Border effects of the main and ratoon crops in the rice ratooning system

The border effect(BE)is widely observed in crop field experiments,and it has been extensively studied in many crops.However,only limited attention has been paid to the BE of ratoon rice.We conducted field experiments on ratoon rice in Qichun County,Hubei Province,Central China in 2018 and 2019 to compare the BE in the main and ratoon crops,and to quantify the contribution of BE in the main crop to that in the ratoon crop.The BE of two hybrid varieties was measured for the outermost,second outermost,and third outermost rows in each plot of both crops.To determine the contribution of BE between the two crops,portions of hills in the outermost and second outermost rows were uprooted during the harvest of the main crop so that the second and third outermost rows then became the outermost rows in the ratoon crop.Overall,the BE on grain yield was greater in the main crop than in the ratoon crop.In the main crop,the BE on grain yield was 98.3%in the outermost row,which was explained by the BE on panicles m^(–2),spikelets/panicle,spikelets m^(–2),and total dry weight.In the ratoon crop,the BE on grain yield was reduced to 60.9 and 27.6%with and without the contribution of the BE in the main crop,respectively.Consequently,55.1%of the BE on grain yield in the ratoon crop was contributed from the main crop.High stubble dry weight and non-structural carbohydrate(NSC)accumulation at the harvest of the main crop were responsible for the contribution of BE in the main crop to that in the ratoon crop.Our results suggest that increases in stubble dry weight and NSC accumulation at the harvest of the main crop could be important strategies for developing high-yielding cropping practices in the rice ratooning system.

ADC border effect and suppression of quantization error in the digital dynamic measurement

The digital measurement and processing is an important direction in the measurement and control field. The quantization error widely existing in the digital processing is always the decisive factor that restricts the development and applications of the digital technology. In this paper, we find that the stability of the digital quantization system is obviously better than the quantization resolution. The application of a border effect in the digital quantization can greatly improve the accuracy of digital processing. Its effective precision has nothing to do with the number of quantization bits, which is only related to the stability of the quantization system. The high precision measurement results obtained in the low level quantization system with high sampling rate have an important application value for the progress in the digital measurement and processing field.

Analysis of coverage problem under border effects in wireless sensor networks

Wireless sensor networks can be used to monitor the interested region by deploying dense sensor nodes. Coverage is a primary metric to evaluate the capacity of monitoring. In this paper, we focus on the coverage problem under border effects, where the sensor nodes are distributed in a circle-shaped region randomly. Under this scenario, we derive the expected coverage of the sensor node and the total network coverage provided by n sensor nodes accurately by probability. These findings are useful to determine the related parameters （sensing range, number of sensor nodes and radius of monitored region） for a specific network coverage ratio. Simulation results demonstrate that our analysis is correct and effective.

Border effect-based precise measurement of any frequency signal

Limited detection resolution leads to fuzzy areas during the measurement, and the discrimination of the border of a fuzzy area helps to use the resolution stability. In this way, measurement precision is greatly improved, hence this phenomenon is named the border effect. The resolution fuzzy area and its application should be studied to realize highresolution measurement. During the measurement of any frequency signal, the fuzzy areas of phase-coincidence detection are always discrete and irregular. In this paper the difficulty in capturing the border information of discrete fuzzy areas is overcome and extra-high resolution measurement is implemented. Measurement precision of any frequency-signal can easily reach better than 1 × 10^-11/s in a wide range of frequencies, showing the great importance of the border effect. An in-depth study of this issue has great significance for frequency standard comparison, signal processing, telecommunication,and fundamental subjects.

Labor Mobility within China:Border Effects on Interregional Wage Differentials

Labor migration is institutionally restricted within China under the hukou system, China registration system. However, what is the pecuniary impact of labor immobility on interregional wage inequality？ To answer this question, we derive a simple wage gap equation including educational attainment, market potential and provincial border indicators. The regressions based on city and sector-level data show that, other things being equal, the wage dispersions within Chinese provincial borders are significantly less pronounced than those among provinces. Such border effects on spatial wage differentials, which have been shown to pervasively exist in all sectors considered in the present paper, reflect the distortions generated by migration controls. Finally, we show that despite the recent hukou reforms aimed at relaxing the restrictions on population movement, border effects appear to persisted over the period 2003-2005.

Administrative Division Adjustment and Housing Price Comovement:Evidence from City-County Mergers in China

Interregional housing price comovement is a stylized fact worldwide.This study explores how it is affected by administrative division adjustment.We exploit city-county mergers in China as a quasi-natural experiment to construct a difference-in-differences strategy for causal identification.Based on monthly housing price data for districts(counties)in China from 2010 to 2019,we find that city-county mergers significantly improve correlations in housing prices between the merged county and the urban district.This effect is more obvious in cities with a large economic gap between merged counties and urban districts,located in the central and western regions,and with lower administrative hierarchies(non-provincial-capital cities).The mechanism test shows that the impact of city-county mergers on housing price comovement results mainly from integrating housing demand rather than integrating housing supply,like the unified land supply policy that local government implements in the new administrative scope after mergers.The results are helpful in understanding housing price comovement from the view of regional integration and provide clear policy implications for housing market regulation in China.