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Experimental study on temperature fluctuations on plate surface induced by coaxial-jet flow

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Nuclear Science and Techniques 2024年第5期35卷 139-153页

作者： Xue-Yao Xiong Zun-Quan Liu Guo-Yan zhou Xing Luo Shan-Tung Tu Key Laboratory of Pressure Systems and Safety(MOE) East China University of Science and TechnologyShanghai 200237China Institute of Thermodynamics Gottfried Wilhelm Leibniz University Hannover30823 GarbsenGermany

In nuclear reactors,temperature fluctuations of fluids may cause fatigue damage to adjacent structures;this is referred to as thermal *** on thermal striping in the upper plenum has mainly focused on fluid *** experimental studies have been reported on solid structures in a fluid field with a coaxial *** study entailed an experimental study of the temperature fluctuations in the fluid and on a plate surface caused by a coaxial *** temperature fluctuations of the fluid and plate surfaces located at different heights were *** cause of the temperature fluctuation was analyzed using a transient temperature *** results show that the mixing of the hot and cold fluids gradually becomes uniform in the positive axial *** average surface temperatures tended to be *** the jet reaches the plate surface,the swing of the jet center,contraction and expansion of the cold jet,and changes in the jet shape result in temperature *** intensity of the temperature fluctuation was affected by the *** attention should be paid when the plate is located at a lower height,and between the hot and cold-fluid nozzles.

关键词： Temperature fluctuation Thermal striping Coaxial jet Thermal mixing The upper plenum of nuclear reactor

A supramolecular self-assembly material based on cucurbituril and cationic TPE as ultra-sensitive probe of energetic pentazolate salts

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Defence Technology（防务技术） 2024年第5期35卷 69-76页

作者： Boan Tang Jingxiang Zhong Shutao Wang Shiyu zhou Yongxing Tang Wei Huang School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing 210094China

The successful synthesis of the pentazolate anion(cyclo-N-5)has been a great breakthrough in the field of energetic ***,the detection methods for these energetic materials based on the pentazolate anion are quite ***,two fluorescent probes for cyclo-N-5anion were *** 1(TPE2N)was synthesized with a tetraphenylethylene functionalized by two cationic groups which can generate strong electrostatic interactions with pentazolate anion and result in specific fluorescent *** 2 was designed based on sensor 1 and supramolecular cucurbit[7]uril(CB[7]).The unique structural features of CB[7]provide sites for the interaction between the cations and N-5anion in its cavity,which would generate a platform for the detection and enhance the recognition *** titration calorimetry(ITC)experiment and fluorescence titration experiment indicate the binding molar ratio between sensor 1 with CB[7]is 1:*** sensors display typical aggregation-induced emission(AIE)features and good *** sensors demonstrate excellent sensitivity to pentazole hydrazine salt with high enhancement constant(sensor 1:1.34×10^(6);sensor 2:3.78×10^(6))and low limit of detection(LOD:sensor 1=4.33μM;sensor 2=1.54μM).The formation of an AIE-based supramolecular sensor effectively improves the sensitivity to *** addition,the probes also have good selectivity of N-5anion *** research would shed some light on the design of novel fluorescent sensors to detect pentazolate-based molecules and provides an example of supramolecular chemistry combined with fluorescent probes.

关键词： Pentazolate anion Explosives detection Aggregation-induced emission(AIE) Host-guest interaction

High-precision parallel computing model of solute transport based on GPU acceleration

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Journal of Hydrodynamics 2024年第1期36卷 202-212页

作者： Shang-hong Zhang Rong-qi Zhang Wen-da Li Xi-yan Yang Yang zhou School of Water Resources and Hydropower Engineering North China Electric Power UniversityBeijing102206China Hubei Key Laboratory of Intelligent Yangtze and Hydroelectric Science China Yangtze Power Co.Ltd.Yichang443133China

The scenario simulation analysis of water environmental emergencies is very important for risk prevention and control,and emergency *** quickly and accurately simulate the transport and diffusion process of high-intensity pollutants during sudden environmental water pollution events,in this study,a high-precision pollution transport and diffusion model for unstructured grids based on Compute Unified Device Architecture(CUDA)is *** finite volume method of a total variation diminishing limiter with the Kong proposed r-factor is used to reduce numerical diffusion and oscillation errors in the simulation of pollutants under sharp concentration conditions,and graphics processing unit acceleration technology is used to improve computational *** advection diffusion process of the model is verified numerically using two benchmark cases,and the efficiency of the model is evaluated using an engineering *** results demonstrate that the model perform well in the simulation of material transport in the presence of sharp ***,it has high computational *** acceleration ratio is 46 times the single-thread acceleration effect of the original *** efficiency of the accelerated model meet the requirements of an engineering application,and the rapid early warning and assessment of water pollution accidents is achieved.

关键词： Pollution transport and diffusion model parallel computing Compute Unified Device Architecture(CUDA) pollution event

Large-area ultrastrong and stiff aramid nanofiber based layered nanocomposite films

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Nano Research 2024年第2期17卷 829-835页

作者： Zhidong Nie Yingzhi Sun Tianxu zhou Shengwen Kong Linxing Liu Chuangqi Zhao Mingjie Liu Key Laboratory of Bioinspired Smart Interfacial Science and Technology of Ministry of Education School of ChemistryBeihang UniversityBeijing 100191China University of Science and Technology of China Hefei 230026China Suzhou Institute for Advanced Research University of Science and Technology of ChinaSuzhou 215123China International Research Institute for Multidisciplinary Science Beihang UniversityBeijing 100191China

One-dimensional(1D)aramid nanofiber(ANF)based nanocomposite films have drawn increasing attentions in various applications due to their excellent mechanical properties and impressive chemical and thermal ***,the large-area fabrication of aramid nanocomposite films with ultrastrong mechanical properties under mild conditions remains a great *** we present a facile superspreading-assisted strategy to produce aramid nanofiber based oriented layered nanocomposites using phase inversion process that occurs at the fully swollen hydrogel *** nanocomposite films based on ANF,carboxylation carbon tube(CNT–COOH),poly(vinyl alcohol)(PVA),and MXene nanosheet exhibit a tensile strength of up to 870.8±85 MPa,a Young’s modulus of 21.8±2.2 GPa,and outstanding toughness(up to 43.2±4.6 MJ/m^(3)),which are much better than those conventional aramid nanofiber based *** conductivity of our nanocomposite films reaches the maximum of about 1100 S/*** fabulous mechanical properties combination and continuous production capability render our strategy representing a promising direction for the development of high-performance nanocomposites.

关键词： aramid nanofibers MXene nanosheets nanocomposites ultrastrong and stiff superspreading large-area production

Martensite decomposition under thermal-mechanical coupling conditions to fabricate an ultrafine-grained Ti6Al4Mo4Zr1W0.2Si alloy

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Journal of Materials Science & Technology 2024年第1期168卷 157-168页

作者： Taoyu zhou Jiuxu Yang Nan Li Hao Sun Bohua Zhang Zibo Zhao Qingjiang Wang Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

The fabrication of ultrafine-grained microstructures(grain size below 1μm)in titanium alloys is beneficial for improving their mechanical properties at room temperature and medium tempera-tures(400-550°C).However,a long-standing challenge involves the low-cost manufacturing of bulk ultrafine-grained titanium *** this work,we developed a facile strategy through martensite de-composition at thermal-mechanical coupling conditions,to fabricate an equiaxed microstructure in a Ti6Al4Mo4Zr1W0.2Si model alloy with an averageαgrain size of 315±62 *** formation of the ultrafine-grained microstructure was because the lattice strain stored in the martensitic initial mi-crostructure enhanced the nucleation rate of dynamic recrystallization,meanwhile,the pinning role of martensite decomposition productsβand(Ti,Zr)_(5)Si_(3)phases suppressed grain coarsening at high *** to conventional(α+β)alloys,the tensile strength of this alloy improved by 20%-30%at both room temperature and 550°C,without decreasing its *** situ SEM observations revealed that the ultrafine-grained microstructure would not only suppress dislocation motions but also contribute to the homogenous deformation in the matrix of the material,therefore,it resulted in higher mechanical *** research results may be of great significance to the development of next-generation aviation titanium alloys.

关键词： Ultrafine-grained Titanium alloy In situ observation Deformation mechanism Thermostability

Mechanical properties and energy evolutions of burst-prone coal samples with holes and fillings

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International Journal of Coal Science & Technology 2024年第3期11卷 176-189页

作者： Yukai Fu Yongzheng Wu Junchen Li Penghe zhou Zhuoyue Sun Jie He CCTEG Coal Mining Research Institute Beijing100013China Coal Mining and Designing Department Tiandi Science and Technology Co.Ltd.Beijing100013China Coal Mining and Designing Branch China Coal Research InstituteBeijing100013China Resource Engineering Department China University of Mining and TechnologyBeijing100083China

During the mining process of impact-prone coal seams,drilling pressure relief can reduce the impact propensity of the coal seam,but it also reduces the integrity and strength of the coal mass at the side of the ***,studying the mechanical properties and energy evolution rules of coal samples containing holes and filled structures has certain practical significance for achieving coordinated control of coal mine rockburst disasters and the stability of roadway surrounding *** achieve this aim,seven types of burst-prone coal samples were prepared and subject to uniaxial compression experiments with the aid of a TAW-3000 electro-hydraulic servo testing ***,the stress–strain curves,acoustic emission signals,DIC strain fields and other data were collected during the ***,the failure modes and energy evolutions of samples with varying drilled hole sizes and filling materials were *** results show that the indexes related to burst propensity of the drilled coal samples decline to some extent compared with those of the intact one,and the decline is positively corelated to the diameter of the drilled *** hole filling,the strain concentration degree around the drilled hole is lowered to a certain degree,and polyurethane filling has a more remarkable effect than cement ***,hole filling can enhance the strength and deformation resistance of *** drilling can accelerate the release of accumulated elastic strain energy,turning the acoustic emission events from low-frequency and high-energy ones to high-frequency and low-energy ones,whereas hole filling can reduce the intensity of energy *** experimental results and theoretical derivation demonstrate that hole filling promotes coal deformability and strength mainly by weakening stress concentration surrounding the drilled ***,the fillings can achieve a better filling effect if their elastic modulus and Poisson’s ratio are closer

关键词： Rock mechanics Coal Mechanical properties Hole filling Energy evolution

Simultaneous removal of Cd(Ⅱ)and As(Ⅴ)by ferrihydrite-biochar composite:Enhanced effects of As(Ⅴ)on Cd(Ⅱ)adsorption

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Journal of Environmental Sciences 2024年第5期139卷 267-280页

作者： Wenjun Zeng Yang Lu Jingyan zhou Jie Zhang Yuanxiao Duan Changxun Dong Wencheng Wu College of Sciences Nanjing Agricultural UniversityNanjing 210095China South China Institute of Environmental Sciences Ministry of Ecology and EnvironmentGuangzhou 510655China Guangdong Engineering&Technology Research Center for System Control of Livestock and Poultry breeding Pollution Guangzhou 510655China

The coexistence of cadmium(Cd(Ⅱ))and arsenate(As(Ⅴ))pollution has long been an environmental ***,a porous carbonaceous material with tunable functionality,has been used for the remediation of contaminated ***,it is still challenging for the dynamic quantification and mechanistic understanding of the simultaneous sequestration of multi-metals in biochar-engineered environment,especially in the presence of *** this study,ferrihydrite was coprecipitated with biochar to investigate how ferrihydritebiochar composite affects the fate of heavy metals,especially in the coexistence of Cd(Ⅱ)and As(Ⅴ).In the solution system containing both Cd(Ⅱ)and As(Ⅴ),the maximum adsorption capacities of ferrihydrite-biochar composite for Cd(Ⅱ)and As(Ⅴ)reached 82.03μmol/g and 531.53μmol/g,respectively,much higher than those of the pure biochar(26.90μmol/g for Cd(Ⅱ),and 40.24μmol/g for As(Ⅴ))and ferrihydrite(42.26μmol/g for Cd(Ⅱ),and 248.25μmol/g for As(Ⅴ)).Cd(Ⅱ)adsorption increased in the presence of As(Ⅴ),possibly due to the changes in composite surface charge in the presence of As(Ⅴ),and the increased dispersion of ferrihydrite by *** microscopic and mechanistic results showed that Cd(Ⅱ)complexed with both biochar and ferrihydrite,while As(Ⅴ)was mainly complexed by ferrihydrite in the Cd(Ⅱ)and As(Ⅴ)coexistence *** posed vital importance for the co-adsorption of Cd(Ⅱ)and As(Ⅴ).The different distribution patterns revealed by this study help to a deeper understanding of the behaviors of cations and anions in the natural environment.

关键词： Ferrihydrite Biochar Cadmium Arsenate Simultaneous sequestration Binding mechanisms

Magneto-electric integrated design strategy of NiCo@C composites for synergistic absorption and conversion in mid-high frequency microwaves

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Nano Research 2024年第4期17卷 2205-2215页

作者： Yijie Liu Jintang zhou Xiaoxuan He Lvtong Duan Yucheng Wang Zhenyu Cheng Zhengjun Yao College of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211100China Key Laboratory of Material Preparation and Protection for Harsh Environment(Nanjing University of Aeronautics and Astronautics) Ministry of Industry and Information TechnologyNanjing 211100China

Achieving synergistic absorption of electromagnetic waves(EMWs)in the mid-high frequency and absorption band conversion is an urgent ***,the present solution is usually a straightforward mixture of magnetic component-carbon ***,we optimize the magnetic properties and electrical relaxation response from a chemical synthesis *** integrated design,the contents of carbon components and multi-dimensional morphology are controlled by retaining strong magnetic *** morphology design and the construction of heterogeneous interfaces will boost the intense response of charge in the surrounding to enhance the polarization *** multi-dimensional structure and electromagnetic(EM)properties of the sample after optimized engineering have an extremely powerful absorption conversion effect on EMW ***@C particles ultimately achieve synergistic absorption effects at low thickness(d<3.5 mm)at middle frequencies(6–10 GHz)and high frequencies(10.5–18 GHz).Our work establishes a correlation mechanism between the physical and chemical properties of materials and EM *** also provides insight into the synergistic absorption of EMWs in the mid-high frequency and absorption band conversion strategies.

关键词： micro-nano composites NiCo@C hollow structure mid-high frequency absorption

A robust triaxial localization method of AE source using refraction path

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International Journal of Mining Science and Technology 2024年第4期34卷 521-530页

作者： Yichao Rui Jie Chen Jiongkun Chen Jiadong Qiu Zilong zhou Wenzhong Wang Jinyang Fan State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400044China School of Resources and Safety Engineering Chongqing UniversityChongqing 400044China School of Resources Environment and Safety Engineering University of South ChinaHengyang 421001China School of Resources and Safety Engineering Central South UniversityChangsha 410083China Coal Geological Exploration Institute of Gansu Lanzhou 730030China

Acoustic emission(AE)localization algorithms based on homogeneous media or single-velocity are less accurate when applied to the triaxial localization *** the end,a robust triaxial localization method of AE source using refraction path is ***,the control equation of the refraction path is established according to the sensor coordinates and arrival ***,considering the influence of time-difference-of-arrival(TDOA)errors,the residual of the governing equation is calculated to estimate the equation ***,the refraction points in different directions are solved using Snell’s law and orthogonal ***,the source coordinates are iteratively solved by weighted correction *** feasibility and accuracy of the proposed method are verified by pencil-lead breaking *** simulation results show that the new method is almost unaffected by the refraction ratio,and always holds more stable and accurate positioning performance than the traditional method under different ratios and scales of TDOA outliers.

关键词： Acoustic emission(AE) Source localization Robust method Refraction paths Weight estimations