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| 1 | A Discrete State Event Driven Simulation based Losses Analysis for Multi-terminal Megawatt Power Electronic Transformer显示文摘At present,power electronic transformers(PETs)have been widely used in power systems.With the increase of PET capacity to the megawatt level.the problem of increased losses need to be taken seriously.As an important indicator of power electronic device designing,losses have always been the focus of attention.At present,the losses are generally measured through experiments,but it takes a lot of time and is difficult to quantitatively analyze the internal distribution of PET losses.To solve the above problems,this article first qualitatively analyzes the losses of power electronic devices and proposes a loss calculation method based on pure simulation.This method uses the Discrete State Event Driven(DSED)modeling method to solve the problem of slow simulation speed of large-capacity power electronic devices and uses a loss calculation method that considers the operating conditions of the device to improve the calculation accuracy.For the PET prototype in this article,a losses model of the PET is established.The comparison of experimental and simulation results verifies the feasibility of the losses model.Then the losses composition of PET was analyzed to provide reference opinions for actual operation.It can help pre-analyze the losses distribution of PET,thereby providing a potential method for improving system efficiency. | Jialin Zheng Zhengming Zhao Bochen Shi Zhujun Yu Jiahe Ju Zhiqiang Fan | 2020 | CES Transactions on Electrical Machines and Systems2020,4,4: | 5 |
| 2 | A Numerical Convex Lens for the State-Discretized Modeling and Simulation of Megawatt Power Electronics Systems as Generalized Hybrid Systems显示文摘Modeling and simulation have emerged as an indispensable approach to create numerical experiment platforms and study engineering systems.However,the increasingly complicated systems that engineers face today dramatically challenge state-of-the-art modeling and simulation approaches.Such complicated systems,which are composed of not only continuous states but also discrete events,and which contain complex dynamics across multiple timescales,are defined as generalized hybrid systems(GHSs)in this paper.As a representative GHS,megawatt power electronics(MPE)systems have been largely integrated into the modern power grid,but MPE simulation remains a bottleneck due to its unacceptable time cost and poor convergence.To address this challenge,this paper proposes the numerical convex lens approach to achieve state-discretized modeling and simulation of GHSs.This approach transforms conventional time-discretized passive simulations designed for pure-continuous systems into state-discretized selective simulations designed for GHSs.When this approach was applied to a largescale MPE-based renewable energy system,a 1000-fold increase in simulation speed was achieved,in comparison with existing software.Furthermore,the proposed approach uniquely enables the switching transient simulation of a largescale megawatt system with high accuracy,compared with experimental results,and with no convergence concerns.The numerical convex lens approach leads to the highly efficient simulation of intricate GHSs across multiple timescales,and thus significantly extends engineers’capability to study systems with numerical experiments. | Bochen Shi Zhengming Zhao Yicheng Zhu Zhujun Yu Jiahe Ju | 2021 | Engineering2021,7,12: | 3 |
| 3 | Effect of co-existent components in CO2 supercritical fluid extract of Angelica Sinensis Radix on metabolism of Z-ligustilide after oral administration in rats显示文摘Objective:To establish a basis for Angelica Sinensis Radix(ASR)as a dietary supplement for colorectal cancer chemoprevention,the effect of co-existent components in supercritical fluid extract(SFE)of ASR on the pharmacokinetics of Z-ligustilide after oral administration was investigated in vitro and in vivo.Methods:Incubation in gastrointestinal contents and incubation in rat liver tissue homogenates post-mitochondrial supernatant(PMS)experiments were used to study changes in the levels of Z-ligustilide in vitro.Results:Within 4 hours,the level of Z-ligustilide in SFE declined at a slower rate than in its pure form.Clearance of Z-ligustilide after administration in its pure form was significantly slower than that of SFE of ASR(CL,0.96±0.16 mL·min/kg versus 1.24±0.21 mL·min/kg P<0.05;AUC,243.37±16.84 versus 176.69±12.59 mg·min/L).Conclusion:These phenomena may be attributed to the interactions between the co-existent components in SFE of ASR and Z-ligustilide enhancing the stability of Z-ligustilide.These results suggest that the bioavailability of Z-ligustilide in SFE of ASR is improved.However,stabilization of plasma concentration was not sustained,so that the efficacy of active components could not be maintained.Thus,further processing of SFE of ASR is required. | Bochen Zhao Qing Zhang Hongmei Lin Qingguo Ru Qian Kang Hui Li Yewen Zhang Qing Wu | 2014 | Journal of Traditional Chinese Medical Sciences2014,1,2: | 2 |
| 4 | One-pot preparation of nanodispersion with readily available components for localized tumor photothermal and photodynamic therapy显示文摘Photothermal(PTT) and photodynamic(PDT) combined therapy has been hindered to clinical translation, due to the lack of available biomaterials, difficult designs of functions,and complex chemical synthetic or preparation procedures. To actualize a high-efficiency combination therapy for cancer via a feasible approach, three readily available materials are simply associated together in one-pot, namely the single-walled carbon nanohorns(SWCNH), zinc phthalocyanine(ZnPc), and surfactant TPGS. The established nanodispersion is recorded as PCT. The association of SWCNH/ZnPc/TPGS was confirmed by energy dispersive spectrum, Raman spectrum and thermogravimetric analysis. Under lighting, PCT induced a temperature rising up to about 60 ℃ due to the presence of SWCNH, production a 7-folds of singlet oxygen level elevation because of ZnPc, which destroyed almost all4T1 tumor cells in vitro. The photothermal effect of PCT depended on both laser intensity and nanodispersion concentration in a linear and nonlinear manner, respectively. After a single peritumoral injection in mice and laser treatment, PCT exhibited the highest tumor temperature rise(to 65 ℃) among all test groups, completely destroyed primary tumor without obvious toxicity, and inhibited distant site tumor. Generally, this study demonstrated the high potential of PCT nanodispersion in tumor combined therapy. | Anpu Yang Yanan Sun Bochen Lyu Binlong Chen Zhipu Fan Minghui Li Yao Zhao Jijun Fu Bing He Hua Zhang Xueqing Wang Wenbing Dai Qiang Zhang | 2022 | Asian Journal of Pharmaceutical Sciences2022,17,1: | 0 |