Analysis and estimation of learning style in Library

根据南京师范大学社科专业图书馆2016年4.22—5.22的在馆读者信息,以可反映学习状态的参数——在位人数、总占位数及吃零食、玩手机、用电脑、睡觉、交谈、学习等的人数,对该馆内读者的实时学习状态进行了抽样分析。首先,通过读者出入馆信息确定了状态参数的抽样时间为上午10—11时,并定义学风指标为学习人数除以实际在位人数;再对抽样时间点的学习状态参数及天气情况建立模型。通过建立负二项回归模型、广义线性模型,并应用稳健性检验方法得到了在馆读者的实时学习状态。结果表明：学风指标区间为60%-80%,处于良好状态;8—11时的进馆人数与学习氛围呈正相关关系,天气因素对馆内读书人数有较大影响,其是无法改变的外生变量,可通过改善图书馆的硬件设施与服务质量提升进馆人数;模型估计的学风指标与实际情况基本一致。Based on the present readers＇ information from Nanjing Normal University professional library between Apr 22 th and May 22 th in 2016, the readers＇ real-time learning style are analyzed by some parameters reflecting learning status such as the present number, the total number of occupied seats, and the numbers of who are eating snack, playing phones, using computer, sleeping, talking and learning. Firstly, the readers＇ entrance information are used to ensure that the sampling time of status parameters is 10—11 a.m. each day, and we define the learning style index as the number of who are learning divided by the real number of who are present seated. Secondly, a model is put forward based on the learning status parameters and weather conditions from sampling time point. By the Negative Binomial Regression, Generalized Linear Model and robust test, the real-time learning status of present readers is put forward. The results show that the interval of the learning style is 60%-80%, which is good; there is a positive correlation between the entrance number of 8—11 o＇clock and the learning atmosphere. The weather condition is an unchanged exogenous variable that affects the number of readers. The improved library＇s hardware facilities and service quality can increase the entrance number. The index made by the model is basically consistence with the actual circumstance.国家自然科学基金（61374080）; 江苏省自然科学基金（BR20161552

基于纳米间隔电极对的DNA分子结电输运的研究进展

脱氧核糖核酸分子是一类重要的生物分子,在生物医学领域之外,该类分子还因为其所具有的独特的双螺旋结构以及长程输运能力,在分子电子学领域也引起了研究者的极大兴趣.本文综述了近年来基于纳米间隔电极对构筑分子结这一研究范式,在构筑脱氧核糖核酸分子结以及研究后者的电输运性质等方面的研究进展.依据研究者所采用的不同纳米间隔电极对构筑技术,主要围绕裂结法和切割法两大类研究方法所展开.前者主要包括扫描隧道显微镜裂结法、导电原子力显微镜法、机械可控裂结法,后者则主要包括碳纳米管切割法、石墨烯切割法、硅纳米线切割法.在梳理不同实验方法的发展脉络、比较不同实验方法的各自特点的基础上,对一些具有代表性的关于脱氧核糖核酸分子结的研究工作进行了重点介绍,探讨了脱氧核糖核酸分子结所具有的与常规小分子体系所不同的特殊电学性质,同时对该领域的未来发展进行了展望.中南大学湘雅三医院“新湘雅人才工程”(No.20150203)国家重点研发计划(No.2017YFA0204902)国家自然科学基金(No.21722305)资助~

一种新颖的低温漂高电源抑制比带隙基准源

介绍了一种基于0.6μm BiCMOS工艺的高阶曲率补偿、高电源抑制比的带隙基准源。利用三极管电流增益的温度特性来实现低温度系数,并且不需要额外的电路。采用一种新颖的电压预调整器来实现高电源抑制比。结果表明,该带隙基准源在-40℃120℃内的温度系数为2.83×10-6/℃,在低频、100kHz、1MHz处的电源抑制比分别为-127、-98、-67dB。最低工作电压为1.8V,在1.83V电源电压范围内的线性调整率为4×10-5/V,功耗为57μW

Caging Porous Co-N-C Nanocomposites in 3D Graphene as Active and Aggregation-Resistant electrocatalyst for Oxygen Reduction Reaction

氧还原反应是决定燃料电池、金属-空气电池等多种新型清洁能源存储与转化技术之性能与应用的关键反应. 铂及其合金是目前催化活性最好的氧还原反应催化剂，但其高昂的成本限制了规模化应用. 在小尺寸效应作用下，微纳米结构催化剂颗粒在电极制备与电化学反应过程中的团聚限制了催化剂本征催化活性的充分发挥. 本文基于喷雾热解技术，发展了一种基于内嵌钴/氮掺杂多孔碳三维石墨烯笼的高活性、抗团聚非贵金属氧还原反应催化剂. 此结构中，金属有机骨架化合物ZIF-67衍生的钴/氮掺杂多孔碳纳米结构是催化氧还原反应的活性中心，包覆其外的三维石墨烯笼不仅可在钴/氮掺杂碳纳米结构之间构建连续的三维载流子传导网络，且可高效抑制其在催化剂制备与电化学反应过程中的团聚与活性损失. 在碱性电解液中，此类非贵金属催化剂表现出可与铂基催化剂媲美的氧还原反应活性和优异的稳定性.Oxygen reduction reaction (ORR) is the cornerstone reaction of many renewable energy technologies such as fuel cells and rechargeable metal-air batteries. The Pt-based electrocatalysts exhibit the highest activity toward ORR, but their large implementation is greatly prohibiting by unaffordable cost and inferior durability. During electrode manufacturing and electrochemical reaction, severe aggregation of catalyst nanoparticles induced by size effect further limits the operational performance of electrocatalysts. We report a new strategy for fabrication of active and aggregation-resistant ORR electrocatalyst by caging metal-organic frameworks derived Co-N-C nanocomposites in permeable and porous 3D graphene cages via sprayed drying the mixed colloids of ZIF-67 nanoparticles and graphene oxide, followed by annealing. The 3D graphene cages around Co-N-C nanocomposites not only provide a continuous conductive network for charge transfer, but also prevent the active phase from aggregation during electrode manufacturing and electrochemical reactions. When evaluated as an ORR electrocatalyst, the material exhibited comparable activity but superior stability to commercial Pt/C catalyst in an alkaline electrolyte.国家自然科学基金优秀青年基金（No. 51522203）及面上项目（No. 51772040）、霍英东青年教师基金（No. 151047）与中央高校基本科研业务费（No. DUT18LAB19）资助作者联系地址：精细化工国家重点实验室，辽宁省能源材料化工重点实验室，大连理工大学化工学院，甘井子区凌工路2号，大连，116024Author's Address: State Key Lab of Fine Chemicals, Liaoning Key Lab for Energy Materials and Chemical Engineering, Carbon Research Laboratory, Dalian University of Technology, Dalian 116024, China通讯作者E-mail：[email protected]；[email protected]

东北亚区域可持续发展的主要科学问题探讨(英文)

东北亚各国自然地域相连,社会经济联系密切,形成了东北亚独特的经济地域系统。在全球变化背景下,深入探讨东北亚区域可持续发展面临的主要科学问题具有重要的理论与实践意义。东北亚区域生态经济巨系统的结构、功能和地域分异规律及其动态演变格局是该区域可持续发展的基本科学问题;驱动力因子是该区域可持续发展研究的重要问题;跨境区域社会经济可持续发展模式是该区域可持续发展的核心问题和归宿,而东北亚区域可持续发展支撑平台建设是重要的技术支撑和保障。东北亚、中亚地区作为一个资源、环境、经济和社会复杂巨系统,其可持续发展还有许多重要科学问题,需要该区域科学家联合攻关,共同探索