The binary vapor–liquid equilibrium data of CO_2 in diethylene glycol(monomethyl,monoethyl,monobutyl,dimethyl,diethyl,dibutyl)ether were determined from 288.15 to 318.15 K at pressure up to 6 MPa based on the constan...The binary vapor–liquid equilibrium data of CO_2 in diethylene glycol(monomethyl,monoethyl,monobutyl,dimethyl,diethyl,dibutyl)ether were determined from 288.15 to 318.15 K at pressure up to 6 MPa based on the constant-volume method.It was found by contrast that the ether group in solvents can promote the CO_2 absorption,but the hydroxyl group will inhibit the CO_2 absorption.Furthermore,the solubilities of CO_2 showed an upward trend with the increasing molecular lengths of absorbents.The experimental data were also correlated with a modified Patel–Teja equation of state(PT EOS)combined with the traditional van der Waals one-fluid mixing rules and the results showed a satisfactory agreement between the model and the experimental data.展开更多
A mathematical model of nitrogen oxide (NOx) absorption is adopted and solved for adiabatic operation of a column with structured packings on the basis of the film theory. Removal rate, outlet concentration, oxidati...A mathematical model of nitrogen oxide (NOx) absorption is adopted and solved for adiabatic operation of a column with structured packings on the basis of the film theory. Removal rate, outlet concentration, oxidation degree of NOx and outlet acid concentration, liquid acid temperature are simulated and tested. The gas phase reactions and equilibria, gas phase mass transfer, interracial equilibria, and liquid phase reactions are considered in the model. Absorption of nitrogen oxides is studied in packed with Mellapak 250Y columns in series in an industrial process of 20000 t oxalic acid per year. Favorable agreement is shown between the model predictions and the on-site observations.展开更多
Plain round bars were commonly used as main bars in the design of RC (reinforced concrete) buildings prior to the 1970s. According to previous research investigating the seismic performance of reinforced concrete me...Plain round bars were commonly used as main bars in the design of RC (reinforced concrete) buildings prior to the 1970s. According to previous research investigating the seismic performance of reinforced concrete members constructed with plain round bars, the strength of those members did not reach the calculated flexural strength due to bond slippage of main bars before yielding. It is important, therefore, to investigate the hysteretic bond mechanisms of plain round bars in concrete. In this research, analytical models were proposed to predict hysteretic bond-slip mechanisms between plain round bar and concrete depending on the results of experiments performed by the authors. In addition, the energy absorption capacity and the equivalent viscous damping factors obtained from the experimental results and analytical models are discussed. As a result of comparisons between the experimental data and the analysis models, good agreements were obtained.展开更多
The issue of income distribution in the modern sense emerged with the creation of the capitalist mode of production-a process characterized by income gaps, at first widening, then narrowing, and widening once again. I...The issue of income distribution in the modern sense emerged with the creation of the capitalist mode of production-a process characterized by income gaps, at first widening, then narrowing, and widening once again. In the classical economic stage featuring dual economy, income distribution was dominated by capital due to scarce capital and cheap labor, which led to widening income gaps. Entering the neoclassical economic stage, income distribution was dominated by the game between capital and labor due to diminishing marginal return to capital and relatively scarce labor, which led to the growing share of labor compensation and narrowing income gaps. Yet since the 1970s, the deepening of financialization of capital has once again magnified the effect of capital-dominated income distribution, which, together with working class polarization, led to another round of widening income gaps. An observation of the long-term evolution of world economic development and income distribution gives us a clearer view on the intrinsic rationale of change in income distribution: The mode of production determines the mode of distribution and functional distribution shares intrinsic consistency with quantitative distribution.展开更多
Electrical capacitance volume tomography(ECVT) is a recently-developed technique for real-time,non-invasive 3D monitoring of processes involving materials with strong contrasts in dielectric permittivity.This work is ...Electrical capacitance volume tomography(ECVT) is a recently-developed technique for real-time,non-invasive 3D monitoring of processes involving materials with strong contrasts in dielectric permittivity.This work is first application of the method to visualization of water flow in soil.We describe the principles behind the method,and then demonstrate its use with a simple laboratory infiltration experiment.32 ECVT sensors were installed on the sides of an empty PVC column.Water was poured into the column at a constant rate,and ECVT data were collected every second.The column was then packed with dry sand and again supplied with water at a constant rate with data collected every second.Data were analyzed to give bulk average water contents,which proved consistent with the water supply rates.Data were also analyzed to give 3D images(216 voxels) allowing visualization of the water distribution during the experiments.Result of this work shows that water infiltration into the soil,wall flow,progress of the unstable wetting front and the final water distribution are clearly visible.展开更多
The study is conducted to examine the differences of gender perception among educators who are teaching in local higher learning institutions in Malaysia, in viewing their roles as the '~teacher". Several higher lea...The study is conducted to examine the differences of gender perception among educators who are teaching in local higher learning institutions in Malaysia, in viewing their roles as the '~teacher". Several higher learning institutions were randomly targeted. Several researchers were involved in the data collection by means of using questionnaires in the survey over a period of several weeks. The questionnaires were used to fred out about their academic and professional backgrounds, requiring them to list their roles pertinent to their experiences in teaching, ranked them and provided the rationale behind the choices made. Twenty-five samples were collected to scrutinize the data by categorizing the information according to gender and teaching experiences and recording the frequencies of answers. From the study, it is found that regardless of gender and teaching experiences, most participants would consider themselves as "Provider of knowledge", followed by "N^r", especially those who are relatively new in teaching. There is also an indication that teacher's experiences and gender might affect their perception in mirroring themselves. A larger scale of study is needed in validating the findings of this study for it to be empirical, thus promoting in-depth investigations in viewing whether gender and cultural background may be vital factors that has profound effects towards their professionalism. It is hoped that future studies will shed some light to this rather controversial claims.展开更多
With the increased number of low Earth orbit(LEO) satellites equipped with global navigation satellite system(GNSS) receiver,the LEO based GNSS slant total electron content(TEC) and electron density profile(EDP) data ...With the increased number of low Earth orbit(LEO) satellites equipped with global navigation satellite system(GNSS) receiver,the LEO based GNSS slant total electron content(TEC) and electron density profile(EDP) data play an increasingly important role in space weather and ionospheric research due to improved global coverage. China Seismo-Electromagnetic Satellite(CSES), which was launched in February 2018, is equipped with GNSS receiver for either precise orbit determination(POD) and ionospheric inversion. The purpose of the present paper is to validate CSES GNSS ionospheric inversion technique based on the real observations and verify the accuracy of TEC and EDP retrieval based on the simulated data. The following conclusions can be drawn: the epoch difference inversion(EDI) derived from CSES can successfully retrieve the EDPs without non-occultation side measurements; the technique of EDI and the calibrated TEC inversion(CTI) have similar behaviors in inversion errors,however, the retrieved Nm F2 and hm F2 have a larger systematic error surrounding the equatorial ionization anomaly(EIA)where the assumption of spherical symmetry is often invalid; the precision and accuracy of retrieved TEC have been investigated in the paper based on the simulated data, and it is found that the accuracy of the retrieved TEC is relative to solar activity: the lower the F10.7 index, the higher the accuracy of retrieved TEC.展开更多
To meet the requirement of high tracking angular accuracy for the acquisition, tracking, and pointing (ATP) subsystem of the free-space optical communication, and provide the basis for the further optical communicatio...To meet the requirement of high tracking angular accuracy for the acquisition, tracking, and pointing (ATP) subsystem of the free-space optical communication, and provide the basis for the further optical communication between maritime mobile platforms, the experimental system, which executing part for the fine tracking is voice coil motor with high frequency and good performance for error compensation, is established, and the whole system can be controlled by personal computer. A series of experiments has been done for the simulation target of different uniform speed, and the data of tracking error for fine tracking and coarse tracking are collected, analyzed and evaluateds separately, and the real-time optical power of communication laser is also collected. The result shows that standard deviation for ATP system tracking error increases with the increase of target speed, while the range of tracking error appears to be no order. Furthermore, communication link can be hold for a long time.展开更多
Motivated by a phenomenon in an experiment conducted in the Northwestern Pacific indicating that the energy of the received signal around the sound channel axis is much greater than that at shallower depths,we study s...Motivated by a phenomenon in an experiment conducted in the Northwestern Pacific indicating that the energy of the received signal around the sound channel axis is much greater than that at shallower depths,we study sound propagation from the transitional area(shelfbreak)to deep water.Numerical simulations with different source depths are first performed,from which we reach the following conclusions.When the source is located near the sea surface,sound will be strongly attenuated by bottom losses in a range-independent oceanic environment,whereas it can propagate to a very long range because of the continental slope.When the source is mounted on the bottom in shallow water,acoustic energy will be trapped near the sound channel axis,and it converges more evidently than the case where the source is located near the sea surface.Then,numerical simulations with different source ranges are performed.By comparing the relative energy level in the vertical direction between the numerical simulations and the experimental data,the range of the air-gun source can be approximated.展开更多
In this paper,a residual type of a posteriori error estimator for the general second order elliptic eigenpair approximation by the mixed finite element method is derived and analyzed,based on a type of superconvergenc...In this paper,a residual type of a posteriori error estimator for the general second order elliptic eigenpair approximation by the mixed finite element method is derived and analyzed,based on a type of superconvergence result of the eigenfunction approximation.Its efficiency and reliability are proved by both theoretical analysis and numerical experiments.展开更多
One important model in handling the multivariate data is the varying-coefficient partially linear regression model. In this paper, the generalized likelihood ratio test is developed to test whether its coefficient fun...One important model in handling the multivariate data is the varying-coefficient partially linear regression model. In this paper, the generalized likelihood ratio test is developed to test whether its coefficient functions are varying or not. It is showed that the normalized proposed test follows asymptotically x2-distribution and the Wilks phenomenon under the null hypothesis, and its asymptotic power achieves the optimal rate of the convergence for the nonparametric hypotheses testing. Some simulation studies illustrate that the test works well.展开更多
基金the National Natural Science Foundation of China(21306088)the State Key Laboratory of Chemical Engineering(SKL-Ch E-13A01,Tsinghua University,China)the Priority Academic Program Development of Jiangsu Higher Education Institutions(China)
文摘The binary vapor–liquid equilibrium data of CO_2 in diethylene glycol(monomethyl,monoethyl,monobutyl,dimethyl,diethyl,dibutyl)ether were determined from 288.15 to 318.15 K at pressure up to 6 MPa based on the constant-volume method.It was found by contrast that the ether group in solvents can promote the CO_2 absorption,but the hydroxyl group will inhibit the CO_2 absorption.Furthermore,the solubilities of CO_2 showed an upward trend with the increasing molecular lengths of absorbents.The experimental data were also correlated with a modified Patel–Teja equation of state(PT EOS)combined with the traditional van der Waals one-fluid mixing rules and the results showed a satisfactory agreement between the model and the experimental data.
文摘A mathematical model of nitrogen oxide (NOx) absorption is adopted and solved for adiabatic operation of a column with structured packings on the basis of the film theory. Removal rate, outlet concentration, oxidation degree of NOx and outlet acid concentration, liquid acid temperature are simulated and tested. The gas phase reactions and equilibria, gas phase mass transfer, interracial equilibria, and liquid phase reactions are considered in the model. Absorption of nitrogen oxides is studied in packed with Mellapak 250Y columns in series in an industrial process of 20000 t oxalic acid per year. Favorable agreement is shown between the model predictions and the on-site observations.
文摘Plain round bars were commonly used as main bars in the design of RC (reinforced concrete) buildings prior to the 1970s. According to previous research investigating the seismic performance of reinforced concrete members constructed with plain round bars, the strength of those members did not reach the calculated flexural strength due to bond slippage of main bars before yielding. It is important, therefore, to investigate the hysteretic bond mechanisms of plain round bars in concrete. In this research, analytical models were proposed to predict hysteretic bond-slip mechanisms between plain round bar and concrete depending on the results of experiments performed by the authors. In addition, the energy absorption capacity and the equivalent viscous damping factors obtained from the experimental results and analytical models are discussed. As a result of comparisons between the experimental data and the analysis models, good agreements were obtained.
文摘The issue of income distribution in the modern sense emerged with the creation of the capitalist mode of production-a process characterized by income gaps, at first widening, then narrowing, and widening once again. In the classical economic stage featuring dual economy, income distribution was dominated by capital due to scarce capital and cheap labor, which led to widening income gaps. Entering the neoclassical economic stage, income distribution was dominated by the game between capital and labor due to diminishing marginal return to capital and relatively scarce labor, which led to the growing share of labor compensation and narrowing income gaps. Yet since the 1970s, the deepening of financialization of capital has once again magnified the effect of capital-dominated income distribution, which, together with working class polarization, led to another round of widening income gaps. An observation of the long-term evolution of world economic development and income distribution gives us a clearer view on the intrinsic rationale of change in income distribution: The mode of production determines the mode of distribution and functional distribution shares intrinsic consistency with quantitative distribution.
文摘Electrical capacitance volume tomography(ECVT) is a recently-developed technique for real-time,non-invasive 3D monitoring of processes involving materials with strong contrasts in dielectric permittivity.This work is first application of the method to visualization of water flow in soil.We describe the principles behind the method,and then demonstrate its use with a simple laboratory infiltration experiment.32 ECVT sensors were installed on the sides of an empty PVC column.Water was poured into the column at a constant rate,and ECVT data were collected every second.The column was then packed with dry sand and again supplied with water at a constant rate with data collected every second.Data were analyzed to give bulk average water contents,which proved consistent with the water supply rates.Data were also analyzed to give 3D images(216 voxels) allowing visualization of the water distribution during the experiments.Result of this work shows that water infiltration into the soil,wall flow,progress of the unstable wetting front and the final water distribution are clearly visible.
文摘The study is conducted to examine the differences of gender perception among educators who are teaching in local higher learning institutions in Malaysia, in viewing their roles as the '~teacher". Several higher learning institutions were randomly targeted. Several researchers were involved in the data collection by means of using questionnaires in the survey over a period of several weeks. The questionnaires were used to fred out about their academic and professional backgrounds, requiring them to list their roles pertinent to their experiences in teaching, ranked them and provided the rationale behind the choices made. Twenty-five samples were collected to scrutinize the data by categorizing the information according to gender and teaching experiences and recording the frequencies of answers. From the study, it is found that regardless of gender and teaching experiences, most participants would consider themselves as "Provider of knowledge", followed by "N^r", especially those who are relatively new in teaching. There is also an indication that teacher's experiences and gender might affect their perception in mirroring themselves. A larger scale of study is needed in validating the findings of this study for it to be empirical, thus promoting in-depth investigations in viewing whether gender and cultural background may be vital factors that has profound effects towards their professionalism. It is hoped that future studies will shed some light to this rather controversial claims.
基金supported by Spark Program from China Earthquake Administration(Grant No.XH18032)the Scientific Research Fund of Institute of Seismology,China Earthquake Administration(Grant No.IS201716161)
文摘With the increased number of low Earth orbit(LEO) satellites equipped with global navigation satellite system(GNSS) receiver,the LEO based GNSS slant total electron content(TEC) and electron density profile(EDP) data play an increasingly important role in space weather and ionospheric research due to improved global coverage. China Seismo-Electromagnetic Satellite(CSES), which was launched in February 2018, is equipped with GNSS receiver for either precise orbit determination(POD) and ionospheric inversion. The purpose of the present paper is to validate CSES GNSS ionospheric inversion technique based on the real observations and verify the accuracy of TEC and EDP retrieval based on the simulated data. The following conclusions can be drawn: the epoch difference inversion(EDI) derived from CSES can successfully retrieve the EDPs without non-occultation side measurements; the technique of EDI and the calibrated TEC inversion(CTI) have similar behaviors in inversion errors,however, the retrieved Nm F2 and hm F2 have a larger systematic error surrounding the equatorial ionization anomaly(EIA)where the assumption of spherical symmetry is often invalid; the precision and accuracy of retrieved TEC have been investigated in the paper based on the simulated data, and it is found that the accuracy of the retrieved TEC is relative to solar activity: the lower the F10.7 index, the higher the accuracy of retrieved TEC.
基金supported by the Natural Science foundation of Hubei Province (No.2010CDB08502)
文摘To meet the requirement of high tracking angular accuracy for the acquisition, tracking, and pointing (ATP) subsystem of the free-space optical communication, and provide the basis for the further optical communication between maritime mobile platforms, the experimental system, which executing part for the fine tracking is voice coil motor with high frequency and good performance for error compensation, is established, and the whole system can be controlled by personal computer. A series of experiments has been done for the simulation target of different uniform speed, and the data of tracking error for fine tracking and coarse tracking are collected, analyzed and evaluateds separately, and the real-time optical power of communication laser is also collected. The result shows that standard deviation for ATP system tracking error increases with the increase of target speed, while the range of tracking error appears to be no order. Furthermore, communication link can be hold for a long time.
基金supported by the National Natural Science Foundation of China(Grant No.11125420)
文摘Motivated by a phenomenon in an experiment conducted in the Northwestern Pacific indicating that the energy of the received signal around the sound channel axis is much greater than that at shallower depths,we study sound propagation from the transitional area(shelfbreak)to deep water.Numerical simulations with different source depths are first performed,from which we reach the following conclusions.When the source is located near the sea surface,sound will be strongly attenuated by bottom losses in a range-independent oceanic environment,whereas it can propagate to a very long range because of the continental slope.When the source is mounted on the bottom in shallow water,acoustic energy will be trapped near the sound channel axis,and it converges more evidently than the case where the source is located near the sea surface.Then,numerical simulations with different source ranges are performed.By comparing the relative energy level in the vertical direction between the numerical simulations and the experimental data,the range of the air-gun source can be approximated.
基金supported by National Natural Science Foundation of China(Grant Nos.11001259,11031006,11071265,11201501 and 91230110)National Basic Research Program of China(973 Project)(Grant No. 2011CB309703)+3 种基金International S&T Cooperation Program of China(Grant No. 2010DFR00700)Croucher Foundation of Hong Kong Baptist Universitythe National Center for Mathematics and Interdisciplinary Science,CAS,the President Foundation of AMSS-CASthe Fundamental Research Funds for the CentralUniversities(Grant No. 2012121003)
文摘In this paper,a residual type of a posteriori error estimator for the general second order elliptic eigenpair approximation by the mixed finite element method is derived and analyzed,based on a type of superconvergence result of the eigenfunction approximation.Its efficiency and reliability are proved by both theoretical analysis and numerical experiments.
基金supported by National Natural Science Foundation of China under Grant No.1117112the Fund of Shanxi Datong University under Grant No.2010K4+1 种基金the Doctoral Fund of Ministry of Education of China under Grant No.20090076110001National Statistical Science Research Major Program of China under Grant No.2011LZ051
文摘One important model in handling the multivariate data is the varying-coefficient partially linear regression model. In this paper, the generalized likelihood ratio test is developed to test whether its coefficient functions are varying or not. It is showed that the normalized proposed test follows asymptotically x2-distribution and the Wilks phenomenon under the null hypothesis, and its asymptotic power achieves the optimal rate of the convergence for the nonparametric hypotheses testing. Some simulation studies illustrate that the test works well.