Metastable equilibrium for the quaternary system containing with lithium+ potassium+magnesium+chloride in aqueous solution at 323K

Xudong Yu,Ying Zeng,Qinghong Yin,Dongbo Jiang 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.6

The metastable equilibrium of the system contained with lithium, potassium, magnesium, and chloridein aqueous system was investigated at 323 K using an isothermal evaporation method. The isothermal experimentaldata and physicochemical properties, such as density and refractive index of the equilibrated solution, were determined. With the experimental results, the stereo phase diagram, the projected phase diagram, the water content diagram andthe physicochemical properties versus composition diagrams were constructed. The projected phase diagram consistsof three invariant points, seven univariant curves and five crystallization fields corresponding to single salts potassiumchloride (KCl), lithium chloride monohydrate (LiCl·H2O), bischofite (MgCl2·6H2O) and two double salts lithium carnallite(LiCl·MgCl2·7H2O) and potassium carnallite (KCl·MgCl2·6H2O). Salt KCl has the largest crystallization region;it contains almost 95% of the general crystallization field.

A high concentration of genistein down-regulates activin A, Smad3 and other TGF-β pathway genes in human uterine leiomyoma cells

Xudong Di,Danica M.K. Andrews,Charles J. Tucker,Linda Yu,Alicia B. Moore,Xiaolin Zheng,Lysandra Castro,Tonia Hermon,Hang Xiao,Darlene Dixon 생화학분자생물학회 2012 Experimental and molecular medicine Vol.44 No.4

Previously, we found that high doses of genistein show an inhibitory effect on uterine leiomyoma (UtLM) cell proliferation. In this study, using microarray analysis and Ingenuity Pathways AnalysisTM, we identified genes (up- or down-regulated, ≥ 1.5 fold, P ≤ 0.001),functions and signaling pathways that were altered following treatment with an inhibitory concentration of genistein (50 μg/ml) in UtLM cells. Downregulation of TGF-β signaling pathway genes, activin A, activin B,Smad3, TGF-β2 and genes related to cell cycle regulation,with the exception of the upregulation of the CDK inhibitor P15, were identified and validated by real-time RT-PCR studies. Western blot analysis further demonstrated decreased protein expression of activin A and Smad3 in genistein-treated UtLM cells. Moreover, we found that activin A stimulated the growth of UtLM cells, and the inhibitory effect of genistein was partially abrogated in the presence of activin A. Overexpression of activin A and Smad3 were found in tissue samples of leiomyoma compared to matched myometrium, supporting the contribution of activin A and Smad3 in promoting the growth of UtLM cells. Taken together, these results suggest that downregulation of activin A and Smad3, both members of the TGF-β pathway, may offer a mechanistic explanation for the inhibitory effect of a high-dose of genistein on UtLM cells, and might be potential therapeutic targets for treatment of clinical cases of uterine leiomyomas.

Effect of BRBs on the Seismic Resistance of Single-Layer Reticulated Domes

Xudong Zhi,Feng Fan,Feng Shi,Zhiwei Yu 한국강구조학회 2013 International Journal of Steel Structures Vol.13 No.1

This paper considers the seismic resistance of buckling restrained braces (BRB) in single-layer reticulated domes and their substructures. The method of tracing the full-range dynamic response is used to analyze the seismic response of dome structures with different embedded braces. Based on results relating to critical responses, such as displacement, development of plastic deformation and ultimate load, the effect of BRBs on key design parameters, including core area, yield stress, installing forms etc., is examined. The effect of a dome’s rise-span ratio on the structure is also investigated. It is concluded that BRBs between supporting columns can effectively improve a structure’s seismic performance.

Thermally Self-Healable Titanium Dioxide/Polyurethane Nanocomposites with Recoverable Mechanical and Dielectric Properties

Xudong Wu,Jingyu Huang,Shuhui Yu,Panpan Ruan,Rong Sun,Ching-Ping Wong 한국고분자학회 2020 Macromolecular Research Vol.28 No.4

Dielectric materials with self-healing property after the occurrence of detrimental events such as tearing or scratch are highly desired, which guarantees reliability and lifetime of the electric and electronic systems. Here, a self-healing covalently bonded titanium dioxide/polyurethane (TiO2/PU) nanocomposite with enhanced dielectric constant was prepared by in-situ polymerization based upon Diels-Alder reaction. The PU prepolymer was prepared from TiO2, poly(tetramethylene glycol) and 4,4-diphenylmethane diisocyanate. Then the linking between the prepolymer and Diels-Alder adducts of bifunctional maleimide blocked by furfuryl alcohol was carried out. The in-situ polymerization method allows the TiO2 filler, the PU polymer matrix, and the DA healing portion to be tightly connected, resulting in a stable nanocomposite system. Due to the reversibility of covalent bonds, the TiO2/PU nanocomposites exhibited thermal self-healing properties after being cut. The dielectric constant and loss, mechanical properties can be effectively restored to their original state after damage.

A numerical and theoretical investigation on composite pipe-in-pipe structure under impact

Xudong Qian,Yu Wang,J.Y. Richard Liew,Min-Hong Zhang 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.22 No.5

This paper investigates the transverse impact response for ultra lightweight cement composite (ULCC) filled pipe-in-pipe structures through a parametric study using both a validated finite element procedure and a validated theoretical model. The parametric study explores the effect of the impact loading conditions (including the impact velocity and the indenter shape), the geometric properties (including the pipe length and the dimensions of the three material layers) as well as the material properties (including the material properties of the steel pipes and the filler materials) on the impact response of the pipe-in-pipe composite structures. The global impact responses predicted by the FE procedure and by the theoretical model agree with each other closely. The parametric study using the theoretical approach indicates the close relationships among the global impact responses (including the maximum impact force and the maximum global displacement) in specimens with the equivalent thicknesses, proposed in the theoretical model, for the pipe-in-pipe composite structures. In the pipe-in-pipe composite structure, the inner steel pipe, together with the outer steel pipe, imposes a strong confinement on the infilled cement composite and enhances significantly the composite action, leading to improved impact resistance, small global and local deformations.

Study on mechanical performance of composite beam with innovative composite slabs

Yunlong Yu,Yong Yang,Xianwei Zhou,Charles W. Roeder,Xudong Huo 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.21 No.3

A new type of composite beam which consists of a wide flange steel shape beam and an innovative type of composite slab was introduced. The composite slab is composed of concrete slab and normal flat steel plates, which are connected by perfobond shear connectors (PBL shear connectors). This paper describes experiments of two large-scale specimens of that composite beam. Both specimens were loaded at two symmetric points for 4-point loading status, and mechanical behaviors under hogging and sagging bending moments were investigated respectively. During the experiments, the crack patterns, failure modes, failure mechanism and ultimate bending capacity of composite beam specimens were investigated, and the strains of concrete and flat steel plate as well as steel shapes were measured and recorded. As shown from the experimental results, composite actions were fully developed between the steel shape and the composite slab, this new type of composite beams was found to have good mechanical performance both under hogging and sagging bending moment with high bending capacity, substantial flexure rigidity and good ductility. It was further shown that the plane-section assumption was verified. Moreover, a design procedure including calculation methods of bending capacity of this new type of composite beam was studied and proposed based on the experimental results, and the calculation methods based on the plane-section assumption and plastic theories were also verified by comparisons of the calculated results and experimental results, which were agreed with each other.

Failure Mechanism of Single-layer Saddle-curve Reticulated Shells with Material Damage Accumulation Considered under Severe Earthquake

Zhiwei Yu,Xudong Zhi,Feng Fan,Chen Lu 한국강구조학회 2012 International Journal of Steel Structures Vol.12 No.1

This paper presents the study on failure mechanism of single-layer saddle-curve reticulated shells subjected to severe earthquake. Failure mode of single-layer saddle-curve reticulated shells is illustrated with the consideration of material damage accumulation. The effects of different parameters on failure characteristics of single-layer saddle-curve reticulated shells are discussed. The influence of substructure upon failure behaviors of single-layer saddle-curve reticulated shells is particularly investigated. It is observed that dynamic strength failure is the failure mode of single-layer saddle-curve reticulated shells. The substructure has great influence on failure characteristics of single-layer saddle-curve reticulated shells subjected to the severe earthquake.

Low-Voltage and High-Current DC Output Realized by Multiple Power Cells Based on Deadbeat and Automatic Current Sharing Control

Jinfeng Liu,Yu Zhang,Xudong Wang,Herbert Ho-Ching IU 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.4

This paper presents a synchronous generator with a distributed system of multiple parallel three-phase power cells. This generator can immediately output high DC. Each power cell comprises three-phase windings and a three-phase synchronous rectification bridge with a deadbeat control of load power feedforward, which can improve the characteristics of dynamic response and reflect the load variance in real time. Furthermore, each power cell works well independently and modularly using the method of automatic maximum current sharing. The simulation and experimental results for the distributed controller of multiple power cells demonstrate that the deadbeat control method can respond quickly and optimize the quality of the energy. Meanwhile, automatic maximum current sharing can realize the validity of current sharing among power cells.

Fabrication of free-standing fluorescent mesoporous silica films for detection of nitrobenzene

Fusheng Zhang,Xudong Zheng,Enli Liu,Longbao Yu,Yongsheng Yan 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.46 No.-

We report a facile two-step strategy for grafting lanthanide complexes onto the surface of nanocrystallinecellulose-templated mesoporous silicafilms to prepare luminescence mesoporous silicafilms, whichretain both chiral nematic order of the cellulose nanocrystals andfluorescence of the lanthanidecomplexes are successfully co-assembled after removal of the cellulose and grafting lanthanidecomplexes. Thefilms exhibit well-definedfluorescence combining the assembly lanthanide complexes. The mesoporous channels offluorescent mesoporous silicafilms are more accessible to the analytescompared with traditionalfluorescent materials. So, ourfluorescent mesoporous silicafilms were used asfluorescent sensor for the detection of nitrobenzene.

A flexible imprinted photonic resin film templated by nanocrystalline cellulose for naked-eye recognition of sulfonamides

Fusheng Zhang,Enxiu Liu,Xudong Zheng,Longbao Yu,Yongsheng Yan 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.58 No.-

An optical sulfonamides sensor is fabricated based on a molecular imprinted resin templated bynanocrystalline cellulose. A chiral nematic imprinted compositefilm is synthesized which issubsequently treated with removal of templates to generate a red reflecting photonicfilm. Thefilmshows a naked-eye color response to sulfanilamide, which is related to reassemble imprinted sites in thechiral nematic structure, resulting in a yellow reflectingfilm. Upon exposure to various antibiotics, it canbe simultaneously in selectively response to three sulfonamides. This strategy facilitates enormouslypotential application of the resin as battery-free and portative optical monitoring sensors.