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      • Design and Operational Performance of a Full Scale MWWTP with EHYBFAS Process

        Wang Baozhen,Jin Wenbiao,Wang Shume,Cao Xiangdong,MA Zhiguang 대전대학교 환경문제연구소 2007 환경문제연구소 논문집 Vol.11 No.-

        To improve water quality of Buji Stream and Shenzhen River, the Bujihe Wastewater Treatment Plant has been reconstructed from the original coagulkation-flocculation sedimentation system into the enhanced hybrid submerged biofilm-activated sludge (EHYBFAS)system developed by the authors. The main design parameters of the EHYBFAS system, process characteristics, operational performance, techno-economic index, and experience in design, construction and operation are described,which set up an example of the municipal wastewater treatment plants using the novel process of EHYBFAS, which has lots of advantages, such as stable and high operational performance with the final effluent quality well meeting 1A-1B standard of GB 18918-2002( Chinese national standard for pollutants of effluent from the MWWTPs), much less footprint of 1ha/(100×103m3/d)) vs 4-5ha/(100×103m3/d), much lower capital and operation costs of 700-800 Yuan(RMB)/(m3/d) and 0.5 Yuan(RMB)/m3 vs 1200-1500 Yuan/(m3/d)and 1.0-1.2 Yuan/m3 and much less sludge production of 0.3g dry solid/g removed BOD5 vs 0.7 g dry solid/removed BOD5 respectively for the MWWTP with AS process.

      • KCI등재

        Trajectory sensitivity analysis of first order and second order on position control system of highly integrated valve-controlled cylinder

        Xiangdong Kong,Kaixian Ba,Bin Yu,Yuan Cao,Liujie Wu,Lingxiao Quan 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.10

        A Highly-integrated valve-controlled cylinder (HIVC) that has the advantage of large power weight ratio and fast response is widelyapplied in many fields. To ensure high performance of HIVC, control strategy selection and structure parameters optimization are essential;thus, performance-influenced main parameters and secondary parameters should be well-grasped to target control compensation andstructure optimization. Trajectory sensitivity analysis (TSA), a branch of sensitivity analysis, can be adapted to research on the effects ofcontrol and structure parameter variation on system performance; the analysis conclusions can be used to improve system performanceand the analysis has been applied in many applications in various fields. In this paper, based on the mathematical model of the First-ordertrajectory sensitivity analysis (FOTSA), the mathematical model of Second trajectory sensitivity analysis (SOTSA) is further derived; thegeneral expression of the second-order trajectory sensitivity equations and the special expression that is applicable to each system parametersensitivity analysis of HIVC are built respectively. Furthermore, based on the position control system of the nonlinear mathematicalmodel of HIVC involved with servo valve dynamic characteristics, flow-pressure nonlinearity, initial piston position of servocylinder, and friction nonlinearity, the coefficient items and the free items matrices of the special expression are calculated. Moreover, theFirst-order trajectory sensitivity function (FOTSF) and the Second trajectory sensitivity function (SOTSF) of the 17 main parameters inHIVC are computed on the MATLAB/Simulink platform under nine typical working conditions of the displacement step response. Then,the dynamic change rules and the differences and similarities of each parameter sensitivity analysis results are obtained through FOTSAand SOTSA under different working conditions with different parameter variations; each parameter sensitivity variation histogram basedon the two kinds of sensitivity indexes, including the maximum value of the percentage absolute value and the absolute value summationwithin the sampling time, are given. Furthermore, differences and similarities of each parameter sensitivity index change rule and valueare quantitatively analyzed. Finally, the sensitivity index change rules and values of the four parameters in the position control system ofHIVC, including system supply oil pressure, proportion gain, initial piston position of servo cylinder, and load are experimentally verified. All above studies indicate that each parameter SOTSA result of HIVC vary under different working conditions. When parametervariation is significant, the differences in certain parameter sensitivity analysis between FOSTA and SOTSA are relatively significant;and SOTSA results are more similar to the test results, which illustrates that SOTSA results are more accurate.

      • KCI등재

        Design, Simulation and Experiment for a Vortex-Induced Vibration Energy Harvester for Low-Velocity Water Flow

        Dongxing Cao,Xiangdong Ding,Xiangying Guo,Minghui Yao 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.8 No.4

        Piezoelectric vibration energy harvesting has attracted considerable attention because of its prospects in self-powered electronic applications. There are a many low-velocity waters in nature, such as rivers, seas and oceans, which contain abundant hydrokinetic energy. In this paper, an optimal geometric piezoelectric beam combining magnetic excitation is identified and applied to a vortex-induced vibration energy harvester (ViVEH) for low velocity water flow, which is composed of a continuous variable-width piezoelectric beam carrying a cylindrical bluff body. The finite element simulation and experiment are first carried out to study the harvesting characteristics of the designed variable-width beam ViVEH without considering the magnetic excitation. The influence of the width-ratio and flow velocity on the harvesting voltage is studied in detail. The optimal structure, a ViVEH equipped with triangular piezoelectric beam, is then obtained by the superior energy harvesting performance for low velocity water flow. From the experimental results, at a flow velocity of 0.6 m/s, the highest root mean square (RMS) voltage and RMS voltage per unit area are 19.9 V and 0.07 V/mm 2 , respectively. Furthermore, magnetic excitation is introduced to improve the scavenging performance of the optimal triangular beam ViVEH, different polarity arrangements are compared, and the optimal case, the arrangement of horizontal repulsion and vertical attraction (HR-VA), is obtained. This case can scavenge the highest power of 173 μW at a flow velocity of 0.5 m/s, which is increased by 127% compared to a conventional constant-width beam ViVEH with no magnetic excitation.

      • KCI등재

        Improved Flow-Induced Vibration Energy Harvester by Using Magnetic Force: An Experimental Study

        Dongxing Cao,Xiangdong Ding,Xiangying Guo,Minghui Yao 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.8 No.3

        Vibration energy harvesting has attracted considerable attention because of its application prospects for charging or powering micro-electro-mechanical system. Abundant hydrokinetic energy of water at low velocity is contained in the fluid environment, such as rivers and oceans, which are widely existing in nature. In this paper, a flow-induced piezoelectric vibration energy harvester (PVEH) with magnetic force enhancement, which is integrated by piezoelectric beam, circular cylinder bluff body and magnets, is proposed and experimental investigated. It could transfer the hydrokinetic energy, both the vortex-induced vibration and magnetic force excitation underwater, into electricity. First, the frequency sweep experiment of the piezoelectric cantilever beam is carried out to determine the resonance frequency where the effect of magnetic force on the vibration characteristic is obtained. Furthermore, the flow-induced vibration experiment platform is setup and the energy harvesting performance of the PVEH is investigated in detail. The effects of the magnet property, flow velocity and the magnetic poles distance on the vibration frequency and the acquisition voltage are demonstrated and discussed. The results show that it could improve the harvesting performance by introducing magnetic force. It has advantages in higher output voltage for the flow-induced PVEH, especially in low velocity water flow, when the flow velocity is 0.35 m/s, the PVEH under attractive magnetic force with magnetic distance of 20 mm scavenges the higher acquisition voltage of 5.2 V, which is increased by 225% than the PVEH with non-magnetic. The results can be applied to guide further fabrication process and optimized design of the proposed flow-induced PVEH underwater with low flow velocity.

      • KCI등재

        Prevalence of Allergic Rhinitis Among Adults in Urban and Rural Areas of China: A Population-Based Cross-Sectional Survey

        Ming Zheng,Xiangdong Wang,Mingyu Bo,Kuiji Wang,Yan Zhao,Fei He,Feifei Cao,Luo Zhang,Claus Bachert 대한천식알레르기학회 2015 Allergy, Asthma & Immunology Research Vol.7 No.2

        Purpose: The aim of the present study was to compare the prevalence of self-reported and confirmable allergic rhinitis (AR) with positive skin pricktest (SPT) results among adults living in urban and rural areas of China. Methods: Adults from a community in Beijing and a village in Baoding wereselected as representative urban and rural dwellers, respectively. All eligible residents were enrolled from the population register and received aface-to-face interview using modified validated questionnaires. Equal sets of randomly selected self-reporting AR-positive and AR-negative participantswho responded to the questionnaires were also investigated using skin prick tests. Results: A total of 803 participants in the rural area and atotal of 1,499 participants in the urban area completed the questionnaires, with response rates being 75.9% and 81.5% respectively. The prevalenceof self-reported AR of the rural area (19.1%) was significantly higher than that of the urban area (13.5%). The elementary school of educational levelincreased the risk of having AR (adjusted OR=2.198, 95% CI=1.072-2.236) .The positive SPT rates among subjects with self-reported AR in therural and urban areas were 32.5% and 53.3%, respectively; the confirmable AR prevalence of 6.2% and 7.2% among the rural and urban adults, respectively. Conclusions: The prevalence of confirmable AR is similar between rural and urban areas in China, although there is a higher prevalenceof self-reported AR in the former. Purpose: The aim of the present study was to compare the prevalence of self-reported and confirmable allergic rhinitis (AR) with positive skin prick test (SPT) results among adults living in urban and rural areas of China. Methods: Adults from a community in Beijing and a village in Baoding were selected as representative urban and rural dwellers, respectively. All eligible residents were enrolled from the population register and received a face-to-face interview using modified validated questionnaires. Equal sets of randomly selected self-reporting AR-positive and AR-negative participants who responded to the questionnaires were also investigated using skin prick tests. Results: A total of 803 participants in the rural area and a total of 1,499 participants in the urban area completed the questionnaires, with response rates being 75.9% and 81.5% respectively. The prevalence of self-reported AR of the rural area (19.1%) was significantly higher than that of the urban area (13.5%). The elementary school of educational level increased the risk of having AR (adjusted OR=2.198, 95% CI=1.072-2.236) .The positive SPT rates among subjects with self-reported AR in the rural and urban areas were 32.5% and 53.3%, respectively; the confirmable AR prevalence of 6.2% and 7.2% among the rural and urban adults, respectively. Conclusions: The prevalence of confirmable AR is similar between rural and urban areas in China, although there is a higher prevalence of self-reported AR in the former.

      • KCI등재

        Allergen-Dependent Differences in ILC2s Frequencies in Patients With Allergic Rhinitis

        Dachuan Fan,Xiangdong Wang,Min Wang,Yang Wang,Liang Zhang,Ying Li,Erzhong Fan,Feifei Cao,Koen Van Crombruggen,Luo Zhang 대한천식알레르기학회 2016 Allergy, Asthma & Immunology Research Vol.8 No.3

        Purpose: Group 2 innate lymphoid cells (ILC2s) are a novel population of lineage-negative cells that induce innate type 2 responses by producing the critical Th2-type cytokines IL-5 and IL-13 in response to IL-25 and IL-33 stimulation. ILC2s accumulation in the peripheral blood of patients with allergic rhinitis (AR) is controversial; the precise role of ILC2s in the immunopathogenesis of AR is still not clear. We investigated the role of ILC2s in phenotypic AR sensitized to distinct allergens. Methods: Flow cytometric analysis of the peripheral blood of 7 healthy controls (HCs), 9 patients monosensitized to house dust mite (HDM), and 8 patients monosensitized to mugwort was performed to quantify ILC2s frequency. Peripheral blood mononuclear cells (PBMCs) were isolated from HDM-AR and mugwort-AR patients, and Lineage- and Lineage+ cells were separated using a fluorescence-activated cell sorter (FACS). IL-5 and IL-13 levels in the supernatants of PBMCs, and Lineage- and Lineage+ cells stimulated with IL-25 and/or IL-33 combined with IL-2 in vitro were assessed using the Milliplex magnetic bead kit. Results: The percentage of ILC2s was significantly elevated in HDM-AR patients compared to mugwort-AR patients and HCs, while no significant difference was found between mugwort-AR patients and HCs. IL-33±IL-25 plus IL-2 induced a significantly greater release of IL-5 and IL-13 in the PBMCs of HDM-AR patients compared to PBMCs of mugwort-AR patients. IL-25 plus IL-2 also induced a significantly greater release of IL-13 in the PBMCs of HDM-AR patients compared to PBMCs of mugwort-AR patients. Stimulation with IL-33 and/or IL-25 combined with IL-2 also induced a significantly greater IL-5 and IL-13 release from Lineage- cells compared to Lineage+ cells. Conclusions: AR patients sensitized to HDM or mugwort allergen have distinct phenotypic and functional profiles in ILC2s frequencies. ILC2s mediate major type 2 immunity in the development of HDM-AR and may be a potential therapeutic target.

      • Design and Operational Performance of a Full Scale MWWTP with EHYBFAS Process

        Wang Baozhen,Jin Wenbiao,Wang Shume,Cao Xiangdong,MA Zhiguang 대전대학교 환경문제연구소 2007 환경문제연구소 논문집 Vol.11 No.-

        To improve water quality of Buji Stream and Shenzhen River, the Bujihe Wastewater Treatment Plant has been reconstructed from the original coagulkation-flocculation sedimentation system into the enhanced hybrid submerged biofilm-activated sludge (EHYBFAS)system developed by the authors. The main design parameters of the EHYBFAS system, process characteristics, operational performance, techno-economic index, and experience in design, construction and operation are described,which set up an example of the municipal wastewater treatment plants using the novel process of EHYBFAS, which has lots of advantages, such as stable and high operational performance with the final effluent quality well meeting 1A-1B standard of GB 18918-2002( Chinese national standard each one capable of treating 1.0×10<sup>4</sup> for pollutants of effluent from the MWWTPs), much less footprint of 1ha/(100×103㎥/d)) vs 4-5ha/(100×103㎥/d), much lower capital and operation costs of 700-800 Yuan(RMB)/(㎥/d) and 0.5 Yuan(RMB)/㎥ vs 1200-1500 Yuan/(㎥/d)and 1.0-1.2 Yuan/㎥ and much less sludge production of 0.3g dry solid/g removed BOD<sub>5</sub> vs 0.7 g dry solid/removed BOD5 respectively for the MWWTP with AS process.

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