Extremely fast-charging and longlife span are critical yet challenging for the development of cost-effective and sustainable potassium-ion batteries(PIBs)due to the sluggish kinetics and rapid capacity decay of graphi...Extremely fast-charging and longlife span are critical yet challenging for the development of cost-effective and sustainable potassium-ion batteries(PIBs)due to the sluggish kinetics and rapid capacity decay of graphite anodes caused by the large radius of K ions(1.38 A).To tackle this issue,here a new type of nitrogen-doped graphitic carbon tubes(NGCTs)is reported via a ZrO_(2)-templated chemical vapor deposition(CVD)approach.The carbon interlayer spacing,crystallite size,and Nconfigurations in NGCTs are controlled by adjusting the CVD temperature(800,900,and 1000℃).The optimized NGCT-900 sample well balances the graphitic domains and structural defects,thus enabling fast K^(+)insertion/extraction below 1 V(vs.K^(+)/K).These tubular carbon membranes achieve exceptional K^(+)-storage performance including high K^(+)-storage capacities of 404 mAh·g^(-1)at 0.1 A·g^(-1),ultrafast charging at 50 A·g^(-1)and a super-long cycle life of up to 6000 cycles.Ex-situ X-ray diffraction(XRD),insitu Raman,and galvanostatic intermittent titration technique(GITT)analyses reveal a synergistic K^(+)-adsorptionintercalation mechanism.Further comparison with S or P heteroatoms underscores the significance of N-doping in enhancing reversible K^(+)intercalation into graphitic domains and boosting surface adsorption capacity.The fabricated NGCT-900//K_(x)Ni_(0.33)Mn_(0.67)O_(2)PIB(1.2-3.2 V)provides both a high-energy density of 187 Wh·kg^(-1)(comparable to graphite//LiFePO_(4)lithium-ion batteries(LIBs))and a high-power density of 2200 W·kg^(-1)at 123 Wh·kg^(-1).This study establishes a carbon anode design strategy for advanced potassium storage.展开更多
针对500米口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)运行过程中存在馈源接收机安装及更换时设备精密且拆装过程复杂、馈源舱内安装空间狭小、馈源舱停靠平台处安装空间有限、连接螺栓数量多、...针对500米口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)运行过程中存在馈源接收机安装及更换时设备精密且拆装过程复杂、馈源舱内安装空间狭小、馈源舱停靠平台处安装空间有限、连接螺栓数量多、下平台尺寸重量大且安装精度要求高、更换时间长和运输困难等问题,提出FAST运行维护作业机器人总体技术解决方案。通过机器人总体技术需求分析、机器人总体技术设计、机器人关键技术研究及仿真分析,该方案可满足馈源接收机拆装过程中定位、识别、拆装和运输等应用需求,减小运行维护的时间成本和经济成本,确保FAST运行维护的安全,提高使用效率,延长FAST的全年观测时间,从而促进天文成果的产出。展开更多
为保障500 m口径球面射电望远镜(FAST)的安全稳定运行,提出基于实时信息数据的三维可视化监测方法。融合三维静态/动态建模、多源数据实时处理、Ansys仿真分析等关键技术,构建FAST高保真数字孪生模型,基于LightningChart图形库开发图形...为保障500 m口径球面射电望远镜(FAST)的安全稳定运行,提出基于实时信息数据的三维可视化监测方法。融合三维静态/动态建模、多源数据实时处理、Ansys仿真分析等关键技术,构建FAST高保真数字孪生模型,基于LightningChart图形库开发图形用户界面(graphical user interface,GUI)系统,实现设备异常信号的秒级可视化预警,故障响应时间显著缩短。该方法为大型射电望远镜及其阵列实施基于数字孪生的可视化监测提供参考。展开更多
非量测相机以价格低、体积小、使用灵活等优势被广泛应用于高精度测量工作中,但相机标定结果对测量精度影响较大,针对现有相机标定方法存在着精度不够或标定效率不高等问题,文章提出一种联合加速分割检测特征(features from accelerated...非量测相机以价格低、体积小、使用灵活等优势被广泛应用于高精度测量工作中,但相机标定结果对测量精度影响较大,针对现有相机标定方法存在着精度不够或标定效率不高等问题,文章提出一种联合加速分割检测特征(features from accelerated segment test,FAST)算法和双像光束法平差的相机标定方法。首先利用FAST算法对像片标志点自动提取,利用直接线性变换方法解得相机内、外参数初值;然后基于固定基线长度约束的双像光束法平差模型解算相机相关参数,并通过分类阈值方法提高模型收敛效率。结果表明:该方法相较于普通双像光束法平差的精度有所提升,其标定后的中误差达到0.0064 mm,且实现了相机标定流程的半自动化,提高了作业效率,有望应用于实际场景的相机标定作业。展开更多
The properties of electrolytes are critical for fast-charging and stable-cycling applications in lithium metal batteries(LMBs).However,the slow kinetics of Li^(+)transport and desolvation in commercial carbonate elect...The properties of electrolytes are critical for fast-charging and stable-cycling applications in lithium metal batteries(LMBs).However,the slow kinetics of Li^(+)transport and desolvation in commercial carbonate electrolytes,cou pled with the formation of unstable solid electrolyte interphases(SEI),exacerbate the degradation of LMB performance at high current densities.Herein,we propose a versatile electrolyte design strategy that incorporates cyclohexyl methyl ether(CME)as a co-solvent to reshape the Li^(+)solvation environment by the steric-hindrance effect of bulky molecules and their competitive coordination with other solvent molecules.Simulation calculations and spectral analysis demonstrate that the addition of CME molecules reduces the involvement of other solvent molecules in the Li solvation sheath and promotes the formation of Li^(+)-PF_(6)^(-)coordination,thereby accelerating Li^(+)transport kinetics.Additionally,this electrolyte composition improves Li^(+)desolvation kinetics and fosters the formation of inorganic-rich SEI,ensuring cycle stability under fast charging.Consequently,the Li‖LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)battery with the modified electrolyte retains 82% of its initial capacity after 463 cycles at 1 C.Even under the extreme fast-charging condition of 5 C,the battery can maintain 80% capacity retention after 173 cycles.This work provides a promising approach for the development of highperformance LMBs by modulating solvation environment of electrolytes.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.22579153 and 22279122)Shenzhen Science and Technology Program(No.JCYJ20220530162402005)Wuhan Key Research and Development Program(No.2025060102030012).
文摘Extremely fast-charging and longlife span are critical yet challenging for the development of cost-effective and sustainable potassium-ion batteries(PIBs)due to the sluggish kinetics and rapid capacity decay of graphite anodes caused by the large radius of K ions(1.38 A).To tackle this issue,here a new type of nitrogen-doped graphitic carbon tubes(NGCTs)is reported via a ZrO_(2)-templated chemical vapor deposition(CVD)approach.The carbon interlayer spacing,crystallite size,and Nconfigurations in NGCTs are controlled by adjusting the CVD temperature(800,900,and 1000℃).The optimized NGCT-900 sample well balances the graphitic domains and structural defects,thus enabling fast K^(+)insertion/extraction below 1 V(vs.K^(+)/K).These tubular carbon membranes achieve exceptional K^(+)-storage performance including high K^(+)-storage capacities of 404 mAh·g^(-1)at 0.1 A·g^(-1),ultrafast charging at 50 A·g^(-1)and a super-long cycle life of up to 6000 cycles.Ex-situ X-ray diffraction(XRD),insitu Raman,and galvanostatic intermittent titration technique(GITT)analyses reveal a synergistic K^(+)-adsorptionintercalation mechanism.Further comparison with S or P heteroatoms underscores the significance of N-doping in enhancing reversible K^(+)intercalation into graphitic domains and boosting surface adsorption capacity.The fabricated NGCT-900//K_(x)Ni_(0.33)Mn_(0.67)O_(2)PIB(1.2-3.2 V)provides both a high-energy density of 187 Wh·kg^(-1)(comparable to graphite//LiFePO_(4)lithium-ion batteries(LIBs))and a high-power density of 2200 W·kg^(-1)at 123 Wh·kg^(-1).This study establishes a carbon anode design strategy for advanced potassium storage.
文摘针对500米口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)运行过程中存在馈源接收机安装及更换时设备精密且拆装过程复杂、馈源舱内安装空间狭小、馈源舱停靠平台处安装空间有限、连接螺栓数量多、下平台尺寸重量大且安装精度要求高、更换时间长和运输困难等问题,提出FAST运行维护作业机器人总体技术解决方案。通过机器人总体技术需求分析、机器人总体技术设计、机器人关键技术研究及仿真分析,该方案可满足馈源接收机拆装过程中定位、识别、拆装和运输等应用需求,减小运行维护的时间成本和经济成本,确保FAST运行维护的安全,提高使用效率,延长FAST的全年观测时间,从而促进天文成果的产出。
文摘为保障500 m口径球面射电望远镜(FAST)的安全稳定运行,提出基于实时信息数据的三维可视化监测方法。融合三维静态/动态建模、多源数据实时处理、Ansys仿真分析等关键技术,构建FAST高保真数字孪生模型,基于LightningChart图形库开发图形用户界面(graphical user interface,GUI)系统,实现设备异常信号的秒级可视化预警,故障响应时间显著缩短。该方法为大型射电望远镜及其阵列实施基于数字孪生的可视化监测提供参考。
基金supported by the Lithium Resources and Lithium Materials Key Laboratory of Sichuan Province(LRMKF202405)the National Natural Science Foundation of China(52402226)+3 种基金the Natural Science Foundation of Sichuan Province(2024NSFSC1016)the Scientific Research Startup Foundation of Chengdu University of Technology(10912-KYQD2023-10240)the opening funding from Key Laboratory of Engineering Dielectrics and Its Application(Harbin University of Science and Technology)(KFM202507,Ministry of Education)the funding provided by the Alexander von Humboldt Foundation。
文摘The properties of electrolytes are critical for fast-charging and stable-cycling applications in lithium metal batteries(LMBs).However,the slow kinetics of Li^(+)transport and desolvation in commercial carbonate electrolytes,cou pled with the formation of unstable solid electrolyte interphases(SEI),exacerbate the degradation of LMB performance at high current densities.Herein,we propose a versatile electrolyte design strategy that incorporates cyclohexyl methyl ether(CME)as a co-solvent to reshape the Li^(+)solvation environment by the steric-hindrance effect of bulky molecules and their competitive coordination with other solvent molecules.Simulation calculations and spectral analysis demonstrate that the addition of CME molecules reduces the involvement of other solvent molecules in the Li solvation sheath and promotes the formation of Li^(+)-PF_(6)^(-)coordination,thereby accelerating Li^(+)transport kinetics.Additionally,this electrolyte composition improves Li^(+)desolvation kinetics and fosters the formation of inorganic-rich SEI,ensuring cycle stability under fast charging.Consequently,the Li‖LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)battery with the modified electrolyte retains 82% of its initial capacity after 463 cycles at 1 C.Even under the extreme fast-charging condition of 5 C,the battery can maintain 80% capacity retention after 173 cycles.This work provides a promising approach for the development of highperformance LMBs by modulating solvation environment of electrolytes.
