A parameterized internal tide dissipation term and self-attraction and loading(SAL) tide term are introduced in a barotropic numerical model to investigate the dynamics of semidiurnal tidal constituents M_2 and S_2 in...A parameterized internal tide dissipation term and self-attraction and loading(SAL) tide term are introduced in a barotropic numerical model to investigate the dynamics of semidiurnal tidal constituents M_2 and S_2 in the Bohai Sea, Yellow Sea and East China Sea(BYECS). The optimal parameters for bottom friction and internal dissipation are obtained through a series of numerical computations. Numerical simulation shows that the tide-generating force contributes 1.2% of M_2 power for the entire BYECS and up to 2.8% for the East China Sea deep basin. SAL tide contributes 4.4% of M_2 power for the BYECS and up to 9.3% for the East China Sea deep basin. Bottom friction plays a major role in dissipating tidal energy in the shelf regions, and the internal tide eff ect is important in the deep water regions. Numerical experiments show that artifi cial removal of tide-generating force in the BYECS can cause a signifi cant dif ference(as much as 30 cm) in model output. Artifi cial removal of SAL tide in the BYECS can cause even greater diff erence, up to 40 cm. This indicates that SAL tide should be taken into account in numerical simulations, especially if the tide-generating force is considered.展开更多
The loading tides are calculated by means of the Green's function method based on a high-resolution regional ocean tide model, the TOPO7.0 global ocean tide model, and the Gutenberg-Bullen A Earth model. The resul...The loading tides are calculated by means of the Green's function method based on a high-resolution regional ocean tide model, the TOPO7.0 global ocean tide model, and the Gutenberg-Bullen A Earth model. The results show that the maximal amplitude of M2 vertical displacement loading (VDL) tide in the Bohai, Yellow, and East China Seas exceeding 28mm appears 150km off the Zhejiang coast; the second maximum exceeding 20mm appears in Inchon Bay; and the third maximum exceeding 14mm is located in the northeast of the North Yellow Sea. The maximal amplitudes of S2 VDL tide at the above three locations exceed 10, 8, and 4mm, respectively. The maximal amplitudes of the K1 and O1 VDL tides, exceeding 13 and 10 mm respectively, appear near the central and north Ryukyu Islands; the amplitudes tend to decease toward the inward areas. The phases of semidiurnal VDL tides are basically opposite to those of corresponding ocean tides. The phases of diurnal VDL tides are basically opposite to those of corresponding ocean tides in the most part of the East China Sea and the eastern part of the South Yellow Sea. This anti-phase relationship generally does not hold in the rest parts of the Bohai and Yellow Seas. The distribution patterns of self-attraction and loading (SAL) tides are very similar to those of VDL tides. The SAL tides have amplitudes about 1.2-1.7 times of the corresponding VDL tides and their phases are basically opposite to the corresponding VDL tides. The maximal amplitude of M2 SAL tide also appears off the Zhejiang coast, with a magnitude exceeding 42mm.展开更多
The self-attraction of nanowires(NWs)would lead to NWs bunching up together when fabricated in high density and the short circuit of NW-based devices during service.However,the underlying mechanism of the self-attract...The self-attraction of nanowires(NWs)would lead to NWs bunching up together when fabricated in high density and the short circuit of NW-based devices during service.However,the underlying mechanism of the self-attraction of NWs remains debatable due to the lack of in situ characterization of the attraction.In this study,a versatile method of in situ investigating the self-attraction of NWs was developed.The attractive force between two NWs and their distance can be determined quantitatively in the process of attraction under an optical microscope,eliminating the influence of electron beam in electron microscopes.With this approach,the self-attraction of SiC NWs was investigated and a two-stage mechanism for the self-attraction was proposed.The electrostatic force between two individual SiC NWs increased as their distance decreased,and acted as the initial driving force for the attraction of NWs.SiC NWs remained in contact under van der Waals force until they separated when external force exceeded van der Waals force.The charge density and the Hamaker constant of SiC NWs were determined to be 1.9×10^(-4)C·m^(-2)and 1.56×10^(-19)J,which played an important role in the attraction of NWs.The results shed light on the mechanism of selfattraction among NWs and provide new insights into fabricating high-quality NWs and developing high-performance NW-based devices.展开更多
By employing dynamic Monte Carlo simulations, we investigate a coil-to-toroid transition of self-attractive semiflexible polymers and the spatial distributions of nanoparticles in self- attractive semiflexible polymer...By employing dynamic Monte Carlo simulations, we investigate a coil-to-toroid transition of self-attractive semiflexible polymers and the spatial distributions of nanoparticles in self- attractive semiflexible polymer/nanoparticle composites. The conformation of self-attractive semiflexible polymers depends on bending energy and self-attractive interactions between monomers in polymer chains. A three-stage process of toroid formation for self-attractive semiflexible chains is shown： several isolated toroids, a loose toroid structure, and a compact toroid structure. Utilizing the compact toroid conformations of self-attractive semiflexible chains, we can control effectively the spatial distributions of nanoparticles in self-attractive semiflexible polymer nanocomposites, and an unconventional toroid structure of nanoparti- cles is observed.展开更多
Let B^(a,b)be a weighted-fractional Brownian motion with Hurst indices a and b such that a>-1 and 0≤b<1∧(1+a).In this paper,we consider the linear self-attracting diffusion dX_(t)^(a,b)=dB_(t)^(a,b)−θ(∫t 0(X...Let B^(a,b)be a weighted-fractional Brownian motion with Hurst indices a and b such that a>-1 and 0≤b<1∧(1+a).In this paper,we consider the linear self-attracting diffusion dX_(t)^(a,b)=dB_(t)^(a,b)−θ(∫t 0(X_(t)^(a,b)−X_(s)^(a,b))ds)dt+νdt with X_(0)^(a,b),whereθ>0 andν∈R are two real parameters.The model is an analog of the linear selfinteracting diffusion(see Cranston and Le Jan(1995)).Under the continuous observation,we study asymptotic behaviors of the least squares estimatorsθˆT andνˆT.In particular,when b>1/2,we obtain a new random variable Z_(1)^(a,b)which is called the Rosenblatt random variable if a=0,and we show that C_(a,b)T^(2-2b)(θ_(T)-θ)converges in distribution to the sum of the chi-square random variable with 1 degree of freedom and the random variable Z_(1)^(a,b).展开更多
基金Supported by the National Natural Science Foundation of China(Nos.40676009,40606006)the Qingdao Science and Technology Basic Research Program(No.11-1-4-98-jch)
文摘A parameterized internal tide dissipation term and self-attraction and loading(SAL) tide term are introduced in a barotropic numerical model to investigate the dynamics of semidiurnal tidal constituents M_2 and S_2 in the Bohai Sea, Yellow Sea and East China Sea(BYECS). The optimal parameters for bottom friction and internal dissipation are obtained through a series of numerical computations. Numerical simulation shows that the tide-generating force contributes 1.2% of M_2 power for the entire BYECS and up to 2.8% for the East China Sea deep basin. SAL tide contributes 4.4% of M_2 power for the BYECS and up to 9.3% for the East China Sea deep basin. Bottom friction plays a major role in dissipating tidal energy in the shelf regions, and the internal tide eff ect is important in the deep water regions. Numerical experiments show that artifi cial removal of tide-generating force in the BYECS can cause a signifi cant dif ference(as much as 30 cm) in model output. Artifi cial removal of SAL tide in the BYECS can cause even greater diff erence, up to 40 cm. This indicates that SAL tide should be taken into account in numerical simulations, especially if the tide-generating force is considered.
基金supported by National Natural Science Foundation of China (Grant Nos. 40676009 and 40606006)Qingdao Science and Technology Basic Research Program (Grant No. 11-1-4-98-JCH)
文摘The loading tides are calculated by means of the Green's function method based on a high-resolution regional ocean tide model, the TOPO7.0 global ocean tide model, and the Gutenberg-Bullen A Earth model. The results show that the maximal amplitude of M2 vertical displacement loading (VDL) tide in the Bohai, Yellow, and East China Seas exceeding 28mm appears 150km off the Zhejiang coast; the second maximum exceeding 20mm appears in Inchon Bay; and the third maximum exceeding 14mm is located in the northeast of the North Yellow Sea. The maximal amplitudes of S2 VDL tide at the above three locations exceed 10, 8, and 4mm, respectively. The maximal amplitudes of the K1 and O1 VDL tides, exceeding 13 and 10 mm respectively, appear near the central and north Ryukyu Islands; the amplitudes tend to decease toward the inward areas. The phases of semidiurnal VDL tides are basically opposite to those of corresponding ocean tides. The phases of diurnal VDL tides are basically opposite to those of corresponding ocean tides in the most part of the East China Sea and the eastern part of the South Yellow Sea. This anti-phase relationship generally does not hold in the rest parts of the Bohai and Yellow Seas. The distribution patterns of self-attraction and loading (SAL) tides are very similar to those of VDL tides. The SAL tides have amplitudes about 1.2-1.7 times of the corresponding VDL tides and their phases are basically opposite to the corresponding VDL tides. The maximal amplitude of M2 SAL tide also appears off the Zhejiang coast, with a magnitude exceeding 42mm.
基金The authors acknowledge the financial supports from the Youth Innovation Promotion Association CAS(No.2019295)the Science and Technology Major Project of Ningbo(No.2018B10046)+2 种基金the National Key R&D Program of China(No.2018YFA0703400)the National Natural Science Foundation of China(Nos.51573201 and 52142501)Changjiang Scholars Program of Chinese Ministry of Education,the Xinghai Science Funds for Distinguished Young Scholars at Dalian University of Technology,and the Collaborative Innovation Center of Major Machine Manufacturing in Liaoning。
文摘The self-attraction of nanowires(NWs)would lead to NWs bunching up together when fabricated in high density and the short circuit of NW-based devices during service.However,the underlying mechanism of the self-attraction of NWs remains debatable due to the lack of in situ characterization of the attraction.In this study,a versatile method of in situ investigating the self-attraction of NWs was developed.The attractive force between two NWs and their distance can be determined quantitatively in the process of attraction under an optical microscope,eliminating the influence of electron beam in electron microscopes.With this approach,the self-attraction of SiC NWs was investigated and a two-stage mechanism for the self-attraction was proposed.The electrostatic force between two individual SiC NWs increased as their distance decreased,and acted as the initial driving force for the attraction of NWs.SiC NWs remained in contact under van der Waals force until they separated when external force exceeded van der Waals force.The charge density and the Hamaker constant of SiC NWs were determined to be 1.9×10^(-4)C·m^(-2)and 1.56×10^(-19)J,which played an important role in the attraction of NWs.The results shed light on the mechanism of selfattraction among NWs and provide new insights into fabricating high-quality NWs and developing high-performance NW-based devices.
文摘By employing dynamic Monte Carlo simulations, we investigate a coil-to-toroid transition of self-attractive semiflexible polymers and the spatial distributions of nanoparticles in self- attractive semiflexible polymer/nanoparticle composites. The conformation of self-attractive semiflexible polymers depends on bending energy and self-attractive interactions between monomers in polymer chains. A three-stage process of toroid formation for self-attractive semiflexible chains is shown： several isolated toroids, a loose toroid structure, and a compact toroid structure. Utilizing the compact toroid conformations of self-attractive semiflexible chains, we can control effectively the spatial distributions of nanoparticles in self-attractive semiflexible polymer nanocomposites, and an unconventional toroid structure of nanoparti- cles is observed.
基金supported by National Natural Science Foundation of China(Grant No.11971101)。
文摘Let B^(a,b)be a weighted-fractional Brownian motion with Hurst indices a and b such that a>-1 and 0≤b<1∧(1+a).In this paper,we consider the linear self-attracting diffusion dX_(t)^(a,b)=dB_(t)^(a,b)−θ(∫t 0(X_(t)^(a,b)−X_(s)^(a,b))ds)dt+νdt with X_(0)^(a,b),whereθ>0 andν∈R are two real parameters.The model is an analog of the linear selfinteracting diffusion(see Cranston and Le Jan(1995)).Under the continuous observation,we study asymptotic behaviors of the least squares estimatorsθˆT andνˆT.In particular,when b>1/2,we obtain a new random variable Z_(1)^(a,b)which is called the Rosenblatt random variable if a=0,and we show that C_(a,b)T^(2-2b)(θ_(T)-θ)converges in distribution to the sum of the chi-square random variable with 1 degree of freedom and the random variable Z_(1)^(a,b).
