To better understand the effect of a new split variant of human asialoglycoprotein receptor (ASGPR H1b) on ASGPR ligands’ binding ability, we established a functional cell line which expresses ASGPR.The full lengths ...To better understand the effect of a new split variant of human asialoglycoprotein receptor (ASGPR H1b) on ASGPR ligands’ binding ability, we established a functional cell line which expresses ASGPR.The full lengths of ASGPRH1a and H2c fragments from human liver were amplified by reverse transcript PCR (RT-PCR) and inserted into eukaryotic expression vector pIRES2EFP, pCDNA3.1 (Zeo+) respectively.The recombinants were cotransfected into HeLa cells.After selection by using Neocin and Zeocin, a stably transfected cell line was established, which was designated 4-1-6.The transcription and expression of ASGPRH1a and H2c in 4-1-6 were confirmed by RT-PCR, Western blotting and immunofluorescence.The endocytosis function of the artificial "ASGPR" on the surface of 4-1-6 was tested by FACS.It was found that the cell line 4-1-6 could bind ASGPR natural ligand molecular asialo-orosomucoid (ASOR).After the eukaryotic plasmid H1b/pCDNA3.1 (neo) was transfected into cell line 4-1-6, H1b did not down-regulate the ligand binding ability of ASGPR.The eukaryotic expression plasmid H1b/pcDNA3.1 (neo) and H2c/pcDNA3.1 (neo) were co-transfected transiently into Hela cell.Neither single H1b nor H1b and H2c could bind ASOR.In conclusion, a functional cell line of human asialoglycoprotein receptor (ASGPR) which expresses both H1a and H2c stably was established.The new split variant H1b has no effect on ASGPR binding to ASOR.ASGPRH1b alone can’t bind to ASOR, it yet can’t form functional complex with ASGPRH2c.展开更多
Objective: To report a mathematical function that characterizes the double-pass line spread function (LSF) of the human eye. Determining analytical functions that represent the double-pass LSF is important because it ...Objective: To report a mathematical function that characterizes the double-pass line spread function (LSF) of the human eye. Determining analytical functions that represent the double-pass LSF is important because it allows modeling the optical performance of the eye. Methods: Optical section retinal images, generated in normal human eyes using a modified slit-lamp biomicroscope, were analyzed to derive the double-pass LSF by plotting the intensity distribution of laser light reflected/ scattered from the vitreoretinal interface. Three mathematical functions (Lorentzian, Gaussian, exponential) were fitted to the double-pass LSF and the root mean square error (RMSE) was calculated to provide a measure of the goodness of fit. Results: The Lorentzian function provided the best representation of the double-pass LSF of normal human eyes. The full width at half maximum (FWHM) of the Lorentzian fitted curve was positively correlated with age, indicating that the double-pass LSF broadens with age. Furthermore, the goodness of fit of the Lorentzian function was significantly better in younger subjects as compared with older subjects, suggesting that the fitted function to the double-pass LSF may vary according to age. Conclusion: The results demonstrate an age-related change in the double-pass LSF width and the goodness of fit of the Lorentzian function.展开更多
By exploring the space and the design techniques of roof garden in Frank Gehry's Walt Disney Concert Hall, this paper made further research on the combination of architectural functions and pedestrian fl ow lines,...By exploring the space and the design techniques of roof garden in Frank Gehry's Walt Disney Concert Hall, this paper made further research on the combination of architectural functions and pedestrian fl ow lines, and attempted to summarize the unique design techniques of Frank Gehry by analyzing his works, improve and develop design theories of roof garden, and attract more attention from the public to roof garden design.展开更多
The finite element method (FEM) and the boundary element method (BEM) are often adopted. However, they are not convenient to spatially vary thermal properties of functionally graded material (FGM). Therefore, the meth...The finite element method (FEM) and the boundary element method (BEM) are often adopted. However, they are not convenient to spatially vary thermal properties of functionally graded material (FGM). Therefore, the method of lines (MOL) is introduced to solve the temperature field of FGM. The basic idea of the method is to semi-discretize the governing equation into a system of ordinary differential equations (ODEs) defined on discrete lines by means of the finite difference method. The temperature field of FGM can be obtained by solving the ODEs. The functions of thermal properties are directly embodied in these equations and these properties are not discretized in the domain. Thus, difficulty of FEM and BEM is overcome by the method. As a numerical example, the temperature field of a plane problem is analyzed for FGMs through varying thermal conductivity coefficient by the MOL.展开更多
Dehydroepiandrosterone (DHEA) is a weak androgen and is shown to have anti-cancer, anti-atherogenic, anti-adipogenic and anti-inflammatory effects on mouse, rat and rabbit models. However, human clinical trials data d...Dehydroepiandrosterone (DHEA) is a weak androgen and is shown to have anti-cancer, anti-atherogenic, anti-adipogenic and anti-inflammatory effects on mouse, rat and rabbit models. However, human clinical trials data did not support animal findings and were inconclusive. These systemic differences in biological actions between rodents and humans were attributed to the low level of DHEA in rodents. In order to further understand the differences in biological functions between rodents and humans, we resorted to an in-vitroapproach involving mouse, rat and human cell lines to assess DHEA biological and anabolic functions separately and independently without systemic influence. Results indicated that DHEA was effective on mouse and rat cell lines but not on human cell lines, as observed in in-vivo studies. In addition, our in-vitrostudy showed that DHEA was able to induce myogenesis in mouse mesenchymal cells revealing its anabolic function, even though DHEA was considered as a weak androgen. This observation lent credence to the ban on DHEA by IOC medical commission, citing DHEA as an anabolic steroid. These in-vitro experiments suggested that the differences in biological actions of DHEA between rodents and humans existed not only in-vivo at the systemic level, but also in-vitro at the cellular level and thus paving the way to study the mechanism responsible for these differences at the cellular level itself.展开更多
Half-space Green's function due to a spatially harmonic line load has been expressed as a sum of the full-space Green's functions and a 2-D integral representation of the reflected waves by the free surface of...Half-space Green's function due to a spatially harmonic line load has been expressed as a sum of the full-space Green's functions and a 2-D integral representation of the reflected waves by the free surface of the half-space.By using the obtained half-space Green's function,an integral rep- resentation of the scattered waves by a cylindrical obstacle is then derived.Finally,by analyzing the far-zone behavior of the integrands of the integral representation.the far-field pattern of the scattered waves in a half-space obtained.展开更多
The electromagnetic wave growth or damping depends basically on the number density and anisotropy of energetic particles as the resonant interaction takes place between the particles and waves in the magnetosphere. Th...The electromagnetic wave growth or damping depends basically on the number density and anisotropy of energetic particles as the resonant interaction takes place between the particles and waves in the magnetosphere. The variance of both the number density and anisotropy along the magnetic field line is evaluated systematically by modeling four typically prescribed distribution functions. It is shown that in the case of "the positive anisotropy" (namely, the perpendicular temperature T⊥ exceeds the parallel temperature T||), the number density of energetic electrons always decreases with the magnetic latitude for a regular increasing magnetic field and the maximum wave growth is therefore generally confined to the equator where the resonant energy is minimum, and the number density is the largest. However, the "loss-cone" anisotropy of the electrons with a "pancake" distribution or kappa distribution keeps invariant or nearly invariant, whereas the "temperature" anisotropy with a pure bi-Maxwellian distribution or Ashour-Abdalla and Kennel's distributions decreases with the magnetic latitude. The results may provide a useful approach to evaluating the number density and anisotropy of the energetic electrons at latitudes where the observation information is not available.展开更多
The total internal partition sums were calculated in the product approximation at temperatures up to 5000 K for the asymptotic asymmetric-top HO2 molecule. The calculations of the rotational partition function and the...The total internal partition sums were calculated in the product approximation at temperatures up to 5000 K for the asymptotic asymmetric-top HO2 molecule. The calculations of the rotational partition function and the vibrational partition function were carried out with the rigid-top model and in the harmonic oscillator approximation, respectively. Our values of the total internal partition sums are consistent with the data of HITRAN database with -0.14% at 296 K. Using the calculated partition functions, we have calculated the line intensities of υ2 band of HO2 at several high temperatures. The results showed that the calculated line intensities are in very good agreement with those of HITRAN database at temperatures up to 3000 K, which provides a strong support for the calculations of partition functions and line intensities at high temperatures. Then we have extended the calculation to higher temperatures. The simulated spectra of υ2 band of the asymptotic asymmetric-top HO2 molecule at 4000 and 5000 K are also obtained.展开更多
By using density functional theory(DFT)-based first-principles calculations, the structural stability and electronic properties for two kinds of silicene domain boundaries, forming along armchair edge and zigzag edge,...By using density functional theory(DFT)-based first-principles calculations, the structural stability and electronic properties for two kinds of silicene domain boundaries, forming along armchair edge and zigzag edge, have been investigated. The results indicate that a linkage of tetragonal and octagonal rings(4|8) appears along the armchair edge, while a linkage of paired pentagonal and octagonal rings(5|5|8) appears along the zigzag edge. Different from graphene, the buckling properties of silicene lead to two mirror symmetrical edges of silicene line-defect. The formation energies indicate that the 5|5|8 domain boundary is more stable than the 4|8 domain boundary. Similar to graphene, the calculated electronic properties show that the 5|5|8 domain boundaries exhibit metallic properties and the 4|8 domain boundaries are half-metal.Both domain boundaries create the perfect one-dimensional(1D) metallic wires. Due to the metallic properties, these two kinds of nanowires can be used to build the silicene-based devices.展开更多
It is shown that any polynomial written as an infinite product with all positive real roots may be split in two steps into the product of four infinite polynomials: two with all imaginary and two with all real roots. ...It is shown that any polynomial written as an infinite product with all positive real roots may be split in two steps into the product of four infinite polynomials: two with all imaginary and two with all real roots. Equations between such infinite products define adjoint infinite polynomials with roots on the adjoint roots (real and imaginary). It is shown that the shifting of the coordinates to a parallel line of one of the adjoint axes does not influence the relative placement of the roots: they are shifted to the parallel line. General relations between original and adjoint polynomials are evaluated. These relations are generalized representations of the relations of Euler and Pythagoras in form of infinite polynomial products. They are inherent properties of split polynomial products. If the shifting of the coordinate system corresponds to the shifting of the imaginary axes to the critical line, then the relations of Euler take the form corresponding to their occurrence in the functional equation of the Riemann zeta function: the roots on the imaginary axes are all shifted to the critical line. Since it is known that the gamma and the zeta functions may be written as composed functions with exponential and trigonometric parts, this opens the possibility to prove the placement of the zeta function on the critical line.展开更多
The statistical and distribution characteristics of the responses of a floater and its mooring lines are essential in designing floating/mooring systems.In general,the dynamic responses of offshore structures obey a G...The statistical and distribution characteristics of the responses of a floater and its mooring lines are essential in designing floating/mooring systems.In general,the dynamic responses of offshore structures obey a Gaussian distribution,assuming that the structural system,and sea loads are linear or weakly nonlinear.However,mooring systems and wave loads are considerably nonlinear,and the dynamic responses of hull/mooring systems are non-Gaussian.In this study,the dynamic responses of two types of floaters,semi-submersible and spar platforms,and their mooring lines are computed using coupled dynamic analysis in the time domain.Herein,the statistical characteristics and distributions of the hull motion and mooring line tension are discussed and compared.The statistical distributions of the dynamic responses have strong non-Gaussianity and are unreasonably fitted by a Gaussian distribution for the two floating and mooring systems.Then,the effects of water depth,wave parameters,and low-frequency and wave-frequency components on the non-Gaussianity of the hull motion,and mooring line tension are investigated and discussed.A comparison of the statistical distributions of the responses with various probability density functions,including the Gamma,Gaussian,General Extreme Value,Weibull,and Gaussian Mixture Model(GMM)distributions,shows that the GMM distribution is better than the others for characterizing the statistical distributions of the hull motion,and mooring line tension responses.Furthermore,the GMM distribution has the best accuracy of response prediction.展开更多
The universal creep function derived from the kinetic equations is successful in relating the creep (ε) to the aging time (t a), coefficient of retardation time (β), and intrinsic time (t 0). The rel...The universal creep function derived from the kinetic equations is successful in relating the creep (ε) to the aging time (t a), coefficient of retardation time (β), and intrinsic time (t 0). The relation was used to treat the creep experimental data for polystyrene (PS) specimens which were aged at a given temperature and different times (short term) and tested at a certain temperature and different stress levels. Then unified master lines were constructed with the treated data and curves according to the universal equation. The master lines can be used to predict the long term creep behaviour and lifetime by extrapolating to a required ultimate strain. The verifications of results obtained with this method were shown as well.展开更多
An analytical solution of the unit pressure on a thin workpiece under compression has been obtained by using the inverse function of φ to the integral integral from 0 to x φ dx. Its result is basically the same as t...An analytical solution of the unit pressure on a thin workpiece under compression has been obtained by using the inverse function of φ to the integral integral from 0 to x φ dx. Its result is basically the same as the prevailing numerical formula integral from 0 to x φdx=∑√<sub>1</sub>-Δx<sub>1</sub>. However, the new integral is simpler and more convenient to use.展开更多
Starting with the binomial coefficient and using its infinite product representation, the infinite product representation of the gamma function and of the zeta function are composed of an exponential and of a trigonom...Starting with the binomial coefficient and using its infinite product representation, the infinite product representation of the gamma function and of the zeta function are composed of an exponential and of a trigonometric component and proved. It is proved, that all these components define imaginary roots on the critical line, if written in the form as they are in the functional equation of the zeta function.展开更多
The universal creep equation relates creep behavior (ε/ε 0) to aging time (t a), coefficient of retardation time (β), and intrinsic time (t 0). The relation was used to treat the creep experimental ...The universal creep equation relates creep behavior (ε/ε 0) to aging time (t a), coefficient of retardation time (β), and intrinsic time (t 0). The relation was used to treat the creep experimental data for pipe specimens of polypropylene block copolymer (PPC), which were aged for different days (short term) and tested under different stress levels at a certain temperature. Then unified master lines were constructed with the treated data and curves according to the universal equation. The master straight lines can be used for extrapolation to predict the long term creep behavior and lifetime of the pipe materials of PPC in the same way as plate materials.展开更多
In this paper, we present a nonmonotone algorithm for solving nonsmooth composite optimization problems. The objective function of these problems is composited by a nonsmooth convex function and a differentiable funct...In this paper, we present a nonmonotone algorithm for solving nonsmooth composite optimization problems. The objective function of these problems is composited by a nonsmooth convex function and a differentiable function. The method generates the search directions by solving quadratic programming successively, and makes use of the nonmonotone line search instead of the usual Armijo-type line search. Global convergence is proved under standard assumptions. Numerical results are given.展开更多
SUN Gen nian (Shaanxi Normal University, Xi’an 710062,P.R.China) ABSTRACE:Modern inbound tourism in China has been developing for 20 years, a trend line of inbound tourists in statistical data began to show. This pap...SUN Gen nian (Shaanxi Normal University, Xi’an 710062,P.R.China) ABSTRACE:Modern inbound tourism in China has been developing for 20 years, a trend line of inbound tourists in statistical data began to show. This paper introduces the concept of tourism background trend line, and explores its two functions as a barometer in demonstrating fluctuation in the tourism economy and as a forecaster in forecasting tourism development. The tourism background trend line is a new concept, the word "background" derived from environment science, refers to the trend line" which reflects the dynamic curve or dynamic equation of tourism development without considering the impact of unexpected incidents. The introduction of this concept was inspired by Karl Marx’s comments on the relation between value and price. Tourism background trend line reflects the summary of multiple factors involving tourism resources, tourism demand, population growth, the scale and speed of economic development, and the spatial interaction between tourism origins and destimations. It demonstrates the natural and stable trend and the temporal law of tourism development in a country or region. The tourism statistical curve is at random, susceptible to disruptions and disturbances from serious political, economic and environmental happenings, but it always fluctuates around the background line. Tourism background line can reveal the potential of a country’s tourism development. Compared with the statistical line, it can be used as a barometer" indicating ups and downs of tourism industry in the past. When naturally extended, the background trend line also can be used for forecasting the trend of tourism development in future. In this paper, 4 tourism background trend lines of China’s inbound tourists, i.e. foreign tourists, Hong Kong/Macao/Taiwan tourists, overseas Chinese tourists and total tourists from abroad, were established with statistical data from 1978 to 1996. And the impacts of the Political Event in 1989(or Tiananmen Square Incident) on China’s inbound tourism were evaluated. The result shows that the impact of the Event was not limited within one year, but it stretched over 3 years. The total loss was 20 million in tourist arrivals and $ 1620 million in foreign currency income. The paper also studied the trend of China’s inbound tourism in the next 4 years.展开更多
基金supported by grants from the National Major Science and Technology Special Project for Infectious Diseases of China (No.2008ZX10002-011)National High Technology Research and Development of China (Program 863) (No.2006AA02Z128)the National Natural Science Foundation of China (Nos.30700701,30571646)
文摘To better understand the effect of a new split variant of human asialoglycoprotein receptor (ASGPR H1b) on ASGPR ligands’ binding ability, we established a functional cell line which expresses ASGPR.The full lengths of ASGPRH1a and H2c fragments from human liver were amplified by reverse transcript PCR (RT-PCR) and inserted into eukaryotic expression vector pIRES2EFP, pCDNA3.1 (Zeo+) respectively.The recombinants were cotransfected into HeLa cells.After selection by using Neocin and Zeocin, a stably transfected cell line was established, which was designated 4-1-6.The transcription and expression of ASGPRH1a and H2c in 4-1-6 were confirmed by RT-PCR, Western blotting and immunofluorescence.The endocytosis function of the artificial "ASGPR" on the surface of 4-1-6 was tested by FACS.It was found that the cell line 4-1-6 could bind ASGPR natural ligand molecular asialo-orosomucoid (ASOR).After the eukaryotic plasmid H1b/pCDNA3.1 (neo) was transfected into cell line 4-1-6, H1b did not down-regulate the ligand binding ability of ASGPR.The eukaryotic expression plasmid H1b/pcDNA3.1 (neo) and H2c/pcDNA3.1 (neo) were co-transfected transiently into Hela cell.Neither single H1b nor H1b and H2c could bind ASOR.In conclusion, a functional cell line of human asialoglycoprotein receptor (ASGPR) which expresses both H1a and H2c stably was established.The new split variant H1b has no effect on ASGPR binding to ASOR.ASGPRH1b alone can’t bind to ASOR, it yet can’t form functional complex with ASGPRH2c.
基金supported by the National Eye Institute, Bethesda, MD (Nos. EY14275 and EY1792)Department of Veteran Affairs, and the Research to Prevent Blindness, UIC Eye Center, New York, NY, USA
文摘Objective: To report a mathematical function that characterizes the double-pass line spread function (LSF) of the human eye. Determining analytical functions that represent the double-pass LSF is important because it allows modeling the optical performance of the eye. Methods: Optical section retinal images, generated in normal human eyes using a modified slit-lamp biomicroscope, were analyzed to derive the double-pass LSF by plotting the intensity distribution of laser light reflected/ scattered from the vitreoretinal interface. Three mathematical functions (Lorentzian, Gaussian, exponential) were fitted to the double-pass LSF and the root mean square error (RMSE) was calculated to provide a measure of the goodness of fit. Results: The Lorentzian function provided the best representation of the double-pass LSF of normal human eyes. The full width at half maximum (FWHM) of the Lorentzian fitted curve was positively correlated with age, indicating that the double-pass LSF broadens with age. Furthermore, the goodness of fit of the Lorentzian function was significantly better in younger subjects as compared with older subjects, suggesting that the fitted function to the double-pass LSF may vary according to age. Conclusion: The results demonstrate an age-related change in the double-pass LSF width and the goodness of fit of the Lorentzian function.
文摘By exploring the space and the design techniques of roof garden in Frank Gehry's Walt Disney Concert Hall, this paper made further research on the combination of architectural functions and pedestrian fl ow lines, and attempted to summarize the unique design techniques of Frank Gehry by analyzing his works, improve and develop design theories of roof garden, and attract more attention from the public to roof garden design.
文摘The finite element method (FEM) and the boundary element method (BEM) are often adopted. However, they are not convenient to spatially vary thermal properties of functionally graded material (FGM). Therefore, the method of lines (MOL) is introduced to solve the temperature field of FGM. The basic idea of the method is to semi-discretize the governing equation into a system of ordinary differential equations (ODEs) defined on discrete lines by means of the finite difference method. The temperature field of FGM can be obtained by solving the ODEs. The functions of thermal properties are directly embodied in these equations and these properties are not discretized in the domain. Thus, difficulty of FEM and BEM is overcome by the method. As a numerical example, the temperature field of a plane problem is analyzed for FGMs through varying thermal conductivity coefficient by the MOL.
文摘Dehydroepiandrosterone (DHEA) is a weak androgen and is shown to have anti-cancer, anti-atherogenic, anti-adipogenic and anti-inflammatory effects on mouse, rat and rabbit models. However, human clinical trials data did not support animal findings and were inconclusive. These systemic differences in biological actions between rodents and humans were attributed to the low level of DHEA in rodents. In order to further understand the differences in biological functions between rodents and humans, we resorted to an in-vitroapproach involving mouse, rat and human cell lines to assess DHEA biological and anabolic functions separately and independently without systemic influence. Results indicated that DHEA was effective on mouse and rat cell lines but not on human cell lines, as observed in in-vivo studies. In addition, our in-vitrostudy showed that DHEA was able to induce myogenesis in mouse mesenchymal cells revealing its anabolic function, even though DHEA was considered as a weak androgen. This observation lent credence to the ban on DHEA by IOC medical commission, citing DHEA as an anabolic steroid. These in-vitro experiments suggested that the differences in biological actions of DHEA between rodents and humans existed not only in-vivo at the systemic level, but also in-vitro at the cellular level and thus paving the way to study the mechanism responsible for these differences at the cellular level itself.
文摘Half-space Green's function due to a spatially harmonic line load has been expressed as a sum of the full-space Green's functions and a 2-D integral representation of the reflected waves by the free surface of the half-space.By using the obtained half-space Green's function,an integral rep- resentation of the scattered waves by a cylindrical obstacle is then derived.Finally,by analyzing the far-zone behavior of the integrands of the integral representation.the far-field pattern of the scattered waves in a half-space obtained.
基金supported by National Natural Science Foundation of China (Nos. 40474064, 40404012)the Scientific Research Foundation for ROCS, SEMthe Outstanding Youth Foundation of the Education Bureau of Hunan Province (No. 04B003)
文摘The electromagnetic wave growth or damping depends basically on the number density and anisotropy of energetic particles as the resonant interaction takes place between the particles and waves in the magnetosphere. The variance of both the number density and anisotropy along the magnetic field line is evaluated systematically by modeling four typically prescribed distribution functions. It is shown that in the case of "the positive anisotropy" (namely, the perpendicular temperature T⊥ exceeds the parallel temperature T||), the number density of energetic electrons always decreases with the magnetic latitude for a regular increasing magnetic field and the maximum wave growth is therefore generally confined to the equator where the resonant energy is minimum, and the number density is the largest. However, the "loss-cone" anisotropy of the electrons with a "pancake" distribution or kappa distribution keeps invariant or nearly invariant, whereas the "temperature" anisotropy with a pure bi-Maxwellian distribution or Ashour-Abdalla and Kennel's distributions decreases with the magnetic latitude. The results may provide a useful approach to evaluating the number density and anisotropy of the energetic electrons at latitudes where the observation information is not available.
基金Project supported by the Major Program for Basic Research of National Security, China (Grant No 5134202-04)the National Natural Science Foundation of China (Grant No 10574096)the Natural Science Foundation of the Bureau of Education of Guizhou Province, China (Grant No 2006204)
文摘The total internal partition sums were calculated in the product approximation at temperatures up to 5000 K for the asymptotic asymmetric-top HO2 molecule. The calculations of the rotational partition function and the vibrational partition function were carried out with the rigid-top model and in the harmonic oscillator approximation, respectively. Our values of the total internal partition sums are consistent with the data of HITRAN database with -0.14% at 296 K. Using the calculated partition functions, we have calculated the line intensities of υ2 band of HO2 at several high temperatures. The results showed that the calculated line intensities are in very good agreement with those of HITRAN database at temperatures up to 3000 K, which provides a strong support for the calculations of partition functions and line intensities at high temperatures. Then we have extended the calculation to higher temperatures. The simulated spectra of υ2 band of the asymptotic asymmetric-top HO2 molecule at 4000 and 5000 K are also obtained.
基金supported by the National Natural Science Foundation of China(Grant Nos.61390501 and 51325204)the National Basic Research Program of China(Grant Nos.2011CB808401 and 2011CB921702)the Tainjin Supercomputing Center,Chinese Academy of Sciences
文摘By using density functional theory(DFT)-based first-principles calculations, the structural stability and electronic properties for two kinds of silicene domain boundaries, forming along armchair edge and zigzag edge, have been investigated. The results indicate that a linkage of tetragonal and octagonal rings(4|8) appears along the armchair edge, while a linkage of paired pentagonal and octagonal rings(5|5|8) appears along the zigzag edge. Different from graphene, the buckling properties of silicene lead to two mirror symmetrical edges of silicene line-defect. The formation energies indicate that the 5|5|8 domain boundary is more stable than the 4|8 domain boundary. Similar to graphene, the calculated electronic properties show that the 5|5|8 domain boundaries exhibit metallic properties and the 4|8 domain boundaries are half-metal.Both domain boundaries create the perfect one-dimensional(1D) metallic wires. Due to the metallic properties, these two kinds of nanowires can be used to build the silicene-based devices.
文摘It is shown that any polynomial written as an infinite product with all positive real roots may be split in two steps into the product of four infinite polynomials: two with all imaginary and two with all real roots. Equations between such infinite products define adjoint infinite polynomials with roots on the adjoint roots (real and imaginary). It is shown that the shifting of the coordinates to a parallel line of one of the adjoint axes does not influence the relative placement of the roots: they are shifted to the parallel line. General relations between original and adjoint polynomials are evaluated. These relations are generalized representations of the relations of Euler and Pythagoras in form of infinite polynomial products. They are inherent properties of split polynomial products. If the shifting of the coordinate system corresponds to the shifting of the imaginary axes to the critical line, then the relations of Euler take the form corresponding to their occurrence in the functional equation of the Riemann zeta function: the roots on the imaginary axes are all shifted to the critical line. Since it is known that the gamma and the zeta functions may be written as composed functions with exponential and trigonometric parts, this opens the possibility to prove the placement of the zeta function on the critical line.
基金the support by the National Natural Science Foundation of China(Nos.51709247 and 51490675)the National Key R&D Program of China(No.2016YFE0200100)
文摘The statistical and distribution characteristics of the responses of a floater and its mooring lines are essential in designing floating/mooring systems.In general,the dynamic responses of offshore structures obey a Gaussian distribution,assuming that the structural system,and sea loads are linear or weakly nonlinear.However,mooring systems and wave loads are considerably nonlinear,and the dynamic responses of hull/mooring systems are non-Gaussian.In this study,the dynamic responses of two types of floaters,semi-submersible and spar platforms,and their mooring lines are computed using coupled dynamic analysis in the time domain.Herein,the statistical characteristics and distributions of the hull motion and mooring line tension are discussed and compared.The statistical distributions of the dynamic responses have strong non-Gaussianity and are unreasonably fitted by a Gaussian distribution for the two floating and mooring systems.Then,the effects of water depth,wave parameters,and low-frequency and wave-frequency components on the non-Gaussianity of the hull motion,and mooring line tension are investigated and discussed.A comparison of the statistical distributions of the responses with various probability density functions,including the Gamma,Gaussian,General Extreme Value,Weibull,and Gaussian Mixture Model(GMM)distributions,shows that the GMM distribution is better than the others for characterizing the statistical distributions of the hull motion,and mooring line tension responses.Furthermore,the GMM distribution has the best accuracy of response prediction.
文摘The universal creep function derived from the kinetic equations is successful in relating the creep (ε) to the aging time (t a), coefficient of retardation time (β), and intrinsic time (t 0). The relation was used to treat the creep experimental data for polystyrene (PS) specimens which were aged at a given temperature and different times (short term) and tested at a certain temperature and different stress levels. Then unified master lines were constructed with the treated data and curves according to the universal equation. The master lines can be used to predict the long term creep behaviour and lifetime by extrapolating to a required ultimate strain. The verifications of results obtained with this method were shown as well.
文摘An analytical solution of the unit pressure on a thin workpiece under compression has been obtained by using the inverse function of φ to the integral integral from 0 to x φ dx. Its result is basically the same as the prevailing numerical formula integral from 0 to x φdx=∑√<sub>1</sub>-Δx<sub>1</sub>. However, the new integral is simpler and more convenient to use.
文摘Starting with the binomial coefficient and using its infinite product representation, the infinite product representation of the gamma function and of the zeta function are composed of an exponential and of a trigonometric component and proved. It is proved, that all these components define imaginary roots on the critical line, if written in the form as they are in the functional equation of the zeta function.
文摘The universal creep equation relates creep behavior (ε/ε 0) to aging time (t a), coefficient of retardation time (β), and intrinsic time (t 0). The relation was used to treat the creep experimental data for pipe specimens of polypropylene block copolymer (PPC), which were aged for different days (short term) and tested under different stress levels at a certain temperature. Then unified master lines were constructed with the treated data and curves according to the universal equation. The master straight lines can be used for extrapolation to predict the long term creep behavior and lifetime of the pipe materials of PPC in the same way as plate materials.
文摘In this paper, we present a nonmonotone algorithm for solving nonsmooth composite optimization problems. The objective function of these problems is composited by a nonsmooth convex function and a differentiable function. The method generates the search directions by solving quadratic programming successively, and makes use of the nonmonotone line search instead of the usual Armijo-type line search. Global convergence is proved under standard assumptions. Numerical results are given.
基金Under the auspices of National Natural Science Foundation of China.
文摘SUN Gen nian (Shaanxi Normal University, Xi’an 710062,P.R.China) ABSTRACE:Modern inbound tourism in China has been developing for 20 years, a trend line of inbound tourists in statistical data began to show. This paper introduces the concept of tourism background trend line, and explores its two functions as a barometer in demonstrating fluctuation in the tourism economy and as a forecaster in forecasting tourism development. The tourism background trend line is a new concept, the word "background" derived from environment science, refers to the trend line" which reflects the dynamic curve or dynamic equation of tourism development without considering the impact of unexpected incidents. The introduction of this concept was inspired by Karl Marx’s comments on the relation between value and price. Tourism background trend line reflects the summary of multiple factors involving tourism resources, tourism demand, population growth, the scale and speed of economic development, and the spatial interaction between tourism origins and destimations. It demonstrates the natural and stable trend and the temporal law of tourism development in a country or region. The tourism statistical curve is at random, susceptible to disruptions and disturbances from serious political, economic and environmental happenings, but it always fluctuates around the background line. Tourism background line can reveal the potential of a country’s tourism development. Compared with the statistical line, it can be used as a barometer" indicating ups and downs of tourism industry in the past. When naturally extended, the background trend line also can be used for forecasting the trend of tourism development in future. In this paper, 4 tourism background trend lines of China’s inbound tourists, i.e. foreign tourists, Hong Kong/Macao/Taiwan tourists, overseas Chinese tourists and total tourists from abroad, were established with statistical data from 1978 to 1996. And the impacts of the Political Event in 1989(or Tiananmen Square Incident) on China’s inbound tourism were evaluated. The result shows that the impact of the Event was not limited within one year, but it stretched over 3 years. The total loss was 20 million in tourist arrivals and $ 1620 million in foreign currency income. The paper also studied the trend of China’s inbound tourism in the next 4 years.