<i>Prorocentrum shikokuense</i> Hada and <i>P. donghaiense</i> Lu are junior synonyms of <i>P. obtusidens</i> Schiller, but not of <i>P. dentatum</i> Stein (Prorocentrales, Dinophyceae)

Shin, Hyeon Ho,Li, Zhun,Mertens, Kenneth Neil,Seo, Min Ho,Gu, Haifeng,Lim, Weol Ae,Yoon, Yang Ho,Soh, Ho Young,Matsuoka, Kazumi Elsevier 2019 Harmful algae Vol.89 No.-

<P><B>Abstract</B></P> <P>In Japanese, Chinese and Korean coastal waters, recurrent blooms of a small, elongate <I>Prorocentrum</I> species have been observed in recent years. In previous studies, this species has been respectively identified as <I>P. shikokuense</I>, <I>P. donghaiense</I> and <I>P. dentatum</I>, despite morphological similarity and identical rDNA sequences. To resolve the confusion, morphological features, including the architectural details of the periflagellar area, were examined and ribosomal DNA (rDNA) sequences were obtained from specimens collected from the East China Sea and Korean coast, and a strain established in the waters off the Canary Islands of Spain. In addition, the descriptions of the three species and allied species were reviewed. Morphological observations and a phylogeny based on the SSU, ITS region and LSU rDNA sequences revealed that the previously confused species and our studied strains are conspecific and that the morphology of strains identified as <I>P. dentatum</I> in the phylogenetic trees does not coincide with <I>P. dentatum sensu stricto</I>. The confusion can be traced back to Dodge (1975, p. 116), who considered <I>P. veloi, P. monacense</I> and <I>P. obtusidens</I> as junior heterotypic synonyms of <I>P. dentatum</I>. However, Dodge’s <I>P. dentatum</I> are closer to <I>P. obtusidens sensu stricto</I>, rather than <I>P. dentatum sensu stricto</I>. <I>P. obtusidens sensu stricto</I> can be distinguished from <I>P. dentatum sensu stricto</I> by its relatively small size, parallel sides towards the anterior and a blunt anterior extension on one side. This indicates that <I>P. obtusidens</I> should not be considered a synonym of <I>P. dentatum sensu stricto</I>. In addition, a comparison of the original descriptions of <I>P. obtusidens</I> and allied species allowed to conclude that small, elongate <I>Prorocentrum</I> from Japanese, Chinese and Korean coastal waters previously identified as <I>P. shikokuense</I>, <I>P. donghaiense</I>, <I>P. dentatum sensu</I> Yoo and Lee (1986) and the specimens studied herein, which share identical rDNA sequences, morphologically coincide with <I>P. obtusidens.</I> Therefore, it is proposed that <I>P. shikokuense</I> and <I>P. donghaiense</I> should be regarded as junior synonyms of <I>P. obtusidens.</I> </P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>Prorocentrum shikokuense</I> Hada, <I>P. donghaiense</I> Lu and <I>Prorocentrum obtusidens</I> Schiller are conspecific. </LI> <LI> <I>Prorocentrum obtusidens</I> is a senior to <I>P. shikokuense</I> and <I>P. donghaiense</I>. </LI> <LI> <I>Prorocentrum obtusidens</I> is a separate species from <I>P. dentatum sensu stricto</I>, <I>P. veloi</I> and <I>P. monacense</I>. </LI> <LI> The periflagellar area of <I>Prorocentrum obtusidens</I> consists of seven platelets bearing a wing-like structure and two platelets without a wing-like structure, one flagellar pore and one accessory pore. </LI> </UL> </P>

Multivariable Gain Scheduling Model Predictive Control for Post-Combustion CO₂ Capture System

Haifeng Li,Aimin An 제어로봇시스템학회 2023 제어로봇시스템학회 국제학술대회 논문집 Vol.2023 No.10

Experimental Study on Seismic Behavior of New Steel Box Bridge Piers with Embedded Energy Dissipation Shells

Haifeng Li,Jun Luo,Feng Han,Jiexin Luo 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.3

An investigation was conducted to evaluate the seismic behavior of a new type of steel box-section bridge piers with embedded energy dissipation shell plates. In this study, two sets of the new steel box-section bridge piers were designed and pseudo-static tests were carried out on ten steel box bridge piers under constant axial force, with a horizontal cyclic load on top of the piers. The change regularities of the failure mode, the patterns of local buckling, the load–displacement hysteresis curve and its curve skeletons, and the load-strain hysteresis curves of the specimens were analyzed. The rules of horizontal stiff ener spacing on embedded shell plates, the axial compression ratio, the embedded shell strength, and the layout of longitudinal ribs in the box-section wallboards were obtained to evaluate their infl uence on the seismic behavior of the new-type steel piers. The test results indicated that, after installing the embedded shells, the deformation ability of steel box-section bridge piers was enhanced and their ductility was improved. The eff ects of axial compression ratio and the space of transverse stiff eners in embedded shells on the seismic behavior of the new steel piers were signifi cant. When the space of the horizontal stiff eners on the embedded shells and the axial compression ratio become smaller, the bearing capacity and ultimate displacement capability of the specimens would be greater, the descent segment of the curve skeleton would be more gradual, and the deformability and ductility of the new-type steel piers would be better. The eff ects of setting longitudinal stiff ening ribs and enhanced embedded shell strength on the bearing capacity and ductility of the steel box bridge piers were relatively small. Based on the experimental results, calculation equations were established for stable bearing capacity and maximum deformation of the new-type steel piers, under the constant axial force and horizontal cyclic loading, in order to promote their seismic design.

Seismic Performance of New-type Box Steel Bridge Piers with Embedded Energy-Dissipating Shell Plates under Tri-directional Seismic Coupling Action

Haifeng Li,Xuanneng Gao,Yang Liu,Yongfeng Luo 한국강구조학회 2017 International Journal of Steel Structures Vol.17 No.1

Accurate numerical models are necessary to evaluate the seismic performance and load-bearing mechanism of new-type box steel bridge piers with embedded energy-dissipating shell plates under tri-directional seismic coupling action. Numerical simulations of seismic performance under six types of tri-directional seismic coupling action was conducted. The effects of this stress on the seismic performance of the new-type steel bridge piers was evaluated through analysis of damage mode, hysteresis curve, skeleton curve, stiffness and strength degradation characteristic, and energy-dissipating capacity. This study also compared the numerical analysis with experimental results in order to validate the accuracy of the proposed finite element model. Based on this model, the range of relevant parameters expanded and 88 numerical specimens were analysed for seismic performance, producing further information about the influence of thickness and curvature of the embedded shell plate, spacing of transverse stiffening ribs of the shell, axial compression ratio, and slenderness ratio. Results showed that tri-directional seismic coupling action significantly affects the specimen’s deformation capacity; the embedded shell plate effectively improves the piers’ loadcarrying and deformation capacity; and the thickness of the embedded shell plate, width-to-thickness ratio of the wall plate, axial compression ratio, and slenderness ratio significantly affect the seismic performance of the new-type steel bridge piers. To promote the ease of seismic design of new-type box steel bridge piers, this study used theoretical analysis and numerical simulation to calculate equations for the minimum height of the energy-dissipating zone of the bottom embedded shell plate. Finally, formulas were also established to calculate the relevant stability bearing capacity and displacement ductility factor of the new-type steel bridge piers under tri-directional seismic coupling action in order to improve their seismic design.

Convenient and Robust Route to Photoswitchable Hierarchical Liquid Crystal Polymer Stripes via Flow-Enabled Self-Assembly

Li, Xiao,Li, Bo,He, Ming,Wang, Wei,Wang, Tianjie,Wang, Aurelia,Yu, Jiwoo,Wang, Zhonglin,Hong, Suck Won,Byun, Myunghwan,Lin, Shaoliang,Yu, Haifeng,Lin, Zhiqun American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.5

<P>Hierarchically arranged stripes of photoswitchable liquid crystal polymers (LCPs) containing azobenzene moieties were conveniently crafted via a flow-enabled self-assembly (FESA). Interestingly, by subjecting a drop of LCP solution to dry in a restricted geometry comprising two nearly parallel plates with a stationary upper plate and a movable lower plate that programmably traveled in a 'stop -and-move' manner during the FESA process, photoswitchable LCP stripes were yielded, displaying two modes of deposition, namely, periodic primary stripes of large dimensions and regularly spaced secondary stripes of small dimensions situated between adjacent, primary stripes (i.e., forming hierarchical LCP stripes). Notably, these hierarchical azobenzene moieties-containing stripes demonstrated sequential photoinduced reversible phase transition (i.e., photoswitching) due to the thickness difference between primary and secondary stripes. A UV light-induced expansion effect. was observed on the LCP stripes. Clearly, such rapid creation of hierarchical stripes by FESA represents a robust means of organizing polymers, nanoparticles, colloids, DNA, etc. into complex yet ordered patterns over a large area in a simple and controllable manner for potential use in surface relief grating, photoactuators, photoswitchable devices, antifake labels, etc.</P>

Tests of New Box Steel Replaceable Piers Under Axial Compression

Haifeng Li,Jun Luo,Feng Han,Jiexin Luo 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.3

A new recoverable box steel bridge column with bottom replaceable piers was proposed. The axial compressive tests were initially performed on fourteen specimens which have three diff erent types of steel replaceable piers. Results demonstrate that all three types of structural measures improve the specimens’ strength and deformation performance. Compared to the installing of the low yield point steel plates, the embedded shell plates and the longitudinal ribs on the box walls result in a greater increase of the specimens’ bearing capacity and ductile performance. When the specimen has the longitudinal ribs installed on the box walls and the smaller space of transverse stiff eners, its bearing capacity is increased. The specimens’ ductility is improved when the space of transverse stiff eners and the height of low yield point steel plates decrease. The specimens’ bearing capacity and ductility are only slightly aff ected by the variation of the embedded shell’s radian. Finally, a simplifi ed calculation formula for the axial compressive bearing capacity of the bottom replaceable piers is proposed.

Nonlinear Control of Heterogeneous Vehicle Platoon with Time-varying Delays and Limited Communication Range

Haifeng Li,Zhenping Chen,Baochuan Fu,Manman Sun 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.6

Vehicle platooning can significantly increase throughput of transportation, while the impairment of communication may affect the control performance of vehicle platooning. Communication delays are inevitable in the process of driving, which will cause the instability of the platoon. Moreover, the transmission power level between vehicles is finite, resulting in a limited communication range. A nonlinear control algorithm is proposed where the car-following interactions between vehicles are considered. First, a third-order heterogeneous dynamic model is established for vehicles in the platoon. The control gains and parameters are heterogeneous. Then considering the constant time headway spacing policy and the gap supplement, conditions of the control gains for maintaining the internal stability of the platoon are obtained. Second, with time-varying communication delays taken into account, the allowed upper bound of communication delays is derived. Third, given the ability of each vehicle to receive information from multiple predecessors and followers, conditions of string stability are obtained, where the communication range is limited. Finally, numerical simulations are conducted to demonstrate the effectiveness of the proposed controller.

A Meso-Macro Method of Evaluating Water Content Effect on Direct Tensile Fracture in Brittle Rocks

Xiaozhao Li,Xing Che,Haifeng Li,Chengzhi Qi 대한토목학회 2024 KSCE Journal of Civil Engineering Vol.28 No.4

Tensile stress is one of the primary forms of loading triggering the fracture in brittle rocks. Water content strongly affects the fracture process induced by meso-crack extension under the direct tensile loading of brittle rocks. Due to limitation of current equipments, the experiment of direct tensile fracture considering water content effect of brittle rocks is hardly implemented. Furthermore, the meso-macro model simultaneously considering the influence of water content and tensile loading on fracture behaviours of brittle rocks is also rarely studied. This paper proposes a meso-macro mechanical model to evaluate the water content effect on the fracture process under direct tensile loading of brittle rocks. This model is developed by combining the suggested model of meso-crack extension under direct tensile loading, the correlation of macroscopic strain and meso-crack extension, and considering the effect of water content on fracture toughness KIC and initial damage D0. This meso-macro model is linking the development process of meso-crack initiation, extension and coalescence to macroscopic fracture. The axial stress-strain curves during progressive tensile fracture under different water contents were studied, and the rationality of the suggested theoretical model was validated by the test results. The influences of water content on the relation between wing crack length and axial stress, the relation between wing crack length and stress intensity factor KI, crack initiation stress, peak stress, and elastic modulus were analyzed. The influences of the model parameter  and the initial crack angle  on the peak stress and crack initiation stress under the different water contents are also discussed.

Preparation and Microwave Absorption Properties of the Fe/TiO2/Al2O3 Composites

Yun Li,Haifeng Cheng,Nannan Wang,Shen Zhou,Dongjin Xie,Tingting Li 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.11

To reduce the imbalance of impedance matching between the magnetic metal nanowires and free space, Fe/TiO2 core/shell nanowire arrays with different diameters were fabricated in the templates of anodic aluminum oxide membranes by electrodeposition. The influences of the microstructure on the microwave absorption properties of the Fe/TiO2/Al2O3 composites were studied by the transmission/reflection waveguide method. It was demonstrated experimentally that both the interfacial polarization and the diameter of the Fe/TiO2 core/shell nanowires have critical effects on the microwave absorption properties. We also investigated the angle dependence of the microwave absorption properties. Due to the interfacial polarization and associated relaxation, the Fe/TiO2/Al2O3 composites exhibited optimal microwave absorption properties when microwave propagation direction was accordant with the axis of the nanowires. Finally, we managed to obtain an optimal reflection loss of below -10 dB (90% absorption) over 10.2–14.8 GHz, with a thickness of 3.0mm and the minimum value of -39.4 dB at 11.7 GHz.

The Effect of H2O2/Fe2+ Catalytic Oxidation System on the Morphology, Structure and Properties of Flake-Like Poly(2,3-dimethylaniline)

Jun Yan,Li Ma,Mengyu Gan,Xiao Li,Zhitao Li,Jihai Tang,Ying Tu,Haifeng Hu 한국고분자학회 2014 Macromolecular Research Vol.22 No.8

In this work, flake-like poly(2,3-dimethylaniline) (P(2,3-DMA)) with enhanced thermal stability andanticorrosive ability was synthesized by in situ polymerization using H2O2/Fe2+ catalytic oxidation system, comparingwith traditional oxidant ammonium persulfate (APS) synthetic method. The structure and morphology of thesamples were characterized Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD) and field-emissionscanning electron microscope (FESEM). The experimental results demonstrated that using H2O2/Fe2+ catalytic oxidationsystem was more inclined to form the two-dimensional P(2,3-DMA) flakes. The enhancement in thermostabilityand corrosion resistance was attributed to the formation of phenazine-like structures in the polymer chains,which could serve as templates to form the flake-like morphology. In addition, using H2O2/Fe2+ catalytic oxidationsystem is more environmental friendly than the APS method that can avoid ammonium pollution on aquatic life aswell as waters.