调制比对TiB2/TiAlN纳米多层膜结构和机械性能的影响

利用射频磁控溅射技术在室温下合成了具有纳米调制周期的TiB2/TiAlN多层膜.分别采用X射线衍射仪(XRD)、表面轮廓仪、纳米力学测试系统和多功能材料表面性能实验仪分析了调制比对TiB2/TiAlN纳米多层膜结构和机械性能的影响.结果表明:大部分多层膜的纳米硬度和弹性模量值均高于两种个体材料混合相的值,在调制比为t ...     

脑裂头蚴病的临床及影像学分析

探讨脑裂头蚴病的临床及影像学表现,以提高本病的影像诊断水平。回顾性分析9例手术病理证实的脑裂头蚴病的临床及影像学资料。9例均行CT检查,其中8例行MRI检查。结果为脑裂头蚴病临床表现以癫痫、轻偏瘫和头痛多见。CT表现特点为低密度灶伴点状钙化,不规则或点状强化。MRI可见病灶区有串珠状增强或扭曲的条索样增强影。患者血清免疫学检查均显示裂头蚴抗体阳性。本组9例中8例在CT定位下行立体定向活检,1例手术开颅取出,预后均良好。多数脑裂头蚴病的CT和MRI表现具有特征性。血清免疫学检查及CT引导下立体定向活检在诊断和处理脑裂头蚴病中起到重要作用。     

层间有反铁磁交换相互作用的磁性超晶格的推迟模式

我们用等效介质理论计算了层间有反铁磁交换的侧向晶格。当外场垂直于磁性或非磁性层时,在这种超晶格中存在两种磁序：反转自旋（flop)和平行自旋磁序。我们发现,这两种磁序的表面模的频率随外场和层间耦合的变化情况很不同。前一种磁序中,模式的频率对层间耦合非常敏感,我们还发现使表面模存在的两个外场临界值。     

多级Nd－Fe－B强永磁体悬挂带式除铁器的研究

利用Ｎｄ—Ｆｅ—Ｂ强永磁合金研制成多级悬挂带式除铁器，其综合性能优于目前国内外使用的电磁铁和铁氧体型除铁器，具有磁力强、轻便及除铁效果好等特点。     

基于神经网络的舰船全磁场部位识别

利用人工神经网络将舰船磁场的三个分量进行序贯融合处理 ,从而进行对舰船关键部位的精确识别 ,给出了处理方法及检验结果 ,并分析了提高网络推广性能的措施。     

磁场强度仅与传导电流有关的条件

以静磁场的基本方程为基础，利用矢量分析的有关知识对磁场强度H的一般形式作一些理论分析，给出磁场强度日仅与传导电流有关的条件．     

建立麦克斯韦方程组的新途径

用普通物理学的方法推导了不同惯性系之间产场量的变换式，在此基础上，给出了一咱简便、快捷并且物理意义清晰的建立麦克斯韦方程组的新途径。     

Numerical modeling and simulation of temperature distribution uncertainty subject to ferromagnetic thermoseeds hyperthermia

In the process of ferromagnetic thermoseeds mediated magnetic induction hyperthermia, the tempera- ture distribution in the tumor region is a key factor to determine the therapy effect. During the preoperative treatment planning, discrepancies of the treatment parameters may lead to the temperature distribution uncertainty within the target area. Inaccurate prediction of temperature distribution may induce the treatment failure; therefore, it would be significant to investigate the uncertainty of tissue temperature prediction caused by the disturbance of calculation parameters. In this paper, 3D temperature field and necrosis zone of tissues in ferromagnetic thermoseeds hyperthermia are simulated by the finite volume algorithm, and effects of parameter uncertainties on the temperature distribution are revealed. Results show that selecting appropriate magnetic field parameters for treatment is a priority to guarantee therapeutic effect. Thermoseed properties and blood perfusion rate are the obvious disturbing terms for temperature distribution, while the metabolic heat of bio-tissues can often be ignored within limits. Our investigation is of importance for guiding reasonable and optimal preoperative treatment planning.     

Structure and magnetic properties of Ni50Mn35In15 thin film

Thin film of Ni50Mn35In15 Heusler alloy was prepared on Mg O(001) substrate by epitaxial growth in an ultra-high vacuum(UHV) chamber by a Pulsed Laser Deposition(PLD) method. The epitaxial growth process was monitored by in situ reflection high energy electron diffraction(RHEED) and the structure of the film was checked by ex situ X-ray diffraction(XRD), which indicates that high quality Ni50Mn35In15 single crystal film with a face-centered-cubic(fcc) structure could be stabilized on Mg O(001). Magnetic property measurement was also conducted at various temperatures by using physical property measurement system(PPMS). A significant exchange bias was observed for Ni50Mn35In15 film,and the strength of the exchange bias field(HEB) increases with the decrease of temperature. Such a behavior can be ascribed to the fact that the interfacial spin interaction between ferromagnetic(FM) and antiferromagnetic(AFM) cluster is enhanced with the decrease of temperature.     

Magnetoelectric Bi_(3.15)Nd_(0.85)Ti_3O_(12)–NiFe_2O_4 bilayer films derived by a SOL–GEL method

Magnetoelectric Bi3.15Nd0.85Ti3O12–NiFe2O4(BNT–NFO) bilayer films were deposited on Pt/Ti/SiO2/Si(100) substrates by a simple SOL–GEL method and spin-coating process with different growth sequences of BNT and NFO yielding the following layered structures: BNT/NFO/substrate(BNS) and NFO/BNT/substrate(NBS). Such heterostructures present simultaneously strong ferroelectric and ferromagnetic responses,as well as magnetoelectric effects at room temperature. BNS thinfilms showed larger ME voltage coefficient than NBS films, revealing that the layer sequences have a significant in fluence on the magnetoelectric coupling behavior of these bilayer structures, which may be caused by a interfacial effect.