Interconnected hollow carbon nanospheres for stable lithium metal anodes

Zheng, Guangyuan,Lee, Seok Woo,Liang, Zheng,Lee, Hyun-Wook,Yan, Kai,Yao, Hongbin,Wang, Haotian,Li, Weiyang,Chu, Steven,Cui, Yi Nature Publishing Group, a division of Macmillan P 2014 Nature nanotechnology Vol.9 No.8

For future applications in portable electronics, electric vehicles and grid storage, batteries with higher energy storage density than existing lithium ion batteries need to be developed. Recent efforts in this direction have focused on high-capacity electrode materials such as lithium metal, silicon and tin as anodes, and sulphur and oxygen as cathodes. Lithium metal would be the optimal choice as an anode material, because it has the highest specific capacity (3,860 mAh g<SUP>–1</SUP>) and the lowest anode potential of all. However, the lithium anode forms dendritic and mossy metal deposits, leading to serious safety concerns and low Coulombic efficiency during charge/discharge cycles. Although advanced characterization techniques have helped shed light on the lithium growth process, effective strategies to improve lithium metal anode cycling remain elusive. Here, we show that coating the lithium metal anode with a monolayer of interconnected amorphous hollow carbon nanospheres helps isolate the lithium metal depositions and facilitates the formation of a stable solid electrolyte interphase. We show that lithium dendrites do not form up to a practical current density of 1 mA cm<SUP>–2</SUP>. The Coulombic efficiency improves to ∼99% for more than 150 cycles. This is significantly better than the bare unmodified samples, which usually show rapid Coulombic efficiency decay in fewer than 100 cycles. Our results indicate that nanoscale interfacial engineering could be a promising strategy to tackle the intrinsic problems of lithium metal anodes.

A novel design method for improving collapse resistances of multi-story steel frames with unequal spans using steel braces

Zheng Tan,Wei-hui Zhong,Bao Meng,Shi-chao Duan,Hong-chen Wang3,Xing-You Yao,Yu-hui Zheng 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.47 No.2

The bearing capacities resisted by the two-bay beams of multi-story planar frames with unequal spans under column removal scenarios differ considerably owing to the asymmetric stress on the left and right beams connected to the failed column and cause the potential for beams with larger span-to-depth ratios to be unable to exert effectively, which is disadvantageous for resisting the vertical load in unequal-span frame structures. To address this problem, the structural measure of adding braces to the weak bays of multi-story unequal-span frames was proposed, with the objective of achieving a coordinated stress state in two-bay beams with unequal spans, thereby improving the collapse resistance of unequal-span frame structures. Before conducting the numerical simulation, the modeling methods were verified by previous experimental results of two multi-story planar frames with and without steel braces. Thereafter, the effects of the tensile and compressive braces on the collapse behavior of the frame structures were elucidated. Then, based on the mechanical action laws of the braces throughout the collapse process, a detailed design method for improving the collapse resistance of unequal-span frame structures was proposed. Finally, the proposed design method was verified by using sufficient example models, and the results demonstrated that the design method has good application prospects and high practical value.

Research Articles : The Influence of Challenge on Cathepsin B and D Expression Patterns in the Silkworm Bombyx mori L

( Feng Yao Wu ),( Feng Ming Zou ),( Jun Qiang Jia ),( Sheng Peng Wang ),( Guo Zheng Zhang ),( Xi Jie Guo ),( Zhong Zheng Gui ) 한국잠사학회 2011 International Journal of Industrial Entomology Vol.23 No.1

Cathepsins are well-characterized proteases that are ubiquitously expressed in lysosomes. Previous work revealed that Bombyx mori cathepsins B and D are expressed in the fat body and undergo decomposition during larval-pupal metamorphosis. Quantitative RTPCR was performed to detect cathepsin gene expression at the transcription level when challenged by B. mori nuclear polyhedrosis virus (BmNPV), temperature and hormones (20-hydroxyecdysone (20E) and juvenile hormone analogue (JHA)). mRNAs encoding cathepsins B and D were significantly enhanced after the larvae were infected with BmNPV, and the peak of the induction appeared at 1 day before spinning. This attenuated the inducing effect on cathepsin expression caused by infection. Temperature shock induced cathepsin expression at the later stage of the 5th instar, and transcription levels varied with development stage and temperature. Cathepsin B and D mRNA expression in the fat body were significantly induced by JHA at the day before spinning, and with 20E, the expression reached a peak at the last day of the 5th instar. Cathepsin B and D mRNA expression exhibited detectable changes post-treatment, without significant differences between or among the hormone concentrations.

The Influence of Challenge on Cathepsin B and D Expression Patterns in the Silkworm Bombyx mori L.

Wu, Feng-Yao,Zou, Feng-Ming,Jia, Jun-Qiang,Wang, Sheng-Peng,Zhang, Guo-Zheng,Guo, Xi-Jie,Gui, Zhong-Zheng Korean Society of Sericultural Science 2011 International Journal of Industrial Entomology Vol.23 No.1

Cathepsins are well-characterized proteases that are ubiquitously expressed in lysosomes. Previous work revealed that $Bombyx$ $mori$ cathepsins B and D are expressed in the fat body and undergo decomposition during larval-pupal metamorphosis. Quantitative RT-PCR was performed to detect cathepsin gene expression at the transcription level when challenged by $B.$ $mori$ nuclear polyhedrosis virus (BmNPV), temperature and hormones (20-hydroxyecdysone (20E) and juvenile hormone analogue (JHA)). mRNAs encoding cathepsins B and D were significantly enhanced after the larvae were infected with BmNPV, and the peak of the induction appeared at 1 day before spinning. This attenuated the inducing effect on cathepsin expression caused by infection. Temperature shock induced cathepsin expression at the later stage of the $5^{th}$ instar, and transcription levels varied with development stage and temperature. Cathepsin B and D mRNA expression in the fat body were significantly induced by JHA at the day before spinning, and with 20E, the expression reached a peak at the last day of the $5^{th}$ instar. Cathepsin B and D mRNA expression exhibited detectable changes post-treatment, without significant differences between or among the hormone concentrations.

RBBP4 plays a vital role in the malignant progression of triple-negative breast cancer by regulating epithelial-mesenchymal transition

Zheng Zitong,Yao Xu,Liu Yi 한국유전학회 2022 Genes & Genomics Vol.44 No.10

Background: Mounting findings have revealed the increasingly appreciated functional importance of Retinoblastoma binding protein (RBBP) family members in tumorigenesis. However, the biological function of RBBP4 in breast cancer, especially in the most malignant and aggressive subtype, i.e., triple-negative breast cancer (TNBC), remains to be elucidated. Objective: The present study was aimed at elucidating the role of RBBP4 in TNBC pathogenesis. Methods: The expression of RBBP4 in TNBC tissues and cell lines was examined and its oncogenic-related functions were verified by performing a series of in vitro and in vivo experiments. Results: At the cellular and tissue level, a marked increase in the RBBP4 expression was observed. Functionally, RBBP4 knockdown dramatically inhibited the proliferation, invasion, and migration of TNBC cells in vitro. Further, mechanistically, RBBP4 downregulation regulated the inactivation of epithelial-mesenchymal transition (EMT) of TNBC cells. In vivo xenograft model in nude mice also validated these results. Conclusion: Collectively, our results showed that the inhibition of RBBP4 suppresses the malignant progression of TNBC cells by regulating EMT. Thus, RBBP4 could serve as a novel biomarker and target for TNBC diagnosis and treatment.

Mixed Reinforcement Learning for Efficient Policy Optimization in Stochastic Environments

Yao Mu,Baiyu Peng,Ziqing Gu,Shengbo Eben Li,Chang Liu,Bingbing Nie,Jianfeng Zheng,Bo Zhang 제어로봇시스템학회 2020 제어로봇시스템학회 국제학술대회 논문집 Vol.2020 No.10

Reinforcement learning has the potential to control stochastic nonlinear systems in optimal manners successfully. We propose a mixed reinforcement learning (mixed RL) algorithm by simultaneously using dual representations of environmental dynamics to search the optimal policy. The dual representation includes an empirical dynamic model and a set of state-action data. The former can embed the designer’s knowledge and reduce the difficulty of learning, and the latter can be used to compensate the model inaccuracy since it reflects the real system dynamics accurately. Such a design has the capability of improving both learning accuracy and training speed. In the mixed RL framework, the additive uncertainty of stochastic model is compensated by using explored state-action data via iterative Bayesian estimator (IBE). The optimal policy is then computed in an iterative way by alternating between policy evaluation (PEV) and policy improvement (PIM). The effectiveness of mixed RL is demonstrated by a typical optimal control problem of stochastic non-affine nonlinear systems (i.e., double lane change task with an automated vehicle).

Complex Current Controller Design Based on Multiple Equations Construction of Three-Phase Inverter

Zheng Xinxin,Sun Shangyuan,Liu Xintian,He Yao,Liu Yunbo 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.4

This paper proposes a complex PI current controller design method of three-phase inverter based on multiple equations construction. The mathematical model of three-phase inverter system plays an important role in the controller design process. In the synchronous reference frame, the inverter model introduces coupling elements, which is diff erent from the model in the stationary reference frame and brings diffi culty for current controller design. Complex vector model (CVM) is introduced in the current loop, which is established in the synchronous reference frame and takes part in the current controller design. Multiple equations construction is established to solve the parameters of the complex PI current controller. Because the controller satisfi es the restrictions of the multiple equations, it can realize good dynamic performance and the coupling characteristic of the three-phase system. In this paper, the CVM is established. The process of construct and solve the multiple equations is analyzed in detail. The accuracy of the inverter system is validated. Finally the simulation and experimental results are given to verify the theoretical analysis.

Thermal Behavior Analysis and Thermal Error Compensation for Motorized Spindle of Machine Tools

Zheng-Chun Du,Si-Yu Yao,Jian-Guo Yang 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.

The thermal error deformation of motorized spindle plays an important role in the precision machining, while error compensation has been proved to be a cost-effective way. Herein a symmetrical solution for the thermal error problem of spindle is proposed based on the thermal behavior analysis. Firstly, the heat generating and transfer mechanism are described considering the heat sources. Next, ANSYS is used to achieve the steady-state and the transient thermal field distribution as well as the related deformation with the given thermal load and boundary condition. Furthermore, the NEM is proposed to predict the thermal error under random rotating speed with no use of thermal sensors, followed by the determination of two important parameters. The verification experiment of the thermal error under random rotating speed is executed. The External Machine Zero Point Shift function of the CNC system is adopted to develop the real-time compensation system on the spindle of HDBS-63 machining center. The maximum axial thermal error is greatly reduced from 55 to 16 um, while the radial one similarly reduced from 15 to 6 um. Both are improved 73% and 63% respectively. The experiment results show that NEM method is simple but of good reliability and practicality.

Primary Double Winding Coupling DC Transformer for DC Micro-Grid Applications

Zheng Xinxin,Pan Weijie,Liu Xintian,He Yao 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.3

In recent years, DC micro-grid has attracted widespread attention due to the signifi cant increase in DC loads and the demand for high-quality power. This paper proposes a novel primary double winding coupling topology of the DC transformer (DCT) for DC micro-grid applications. The primary side high-frequency full-bridge inverter is replaced by a novel topology without shoot-through problem. As a result, the reliability of the system is improved, and dead-time is unnecessary to be added to the driving signals thus the dc voltage utilization is higher. Compared to the no dead-time dual-buck inverter, the proposed topology has more advantages in the size and cost, because the primary two windings can be integrated on the same core. What’s more, the infl uence of the leakage inductance can be decreased by the parallel eff ect, so that the transmission effi - ciency of the DCT can be improved. In this paper, the evolution process of the non-dead zone and comparison with other topologies are given. The equivalent circuit and the compensation design are described in detail. The working principle and effi ciency of the proposed topology are analysed and calculated. The simulation and a simple prototype were built up for the experimental tests to verify the advancement of the proposed DCT.

Cephalosporolides H and I, Two Novel Lactones from a Marine-Derived Fungus, Penicillium sp.

Yao, Yanhua,Zheng, Yinan,Sattler, Isabel,Lin, Wenhan,Li, Xiang 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.7

Two novel lactones, Cephalosporolides H (1) and I (2), were isolated from the lyophilized culture broth of the marine-derived fungus, Penicillium sp. The structures were elucidated on the basis of extensive 1D- and 2D-NMR, as well as HRESI-MS spectroscopic analyses. The relative stereochemistries of the compounds were assessed by comparison of the NOESY analysis and spectral data with those in the literature.