http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Guodong Feng,Puyou Jia,Liqiang Zhang,Lihong Hu,Meng Zhang,Yonghong Zhou 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.6
A novel flame-retardant plasticizer based on castor oil (FRC) was synthesized, and its potential application for polyvinyl chloride (PVC) was evaluated through the study of torque during melt processing, thermogravimetric analysis (TGA), limiting oxygen index instrument, scanning electron microscope (SEM) and mechanical tests. The results suggested that the FRC has a plasticizing effect in blends with PVC. The addition of FRC resulted in reduction of processing torque, good compatibility, improvement in thermal stability and efficient flame retardant. Torque reduction was observed (33.6%), indicating the reduction of viscosity and the improvement of process. The increase (31.9%) of LOI value indicated that incorporation of FRC system had obviously improved the flame retardant property of PVC blends. The excellent flame retardant properties were obtained by forming an isolation layer on the surface of PVC blends in the process of FRC burning. FRC could improve the thermal ability of PVC blends by enhancing the decomposition temperature of PVC. The performance in all properties of PVC products could be obtained by controlling the formula blends. Therefore, castor oil-based flame retardant plasticizers would appear suitable for a wide range of application.
Influence of carbon fibers on interfacial bonding properties of copper-coated carbon fibers
Zhang Guodong,Yang Weizhuang,Ding Jianan,Liu Mengxiang,Di Chengrui,Ci Shengzong,Qiao Kun 한국탄소학회 2024 Carbon Letters Vol.34 No.3
Copper-coated carbon fibers have excellent conductivity and mechanical properties, making them a promising new light-weight functional material. One of the main challenges to their development is the poor affinity between carbon fiber and metals. This paper selects different carbon fibers for copper electroplating experiments to study the effect of carbon fiber properties on the interface bonding performance between the copper plating layer and carbon fibers. It has been found that the interfacial bonding performance between copper and carbon fiber is related to the degree of graphitization of carbon fiber. The lower the degree of graphitization of carbon fiber, the smaller the proportion of carbon atoms with sp2 hybrid structure in carbon fiber, the stronger the interfacial bonding ability between carbon fiber and copper coating. Therefore, carbon fiber with lower graphitization degree is conducive to reducing the falling off rate of copper coating and improving the quality of copper coating, and the conductivity of copper-plated carbon fibers increases with the decrease of graphitization degree of carbon fibers. The conductivity of copper-plated carbon fibers increases by more than six times when the graphitization degree of carbon fibers decreases by 23.9%. This work provides some benchmark importance for the preparation of high-quality copper-plated carbon fibers.
Guodong Zhang,Yang Xu,Peng Jin,Zhiyong Xie,Gang Sun 대한비뇨의학회 2013 Investigative and Clinical Urology Vol.54 No.12
Purpose: The aim of this research was to evaluate the efficacy of the cystoscopic extraction and external drainage techniques for unsuccessful antegrade stenting in transplanted severe ureteral obstruction. Materials and Methods: A total of 26 patients with severe transplanted ureteral obstruction in whom the cystoscopic extraction technique and/or external drainage technique was performed were retrospectively evaluated. After the severe obstruction was successfully traversed, balloon dilatation followed by double-J stent insertion was performed. Results: Of the 26 patients (male:female, 9:4; mean age, 38.1 years) who underwent failed ureteral stenting with the conventional procedure, 16 patients underwent successful stenting with the cystoscopic extraction technique, and 10 patients underwent successful stenting following external drainage. The mean serum creatinine of the 26 patients before stenting was 42.9 mg/dL (range, 32.7 to 54.1 mg/dL), which decreased to 10.3 mg/dL (range, 8.7 to 11.8 mg/dL) after stenting. The complications of the procedure were lower abdominal pain in 22 patients and gross hematuria in 9 patients. All complications were relieved with medical care within 3 to 5 days after the procedure. No major complications occurred. Conclusions: The cystoscopic extraction technique and external drainage technique are safe and useful for traversing a severe transplanted ureteral obstruction after a failed conventional procedure.
Wang Guodong,Li Yang,Zhang Chenggui,Liu Ping,Sun Jianmin 대한척추외과학회 2024 Asian Spine Journal Vol.18 No.1
Study Design: Retrospective cohort study. Purpose: This study aimed to investigate the relationship between lumbar erector muscle atrophy and global sagittal imbalance in lumbar degenerative kyphosis (LDK) and with postoperative proximal junctional kyphosis. Overview of Literature: Lumbar erector muscle atrophy has been studied in LDK. However, its role in the compensatory mechanism is still under intense discussion, and the role of erector spinae (ES) muscle is always overlooked. Methods: This study enrolled 51 patients with LDK out of 382 patients with adult degenerative spinal deformity. Baseline information was reviewed including demographic data and complications. Sagittal spinopelvic alignments and global imbalance parameters were assessed on full-length X-ray images of the spine. Muscularity and the fatty infiltration area of the ES and multifidus (MF) were measured at the L4/5 level on preoperative magnetic resonance image to evaluate the lumbar erector muscle atrophy. Stratification by sagittal vertical axis (SVA) was performed: group 1 with SVA <100 mm and group 2 with SVA >100 mm, and these groups were compared. Spearman correlation and multivariable logistic regression analyses were performed to analyze and define risk factors of postoperative proximal junctional kyphosis (PJK). Results: Group 2 had lower ES and MF muscularity than group 1. ES muscularity correlated with SVA (r=−0.510, p=0.003), lumbar lordosis (r=−0.415, p=0.018), and postoperative PJK (r=−0.508, p=0.022). MF muscularity did not correlate with the above parameters. Multivariable logistic regression analysis verified ES muscularity (odds ratio [OR], 0.001; p=0.039) and SVA (OR, 1.034; p=0.048) as the risk factors for postoperative PJK. Conclusions: ES atrophy, besides the MF, is an important predictor in distinguishing decompensated LDK from well-compensated ones. It plays an important role in compensatory mechanism, not only correlates with global sagittal imbalance but also ties to PJK after deformity corrective surgery.
High-performance Zinc-Tin-Oxide thin film transistors based on environment friendly solution process
Qian Zhang,Guodong Xia,Lubin Li,Wenwen Xia,Hong-Yu Gong,Sumei Wang 한국물리학회 2019 Current Applied Physics Vol.19 No.2
Zinc-Tin-Oxide (ZTO) thin films were fabricated using a simple and eco-friendly sol-gel method and their application in thin film transistors (TFTs) was investigated. Annealing temperature has a crucial influence on the structure and electrical properties of sol-gel ZTO thin films. The ZTO thin films annealed at 300–600 °C revealed smooth and uniform surfaces with amorphous state, in addition, a high optical transparency over 90% of the ZTO films in the visible range was obtained. The electrical performance of ZTO TFTs showed obvious dependence on annealing temperature. The ZTO TFTs annealed at 500 °C showed a high carrier mobility of 5.9 cm2 /V, high on/off current ratio (Ion/off) of 106 -107 , and threshold voltage (Vth) of 1.03 V. To demonstrate the application of sol-gel ZTO films in low-power display fields, we also fabricated ZTO TFTs with a solution-processed high-permittivity (high-k) ZrTiOx dielectric layer. The ZTO/ZrTiOx TFTs showed high mobility of 17.9 cm2 /V and Ion/off of 105 -106 at a low operation voltage of 3 V, indicating that Indium-free ZTO thin films would be potential candidates for low cost, high performance oxide TFT devices.
Investigating the effects of a range shifter on skin dose in proton therapy
Wang Ming,Zhang Lei,Zheng Jinxing,Li Guodong,Dai Wei,Dong Lang 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.1
Proton treatment may deliver a larger dose to a patient’s skin than traditional photon therapy, especially when a range shifter (RS) is inserted in the beam path. This study investigated the effects of an RS on skin dose while considering RS with different thicknesses, airgaps and materials. First, the physical model of the scanning nozzle with RS was established in the TOol for PArticle Simulation (TOPAS) code, and the effects of the RS on the skin dose were studied. Second, the variations in the skin dose and isocenter beam size were examined by reducing the air gap. Finally, the effects of different RS materials, such as polymethylmethacrylate (PMMA), Lexan, polyethylene and polystyrene, on the skin dose were analysed. The results demonstrated that the current RS design had a negligible effect on the skin dose, whereas the RS significantly impacted the isocenter beam size. The skin dose was increased considerably when the RS was placed close to the phantom. Moreover, the magnitude of the increase was related to the thickness of the inserted RS. Meanwhile, the results also revealed that the secondary proton primarily contributed to the increased skin dose.
VEHICLE YAW STABILITY CONTROL AT THE HANDLING LIMITS BASED ON MODEL PREDICTIVE CONTROL
Shaosong Li,Guodong Wang,Bangcheng Zhang,Zhixin Yu,Gaojian Cui 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.2
This study proposes a double linear model predictive control (DLMPC) structure to improve the tyre force utilization of active front steering (AFS) vehicle at the handing limits. The DLMPC structure consists of a linear model predictive control (LMPC) and a linear time-varying model predictive control (LTV-MPC). During normal driving conditions, the AFS adopts LMPC to control the vehicle. When vehicle running at the handing limits, the tyre force is near saturation, LTV-MPC is activated to prevent tyre force from entering unstable region. The proposed DLMPC controller can reflect the nonlinear dynamic characteristic of tyres by the expression design of tyre force. Double lane change and sine with dwell maneuver tests are provided to demonstrate the effectiveness and feasibility of the DLMPC controller. Results corroborate that the proposed DLMPC controller can fully exploit the potential of AFS and maintain the yaw stability of the vehicle at the handling limits.