Design study of APS-U-type hybrid-MBA lattice for mid-energy DLSR

In recent years,a new generation of storage ring-based light sources,known as diffraction-limited storage rings(DLSRs),whose emittance approaches the diffractio...     

GB 18580与JIS A 1460干燥器法测定刨花板甲醛释放量的比较分析

依据GB 18580-2001《室内装饰装修材料人造板及其制品中甲醛释放限量》中的(9~11)L干燥器法和JIS A 1460:2001《建筑板材甲醛释放量的测定——干燥器法》两种标准对几组不同厚度刨花板的甲醛释放量进行了检测,得出了两种检测方法对甲醛释放量检测结果的影响并分析了原因。     

Effect of particle size distribution on green properties during high velocity compaction

Iron powders with two different particle size distributions were compacted by high velocity compaction. The influences of particle size distribution and impact velocity on green properties, including green density, springback, tensile strength and bending strength etc., were studied with scanning electron microscopy (SEM) and a computer controlled universal testing machine. The results show that the particle size distribution and the impact velocity strongly affect its properties. Wider size distribution results in green compact with higher density and better strength. Furthermore, springback of compacts is lower produced by the powder with wider size distribution, especially for radial springback. As impact velocity increases, its green density and green strength gradually increases, but the increasing rate of density decreases gradually. No special relation is found between springback and impact velocity. In addition, the axial springback and the bending strength are higher than the radial springback and the tensile strength, respectively.     

Effect of carrier screening on ZnO-based resistive switching memory devices

The carrier screening effect occurs commonly in dielectric materials. It reduces the electric potential gradient, thus negatively affecting the functionality of resistive random access memory (RRAM) devices. An Au/ZnO film/Al-doped ZnO device fabricated in this work exhibited no resistive switching (RS), which was attributed to the carrier screening effect. Therefore, annealing was used for alleviating the screening effect, significantly enhancing the RS property. In addition, different on/off ratios were obtained for various bias values, and the screening effect was accounted for by investigating electron transport mechanisms. Furthermore, different annealing temperatures were employed to modulate the free carrier concentration in ZnO films to alleviate the screening effect. The maximal on/off ratio reached 10⁵ at an annealing temperature of 600 °C, yielding the lowest number of free carriers and the weakest screening effect in ZnO films. This work investigates the screening effect in RS devices. The screening effect not only modulates the characteristics of memory devices but also provides insight into the mechanism of RS in these devices.

Open image in new window

     

Metallic Graphene Nanoribbons

Isolated graphene nanoribbons(GNRs)usually have energy gaps,which scale with their widths,owing to the lateral quantum confinement effect of GNRs.The absence of metallic GNRs limits their applications in device interconnects or being one-dimensional physics platform to research amazing properties based on metallicity.A recent study published in Science provided a novel method to produce metallic GNRs by inserting a symmetric superlattice into other semiconductive GNRs.This finding will broader the applications of GNRs both in nanoelectronics and fundamental science.     

大洪沟矿构建和谐本质安全型矿井的做法

介绍了神新公司大洪沟煤矿坚持以人为本,科技兴矿,强化矿井安全质量标准化,实现安全生产10周年安全管理的经验做法。     

A formal architectural model for logical agent mobility

The process of agent migration is the major difference between logical code mobility of software agents and physical mobility of mobile nodes in ad hoc networks. Without considering agent transfer, it would make little sense to mention the modeling of strong code mobility, which aims to make a migrated agent restarted exactly from the state when it was stopped before migration. From the perspective of system's architecture, this paper proposes a two-layer approach for the formal modeling of logical agent mobility (LAM) using predicate/transition (PrT) nets. We view a mobile agent system as a set of agent spaces and agents could migrate from one space to another. Each agent space is explicitly abstracted to be a component, consisting of an environmental part and an internal connector dynamically binding agents with their environment. We use a system net, agent nets, and a connector net to model the environment, agents, and the connector, respectively. In particular, agent nets are packed up as parts of tokens in system nets, so that agent transfer and location change are naturally captured by transition firing (token game) in Petri nets. Agent nets themselves are active only at specific places and disabled at all the other places in a system net. The semantics of such a two-layer LAM model is defined by transforming it into a PrT net. This facilitates the analysis of several properties about location, state, and connection. In addition, this paper also presents a case study of modeling and analyzing an information retrieval system with mobile agents.     

石灰粉球在电石生产中的使用

石灰粉通过高压压球机成球用于生产电石在巨化电石有限公司取得成功,使得石灰的石灰石单耗与焦炭单耗显著下降,在大幅降低石灰生产成本的同时,实现了电石生产“三废”——石灰粉末的综合利用。     

动力调谐陀螺仪的瞬态动力学及误差分析

为了建立陀螺仪在过载—振动复合环境下的误差模型,应用有限元分析软件ANSYS,针对某型导弹使用的动力调谐陀螺仪的结构,建立基于具体参数的实体和有限元动力学模型,并开展了陀螺仪的瞬态动力学分析研究,由此计算由于陀螺转子和平衡环的质心偏移造成的陀螺仪漂移误差,得到在过载—振动复合环境下陀螺仪漂移角速度与在过载、振动单一环境下漂移角速度之间的关系。