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Journal of Bionic Engineering 2021年第5期18卷 1192-1201页

作者： Junyue Chen Lingling Cui Chengqi Yan Dangsheng Xiong School of Materials Science and Engineering Nanjing University of Science and TechnologyNanjing 210094China

Hydrogel has been widely used in the research of bionic articular cartilage due to their similarity in structure and functional properties to natural articular *** this research,polyvinyl alcohol and betaine monomer were used as raw materials to prepare a high-strength double-network hydrogel by a combination of ultraviolet(UV)irradiation and freeze–thaw *** structure of samples was characterized by Fourier transform infrared spectroscopy and X-ray diff raction,and the morphology of the samples was characterized by scanning electron microscope and three-dimensional white light *** addition,we also studied the swelling ratio,water content,mechanical properties and tribological properties of the *** found that the addition of betaine monomer and the UV irradiation time had a positive eff ect on the mechanical properties and tribological properties of the samples.

关键词： Polyvinyl alcohol Double-network hydrogel ultraviolet irradiation Low friction High strength

Enhanced methanol oxidation activity of Au@Pd nanoparticles supported on MWCNTs functionalized by MB under ultraviolet irradiation

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Rare Metals 2015年第1期34卷 12-16页

作者： Ming-Li Xu Xi-Kun Yang Ying-Jie Zhang Shu-Biao Xia Peng Dong Guo-Tao Yang Faculty of Science Kunming University of Science and Technology Research Center for Analysis and Measurement Kunming University of Science and Technology Faculty of Metallurgical and Energy Engineering Kunming University of Science and Technology

A successful approach to assemble Au core Pd shell （Au@Pd） nanoparticles on the surface of multi-walled carbon nanotubes functionalized by methylene blue （MB）（Au@Pd/fuv-MWCNTs） was reported. In this method, MWCNTs were functionalized under ultraviolet irradiation. UV-Vis analysis and high-angle annular dark-field trans- mission electron microscope （HAADF-TEM） image prove that core-shell structure of Au@Pd nanoparticles forms. TEM results indicate that Au@Pd nanoparticles （ - 5.2 nm） are well-dispersed on the surface of fuv-MWCNTs. X-ray photoelectron spectroscopy （XPS） reveals that ultraviolet irradiation can promote the interaction between Au@Pd nanoparticles and the functional groups on the surface of MWCNTs. Cyclic voltammograms （CV）, chronoampero- grams （CA）, and electrochemical impedance spectroscopy （EIS） results demonstrate that the Au@Pd/fuv-MWCNTs catalysts show excellent electrocatalytic performance for methanol oxidation in alkaline media. The catalytic activity of the Au@Pd/fuv-MWCNTs is ~ 2 times higher than that of the commercial Pd/C catalysts. This is mostly attributed to that ultraviolet irradiation can make the moieties of MB provide a uniform surface with active and anchoring sites, and improves the functional effect of MB on the surface of MWCNTs. Especially, ultraviolet irradiation modifies electronic structure of Pd and is beneficial for the enhance- ment of catalytic activity.

关键词： Au@Pd core-shell nanoparticle Multi-walledcarbon nanotube Methylene blue Electrocatalyst Methanol oxidation ultraviolet irradiation

Effect of ultraviolet irradiation and chlorination on ampicillin-resistant Escherichia coli and its ampicillin resistance gene

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Frontiers of Environmental Science & Engineering 2016年第3期10卷 522-530页

作者： Yuchen PANG Jingjing HUANG Jinying XI Hongying HU Yun ZHU Environmental Simulation and Pollution Control State Key Joint Laboratory School of Environment Tsinghua University Beijing 100084 China State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC) Graduate School at Shenzhen Tsinghua University Shenzhen 518055 China China Power Engineering Consulting Group Corporation Beijing 100120 China Institute of Biophysics Chinese Academy of Sciences Beijing 100101 China School of Life Sciences Tsinghua University Beijing 100084 China

Antibiotic resistance is a serious public health risk that may spread via potable and reclaimed water. Effective disinfection is important for inactivation of antibiotic-resistant bacteria and disruption of antibiotic resistance genes. Ampicillin is a widely prescribed antibiotic but its effectiveness is increasingly undermined by resistance. In this study, changes in ampicillin resistance for Escherichia coli （E. coli） CGMCC 1.1595 were analyzed after exposure to different doses of ultraviolet （UV） or chlorine, and damage incurred by the plasmid encoding ampicillin resistance gene blaTEM-1 was assessed. We reported a greater stability in ampicillinresistant E. coli CGMCC 1.1595 after UV irradiation or chlorination when compared with previously published data for other E. coli strains. UV irradiation and chlorination led to a shift in the mortality frequency distributions of ampicillin-resistant E. coli when subse-quently exposed to ampicillin. The ampicillin hemiinhibitory concentration （IC5o） without disinfection was 3800mg·L^-1, and an increment was observed after UV irradiation or chlorination. The IC50 of ampicillin-resistant E. coli was 1.5-fold higher at a UV dose of 40 mJ·cm^-2, and was 1.4-fold higher when exposed to 2.0 mg·L^-1 chlorine. These results indicate that UV irradiation and chlorination can potentially increase the risk of selection for E. coli strains with high ampicillin resistance. There was no evident damage to blaTEM-1 after 1-10 mg Cl2· L^-1 chlorination, while a UV dose of 80 mJ·cm^-2 yielded a damage ratio for blaTEM-1 of approximately ***, high UV doses are required for effective disruption of antibiotic resistance genes in bacteria.

关键词： antibiotic resistance Escherichia coli ampicillin resistance gene ultraviolet irradiation chlorination

Dust Acoustic Wave in Dusty Plasmas With Streaming Ions Under ultraviolet irradiation

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空间科学学报 2012年第2期32卷 191-196页

作者： REN Liwen WANG Chi State Key Laboratory of Space Weather Center for Space Science and Applied ResearchChinese Academy of SciencesBeijing 100190

The reductive perturbation method is applied to investigate the dust acoustic soliton in dusty plasmas with streaming ions under ultraviolet irradiation theoretically and *** self-consistent dust charge variation is taken into *** is shown that the ultraviolet irradiation can significantly lower the magnitude of the dust negative charge,and ion streaming velocity firstly raise the magnitude of the dust negative charge and then lower *** the growth of(ultraviolet) UV photo flux or ion streaming velocity,the phase velocity and width of the solitary waves decrease, whereas its amplitude increases.

关键词： Dusty plasma Solitary wave ultraviolet irradiation Streaming ion

Photoprotective Effects of Hydroxychloroqine and TCMs on Human Keratinocytes Damaged from ultraviolet irradiation

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Journal of Nanjing Medical University 2004年第4期18卷 172-177页

作者： LUODan MINWei LINXiang-fei WUDi MIAOXu DepartmentofDermatology theFirstAffiliatedHospitalofNanjingMedicalUniversityNanjing210029P.R.China

Objective: To investigate damage effects of ultraviolet irradiation on eternal keratinocyte-HaCaT cells and to evaluate photo-protective efficiency of hydroxychloroqine and Traditional Chinese Medicines(epigallocatechingallate[EGCG], baikal skullcap root and szechwan lovge rhizome) on HaCaT cells damaged by middle wave ultraviolet(UVB) irradiation. Methods: Subconfluent HaCaT cells were sham or UVB irradiated and treated with above TCM agents. The damage degree of HaCaT cells was observed by a light microscop. Cell growth was recorded by cell count and cellular activity was detected by MTT method. The secretion amount of IL-6 and TNF-α was measured by ELISA. Results: The irradiation damage of HaCaT cells was depended on the irradiated dosages and cellular activity was reduced by 36%-80%, with a maximum decrease over 90% after 72 h. The intervention of the above drugs may increase the cellular activity by 10%-72%. The photo-protective efficiency was more apparent in EGCG (from 1.19±0.07 to 1.28±0.06, Pirradiation on cultured keratinocytes is dose-dependent and the tested drugs have photo-protective potency. Inhibition of cytokine secretion may be one of the mechanisms related to reducing the damage effect of UVB irradiation.

关键词： ultraviolet irradiation photodamage and photoprotection keratinocytes hydroxychloroqine Traditional Chinese Medicine baikal skullcap root szechwan lovge rhizome epigallocatechingallate

UV irradiation-H2O2 system as an effective combined depolymerization technique to produce oligosaccharides from chitosan

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Bio-Design and Manufacturing 2018年第1期1卷 62-68页

作者： Seyed Ahmad Ayati Najafabadi Hengameh Honarkar Majid Moghadam Valiollah Mirkhani Mohammadreza Tahriri Lobat Tayebi Biomaterials Group Faculty of Biomedical Engineering Amirkabir University of Technology Tehran Iran Polyurethane and Advanced polymers Faculty of Science Iran Polymer and Petrochemical Institute Tehran Iran Catalysis Divisions Department of Chemistry University of Isfahan Isfahan Iran Marquette University School of Dentistry Milwaukee WI 53233 USA Department of Engineering Science University of Oxford Oxford OX13PJ UK

UV irradiation hydrogen peroxide （H202） system is used as an effective, easy and low-cost combined depolymerization technique to produce oligosaccharides from chitosan. UV-Vis spectroscopic studies explained that with increasing treatment time, the absorption of the depolymerized chitosan solution has increased, indicating the increase in the carbonyl and amino groups in their structure. Fourier transform infrared spectroscopy and nuclear magnetic resonance （1H NMR） analysis showed that the 1,4-β-D-glucoside linkages of chitosan are degraded without important changes in chemical structure of decomposed samples. X-ray diffraction patterns verified the polymerization of chitosan to produce oligomers, changing in structure from crystalline to amorphous. Viscosity-average molecular weight measurements of fragmented chitosan samples and MarkHouwink equation are used to demonstrate the efficiency of this depolymerization method. Finally, the obtained results ascertained that this combined method could produce water soluble chitosan with significant efficiency and no essential change in its chemical *** irradiation hydrogen peroxide （H202） system is used as an effective, easy and low-cost combined depolymerization technique to produce oligosaccharides from chitosan. UV-Vis spectroscopic studies explained that with increasing treatment time, the absorption of the depolymerized chitosan solution has increased, indicating the increase in the carbonyl and amino groups in their structure. Fourier transform infrared spectroscopy and nuclear magnetic resonance （1H NMR） analysis showed that the 1,4-β-D-glucoside linkages of chitosan are degraded without important changes in chemical structure of decomposed samples. X-ray diffraction patterns verified the polymerization of chitosan to produce oligomers, changing in structure from crystalline to amorphous. Viscosity-average molecular weight measurements of fragmented chitosan samples and MarkHouwink equation are used to dem

关键词： Chitosan Depolymerization ultraviolet irradiation Hydrogen peroxide Oligosaccharides

Preparation and characterization of high photoactive TiO_2 catalyst using the UV irradiation-induced sol-gel method

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Journal of University of Science and Technology Beijing 2006年第4期13卷 350-354页

作者： Jianhua Liu Rong Yang Songmei Li School of Materials Science and Engineering Beijing University of Aeronautics ＆ Astronautics Beijing 100083 China

High photoactive TiO2 catalyst was prepared using the sol-gel method through UV irradiation during the formation stage of nuclei. The surface morphology and microstructure of the prepared catalyst were characterized using scanning electron microscopy （SEM）, X-ray diffraction patterns （XRD）, and Fourier transform infrared spectroscopy （FF-IR）. The photoactivity was evaluated by the degradation of methylene blue. The results show that the photocatalysis of the prepared catalyst is higher than that of conventional heat-treated particles. The higher photoactivity is a combined result of favorable microstructure, appropriate hydroxyl groups, and active sites of Ti^3＋ ions on the surface of TiO2. It is concluded that the ultraviolet irradiation-induced sol-gel method is an effective method to enhance the photocatalysis of TiO2.

关键词： titanium oxide photocatalysis sol-gel ultraviolet irradiation

Characterization of nano-Ag/PVP composites synthesized via ultra-violet irradiation

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Journal of Coal Science & Engineering(China) 2010年第2期16卷 188-192页

作者： HUANG Wen-yao XU Guo-cai School of Chemical Engineering Anhui University of Science and Technology Huainan 232001 China

Nano-silver/polyvinylpyrrolidone(PVP)composite materials were successfully synthesized bi-insitu from silver nitrate solution with N-vinyl pyrrolidone (NVP) monomer,containing neither initiator nor reductant, in ultraviolet irradiation *** resultant Ag/PVP nanocomposites were characterized by infrared spectroscopy (FT-IR), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD).TEM show that nano silver particles are homogeneously dispersed in PVP polymer matrix, and the mean size of spherical silver particles is about 5 *** spectroscopy of XPS and FTIR showed that there is an interaction between nano silver not only with carbonyl oxygen but also with the nitrogen group within the NVP molecule through the p-π conjugation effect in the nano-silver/PVP composites system.

关键词： nano-Ag NVP nanocomposites ultraviolet irradiation

ultraviolet‑Irradiated All‑Organic Nanocomposites with Polymer Dots for High‑Temperature Capacitive Energy Storage

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Nano-Micro Letters 2024年第3期16卷 398-406页

作者： Jiale Ding Yao Zhou Wenhan Xu Fan Yang Danying Zhao Yunhe Zhang Zhenhua Jiang Qing Wang College of Chemistry Jilin UniversityChangchun 130012People’s Republic of China Department of Materials Science and Engineering The Pennsylvania State UniversityUniversity ParkPA 16802USAs Deutsches Elektronen-Synchrotron DESY Notkestr.8522607 HamburgGermany

Polymer dielectrics capable of operating efficiently at high electric fields and elevated temperatures are urgently demanded by next-generation electronics and electrical power *** inorganic fillers have been extensively utilized to improved high-temperature capacitive performance of dielectric polymers,the presence of thermodynamically incompatible organic and inorganic components may lead to concern about the long-term stability and also complicate film ***,zero-dimensional polymer dots with high electron affinity are introduced into photoactive allyl-containing poly(aryl ether sulfone)to form the all-organic polymer composites for hightemperature capacitive energy *** ultraviolet irradiation,the crosslinked polymer composites with polymer dots are efficient in suppressing electrical conduction at high electric fields and elevated temperatures,which significantly reduces the high-field energy loss of the composites at 200℃.Accordingly,the ultraviolet-irradiated composite film exhibits a discharged energy density of 4.2 J cm^(−3)at 200℃.Along with outstanding cyclic stability of capacitive performance at 200℃,this work provides a promising class of dielectric materials for robust high-performance all-organic dielectric nanocomposites.

关键词： High-temperature energy storage Polymer dots ultraviolet irradiation All-organic composite dielectrics

Factors influencing the photodegradation of Nnitrosodimethylamine in drinking water

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Frontiers of Environmental Science & Engineering 2009年第1期3卷 91-97页

作者： Bingbing XU Zhonglin CHEN Fei QI Jimin SHEN Fengchang WU State Key Laboratory of Urban Water Resource and Environment Harbin Institute of TechnologyHarbin 150090China State Environmental Protection Key Laboratory for Lake Pollution Control Chinese Research Academy of Environmental SciencesBeijing 100012China College of Environmental Science and Engineering Beijing Forestry UniversityBeijing 100083China

In order to provide basic data for practical application,photodegradation experiment of Nnitrosodimethylamine(NDMA)in aqueous solution was carried out with a low-pressure Hg *** of the initial concentration of NDMA,solution pH,dissolved oxygen,and the presence of humic acid on NDMA photodegradation were *** at various initial concentrations selected in this study was almost completely photodegraded by UV irradiation within 20 min,except that at 1.07 mmol/L,NDMA could be photodegraded almost completely in the acidic and neutral solutions,while the removal efficiency decreased remarkably in the alkaline *** oxygen enhanced the NDMA photodegradation,and the presence of humic acid inhibited the degradation of *** on the initial concentration of NDMA,NDMA photodegradation by UV obeyed the pseudo-first-order ***,nitrite,and nitrate were detected as the photodegradation products of NDMA.^(1)O_(2) was found to be the reactive oxygen species present in the NDMA photodegradation process by UV,based on the inhibiting experiments using tert-butanol and sodium azide.

关键词： N-nitrosodimethylamine(NDMA) ultraviolet irradiation degradation kinetic dimethylamine photodegradation product