Preparation and characterization of flaky FeSiAl composite magnetic powder core coated with MnZn ferrite

Zhen Wang,Xiansong Liu,Xucai Kan,Ruiwei Zhu,Wei Yang,Qiuyue Wu,Shengqiang Zhou 한국물리학회 2019 Current Applied Physics Vol.19 No.8

The flattening of FeSiAl soft magnetic powder was achieved by ball milling process, and MnZn/FeSiAl composite magnetic powder core was prepared by press molding. The effect of different coating amount of MnZn ferrite on the soft magnetic properties of FeSiAl was studied. At the same time, the optimal stress-relieving annealing temperature of the composite magnetic powder core is revealed. The results showed that the addition of MnZn ferrite affected the magnetic properties such as saturation magnetization (Ms), initial permeability (μi) and power loss (Pcm) of FeSiAl soft magnetic. With the increase of MnZn ferrite addition content, the saturation magnetization of composites decreased gradually, and the magnetic permeability increased first and then decreased, and the loss decreased first and then increased. When the addition content of MnZn ferrite was 5%, the permeability reached the maximum, which was 28.1% higher than that of the pure FeSiAl magnetic powder core under the same conditions. At the same time, the loss was the lowest, which was 13.3% lower than the pure FeSiAl powder core under the same conditions. When the annealing temperature is around 650 °C, the magnetic powder core has the largest magnetic permeability and the lowest loss.

Preparation and characterization of hexaferrites Ba0.40Sr0.60-xNdxFe12.00-xZnxO19 by the solid-state reaction route

Yujie Yang,Xiansong Liu,Shuangjiu Feng,Xucai Kan,Qingrong Lv,Feng Hu,Jiangli Ni,Chaocheng Liu,Wei Wang 한양대학교 세라믹연구소 2020 Journal of Ceramic Processing Research Vol.21 No.4

The microstructural, spectral, magnetic and electric properties of hexaferrites Ba0.40Sr0.60-xNdxFe12.00-xZnxO19 (0.00 ≤ x ≤ 0.30)synthesized by the solid-state reaction route have been studied. XRD results confirmed that the hexaferrites with Nd-Zncontent (x) of 0.00 ≤ x ≤ 0.24 were single M-type phase, and the hexaferrite with x = 0.30 exhibited the M-type phase andimpurity phase. The remanence (Br) increased with x from 0.00 to 0.06, and then decreased when x ≥ 0.06. The intrinsiccoercivity (Hcj) and magnetic induction coercivity (Hcb) decreased with x from 0.00 to 0.30. Br indicated a linear decreasingbehavior with increasing temperature from 20 oC to 140 oC. Hcj raised linearly with increasing temperature from 20 oC to 140oC. The value of aBr basically remained constant with Nd-Zn content (x). The value of aHcj increased with x from 0.00 to 0.12,and began to decrease when x ≥ 0.12. The electrical resitivity (ρ) presented a decreasing trend with x from 0.00 to 0.30.

Impacts of praseodymium substitution on structural, spectral, magnetic and electrical properties of strontium W-type hexaferrites

Yujie Yang,Xiansong Liu,Shuangjiu Feng,Qingrong Lv,Xucai Kan,Ruiwei Zhu 한양대학교 세라믹연구소 2020 Journal of Ceramic Processing Research Vol.21 No.3

Praseodymium substituted strontium W-type hexaferrites Sr1-xPrxZn0.8Co1.2Fe16O27 (0.00 ≤ x ≤ 0.40) were prepared via theconventional ceramic technique. XRD analysis of W-type hexaferrites with Pr content (x) of 0.00 ≤ x ≤ 0.24 shows the single Wtypehexaferrite phase. However, for the W-type hexaferrites with Pr content (x) ≥ 0.32, the impurity phase (α-Fe2O3) is detected. FE-SEM images show that the grains are platelet-like shapes. The saturation magnetization (Ms), remanent magnetization (Mr)and magneton number (nB) first increase with Pr content (x) from 0.00 to 0.16, and then decrease when Pr content (x) ≥ 0.16. The Mr/Ms ratio, magnetic anisotropy field (Ha), coercivity (Hc) and maximum energy product [(BH)max] increase with Pr content(x) from 0.00 to 0.40. While the first anisotropy constant (K1) increases with Pr content (x) from 0.00 to 0.16, and then decreaseswhen Pr content (x) ≥ 0.16. The DC electrical resistivity (ρ) decreases with Pr content (x) from 0.00 to 0.40.

Intrinsic magnetic properties and microstructures of Bi-substituted M-type SrBaLa hexaferrite powders

Yujie Yang,Fanhou Wang,Xiansong Liu,Juxiang Shao 한양대학교 세라믹연구소 2016 Journal of Ceramic Processing Research Vol.17 No.12

In this study, M-type hexagonal Sr0.4Ba0.3La0.3Fe12-xBixO19 (0 ≤ x ≤ 0.4) magnetic powders were synthesized by the solid statereaction method. The phase composition and magnetic properties of the magnetic powders were characterized by an X-raydiffractometer (XRD) and a vibrating sample magnetometer (VSM), respectively. The results of XRD show that all samplesexhibit a well-defined M-type hexaferrite phase when Bi content (x) ≤ 0.2, while for the magnetic powder with x ≥ 0.3, the XRDpatterns show the M-type strontium hexaferrite structure and two peaks of BiFeO3 as a second phase are observed. Thesaturation magnetization (Ms) and remanent magnetization (Mr) first increase with Bi content (x) from 0 to 0.1, and thendecrease when Bi content (x) ≥ 0.1. The coercivity (Hc) decreases quickly with Bi content (x) from 0 to 0.1, then begins toincrease with Bi content (x) from 0.1 to 0.3, and when x > 0.3 the coercivity (Hc) decreases significantly.

Parameters Tuning via Simplex-Search based Model-Free Optimization for the Steam Generator Level Control

Guan Jiansheng,Kong Xiansong 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.4

Control performance is critical to a control system. To improve the performance of the steam generator level control system, the control system parameters need to be optimized. Traditional parameters tuning methods, such as trial and error and Design of Experiments etc., are usually experience-based, cumbersome and time-consuming. To address the above inefficiencies, in this paper, the simplex-search based Model-Free Optimization (MFO) has been proposed to search for the optimal control system parameters. The optimized parameters will be gained to maximize the system’s control performance. Rather than traditional controller parameter tuning method, this method optimizes the control system by directly using measurements of control performance. An example of the PID parameters tuning for the steam generator level control was illustrated. The efficiency and the effectiveness of the Simplex-search based Model-Free Optimization – based control parameters tuning methodology has been verified through simulation experiments.

Decreasing in pressure interval of near-miscible flooding by adding intermediate hydrocarbon components

Hao Chen,He Tang,Xiansong Zhang,Bowen Li,Baozhen Li,Xiong Shen 한국자원공학회 2018 Geosystem engineering Vol.21 No.3

Oil quality and gas sources are two main limitations for the promotion of CO2 miscible flooding in China. However, near-miscible flooding was proposed recently which can obtain comparable recovery based on both experiments and field tests. The discovery of gas reservoir, which contains high content (24–90 mol%) of CO2 in QHD offshore oilfield, provides big potential for the implementation of CO2 flooding in China. In this paper, based on the slim tube test and slim tube simulation with denser test points, specific regions of near-miscible flooding for different CO2 contents were determined by the relation curves of displacement efficiency, IFT, and pressure. For the targeted well QHD 29-2E-5, the lower limit of CO2 content for achieving near-miscible flooding is 64%. To enlarge the scope and potential of near-miscible flooding, the feasibility of adding intermediate components (C2–C6) in the injection gas to decrease the pressure interval of near-miscible flooding was investigated. Results showed that for each 10% decrease in CO2 content, 2.5% of the intermediate components (C2–C6) of the production gas are needed to add for achieving near-miscible flooding in the well QHD 29-2E-5.

Polysaccharides from the Fleshy Fruits of Camellia oleifera Attenuate the Kidney Injury in High-Fat Diet/Streptozotocin-Induced Diabetic Mice

Jialin Li,Fuhua Xie,Xiuzhi Zhu,Haibo Hu,Xiansong Fang,Zhiwei Huang,Zhiping Liu,Suzhen Wu 한국식품영양과학회 2020 Journal of medicinal food Vol.23 No.12

The fleshy fruits of Camellia oleifera Abel are the immature fruits of C. oleifera, which are infected by Exobasidium vexans Massee and then turn to be intumescent and hollowed. They contain rich trace elements and vitamin C and are eaten directly as wild fruits in the Chinese countryside. Recent studies report that C. oleifera has anti-inflammatory and antioxidative effects. The current study, for the first time, evaluates the renal protective capacity of polysaccharides from the fleshy fruits of C. oleifera (CFFP) in streptozotocin-induced diabetic mice fed high-fat diets. The diabetic mice were orally administered CFFP for 3 months to evaluate the renoprotective function of CFFP. Our results indicated that 250 mg/kg CFFP significantly alleviated diabetes-induced renal injury by decreasing serum creatine, blood urea nitrogen levels, the kidney/body weight ratio, expression of fibronectin and collagen, as well as the secretion of tumor necrosis factor-α and interleukin-6. Additionally, 250 mg/kg CFFP could significantly ameliorate renal oxidative stress through increasing glutathione levels and lowering malondialdehyde contents. We confirmed that CFFP could exert antioxidative, anti-inflammatory, and antifibrosis activities. CFFP might be a potential therapeutic agent, and the fleshy fruits of C. oleifera might be a diet therapy for diabetic patients in the future.