Enhancement of Impurity, Machinability and Mechanical Properties in Te-Treated 0Cr18Ni9 Steel

Jian‑bo Xie,Tian Fan,Han Sun,Zhi‑qi Zeng,Jian‑xun Fu 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.6

To enhance the machinability and mechanical properties of 0Cr18Ni9 steel, free-machining element Te was introduced inthis work. By adding various quantities of Te to steel, several machining and tensile tests were carried out. Results show thatwith Te addition of 530 ppm, the number of inclusion sizes below 1 μm disappeared. With raising Te from 360 to 530 ppm,more MnTe–MnS inclusions of 10–40 μm were in spherical shape; above 50 μm2, the ratio of inclusion area at 530 ppmwas greatest among all, and the large-sized inclusions occupied a larger share. Te addition contributed to the surfaces ofmachining steels more smooth. The ultimate tensile strength of steel increased from 399 to 435 MPa. Te resulted in growthof sulfides and improved the machinability of steel.

Distribution of Bi–MnS Inclusions Existing in 1215MS Steels: Correlation with Thermal Physical Coefficient

Jian‑bo Xie,Bei‑bei Liu,Xiang‑yu Wu,Jian‑xun Fu 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.5

This work aims to comprehensively summarize the types and distribution of the isolated Bi particles and MnS inclusions inthe Bi-bearing steels, to study the precipitated behavior of sulfide, and to study the effect of Bi particles on grain sizes andthe volume thermal expansion coefficients of the steels. Results show that the average percentage of the isolated Bi particles,semi-encapsulation, complete encapsulation, back-bridge, tiny encapsulation, cavity bridge Bi–MnS inclusions in the Bibearingsteels was 16.89%, 20.49%, 3.44%, 16.89%, 31.63%, 10.66%, respectively. The average equivalent diameters of thegrains in the 0 ppm, 130 ppm, 240 ppm, 760 ppm, 1200 ppm and 2300 ppm Bi content steels were 20.88, 20.17, 19.54, 18.13,13.98 and 13.25 μm, respectively. The precipitated equilibrium mass concentration product of the MnS (w[Mn]·w[S]) wascalculated to be 1.07, and the solid fraction fS value was 0.61. At 950 °C, the volume thermal expansion coefficient change(ΔVE) in 760 ppm Bi content steel was minimum 4 × 10–10%, while at 461.6 °C the ΔVE was maximum, 0.09%, which meansthat Bi affected the volume thermal expansion of the steel strongest in this temperature range.

Quantitative Reduction of Basilar Invagination With Atlantoaxial Dislocation by a Posterior Approach

Jian Guan,Fengzeng Jian,Qingyu Yao,Chenghua Yuan,Can Zhang,Longbing Ma,Zhenlei Liu,Wanru Duan,Xingwen Wang,Xuefeng Bo,Zan Chen 대한척추신경외과학회 2020 Neurospine Vol.17 No.3

Objective: This study evaluated the feasibility and efficacy of quantitative reduction and fixation to treat basilar invagination (BI) with atlantoaxial dislocation (AAD). Methods: Posterior occipitocervical angle (POCA), occiput–C2 angle (Oc–C2A), clivusaxial angle (CAA), and C2–7 angle (C2–7A) were considered for quantitative reduction. Twelve patients with BI complicated with AAD received posterior interarticular release and individualized cage implantation to restore vertical dislocation. The POCA was adjusted using cantilever technology to further reduce the horizontal dislocation and adjust lower cervical vertebral angle. All patients received a radiological follow-up for ≥12 months. Improvements in spinal cord function were evaluated using Japanese Orthopedic Association (JOA) score. Results: All the patients received successful quantitative reduction for BI-AAD, and bony fusion was achieved without spinal cord injury after surgery for 12 months. The JOA score was improved significantly to 15.2 ± 0.9 twelve months after surgery (p < 0.01). Radiological follow-up revealed that individualized cage and POCA play vital roles in quantitative correction: (1) distance of the dens above McRae’s line and atlantodens interval were restored to normal level, respectively; (2) changes in Oc–C2 angle (ΔOc–C2A), C2–7 angle (ΔC2–7A), clivus-axial angle (ΔCAA), and POCA (ΔPOCA) were all caused by changes in axis tilt. Based on the changes of radiological parameter we deduced the formula for quantitative reduction by linear regression analysis: -ΔPOCA = ΔOc–C2A = -ΔC2–7A = ΔCAA. Conclusion: Quantitative posterior reduction by individualized cage and adjusting ΔPOCA is feasible for treating BI with AAD.

The Preparation and the Effects of K/Na Ratio on the Electrical Properties of 0.95(Na0.96−xKxLi0.04)(Nb0.89Sb0.07Ta0.04)O3-0.05KNbO3 Lead-free Ceramics

Jian Ma,Dingquan Xiao,Bo Wu,Jia-gang Wu,Jian-guo Zhu 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.65 No.2

0.95(Na0.96−xKxLi0.04)(Nb0.89Sb0.07Ta0.04)O3-0.05KNbO3 (abbreviated as KxNLNST-KN, x =0.32 − 0.52) lead-free piezoelectric ceramics were prepared by using the conventional solid-statesintering method, and the intentional addition of a pre-calcined KNbO3 powder was used as asintering aid that might inhibit and compensate for the volatilization of alkali metals during thesintering process. The preparation of the ceramics and the effects of K/Na ratio on the structureand the electrical properties of these ceramics were studied in detail. Compared with the relativelyhigher sintering temperature of Li-, Sb-, and Ta-modified KNN ceramics reported in the literature,the dense ceramic samples were obtained at a reduced temperature of 1060 C, and the ceramicswith x = 0.44 possessed optimal properties: d33 = 298 pC/N, kp = 48%, Pr = 21.9 μC/cm2, andEc = 11.5 kV/cm.

Neural Network Sliding Mode Control Based on On-Line Identification for Electric Vehicle with Ultracapacitor-Battery Hybrid Power

Jian-Bo Cao,Bing-Gang Cao 제어·로봇·시스템학회 2009 International Journal of Control, Automation, and Vol.7 No.3

In order to deal with three major problems of electric vehicle (EV): the short driving range, the short life of batteries, and the poor ability of start-up, a hybrid power system was designed and applied to the EV. It was composed of an ultracapacitor with high-specific power and long life, four lead-acid batteries, and a bi-directional DC/DC converter. To improve the stability and reliability of the hybrid-power EV, based on establishing the mathematical models of driving and regenerative-braking processes, a novel neural network sliding mode controller (NNSMC) was researched and designed for the EV. The controller comprises a back propagation neural network (BPNN), a radial basis function neural network (RBFNN), and a sliding mode controller (SMC). The BPNN is used to adaptively ad-just the switching gain of the SMC on-line so as to avoid the whippings. The RBFNN is used to per-form system identification and parameter prediction. The experimental results show that the NNSMC is superior to PID controller at response speed, steady-state tracking error and resisting perturbation whenever driving or braking. Additionally, the hybrid-power EV with NNSMC can improve the ability of start-up, recover more energy, lengthen the life of batteries, and increase the driving range than the EV using batteries as its single power source by about 40%, and than the hybrid-power EV with PID controller by about 4%.

An Effective Guidewire Looping Technique for the Recanalization of Occlusive Segments of Infrapopliteal Vessels

Jian-bo Wang,Jun-gong Zhao,Ming-hua Li,Yue-qi Zhu,Jue Wang,Pei-lei Zhang 대한영상의학회 2010 Korean Journal of Radiology Vol.11 No.4

Objective: To determine the efficacy, safety and primary follow-up results of a guidewire looping technique for the treatment of infrapopliteal arteries. Materials and Methods: From October 2006 to May 2008, an intraluminal angioplasty of the infrapopliteal arteries was attempted in 200 consecutive patients. Altogether, 417 infrapopliteal lesions, with lengths varying from 2 cm to 32 cm, were treated as part of this study, including 305 lesions in the anterior tibial arteries, 89 in the posterior tibial arteries, and 23 in the peroneal arteries. The ‘U’-shaped guidewire technique was attempted in 393 lesions from 361 limbs. The tip of a hydrophilic 0.035-inch guidewire was formed into a ‘U’ shape with the aid of a 4-Fr catheter and collateral branch vessel to recanalize the completely occluded long segment lesions. Results: A successful angioplasty with at least one artery recanalized directly to the malleolar or dorsal foot was achieved in 322 limbs (89%). The looping technique had a success rate of 90% (352 of 393 lesions). After the procedure, the rest pain was relieved in 58 of 69 patients, while 207 of 245 limbs (85%) showed improvement for intermittent claudication. Complete wound healing was noted in 21 of 54 patients, while 20 of 54 patients showed an improvement in the wound size or depth. A total of 38 major immediate procedure-related complications were noted, including retroperitoneal hematoma, distal emboli, and vessel rupture. Conclusion: The results of this study suggests that the guidewire looping technique is a safe and effective method for the recanalization of the occluded lesions in infrapopliteal vessels. Objective: To determine the efficacy, safety and primary follow-up results of a guidewire looping technique for the treatment of infrapopliteal arteries. Materials and Methods: From October 2006 to May 2008, an intraluminal angioplasty of the infrapopliteal arteries was attempted in 200 consecutive patients. Altogether, 417 infrapopliteal lesions, with lengths varying from 2 cm to 32 cm, were treated as part of this study, including 305 lesions in the anterior tibial arteries, 89 in the posterior tibial arteries, and 23 in the peroneal arteries. The ‘U’-shaped guidewire technique was attempted in 393 lesions from 361 limbs. The tip of a hydrophilic 0.035-inch guidewire was formed into a ‘U’ shape with the aid of a 4-Fr catheter and collateral branch vessel to recanalize the completely occluded long segment lesions. Results: A successful angioplasty with at least one artery recanalized directly to the malleolar or dorsal foot was achieved in 322 limbs (89%). The looping technique had a success rate of 90% (352 of 393 lesions). After the procedure, the rest pain was relieved in 58 of 69 patients, while 207 of 245 limbs (85%) showed improvement for intermittent claudication. Complete wound healing was noted in 21 of 54 patients, while 20 of 54 patients showed an improvement in the wound size or depth. A total of 38 major immediate procedure-related complications were noted, including retroperitoneal hematoma, distal emboli, and vessel rupture. Conclusion: The results of this study suggests that the guidewire looping technique is a safe and effective method for the recanalization of the occluded lesions in infrapopliteal vessels.

Comparison Study of the Band-gap Structure of a 1D-Photonic Crystal by Using TMM and FDTD Analyses

Jian-Bo Chen,Yan Shen,Wei-Xi Zhou,Yu-Xiang Zheng,Hai-Bin Zhao,Liang-Yao Chen 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.58 No.42

A variety of numerical methods has been developed to demonstrate the nature of photons propagating in an artificially-composed periodic structure. Differences will be generated by different kinds of numerical approaches. In this work, we carry out two types of numerical calculations, TMM (transfer matrix method) and FDTD (finite different time domain) calculations. In terms of the 1D-photonic crystal structures with two different structures, we illustrate the energy band spectra, and the results show dispersive characteristics for the optical transmission and reflection of the crystal material. Through a discussion of the mechanism, detailed comparison studies are preformed based on the different physical conditions. The results given in the work will help in better understanding the ways in which photons propagate in an artificially-composed periodic structure.

Adsorption of Nucleotides on ß-Cyclodextrin Derivative Grafted Chitosan

Jian Bo Xiao,Xiao Qing Chen,Hong Zhu Yu,Ming Xu 한국고분자학회 2006 Macromolecular Research Vol.14 No.4

A novel ß-cyclodextrin derivative (CCD-C) was synthesized with chitosan and carboxymethyl-ß-cyclodextrin. Its structure was characterized by elemental analysis, infrared spectra analysis, and X-ray diffraction analysis. The adsorption properties for guanosine 5'-monophosphate, cytidine 5'-monophosphate and uridine 5'-monophosphate were studied. Experimental results demonstrated that CCD-C had higher adsorption capability for guanosine 5'-mono phosphate, and that the adsorption capacity for guanosine 5'-monophosphate was 74.20mg/g. The adsorption capacity was greatly influenced by pH, time and temperature. The introduction of chitosan enhanced the adsorption ability and adsorption selectivity of ß-cyclodextrin for guanosine 5'-monophosphate. This novel derivative of chitosan is expected to have wide applications in the separation, concentration and analysis of nucleotides in biological samples.

Soliton Transmission Experiment Employing Normal Dispersion Fiber with Large Dispersion

Jian Jun Yu,Ke Jian Guan,Bo Jun Yang 한국통신학회 1997 OPTOELECTRONICS & COMMUNICATIONS CONFERENCE Vol.2 No.1

Optimized Design of a Facility for Measuring Sodium-24 in Blood by Using Monte Carlo Simulations

Jian-Bo Yang,Rui Li,Zhi Liu,Hong Huang 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.68 No.8

The Monte Carlo N-Particle Transport Code is adopted for numerical calculations and simulation analyses of the parameters for the designed irradiation facility for human blood (including the neutron moderator and its thickness, the neutron source’s location, and the collimator’s radius) and of the parameters for the unit for measuring human blood (such as the crystal thickness and radius of NaI) to measure the activity of 24Na in the human body exposed to neutron irradiation in nuclear accidents. Calculation results show that the most suitable parameters for the irradiation facility for human blood include 6-cm polyethylene as the neutron moderator, collimator radius of 7 mm, and a neutron source placed at the bottom of the collimator. However, the parameters for the unit to measure human blood are as follows: both the thickness and the radius of the crystal at the bottom of the NaI detector are 5 cm. The effectiveness of the design parameters was verified by using actual experiments.