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27 results on '"Dai, Jiakun"'

3. Slow-Release Urea Fertilizer with Water Retention and Photosensitivity Properties Based on Sodium Alginate/Carboxymethyl Starch Sodium/Polydopamine.

Author

Li, Yan, Ma, Yu, Chang, Fan, Zhu, Haiyun, Tian, Chengshan, Jia, Fengan, Ke, Yang, and Dai, Jiakun

Subjects
SODIUM alginate, UREA as fertilizer, FOURIER transform infrared spectroscopy, SUSTAINABLE agriculture, PHOTOSENSITIVITY, FERTILIZER application
Abstract

Using slow-release fertilizer is one of the sustainable strategies to improve the effectiveness of fertilizers and mitigate the environmental pollution caused by excess usage of fertilizer. In this study, a slow-release urea fertilizer with water retention and photosensitivity properties was prepared by a two-step method. It was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and an infrared camera. This fertilizer can prolong the release period of urea, improve water-retention capacity of soil, and carry out photothermal conversion under illumination. Comparing four release kinetics models, the Ritger–Peppas model was the best fitting model for releasing behavior in soil, and diffusion followed the Fickian mechanism. The application of fertilizer on winter wheat was carried out to intuitively evaluate the fertilizer's effects on promoting plant growth and resisting water stress. Thus, this study provides a new strategy for improving fertilizer utilization rate and maintaining soil moisture, which will be beneficial for sustainable agriculture. [ABSTRACT FROM AUTHOR]

Published
2024
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6. Optimal Peer-to-Peer Energy Transaction of Distributed Prosumers in High-Penetrated Renewable Distribution Systems

Author

Ma, Huangqi, Xiang, Yue, Sun, Wei, Dai, Jiakun, Zhang, Shenxi, Liu, Youbo, and Liu, Junyong

Abstract

Emerging prosumers are driving changes in the way traditional distribution systems operate. With the increase in the penetration of renewable energy, the energy management of prosumers has created new challenges. This article proposes a novel peer-to-peer (P2P) transaction strategy for coupling distributed energy resources (DERs) and electric vehicles (EVs) to achieve optimal energy transaction in high-penetration distribution systems. Firstly, the model of a prosumer aggregate is established. Secondly, the economic models of prosumers and P2P transaction are constructed. Prosumers can evaluate the response benefits of internal distributed generation (DG), energy storage systems (ESSs), flexible load, EVs, and external P2P benefits and propose a joint response mechanism with mutual benefit priority to solve the problem of joint optimization. In addition, to ensure compliance with network constraints, a P2P transaction negotiation algorithm considering network charges is proposed. This algorithm guides prosumers to reach a transaction by modifying the transaction price, enabling fast negotiation without intermediaries. Finally, the proposed method is validated on an IEEE 33-bus test system, demonstrating its ability to reduce internal energy imbalances and improve economic benefits for prosumers.

Published
2024
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8. Screening and evaluation of selenium-rich maize cultivars in Ziyang area

Author

Li Yan, Yue Jianwu, Duan Zhibin, Wu Shuangquan, Li Bo, Sun Chao, Dai Jiakun, and Dou Bingde

Subjects
Environmental sciences, GE1-350
Abstract

To study selenium (Se)-enriched characteristics of maize in Ziyang area and to select cultivars, six cultivars were planted on three different soils with high-Se, middle-Se and low-Se. The Se content of grain, stalk & leaf and cob were tested separately, and the relationship between Se content in soil and the capability of Se-enrichment in different organs of six cultivars were analyzed. The result showed that the Se content of maize organs is positively correlated with the Se in soil. Meanwhile, on the soil with different Se content, the trends of Se-enriching capacity in different organs of maize cultivars were as follows: stalk & leaf > grain > cob. Further comparison of the ratio of the Se content of various organs to the Se content of soil showed that, the maize planted on the middle-Se soil has the highest capability of Se-enrichment. Considering the biomass, the accumulation of Se in the grains of sweet maize Shaan K512 and waxy maize Shaan K818 were relatively higher. This study has implications for Se-rich maize and comprehensive utilization of Se in Ziyang.

Published
2020
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20. Experiment study of the altitude effects on spontaneous ignition characteristics of wood

Author

Deng Zhihua, Dai Jiakun, Zhou Xiaodong, Yang Lizhong, Wang Yafei, and Zhou Yupeng

Subjects
Chemistry, General Chemical Engineering, Organic Chemistry, Energy Engineering and Power Technology, Mineralogy, Autoignition temperature, Effects of high altitude on humans, Atmospheric sciences, law.invention, Ignition system, Fuel Technology, Altitude, Physics::Plasma Physics, law, Slab, Physics::Chemical Physics, Pyrolysis, Spontaneous combustion, Ambient pressure
Abstract

This paper has studied the influence of ambient pressure and oxygen content on spontaneous ignition of wood by conducting contrastive experiments with wood slab exposed to high temperature radiation at two different altitudes. The measurement of mass loss, time to ignition, and surface temperature of wood are carried out. Results show that mass loss rate of wood at high altitudes (3650 m) is higher than the one at low altitudes (50 m), while ignition delay time of the sample at high altitude is shorter. The surface temperatures at the time of ignition in the two different places are both close to each other, which indicates that the pressure did not affects the ignition temperature. The theoretical analysis on the phenomenon of different ignition behavior of wood in these two altitude environments has been presented.

Published
2010

21. Autoignition of solid combustibles subjected to a uniform incident heat flux: The effect of distance from the radiation source

Author

Dai Jiakun, Wang Yafei, Zhou Yupeng, Deng Zhihua, Zhou Xiaodong, and Yang Lizhong

Subjects
Mass flux, Chemistry, General Chemical Engineering, General Physics and Astronomy, Energy Engineering and Power Technology, Thermodynamics, Autoignition temperature, General Chemistry, Radiation, law.invention, Ignition system, Fuel Technology, Radiant heating, Heat flux, law, Physics::Chemical Physics, Pyrolysis, Dimensionless quantity
Abstract

The ignitability of solid combustibles by a radiation source has been investigated experimentally as a function of distance between the solid and the source, for heating with a uniform incident heat flux. Unlike piloted ignition, the critical incident heat flux for autoignition increases with the increase of radiant distance, which is a result that has not been reported before. It is found that the generation rate of combustible pyrolysis volatiles is a necessary but not sufficient condition for autoignition. By two dimensionless parameters, it is clearly indicated that the occurrence of autoignition needs both sufficient gas-phase temperature and sufficient concentration of combustible pyrolysis volatiles simultaneously, especially for the larger radiant heating distance condition which is also closer to realistic fire conditions.

Published
2011

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