Nanocomposite of Ni–Ti-layered double hydroxide and graphene for enhanced vis-light photocatalysis

Micro & nano letters

article

Chao Liu¹  Huajun Zhu¹  Yisong Zhu¹  Jinshan Wang¹  Fenghua Xu¹  Haijun Hou¹  Xiaowei Chen¹  Cuifeng Jiang¹  Wenhua Hou² 

[1] School of Materials Engineering, Yancheng Institute of Technology;Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University

关键词: nanocomposites;    graphene;    nickel compounds;    titanium compounds;    catalysis;    nanofabrication;    crystallisation;    visible spectra;    electron-hole recombination;    dyes;    photodissociation;    Ni–Ti-layered double hydroxide;    enhanced vis-light photocatalysis;    nickel–titanium-layered double hydroxide nanoplate deposition;    graphene nanosheet surface;    in situ crystallisation technique;    layered heterostructure formation;    visible-light absorption;    photogenerated electron–hole pair recombination probability;    Ni–Ti LDH-GNS composites;    vis-light photocatalytic performance;    methylene blue;    degradation;    photocatalytic mechanism;    graphene-based layered photocatalysts;   

DOI  :  10.1049/mnl.2017.0414

学科分类：计算机科学（综合）

来源: Wiley

【 摘 要 】

Background: Volumetric modulated arc therapy (VMAT) is the standard of care for many clinical indications, but should only be considered with proper technical support and quality assurance (QA) in place. Despite the high accuracy of VMAT systems, errors can be present and adequate verification is required. Dosimetric VMAT verification systems have a broadly similar analysis philosophy. However, many factors influence the analyses and the subsequent QA outcome, based on which the plan will pass or fail. Aim: This study investigated various factors that influence the dosimetric impact and detectability of known linac component deviations on VMAT QA, including geometries, tissue densities, gamma criteria and dose–volume differences. Setting: Universitas Hospital (Annex), Bloemfontein, South Africa. Methods: Deliberate multi-leaf collimator (MLC)-bank offsets were introduced on four different VMAT plans of the prostate, nasopharynx and brain. Measured reference dose sets were compared to measured QA results, using the IBA Dolphin© detector and Compass© software for three dosimetric scenarios. Gamma pass rates over a range of criteria from 1%/2-mm to 4%/4-mm in the total volumes and per structure, as well as dose–volume differences were studied. Results: Gamma tests in the total patient/phantom did not sufficiently detect errors. The calculation media did not influence the QA outcome greatly. However, the detection geometry affected the results. Per structure gamma analyses provided superior error detection, although still missed some clinically relevant differences. The addition of dose–volume analyses highlighted several important errors. Conclusion: Volumetric modulated arc therapy using only total volume gamma analyses can easily overlook clinically relevant errors. The choice of gamma criterion is crucial. Verification with at least a per structure gamma test in combination with dose–volume checks is recommended, especially in small target volume cases.

【 授权许可】

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