基于YOLOv5的伪装数据增广方法研究

数据作为深度学习的驱动力,对于模型的训练至关重要。为解决自然伪装数据集样本数量不足的问题,提出一种基于纹理置乱的数据增广方法,可有效扩充数据集样本数量。首先,根据目标像素多少动态选择置乱尺度,然后,将目标区域按置乱尺度切分为若干纹理块,最后将这些纹理块的排列顺序进行置乱。实验证明,使用基于纹理空间置乱的数据增广方法生成的数据保留了模型学习伪装目标的语义特征,同时增加了样本的多样性。在YOLOv5s模型上使用扩充的数据集进行训练,模型的检测性能提升了2.4个百分点,与传统数据增广方法相比,所提方法取得了更好的效果。

基于网络划分的SDN分布式控制器部署

针对大规模SDN(software defined networking)网络中分布式控制器部署问题,以优化网络弹性和可靠性为目标,提出两阶段控制器部署算法(TSCP, two-stage controller placement):利用节点相似度划分控制域,使得控制域内设备之间的连通性强、连接紧密,增强控制域的网络弹性;选择控制路径平均失效率最小的控制器集合作为控制器部署,提高网络可靠性。通过约束控制域的规模和设备(交换机或控制器)之间传播时延,使控制域的交换机个数均衡,控制器的部署合理。通过定义性能指标,实验对比GCP算法、K*-means算法,结果表明TSCP算法可以优化控制域的规模,均衡控制域的交换机个数,减少控制器个数,网络弹性和可靠性均表现较好。

黄连解毒液防治头颈部肿瘤放射性皮炎的随机对照双盲临床研究

目的:观察黄连解毒液外用防治头颈部肿瘤放射性皮炎的临床疗效。方法:将90例头颈部恶性肿瘤放疗患者随机分成治疗组及对照组,各45例,治疗组给予黄连解毒液外用涂擦放疗区域皮肤,2次/d;对照组给予重组人表皮生长因子外用溶液(金因肽)外喷于放疗区域皮肤,2次/d,放疗第一天开始,观察至治疗结束。观察2组患者首次发生放射性皮炎的时间、Ⅲ度以上放射性皮炎发生率、发生放射性皮炎皮损程度、放射性皮炎临床治疗疗效及不良反应。结果:治疗组首次发生放射性皮炎的时间治疗组晚于对照组(13.22±3.87dvs11.44±3.79d,P=0.030),Ⅲ度以上放射性皮炎发生率(46.7%vs75.6%,P=0.005)、放射性皮炎治疗有效率(95.6%vs82.2%,P=0.044)均优与对照组,2组均未出现严重不良反应。结论:在观察病例中,黄连解毒液外用凃擦,能延缓首次发生放射性皮炎的时间、降低Ⅲ度以上放射性皮炎发生率及放射性皮炎皮损程度、提高放射性皮炎临床治疗效果,具体机制有待进一步深入研究。

中医情志护理对乳腺癌患者癌因性疲乏的干预效果

目的:探讨中医情志护理对乳腺癌患者癌因性疲乏(CRF)的干预效果。方法:2018年1月-2019年1月收治乳腺癌患者90例,随机分为两组,各45例。对照组采取常规形式和中医特色治疗相结合的护理方法,试验组在常规形式和中医特色治疗相结合护理基础上实施中医情志护理。比较两组癌症疲乏量表(CFS)评分情况。结果:试验组干预2周后CFS得分明显低于护理干预前,且低于对照组,差异有统计学意义(P<0.05)。结论:针对乳腺癌患者实施中医情志护理可以有效缓解CRF,为患者有效恢复提供帮助。

A first-principles study of site occupancy and interfacial energetics of an H-doped TiAl-Ti_3 Al alloy

We investigate the site occupancy and the interfacial energetics of TiAl-Ti 3 Al binary-phase system with H using a first-principles method.H energetically prefers to occupy the Ti-rich octahedral interstitial site because H prefers to bond with Ti rather than with Al.The occupancy tendency of H in the binary phase TiAl-Ti 3 Al alloy from high to low is 2-Ti 3 Al to/2 interface and-TiAl,because the decrease of the Ti local concentration is in the same order.We demonstrate that H can largely affect the mechanical properties of the TiAl-Ti 3 Al system.On the one hand,H at the interface reduces the interface energy with the H 2 molecule as a reference,implying the TiAl/Ti 3 Al interface is stabilized.On the other hand,the ratio between the cleavage energy and the unstable stacking fault energy decreases after H-doping,indicating H will reduce the ductility of the TiAl/Ti 3 Al interface.Consequently,the mechanical property variation of TiAl alloy due to the presence of H not only depends on the amount of TiAl/Ti 3 Al interfaces but also is related to the H concentration in the alloy.

Effect of helium implantation on mechanical properties of niobium doped tungsten

Helium atoms were implanted into niobium-doped tungsten and pure tungsten via ion implantation, and the effect of helium implantation on mechanical properties of two types of sample was studied by X-ray photoelectron spectroscopy, scanning electron microscope and nano-hardness tester. The results clearly show that the surface hardness and elastic modulus of tungsten are improved by implanted niobium ions, and the degradation of mechanical properties is mitigated comparing to pure tungsten under identical helium implantation fluence. It can be concluded that the defects induced by niobium implantation improved the mechanical properties of tungsten by obstructing the slip of dislocation.

Stability and diffusion properties of self-interstitial atoms in tungsten:a first-principles investigation

基于密度功能理论采用一个第一原则的方法，我们系统地在钨(W) 调查自我空隙的原子(SIA ) 的结构，稳定性和散开。The111 哑铃被显示是有 9.43 eV 的形成精力的最稳定的 SIA 缺点配置。所在地的旋转模式罐头被相当软的漂浮机制和一个下坡的飘移散开过程分别地从 110 哑铃描述到 111 哑铃并且从 001 哑铃到 110 哑铃。在跳接近附近的地点的不同 SIA 配置之中， 111 哑铃更更好与 0.004 eV 的一个低得多的精力障碍直接移居到 first-nearest-neighboring 地点。这些结果作为在熔化 Tokamak 面对材料的候选人血浆为 W 提供一本有用参考书。

Connecting microscopic structure and macroscopic mechanical properties of structural materials from first-principles

Computer simulation plays a critical role in connecting microscopic structure and macroscopic mechanical properties of structural material,which is a key factor that needs to be considered in design of such kind of material.Via the quantum mechanics first-principles calculations,one can gain structure,elastic constant,energetics,and stress of selected material system,based on which one is able to predict the mechanical properties or provide useful insights for the mechanical properties of the materials.This can be done either directly or in combination with the empirical criterions.This paper reviews the recent research advances on the attempts to predict the mechanical properties of structural materials from first principles.

Effect of hydrogen on grain boundary migration in tungsten

Motivated by a grain boundary(GB) healing mechanism that GB turns into a mobile sink through migration to eliminate the vacancies in a bulk, we have further investigated the influence of the retained hydrogen(H) on the GB migration in tungsten using a molecular dynamics simulation. We show that H hinders the GB migration at different H concentrations and temperatures, and such friction of GB migration due to the presence of H increases with the H concentration and decreases with temperature. We demonstrate that H follows the GB-migration as the temperature is higher than 300 K. Most importantly, the presence of H induces a disordering of GB, which affects the GB migration significantly.