A lithium–oxygen battery based on lithium superoxide

Lu, Jun,Jung Lee, Yun,Luo, Xiangyi,Chun Lau, Kah,Asadi, Mohammad,Wang, Hsien-Hau,Brombosz, Scott,Wen, Jianguo,Zhai, Dengyun,Chen, Zonghai,Miller, Dean J.,Sub Jeong, Yo,Park, Jin-Bum,Zak Fang, Zhigang Nature Publishing Group, a division of Macmillan P 2016 Nature Vol.529 No.7586

<P>Batteries based on sodium superoxide and on potassium superoxide have recently been reported(1-3). However, there have been no reports of a battery based on lithium superoxide (LiO2), despite much research(4-8) into the lithium-oxygen (Li-O-2) battery because of its potential high energy density. Several studies(9-16) of Li-O-2 batteries have found evidence of LiO2 being formed as one component of the discharge product along with lithium peroxide (Li2O2). In addition, theoretical calculations have indicated that some forms of LiO2 may have a long lifetime(17). These studies also suggest that it might be possible to form LiO2 alone for use in a battery. However, solid LiO2 has been difficult to synthesize in pure form(18) because it is thermodynamically unstable with respect to disproportionation, giving Li2O2 (refs 19, 20). Here we show that crystalline LiO2 can be stabilized in a Li-O-2 battery by using a suitable graphene-based cathode. Various characterization techniques reveal no evidence for the presence of Li2O2. A novel templating growth mechanism involving the use of iridium nanoparticles on the cathode surface may be responsible for the growth of crystalline LiO2. Our results demonstrate that the LiO2 formed in the Li-O-2 battery is stable enough for the battery to be repeatedly charged and discharged with a very low charge potential (about 3.2 volts). We anticipate that this discovery will lead to methods of synthesizing and stabilizing LiO2, which could open the way to high-energy-density batteries based on LiO2 as well as to other possible uses of this compound, such as oxygen storage.</P>

Design and Control of DC/AC Converters in Parallel with Diode Rectifiers for Regenerative Applications

Zhigang Gao,Rui Li,Qi Lu 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.4

This paper introduces a DC/AC converter, which can be connected in parallel with a diode rectifier for regenerative applications. The DC/AC converter is supposed to transmit regenerative energy to the power grid when a motor is braking. Isolation transformers are not needed in the topology, which can reduce the size and cost. An analysis of the zero-order current existing in the system is carried out. In addition, algorithms to minimize the zero-order current, control the power factor and keep the DC bus voltage stable are discussed. A 55kW industrial prototype is built to verify the proposed analysis and control strategies.

RNA Interference to Prevent Bombyx mori Nuclear Polyhedrosis Virus Infection in Vivo

Hu Zhigang,Chen Keping,Gao Lu,Yao Qin Korean Society of Sericultural Science 2006 International Journal of Industrial Entomology Vol.12 No.1

RNA interference has been used as a powerful tool in preventing virus proliferation in many species. In this study, we injected the dsRNA in vitro transcripts into Bombyx mori to investigate the resistance to B. mori nuclear polyhedrosis virus (BmNPV). Through vivisectional observation and real-time quantities PCR analysis, we found that these dsRNA can prevent the BmNPV to a certain extent, and delay the viruses' proliferation.

Development and verification of PWR core transient coupling calculation software

Li, Zhigang,An, Ping,Zhao, Wenbo,Liu, Wei,He, Tao,Lu, Wei,Li, Qing Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.11

In PWR three-dimensional transient coupling calculation software CORCA-K, the nodal Green's function method and diagonal implicit Runge Kutta method are used to solve the spatiotemporal neutron dynamic diffusion equation, and the single-phase closed channel model and one-dimensional cylindrical heat conduction transient model are used to calculate the coolant temperature and fuel temperature. The LMW, NEACRP and PWR MOX/UO₂ benchmarks and FangJiaShan (FJS) nuclear power plant (NPP) transient control rod move cases are used to verify the CORCA-K. The effects of burnup, fuel effective temperature and ejection rate on the control rod ejection process of PWR are analyzed. The conclusions are as follows: (1) core relative power and fuel Doppler temperature are in good agreement with the results of benchmark and ADPRES, and the deviation between with the reference results is within 3.0% in LMW and NEACRP benchmarks; 2) the variation trend of FJS NPP core transient parameters is consistent with the results of SMART and ADPRES. And the core relative power is in better agreement with the SMART when weighting coefficient is 0.7. Compared with SMART, the maximum deviation is -5.08% in the rod ejection condition and while -5.09% in the control rod complex movement condition.

Verification of neutronics and thermal-hydraulic coupled system with pin-by-pin calculation for PWR core

Li Zhigang,Pan Junjie,Xia Bangyang,Qiang Shenglong,Lu Wei,Li Qing 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.9

As an important part of the digital reactor, the pin-by-pin wise fine coupling calculation is a research hotspot in the field of nuclear engineering in recent years. It provides more precise and realistic simulation results for reactor design, operation and safety evaluation. CORCA-K a nodal code is redeveloped as a robust pin-by-pin wise neutronics and thermal-hydraulic coupled calculation code for pressurized water reactor (PWR) core. The nodal green's function method (NGFM) is used to solve the threedimensional space-time neutron dynamics equation, and the single-phase single channel model and one-dimensional heat conduction model are used to solve the fluid field and fuel temperature field. The mesh scale of reactor core simulation is raised from the nodal-wise to the pin-wise. It is verified by two benchmarks: NEACRP 3D PWR and PWR MOX/UO2. The results show that: 1) the pin-by-pin wise coupling calculation system has good accuracy and can accurately simulate the key parameters in steadystate and transient coupling conditions, which is in good agreement with the reference results; 2) Compared with the nodal-wise coupling calculation, the pin-by-pin wise coupling calculation improves the fuel peak temperature, the range of power distribution is expanded, and the lower limit is reduced more

Design and Control of DC/AC Converters in Parallel with Diode Rectifiers for Regenerative Applications

Gao, Zhigang,Li, Rui,Lu, Qi The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.4

This paper introduces a DC/AC converter, which can be connected in parallel with a diode rectifier for regenerative applications. The DC/AC converter is supposed to transmit regenerative energy to the power grid when a motor is braking. Isolation transformers are not needed in the topology, which can reduce the size and cost. An analysis of the zero-order current existing in the system is carried out. In addition, algorithms to minimize the zero-order current, control the power factor and keep the DC bus voltage stable are discussed. A 55kW industrial prototype is built to verify the proposed analysis and control strategies.

Molecular Cloning and Characterization of a Muscle-Specific Lipase from the Bumblebee Bombus ignitus

Hu, Zhigang,Wang, Dong,Lu, Wei,Cui, Zheng,Jia, Jing-Ming,Yoon, Hyung-Joo,Sohn, Hung-Dae,Kim, Doh-Hoon,Jin, Byung-Rae Korean Society of Sericultural Science 2008 International Journal of Industrial Entomology Vol.17 No.1

A muscle-specific lipase gene of the bumblebee Bombus ignitus was cloned and characterized. This gene, which we named Bi-Lipase, consists of seven exons encoding 317 amino acid residues. Bi-Lipase possesses all the features of lipases, including GXSXG consensus motif and Ser-Asp-His catalytic triad. Expressed as a 37-kDa polypeptide in baculovirus-infected insect Sf9 cells, recombinant Bi-Lipase showed an optimal pH of 9.0 and exhibited its highest catalytic activity at $40^{\circ}C$. Furthermore, through the addition of tunicamycin to the recombinant virus-infected Sf9 cells, recombinant Bi-Lipase was found to be N-glycosylated. Northern and western blot analyses indicated that Bi-Lipase was expressed in the wing, thorax, and leg muscles. These results show that Bi-Lipase is a muscle-specific lipase, suggesting a possible role of Bi-Lipase in the utilization of lipids for muscular activity in B. ignitus.

MiR-200c-3p aggravates gastric cell carcinoma via KLF6

Wang Ying,Lu Kaijuan,Li Weibing,Wang Zhigang,Ding Jing,Zhu Zeyu,Li Zhipeng 한국유전학회 2021 Genes & Genomics Vol.43 No.11

Background Gastric cell carcinoma (GCC) is a common and high-incidence malignant gastrointestinal cancer that seriously threatens human life and safety. Evidences suggest that microRNAs (miRNAs) exhibit an essential role in regulating the occurrence and development of GCC, while the efects and possible mechanisms remain to be further explored. Objective This study was designed to explore whether miR-200c-3p exerted its functional role in the growth and metastasis of GCC, and investigate the possible mechanisms. Methods The expression levels of miR-200c-3p in GCC tissues and cell lines were detected by qRT-PCR analysis. The functional role of miR-200c-3p in the viability, proliferation, migration and invasion of GCC cells were evaluated by CCK-8, EdU, wound healing and Transwell assays. In addition, the candidate targets of miR-200c-3p was predicted and confrmed by dual-luciferase reporter assay. Moreover, the relationship between miR-200c-3p and target (Krüppel like factor 6, KLF6) was assessed by qRT-PCR and western blot assays. Besides, the expression levels of KLF6 in GCC cells were determined by qRT-PCR and western blot assays. Furthermore, the role of KLF6 in the viability, proliferation, migration and invasion of GCC cells mediated with miR-200c-3p mimics was evaluated by CCK-8, EdU, wound healing and Transwell assays. Results In the present study, a new tumor promoting function of miR-200c-3p was disclosed in GCC. We found that the expression of miR-200c-3p was obviously increased in clinic GCC tissues and cell lines. In addition, down-regulation of miR-200c-3p suppressed cell viability, proliferation, migration, and invasion in GCC cells. Moreover, KLF6 was verifed as a direct target of miR-200c-3p by binding its 3’-UTR. Additionally, KLF6 was remarkably decreased and was negatively associated with the miR-200c-3p expression in GCC cell lines. Furthermore, over-expression of KLF6 retarded the efects of miR-200c-3p on the growth and metastasis of GCC cell lines. Conclusions MiR-200c-3p potentially played a tumor-promoting role in the occurrence and development of GCC, which may be achieved by targeting KLF6.

Hierarchical Optimal Reactive Power Dispatch for Active Distribution Network with Multi-microgrids

Li Xueping,Zhao Wanzhao,Lu Zhigang 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.3

The interconnection of active distribution network and multi-microgrids leads to the increase of variable dimension of optimal reactive power dispatch. The overall reactive power dispatch will face the problems of high dimension, slow convergence, and reduced accuracy. Meanwhile, the decomposition dispatch requires a large number of coordination iterations. Hence, this paper proposes a hierarchical optimal reactive power dispatch method for active distribution network with multi-microgrids based on differential evolution algorithm and the network loss sensitivity. In this method, the upper layer takes the minimum loss of the distribution network as the goal, regards each microgrid as a generator node, and formulates the interactive power between each microgrid and the distribution network. The lower layer aims to minimize the network loss of the microgrid, regards the point of common coupling as the balance node, and make the power of the lower layer meet the constraints of the upper layer in the form of penalty function. To minimize the network loss of the whole network, the sensitivity is calculated to correct the output of reactive power equipment for further optimization. The improved IEEE-33 bus distribution network system is used to verify the method, and the results are compared with the global optimization results. Due to the reduction of the network scale, the number of iterations of each system of hierarchical optimization is 1000, which is greatly reduced compared with 10,000 of the overall optimization. The results show that the proposed method improves the economy of active distribution network system with multi-microgrids and significantly shortens the running time.

Differential Evolution Algorithm Based on State Transition of Specific Individuals for Economic Dispatch Problems with Valve Point Effects

Li Xueping,Xu Jian,Lu Zhigang 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.2

Economic Dispatch problem with valve-point eff ects is a complex solution problem involving the practical constraints of equality and inequality. The paper proposes a diff erential evolution algorithm based on specifi c individuals of state transition to solve small, medium and large-economic dispatch problems with valve-point eff ects. The core of DE-STA is to use the state transition to update specifi c individuals after a diff erential evolution of the population, which improves the optimization effi ciency, robustness and accuracy of the algorithm. Moreover, a new state operator of translation transformation is adopted to improve effi ciency of state transition, which introduces individuals of information exchange. Compared with the traditional DE and other algorithms, better robustness, faster convergence speed and accuracy results of the DE-STA are demonstrated by solving small, medium and large-economic dispatch problems with valve-point eff ects related to 13-, 40- and 140-unit test system