The motion rule of sand particles under control of the sand transportation engineering

Xin, Lin-gui,Cheng, Jian-jun,Chen, Bo-yu,Wang, Rui Techno-Press 2018 Wind and Structures, An International Journal (WAS Vol.27 No.4

In the desert and Gobi regions with strong wind and large sediment discharge, sand transporting engineering is more effective than sand blocking and sand fixing measures in sand prevention. This study uses the discrete phase model of 3D numerical simulation to study the motion trail, motion state and distribution rule of sand particles with different grain diameters when the included angle between the main shaft of the feather-row lateral transportation sand barrier and the wind direction changes, and conducts a comparison in combination with the wind tunnel test and the flow field rule of common sand barrier. According to the comparison, when wind-sand incoming flow passes through a feather-row sand barrier, sand particles slow down and deposit within the deceleration area under the resistance of the feather-row sand barrier, move along the transportation area formed by the transportation force, and accumulate as a ridge at the tail of the engineering. With increasing wind speed, the eolian erosion of the sand particles to the ground and the feather-row sand barrier is enhanced, and the sand transporting quantity and throw-over quantity of the feather-row sand barrier are both increased. When sand particles with different grain diameters bypass the feather-row sand barrier, the particle size of the infiltrating sands will increase with the included angle between the main shaft of the feather-row sand barrier and the wind direction. The obtained result demonstrates that, at a constant wind speed, the flow field formed is most suitable for the lateral transportation of the wind-drift flow when the included angle between the main shaft of the feather-row sand barrier lateral transportation engineering and the wind speed is less than or equal to $30^{\circ}$.

Light Load Efficiency Improvement Method for GaN-Based DAB Converter with Hybrid Discontinuous Current Mode

Bo Long,Wei Wang,Xin Lu,YuFei Dai,LiJun Huang,YuCheng Qian,Yong Chen,FuSheng Li 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Conventional phase-shift controlled dual active bridge (DAB) converters which operate in discontinuous current mode (DCM) are hard to realize the zero-voltage switching (ZVS) due to the light load. This paper proposed an efficiency improvement method for the DAB converter with fix-frequency hybrid discontinue current mode (HDCM). By adopting the HDCM control method, synchronous rectification and wide load range ZVS of switching devices are realized simultaneously without changing the components of the conventional DAB power stage in DCM. Besides, to further improve the conversion ratio and efficiency, the voltage-doubled rectification (VDR) is adopted. The HDCM implementation method with a digital signal processor (DSP) is proposed. A 200W laboratory prototype is designed to validate the correctness of HDCM. Compared to the conventional DAB converter which operates in DCM, experimental results demonstrate that the efficiency was increased 1.2% at 10% rated load.

DC component Mitigation Utilizing BP-PI and Repetitive Control in Transformless Grid-Connected Inverters

Bo Long,Yong Liao,YuFei Dai,LiJun Huang,Xin Lu,Yong Chen,FuSheng Li 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Transformerless grid-connected inverters, due to their advantages in high efficiency, small volume and light weight, gain more research and interest in recent years. Due to the asymmetrical driving signal in pulse-width-modulation (PWM) caused by time-delay, zero-drift of the current sensors and imparities of the power transistors, etc. Output of the grid current contains dc component. As a result, power quality of the grid is degraded. In this paper, a dc component suppression scheme with recursive integral PI controller are introduced, according to the change tendency of tracking error, the coefficients of PI controller are regulated by BP neural network in real time, and the global optimization requirements are met. Sliding-Window-Double-Iteration-Method (SWDIM) is utilized for fast dc current extraction. Simulation results from a 2-kW three-phase grid-connected inverter confirm the effectiveness of the proposed scheme.

Knockdown of HMGN5 Expression by RNA Interference Induces Cell Cycle Arrest in Human Lung Cancer Cells

Chen, Peng,Wang, Xiu-Li,Ma, Zhong-Sen,Xu, Zhong,Jia, Bo,Ren, Jin,Hu, Yu-Xin,Zhang, Qing-Hua,Ma, Tian-Gang,Yan, Bing-Di,Yan, Qing-Zhu,Li, Yan-Lei,Li, Zhen,Yu, Jin-Yan,Gao, Rong,Fan, Na,Li, Bo,Yang, Jun Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.7

HMGN5 is a typical member of the HMGN (high mobility group nucleosome-binding protein) family which may function as a nucleosomal binding and transcriptional activating protein. Overexpression of HMGN5 has been observed in several human tumors but its role in tumorigenesis has not been fully clarified. To investigate its significance for human lung cancer progression, we successfully constructed a shRNA expression lentiviral vector in which sense and antisense sequences targeting the human HMGN5 were linked with a 9-nucleotide loop. Inhibitory effects of siRNA on endogenous HMGN5 gene expression and protein synthesis were demonstrated via real-time RT-PCR and western blotting. We found HMGN5 silencing to significantly inhibit A549 and H1299 cell proliferation assessed by MTT, BrdU incorporation and colony formation assays. Furthermore, flow cytometry analysis showed that specific knockdown of HMGN5 slowed down the cell cycle at the G0/G1 phase and decreased the populations of A549 and H1299 cells at the S and G2/M phases. Taken together, these results suggest that HMGN5 is directly involved in regulation cell proliferation in A549 and H1299 cells by influencing signaling pathways involved in cell cycle progression. Thus, our finding suggests that targeting HMGN5 may be an effective strategy for human lung cancer treatment.

Improved Dyeing of Meta-aramid Based on Particle Flow Dyeing Mechanism Using Hot-pressing Dyeing Method

Xin Chen,Dan Sheng,Honghui Xia,Weilin Xu,Bo Deng,Genyang Cao 한국섬유공학회 2020 Fibers and polymers Vol.21 No.12

In this study, a combined dyeing method by integrating the advantages of both carrier dyeing and hot-pressingdyeing was utilized for the dyeing of meta-aramid. A rapid dyeing with increased mechanical properties of the fibers wasachieved for the meta-aramid fiber. A so-called particle flow mechanism involving both N,N-dimethylacetamide (DMAc)and dye molecules was proposed to explain the accelerating effect of this unique dyeing method. The mechanical propertiesand thermodynamic stability of the fiber after hot-pressing were both increased. XRD results showed increasedcorresponding fiber crystallinity. TEM showed that the disperse dyes were well dispersed in DMAc. Cross-sectional opticalphotographs of dyed fibers revealed that the dyes were successfully carried into the interior of the fiber under the synergiceffect of temperature and pressure. Combined with hot-pressing dyeing, the dyeing cycle for the meta-aramid could begreatly shortened and the amounts of dyes and carriers could be significantly reduced.

Preparation and Characterization of Mg Alloy Rods with Gradient Microstructure by Torsion Deformation

Bo Song,Huaizhi Zhao,Linjiang Chai,Ning Guo,Hucheng Pan,Hongbing Chen,Renlong Xin 대한금속·재료학회 2016 METALS AND MATERIALS International Vol.22 No.5

Extruded AZ31 Mg alloy rods were subject to free-end torsion deformation at room temperature. The microstructure features of the torsion deformed samples were characterized using electron backscatter diffraction technique. Mg rods with gradient microstructure can be fabricated by torsion deformation. Inhomogeneous distribution of microstructure along the radial direction of the twisted rods is attributed to the linearly increasing strain accumulation and strain rate from core to surface. With increasing equivalent strain, both the amount of {10- 12} twins and dislocation density increase and the c-axes of texture tend to rotate towards torsion axis. Although both dislocation slips and {10-12} twinning can be activated during torsion, dislocation slips are considered as the dominated deformation mechanism and responsible for the change of macro-texture for present torsion deformation. {10-12} twins and dislocations in the twisted samples can generate refinement hardening and dislocation hardening, respectively, to increase the hardness value.

Containment Control for Directed Networks Multi-agent System with Nonlinear Dynamics and Communication Time-delays

Bo Li,Zengqiang Chen,Chun-yan Zhang,Zhong-Xin Liu,Qing Zhang 제어·로봇·시스템학회 2017 International Journal of Control, Automation, and Vol.15 No.3

In this paper, containment control problem in directed networks for second-order multi-agent systemswith inherent nonlinear dynamics and time-delays are investigated. A distributed control protocol is proposedfor each follower using the relative states among neighboring agents. Based on Lyapunov-Razumikhin theorem,some sufficient conditions in terms of linear matrix inequalities (LMIs) are derived to ensure that all followersasymptotically converge to the convex hull spanned by the dynamic leaders. Finally, simulation results are presentedto illustrate the effectiveness of the conclusion.

Containment Control of Multi-agent Systems with Time-delays over Heterogeneous Networks

Bo Li,Hong-yong Yang,Zeng-qiang Chen,Zhong-Xin Liu 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.10

Containment control problems for second-order multi-agent systems with fixed communication timedelays under heterogeneous networks topologies are investigated. Based on Lyapunov-Krasovskii functional method and the linear matrix inequality (LMI) method, sufficient conditions on the communication digraph, the feedback gains, and the allowed upper bound of the time-delays to ensure containment control of the multi-agent systems using the different containment control algorithms are given. Finally, numerical simulations are presented to demonstrate theoretical results.

Molecular evolutionary analysis reveals Arctic-like rabies viruses evolved and dispersed independently in North and South Asia

Xin Yu,Hongwei Zhu,Yongheng Bo,Youzhi Li,Jianlong Zhang,Linlin Jiang,Guozhong Chen,Xingxiao Zhang,Yongjun Wen 대한수의학회 2021 Journal of Veterinary Science Vol.22 No.1

Background: Arctic-like (AL) lineages of rabies viruses (RABVs) remains endemic in some Arctic and Asia countries. However, their evolutionary dynamics are largely unappreciated. Objectives: We attempted to estimate the evolutionary history, geographic origin and spread of the Arctic-related RABVs. Methods: Full length or partial sequences of the N and G genes were used to infer the evolutionary aspects of AL RABVs by Bayesian evolutionary analysis. Results: The most recent common ancestor (tMRCA) of the current Arctic and AL RABVs emerged in the 1830s and evolved independently after diversification. Population demographic analysis indicated that the viruses experienced gradual growth followed by a sudden decrease in its population size from the mid-1980s to approximately 2000. Genetic flow patterns among the regions reveal a high geographic correlation in AL RABVs transmission. Discrete phylogeography suggests that the geographic origin of the AL RABVs was in east Russia in approximately the 1830s. The ancestral AL RABV then diversified and immigrated to the countries in Northeast Asia, while the viruses in South Asia were dispersed to the neighboring regions from India. The N and G genes of RABVs in both clades sustained high levels of purifying selection, and the positive selection sites were mainly found on the C-terminus of the G gene. Conclusions: The current AL RABVs circulating in South and North Asia evolved and dispersed independently.

Urchin-like alkaline nickel–cobalt carbonate derived Ni3S4/Co3S4 nanoparticles anchored on rGO for lithium/sodium-ion batteries with enhanced capacity

Bo-Han Zhang,Yu-Qian Wang,Fen Gao,Hua-Ying Wang,Wan-Xin Wen,Yun-Lei Hou,Jing-Zhou Chen,Dong-Lin Zhao 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.128 No.-

Transition metal sulfides (TMS) have emerged as promising anode materials for lithium and sodium ionbatteries due to their high theoretical capacity and low cost. However, the severe volume expansion duringthe conversion reaction causes rapid collapse inevitability when used as anode material. Herein, wepertinently fabricated nanoscale Ni3S4/Co3S4 with uniform particle size homogeneously dispersedbetween pleated graphene (Ni3S4/Co3S4@rGO) through facile hydrothermal assisted by cationic surfactants. The construction of 3D nanocomposites significantly shortens ion migration distances and enricheselectronic pathways, accelerating charge transfer kinetics while maintaining good stability. Uniformlydistributed bimetallic sulfides and rGO limit each other’s aggregation, allowing the excellent structuralproperties of the material to be maintained over time. Thus, the Ni3S4-Co3S4@rGO electrodes deliver ahigh reversible capacity of 972.5 mAh/g upon 200 cycles at 100 mA g1 in Lithium-ion battery and487.5 mAh/g upon 150 cycles at 100 mA g1 in Sodium-ion battery, as well as excellent rate capacityin both. These excellent properties show the potential for expansion of this simple synthetic methodin the field of alkali metal batteries.