A novel approach of data race detection based on CNN-BiLSTM hybrid neural network

Neural Computing and Applications - Existing data race detection approaches based on deep learning are suffering from the problems of unique feature extraction and low accuracy. To this end, this...     

基于离子交换机理的尖晶石型LiMn2O4脱/嵌锂模拟

基于离子交换机理,以ICSD(The Inorganic Crystal Structure Database)中LiMn_2O_4的结构数据为基础,利用Materials Studio软件包中Visualizer模块和CASTEP模块构建并优化了尖晶石型LiMn_2O_4和HMn_2O_4以及λ-MnO_2的晶体结构,并通过对比涉及各自晶体结构的系统能值、晶胞参数、键长及键角等的变化,初步验证了离子筛提锂过程是自发吸热过程;分别通过对LiMn2O4和HMn2O4添加H和Li,模拟考察了脱锂和嵌锂(即酸洗和吸附)过程中的活性原子位及H和Li的迁移轨迹,得出8a位置Li和H的离子性较强,脱锂为H置换四面体8a位置Li,并与邻近位置O形成键长约为0.098 9nm的O-H键;嵌锂为Li取代8a-16c-8a孔道中8a位置H的动力学过程。研究结果对锰基离子筛提锂的后续工作具有一定的指导意义。     

添加Al-5Ti-B和Al-2Zr-Er对铸态铝锌镁合金力学性能的影响

铝锌镁合金以其优异的力学性能广泛应用于航空、航天、交通运输等工业领域,而铝合金的细化一直是铝加工行业的研究重点.为细化晶粒并提高其力学性能,本文将传统细化剂Al-Ti-B与RE复合添加到铝锌镁合金中,借助于XRD、光学显微镜、扫描电镜、拉伸实验等测试方法研究了不同细化剂对Al7Zn2.4Mg合金组织及其力学性能的影响.试验结果表明,合金中加入Al-5Ti-B和Al-Zr-Er后细化效果明显,单独添加Al-Ti-B的细化效果最好,但仍有少部分的晶粒保留的树枝晶形态.随着Al-Ti-B和Al-Zr-Er添加量的增多,合金的晶粒发生明显变化,塑性也随之增加,其中,添加0.4wt.%Al-5Ti-B细化剂对合金的塑性影响最大,而抗拉强度呈先增大后减小的趋势,复合添加0.2wt.%Al-2Zr-Er和0.2wt.%Al-5Ti-B细化剂的合金晶粒圆整且未出现树枝晶,晶界析出物最少平均抗拉强度最高.Al-Ti-B和Al-Zr-Er均可细化铸态铝锌镁合金的晶粒,同时添加两种细化剂更有利于提高合金的综合力学性能.     

ZIF‐8/ZIF‐67‐Derived Co‐Nx‐Embedded 1D Porous Carbon Nanofibers with Graphitic Carbon‐Encased Co Nanoparticles as an Efficient Bifunctional Electrocatalyst

Herein, an approach is reported for fabrication of Co‐N_x‐embedded 1D porous carbon nanofibers (CNFs) with graphitic carbon‐encased Co nanoparticles originated from metal–organic frameworks (MOFs), which is further explored as a bifunctional electrocatalyst for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Electrochemical results reveal that the electrocatalyst prepared by pyrolysis at 1000 °C (CoNC‐CNF‐1000) exhibits excellent catalytic activity toward ORR that favors the four‐electron ORR process and outstanding long‐term stability with 86% current retention after 40 000 s. Meanwhile, it also shows superior electrocatalytic activity toward OER, reaching a lower potential of 1.68 V at 10 mA cm^?2 and a potential gap of 0.88 V between the OER potential (at 10 mA cm^?2) and the ORR half‐wave potential. The ORR and OER performance of CoNC‐CNF‐1000 have outperformed commercial Pt/C and most nonprecious‐metal catalysts reported to date. The remarkable ORR and OER catalytic performance can be mainly attributable to the unique 1D structure, such as higher graphitization degree beneficial for electronic mobility, hierarchical porosity facilitating the mass transport, and highly dispersed CoN_xC active sites functionalized carbon framework. This strategy will shed light on the development of other MOF‐based carbon nanofibers for energy storage and electrochemical devices.     

Solvent-free microwave-assisted synthesis of tenorite nanoparticle-decorated multi-walled carbon nanotubes

Copper-decorated carbon nanotubes (CNTs) have important applications as precursors for ultra-conductive copper wires. Tenorite-decorated CNTs (CuO-CNTs) are ideal candidates and are currently developed using laborious processes. For this reason, we have developed a facile and scalable method for the synthesis of CuO-CNTs from copper acetate. It was found that the optimal loading of copper acetate onto the CNTs was 23.1 wt% and that three 1-minute microwave treatments were sufficient for the decomposition of copper acetate to copper oxide. The loading of copper oxide onto the nanotubes was confirmed using X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy and thermogravimetric analysis. The materials were characterised using X-ray diffraction and scanning electron microscopy.     

食品包装材质对消费者绿色购买意愿影响的眼动研究

目的 探讨食品包装材质对消费者注意加工流程和绿色购买意愿影响的内在机制。方法 采用包装材质2(环保/普通)×食品类型2(实用品/享乐品)双因素实验设计,在货架购物场景下采用Tobii Glasses 2眼镜式眼动仪,采集被试者浏览货架不同食品时的眼动数据(平均注视时间、注视次数、热点图),并结合行为数据综合分析。结果 在平均注视时间上,包装材质与食品类型的交互作用显著,注视次数交互作用不显著;环保材质包装的食品获得更多关注,被试者偏好于选择环保包装的享乐食品。结论 包装材质与食品类型共同影响消费者的视觉感知效果与加工过程,环保包装对青年消费者的绿色购买意愿有正向促进作用。     

Reliability analysis on systems with self-healing and self-repairing under different environments and shock models

Inspired by the process of self-healing of biological damage, high technology materials with self-healing and self-repairing mechanisms have been developed for high reliability and long lifetime. Therefore, the reliability modeling on intelligent systems with healing performance has become a research hotspot. Based on the diversity of healing mechanisms, this paper proposes a two-phase reliability model method on self-healing and self-repairing systems. Impacts of environments, shock loads, self-healing, and self-repairing mechanisms are taken into account in this novel model. Besides, system lifetime and some reliability indexes under two shock models are derived, respectively. Moreover, Monte Carlo simulations are conducted to verify the accuracy of reliability under two models. Finally, an engineering case of metallized film capacitor is provided to illustrate the effectiveness and applicability of the proposed models by comparing numerical results and simulation results.     

Energy-efficient multipath routing in wireless sensor network considering wireless interference

Due to the energy and resource constraints of a wireless sensor node in a wireless sensor network (WSN), design of energy-efficient multipath routing protocols is a crucial concern for WSN applications. To provide high-quality monitoring information, many WSN applications require high-rate data transmission. Multipath routing protocols are often used to increase the network transmission rate and throughput. Although large-scale WSN can be supported by high bandwidth backbone network, the WSN remains the bottleneck due to resource constraints of wireless sensors and the effects of wireless interference. In this paper, we propose a multipath energy-efficient routing protocol for WSN that considers wireless interference. In the proposed routing protocol, nodes in the interference zone of the discovered path are marked and not allowed to take part in the subsequent routing process. In this way, the quality of wireless communication is improved because the effects of wireless interference can be reduced as much as possible. The network load is distributed on multiple paths instead of concentrating on only one path, and node energy cost is more balanced for the entire wireless network. The routing protocol is simulated in NS2 software. Simulation result shows that the proposed routing protocol achieves lower energy cost and longer network lifetime than that in the literature.     

人工智能概论课程的教学思考

从智能科学与技术专业所设置的人工智能概论课程的自身特点和发展需要出发,在教学目标、授课内容、教材选择、讲授方法和考核形式等方面进行全方位的思考与探讨,力争开拓出新的教学思路,形成独特的教学风格,取得良好的教学效果。