The effects of grain size on the shift of neutral layer of AZ31 magnesium alloy sheets with different grain sizes ranging from 12.1 to 34.7μm were investigated by the 90° V-bending tests at 150 °C. The resu...The effects of grain size on the shift of neutral layer of AZ31 magnesium alloy sheets with different grain sizes ranging from 12.1 to 34.7μm were investigated by the 90° V-bending tests at 150 °C. The results show that the neutral layer tends to shift to outer region of the sheets and the coefficient of neutral layer value (k-value) increases with the increasing grain size. This phenomenon is mainly owing to the enhanced asymmetry between the outer tension region and inner compression region with the increase of grain size. Twinning dominates the deformation in inner region while slips dominate the deformation in outer region.展开更多
Let Ω be a finite dimensional central algebra and chart Ω≠2 .The matrix equation AXB-CXD=E over Ω is considered.Necessary and sufficient conditions for the existence of centro(skew)symmetric solutions of the matri...Let Ω be a finite dimensional central algebra and chart Ω≠2 .The matrix equation AXB-CXD=E over Ω is considered.Necessary and sufficient conditions for the existence of centro(skew)symmetric solutions of the matrix equation are given.As a particular case ,the matrix equation X-AXB=C over Ω is also considered.展开更多
In this paper, we study the performance of physical-layer network coding in asymmetric two-way relay channels using four different cases having different poor channels:phase asymmetry, downlink asymmetry, uplink asymm...In this paper, we study the performance of physical-layer network coding in asymmetric two-way relay channels using four different cases having different poor channels:phase asymmetry, downlink asymmetry, uplink asymmetry and node asymmetry. The decision and mapping rule for symmetric and asymmetric cases are studied. The performance in terms of bit error rate for each case will be studied and analysed by computer simulation. Analytical and simulation results show that uplink asymmetry is the worst case;intra-phase asymmetry and unreliable uplink channels will more severely affect the performance degradation, which is caused by channel asymmetry.展开更多
A general research on chiral symmetry restoring phase transitions at zero temperature and finite chemical potentials under electrical neutrality condition has been conducted in a Nambu-Jona-Lasinio model to describe t...A general research on chiral symmetry restoring phase transitions at zero temperature and finite chemical potentials under electrical neutrality condition has been conducted in a Nambu-Jona-Lasinio model to describe twoflavor normal quark matter. Depending on whether mo/A, the ratio of dynamical quark mass in vacuum and the 3D momentum cutoff in the loop integrals, is less or greater than 0.413, the phase transition will be of the second or first order. A complete phase diagram of u quark chemical potential versus mo is given. With the electrical neutrality constraint, the region where the second order phase transition happens will be wider than the one without electrical neutrality limitation. The results also show that, for the value ofmo/A from QCD phenomenology, the phase transition must be of the first order.展开更多
We consider that the Higgs triplet Yukawa coupling takes the Friedberg-Lee texture, and the Higgs doublet Yukawa coupling simply identifies with the diagonal Yutawa coupling of charged lepton in the context of left-ri...We consider that the Higgs triplet Yukawa coupling takes the Friedberg-Lee texture, and the Higgs doublet Yukawa coupling simply identifies with the diagonal Yutawa coupling of charged lepton in the context of left-right symmetric model. In this scenario, the phenomenology, including effective neutrino masses, mixings, and thermal flavor-dependent leptogenesis and lepton flavor violation decays are studied. We investigate the combined constrain of the parameters in this scenario and test its consistency with present data.展开更多
This paper presents modified version of an affirmative answer of Centro symmetric convex body Busemann-Petty problem, and proved that at all strings about the origin, the star dual of ball has the smallest volume.
Slow diffusion of diethylether into a concentrated solution of K2C454.H20 and two equivalents of 18-crown-6 in pyridine affords dark orange crystals of bis(potassium{18-crown-6})(3-cyclobutene-1,2-dithione-3,4-dith...Slow diffusion of diethylether into a concentrated solution of K2C454.H20 and two equivalents of 18-crown-6 in pyridine affords dark orange crystals of bis(potassium{18-crown-6})(3-cyclobutene-1,2-dithione-3,4-dithiolate) [K(C12H2406)]2(CnS4). The crystal structure determination (monoclinic, P 2t/n, a = 12.2095(8) A, b = 11.3263(8) A, c = 14.0552(7) A, fl = 101.032(3)~, Z = 2) shows the presence of C4S42 - ions with almost undistorted D4h symmetry having C-C bond lengths of 1.442(10) A and 1.478(8) A and C-S bond lengths of 1.651(8) A and 1.664(7) A. Since the K+ ions are shielded in a half-spherical way by the crown ether ligands, the crystal structures is built of centrosymmetric molecular entities [(18-crown-6)K(C4S4)K(18-crown-6)]. The K+ ions have eight of coordination number, C4S42- acts as a chelating and bridging ligand towards two K+ with K-S distances of 3.434(2) A and 3.380(2) A.展开更多
A centre symmetric quadruple pattern-based illumination invariant measure(CSQPIM)is proposed to tackle severe illumination variation face recognition.First,the subtraction of the pixel pairs of the centre symmetric qu...A centre symmetric quadruple pattern-based illumination invariant measure(CSQPIM)is proposed to tackle severe illumination variation face recognition.First,the subtraction of the pixel pairs of the centre symmetric quadruple pattern(CSQP)is defined as the CSQPIM unit in the logarithm face local region,which may be positive or negative.The CSQPIM model is obtained by combining the positive and negative CSQPIM units.Then,the CSQPIM model can be used to generate several CSQPIM images by controlling the proportions of positive and negative CSQPIM units.The single CSQPIM image with the saturation function can be used to develop the CSQPIM-face.Multi CSQPIM images employ the extended sparse representation classification(ESRC)as the classifier,which can create the CSQPIM image-based classification(CSQPIMC).Furthermore,the CSQPIM model is integrated with the pre-trained deep learning(PDL)model to construct the CSQPIM-PDL model.Finally,the experimental results on the Extended Yale B,CMU PIE and Driver face databases indicate that the proposed methods are efficient for tackling severe illumination variations.展开更多
Measurements of seafloor asymmetry at about 360 000 pairs of conjugate points along 1250 profiles across the mid-Atlantic Ridge (MAR) provide new constraints on models for the upwelling of the buoyant asthenosphere. T...Measurements of seafloor asymmetry at about 360 000 pairs of conjugate points along 1250 profiles across the mid-Atlantic Ridge (MAR) provide new constraints on models for the upwelling of the buoyant asthenosphere. The sign and amplitude of the asymmetry vary systematically and are functions of the distance between the spreading center and the location of the inferred location of maximum regional buoyancy (LMRB) in the asthenosphere. The LMRB is a smooth line derived from the observed asymmetry and is more centered at the regional topographic high than the spreading center. These observations are best explained by active upwelling of the underlying buoyant asthenosphere rather than by pressure-release melting.展开更多
Basing on a generalization of Wong's equations, the problem of motions for particles in the Lorentz gauge field configuration, which is Schwarzschild-like solution of Yang-Mills equations, is studied. The picture of ...Basing on a generalization of Wong's equations, the problem of motions for particles in the Lorentz gauge field configuration, which is Schwarzschild-like solution of Yang-Mills equations, is studied. The picture of interaction between particles with the Lorentz gauge field is described in an analogous manner to that between isotopic-spin-carrying particles and Yang-Mills field. By examining the effective potential and the equations of orbits for particles, it is found that the considered motions possess some qualitative features resembling to motions of particles in a centrally symmetric gravitational field.展开更多
By employing three typical equations of states (EOSs) of the crust matter, the effect of the crust on the structure and properties are investigated, where the core matter is described by the MDIxl model and the non-...By employing three typical equations of states (EOSs) of the crust matter, the effect of the crust on the structure and properties are investigated, where the core matter is described by the MDIxl model and the non-Newtonian gravity (described by the Yukawa contribution) is considered. It is shown that the EOSs of the crust matter have a notable effect on the mass-radius relation and the moment of inertia.展开更多
The analytical and numerical solutions of structure and curvature of two kinds of static spherically symmetric neutron stars are calculated. The results show that Ricci tensor and curvature scalar cannot denote the cu...The analytical and numerical solutions of structure and curvature of two kinds of static spherically symmetric neutron stars are calculated. The results show that Ricci tensor and curvature scalar cannot denote the curly character of the space directly, however, to static spherically symmetric stars, these two quantities can present the relative curly degree of the space and the matter distribution to a certain extent.展开更多
Using the WRF(Weather Research Forecast)model,this work performed analysis and simulation on the rainband change during the landfall of Typhoon Haitang(2005)and found that breaking may occur over land and oceans leads...Using the WRF(Weather Research Forecast)model,this work performed analysis and simulation on the rainband change during the landfall of Typhoon Haitang(2005)and found that breaking may occur over land and oceans leads to distinct asymmetric precipitation.The breaking is related to the topographic effect as well as interactions between the typhoon and midlatitude systems at upper levels.During the landfall,divergent flows at the 200-hPa level of the South-Asian high combined with divergent flows at the periphery of the typhoon to form a weak,inverted trough in the northwest part of the storm,with the mid- and low-level divergence fields on the west and northwest side of the typhoon center maintaining steadily.It intensifies the upper-level cyclonic flows,in association with positive vorticity rotating counterclockwise together with air currents that travel stepwise into a vorticity zone in the vicinity of the typhoon core, thereby forming a vorticity transfer belt in 22–25°N that extends to the eastern part of the storm.It is right here that the high-level vorticity band is subsiding so that rainfall is prevented from developing,resulting in the rainbelt breaking,which is the principal cause of asymmetric precipitation occurrence.Migrating into its outer region,the banded vorticity of Haitang at high levels causes further amplification of the cyclonic circulation in the western part and transfer of positive vorticity into the typhoon such that the rainband breaking is more distinct.展开更多
Along with the rapid development of modem China economy, some new business modes and sale areas continuously emerge in markets. For example with the continuous popularity of consumer online shopping, rapid development...Along with the rapid development of modem China economy, some new business modes and sale areas continuously emerge in markets. For example with the continuous popularity of consumer online shopping, rapid development of TV shopping industry, compared with traditional store sales, in these special sale areas consumers' rights and interests are more likely to get harmed. From March 15, 2014, the newly revised "China consumer protection law" will formally implement cooling-off period legal system in special sale areas.2 Because it is a new system different from "obligatory compact principle" in traditional civil law, the scholars' theoretical research on cooling-off period system is still not mature enough. This paper discusses cooling-off period system from the theoretical level, puts forward the designation problem of cooling-off period system, discusses complete concepts of cooling-off period system, and puts forward its legal characteristics as a new consumer rights.展开更多
Some cylindrically symmetric inhomogeneous viscous fluid string cosmological models with magnetic field and cosmological term A varying with time are investigated. To get the deterministic solution, it has been assume...Some cylindrically symmetric inhomogeneous viscous fluid string cosmological models with magnetic field and cosmological term A varying with time are investigated. To get the deterministic solution, it has been assumed that the expansion (θ) in the model is proportional to the eigen value σ^11 of the shear tensor σ^ij. The value of cosmological constant for the model is found to be small and positive, which is supported by the results from recent supernovae Ia observations. The effect of bulk viscosity is to produce a change in perfect fluid and hence exhibits essential influence on the character of the solution. The physical and geometric properties of the models are also discussed in presence and absence of magnetic field.展开更多
The present study was an attempt made to explore the nature of utilizing nicknames, as an insufficiently researched area, in the context of Ilami Kurdish highschools. To realize this purpose, randomly as many as 200 m...The present study was an attempt made to explore the nature of utilizing nicknames, as an insufficiently researched area, in the context of Ilami Kurdish highschools. To realize this purpose, randomly as many as 200 male and female highschool students from both state and non-state schools were asked to participate in the survey by filling in the forms given to them. The elicited nicknames were those commonly used by students in their own mother tongue, that is Ilami Kurdish and not in Persian, as the formal language of people across lran. The data gathered were then analyzed using descriptive statistics. The findings revealed that physical characteristics, both for male and female students, accounted for the greatest category based on which nicknames were shaped among highschool students. Moreover, the most nicknames applied by llami Kurdish highschool students were found to be neutrally evaluated followed by positive and negative evaluation, respectively. Finally, statistical computation done by SPSS package demonstrated that gender did not act as a significant variable in this inquiry.展开更多
This paper investigates the device-to-device(D2D) communication underlaying cellular network assisted by a two-way decode-and-forward relay node. We assume the base station(BS) is equipped with M-antenna and serves it...This paper investigates the device-to-device(D2D) communication underlaying cellular network assisted by a two-way decode-and-forward relay node. We assume the base station(BS) is equipped with M-antenna and serves its own cellular user while the D2D users communicate via a two-way decode-and-forward relay node. Both beamforming(BF) and interference cancellation(IC) strategies at the BS are considered to improve the performance for the cellular link and D2D link, respectively. We first analyze the received signal-to-interference-plus-noise for the cellular link under BF and IC strategies and then derive the exact closed-form expressions for the cellular link. Asymmetric and symmetric cases are discussed for various locations of each user. Finally, the approximations for high signal-to-noise regime are also presented. Numerical results demonstrate the accuracy of the analytical and asymptotic results.展开更多
In-situ measurements in Xiangshan Bay, the East China Sea, show that the duration of the rising tide is shorter than that of the falling tide around the bay mouth, while it becomes much longer in the inner bay. A fini...In-situ measurements in Xiangshan Bay, the East China Sea, show that the duration of the rising tide is shorter than that of the falling tide around the bay mouth, while it becomes much longer in the inner bay. A finite volume coastal ocean model(FVCOM) with an unstructured mesh was applied to simulate the asymmetric tidal field of Xiangshan Bay. The model reproduced the observed tidal elevations and currents successfully. Several numerical experiments were conducted to clarify the roles of primary mechanisms underlying the asymmetric tidal field. According to the model results, the time-varying channel depth and nonlinear advection prefer shorter duration of the rising tide in Xiangshan Bay, while the time-varying bay width favors longer duration of the rising tide. The overtides generated by these two opposite types of nonlinear mechanisms are out of phase, resulting in smaller M4 amplitude than the sumfold of each individual contribution. Although the bottom friction as a nonlinear mechanism contributes little to the generation of overtide M4, it is regarded as a mechanism that could cause a shorter duration of the rising tide, for it can slow down the M2 phase speed much more than it slows down the M4 phase speed. The time-varying depth, nonlinear advection and bottom friction are dominating factors around the bay mouth, while the time-varying width dominates in the inner bay, causing the tidal elevation asymmetry to be inverted along the bay.展开更多
The main classical schools of Chinese philosophy can be characterized as process thinking and their concepts are related to those of Whitehead's philosophy of organism. (Neo-)Confucianism, Daoism, and Chinese Buddh...The main classical schools of Chinese philosophy can be characterized as process thinking and their concepts are related to those of Whitehead's philosophy of organism. (Neo-)Confucianism, Daoism, and Chinese Buddhism all find their roots in the Yi ding with a strong emphasis on human experience of the flux of time. These Eastern and Western world views allow attempts to consciously experience experiential reality in terms of immanent transcendence. These attempts are discussed also by considering the functioning of the human brain, emphasizing the importance of brain asymmetry.展开更多
基金Project(CSTC2012GGB50003)supported by Scientific and Technological Project of Chongqing Science and Technology Commission,ChinaProject(CDJZR13130081)supported by the Fundamental Research Funds for the Central Universities,China
文摘The effects of grain size on the shift of neutral layer of AZ31 magnesium alloy sheets with different grain sizes ranging from 12.1 to 34.7μm were investigated by the 90° V-bending tests at 150 °C. The results show that the neutral layer tends to shift to outer region of the sheets and the coefficient of neutral layer value (k-value) increases with the increasing grain size. This phenomenon is mainly owing to the enhanced asymmetry between the outer tension region and inner compression region with the increase of grain size. Twinning dominates the deformation in inner region while slips dominate the deformation in outer region.
基金Supported by the Natural Science Foundation of China(10071078)Supported by the Natural Science Foundation of Shandong Province(Q99A08)
文摘Let Ω be a finite dimensional central algebra and chart Ω≠2 .The matrix equation AXB-CXD=E over Ω is considered.Necessary and sufficient conditions for the existence of centro(skew)symmetric solutions of the matrix equation are given.As a particular case ,the matrix equation X-AXB=C over Ω is also considered.
基金supported by the National Natural Science Foundation of China under Grant No.61101248the Equipment Advance Research Projectof"Twelfth Five-Year"Plan under Grant No.51306040202And this work has been performed in the Project"Advanced Communication Research Program(ACRP)"supported by the Directorate of Research and Development,Defense Science and Technology Agency,Singapore under Grant No.DSOCL04020
文摘In this paper, we study the performance of physical-layer network coding in asymmetric two-way relay channels using four different cases having different poor channels:phase asymmetry, downlink asymmetry, uplink asymmetry and node asymmetry. The decision and mapping rule for symmetric and asymmetric cases are studied. The performance in terms of bit error rate for each case will be studied and analysed by computer simulation. Analytical and simulation results show that uplink asymmetry is the worst case;intra-phase asymmetry and unreliable uplink channels will more severely affect the performance degradation, which is caused by channel asymmetry.
基金The project supported by National Natural Science Foundation of China under Grant No. 10475113
文摘A general research on chiral symmetry restoring phase transitions at zero temperature and finite chemical potentials under electrical neutrality condition has been conducted in a Nambu-Jona-Lasinio model to describe twoflavor normal quark matter. Depending on whether mo/A, the ratio of dynamical quark mass in vacuum and the 3D momentum cutoff in the loop integrals, is less or greater than 0.413, the phase transition will be of the second or first order. A complete phase diagram of u quark chemical potential versus mo is given. With the electrical neutrality constraint, the region where the second order phase transition happens will be wider than the one without electrical neutrality limitation. The results also show that, for the value ofmo/A from QCD phenomenology, the phase transition must be of the first order.
基金supported by National Natural Science Foundation of China under Grant No.90203002
文摘We consider that the Higgs triplet Yukawa coupling takes the Friedberg-Lee texture, and the Higgs doublet Yukawa coupling simply identifies with the diagonal Yutawa coupling of charged lepton in the context of left-right symmetric model. In this scenario, the phenomenology, including effective neutrino masses, mixings, and thermal flavor-dependent leptogenesis and lepton flavor violation decays are studied. We investigate the combined constrain of the parameters in this scenario and test its consistency with present data.
文摘This paper presents modified version of an affirmative answer of Centro symmetric convex body Busemann-Petty problem, and proved that at all strings about the origin, the star dual of ball has the smallest volume.
文摘Slow diffusion of diethylether into a concentrated solution of K2C454.H20 and two equivalents of 18-crown-6 in pyridine affords dark orange crystals of bis(potassium{18-crown-6})(3-cyclobutene-1,2-dithione-3,4-dithiolate) [K(C12H2406)]2(CnS4). The crystal structure determination (monoclinic, P 2t/n, a = 12.2095(8) A, b = 11.3263(8) A, c = 14.0552(7) A, fl = 101.032(3)~, Z = 2) shows the presence of C4S42 - ions with almost undistorted D4h symmetry having C-C bond lengths of 1.442(10) A and 1.478(8) A and C-S bond lengths of 1.651(8) A and 1.664(7) A. Since the K+ ions are shielded in a half-spherical way by the crown ether ligands, the crystal structures is built of centrosymmetric molecular entities [(18-crown-6)K(C4S4)K(18-crown-6)]. The K+ ions have eight of coordination number, C4S42- acts as a chelating and bridging ligand towards two K+ with K-S distances of 3.434(2) A and 3.380(2) A.
基金The National Natural Science Foundation of China(No.61802203)the Natural Science Foundation of Jiangsu Province(No.BK20180761)+1 种基金China Postdoctoral Science Foundation(No.2019M651653)Postdoctoral Research Funding Program of Jiangsu Province(No.2019K124).
文摘A centre symmetric quadruple pattern-based illumination invariant measure(CSQPIM)is proposed to tackle severe illumination variation face recognition.First,the subtraction of the pixel pairs of the centre symmetric quadruple pattern(CSQP)is defined as the CSQPIM unit in the logarithm face local region,which may be positive or negative.The CSQPIM model is obtained by combining the positive and negative CSQPIM units.Then,the CSQPIM model can be used to generate several CSQPIM images by controlling the proportions of positive and negative CSQPIM units.The single CSQPIM image with the saturation function can be used to develop the CSQPIM-face.Multi CSQPIM images employ the extended sparse representation classification(ESRC)as the classifier,which can create the CSQPIM image-based classification(CSQPIMC).Furthermore,the CSQPIM model is integrated with the pre-trained deep learning(PDL)model to construct the CSQPIM-PDL model.Finally,the experimental results on the Extended Yale B,CMU PIE and Driver face databases indicate that the proposed methods are efficient for tackling severe illumination variations.
基金supported by the U.S.National Science Foundation under contract No.0207466.
文摘Measurements of seafloor asymmetry at about 360 000 pairs of conjugate points along 1250 profiles across the mid-Atlantic Ridge (MAR) provide new constraints on models for the upwelling of the buoyant asthenosphere. The sign and amplitude of the asymmetry vary systematically and are functions of the distance between the spreading center and the location of the inferred location of maximum regional buoyancy (LMRB) in the asthenosphere. The LMRB is a smooth line derived from the observed asymmetry and is more centered at the regional topographic high than the spreading center. These observations are best explained by active upwelling of the underlying buoyant asthenosphere rather than by pressure-release melting.
文摘Basing on a generalization of Wong's equations, the problem of motions for particles in the Lorentz gauge field configuration, which is Schwarzschild-like solution of Yang-Mills equations, is studied. The picture of interaction between particles with the Lorentz gauge field is described in an analogous manner to that between isotopic-spin-carrying particles and Yang-Mills field. By examining the effective potential and the equations of orbits for particles, it is found that the considered motions possess some qualitative features resembling to motions of particles in a centrally symmetric gravitational field.
基金Supported by the National Natural Science Foundation of China under Grant No.10947023the Fundamental Research Funds for the Central Universities under Grant No.2009ZM0193the SRP of SCUT under Grant No.D210632w
文摘By employing three typical equations of states (EOSs) of the crust matter, the effect of the crust on the structure and properties are investigated, where the core matter is described by the MDIxl model and the non-Newtonian gravity (described by the Yukawa contribution) is considered. It is shown that the EOSs of the crust matter have a notable effect on the mass-radius relation and the moment of inertia.
基金The project supported by National Natural Science Foundation of China under Grant No. 10275099 and the China Postdoctoral Science Foundation under Grant No. 2005037175
文摘The analytical and numerical solutions of structure and curvature of two kinds of static spherically symmetric neutron stars are calculated. The results show that Ricci tensor and curvature scalar cannot denote the curly character of the space directly, however, to static spherically symmetric stars, these two quantities can present the relative curly degree of the space and the matter distribution to a certain extent.
基金Natural Foundamental Research and Development Project"973"Program(2009CB421503)Natural Science Foundation of China(4097503740775033)
文摘Using the WRF(Weather Research Forecast)model,this work performed analysis and simulation on the rainband change during the landfall of Typhoon Haitang(2005)and found that breaking may occur over land and oceans leads to distinct asymmetric precipitation.The breaking is related to the topographic effect as well as interactions between the typhoon and midlatitude systems at upper levels.During the landfall,divergent flows at the 200-hPa level of the South-Asian high combined with divergent flows at the periphery of the typhoon to form a weak,inverted trough in the northwest part of the storm,with the mid- and low-level divergence fields on the west and northwest side of the typhoon center maintaining steadily.It intensifies the upper-level cyclonic flows,in association with positive vorticity rotating counterclockwise together with air currents that travel stepwise into a vorticity zone in the vicinity of the typhoon core, thereby forming a vorticity transfer belt in 22–25°N that extends to the eastern part of the storm.It is right here that the high-level vorticity band is subsiding so that rainfall is prevented from developing,resulting in the rainbelt breaking,which is the principal cause of asymmetric precipitation occurrence.Migrating into its outer region,the banded vorticity of Haitang at high levels causes further amplification of the cyclonic circulation in the western part and transfer of positive vorticity into the typhoon such that the rainband breaking is more distinct.
文摘Along with the rapid development of modem China economy, some new business modes and sale areas continuously emerge in markets. For example with the continuous popularity of consumer online shopping, rapid development of TV shopping industry, compared with traditional store sales, in these special sale areas consumers' rights and interests are more likely to get harmed. From March 15, 2014, the newly revised "China consumer protection law" will formally implement cooling-off period legal system in special sale areas.2 Because it is a new system different from "obligatory compact principle" in traditional civil law, the scholars' theoretical research on cooling-off period system is still not mature enough. This paper discusses cooling-off period system from the theoretical level, puts forward the designation problem of cooling-off period system, discusses complete concepts of cooling-off period system, and puts forward its legal characteristics as a new consumer rights.
文摘Some cylindrically symmetric inhomogeneous viscous fluid string cosmological models with magnetic field and cosmological term A varying with time are investigated. To get the deterministic solution, it has been assumed that the expansion (θ) in the model is proportional to the eigen value σ^11 of the shear tensor σ^ij. The value of cosmological constant for the model is found to be small and positive, which is supported by the results from recent supernovae Ia observations. The effect of bulk viscosity is to produce a change in perfect fluid and hence exhibits essential influence on the character of the solution. The physical and geometric properties of the models are also discussed in presence and absence of magnetic field.
文摘The present study was an attempt made to explore the nature of utilizing nicknames, as an insufficiently researched area, in the context of Ilami Kurdish highschools. To realize this purpose, randomly as many as 200 male and female highschool students from both state and non-state schools were asked to participate in the survey by filling in the forms given to them. The elicited nicknames were those commonly used by students in their own mother tongue, that is Ilami Kurdish and not in Persian, as the formal language of people across lran. The data gathered were then analyzed using descriptive statistics. The findings revealed that physical characteristics, both for male and female students, accounted for the greatest category based on which nicknames were shaped among highschool students. Moreover, the most nicknames applied by llami Kurdish highschool students were found to be neutrally evaluated followed by positive and negative evaluation, respectively. Finally, statistical computation done by SPSS package demonstrated that gender did not act as a significant variable in this inquiry.
基金supported by the National Science Foundation for Distinguished Young Scholars of China(No.61701201)the Natural Science Foundation of Jiangsu Province(No.BK20170758,BK20170757)+1 种基金the Natural Science Foundation for colleges and universities of Jiangsu Province(No.17KJB510011)Project of Key Laboratory of Wireless Communications of Jiangsu Province
文摘This paper investigates the device-to-device(D2D) communication underlaying cellular network assisted by a two-way decode-and-forward relay node. We assume the base station(BS) is equipped with M-antenna and serves its own cellular user while the D2D users communicate via a two-way decode-and-forward relay node. Both beamforming(BF) and interference cancellation(IC) strategies at the BS are considered to improve the performance for the cellular link and D2D link, respectively. We first analyze the received signal-to-interference-plus-noise for the cellular link under BF and IC strategies and then derive the exact closed-form expressions for the cellular link. Asymmetric and symmetric cases are discussed for various locations of each user. Finally, the approximations for high signal-to-noise regime are also presented. Numerical results demonstrate the accuracy of the analytical and asymptotic results.
基金sponsored by the National Natural Science Foundation of China (41106006)the National Key Technology R&D Program of China (2011BAC03 B02)
文摘In-situ measurements in Xiangshan Bay, the East China Sea, show that the duration of the rising tide is shorter than that of the falling tide around the bay mouth, while it becomes much longer in the inner bay. A finite volume coastal ocean model(FVCOM) with an unstructured mesh was applied to simulate the asymmetric tidal field of Xiangshan Bay. The model reproduced the observed tidal elevations and currents successfully. Several numerical experiments were conducted to clarify the roles of primary mechanisms underlying the asymmetric tidal field. According to the model results, the time-varying channel depth and nonlinear advection prefer shorter duration of the rising tide in Xiangshan Bay, while the time-varying bay width favors longer duration of the rising tide. The overtides generated by these two opposite types of nonlinear mechanisms are out of phase, resulting in smaller M4 amplitude than the sumfold of each individual contribution. Although the bottom friction as a nonlinear mechanism contributes little to the generation of overtide M4, it is regarded as a mechanism that could cause a shorter duration of the rising tide, for it can slow down the M2 phase speed much more than it slows down the M4 phase speed. The time-varying depth, nonlinear advection and bottom friction are dominating factors around the bay mouth, while the time-varying width dominates in the inner bay, causing the tidal elevation asymmetry to be inverted along the bay.
文摘The main classical schools of Chinese philosophy can be characterized as process thinking and their concepts are related to those of Whitehead's philosophy of organism. (Neo-)Confucianism, Daoism, and Chinese Buddhism all find their roots in the Yi ding with a strong emphasis on human experience of the flux of time. These Eastern and Western world views allow attempts to consciously experience experiential reality in terms of immanent transcendence. These attempts are discussed also by considering the functioning of the human brain, emphasizing the importance of brain asymmetry.