Effects of Salt Water Drip Irrigation on Jujube Roots Soil Available Nitrogen Distribution : A Security Assurance Perspective

Xingpeng Wang,Tiecheng Bai,Jinhu Zhi,Zhaoyang Li 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.2

Field experiment was used in this research to study influences brought by salt water with different degrees of mineralization to distribution characteristics of soil available nitrogen and nitrate nitrogen in red jujube root zones when the salt water drip irrigation was carried out to jujubes. It is shown in the results that the distribution content of soil available nitrogen in jujube tree root zones tended to gradually decrease from top to bottom in the soil profile at different growth stages. The soil available nitrogen contents at different growth stages exceeded initial values. The mineralization degrees of salt water which influenced the available nitrogen were successively 3 g/L>4 g/L>2 g/L>CK, wherein the salt water with mineralization degree of 3g/L brought largest influences to transformation and utilization of available nitrogen in jujube tree root zones; with regard to different growth stages, the available nitrogen content was high in the soil layer with depth of 0-20 cm in the jujube root zone, and the content was small in the soil layer with depth o 30-50 cm; during drip irrigation with the mineralization degree of over 3g/L, the nitrate nitrogen content in soil layers of the jujube tree root zone exceeded the content under fresh water irrigation treatment as a whole.

Continuous Sliding Mode Control for Permanent Magnet Synchronous Motor Speed Regulation Systems Under Time-Varying Disturbances

Wang, Huiming,Li, Shihua,Yang, Jun,Zhou, XingPeng The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.4

This article explores the speed regulation problem of permanent magnet synchronous motor (PMSM) systems subjected to unknown time-varying disturbances. A continuous sliding mode control (CSMC) technique is introduced for the speed loop to enhance the robustness of PMSM systems and eliminate the chattering phenomenon caused by high-frequency switch function in the conventional control law. However, the high control gain of the CSMC law in the presence of strong disturbances leads to large steady-state speed fluctuations for PMSM systems. In many application fields, PMSM systems are affected by time-varying disturbances instead of constant disturbances. For example, electric bicycles are usually affected by changing environmental disturbances, including wind speeds, road conditions, etc. These disturbances may be in the form of constant, ramp, and parabolic disturbances. Hence, a generalized proportional integral (GPI) observer is employed to estimate these types of disturbances. Then, the disturbance estimation method and the aforementioned CSMC method are combined to establish a composite sliding mode control method called the CSMC+GPI method for the speed loop of PMSM systems. Contrary to the conventional sliding mode control technique, the proposed method completely eliminates the chattering phenomenon caused by the switching function in the conventional control law. Moreover, a small control gain for the CSMC+GPI method is chosen by feed-forwarding estimated values to the speed controller. Hence, the steady-state speed fluctuations are small. The effectiveness of the proposed control scheme is verified by simulation and experimental result.

Continuous Sliding Mode Control for Permanent Magnet Synchronous Motor Speed Regulation Systems Under Time-Varying Disturbances

Huiming Wang,Shihua Li,Jun Yang,XingPeng Zhou 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.4

This article explores the speed regulation problem of permanent magnet synchronous motor (PMSM) systems subjected to unknown time-varying disturbances. A continuous sliding mode control (CSMC) technique is introduced for the speed loop to enhance the robustness of PMSM systems and eliminate the chattering phenomenon caused by high-frequency switch function in the conventional control law. However, the high control gain of the CSMC law in the presence of strong disturbances leads to large steady-state speed fluctuations for PMSM systems. In many application fields, PMSM systems are affected by time-varying disturbances instead of constant disturbances. For example, electric bicycles are usually affected by changing environmental disturbances, including wind speeds, road conditions, etc. These disturbances may be in the form of constant, ramp, and parabolic disturbances. Hence, a generalized proportional integral (GPI) observer is employed to estimate these types of disturbances. Then, the disturbance estimation method and the aforementioned CSMC method are combined to establish a composite sliding mode control method called the CSMC+GPI method for the speed loop of PMSM systems. Contrary to the conventional sliding mode control technique, the proposed method completely eliminates the chattering phenomenon caused by the switching function in the conventional control law. Moreover, a small control gain for the CSMC+GPI method is chosen by feed-forwarding estimated values to the speed controller. Hence, the steady-state speed fluctuations are small. The effectiveness of the proposed control scheme is verified by simulation and experimental result.

Adaptive Synchronization of Time Delay Chaotic Systems with Uncertain and Unknown Parameters via Aperiodically Intermittent Control

Yuangan Wang,Xingpeng Zhang,Liping Yang,Hong Huang 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.3

Time delay and uncertainty are the two common phenomena in nonlinear systems, which seriously influence the control and synchronization of nonlinear systems. In this paper, an adaptive intermittent control strategy is proposed to realize the synchronization of time delay chaotic systems with uncertain and unknown parameters. For the uncertain and unknown parameters, some sufficient conditions for complete synchronization are derived based on the stability theory. In the part of numerical simulation, two cases of linear and non-linear delay are discussed, which both show the effectiveness of the theoretical results.

Removal of NO by carbon-based catalytic reduction bed loaded with Mn induced by dielectric barrier discharge at low temperature

Fan Gao,Xingpeng Jin,Guicheng Wang,Luying Sun,Yujie Tan,Renxi Zhang,Weixuan Zhao,Jianyuan Hou,Ruina Zhang 대한환경공학회 2023 Environmental Engineering Research Vol.28 No.1

The current paper reports on a newly developed DBD-Mn/FCRB hybrid system to explore the removal of NO<SUB>x </SUB> by reduction without adding reducing gas at low temperature (below 80℃). This technology was established with a fixed carbon-based reduction catalytic reduction bed loaded with manganese (Mn/FCRB) induced by dielectric barrier discharge (DBD). The NO conversion and N₂ selectivity in the new hybrid system reached 90.9 and 79.9%, respectively under 8% oxygen content, 1,200 J/L specific input energy (SIE), which were all higher than in the single DBD and DBD-FCRB systems, respectively. The Mn/FCRB was further characterized before and after activation by SEM, XRD and XPS. The possible reaction pathways of denitration were proposed through three processes based on the experimental results: direct denitration of active carbon atoms excited by plasma, reduction by adsorptive C(N) and C(O) complexes on the FCRB surface, and the reaction of nitrogen oxides with by-product CO. In addition, the results also showed that the new in-situ reduction denitration system had strong oxygen shock resistance and water resistance.

Rhamnolipids amendment improves soil properties and enhances microecological functions in the saline-alkali soil

Shichen Li,Hanghai Zhou,Chunlei Chen,Feng Zeng,Gang Zheng,Xingpeng Wang,Chunfang Zhang 대한환경공학회 2023 Environmental Engineering Research Vol.28 No.4

A laboratory-scale study was conducted to investigate the effect of rhamnolipids (RLs) supplement on the amelioration of saline-alkali soils. The RLs supplement improved the soil aggregates stability and promoted the formation of macro-aggregates which increased by up to 10.84% and 15.92% in alkaline soil and saline soil, respectively. In addition, RLs amendment led to a pH reduction from initial 8.87 to 7.80-7.84 in alkaline soil, and a salt rejection up to 20.72% in saline soil, remarkably alleviating the saline-alkali stress on microorganisms and plants. Meanwhile, microbial growth and activity as well as the seed germination performance were greatly improved in both types of soil. Furthermore, RLs addition greatly altered the microbial community structure and supported the proliferation of bacterial species (e.g., Pseudomonas oleovorans, Pseudomonas stutzeri, and Alcanivorax dieselolei) that favored the improvement of soil properties and nutrients circulation, thus markedly enhancing the microecological functions including carbon and nitrogen metabolisms. Further supplement of γ-PGA only exhibited promoting effect on aggregates formation and microbial growth and activity. The findings obtained in this study prove the application of RLs as a promising approach for saline-alkali soil amelioration.