H ₂ CS IN OUTFLOWS OF THE MASSIVE STAR-FORMING CORE DR21(OH)

Minh, Y. C.,Liu, S.-Y.,Chen, H.-R.,Su, Y.-N. IOP Publishing 2011 ASTROPHYSICAL JOURNAL LETTERS - Vol.737 No.1

<P>For the first time, using the Submillimeter Array, H2CS emission was observed to show a typical bipolar outflow morphology toward DR21(OH). The emission consisted of a strong concentration toward a hot molecular core (MM1a) and a symmetrically extended feature aligned roughly in the north-south direction. H2CS is one of the hot core species, and its extended emission is expected to result from the interaction between the outflow of MM1a and the dense ambient gas. We derive H2CS column densities of similar to 3 x 10(15) cm(-2) and similar to 1 x 10(15) cm(-2) toward MM1a and the centers of the extended emission, respectively. Its fractional abundance, f(H2CS) similar to 10(-9) relative to the total H-2 abundance, is comparable to those in other star-forming regions, suggesting that H2CS may be present in a region closer to the center than previously thought. Our results suggest that the observed H2CS emission arises via direct evaporation or sputtering of the solid H2CS on the grain surface, and H2CS may be one of the major sulfur-bearing species residing in the ice grain mantles in a solid form, at least in the case of DR21(OH).</P>

Characterization and Formation Mechanism of Ni3Si–Al2O3 Nanocomposite Prepared by Mechanochemical Reduction Method

H. Chen,D. M. Zhou,L. Cai,Y. Y. Wang,K. Yu 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.2

In this present work, Ni3Si–Al2O3 nanocomposite powders were synthesized by mechanical milling using NiO, Si and Alas raw materials. The phase transformation, formation mechanism and microstructure evolution of the powders duringmechanical milling were investigated by X-ray difraction (XRD), diferential thermal analysis (DTA), scanning electronmicroscopy (SEM), transition electron microscopy (TEM) and microhardness measurements. Results showed that the Ni3Si,Al2O3 and Ni31Si12 phases formed after 5 h of milling with a rapid mechanically induced self-propagating synthesis mode. The average grain size and internal strain of Ni3Si and Al2O3 after 30 h of milling were (16.8 nm, 1.27%) and (19.6 nm,0.94%), respectively. The maximum microhardness value of 813 HV was obtained in the 30 h milled powder. The relationship between the hardness and grain size of the powders satisfes the Hall–Petch relationship. Ni3Si–Al2O3 nanocompositepowders are very stable during heating at 950 °C. By annealing of the milled powders leads to grain growth, internal strainand microhardness of Ni3Si powder decrease and transformation of disordered structure to an ordered state. A long-rangeordering parameter (LRO) of 0.97 for the ordered Ni3Si can be achieved after annealing at 950 °C for 2 h.

Pseudonocardia endophytica sp. nov., isolated from the pharmaceutical plant Lobelia clavata

Chen, H.-H.,Qin, S.,Li, J.,Zhang, Y.-Q.,Xu, L.-H.,Jiang, C.-L.,Kim, C.-J.,Li, W.-J. Microbiology Society 2009 International journal of systematic and evolutiona Vol.59 No.3

<P>An endophytic actinomycete strain, designated YIM 56035(T), was isolated from the inner tissue of the traditional Chinese medicinal plant Lobelia clavata. The strain stained Gram-positive, was aerobic and exhibited branching, white aerial mycelium and yellowish-brown substrate mycelium. The strain formed spore chains on aerial hyphae. The G+C content of the genomic DNA was 70.3 mol%. On the basis of morphological, physiological, chemotaxonomic and phylogenetic characteristics, strain YIM 56035(T) was assigned to the genus Pseudonocardia. Analysis of 16S rRNA gene sequences showed 98.5, 97.3, 97.3 and 97.1 % similarity to the closely related type strains Pseudonocardia kongjuensis LM 157(T), Pseudonocardia autotrophica IMSNU 20050(T), Pseudonocardia ammonioxydans H9(T) and Pseudonocardia compacta IMSNU 20111(T), respectively. The results of DNA-DNA hybridizations and comparison of some phenotypic characteristics revealed that the strain represents a novel species of the genus Pseudonocardia. The name Pseudonocardia endophytica sp. nov. is proposed, with the type strain YIM 56035(T) (=DSM 44969(T) =CCTCC AA 206026(T) =KCTC 19150(T)).</P>

Evaluation of mango saponin in broilers: effects on growth performance, carcass characteristics, meat quality and plasma biochemical indices

Y.N. Zhang,J. Wang,B. Qi,S.G. Wu,H.R. Chen,H.Y. Luo,D.J. Yin,F.J. Lu,H.J. Zhang,G.H. Qi 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.8

Objective: The objective of the present study was to determine whether mango saponin (MS) could be used as a feed additive in broiler chicks by evaluating growth performance, carcass characteristics, meat quality, and plasma biochemical indices. Methods: A total of 216 1-d-old Arbor Acres male broiler chicks were randomly assigned into three dietary treatments supplemented with 0 (control), 0.14% (MS 0.14%), or 0.28% (MS 0.28%) MS. Each treatment had six replicates (cages) with 12 chicks each. The feeding trial lasted for six weeks. Results: Compared with the control, dietary supplemented with 0.14% or 0.28% MS increased average daily weight gain of chicks in the grower (22 to 42 d) and the whole (1 to 42 d) phases, and the final body weight of chicks on d 42 was higher in MS supplemented groups (p<0.05). Lower L45 min* (lightness) and L24 h* values, lower b24 h* (yellowness) value, and higher a45 min* (redness) and a24 h* values of the breast muscle were observed in chicks fed with 0.28% MS on d 42 (p<0.05). The total antioxidant capacity in plasma increased in MS 0.14% group on d 21 (p<0.001). Lower contents of plasma total cholesterol and triglyceride were observed in chicks fed with 0.28% MS on d 21 and d 42, whereas the group supplemented with 0.14% MS only decreased plasma triglyceride content on d 21 (p<0.05). The glucose content in plasma decreased in MS 0.28% group on d 42 (p<0.001). Conclusion: Overall, MS could be used as a feed additive in broiler chicks, and the supplemental level of 0.28% MS in diet could improve growth performance, meat quality, and plasma lipid metabolism in broiler chicks.

Asymptotic stability and bifurcation of time-periodic solutions for the viscous Burgers' equation

Chen, S.H.,Hsia, C.H.,Jung, C.Y.,Kwon, B. Academic Press 2017 Journal of mathematical analysis and applications Vol.445 No.1

<P>We consider the Dirichlet boundary value problem for the viscous Burgers' equation with a time periodic force on a one dimensional finite interval. Under the boundedness assumption on the external force, we prove the existence of the time-periodic solution by using the Galerkin method and Schaefer's fixed point theorem. Furthermore, we show that this time-periodic solution is unique and time asymptotically stable in the H-1 sense under an additional smallness condition on the external force. It is naturally expected that when the amplitude of the external force increases and crosses a certain critical value, the time-periodic solution is no longer asymptotically stable. In the last part of the article, to support our theory, numerical experiments are carried out to investigate the exchange of stabilities of the time-periodic solutions when the amplitude of the force crosses the first critical value. We numerically find this critical value at which the stable solutions turn into the unstable ones. (C) 2016 Elsevier Inc. All rights reserved.</P>

Sparse feature selection identifies H2A.Z as a novel, pattern-specific biomarker for asymmetrically self-renewing distributed stem cells

Huh, Y.H.,Noh, M.,Burden, F.R.,Chen, J.C.,Winkler, D.A.,Sherley, J.L. Elsevier 2015 Stem cell research Vol.14 No.2

There is a long-standing unmet clinical need for biomarkers with high specificity for distributed stem cells (DSCs) in tissues, or for use in diagnostic and therapeutic cell preparations (e.g., bone marrow). Although DSCs are essential for tissue maintenance and repair, accurate determination of their numbers for medical applications has been problematic. Previous searches for biomarkers expressed specifically in DSCs were hampered by difficulty obtaining pure DSCs and by the challenges in mining complex molecular expression data. To identify such useful and specific DSC biomarkers, we combined a novel sparse feature selection method with combinatorial molecular expression data focused on asymmetric self-renewal, a conspicuous property of DSCs. The analysis identified reduced expression of the histone H2A variant H2A.Z as a superior molecular discriminator for DSC asymmetric self-renewal. Subsequent molecular expression studies showed H2A.Z to be a novel ''pattern-specific biomarker'' for asymmetrically self-renewing cells, with sufficient specificity to count asymmetrically self-renewing DSCs in vitro and potentially in situ.

Shakedown analysis of trusses under cyclic thermal load with temperature-dependent yield stress

S.Y. Leu,Y.H. Chen,K.C. Liao 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.78 No.6

The paper aims to revisit shakedown analysis involving temperature-dependent yield stress. Formulations and numerical implementations are focused on truss structures subjected to cyclic thermal and constant mechanical loads. In particular, a systematic approach based on the duality relationship of l∞-norm and l1-norm is established to state the dual formulations for static and kinematic shakedown analysis of truss structures. Illustrative examples are involved statically indeterminate three-bar and five-bar trusses, respectively. Numerical effort is made to acquire shakedown limit temperature by using the linprog function provided by MATLAB. Furthermore, the finite-element analysis using ABAQUS is also performed for rigorous comparisons.

Immobilization of hemoglobin on functionalized multi-walled carbon nanotubes-poly-l-histidine-zinc oxide nanocomposites toward the detection of bromate and H₂O₂

Vilian, A.,Chen, S.M.,Kwak, C.H.,Hwang, S.K.,Huh, Y.S.,Han, Y.K. Elsevier Sequoia 2016 Sensors and actuators. B Chemical Vol.224 No.-

A novel biocompatible sensing strategy has been developed based on functionalized multi-walled carbon nanotube (f-MWCNT), poly-l-histine (P-l-His), and ZnO nanocomposite film for the immobilization of hemoglobin (Hb). The direct electron transfer properties and bioelectrocatalytic activity of the Hb in f-MWCNT-P-l-His-ZnO composite film is further investigated. The apparent heterogeneous electron transfer rate constant (k<SUB>s</SUB>) of Hb confined to f-MWCNT-P-l-His-ZnO nanocomposite is found to be 5.16s<SUP>-1</SUP> using Laviron's equation. Moreover, the surface coverage concentration (Γ) of the electroactive Hb in the f-MWCNT-P-l-His-ZnO film is estimated to be 1.88x10<SUP>-9</SUP>molcm<SUP>-2</SUP>. The fabricated electrochemical biosensor based on the immobilized Hb revealed a fast response time (<3s) with a wide linear range (4-18,000μM and 2-15,000μM) and detection limit (as low as 0.01μM and 0.30μM) for the electrocatalytic determination of a mediator-free H<SUB>2</SUB>O<SUB>2</SUB> and bromate under optimal experimental conditions. The ca. apparent Michaelis-Menten constant is 0.14mM, which indicates that the Hb has a high affinity to H<SUB>2</SUB>O<SUB>2</SUB>. The high sensitivity, good reproducibility, and long-term stability of the proposed nanocomposite film indicates that it can serve as an electrode for the development of an amperometric H<SUB>2</SUB>O<SUB>2</SUB> and bromate-based biosensor. The proposed third-generation biosensor was successfully applied to milk and urine samples for the detection of H<SUB>2</SUB>O<SUB>2</SUB> and bromate.

Two S-wave gap symmetry for single crystals of the superconductor BaFe_1.8Co_0.2As₂

Choi, K.Y.,Kim, S.H.,Choi, C.,Jung, M.H.,Wang, X.F.,Chen, X.H.,Noh, J.D.,Lee, S.I. North-Holland 2010 Physica. C, Superconductivity Vol.470 No.suppl1

To clarify the gap structure of the iron-pnictide superconductors, we synthesized optimally doped single crystals of BaFe<SUB>1.8</SUB>Co<SUB>0.2</SUB>As<SUB>2</SUB>, which had a critical temperature, T<SUB>c</SUB>, of 23.6K. The initial M-H curve was used to find the lower critical field, H<SUB>c1</SUB>. The full range of the temperature dependence of H<SUB>c1</SUB> was explained by using a two S-wave gap symmetry. We estimate the two gap as Δ<SUB>1</SUB>(0)=1.64+/-0.2meV for the small gap and Δ<SUB>2</SUB>(0)=6.20+/-0.2meV for the large gap.

A facile sol-gel method for synthesis of porous Nd-doped TiO₂ monolith with enhanced photocatalytic activity under UV-Vis irradiation

Du, J.,Chen, H.,Yang, H.,Sang, R.,Qian, Y.,Li, Y.,Zhu, G.,Mao, Y.,He, W.,Kang, D.J. Elsevier 2013 Microporous and mesoporous materials Vol.182 No.-

A porous Nd-doped TiO<SUB>2</SUB> monolith was successfully synthesized with polystyrene spheres as a template using a sol-gel method followed by calcination at high temperature. The porous Nd-doped TiO<SUB>2</SUB> monolith was characterized by X-ray diffractometry, scanning electron microscopy and Brunauer-Emmett-Teller measurements. Nd doping can increase the TiO<SUB>2</SUB> surface area by hindering the growth of large TiO<SUB>2</SUB> particles, and suppressing the recombination of photo-produced hole/electron (h<SUP>+</SUP>/e<SUP>-</SUP>) pairs. Moreover, its porous structure can provide a large surface area, facilitating enhanced adsorption and fast transfer of pollutants. To evaluate the photocatalytic activity of the porous Nd-doped TiO<SUB>2</SUB> monolith, the photo-degradation for methyl orange was investigated under UV-Vis irradiation. The porous 0.5% Nd-doped TiO<SUB>2</SUB> monolith showed better behavior than the other as-prepared samples and Degussa P25 due to its narrow band gap, high efficiency for h<SUP>+</SUP>/e<SUP>-</SUP> pair separation, and large surface area. The synergistic combination of Nd doping and the porous structure is a promising material design strategy for use in the degradation of organic pollutants.