SIMULATION AND OPTIMIZATION METHODS OF THE THERMAL CONTROL LOOP OF SPACECRAFT

Xin Gang Liang,Qun Chen,Xiang Hua Xu 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.5

Power consumption keeps increasing with increase in their functions and capabilities of spacecraft, which in turn results in the requirement of thermal control techniques, efficient that dissipation and thermal management. The numerical simulation of the thermal control loop should be performed before and after its design and ground test of the thermal control and management is necessary to measure their reliability. A semi-physical ground test method for the thermal control loop of space station is proposed which can realize dynamic measurement of the thermal control loop. A method of simplifying the numerical simulation of the thermal control loop is developed and a new technique, the heat flow circuit, is induced for the numerical simulation and optimization of the thermal control loop.

Robust Discrete-time Control for Uncertain time-delay Systems with Nonlinearities Under Hölder Continuity

Xin Wang,Xin Zuo,Jianwei Liu,Huaqing Liang,Qi Pan 제어로봇시스템학회 2016 제어로봇시스템학회 국제학술대회 논문집 Vol.2016 No.10

This paper is concerned with the robust discrete-time control for uncertain time-delay systems with nonlinearities and external noises. The parameter uncertainties enter into all the system matrices. The time-varying delay is unknown with given lower and upper bounds. The stochastic nonlinearities are described by satisfying a class of α Hölder condition. The problem addressed is the analysis and design of a stable controller such that, for all the parameter uncertainties, time-delay, stochastic nonlinearities and external noises, the resulting closed-loop system is exponentially stabile. The controller gain can be got by linear matrix inequalities (LMIs). Numerical examples are given to illustrate the effectiveness and verify the proposed theoretical results.

Abundant Manganese Complex-Anchored BiOI Hybrid Photocatalyst for Visible Light-Driven CO2 Reduction

Xin Xin,Ning Ma,Changying Hu,Qi Liang,Zhaoyong Bian 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.2

An abundant manganese complex-anchored BiOI hybrid system for CO2 photocatalytic conversion was constructed. Layered BiOI and tricarbonyl Mn bipyridyl complex with carboxyl acid groups were connected with covalent bonds and used as visible light antenna and CO2 reduction reaction centers, respectively. The covalent connection of this hybrid system benefits the transfer of electrons from the semiconductor to the Mn complex. The anchoring group (carboxyl) is the key to CO2 reduction for the direct coupling of the two units, facilitating the transfer of electrons from BiOI to the manganese complexes. The photocatalytic properties and stability of the tri-carbonyl Mn–bipyridyl complex were significantly enhanced with the aid of anchored BiOI. A high turnover number (TON = 74) of HCOO- formation from CO2 could be achieved using this hybrid system under visible light irradiation.

Surface structure-dependent hydrophobicity/oleophilicity of pyrite and its influence on coal flotation

Xin Qi,Xin Li,Yannan Liang,Hainan Wang,Wei Guo,Xingshun Cong,Fakui Lv,Haijun Zhang 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.87 No.-

Flotation is an important method to remove the inorganic sulfur from coal. Its effect depends on thedifference in adhesion between coal and pyrite to air bubbles andflotation reagents. In this study, theinterface properties of coal powder/plate and pyrite powder/crystals were investigated using acomprehensive approach combining wetting process, induction time, contact angle, and X-rayphotoelectron spectroscopy. The experimental results show that the spreading and adsorption speedof diethyl phthalate on pyrite crystals and powder is close to that on coal surface in the air. However, theadsorption rate of pyrite to water is much higher than that of coal. In aqueous environment, it is difficultfor diethyl phthalate to spread on pyrite crystals, especially in alkaline solution. The difference ofhydrophobicity between coal and pyrite at air–water interface is smaller than that at oil–water interface. The adhesion of air bubble and reagent droplet on three pyrite facets is also different. The oxidation ofpyrite {100} is faster and greater than that of {210} and {111} facets in alkaline solution, which is beneficialto the coal desulfurization. Thesefindings disclose the hydrophobicity/oleophilicity and structure-reactivity dependence of pyrite in theflotation.

The Effect of Mn/Al Substitution on the Structural Stability and Magnetic Properties of Mn₃AlC

Xin-You Wang,Ping-Zhan Si,Hui-Dong Qian,Yang Yang,Hong-Liang Ge,Jihoon Park,Xin-Qing Wang,Chul-Jin Choi 한국자기학회 2019 Journal of Magnetics Vol.24 No.1

The structural stability and magnetic properties of Mn3+xAl1-xC antiperovskite with varied Mn/Al substitution were studied systematically. Single phase Mn3+xAl1-xC alloys with antiperovskite structure were obtained in samples with x = −1/4, 0, 1/4, 1/2. An additional Mn23C₆ phase was precipitated from Mn3+xAl1-xC antiperovskite for x = 3/4 while Mn23C₆ phase was formed as major phase for x = 1. The mutual substitution of Mn and Al atoms has substantial effect on the Curie temperature and the saturation magnetization of the Mn3+xAl1-xC alloys. In comparison with the as-cast alloys, the as-annealed Mn3+xAl1-xC alloys exhibit reduced Mn/Al substitutions after high temperature homogenization, which enhances the ordering of Mn and Al atoms in the lattices. The Curie temperature of the homogenized Mn3+xAl1-xC increases with increasing Mn substitution to Al. The Mn₃AlC alloy shows the highest saturation magnetization among all samples with varied Mn/Al ratios. Most samples show zero coercivity and zero remanent magnetization. The maximum value of the magnetic entropy changes of Mn2.75Al1.25C at 285 K is 2.26 J/㎏ K in fields up to 3 T.

A PSTN Terminal for FSK Decoding and DTMF Dialing Applications

Liang Xin-Tao,Fan Qing-Yu,Lin Wen-Chang 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.5

To realize Frequency Shift Keying (FSK) decoding and Dual-Tone Multi-Frequency (DTMF) dialing, a novel hardware and software solution is presented. These two signals are used to receive or send messages respectively in this solution which can meet different requirements of many Public Switched Telephone Network (PSTN) applications. The hardware used CPC5622 as the phone line interface Data access arrangement (DAA), HT9032D as the FSK decoder, and C8051f120 as the DTMF generator and system controller. The software, mainly composed of DTMF dialing and FSK decoding subprograms, was written and debugged with the hardware and finally succeeded to realize the terminal. The results performed under Huawei C&C08 switch show that the terminal can realize dialing by encoding standard DTMF signals and extracting the caller's information from the standard FSK signals in the PSTN. The CPC5622 as well as C8051f120 has some free Inputs, outputs, and other hardware resources, which make the PSTN terminal scalable and available to a variety of PSTN devices and applications.

Anisotropic Thermal Conductance in Thin Layers of Disordered Packed Spheres

Xin Gang Liang,Jennifer R. Lukes,Chang Lin Tien 대한기계학회 1998 Heat transter conference Vol.7 No.1

Chemosensitizing effect and mechanism of imperatorin on the anti-tumor activity of doxorubicin in tumor cells and transplantation tumor model

Xin-li Liang,Miao-miao Ji,Zheng-gen Liao,Guo-wei Zhao,Xi-lan Tang,Wei Dong 대한약리학회 2022 The Korean Journal of Physiology & Pharmacology Vol.26 No.3

Multidrug resistance of tumors has been a severe obstacle to the success of cancer chemotherapy. The study wants to investigate the reversal effects of imperatorin (IMP) on doxorubicin (DOX) resistance in K562/DOX leukemia cells, A2780/Taxol cells and in NOD/SCID mice, to explore the possible molecular mechanisms. K562/ DOX and A2780/Taxol cells were treated with various concentrations of DOX and Taol with or without different concentrations of IMP, respectively. K562/DOX xenograft model was used to assess anti-tumor effect of IMP combined with DOX. MTT assay, Rhodamine 123 efflux assay, RT-PCR, and Western blot analysis were determined in vivo and in vitro. Results showed that IMP significantly enhanced the cytotoxicity of DOX and Taxol toward corresponding resistance cells. In vivo results illustrated both the tumor volume and tumor weight were significantly decreased after 2-week treatment with IMP combined with DOX compared to the DOX alone group. Western blotting and RT-PCR analyses indicated that IMP downregulated the expression of P-gp in K562/DOX xenograft tumors in NOD/SCID mice. We also evaluated glycolysis and glutamine metabolism in K562/DOX cells by measuring glucose consumption and lactate production. The results revealed that IMP could significantly reduce the glucose consumption and lactate production of K562/DOX cells. Furthermore, IMP could also remarkably repress the glutamine consumption, α-KG and ATP production of K562/DOX cells. Thus, IMP may sensitize K562/DOX cells to DOX and enhance the antitumor effect of DOX in K562/DOX xenograft tumors in NOD/SCID mice. IMP may be an adjuvant therapy to mitigate the multidrug resistance in leukemia chemotherapy.

The Experimental Practices of VoIP Based on the Commercial Softswitch Device

Liang Xin-tao,Zhu Hong-yuan,Wang Dun-ci 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.5

A softswitch is the central device of the next-generation network (NGN) which is the hotspot in telecommunication industry. So it’s of great significance for the students and related companies to carry out practical experiments and researches based on the commercial softswitch device. Three stage targets of the VoIP, from the elementary to the profound, are proposed according to the characters of the softswitch teaching. The hardware and the software queuing system of the NGN laboratory of Harbin University of Science and Technology, which was designed and built for the targets, are introduced. Students can be queued for experiments with commercial VoIP devices in the NGN laboratory. Three categories of experiments, IP to IP, IP to Phone, and Softphone application development, are designed to cultivate innovative talents.

SDC4 Gene Silencing Favors Human Papillary Thyroid Carcinoma Cell Apoptosis and Inhibits Epithelial Mesenchymal Transition via Wnt/β-Catenin Pathway

Liang-Liang Chen,Ge-Xin Gao,Fei-Xia Shen,Xiong Chen,Xiao-Hua Gong,Wen-Jun Wu 한국분자세포생물학회 2018 Molecules and cells Vol.41 No.9

As the most common type of endocrine malignancy, papillary thyroid cancer (PTC) accounts for 85-90% of all thyroid cancers. In this study, we presented the hypothesis that SDC4 gene silencing could effectively attenuate epithelial mesenchymal transition (EMT), and promote cell apoptosis via the Wnt/β-catenin signaling pathway in human PTC cells. Bioinformatics methods were employed to screen the determined differential expression levels of SDC4 in PTC and adjacent normal samples. PTC tissues and adjacent normal tissues were prepared and their respective levels of SDC4 protein positive expression, in addition to the mRNA and protein levels of SDC4, Wnt/β-catenin signaling pathway, EMT and apoptosis related genes were all detected accordingly. Flow cytometry was applied in order to detect cell cycle entry and apoptosis. Finally, analyses of PTC migration and invasion abilities were assessed by using a Transwell assay and scratch test. In PTC tissues, activated Wnt/β-catenin signaling pathway, increased EMT and repressed cell apoptosis were determined. Moreover, the PTC K1 and TPC-1 cell lines exhibiting the highest SDC4 expression were selected for further experiments. In vitro experiments revealed that SDC4 gene silencing could suppress cell migration, invasion and EMT, while acting to promote the apoptosis of PTC cells by inhibiting the activation of the Wnt/β-catenin signaling pathway. Besides, si-β-catenin was observed to inhibit the promotion of PTC cell migration and invasion caused by SDC4 overexpression. Our study revealed that SDC4 gene silencing represses EMT, and enhances cell apoptosis by suppressing the activation of the Wnt/β-catenin signaling pathway in human PTC.