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Numerical simulation of coupling heat transfer and thermal stress for spent fuel dry storage cask with different power distribution and tilt angles

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Nuclear Science and Techniques 2023年第2期34卷 109-127页

作者： Wei‑Hao Ji Jian‑Jie Cheng han‑zhong Tao Wei Li College of Urban Construction Nanjing Tech UniversityNanjing 211800China School of Energy Science and Engineering Nanjing Tech UniversityNanjing 211800China

Dry storage containers must be secured and reliable during long-term storage,and the effect of decay heat released from the internal spent fuel on the cask has become an important research *** this paper,a 3D computational fluid dynamics model is presented,and the accuracy of the calculation is verified,with computational errors of less than 6.2%.The thermal stress of the dry storage cask was estimated by coupling it with a transient temperature *** total power remained constant and adjusting the power ratio of the inner and outer zones had a small effect on the stress results,with a maximum equivalent stress of approximately 5.2 kPa,which occurred at the lower edge of the *** the case of tilt,the temperature gradient varied in a wavy distribution,and the wave crest moved from right to *** the tilt angle affects the air distribution in the annular gap,leading to the shell temperature being transformed,with a maximum equivalent stress of 202 MPa at the bottom of the ***,the equivalent stress in both cases was less than the yield stress(205 MPa).

关键词： Thermal stress CFD simulation Spent nuclear fuel Dry storage cask

Two New Norsesquiterpenes from Ixeris polycephala

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Chinese Chemical Letters 2006年第7期17卷 913-915页

作者： Yi Feng han Kun GAO zhong Jian JIA State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical Engineering Lanzhou University Lanzhou 730000

The chemical investigation of Ixeris polycephala afforded two new norsesquiterpenes, named as ixerols A and B （1-2）. Their structures were established based on spectroscopic methods including 2D NMR experiments. The... 详细信息

关键词： Ixeris polycephala Compositae ixerols A and B norsesquiterpene.

Experimental and theoretical study of coupled influence of flow velocity increment and particle size on particle retention and release in porous media

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Water Science and Engineering 2017年第3期10卷 236-245页

作者： Xing-xin Chen Qi-peng Cai zhong-han Wu School of Transportation Southeast University School of Civil Engineering Huaqiao University School of Civil Engineering Beijing Jiaotong University

Experimental and theoretical studies were carried out to investigate the coupled influence of flow velocity increment and particle size on the retention and release of particles in porous media. Particle release was examined through measurement of changes in effluent particle concentrations, and particle retention was assessed through measurement of the final spatial distribution of particles remaining in the soil columns after the experiments. Particle release curves were simulated using a convection-dispersion model that includes the instantaneous release of the line source. Fitted model parameters were used to gain insights into the mechanisms that control particle retention and release. When the flow velocity increment was 0.0435 cm/s, the peak concentration of particles decreased with increasing flow velocity until the latter approached a critical level, beyond which the particle concentration increased. Particle wedging and fouling were considered the primary mechanisms that controlled particle retention and release beyond the critical particle velocity. In experiments with large flow velocity increments, small particles exhibited lower particle mass fraction than large particles as particle wedging and fouling increased with particle size. The range of longitudinal dispersivity decreased with an increasing particle size and flow velocity increment. Moreover, the mean particle velocity increased with the mean interstitial fluid velocity. The mean particle velocity profile was highly sensitive to the particle size at low velocity increments. In general,particle release rates increased with both flow velocity and velocity increment. The mass of the released particles provides further evidence that particle wedging and fouling are the major factors that control particle release in sand columns.

关键词： Particle Porous media Retention Release Hydrodynamic force

Lateral earth pressure of granular backfills on retaining walls with expanded polystyrene geofoam inclusions under limited surcharge loading

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1388-1397页

作者： Kewei Fan Guangqing Yang Weilie Zou zhong han Yang Shen Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNanjing210098China School of Civil Engineering Wuhan UniversityWuhan430072China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang050043China

Existing studies have focused on the behavior of the retaining wall equipped with expanded polystyrene(EPS)geofoam inclusions under semi-infinite surcharge loading rather than limited surcharge *** this paper,the failure mode and the earth pressure acting on the rigid retaining wall with EPS geofoam inclusions and granular backfills(henceforth referred to as EPS-wall),under limited surcharge loading are investigated through two-and three-dimensional model *** testing results show that different from the sliding of almost all the backfill in the EPS-wall under semi-infinite surcharge loading,only an approximately triangular backfill slides in the wall under limited surcharge *** distribution of the lateral earth pressure on the EPS-wall under limited surcharge loading is non-linear,and the distribution changes from the increase of the wall depth to the decrease with the increase of the limited surcharge *** approach based on the force equilibrium of a differential element is developed to predict the lateral earth pressure behind the EPS-wall subjected to limited surcharge loading,and its performance was fully validated by the three-dimensional model tests.

关键词： Retaining wall Expanded polystyrene(EPS)geofoam Limited surcharge loading Lateral earth pressure Model test Prediction

Photon sphere and phase transition of ddimensional(d≥5) charged Gauss–Bonnet AdS black holes

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Communications in Theoretical Physics 2020年第10期72卷 131-138页

作者： Shan-zhong han Jie Jiang Ming Zhang Wen-Biao Liu Department of Physics Beijing Normal UniversityBeijing 100875China College of Physics and Communication Electronics Jiangxi Normal UniversityNanchang 330022China Perimeter Institute for Theoretical Physics WaterlooOntario N2L 2Y5Canada Department of Physics and Astronomy University of WaterlooOntario N2L 3G1Canada

Motivated by recent work,nonmonotonic behaviors of photon sphere radius can be used to reflect black hole phase transition for Reissner–Nordstr?m–AdS(RN–AdS)black holes,we study the case of five-dimensional charged Gauss–Bonnet–AdS black holes in the reduced parameter *** find that the nonmonotonic behaviors of photon sphere radius still *** the coexistence line calculated from P–V plane,we capture the photon sphere radius of saturated small and large black holes(the boundary of the coexistence phase),then illustrate the reduced coexistence *** results show that,reduced coexistence region decreases with charge Q but increases with Gauss–Bonnet coefficientα.When the charge vanishes,reduced coexistence region does not vary with Gauss–Bonnet coefficientαany *** this case,the Gauss–Bonnet coefficientαplays the same role as the charge of five-dimensional RN–AdS black ***,the situation of higher dimension is studied in the end.

关键词： Gauss–Bonnet AdS black hole phase transition photon sphere black hole thermodynamics

Structural,volumetric and water retention behaviors of a compacted clay upon saline intrusion and freeze-thaw cycles

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第3期14卷 953-966页

作者： Jianguo Lin Weilie Zou zhong han Ziwei Zhang Xiequn Wang School of Civil Engineering Wuhan UniversityWuhan430072China Key Laboratory of Hydraulic Rock Mechanics of Ministry of Education Wuhan UniversityWuhan430072China School of Civil Engineering and Architecture Wuhan University of TechnologyWuhan430070China

This study investigates the evolution of the structural,volumetric and water retention behaviors of a compacted clay during soaking and desiccation considering the influences of freeze-thaw(FT)cycles and saline *** specimens were subjected to different FT cycles and then submerged in NaCl solution with different concentrations to facilitate the saline intrusion and measure the swelling *** curve and filter paper tests were thereafter performed to reveal the clay’s volumetric and water-retention characteristics during *** intrusion porosimetry and field emission scanning electron microscopy tests were conducted to observe the evolution of the clay’s *** results show that the clay’s micropores decrease and macropores increase after FT cycles,which is associated with the migration of water,growth of ice crystals,and development of FT-induced cracks during FT *** observations were obtained from specimens after the saline intrusion,which is attributed to the osmotic and osmotically-induced ***-induced cracks significantly reduce the clay’s swelling and shrinkage *** cycles result in the shrinkage of micropores which leads to a reduction in the water retention capacity in the low suction range(capillary regime).The salinization suppresses the swelling of the clay and prolongs its primary and secondary swelling *** shrinkage potential initially increases and then decreases with increasing saline *** has significant influences on the osmotic suction and thus alters the clay’s water-retention curves in terms of total *** demonstrates little impact on the clay’s water-retention curves in terms of matric suction.

关键词： Compacted clay Microstructure Volumetric behavior Water-retention capacity Salinization Freeze-thaw(FT)cycles

Studies on sulfinatodehalogenation——ⅪⅩ.The reaction of perfluoroalkyl iodides and perfluoroalkane-sulfonyl bromides with conjugated dienes

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Chinese Journal of Chemistry 1991年第1期9卷 76-83页

作者： HUANG Wei-Yuan ZhanG han-zhong Shanghai Institute of Organic Chemistry Academia SinicaShanghai 200032

The reaction of TbCl_3 with K[2,4-(CH_2)_2C_5H_5] at 0℃ in THF followed by crystalliza- tion at -90℃ led to a pale yellow hexagonal prismatic crystalline product [2,4-[CH_3)_2-η~5-C_5H_5]_(2-) Tb·1/2THF, which is highly sensitive to air and water and rapidly efflorescent at ambient temper- ature. The single Crystal X-ray diffraction data of the compound have been collected at low tem- perature (-60℃) and the crystal structure has been solved by heavy atom method. It belongs to triclinic system, space group Pl with lattice parameters a=8.477 (?),b=12.583 (?),c=12.858 (?), a=118.08°,β=91.38°,γ=108.75°,V=1120.36 (?)~ 3 and Z=2. Least-squares refinement converged to a final value R=0.043. The compound possesses an idealized G_(2h) symmetry、with three 2,4- dimethylpentadienyl ligands bound to the central terbium atom in a pentahapto mode (η~5). Each unit cell contains two molecules of[2,4-(CH_3)_2-η~5-C_5H_5]_3Tb and one molecule of solvent THF, of which the role in the lattice has been discussed in detail.

关键词： Br The reaction of perfluoroalkyl iodides and perfluoroalkane-sulfonyl bromides with conjugated dienes

Enantioselective[2+2]cycloaddition of 1,2-dihydroquinolines with 3-olefinic oxindoles via Brønsted acid catalysis

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Organic Chemistry Frontiers 2022年第6期9卷 1621-1627页

作者： Biao Wang Xiao Yan han zhong Qin Ouyang Xu Tian Key Laboratory of Molecular Target&Clinical Pharmacology and the State Key Laboratory of Respiratory Disease School of Pharmaceutical Sciences&the Fifth Affiliated HospitalGuangzhou Medical UniversityXinzaoPanyu DistrictGuangzhou511436China College of Pharmacy Third Military Medical UniversityChongqing400038China

Mutually complementary regiodivergent Brønsted acid-catalyzed atom-economical[2+2]cycloadditionand ene reactions of 1,2-dihydroquinolines with 3-olefinic oxindoles are *** the presence of achiral phosphoramide catalyst,the[2+2]cycloaddition affords products with four contiguous stereocenters in good to excellent yields(up to 95%)and with high stereoselectivities(up to>99%ee,>20:1 dr).Conversely,with a stronger Brønsted acid,the trifluoromethanesulfonic acid catalyst leads to ene reactionproducts in high yields(up to 77%).Furthermore,the mechanisms of the reactions are discussed based oncontrol experiments and DFT calculations.

关键词： catalyst cycloaddition indole

Study on the Estimation of Groundwater Withdrawals Based on Groundwater Flow Modeling and Its Application in the North China Plain

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Journal of Earth Science 2014年第6期25卷 1033-1042页

作者： Jingli Shao Yali Cui Qichen Hao zhong han Tangpei Cheng School of Water Resources and Environment China University of Geosciences Institute of Applied Physics and Computational Mathematics CAEP Software Center for High Performance Numerical Simulation

The amount of water withdrawn by wells is one of the quantitative variables that can be applied to estimate groundwater resources and further evaluate the human influence on groundwater systems. The accuracy for the calculation of the amount of water withdrawal significantly influences the regional groundwater resource evaluation and management. However, the decentralized groundwater pumping, inefficient management, measurement errors and uncertainties have resulted in considerable errors in the groundwater withdrawal estimation. In this study, to improve the estimation of the groundwater withdrawal, an innovative approach was proposed using an inversion method based on a regional groundwater flow numerical model, and this method was then applied in the North China Plain. The principle of the method was matching the simulated water levels with the observation ones by adjusting the amount of groundwater withdrawal. In addition, uncertainty analysis of hydraulic conductivity and specific yield for the estimation of the groundwater withdrawal was conducted. By using the proposed inversion method, the estimated annual average groundwater withdrawal was approximately 24.92×10^9 m^3 in the North China Plain from 2002 to 2008. The inversion method also significantly improved the simulation results for both hydrograph and the flow field. Results of the uncertainty analysis showed that the hydraulic conductivity was more sensitive to the inversion results than the specific yield.

关键词： inversion method North China Plain groundwater withdrawal numerical modeling