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Chinese Chemical Letters 2024年第2期35卷 534-538页

作者： bing Jiang hao Li Bi Luo Lehao Liu Lihua Chu Qiaobao z.ang Meicheng Li State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources School of New EnergyNorth China Electric Power UniversityBeijing 102206China State Key Laboratory of Physical Chemistry of Solid Surfaces College of MaterialsXiamen UniversityXiamen 361005China

Boosting the interfacial stability between electrolyte and Li-rich cathode material at high operating voltage is vital important to enhance the cycling stability of Li-rich cathode materials for high-performance Li-ion *** this work,vinyltrimethylsilane as a new type of organic silicon electrolyte additive is studied to address the interfacial instability of Li-rich cathode material at high operating *** cells using vinyltrimethylsilane additive shows the high capacity retention of 73.9%after 300 cycles at 1 C,whereas the cells without this kind of additive only have the capacity retention of 58.9%.The improvement of stability is mainly attributed to the additive helping to form a more stable surface film for Li-rich cathode material,thus avoiding direct contact between the electrolyte and the cathode material,slowing down the dissolution of metal ions and the decomposition of the electrolyte under high operating *** findings in this work shed some light on the design of stable cycling performance of Li-rich cathode toward advanced Li-ion batteries.

关键词： Vinyltrimethylsilane Electrolyte additive Li-rich cathode Interfacial stability Capacity retention

Quantitative analysis of the protective performance of bicycle helmet with multidirection impact protection system in oblique impact tests

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Chinese Journal of Traumatology 2024年第4期27卷 226-234页

作者： Yong Han hao Yang He Wu Di Pan bing-Yu Wang School of Mechanical and Automotive Engineering Xiamen University of TechnologyXiamen361024Fujian provinceChina Fujian Key Laboratory of Bus Advanced Design and Manufacturing Xiamen361024Fujian provinceChina School of Aerospace Engineering Xiamen UniversityXiamen361005Fujian provinceChina

Purpose:The current study aimed to assess the protective performance of helmets equipped with multidirectional impact protection system(MIPS)under various oblique impact ***:Initially,a finite element model of a bicycle helmet with MIPS was developed based on thescanned geometric parameters of an actual bicycle ***,the validity of model wasconfirmed using the KASK WG11 oblique impact test *** different impact angles(30°,45°,and 60°)and 2 varying impact speeds(5 m/s and 8 m/s)were employed in oblique tests to evaluateprotective performance of MIPS in helmets,focusing on injury assessment parameters such as peaklinear acceleration(PLA)and peak angular acceleration(PAA)of the ***:The results demonstrated that in all impact simulations,both assessment parameters werelower during impact for helmets equipped with MIPS compared to those *** PAA wasconsistently lower in the MIPS helmet group,whereas the difference in PLA was not significant in the noMIPS helmet *** instance,at an impact velocity of 8 m/s and a 30°inclined anvil,the MIPS helmetgroup exhibited a PAA of 3225 rad/s^(2) and a PLA of 281 *** contrast,the no-MIPS helmet group displayeda PAA of 8243 rad/s^(2) and a PLA of 292 ***,both PAA and PLA parameters decreased with theincrease of anvil *** a 60°anvil angles,PAA and PLA values were 664 rad/s^(2) and 20.7 g,respectively,reaching their ***:The findings indicated that helmets incorporating MIPS offer enhanced protection againstvarious oblique impact *** assessing helmets for oblique impacts,the utilization of larger angleanvils and rear impacts might not adequately evaluate protective performance during an impact *** findings will guide advancements in helmet design and the refinement of oblique impact testprotocols.

关键词： Oblique impact Multi-direction impact protection system WG11 oblique impact test angular acceleration

Insight into structural degradation of NCMs under extreme fast charging process

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Rare Metals 2024年第1期43卷 41-50页

作者： Yu Tang Xing-Yu Wang Jin-Can Ren Bo-Wen Chen zhi-Yong Huang Wei Wang Ya-Lan Huang bing-hao z.ang Si Lan z.ang-Long He Qi Liu hao He Department of Physics City University of Hong KongHong Kong 999077China Shenzhen Research Institute City University of Hong KongShenzhen 518057China College of Materials Science and Engineering Changsha University of Science&TechnologyChangsha 410114China

Lithium-ion batteries(LIBs)with extreme fast charging(XFC)capability are considered an effective way to alleviate range anxiety for electric vehicle(EV)*** to the high ionic and electronic conductivity of LiNi_(x)Co_(y)Mn_zO_(2)(x+y+z=1,NCM)cathodes,the inevitable Li plating of graphite in NCM|graphite cell is usually identified as a key bottleneck for XFC ***,the capacity decay mechanism of cathode materials under XFC has not been fully *** this work,three typical NCM cathode materials with different Ni fractions were chosen and their electrochemical performances under XFC associated with structural evolution were investigated.A faster capacity decay of NCMs under XFC conditions is observed,especially for Ni-rich ***-situ X-ray diffraction(XRD)reveals that the multiple caxis parameters appear at the high-voltage regions in Nirich NCMs,which is probably triggered by the larger obstruction of Li(de)***,NCMs with moderate Ni fraction also present a similar trend under XFC *** phenomenon is more detrimental to the structural and morphological stability,resulting in a faster capacity decay than that under low current *** work provides new insight into the degradation mechanism of NCMs under XFC conditions,which can promote the development of NCM cathode materials with XFC capability.

关键词： Lithium-ion batteries Ni fraction Extreme fast charging Structural evolution

Cationic ordering transition in oxygen-redox layered oxide cathodes

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Carbon Energy 2024年第1期6卷 197-206页

作者： Xinyan Li ang Gao Qinghua z.ang hao Yu Pengxiang Ji Dongdong Xiao Xuefeng Wang Dong Su Xiaohui Rong Xiqian Yu Hong Li Yong-Sheng Hu Lin Gu Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijingChina College of Materials Science and Opto-Electronic Technology University of Chinese Academy of SciencesBeijingChina Beijing National Center for Electron Microscopy and Laboratory of Advanced Materials School of Materials Science and EngineeringTsinghua UniversityBeijingChina Beijing Advanced Innovation Center for Materials Genome Engineering Huairou DivisionInstitute of PhysicsChinese Academy of SciencesBeijingChina

Understanding the structural origin of the competition between oxygen 2p and transition-metal 3d orbitals in oxygen-redox(OR)layered oxides is eminently desirable for exploring reversible and high-energy-density Li/Na-ion ***,we reveal the correlation between cationic ordering transition and OR degradation in ribbon-ordered P3-Na_(0.6)Li_(0.2)Mn_(0.8)O_(2) via in situ structural *** two different voltage windows,the OR capacity can be improved approximately twofold when suppressing the in-plane cationic ordering *** find that the intralayer cationic migration is promoted by electrochemical reduction from Mn^(4+)to Jahn–Teller Mn^(3+)and the concomitant NaO_(6) stacking transformation from triangular prisms to octahedra,resulting in the loss of ribbon ordering and electrochemical ***-principles calculations reveal that Mn^(4+)/Mn^(3+)charge ordering and alignment of the degenerate eg orbital induce lattice-level collective Jahn–Teller distortion,which favors intralayer Mn-ion migration and thereby accelerates OR *** findings unravel the relationship between in-plane cationic ordering and OR reversibility and highlight the importance of superstructure protection for the rational design of reversible OR-active layered oxide cathodes.

关键词： cationic ordering layered oxide cathodes oxygen redox sodium-ion batteries

考虑结合面特性影响的机床整机有限元静力学分析模型

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机电工程 2024年第4期41卷 732-738页

作者：王豪黄为彬方兵福建农林大学机电工程学院福建福州350002 福建省农业信息感知技术重点实验室福建福州350002

针对机床数字化设计中典型结合面建模精度误差较大的问题,提出了一种采用虚拟材料等效结合面静力学特性的方法,建立了考虑结合面特性影响的机床整机有限元静力学分析模型,并完成了相应的静刚度测试实验。首先,综合考虑了弹塑性变形机制... 详细信息

针对机床数字化设计中典型结合面建模精度误差较大的问题,提出了一种采用虚拟材料等效结合面静力学特性的方法,建立了考虑结合面特性影响的机床整机有限元静力学分析模型,并完成了相应的静刚度测试实验。首先,综合考虑了弹塑性变形机制和摩擦力的影响,提出了一种新的结合面法向和切向刚度的分析模型;其次,根据不同类型结合面的特点,采用虚拟材料模拟结合面的刚度特性,建立了刚度特性与虚拟材料弹性模量和泊松比的关系,并将其应用于精密数控机床整机的静刚度分析;最后,开展了整机工艺系统的静刚度测试实验,得到了主轴末端X、Y、z三个方向的刚度分别为26.60 N/μm、41.87 N/μm和40.17 N/μm,并将其与仿真数据进行了对比。研究结果表明:不考虑结合面影响的模型相对误差将近17%,而考虑结合面影响的模型相对误差在5%以内,验证了考虑结合面特性影响的机床整机有限元静力学分析模型的有效性;采用虚拟材料等效结合面静力学特性的方法可作为机床数字化设计的一种可行的方法。

关键词：机床数字化设计虚拟材料法结合面静力学特性静刚度测试有限元静力学分析模型弹塑性模型

淮安市临床分离金黄色葡萄球菌耐药性及全基因组测序分析

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现代预防医学 2024年第9期51卷 1689-1694+1701页

作者：李兵兵汪浩杨鹏飞宋志洲孙敏邢亚东淮安市疾病预防控制中心淮安市突发公共卫生事件应急检测重点实验室涟水县疾病预防控制中心

目的探究淮安市临床分离金黄色葡萄球菌的耐药性及分子流行病学特征，为其感染的诊治和防控提供参考。方法收集从临床标本中分离的金黄色葡萄球菌，通过头孢西丁或苯唑西林耐药表型或mec A基因检测耐甲氧西林金黄色葡萄球菌（methicill... 详细信息

目的探究淮安市临床分离金黄色葡萄球菌的耐药性及分子流行病学特征，为其感染的诊治和防控提供参考。方法收集从临床标本中分离的金黄色葡萄球菌，通过头孢西丁或苯唑西林耐药表型或mec A基因检测耐甲氧西林金黄色葡萄球菌（methicillin-resistant Staphylococcus aureus,MRSA）。采用微量肉汤稀释法进行药敏试验。基于全基因组测序，对菌株进行单核苷酸多态性分析和多位点序列分型。利用在线数据库鉴定菌株携带的毒力和耐药基因。结果从7种类型临床标本中共分离到83株金黄色葡萄球菌，MRSA占59.04%。分离菌株对青霉素耐药率最高，为97.59%，对奈唑胺、替加环素、万古霉素、替考拉宁和呋喃妥因均敏感，多重耐药菌株占57.83%。83株金黄色葡萄球菌有20个ST型，ST398(21.69%)为主要型别。83个基因组存在187 292个SNPs位点。这些菌株携带有38种耐药基因，其中tet(38)、bla z、arl R、arl S、mgr A、nor A、mep A、Erm C、Lmr S、mep R携带率较高。携带sea、seb、sec、sed、seh、selk、sell、selq 8种肠毒素基因，selk和selq携带率最高，均为32.53%,ST1菌株携带肠毒素基因种类最多。杀白细胞素PVL编码基因lukF-PV和lukS-PV携带率分别为49.40%和6.02%。中毒性休克综合征毒素TSST-1编码基因tsst-1的携带率为3.61%。结论淮安地区临床分离金黄色葡萄球菌的耐药性较强，MRSA检出率较高。菌株ST型别丰富，ST型别与致病性存在一定相关性。

关键词：金黄色葡萄球菌耐药性分子流行病学

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细长焊接圆钢管轴心受压稳定承载力研究

建筑结构 2024年第14期54卷 61-68页

作者：林冰张志超张淏丛峻张磊中建工程产业技术研究院有限公司北京101300 中国建筑股份有限公司技术中心北京101300 中央司法警官学院保定071000

为研究细长焊接圆钢管轴压稳定性能,对30根试件进了轴压试验,分析了试件失稳变形的特征,比较了试件的稳定系数与我国规范中稳定曲线的关系,并考虑钢管几何初始缺陷和残余应力对其稳定承载力进行了有限元分析。研究表明:细长焊接圆钢管... 详细信息

为研究细长焊接圆钢管轴压稳定性能,对30根试件进了轴压试验,分析了试件失稳变形的特征,比较了试件的稳定系数与我国规范中稳定曲线的关系,并考虑钢管几何初始缺陷和残余应力对其稳定承载力进行了有限元分析。研究表明:细长焊接圆钢管的几何初始缺陷具有较大离散性,与我国规范规定值不同,正则化长细比在1.0~1.3区间时,试验得到的稳定系数低于规范值,最大相差-24.4%;几何初始缺陷小于1/500杆长时,可采用规范值进行设计;而几何初始缺陷大于1/500杆长时,建议重新制定压杆曲线。最后,给出了细长焊接圆钢管在8种初始缺陷下的压杆稳定曲线。

关键词：细长焊接圆钢管稳定系数轴压试验设计方法

具有恐惧效应的生态流行病模型的稳定性分析与最优控制

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数学的实践与认识 2024年第6期54卷 151-160页

作者：胡皓宇张学兵张韵卓李顺杰南京信息工程大学数学与统计学院江苏南京210044 江苏省应用数学(南京信息工程大学)中心江苏省系统建模与数据分析国际合作联合实验室江苏南京210044

考虑了一个猎物种群具有疾病的生态流行病学模型,该模型考虑捕食者对猎物的恐惧效应,假设恐惧可以降低猎物的种群繁殖率,降低猎物种群的活动,从而降低疾病的传播率.首先讨论模型解的非负性和有界性,然后研究了非负平衡点的存在性和稳定... 详细信息

考虑了一个猎物种群具有疾病的生态流行病学模型,该模型考虑捕食者对猎物的恐惧效应,假设恐惧可以降低猎物的种群繁殖率,降低猎物种群的活动,从而降低疾病的传播率.首先讨论模型解的非负性和有界性,然后研究了非负平衡点的存在性和稳定性,最后讨论了模型的最优控制问题.

关键词：恐惧效应稳定性生态流行病最优控制

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3种天牛信息素和荜澄茄油对天牛科昆虫的林间引诱效果研究

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西南林业大学学报（自然科学） 2024年第2期44卷 155-162页

作者：徐炜超孟庆繁李燕郝元渤王雪刘冰北华大学林学院长白山区昆虫生物多样性与生态系统功能重点实验室吉林吉林132013 国家林业和草原局生物灾害防控中心辽宁沈阳110034

选用2-(十一烷氧基)-乙醇(Monochamol)、6,10-二甲基十一烷-5,9-二烯醇(E/z-fuscumol)、6,10-二甲基-5,9-十一二烯-2-乙酸乙酯(E/z-fuscumol acetate)3种天牛信息素和荜澄茄油(cubeb oil)诱芯,辅以黑色飞翔拦截诱捕器进行林内诱集,筛选不同天牛种类高效信息化合物诱芯,监测阔叶红松林内天牛种类和数量,以及松材线虫病潜在媒介天牛的种群动态。结果表明:cubeb oil增加E/z-fuscumol+E/z-fuscumol acetate对花天牛亚科的诱集作用,降低Monochamol对云杉花墨天牛的诱集数量;E/z-fuscumol+E/z-fuscumol acetate与Monochamol和/或cubeb oil组合可增加诱集的天牛种类。在实际应用中应根据特定天牛种类选择植物挥发物作为信息素诱芯的增效剂;在云杉花墨天牛、云杉大墨天牛的监测和大量诱捕时可选用Monochamol+E/z fuscumol acetate+E/z fuscumol组合,提高诱捕效率;在一般性天牛种群监测调查中为降低成本可使用单一Monochamol诱芯。

关键词：天牛信息素荜澄茄油挥发物诱捕器

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Symmetry-driven half-integer conductance quantization in Cobalt–fulvalene sandwich nanowire

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npj Computational Materials 2023年第1期9卷 314-321页

作者： zhuoling Jiang Kah-Meng Yam Yee Sin ang Na Guo Yongjie z.ang hao Wang Chun z.ang Department of Physics and Centre for Advanced 2D Materials National University of SingaporeSingapore 117551Singapore Science Mathematics and Technology(SMT)ClusterSingapore University of Technology and DesignSingapore 487372Singapore Department of Chemistry National University of SingaporeSingapore 117543Singapore National University of Singapore Chongqing Research Institute 401123 ChongqingChina

Precise manipulation and monitoring spin transport in one-dimensional (1D) systems is a long-sought goal in the field of nano-spintronics. Based on first-principles calculations, we report the observation of half-integer conductance quantization in the Cobalt-fulvalene sandwich nanowire. Compared with a pure monatomic Cobalt wire, the introduction of fulvalene molecules leads to threeimportant features: Firstly, the strong coupling between the fulvalene and the Cobalt prevents the contamination of the ambientair, ensuring both chemical and physical stabilities;Secondly, the fulvalene symmetry-selectively filters out most of the d-typeorbitals of the Cobalt while leaving a single d-type orbital to form an open spin channel around the Fermi level, which offers amechanism to achieve the observed half-integer conductance;Thirdly, it maintains a superexchange coupling between adjacent Coatoms to achieve a high Curie temperature. Spin transport calculations show that this half-metallic nanowire can serve as a perfectspin filter or a spin valve device, thus revealing the potential of Cobalt-fulvalene sandwich nanowire as a promising building blockof high-performance spintronics technology.

关键词： sandwich coupling transport