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Symmetry-breaking of LiMn6 hexatomic-ring in grain surface of Li2MnO3

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Journal of Energy Chemistry 2023年第6期81卷 110-117页

作者： lihang wang Shu Zhao Boya wang Haijun Yu Institute of Advanced Battery Materials and Devices Faculty of Materials and Manufacturing Beijing University of Technology Key Laboratory of Advanced Functional Materials Ministry of Education Beijing University of Technology

LiMn6hexatomic-rings act as functional units in Li-rich layered oxides(LLOs), which determine the capacity, voltage, and structural stability of LLOs. However, the symmetry of the LiMn6hexatomic-ring is always broken, especially in the grain surface of LLOs, which will greatly affect its electrochemical performance. Herein, the symmetry-breaking of LiMn6hexatomic-ring in the grain surface of Li2MnO3was studied, and their effect on charge compensation mechanism and structure evolution behavior was thoroughly investigated. The results show that the electrochemical activity of the symmetry-broken LiMn6hexatomic-ring is higher than that of the unbroken LiMn6, and the former is more favorable for spinelization on the grain surface. Furthermore, the exposure proportion of crystallographic planes with different symmetry-broken LiMn6hexatomic-ring has also been discussed, which can be adjusted by changing the partial pressure of oxygen. The in-depth understanding of the symmetry-breaking of LiMn6hexatomic-ring will provide more targeted strategies for designing high-performance LLOs cathodes for lithium-ion batteries.

关键词： Li-rich layered oxides LiMn6 functional unit Symmetry-breaking Surface structure Density functional theory

Reliability Analysis of Gas Pipeline with Corrosion Defects

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材料科学与工程（中英文B版） 2016年第2期6卷 101-104页

作者： wang lihang School of Petroleum Engineering Yangtze University Wuhan 430100 China

Symmetry-breaking of LiMn_(6) hexatomic-ring in grain surface of Li_(2)MnO_(3)

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Journal of Energy Chemistry 2023年第6期 110-117,I0004页

作者： lihang wang Shu Zhao Boya wang Haijun Yu Institute of Advanced Battery Materials and Devices Faculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China Key Laboratory of Advanced Functional Materials Ministry of EducationBeijing University of TechnologyBeijing 100124China

LiMn_(6) hexatomic-rings act as functional units in Li-rich layered oxides(LLOs),which determine the capacity,voltage,and structural stability of LLOs.However,the symmetry of the LiMn_(6) hexatomic-ring is always broken,especially in the grain surface of LLOs,which will greatly affect its electrochemical performance.Herein,the symmetry-breaking of LiMn_(6) hexatomic-ring in the grain surface of Li_(2)MnO_(3) was studied,and their effect on charge compensation mechanism and structure evolution behavior was thoroughly investigated.The results show that the electrochemical activity of the symmetry-broken LiMn_(6) hexatomic-ring is higher than that of the unbroken LiMn_(6),and the former is more favorable for spinelization on the grain surface.Furthermore,the exposure proportion of crystallographic planes with different symmetry-broken LiMn_(6) hexatomic-ring has also been discussed,which can be adjusted by changing the partial pressure of oxygen.The in-depth understanding of the symmetry-breaking of LiMn_(6) hexatomic-ring will provide more targeted strategies for designing high-performance LLOs cathodes for lithium-ion batteries.

关键词： Li-rich layered oxides LiMn_(6)functional unit Symmetry-breaking Surface structure Density functional theory

Compound Impedance Control of a Hydraulic Driven Parallel 3UPS/S Manipulator

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Chinese Journal of Mechanical Engineering 2020年第4期33卷 63-76页

作者： lihang wang Shaofei Cui Chong Ma Lijie Zhang Hebei Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan UniversityQinhuangdao 066004China Key Laboratory of Advanced Forging&Stamping Technology and Science Ministry of Education of ChinaYanshan UniversityQinhuangdao 066004China

The hydraulic parallel manipulator combines the high-power density of the hydraulic system and high rigidity of the parallel mechanism with excellent load-carrying capacity.However,the high-precision trajectory tracking control of the hydraulic parallel manipulator is challenged by the coupling dynamics of the parallel mechanism and the high nonlinearities of the hydraulic system.In this study,the trajectory control of a 3-DOF symmetric spherical parallel 3UPS/S manipulator is evaluated.Focusing on the highly coupling and nonlinear system dynamics,a compound impedance control method for a hydraulic driven parallel manipulator is proposed,which combines impedance control with the spatial motion characteristics of a parallel manipulator.The control strategy is divided into the inner and outer loops.The inner loop controls the impedance of the actuator in the joint space,and the outer loop controls the impedance of the entire platform in the task space to compensate the coupling of the actuators and improve the tracking accuracy of the moving platform.Compound impedance control does not require force or pressure sensors and is less dependent on modeling precision.The experimental results show that the compound impedance control effectively improves the tracking accuracy of the moving platform.This research proposes a compound impedance control strategy for a 3-DOF hydraulic parallel manipulator,which has high tracking precision with a simple and cheap system configuration.

关键词： Parallel manipulator Impedance control Hydraulic servo system Trajectory tracking

脊柱侧弯复杂椎弓根情况下5点定位法点状接触式椎弓根导航模板的应用

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中国组织工程研究 2024年第18期28卷 2859-2864页

作者：王力航陆廷盛陈啟鸰姚书眈蒲兴魏姬林松赵国权欧阳北平张斌杨再松罗春山北京积水潭医院贵州医院脊柱外科贵州省贵阳市550004

背景:椎弓根导板具有多种优势,但仍然存在一些问题,例如软组织剥离不干净导致导板贴合不严密的钉道偏差;为了贴合导板仔细剥离软组织导致手术时间延长,出血量增加;导板的设计无法预知椎体旋转及体位变化影响导致贴合不严密等。目的:探... 详细信息

背景:椎弓根导板具有多种优势,但仍然存在一些问题,例如软组织剥离不干净导致导板贴合不严密的钉道偏差;为了贴合导板仔细剥离软组织导致手术时间延长,出血量增加;导板的设计无法预知椎体旋转及体位变化影响导致贴合不严密等。目的:探讨新型5点定位法点状接触式椎弓根导航模板在脊柱侧弯复杂椎弓根情况下的效用。方法:筛选2020年2月至2023年2月北京积水潭医院贵州医院脊柱外科收治的存在椎弓根复杂情况的脊柱侧弯患者20例,行脊柱侧弯矫形术,术中使用5点定位法点状接触式椎弓根导航模板引导置钉;按纳入排除标准匹配34例既往病例资料作为经验置钉组,常规徒手置钉。对比两组患者的置钉时间、置钉出血量、置钉透视次数、手动改道次数、置钉等级及准确率、置钉并发症和主弯矫形率等指标。结果与结论:①导航模板组与经验置钉组在性别、年龄、主弯冠状面Cobb’s角、主弯bending位Cobb’s角、椎弓根变异、顶椎旋转、融合节段、置钉数、置钉等级、置钉准确率、主弯矫形率方面差异均无显著性意义(P>0.05);②与经验置钉组相比,导航模板组在置钉时间(P=0.034)、置钉出血量(P=0.036)、置钉透视次数(P=0.000)、手动改道次数(P=0.021)方面更具优势;③两组患者的置钉相关并发症均为0例;④提示5点定位法点状接触式3D打印椎弓根导航模板具有爪状结构,牢固适配各种畸形椎板关节突,可避免漂移现象,准确置钉;具有尖端点状接触椎板结构,避免广泛彻底剥离后方结构,可减少出血量及手术时间,减少创伤;提前设计了进钉点进钉方向,可减少透视次数及手术时间;分节段设计,避免因麻醉体位改变等不适配;操作简便,置钉准确率高。

关键词：脊柱侧弯复杂椎弓根 3D打印椎弓根导航模板 5点定位法点状接触式模板

Research of Pipeline Pressure Based on the Reliability Theory

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Journal of Energy and Power Engineering 2016年第5期10卷 292-295页

作者： lihang wang Pingping Sun School of Petroleum Engineering Yangtze University Wuhan 430100 China

The former gas pipeline operating pressure transmission determined mostly according to the determined formula into the corresponding pipeline parameters are obtained, and the parameters of the actual pipeline due to many reasons, such as measurement error, production batch, etc., is not a fixed value. This paper on pipeline integrity established limit state equation, using Monte Carlo method to calculate the gas pipeline in different pressures of reliability, according to the API (American Petroleum Institute) 579 recommended target reliability to determine the operating pressure of the different regions, and design coefficient method, the calculated results are compared, results of calculation reliability is more reasonable and improve the delivery pressure of the area, the pipeline safety management provides the basis.

关键词：可靠性理论管道压力美国石油学会极限状态方程蒙特卡罗方法计算结果工作压力输气管道

基于特征事件的数控电火花线切割加工工艺过程建模及能耗计算

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计算机集成制造系统 2018年第5期24卷 1124-1137页

作者：郑军王黎航浙江大学机械工程学院浙江杭州310027 浙江科技学院机械与汽车工程学院浙江杭州310023

为了科学准确地分析数控电火花线切割加工工艺过程的电能消耗情况,实现对线切割加工工艺过程的准确描述,提出一种基于特征事件的数控电火花线切割加工工艺过程建模方法。根据数控电火花线切割加工工艺过程特性,将加工工艺过程分解为5类... 详细信息

为了科学准确地分析数控电火花线切割加工工艺过程的电能消耗情况,实现对线切割加工工艺过程的准确描述,提出一种基于特征事件的数控电火花线切割加工工艺过程建模方法。根据数控电火花线切割加工工艺过程特性,将加工工艺过程分解为5类典型事件和4类典型特征;结合正常加工时的运动特性,总结了正常加工时的9种基本事件和14种基本特征,并从NC代码中提取工艺过程的事件及能耗特征,实现了对加工工艺过程的建模。在该模型基础上,利用特征事件实现了数控电火花线切割加工工艺过程的能耗计算,为后续优化数控电火花线切割加工工艺奠定了理论基础。结合某典型凸模零件电火花线切割加工工艺过程进行验证,估算了该零件的加工工艺过程能耗。

关键词：电火花线切割加工特征事件过程建模 NC代码数控系统

基于NTIS的美国政府人工智能科技合同分析

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科技情报研究 2023年第3期5卷 103-118页

作者：王立航陈果南京理工大学经济管理学院南京210094

[目的/意义]科技合同是美国政府资助相关机构开展基础性、系统性研究的重要形式。文章创新性地探索利用科技合同揭示美国政府在人工智能领域的科技资助和战略布局。[方法/过程]NTIS科技报告的合同号字段,可用于揭示若干科技报告围绕同... 详细信息

[目的/意义]科技合同是美国政府资助相关机构开展基础性、系统性研究的重要形式。文章创新性地探索利用科技合同揭示美国政府在人工智能领域的科技资助和战略布局。[方法/过程]NTIS科技报告的合同号字段,可用于揭示若干科技报告围绕同一合同目标开展持续性研究的情况。文章以NTIS中人工智能领域科技报告合同号为切入点,识别其中多个重要的科技合同,并逐一解读其背景信息;随后,进一步围绕最重要的4个科技合同,以点带面地揭示它们在全领域和人工智能领域的研究主题。[结果/结论]对重要科技合同的解读结果,能够深入揭示美国政府在引导人工智能研究上的战略布局和行业特点,弥补了传统基于科技论文、科技项目分析结果的片面性,表明基于NTIS的科技合同分析是跟踪美国科技战略布局的有效方法。

关键词：人工智能 NTIS 科技报告科技合同

Assessment of tree-ring mercury radial translocation and age effect in Masson pine:Implications for historical atmospheric mercury reconstruction

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Journal of Environmental Sciences 2024年第4期138卷 266-276页

作者： Xu Liu Xun wang Dingyong wang College of Resources and Environment Southwest UniversityChongqing 400715China State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China

The tree ring has been regarded as an emerging archive to reconstruct historical atmospheric mercury(Hg)trends,but with the large knowledge gaps in the reliability.In this study,we comprehensively evaluated the Hg source,radial translocation and age effect of Masson pine(Pinus massoniana)tree ring at Mt.Jinyun in Chongqing,to assess the suitability of such tree ring as the archive of atmospheric Hg.Results showed that distinct variabilities among Masson pine tree-ring Hg concentration profiles.The Hg concentration significantly increased along with stem height(P<0.05),indicating the Hg in tree rings mainly derived from foliage uptake atmospheric Hg.We found a distinct age effect that the tree ring of young trees had the higher Hg concentration.Besides,we used the advection-diffusion model to demonstrate how Hg concentration shifted by the advection or/and diffusion in tree rings.The modeling results showed that the advection induced radial translocation during the young growth period of tree was a plausible mechanism to result in the tree-ring Hg record largely different from the trend of anthropogenic Hg emissions in Chongqing.We finally suggest that in further Hg dendrochemistry,better discarding the tree-ring Hg profile of the young growth period to reduce impacts of the radial translocation and age effect.

关键词： Masson pine Tree-ring mercury Radial translocation Tree age effect