Microstructure and property evolution of diamond-like carbon films co-doped by Al and Ti with different ratios

Zhou, Yong,Guo, Peng,Sun, Lili,Liu, Linlin,Xu, Xiaowei,Li, Wenxian,Li, Xiaowei,Lee, Kwang-Ryeol,Wang, Aiying Elsevier Sequoia 2019 Surface & coatings technology Vol.361 No.-

<P><B>Abstract</B></P> <P>Diamond-like carbon (DLC) films with weak carbide metal Al and carbide metal Ti co-doping (Al/Ti-DLC) were prepared by a hybrid ion beam deposition system. The atomic ratios of doped Al to Ti were tailored via designing the special Al/Ti combined sputtering target. The composition, microstructure, roughness, residual stress, hardness, toughness, and tribological behaviors of the deposited films were systematically evaluated to explore the dependence of structural properties on Al/Ti ratios. Results indicated that the high-throughput preparation of DLC films with different Al/Ti atomic ratios was achieved by tailoring the sputtering target and process parameters without the difference in both the film thickness and total Al/Ti content. With the Al/Ti ratios in the films decreased from 8.8 to 3.0, the residual stress, hardness, and toughness of Al/Ti-DLC films increased obviously, originating from the increased fraction of titanium carbide and the reduced Al content. However, the coefficient of friction and wear rate with decreasing the Al/Ti ratio were obviously improved, which was related with the transformation of underlying friction mechanism from the sliding interface graphitization to dangling bond-passivation. The present results not only suggest a high-throughput method to fabricate co-doped DLC films, but also promote the scientific understanding and engineering application of DLC films with high performance.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ti/Al co-doped diamond-like carbon films were fabricated by a hybrid ion beam method. </LI> <LI> Different Al/Ti ratios were successfully achieved at one time using designed target. </LI> <LI> Al/Ti ratios had no effect on the chemical state of co-doped Ti and Al atoms. </LI> <LI> The mechanical and tribological properties were strongly dependent on Ti/Al ratios. </LI> <LI> Different friction mechanisms were observed with Al/Ti ratios ranged from 8.8 to 3.0. </LI> </UL> </P>

Oxygen tank for synergistic hypoxia relief to enhance mitochondria-targeted photodynamic therapy

Xianghui Li,Haoran Wang,Zhiyan Li,Dandan Li,Xiaofeng Lu,Shichao Ai,Yuxiang Dong,Song Liu,Jinhui Wu,Wenxian Guan 한국생체재료학회 2022 생체재료학회지 Vol.26 No.4

Background: Mitochondria play an essential role in cellular redox homeostasis maintenance and meanwhile serve as an important target for organelle targeted therapy. Photodynamic therapy (PDT) is a promising strategy for organelle targeted therapy with noninvasive nature and highly spatiotemporal selectivity. However, the efficacy of PDT is not fully achieved due to tumor hypoxia. Moreover, aerobic respiration constantly consumes oxygen and leads to a lower oxygen concentration in mitochondria, which continuously limited the therapeutic effects of PDT. The lack of organelle specific oxygen delivery method remains a main challenge. Methods: Herein, an Oxygen Tank is developed to achieve the organelle targeted synergistic hypoxia reversal strategy, which not only act as an oxygen storage tank to open sources and reduce expenditure, but also coated with red blood cell membrane like the tank with stealth coating. Within the oxygen tank, a mitochondrion targeted photosensitizer (IR780) and a mitochondria respiration inhibitor (atovaquone, ATO) are co-loaded in the RBC membrane (RBCm) coated perfluorocarbon (PFC) liposome core. Results: Inside these bio-mimic nanoparticles, ATO effectively inhibits mitochondrial respiration and economized endogenous oxygen consumption, while PFC supplied high-capacity exogenous oxygen. These Oxygen modulators reverse the hypoxia status in vitro and in vivo, and exhibited a superior anti-tumor activity by mitochondria targeted PDT via IR780. Ultimately, the anti-tumor effects towards gastric cancer and colon cancer are elicited in vivo. Conclusions: This oxygen tank both increases exogeneous oxygen supply and decreases endogenous oxygen consumption, may offer a novel solution for organelle targeted therapies.

Coral‑Like NiFe2O4/C Composite as the High‑Performance Anode Material for Lithium‑Ion Batteries

Shanshan Bao,Yifei Xiao,Junfeng Li,Bo Yue,Yanjun Li,Wenxian Sun,Lei Liu,Yi Huang,Li Wang,Peicong Zhang,Xuefei Lai 대한금속·재료학회 2020 ELECTRONIC MATERIALS LETTERS Vol.16 No.3

In this work, we fabricated NiFe2O4/C composite with a coral-like structure through co-precipitation approach followed bythermal decomposition. The composite with a large surface area of 162.1 m2 g−1 and an average pore size of 11.8 nm wasobtained. The porous structure in the composite derived from oxalate can Effectively accommodate the volume changesof NiFe2O4 during the cycling processes. When used as anode materials, the initial charge and discharge capacities of thecomposite were 926.7 and 1277.7 mAh g−1 at 100 mA g−1. After 50 cycles, the reversible capacity of NiFe2O4/C could stillremain at 892.4 mAh g−1. Even at a current density of 2000 mA g−1, the reversible capacity still reached 523.3 mAh g−1. The results showed that the synergy between NiFe2O4 and carbon improved the electrochemical performance, and the porouscomposite could stabilize the structure of the electrode.

Enhanced electrochemical performances of LiNi0.5Co0.2Mn0.3O2 cathode material co-coated by graphene/TiO2

Dang Mengyue,Li Ying,Xu Chaoxiang,He Yulin,Yu Chunpeng,Liu Wenbo,Jin Hongming,Zhu Mingyuan,Zhang Jiujun,Li Wenxian 한국물리학회 2021 Current Applied Physics Vol.32 No.-

The electrochemical performances of LiNi0.5Co0.2Mn0.3O2 (NCM523) layered cathode material, such as poor rate capacity and cycling stability caused by undesirable intrinsic conductivity and low rate of lithium ion transportation, are not fairly good especially at elevated rate and cut-off voltage. To improve these properties, in this study, the co-coating layer of graphene and TiO2 was constructed on NCM523 surface. The graphene/TiO2 coating layer could effectively prevent hydrofluoric acid (HF) attacks, suppress the side reaction, accelerate the lithium ion diffusion and facilitate the electron migration. The enhancement of cycle performance and rate capacity was contributed to the uniform co-modified surface, interacting each other and thus exhibiting synergistic effects.

Finite Element Modeling of Steel-concrete Composite Beams with Diff erent Shear Connection Degrees

Xing Zheng,Wenxian Li,Qiao Huang,Bing Wang 한국강구조학회 2021 International Journal of Steel Structures Vol.21 No.1

In order to study the behavior of Steel-concrete composite beams with diff erent shear connection degrees, using fi nite element software ABAQUS, four models with diff erent numbers of headed studs are established, all of which apply appropriate concrete and steel constitutive models, and contact relationship. The accuracy of fi nite element models is verifi ed by comparing the simulation results with corresponding beam tests in multiple aspects, for instance, the interface slip, the ultimate capacity, the failure modes and the load-strain distribution. The analysis focuses on the interface slip development of composite beams with diff erent connection degrees, and the results show that the interface slip seldom becomes the control condition when designing composite beams. A further parametric study is performed to investigate the eff ect of various parameters on the static response of composite beams. Finally, the applicable conditions and limitations of diff erent modeling methods are discussed. The modeling method used in this paper is suitable for simulating the static performance of composite beams, especially in the investigation of the interface slip development.

Dominant genera of cyanobacteria in Lake Taihu and their relationships with environmental factors

Lijun Feng,Shiyou Liu,Wenxian Wu,Jiawen Ma,Pei Li,Hailing Xu,Na Li,Yaoyu Feng 한국미생물학회 2016 The journal of microbiology Vol.54 No.7

Cyanobacterial blooms in freshwaters have become one of the most widespread of environmental problems and threaten water resources worldwide. Previous studies on cyanobacteria in Lake Taihu often collected samples from one site (like Meiliang Bay or Zhushan Bay) and focused on the variation in patterns or abundance of Microcystis during the blooming season. However, the distribution of cyanobacteria in Lake Taihu shows differing pattern in various seasons. In this study, water samples were collected monthly for one year at five sites in Lake Taihu with different trophic status and a physicochemical analysis and denaturing gradient gel electrophoresis (DGGE) were conducted. DGGE fingerprint analysis showed that Microcystis (7/35 bands) and Synechococcus (12/35 bands) were the two most dominant genera present during the study period at all five sites. Cyanobium (3/35 bands) was the third most common genus which has seldom been previously reported in Lake Taihu. Redundancy analysis (RDA) indicated that the cyanobacterial community structure was significantly correlated with NO3 --N, CODMn, and NH4 +-N in the winter and spring, whereas it was correlated with water temperature in the summer and autumn. Limiting the nutrient input (especially of N and C loading) in Lake Taihu would be a key factor in controlling the growth of different genera of cyanobacteria.

TM-doped ZnO DMS synthesized by hydrothermal method under high magnetic field

Min Zhong,Muhammad Tariq,Zihao Zhang,Chunli Liu,Yemin Hu,Wenxian Li,Ying Li 한국자기학회 2015 한국자기학회 학술연구발표회 논문개요집 Vol.2015 No.11