The fluid viscosity is known to have a significant effect on the hydrodynamic characteristics which are linked to the power conversion ability of the wave energy converter(WEC). To overcome the disadvantages of case-b...The fluid viscosity is known to have a significant effect on the hydrodynamic characteristics which are linked to the power conversion ability of the wave energy converter(WEC). To overcome the disadvantages of case-by-case study through the experiments and numerical computations employed by the former researches, the viscous effect is studied comprehensively for multiple geometries in the present paper. The viscous effect is expressed as the viscous added mass and damping solved by the free-decay method. The computational fluid dynamics(CFD) method is employed for the calculation of the motion and flow field around the floater. The diameter to draft ratio and bottom shape are considered for the geometrical evaluation on the viscous effect. The results show that a slenderer floater presents a stronger viscous effect. Through the comparisons of the floaters with four different bottom shapes, the conical bottom is recommended in terms of low viscous effect and simple geometry for manufacture. A viscous correction formula for a series of cylindrical floaters is put forward, for the first time, to help the engineering design of outer-floaters of point-absorber WECs.展开更多
Main observation and conclusion Two new uranium(VI)phosphonate compounds,namely K_(8)[N(C_(2)H_(5))_(4)]_(2)(UO_(2))_(17)(H_(2)O)_(4)[CH_(2)(PO_(3))_(2)]_(8)[CH_(2)(PO_(3))(PO_(3)H)]_(4)·16(H_(2)O)(1)and[N(C_(2)H...Main observation and conclusion Two new uranium(VI)phosphonate compounds,namely K_(8)[N(C_(2)H_(5))_(4)]_(2)(UO_(2))_(17)(H_(2)O)_(4)[CH_(2)(PO_(3))_(2)]_(8)[CH_(2)(PO_(3))(PO_(3)H)]_(4)·16(H_(2)O)(1)and[N(C_(2)H_(5))_(4)]_(4)(H_(3)O)_(2)(UO_(2))_(10)[CH_(2)(PO_(3))_(2)]_(5)[CH_(2)(PO_(3))(PO_(3)H)]_(2)·10H_(2)O(2),have been synthesized under mild hydro/solvothermal condition.The structural analysis of the two compounds reveals that they both contain all three typical coordination geometries of the U(VI)ions,including UO;tetragonal,UO,pentagonal,and UOg hexagonal bipyramids.Moreover,compound 1 displays a tempera-ture-induced single crystal to single crystal phase transformation as confirmed by the Single-crystal X-ray diffraction data collected at different temperatures.Temperature-dependent fluorescence spectra presented herein illustrate the perturbation of the electronic structure of uranyl centers.展开更多
Reflected wave seismology has the following defects:the acquisition design is based on the assumption of layered media,the signal processing suppresses weak signals such as diffracted wave and scattered wave,and the s...Reflected wave seismology has the following defects:the acquisition design is based on the assumption of layered media,the signal processing suppresses weak signals such as diffracted wave and scattered wave,and the seismic wave band after the image processing is narrow.They limit the full utilization of broadband raw data.The concept of full wave seismic exploration is redefined based on the idea of balanced utilization of reflected wave,diffracted wave and scattered wave information,its characteristics and adaptive conditions are clarified.A set of key technologies suitable for full wave seismic exploration are put forward.During seismic acquisition period,it is necessary to adopt multi geometry,i.e.embed small bin,small offset and small channel interval data in conventional geometry.By discretizing of common midpoint(CMP)gathers,small offset with high coverage,the weak signals such as diffracted wave and scattered wave in the raw seismic data can be enhanced.During seismic processing,the signal and noise in the original seismic data need to be redefined at first.The effective signals of seismic data are enhanced through merging of multi-geometry data.By means of differential application of data with different bin sizes and different arrangement modes,different regimes of seismic waves can be effectively decomposed and imaged separately.During seismic interpretation stage,making the most of the full wave seismic data,and adopting well-seismic calibration on multi-scale and multi-dimension,the seismic attributes in multi-regimes and multi-domains are interpreted to reveal interior information of complex lithology bodies and improve the lateral resolution of non-layered reservoirs.展开更多
The chiral geometry of multiple chiral doublet bands with identical configuration is discussed for different triaxial deformation parameters γ in the particle rotor model with πh11/2×γh11/2^-1.The energy spect...The chiral geometry of multiple chiral doublet bands with identical configuration is discussed for different triaxial deformation parameters γ in the particle rotor model with πh11/2×γh11/2^-1.The energy spectra,electromagnetic transition probabilities B（M1） and B（E2）,angular momenta,and K-distributions are studied.It is demonstrated that the chirality still remains not only in the yrast and yrare bands,but also in the two higher excited bands whenγ deviates from 30°.The chiral geometry relies significantly on γ,and the chiral geometry of the two higher excited partner bands is not as good as that of the yrast and yrare doublet bands.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.51761135013)the High Technology Ship Scientific Research Project from Ministry of Industry and Information Technology of the People’s Republic of China–Floating Security Platform Project(the second stage,201622)+1 种基金the Fundamental Research Fund for the Central University(Grant Nos.HEUCF180104 and HEUCFP201809)the China Scholarship Council(the International Clean Energy Talent Program,2017)
文摘The fluid viscosity is known to have a significant effect on the hydrodynamic characteristics which are linked to the power conversion ability of the wave energy converter(WEC). To overcome the disadvantages of case-by-case study through the experiments and numerical computations employed by the former researches, the viscous effect is studied comprehensively for multiple geometries in the present paper. The viscous effect is expressed as the viscous added mass and damping solved by the free-decay method. The computational fluid dynamics(CFD) method is employed for the calculation of the motion and flow field around the floater. The diameter to draft ratio and bottom shape are considered for the geometrical evaluation on the viscous effect. The results show that a slenderer floater presents a stronger viscous effect. Through the comparisons of the floaters with four different bottom shapes, the conical bottom is recommended in terms of low viscous effect and simple geometry for manufacture. A viscous correction formula for a series of cylindrical floaters is put forward, for the first time, to help the engineering design of outer-floaters of point-absorber WECs.
基金the National Natural Science Foundation of China(21906113,21561018,21790374,and 22066014)the Priority Academic Pro-gram Development of Jiangsu Higher Education Institutions(PAPD)the Applied Basic Research Foundation of Yunnan Province(2017FH001-023).
文摘Main observation and conclusion Two new uranium(VI)phosphonate compounds,namely K_(8)[N(C_(2)H_(5))_(4)]_(2)(UO_(2))_(17)(H_(2)O)_(4)[CH_(2)(PO_(3))_(2)]_(8)[CH_(2)(PO_(3))(PO_(3)H)]_(4)·16(H_(2)O)(1)and[N(C_(2)H_(5))_(4)]_(4)(H_(3)O)_(2)(UO_(2))_(10)[CH_(2)(PO_(3))_(2)]_(5)[CH_(2)(PO_(3))(PO_(3)H)]_(2)·10H_(2)O(2),have been synthesized under mild hydro/solvothermal condition.The structural analysis of the two compounds reveals that they both contain all three typical coordination geometries of the U(VI)ions,including UO;tetragonal,UO,pentagonal,and UOg hexagonal bipyramids.Moreover,compound 1 displays a tempera-ture-induced single crystal to single crystal phase transformation as confirmed by the Single-crystal X-ray diffraction data collected at different temperatures.Temperature-dependent fluorescence spectra presented herein illustrate the perturbation of the electronic structure of uranyl centers.
基金Supported by the Sinopec Ministry of Science and Technology Project(P21038-3)。
文摘Reflected wave seismology has the following defects:the acquisition design is based on the assumption of layered media,the signal processing suppresses weak signals such as diffracted wave and scattered wave,and the seismic wave band after the image processing is narrow.They limit the full utilization of broadband raw data.The concept of full wave seismic exploration is redefined based on the idea of balanced utilization of reflected wave,diffracted wave and scattered wave information,its characteristics and adaptive conditions are clarified.A set of key technologies suitable for full wave seismic exploration are put forward.During seismic acquisition period,it is necessary to adopt multi geometry,i.e.embed small bin,small offset and small channel interval data in conventional geometry.By discretizing of common midpoint(CMP)gathers,small offset with high coverage,the weak signals such as diffracted wave and scattered wave in the raw seismic data can be enhanced.During seismic processing,the signal and noise in the original seismic data need to be redefined at first.The effective signals of seismic data are enhanced through merging of multi-geometry data.By means of differential application of data with different bin sizes and different arrangement modes,different regimes of seismic waves can be effectively decomposed and imaged separately.During seismic interpretation stage,making the most of the full wave seismic data,and adopting well-seismic calibration on multi-scale and multi-dimension,the seismic attributes in multi-regimes and multi-domains are interpreted to reveal interior information of complex lithology bodies and improve the lateral resolution of non-layered reservoirs.
基金Supported by Plan Project of Beijing College Students' Scientific Research and Entrepreneurial Action,Major State 973 Program of China(2013CB834400)National Natural Science Foundation of China(11175002,11335002,11375015,11461141002)+2 种基金National Fund for Fostering Talents of Basic Science(NFFTBS)(J1103206)Research Fund for Doctoral Program of Higher Education(20110001110087)China Postdoctoral Science Foundation(2015M580007)
文摘The chiral geometry of multiple chiral doublet bands with identical configuration is discussed for different triaxial deformation parameters γ in the particle rotor model with πh11/2×γh11/2^-1.The energy spectra,electromagnetic transition probabilities B（M1） and B（E2）,angular momenta,and K-distributions are studied.It is demonstrated that the chirality still remains not only in the yrast and yrare bands,but also in the two higher excited bands whenγ deviates from 30°.The chiral geometry relies significantly on γ,and the chiral geometry of the two higher excited partner bands is not as good as that of the yrast and yrare doublet bands.
