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Response of Ammonia Assimilation in Cucumber Seedlings to Nitrate Stress
Xiaoyu Yang,Xiufeng Wang,Min Wei,Shoko Hikosaka,Eiji Goto 한국식물학회 2010 Journal of Plant Biology Vol.53 No.3
The influence of increased nitrate concentration—14 (control) and 140 mmol L−1 (T)—in hydroponic culture on ammonia assimilation in cucumber (Cucumis sativus L. cv. Xintaimici) seedlings was investigated. The results showed that NH3 accumulation in the roots and leaves of T seedlings increased significantly, indicating that NH3toxicity might be involved in nitrate stress. Under control conditions, GS and GOGAT activity were much higher in the leaves than in the roots, whereas GDH activity was much higher in the roots than in the leaves. Correlation analysis showed that NH3 concentration had a strong negative linear relationship with GDH activity in the roots but had a strong negative linear relationship with GS and GOGAT activity in the leaves. These results indicate that NH3 might be assimilated primarily via GDH reaction in the roots and via GS/GOGAT cycle in the leaves. Shortterm nitrate stress resulted in the increase of GS and GOGAT activity in the roots and GDH activity in the leaves of T seedlings, indicating possible shifts in ammonia assimilation from the normal GDH pathway to GS/GOGAT pathway in the roots and from the normal GS/GOGAT pathway to the GDH pathway in the leaves under nitrate stress, but with the increase of treatment time, GS, GOGAT,and GDH activity in the roots and leaves of T seedlings decreased possibly due to low water potential and NH3toxicity.
Hongbin Yang,Shuo Shao,Tongyu Zhu,Chaocheng Zhao,Shuren Liu,Bobo Zhou,Xiaoyu Hou,Yang Zhang,Wanli Kang 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.79 No.-
Low elastic polymer microsphere (L-EPM) has been proposed as a functional polymer microsphere theseyears. L-EMP has the excellent deformation ability in the porous medium due to the low storage modulus. Herein, one kind of L-EPM with storage modulus (G0) of 23.6 Pa was prepared by inverse suspensionpolymerization. The shear resistance of L-EPM was researched by using coreflooding experiment andhigh shear rate emulsifier. The conformance control behavior of L-EPM was investigated by using doubleparallel sandpackflooding experiment. The results showed that L-EPM was a kind of swollen particle gelwith three-dimensional net structure and contained amide, carboxyl, and sulfonate groups. Themechanism of water swelling property was mainly due to the formation of hydrogen bonds, hydrolysis ofhydrophilic groups and the diffusion caused by osmotic pressure difference. Compared with high elasticpolymer microspheres (H-EPM) and low elastic preformed particle gel (L-PPG), L-EPM had better shearresistance in the porous medium and the well casing perforation. In addition, the critical shear points ofL-EPM was proposed in this work. Due to the better shear resistance and deformation ability, theconformance control behavior of L-EPM showed that L-EPM was a promising conformance control agentin the heterogeneous reservoirs.
XIAOYU LI,HUAMING YANG,LIANGJIE FU,TIANCHENG LIU 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.4
Nickel oxide (NiO) nanoparticles were synthesized by calcination at 400?C to 700?C for 8 h of theprecursor obtained via mechanochemical reaction of Ni(NO 3 ) 2 ? 6 H 2 O with citric acid as a dis-persant. The nanoparticles were characterized by thermogravimetric-diferential scanningcalorimetry (TG-DSC), X-ray difraction (XRD) and transmission electron microscopy (TEM). The kinetics of diferent surfaces of the nanocrystals under nonisothermal conditions wasinvestigated. The activation energies for diferent lattice planes of NiO nanoparticles weredetermined using the Arrhenius equation, revealing their preferred orientation. The growth ofNiO obeyed the general theory that nanoparticles with the largest surface energy tend to form. XRD data reveal that the NiO nanoparticles possess preferred (111) or (200) orientations thatre°ect their complex activity. The nature of preferred growth orientation was found to benegative difusion activity among diferent lattice surfaces, which indicates that oxygen atomsdi®use from low oxygen concentration on the lattice surface to high concentration on the latticesurface.
Yang, Xu,Chen, Wenjie,He, Xiaoyu,Zeng, Xiangjun,Wang, Zhaoan The Korean Institute of Power Electronics 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.4
This paper presents a novel spring pressure contact interconnect technique for medium power integrated power electronics modules (IPEMs). The key technology of this interconnection is a spring which is made from Be-Cu alloy. By means of the string pressure contact, sufficient press-contact force and good electrical interconnection can be achieved. Another important advantage is that the spring exhibits excellent performance in enduring thermo-mechanical stress. In terms of manufacture procedure, it is also comparatively simple. A 4 kW half-bridge power inverter module is fabricated to demonstrate the performance of the proposed pressure contact technique. Electrical, thermal and mechanical test results of the packaged device are reported. The results of both the simulation and experiment have proven that a good performance can be achieved by the proposed pressure contact technique for the medium power IPEMs.
Characterizing nonlinear oscillation behavior of an MRF variable rotational stiffness device
Yang Yu,Yancheng Li,Jianchun Li,Xiaoyu Gu 국제구조공학회 2019 Smart Structures and Systems, An International Jou Vol.24 No.3
Magneto-rheological fluid (MRF) rotatory dampers are normally used for controlling the constant rotation of machines and engines. In this research, such a device is proposed to act as variable stiffness device to alleviate the rotational oscillation existing in the many engineering applications, such as motor. Under such thought, the main purpose of this work is to characterize the nonlinear torque-angular displacement/angular velocity responses of an MRF based variable stiffness device in oscillatory motion. A rotational hysteresis model, consisting of a rotatory spring, a rotatory viscous damping element and an error function-based hysteresis element, is proposed, which is capable of describing the unique dynamical characteristics of this smart device. To estimate the optimal model parameters, a modified whale optimization algorithm (MWOA) is employed on the captured experimental data of torque, angular displacement and angular velocity under various excitation conditions. In MWOA, a nonlinear algorithm parameter updating mechanism is adopted to replace the traditional linear one, enhancing the global search ability initially and the local search ability at the later stage of the algorithm evolution. Additionally, the immune operation is introduced in the whale individual selection, improving the identification accuracy of solution. Finally, the dynamic testing results are used to validate the performance of the proposed model and the effectiveness of the proposed optimization algorithm.
A NOVEL COMPACT BANDSTOP FILTER WITH IMPROVED PERFORMANCES
Xiaoyu Jang,Yang Wang,Fuxing Liu,Jong-Chul Lee 한국ITS학회 2016 한국ITS학회 학술대회 Vol.2016 No.10
In this paper, a compact bandstop filter(BSF) based on frequency-selecting coupling structure(FSCS) is presented. The proposed BSF consists of a quarter-wavelength coupled line and a quarter-wavelength open-circuited transmission stub in shunt. For the purpose of further miniaturization, a novel structure is adopted. The performance of this filter is shown in both simulations and measurements. The stopband frequency contains 2.45 GHz and 5.8 GHz, which can be widely used in Wi-Fi, GSMand many other applications. There is a good agreement between the simulation and measurement results. The size of the proposed filter is 4.6×8.79 mm2.
Xiaoyu Li,Chuhao Li,Yang Hu,Yongqi Yu,Wenjie Zeng,Haibiao Wu 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.6
The coolant temperature feedback coefficient is an important parameter of reactor core power controlsystem. To study the coolant temperature feedback coefficient influence on the core power controlsystem of small PWR, the core power control system is built with the nonlinear model and fuzzy controltheory. Then, the uncertainty quantification method of reactor core parameters is established based onthe Latin hypercube sampling method and the Bootstrap method. Finally, under the conditions ofreactivity step perturbation and coolant inlet temperature step perturbation, uncertainty analysis for twocases is carried out. The result shows that with fuzzy controller and fuzzy PID controller, the uncertaintyof the coolant temperature feedback coefficient affects the core power control system, and the maximumuncertainties of core relative power, coolant temperature deviation, fuel temperature deviation and totalreactivity are acceptable