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Nano Research 2024年第5期17卷 4203-4210页

作者： Gangyi Xiong Jiayu Yu Yalan Xing puheng yang Shichao Zhang School of Materials Science and Engineering Beihang UniversityBeijing 100191China School of Physics Science and Nuclear Energy Engineering Beihang UniversityBeijing 100191China

Although lithium metal is considered a promising anode for advanced Li-S and Li-air batteries,the uncontrolled dendrite growth and infinite volume change impede its practical ***,we report an ideal framework composed of carbonized bacterial cellulose(CBC)nanofibers,which shows intrinsic lithiophilicity to molten lithium without any lithiophilic surface *** wetting behavior of molten lithium can be significantly improved because its surface functional groups provide thermodynamical driving force,and the high surface roughness derived from nanocracks leads to rapid infusion in *** hybrid anode exhibits long cycle life up to 2000 h and excellent deep stripping-platting capacity up to 20 mAh·cm^(-2).When the anode is assembled with LiFePO_(4) cathode,the full cell delivers a good cycling stability up to 700 *** is attributed to the intrinsic lithiophilic scaffold,which can not only lower the nucleation barrier of Li and provide uniform nucleation sites for stable Li stripping/plating,but also offer interspace to accommodate volume fluctuation of lithium during long *** work provides a new manner to achieve a series of intrinsic lithiophilic carbon skeletons based on the large family of biomass materials and organic materials.

关键词： intrinsic lithiophilicity lithium metal anode bacterial cellulose lithium dendrite long cycling life

Investigation of Co_3O_4 nanorods supported Pd anode catalyst for methanol oxidation in alkaline solution

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Journal of Energy Chemistry 2014年第6期23卷 801-808页

作者： Yanbiao Ren Shichao Zhang Hua Fang Xin Wei puheng yang School of Materials Science and Engineering Beijing University of Aeronautics and Astronautics

A CO3O4 nanorod supported Pd electro-catalyst for the methanol electro-oxidation （MEO） has been fabricated by the combination of hydrother- mal synthesis and microwave-assisted polyol reduction processes. The crystallographic property and microstructure have been characterized using XRD, SEM and TEM. The results demonstrate that Pd nanoparticles （PdNPs） with a narrow particle size distribution （3-5 nm） are uni- formly deposited onto the surface of Co304 nanorods. Electrochemical measurements show that this catalyst having a larger electrochemically active surface area and a more negative onset-potential exhibits enhanced catalytic activity of 504 mA/mg Pd for MEO comparing with the Pd/C catalyst （448 mA/mg Pd）. The dependency of log/against logv reveals that MEO on Pd-CO304 electrode is under a diffusion control. Electrochemical impedance spectroscopy （EIS） measurement agrees well with the CV results. The minimum charge transfer resistance of MEO on Pd-CO304 is observed at -0.05 V, which coincides with the potential of MEO peak.

关键词： Pd nanoparticles C0304 nanorods methanol electrooxidation catalytic activity charge transfer resistance

Structure-design and theoretical-calculation for ultrasmall Co_(3)O_(4) anchored into ionic liquid modified graphene as anode of flexible lithium-ion batteries

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Nano Research 2022年第3期15卷 2104-2111页

作者： Longda Cong Shichao Zhang Hengyao Zhu Weixin Chen Xueyan Huang Yalan Xing Jun Xia puheng yang Xia Lu School of Materials Science and Engineering Beihang UniversityBeijing 100191China School of Physics Science and Nuclear Energy Engineering Beihang UniversityBeijing 100191China School of Materials Sun Yat-sen UniversityShenzhen 518107China School of Materials Science and Engineering Sun Yat-sen UniversityGuangzhou 510275China

Cobalt oxide(Co_(3)O_(4))is currently suitable in energy storage applications because of its high capacity based on the conversion reaction ***,unmodified Co_(3)O_(4)suffers from distinctly inferior rate capability and poor cycling *** the basis of the aforementioned considerations and density functional theory(DFT)simulations,the three-dimensional hierarchical porous structure(HPS)ultrasmall Co_(3)O_(4)anchored into ionic liquid(IL)modified graphene oxide(GO)has been successfully prepared(ultrasmall/Co_(3)O_(4)-GA-IL).The ultrasmall/Co_(3)O_(4)-GA-IL consists of Co_(3)O_(4)co-assembled with IL modified GO to generate the HPS which can facilitate ion transfer channels through reduction of the electron and ion transportation path and transmission *** addition,N-doping graphene can enhance the inherent electrical conductivity of Co_(3)O_(4),which is proved by the DFT *** virtue of the novel superstructure,the ultrasmall/Co_(3)O_(4)-GA-IL electrode demonstrates a high reversible capacity of 1,304 mAh·g^(−1),an enhanced high-rate capability(715 mAh·g^(−1)at 5 C),and a capacity retention of 98.4%even after 500 cycles at 5 C rate,which corresponds to 0.0003%capacity loss per *** cells based on the cathode are further fabricated and demonstrate excellent mechanical and electrochemical properties under bent and folded state,highlighting the practical application of our deliberately designed electrode in wearable electronics.

关键词： co-assembly ultrasmall cobalt oxide ionic liquid flexible lithium-ion batteries hierarchical porous structure density functional theory simulations

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富锂正极材料的制备及电化学性能研究

北京航空航天大学学报 2016年第8期42卷 1627-1631页

作者：魏欣张世超刘冠娆杨埔蘅孟娟李红磊北京航空航天大学材料科学与工程学院北京100083

用溶胶-凝胶法结合高温煅烧过程制备富锂正极材料Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_2,对800°C和900°C煅烧后得到的2种材料(标记为S8和S9)进行物相和形貌表征以及电化学测试。电化学测试结果表明,样品S9具有较高的放电容量、较好... 详细信息

用溶胶-凝胶法结合高温煅烧过程制备富锂正极材料Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_2,对800°C和900°C煅烧后得到的2种材料(标记为S8和S9)进行物相和形貌表征以及电化学测试。电化学测试结果表明,样品S9具有较高的放电容量、较好的循环稳定性和较小的电荷转移电阻。样品S9在0.1 C(25 m A·g^(-1))时的首次充电容量为345.0 m A·h·g^(-1),首次放电容量为273.9 m A·h·g^(-1),首次库伦效率为79.4%。1 C时,首次放电容量为188.1 m A·h·g^(-1),循环30周后放电容量为173.3 m A·h·g^(-1),容量保持率为92.1%。结果表明,尽管富锂正极材料R-3m层状结构在800°C煅烧后已经形成,但仍需要经过更高温度煅烧,以提高锂离子和过渡金属离子在各自层中的有序度,从而有效地提高材料的电化学性能。

关键词：锂离子电池富锂正极材料溶胶-凝胶法电化学性能煅烧温度

Performance Evaluation and Optimization of Hierarchical Routing in SDN Control Plane

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Chinese Journal of Electronics 2018年第2期27卷 342-350页

作者： HU Jie LIN Chuang ZHANG puheng Department of Computer Science and Technology Tsinghua University

In Software defined networking(SDN), distributed control plane is becoming a promising solution to tackle with scalability and performance. We propose a tree-like hierarchical routing architecture which employs the divide-and-conquer strategy to enhance routing performance on the distributed control plane. To evaluate and optimize the performance of the hierarchical architecture,we apply queuing theory to modeling routing request arrival and processing, and derive an explicit expression of the routing response time. Then we formulate the resource allocation problem in the hierarchical architecture as an optimization problem whose objective is to minimize the response time subject to queue stability and resource constraints. Using the Karush-Kuhn-Tucker(KKT) condition we obtain the optimal resource allocation policy. Based on that, we theoretically prove that the response time under the hierarchical routing architecture is strictly less than that under the Peer to peer(P2 P) architecture. Finally,we perform numerical analyses to confirm the conclusions.

关键词： Software defined networking(SDN) Control plane Routing Performance evaluation Resource allocation

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不同改良措施对黄泛区沙性土壤性能影响研究

水利技术监督 2023年第5期 139-142页

作者：黄埔恒山东省菏泽市河湖流域管理服务中心山东菏泽274000

为有效改善黄泛区沙性土壤的结构,提升保水保肥能力,文章对某黄泛区沙土进行了多种改良措施试验,并对改良前后的土壤结构和入渗特性进行对比。结果表明:采取施复合肥+污泥生物质炭的改良效果最好,在该措施下0~20cm、20~40cm厚度沙土的PA... 详细信息

为有效改善黄泛区沙性土壤的结构,提升保水保肥能力,文章对某黄泛区沙土进行了多种改良措施试验,并对改良前后的土壤结构和入渗特性进行对比。结果表明:采取施复合肥+污泥生物质炭的改良效果最好,在该措施下0~20cm、20~40cm厚度沙土的PAD指数仅为9%和10%,土壤容重仅为1.49和1.59g/cm^(3),孔隙比为2.82和2.21,土壤含水量为8.5%和7%,土壤贮水量为94.99mm和85.99%,初始入渗率和稳定入渗率分别为8.76和5.28mm/min,各项指标均较原状沙土有较为明显的改善。

关键词：黄泛区沙性土壤改良措施土壤结构入渗特性

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盾构切桩后桩基对管片作用力确定及控制措施

隧道建设（中英文） 2020年第S2期40卷 122-127页

作者：白东锋荆玉明薛普恒中交第一公路勘察设计研究院有限公司陕西西安710000 辽宁省交通规划设计院有限责任公司辽宁沈阳110166

为获得盾构切除桥梁桩基后残桩对管片的竖向荷载及残桩的承载力,评估切桩后桥梁和盾构隧道结构安全,开展残桩对管片作用力的计算分析。首先,分析盾构切桩后残桩对管片作用力的影响因素,包括桩长减短、施工扰动及桥桩竖向刚度变化等。然... 详细信息

为获得盾构切除桥梁桩基后残桩对管片的竖向荷载及残桩的承载力,评估切桩后桥梁和盾构隧道结构安全,开展残桩对管片作用力的计算分析。首先,分析盾构切桩后残桩对管片作用力的影响因素,包括桩长减短、施工扰动及桥桩竖向刚度变化等。然后,在考虑这些因素影响的基础上建立残桩承载能力和所受竖向荷载计算公式,并以具体工程为例进行计算对比,结果表明:本工程残桩承载力无法满足所受竖向荷载,需进行残桩周围地基加固;通过对地基注浆加固计算,残桩承载力可满足竖向荷载,能够保证管片和上部桥梁结构安全。最后,根据理论和实例分析,提出减小残桩对管片受力影响的施工控制措施,包括减小施工扰动、提高桩侧摩阻力及加强管片配筋和螺栓强度等。

关键词：盾构隧道盾构切桩管片作用力控制措施

不同水闸调控方式对下游富营养演变的影响研究

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水利科学与寒区工程 2023年第9期6卷 20-23页

作者：黄埔恒山东省菏泽市河湖流域管理服务中心山东菏泽274000

为了解闸坝水闸调控对下游河流水体富营养演变的规律,基于MIKE 21构建起闸控河流二维富营养化模型,并结合现场试验数据,对不同水闸调控方式下的富营养演变过程进行对比。结果表明:当采取5孔10 cm开度时,水体中溶解相和悬浮相污染物会沉... 详细信息

为了解闸坝水闸调控对下游河流水体富营养演变的规律,基于MIKE 21构建起闸控河流二维富营养化模型,并结合现场试验数据,对不同水闸调控方式下的富营养演变过程进行对比。结果表明:当采取5孔10 cm开度时,水体中溶解相和悬浮相污染物会沉积在底泥中,导致底泥相污染物含量大幅度提升,而当增加闸孔开启数量和开度时(集中下泄方式),下游水体溶解相和悬浮相的污染物会显著增加;单纯采取水闸调控方式不足以对下游富营养产生根本性的作用,还需要借助于污染物削减方式对水体中污染物进行清除,才能从根本上解决闸坝下游的水体富营养问题;研究结果对于闸坝下游水环境和水生态治理问题具有一定的指导作用。

关键词：水闸调控方式二维富营养化模型溶解相悬浮相底泥相

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大跨扁平浅埋隧道安全风险评估研究

山西建筑 2016年第11期42卷 177-178页

作者：杨绍战薛普恒中交第一公路勘察设计研究院有限公司陕西西安710075

以龙头山隧道为例,对该隧道主要风险事件进行了分段分析与综合评价,并提出了降低风险的对策,指出在采取合理的风险控制措施后,可以大大降低隧道工程建设风险,将隧道总体风险水平控制在可接受范围。

关键词：隧道风险评估围岩风险事件

骨髓潜伏态巨细胞病毒痕量反复激活诱导免疫衰老的单细胞RNA测序技术研究进展

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中国比较医学杂志 2020年第9期30卷 91-95页

作者：刘普恒韩辉王宇虹哈尔滨医科大学附属第一医院老年医学科哈尔滨100081

全球老龄化是一个严峻的公共健康问题。免疫衰老作为衰老的核心机制之一,在抗衰老战略中发挥重要的作用。巨细胞病毒(Cytomegalovirus,CMV)是一个大型疱疹病毒,在人群中普通携带。它一旦进入人体,即终生潜伏在骨髓干细胞中,因此,老年人... 详细信息

全球老龄化是一个严峻的公共健康问题。免疫衰老作为衰老的核心机制之一,在抗衰老战略中发挥重要的作用。巨细胞病毒(Cytomegalovirus,CMV)是一个大型疱疹病毒,在人群中普通携带。它一旦进入人体,即终生潜伏在骨髓干细胞中,因此,老年人群的CMV病毒携带率接近100%。这些终生潜伏在骨髓干细胞的CMV,通过一个分化依赖的痕量激活模式,反复诱导机体的T细胞免疫应答,产生大量CMV特异性“无效”克隆扩增,逐步消耗了纯真T细胞储备池的多样性,伴有持续低水平炎性细胞因子的表达,累积成为免疫衰老的核心诱导机制。由于骨髓干细胞获取困难,加上骨髓干细胞内的CMV潜伏比例很低,CMV痕量反复激活的表达量也很低,潜伏态CMV诱导免疫衰老的检测与评估常规很难获取。伴随单细胞RNA测序技术的发展,针对骨髓干细胞潜伏态CMV痕量激活诱导免疫衰老的机制研究,得到了一定程度的推进。

关键词：巨细胞病毒潜伏再激活免疫衰老单细胞测序