Fluid Mud Dynamics and Its Correlation to Hydrodynamics in Jiaojiang River Estuary, China

Li Li,Wang Jiachen,Zheng Yiqun,Yao Yanming,Guan Weibing 한국해양과학기술원 2023 Ocean science journal Vol.58 No.1

The Jiaojiang Estuary is a macro-tidal estuary with high turbidity and funnel-shaped geomorphology. Estuarine geomorphology and shipping are highly afected by sediments and heavy coastal engineering. Based on observed data and numerical simulation results, we studied the characteristics of the suspended sediments and fuid mud in the estuary. By considering two-way coupling of water–sediment density and the process of fne sediment focculation, a three-dimensional sediment model of the Jiaojiang Estuary was established and efectively calibrated using the measured data on tides, currents, and suspended sediment concentration (SSC). Field data analysis indicated that SSC and sediment transport rate in both the main tidal channel and shoals were positively correlated with the fow velocity in the low-frequency part during both the spring and neap tides. The model results revealed that the net sediment fux is controlled by advection and moves landward upstream of the main tidal channel. Fluid mud is formed near Haimen station, with tides infuencing the spatial and temporal variations in its thickness and speed. Sediment is actively exchanged among fuid mud-water-seabed, with sink and source processes dominating near the bay mouth and the Haimen station, respectively. Sediments weaken the seaward residual currents slightly by changing their viscosity and the von Karman constant, and the stratifcation process is afected by changes in water density. The fndings of this study provide a foundation for the study of material transportation in an estuarine ecosystem.

Flight and Hover Control System Design for a Mini-quadrotor Based on Multi-sensors

Zhongli Ma,Huixin Li,Yanming Gu,Zuoyong Li,Qianqian Li 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.2

Mini-quadrotor is difficult to control in the air due to its small size and light weight. This paper presentsthe flight and hover control system for a mini-quadrotor, including design and simulation of calculations and controllers. Firstly, the attitude and position of the mini-quadrotor are obtained by distributed multi-sensors. Since attitudecalculation of aircraft needs a number of combined rotations and vectors transformed by rotation, quaternionsare applied to express the attitude model. About error compensation of gyroscope and accelerometer, IMU_Updataalgorithm of Mahony filter are applied and improved to realize data fusion [1]. In order to realize accurate hoveringat certain position, UWB (UltraWideband) are applied to gain positional information of mini-quadrotor and correctthe antenna delay caused sensor error by base station positioning. The discrete Kalman filter of original data is usedto achieve the optimized estimation of the airborne position. Px4flow optical flow sensor is able to gets velocityinformation and avoid the noise problem, which is caused by differential of position data. Then, the mathematicalmodel of a mini-quadrotor’s flight and hover control system can be established. Herein, integral items are solved bythe integral separation and integral limiting to mitigate the serious overshoot and oscillation of the system caused bythe cascade PID. Finally, the simulation of the attitude controller and position controller are applied with the MATLABSimulink library. The simulation result shows that the designed attitude controller and position controller canenable the mini-quadrotor to fly smoothly, move in all directions and hover.

Resequencing 302 wild and cultivated accessions identifies genes related to domestication and improvement in soybean

Zhou, Zhengkui,Jiang, Yu,Wang, Zheng,Gou, Zhiheng,Lyu, Jun,Li, Weiyu,Yu, Yanjun,Shu, Liping,Zhao, Yingjun,Ma, Yanming,Fang, Chao,Shen, Yanting,Liu, Tengfei,Li, Congcong,Li, Qing,Wu, Mian,Wang, Min,Wu, Nature Publishing Group, a division of Macmillan P 2015 Nature biotechnology Vol.33 No.4

Understanding soybean (Glycine max) domestication and improvement at a genetic level is important to inform future efforts to further improve a crop that provides the world's main source of oilseed. We detect 230 selective sweeps and 162 selected copy number variants by analysis of 302 resequenced wild, landrace and improved soybean accessions at >11× depth. A genome-wide association study using these new sequences reveals associations between 10 selected regions and 9 domestication or improvement traits, and identifies 13 previously uncharacterized loci for agronomic traits including oil content, plant height and pubescence form. Combined with previous quantitative trait loci (QTL) information, we find that, of the 230 selected regions, 96 correlate with reported oil QTLs and 21 contain fatty acid biosynthesis genes. Moreover, we observe that some traits and loci are associated with geographical regions, which shows that soybean populations are structured geographically. This study provides resources for genomics-enabled improvements in soybean breeding.

Removal of Pb2+ from the aqueous solution by tartrate intercalated layered double hydroxides

Yanming Shen,Xiaolei Zhao,Xi Zhang,Shifeng Li,Dongbin Liu,Lihui Fan 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.1

Adsorption of Pb2+ ion by a tartrate intercalated MgAl layered double hydroxides (MgAl-TA LDHs) was studied. The adsorption isotherms and kinetics were investigated as a function of various experimental parameters using batch adsorption experiments. The results indicated that the adsorption isotherm was well described by Sips model. The kinetic adsorption data were fitted well to the pseudo-second-order kinetic equation. The adsorption of Pb2+ was controlled mainly by the chemical process combined with intraparticle diffusion. Parameters of adsorption thermodynamic suggested that the interaction of Pb2+ adsorbed by MgAl-TA LDHs adsorbents was thermodynamically spontaneous and endothermic.

Spontaneous, Defect-Free Kinking via Capillary Instability during Vapor–Liquid–Solid Nanowire Growth

Li, Yanying,Wang, Yanming,Ryu, Seunghwa,Marshall, Ann F.,Cai, Wei,McIntyre, Paul C. American Chemical Society 2016 Nano letters Vol.16 No.3

<P>Kinking, a common anomaly in nanowire (NW) vapor-liquid-solid (VLS) growth, represents a sudden change of the wire's axial growth orientation. This study focuses on defect-free kinking during germanium NW VLS growth, after nucleation on a Ge (111) single crystal substrate, using Au-Ge catalyst liquid droplets of defined size. Statistical analysis of the fraction of kinked NWs reveals the dependence of kinking probability on the wire diameter and the growth temperature. The morphologies of kinked Ge NWs studied by electron microscopy show two distinct, defect-free, kinking modes, whose underlying mechanisms are explained with the help of 3D multiphase field simulations. Type I kinking, in which the growth axis changes from vertical [111] to < 110 >, was observed in Ge NWs with a nominal diameter of similar to 20 nm. This size coincides with a critical diameter at which a spontaneous transition from < 111 > to < 110 > growth occurs in the phase field simulations. Larger diameter NWs only exhibit Type II kinking, in which the growth axis changes from vertical [111] directly to an inclined < 111 > axis during the initial stages of wire growth. This is caused by an error in sidewall facet development, which produces a shrinkage in the area of the (111) growth facet with increasing NW length, causing an instability of the Au-Ge liquid droplet at the tip of the NW.</P>

Encapsulation of 2,4-Dihydroxybenzophenone into Dodecylbenzenesulfonate Modified Layered Double Hydroxide for UV Absorption Properties

Li, Shifeng,Shen, Yanming,Liu, Dongbin,Fan, Lihui,Wu, Keke Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.2

New organic-inorganic composite of 2,4-dihydroxybenzophenone (BP-1) encapsulation into dodecylbenzenesulfonate (DBS) modified layered double hydroxide (LDH) was successfully prepared. The surface, structural, thermal and absorption properties of the BP-1/DBS-LDH nanohybrid was characterized by BET analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TG) and diffuse reflectance UV-Vis absorbance spectra (DRUV-vis). The interlayer configuration of composite and the adsorption mechanism of BP-1 on MgAl-DBS-LDH were discussed. It was suspected that DBS anions located in the form of monolayer arrangement with a $75^{\circ}$ anti parallel angle between dodecylbenzenesulfonate chain axis. The diffuse reflectance UV-Vis absorbance results revealed that the UV absorbing wavelength of BP-1/DBS-LDH evidently extends to about 400 nm, which shows that the BP-1/DBS-LDH has the potential application as a UV absorber.

Erratum: Characterization of HC58cDNA, a putative cysteine protease from the parasite Haemonchus contortus

Li Xiangrui,Charles I. Muleke,Yan Ruofeng,Xu Lixin,Sun Yanming 대한수의학회 2006 Journal of Veterinary Science Vol.7 No.4

Vol. 7, No. 3, pp. 249-255, 2006 The correspondence is changed by authors' request.

Asymmetric selenophene-based non-fullerene acceptors for high-performance organic solar cells

Li, Chao,Xia, Tian,Song, Jiali,Fu, Huiting,Ryu, Hwa Sook,Weng, Kangkang,Ye, Linglong,Woo, Han Young,Sun, Yanming The Royal Society of Chemistry 2019 Journal of materials chemistry. A, Materials for e Vol.7 No.4

<P>Compared to thiophene-based non-fullerene acceptors (NFAs), selenophene-based NFAs have received much less attention. And organic solar cells (OSCs) based on selenophene-containing NFAs typically exhibit relatively low power conversion efficiency (PCE < 12%) and fill factor (FF < 70%). In this contribution, we have designed and synthesized two asymmetric selenophene-based NFAs, named SePTT-2F and SePTTT-2F, which possess the same end-capping group but different selenophene-containing conjugated backbones. On comparing the two NFAs, SePTTT-2F with more extended conjugation in the backbone was found to have almost the same maximum absorption peak and optical bandgap in film as SePTT-2F but an up-shifted lowest unoccupied molecular orbital (LUMO) energy level and higher electron mobility. By pairing the NFAs with the polymer donor PBT1-C, the resultant blend film based on SePTTT-2F exhibited higher and more balanced charge mobilities and more efficient exciton dissociation and charge collection in comparison with the SePTT-2F-based blend film. As a result, OSCs based on SePTTT-2F delivered an impressively high PCE of 12.24% with an outstanding FF of 75.9%, much higher than those of the SePTT-2F-based OSCs. To the best of our knowledge, the PCE of 12.24% and FF of 75.9% are among the highest values reported in the literature so far for both the parameters amongst selenophene-containing NFA-based OSCs. Our results demonstrate that extending the conjugation in the selenophene-containing backbone is an effective strategy to design highly efficient selenophene-based NFAs.</P>

Reduction of Energy Comsumptiuon and Thermal Deformation in WEDM by Magnetic Field Assisted Technology

Yanming Zhang,Zhen Zhang,Guojun Zhang,Wenyuan Li 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.7 No.2

Energy consumption and machining accuracy are considered to be two important attributes of performance indicators for green operations of wire electric discharge machining (WEDM). However, there is a paucity of studies that focus on the energy consumption and geometric error caused by thermal deformation. In this paper, a hybrid technique of WEDM with assisted magnetic field (MF) is proposed for enhancing machining performance to reduce energy consumption and thermal deformation. Based on the principles of thermal deformation, energy consumption, and magnetic field-assisted WEDM, a set of experiments is conducted to investigate thermal deformation and energy consumption of MF-assisted WEDM and conventional WEDM machining of Inconel 718. The effects of magnetic field on thermal deformation, discharge waveforms, surface integrity, and energy consumption are analyzed, and it is concluded that the proposed hybrid technique of MF-assisted WEDM offers numerous advantages and potential for applications in the green precision manufacturing field.

Intercalation of 2,4-dihydroxybenzophenone-5-sulfonate anion into Zn/Al layered double hydroxides for UV absorption properties

Shifeng Li,Yanming Shen,Min Xiao,Dongbin Liu,Lihui Fan,Keke Wu 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

Zn/Al-layered double hydroxides (LDHs) containing the organic anion of 2,4-dihydroxybenzophenone-5-sulfonate (DHBS) have been synthesized by co-precipitation method. Surface, structural, thermal and absorption properties of the ZnAl-DHBS-LDHs nanohybrids were characterized by BET analysis, scanning electron microscope, X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetry and differential thermal analysis and UV–visible spectroscopy. The results revealed that organic UV absorbent-DHBS has been intercalated into the interlayer spaces of ZnAl-LDHs and the intercalation of DHBS in LDHs interlayer galleries resulted to higher thermal stability and better UV absorption ability; these show that the hybrid ZnAl-DHBS-LDHs phase has potential applications as a UV absorber.