Sodium Alginate-Assisted Synthesis of PdAg Bimetallic Nanoparticles and their Enhanced Activity for Electrooxidation of Ethanol

Yanru Yin,Changna Wen,Ning Ma,Baoyan Wang,Lianying Zhang,Hongliang Li,Peizhi Guo 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.9

Palladium and palladium-silver bimetallic nanocrystals have been synthesized hydrothermally by using environmental-friendly sodium alginate as the stabilizer and reducing agent. The pure palladium nanoparticles were spherical-like possibly due to the principle of the lowest surface energy, however, the formation of bimetallic palladium-silver nanoparticles was much more complicated, which was thinner and more irregular nanostructures than pure palladium nanoparticles. Electrochemical measurements showed that the electrocatalytic activity toward ethanol oxidation was increased first with the increase of silver content in bimetallic nanoparticles, from pure palladium of around 1070 mA/mg, to PdAg-20 of 1160 mA/mg and to PdAg-10 of 1750 mA/mg, and declined greatly at a high content of silver, approximately 279 mA/mg. Electrochemical stability test showed that PdAg-10 and PdAg-5 were the best and worst among four palladium-based samples, respectively. Based on the experimental data, the formation mechanism of pure palladium and palladium-silver bimetallic nanoparticles and the structure-property relationship of these samples have been discussed.

Effects of Freeze and Cyclic Load on Impact Resistance of Filling Layer Self-Compacting Concrete (FLSCC)

Ning Li,Guangcheng Long,Qiang Fu,Cong Ma,Kunlin Ma,Youjun Xie 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.7

Filling layer self-compacting concrete (FLSCC) is a key material in newly-built China Rail Track System (CRTS), which is commonly subjected to cyclic dynamic load from high-speed train and various ambient temperature during service. In this paper, a series of indoor simulating experiments was conducted to investigate the impact resistance of FLSCC suffering from cyclic flexural load and different temperature conditions with a Φ75 mm split Hopkinson pressure bar (SHPB). The dynamic increase factors were introduced to evaluate the strain rate effect on various mechanical properties of FLSCC and the corresponding mechanisms were explained. Results show that the dynamic increase factor of compressive strength (DIFc) and peak strain (DIFε) of FLSCC increase linearly with logarithm of strain rate, while specific energy absorption increases exponentially with strain rate. The impact resistance of FLSCC is greatly influenced by cyclic flexural load and low temperature. The strain rate sensitivity of compressive strength of FLSCC at minus temperature (-20°C) is weaker than that at normal temperature (20°C) and after freeze-cyclic load coupling action the sensitivity decreases further. Similar tendencies were also observed in peak strain and specific energy absorption.

Two Androstane Derivatives from the Cultures of Fungus Marasmiellus ramealis (Bull.) Singer

Ning-Ning Yang,Qing-Yun Ma,Sheng-Zhuo Huang,Hao-Fu Dai,Zhi-Kai Guo,Zhi-Fang Yu,You-Xing Zhao 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.11

A new androstane derivative, 4β-methyl-15-oxa-14β-androstane-7-ene-4α-carboxylic acid (1) and a known one 4β-methyl-15-oxa-14β-androstane-7-ene-4α-hydroxyl (2) were isolated from the EtOAc extract of the cultures of the fungus Marasmiellus ramealis (Bull.) Singer. Their structures were elucidated on the basis of 1D and 2D NMR as well as MS spectroscopic data analysis. The inhibitory activity of two isolates against acetylcholinesterase (AChE) revealed that compound 1 exhibited definitely inhibitory activity.

Influencing Factors of Information Channels Adoption of Forest Farmers on Grain for Green Program in Western China

Ma Ning,Yu Jinyu 보안공학연구지원센터 2014 International Journal of Hybrid Information Techno Vol.7 No.6

Forestry ecological projects have a huge impact on the living standard of forest farmers. Thus, information channels forest farmers choose to know about the information of these projects have great importance. The purpose of this study is to find out the main factors that influencing the adoption of these information channels of forest farmers in Western China. Rough set theory is used to solve the problem of main factors reduction. The result shows that total income from working outside, income of forestry, income of agriculture, forestry reforestation subsidy, non-commercial forest subsidy, forest seed subsidy, living expenditure and forest areas are the main factors that influencing the adoption of different channels.

Modeling, Testing and Numerical Simulation on Hot Forming of HSS

Ning Ma Ping Hu,Guozhe Shen Wenhua Wu 한국소성가공학회 2010 기타자료 Vol.2010 No.6

The thermal-mechanical-transformation coupled relationship of microalloy steel has important significance in forming mechanism and numerical simulation of hot forming. Tensile and quenching experiments are implemented at high temperature, and then the thermal-mechanical-transformation coupled constitutive models of hot forming are developed. Based these models, the nonlinear large-deformation dynamic explicit finite element equations are proposed. The phase transformation latent heat is introduced into the analysis of temperature field during the hot forming process. Based on the independently developed commercial CAE software for sheet metal forming, named KMAS (King-Mesh Analysis System), the numerical simulation module of hot forming is developed, which considers multi-field coupled models, nonlinear and large deformation analysis. Then the hot forming process of a reinforced beam inside the automobile door is simulated by the KMAS software, and compared with its hot forming experimental testing. The experimental results indicate the validity and efficiency of the present multi-field coupled constitutive models and numerical simulation software KMAS of hot forming.

Numerical and experimental evaluation of the impact performance of advanced high-strength steel sheets based on a damage model /

Ma, Ning,Park, Tae Joon,Kim, Dongun,Kim, Chong Min,Chung, Kwan Soo The Korean Institute of Metals and Materials 2010 METALS AND MATERIALS International Vol.16 No.3

Carbon-Ion-Implanted Nd, MgO-Codoped Near-Stoichiometric Lithium-Niobate Optical Waveguides

Ning-Ning Dong,Yang Tan,Yan-Xia Kong,Feng Chen,Hong-Ji Ma 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.6

Nd, MgO codoped near stoichiometric lithium niobate (Nd:MgO:SLN) is a promising laser gain crystal for infrared laser generations. We report on, to our knowledge for the first time, the planar waveguide formation in Nd:MgO:SLN crystal by MeV carbon ion implantation at dose of 1014 ions/cm2. The guiding properties are investigated by using the well-known m-line technique and end-face arrangement. The refractive index profiles of the waveguides show a typical “well + barrier” distribution, which could confine the light propagation in a non-leaky way. In addition, a numerical simulation of the light propagation shows that the waveguide modal distributions are in good agreement with the experimental data, which means potential applications for the formation of designable devices in Nd:MgO:SLN by using carbon ion implantation. Nd, MgO codoped near stoichiometric lithium niobate (Nd:MgO:SLN) is a promising laser gain crystal for infrared laser generations. We report on, to our knowledge for the first time, the planar waveguide formation in Nd:MgO:SLN crystal by MeV carbon ion implantation at dose of 1014 ions/cm2. The guiding properties are investigated by using the well-known m-line technique and end-face arrangement. The refractive index profiles of the waveguides show a typical “well + barrier” distribution, which could confine the light propagation in a non-leaky way. In addition, a numerical simulation of the light propagation shows that the waveguide modal distributions are in good agreement with the experimental data, which means potential applications for the formation of designable devices in Nd:MgO:SLN by using carbon ion implantation.

Physalin D inhibits RANKL-induced osteoclastogenesis and bone loss via regulating calcium signaling

( Ning Ding ),( Yanzhu Lu ),( Hanmin Cui ),( Qinyu Ma ),( Dongxia Qiu ),( Xueting Wei ),( Ce Dou ),( Ning Cao ) 생화학분자생물학회(구 한국생화학분자생물학회) 2020 BMB Reports Vol.53 No.3

We investigated the effects of physalin A, B, D, and F on osteoclastogenesis induced by receptor activator of nuclear factor кB ligand (RANKL). The biological functions of different physalins were first predicted using an in silico bioinformatic tool (BATMAN-TCM). Afterwards, we tested cell viability and cell apoptosis rate to analyze the cytotoxicity of different physalins. We analyzed the inhibitory effects of physalins on RANKL-induced osteoclastogenesis from mouse bone-marrow macrophages (BMMs) using a tartrate-resistant acid phosphatase (TRAP) stain. We found that physalin D has the best selectivity index (SI) among all analyzed physalins. We then confirmed the inhibitory effects of physalin D on osteoclast maturation and function by immunostaining of F-actin and a pit-formation assay. On the molecular level, physalin D attenuated RANKLevoked intracellular calcium ([Ca(2+)](i)) oscillation by inhibiting phosphorylation of phospholipase Cγ2 (PLCγ2) and thus blocked the downstream activation of Ca2+/calmodulindependent protein kinases (CaMK)IV and cAMP-responsive element-binding protein (CREB). An animal study showed that physalin D treatment rescues bone microarchitecture, prevents bone loss, and restores bone strength in a model of rapid bone loss induced by soluble RANKL. Taken together, these results suggest that physalin D inhibits RANKL-induced osteoclastogenesis and bone loss via suppressing the PLCγ2-CaMK-CREB pathway. [BMB Reports 2020; 53(3): 154-159]

SERS study of Ag/FeS/4-MBA interface based on the SPR effect

Ma, Ning,Zhang, Xin-Yuan,Fan, Wenyue,Guo, Shuang,Zhang, Yongjun,Liu, Yang,Chen, Lei,Jung, Young Mee Elsevier 2019 Spectrochimica acta. Part A, Molecular and biomole Vol.219 No.-

<P><B>Abstract</B></P> <P>In this work, an ordered metal-semiconductor molecular system was introduced, and 4-mercaptobenzoic acid (4-MBA) was employed to study the charge transfer (CT) at the metal-semiconductor interface based on surface-enhanced Raman scattering (SERS) spectra. The thickness of the sputtered FeS was controlled so that the surface plasmon resonance (SPR) of Ag underwent a displacement change, and the contribution of the SPR to the CT was studied through surface plasmon (SP) absorption. Furthermore, SERS spectra obtained at different excitation wavelengths were used to calculate the degree of CT in the layer-by-layer sputtering system. When Ag was irradiated with incident light, the strong SPR of Ag was excited, generating an increased electromagnetic field (EM). This amplified EM generated hot electrons at the interface between the FeS and Ag, and then the hot electrons were rearranged. Therefore, we established a simple and effective method for studying the impact of SPR on interfacial CT and analyzed the SERS spectra in accordance with Lombardi's basic theory and the physical effects associated with SPR. This theory is in good agreement with the experimental results. On this basis, we also proposed a mechanism by which SPR impacts the CT, which is beneficial for studying interfacial CT and obtaining an in-depth understanding of the CT mechanism in SERS. This work also enables the expansion of the applications of the SERS technique in the field of nanomaterials.</P> <P><B>Highlights</B></P> <P> <UL> <LI> SERS substrate was designed based on the layer-by-layer sputtering of Ag/FeS. </LI> <LI> 4-MBA was employed to study the CT at the metal-semiconductor interface. </LI> <LI> The SPR of Ag promotes the electron transfer process of the Ag/FeS/4-MBA system. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>In this paper, we designed a layer-by-layer sputtering of Ag and FeS on the PS template. FeS, as an ultranarrow bandgap semiconductor with a bandgap width of only 0.1 eV, exhibited different properties for SERS. The SPR of Ag can be tuned by controlling the FeS film thickness, which is beneficial for studying interface CT and obtaining an in-depth understanding of the CT mechanism in SERS.</P> <P>[DISPLAY OMISSION]</P>

Comparative Genomic and Genetic Functional Analysis of Industrial L-Leucine- and L-Valine-Producing Corynebacterium glutamicum Strains

( Yuechao Ma ),( Qixin Chen ),( Yi Cui ),( Lihong Du ),( Tuo Shi ),( Qingyang Xu ),( Qian Ma ),( Xixian Xie ),( Ning Chen ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 Journal of microbiology and biotechnology Vol.28 No.11

Corynebacterium glutamicum is an excellent platform for the production of amino acids, and is widely used in the fermentation industry. Most industrial strains are traditionally obtained by repeated processes of random mutation and selection, but the genotype of these strains is often unclear owing to the absence of genomic information. As such, it is difficult to improve the growth and amino acid production of these strains via metabolic engineering. In this study, we generated a complete genome map of an industrial L-valine-producing strain, C. glutamicum XV. In order to establish the relationship between genotypes and physiological characteristics, a comparative genomic analysis was performed to explore the core genome, structural variations, and gene mutations referring to an industrial L-leucine-producing strain, C. glutamicum CP, and the widely used C. glutamicum ATCC 13032. The results indicate that a 36,349 bp repeat sequence in the CP genome contained an additional copy each of lrp and brnFE genes, which benefited the export of L-leucine. However, in XV, the kgd and panB genes were disrupted by nucleotide insertion, which increase the availability of precursors to synthesize L-valine. Moreover, the specific amino acid substitutions in key enzymes increased their activities. Additionally, a novel strategy is proposed to remodel central carbon metabolism and reduce pyruvate consumption without having a negative impact on cell growth by introducing the CP-derived mutant H+/citrate symporter. These results further our understanding regarding the metabolic networks in these strains and help to elucidate the influence of different genotypes on these processes.