锂离子电池正极材料量LiMn2O4的研究动态

作为锂离子电池正极材料的锂锰氧化物体系因其价格便宜，无污染，安全，被认为是锂离子电池中最有发展前景的正极材料，但由于其在高温下的循环性能不好，容量衰减较快，大大影响了其商业化的进程。介绍了造成其容量衰减的主要原因，总结并比较了近来用于提高其电化学性能的几种方式——优化合成条件及合成方法，掺杂和表面修饰，以及以上几种方式相结合的方法。而将以上入种方式结合起来的方法是今后解决锂锰氧化物正极材料容量衰减的最好途径。     

锂离子正极材料重点技术专利分析

正极材料是制造锂离子电池的关键材料之一,占据电池成本的25%以上,在锂离子电池中占据核心地位。该文对锂离子正极材料进行专利信息的挖掘和数据分析,通过专利申请趋势、布局、企业专利实力对锂离子正极材料的技术专利展开分析,总结了锂离子正极材料技术的发展、企业专利实力与保护情况。同时对主要用于动力型锂离子电池中的锰酸锂正极材料进行了申请态势、竞争格局、实力排查以及技术主题和技术功效的分析,可为相关研发人员及企业开发外围专利或改进专利提供思路。     

LiNi1/3CO1/3Mn1/3O2的合成及其表征

以共沉淀氢氧化物Mi1/3Co1/3Mn1/3(OH)2和Li2CO3为原料合成了锂离子电池正极材料LiNi1/3Co1/3Mn1/3O2.用XRD、SEM和电化学性能测试对材料的结构、形貌及电化学性能进行了表征.试验结果表明,850 ℃烧结20 h所合成的LiNi1/3Co1/3Mn1/3O2样品的层状结构明显,颗粒形貌清晰,其首次放电容量达到143.8 mAhg-1,循环40次的平均容量衰减为0.72%/次,循环性能较好.循环伏安实验表明,该材料在3.9 V附近出现了一对对称性好的氧化还原峰.     

锂离子正极材料重点技术专利分析

正极材料是制造锂离子电池的关键材料之一，占据电池成本的25%以上，在锂离子电池中占据核心地位。该文对锂离子正极材料进行专利信息的挖掘和数据分析，通过专利申请趋势、布局、企业专利实力对锂离子正极材料的技术专利展开分析，总结了锂离子正极材料技术的发展、企业专利实力与保护情况。同时对主要用于动力型锂离子电池中的锰酸锂正极材料进行了申请态势、竞争格局、实力排查以及技术主题和技术功效的分析，可为相关研发人员及企业开发外围专利或改进专利提供思路。     

Al掺杂对尖晶石型LiMn2O4结构及循环性能的影响

用柠檬酸作为螯合物的载体,采用溶胶-凝胶法合成了Al3+掺杂的锂离子电池正极材料LiAlxMn2-xO4,并用XRD、SEM等多种测试手段研究了不同掺杂铝量对粉体形貌、晶体结构的影响。结果表明,800℃烧结可获得单一尖晶石结构的物相。随着Al3+掺入量的增加,LiAlxMn2-xO4的晶格常数变小,晶格更趋于完整,有利于抑制因锂的反复脱嵌而造成结构的破坏。实验表明,当掺Al量为0.05时,首次放电容量为103.8 mAh/g,25次循环后容量还有100.6 mAh/g,容量衰减仅为3.08%。该正极材料具备高的容量和优异的循环性能。     

废旧锂离子电池回收利用研究进展

综述了近几年来国内外锂离子正极材料的发展概况及贵重金属回收利用现状。着重概述了钴酸锂正极材料的预处理方法、回收提纯钴元素的工艺技术现状。总结了多种从废旧锂离子电池中浸出和提纯工艺技术的优缺点,对下一步废旧锂离子电池回收利用研究提出了建议。     

Cr、Al掺杂尖晶石锂锰氧化物材料研究

二次锂电池是以金属锂为负极 (阳极 ) ,适合于Ｌｉ+迁移的锂盐溶液为电解质 (非水溶液或固体电解质 ) ,Ｌｉ+可以方便嵌入、脱出的材料为正极 (阴极 )的电池体系。二次锂离子电池是从二次锂电池的研究、开发、改进过程中产生和发展而来的。对于锂离子电池 ,尖晶石ＬｉＭｎ2 Ｏ4是最吸引人的 ,它可同碳对电极组成高能量密度的锂离子电池 ,它具有相对较高的电池输出电压 ( 3 75Ｖ)和最高的析氧温度( 40 0℃ ) ,较ＬｉＣｏＯ2 、ＬｉＮｉＯ2 稳定。尖晶石ＬｉＭｎ2 Ｏ4在内部有较好的循环特性 ,但随着充放电循环的进行 ,其容量缓慢衰减 ,且具…     

锂电池的发展与前景

介绍了电池的发展过程，锂离子电池的正极材料和负极材料及电解质的发展概况以及当今锂离子电池发展所面临的问题和发展前景。     

生物质炭基硫正极材料的制备及其电化学性能研究

锂硫电池因较高的理论比容量和能量密度在动力汽车和储能装置等领域具有广阔的应用前景,因此设计制备低成本和高性能的锂硫电池正极材料具有重要研究价值。以廉价易得且可再生的红薯淀粉为生物质碳源,经水热反应、高温石墨化以及碱活化等方法,得到表面富含多孔的碳材料。再将其与硫单质按不同比例混合,通过熔融扩散法制备锂硫电池正极材料。运用X射线衍射、氮气吸附、X射线光电子能谱等手段对材料的表面形貌和结构进行了表征。另外,对利用该材料组装的电池进行电化学测试,结果显示碳/硫比为1∶2时,电池具有更优良的循环及倍率等电化学性能,其在0.1 A g^-1下的初始放电容量为1 470.6 mAhg^-1,恒电流循环300圈后容量为754.6 mAhg^-1;并在3 C下的放电容量达到864.1 mAhg^-1。研究成果为自然界中生物质转化为功能性碳材料提供了一种新思路。     

LiFePO4的电化学性能和锂离子扩散研究

采用溶胶凝胶法制得了锂离子电池正极材料LiFePO4/C。样品在0.5 C(1 C=150 mA/g)放电倍率下,40次充放电循环后的容量为153.3 mAh.g-1。对样品的元素含量进行了精确分析,结果与理论值接近。基于阻抗的两种理论模型,计算了锂离子扩散系数,样品1和样品2的锂离子扩散系数分别为1.7×10-12cm2/s和3.8×10-12cm2/s。     

Diversifying Ethnicity in Australia's Population and Environment Debates

Population–environment debates in Australia are at an impasse. While the ability of this continent to sustain more migrants has attracted persistent scrutiny, nuanced explorations of diverse migrant cultures and their engagements with Australian landscapes have scarcely begun. Yet as we face the challenges of a climate changing world we would undoubtedly benefit from the most varied knowledges we can muster. This paper brings together three arenas of environmental debate circulating in Australia—the immigration/carrying capacity debate, comparisons between Indigenous and Anglo-European modes of environmental interaction, and research on household sustainability dilemmas—to demonstrate the exclusionary tendencies of each. We then attempt to reorient them in productive ways, by attending to the complexity of environmental sustainability in a context of immense ethnic diversity. Attentiveness to ethnic diversity offers three important insights: (1) Anglo-European Australian understandings of nature and environmentalism are culturally specific, but other perspectives are possible; (2) tensions can arise when ethnic differences in environmental attitude or practice come into contact; and (3) cultural environmental research offers scope to identify ethnically diverse vernacular sustainability practices that should be supported. Each of these threads requires attention in a context where population–environment debates often overlook cultural complexity, and readily spiral into strident anti-immigration sentiments.     

The Situation with College Express Packaging Waste and Recycling Recommendations—Taking the Graduate School of the Chinese Academy of Social Sciences as an Example

Questionnaires and interviews are employed in this paper to investigate and analyze the situation with respect to express packaging waste at the Graduate School of the Chinese Academy of Social Sciences (GCASS). The survey results show that: (1) the campus receives a large number of express packages and there is, in turn, a considerable amount of packaging waste; (2) there are four main types of express packaging materials: paper packaging, plastic bags, wrapping tapes and package fillers; (3) neither the students nor the school perform well in the recycling of express packaging waste; (4) the samples investigated in this paper can be divided into four categories by cluster analysis, and the author infers from this that the colleges and universities with a large proportion of female students should pay more attention to the issue of recycling of express packaging waste. Several suggestions are presented based on the research results: (1) establishing a campus waste recycling system is the most efficient way to solve the problem of express packaging waste at GCASS; (2) we should advocate for green packaging and manage it from the source of waste generation because most of the express packaging material does not easily degrade naturally, and this represents a huge hidden danger to human health and the environment; (3) the school should cultivate student awareness of environmental protection. If education and penalties are implemented together, the recovery system will run better.     

地理数据尺度转换方法研究进展

尺度问题在地理学、生态学和水文科学等众多领域都具有非常重要的地位。近年来,随着对地观测技术和地理信息科学的飞速发展,解决地理数据的尺度转换问题成为目前地理信息科学及相关研究中的热点和难点问题之一。在地理信息科学相关领域中,地图学和遥感科学研究人员从尺度概念的理解到尺度转换的理论和方法都做了大量的研究,对解决地理数据空间特征的尺度转换做出了重要的贡献。在地理数据属性特征的尺度转换研究领域,地理信息科学研究者提出的面域插值方法是解决此问题的主要方法之一。同时,在社会经济科学领域,“小区域统计学”也发展了一套相关的理论和方法,试图解决统计单元的变更问题。文章在全面回顾和比较不同研究领域解决“尺度转换”问题方法的基础上,重点介绍面域插值方法和小区域统计学的基本原理及其典型应用。     

试论环渤海节淡水产业带建设

本文从区域资源与产业结构、空间结构的协调机制出发,认为解决环渤海地区水资源短缺问题,不在于大规模压缩,调整大耗水的重化工业的发展,而在于建设滨海节淡水产业带,即将重化工业项目布局于滨海以尽可能利用海水节约淡水。本文还论述了工业大规模利用海水的可行性以及主要工业部门可利用海水趋势。     

An improved ant colony optimization (I-ACO) method for the quasi travelling salesman problem (Quasi-TSP)

Traveling salesman problem (TSP) and its quasi problem (Quasi-TSP) are typical problems in path optimization, and ant colony optimization (ACO) algorithm is considered as an effective way to solve TSP. However, when the problems come to high dimensions, the classic algorithm works with low efficiency and accuracy, and usually cannot obtain an ideal solution. To overcome the shortcoming of the classic algorithm, this paper proposes an improved ant colony optimization (I-ACO) algorithm which combines swarm intelligence with local search to improve the efficiency and accuracy of the algorithm. Experiments are carried out to verify the availability and analyze the performance of I-ACO algorithm, which cites a Quasi-TSP based on a practical problem in a tourist area. The results illustrate the higher accuracy and efficiency of the I-ACO algorithm to solve Quasi-TSP, comparing with greedy algorithm, simulated annealing, classic ant colony algorithm and particle swarm optimization algorithm, and prove that the I-ACO algorithm is a positive effective way to tackle Quasi-TSP.     

粤西地区县域城镇化发展探讨——以广东省高州市为例

受地理条件、经济基础等因素的制约,粤西地区面临着城镇化进程滞后、整体发展层次偏低等一系列问题。加速推进县域城镇化是加快粤西地区经济发展,缩小与发达地区差距的内在要求和必然选择。以高州市为例,全面总结了粤西地区县域城镇化发展的特点及存在的主要问题,并在系统分析其城镇化发展机制的基础上,提出通过完善城镇体系,加强产业集聚,提升建设品位,增强城镇自我发展能力等促进县域城镇化发展。     

基于水资源可持续利用的流域产业结构分析

本文以官厅水库流域为例，从宏观经济学角度出发，将流域水资源利用中存在的污染、浪费问题与产业结构的合理性结合起来进行研究。首次采用Fuzzy分析模型对流域产业结构进行分析，据此按发展的适宜性对流域产业进行排序；探讨了导致流域水资源利用问题的深层原因在于产业结构不合理。根据流域现状，提出了产业结构的调整方案，为流域可持续发展决策提供了依据。     

A Balanced Route Design for Min-Max Multiple-Depot Rural Postman Problem (MMMDRPP): a police patrolling case

Providing distributed services on road networks is an essential concern for many applications, such as mail delivery, logistics and police patrolling. Designing effective and balanced routes for these applications is challenging, especially when involving multiple postmen from distinct depots. In this research, we formulate this routing problem as a Min-Max Multiple-Depot Rural Postman Problem (MMMDRPP). To solve this routing problem, we develop an efficient tabu-search-based algorithm and propose three novel lower bounds to evaluate the routes. To demonstrate its practical usefulness, we show how to formulate the route design for police patrolling in London as an MMMDRPP and generate balanced routes using the proposed algorithm. Furthermore, the algorithm is tested on multiple adapted benchmark problems. The results demonstrate the efficiency of the algorithm in generating balanced routes.     

东昆仑迪木那里克铁矿地质特征与找矿标志

迪木那里克铁矿位于阿尔金大断裂南侧,矿体主要赋存于中-上奥陶统祁曼塔格群浅变质的碎屑岩-火山碎屑岩中.矿体多呈似层状、条带状产出,部分矿体塑性变形较强,矿体与地层产状基本一致,层控作用比较明显;矿石主要为条带状石英-磁铁矿和块状磁铁矿矿石;矿石品位较低(TFe=20%～40%);围岩蚀变特征明显.该铁矿属沉积变质型铁矿.综合研究发现,可利用矿区地层、构造、岩石蚀变情况、航磁异常等作为矿区和区域找矿标志.     

Far from Being "Home Alone": The Dynamics of Accompanied Fieldwork

Despite persistent images to the contrary, most fieldworkers are accompanied. Yet, there has been limited discussion on the nature of accompanied fieldwork, particularly by geographers. Drawing on our experiences in three countries in the tropics, we discuss the dynamics of being accompanied in “the field” by our children and female co‐researchers. Specifically, we focus on issues of access and rapport; the impacts of their presence on our positionality; and the implications these have for power relations and research outcomes. We demonstrate how being accompanied entangles our personal and professional selves and can result in more egalitarian power relations as we become “observers observed”. We argue that by paying attention to the dynamics of accompanied fieldwork, there is the potential to enhance the conceptual focus of our methodological concerns and to provide a more theoretically sophisticated mode of exploring the ways in which our multiple identities intersect while in “the field”.