SIMPLE SYNTHESIS OF UNIFORM α-Fe2O3 MICROSPHERES WITH EXCELLENT PHOTOCATALYTIC PERFORMANCE USING POLY (N-VINYL-2-PYRROLIDONE)

TING-TING ZHANG,TING-TING GUO,ZHI-PING WU,SI-WEI YANG,ZHOU-FENG WANG,FANG LIAO 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2013 NANO Vol.8 No.5

In this paper, a new simple approach has been developed for the preparation of α-Fe2O3 microspheres by a facile hydrothermal method using PVP as a surfactant. Uniform α-Fe2O3 microspheres could be routinely synthesized through solvothermal approach by controlling the PVP/FeCl3⋅6H2O ratio. The as-obtained α-Fe2O3 microspheres exhibit high efficiency on the decolorization of RhB aqueous solution in the presence of H2O2 at room temperature.

Chitosan/hydroxyapatite composite coatings on porous Ti6Al4V titanium implants: in vitro and in vivo studies

Zhang, Ting,Zhang, Xinwei,Mao, Mengyun,Li, Jiayi,Wei, Ting,Sun, Huiqiang Korean Academy of Periodontology 2020 Journal of Periodontal & Implant Science Vol.50 No.6

Purpose: Titanium implants are widely used in the treatment of dentition defects; however, due to problems such as osseointegration failure, peri-implant bone resorption, and periimplant inflammation, their application is subject to certain restrictions. The surface modification of titanium implants can improve the implant success rate and meet the needs of clinical applications. The goal of this study was to evaluate the effect of the use of porous titanium with a chitosan/hydroxyapatite coating on osseointegration. Methods: Titanium implants with a dense core and a porous outer structure were prepared using a computer-aided design model and selective laser sintering technology, with a fabricated chitosan/hydroxyapatite composite coating on their surfaces. In vivo and in vitro experiments were used to assess osteogenesis. Results: The quasi-elastic gradient and compressive strength of porous titanium implants were observed to decrease as the porosity increased. The in vitro experiments demonstrated that, the porous titanium implants had no biological toxicity; additionally, the porous structure was shown to be superior to dense titanium with regard to facilitating the adhesion and proliferation of osteoblast-like MC3T3-E1 cells. The in vivo experimental results also showed that the porous structure was beneficial, as bone tissue could grow into the pores, thereby exhibiting good osseointegration. Conclusions: Porous titanium with a chitosan/hydroxyapatite coating promoted MC3T3-E1 cell proliferation and differentiation, and also improved osseointegration in vitro. This study has meaningful implications for research into ways of improving the surface structures of implants and promoting implant osseointegration.

Stab/Puncture Resistance Performance of Needle Punched Nonwoven Fabrics: Effects of Filament Reinforcement and Thermal Bonding

Xiayun Zhang,Ting-Ting Li,Ting-Ting Li,Hao-Kai Peng,Zhike Wang,Jia-Horng Lin,Ching-Wen Lou 한국섬유공학회 2022 Fibers and polymers Vol.23 No.8

This paper fabricated two types stab-resistant nonwoven fabric and the stab/puncture resistance of nonwoven werestudied. Nylon fibers, Kevlar fibers, and two types of low-melting point fibers-low-melting point polyester (LPET) fibers andpolypropylene(PP) fibers-are made into PP/nylon/Kevlar and LPET/nylon/Kevlar nonwoven fabrics. Needle punching andthermal bonding technology are used to made stab-resistant nonwoven fabric, thereby examining the influence of lowmeltingpoint fibers content (i.e. LPET or PP fibers) and bonding mode with other fibers on the stab/puncture resistanceproperty of nonwoven fabrics. The quasi-static stab resistance and bursting properties were compared between nonwovenfabrics and nonwoven fabric of PET filament reinforced nonwovens. The test results show that PET filament reinforcementhas a positive influence on the mechanical properties of composite nonwoven fabrics, especially puncture/stab resistanceperformance.

Effect of Continuous Stress-annealing on the Structure and Magnetic Properties of Fe72.9Si15.8B6.9Nb3.2Cu1Co0.2 Amorphous Alloy

Wenfeng Zhang,Jianfeng Wang,Cheng Sun,Ting Zhang,Xueying Zhang,Tao Zhang 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.10

The induced magnetic anisotropy, domain structure and magnetic properties of nanocrystallized Fe72.9Si15.8B6.9Nb3.2Cu1Co0.2 materials by continuous stress-annealing at 803–903 K under 0–75 MPa were systematically investigated. It was found that the tensile stress applied during annealing is beneficial to reduce the coercivity and core loss by refining the grain size of α-Fe phase. The remanence and permeability for the annealed samples at 853–903 K are negatively correlated with the induced anisotropy, which increases with the applied tensile stress. The stress-annealed samples yield magnetic easy plane perpendicular to the stress axis with an induced anisotropy constant greater than 1200 J/m3. The nanocrystalline cores with a low AC coercivity of 6.0 A/m and low core loss of 16.1 W/kg in combination with a high DC bias capability was successfully fabricated by stress-annealing the amorphous precursor at 878 K under 40 MPa. The current nanocrystalline material has potential for the application as anti-DC transformers in the electronic field.

중국 백화점의 물리적 환경에 따른 소비자의 내적반응이 점포충성도에 미치는 영향

장정정 ( Ting Ting Zhang ),전지현 ( Ji Hyun Jun ),이영선 ( Young Sun Rhee ) 한국의류학회 2013 한국의류학회지 Vol.37 No.2

Outstanding service quality is a crucial factor to increase customer revisits to increase customer revisits to create new customers through positive word-of-mouth marketing and increase profits; in conjunction the physical environment of department stores have a firsthand impact on customer purchasing behavior. This study examines the physical environment dimensions of department stores in China and the causal re-lationship with the physical environment service environment internal responses and store loyalty. The subjects in this study were male and female adults who finished the shopping the Lotte and Wangfujing Department Store located in Beijing. All participants were over the age of 20 and a one-on-one survey was conducted to gather data from October to November 2011. Data from 424 respondents were analyzed: in addition AMOS factor analysis and path analysis were used. The results were as follows. First physical environment factors consist of exterior aesthetic attraction convenience cleanliness and an interior aesthetic attraction. Second exterior aesthetic attraction convenience and cleanliness affect the overall service envir-onment perception. Third the service environment exercised an influence on internal responses and internal impacted store loyalty. Fourth a comparative analysis was made over korean and Chinese de-partment stores in China to check the research model. In Wangfujing Department Store exterior aesthetic attraction cleanliness and convenience had a statistically significant impact on service environment percep-tions. In Lotte Department Store the perception of service environment was under the statistically significant influence of all physical factors (exterior aesthetic attraction interior aesthetic attraction convenience and cleanliness). The findings of this study are helpful for Korean Department stores that plan to make inroads into China to formulate efficient service environment strategies tailored to local consumer characteristics.

Research on enterprise performance evaluation system under carbon emissions constraints

Zhang, Ting,Xia, Tongshui 한중경제문화학회 2015 한중경제문화연구 Vol.4 No.-

On the basis of specifications to improve our carbon emissions constraints mechanism, making the appropriate improvements of the traditional performance evaluation index system. Increase carbon constraints performance indicators: the amount of carbon emissions trading, Carbon assets net profit margin, carbon-income ratio, the ratio of carbon costs, carbon assets turnover, unit profit of carbon emissions, CO2 emissions of Yuan output value, in order to fully assess the financial performance and non-financial performance, enable the enterprise performance evaluation system better and more responsive to the requirements of sustainable development, and more convincing.

Overexpression of NDRG2 Can Inhibit Neuroblastoma Cell Proliferation through Negative Regulation by CYR61

Zhang, Zhi-Guo,Li, Gang,Feng, Da-Yun,Zhang, Jian,Zhang, Jing,Qin, Huai-Zhou,Ma, Lian-Ting,Gao, Guo-Dong,Wu, Lin Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.1

Several recent studies have showed that the n-myc downstream regulated gene 2 (NDRG2) is a new tumor suppressor gene, and that it plays an important role in tumor suppression in several cancers or cancer cell lines. However, few studies focused on its function in neuroblastoma cells. In the present investigation, we demonstrated that NDRG2 overexpression inhibited their proliferation. Using a cDNA microarray, we found that overexpression of NDRG2 inhibited the expression of cysteine-rich protein 61 (CYR61), a proliferation related gene. From our research, CYR61 may partially hinder NDRG2-mediated inhibition of cell proliferation. Overexpression of NDRG2 resulted in accumulation of cells in the G1 phase, which was accompanied by upregulation of p21 and p27 and downregulation of CDK4 and cyclin D1. Taken together, these data indicate that NDRG2 inhibits the proliferation of neuroblastoma cells partially through suppression of CYR61. Our findings offer novel insights into the physiological roles of NDRG2 in neuroblastoma cell proliferation, and NDRG2 may prove to be effective candidate for the treatment of children with neuroblastoma.

Efficient Signature Schemes from R-LWE

( Ting Wang ),( Jianping Yu ),( Peng Zhang ),( Yong Zhang ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.8

Compared to the classical cryptography, lattice-based cryptography is more secure, flexible and simple, and it is believed to be secure against quantum computers. In this paper, an efficient signature scheme is proposed from the ring learning with errors (R-LWE), which avoids sampling from discrete Gaussians and has the characteristics of the much simpler description etc. Then, the scheme is implemented in C/C++ and makes a comparison with the RSA signature scheme in detail. Additionally, a linearly homomorphic signature scheme without trapdoor is proposed from the R-LWE assumption. The security of the above two schemes are reducible to the worst-case hardness of shortest vectors on ideal lattices. The security analyses indicate the proposed schemes are unforgeable under chosen message attack model, and the efficiency analyses also show that the above schemes are much more efficient than other correlative signature schemes.

Construction of DOPA-SAM multilayers with corrosion resistance via controlled molecular self-assembly

Ting Chen,Ming Yang,Hui Yang,Ruining Wang,Shujuan Wang,Hang Zhang,Xiaoyu Zhang,Zhijuan Zhao,Jinben Wang 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.69 No.-

Although nano “green” coatings with excellent corrosion resistance have attracted great attention, the inhibition efficiency is still limited due to the lack of knowledge about the correlation between molecular structure and anticorrosion performance. Here, we fabricated a series of 3,4-dihydroxy-l-phenylalanine adlayers on self-assembled monolayers (SAMs) with varying end groups. We found that both NH2 and CF3SAMs were more conducive to the adsorption of DOPA and a flat adsorption conformation was preferentially adopted, with the plane of the phenylene ring parallel to the surface via cation-π interactions or hydrophobic interactions, leading to a compact and dense adlayer. Such DOPA-SAM multilayers can effectively protect the substrate from corrosion by suppressing the diffusion of aggressive water and acid molecules as well as the electrodissolution of metals. The lowest corrosion current of adlayers reaches 6.96 μA cm−2 which is much lower than that of bare substrate and other anticorrosion surfaces reported previously. The results provide guidance on the design of green anticorrosion materials via selecting SAMs that bridge organic and metal interface.

Smoothed partially linear quantile regression with nonignorable missing response

Zhang Ting,Wang Lei 한국통계학회 2022 Journal of the Korean Statistical Society Vol.51 No.2

In this paper, we propose a smoothed estimator and variable selection method forpartially linear quantile regression models with nonignorable missing responses. Toaddress the identifiability problem, a parametric propensity model and an instrumental variable are used to construct sufficient instrumental estimating equations.Subsequently, the nonparametric function is approximated by B-spline basis functions and the kernel smoothing idea is used to make estimation statistically and computationally efficient. To accommodate the missing response and apply thepopular empirical likelihood (EL) to obtain an unbiased estimator, we construct bias corrected and smoothed estimating equations based on the inverse probability weighting approach. The asymptotic properties of the maximum EL estimator for the parametric component and the convergence rate of the estimator for the non-parametric function are derived. In addition, the variable selection in the linear component based on the penalized EL is also proposed. The finite-sample performance of the proposed estimators is studied through simulations, and an applicationto HIV-CD4 data set is also presented.