The derivation and validation of analytical equations for predicting the tensile initial stiffness of threadfixed one-side bolts(TOBs),connected to enclosed rectangular hollow section(RHS)columns,is presented in this ...The derivation and validation of analytical equations for predicting the tensile initial stiffness of threadfixed one-side bolts(TOBs),connected to enclosed rectangular hollow section(RHS)columns,is presented in this paper.Two unknown stiffness components are considered:the TOBs connection and the enclosed RHS face.First,the trapezoidal thread of TOB,as an equivalent cantilevered beam subjected to uniformly distributed loads,is analyzed to determine the associated deformations.Based on the findings,the thread-shank serial-parallel stiffness model of TOB connection is proposed.For analysis of the tensile stiffness of the enclosed RHS face due to two bolt forces,the four sidewalls are treated as rotation constraints,thus reducing the problem to a two-dimensional plate analysis.According to the load superposition method,the deflection of the face plate is resolved into three components under various boundary and load conditions.Referring to the plate deflection theory of Timoshenko,the analytical solutions for the three deflections are derived in terms of the variables of bolt spacing,RHS thickness,height to width ratio,etc.Finally,the validity of the above stiffness equations is verified by a series of finite element(FE)models of T-stub substructures.The proposed component stiffness equations are an effective supplement to the component-based method.展开更多
The Turonian aquifer of the Tadla’s basin shows at present a pronounced reduction of its hydraulic potential linked to overexploitation and deficiency of effective rains.In order to make an evaluation of the resource...The Turonian aquifer of the Tadla’s basin shows at present a pronounced reduction of its hydraulic potential linked to overexploitation and deficiency of effective rains.In order to make an evaluation of the resources of water and implant the exploitation’s drillings of groundwater,a geophysical study by展开更多
The United Arab Emirates lacks conventional water resources and relies primarily on desalination plants powered by fossil fuels to produce fresh water.Nuclear desalination is a proven technology,cost-competitive,and s...The United Arab Emirates lacks conventional water resources and relies primarily on desalination plants powered by fossil fuels to produce fresh water.Nuclear desalination is a proven technology,cost-competitive,and sustainable option capable of integrating the existing largescale desalination plants to produce both freshwater and electricity.However,Small Modular Reactors(SMRs)are promising designs with advanced simplified configurations and inherent safety features.In this study,an Integrated Desalination SMR that produces thermal energy compatible with the capacity of a fossil fuel-powered desalination plant in the UAE was designed.First,the APR-1400 reactor core was used to investigate two 150 MWthconceptual SMR core designs,core A and core B,based on two-dimensional parameters,radius,and height.Then,the CASMO-4 lattice code was used to generate homogenized few-group constants for optimized fuel assembly loading patterns.Finally,to find the best core configuration,SIMULATE-3 was used to calculate the core key physics parameters such as power distribution,reactivity coefficients,and critical boron concentration.In addition,different reflector materials were investigated to compensate for the expected high leakage of the small-sized SMR cores.The pan shape core B model(142.6132 cm diameter,100 cm height,and radially reflected by Stainless Steel)was selected as the best core configuration based on its calculated physics parameters.Core B met the design and safety criteria and indicated low total neutron leakage of 11.60%and flat power distribution with 1.50 power peaking factor.Compared to core A,it has a more negative MTC value of-6.93 pcm/°F with lower CBC.In a 2-batch scheme,the fuel is discharged at 42.25 GWd/MTU burnup after a long cycle length of 1.58 years.The core B model offers the highest specific power of 36.56 kW/kgU while utilizing the smallest heavy metal mass compared with the SMART and NuScale models.展开更多
The phase diagram of ZrO_(2)−CaO−TiO_(2)system was essential for the development of photocatalytic materials and refractory materials.In this work,the ZrO_(2)−CaO−TiO_(2)system was accessed by using the CALPHAD method...The phase diagram of ZrO_(2)−CaO−TiO_(2)system was essential for the development of photocatalytic materials and refractory materials.In this work,the ZrO_(2)−CaO−TiO_(2)system was accessed by using the CALPHAD method.The substitutional solution models were used to describe liquid and solid solution phases,the sub-lattice models were used to describe ternary compounds,and then the thermodynamic parameters were obtained by the least square method combined with literature experiment results.The acquired thermodynamic parameters were used to calculate the isothermal sections of the ZrO_(2)−CaO−TiO_(2)system at 1473 and 1673 K.There existed a good agreement between experimental and predicted phase relationships,the experimental points which were inconsistent with calculated results may be attributed to experimental errors and the sluggish kinetics of cations for ZrO_(2)-based materials.In order to further verify the validity of the database,the thermodynamic parameters were also used to simulate the thermodynamic properties(specific heat capacity,enthalpy,and entropy)of CaZrTi_(2)O_(7) within 5%errors.Good consistency demonstrated that the present thermodynamic database was self-consistent and credible.展开更多
State-to-state time-dependent quantum dynamics calculations have been carried out to study H+DH'→HH'+D/HD+H'reactions on BKMP2 surface.The total integral cross sections of both reactions are in good agree...State-to-state time-dependent quantum dynamics calculations have been carried out to study H+DH'→HH'+D/HD+H'reactions on BKMP2 surface.The total integral cross sections of both reactions are in good agreement with earlier theoretical and experimental results,moreover the rotational state-resolved reaction cross sections of H+DH'→HH‘+D at collision energy Ec=0.5 eV are closer to the experimental values than the ones calculated by Chao et al[J.Chem.Phys.1178341(2002)],which proves the higher precision of the quantum calculation in this work.In addition,the state-to-state dynamics of H+DH'→HD'+H reaction channel have been discussed in detail,and the differences of the micro-mechanism of the two reaction channels have been revealed and analyzed clearly.展开更多
In this paper, the step reduction method is discussed, which was advanced by Prof. Yeh Kai-yuan for calculating a non-uniform beam with various sections. The following result is proved. The approximate solution by thi...In this paper, the step reduction method is discussed, which was advanced by Prof. Yeh Kai-yuan for calculating a non-uniform beam with various sections. The following result is proved. The approximate solution by this method approaches the true solution if the number of the steps approaches the infinity. However, the measure of the error between the limit solution and the ture solution is not in the pure mathematics sense but in the mechanics sense.展开更多
基金This study was supported by the National Natural Science Foundation of China(Grant Nos.51978500 and 51538002).
文摘The derivation and validation of analytical equations for predicting the tensile initial stiffness of threadfixed one-side bolts(TOBs),connected to enclosed rectangular hollow section(RHS)columns,is presented in this paper.Two unknown stiffness components are considered:the TOBs connection and the enclosed RHS face.First,the trapezoidal thread of TOB,as an equivalent cantilevered beam subjected to uniformly distributed loads,is analyzed to determine the associated deformations.Based on the findings,the thread-shank serial-parallel stiffness model of TOB connection is proposed.For analysis of the tensile stiffness of the enclosed RHS face due to two bolt forces,the four sidewalls are treated as rotation constraints,thus reducing the problem to a two-dimensional plate analysis.According to the load superposition method,the deflection of the face plate is resolved into three components under various boundary and load conditions.Referring to the plate deflection theory of Timoshenko,the analytical solutions for the three deflections are derived in terms of the variables of bolt spacing,RHS thickness,height to width ratio,etc.Finally,the validity of the above stiffness equations is verified by a series of finite element(FE)models of T-stub substructures.The proposed component stiffness equations are an effective supplement to the component-based method.
文摘The Turonian aquifer of the Tadla’s basin shows at present a pronounced reduction of its hydraulic potential linked to overexploitation and deficiency of effective rains.In order to make an evaluation of the resources of water and implant the exploitation’s drillings of groundwater,a geophysical study by
基金supported by the Office of Vice Chancellor for Research&Graduate Studies,University of Sharjah,under grant no. V.C.R.G./R.1325/2021
文摘The United Arab Emirates lacks conventional water resources and relies primarily on desalination plants powered by fossil fuels to produce fresh water.Nuclear desalination is a proven technology,cost-competitive,and sustainable option capable of integrating the existing largescale desalination plants to produce both freshwater and electricity.However,Small Modular Reactors(SMRs)are promising designs with advanced simplified configurations and inherent safety features.In this study,an Integrated Desalination SMR that produces thermal energy compatible with the capacity of a fossil fuel-powered desalination plant in the UAE was designed.First,the APR-1400 reactor core was used to investigate two 150 MWthconceptual SMR core designs,core A and core B,based on two-dimensional parameters,radius,and height.Then,the CASMO-4 lattice code was used to generate homogenized few-group constants for optimized fuel assembly loading patterns.Finally,to find the best core configuration,SIMULATE-3 was used to calculate the core key physics parameters such as power distribution,reactivity coefficients,and critical boron concentration.In addition,different reflector materials were investigated to compensate for the expected high leakage of the small-sized SMR cores.The pan shape core B model(142.6132 cm diameter,100 cm height,and radially reflected by Stainless Steel)was selected as the best core configuration based on its calculated physics parameters.Core B met the design and safety criteria and indicated low total neutron leakage of 11.60%and flat power distribution with 1.50 power peaking factor.Compared to core A,it has a more negative MTC value of-6.93 pcm/°F with lower CBC.In a 2-batch scheme,the fuel is discharged at 42.25 GWd/MTU burnup after a long cycle length of 1.58 years.The core B model offers the highest specific power of 36.56 kW/kgU while utilizing the smallest heavy metal mass compared with the SMART and NuScale models.
基金the Open Project of State Key Laboratory of Advanced Special Steel and Shanghai Key Laboratory of Advanced Ferrometallurgy,China(No.SKLASS2019-11)the National Natural Science Foundation of China(No.52104305).
文摘The phase diagram of ZrO_(2)−CaO−TiO_(2)system was essential for the development of photocatalytic materials and refractory materials.In this work,the ZrO_(2)−CaO−TiO_(2)system was accessed by using the CALPHAD method.The substitutional solution models were used to describe liquid and solid solution phases,the sub-lattice models were used to describe ternary compounds,and then the thermodynamic parameters were obtained by the least square method combined with literature experiment results.The acquired thermodynamic parameters were used to calculate the isothermal sections of the ZrO_(2)−CaO−TiO_(2)system at 1473 and 1673 K.There existed a good agreement between experimental and predicted phase relationships,the experimental points which were inconsistent with calculated results may be attributed to experimental errors and the sluggish kinetics of cations for ZrO_(2)-based materials.In order to further verify the validity of the database,the thermodynamic parameters were also used to simulate the thermodynamic properties(specific heat capacity,enthalpy,and entropy)of CaZrTi_(2)O_(7) within 5%errors.Good consistency demonstrated that the present thermodynamic database was self-consistent and credible.
基金the National Natural Science Foundation of China(Grant Nos.11504206 and 12004216)the Ph.D.Research Start-up Fund of Shandong Jiaotong University(Grant No.BS2020025)the Shandong Natural Science Foundation,China(Grant Nos.ZR2020MF102 and ZR2020QA064)。
文摘State-to-state time-dependent quantum dynamics calculations have been carried out to study H+DH'→HH'+D/HD+H'reactions on BKMP2 surface.The total integral cross sections of both reactions are in good agreement with earlier theoretical and experimental results,moreover the rotational state-resolved reaction cross sections of H+DH'→HH‘+D at collision energy Ec=0.5 eV are closer to the experimental values than the ones calculated by Chao et al[J.Chem.Phys.1178341(2002)],which proves the higher precision of the quantum calculation in this work.In addition,the state-to-state dynamics of H+DH'→HD'+H reaction channel have been discussed in detail,and the differences of the micro-mechanism of the two reaction channels have been revealed and analyzed clearly.
文摘In this paper, the step reduction method is discussed, which was advanced by Prof. Yeh Kai-yuan for calculating a non-uniform beam with various sections. The following result is proved. The approximate solution by this method approaches the true solution if the number of the steps approaches the infinity. However, the measure of the error between the limit solution and the ture solution is not in the pure mathematics sense but in the mechanics sense.
