Prediction method for steady-state response of local rubbing blade-rotor systems

Qian Zhao,Hongliang Yao,Qi Xu,Bang-chun Wen 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.4

Blade-rotor systems frequently encounter the problem of blade-to-case rubbing, which affects their safety and stability. Numericalsimulation can be used to predict the steady-state response of these systems. However, such simulation is frequently computationallyexpensive because of the high dimensions of the dynamic model of a blade-rotor system. To overcome this problem, a new method thatcombines the receptance-based dimension-reduction approach with the incremental harmonic balance (IHB) method is presented in thisstudy. First, a dynamic model of a blade-rotor system is developed using the finite element method, and the number of dimensions of themodel is reduced by the receptance method. Subsequently, the steady-state response is obtained by the improved IHB method to convenientlymanage the large number of super-harmonic components of the local rubbing system. Finally, the precision and efficiency of theproposed method is verified by comparing its results with those obtained by the Newmark-b method. The proposed method is found to beefficient in analyzing local rubbing blade-rotor systems with high dimensions, local nonlinearities, and rich super-harmonics.

Infuence of Diferent XLPE Cable Defects on the Initiation of Electric Trees

Fei Qi,Dai Wan,Xi OuYang,Qian Jiang,Miao Zhao,Hengyi Zhou 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.6

Defects in the insulation layer of cross-linked polyethylene (XLPE) cable are the leading cause of electrical tree. The mechanism that how the diferent insulation defects infuence on the starting of electrical tree should be explored, and it will be utilized to improve cable insulation in the production and installation. In the paper, frstly the spike-air gap defect as the main defect characteristics of cable fault has been determined by analyzing the actual cable defect type and infuence. Then, the needle-electrode short cable test system was built and the representative defect model was constructed, in order to simulate the infuence of the spike-air gap defect of diferent sizes in the outer semiconductor layer on the initial voltage of electrical tree. Thirdly, the Physical model was created to analyze the infuence of each defect parameters. The research showed that the electrical tree of XLPE cable was mainly caused by defects in the semiconductor layer. The maximum electric feld distribution can be formulized by the maximum feld strength Mason model. According to the formulation and the test results, the main parameters, including the spur curvature, the micro-pore pressure and the initial energy of generating electric tree, have a positive promotion on the initial voltage of the electrical tree and can hinder the tree developing. Therefore, utilizing the interface treatment method between the insulation layer and the semiconductor layer, the insulation heat treatment process and the flling of the inert gas are to improve the parameters and further resist electrical tree aging in the production and installation.

Experimental Study on the Preparation of MA@PS@Fe3O4 Phase Change Microcapsules to Inhibit the Development of Electric Branches in Epoxy Resin Cured Compounds

Liu Qian,Du Bin,Qi Wei,Mai Yuxiang,Zhao Yushun,Chen Nanqing 대한금속·재료학회 2022 ELECTRONIC MATERIALS LETTERS Vol.18 No.5

Development of electric branches caused by partial discharge leads to degradation in the performance of epoxy resin insulation materials, which seriously threatens the safe and stable operation of power equipment. In this study, n-tetradecanol (MA)@polystyrene microsphere (PS)@Fe3O4 core–shell phase change microcapsules were designed and prepared. Doping 0.1 wt% phase change microcapsular material into the epoxy resin cured compound inhibited the development of electric branches. SEM and EDS tests showed that the phase-change microcapsules had monodisperse spherical core–shell structures with an MA encapsulation rate of 24.73% and excellent phase-change thermal storage capacity. Electric field simulations revealed that Fe3O4 nanoparticles in the microcapsule shell enhanced the local field strength of the cured epoxy resin and induced the development of electric branches toward the interior of the microcapsule. Moreover, doping of microcapsules into the epoxy resin significantly slowed the rate of temperature rise and thus inhibited further development of electric branches in epoxy resin cured products. In comparison with the epoxy resin cured without microcapsules, it was found that the longitudinal and transverse lengths of electric branches were reduced by 56.6% and 69.1%, respectively, in the epoxy resin cured with 0.1 wt% MA@PS@Fe3O4 microcapsules, and the electric branch initiation field strength was increased from 0.57 to 0.68 kV/mm. This indicated that MA@PS@Fe3O4 microcapsules significantly improved the electrical branch resistance of epoxy resin cured products, and this provides a new approach for extensive applications of epoxy resin insulation materials and safe and stable operation of power equipment.

AP-SDN: Action Program enabled Software-Defined Networking Architecture

Zheng Zhao,Xiaoya Fan,Xin Xie,Qian Mao,Qi Zhao 한국인터넷정보학회 2023 KSII Transactions on Internet and Information Syst Vol.17 No.7

Software-Defined Networking (SDN) offers several advantages in dynamic routing, flexible programmable control and custom application-driven network management. However, the programmability of the data plane in traditional SDN is limited. A network operator cannot change the ability of the data plane and perform complex packet processing on the data plane, which limits the flexibility and extendibility of SDN. In the paper, AP-SDN (Action Program enabled Software-Defined Networking) architecture is proposed, which extends the action set of SDN data plane. In the proposed architecture, a modified Open vSwitch is utilized in the data plane allowing the execution of action programs at runtime, thus enabling complex packet processing. An example action program is also implemented which transparently encrypts traffic for terminals. At last, a prototype system of AP-SDN is developed and experiments show its effectiveness and performance.

Three P5CS genes including a novel one from Lilium regale play distinct roles in osmotic, drought and salt stress tolerance

Chi Wei,Qi Cui,Xi-Qing Zhang,Yu-Qian Zhao,Gui-Xia Jia 한국식물학회 2016 Journal of Plant Biology Vol.59 No.5

Proline accumulations in abiotically stressed plants is generally considered to benefit their stress tolerance. The Δ1-Pyrroline-5-carboxylate synthetase (P5CS) gene family, which encodes the rate-limiting enzyme in proline biosynthesis pathway, usually contains two duplicated genes in most plants. However, three P5CS genes including LrP5CS1, LrP5CS2 as well as a third one, LrP5CS3, were isolated from Lilium regale. LrP5CS3 is highly identical to LrP5CS1 in amino acid sequences, indicating they could come from a paralogous duplication. The phylogenetic tree suggested that the duplication of LrP5CS occurred independently after the divergence of Liliales and commelinoids. The expression of LrP5CS1 was strongly induced in leaves and roots both under drought and salinity, while that of LrP5CS3 was upregulated more moderately. LrP5CS2 stayed almost constitutive under stress. LrP5CS1 exhibited the highest activity after expressed in E. coli. Overexpression of LrP5CS genes conferred enhanced osmotic, drought and salt tolerance on transgenic Arabidopsis without negative effects in unstressed condition. Under salt stress, lines LrP5CS2 accumulated fewer proline than others, and lines LrP5CS1 grew better in root elongation. The roots of lines LrP5CS3 grew better than all others under unstressed condition and osmotic stress. Our study suggests that the three LrP5CS genes play distinct roles respectively in proline accumulation and abiotic stress tolerance.

Theoretical study on photoelectric properties of lead-free mixed inorganic perovskite RbGe1-xSnxI3

Xi-Zi Deng,Qian-Qi Zhao,Yu-Qing Zhao,Meng-Qiu Cai 한국물리학회 2019 Current Applied Physics Vol.19 No.3

The recent discoveries of lead-free halide perovskites have come into notice as promising photovoltaic materials due to their high solar-to-electrical efficiency conversion. However, these perovskites suffer from large effective masses, wide band gap and affected photovoltaic performance. It is well known that it is an effective means to overcome the above shortcomings by changing the metallic ion concentration and position for the inorganic perovskite. Herein, we study the geometrical, electronic, and optical properties of RbGe1-xSnxI3 with various compositions of metal atoms by performing the Density Functional Theory (DFT). Besides, we systematically investigate how the doping positions of stannum (Sn) atoms affect the electronic structure by taking mixed metal RbGe0.50Sn0.50I3 compound as an example. The results show that RbGe1-xSnxI3 exhibits the semiconducting property with the tunable direct band gaps by changing its proportions. Compared to other two doping positions in the perovskite RbGe0.50Sn0.50I3, the configuration with Sn atom at equator plane has better mobility of electron and optical absorption properties. Our works demonstrate that the modification of metal concentration and position will modulate the optoelectronic performance and photovoltaic properties of mixed metal perovskites.

Repairing Facial Soft Tissue Defects by Swelling Anesthesia after Tumor Resection with Narrow Pedicle Flaps

Huang, Chun-Hui,Qian, Han-Gen,Zhao, Xiao-Yu,Shen, Guo-Liang,Lin, Wei,Qi, Qiang Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.15

Aims: To investigate the role of swelling anesthesia in repairing facial soft tissue defects after tumor resection and temporal superficial artery frontal branch of narrow pedicle flap. Materials and Methods: From January 2008 to June 2008, 16 patients from Department of Ophthalmology with eye or eyelid tumors after eyeball removal of eye and part resection of surrounding soft tissue, undergoing postoperative swelling anesthesia with superficial temporal artery flap repair to prevent facial soft tissue defect formation and bone exposure, were recruited. Results: In all 16 patients facial soft tissue defect repair had good effects, with limited bleeding, and short operation times. Seven days after surgery, all flaps were in good repair. On postoperative follow-up after 3 months, flaps showed a similar appearance as with facial tissue. Conclusions: Swelling anesthesia for superficial temporoparietal artery frontal branch of narrow pedicle flap to repair soft tissue defect after facial tumor resection is feasible, and is linked with good analgesic effects, high postoperative survival of skin flaps, and good cosmetic effects.

Selection signature reveals genes associated with susceptibility loci affecting respiratory disease due to pleiotropic and hitchhiking effect in Chinese indigenous pigs

Xu, Zhong,Sun, Hao,Zhang, Zhe,Zhang, Cheng-Yue,Zhao, Qing-bo,Xiao, Qian,Olasege, Babatunde Shittu,Ma, Pei-Pei,Zhang, Xiang-Zhe,Wang, Qi-Shan,Pan, Yu-Chun Asian Australasian Association of Animal Productio 2020 Animal Bioscience Vol.33 No.2

Objective: Porcine respiratory disease is one of the most important health problems causing significant economic losses. To understand the genetic basis for susceptibility to swine enzootic pneumonia (EP) in pigs, we detected 102,809 single nucleotide polymorphisms in a total of 249 individuals based on genome-wide sequencing data. Methods: Genome comparison of susceptibility to swine EP in three pig breeds (Jinhua, Erhualian, and Meishan) with two western lines that are considered more resistant (Duroc and Landrace) using cross-population extended haplotype homozygosity and F-statistic (F_ST) statistical approaches identified 691 positively selected genes. Based on quantitative trait loci, gene ontology terms and literature search, we selected 14 candidate genes that have convincible biological functions associated with swine EP or human asthma. Results: Most of these genes were tested by several methods including transcription analysis and candidate genes association study. Among these genes: cytochrome P450 1A1 and catenin beta 1 (CTNNB1) are involved in fertility; transforming growth factor beta receptor 3 plays a role in meat quality traits; Wnt family member 2, CTNNB1 and transcription factor 7 take part in adipogenesis and fat deposition simultaneously; plasminogen activator, urokinase receptor (completely linked to AXL receptor tyrosine kinase, r² = 1) plays an essential role in the successful ovulation of matured oocytes in pigs; colipase like 2 (strongly linked to SAM pointed domain containing ETS transcription factor, r² = 0.848) is involved in male fertility. Conclusion: These adverse genes susceptible to swine EP may be selected while selecting for economic traits (especially reproduction traits) due to pleiotropic and hitchhiking effect of linked genes. Our study provided a completely new point of view to understand the genetic basis for susceptibility or resistance to swine EP in pigs thereby, provides insight for designing sustainable breed selection programs. Finally, the candidate genes are crucial due to their potential roles in respiratory diseases in a large number of species, including human.