Neutron powder diffraction and high-pressure synchrotron x-ray diffraction study of tantalum nitrides

Tantalum nitride(TaN) compact with a Vickers hardness of 26 GPa is prepared by a high-pressure and hightemperature(HPHT) method. The crystal structure and atom occupations of WC-type TaN have been investigated by neutron powder diffraction, and the compressibility of WC-type TaN has been investigated by using in-situ high-pressure synchrotron x-ray diffraction. The third-order Birch–Murnaghan equation of state fitted to the x-ray diffraction pressure–volume(P–V) sets of data, collected up to 41 GPa, yields ambient pressure isothermal bulk moduli of B'_0= 369(2) GPa with pressure derivatives of B 0= 4 for the WC-type TaN. The bulk modulus of WC-type TaN is not in good agreement with the previous result(B_0= 351 GPa), which is close to the recent theoretical calculation result(B_0= 378 GPa). An analysis of the experiment results shows that crystal structure of WC-type TaN can be viewed as alternate stacking of Ta and N layers along the c direction, and the covalent Ta–N bonds between Ta and N layers along the c axis in the crystal structure play an important role in the incompressibility and hardness of WC-type TaN.     

基于MobileNet的地基云图分割方法研究

本文利用深度卷积神经网络技术,针对全天相机的云图分割方法进行了改进,将MobileNet作为三种分割模型U-Net、SegNet和DeepLabV3+的主干,再分别使用白天和夜间云图进行训练预测,利用一些评价指标对于其性能做出评价。结果表明,MobileNet可以更好的提取网络特征信息,经过改良后的U-Net网络更适合于地基云图的分割,对于白天云图和夜间云图的分割精确度分别达到了89%和95%。     

基于深度学习的交通标志物识别研究

随着城市交通流量日益增大,交通管制难度也不断增大.拥堵、路况复杂等因素,不仅对交通管制形成严峻挑战,作为驾驶员来说,也是压力倍增.针对这种形式,相关人员陆续着手研发智能交通系统(TSI),TSI自诞生以来,在缓解交通拥堵和强化交通管制方面发挥着越来越重要的作用,TSI的应用越来越广泛.不管是无人驾驶技术,还是智能辅助驾...     

移动通信数据支持下的用户识别与移动性预测

阐述移动通信数据的特点,移动通信数据的用户识别,神经网络辅助识别移动游客,探讨移动通信数据的用户移动性预测,包括下一步的行程预测、行程的多步预测。     

PLATE COLLISION IN EAST TAIWAN AND COAST AL AREA OF FUJIAN AND GUANGDONG AS WELL AS FORMATION OF SEISMIC SCREEN REGION

Based on the comparative study of geophysical data, geotectonic features, seismicity and other rela-tive data of Taiwan and the coastal area of southern Fujian and eastern Guangdong, it was found that theSouth China continent is linked to the western part of the longitudinal valley in the east coast of Taiwanthrough the Dongshan-Beigang undersea uplift. The unique collision between the Philippine Sea plate andthe Eurasian plate east of Taiwan coupled with the characteristic plate margin structures causes a stressconcentration in this region. Most of the resulting strain energy was released by volcanism, seismicity, hotsprings, crusta1 deformation. And part of the stress was transmitted into the coastal area of Fujian andGuangdong through the Dongshan-Beigang uplift to form the Quanzhou-Shantou seismic zone whichacted as a screen to make the South China inland region of few and weak shocks.     

多晶Sr2Fe1－xAlxMoO6的晶粒内低场磁电阻效应

用传统的固相反应法合成了Fe位掺杂Al的双钙钛矿型氧化物Sr2Fe1-xAlxMoO6 (x=00，005，010，015，03)多晶材料. x射线衍射和扫描电子显微分析显示，在Fe位掺杂Al既没有引入杂相，也没有明显改变Sr2FeMoO6多晶材料的晶粒尺寸和晶界状态. 非磁性Al离子的掺杂使晶粒内部磁有序区细化成更小的区域，同时使反铁磁区内的磁耦合作用变弱. 这一方面提高了亚铁磁区磁化方向的磁场灵敏度；另一方面也降低了反铁磁区对自旋相关电子的散射；两方面的共同作用使Sr2FeMoO6的低场磁电阻效应明显增强，但这种尺寸效应也使材料的磁电阻在高温下下降得更快. 关键词： 低场磁电阻 掺杂 自旋极化电子     

钙浓度影响心肌细胞钙泵活性定位的电镜观察

钙浓度影响心肌细胞钙泵活性定位的电镜观察韩芳（沈阳医学院，沈阳１１００３１）刘闺男＊石玉秀＊＊（中国医大一院循环内科＊，组胚教研室＊＊，沈阳１１０００１）钙泵又称Ｃａ＋＋－ＡＴＰ酶［１］，在心肌细胞收缩过程起重要作用。但因心肌细胞各超微部位Ｃａ＋＋－...     

135MeV/u 12C和铁相互作用中靶余核的质量分布

用核化学技术测定了135MeV/u ¹²C和铁相互作用中的靶余核的生成截面,通过高斯电荷分布函数得到了靶余核的质量分布.与46MeV/u ¹²C+Cu相比,发现A<30质量区的产额明显增加,且产物有偏向丰中子一侧的趋势.实验测定的质量分布与熔合碎裂模型和级联两体模型的计算结果进行了比较,结果似乎表明在很高入射能情况下多重碎裂衰变是A<30靶余核生成的主要反应机制.