Fabrication and Characterization of Bimetal Sulfide Hybrid Ag/S-ZVI for Dechlorination of Trichloroethylene

Shubin Zhang,Tianxiao Wang,Xin Guo,Shengwen Chen,Lijun Wang 대한환경공학회 2023 Environmental Engineering Research Vol.28 No.4

Sulfidated and bimetal modification can improve the reactivity and selectivity of zero-valent iron in contaminant removal. However, previous studies were focused on unilateral material approaches. In this article, a new hybrid composite Ag/S-ZVI was prepared by doping elemental silver on surface of sulfidated nanoscale zerovalent iron (S-nZVI). The results of X-Ray Diffraction (XRD), energy dispersive spectrometer (EDS) and X-ray Photoelectron Spectroscopy (XPS) indicated Ag was dispersed on the surface of S-nZVI. Scanning electron microscope (SEM) images displayed Ag/S-ZVI was irregular clusters with rough surfaces, small agglomeration, and quasi-spherical in shape. The removal of TCE by Ag/S-ZVI was 90.4% within 20 min. The reaction rate constant Kobs of Ag/S-ZVI was 2.59 times or 1.85 times of nZVI or S-nZVI, respectively. Cycling experiments showed that Ag/S-ZVI had good recycling ability, and the removal rate of TCE reached 72.6% at the third cycle. The addition of Ag+ makes S-nZVI as an abundant and efficient source of reducing electrons. The Fe<SUP>0</SUP> core can break C-Cl bonds by releasing electrons and the surface layer of Ag favors the transfer efficiency of electrons. Such study provides an efficient and robust ternary system for the remediation of TCE in groundwater.

GROUND STATE SIGN-CHANGING SOLUTIONS FOR NONLINEAR SCHRÖDINGER-POISSON SYSTEM WITH INDEFINITE POTENTIALS

Yu, Shubin,Zhang, Ziheng Korean Mathematical Society 2022 대한수학회논문집 Vol.37 No.4

This paper is concerned with the following Schrödinger-Poisson system $$\{\begin{array}{lll}-{\Delta}u+V(x)u+K(x){\phi}u=a(x){\mid}u{\mid}^{p-2}u&&\text{ in }{\mathbb{R}}^3,\\-{\Delta}{\phi}=K(x)u^2&&\text{ in }{\mathbb{R}}^3,\end{array}$$ where 4 < p < 6. For the case that K is nonnegative, V and a are indefinite, we prove the above problem possesses one ground state sign-changing solution with exactly two nodal domains by constraint variational method and quantitative deformation lemma. Moreover, we show that the energy of sign-changing solutions is larger than that of the ground state solutions. The novelty of this paper is that the potential a is indefinite and allowed to vanish at infinity. In this sense, we complement the existing results obtained by Batista and Furtado [5].

Mechanical and surface properties of HF50S carbon fibers

Gu Hongxing,Zhang Ming,Zhang Shubin,Qi Jingyao 한국탄소학회 2022 Carbon Letters Vol.32 No.3

To thoroughly analyze the mechanical properties and surface conditions of HF50S carbon fibers, the tensile properties, surface morphology, surface chemical element, surface energy, sizing agent properties, and Naval Ordnance Laboratory (NOL) ring of their composites were characterized. Furthermore, the aforementioned properties were exhaustively compared with those of T1000G carbon fibers. The results showed that the tensile strength, modulus, and elongation of the HF50S carbon fibers were 6638 MPa, 297 GPa, and 2.2%, respectively, thus demonstrating that the mechanical properties of the HF50S carbon fibers were on par with those of the T1000G carbon fibers, in addition, the coefficient of variation (Cv) indices of HF50S carbon fiber were below 3%, indicating good stability. The HF50S carbon fibers have a smooth surface without grooves, which is analogous to that of the T1000G carbon fibers prepared by the typical dry jet–wet spinning process. The main component of the sizing agent of the HF50S carbon fibers is an epoxy resin, which is also used for the preparation of epoxy matrix composites. Because the HF50S carbon fiber surface has greater O and N contents than the T1000G carbon fiber surface, the HF50S carbon fibers have more active functional groups and higher surface activity. The surface energy of the HF50S carbon fibers is 30.13 mJ/m2, which is higher than that of the T1000G carbon fibers (28.42 mJ/m2). Owing to the higher strength and surface activity of the HF50S carbon fibers than those of the T1000G carbon fibers, the strength and strength conversion of NOL ring based on the former are slightly higher than those of that prepared using the latter.

Wrinkled rGO Sheets-Wrapped Carbon Fibers with High Tensile Strength and Excellent Electrochemical Stability as Anodes for Structural Li-Ion Battery

Huagen Li,Shubin Wang,Mengjie Feng,Jiping Yang,Boming Zhang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.08

Herein, we report a hierarchical structure formed by wrinkled reduced graphene oxide (rGO) sheets-wrapped carbon fiber via a facile and efficient electrostatic self-assembly method and subsequent annealing treatment. For this material, the Weibull scale parameter is 4.77 GPa. After 100 cycles, the rGO@CF retains 91% of its second charge capacity at 50mA· g -1, corresponding to a capacity fading of only 0.09% per cycle. Thus, this structural anode material exhibits enhanced capacity, high initial Coulombic efficiency and high tensile strength. Meanwhile, the carbon fiber and interweaved rGO sheets together form the whole conductive networks to provide multichannel highways for charge transfer (lithium-ion diffusion and electron transport) during discharge–charge processes, promising excellent electrochemical performance of this structural anode material.

Engineered biomaterials for development of nucleic acid vaccines

Jun Yang,Yan Li,Shubin Jin,Jing Xu,Paul C Wang,Xing-Jie Liang,Xin Zhang 한국생체재료학회 2015 생체재료학회지 Vol.19 No.1

Nucleic acid vaccines have attracted many attentions since they have presented some superiority over traditional vaccines. However, they could only induce moderate immunogenicity. The route and formulation of nucleic acid vaccines have strong effects on the immune response and efficiency. Numerous biomaterials are used as a tool to enhance the immunogenicity of antigens. They deliver the antigens into the cells through particle- and non-particle-mediated pathway. However, challenges remain due to lack of comprehensive understanding of the actions of these biomaterials as a carrier/adjuvant. Herein, this review focuses on the evolution of biomaterials used for nucleic acid vaccines, discusses the advantages and disadvantages for gene delivery and immunostimulation of variety of structures of the biomaterials, in order to provide new thought on rational design of carrier/adjuvant and better understanding of mechanism of action in both immunostimulatory and delivery methods.

Decision diagram based methods and reliability analysis for k-out-of-n: G systems

Shumin Li,Shudong Sun,Shubin Si,Shuai Zhang,Hongyan Dui 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.10

Binary k-out-of-n systems are commonly used reliability models in engineering practice. Many authors have extended the concept ofk-out-of-n system to multi-state k-out-of-n systems. This paper proposes a binary decision diagram (BDD) based approach for binary kout-of-n: G system and a multi-state multi-valued decision diagram (MMDD) based approach for multi-state k-out-of-n: G system. BDDand MMDD have been extensively used for representing and manipulating logic functions in many areas, including reliability modelingand analysis. In this paper, patterns of BDD/MMDD for binary/multi-state k-out-of-n: G system are summarized and proved, a two-stepalgorithmic process is proposed for modeling the BDD/MMDD and three case studies are implemented to demonstrate the presentedmethods. Complexity analysis shows that the presented method is more computationally efficient than the traditional algorithms for kout-of- n: G system.

Morphogenesis and global analysis of transcriptional profiles of Celastrus orbiculatus aril: unravelling potential genes related to aril development

Kuiling Zu,Jianxia Li,Shubin Dong,Yunyu Zhao,Shenjian Xu,Zhixiang Zhang,Liangcheng Zhao 한국유전학회 2017 Genes & Genomics Vol.39 No.6

As a specialized seed appendage, the aril is a noteworthy and taxonomically important feature of Celastrus orbiculatus; the aril also has important ornamental value and biological functions. To better understand the mechanism of aril development, paraffin sections were used to examine its morphogenesis, and RNA-sequencing (RNA-seq) technology was employed for transcriptional profiling of the developing aril. Our results revealed that the aril of C. orbiculatus was formed by the cells of the exostomal region of the outer integument. By analyzing global changes in the transcriptome, 41,560,806, 42,789,340, and 44,496,748 clean reads from three cDNA libraries were generated and assembled into 87,600 unigenes with N50 of 1328 bp, in which 31,971 (36.49%) were annotated to Nr database. Furthermore, a total of 25,914 (29.79%), 14,394 (16.4%) and 11,957 (13.65%) genes were successfully annotated with hierarchical 48 GO terms, 26 KOGs and 32 KEGG pathways. Totally, 104, 1887 and 1967 differently expressed genes were identified in CO-F2 versus CO-F3, CO-F2 versus CO-YF1 and CO-F3 versus CO-YF1, respectively. GO and KEGG pathway analyses of DEGs involved in cell–cell communication and plant hormone signal transduction contributed to aril development were identified. Furthermore, we found putative key target genes of WRKY, Aux/IAA, ARF and MADS-box family’s transcription factors related to aril development. Real-time qPCR was performed on eight genes randomly selected from important transcription factors to validate the expression profiles obtained by RNA-seq. This work provides a platform for future genetic and functional genomics research on the molecular mechanisms of aril structure, and expands our understanding of the molecular mechanism and evolutionary analysis of aril development in other members of the Celastraceae.

Forage Production and Water Use Efficiency of Three Lucerne Varieties at Different Soil Water Availabilities

Huimin Yang,Guoli Liu,Shubin He,Yuying Shen,Xiaoyan Zhang 한국초지조사료학회 2009 한국초지조사료학회 학술대회논문집 Vol.2009 No.08

Forage production and water use efficiency (WUE) of Lucerne were investigated in three varieties at different water availabilities. Forage production decreased with the severity of soil water availability. At 50% field water capacity (FWC), forage production dropped but in two varieties, Algonquin and Longdong, was still high and from 75%FWC to 50%FWC, forage production in Longdong decreased at the least rate. The greatest leaf WUE was observed in Longdong at all soil water availabilities. From 75%FWC to 50%FWC, it increased in Longdong and Xinjiangdaye, but decreased in Algonquin. With the severity of water deficit, δ¹³C value increased in all three varieties. At the same water availability, the greatest value was observed in Longdong. It suggested that moderate water stress can improve WUE in Lucerne. Longdong is to some extent more efficient in water use and may be more drought-tolerant with more steady production at moderate water deficit.

Dynamic characteristics analysis of partial-interaction composite continuous beams

Genshen Fang,Jingquan Wang,Shuai Li,Shubin Zhang 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.21 No.1

The dynamic characteristics of continuous steel-concrete composite beams considering the effect of interlayer slip were investigated based on Euler Bernoulli's beam theory. A simplified calculation model was presented, in which the Mode Stiffness Matrix (MSM) was developed. The natural frequencies and modes of partialinteraction composite continuous beams can be calculated accurately and easily by the use of MSM. Proceeding from the present method, the natural frequencies of two-span steel-concrete composite continuous beams with different span-ratios (0.53, 0.73, 0.85, 1) and different shear connection stiffnesses on the interface are calculated. The influence pattern of interfacial stiffness on bending vibration frequency was found. With the decrease of shear connection stiffness on the interface, the flexural vibration frequencies decrease obviously. And the influence on low order modes is more obvious while the reduction degree of high order is more sizeable. The real natural frequencies of partial-interaction continuous beams commonly used could have a 20% to 40% reduction compared with the fully-interaction ones. Furthermore, the reduction-ratios of natural frequencies for different span-ratios two-span composite beams with uniform shear connection stiffnesses are totally the same. The span-ratio mainly impacts on the mode shape. Four kinds of shear connection stiffnesses of steel-concrete composite continuous beams are calculated and compared with the experimental data and the FEM results. The calculated results using the proposed method agree well with the experimental and FEM ones on the low order modes which mainly determine the vibration properties.