Decoupled SVPWM for Five-Phase Permanent Magnet Machines with Trapezoidal Back-EMF

Zhipeng Lin,Guohai Liu,Wenxiang Zhao,Qian Chen 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.5

This paper presents a novel space vector pulse-width modulation (SVPWM) to synthesize an arbitrary non-sinusoidal phase voltage. The key of the proposed method is that the switching vectors used to comprise the reference vectors in the α₁-β₁ frame and the α₃-β₃ frame are decoupled. In the α₁-β₁ frame, the reference vector is comprised by near two large vectors. The corresponding vector comprised by the two vectors in the α₃-β₃ frame is considered as a disturbance, which is restrained by close-loop control. In the α₃-β₃ frame, there are two methods to comprise the reference vector. Method I is a near two middle vectors method. Method II uses near four vectors (two middle and two little vectors). The proposed SVPWM using decoupled switching vectors can guarantee a maximum modulation index in the α₁-β₁ frame. The effectiveness of the proposed method is verified by simulated and experimental results under various operation conditions.

Efficiently targeted therapy of glioblastoma xenograft via multifunctional biomimetic nanodrugs

Zhipeng Yao,Xiaochun Jiang,Hong Yao,Yafeng Wu,Fan Zhang,Cheng Wang,Chenxue Qi,Chenhui Zhao,Zeyu Wu,Min Qi,Jia Zhang,Xiaoxiang Cao,Zhichun Wang,Fei Wu,Chengyun Yao,Songqin Liu,Shizhang Ling,Hongping Xi 한국생체재료학회 2022 생체재료학회지 Vol.26 No.4

Background: Glioblastoma multiforme (GBM) is a fatal malignant primary brain tumor in adults. The therapeutic efficacy of chemotherapeutic drugs is limited due to the blood-brain barrier (BBB), poor drug targeting, and short biological half-lives. Multifunctional biomimetic nanodrugs have great potential to overcome these limitations of chemotherapeutic drugs. Methods: We synthesized and characterized a biomimetic nanodrug CMS/PEG-DOX-M. The CMS/PEG-DOX-M effectively and rapidly released DOX in U87 MG cells. Cell proliferation and apoptosis assays were examined by the MTT and TUNEL assays. The penetration of nanodrugs through the BBB and anti-tumor efficacy were investigated in the orthotopic glioblastoma xenograft models. Results: We showed that CMS/PEG-DOX-M inhibited cell proliferation of U87 MG cells and effectively induced cell apoptosis of U87 MG cells. Intracranial antitumor experiments showed that free DOX hardly penetrated the BBB, but CMS/PEG-DOX-M effectively reached the orthotopic ntracranial tumor through the BBB and significantly inhibited tumor growth. Immunofluorescence staining of orthotopic tumor tissue sections confirmed that nanodrugs promoted apoptosis of tumor cells. This study developed a multimodal nanodrug treatment system with the enhanced abilities of tumor-targeting, BBB penetration, and cancer-specific accumulation of chemotherapeutic drugs by combining chemotherapy and photothermal therapy. It can be used as a flexible and effective GBM treatment system and it may also be used for the treatment of other central nervous systems (CNS) tumors and extracranial tumors.

ZigBee Netwrok Tree Routing Algorithm based on Energy Balance

Zhipeng Song 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.4

ZigBee is a relatively recent rise of short-range wireless communication standard, due to the energy resources ZigBee nodes in the network, computing power and bandwidth are very limited, which determines the ZigBee network protocol stack layers are designed to be energy effectiveness led to the design elements. The primary design goal is to establish a network layer path of energy efficiency, reliable data forwarding mechanism of formation and prolong achieve network lifecycle. Aiming at non-optimal and some nodes may be depleted prematurely because the business is too large battery energy issues ZigBee network routing tree routing algorithm, an improved routing algorithm for ZigBee network tree. Achieve network load balancing, saving overall energy consumption of the network, and maximize the lifetime of the network. Finally, the simulation of energy balance ZigBee tree routing algorithm implementation and simulation results.

Fabrication of Si3N4/SiC nanocomposites by spark plasma sintering of amorphous SiCN powders derived from a polymeric precursor

Zhipeng Xie,Weiyou Yang,Zhenkun Fan,Huatao Wang,Hezhuo Miao,Linan An 한양대학교 세라믹연구소 2006 Journal of Ceramic Processing Research Vol.7 No.4

Si3N4/SiC nanocomposites were fabricated by spark plasma sintering (SPS) of amorphous SiCN ceramic powders derived from a polymeric precursor with 3 wt% yttria as an additive. It was found that the SPS parameters, such as sintering temperature, dwell time, pressure and heating rate, remarkably affected the density and grain size of the nanocomposites obtained. This provided a new method to fabricate Si3N4/SiC nanocomposites without applying the high pressure and high sintering temperature used by the conventional process. Si3N4/SiC nanocomposites were fabricated by spark plasma sintering (SPS) of amorphous SiCN ceramic powders derived from a polymeric precursor with 3 wt% yttria as an additive. It was found that the SPS parameters, such as sintering temperature, dwell time, pressure and heating rate, remarkably affected the density and grain size of the nanocomposites obtained. This provided a new method to fabricate Si3N4/SiC nanocomposites without applying the high pressure and high sintering temperature used by the conventional process.

木蘭 이미지의 발전과 변화

ZHIPENG LI,변혁 부산대학교 영화연구소 2019 아시아영화연구 Vol.12 No.3

천 년이 넘는 발전 과정에서 목란(木蘭)이 아버지를 대신해 전쟁터에 나간 이야기는 민요, 시가, 소설, 희곡, 희극, 영화, 드라마, 컴퓨터게임 등 다양한 장르를 변형되어 왔다. 그 내용 역시 초창기의 수백 글자에서부터 백만 자가 넘게 변화하였으며, 목란의 이미지는 끊임없이 변모했고, 이야기 속 등장인물도 점차 늘어났으며 줄거리도 더욱 풍부해져 방대한 이야기가 되었다. 각기 다른 시대에서 묘사되는 목란의 이미지는 해당 시대의 특징과 가치관을 보여준다. 그리고 목란 이야기에서 가장 사람들을 매료시키는 부분은 바로 목란이라는 캐릭터가 효심, 영웅적인 면모, 여성으로서의 정체성 측면에서 가지는 가치이다. 목란의 이미지 변화는 과거 전통적인 효녀의 표본으로부터, 가정과 나라를 위해 효심과 충성심을 다하는 표본으로, 나아가 아버지를 사랑하고 자아의 자립을 실현하는 표본으로까지 발전하였다. 현대 중국의 계몽운동과 여성해방운동이라는 배경 하에서 목란 이야기 속의 현대적인 여성의식은 더욱 확산되었다. 변화하는 목란의 이야기와 목란의 이미지가 지니는 정신적 가치를 정리하는 과정을 통해, 목란의 이야기가 다른 시대와 문화적 배경마다 다르게 나타난다는 점에 착안해 이와 같은 변화과정에서 정신적 가치가 실현되고 있음을 알 수 있다. 목란의 이야기가 갖는 전기성(傳奇性)은 중국 여성 영웅담의 서사 패턴 형성과정에서 보여지는 중요 신화소로 평가될 수 있다.

Investigation on fixture design and precision stability of new-type double collect chuck for machining of long ladder shaft gear

Zhipeng Liang,Chunju Zhao,Huawei Zhou,Yihong Zhou 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.1

To solve the problems of poor positioning accuracy and non-automatic processing seen in the machining of long ladder shaft gears, a fixture structure scheme with a new type of double collect chuck (DCC) is proposed. The design rationality, clamping stability, and repeat clamping positioning accuracy of the proposed DCC were analyzed and investigated based on theory calculation, simulation analysis, and engineering application tests. First, the clamping performance of DCC was investigated through theory calculation and simulation analysis. The test results showed that the structure of DCC maintained effective clamping and the repeat clamping positioning accuracy was steadily controlled within 0.008 mm. Meanwhile, efficiently automated machining of long ladder shaft gear was realized based on extended design and engineering application of automatic up and down mechanism when the structure of DCC was applied. Furthermore, the machining accuracy of the gear was steadily controlled within DIN8 (DIN5480-2 standard). Additionally, based on extended design and engineering tests, the automatic up and down machining improves production efficiency and machining accuracy. Thus, the novel fixture structure scheme provides a new approach for automatic up and down machining of long ladder shaft gear.

Acupuncture for Pain Management in Evidence-based Medicine

Zhipeng Ning,Lixing Lao 사단법인약침학회 2015 Journal of Acupuncture & Meridian Studies Vol.8 No.5

Pain is an enormous and prevalent problem that troubles people of all ages worldwide. The effectiveness of acupuncture for pain management has been strongly verified by large randomized controlled trials (RCTs) and meta-analyses. Increasing numbers of patients with pain have accepted acupuncture treatment worldwide. However, some challenges exist in establishing evidence for the efficacy of acupuncture. A more applicable and innovative research methodology that can reflect the effect of acupuncture in the settings of daily clinical practice needs to be developed.

Methanol dehydrogenation to methyl formate catalyzed by SiO2-, hydroxyapatite-, and MgO-supported copper catalysts and reaction kinetics

Zhipeng Lu,Hengbo Yin,Dezhi Gao,Aili Wang,Shuxin Liu 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.31 No.-

Catalytic dehydrogenation of methanol to methyl formate over SiO2-, hydroxyapatite (HAP)-, and MgOsupportedcopper catalysts was investigated. Metallic copper (Cu0) was the active site for the methanoldehydrogenation to methyl formate. Cu/SiO2 catalyst with low basicity and weak-strength basic siteeffectively catalyzed the methanol dehydrogenation to methyl formate. Cu/HAP and Cu/MgO catalystswith high basicities and strong-strength basic sites caused the degradation of the resultant methylformate to CO and H2. Over Cu(5)/SiO2 catalyst, the reaction activation energies for methanoldehydrogenation to methyl formate and methyl formate degradation to CO and H2 were 58.3 and91.1 kJ mol 1, respectively.

A helix slope deviation compensation model for milling small modulus copper electrode gears

Zhipeng Feng,Zhao-Yao Shi,Shoujin Lin,Aijun Tong,Peng Wang,Guoqing Wu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.7

When a milling tool is used to mill small modulus copper electrode gears (SMCEG), the deformation is inevitable, thus leading to the helix slope deviation (HSD) of copper electrode gears (CEG). To compensate the influence of milling tool deflection (MTD) on the HSD, a universal HSD compensation model was established for different sizes of milling tools. First, using the principle of orthogonal experiment, a linear regression model of milling parameters and milling tool radius is established. Secondly, the average value of the HSD obtained by the gear measuring instrument is converted into the maximum of MTD according to the principle of helix line formation. The maximum deflections of the milling tools are used as the response value of the regression analysis to fit the maximum deflection curve of the milling tool. Through the reverse adjustment of the rotation angle of the rotating motor, the HSD compensation is realized. Finally, the model was verified by the milling tests. The results showed that the helix deviation reached the requirements of level 4 to 5 in GB/T 38192-2019, and proved the correctness of the established MTD model. The model is significant for milling SMCEG.

Hydrogenation of ethyl acetate to ethanol over Cu/ZnO/MOx (MOx = SiO2, Al2O3, and ZrO2) catalysts

Zhipeng Lu,Hengbo Yin,Aili Wang,Jing Hu,Wuping Xue,Haixu Yin,Shuxin Liu 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.37 No.-

The Cu/ZnO/SiO2, Cu/ZnO/Al2O3, and Cu/ZnO/ZrO2 catalysts prepared by the co-precipitation methodwere used for the catalytic hydrogenation of ethyl acetate to ethanol. The addition of ZnO in the Cu/ZnO/MOx catalysts improved their catalytic activities for the hydrogenation reaction. Small-sized coppercrystallite and high surface acidity favored the catalytic hydrogenation of ethyl acetate to ethanol. TheCu/ZnO/Al2O3 catalyst gave the ethanol selectivity of ca. 95% at the ethyl acetate conversion of ca. 80%when the reaction temperature was 280 8C. The reaction activation energy over Cu/ZnO/Al2O3 catalystwas 115 kJ mol 1, lower than those over the Cu/ZnO/SiO2 and Cu/ZnO/ZrO2 catalysts.