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集成有CNTs和Ni-Ni(OH)_(2)异质结构的电解析氢自支撑薄膜催化剂
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作者 赵万成 马加朋 +6 位作者 田栋 康宝涛 夏方诠 成婧 吴亚军 王梦遥 武刚 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第7期287-295,共9页
氢气是一种重要的能量储存载体.通过电解水析氢的方式,可以将其他可再生能源转化为电能,并以化学能的形式储存于氢气中.为了提高电解析氢过程的能量转化效率、降低能耗,需要高活性的析氢催化剂.这些催化剂不仅应具有巨大的比表面积,还... 氢气是一种重要的能量储存载体.通过电解水析氢的方式,可以将其他可再生能源转化为电能,并以化学能的形式储存于氢气中.为了提高电解析氢过程的能量转化效率、降低能耗,需要高活性的析氢催化剂.这些催化剂不仅应具有巨大的比表面积,还应具备适中的氢吸附能和较强的解离水的能力.铂基催化剂在电解析氢方面展现出了显著的优势,而同族的镍基催化剂因其高性价比而备受关注.然而,在电解析氢过程中,镍基催化剂存在氢吸附强度高和解离水能力弱两个重要缺陷,这导致析氢过程动力学不理想.因此,本文的研究思路是探索如何在镍基催化剂中引入功能性组分,以平衡氢吸附能和催化水解离的能力,从而实现析氢性能的提升.研究表明,碳纳米管(CNTs)可以改善催化剂的电解析氢性能,而Ni(OH)_(2)则可以提升催化剂解离水的能力.因此,本文采用复合电沉积法制得CNTs-Ni薄膜,并通过原位氧化在其表面形成Ni-Ni(OH)_(2)异质结构,构建了包含CNTs和Ni-Ni(OH)_(2)两种功能组分的CNTs-Ni-Ni(OH)_(2)薄膜.该薄膜展现出与Pt/C相当的析氢活性和更出色的稳定性.微观形貌分析显示,CNTs的引入使CNTs-Ni薄膜具有复杂的三维结构,镍以高度褶皱的微球形态均匀负载在CNTs表面,形成巨大的比表面积.电化学测试和模拟计算结果证实,CNTs-Ni薄膜的析氢活性较纯镍有显著提高,这归因于其巨大的电化学活性面积以及CNTs对析氢过程动力学的积极影响.当优化沉积时间和CNTs表面镍的负载量时,CNTs-Ni薄膜的电化学活性面积和析氢活性均得到显著提升.进一步氧化处理后,通过X射线光电子能谱和X射线衍射等测试手段证实了Ni-Ni(OH)_(2)异质结构的形成,并观察到电化学活性面积的增大和析氢活性的改善.此外,深入研究发现,随着氧化时间的延长,单位电化学活性面积上的析氢活性出现下降.结合析氢过程的背景电流分析推测,在析氢过程中CNTs-Ni-Ni(OH)_(2)表面发生氢氧化镍的还原,重新生成的镍活性位点对提升析氢过程动力学起到关键作用.但过长的氧化时间可能会破坏镍活性位点的再生.基于此理论构建的计算模型验证了CNTs和异质结构对析氢活性的协同增强作用,使氢的吸附自由能达到理想值,理论上氢在复合薄膜表面的析出过电位接近于0 V.因此,在碱性溶液中,集成有CNTs和Ni-Ni(OH)_(2)异质结构的CNTs-Ni-Ni(OH)_(2)析氢催化剂表现出优异的性能,其氢气起始析出电位为0 V,当阴极电流密度分别为10和50 mA/cm^(2)时,析氢过电位也仅为65和109 mV.综上所述,本文通过复合电沉积和原位氧化的方式获得了CNTs-Ni-Ni(OH)_(2)自支撑析氢催化剂,不仅体现出明显的几何效应,而且也对析氢过程的动力学产生了积极影响.这种整合多种功能性组分的方式,为未来设计和制备高活性、高性价比的电解析氢材料提供了新的思路. 展开更多
关键词 Ni-Ni(OH)_(2)异质结构 电解催化剂 析氢反应 碳纳米管 吸附自由能
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2DGE-coomassie brilliant blue staining used to differentiate pasteurized milk from reconstituted milk 被引量:3
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作者 yajun wu Ying Chen +3 位作者 Bin Wang Haiyan Wang Fei Yuan Guiming Zhao 《Health》 2009年第3期146-151,共6页
Differentiating pasteurized milk and reconsti-tuted milk by scientific approach was necessary to defend consumer from economic fraud of wrong labeling. In this paper 2DGE (2 Dimen-sional Gel Electrophoresis)-coomassie... Differentiating pasteurized milk and reconsti-tuted milk by scientific approach was necessary to defend consumer from economic fraud of wrong labeling. In this paper 2DGE (2 Dimen-sional Gel Electrophoresis)-coomassie brilliant blue staining method was employed and sig-nificant color intensity changing was observed among raw milk, pasteurized milk, UHT milk and reconstituted milk. For example, the intensity of 10 protein spots including casein and lac-toglobulin reduced more than two folds from pasteurized milk to reconstituted milk. However, DIGE (Differential Gel Electrophoresis) assay showed that the majority protein remained simi-lar level from pasteurized milk to reconstituted milk. Therefore the color fading of coomassie brilliant blue stained 2D gels may be due to other biochemical reaction, such as Maillard reaction, instead of protein degradation. Stability of 2DGE pattern was confirmed by running six gels of the same sample in parallel and software analysis showed that all proteins were at similar level. Two commercialized pasteurized milk samples and one reconstituted milk sample were tested by 2DGE-coomassie blue staining method and re-constituted milk could be easily identified. 展开更多
关键词 2DGE Coomassie BRILLIANT BLUE Pasteurized MILK RECONSTITUTED MILK
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Designing of Hot Strip Rolling Mill Control System
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作者 yajun wu 《World Journal of Engineering and Technology》 2016年第3期413-417,共6页
Aimed at the complex demand of hot strip rolling mill in practicing, the configuration of the coiler and the technological process is analyzed. The arithmetic of coiling tension and the control process is introduced. ... Aimed at the complex demand of hot strip rolling mill in practicing, the configuration of the coiler and the technological process is analyzed. The arithmetic of coiling tension and the control process is introduced. The frame of the tension adjusting system is given. The coiler control system hardware is designed. The system is designed scientifically with steady control and meets demand of the market. 展开更多
关键词 Hot Strip Rolling COILER Tension Control
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Three-dimensional parametric contact analysis of planetary roller screw mechanism and its application in grouping for selective assembly
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作者 Huilin HE Peitang WEI +4 位作者 Huaiju LIU Xuesong DU Rui HU Genshen LIU yajun wu 《Frontiers of Mechanical Engineering》 SCIE CSCD 2024年第1期53-72,共20页
The planetary roller screw mechanism(PRSM)is a novel precision transmission mechanism that realizes the conversion between linear and rotary motions.The contact characteristics of helical surfaces directly determine P... The planetary roller screw mechanism(PRSM)is a novel precision transmission mechanism that realizes the conversion between linear and rotary motions.The contact characteristics of helical surfaces directly determine PRSM’s performance in load-carrying capacity and transmission accuracy.Therefore,studying the contact characteristics of PRSM forms the fundamental basis for enhancing its transmission performance.In this study,a three-dimensional parametric analysis method of contact characteristics is proposed based on the PRSM meshing principle and PyVista(a high-level API to the Visualization Toolkit).The proposed method considers the influence of machining errors among various thread teeth.The effects of key machining errors on contact positions and axial clearance,as well as their sensitivities,are analyzed.With excellent solution accuracy,this method exhibits higher calculation efficiency and stronger robustness than the analytical and numerical meshing models.The influence of nominal diameter and pitch errors of the screw,roller,and nut on the axial clearance follows a linear relationship,whereas flank angle errors have negligible effects on the axial clearance.The corresponding influence coefficients for these three machining errors on the axial clearance are 0.623,0.341,and 0.036.The variations in contact positions caused by individual errors are axisymmetric.Flank angle errors and roller diameter errors result in linear displacements of the contact points,whereas pitch errors cause the contact points to move along the arc of the roller diameter.Based on the proposed threedimensional parametric contact characteristics analysis method,the Fuzzy C-Means clustering algorithm considering error sensitivity is utilized to establish a component grouping technique in the selective assembly of critical PRSM components,ensuring the rational and consistent clearances based on the given component’s machining errors.This study provides effective guidance for analyzing contact characteristics and grouping in selective assembly for PRSM components.It also presents the proposed method’s potential applicability to similar calculation problems for contact positions and clearances in other transmission systems. 展开更多
关键词 planetary roller screw mechanism(PRSM) contact position axial clearance machining error grouping for selective assembly
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Microwave triggered multifunctional nanoplatform for targeted photothermal-chemotherapy in castration-resistant prostate cancer 被引量:2
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作者 Pengyuan Liu yajun wu +11 位作者 Xiaogang Xu Xudong Fan Chuan Sun Xiaojie Chen Jindan Xia Shiting Bai Li Qu Huasong Lu Jing wu Jun Chen Ji-Gang Piao Zhibing wu 《Nano Research》 SCIE EI CSCD 2023年第7期9688-9700,共13页
Lacking a precise targeting strategy,castration-resistant prostate cancer(CRPC)is still hard to be treat effectively.Exploring treatment options that can accurately target CPRC is an important issue with urgent need.I... Lacking a precise targeting strategy,castration-resistant prostate cancer(CRPC)is still hard to be treat effectively.Exploring treatment options that can accurately target CPRC is an important issue with urgent need.In this study,a novel nanotechnologybased strategy had been developed for the precise target treatment of CRPC.By combining microwaves and photothermal therapy(PTT),this nanoplatform,cmHSP70-PL-AuNC-DOX,targets tumor tissues with outstanding precision and achieves better anti-tumor activity by simultaneously eliciting photothermal and chemotherapeutic effects.From nanotechnology,cmHSP70-modified and thermo-sensitive liposome-coated AuNC-DOX were prepared and used for CRPC-targeted photothermal ablation and chemotherapy.Doxorubicin(DOX)was selected as the chemotherapeutic agent for cytotoxicity.In terms of the curative scheme,prostate tissues were firstly pre-treated with microwaves to induce the expression of heat shock protein 70(HSP70)and its migration to the cell membrane,which was then targeted by HSP70 antibody(cmHSP70)coated on the nanoparticles to achieve accurate drug delivery.The nanoplatform then achieved precise ablation and controlled release of DOX under external near-infrared(NIR)irradiation.Through the implementation,the targeting,cell killing,and safety of this therapeutical strategy had been verified in vivo and in vitro.This work establishes an accurate,controllable,efficient,non-invasive,and safe treatment platform for targeting CRPC,provides a rational design for CRPC’s PTT,and offers new prospects for nanomedicines with great precision. 展开更多
关键词 castration-resistant prostate cancer gold nanocage heat shock protein 70 targeted drug delivery photothermalchemotherapy
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大型射电望远镜的火星探测器跟踪技术 被引量:4
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作者 刘庆会 赵融冰 +6 位作者 舒逢春 贺庆宝 郑鑫 马茂莉 付丽 吴亚军 虞林峰 《中国科学:信息科学》 CSCD 北大核心 2019年第6期775-782,共8页
我国将于2020年发射由环绕器和着陆巡视器组成的火星探测器,需要利用大型射电望远镜进行跟踪.本文对大型射电望远镜的火星探测器跟踪技术进行了分析,并实际利用上海65 m射电望远镜跟踪火星探测器进行了测试验证.分析和测试结果表明,大... 我国将于2020年发射由环绕器和着陆巡视器组成的火星探测器,需要利用大型射电望远镜进行跟踪.本文对大型射电望远镜的火星探测器跟踪技术进行了分析,并实际利用上海65 m射电望远镜跟踪火星探测器进行了测试验证.分析和测试结果表明,大型射电望远镜跟踪火星探测器时需要考虑和改正座架热变形、大气折射、光行时等引起的指向偏差.不考虑下行单程光行时的接收功率比考虑时降低约0.8 dB.在俯仰指向偏差为36′′和72′′时接收能力分别降低约0.8和3.5 dB.这些研究成果对我国的首次火星探测任务的顺利实施有重要的应用价值. 展开更多
关键词 射电望远镜 火星探测器 跟踪 光行时 指向偏差
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综合治疗医源性库欣综合征患者感染性创面的效果 被引量:1
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作者 李顺堂 林源 +6 位作者 欧斌贤 刘达恩 李德绘 农庆文 吴亚军 邱淑玫 黄振兴 《中华烧伤与创面修复杂志》 CAS CSCD 北大核心 2022年第6期512-519,共8页
目的探讨医源性库欣综合征患者感染性创面的特点及综合治疗方法。方法采用回顾性观察性研究方法。2012年5月—2021年12月,收集广西医科大学第一附属医院烧伤整形外科出院的19例医源性库欣综合征患者资料,患者中男8例、女11例,年龄28~71(... 目的探讨医源性库欣综合征患者感染性创面的特点及综合治疗方法。方法采用回顾性观察性研究方法。2012年5月—2021年12月,收集广西医科大学第一附属医院烧伤整形外科出院的19例医源性库欣综合征患者资料,患者中男8例、女11例,年龄28~71(56±11)岁;其感染性创面中有12例为急性创面,7例为慢性创面,病变位于四肢、肛周及骶尾部,原始感染范围9 cm×5 cm~85 cm×45 cm。入院后行多学科协助诊疗,对创面行清创+负压封闭引流,再根据创面大小、感染严重程度、缝合张力、骨及肌腱等外露情况,选择直接缝合或自体皮和/或人工真皮和/或自体组织瓣移植等不同方法进行创面修复。统计患者入院后24 h内8:00、16:00和24:00的皮质醇及促肾上腺皮质激素(ACTH)水平以及患者入院后的手术次数、创面修复方式、创面愈合情况、供皮/供瓣区愈合情况。随访,观察创面是否复发感染。结果16例患者入院后24 h内8:00、16:00和24:00的皮质醇水平依次为(130±54)、(80±16)、(109±39)nmol/L,ACTH水平依次为(7.2±2.8)、(4.1±1.8)、(6.0±3.0)pg/mL;另外3例患者无此统计结果。入院后,患者手术次数为(3.4±0.9)次。患者创面修复方式:行直接缝合者4例;行自体皮和/或人工真皮移植者9例,其中2例Ⅰ期行人工真皮移植、Ⅱ期行自体皮移植;行带蒂逆行岛状皮瓣+自体皮移植者6例。患者创面愈合情况:行直接缝合的创面均愈合良好;行自体皮和/或人工真皮移植的6例患者创面愈合良好,3例经二次植皮后创面愈合良好;行皮瓣移植的4例患者创面愈合良好,2例患者小腿后侧动脉穿支皮瓣远端回流障碍,经Ⅱ期清创植皮后愈合良好。患者供皮/供瓣区愈合情况:行头部刃厚皮回植的4例患者大腿中厚皮供皮区均愈合良好;3例患者中厚皮供皮区未行刃厚皮回植,其中2例患者供皮区愈合不良,术后2周经二次植皮修复后愈合良好;2例患者头部刃厚皮供区愈合良好;行自体皮移植的供瓣区均愈合良好。随访半年以上,3例痛风患者因痛风石破溃再次住院行手术治疗,4例患者因感染再次住院行手术治疗,其余患者创面未见感染复发。结论医源性库欣综合征患者的感染性创面再生能力差、容易反复感染,宜行创面局部处理+多学科综合治疗,及时控制感染、封闭创面,使患者最大化受益。 展开更多
关键词 自身免疫疾病 感染 伤口愈合 促肾上腺皮质激素 皮肤移植 外科皮瓣 库欣综合征
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