohai UniversityNanjing 210098China Jiangsu Province Engineering research Center for Agricultural Soil-water Efficient Utilization Carbon Sequestration and Emission ReductionNanjing 210098China Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China

Coastal ecosystems are highly susceptible to salt-related problems due to their formation process and geographical location. As such ecosystems are the most accessible land resources on Earth, clarifying and quantifying the effects of salt-alkali conditions on N concentration and ammonia(NH_(3)) volatilization are pivotal for promoting coastal agricultural productivity. The challenge in establishing this effect is to determine how salt-alkali conditions impact NH_(3) volatilization through direct or indirect interactions. An incubation experiment using a coastal soil from a paddy farmland, combined with the structural equation modeling(SEM) method, was conducted to reveal the net effects of salt-alkali on NH_(3) volatilization and the role of environmental and microbial factors in mutual interaction networks. The specific experimental design consisted of four salt treatments(S1, S2, S3, and S4: 1‰, 3‰, 8‰, and 15‰ NaCl by mass of soil, respectively), four alkaline treatments(A1, A2, A3, and A4: 0.5‰, 1‰, 3‰, and 8‰ NaHCO_(3)by mass of soil, respectively) and a control without NaCl or NaHCO_(3) addition(CK), and each treatment had three urea concentrations(N1, N2, and N3: 0.05, 0.10, and 0.15 g N kg^(-1) soil,respectively) and three replicates. At the N1, N2, and N3 levels, NH_(3)volatilization increased by 9.31%–34.98%, 3.07%–26.92%, and 2.99%–43.61% as the NaCl concentration increased from 1‰ to 15‰, respectively, compared with CK. With an increase in the NaHCO_(3)concentration from 0.5‰ to 8‰, NH_(3) volatilization increased by 8.36%–56.46%, 5.49%–30.10%, and 30.72%–73.18% at the N1, N2, and N3 levels, respectively, compared with CK. According to the SEM method, salinity and alkalinity had positive direct effects on NH_(3)volatilization, with standardized path coefficients of 0.40 and 0.19, *** the total effects(net positive and negative effects) in the SEM results, alkalinity had a greater influence than salinity(total standardized coefficien

关键词： alkalinity coastal ecosystem NH_(3)emission N-transforming microbe salinity structural equation modeling

The Response of Carbonate System to watershed Urbanization Process in a Semi-Arid River

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Journal of Ocean University of China 2024年第4期23卷 991-1002页

作者： LI Yunxiao DANG Jiajia HUANG Xiao YANG Hong WANG Xiao LI Lina BAI Jie CHEN Xi Department of Environmental science College of Resource and EnvironmentShanxi Agricultural UniversityTaigu 030801China Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologySchool of Environmental Science and EngineeringNanjing University of Information Science and TechnologyNanjing 210044China Department of Geography and Environmental science University of ReadingWhiteknightsReading RG66ABUK Marine Agriculture research Center Tobacco Research InstituteChinese Academy of Agricultural SciencesQingdao 266101China 5 Key Laboratory of Marine Environmental science and Ecology Ministry of EducationCollege of Environmental Science and EngineeringOcean University of ChinaQingdao 266100China

Different from rivers in humid areas,the variability of riverine CO_(2) system in arid areas is heavily impacted by anthropogenic disturbance with the increasing urbanization and water *** this study,the water chemistry and the controls of carbonate system in an urbanized river(the Fenhe River)on the semi-arid Loess Plateau were *** water chemistry of the river water showed that the high dissolved inorganic carbon(DIC)concentration(about 37 mg L^(-1))in the upstream with a karst land type was mainly sourced from carbonate weathering involved by H_(2)CO_(3) and H_(2)SO_(4),resulting in an oversaturated partial pressure of CO_(2)(pCO_(2))(about 800μatm).In comparison,damming resulted in the widespread appearance of non-free flowing river segments,and aquatic photosynthesis dominated the DIC and pCO_(2) spatiality demonstrated by the enriched stable isotope of DIC(δ^(13)CDIC).Especially in the mid-downstream flowing through major cities in warm and low-runoff August,some river segments even acted as an atmospheric CO_(2) *** noteworthy is wastewater input leading to a sudden increase in DIC(>55 mg L^(-1))and pCO_(2)(>4500μatm)in the downstream of Taiyuan City,and in cold November the increased DIC even extended to the outlet of the *** results highlight the effects of aquatic production induced by damming and urban sewage input on riverine CO_(2) system in semi-arid areas,and reducing sewage discharge may mitigate CO_(2) emission from the rivers.

关键词： dissolved inorganic carbon stable carbon isotope carbonate weathering aquatic photosynthesis sewage input the Fenhe River

Stress relaxation properties of calcium silicate hydrate:a molecular dynamics study

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Journal of Zhejiang University-science A(Applied Physics & Engineering) 2024年第2期25卷 97-115页

作者： Zhicheng GENG Shengwen TANG Yang WANG Hubao A Zhen HE Kai WU Lei WANG State Key Laboratory of water Resources Engineering and Management Wuhan UniversityWuhan430072China Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education School of Materials Science and EngineeringTongji UniversityShanghai200092China College of Materials science and Engineering Xi’an University of Architecture and TechnologyXi’an710055China

The time-dependent viscoelastic response of cement-based materials to applied deformation is far from fully understood at the atomic *** silicate hydrate(C-S-H),the main hydration product of Portland cement,is responsible for the viscoelastic mechanism of cement-based *** this study,a molecular model of C-S-H was developed to explain the stress relaxation characteristics of C-S-H at different initial deformation states,Ca/Si ratios,temperatures,and water contents,which cannot be accessed *** stress relaxation of C-S-H occurs regardless of whether it is subjected to initial shear,tensile,or compressive deformation,and shows a heterogeneous *** plays a crucial role in the stress relaxation process.A large Ca/Si ratio and high temperature reduce the cohesion between the calcium-silicate layer and the interlayer region,and the viscosity of the interlayer region,thereby accelerating the stress relaxation of *** effect of the hydrogen bond network and the morphology of C-S-H on the evolution of the stress relaxation characteristics of C-S-H at different water contents was elucidated by nonaffine mean squared *** results shed light on the stress relaxation characteristics of C-S-H from a microscopic perspective,bridging the gap between the microscopic phenomena and the underlying atomic-level mechanisms.

关键词： Calcium silicate hydrate(C-S-H) Stress relaxation Ca/Si ratio Temperature water content Atomic simulation

Giant low-field reversible magnetocaloric effect at liquid helium temperature of niobium and iron co-substituted EuTiO_(3) compounds

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Journal of Rare Earths 2024年第4期42卷 710-715页

作者： Zhihong Hao Quanyi Liu Huicai Xie Yan Zhang Zhaojun Mo School of Rare Earth and New Materials Engineering Ganzhou Innovation Center of Rare Earth Permanent Magnet Material Advanced Manufacturing and Intelligent Equipment TechnologyGannan University of Science and TechnologyGanzhou341000China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou34119China School of Materials science and Engineering Taiyuan University of Science and TechnologyTaiyuan030024China

Giant magnetocaloric effect(MCE)materials in the liquid helium temperature region have attracted a lot of attention in the field of low-temperature magnetic refrigeration(MR).In this study,a series of niobium(Nb)and iron(Fe)co-substituted EuTiO_(3) perovskites with cubic structure(space group pm3m)was successfully fabricated,and their magnetic properties as well as cryogenic magnetocaloric effects were investigated in *** expected,the introduction of Nb and Fe can significantly modulate the magnetic phase transition and magnetocaloric effect of the EuTiO_(3) *** increasing Fe concentration,two local minima corresponding to the AFM-FM magnetic phase transition near 5.0 K and FM-PM transition near 10 K with no hysteresis in the thermomagnetic curves are observed,which is attributed to an enhancement of FM *** the same time,the gradually widened-ΔSM-T curves and the two peaks with a broad shoulder lead to considerable refrigeration capacity(RC).With the field change ofΔH=2 T,the calculated values of-ΔS_(M)^(max) for the EuTi_(0.9375-x)Nb_(0.0625)Fe_(x)O_(3)(x=0.075,0.1,0.125,0.15)compounds are 24.2,17.6,14.5 and 14.0 J/(kg·K),*** corresponding RC values were calculated to be 144.6,138.3,151.2 and 159 J/kg,***,the values of-ΔS_(M)^(max) for EuTi_(0.8625)Nb_(0.0625)Fe_(0.075)O_(3) are 8.6 and 15.1 J/(kg·K)under low field changes of 0.5 and 1 T,*** giant low-field reversible magnetocaloric effect makes them attractive candidates for magnetic refrigeration in the liquid helium temperature region.

关键词： Magnetocaloric effect Refrigeration capacity Magnetic entropy change Rareearths

Aseismic performances of constrained damping lining structures made of rubber-sand-concrete

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1522-1537页

作者： Xiancheng Mei Qian Sheng Jian Chen Zhen Cui Jianhe Li Chuanqi Li Daniel Dias State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of sciences Beijing100049China Key Laboratory of water Grid project and Regulation of Ministry of water Resources Changjiang Institute of SurveyPlanningDesign and ResearchWuhan430010China Laboratory 3SR CNRS UMR 5521Grenoble Alpes UniversityGrenoble38000France School of Automotive and Transportation Engineering Hefei University of TechnologyHefei23009China

Flexible damping technology considering aseismic materials and aseismic structures seems be a good solution for engineering *** this study,a constrained damping structure for underground tunnel lining,using a rubber-sand-concrete(RSC)as the aseismic material,is *** aseismic performances of constrained damping structure were investigated by a series of hammer impact *** damping layer thickness and shape effects on the aseismic performance such as effective duration and acceleration amplitude of time-domain analysis,composite loss factor and damping ratio of the transfer function analysis,and total vibration level of octave spectrum analysis were *** hammer impact tests revealed that the relationship between the aseismic performance and damping layer thickness was not linear,and that the hollow damping layer had a better aseismic performance than the flat damping layer *** aseismic performances of constrained damping structure under different seismicity magnitudes and geological conditions were *** effects of the peak ground acceleration(PGA)and tunnel overburden depth on the aseismic performances such as the maximum principal stress and equivalent plastic strain(PEEQ)were *** numerical results show the constrained damping structure proposed in this paper has a good aseismic performance,with PGA in the range(0.2-1.2)g and tunnel overburden depth in the range of 0-300 m.

关键词： Constrained damping structure Aseismic performance Hammer impact tests Damping layer Peak ground acceleration Overburden depth

Multifunctional phase change film with high recyclability, adjustable thermal responsiveness, and intrinsic self-healing ability for thermal energy storage

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Journal of Energy Chemistry 2024年第10期97卷 216-227,I0005页

作者： Bo Yang Xuelai Zhang Jun Ji Weisan Hua Miaomiao Jiang Institute of Cool Thermal Storage technology Shanghai Maritime UniversityShanghai 201306China

Phase change materials(PCMs) present promising potential for guaranteeing safety in thermal management ***,most reported PCMs have a single application in energy storage for thermal management systems,which does not meet the growing demand for multi-functional *** this paper,the flexible material and hydrogen-bonding function are innovatively combined to design and prepare a novel multi-functional flexible phase change film(PPL).The 0.2PPL-2 film exhibits solid-solid phase change behavior with energy storage density of 131.8 J/g at the transition temperature of42.1℃,thermal cycling stability(500 cycles),wide-temperature range flexibility(0-60℃) and selfhealing ***,the PPL film can be recycled up to 98.5% by intrinsic ***,the PPL film can be tailored to the desired colors and configurations and can be cleverly assembled on several thermal management systems at ambient temperature through its flexibility combined with shape-memory *** interestingly,the transmittance of PPL will be altered when the ambient temperature changes(60℃),conveying a clear thermal ***,the thermal energy storage performance of the PPL film is successfully tested by human thermotherapy and electronic device temperature control *** proposed functional integration strategy provides innovative ideas to design PCMs for multifunctionality,and makes significant contributions in green chemistry,highefficiency thermal management,and energy sustainability.

关键词： Phase change film Multifunctional material Energy storage Self-healing Recyclability

High-resolution neutronics model for ^(238)Pu production in high-flux reactors

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Nuclear science and Techniques 2024年第5期35卷 226-236页

作者： Qing-Quan Pan Qing-Fei Zhao Lian-Jie Wang Bang-Yang Xia Yun Cai Jin-Biao Xiong Xiao-Jing Liu School of Nuclear science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China science and technology on Reactor System Design technology Laboratory Nuclear Power Institute of ChinaChengdu 610200China

We proposed and compared three methods(filter burnup,single energy burnup,and burnup extremum analysis)to build a high-resolution neutronics model for 238Pu production in high-flux *** filter burnup and single energy burnup methods have no theoretical approximation and can achieve a spectrum resolution of up to~1 eV,thereby constructing the importance curve and yield curve of the full energy *** burnup extreme analysis method combines the importance and yield curves to consider the influence of irradiation time on production efficiency,thereby constructing extreme *** three curves,which quantify the transmutation rate of the nuclei in each energy region,are of physical significance because they have similar distributions.A high-resolution neutronics model for ^(238)Pu production was established based on these three curves,and its universality and feasibility were *** neutronics model can guide the neutron spectrum optimization and improve the yield of ^(238)Pu by up to 18.81%.The neutronics model revealed the law of nuclei transmutation in all energy regions with high spectrum resolution,thus providing theoretical support for high-flux reactor design and irradiation production of ^(238)Pu.

关键词： ^(238)Pu Neutronics model High-flux reactor Spectrum resolution Spectrum optimization

3-Epi-betulinic acid 3-O-β-D-glucopyranoside(eBAG)induces autophagy by activation of AMP-activated protein kinase in hepatocellular carcinoma

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Food science and Human Wellness 2024年第3期13卷 1453-1464页

作者： Mengjie Liu Xuqiang Liu Kaiyue He Yongping Jian Yujia Li Jinrong Guo Jingyu Yang Zhixiang Xu Wenyi Kang School of Life sciences Henan UniversityKaifeng 475004China national R&D Center for Edible Fungus Processing technology Henan UniversityKaifeng 475004China Joint International research Laboratory of Food&Medicine Resource Function Kaifeng 475004China Shenzhen research Institute of Henan University Shenzhen 518000China

3-Epi-betulinic acid 3-O-β-D-glucopyranoside(eBAG)is a pentacyclic triterpene mainly distributed in food and medicinal plants,which exhibits various pharmacological ***,whether these functions are attributed to eBAG or additional components in these plants remain ***,we report that eBAG exerted an inhibitory activity against hepatocellular carcinoma and esophageal cancer *** induced non-apoptotic cell death in hepatocellular carcinoma *** eBAG-induced cell death was inhibited by knock-down of autophagy related gene(ATG)5 and ATG7,by administration of 3-methyladenine,a selective autophagy inhibitor that suppresses phosphoinositide 3-kinase(PI3K),and by chloroquine,a classic autophagy flux *** demonstrated that eBAG induced an autophagy-mediated cell *** of eBAG mimicked cellular bioenergetics depletion leading to the reduction of intracellular ATP,activation of AMP-activated protein kinase(AMPK),and inhibition of ***-treatment with compound C,an AMPK inhibitor,abrogated cell death induced by *** further validated the anti-tumor effect of eBAG in the murine xenograft model of hepatocellular carcinoma and found that eBAG treatment promoted the induction of autophagy and reduction of tumor growth in *** a functional food ingredient,eBAG is a potential therapeutic agent for the treatment of hepatocellular carcinoma and esophageal cancer.

关键词： eBAG Autophagy ATP AMPK Hepatocellular carcinoma