Diversity of non-thermophilic Crenarchaeota associated with gas hydrates in the Gulf of Mexico

Zhiyong Huang,Chuanlun L. Zhang 대한지질학회 2007 대한지질학회 학술대회 Vol.2007 No.0

Numerical simulation study of the Reynolds number effect on two bridge decks based on the deterministic vortex method

Zhiyong Zhou,Rujin Ma 한국풍공학회 2010 Wind and Structures, An International Journal (WAS Vol.13 No.4

Researches on the Reynolds number effect on bridge decks have made slow progress due to the complicated nature of the subject. Heretofore, few studies on this topic have been made. In this paper, aerostatic coefficients, Strouhal number (St), pressure distribution and Reynolds number (Re) of Great Belt East Bridge and Sutong Bridge were investigated based on deterministic vortex method (DVM). In this method, Particle Strength Exchange (PSE) was chosen to implement the simulation of the flow around bluff body and to analyze the micro-mechanism of the aerostatic loading and Reynolds number effect. Compared with the results obtained from wind tunnel tests, reliability of numerical simulation can be proved. Numerical results also showed that the Reynolds number effect on aerostatic coefficients and Strouhal number of the two bridges can not be neglected. In the range of the Reynolds number from 105 to 106, it has great effect on the Strouhal number of Sutong Bridge, while the St is difficult to obtain from wind tunnel tests in this range.

Feeling In Control : Design Tangible Self-Health Management Service Touch-Points For The Elderly With Holistic Experience

Zhiyong Fu,Dandan Yu,Shuangshuang Zhang 한국HCI학회 2013 한국HCI학회 학술대회 Vol.2013 No.1

This paper presents how to improve the holistic user experience for the elderly with chronic disease by designing the new self-health management service based on multi-screen platform and tangible touch points. As the connected touch point, Med-Cube is designed to help the elderly feel in control when they handle with the complicated multi-screen devices, like TV, tablet PC and mobile phone. In order to create seamless connection between the elderly and the multi-screen service system, we designed the context aware interaction flow based on the elderly’s common experience and behavior of everyday self-health management, such as recording, reminding and navigating. This selfhealth service system helps the elderly to create integrated user experience between virtual online world and physical world as well. The self-health service system also links the elderly with family, friends and doctors by cross-media platform and social network. Our vision in this study is to give the elderly independent, healthy, self-controlled life by providing service from the tangible touch points and holistic cross-media interaction mode.

Asynchronous Switching Control for Continuous-time Switched Linear Systems with Output-feedback

Zhiyong Jiang,Peng Yan 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.5

This paper investigates the asynchronous switching control problem for continuous-time switched linear systems via dynamic output-feedback, where the dynamic output-feedback controller contains an impulsive reset law to reset the controller state. A time-varying multiple Lyapunov-like-function (MLF) approach is employed to analyze the stability and weighted L2-gain of the closed-loop systems. The switching stability criteria for the closedloop systems are established in terms of linear matrix inequalities (LMIs), which are dependent on the upper and lower bounds of the switching interval and the asynchronous delays. The switching logic is designed to guarantee the closed-loop systems achieving the weighted L2-gain performance. Two numerical examples are provided to show the effectiveness of the proposed method.

Separation of chalcopyrite from galena with 3-amyl-4-amino-1, 2, 4-triazole-5-thione collector: Flotation behavior and mechanism

Zhiyong Zhang,Yiming Wang,Guangyi Liu,Sheng Liu,Jun Liu,Xianglin Yang 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.92 No.-

3-Amyl-4-amino-1,2,4-triazole-5-thione (AATT) reacted with Cu2+ or Pb2+ ions in aqueous solutions toform CuAATT and Pb(AATT)2 complexes and their solubility product constants were measured as 10 16.17and 10-20.60, respectively. In the moderately-alkaline media, both chalcopyrite and galena chemisorbedAATT on to their surfaces, and the adsorption amount of AATT on chalcopyrite was bigger than that ongalena, which rendered a stronger hydrophobization toward chalcopyrite. While under the high-alkalinepulp, AATT only chemisorbed on chalcopyrite, not on galena. The micro-flotationfindings indicated thatAATT was a favorable collector forflotation enrichment of chalcopyrite and galena at pH <11.0, andrealized an efficientflotation separation of chalcopyrite from galena under pH>11.5. The CuAATTcomplexwas more insoluble than Pb(AATT)2, which implied a stronger affinity of AATT toward chalcopyrite thangalena and returned their selectiveflotation separation at the high-alkaline condition.

Preparation, Characterization and Luminescence Properties of a Novel 1,10-Phenanthroline-Functionalized Polyimide and Its Europium(III) Complexes

Zhiyong Chen,Jianjun Lu,Xuping Li,Xuting Jin,Lijuan Shi,Miaoqing Liu,Zhilin Sun 한국고분자학회 2015 Macromolecular Research Vol.23 No.9

A novel 1,10-phenanthroline-functionalized polyimide (CMPI-Phen) was prepared as polymer matrix by the nucleophilic substitution reaction between chloromethylated polyimide (CMPI) and 5-amino-1,10-phenanthroline (NH2-Phen). Then, two kinds of luminescent materials of 1,10-phenanthroline-functionalized polyimide containing Eu(III) complexes, were obtained by two different methods. Their structures and properties were characterized by Fourier transform infrared (FTIR) spectroscopy, 1H nuclear magnetic resonance (NMR) spectroscopy, elemental analysis, inductively coupled plasma (ICP), gel permeation chromatography (GPC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), luminescence spectrometry, and luminescence decay analysis. Investigations revealed that both the CMPI-Phen-Eu(III) and CMPI-Phen-Eu(TTA)3 display highly efficient red emissions, suggesting their potential application as luminescent materials. However, compared with CMPI-Phen-Eu(III), CMPI-Phen-Eu(TTA)3, where TTA stands for thenoyltrifluoroacetone, exhibits more excellent and stable fluorescence intensity and longer luminescence lifetime (134.30 μs). The weight-average molecular weights of CMPI-Phen-Eu(III) and CMPI-Phen- Eu(TTA)3 are 2.40×104 and 3.11×104, respectively. The Eu contents of CMPI-Phen-Eu(TTA)3 and CMPI-Phen-Eu(III) were measured by ICP to be 7.00% and 5.92%, respectively. TGA demonstrated that both CMPI-Phen-Eu(III) and CMPI-Phen-Eu(TTA)3 have high thermal stability and their 5% loss weight temperatures were 356 and 280 oC, respectively. Moreover, both CMPI-Phen-Eu(III) and CMPI-Phen-Eu(TTA)3 were soluble in polar solvents such as dimethylformamide (DMF), dimethylacetamide (DMAc), 1-methyl-2-pyrrolidone (NMP), and dimethylsulfoxide (DMSO) under heating conditions, and could be easily cast into tough thin films.

Effects of manufacturing process and surface treatments on mechanical properties of PLA/SCF composites using extrusion printing

Zhiyong Ma,Zheng Qian,Jiabin Cai 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.5

Short carbon fiber (SCF) reinforced polylactic acid (PLA) composites were fabricated by extrusion printing, and the effects of process parameters and surface treatments on the mechanical properties of composites were studied. Based on the rheological properties of composites and the extrusion process simulation, pure PLA specimens and PLA/SCF specimens were manufactured under different printing parameters. Three kinds of surface treatment were adopted to improve the mechanical properties. The experimental results show that SCF can effectively improve the tensile strength and bending strength, but the compressive strength decreased. The specimen had the best mechanical properties when the layer height was 0.1 mm and the nozzle diameter was 0.6 mm. The mechanical properties can be further improved by coupling agent coating method, and the compressive strength was even higher than that of pure PLA specimen. The research in this paper can provide a reference for the fabrication of thermoplastic composites with excellent mechanical properties by extrusion printing.

Joint Adaptive Combining and Variable Tap-Length Multiuser Detector for Underwater Acoustic Cooperative Communication

( Zhiyong Liu ),( Yinghua Wang ),( Lizhong Song ),( Yinyin Wang ),( Fusheng Dai ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.1

In this paper, we propose a joint adaptive combining and variable tap-length multiuser detector (MUD) for amplify-and-forward (AF) underwater acoustic cooperative interleave-division multiple access (IDMA) communication system. The proposed MUD jointly realizes tap-length adjustment, adaptive combining, and multiuser detection. In contrast to the existing methods, the proposed detector can adaptively combine the received signals from different nodes at destination, and does not need the assumption that full and perfect channel state information (CSI) of all the links at the receiver is known. Moreover, the proposed detector can adaptively adjust the tap coefficient vector and tap-length of each branch according to the specific channel profile of each branch. Simulation results validate the feasibility and show the advantages of the proposed detector against existing counterparts.

Space‑Vector‑Based Hybrid PWM for Zero‑Sequence‑Circulating‑Current RMS and Common Mode Voltage Reduction in Two Parallel Interleaved Two‑Level Converters

Zhiyong Zeng,Zhongxi Li,Stefan M. Goetz 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.3

This paper aims at reducing the root mean square (RMS) values of the zero-sequence circulating current (ZSCC). The analysis reveals that the ZSCC is determined by the duty ratios of the medium voltage vector and zero vector. Whereas the reference voltage fxes the duty ratio of the medium vector, the duty ratio of the zero-voltage vector depends on the distribution of the small and larger vectors, which can be used to optimize the ZSCC. As such, we propose a generalized PWM architecture, where the distribution of the active vectors is parameterized by a coefcient k. Based on this, we derive regions for k that attain the same minimal ZSCC peak. Within these regions, we further optimize k to minimize the ZSCC RMS. Depending on the reference voltage, the method selects diferent coefcient k for the ZSCC RMS optimizations. The proposed modulation strategy is therefore a HBSVM due to its adaptive feature in the distribution of the active vectors. The proposed HBSVM uniformly applies to the entire vector plane and is computationally afordable for mainstream microcontrollers. Finally, the experimental results validate the merits of the proposed method.

Effects of the Microstructure of Copper Through-Silicon Vias on their Thermally Induced Linear Elastic Mechanical Behavior

ZhiYong Wu,Zhiheng Huang,Yucheng Ma,Hua Xiong,Paul P. Conway 대한금속·재료학회 2014 ELECTRONIC MATERIALS LETTERS Vol.10 No.1

Through-silicon vias (TSVs) have been investigated extensively in recent years. However, the physical mechanisms behind some of the common problems associated with TSVs, such as the protrusion of Cu vias, are still unknown. In addition, since the dimensions of TSVs have been shrunk to microscopic levels, the sizes of the microstructural features of TSVs are no longer small compared to the dimensions of the vias. Therefore, the role and importance of the microstructural features of TSVs need to be studied to enable more accurate reliability predictions. This study focused on the effects the microstructural features of TSVs, i.e., the Cu grains and their [111] texture, grain size distribution, and morphology, have on the thermally induced linear elastic behavior of the vias. The results of the study indicate that stress distribution in the model that takes into account the Cu grains, whose Young’s moduli and Poisson’s ratios are set according to their crystallographic orientations, is more heterogeneous than that in a reference model in which the bulk properties of Cu are used. Stresses as high as 250 MPa are observed in the via of the model that takes into consideration the Cu grains, while stresses in the via of the reference model are all lower than 150 MPa. In addition, smaller Cu grains in the vias result in higher stresses; however, the variation in stress owning to changes in the grain size is within 20 MPa. The frequency of the stresses ranging from 80 MPa to 100 MPa was the highest in the stress distribution of the vias, depending on boundary conditions. The stress level in the vias decreases with the decrease in the number of grains with the [111] texture. Finally, the stress level is lower in the model in which the grain structure is generated using a phase field model and is closer to that of the microstructures present in real materials.