Analysis and modeling of resistive switching mechanisms oriented to resistive random-access memory

With the progress of the semiconductor industry,the resistive random-access memory(RAM) has drawn increasing attention.The discovery of the memristor has brought much attention to this study.Research has focused on the resistive switching characteristics of different materials and the analysis of resistive switching mechanisms.We discuss the resistive switching mechanisms of different materials in this paper and analyze the differences of those mechanisms from the view point of circuitry to establish their respective circuit models.Finally,simulations are presented.We give the prospect of using different materials in resistive RAM on account of their resistive switching mechanisms,which are applied to explain their resistive switchings.     

微量元素添加剂促进赤霉素分泌及赤霉素速测技术研究

研究了赤霉素快速分光光度法测定，并首次应用于微量元素添加剂促进赤霉素分泌的研究．结果表明，固体发酵培养基中添加了硼酸、磷酸二氢钾、硫酸镁对促进赤霉素分泌有重要作用．结合使用作者多次筛选得到的高产赤霉素产生菌株等措施，终于研制得含量高达约１５０００×１０－５的固体粉剂，其含量高出一般固体发酵产品的３～５倍．     

耀斑后环状日珥中的物质运动

利用太阳光谱分光照相仪和3CS密度计,拍摄并测量了耀斑后环状日珥不同时刻的速度场。根据速度场的基本观测特征,文中指出,在耀斑后磁力线重连所形成的环状日珥中,等离子体物质将在重力和环中磁场应力的作用下,从环顶沿螺旋形磁力线下落。由此所得环状日珥中速度的理论分布图与观测结果基本相符。     

Experimental Evidence of Topological Surface States in Mg_3Bi_2 Films Grown by Molecular Beam Epitaxy

Nodal line semimetal(NLS) is a new quantum state hosting one-dimensional closed loops formed by the crossing of two bands. The so-called type-Ⅱ NLS means that these two crossing bands have the same sign in their slopes along the radial direction of the loop, which requires that the crossing bands are either right-tilted or left-tilted at the same time. According to the theoretical prediction, Mg_3Bi_2 is an ideal candidate for studying the type-Ⅱ NLS by tuning its spin-orbit coupling(SOC). High-quality Mg3 Bi2 films are grown by molecular beam epitaxy(MBE). By in-situ angle resolved photoemission spectroscopy(ARPES), a pair of surface resonance bands around the■ point are clearly seen. This shows that Mg_3Bi_2 films grown by MBE are Mg(1)-terminated by comparing the ARPES spectra with the first principles calculations results. Moreover, the temperature dependent weak anti-localization effect in Mg_3Bi_2 films is observed under magneto-transport measurements, which shows clear two-dimensional(2 D) e-e scattering characteristics by fitting with the Hikami–Larkin–Nagaoka model. Therefore, by combining with ARPES, magneto-transport measurements and the first principles calculations, this work proves that Mg_3Bi_2 is a semimetal with topological surface states. This paves the way for Mg_3Bi_2 to be used as an ideal material platform to study the exotic features of type-Ⅱ nodal line semimetals and the topological phase transition by tuning its SOC.     

微肥“稻多收”1995年滁州市应用试验报告

示范了１３３３０×６６７ｍ２施用微肥“稻多收”增产效果，平均每６６７ｍ２增产稻谷７０ｋｇ，共增产稻谷９３３０００ｋｇ，扣除每６６７ｍ２农业成本１２元．净增效益２１１．６８万元．还取得了科教工作者直接投身于经济建设的几点经验体会。     

Speeding up the MATLAB complex networks package using graphic processors

The availability of computers and communication networks allows us to gather and analyse data on a far larger scale than previously. At present, it is believed that statistics is a suitable method to analyse networks with millions, or more, of vertices. The MATLAB language, with its mass of statistical functions, is a good choice to rapidly realize an algorithm prototype of complex networks. The performance of the MATLAB codes can be further improved by using graphic processor units (GPU). This paper presents the strategies and performance of the GPU implementation of a complex networks package, and the Jacket toolbox of MATLAB is used. Compared with some commercially available CPU implementations, GPU can achieve a speedup of, on average, 11.3×. The experimental result proves that the GPU platform combined with the MATLAB language is a good combination for complex network research.     

太阳活动区中电流的作用

本文基于1989年3月超级大活动区AR 53 95中几个与活动区电流密切相关的观测事实,认为导致耀斑发生的直接关键因素在于活动区电流的增强。在这种模式下,分析了耀斑现象的贮能过程,井建立了活动区电流暗条的运动方程和能量方程。根据该活动区的观测数据,从理论上计算和讨论了由活动区电流增强导致耀斑出现的可能性。所得结果与观测基本相符。     

日面Hα耀斑环的动力学问题

本文利用云南天文台对1981年5月16日3B级双带耀斑进行SSHG(太阳光谱分光照相仪)观测和Hα单色光观测的结果,以及日本火鸟卫星对同一耀斑的X射线观测资料,定量讨论了日面Hα耀斑环的动力学过程。发现Hα耀斑环环顶存在着数量级达几百公里的初速度,且环中物质的下落是减速的。文中指出这是关系到耀斑环物理机制的一个值得探讨的动力学问题。     

Betweenness-based algorithm for a partition scale-free graph

Many real-world networks are found to be scale-free. However, graph partition technology, as a technology capable of parallel computing, performs poorly when scale-free graphs are provided. The reason for this is that traditional partitioning algorithms are designed for random networks and regular networks, rather than for scale-free networks. Multilevel graph-partitioning algorithms are currently considered to be the state of the art and are used extensively. In this paper, we analyse the reasons why traditional multilevel graph-partitioning algorithms perform poorly and present a new multilevel graph-partitioning paradigm, top down partitioning, which derives its name from the comparison with the traditional bottom-up partitioning. A new multilevel partitioning algorithm, named betweenness-based partitioning algorithm, is also presented as an implementation of top-down partitioning paradigm. An experimental evaluation of seven different real-world scale-free networks shows that the betweenness-based partitioning algorithm significantly outperforms the existing state-of-the-art approaches.     

常压氢化菜油脚来源不饱和脂肪酸制硬脂酸

由植物油厂副产油脚料能得到廉价的混合脂肪酸。在中国 ,这是一个可持续获得的庞大资源。迄今为止 ,对此类脂肪酸的利用始终没有比较好的办法 ,其中又以南方地区菜油脚酸的开发最不理想。由于菜油脂肪酸是油酸 ( C18∶ 1酸 ) ,亚油酸( C18∶ 2 酸 )和芥酸 ( C2 2∶ 1酸 )等不饱和酸的混杂体系 ,要直接利用极其困难。经多方努力 ,从菜油酸中分离出芥酸 ,用于制备聚烯烃塑料润滑剂等工作已经取得成效[1] ,但以 C18烯酸为主的脱芥脂肪酸却还要寻求出路。比较实际的办法是通过催化加氢 ,使这些脂肪酸分子中的双键饱和 (硬化 ) ,得到工业硬脂酸…