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ionic silver promote the proliferation of human keratinocytes by inducing the production of reactive oxygen

null

《医学前沿（英文）》 2018年 第12卷 第3期   页码 289-300 doi: 10.1007/s11684-017-0550-7

摘要：

Silver-containing preparations are widely used in the management of skin wounds, but the effects of silver ions on skin wound healing remain poorly understood. This study investigated the effects of silver ions (Ag+) on the proliferation of human skin keratinocytes (HaCaT) and the production of intracellular reactive oxygen species (ROS). After treating HaCaT cells with Ag+and/or the active oxygen scavenger N-acetyl cysteine (NAC), cell proliferation and intracellular ROS generation were assessed using CCK-8 reagent and DCFH-DA fluorescent probe, respectively. In addition, 5-bromo-2-deoxyUridine (BrdU) incorporation assays, cell cycle flow cytometry, and proliferating cell nuclear antigen (PCNA) immunocytochemistry were conducted to further evaluate the effects of sub-cytotoxic Ag+ concentrations on HaCaT cells. The proliferation of HaCaT cells was promoted in the presence of 10−6 and 10−5 mol/L Ag+ at 24, 48, and 72 h. Intracellular ROS generation also significantly increased for 5–60 min after exposure to Ag+. The number of BrdU-positive cells and the presence of PCNA in HaCaT cells increased 48 h after the addition of 10−6 and 10−5 mol/L Ag+, with 10−5 mol/L Ag+ markedly increasing the cell proliferation index. These effects of sub-cytotoxic Ag+ concentrations were repressed by 5 mmol/L NAC. Our results suggest that sub-cytotoxic Ag+ concentrations promote the proliferation of human keratinocytes and might be associated with a moderate increase in intracellular ROS levels. This study provides important experimental evidence for developing novel silver-based wound agents or dressings with few or no cytotoxicity.

关键词： ionic silver     human keratinocyte     cell proliferation     reactive oxygen species     active oxygen scavenger     NAC    

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Heterometallic cluster-based organic frameworks as highly active electrocatalysts for oxygen reductionand oxygen evolution reaction: a density functional theory study

《化学科学与工程前沿（英文）》 2023年 第17卷 第5期   页码 570-580 doi: 10.1007/s11705-022-2247-y

摘要： Recently, metal–organic frameworks are one of the potential catalytic materials for electrocatalytic applications. The oxygen reduction reaction and oxygen evolution reaction catalytic activities of heterometallic cluster-based organic frameworks are investigated using density functional theory. Firstly, the catalytic activities of heterometallic clusters are investigated. Among all heterometallic clusters, Fe2Mn–Mn has a minimum overpotential of 0.35 V for oxygen reduction reaction, and Fe2Co–Co possesses the smallest overpotential of 0.32 V for oxygen evolution reaction, respectively 100 and 50 mV lower than those of Pt(111) and RuO2(110) catalysts. The analysis of the potential gap of Fe2M clusters indicates that Fe2Mn, Fe2Co, and Fe2Ni clusters possess good bifunctional catalytic activity. Additionally, the catalytic activity of Fe2Mn and Fe2Co connected through 3,3′,5,5′-azobenzenetetracarboxylate linker to form Fe2M–PCN–Fe2M is explored. Compared with Fe2Mn–PCN–Fe2Mn, Fe2Co–PCN–Fe2Co, and isolated Fe2M clusters, the mixed-metal Fe2Co–PCN–Fe2Mn possesses excellent bifunctional catalytic activity, and the values of potential gap on the Mn and Co sites of Fe2Co–PCN–Fe2Mn are 0.69 and 0.70 V, respectively. Furthermore, the analysis of the electron structure indicates that constructing a mixed-metal cluster can efficiently enhance the electronic properties of the catalyst. In conclusion, the mixed-metal cluster strategy provides a new approach to further design and synthesize high-efficiency bifunctional electrocatalysts.

关键词： bimetallic metal–organic frameworks     bifunctional electrocatalyst     density functional theory     oxygen reduction reaction     oxygen evolution reaction    

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Highly active and durable Pd-Cu catalysts for oxygen reduction in alkaline exchange membrane fuel cells

Xiong PENG, Travis J. OMASTA, Justin M. ROLLER, William E. MUSTAIN

《能源前沿（英文）》 2017年 第11卷 第3期   页码 299-309 doi: 10.1007/s11708-017-0495-1

摘要： A Pd-Cu catalyst, with primary B2-type phase, supported by VulcanXC-7R carbon was synthesized via a solvothermal method. The catalysts were physically and electrochemically characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and both cyclic and linear sweep voltammetry using a rotating disk electrode (RDE). During the RDE testing, the half-wave potential of the Pd-Cu/Vulcan catalyst was 50 mV higher compared to that of commercial Pt/C catalyst for the oxygen reduction reaction (ORR) in alkaline media. The Pd-Cu/Vulcan exhibited a specific activity of 1.27 mA/cm and a mass activity of 0.59 A/mg at 0.9 V, which were 4 and 3 times greater than that of the commercial Pt/C catalyst, respectively. The Pd-Cu/Vulcan catalyst also showed higher alkaline exchange membrane fuel cell (AEMFC) performance, with operating power densities of 1100 MW/cm operating on H /O and 700 MW/cm operating on H /Air (CO -free), which were markedly higher than those of the commercial Pt/C. The Pd-Cu/Vulcan catalyst also exhibited high stability during a short-term, AEMFC durability test, with only around 11% performance loss after 30 hours of operation, an improvement over most AEMFCs reported in the literature to date.

关键词： alkaline exchange membrane (AEM)     fuel cell     Pd-Cu     oxygen reduction     high performance     water    

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3D Network nanostructured NiCoP nanosheets supported on N-doped carbon coated Ni foam as a highly activebifunctional electrocatalyst for hydrogen and oxygen evolution reactions

Miaomiao Tong, Lei Wang, Peng Yu, Xu Liu, Honggang Fu

《化学科学与工程前沿（英文）》 2018年 第12卷 第3期   页码 417-424 doi: 10.1007/s11705-018-1711-1

摘要：

A highly active bi-functional electrocatalyst towards both hydrogen and oxygen evolution reactions is critical for the water splitting. Herein, a self-supported electrode composed of 3D network nanostructured NiCoP nanosheets grown on N-doped carbon coated Ni foam (NiCoP/NF@NC) has been synthesized by a hydrothermal route and a subsequent phosphorization process. As a bifunctional electrocatalyst, the NiCoP/NF@NC electrode needs overpotentials of 31.8 mV for hydrogen evolution reaction and 308.2 mV for oxygen evolution reaction to achieve the current density of 10 mA·cm−2 in 1 mol·L−1 KOH electrolyte. This is much better than the corresponding monometal catalysts of CoP/NF@NC and NiP/NF@NC owing to the synergistic effect. NiCoP/NF@NC also exhibits low Tafel slope, and excellent long-term stability, which are comparable to the commercial noble catalysts of Pt/C and RuO2.

关键词： bimetallic phosphides     N-doped carbon     self-support     hydrogen evolution     oxygen evolution    

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Catalytic combustion of methane over a highly active and stable NiO/CeO

Xiuhui Huang, Junfeng Li, Jun Wang, Zeqiu Li, Jiayin Xu

《化学科学与工程前沿（英文）》 2020年 第14卷 第4期   页码 534-545 doi: 10.1007/s11705-019-1821-4

摘要： In the last decades, many reports dealing with technology for the catalytic combustion of methane (CH ) have been published. Recently, attention has increasingly focused on the synthesis and catalytic activity of nickel oxides. In this paper, a NiO/CeO catalyst with high catalytic performance in methane combustion was synthesized via a facile impregnation method, and its catalytic activity, stability, and water-resistance during CH combustion were investigated. X-ray diffraction, low-temperature N adsorption, thermogravimetric analysis, Fourier transform infrared spectroscopy, hydrogen temperature programmed reduction, methane temperature programmed surface reaction, Raman spectroscopy, electron paramagnetic resonance, and transmission electron microscope characterization of the catalyst were conducted to determine the origin of its high catalytic activity and stability in detail. The incorporation of NiO was found to enhance the concentration of oxygen vacancies, as well as the activity and amount of surface oxygen. As a result, the mobility of bulk oxygen in CeO was increased. The presence of CeO prevented the aggregation of NiO, enhanced reduction by NiO, and provided more oxygen species for the combustion of CH . The results of a kinetics study indicated that the reaction order was about 1.07 for CH and about 0.10 for O over the NiO/CeO catalyst.

关键词： methane combustion     NiO/CeO2 catalyst     interaction     oxygen vacancy     kinetic study    

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Influence of Fe on electrocatalytic activity of iron-nitrogen-doped carbon materials toward oxygen reduction

Lin LI, Cehuang FU, Shuiyun SHEN, Fangling JIANG, Guanghua WEI, Junliang ZHANG

《能源前沿（英文）》 2022年 第16卷 第5期   页码 812-821 doi: 10.1007/s11708-020-0669-0

摘要： The development of highly active nitrogen-doped carbon-based transition metal (M-N-C) compounds for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs) greatly helps reduce fuel cell cost, thus rapidly promoting their commercial applications. Among different M-N-C electrocatalysts, the series of Fe-N-C materials are highly favored because of their high ORR activity. However, there remains a debate on the effect of Fe, and rare investigations focus on the influence of Fe addition in the second heat treatment usually performed after acid leaching in the catalyst synthesis. It is thus very critical to explore the influences of Fe on the ORR electrocatalytic activity, which will, in turn, guide the design of Fe-N-C materials with enhanced performance. Herein, a series of Fe-N-C electrocatalysts are synthesize and the influence of Fe on the ORR activity are speculated both experimentally and theoretically. It is deduced that the active site lies in the structure of Fe-N , accompanied with the addition of appropriate Fe, and the number of active sites increases without the occurrence of agglomeration particles. Moreover, it is speculated that Fe plays an important role in stabilizing N as well as constituting active sites in the second pyrolyzing process.

关键词： oxygen reduction reaction     Fe-N-C     active sites     Fe addition     second heat treatment    

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Interface engineering for enhancing electrocatalytic oxygen evolution reaction of CoS/CeO heterostructures

《化学科学与工程前沿（英文）》 2022年 第16卷 第3期   页码 376-383 doi: 10.1007/s11705-021-2062-x

摘要： To realize renewable energy conversion, it is important to develop low-cost and high-efficiency electrocatalyst for oxygen evolution reaction. In this communication, a novel bijunction CoS/CeO2 electrocatalyst grown on carbon cloth is prepared by the interface engineering. The interface engineering of CoS and CeO2 facilitates a rapid charge transfer from CeO2 to CoS. Such an electrocatalyst exhibits outstanding electrocatalytic activity with a low overpotential of 311 mV at 10 mA∙cm−2 and low Tafel slope of 76.2 mV∙dec–1, and is superior to that of CoS (372 mV) and CeO2 (530 mV) counterparts. And it has long-term durability under alkaline media.

关键词： interface engineering     CoS/CeO2     electrodeposition     electrocatalyst     oxygen evolution reaction    

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advanced engineering measures on displacement and stress field of surrounding rock in tunnels crossing active

《结构与土木工程前沿（英文）》 doi: 10.1007/s11709-023-0966-x

摘要： Based on significant improvements in engineering materials, three advanced engineering measures have been proposed—super anchor cables, high-strength concrete anti-fault caverns, and grouting modification using high-strength concrete-to resist fault dislocation in the surrounding rock near tunnels crossing active strike-slip faults. Moreover, single- or multiple-joint advanced engineering measures form the local rock mass-anti-fault (LRAF) method. A numerical method was used to investigate the influence of LRAF methods on the stress and displacement fields of the surrounding rock, and the anti-fault effect was evaluated. Finally, the mechanism of action of the anchor cable was verified using a three-dimensional numerical model. The numerical results indicated that the anchor cable and grouting modification reduced the displacement gradient of the local surrounding rock near the tunnels crossing fault. Furthermore, anchor cable and grouting modifications changed the stress field of the rock mass in the modified area. The tensile stress field of the rock mass in the modified anchor cable area was converted into a compressive stress field. The stress field in the modified grouting area changed from shear stress in the fault slip direction to tensile stress in the axial tunnel direction. The anti-fault cavern resisted the dislocation displacement and reduced the maximum dislocation magnitude, displacement gradient, and shear stress. Among the three advanced engineering measures, the anchor cable was the core of the three advanced engineering measures. An anchor cable, combined with other LRAF measures, can form an artificial safety island at the cross-fault position of the rock mass to protect the tunnel. The research results provide a new supporting idea for the surrounding rock of tunnels crossing active strike-slip faults.

关键词： anti-fault effect     engineering measures     LRAF method     stress and displacement field     tunnel-crossing active faults    

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High-entropy catalysts for electrochemical water-electrolysis of hydrogen evolution and oxygen evolution

《能源前沿（英文）》 doi: 10.1007/s11708-023-0892-6

摘要： High entropy materials (HEMs) have developed rapidly in the field of electrocatalytic water-electrolysis for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) due to their unique properties. In particular, HEM catalysts are composed of many elements. Therefore, they have rich active sites and enhanced entropy stability relative to single atoms. In this paper, the preparation strategies and applications of HEM catalysts in electrochemical water-electrolysis are reviewed to explore the stabilization of HEMs and their catalytic mechanisms as well as their application in support green hydrogen production. First, the concept and four characteristics of HEMs are introduced based on entropy and composition. Then, synthetic strategies of HEM catalysts are systematically reviewed in terms of the categories of bottom-up and top-down. The application of HEMs as catalysts for electrochemical water-electrolysis in recent years is emphatically discussed, and the mechanisms of improving the performance of electrocatalysis is expounded by combining theoretical calculation technology and ex-situ/in situ characterization experiments. Finally, the application prospect of HEMs is proposed to conquer the challenges in HEM catalyst fabrications and applications.

关键词： high-entropy     electrocatalysis     synthetic methods     water-electrolysis     hydrogen and oxygen evolutions    

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Solid-state NMR for metal-containing zeolites: From active sites to reaction mechanism

Xingling Zhao, Jun Xu, Feng Deng

《化学科学与工程前沿（英文）》 2020年 第14卷 第2期   页码 159-187 doi: 10.1007/s11705-019-1885-1

摘要： Metal-containing zeolite catalysts have found a wide range of applications in heterogeneous catalysis. To understand the nature of metal active sites and the reaction mechanism over such catalysts is of great importance for the establishment of structure-activity relationship. The advanced solid-state NMR (SSNMR) spectroscopy is robust in the study of zeolites and zeolite-catalyzed reactions. In this review, we summarize recent developments and applications of SSNMR for exploring the structure and property of active sites in metal-containing zeolites. Moreover, detailed information on host-guest interactions in the relevant zeolite catalysis obtained by SSNMR is also discussed. Finally, we highlight the mechanistic understanding of catalytic reactions on metal-containing zeolites based on the observation of key surface species and active intermediates.

关键词： metal-containing zeolites     solid-state NMR     active site     host-guest interaction     reaction mechanism    

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A review of Pt-based electrocatalysts for oxygen reduction reaction

Changlin ZHANG, Xiaochen SHEN, Yanbo PAN, Zhenmeng PENG

《能源前沿（英文）》 2017年 第11卷 第3期   页码 268-285 doi: 10.1007/s11708-017-0466-6

摘要： Development of active and durable electrocatalyst for oxygen reduction reaction (ORR) remains one challenge for the polymer electrolyte membrane fuel cell (PEMFC) technology. Pt-based nanomaterials show the greatest promise as electrocatalyst for this reaction among all current catalytic structures. This review focuses on Pt-based ORR catalyst material development and covers the past achievements, current research status and perspectives in this research field. In particular, several important categories of Pt-based catalytic structures and the research advances are summarized. Key factors affecting the catalyst activity and durability are discussed. An outlook of future research direction of ORR catalyst research is provided.

关键词： oxygen reduction reaction (ORR)     electrocatalysis     platinum catalyst     activity     durability    

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Advances in Active Suspension Systems for Road Vehicles

Min Yu,Simos Evangelou,Daniele Dini,

《工程（英文）》 doi: 10.1016/j.eng.2023.06.014

摘要： Active suspension systems (ASSs) have been proposed and developed for a few decades, and have now once again become a thriving topic in both academia and industry, due to the high demand for driving comfort and safety and the compatibility of ASSs with vehicle electrification and autonomy. Existing review papers on ASSs mainly cover dynamics modeling and robust control; however, the gap between academic research outcomes and industrial application requirements has not yet been bridged, hindering most ASS research knowledge from being transferred to vehicle companies. This paper comprehensively reviews advances in ASSs for road vehicles, with a focus on hardware structures and control strategies. In particular, state-of-the-art ASSs that have been recently adopted in production cars are discussed in detail, including the representative solutions of Mercedes active body control (ABC) and Audi predictive active suspension; novel concepts that could become alternative candidates are also introduced, including series active variable geometry suspension, and the active wheel-alignment system. ASSs with compact structure, small mass increment, low power consumption, high-frequency response, acceptable economic costs, and high reliability are more likely to be adopted by car manufacturers. In terms of control strategies, the development of future ASSs aims not only to stabilize the chassis attitude and attenuate the chassis vibration, but also to enable ASSs to cooperate with other modules (e.g., steering and braking) and sensors (e.g., cameras) within a car, and even with high-level decision-making (e.g., reference driving speed) in the overall transportation system—strategies that will be compatible with the rapidly developing electric and autonomous vehicles.

关键词： Active suspension     Vehicle dynamics     Robust control     Ride comfort     Chassis attitude    

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Photoreduction adjusted surface oxygen vacancy of BiMoO for boosting photocatalytic redox performance

《化学科学与工程前沿（英文）》 2023年 第17卷 第12期   页码 1937-1948 doi: 10.1007/s11705-023-2353-5

摘要： In this study, Bi2MoO6 with adjustable rich oxygen vacancies was prepared by a novel and simple solvothermal-photoreduction method which might be suitable for a large-scale production. The experiment results show that Bi2MoO6 with rich oxygen vacancies is an excellent photocatalyst. The photocatalytic ability of BMO-10 is 0.3 and 3.5 times higher than that of the pristine Bi2MoO6 for Rhodamine B degradation and Cr(VI) reduction, respectively. The results display that the band energy of the samples with oxygen vacancies was narrowed and the light absorption was broadened. Meanwhile, the efficiency of photogenerated electron-holes was increased and the separation and transfer speed of photogenerated carriers were improved. Therefore, this work provides a convenient and efficient method to prepare potential adjustable oxygen vacancy based photocatalysts to eliminate the pollution of dyes and Cr(VI) in water.

关键词： Bi2MoO6     oxygen vacancies     photoreduction     Cr(VI)     RhB    

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Role of oxygen vacancy inducer for graphene in graphene-containing anodes

《化学科学与工程前沿（英文）》 2023年 第17卷 第3期   页码 326-333 doi: 10.1007/s11705-022-2213-8

摘要： Currently, graphene is only considered as a conductive additive and expansion inhibitor in oxides/graphene composite anodes. In this study, a new graphene role (oxygen vacancy inducer) in graphene/oxides composites anodes, which are treated at high-temperature, is proposed and verified using experiments and density functional theory calculations. During high-temperature processing, graphene forms carbon vacancies due to increased thermal vibration, and the carbon vacancies capture oxygen atoms, facilitating the formation of oxygen vacancies in oxides. Moreover, the induced oxygen vacancy concentrations can be regulated by sintering temperatures, and the behavior is unaffected by oxide crystal structures (crystalline and amorphous) and morphology (size and shape). According to density functional theory calculations and electrochemical measurements, the oxygen vacancies enhance the lithium-ion storage performance. The findings can result in a better understanding of graphene’s roles in graphene/oxide composite anodes, and provide a new method for designing high-performance oxide anodes.

关键词： oxide     oxygen vacancy     graphene     anode     density functional theory calculation    

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Multivalent manganese oxides with high electrocatalytic activity for oxygen reduction reaction

Xiangfeng Peng, Zhenhai Wang, Zhao Wang, Yunxiang Pan

《化学科学与工程前沿（英文）》 2018年 第12卷 第4期   页码 790-797 doi: 10.1007/s11705-018-1706-y

摘要： A noble-metal-free catalyst based on both Mn O and MnO was prepared by using the dielectric barrier discharge technique at moderate temperature. The prepared catalyst shows a higher electrocatalytic activity towards the oxygen reduction reaction than the catalyst prepared by using the traditional calcination process. The enhanced activity could be due to the coexistence of manganese ions with different valences, the higher oxygen adsorption capacity, and the suppressed aggregation of the catalyst nanoparticles at moderate temperature. The present work would open a new way to prepare low-cost and noble-metal-free catalysts at moderate temperature for more efficient electrocatalysis.

关键词： oxygen reduction reaction     manganese oxides     mixed valences of manganese     oxygen adsorption     dielectric barrier discharge    

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标题 作者 时间 类型 操作

ionic silver promote the proliferation of human keratinocytes by inducing the production of reactive oxygen

null

期刊论文

Heterometallic cluster-based organic frameworks as highly active electrocatalysts for oxygen reductionand oxygen evolution reaction: a density functional theory study

期刊论文

Highly active and durable Pd-Cu catalysts for oxygen reduction in alkaline exchange membrane fuel cells

Xiong PENG, Travis J. OMASTA, Justin M. ROLLER, William E. MUSTAIN

期刊论文

3D Network nanostructured NiCoP nanosheets supported on N-doped carbon coated Ni foam as a highly activebifunctional electrocatalyst for hydrogen and oxygen evolution reactions

Miaomiao Tong, Lei Wang, Peng Yu, Xu Liu, Honggang Fu

期刊论文

Catalytic combustion of methane over a highly active and stable NiO/CeO

Xiuhui Huang, Junfeng Li, Jun Wang, Zeqiu Li, Jiayin Xu

期刊论文

Influence of Fe on electrocatalytic activity of iron-nitrogen-doped carbon materials toward oxygen reduction

Lin LI, Cehuang FU, Shuiyun SHEN, Fangling JIANG, Guanghua WEI, Junliang ZHANG

期刊论文

Interface engineering for enhancing electrocatalytic oxygen evolution reaction of CoS/CeO heterostructures

期刊论文

advanced engineering measures on displacement and stress field of surrounding rock in tunnels crossing active

期刊论文

High-entropy catalysts for electrochemical water-electrolysis of hydrogen evolution and oxygen evolution

期刊论文

Solid-state NMR for metal-containing zeolites: From active sites to reaction mechanism

Xingling Zhao, Jun Xu, Feng Deng

期刊论文

A review of Pt-based electrocatalysts for oxygen reduction reaction

Changlin ZHANG, Xiaochen SHEN, Yanbo PAN, Zhenmeng PENG

期刊论文

Advances in Active Suspension Systems for Road Vehicles

Min Yu,Simos Evangelou,Daniele Dini,

期刊论文

Photoreduction adjusted surface oxygen vacancy of BiMoO for boosting photocatalytic redox performance

期刊论文

Role of oxygen vacancy inducer for graphene in graphene-containing anodes

期刊论文

Multivalent manganese oxides with high electrocatalytic activity for oxygen reduction reaction

Xiangfeng Peng, Zhenhai Wang, Zhao Wang, Yunxiang Pan

期刊论文