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竹定向刨花单元加工技术研究

林产工业 2024年第8期61卷 52-58页

作者：沈周杨兴武魏任重芦童陆铜华千年舟新材科技集团股份有限公司浙江杭州310000 杭州海美自动化设备有限公司浙江杭州310000

我国竹材资源丰富,竹材定向刨花板作为一种绿色高强的生态建材,一直未能被大范围推广。这主要由原料加工的产能较低、产品质量不稳定、加工设备不成熟等因素导致。本文分析了竹材定向刨花板产业化的困境,并通过对原料加工技术的探讨提... 详细信息

我国竹材资源丰富,竹材定向刨花板作为一种绿色高强的生态建材,一直未能被大范围推广。这主要由原料加工的产能较低、产品质量不稳定、加工设备不成熟等因素导致。本文分析了竹材定向刨花板产业化的困境,并通过对原料加工技术的探讨提出了竹刨花加工的技术难点,并提供了一种径向弦切定厚技术及设备,可有效解决产品原料加工效率低、产品质量差的问题。此外,对竹定向刨花板现存的制备问题及行业发展等进行了总结与展望。

关键词：竹材定向刨花板竹刨花原料资源径向弦切定厚技术加工技术

适用于MMC低频控制的三相建模模型预测控制

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电力电子技术 2024年第5期58卷 112-114,132页

作者：吴评杨兴武王祖峰孟致丞上海电力大学电气工程学院上海200090 贵州电网有限责任公司六盘水盘州供电局贵州六盘水553000

模块化多电平变换器(MMC)运行于低频工况时,子模块电容电压波动会急剧增大,严重威胁MMC系统的安全运行。为解决这一问题,此处提出一种基于三相建模的模型预测控制(MPC)策略。该策略分为2个阶段,第一阶段考虑MMC桥臂相间的相互作用,通过... 详细信息

模块化多电平变换器(MMC)运行于低频工况时,子模块电容电压波动会急剧增大,严重威胁MMC系统的安全运行。为解决这一问题,此处提出一种基于三相建模的模型预测控制(MPC)策略。该策略分为2个阶段,第一阶段考虑MMC桥臂相间的相互作用,通过三相建模和整体寻优方式,可实现输出电流的控制,并有效降低计算量;第二阶段提出环流抑制策略,实现低频电压纹波抑制的同时减小环流波动,降低系统损耗。最后通过Matlab/Simulink仿真结果以及实验验证了所提控制方法的可行性与有效性。

关键词：模块化多电平变换器低频工况模型预测控制

Visible-light driven room-temperature coupling of methane to ethane by atomically dispersed Au on WO_(3)

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Journal of Energy Chemistry 2021年第10期30卷 195-202,I0006页

作者： xing yang wu Zhiyuan Tang Xiaoxu Zhao Xin Luo Stephen John Pennycook Song Ling Wang China-UK Low Carbon College Shanghai Jiao Tong UniversityShanghai 201306China School of Environmental Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Optoelectronic Materials and Technologies Centre for Physical Mechanics and BiophysicsSchool of PhysicsSun Yat-sen UniversityGuangzhou 510275GuangdongChina Institute Department of Materials Science and Engineering National University of SingaporeSingapore 117575Singapore Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China

Gold(Au)as co-catalyst is remarkable for activating methane(CH4),especially atomically dispersed Au with maximized exposing active sites and specific electronic ***,singlet oxygen(^(1)O_(2))typically manifests a mild redox capacity with a high selectivity to attack organic ***(PMS)favors to produce oxidative species 102 during the photocatalytic ***,combining atomic Au as co-catalyst and ^(1)O_(2) as oxidant is an effective strategy to selectively convert ***,we synthesized atomically dispersed Au on WO_(3)(Au/WO_(3)),where Au was in the forms of single atoms and *** room temperature,such Au/WO_(3) exhibited enhanced photocata lytic conversion of CH4 to CH3 CH3 with a selectivity,up to 94%,under visible *** radicals-pathway mechanism of CH4 coupling has also been investigated through detection and trapping experiment of active *** calculations further interpret the electronic structure of Au/WO_(3) and tip-enhanced local electric field at the Au sites for promoting CH4 conversion.

关键词： Photocatalysis Single-atom Au Methane Ethane Visible light

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基于阻抗重塑的并网逆变器改进前馈控制策略

电力电子技术 2024年第8期58卷 8-11,34页

作者：杨兴武丁晨瑜章奇勋上海电力大学电气工程学院上海200090

在弱电网下,电网电压前馈环节、数字控制延时等因素与电网阻抗发生耦合,大幅降低系统的稳定性。针对该问题,首先建立并网逆变器输出阻抗模型,分析了传统比例前馈控制方法的局限性。在此基础上提出一种基于阻抗重塑的并网逆变器改进前馈... 详细信息

在弱电网下,电网电压前馈环节、数字控制延时等因素与电网阻抗发生耦合,大幅降低系统的稳定性。针对该问题,首先建立并网逆变器输出阻抗模型,分析了传统比例前馈控制方法的局限性。在此基础上提出一种基于阻抗重塑的并网逆变器改进前馈控制策略,在电压前馈通道中增加带通滤波器,分析改进系统的输出阻抗特性,该方法有效提升了系统的鲁棒性,同时在电压前馈通道中串联谐波控制器,可以进一步改善并网电流质量。最后,通过仿真和实验验证了所提策略的有效性。

关键词：并网逆变器弱电网改进前馈控制阻抗重塑

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基于桥臂能量平衡的MMC故障容错控制策略

电力电子技术 2024年第7期58卷 23-26页

作者：徐浩文王江孟致丞杨兴武上海电力大学电气工程学院上海200090 国网陕西省电力有限公司宝鸡供电公司陕西宝鸡721000

模块化多电平换流器(MMC)子模块(SM)带故障运行时,保证MMC电容电压平衡及减少电容电压纹波是提高换流器运行可靠性的关键。为解决上述问题,此处提出了一种基于桥臂能量平衡、降低开关频率(RSF)算法的MMC容错控制策略。首先,基于上下桥... 详细信息

模块化多电平换流器(MMC)子模块(SM)带故障运行时,保证MMC电容电压平衡及减少电容电压纹波是提高换流器运行可靠性的关键。为解决上述问题,此处提出了一种基于桥臂能量平衡、降低开关频率(RSF)算法的MMC容错控制策略。首先,基于上下桥臂的输入功率积分,得到其公共分量与微分分量,通过环流注入的方式实现能量平衡与电容器电压稳定。其次,建立故障后改进的电容电压成本函数,设定故障标志,绕过故障SM。最后,基于硬件在环(HIL)实验平台进行实验研究,结果表明,所提方法可在MMC发生故障后保证在桥臂不对称运行时输出电压和电流波形质量不受影响,且不会增加成本或复杂性。

关键词：模块化多电平换流器故障容错控制桥臂能量平衡环流注入

New approach to measuring topological phase transitions utilizing Floquet technology

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Chinese Physics B 2024年第9期33卷 282-288页

作者： Xue-Ying yang Wei wu Ping-xing Chen College of Sciences National University of Defense TechnologyChangsha 410073China

The Floquet technique provides a novel anomalous topological phase for non-equilibrium phase *** on the high symmetry of the quantum anomalous Hall model,the findings suggest a one-to-one correspondence between the average spin texture and the Floquet quasi-energy spectrum.A new approach is proposed to directly measure the quasienergy spectrum,replacing previous measurements of the average spin ***,we proposed a reliable experimental scheme based on ion trap *** scheme markedly reduces the measurement workload,improves the measurement fidelity,and is applicable to multiple platforms such as cold atoms and nuclear magnetic resonance.

关键词： topological phase transition Floquet technique ion trap

Differential bonding behaviors of sodium/potassium-ion storage in sawdust waste carbon derivatives

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Chinese Chemical Letters 2024年第4期35卷 496-501页

作者： Jun-Ming Cao Kai-yang Zhang Jia-Lin yang Zhen-Yi Gu xing-Long wu MOE Key Laboratory for UV Light-Emitting Materials and Technology Northeast Normal UniversityChangchun 130024China Department of Chemistry Northeast Normal UniversityChangchun 130024China

Sodium-ion batteries(SIBs) and potassium-ion batteries(PIBs) are the most promising alternatives to lithium-ion batteries, and thus have drawn intensive research attention. Porous carbon materials from different precursors have been widely used as anode materials owing to their compatible storage effectiveness of both larger radii sodium and potassium ions. However, the differential bonding behaviors of Na and K ions with porous carbon-based anode are the significant one worth investigating, which could provide a clean picture of alkali ions storage mechanism. Therefore, in this work, we prepare a porous carbon network derived from sawdust(SDC) wastes, to further analyze the differences on sodium and potassium ions storage behaviors in terms of bond-forming process. It is found that, as-prepared SDC anodes could deliver stable sodium and potassium storage capacities, however, there are notable distinctions in terms of electrochemical behaviors and diffusion processes. By virtue of ex-situ XRD and Raman spectroscopy, the phase transition reaction of potassium ions could be well-observed, and the results shows that the multiple intercalated compounds was formed in SDC network during ions insertion, further resulting in slower diffusion kinetics and larger resistance compared to non-bonded process of sodium ions storage. This study provides more insights into the differences between sodium and potassium ions storage, as well as the energy storage mechanism of porous carbon as anodes for secondary batteries.

关键词： Porous carbon Sodium-ion storage Potassium-ion storage Bonding behaviors Batteries

Microstructure recognition of steels by machine learning based on visual attention mechanism

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Journal of Iron and Steel Research International 2024年第4期31卷 909-923页

作者： xing-yu Chen Lin Cheng Cheng-yang Hu Yu-peng Zhang Kai-ming wu The State Key Laboratory of Refractories and Metallurgy Hubei Province Key Laboratory of Systems Science on Metallurgical ProcessingInternational Research Institute for Steel TechnologyCollaborative Center on Advanced SteelsWuhan University of Science and TechnologyWuhan 430081HubeiChina Metals Valley and Band(Foshan)Metallic Composite Materials Co. Ltd.Foshan 528000GuangdongChina

U-Net has achieved good performance with the small-scale datasets through skip connections to merge the features of the low-level layers and high-level layers and has been widely utilized in biomedical image segmentation as well as recent microstructure image segregation of the *** representative visual attention mechanism modules,named as squeeze-and-excitation networks,convolutional block attention module,and extended calibration algorithm,were intro-duced into the traditional U-Net architecture to further improve the prediction *** is found that compared with the original U-Net architecture,the evaluation index of the improved U-Net architecture has been significantly improved for the microstructure segmentation of the steels with the ferrite/martensite composite microstructure and pearlite/ferrite composite microstructure and the complex martensite/austenite island/bainite microstructure,which demonstrates the advantages of the utilization of the visual attention mechanism in the microstructure *** reasons for the accuracy improvement were discussed based on the feature maps analysis.

关键词： Microstructure recognition-Steel Machine learning Visual attention mechanism Visualization

Selective photocatalytic oxidation of methane to C1 oxygenates by regulating sizes and facets over Au/ZnO

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Nano Research 2024年第5期17卷 3810-3818页

作者： Qiang Zhou Xinyu Wang Xiaojie Tan Qinhua Zhang Hao yang Tao xing Mingqing Wang Mingbo wu Wenting wu State Key Laboratory of Heavy Oil Processing College of Chemistry and Chemical Engineering&Institute of New EnergyChina University of Petroleum(East China)Qingdao 266580China National Engineering Research Center of Coal Gasification and Coal-Based Advanced Materials ShanDong Energy Group CO.LTDJinan 250101China

Photocatalytic oxidation of methane to value-added chemicals is a promising process under mild conditions,nevertheless confronting great challenges in efficiently activating C-H bonds and inhibiting ***,we propose a comprehensive strategy for the selective generation of reactive oxygen species(ROS)by regulating the sizes and facets of Au nanoparticles loaded on *** photocatalytic methane oxidation at ambient temperature,a high oxygenates yield of 36.4 mmol·g^(-1)·h^(-1) with a nearly 100%selectivity has been achieved over the optimized 1.0%Au/ZnO-9.6(1%Au with(111)facet and 9.6 nm size on ZnO)photocatalyst,exceeding most reported *** investigations reveal that 1.0%Au/ZnO-9.6 with the medium size and Au(111)facet guarantees the favourable formation of superoxide radicals(·OOH)through mild oxygen reduction,ultimately leading to excellent photocatalytic methane oxidation *** work provides some guidance for the delicate design of photocatalysts for efficient photocatalytic methane oxidation and oxygen utilization.

关键词： photocatalysis methane oxidation radical regulation oxygen activation nanomaterial