Effect of Nitrogen and Density Interaction on Yield Formation of Late Japonica Rice Under Different Transplanting Dates

[Objectives]This study was conducted to clarify the appropriate nitrogen fertilizer amount and transplanting density that should be selected for different transplanting dates.[Methods]The effects of nitrogen fertilizer rate and transplanting density on the traits and yield of late japonica rice in the Jianghuai rice-wheat cropping area under different transplanting dates(transplanting at an appropriate time and delayed transplanting)were studied.[Results]The transplanting date significantly affected the heading,maturity and whole growth period of rice,and when the transplanting date of early-maturing late japonica rice was delayed by 15 d,the growth period was shortened by about 10 d.Nitrogen and density interaction obviously affected the dry matter accumulation and effective tillers of rice,and the dry matter production and effective tiller number of rice treated with B_(1)N_(2) were greater than other treatments.Under the timely transplanting date,the best nitrogen and density combination was 225-300 kg/hm^(2) and 250500 holes/hm^(2),and the nitrogen use efficiency was ideal.It suggests that under the condition of transplanting rice in a timely manner,applying nitrogen fertilizer at an appropriate rate while ensuring a reasonable population density is conducive to the coordination of the number of stems and tillers,the number of grains per panicle,etc.,thereby ensuring the best formation of yield factors in the middle and late stages of rice growth.[Conclusions]This study provides technical support and theoretical reference for reasonable nitrogen and density interaction of rice.

Discharge Characteristics of an Atmospheric Pressure Argon Plasma Jet Generated with Screw Ring-Ring Electrodes in Surface Dielectric Barrier Discharge

An atmospheric-pressure argon plasma jet with screw ring-ring electrodes in surface dielectric barrier discharge is generated by a sinusoidal excitation voltage at 8 kHz. The discharge characteristics, such as rotational and vibrational temperature of nitrogen, electronic excitation temperature, oxygen atomic density, nitrogen molecular density, and average electron density, are estimated. It is found that the rotational temperature of nitrogen is in the range of 352 ～ 392 K by comparing the simulated spectrum with the measured spectrum at the C3Πu → B3Πg （△ν = 2） band transition, the electronic excitation temperature is found to be in the range of 3127 ～ 3230 K by using the Boltzmann plot method, the oxygen atomic and nitrogen molecular density are of the order of magnitude of 1016 cm-3 by the actinometry method, and the average electron density is of the order of magnitude of 1012 cm-3 by the energy balance equation. Besides, the effective power, conduction, and displacement current are measured during the discharge.

Nitrogen-rich carbon spheres made by a continuous spraying process for high-performance supercapacitors

Supercapacitors have high power densities, high efficiencies, and long cycling lifetimes; however, to enable their wider use, their energy densities must be significantly improved. The design and synthesis of improved carbon materials with better capacitance, rate performance, and cycling stability has emerged as the main theme of supercapacitor research. Herein, we report a facile synthetic method to prepare nitrogen-rich carbon particles based on a continuous aerosol- spraying process. The method yields particles that have high surface areas, a uniform microporous structure, and are highly N-doped, resulting in a synergism that enables the construction of supercapacitors with high energy and power density for use in both aqueous and commercial organic electrolytes. Furthermore, we have used density functional theory calculations to show that the improved performance is due to the enhanced wettability and ion adsorption interactions at the carbon/electrolyte interface that result from nitrogen doping. These findings provide new insights into the role of heteroatom doping in the capacitance enhancement of carbon materials; in addition, our method offers an efficient route for large-scale production of doped carbon.