检索结果-南通市图书馆

云南高原湖泊群的统计学聚类识别及水质响应模式研究

在线全文

学校读者我要写书评

暂无评论

北京大学学报（自然科学版） 2017年第5期53卷 948-956页

作者：蒋青松梁中耀赵磊李玉照吴思枫刘永水沙科学教育部重点实验室北京大学环境科学与工程学院北京100871 云南高原湖泊流域污染过程与管理重点实验室昆明650034

为探究湖泊群水质变量的响应模式,构建适用于监测数据匮乏的湖泊群聚类和响应模式识别方法体系(PCA-BN),包括4个步骤:数据预处理、PCA降维与湖泊聚类、贝叶斯网络构建及参数学习、湖泊响应关系模拟。以云南高原湖泊群为例开展研究,结果... 详细信息

为探究湖泊群水质变量的响应模式,构建适用于监测数据匮乏的湖泊群聚类和响应模式识别方法体系(PCA-BN),包括4个步骤:数据预处理、PCA降维与湖泊聚类、贝叶斯网络构建及参数学习、湖泊响应关系模拟。以云南高原湖泊群为例开展研究,结果表明:所研究的26个湖泊可分为两类;由于第一类湖泊受到的人为干扰更严重,因而叶绿素a对总氮和总磷的响应比第二类湖泊更敏感;第一类湖泊表层水温高,溶解氧趋近饱和,随叶绿素a变化不显著,第二类湖泊溶解氧随叶绿素a升高而显著升高;两类湖泊的透明度与叶绿素a的关系一致。

关键词：湖泊群水质聚类响应模式主成分分析贝叶斯网络

Synergy effect of regulated li-plating and functional solid electrolyte interphase on graphite anodes

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第9期17卷 8077-8085页

作者： Panpan Wang Baojia Xia Jianling li State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Shanghai Institute of Microsystem and Information Technology Chinese Academy of SciencesShanghai 201800China

The growth of li dendrites poses potential safety hazard to lithium-ion batteries(liBs),and eliminating li dendrites thoroughly stills face tough difficulties ***,regulating li-plating is a critical optimization-direction to address the ***,a“graphite-li hybrid”anode with high reversibility is realized under the constant-capacity lithiation(CCL).Within CCL,the uniform distribution of li-plating on the graphite surface is successfully *** evolution in different states of solid electrolyte interphase(SEI)is investigated in detail to study the interaction between the potentials and impedance during the process of liintercalation and *** the potential below 0 V and the state of charge(SOC)of 110%relative to the theoretical capacity,the F-rich SEI with high stability is constructed to hinder the emergency of li dendrites and maintain the intact structure of graphite anode under long *** cell presents more than 100%Coulombic efficiency(CE)with the 900 cycles,demonstrating the reversible li-plating and the utilization of *** the CCL half-cell provides a good cycling performance and specific capacity of 900 cycles at 0.5 C,it is attributed to the synergy effect of stable inorganic-rich SEI and regulated active li-plating.

关键词： "graphite-li hybrid"anode li-plating reversibility solid electrolyte interphase(SEI)

Robust chemo-mechanical stability of additives-free SiO2anode realized by honeycomb nanolattice for high performance li-ion batteries

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第10期35卷 468-472页

作者： Xinpin Pan Yongjian Cui Zhe Wang Bowen li Hailong Wang Jian Hao Feng li Jing li Advanced Energy Storage Materials Lab School of Materials and New Energy Ningxia University School of Chemistry and Chemical Engineering Ningxia University

Silicon-based anodes including Si, Si Oxand SiO2could deliver ultra-large capacities, but degrade fast owing to huge volume change and low conductivity. Generally, large amounts of elastic binder and conductive additives were composited with nanosized silicon-based materials to yield reasonable cycling stability, which nevertheless not only decrease specific capacity but also induce inhomogeneous lithiation/delithiation as well as uneven stress variations. Artificial nanolattice has exhibited superior mechanical properties which could be ideal structure for silicon-based anodes, but yet faces challenges in integration of chemical reactivity, conductivity and mechanical stability. Herein, we fabricate artificial SiO2honeycomb nanolattice consisting of numerous nanoscale SiO2cells interconnected by through-holes,and conformal coating of highly graphitic carbon on the nanolattice is achieved through in situ catalytic graphitization. Moreover, the nanolattice is firmly bonded on Cu substrate through atomic interdiffusion irrespective of surface roughness. This unique structure allows fast charge transportation and homogeneous lithiation/delithiation throughout the micron-meter nanolattice, which results in excellent stability and large reversible capacity over 500 cycles at 1 A/g. The results highlight design and constructing artificial nanolattice can be an effective way to prevent chemo-mechanical degradation of silicon-based anode materials.

关键词： Conductivity li-ion batteries Nanolattice SiO2 anode Stability

Highly-chlorinated inert and robust interphase without mineralization of oxide enhancing high-rate li metal batteries

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第6期35卷 239-243页

作者： Long li Kang Yang Chenpeng Xi Mengchao li Borong li Gui Xu Yuanbin Xiao Xiancai Cui Zhiliang liu lingyun li Yan Yu Chengkai Yang Key Laboratory of Advanced Materials Technologies International(HongKong Macao and Taiwan)Joint Laboratory on Advanced Materials TechnologiesSchool of Materials Science and EngineeringFuzhou UniversityFuzhou 350108China College of Material Sciences and Chemical Engineering Harbin Engineering UniversityHarbin 150001China

Side reactions and dendrite growth triggered by the unstable interface and inhomogeneous deposition have become the biggest obstacle to the commercialization for lithium metal *** this study,a highly-chlorinated organic-inorganic hybrid interfacial protective layer is developed by rationally tuning the interfacial passivation and robustness to achieve the convenient and efficient li metal *** polyvinyl chloride(PVC)can effectively resist water and oxygen,which is confirmed by density functional *** organic-dominant solid electrolyte interphases(SEI)with lithium chloride are investigated by the X-ray photoelectron spectroscopy(XPS)with little mineralization of oxide,such as li_(2)O and li_(2)CO_(3).With such artificial SEI,a uniform and dense lithium deposition morphology are formed and an ultra-long stable cycle of over 500 h are achieved even at an ultra-high current density of 10 m A/cm^(2).Moreover,the simple and convenient protected anode also exhibits excellent battery stability when paired with the liNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)and liFePO_(4)(LFP)cathode,showing great potential for the commercial application of lithium metal batteries.

关键词： Highly-chlorinated Water/oxygen resistance Stable interphase Dendrite-free lithium metal batteries High-rate

在线全文

学校读者我要写书评

暂无评论

浅水湖泊生态系统稳态转换的阈值判定方法

生态学报 2013年第11期33卷 3280-3290页

作者：李玉照刘永赵磊邹锐王翠榆郭怀成北京大学环境科学与工程学院水沙科学教育部重点实验室云南省高原湖泊流域污染过程与管理重点实验室 Tetra Tech Inc.10306 Eaton PlaceSte 340FairfaxVA 22030USA

浅水湖泊生态系统对人类干扰的反应会随着干扰力度的改变或增强而出现突然的变化,即发生稳态转换;对其机理和驱动机制的揭示将有助于对湖泊富营养化的控制及恢复。基于"多稳态"理论的稳态转换研究已广泛开展,但对浅水湖泊生态系统稳态... 详细信息

浅水湖泊生态系统对人类干扰的反应会随着干扰力度的改变或增强而出现突然的变化,即发生稳态转换;对其机理和驱动机制的揭示将有助于对湖泊富营养化的控制及恢复。基于"多稳态"理论的稳态转换研究已广泛开展,但对浅水湖泊生态系统稳态转换的驱动机制结论各异,采用的阈值判定方法相差很大,主要有实验观测、模型模拟和统计分析3种。实验观测多关注少数特定指标,指标筛选过程复杂且工作量大;模型模拟虽能从较为全面的尺度上理解生态系统稳态变化的特征和主要机理过程,但在模型误差和不确定性的处理等问题上尚存在不足;统计分析方法基于对长时间序列数据的统计变化规律分析,用以判断或者预警稳态转换现象的发生,是目前最为常用的方法。目前稳态转换领域的研究大都是对已发生的稳态转换进行机制分析或过程反演,对未来预测与预警的问题仍然亟需加强。

关键词：浅水湖泊稳态转换驱动机制阈值判定统计分析

Accelerating lithium-sulfur battery reaction kinetics and inducing 3D deposition of li_(2)S using interactions between Fe_(3)Se_(4)and lithium polysulfides

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第8期95卷 540-553,I0012页

作者： Yihan lin liheng li Longjie Tan Yongliang li Xiangzhong Ren Peixin Zhang Chuanxin He lingna Sun College of Chemistry and Environmental Engineering Shenzhen UniversityShenzhen 518060GuangdongChina

Although lithium-sulfur batteries(LSBs)exhibit high theoretical energy density,their practical application is hindered by poor conductivity of the sulfur cathode,the shuttle effect,and the irreversible deposition of li_(2)*** address these issues,a novel composite,using electrospinning technology,consisting of Fe_(3)Se_(4)and porous nitrogen-doped carbon nanofibers was designed for the interlayer of *** porous carbon nanofiber structure facilitates the transport of ions and electrons,while the Fe_(3)Se_(4)material adsorbs lithium polysulfides(liPSs)and accelerates its catalytic conversion ***,the Fe_(3)Se_(4)material interacts with soluble liPSs to generate a new polysulfide intermediate,li_(x)FeS_(y)complex,which changes the electrochemical reaction pathway and facilitates the three-dimensional deposition of li_(2)S,enhancing the reversibility of *** designed LSB demonstrates a high specific capacity of1529.6 mA h g^(-1)in the first cycle at 0.2 *** rate performance is also excellent,maintaining an ultra-high specific capacity of 779.7 mA h g^(-1)at a high rate of 8 *** investigation explores the mechanism of the interaction between the interlayer and liPSs,and provides a new strategy to regulate the reaction kinetics and li_(2)S deposition in LSBs.

关键词： lithium-sulfur batteries Polysulfide intermediates li_(2)S electrodeposition Interlayers Electrostatic spinning Adsorption Catalysis

典型云南高原湖泊叶绿素a与影响因子的定量关系及对比分析

在线全文

学校读者我要写书评

暂无评论

环境科学学报 2015年第2期35卷 402-410页

作者：李玉照颜小品吴桢刘永郭怀成赵磊贺彬北京大学环境科学与工程学院水沙科学教育部重点实验室北京100871 云南高原湖泊流域污染过程与管理重点实验室昆明650034

湖泊富营养化的影响因子涉及水文、物化、生物等多方面,具有复合性和非线性特征,定量化其与影响因素间的相关关系有助于识别影响湖泊营养状态的关键因子,可以用较低的成本、较短的时间达到理想的控制效果.云南高原湖泊具有易发生富营养... 详细信息

湖泊富营养化的影响因子涉及水文、物化、生物等多方面,具有复合性和非线性特征,定量化其与影响因素间的相关关系有助于识别影响湖泊营养状态的关键因子,可以用较低的成本、较短的时间达到理想的控制效果.云南高原湖泊具有易发生富营养化的自然和气候特征,对其富营养化发生条件及影响因子的分析可为科学的控制决策提供参考.本文选取云南滇池、程海、抚仙湖和异龙湖4个高原湖泊,比较湖泊自然特征与流域社会经济条件的异同;构建包括绝对主成分多元线性回归分析(APCS-MLR)、结构方程模型(SEM)及人工神经网络模型(ANN)的综合分析方法,重点关注并确定浮游初级生产力的代表指标(叶绿素a,Chla)与相关影响因子间的定量相关关系.研究发现:14个湖泊中,对Chla浓度变化影响最大的均为理化因子,但在各湖中该影响的正、负性及不同理化因子的贡献权重有较大差异;2流域污染源构成的不同在一定程度上影响了入湖的氮、磷负荷,使4个湖泊表现出不同的营养盐限制性特征;3流域面积、湖泊形态及湖体水动力条件影响着营养盐在湖体中的迁移转换,造成4个湖泊富营养化的差异性特征;4对Chla与影响因子间因果关联的识别须结合深入的机理过程分析.

关键词：高原湖泊富营养化结构方程模型人工神经网络绝对主成分多元线性回归分析

Boosting the performance of liNi_(0.90)Co_(0.06)Mn_(0.04)O_(2) electrode by uniform li_(3)PO_(4) coating via atomic layer deposition

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第5期35卷 499-503页

作者： Mingjiao Lu Zhixing Wang Gui Luo Huajun Guo Xinhai li Guochun Yan Qihou li Xianglin li Ding Wang Jiexi Wang School of Metallurgy and Environment Central South UniversityChangsha 410083China BASF ShanShan Battery Materials Co. Ltd.Changsha 410006China Engineering Research Center of the Ministry of Education for Advanced Battery Materials Central South UniversityChangsha 410083China Hunan Provincial Key Laboratory of Nonferrous Value-Added Metallurgy Central South UniversityChangsha 410083China School of Physics and Chemistry Hunan First Normal UniversityChangsha 410205China National and Local Joint Engineering Laboratory for lithium-ion Batteries and Materials Preparation Technology Key Laboratory of Advanced Battery Materials of Yunnan ProvinceFaculty of Metallurgical and Energy EngineeringKunming University of Science and TechnologyKunming 650093China

Ultra-high nickel material is considered to be a promising cathode ***,with the increase of nickel content,the interfacial side reactions between the cathode and electrolyte become increasingly ***,an atomically controllable ionic conductor li_(3)PO_(4)(LPO)coating is deposited on the liNi_(0.90)Co_(0.06)Mn_(0.04)O_(2)(NCM9064)based electrode by the atomic layer deposition *** results shows that the LPO coating is uniformly and densely covered on the surface of secondary particles of NCM9064,helping to prevent the direct contact between the electrolyte and cathode during the chargingdischarging *** addition,the coating layer is electrochemically *** a result,the interfacial side reactions during the long cycle are effectively suppressed,and the solid electrolyte interphase layer at the interface is *** electrode with 20 layers of LPO deposition(ALD-LPO-20)exhibits an excellent capacity retention of 81%after 200 cycles in 2.8-4.3 V at 25℃,which is 18%higher than the unmodified material(ALD-LPO-0).Besides,the moderate LPO coating improves the rate capability and high temperature cycling performance of *** study provides a method for the modification of ultra-high nickel cathode materials and corresponding electrodes.

关键词： Ultra-high nickel material liNi_(0.90)Co_(0.06)Mn_(0.04)O_(2) Atomic layer deposition li_(3)PO_(4) Ionic conductor

Layered niobium carbide enabling excellent kinetics and cycling stability of li-Mg-B-H hydrogen storage material Layered niobium carbide enabling excellent kinetics

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第3期43卷 1153-1166页

作者： li-Wen Lu Hui Luo Guang-Xu li Yun li Xin-Hua Wang Cun-Ke Huang Zhi-QiangLan Wen-Zheng Zhou Jin Guo Mohammad Ismail Hai-Zhen liu Guangxi Novel Battery Materials Research Center of Engineering Technology Guangxi Colleges and Universities Key Laboratory of Blue Energy and Systems IntegrationSchool of Physical Science and TechnologyGuangxi UniversityNanning530004China State Key Laboratory of Featured Metal Materials and life-Cycle Safety for Composite Structures Nanning530004China School of Mechanical and Electrical Engineering Quzhou College of TechnologyQuzhou324000China Department of Materials Science and Engineering Zhejiang UniversityHangzhou310027China Faculty of Ocean Engineering Technology and Informatics Universiti Malaysia Terengganu21030Kuala NerusTerengganuMalaysia Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Nankai UniversityTianjin300071China

The li-Mg-B-H composite(2liBH_(4)+MgH_(2))has a high capacity of 11.4 wt%as a hydrogen storage ***,the slow kinetics and poor cycling stability severely restrict its practical *** this work,a layered Nb_(2)C MXene was first synthesized and then introduced to tailor the kinetics and cycling stability of the li-Mg-B-H *** milled 2liH+MgB_(2)composites were initially hydrogenated to obtain the 2liBH_(4)+MgH_(2)*** 2liBH_(4)+MgH_(2)+5wt%Nb_(2)C can release 9.0 wt%H_(2)in 30 min at 400℃,while it is only 2.7 wt%for the undoped 2liBH_(4)+MgH_(2).The dehydrogenation activation energies of MgH_(2)and liBH_(4)are 123 and 154 kJ·mol^(-1)respectively for the 5 wt%Nb_(2)C-doped composite,lower than the undoped composite(164 and 165 kJ·mol^(-1)).The 2liBH_(4)+MgH_(2)+5 wt%Nb_(2)C possesses excellent cycling stability,with the reversible capacity only slightly reduced from 9.4 wt%for the 1st cycle to 9.3 wt%for the 20th ***_(2)C keeps stable in the composite and acts as an efficient catalyst for the li-Mg-B-H *** is believed that both the layered structure and the active Nb element contribu te to the enhanced hydrogen storage performances of the li-Mg-B-H *** work confirms that the Nb_(2)C MXene with layered stru cture has a significant enhancing impact on the li-Mg-B-H hydrogen storage materials,which is different from the bulk NbC.

关键词： Hydrogen storage lithium borohydride Magnesium hydride Nb_(2)C MXene