二氧化铪材料中Cu的最佳迁移路径

The movement of Cu in a HfO2-based resistive random access memory （RRAM） device is investigated in depth by first-principle calculations. Thermodynamics analysis shows that the dominant motion of Cu tends to be along the [001] orientation with a faster speed. The migration barriers along different routes are compared and reveal that the [001] orientation is the optimal migration route of Cu in HfO2, which is more favorable for Cu transportation. Furthermore, the preferable HfOz growth orientation along [100], corresponding to Cu migration along [001], is also observed. Therefore, it is proposed that the HfO2 material should grow along [100] and the operating voltage should be applied along [001], which will contribute to the improvement of the response speed and the reduction of power consumption of RRAM.     

GD900型定向钻机动力头前进后退缓慢故障排查

正1.故障现象1台GD900型定向钻机施工时,其动力头前进与后退动作突然变慢,动力头左、右旋转速度正常。当时怀疑控制器与GPS终端通讯线路出现故障,或GPS终端损坏导致控制器锁车。鉴于该钻机GPS终端已超过保修期,我们决定屏蔽GPS终端锁车功能。屏蔽GPS终端锁车功能后试机,动力头后退速度恢复正常,但是前进速度依然很慢。     

水平定向钻机动力头推拉马达控制方式的改进

<正>水平定向钻机可在不开挖地表土层的条件下,穿越公路、铁路、河流、闹市区、文物保护区、农作物和植被保护区等,进行供水、煤气、电力、电讯、天然气、石油管线的铺设。本文介绍水平定向钻机动力头推拉马达液压、电控系统控制方式改进方法。1.结构与原理水平定向钻机在钻进施工时,其动力头驱动钻杆旋转,并在钻架上向前推进。当1根钻杆钻到底后,动力头与钻杆分离并向后拉回,在连接上另1根钻杆后继续向前推进。动力头向前推进或向后拉回由电控手柄控制,电控手柄前推或后拉角度越大,动力头向前或向后移     

5000t/a甘氨酸生产技术总结

介绍了江西电化有限责任公司新、老两套甘氨酸生产装置的流程,指出新装置具有下列优点：(1)采用了乌洛托品的溶液投料;(2)采用5℃冷冻水降低醇析温度;(3)采用甲醇高位槽加醇析用甲醇;(4)采用液氨贮槽代替液氨钢瓶供氨;(5)采用精馏塔塔釜连续排液装置;(6)改变氨化釜恒温和醇析加甲醇方法。采用新装置后,5000t/a甘氨酸装置可节省资金354.4万元/a。     

飞秒激光刻蚀微结构对NaOH水热法制备TiO_2光催化性能的影响

Ti基底三维微纳米结构TiO_2(3D-TiO_2)具有比表面积大、光捕获能力强、电荷传输快、可循环利用的优点,在光催化领域具有重要的研究意义和应用前景。采用飞秒激光刻蚀复合Na OH水热法制造Ti基底3D-TiO_2,并研究飞秒激光刻蚀的微阵列结构对3D-TiO_2光催化性能的影响。采用激光共聚焦显微镜(LSCM)、SEM、TEM、XRD对3DTiO_2进行表征分析,并对3D-TiO_2在紫外光照下进行甲基橙降解性能测试。结果表明,复合方法制备的3D-TiO_2由飞秒激光刻蚀的微阵列和Na OH水热法制备的TiO_2纳米线组成。与采用Na OH水热法直接在平整Ti表面制备的TiO_2纳米线相比,3D-TiO_2的染料吸附能力提升100%,光催化性能提升37%。微阵列结构尺寸对3D-TiO_2的性能具有明显影响,随着微阵列宽度的减小或高度的增加,3D-TiO_2的比表面积增大、入射光反射率降低、光催化性能提高。     

缺陷对RRAM材料阻变机理的影响

基于密度泛函理论(DFT)的第一性原理和VASP仿真软件,分析了阻变随机存储器(RRAM)阻变效应的物理机制。对比计算了单斜晶相HfO2中Ag掺杂体系、氧空位缺陷体系和Ag及氧空位缺陷共掺杂复合缺陷体系的能带、态密度、分波电荷态密度面和形成能,结果表明在相同浓度下Ag掺杂体系能形成导电通道,而氧空位缺陷体系不能形成导电通道;共掺杂体系中其阻变机制以Ag传导为主,氧空位缺陷为辅,且其形成能变小,体系更加稳定。计算共掺杂体系的布居数和迁移势垒,得出在氧空位缺陷存在的前提下,Ag—O键长明显增加,Ag离子的迁移势垒变小,电化学性能增强。进一步计算了缺陷间的相互作用能,其值为负,表明缺陷间具有相互缔合作用,体系更加稳定。     

一种稳健的波束域自适应波束形成算法

在波束域算法中,针对波束域期望信号的指向误差落在波束主瓣边缘时波束性能严重恶化,采用波束域旋转矢量法的线性约束来改善波束域自适应算法的性能,同时为提高工程的实施性,减少算法的计算量,利用信号的特征值大于噪声的特征值这一理论,采用空间协方差矩阵逆的高阶次幂来逼近信号子空间,将求得的权矢量投影于改进的波束域的特征信号子空间,该算法在波束域中不但减少了计算量,而且使波束具有更好的信号比和稳健性。实验仿真验证了提出的改进波束域特征空间的稳健自适应算法的正确性和有效性,具有一定的工程实用价值。     

危险废物集中焚烧系统优化设计

根据目前国内已建成的工业危险废物焚烧处置运行情况,针对回转窑式焚烧系统存在的一些问题分析,提出了窑式焚烧系统优化设计的措施。     

基于Si3N4的电荷俘获型存储器中氧缺陷的第一性原理研究

Based on first principle calculations, a comprehensive study of substitutional oxygen defects in hexagonal silicon nitride （β-Si3N4） has been carried out. Firstly, it is found that substitutional oxygen is most likely to form clusters at three sites in Si3N4 due to the intense attractive interaction between oxygen defects. Then, by using three analytical tools （trap energy, modified Bader analysis and charge density difference）, we discuss the trap abilities of the three clusters. The result shows that each kind of cluster at the three specific sites presents very different abilities to trap charge carriers （electrons or holes）： two of the three clusters can trap both kinds of charge carriers, confirming their amphoteric property; While the last remaining one is only able to trap hole carriers. Moreover, our studies reveal that the three clusters differ from each other in terms of endurance during the program/erase progress. Taking full account of capturing properties for the three oxygen clusters, including trap ability and endurance, we deem holes rather than electrons to be optimal to act as operational charge carriers for the oxygen defects in Si3N4-based charge trapping memories.     

震动膜技术在废矿物油处理再生中的应用研究

对国内外几种废矿物油处置工艺进行了分析比较，发现大部分工艺较难达到节能环保的要求．介绍一种应用广泛、成熟可靠、环保节能的新型废矿物油再生技术——震动膜废油处理工艺．该技术已在香港地区得到广泛使用，具有良好的应用前景。