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Development of electron and hole selective contact materials for perovskite solar cells 被引量:1
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作者 Yaming Yu Peng Gao 《Chinese Chemical Letters》 SCIE CAS CSCD 2017年第6期1144-1152,共9页
Nowadays,both n-i-p and p-i-n perovskite solar cells(PSCs) device structures are reported to give high performance with photo conversion efficiencies(PCEs) above 20%.The efficiency of the PSCs is fundementally det... Nowadays,both n-i-p and p-i-n perovskite solar cells(PSCs) device structures are reported to give high performance with photo conversion efficiencies(PCEs) above 20%.The efficiency of the PSCs is fundementally determined by the charge selective contact materials.Hence,by introducing proper contact materials with good charge selectivity,one could potentially reduce interfacial charge recombination as well as increase device performance.In the past few years,copious charge selective contact materials have been proposed.Significant improvements in the corresponding devices were observed and the reported PCEs were close to that of classic Spiro-OMeTAD.This mini-review summarizes the state-of-the-art progress of typical electron/hole selective contact materials for efficient perovskite solar cells and an outlook to their development is made. 展开更多
关键词 Perovskite solar cell Charge selective contact materials Energy level HTM ETM
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A ladder conjugated polymer transducer for solid-contact Cu^(2+)-selective electrodes 被引量:1
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作者 Shun-Yang Yu Yan-Cang Li +4 位作者 Tao Xiong Qun Yuan Yong-Ming Liu Zhong-Yi Yuan Yi Xiao 《Chinese Chemical Letters》 SCIE CAS CSCD 2014年第2期364-366,共3页
In recent years, there has been a pronounced interest in solid-contact ion-selective electrodes (SC-ISEs), with emphasis on the use of conducting polymers as ion-to-electron transducer. In this work, a ladder conjug... In recent years, there has been a pronounced interest in solid-contact ion-selective electrodes (SC-ISEs), with emphasis on the use of conducting polymers as ion-to-electron transducer. In this work, a ladder conjugated polymer, thieno[3,2-b]thiophene (LCPT), was investigated in fabricating Cu2+-selective electrodes for the first time. The resulting electrodes were characterized by electrochemical impedance spectroscopy (EIS), chronopotentiometry, and the water layer test. Results proved that the active LCPT facilitates the ion-to-electron transduction, and avoids the detrimental aqueous layer formed at the interface of SC-ISEs. 展开更多
关键词 Ladder polymer Solid contact Ion-selective electrode COPPER
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A highly selective solid-contact electrode for Ag^+ based on a monoazathiacrown ether ionophore 被引量:1
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作者 Shun Yang Yu Lan Ju +2 位作者 Fu Hai Li Yong Ming Liu Jun Feng Fang 《Chinese Chemical Letters》 SCIE CAS CSCD 2012年第4期488-491,共4页
A new solid-contact Ag~+-selective electrode was prepared with 9,10,12,13,24,25-hexahydro-5H,15H,23H-dibenzo [b,q][1,7,10,13,19,4,16]-entathiadiazacyclodocosine-6,16(7H,17H)-dione as ionophore,and cc,a-dihexylsexit... A new solid-contact Ag~+-selective electrode was prepared with 9,10,12,13,24,25-hexahydro-5H,15H,23H-dibenzo [b,q][1,7,10,13,19,4,16]-entathiadiazacyclodocosine-6,16(7H,17H)-dione as ionophore,and cc,a-dihexylsexithiophene(DH- 6T) ion-to-electron transducer.The sensor exhibited a working concentration range of 10~8 to 10^(-3) mol/L,with a near-Nernstian slope of 55.1±0.2 mV/dec and detection limit of 1.7×10^(-9) mol/L.The fabricated electrodes demonstrated excellent selectivity over the most common monovalent and divalent cations. 展开更多
关键词 Solid contact SILVER Ion-selective electrodes Low detection limit
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Ohmic Contact Formation for n+4H-SiC Substrate by Selective Heating Method Using Hydrogen Radical Irradiation
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作者 Tetsuji Arai Kazuki Kamimura +8 位作者 Chiaya Yamamoto Mai Shirakura Keisuke Arimoto Junji Yamanaka Kiyokazu Nakagawa Toshiyuki Takamatsu Masaaki Ogino Masaaki Tachioka Haruo Nakazawa 《Journal of Materials Science and Chemical Engineering》 2017年第1期35-41,共7页
We developed an apparatus for producing high-density hydrogen plasma. We confirmed that the temperatures of transition-metal films increased to above 800?C within 5 s when they were exposed to hydrogen plasma formed u... We developed an apparatus for producing high-density hydrogen plasma. We confirmed that the temperatures of transition-metal films increased to above 800?C within 5 s when they were exposed to hydrogen plasma formed using the apparatus. We applied this phenomenon to the selective heat treatment of W/Ni films deposited on n+4H-SiC wafers and formed nickel silicide electrodes. To utilize this method, we can perform the nickel silicidation process without heating the other areas such as channel regions and improve the reliability. 展开更多
关键词 selectIVE Heating Nickel SILICIDE Electrode HYDROGEN Plasma Ohmic contact SiC
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基于机器学习的动车传动齿轮修形仿真研究
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作者 刘志超 黄志辉 +2 位作者 李治桦 杨成龙 陈丙硕 《制造技术与机床》 北大核心 2025年第8期87-95,共9页
动车传动齿轮在工作过程中存在齿面偏载和啮合冲击等问题,易造成齿轮失效。为改善此类问题,以CRH3动车为例,在Romax软件中建立了包含车轴和轴承的齿轮传动系统三维模型。基于RFE-XGBoost(recursive feature elimination-extreme gradien... 动车传动齿轮在工作过程中存在齿面偏载和啮合冲击等问题,易造成齿轮失效。为改善此类问题,以CRH3动车为例,在Romax软件中建立了包含车轴和轴承的齿轮传动系统三维模型。基于RFE-XGBoost(recursive feature elimination-extreme gradient boosting)特征选取模型,从通常采用的9个修形参数中筛选出最优修形参数组合。以筛选后的最优修形参数组合为输入变量,单位长度法向载荷为响应变量,分别基于反向传播(back propagation,BP)神经网络神经网络、随机森林回归、XGBoost算法构建了代理模型,并进行对比选择。最后采用粒子群优化(particle swarm optimization,PSO)算法调用代理模型,以单位长度法向载荷最小为优化目标,对齿轮修形参数取值进行寻优计算。优化结果表明,齿向斜度为13.6μm、齿端修薄长度为18.5 mm、齿端修薄量为4.4μm时齿轮修形效果最佳。通过Romax仿真计算验证,其单位长度法向载荷下降了24.36%,传动误差值下降了69.91%,有效改善了齿轮传动性能,缓解了齿面偏载的现象。研究结果可为齿轮修形方案选择和优化设计提供参考。 展开更多
关键词 动车传动齿轮 特征选取 齿轮修形 XGBoost算法 齿面接触分析
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基于金属氧化物载流子选择性传输层的硅异质结太阳电池的研究进展
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作者 胡梦琪 苏炬 +3 位作者 王光红 刁宏伟 赵雷 王文静 《太阳能学报》 北大核心 2025年第3期342-347,共6页
晶硅异质结(HJT)太阳电池的转换效率已达到26.81%,然而其使用有毒有害气体掺杂的传输层存在不可避免的寄生吸收损失,阻止了器件性能的进一步提升。因此,宽带隙非掺杂的钝化接触太阳电池受到极大关注。该文对载流子选择性传输原理、非掺... 晶硅异质结(HJT)太阳电池的转换效率已达到26.81%,然而其使用有毒有害气体掺杂的传输层存在不可避免的寄生吸收损失,阻止了器件性能的进一步提升。因此,宽带隙非掺杂的钝化接触太阳电池受到极大关注。该文对载流子选择性传输原理、非掺杂钝化接触材料及其主要沉积方法、非掺杂空穴/电子选择性材料的研究现状及器件稳定性改善方式进行概述,并对钝化接触型非掺杂晶硅异质结太阳电池存在的问题和前景进行讨论。 展开更多
关键词 载流子传输 过渡金属氧化物 硅太阳电池 载流子选择性接触 异质结太阳电池 非掺杂 异质结太阳电池 非掺杂
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晶体硅太阳电池的BaFx电子选择性接触研究
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作者 狄翀 李文昊 +3 位作者 陈静伟 丁阳 韦德远 许颖 《太阳能学报》 北大核心 2025年第6期245-250,共6页
研究一种利用电子束蒸发方法制备的超薄氟化钡(BaF_(x))薄膜的材料特性,并将其应用为晶体硅异质结电池的新颖的、输运电子而阻挡空穴的免掺杂选择性接触传输材料。紫外光电子能谱测试表明BaF_(x)/Al界面的功函数为2.55 eV,低于铝本身的... 研究一种利用电子束蒸发方法制备的超薄氟化钡(BaF_(x))薄膜的材料特性,并将其应用为晶体硅异质结电池的新颖的、输运电子而阻挡空穴的免掺杂选择性接触传输材料。紫外光电子能谱测试表明BaF_(x)/Al界面的功函数为2.55 eV,低于铝本身的功函数(4.26 eV),可实现对电子的选择性传输功能。加入BaF_(x)导致Al电极和晶体硅之间形成欧姆接触,并实现23.98 mΩ·cm^(2)的低接触电阻率。将此异质结构作为轻掺杂n型单晶硅太阳电池的免掺杂整背面欧姆接触,使电池的填充因子和短路电流密度都有所提升,并最终实现电池的绝对能量转换效率2.53%的提升。 展开更多
关键词 太阳电池 硅异质结 免掺杂 电子选择性接触
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报废银钨类合金触点回收工艺研究及设备选型 被引量:1
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作者 代林涛 周克武 +2 位作者 林应涛 王宝锋 柏小平 《电工材料》 2025年第2期34-36,共3页
以报废银钨类合金触点为原料,针对“一次酸溶—过滤清洗—破碎—氧化焙烧—二次酸溶—过滤清洗-银回收”的回收工艺,考察其工艺条件并进行设备选型。结果表明,采用电加热回转炉作为氧化焙烧设备,采用压滤机作为过滤洗涤设备,在钨氧化温... 以报废银钨类合金触点为原料,针对“一次酸溶—过滤清洗—破碎—氧化焙烧—二次酸溶—过滤清洗-银回收”的回收工艺,考察其工艺条件并进行设备选型。结果表明,采用电加热回转炉作为氧化焙烧设备,采用压滤机作为过滤洗涤设备,在钨氧化温度300℃,硝酸浓度7 mol/L,酸溶温度80℃,一次酸溶时间2 h,二次酸溶时间30 min的条件下可达到最佳回收效果,同时保证成本最低。 展开更多
关键词 报废银钨类合金触点 回收利用 设备选型
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一种节能型异丁烯选择性叠合工艺的研究与探讨
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作者 刘成军 吕晓东 +3 位作者 孙龙江 周璇 李倞琛 于海霞 《中外能源》 CAS 2025年第1期85-90,共6页
提供了一种节能型异丁烯选择性叠合工艺。碳四原料与气相产物在接触式缓冲罐内逆流接触并进行传质和传热,然后触后气相产物进入反应分离塔,触后碳四原料与二异丁烯共沸物、脱氧水混合后作为反应进料一并进入接触式反应器。接触式反应器... 提供了一种节能型异丁烯选择性叠合工艺。碳四原料与气相产物在接触式缓冲罐内逆流接触并进行传质和传热,然后触后气相产物进入反应分离塔,触后碳四原料与二异丁烯共沸物、脱氧水混合后作为反应进料一并进入接触式反应器。接触式反应器设有液位调节器,用于确保叠合反应始终在液相状态下操作,反应完成后该反应器气相产物至接触式缓冲罐进行传质和传热,液相产物至反应分离塔进行分离和深度反应。反应分离塔包含反应段,反应段采用水、水与异丁烯反应生成的叔丁醇作复合抑制剂;在分馏的作用下,剩余碳四、二异丁烯共沸物,二异丁烯产品分别自塔顶、侧线、塔底分出。该异丁烯选择性叠合工艺具有接触式反应器反应效率高、反应热全部用于组分的传质传热、反应分离塔反应段不需设置叔丁醇二次注入设施等特点,可提高二异丁烯选择性并可大幅度降低装置能耗。 展开更多
关键词 选择性叠合 反应热 二异丁烯 传质传热 共沸物 复合抑制剂 物流性质 物料平衡 接触 节能
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Distributed Contact Plan Design for Multi-Layer Satellite-Terrestrial Network 被引量:3
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作者 Wenfeng Shi Deyun Gao +4 位作者 Huachun Zhou Bohao Feng Haifeng Li Guanwen Li Wei Quan 《China Communications》 SCIE CSCD 2018年第1期23-34,共12页
In multi-layer satellite-terrestrial network, Contact Graph Routing(CGR) uses the contact information among satellites to compute routes. However, due to the resource constraints in satellites, it is extravagant to co... In multi-layer satellite-terrestrial network, Contact Graph Routing(CGR) uses the contact information among satellites to compute routes. However, due to the resource constraints in satellites, it is extravagant to configure lots of the potential contacts into contact plans. What's more, a huge contact plan makes the computing more complex, which further increases computing time. As a result, how to design an efficient contact plan becomes crucial for multi-layer satellite network, which usually has a large scaled topology. In this paper, we propose a distributed contact plan design scheme for multi-layer satellite network by dividing a large contact plan into several partial parts. Meanwhile, a duration based inter-layer contact selection algorithm is proposed to handle contacts disruption problem. The performance of the proposed design was evaluated on our Identifier/Locator split based satellite-terrestrial network testbed with 79 simulation nodes. Experiments showed that the proposed design is able to reduce the data delivery delay. 展开更多
关键词 contact GRAPH ROUTING distributedcontact PLAN multi-layered SATELLITE network inter-layer contact selection
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Microstructure and properties of Ag/SnO2 functional material manufactured by selective laser melting 被引量:6
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作者 Yuanjie Zhang Bo Song +1 位作者 Xiao Zhao Yusheng Shi 《Nano Materials Science》 CAS 2019年第3期208-214,共7页
Ag/SnO2,as a promising and environment-friendly electrical contact material,is widely applied in low-voltage apparatus.But the properties of Ag/SnO2 composites is difficult to improve due to the poor distribution phas... Ag/SnO2,as a promising and environment-friendly electrical contact material,is widely applied in low-voltage apparatus.But the properties of Ag/SnO2 composites is difficult to improve due to the poor distribution phases and difficult component design.In this work,the Ag/SnO2 composites are prepared by selective laser melting.To get better performance,Ag/SnO2 composites with different energy density were studied.The microstructure was observed by field emission scanning electron microscope.In addition,reinforced SnO2 phase was characterized by X-ray diffraction and transmission electron microscope.The results indicated that the microstructure,relative density and hardness of are influenced by energy density,while Ag/SnO2 composites with homogeneous microstructure,high relative density,higher hardness and lower electrical resistivity can be obtained by proper energy density(E?68 J/mm^3). 展开更多
关键词 selectIVE laser MELTING AG/SNO2 COMPOSITES Electrical contact material
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Effects of heat input on layer heterogeneity of selective laser melting Ti-6Al-4V components 被引量:5
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作者 陈昌荣 刘畅 +4 位作者 王乾廷 练国富 黄旭 冯美艳 戴继成 《China Welding》 CAS 2023年第3期51-66,共16页
Due to the layer-by-layer manufacturing characteristics,metallurgical process of selective laser melting(SLM)is inherently dif-ferent in the building direction because of varying conditions,thereby resulting inter-lay... Due to the layer-by-layer manufacturing characteristics,metallurgical process of selective laser melting(SLM)is inherently dif-ferent in the building direction because of varying conditions,thereby resulting inter-layer heterogeneity.To mitigate such anisotropy,it is of great significance to understand the effects of processing parameters on the property evolution and thus metallurgy of fabrication process.This research proposes one-factor-at-a-time experiment to investigate the influences of laser power and scanning speed on the surface qual-ity,microstructures and mechanical properties of selective laser melted Ti-6Al-4V parts.Surface quality is assessed by roughness around the printings while mechanical properties are evaluated through microhardness and tensile strengths.Phases in microstructure are quantified by XRD to correlate with mechanical properties.Fracture morphology is analyzed to understand the effect of defects and microstructure on mechanical performance.The optimized parameter corresponding to best surface quality and mechanical properties has been found respect-ively in laser power of 190 W and scanning speed of 800 mm/s.After optimization,surface roughness has decreased by 44.47%for upper surface.Yielding strength,tensile strength and elongation rate have improved by 13.17%,43.34%and 64.51%,respectively,with similar hardness and Young’s modulus.In addition,heterogeneity of mechanical properties has great improvement by a range of 31.63%-92.68%. 展开更多
关键词 selective laser melting TI-6AL-4V inter-layer heterogeneity tensile properties heat input
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Solid-Contact Perchlorate Sensor with Nanomolar Detection Limit Based on Cobalt Phthalocyanine Ionophores Covalently Attached to Polyacrylamide
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作者 Mohammad Nooredeen Abbas Abdel Lattief A. Radwan +1 位作者 Philippe Bühlmann Mahmud A. Abd El Ghaffar 《American Journal of Analytical Chemistry》 2011年第7期820-831,共12页
Novel solid-contact perchlorate sensors based on cobalt phthalocyanine-C-monocarboxylic acid (I), and cobalt phthalocyanine-C,C,C,C-tetracarboxylic acid (II) as free ionophores and covalently attached to polyacryla- m... Novel solid-contact perchlorate sensors based on cobalt phthalocyanine-C-monocarboxylic acid (I), and cobalt phthalocyanine-C,C,C,C-tetracarboxylic acid (II) as free ionophores and covalently attached to polyacryla- mide (PAA)—ionophores III and IV, respectively were prepared. The all solid-state sensors were constructed by the application of a thin film of a polymer cocktail containing a phthalocyanine ionophore and cetyltrimethylammonium bromide (CTMAB) as a lipophilic cationic additive onto a gold electrode precoated with the conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT) as an ion and electron transducer. The sensor with 10.3% of ionophore (III) covalently attached to plasticizer-free poly (butyl methacrylate-co-do- decyl methacrylate) (PBDA) exhibited a good selectivity for perchlorate and discriminated many ions, in- cluding F–, Cl–, Br–, I–, SCN–, , S2– and . The covalent attachment of the ionophore to the polymer resulted in a near-Nernstian anionic slope of –62.3 mV/decade whereas a super-Nernstian slope of –79.9 mV/ decade was obtained for the free ionophore. The sensor covered a linear concentration range of 5 × 10–9 - 1 × 10–2 mol?L–1 with a lower detection limit (LDL) of 1 × 10–9 mol?L–1 and gave a stable response over a pH range of 4 - 10.5. The all-solid state sensors were utilized for the selective flow injection potentiometric determination of perchlorate in natural water and human urine samples in the nanomolar concentration range. 展开更多
关键词 Ion-selective Electrode SOLID contact Covalent IONOPHORE Attachment PERCHLORATE FLOW-INJECTION Analysis Urine
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自适应皮肤像素选择的非接触式心率估计研究 被引量:1
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作者 刘涛 李源 《计算机应用与软件》 北大核心 2024年第10期46-50,70,共6页
为了实现基于IPPG(Image Photoplethysmography)技术多种环境的非接触式心率的测量,针对视频采集图像时,光照射皮肤所产生的色调、饱和度等差异造成的影响,提出自适应HSV阈值设置的皮肤像素选择算法sA-HSV(Self-Adaptive HSV)。摄像头... 为了实现基于IPPG(Image Photoplethysmography)技术多种环境的非接触式心率的测量,针对视频采集图像时,光照射皮肤所产生的色调、饱和度等差异造成的影响,提出自适应HSV阈值设置的皮肤像素选择算法sA-HSV(Self-Adaptive HSV)。摄像头采集整个面部区域,通过sA-HSV算法设定阈值筛选皮肤像素作为特征区域,像素点绿色通道的均值作为原始信号,加入滤波算法得到最终信号,使用傅里叶变换估计心率。仿真结果同真实仪器测量结果相比,自采集数据在LED灯光下平均绝对误差小于2.29 bpm,均方根误差小于3.67 bpm,自然光场景下平均绝对误差小于1.7 bpm,均方根误差小于2.39 bpm,公开数据集VIPL-HR下,平均绝对误差为2.57 bpm,均方根误差为3.25 bpm,该算法更适合于光照环境下的非接触式心率估计。 展开更多
关键词 IPPG 非接触式 自适应HSV 皮肤像素选择
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SF_(6)断路器触头劣化过程合闸预击穿特性研究 被引量:2
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作者 马飞越 黎炜 +4 位作者 孙尚鹏 相中华 吴强 王尧平 王羽 《高压电器》 CAS CSCD 北大核心 2024年第4期113-122,共10页
电容器组投切断路器触头烧蚀劣化后会改变合闸预击穿时间,这不仅会影响选相合闸效果,同时也说明预击穿电弧持续时间可作为衡量触头烧蚀状态的指标之一。建立了126 kV SF_(6)断路器灭弧室内合闸预击穿过程电—流体耦合仿真模型,研究了触... 电容器组投切断路器触头烧蚀劣化后会改变合闸预击穿时间,这不仅会影响选相合闸效果,同时也说明预击穿电弧持续时间可作为衡量触头烧蚀状态的指标之一。建立了126 kV SF_(6)断路器灭弧室内合闸预击穿过程电—流体耦合仿真模型,研究了触头劣化过程中合闸预击穿特性,并提出了预击穿时间带电检测方法。结果表明:合闸过程中场强最大点总是出现在静弧触头表面;灭弧室内SF_(6)气体密度几乎保持不变;110 kV电压等级相电压下,触头预击穿电弧持续时间随烧蚀程度变化的试验值与仿真值吻合良好。从电场畸变角度解释了随着触头的表面烧蚀劣化程度增大对应预击穿时间的变化规律,结果可为断路器选相合闸策略和触头状态评估提供理论指导。 展开更多
关键词 SF_(6)断路器 预击穿特性 多物理场耦合仿真 选相合闸 触头状态评估
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溶质引起的自由液面Marangoni铺展研究综述 被引量:1
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作者 黄彦如 黄睿雯 +2 位作者 马雪 李真珍 滕宏辉 《力学学报》 EI CAS CSCD 北大核心 2024年第6期1511-1528,共18页
Marangoni流动是一种由表面张力梯度驱动的界面铺展和液体内部的对流.其中,表面张力梯度可以通过温度或溶质的不均匀分布来调控.由溶质引起的Marangoni铺展在呼吸道药物输送等生物医学领域、复杂结构颗粒制备和镀膜等先进制造领域有着... Marangoni流动是一种由表面张力梯度驱动的界面铺展和液体内部的对流.其中,表面张力梯度可以通过温度或溶质的不均匀分布来调控.由溶质引起的Marangoni铺展在呼吸道药物输送等生物医学领域、复杂结构颗粒制备和镀膜等先进制造领域有着重要应用.溶质分子的诸多物理化学过程都会对Marangoni铺展的动力学产生影响,例如分子在界面上的输运、液滴与基底之间的物质交换、挥发性溶质在自由液面的蒸发,都会对表面张力梯度起到动态的调控作用.同时,在铺展液体特殊的本构性质和Marangoni铺展提供的强剪切率的共同作用下,流体会呈现一系列复杂而有趣的现象.文章着重介绍近年来领域内开展的由溶质引起的Marangoni铺展,包括表面活性分子参与的Marangoni铺展,互混液体界面、复杂流体自由液面的Marangoni铺展,以及组分差异性蒸发引起的Marangoni铺展,并阐述它们的演化机制.最后将列举Marangoni铺展在新兴工业领域中的应用,为开发借助溶质的本构性质等物理化学性质实现液体驱动的低能耗器件和生产工艺提供参考. 展开更多
关键词 Marangoni流 表面活性分子 接触线不稳定性 差异性蒸发
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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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Unlocking the Potential of Li-Ag Alloys:Phase Selection and Practical Application
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作者 Yuping Huang Shiwei Chen +7 位作者 Yu Yang Zhe-Tao Sun Xinyu Yu Chaohong Guan Runxin Ouyang Yunlong Guo Shou-Hang Bo Hong Zhu 《Energy Material Advances》 CSCD 2024年第1期343-352,共10页
Dendrite formation,contact loss,and continuous formation of the solid electrolyte interphase(SEI)preclude the practical use of the energy-dense lithium(Li)metal.Li-Ag alloys have the potential to address these issues ... Dendrite formation,contact loss,and continuous formation of the solid electrolyte interphase(SEI)preclude the practical use of the energy-dense lithium(Li)metal.Li-Ag alloys have the potential to address these issues due to their exceptional lithiophilicity,outstanding mechanical stability,and moderate chemical stability.This study evaluates all phases in the Li-Ag phase diagram based on lithiation capacity,Li insertion,mechanical property,and chemical stability.Our findings suggest that Li_(4)Ag is the most promising phase,and the Gibbs free energy of nucleation(ΔG_(nucle))for Li-Ag alloys is 3 to 5 orders of magnitude smaller compared to pure Li,resulting in uniform nucleation and deposition behavior.We proposed practical applications within the Li_(4)Ag phases or from the Li_(9)Ag_(4) to the Li_(4)Ag phases,which may provide a usable capacity of 409 to 696 mAh/g,respectively.Experiments indicate that Li_(4)Ag exhibits not only the smallest impedance but also the highest capacity retention compared to Li_(9)Ag_(4) and pure Li.The study provides valuable guidance for the selection and application of Li-containing alloys in future battery development. 展开更多
关键词 phase selection li ag alloys dendrite formation contact loss mechanical stability lithiation capacityli solid electrolyte lithiophilicity
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离子选择电极法测定食品接触用纸中氟含量
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作者 卢诗强 刘能模 +3 位作者 詹雨婷 杨青华 林勤保 马洪生 《包装学报》 2024年第6期72-80,共9页
为加强对我国纸包装行业中全氟和多氟烷基物质合规性的监管,通过采用不同样品前处理,结合离子选择电极法建立食品接触用纸中总氟、无机氟和可提取有机氟含量的测定方法,并对市面收集的纸样进行筛查分析。实验结果表明:3种氟含量测定方... 为加强对我国纸包装行业中全氟和多氟烷基物质合规性的监管,通过采用不同样品前处理,结合离子选择电极法建立食品接触用纸中总氟、无机氟和可提取有机氟含量的测定方法,并对市面收集的纸样进行筛查分析。实验结果表明:3种氟含量测定方法均具有良好线性关系,总氟的检出限(LOD)、定量限(LOQ)分别为2.50,6.25 mg/kg,无机氟的LOD、LOQ分别为0.30,0.75 mg/kg;可提取有机氟的LOD、LOQ分别为0.50,2.00 mg/kg。3种方法加标回收率为80%~120%,精密度均小于10%(n=6)。所筛查的48种食品接触用纸中总氟含量为(9.44±0.12)~(533.77±18.20)mg/kg,与欧盟限量要求相比,不合格率为29.2%,并且超过半数纸样中总有机氟含量不符合丹麦的限量规定。 展开更多
关键词 全氟和多氟烷基物质 食品接触用纸 离子选择电极法 总氟 无机氟 可提取有机氟
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Stabilizing molecular contacts via amorphous structures
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作者 Yongzhen Wu 《Science China Chemistry》 2025年第5期1637-1638,共2页
Perovskite solar cells(PSCs)have achieved remarkable advancements in recent years[1].Devices achieving high power conversion efficiencies(PCEs)typically rely on molecular contacts featuring conjugated cores[2].The pla... Perovskite solar cells(PSCs)have achieved remarkable advancements in recent years[1].Devices achieving high power conversion efficiencies(PCEs)typically rely on molecular contacts featuring conjugated cores[2].The planar and conjugated cores facilitate ordered molecular stacking throughπ-πinteractions,thereby enhancing charge transport and selectivity[3,4]. 展开更多
关键词 perovskite solar cells pscs perovskite solar cells ordered molecular stacking power conversion efficiencies molecular contacts molecular contacts featuring conjugated cores amorphous structures enhancing charge transport selectivity
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