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MoS_(2)/Co_(9)S_(8)/MoC heterostructure connected by carbon nanotubes as electrocatalyst for efficient hydrogen evolution reaction

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Journal of Materials Science & Technology 2021年第20期79卷 29-34页

作者： Meng Wang Kailiang Jian Zepeng lv dong Li Gangqiang Fan Run Zhang Jie Dang College of Materials Science and Engineering Chongqing UniversityChongqing400044China Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials Chongqing UniversityChongqing400044China

High-performance multifunctional materials for water splitting driven by low voltage are crucial for hydrogen evolution reaction(HER),but developing such materials is ***,a simple strategy was designed to build a MoS_(2)/Co_(9)S_(8)/MoC@CNT-N(MCM@CNT-N)heterostructure with a large number of *** the HER,the synthesized MCM@CNT-N heterostructure catalyst showed high efficiency and stable electrocatalytic performance,with a low overpotential of 174.2 mV and a small Tafel slope of 84.7 mV dec^(-1) at a current density of 10 mA cm^(-2) in 0.5 M H_(2)SO_(4).In addition to the function of heterojunctions,the excellent activity is also attributed to the introduction of Co and N atoms and the formation of carbon *** work provides a new approach to build efficient and low-cost electrocatalysts for electrochemical reactions.

关键词： MoS_(2) Heterostructure Hydrogen Electrocatalysis CNT

White up-conversion luminescence and highly-sensitive optical temperature sensing in Na_(3)La(VO_(4))_(2):Yb,Er,Tm,Ho phosphors

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Journal of Rare Earths 2023年第7期41卷 981-988,I0001页

作者： Qi Xiao Xiumei Yin Lin lv Xinyao dong Na Zhou Kuichao Liu Xixian Luo Key Laboratory of New Energy and Rare Earth Resource Utilization of State Ethnic Affairs Commission Key Laboratory of Photosensitive Materials&Devices of Liaoning ProvinceSchool of Physics and Materials EngineeringDalian Minzu UniversityDalian 116600China Department of Physics Dalian Maritime UniversityDalian 116026China

In this work,tunable white up-conversion luminescence was achieved in the Yb^(3+),Er^(3+),Tm^(3+),Ho^(3+) codoped Na_(3)La(VO_(4))_(2) phosphors under 980 nm *** emissions of three primary colors are mainly attributed to the ~2H_(11/2)/~4S_(3/2)→~4I_(15/2) transitions of Er^(3+),~1G_(4)→~3H_6 transition of Tm^(3+),and_5F_5→~5I_8 transition of Ho^(3+).White luminescence characteristics and mechanisms of up-conversion system were investigated in *** addition,the temperature sensing behaviors of multiple levels emission combinations for Na_(3)La(VO_(4))_(2):Yb^(3+),Er^(3+),Tm^(3+),Ho^(3+) were analyzed by employing thermally coupled and non-thermally coupled energy *** on the emissions of ~3F_(2,3)/~1G_(4) energy levels,the maximum relative and absolute sensitivities were obtained to be 2.20%/K and 0.279 K^(-1).The design of up-conversion luminescence materials with high-quality white luminescence and excellent sensitivity performance is critical in the field of optical applications.

关键词： Up-conversion Na_(3)La(VO_(4))_(2) White luminescence Temperature sensing Sensitivity Rare earths

Cetus: an efficient symmetric searchable encryption against file-injection attack with SGX

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Science China(Information Sciences) 2021年第8期64卷 195-212页

作者： Yanyu HUANG Siyi lv Zheli LIU Xiangfu SONG Jin LI Yali YUAN Changyu dong College of Cyber Science and the College of Computer Science Tianjin Key Laboratory of Network and Data Security TechnologyNankai University School of Computer Science and Technology Shandong University School of Computer Science Guangzhou University Department of Computer Science University of G?ttingen School of Computing Newcastle University

Symmetric searchable encryption(SSE) allows the users to store and query their private data in the encrypted database. Many SSE schemes for different scenarios have been proposed in the past few years, however, most of these schemes still face more or fewer security issues. Using these security leakages,many attacks against the SSE scheme have been proposed, and especially the non-adaptive file injection attack is the most serious. Non-adaptive file injection attack(NAFA) can effectively recover some extremely important private information such as keyword plaintext. As of now, there is no scheme that can effectively defend against such attacks. We first propose the new security attribute called toward privacy to resist nonadaptive file injection attacks. We then present an efficient SSE construction called Cetus to achieve toward privacy. By setting up a buffer and designing the efficient oblivious reading algorithm based on software guard extensions(SGX), we propose the efficient one-time oblivious writing mechanism. Oblivious writing protects the update pattern and allows search operations to be performed directly on the data. The experiment results show that Cetus achieves O(aw) search time and O(1) update communication. The practical search time, communication, and computation overheads incurred by Cetus are lower than those of state-of-the-art.

关键词： searchable encryption SGX technique file injection attack forward/toward privacy cloud databases

Effect of electrokinetic property membrane on bovine serum of charged polyether sulfone albumin fouling behavior

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Frontiers of Environmental Science & Engineering 2017年第2期11卷 43-54页

作者： Xiaorong Meng Shanshan Huo Lei Wang Xudong Wang Yongtao lv Weiting Tang rui Miao Danxi Huang School of Science Xi'an University of Architecture and Technology Xi'an 710055 China School of Environmental & Municipal Engineering Xi'an University of Architecture and Technology Xi'an 710055 China

Negatively charged carboxymethylated polyethersulfone （CMPES） and positively charged quater- nized polyethersulfone （QAPES） ultrafiltration （UF） membranes were prepared by bulk chemical modification and non-solvent induced phase separation method. The effects of PES membrane interracial electrokinetic property on the bovine serum albumin （BSA） membrane fouling behavior were studied with the aid of the membrane-modified colloidal atomic force microscopy （AFM） probe. Electrokinetic test results indicated that the streaming potential （AE） of QAPES membrane was not consistent with its expected 1EC value, however, within the pH range of 3-10, the ζpotentials of two charged-modified PES membranes were more stable than the unmodified membrane. When pH value was 3, 4.7 or 9, the interaction behavior between charged PES membrane and BSA showed that there was significant linear correlation between the jump distance ro ofmembrane-BSA adhesion force （F/R） and the ~＂ potential absolute value. Charged modification significantly reduced the adhesion of PES membrane-BSA, and the adhesion data was good linear correlated with the flux decline rate in BSA filtration process, especially reflected in the CMPES membrane. The above experimental facts proved that the charged membrane interracial electric double layer structure and its electrokinetic property had strong ties with the protein membrane fouling behavior.

关键词： Charged PES UF membraneBSAElectrokinetic characterizationAdhesion forceJump distance

An ultrafast carrier dynamics system from oxygen vacancies modified SnO_(2)QDs and Zn_(2)SnO_(4)heterojunction for deeply photocatalytic oxidation of NO

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Journal of Materials Science & Technology 2023年第34期165卷 85-93页

作者： Yuhan Li Min Zhang Bangfu Chen Ping Ouyang Youyu Duan Kangle lv Fan dong Engineering Research Center for Waste Oil Recovery Technology and Equipment Ministry of EducationChongqing Key Laboratory of Catalysis and New Environmental MaterialsChongqing Technology and Business UniversityChongqing 400067China Nanchang Institute of Technology Nanchang 33044China College of Physics and Center of Quantum Materials and Devices Chongqing UniversityChongqing 401331China Key Laboratory of Resources Conversion and Pollution Control of the State Ethnic Affairs Commission College of Resources and Environmental ScienceSouth-Central Minzu UniversityWuhan 430074China

Deeply photocatalytic oxidation of NO-to-NO_(3)holds great promise for alleviating NO_(x) *** major challenge of NO photo-oxidation is the highly in-situ generated NO_(2) concentration,and the formation of unstable nitrate species causes desorption to release NO_(2).In this study,SnO_(2) quantum dots and oxygen vacancies co-modified Zn_(2)SnO_(4)(ZSO-SnO_(2)-OVs)were prepared by a one-step hydrothermal procedure,the NO photo-oxidation was investigated by a combination of solid experimental and theoretical ***,spectroscopic measurements indicate that fast carrier dynamics can be achieved due to the electron transfer efficiency of ZSO-SnO_(2)-OVs reaching 99.99%,far outperforming the counterpart and previously reported *** NO oxidation,molecular NO/O_(2) and H2O are efficiently adsorbed/activated around OVs and SnO_(2) QDs,***-situ infrared measurements and calculated electron localized function disclose two main findings:(1)richly electrons enable NO promptly form NOinstead of toxic NO_(2) or NO^(+);(2)the generation of stable and undecomposed bidentate NO_(3)rather than bridging or monodentate one benefits the deep oxidation of NO via shifting reaction sites from O terminals for original ZSO to Sn ones for ZSO-SnO_(2)-*** synergistic action of SnO_(2) QDs and OVs positively contributes to the NO oxidation performance enhancement(60.6%,0.1 g of sample)and high selectivity of NO to NO_(3)(99.2%).Results from this study advance the mechanistic understanding of NO photooxidation and its selectivity to NO_(3)over photocatalysts.

关键词： Zn_(2)SnO_(4) Modification NO photo-oxidation Charge transfer efficiency Reaction mechanism

CdTe/CdSe-sensitized photocathode coupling with Ni-substituted polyoxometalate catalyst for photoelectrochemical generation of hydrogen

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Nano Research 2022年第2期15卷 1347-1354页

作者： Junhao Zhang Mo Zhang Yuanyuan dong Congcong Bai Yeqin Feng Le Jiao Hongjin lv MOE Key Laboratory of Cluster Science School of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 102488China

In terms of photoelectrochemical(PEC)hydrogen evolution,substantial challenge still remains regarding the controllable fabrication of quantum dots(QDs)-sensitized photocathodes with enhanced visible-light absorption,efficient charge carrier separation,and directional migration at the electrode *** this work,the CdTe/CdSe QDs-sensitized photocathodes were delicately constructed on p-type NiO-coated indium tin oxide(ITO)electrodes by spin-coating *** resulting co-sensitized photocathode exhibits a favorable pseudo-Type Ⅱ energetic band alignment that combines the advantages of strong light absorption of constituent QDs as well as the effective and oriented charge separation and *** green LED light illumination,the photogenerated electrons could be effectively transferred to a tetra-nickel-substituted polyoxometalate catalyst for hydrogen production while photogenerated holes will be scavenged at the NiO/ITO *** minimally optimized conditions,the pseudo-Type Ⅱ CdTe/CdSe-sensrtized photocathode yields a photcx:urrent density of over 100 pA/cm^(2) and a Faradaic efficiency of〜100%,which is among one of the most efficient QDs-based photocathode systems coupling with Ni-substituted polyoxometalate catalyst for photoelectrochemical hydrogen generation.

关键词： polyoxometalates quantum dots-sensitized photocathode favorable energetic gradient photoelectrochemical water splitting hydrogen generation

Effect of different bottom blowing elements on stirring characteristics of molten bath in converter

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Journal of Iron and Steel Research International 2024年第2期31卷 368-376页

作者： Ming lv Shuang-ping Chen Hong-min Guo Yi-jie Hao Xiang-dong Xing School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an710055ShaanxiChina Shaanxi Longmen Steel Company Hancheng715405ShaanxiChina

The bottom blowing element is the key equipment to ensure the bottom blowing effect of the *** types of bottom blowing elements,dispersive type(D1),double circular seam(D2)and straight cylinder type(D3),were built,and the effects of bottom blowing element type on molten bath flow,wall erosion and furnace bottom erosion were *** was found that when the bottom blowing elements of dispersive type(D1)and double circular seam(D2)were used,the dead zone area in the lower part of the molten bath was smaller,and the high-speed zone area was larger;therefore,the stirring effect on the bottom melt was *** the straight cylinder type(D3)bottom blowing element was used,the gas penetrated the molten bath at a faster rate to reach the surface of molten bath and failed to disperse in the bottom molten bath,and the wall shear stress near the nozzle outlet was *** argon was blown by three different bottom blowing elements,the area of the wall shear stress greater than 3 Pa was 4.8,5.6 and 8.7 cm2,respectively,within 0.2 m of the bottom blowing nozzle outlet.

关键词： Converter steelmaking Bottom blowing element Molten bath stirring Wall erosion

Environmental Characteristics of Groundwater:an Application of PCA to Water Chemistry Analysis in Yulin

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Journal of China University of Mining and Technology 2007年第1期17卷 73-77页

作者： dong dong-lin WU Qiang ZHANG rui SONG Ying-xia CHEN Shu-ke LI Pei LIU Shou-qiang BI Cen-cen lv Zhen-qi HUANG Song-lin State Key Lab of Coal Resources and Safe Mining China University of Mining ＆ Technology Beijing 100083 China

For our investigation into the water quality in Yulin city, we collected 76 typical water samples to be tested for particle quality. By applying a Romani type classification method the groundwater of Yulin city was classified into nine categories by type, i.e., Ca-HCO3, Na-HCO3, Na-HCO3-SO4-Cl, Na-HCO3-SO4, Na-Cl, Na-Cl-HCO3, Na-Ca- HCO3, Ca-Cl-HCO3 and Ca-HCO3-SO4-Cl. A principal component analysis was carried out in order to analyze the groundwater environment. From this analysis we considered that the information collected could be represented by 21 indices from which we extracted seven principal components, which, respectively, accounted for 37.4%, 13.0%, 8.1%, 7.2%, 6.3%, 5.9% and 4.6% of the total variation. The results show that the groundwater environment of this region is largely determined by characteristic components of the natural groundwater background. One part of the water was polluted by leaching/eluviation of solid waste generated from coal mining. Another part of the ground water was contaminated by acid mine water from the coal layer and from improper irrigation. In addition, geological and hydrogeological conditions also cause changes in the water environment.

关键词： water environment principal component analysis component loading groundwater type Yulin city

Photoelectrochemical properties of BiVO4 thin films with NaOH chemical treatment

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Rare Metals 2019年第5期38卷 446-452页

作者： dong-dong lv Jiao-Feng Liu Zheng Zhang Ying-You Ma Yan Liang Zhi-Tai Zhou Wei-Chang Hao School of Physics Beihang University

BiVO4 thin films were prepared by a mature and simple electrochemical deposition method on F-doped SnO2 substrate electrode(FTO).The influence of a chemical treatment using sodium hydroxide(NaOH)on the photoelectrochemical properties of BiVO4 thin films was *** was found that NaOH can etch the crystal surface of BiVO4,which leads to the increase in specific surface area and improved photoelectrochemical *** photocurrent density of the BiVO4 thin films showed an enhancement of photoelectronic current from 0.50 to0.65 mAácm-2 at 1.23 V(***)after the treatment for5 h by NaOH,which supplies a stronger potential for H2 O oxidation.

关键词： BiVO4 Photoelectrochemical Surface treatment NaOH