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Journal of Energy Chemistry 2025年第1期100卷 317-326页

作者： Binglu Deng Jie Shen Jinxing Lu Chuqiang Huang Zhuoyuan Chen Feng Peng yunpeng liu School of Materials Science and Hydrogen Energy Foshan UniversityFoshan 528000GuangdongChina School of Chemistry and Chemical Engineering Guangzhou UniversityGuangzhou 510006GuangdongChina Guangdong Key Laboratory for Hydrogen Energy Technologies Foshan 528000GuangdongChina

Seawater electrolysis is a promising approach for sustainable energy without relying on precious ***,the large-scale seawater electrolysis is hindered by low catalytic efficiency and severe anode corrosion caused by the harmful *** contrast to the oxygen evolution reaction (OER)and chlorin ion oxidation reaction (ClOR),glycerol oxidation reaction (GOR) is more thermodynamically and kinetically favorable ***,a Ru doping cobalt phosphide (Ru-CoP_(2)) is proposed as a robust bifunctional electrocatalyst for seawater electrolysis and GOR,for the concurrent productions of hydrogen and value-added *** in situ and ex situ characterization analyses demonstrated that Ru doping featured in the dynamic reconstruction process from Ru-CoP_(2)to Ru-CoOOH,accounting for the superior GOR *** coupling GOR with hydrogen evolution was realized by employing Ru-CoP_(2)as both anode and cathode,requiring only a low voltage of 1.43 V at 100 mA cm^(-2),which was 250 m V lower than that in alkaline *** work guides the design of bifunctional electrocatalysts for energy-efficient seawater electrolysis coupled with biomass resource upcycling.

关键词： Glycerol electrooxidation Hydrogen evolution Ru doping Cobalt phosphide Bifunctional electrocatalysts

g-C_(3)N_(4)nanosheets coupled with CoSe_(2)as co-catalyst for efficient photooxidation of xylose to xylonic acid

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Green Energy & Environment 2025年第1期10卷 231-238页

作者： Qi Hao Yijun liu Ren Zou Ge Shi Shilian Yang Linxin Zhong Wu Yang Xiao Chi yunpeng liu Shimelis Admassie Xinwen Peng State Key Laboratory of Pulp and Paper Engineering South China University of TechnologyGuangzhou510641GuangdongChina Hainan Key Laboratory of Storage&Processing of Fruits and Vegetables Agricultural Products Processing Research InstituteChinese Academy of Tropical Agricultural SciencesZhanjiangGuangdong524001China Department of Chemistry and Centre for Advanced 2D Materials(CA2DM)National University of Singapore 3 Science Drive 3 Singapore117543Singapore School of Materials Science and Hydrogen Energy Foshan UniversityFoshan528231GuangdongChina Department of Chemistry Addis Ababa UniversityPO BOX 1176Addis AbabaEthiopia

Photocatalysis has emerged as an effective approach to sustainably convert biomass into value-added ***_(2)is a promising nonprecious,efficient cocatalyst for photooxidation,which can facilitate the separation of photogenerated electron–holes,increase the reaction rates,and enhance photocatalytic *** this work,we synthesized a stable and efficient photocatalysis system of CoSe_(2)/g-C_(3)N_(4)through attaching CoSe_(2)on g-C_(3)N_(4)sheets,with a yield of 50.12%for the selective photooxidation of xylose to xylonic *** light illumination,the photogenerated electrons were prone to migrating from g-C_(3)N_(4)to CoSe_(2)due to the higher work function of CoSe_(2),resulting in the accelerated separation of photogenerated electron–holes and the promoted ***,this study reveals the unique function of CoSe_(2),which can significantly promote oxygen adsorption,work as an electron sink and accelerate the generation of ·O_(2)^(-),thereby improving the selectivity toward xylonic acid over other *** work provides useful insights into the design of selective photocatalysts by engineering g-C_(3)N_(4)for biomass high-value utilization.

关键词： Biomass photooxidation Hemicelluloses Xylose g-C_(3)N_(4) Xylonic acid

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温度对纤维素绝缘中水分吸附和解吸的影响

电工技术学报 2025年第1期40卷 300-311页

作者：杨超杰刘云鹏赵涛杨家骏刘一瑾华北电力大学河北省输变电设备安全防御重点实验室保定071003 新能源电力系统全国重点实验室(华北电力大学) 北京102206

变压器内部温度的变化会促使水分改变其分布和聚集位置,而局部高含水量会严重影响油纸绝缘的电气强度。因此,有必要对不同温度下纤维素绝缘中水分的吸附和解吸进行研究。该文采用分子动力学的方法建立了三个不同含水量的105原子量级的油... 详细信息

变压器内部温度的变化会促使水分改变其分布和聚集位置,而局部高含水量会严重影响油纸绝缘的电气强度。因此,有必要对不同温度下纤维素绝缘中水分的吸附和解吸进行研究。该文采用分子动力学的方法建立了三个不同含水量的105原子量级的油-纤维素混合体系(OCS),分别对其进行温升和温降模拟,得到了界面域和油域水分子数目(NW)的变化规律。通过分析纤维素绝缘的溶剂可及表面积(SASA)和微观扫描电镜(SEM)图,研究了温度变化和纤维素分子劣化对纤维素绝缘中水分吸附和解吸的影响。结果表明,高温体系反向冷却后,油域的水分子会快速迁移到纤维素域,而纤维素在高温后的不可逆劣化会导致其吸附能力减弱。因此,大量的水分被滞留在界面域。对于温升模拟,温度越高,油域和界面域积累的水分越多,纤维素对水分的解吸作用越强。值得注意的是,界面域的NW并不是一个单纯的增加趋势,而是先减后增的振荡增减趋势,温度越高,该趋势越明显。该文对油浸式电力设备水分的实时监测和绝缘性能评估具有重要的理论价值。

关键词：纤维素绝缘水分吸附解吸温度分子模拟

基于带状光纤分布式传感的变压器绕组轴向与辐向形变区分及程度检测

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中国电机工程学报 2025年第2期45卷 803-812,I0034页

作者：李东阳刘云鹏范晓舟李欢黎晏霖刘海琳河北省输变电设备安全防御重点实验室(华北电力大学) 河北省保定市071003 国网冀北电力有限公司电力科学研究院北京市西城区100045

为对变压器绕组形变状态有更清晰的感知,需要对绕组轴向及辐向形变进行同时检测。该文首先分析绕组弯曲时的应变分布规律,并提出应变向量的概念及绕组轴向与辐向应变解耦方法。随后,在35 kV连续式绕组模型上布置带状光纤并搭建试验平台... 详细信息

为对变压器绕组形变状态有更清晰的感知,需要对绕组轴向及辐向形变进行同时检测。该文首先分析绕组弯曲时的应变分布规律,并提出应变向量的概念及绕组轴向与辐向应变解耦方法。随后,在35 kV连续式绕组模型上布置带状光纤并搭建试验平台,借助布里渊光时域分析技术以进行应变分布式传感,完成对绕组形变的轴向、辐向区分测量,应变向量相对误差在7.5%以内。最后,得出绕组轴向、辐向挠度都与带状光纤平均应变满足二次函数关系,拟合系数R^(2)>0.99,并利用该关系预测绕组的变形程度,误差小于5%。该文方法不仅能单独检测轴向或辐向形变,也能在同时发生两种形变时分别得出轴向和辐向形变;可以解决绕组轴向形变无法有效传感及变形程度难以定量判断的难题,为变压器绕组形变的检测提供新的方案。

关键词：变压器绕组形变轴向与辐向应变解耦分布式光纤传感布里渊光时域分析技术

A modified Euler–Maclaurin formula in 1D and 2D with applications in statistical physics

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Communications in Theoretical Physics 2021年第7期73卷 7-18页

作者： Jihong Guo yunpeng liu Department of Applied Physics Tianjin UniversityTianjin 300350China

The Euler–Maclaurin summation formula is generalized to a modified form by expanding the periodic Bernoulli polynomials as its Fourier series and taking cuts,which includes both the Euler–Maclaurin summation formula and the Poisson summation formula as special *** making use of the modified formula,a possible numerical summation method is obtained and the remainder can be *** modified formula is also generalized from one dimension to two *** expressions of partition functions of a classical particle in square well in 1D and 2D and that of a quantum rotator are obtained with error estimation.

关键词： summation technique square well quantum rotator statistical physics

基于绕组首饼温度及温度梯度的变压器热点模型

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中国电机工程学报 2025年第1期45卷 361-369,I0030页

作者：范晓舟刘云鹏律方成李欢徐永超闫泽玉河北省输变电设备安全防御重点实验室(华北电力大学) 河北省保定市071003 国网冀北电力有限公司电力科学研究院北京市西城区100045

变压器热点温度是衡量变压器负载潜力及运行安全性的重要指标,是变压器状态监测以及预测的重点。绕组底部首饼直接与散热片回流的冷油接触,周围油温与冷油近似相等,可以较为准确地分析其散热。该文从变压器传热原理出发,提出一种新的热... 详细信息

变压器热点温度是衡量变压器负载潜力及运行安全性的重要指标,是变压器状态监测以及预测的重点。绕组底部首饼直接与散热片回流的冷油接触,周围油温与冷油近似相等,可以较为准确地分析其散热。该文从变压器传热原理出发,提出一种新的热点温度计算模型。首先,基于理论推导建立绕组首饼温度的控制方程,并使用热电类比方法建立可用于实际运行的绕组首饼局部热路模型。通过对一台内置传感光纤的110 kV油浸式变压器进行11级不同负载共21 h温升试验,获得不同负载率下绕组温度变化情况,并提出基于绕组首饼温度及绕组温度梯度的热点温度模型。基于局部热路模型,使用负载率及散热片进出口油温作为输入变量,成功预测绕组首饼温度。随后,建立绕组整体温度梯度的指数、差分方程模型,并基于提出的热点计算模型对连续变负载试验的结果进行预测。结果表明,模型预测均方根误差为4.02 K,相较传统模型,最大误差降低21%,验证所提计算模型的有效性。

关键词：变压器热点温度温度梯度温升试验分布式光纤传感

STUDY OF PHASE BOUNDARIES FOR SITE-BOND PERCOLATION

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Chinese Physics Letters 1990年第5期7卷 234-236页

作者： liu yunpeng ZHENG Maosheng Department of Physics Xian University of Electronic-Sdience and Technology710071

Relations of phase boundaries and phase region for site-bond percolation are *** can be seen from the simulation of Monte Carlo that the relations describe the site-bond percolation process much better than others pra... 详细信息

关键词： phase bond percolation

Compressive fatigue behavior and failure evolution of additive fiber-reinforced cemented tailings composites

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International Journal of Minerals,Metallurgy and Materials 2022年第2期29卷 345-355页

作者： Jiajian Li Shuai Cao Erol Yilmaz yunpeng liu School of Civil and Resources Engineering University of Science and Technology BeijingBeijing 100083China State Key Laboratory of High-Efficient Mining and Safety of Metal Mines of Ministry of Education University of Science and Technology BeijingBeijing 100083China Department of Civil Engineering Geotechnical DivisionRecep Tayyip Erdogan UniversityFenerRize TR53100Turkey State Key Laboratory of Silicate Materials for Architectures(Wuhan University of Technology) Wuhan 430070China

The ordinary cemented tailings backfill(CTB)is a cement-based composite prepared from tailings,cementitious materials,and *** this study,a series of laboratory tests,including uniaxial compression,digital image correlation measurement,and scanning electron microscope characteristics of fiber-reinforced CTB(FRCTB),was conducted to obtain the uniaxial compressive strength(UCS),failure evolution,and microstructural characteristics of FRCTB *** results show that adding fibers could increase the UCS values of the CTB by 6.90%to 32.76%.The UCS value of the FRCTB increased with the increase in the polypropylene(PP)fiber ***,the reinforcement effect of PP fiber on the CTB was better than that of glass *** addition of fiber could increase the peak strain of the FRCTB by0.39%to 1.45%.The peak strain of the FRCTB increased with the increase in glass fiber *** failure pattern of the FRCTB was coupled with tensile and shear *** addition of fiber effectively inhibited the propagation of cracks,and the bridging effect of cracks by the fiber effectively improved the mechanical properties of the *** findings in this study can provide a basis for the backfilling design and optimization of mine backfilling methods.

关键词： cemented tailings backfill uniaxial compressive strength combined fiber reinforcement digital image correlation microstructural characteristics

Vacuum degree effects on betavoltaics irradiated by ^(63)Ni with differently apparent activity densities

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Science China(Technological Sciences) 2017年第2期60卷 282-288页

作者： liu yunpeng XU ZhiHeng WANG Hao TANG XiaoBin Department of Nuclear Science and Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China jiangsu Key Laboratory of Material and Technology for Energy Conversion Nanjing 210016 China

For many current betavoltaics, beta sources and PN junction energy conversion units are separated. The air gap between the two parts could stop part of decay beta particles, which results in inefficient performance of the betavoltaic. By employing 63Ni with an apparent emission activity density of 7.26×10~7 and 1.81×10~8 Bq cm^(-2), betavoltaic performance levels were calculated at a vacuum degree range of 1×10~5 to 1×10^(-1) Pa and measured at 1.0×10~5 and 1.0×10~4 Pa, respectively. Results show that betavoltaic performance levels improve significantly as the vacuum degree increases. The maximum output power (P_(max)) exhibits the largest change, followed by short-circuit current (I_(sc)), open-circuit voltage (V_(oc)), and fill factor. The vacuum degree effects on Isc, Voc,and Pmax of the betavoltaic with low apparent activity density 63Ni are more significant than those of the betavoltaic with high apparent activity density ^(63)Ni. Moreover, the improved efficiencies of the measured performances are larger than the calculated efficiencies because of the low ratio of Isc and reverse saturation current (I_0). The values of I0, ideality factor, and shunt resistance were estimated to modify the equivalent circuit model. The calculation results based on this model are closer to the measurement results. The results of this research can provide a theoretical foundation and experimental reference for the study of vacuum degree effects on betavoltaics of the same kind.

关键词： vacuum degree betavoltaic apparent activity density energy conversion unit MCNP5

The influences of silane coupling agents on the heat and moisture resistance of basalt fibre-reinforced composites

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High Voltage 2023年第1期8卷 38-47页

作者： yunpeng liu Mingjia Zhang Hechen liu Yu Sun Wanxian Wang Jie liu Hebei Provincial Key Laboratory of Power Transmission Equipment Security Defence North China Electric Power UniversityBaodingChina State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBaodingChina State Grid Hebei Electric Power Company Electric Power Research Institute ShijiazhuangChina

Basalt fibre composite materials have shown good application prospects in electrical equipment,but their reliability can be affected by damp-heat *** this work,the interface,mechanical,and electrical properties of basalt fibre composites treated with three coupling agents via damp-heat ageing were *** simulations were conducted to reveal the damp-heat ageing mechanism of the *** results show thatγ-aminopropyl triethoxy silane(KH-550)andγ-glycidoxy propyl trimethoxy silane(KH-560)perform better as coupling agents as they form bonds with the matrix resin,compared withγ-methacryloxy propyl trimethoxy silane(KH-570).After the dampheat ageing treatment,the hydrolysis of the defects of the amino groups in the interface of the KH-550-treated sample can weaken its mechanical properties and insulation properties *** interface layer of the KH-560-treated sample is mostly composed of carbon–oxygen single bonds and methylene groups with its interface structure more stable,which endows the sample with better stability of its mechanical and insulating ***,KH-560 is a more suitable coupling agent for processing basalt fibres to be used in electrical equipment.

关键词： composites coupling fibre