Bulletin of Materials Science最新文献_第6页

Phytochemically modified copper oxide-doped yttrium oxide nanoparticles for antibacterial, photocatalytic and ultralow limit biomarker detection applications 用于抗菌、光催化和超低限生物标记物检测的植物化学修饰氧化铜掺杂氧化钇纳米粒子

IF 1.9 4区材料科学

Bulletin of Materials Science Pub Date : 2024-09-18 DOI: 10.1007/s12034-024-03321-1

Sathish Kumar Somu, Powrnika Selvakumar, Sri Vanaja Swaminathan, Soumyajit Ghosh, Tanay Kundu

{"title":"Phytochemically modified copper oxide-doped yttrium oxide nanoparticles for antibacterial, photocatalytic and ultralow limit biomarker detection applications","authors":"Sathish Kumar Somu, Powrnika Selvakumar, Sri Vanaja Swaminathan, Soumyajit Ghosh, Tanay Kundu","doi":"10.1007/s12034-024-03321-1","DOIUrl":"10.1007/s12034-024-03321-1","url":null,"abstract":"<div>Sustainable production of multifunctional nanomaterials is a key challenge for their widespread use. Phytochemical-assisted synthesis provides an environmentally benign route of nanoparticle modifications towards desired applications. Herein, Catharanthus roseus (CR) leaves extract has been used as a phytochemical modifier for copper oxide-doped yttrium oxide nanoparticles (CuO/Y2O3 NPs). The composition, structure, morphology and functional groups of CuO/Y2O3 NPs have been extensively modulated via green synthesis. The excellent antibacterial activities against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) pathogens suggest an increasing rate of antibacterial behaviour. Besides, the sheet-like morphology of CuO/Y2O3 NPs promotes photocatalytic activities by methylene blue, phenol and methyl orange degradation under sunlight with rates of 0.0203, 0.0152 and 0.0167 min−1. Most importantly, CuO/Y2O3 NPs facilitate low oxidation peak potential (−0.58 V), extended frequency linear range (1–300 nM), and ultralow detection limit (up to 0.58 nM) for an important biomarker threonine, which is the best among any nanomaterials reported till date. Such achievement paved the way for sustainable nanomaterial modifications towards multifunctionality.</div>","PeriodicalId":502,"journal":{"name":"Bulletin of Materials Science","volume":"47 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142259800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of different heat-treatment processes on corrosion resistance of 17-4PH steel 不同热处理工艺对 17-4PH 钢耐腐蚀性的影响

IF 1.9 4区材料科学

Bulletin of Materials Science Pub Date : 2024-09-18 DOI: 10.1007/s12034-024-03300-6

Xiaoqin Chen, Xiaofei Qin, Yue Li, Wenjia Cheng, Haonan Jin, Quan Li

{"title":"Effect of different heat-treatment processes on corrosion resistance of 17-4PH steel","authors":"Xiaoqin Chen, Xiaofei Qin, Yue Li, Wenjia Cheng, Haonan Jin, Quan Li","doi":"10.1007/s12034-024-03300-6","DOIUrl":"10.1007/s12034-024-03300-6","url":null,"abstract":"<div>The heat-treatment process exerts a substantial influence on both the quantity and morphology of reversed austenite in 17-4PH stainless steel. In this study, the effects of different ageing treatment methods on the microstructure and corrosion resistance of the steel were investigated. Through the observation of microscopic morphology, it was found that adjustment and ageing treatment and double ageing treatment were more conducive to the migration of elements in the steel than single ageing treatment, and they also improved the microstructure. In addition to improving the uniformity of alloy element distribution, uniformity also controls the reversed austenite content. By controlling the content and distribution of reversed austenite, the stability of the corrosion film formed at the interface can be improved, thereby improving the corrosion resistance of stainless steel. The stainless steel, after adjustment treatment and ageing treatment, has better corrosion resistance. The electrochemical corrosion resistance in a high-temperature and high-pressure underground environment was evaluated based on parameters including passivation current density and passivation potential. The results revealed a significant improvement of 50.5% in electrochemical corrosion resistance and a remarkable increase of 45.96% in pitting corrosion resistance. Furthermore, the FeCl3 pitting test demonstrated a substantial decrease of 63.16% in pitting density and a reduction of 27.96% in the uniform corrosion rate.</div>","PeriodicalId":502,"journal":{"name":"Bulletin of Materials Science","volume":"47 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142259801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Positron effective mass and positronium work function in ZnxCd1−xS ZnxCd1-xS 中的正电子有效质量和正电子功函数

IF 1.9 4区材料科学

Bulletin of Materials Science Pub Date : 2024-09-14 DOI: 10.1007/s12034-024-03311-3

Abdelaziz Gassoumi, Nadir Bouarissa

{"title":"Positron effective mass and positronium work function in ZnxCd1−xS","authors":"Abdelaziz Gassoumi, Nadir Bouarissa","doi":"10.1007/s12034-024-03311-3","DOIUrl":"10.1007/s12034-024-03311-3","url":null,"abstract":"<div>Electron and positron chemical potentials, positron affinity and bulk lifetime, positronium work function and positron effective mass have been computed for ZnxCd1−xS using a pseudo-potential approach within the virtual crystal approximation (VCA) and the independent particle model. A correction to VCA is included taking into consideration the disorder effect. This has permitted the computation of the positron affinity to separate materials of interest. The performances indicated that the positron annihilates differently in CdS than in ZnS. The bulk lifetime of positron has been obtained as 241.17 ps for CdS and 215.47 ps for ZnS. Hence, it decreases when going from CdS to ZnS. The positronium work function increases from 2.245 to 3.08 eV when augmenting the composition x from 0 to 1, indicating that only fewer positronium atoms are figured in a specimen surface and ejected for the vacuum. The positron effective mass augments from 0.96 to 1.34 m0 when going from CdS to ZnS materials. The details collected from the assisted investigation are of a former significance for an ameliorate accordance of positron annihilation in ZnxCd1−xS.</div>","PeriodicalId":502,"journal":{"name":"Bulletin of Materials Science","volume":"47 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142259803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Formation and properties of silicon vacancies in MPCVD-grown polycrystalline diamond MPCVD 生长的多晶金刚石中硅空位的形成和特性

IF 1.9 4区材料科学

Bulletin of Materials Science Pub Date : 2024-09-14 DOI: 10.1007/s12034-024-03284-3

Rahul Raj, K G Pradeep, M S Ramachandra Rao

引用次数: 0

Facile strategy to protect material surface using peelable film from prevulcanized rubber latex 使用预硫化橡胶胶乳可剥离薄膜保护材料表面的简便策略

IF 1.9 4区材料科学

Bulletin of Materials Science Pub Date : 2024-09-13 DOI: 10.1007/s12034-024-03304-2

Yaowaret Maiket, Rungsima Yeetsorn, Waritnan Wanchan, Sunanta Chuayprakong, Thitinun Ungtrakul, Mesum Abbas, Edmund Haberstroh

{"title":"Facile strategy to protect material surface using peelable film from prevulcanized rubber latex","authors":"Yaowaret Maiket, Rungsima Yeetsorn, Waritnan Wanchan, Sunanta Chuayprakong, Thitinun Ungtrakul, Mesum Abbas, Edmund Haberstroh","doi":"10.1007/s12034-024-03304-2","DOIUrl":"10.1007/s12034-024-03304-2","url":null,"abstract":"<div>This study introduces a method for producing environmentally friendly peelable film using prevulcanized rubber latex, offering a simple and cost-effective solution capable of covering complex shapes. The synthesis investigation explores the relationship between conventional rubber formulations and the film’s performance, highlighting the significance of selecting appropriate chemicals to improve functionality. Key considerations for selecting the latex compound formulation include the solution's properties, particularly focussing on flow behaviour and coating time, as well as the mechanical properties, fire resistance, peel ability and durability of the resulting film under challenging conditions. The primary investigation into the impact of the zinc diethyldithiocarbamate : sulphur (ZDEC : S) ratio on crosslink density provides insight into rheological and mechanical properties. Furthermore, the addition of phenol, 4-methyl-, reaction products with dicyclopentadiene and isobutene (CPL) as an antioxidant improves heat resistance and oxygen tolerance. The remarkable versatility of peelable film allows for its application through various methods, including sagging (1–10 s–1), painting and spraying (10–100 s–1), effectively protecting against dust, scratches and temperatures exceeding 200°C. Particularly noteworthy are its low peel force of 0.139 N, 44 mm removal path and 2-month service life. The findings from testing the crucial properties of the manufactured films, which meets industrial standards, indicate a pathway to produce environmentally sustainable products, with a strong potential for further advancement towards commercial production.</div>","PeriodicalId":502,"journal":{"name":"Bulletin of Materials Science","volume":"47 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Bipolar-resistive switching characteristics in lead-free inorganic double-halide perovskite-based memory devices 无铅无机双卤化物过氧化物基存储器件中的双极电阻开关特性

IF 1.9 4区材料科学

Bulletin of Materials Science Pub Date : 2024-09-12 DOI: 10.1007/s12034-024-03286-1

Susmita Das, Prabir Kumar Haldar, Pranab Kumar Sarkar

{"title":"Bipolar-resistive switching characteristics in lead-free inorganic double-halide perovskite-based memory devices","authors":"Susmita Das, Prabir Kumar Haldar, Pranab Kumar Sarkar","doi":"10.1007/s12034-024-03286-1","DOIUrl":"10.1007/s12034-024-03286-1","url":null,"abstract":"<div>Owing to the increasing demands of high-density data storage double-halide perovskite-based resistive random access memory (RRAM) have recently emerged as a promising candidate in the forefront of next-generation optoelectronic memory applications. The ionic motion-based quick switching is the key feature of this kind of material, which plays a significant role in resistive switching (RS) applications. Recently, lead-free tin-based double-halide perovskites have been considered as favourable material due to their superior stability, functionality and eco-friendly nature. Here, we report the synthesis of cesium tin (IV) iodide (Cs2SnI6) perovskites. X-ray diffraction (XRD) pattern of the as-synthesized perovskite confirms the formation of Cs2SnI6 material. The crystallographic data corroborate the formation of a pure cubic phase, free of any other phase at room temperature. We also studied optical properties of the sample by using the ultraviolet–visible (UV) spectra and photoluminescence (PL) spectra. A broadband at around 580 nm is observed in the UV−Vis absorption spectra. The optical band gap of the sample is found to be 1.68 eV. Cs2SnI6 perovskite exhibited intense PL emission at ~540 nm. In this work, to fabricate a flexible Al/Cs2SnI6/ITO-PET memory device, we used Cs2SnI6 film as a switching layer and the device exhibits bipolar RS characteristics.</div>","PeriodicalId":502,"journal":{"name":"Bulletin of Materials Science","volume":"47 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Synergistic effect of anisotropic ZnO nanoparticle shape on its photocatalytic performance for drug degradation in water 各向异性氧化锌纳米粒子形状对其光催化性能的协同效应，用于降解水中的药物

IF 1.9 4区材料科学

Bulletin of Materials Science Pub Date : 2024-09-11 DOI: 10.1007/s12034-024-03234-z

Sukesh Kashiram Tumram, Rajdip Bandyopadhyaya

{"title":"Synergistic effect of anisotropic ZnO nanoparticle shape on its photocatalytic performance for drug degradation in water","authors":"Sukesh Kashiram Tumram, Rajdip Bandyopadhyaya","doi":"10.1007/s12034-024-03234-z","DOIUrl":"10.1007/s12034-024-03234-z","url":null,"abstract":"<div>Increasing environmental issues have emerged due to various pharmaceutical wastes. These wastes are difficult to remove by treatment due to their continuous consumption and long-term persistence. We have synthesized two different shapes of zinc oxide (ZnO) nanoparticles as catalysts—nanorod (ZnO–NR) and oval-shape (ZnO–OS). A comparative performance of these two catalyst shapes on photocatalytic degradation of rifampicin (RIF) in water—a first-line anti-tuberculosis drug, was carried out. ZnO–NR showed three times higher normalized first-order degradation rate constant of RIF under UV light than that with ZnO–OS. This is due to: (i) specific surface area and specific pore volume of ZnO–NR being 25 and six times higher, respectively, than ZnO–OS; (ii) oxygen vacancy in ZnO–NR being 1.7 times higher than ZnO–OS; (iii) slightly lower band gap energy in ZnO–NR than ZnO–OS, adding to carrier concentration; and (iv) ZnO–NR additionally showing 12.4% chemisorbed oxygen also. Towards RIF degradation, ZnO–NR shows a much improved synergistic effect than ZnO–OS under UV light, as ZnO–NR under UV light is found to give 2.7 times higher degradation than when the catalyst and UV act independently and hence only additively. Therefore, this study is helpful in tuning the shape-dependent chemical reactivity of nanoparticles in water treatment.</div>","PeriodicalId":502,"journal":{"name":"Bulletin of Materials Science","volume":"47 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Non-enzymatic approach of H2O2 and glucose sensing using NiO–MoS2-derived electrochemical sensor 利用源自 NiO-MoS2 的电化学传感器以非酶方法传感 H2O2 和葡萄糖

IF 1.9 4区材料科学

Bulletin of Materials Science Pub Date : 2024-09-11 DOI: 10.1007/s12034-024-03291-4

Ankush Medhi, Manas Kumar Giri, D Mohanta

{"title":"Non-enzymatic approach of H2O2 and glucose sensing using NiO–MoS2-derived electrochemical sensor","authors":"Ankush Medhi, Manas Kumar Giri, D Mohanta","doi":"10.1007/s12034-024-03291-4","DOIUrl":"10.1007/s12034-024-03291-4","url":null,"abstract":"<div>At present, selective and accurate determination of hydrogen peroxide (H2O2) and glucose has become essential for routine diagnosis. The present work demonstrates the hydrothermal synthesis of NiO nanosheet (NS)–MoS2-based composite system for non-enzymatic electrochemical detection of H2O2 and glucose. To understand the structure, morphology and elemental constituents of the prepared composite system, various characterization techniques were employed, namely XRD, FTIR, FESEM, TEM and EDX. Redox activity and charge transfer process of the NiO–MoS2-based sensor electrode towards H2O2 and glucose were realized via using electrochemical techniques: cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry. To be mentioned, limit of detection (LOD) and sensitivity for detection of H2O2 are calculated to be 3 µM and 3925 µA mM−1 cm−2, respectively, under the linear range of 5–455 µM in 0.1 M PBS solution. Similarly, the LOD and sensitivity for sensing glucose is estimated to be 3.53 µM and 1880 µA mM−1 cm−2, respectively, under the linear range of 5–370 µM in 0.1 M NaOH solution. The cost-effective fabricated sensor exhibited good stability with a high selectivity towards the specific analytes only.</div>","PeriodicalId":502,"journal":{"name":"Bulletin of Materials Science","volume":"47 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of morphology on the thermoelectric properties of pure nanostructured zinc oxide 形态对纯纳米结构氧化锌热电性能的影响

IF 1.9 4区材料科学

Bulletin of Materials Science Pub Date : 2024-09-11 DOI: 10.1007/s12034-024-03309-x

Rahul Madan, Vikas Kumar, Bajinder Singh, Devendra Mohan

{"title":"Effect of morphology on the thermoelectric properties of pure nanostructured zinc oxide","authors":"Rahul Madan, Vikas Kumar, Bajinder Singh, Devendra Mohan","doi":"10.1007/s12034-024-03309-x","DOIUrl":"10.1007/s12034-024-03309-x","url":null,"abstract":"<div>This article investigates the effect of morphology on the thermoelectric properties of nanostructured zinc oxide. Three different samples of nanostructured zinc oxide, named ZnO, ZnO triethanol amine (TEA) and ZnO Calc., were synthesized. ZnO and ZnO TEA samples were synthesized by the chemical precipitation method, while ZnO Calc. sample was prepared by the direct calcination method. The FESEM analysis revealed that ZnO and ZnO Calc. samples have flakes and nanorod-like morphology, respectively, while ZnO TEA has a mixed hexagonal and irregularly shaped morphology. The Rietveld refinement of X-ray diffraction data confirmed that all the prepared samples have a hexagonal wurtzite phase of ZnO with space group P63mc. The energy-dispersive X-ray spectroscopy confirmed the presence of zinc and oxygen in all the synthesized samples. The electrical resistivity and Seebeck coefficient were recorded in the temperature range of 300–950 K. The negative values of the Seebeck coefficient revealed the n-type nature of all the samples. The increase in electrical resistivity with the increase in temperature confirmed that all three prepared ZnO samples show metallic behaviour. The highest Seebeck coefficient of –245 μV K–1 was attained by ZnO nanorods at 950 K, while the lowest Seebeck coefficient of –212 μV K–1 was obtained for ZnO TEA at 950 K. The highest thermoelectric power factor of 2.11 (times , {10}^{-3}) W m–1 K–2 was attained by the ZnO Calc. sample at 950 K. The results indicate that the synthesized ZnO Calc. sample with nanorod-like morphology has better thermoelectric performance as compared to flakes and platelets-like morphology.</div>","PeriodicalId":502,"journal":{"name":"Bulletin of Materials Science","volume":"47 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Preparation and properties of electrochemically assisted electroless Ni–P–TiO2–NG composite coatings 电化学辅助无电解 Ni-P-TiO2-NG 复合涂层的制备与性能

IF 1.9 4区材料科学

Bulletin of Materials Science Pub Date : 2024-09-05 DOI: 10.1007/s12034-024-03325-x

Guanghui Zhao, Chunyu Ma, Ruiteng Wang, Penghui Liu, Nan Zhou, Fuwen Qin, Qingyu Zhang

{"title":"Preparation and properties of electrochemically assisted electroless Ni–P–TiO2–NG composite coatings","authors":"Guanghui Zhao, Chunyu Ma, Ruiteng Wang, Penghui Liu, Nan Zhou, Fuwen Qin, Qingyu Zhang","doi":"10.1007/s12034-024-03325-x","DOIUrl":"10.1007/s12034-024-03325-x","url":null,"abstract":"<div>Inspired by NG/TiO2 composite reinforcing particles in the Ni–P matrix, an electrochemically assisted electroless deposition method was used to deposit Ni–P–TiO2–NG composite coatings on steel substrates in order to enhance their electrochemical and photocatalytic properties. The effects of current density on the microstructure, surface morphology and phase composition of the coatings were investigated. Statistical analysis based on multifractal formalism shows that the uniformity of the height distribution shows an increasing and then a decreasing trend as the current density increases. The results show that the average hardness reached a maximum value of 966 HV0.1 for the optimum coating obtained at a current density of 4 A dm–2, the corrosion current reached a minimum value of 2.041 × 10–5 A cm–2, with a maximum corrosion potential of –0.281 V vs. SCE. These improvements can be attributed to high phosphorus Ni–P composite coatings with smooth and dense morphology, TiO2/NG nanocomposite impermeability and excellent mechanical properties. In addition, the photocatalytic activity of the Ni–P–TiO2–NG coating gradually increases with increasing current density.</div>","PeriodicalId":502,"journal":{"name":"Bulletin of Materials Science","volume":"47 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0