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Rapid synthesis of highly active Pt/C catalysts with various metal loadings from single batch platinum colloid

Journal of Energy Chemistry 2020年第8期29卷 138-145,I0005页

作者： Yuxin Li Xiang Zhu Yawen Chen shiqiao zhang Jia Li Jianguo Liu Jiangsu Key Laboratory for Nano Technology National Laboratory of Solid State MicrostructuresCollege of Engineering and Applied Sciencesand Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093JiangsuChina Kunshan Innovation Institute of Nanjing University Kunshan Sunlaite New Energy Co.Ltd.Suzhou 215347JiangsuChina

A series of Pt/C catalysts for proton exchange membrane fuel cells(PEMFCs) with various metal loadings is synthesized by a microwave-assisted polyol process via mixing an extremely stable platinum colloid(> 3 months’ shelf life) from single batch preparation with activated carbon ethylene glycol suspension.21 wt%, 42 wt% and 61 wt% Pt loadings are employed to showcase the advantages of the improved polyol process. The ultraviolet(UV)–visible spectra and ζ-potential measurements are conducted to monitor the wet chemistry process during catalyst preparation. The powder X-ray diffraction(XRD), transmission electron microscopy(TEM) and thermogravimetric analysis(TGA) characterizations are carried out on catalysts. The catalyst activities are investigated using electrochemical and single cell tests. The stability of Pt nanoparticle colloid is explored by ORR, cyclic voltammetry(CV) and ζ-potential measurements. The TEM results show the Pt particle sizes of the colloid, and the sizes of the 21 wt%, 42 wt% and 61 wt%Pt/C samples are 2.1–3.9 nm. Because of the high Pt dispersion, the Pt/C catalysts exhibit superior electroactivity toward ORR. In addition, four 61 wt% Pt/C catalysts made from the Pt colloid with 0–3 months’ shelf life show almost the same performance, which exhibits superior stability of the Pt colloid system without surfactant protection.

关键词： PEMFC Pt/C catalyst Microwave irradiation Modified polyol process Platinum nanocolloid Oxygen reduction reaction

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阿戈美拉汀分别联合文拉法辛、安慰剂对老年抑郁症患者BDNF、5-HT、FGF-22、ACTH水平的影响

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分子诊断与治疗杂志 2024年第6期16卷 1147-1151页

作者：杜颖李旭丹张士巧马占平衡水市第七人民医院精神科河北衡水053000 衡水市第七人民医院心理一科河北衡水053000

目的分析阿戈美拉汀分别联合文拉法辛、安慰剂对老年抑郁症患者脑源性神经生长因子(BDNF)、5-羟色胺(5-HT)、成纤维细胞生长因子-22(FGF-22)和促肾上腺皮质激素(ACTH)水平的影响。方法选取2022年1月至2023年6月衡水市第七人民医院收... 详细信息

目的分析阿戈美拉汀分别联合文拉法辛、安慰剂对老年抑郁症患者脑源性神经生长因子(BDNF)、5-羟色胺(5-HT)、成纤维细胞生长因子-22(FGF-22)和促肾上腺皮质激素(ACTH)水平的影响。方法选取2022年1月至2023年6月衡水市第七人民医院收治的老年抑郁症患者110例,采用随机数字表法分为A组(阿戈美拉汀联合安慰剂,n=55)以及B组(阿戈美拉汀联合文拉法辛,n=55),均连续进行治疗12周。比较两组治疗12周后临床疗效,比较两组治疗前、治疗12周后血清BDNF、5-HT、FGF-22、ACTH水平、心率变异性指标、韦氏成人记忆量表(WMS-RC)评分,比较两组不同时间点汉密顿抑郁量表(HAMD)、匹兹堡睡眠质量指数(PSQI)评分。结果 B组的临床总有效率高于A组,差异有统计学意义(P<0.05)。与治疗前比较,两组血清ACTH水平均降低,且B组低于A组,血清BDNF、5-HT、FGF-22水平、频域总值(TP)、正常RR间期标准差(SDNN)、高频(HF)、低频(LF)、WMS-RC各个评分均升高,且B组高于A组,差异有统计学意义(P<0.05)。与治疗前比较,治疗3~12周后两组HAMD、PSQI评分均逐渐降低,且B组低于A组,差异有统计学意义(P<0.05)。结论应用阿戈美拉汀联合文拉法辛能够改善老年抑郁症患者心率变异性,调节患者神经系统相关因子水平提高患者认知功能的同时疗效显著。

关键词：文拉法辛阿戈美拉汀脑源性神经生长因子 5-羟色胺成纤维细胞生长因子-22 促肾上腺皮质激素

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丙戊酸镁联合多奈哌齐在治疗老年痴呆中的效果分析

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分子诊断与治疗杂志 2024年第7期16卷 1208-1211页

作者：李旭丹杜颖张士巧马占平衡水市第七人民医院精神科河北衡水053000 衡水市第七人民医院心理一科河北衡水053000

目的分析老年痴呆患者应用丙戊酸镁联合多奈哌齐治疗后其认知功能及血清神经营养因子(BDNF)、铜蓝蛋白(CER)、微小核糖核酸-132(miRNA-132)水平等指标变化情况。方法选取2020年10月至2022年10月衡水市第七人民医院收治的110例老年痴... 详细信息

目的分析老年痴呆患者应用丙戊酸镁联合多奈哌齐治疗后其认知功能及血清神经营养因子(BDNF)、铜蓝蛋白(CER)、微小核糖核酸-132(miRNA-132)水平等指标变化情况。方法选取2020年10月至2022年10月衡水市第七人民医院收治的110例老年痴呆患者作为研究对象,以随机数字表法将其分为试验组和对照组,各55例。对照组给予盐酸多奈哌齐片,试验组在此基础上给予丙戊酸镁片,治疗疗程均为3个月。比较两组认知功能、精神行为症状、炎性因子、神经功能及安全性。结果与治疗前比较,两组治疗3个月后的简明蒙特利尔认知评估量表(MoCA)、简易精神状态检查量表(MMSE)评分、BDNF、CER、miRNA-132水平均升高,试验组高于对照组更高,差异有统计学意义(t=12.322、9.215、20.914、18.728、11.721,P0.05)。结论老年痴呆患者应用丙戊酸镁联合多奈哌齐治疗后其血清BDNF、CER、miRNA-132水平升高,神经功能改善,机体炎症减轻,认知功能及神经行为症状进一步改善,且安全性良好。

关键词：老年痴呆丙戊酸镁多奈哌齐认知功能脑源性神经营养因子铜蓝蛋白微小核糖核酸-132

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Application of Machine Learning in Optimizing Proton Exchange Membrane Fuel Cells: A Review

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能源与人工智能(英文) 2022年第3期9卷 88-120页

作者： Rui Ding shiqiao zhang Yawen Chen Zhiyan Rui Kang Hua Yongkang Wu Xiaoke Li Xiao Duan Xuebin Wang Jia Li Jianguo Liu Institute of Energy Power Innovation North China Electric Power University2 Beinong RoadBeijing102206 P.R.China National Laboratory of Solid State Microstructures College of Engineering and Applied SciencesNanjing University22 Hankou RoadNanjing 210093P.R.China

Proton exchange membrane fuel cells (PEMFCs) as energy conversion devices for hydrogen energy are crucial for achieving an eco-friendly society, but their cost and performance are still not satisfactory for large-scale commercialization. Multiple physical and chemical coupling processes occur simultaneously at different scales in PEMFCs. Hence, previous studies only focused on the optimization of different components in such a complex system separately. In addition, the traditional trial-and-error method is very inefficient for achieving the performance breakthrough goal. Machine learning (ML) is a tool from the data science field. Trained based on datasets built from experimental records or theoretical simulation models, ML models can mine patterns that are difficult to draw intuitively. ML models can greatly reduce the cost of experimental attempts by predicting the target output. Serving as surrogate models, the ML approach could also greatly reduce the computational cost of numerical simulations such as first-principle or multiphysics simulations. Related reports are currently trending, and ML has been proven able to speed up tasks in this field, such as predicting active electrocatalysts, optimizing membrane electrode assembly (MEA), designing efficient flow channels, and providing stack operation strategies. Therefore, this paper reviews the applications and contributions of ML aiming at optimizing PEMFC performance regarding its potential to bring a research paradigm revolution. In addition to introducing and summarizing information for newcomers who are interested in this emerging cross-cutting field, we also look forward to and propose several directions for future development.

关键词： Proton Exchange Membrane Fuel Cell Machine Learning Artificial Intelligence Data Science

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Temperature-adaptive metasurface radiative cooling device with excellent emittance and low solar absorptance for dynamic thermal regulation

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Advanced Photonics 2024年第4期6卷 70-82页

作者： Junlin Yang Qianyi Li shiqiao Liu Debao Fang Jingyao zhang Haibo Jin Jingbo Li Beijing Institute of Technology School of Materials Science and Engineering Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications

Passive radiative cooling is a promising passive cooling technology that emits heat to deep space without energy consumption. Nevertheless, the persistent challenge of overcooling in static radiative techniques has raised concerns. Although a desirable solution is suggested based on vanadium dioxide（VO2）in the form of a Fabry–Perot（F–P） resonant cavity, the inherent contradiction between desired high emissivity（ε） and low solar absorptance(αsol) remains a notable limitation. Here, we employed a simple mask-filling technique to develop a temperature-adaptive metasurface radiative cooling device（ATMRD） for dynamic thermal regulation. Simulation and experimental results substantially evidenced that multiple localized polariton resonances were induced by the VO2metasurface, significantly enhancing the thermal emittance of the ATMRDs. The engineered ATMRD achieved an amazing switch of the atmospheric window emittance from 0.13 to 0.85 when the surface temperature exceeds a pre-set transition temperature, accompanied by a commendable αsolof 27.71%. The mechanism of multiple localized polariton resonances is discussed in detail to understand the enhanced performance based on the investigation of the relationship between the metasurface structure and multiple localized polariton resonances. We demonstrate an efficient smart radiative technique achieved by a simple micro/nanoprocess and, most importantly, contribute a valuable reference for the design of radiative devices, which is crucial in various areas such as passive cooling,smart windows, multifunctional electromagnetic response, and space application technologies.

关键词： dynamic radiative cooling emittance metasurface plasmon resonance vanadium dioxide

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Electrically-driven ultrafast out-of-equilibrium light emission from hot electrons in suspended graphene/hBN heterostructures

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International Journal of Extreme Manufacturing 2024年第1期6卷 328-338页

作者： Qiang Liu Wei Xu Xiaoxi Li Tongyao zhang Chengbing Qin Fang Luo Zhihong Zhu shiqiao Qin Mengjian Zhu Kostya S Novoselov College of Advanced Interdisciplinary Studies&Hunan Provincial Key Laboratory of Novel Nano-optoelectronic Information Materials and Devices National University of Defense TechnologyChangshaHunan 410073People’s Republic of China Nanhu Laser Laboratory National University of Defense TechnologyChangshaHunan 410073People’s Republic of China State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Opto-ElectronicsShanxi UniversityTaiyuan 030006People’s Republic of China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006People’s Republic of China State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Laser SpectroscopyShanxi UniversityTaiyuan 030006People’s Republic of China Institute for Functional Intelligent Materials National University of SingaporeSingapore 117544Singapore Department of Materials Science and Engineering National University of SingaporeSingapore 117575Singapore

Nanoscale light sources with high speed of electrical modulation and low energy consumption are key components for nanophotonics and *** record-high carrier mobility and ultrafast carrier dynamics of graphene make it promising as an atomically thin light emitter which can be further integrated into arbitrary platforms by van der Waals ***,due to the zero bandgap,graphene is difficult to emit light through the interband recombination of carriers like conventional ***,we demonstrate ultrafast thermal light emitters based on suspended graphene/hexagonal boron nitride(Gr/hBN)*** in biased graphene are significantly heated up to 2800 K at modest electric fields,emitting bright photons from the near-infrared to the visible spectral *** eliminating the heat dissipation channel of the substrate,the radiation efficiency of the suspended Gr/hBN device is about two orders of magnitude greater than that of graphene devices supported on SiO2or *** demonstrate that hot electrons and low-energy acoustic phonons in graphene are weakly coupled to each other and are not in full thermal *** cooling ofhigh-temperature hot electrons to low-temperature acoustic phonons is enabled by the significant near-field heat transfer at the highly localized Gr/hBN interface,resulting in ultrafast thermal emission with up to 1 GHz bandwidth under electrical *** is found thatsuspending the Gr/hBN heterostructures on the SiO2trenches significantly modifies the light emission due to the formation of the optical cavity and showed a~440%enhancement inintensity at the peak wavelength of 940 nm compared to the black-body thermal *** demonstration of electrically driven ultrafast light emission from suspended Gr/hBNheterostructures sheds the light on applications of graphene heterostructures in photonicintegrated circuits,such as broadband light sources and ultrafast thermo-optic phase modulat

关键词： suspended graphene ultrafast light emitter van der Waals heterostructures thermal radiation electron–phonon interaction

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中和法处理焦化蜡油酸渣的实验研究

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石油炼制与化工 2010年第4期41卷 71-73页

作者：张士锹蓝星化工有限责任公司太原030021

采用中和法处理焦化蜡油酸渣使酸渣生成渣油和无机盐,筛选了适宜的中和剂,通过单因素实验考察了中和剂用量、反应温度、反应时间对渣油收率和酸值的影响。结果表明,适宜的操作条件为:中和剂用量13%,反应温度80℃,反应时间15 min。在此... 详细信息

采用中和法处理焦化蜡油酸渣使酸渣生成渣油和无机盐,筛选了适宜的中和剂,通过单因素实验考察了中和剂用量、反应温度、反应时间对渣油收率和酸值的影响。结果表明,适宜的操作条件为:中和剂用量13%,反应温度80℃,反应时间15 min。在此条件下,渣油收率为75.69%,酸值为7.7 mgKOH/g。采取二次结晶法回收无机盐,回收率可达80.22%。

关键词：中和焦化蜡油酸渣

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新媒体时代传统媒体提升竞争力的具体途径研究

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新闻研究导刊 2023年第3期14卷 112-114页

作者：张世巧皖西日报社安徽六安237000

新媒体是一种依托数字技术,通过信息网络,以及手机、电脑等智能终端,向用户提供信息服务的传播形态。随着信息技术、互联网技术的不断发展,新兴媒体大量涌现,凭借在信息传播方面的巨大优势,新媒体很快赢得了大量用户的青睐。中国报告大... 详细信息

新媒体是一种依托数字技术,通过信息网络,以及手机、电脑等智能终端,向用户提供信息服务的传播形态。随着信息技术、互联网技术的不断发展,新兴媒体大量涌现,凭借在信息传播方面的巨大优势,新媒体很快赢得了大量用户的青睐。中国报告大厅网讯发布的关于新媒体市场的调查分析报告显示,2018—2023年中国新媒体行业企业数量呈现逐步上升趋势,至2022年末中国新媒体行业企业数量超4000家。从市场发展的角度来看,新媒体正处于迅速发展阶段,具有广阔的发展前景。随着新媒体的不断发展,传统媒体逐渐式微,不仅用户数量不断减少,市场收益也迅速下滑。因此,传统媒体如何提高自身竞争力,已经成为众多从业者重点讨论的话题。新媒体的兴起让传统媒体面临机遇和挑战并存的局面。媒体工作者应正视新媒体的挑战,从内容时效性、内容特色等方面着手,弥补自身的不足,并采取正确的策略积极应对挑战,不断提升自身的竞争力。基于此,文章首先分析新媒体背景下传统媒体面临的挑战,然后探讨传统媒体提升自身竞争力的必要性,最后结合具体实践,分别从媒体理念、内容创作、传播渠道拓展等方面,探索提高传统媒体竞争力的具体途径,希望能为促进传统媒体健康发展提供一定参考。

关键词：传统媒体新媒体挑战竞争力提升策略

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Intrinsic polarization conversion and avoided-mode crossing in X-cut lithium niobate microrings

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Chinese Physics B 2024年第6期33卷 398-403页

作者：谭泽林张检发朱志宏陈伟邵铮铮刘肯秦石乔 College of Advanced Interdisciplinary Studies&Hunan Provincial Key Laboratory of Novel Nano Optoelectronic Information Materials and Devices National University of Defense TechnologyChangsha 410073China Nanhu Laser Laboratory National University of Defense TechnologyChangsha 410073China College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073China School of Physics Central South UniversityChangsha 410083China

Compared with well-developed free space polarization converters, polarization conversion between TE and TM modes in the waveguide is generally considered to be caused by shape birefringence, like curvature, morphology of waveguide cross section and scattering. Here, we study the polarization conversion mechanism in 1-THz-FSR X-cut lithium niobate microrings with multiple-resonance condition, that is the conversion can be implemented by birefringence of waveguides,which will also introduce an avoided-mode crossing. In the experiment, we find that this mode crossing results in severe suppression of one sideband in local nondegenerate four-wave mixing and disrupts the cascaded four-wave mixing on this side. Simultaneously, we propose one two-dimensional method to simulate the eigenmodes(TE and TM) in X-cut microrings, and the mode crossing point. This work will provide one approach to the design of polarization converters and simulation for monolithic photonics integrated circuits, and may be helpful to the studies of missed temporal dissipative soliton formation in X-cut lithium niobate rings.

关键词： polarization conversion birefringence nondegenerate four-wave mixing

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An investigation of coupled-cavity diode lasers

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Chinese Journal of Lasers 1993年第6期 11-18页

作者： Qunzhu Li, shiqiao zhang (Taiyuan University of Technology, Taiyuan 030024, China)Wanru Zhuang(National Laboratory of Integrated Optoelectronics, Institute of Semiconductor, Academia Sinica, Beijing 100083, China)

In this paper, the rate equations of coupled-cavity diode lasers are studied and their improvements in the case of strong coupling are presented, and therefore, the mechanism of single-mode oscillation of the devices ... 详细信息

关键词： diode lasers rate equations single mode operation optoelectronic integrated circuits(OEICs)

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