Nowadays the rising of opportunity cost of farm labor comes to the forefront of attention in China. In order to understand its impact on agricultural land-use structure, a theoretical framework of household economics ...Nowadays the rising of opportunity cost of farm labor comes to the forefront of attention in China. In order to understand its impact on agricultural land-use structure, a theoretical framework of household economics is formulated drawn on Low's model. Under the theoretical framework, the impact of the rising opportunity cost of on-farm on cropping structure is deduced in theory. And then, using statistic and survey data, taking mountain area of southern Ningxia as an example, the theoretical assumes are verified. The results show that the rise of opportunity cost of farm labor leads to less diversified cropping structure.展开更多
We perform Rayleigh wave tomography in east Guangdong and its surrounding regions by applying the ambient noise method to broadband data recorded at 26 stations from Guangdong,Fujian and Jiangxi Digital Seismic Networ...We perform Rayleigh wave tomography in east Guangdong and its surrounding regions by applying the ambient noise method to broadband data recorded at 26 stations from Guangdong,Fujian and Jiangxi Digital Seismic Networks.Cross-correlations of verticalcomponent ambient noise data are computed in one-day segments and stacked over seven months from March to September,2011.Then Rayleigh wave group dispersion curves are measured using the frequency-time analysis method.Group velocity maps at periods from5s to 15s are inverted.The resulting group velocity maps generally show good correlation with tectonic features,reflecting the velocity variations in the shallow crust.The basin areas are clearly resolved with lower group velocities at the short periods due to thick sedimentary layers,and the mountain areas with higher group velocities due to thin sedimentary layers.The variations of group velocity on the map can draw out the distribution of basins and mountains in study areas.The geothermal field can change the group velocity obviously,and lower group velocities are always found in high geothermal areas.The velocity maps indicate that a low-velocity layer may be found in the study areas.展开更多
Network Coding (NC) brings correlation between the coded signals from different sources, which makes the system more vulnerable to the decode error at relay. Conventional Cyclic Redundancy Code (CRC) has been implemen...Network Coding (NC) brings correlation between the coded signals from different sources, which makes the system more vulnerable to the decode error at relay. Conventional Cyclic Redundancy Code (CRC) has been implemented for error bit detection. However, its error correction is simply ignored. To fully exploit this feature, this paper proposes a novel joint Log-Likelihood Ratio (LLR) CRC error mitigation for NC two way relay channel. Specific thresholds are designed to estimate the error number of data block and identify those which can be recovered if the number is within the error correction scope of CRC. We examine two modes of the thresholds, one based on the average Bit Error Rate (BER) of source-relay link, while the other based on that of instantaneous one. We provide the full analysis for the Pair-wise Error Probability (PEP) performance of the scheme. A variety of numerical results are presented to reveal the superiority of the proposed scheme to conventional CRC NC under independent Rayleigh fading channels. Moreover, the efficiencies of the proposed thresholds are also validated.展开更多
Chemical composition of Brahman cattle was studied and determined in this study. Fifty males had been castrated at birth, farmed semi-intensively on the Venezuelan plain and then slaughtered at the age of 31 months wi...Chemical composition of Brahman cattle was studied and determined in this study. Fifty males had been castrated at birth, farmed semi-intensively on the Venezuelan plain and then slaughtered at the age of 31 months with an approximate weight of 500 kilograms. The average pH value of beef was 5,84 after obtained for 24 hours after staughtering, which matches the ~atue found in similar studies made on the same breed in Venezuela （5.8）. The moisture, crude protein and ash contents correspond to the expected values of cattle, while the intramuscular fat values are slightly higher than those of the different breeds ofBos indicus. The total collagen values found in this study are either similar or lower than those found by other researches from the different breeds ofBos indicus and their crossbreeds, while the collagen solubility value （39%） was higher than the one found in other studies on the Brahman breed.展开更多
In this article,the vertical components of the continuous waveform data of 90 seismic stations in Ningxia and its adjacent regions recorded from January 2012 to December 2013 are used to obtain the Rayleigh surface wa...In this article,the vertical components of the continuous waveform data of 90 seismic stations in Ningxia and its adjacent regions recorded from January 2012 to December 2013 are used to obtain the Rayleigh surface wave group velocity dispersion images in the study area( 101°- 112°E,31°-42°N) according to the method of noise imaging,with period between 6s - 50s and resolution of 0.5°. The Yinchuan basin in the 6s - 26 s period obviously shows a low velocity anomaly,which is not uniform and has a tendency to gradually weaken; the Guanzhong Basin in 6 s-22s shows a strip of low velocity anomaly and demonstrates a transverse inhomogeneity,where velocity in the southeast is slightly faster than that in the northwest. In the 30s - 50s period it shows that in the Yinchuan graben basin and its southern area,there is a large low velocity anomaly area,which moves from northeast to southwest. It shows that between the main active tectonic zones,like mountains and basins,there are obvious geomorphologic boundaries. For example,the deep fault near Liupan Mountain is the dividing line between two large tectonic units of eastern and western of China. The inversion results have good correlation with the geological structure and the stratigraphic landform. The results are consistent with the results of artificial seismic section tomography across the basin. It provides an important basis for the dynamics of active tectonic zones and the mechanism of earthquake occurrence in this area.展开更多
Fluctuations of the world oil prices affect economic performance. Outside the impact on the sector of energy production, the rising oil price has consequences on inflationary pressures and a deteriorating fiscal posit...Fluctuations of the world oil prices affect economic performance. Outside the impact on the sector of energy production, the rising oil price has consequences on inflationary pressures and a deteriorating fiscal position of Burkina Faso. In this context, studying the impact of rising oil prices on the economy, especially the cost of living of its population has a great interest because although many studies have attempted to link 〈〈oil prices〉~ and 〈〈cost of living~, very few have focused on the specific case of Burkina Faso. This allows us to make our contribution to this construction literature. This contribution will consist to highlight the relation between changes in oil prices and the cost of living in Burkina Faso. Also to be reached, we will find the best indicator to reflect the cost of living in Burkina Faso, identify the suitable econometric model for estimating the correlation and verify the existence of the relation between oil prices and the cost of living. For a better approach to this study, we used a VAR （Vector Auto-Regressive） model. Also, we will use documentary research that will make an assessment on the existing in terms of theoretical debates around the theme descriptive statistics that will help to introduce and describe the variables used in the study, and econometric analysis will analyze and estimate the parameters of our objective function using Eviews.展开更多
基金support of research grants from the National Key Technology R&D Program(Grant No.2006BAB15B02)the National Natural Science Fund of China(Grant No.40971062 and 404801051)
文摘Nowadays the rising of opportunity cost of farm labor comes to the forefront of attention in China. In order to understand its impact on agricultural land-use structure, a theoretical framework of household economics is formulated drawn on Low's model. Under the theoretical framework, the impact of the rising opportunity cost of on-farm on cropping structure is deduced in theory. And then, using statistic and survey data, taking mountain area of southern Ningxia as an example, the theoretical assumes are verified. The results show that the rise of opportunity cost of farm labor leads to less diversified cropping structure.
基金funded by the 2011 Earthquake Tracking Project of CEA(Grant No.2011020105)the open fund project of State Key Laboratory of Earthquake Dynamics(Grant No.LED2011B04)
文摘We perform Rayleigh wave tomography in east Guangdong and its surrounding regions by applying the ambient noise method to broadband data recorded at 26 stations from Guangdong,Fujian and Jiangxi Digital Seismic Networks.Cross-correlations of verticalcomponent ambient noise data are computed in one-day segments and stacked over seven months from March to September,2011.Then Rayleigh wave group dispersion curves are measured using the frequency-time analysis method.Group velocity maps at periods from5s to 15s are inverted.The resulting group velocity maps generally show good correlation with tectonic features,reflecting the velocity variations in the shallow crust.The basin areas are clearly resolved with lower group velocities at the short periods due to thick sedimentary layers,and the mountain areas with higher group velocities due to thin sedimentary layers.The variations of group velocity on the map can draw out the distribution of basins and mountains in study areas.The geothermal field can change the group velocity obviously,and lower group velocities are always found in high geothermal areas.The velocity maps indicate that a low-velocity layer may be found in the study areas.
基金Supported by the National 973 Programs (2013CB329104)the National Natural Science Foundations of China (No. 61071090, No. 61171093)+3 种基金the Postgraduate Innovation Programs of Scientific Research of Jiangsu Province (CXZZ11_0388)Jiangsu Province Natural Science Foundation Key Projects (11KJA510001)National Science and Technology Key Projects (2011ZX03005-004-003)Jiangsu 973 Projects (BK2011027)
文摘Network Coding (NC) brings correlation between the coded signals from different sources, which makes the system more vulnerable to the decode error at relay. Conventional Cyclic Redundancy Code (CRC) has been implemented for error bit detection. However, its error correction is simply ignored. To fully exploit this feature, this paper proposes a novel joint Log-Likelihood Ratio (LLR) CRC error mitigation for NC two way relay channel. Specific thresholds are designed to estimate the error number of data block and identify those which can be recovered if the number is within the error correction scope of CRC. We examine two modes of the thresholds, one based on the average Bit Error Rate (BER) of source-relay link, while the other based on that of instantaneous one. We provide the full analysis for the Pair-wise Error Probability (PEP) performance of the scheme. A variety of numerical results are presented to reveal the superiority of the proposed scheme to conventional CRC NC under independent Rayleigh fading channels. Moreover, the efficiencies of the proposed thresholds are also validated.
文摘Chemical composition of Brahman cattle was studied and determined in this study. Fifty males had been castrated at birth, farmed semi-intensively on the Venezuelan plain and then slaughtered at the age of 31 months with an approximate weight of 500 kilograms. The average pH value of beef was 5,84 after obtained for 24 hours after staughtering, which matches the ~atue found in similar studies made on the same breed in Venezuela （5.8）. The moisture, crude protein and ash contents correspond to the expected values of cattle, while the intramuscular fat values are slightly higher than those of the different breeds ofBos indicus. The total collagen values found in this study are either similar or lower than those found by other researches from the different breeds ofBos indicus and their crossbreeds, while the collagen solubility value （39%） was higher than the one found in other studies on the Brahman breed.
基金sponsored by the Earth quake Science and Technology Spark Plan(XH14051YSX)the Natural Science Foundation of Ningxia,China(NZ15213)
文摘In this article,the vertical components of the continuous waveform data of 90 seismic stations in Ningxia and its adjacent regions recorded from January 2012 to December 2013 are used to obtain the Rayleigh surface wave group velocity dispersion images in the study area( 101°- 112°E,31°-42°N) according to the method of noise imaging,with period between 6s - 50s and resolution of 0.5°. The Yinchuan basin in the 6s - 26 s period obviously shows a low velocity anomaly,which is not uniform and has a tendency to gradually weaken; the Guanzhong Basin in 6 s-22s shows a strip of low velocity anomaly and demonstrates a transverse inhomogeneity,where velocity in the southeast is slightly faster than that in the northwest. In the 30s - 50s period it shows that in the Yinchuan graben basin and its southern area,there is a large low velocity anomaly area,which moves from northeast to southwest. It shows that between the main active tectonic zones,like mountains and basins,there are obvious geomorphologic boundaries. For example,the deep fault near Liupan Mountain is the dividing line between two large tectonic units of eastern and western of China. The inversion results have good correlation with the geological structure and the stratigraphic landform. The results are consistent with the results of artificial seismic section tomography across the basin. It provides an important basis for the dynamics of active tectonic zones and the mechanism of earthquake occurrence in this area.
文摘Fluctuations of the world oil prices affect economic performance. Outside the impact on the sector of energy production, the rising oil price has consequences on inflationary pressures and a deteriorating fiscal position of Burkina Faso. In this context, studying the impact of rising oil prices on the economy, especially the cost of living of its population has a great interest because although many studies have attempted to link 〈〈oil prices〉~ and 〈〈cost of living~, very few have focused on the specific case of Burkina Faso. This allows us to make our contribution to this construction literature. This contribution will consist to highlight the relation between changes in oil prices and the cost of living in Burkina Faso. Also to be reached, we will find the best indicator to reflect the cost of living in Burkina Faso, identify the suitable econometric model for estimating the correlation and verify the existence of the relation between oil prices and the cost of living. For a better approach to this study, we used a VAR （Vector Auto-Regressive） model. Also, we will use documentary research that will make an assessment on the existing in terms of theoretical debates around the theme descriptive statistics that will help to introduce and describe the variables used in the study, and econometric analysis will analyze and estimate the parameters of our objective function using Eviews.
