We consider the scattering of time-harmonic plane waves by an infinitely long penetrable chiral cylinder. The electromagnetic scattering problem is reduced to a transmission problem for a system of two-dimensional Hel...We consider the scattering of time-harmonic plane waves by an infinitely long penetrable chiral cylinder. The electromagnetic scattering problem is reduced to a transmission problem for a system of two-dimensional Helmholtz equations. We prove the classical reciprocity principle, a general scattering theorem and an optical theorem in R<sup>2</sup>. Using Herglotz wave functions we define the corresponding far field operator. Applying the general scattering theorem useful relations are proved for the reconstruction of the scatterer. We also prove that for real chirality measure of the penetrable scatterer the far field operator has a countable number of eigenvalues which lie on a circle.展开更多
The multi-fractal ity over China are studied behaviors of relative humid using the multi-fractal de trended fluctuation analysis (DFA) method. Three multi fractal parameters (the spectrum width Aa, the asymmetry Aa...The multi-fractal ity over China are studied behaviors of relative humid using the multi-fractal de trended fluctuation analysis (DFA) method. Three multi fractal parameters (the spectrum width Aa, the asymmetry Aaas, and the long-range correlation exponent a0) of the singularity spectrum are introduced to quantify the multi-fractal behaviors. The results show that multi-frac tality exists in daily humidity records over most stations in China and is mainly due to the broad distribution of the probability density of the sequence values. Strong multi fractal behaviors over some stations in the Yunnan, Guangdong, and Inner Mongolia provinces are obvious. These behaviors are mainly caused by different long range correlations between large and small fluctuations. The asymmetry of the singularity of relative humidity records is weak, except for a small number of stations in the far east and west of China, where the singularity spec trum is left-skewed. Finally, the long-range correlations in North China are stronger than those in South China, which indicates better predictability in North China. By studying the parameters of the multi-fractal spectrum, various data of long-range power law correlations of the relative humidity records are obtained, which may pro vide theoretical support for climate prediction.展开更多
To investigate the correlation between environmental-meteorological factors and daily visits for acute otitis media(AOM)in Lanzhou,China.Methods:Data were collected in 2014e2016 by the Departments of Otolaryngology-He...To investigate the correlation between environmental-meteorological factors and daily visits for acute otitis media(AOM)in Lanzhou,China.Methods:Data were collected in 2014e2016 by the Departments of Otolaryngology-Head and Neck Surgery at two hospitals in Lanzhou.Relevant information,including age,sex and visiting time,was collected.Environmental data included air quality index,PM10,PM2.5,O3,CO,NO2 and SO2,and meteorological data included daily average temperature(T,C),daily mean atmospheric pressure(AP,hPa),daily average relative humidity(RH,%)and daily mean wind speed(W,m/s).The SPSS22.0 software was used to generate Spearman correlation coefficients in descriptive statistical analysis,and the R3.5.0 software was used to calculate relative risk(RR)and to obtain exposure-response curves.The relationship between meteorological-environmental parameters and daily AOM visits was summarized.Results:Correlations were identified between daily AOM visits and CO,O3,SO2,CO,NO2,PM2.5 and PM10 levels.NO2,SO2,CO,AP,RH and T levels significantly correlated with daily AOM visits with a lag exposure-response pattern.The effects of CO,NO2,SO2 and AP on daily AOM visits were significantly stronger compared to other factors(P<0.01).O3,W,T and RH were negatively correlated with daily AOM visits.The highest RR lagged by 3e4 days.Conclusions:The number of daily AOM visits appeared to be correlated with short-term exposure to mixed air pollutants and meteorological factors from 2014 through 2016 in Lanzhou.展开更多
Air pollution has environmental issue owing become a serious to its diverse harmful effects on the physical and biological environment. According to the Environmental Protection Agency (EPA) and the World Health Org...Air pollution has environmental issue owing become a serious to its diverse harmful effects on the physical and biological environment. According to the Environmental Protection Agency (EPA) and the World Health Organization (WHO), air pollution affects millions of people worldwide. Hundreds of thousands of deaths each year and a range of diseases, particularly among vulnerable groups (i.e., children, the elderly, and people with special medical conditions), are attributed to air pollution. These effects are not always caused by single pollutant in the air; rather, they are considered consequences of the multi-pollutants to which people are simultaneously exposed.展开更多
Formation and flow of emulsions in porous media are common in all enhanced oil recovery tech- niques. In most cases, oil-in-water (O/W) emulsions are formed in porous media due to oil-water interaction. Even now, de...Formation and flow of emulsions in porous media are common in all enhanced oil recovery tech- niques. In most cases, oil-in-water (O/W) emulsions are formed in porous media due to oil-water interaction. Even now, detailed flow mechanisms of emulsions through porous media are not well understood. In this study, variation of rate of flow of O/W emulsions with pressure drop was studied experimentally, and rheological pa- rameters were calculated. The pressure drop increases with an increase in oil concentration in the O/W emulsion due to high viscosity. The effective viscosity of the emulsion was calculated from the derived model and expressed as a function of shear rate while flowing through porous media. Flow of O/W emulsions of different concentrations was evaluated in sand packs of different sand sizes. Emulsions were characterized by analyzing their stability, rheological properties, and tem- perature effects on rheological properties.展开更多
A single set of vertically aligned cracks embedded in a purely isotropic background may be con- sidered as a long-wavelength effective transversely iso- tropy (HTI) medium with a horizontal symmetry axis. The crack-...A single set of vertically aligned cracks embedded in a purely isotropic background may be con- sidered as a long-wavelength effective transversely iso- tropy (HTI) medium with a horizontal symmetry axis. The crack-induced HTI anisotropy can be characterized by the weakly anisotropic parameters introduced by Thomsen. The seismic scattering theory can be utilized for the inversion for the anisotropic parameters in weakly aniso- tropic and heterogeneous HTI media. Based on the seismic scattering theory, we first derived the linearized PP- and PS-wave reflection coefficients in terms of P- and S-wave impedances, density as well as three anisotropic parameters in HTI media. Then, we proposed a novel Bayesian Mar- kov chain Monte Carlo inversion method of PP- and PS- wave for six elastic and anisotropic parameters directly. Tests on synthetic azimuthal seismic data contaminated by random errors demonstrated that this method appears more accurate, anti-noise and stable owing to the usage of the constrained PS-wave compared with the standards inver- sion scheme taking only the PP-wave into account.展开更多
There is a growing interest in using miniature multi-sensor technology to monitor plant, soil, and environmental conditions in greenhouses and in field settings. The objectives of this study were to build a small mult...There is a growing interest in using miniature multi-sensor technology to monitor plant, soil, and environmental conditions in greenhouses and in field settings. The objectives of this study were to build a small multi-channel sensing system with ability to measure visible and near infrared light reflectance, relative humidity, and temperature, to test the light reflectance sensors for measuring spectral characteristics of plant leaves and soilless media, and to compare results of the relative humidity and temperature sensors to identical measurement obtained from a greenhouse sensor. The sensing system was built with off-the-shelf miniature multispectral spectrometers and relative humidity and temperature sensors. The spectrometers were sensitive to visible, red-edge, and near infrared light. The system was placed in a greenhouse setting and used to obtain relative reflectance measurements of plant leaves and soilless media and to record temperature and relative humidity conditions in the greenhouse. The spectrometer data obtained from plant leaf and soilless media were compatible with baseline spectral data collected with a hyperspectral spectroradiometer. The greenhouse was equipped with a relative humidity and temperature sensor. The relative humidity and temperature sensor measurements from our sensor system were strongly correlated with the relative humidity and temperature results obtained with the greenhouse sensors...展开更多
The exact analytic solution of the pure bending beam of metallic foams is given. The effects of relative density of the material on stresses and deformation are revealed with the Triantafillou and Gibson constitutive ...The exact analytic solution of the pure bending beam of metallic foams is given. The effects of relative density of the material on stresses and deformation are revealed with the Triantafillou and Gibson constitutive law (TG model) taken as the analysis basis. Several examples for individual foams are discussed, showing the importance of compressibility of the cellular materials. One of the objects of this study is to generalize Hill's solution for incompressible plasticity to the case of compressible plasticity, and a kinematics parameter is brought into the analysis so that the velocity field can be determined.展开更多
To identify target energy balance-related behaviors(ERBs),baseline data from 141overweight or obese schoolchildren(aged 8-14years old)was used to predict adiposity[body mass index(BMI)and fat percentage]one year...To identify target energy balance-related behaviors(ERBs),baseline data from 141overweight or obese schoolchildren(aged 8-14years old)was used to predict adiposity[body mass index(BMI)and fat percentage]one year later.The ERBs included a modified Dietary Approach to Stop Hypertension diet score(DASH score),leisure-time physical activity(PA,days/week),and leisure screen time(minutes/day).Several cardiometabolic variables were measured in the fasting state, including systolic blood pressure (SBP), diastolic blood pressure (DBP), blood glucose (GLU), total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL-C), and high-density lipoprotein (HDL-C).展开更多
We study a general framework for assessing the injury probability corresponding to an input dose quantity. In many applications, the true value of input dose may not be directly measurable. Instead, the input dose is ...We study a general framework for assessing the injury probability corresponding to an input dose quantity. In many applications, the true value of input dose may not be directly measurable. Instead, the input dose is estimated from measurable/controllable quantities via numerical simulations using assumed representative parameter values. We aim at developing a simple modeling framework for accommodating all uncertainties, including the discrepancy between the estimated input dose and the true input dose. We first interpret the widely used logistic dose-injury model as the result of dose propagation uncertainty from input dose to target dose at the active site for injury where the binary outcome is completely determined by the target dose. We specify the symmetric logistic dose-injury function using two shape parameters: the median injury dose and the 10 - 90 percentile width. We relate the two shape parameters of injury function to the mean and standard deviation of the dose propagation uncertainty. We find 1) a larger total uncertainty will spread more the dose-response function, increasing the 10 - 90 percentile width and 2) a systematic over-estimate of the input dose will shift the injury probability toward the right along the estimated input dose. This framework provides a way of revising an established injury model for a particular test population to predict the injury model for a new population with different distributions of parameters that affect the dose propagation and dose estimation. In addition to modeling dose propagation uncertainty, we propose a new 3-parameter model to include the skewness of injury function. The proposed 3-parameter function form is based on shifted log-normal distribution of dose propagation uncertainty and is approximately invariant when other uncertainties are added. The proposed 3-parameter function form provides a framework for extending skewed injury model from a test population to a target population in application.展开更多
User-analysis techniques are mainly used to recommend friends and information. This paper discusses the data characteristics of microblog users and describes a multidimensional user rec- ommendation algorithm that tak...User-analysis techniques are mainly used to recommend friends and information. This paper discusses the data characteristics of microblog users and describes a multidimensional user rec- ommendation algorithm that takes into account microblog length, relativity between microblog and users, and familiarity between users. The experimental results show that this multidi- mensional algorithm is more accurate than a traditional recom- mendation algorithm.展开更多
How to solve the coupling relations in a 6 - DOF parallel robot quickly and accurately within the limits of realtime control is a critical problem. In traditional analytic method, the complicated mathemtical model mus...How to solve the coupling relations in a 6 - DOF parallel robot quickly and accurately within the limits of realtime control is a critical problem. In traditional analytic method, the complicated mathemtical model must first be constructed and then solved by programming.Obviously, this method is not very practical. This paper,therefore, proposes a new way of approach with a new method using 3- D animation for the solving of coupling relations in the 6 - DOF parallel robot. This method is much simpler and its solving accuracy approaches that of the more complicated analytic method.展开更多
The study was concerned with the problem of the Russian youth, with a special emphasis on the history of the theoretical and empirical researches devoted to the youth issues. The research delineates the term thesaurus...The study was concerned with the problem of the Russian youth, with a special emphasis on the history of the theoretical and empirical researches devoted to the youth issues. The research delineates the term thesaurus and its connection with the formation of youth's outlook. The central focus of the research is social and cultural value orientations of the young Russian. The study presents a detailed analysis of impact that mass media plays in socialization of youth, its generations, its influence on public opinion formation and priority directions of national policy of regulation of mutual relations between youth and mass media. It attempts to examine the presence of mass media in youth's everyday life. The research provides a detailed analysis of contemporary state of the youth's trust to the mass media and degree of dependence on it. The study also presents a detailed analysis of the traces of mass media's influence on young Russians. The completed research is fundamental for the sociological and the philosophical generalisations that underline comparative research on the youth problems in Russia, its social and cultural value orientations and the influence on public opinion formation and priority directions of national policy of regulation of mutual relations between youth and mass media.展开更多
The characteristics of 30-60 day oscillation (hereafter called LFO ) of the outgoing longwave radiation data (OLR) and its relations to the interannual oscillations of the sea surface temperature (SST) are investigate...The characteristics of 30-60 day oscillation (hereafter called LFO ) of the outgoing longwave radiation data (OLR) and its relations to the interannual oscillations of the sea surface temperature (SST) are investigated by using the daily OLR data for the period from January, 1979 to December, 1987 and the corresponding monthly SST data. It is found that the LFO the band the interannual oscillations of the SST monthly anomaly (SSTA) interact each other and they all relate to the occurrence and development of El Nino events closely. Before El Nino event happens, it contributes to the SST's wanning up and to the SST's quasi-biennial oscillation (called QBO for brevity) and three and half years oscillation (called SO for short) being in warm water phase in the equatorial central and eastern Pacific (ECP and EEP) that the LFO in the equatorial western Pacific (EWP) enhances and propagates eastward; When El Nino event takes place, the LFO, SSTA and SSTA's QBO and SO in the EEP interact and strengthen each other; But the warmer SST and the SSTA's QBO and SO in the warm water phase in the EEP contribute to the LFO's weakening in the equatorial Pacific. Moreover, these contribute to the SST in the EEP becoming cold and the SSTA's QBO and SO in the EWP being in cold water phase and then impel the El Nino event to end.展开更多
To provide a theoretical basis for further improvement of Brassica napus yield, additive dominance with additive - by - additive epistatic effects ( ADAA) genetic model and a 6 X 8 partial dial- lel cross des...To provide a theoretical basis for further improvement of Brassica napus yield, additive dominance with additive - by - additive epistatic effects ( ADAA) genetic model and a 6 X 8 partial dial- lel cross design were used to analyze the genetic effects and correlations of five yield related traits of 14 excellent Brassica napus parental lines and their 46 and F2 populations. The results showed that silique density (SD) , siliques per plant (SPP) , seeds per silique (SPS) and thousand - seed weight (TSW) exhibited not only additive and dominant effects, but also significant epistatic effects. The dominant effects of all five yield - related traits were obviously greater than their additive effects and epistatic effects. Yield per plant (YPP) showed significant genetic correlation with SD, SPP and SPS, and the main component of the genetic correlation was the dominance correlation. SPP and SPS both showed a significant negative correlation with TSW. The SD of rapeseed was genetically correlated with all three components of yield to a certain extent, and there were different components of genetic effects positively correlated with the three yield components, indicating that SD is a potential trait to reconcile the conflict between TSW and SPP as well as SPS.展开更多
文摘We consider the scattering of time-harmonic plane waves by an infinitely long penetrable chiral cylinder. The electromagnetic scattering problem is reduced to a transmission problem for a system of two-dimensional Helmholtz equations. We prove the classical reciprocity principle, a general scattering theorem and an optical theorem in R<sup>2</sup>. Using Herglotz wave functions we define the corresponding far field operator. Applying the general scattering theorem useful relations are proved for the reconstruction of the scatterer. We also prove that for real chirality measure of the penetrable scatterer the far field operator has a countable number of eigenvalues which lie on a circle.
基金supported by the National Natural Science Foundation of China (40975027)
文摘The multi-fractal ity over China are studied behaviors of relative humid using the multi-fractal de trended fluctuation analysis (DFA) method. Three multi fractal parameters (the spectrum width Aa, the asymmetry Aaas, and the long-range correlation exponent a0) of the singularity spectrum are introduced to quantify the multi-fractal behaviors. The results show that multi-frac tality exists in daily humidity records over most stations in China and is mainly due to the broad distribution of the probability density of the sequence values. Strong multi fractal behaviors over some stations in the Yunnan, Guangdong, and Inner Mongolia provinces are obvious. These behaviors are mainly caused by different long range correlations between large and small fluctuations. The asymmetry of the singularity of relative humidity records is weak, except for a small number of stations in the far east and west of China, where the singularity spec trum is left-skewed. Finally, the long-range correlations in North China are stronger than those in South China, which indicates better predictability in North China. By studying the parameters of the multi-fractal spectrum, various data of long-range power law correlations of the relative humidity records are obtained, which may pro vide theoretical support for climate prediction.
文摘To investigate the correlation between environmental-meteorological factors and daily visits for acute otitis media(AOM)in Lanzhou,China.Methods:Data were collected in 2014e2016 by the Departments of Otolaryngology-Head and Neck Surgery at two hospitals in Lanzhou.Relevant information,including age,sex and visiting time,was collected.Environmental data included air quality index,PM10,PM2.5,O3,CO,NO2 and SO2,and meteorological data included daily average temperature(T,C),daily mean atmospheric pressure(AP,hPa),daily average relative humidity(RH,%)and daily mean wind speed(W,m/s).The SPSS22.0 software was used to generate Spearman correlation coefficients in descriptive statistical analysis,and the R3.5.0 software was used to calculate relative risk(RR)and to obtain exposure-response curves.The relationship between meteorological-environmental parameters and daily AOM visits was summarized.Results:Correlations were identified between daily AOM visits and CO,O3,SO2,CO,NO2,PM2.5 and PM10 levels.NO2,SO2,CO,AP,RH and T levels significantly correlated with daily AOM visits with a lag exposure-response pattern.The effects of CO,NO2,SO2 and AP on daily AOM visits were significantly stronger compared to other factors(P<0.01).O3,W,T and RH were negatively correlated with daily AOM visits.The highest RR lagged by 3e4 days.Conclusions:The number of daily AOM visits appeared to be correlated with short-term exposure to mixed air pollutants and meteorological factors from 2014 through 2016 in Lanzhou.
文摘Air pollution has environmental issue owing become a serious to its diverse harmful effects on the physical and biological environment. According to the Environmental Protection Agency (EPA) and the World Health Organization (WHO), air pollution affects millions of people worldwide. Hundreds of thousands of deaths each year and a range of diseases, particularly among vulnerable groups (i.e., children, the elderly, and people with special medical conditions), are attributed to air pollution. These effects are not always caused by single pollutant in the air; rather, they are considered consequences of the multi-pollutants to which people are simultaneously exposed.
文摘Formation and flow of emulsions in porous media are common in all enhanced oil recovery tech- niques. In most cases, oil-in-water (O/W) emulsions are formed in porous media due to oil-water interaction. Even now, detailed flow mechanisms of emulsions through porous media are not well understood. In this study, variation of rate of flow of O/W emulsions with pressure drop was studied experimentally, and rheological pa- rameters were calculated. The pressure drop increases with an increase in oil concentration in the O/W emulsion due to high viscosity. The effective viscosity of the emulsion was calculated from the derived model and expressed as a function of shear rate while flowing through porous media. Flow of O/W emulsions of different concentrations was evaluated in sand packs of different sand sizes. Emulsions were characterized by analyzing their stability, rheological properties, and tem- perature effects on rheological properties.
基金sponsorship of the National Natural Science Foundation of China (No.41674130)the National Basic Research Program of China (973 Program,Nos.2013CB228604,2014CB239201)+1 种基金the National Oil and Gas Major Projects of China (Nos.2016ZX05027004-001,2016ZX05002005-009)the Fundamental Research Funds for the Central Universities (15CX08002A) for their funding in this research
文摘A single set of vertically aligned cracks embedded in a purely isotropic background may be con- sidered as a long-wavelength effective transversely iso- tropy (HTI) medium with a horizontal symmetry axis. The crack-induced HTI anisotropy can be characterized by the weakly anisotropic parameters introduced by Thomsen. The seismic scattering theory can be utilized for the inversion for the anisotropic parameters in weakly aniso- tropic and heterogeneous HTI media. Based on the seismic scattering theory, we first derived the linearized PP- and PS-wave reflection coefficients in terms of P- and S-wave impedances, density as well as three anisotropic parameters in HTI media. Then, we proposed a novel Bayesian Mar- kov chain Monte Carlo inversion method of PP- and PS- wave for six elastic and anisotropic parameters directly. Tests on synthetic azimuthal seismic data contaminated by random errors demonstrated that this method appears more accurate, anti-noise and stable owing to the usage of the constrained PS-wave compared with the standards inver- sion scheme taking only the PP-wave into account.
文摘There is a growing interest in using miniature multi-sensor technology to monitor plant, soil, and environmental conditions in greenhouses and in field settings. The objectives of this study were to build a small multi-channel sensing system with ability to measure visible and near infrared light reflectance, relative humidity, and temperature, to test the light reflectance sensors for measuring spectral characteristics of plant leaves and soilless media, and to compare results of the relative humidity and temperature sensors to identical measurement obtained from a greenhouse sensor. The sensing system was built with off-the-shelf miniature multispectral spectrometers and relative humidity and temperature sensors. The spectrometers were sensitive to visible, red-edge, and near infrared light. The system was placed in a greenhouse setting and used to obtain relative reflectance measurements of plant leaves and soilless media and to record temperature and relative humidity conditions in the greenhouse. The spectrometer data obtained from plant leaf and soilless media were compatible with baseline spectral data collected with a hyperspectral spectroradiometer. The greenhouse was equipped with a relative humidity and temperature sensor. The relative humidity and temperature sensor measurements from our sensor system were strongly correlated with the relative humidity and temperature results obtained with the greenhouse sensors...
文摘The exact analytic solution of the pure bending beam of metallic foams is given. The effects of relative density of the material on stresses and deformation are revealed with the Triantafillou and Gibson constitutive law (TG model) taken as the analysis basis. Several examples for individual foams are discussed, showing the importance of compressibility of the cellular materials. One of the objects of this study is to generalize Hill's solution for incompressible plasticity to the case of compressible plasticity, and a kinematics parameter is brought into the analysis so that the velocity field can be determined.
基金Research special fund of the Ministry of Health public service sectors funded projects(201202010)The 12th Five-year Key Project of Beijing Education Sciences Research Institute(AAA12011)
文摘To identify target energy balance-related behaviors(ERBs),baseline data from 141overweight or obese schoolchildren(aged 8-14years old)was used to predict adiposity[body mass index(BMI)and fat percentage]one year later.The ERBs included a modified Dietary Approach to Stop Hypertension diet score(DASH score),leisure-time physical activity(PA,days/week),and leisure screen time(minutes/day).Several cardiometabolic variables were measured in the fasting state, including systolic blood pressure (SBP), diastolic blood pressure (DBP), blood glucose (GLU), total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL-C), and high-density lipoprotein (HDL-C).
文摘We study a general framework for assessing the injury probability corresponding to an input dose quantity. In many applications, the true value of input dose may not be directly measurable. Instead, the input dose is estimated from measurable/controllable quantities via numerical simulations using assumed representative parameter values. We aim at developing a simple modeling framework for accommodating all uncertainties, including the discrepancy between the estimated input dose and the true input dose. We first interpret the widely used logistic dose-injury model as the result of dose propagation uncertainty from input dose to target dose at the active site for injury where the binary outcome is completely determined by the target dose. We specify the symmetric logistic dose-injury function using two shape parameters: the median injury dose and the 10 - 90 percentile width. We relate the two shape parameters of injury function to the mean and standard deviation of the dose propagation uncertainty. We find 1) a larger total uncertainty will spread more the dose-response function, increasing the 10 - 90 percentile width and 2) a systematic over-estimate of the input dose will shift the injury probability toward the right along the estimated input dose. This framework provides a way of revising an established injury model for a particular test population to predict the injury model for a new population with different distributions of parameters that affect the dose propagation and dose estimation. In addition to modeling dose propagation uncertainty, we propose a new 3-parameter model to include the skewness of injury function. The proposed 3-parameter function form is based on shifted log-normal distribution of dose propagation uncertainty and is approximately invariant when other uncertainties are added. The proposed 3-parameter function form provides a framework for extending skewed injury model from a test population to a target population in application.
文摘User-analysis techniques are mainly used to recommend friends and information. This paper discusses the data characteristics of microblog users and describes a multidimensional user rec- ommendation algorithm that takes into account microblog length, relativity between microblog and users, and familiarity between users. The experimental results show that this multidi- mensional algorithm is more accurate than a traditional recom- mendation algorithm.
文摘How to solve the coupling relations in a 6 - DOF parallel robot quickly and accurately within the limits of realtime control is a critical problem. In traditional analytic method, the complicated mathemtical model must first be constructed and then solved by programming.Obviously, this method is not very practical. This paper,therefore, proposes a new way of approach with a new method using 3- D animation for the solving of coupling relations in the 6 - DOF parallel robot. This method is much simpler and its solving accuracy approaches that of the more complicated analytic method.
文摘The study was concerned with the problem of the Russian youth, with a special emphasis on the history of the theoretical and empirical researches devoted to the youth issues. The research delineates the term thesaurus and its connection with the formation of youth's outlook. The central focus of the research is social and cultural value orientations of the young Russian. The study presents a detailed analysis of impact that mass media plays in socialization of youth, its generations, its influence on public opinion formation and priority directions of national policy of regulation of mutual relations between youth and mass media. It attempts to examine the presence of mass media in youth's everyday life. The research provides a detailed analysis of contemporary state of the youth's trust to the mass media and degree of dependence on it. The study also presents a detailed analysis of the traces of mass media's influence on young Russians. The completed research is fundamental for the sociological and the philosophical generalisations that underline comparative research on the youth problems in Russia, its social and cultural value orientations and the influence on public opinion formation and priority directions of national policy of regulation of mutual relations between youth and mass media.
基金This work is supported by the National Natural Science foundation of China under Program49070240.
文摘The characteristics of 30-60 day oscillation (hereafter called LFO ) of the outgoing longwave radiation data (OLR) and its relations to the interannual oscillations of the sea surface temperature (SST) are investigated by using the daily OLR data for the period from January, 1979 to December, 1987 and the corresponding monthly SST data. It is found that the LFO the band the interannual oscillations of the SST monthly anomaly (SSTA) interact each other and they all relate to the occurrence and development of El Nino events closely. Before El Nino event happens, it contributes to the SST's wanning up and to the SST's quasi-biennial oscillation (called QBO for brevity) and three and half years oscillation (called SO for short) being in warm water phase in the equatorial central and eastern Pacific (ECP and EEP) that the LFO in the equatorial western Pacific (EWP) enhances and propagates eastward; When El Nino event takes place, the LFO, SSTA and SSTA's QBO and SO in the EEP interact and strengthen each other; But the warmer SST and the SSTA's QBO and SO in the warm water phase in the EEP contribute to the LFO's weakening in the equatorial Pacific. Moreover, these contribute to the SST in the EEP becoming cold and the SSTA's QBO and SO in the EWP being in cold water phase and then impel the El Nino event to end.
基金This research was supported by the National Basic Research Program of China ( 973 Program, 2011CB109302);the National High - Tech R&D Pro-gram of China (863 Program, 2011AA10A104, 2012AA101107) ; Natural Science Foundation of Hu-bei Province (2015CFA103) ; Hubei Agricultural Science and Technology Innovation Center.
文摘To provide a theoretical basis for further improvement of Brassica napus yield, additive dominance with additive - by - additive epistatic effects ( ADAA) genetic model and a 6 X 8 partial dial- lel cross design were used to analyze the genetic effects and correlations of five yield related traits of 14 excellent Brassica napus parental lines and their 46 and F2 populations. The results showed that silique density (SD) , siliques per plant (SPP) , seeds per silique (SPS) and thousand - seed weight (TSW) exhibited not only additive and dominant effects, but also significant epistatic effects. The dominant effects of all five yield - related traits were obviously greater than their additive effects and epistatic effects. Yield per plant (YPP) showed significant genetic correlation with SD, SPP and SPS, and the main component of the genetic correlation was the dominance correlation. SPP and SPS both showed a significant negative correlation with TSW. The SD of rapeseed was genetically correlated with all three components of yield to a certain extent, and there were different components of genetic effects positively correlated with the three yield components, indicating that SD is a potential trait to reconcile the conflict between TSW and SPP as well as SPS.