多层非晶薄膜爆炸焊接原理

 从冲击动力学原理出发，建立了多层薄膜爆炸焊接的动力学模型。多层薄膜组合从某种意义上讲可以看成是一种特殊的多孔材料，其在冲击波作用下的行为完全可用多孔材料状态方程来描述。文中还针对非晶态材料的特点，建立了多层焊接的传热模型。计算结果表明，多层爆炸焊接完全可以保证非晶态材料不发生相变。     

多层非晶薄带爆炸焊接温度场模型

 从非晶合金形成的特点出发，结合爆炸焊接传热的特殊性，提出用一种方波形温度场模型来解释非晶薄带爆炸焊接后能保证非晶态的原因。结果表明此模型符合非晶薄带爆炸焊接的实际情况。     

超薄LiTaO3晶片的键合减薄技术

在制造红外热释电探测器阵列过程中，需要利用超薄钽酸锂(LiTaO₃)晶片作为红外热释电探测器件的敏感层。通常LiTaO₃晶片的厚度远厚于红外热释电探测器件要求的厚度，所以需要采用键合减薄技术对LiTaO₃晶片进行加工处理。键合减薄技术主要包括：苯并环丁烯（BCB）键合、铣磨、抛光、加热剥离、刻蚀BCB。加工后得到面积为10mm×10mm、厚度为25μm的超薄单晶LiTaO₃薄膜，晶片厚度、表面粗糙度和面形精度比较理想。测得了LT晶片减薄后的热释电系数为1.6×10^-4Cm^-2K^-1。得到的单晶LiTaO₃薄膜满足红外热释电探测器敏感层的要求。     

高组份Al值的AlxGa1-x As和AlxGa1-x As/GaAs/AlxGa1-xAs/GaAs多层结构的MOCVD生长

用自制常压MOCVD系统,在半绝缘GaAs衬底上生长高Al组份Al_xGa_1-xAs（其x值达0.83）,和Al_xGa_1-xAs/GaAs/Al_xGa_1-xAs/GaAs多层结构,表面镜面光亮。生长层厚度从几十到十几μm可控,测试表明外延层晶格结构完整,x值调节范围宽,非有意掺杂低,高纯GaAs外延层载流子浓度n_300K=1.7×10¹⁵cm^-3,n_77K=1.4×10¹⁵cm^-3,迁移率μ_300K=5900cmcm²/V.S,μ_77K=55500cm²/V.S。用电子探针,俄歇能谱仪测不出非有意掺杂的杂质,各层间界面清晰平直。 对GaAs,AlGaAs生长层表面缺陷,衬底偏角生长温度及其它生长条件也进行了初步探讨。     

脉冲激光作用下铝靶的层裂

 本文报导波长为1.06 μm脉宽（FWHM）约4 ns的强脉冲激光辐照下，铝靶发生层裂的实验结果。当入射功率密度在2.0×10¹¹~5×10¹¹ W/cm²范围的激光束作用下，厚度为0.1 mm、0.2 mm的靶在超临界条件下发生层裂，层裂厚度分别在(17±6) μm及(35±5) μm范围。文中使用一种简化模型对阈值条件下不同厚度的靶发生层裂时的层裂片厚度作了近似估算，并与已有的实验结果较好地符合。     

等离子体全息干涉条纹的数据处理

本文介绍了用全息干涉法诊断爆炸丝等离子体的数据处理方法。在考虑等离子体区域为轴对称的情况下,给出了由折射率计算等离子体电子密度的计算公式。在爆炸丝能量为9.6J的情况下,拍摄到了延时3μs的爆炸丝等离子体干涉图。运用计算机图象处理技术对反拍后的干涉图进行了处理,获得了较为理想的干涉图。用微机控制的线阵CCD摄像机判读了干涉条纹漂移。给出了等离子体密度随径向分布的曲线,并得到相应的等离子体密度在中心处约为10¹⁶个/cm³。     

铝粉快速反应光谱的研究

 使用光学多道分析仪（OMA）详细收集了氢氧气体爆炸产物激励下，两种不同粒度的铝粉在不同氧含量条件下快速反应的低分辨和高分辨光谱。实验结果表明在240~850 nm的光谱范围内的辐射以连续辐射为主，并有较弱的铝原子线和AlO的B²Σ⁺→X²Σ⁺带光谱。     

三代微光像增强器制管工艺对阴极光电发射性能的影响

主要论述制管工艺对光电阴极发射性能的影响。通过分析仪器和光学检测方法对管子阴极制备的台内及台外工艺质量进行了在线追踪和监测．结果表明，影响台外工艺质量的主要因素是外延材料缺陷多、发射层表面氧化、杂质污染、掺杂浓度不均匀、掺杂浓度陡度变化小及GaAs与玻璃粘接产生的应力大；影响台内工艺质量的主要因素为阴极激活真空度低于8×10^-8Pa．真空残气H2O．CO．CO2及C分压大于10^-8Pa．阴极激活铯和氧源提纯不彻底。利用透反射光照法激活台内对组件表面测线．发现发射层表面针孔、裂纹和发雾是造成阴极发射性能低的关键因素。     

一种可能的新型反应机制——双α直接转移反应

假定8Be是由两个在组态空间相邻的α粒子组成的, 因而获得在余核中⁸Be集团的谱密度正比于核表面α粒子预形成几率P_α的平方. 利用改进了的EFRDWBA重叠积分的参数化方法^[1—2], 我们计算了²⁰⁹Bi(¹²C, α)²¹⁷Fr反应中出射的α粒子的角分布和双微分能谱, 而且通过拟合实验数据提取了在²¹⁷Fr核表面的α粒子的预形成几率, 结果与由α衰变数据提取的预形成几率在计算误差范围内一致. 这个事实说明, ²⁰⁹Bi(¹²C, α)²¹⁷Fr可能是双α直接转移反应.     

铝靶动态激光反射率的数值模拟

 从金属近自由电子模型——Prude/Fresnel理论出发，分析了激光作用下铝靶表面反射率的动态变化规律。通过对铝电导率与温度变化关系的数值模拟，得到了凝聚态、液态、气态反射率的动态变化规律，且与实验结果基本符合。当激光功率密度处于10¹¹~10¹⁵ W/cm^-2范围内时，由等离子体模型和局部热力学平衡（LTE）理论，亦得到了反射率随温度变化的数值模拟结果，与国外的实验结果符合得较好。     

Effect of uniaxial tension and hydrostatic compression on the geometry and morphology of amorphous Fe<Subscript>77</Subscript>Ni<Subscript>1</Subscript>Si<Subscript>9</Subscript>B<Subscript>13</Subscript> alloy ribbon surface

The effect of hydrostatic pressure and uniaxial compression on the relief of an amorphous Fe₇₇Ni₁Si₉B₁₃ alloy ribbon surface was studied using scanning tunneling and atomic-force microscopy. The fracture surfaces of samples were also studied. It is found that both the initial surfaces and the surfaces of samples subjected to hydrostatic compression or tension, as well as fracture surfaces, are fractal or multifractal, but their fractality parameters are different. Hydrostatic pressure decreases the surface roughness and the average fractal dimension of the surface on both sides of the ribbons. The dependence of the surface fractal characteristics on tension is more complex. Prior to the occurrence of a “critical event” on the surface (formation of a deformation band or a through crack), the Hölder index and the half-width of the singularity spectrum decrease. The correlation is discussed between the fractal characteristics of the ribbon surface and those of a fracture surface, and the role of an excess free volume in the initiation of fracture of amorphous alloys is analyzed.     

Effects of Slight Plastic Deformation on Magnetic Properties and Giant Magnetoimpedance of FeCoCrSiB Amorphous Ribbons

Slight plastic deformation of 0 to 1% by cold rolling is proposed as a treatment which may modify the responses of magnetoimpedance （MI） sensor with an amorphous ribbon used as a sensitive element. The dependence of the magnetic properties of melt spun Fe3Co67Cr3Si15B12 amorphous ribbons and their MI responses in the initial state and after slight plastic deformation on the value of the deformation were comparatively analysed. The shape of the hysteresis loops shows a clear correlation with the value of the deformation. The variations of the total impedance, the real and the imaginary components, are measured for the current intensity of 1.S mA for the frequency of lO MHz. Slight plastic deformation affects both real and imaginary components and allows a control of the shape of the MI curves in a small field in a range usually used in biomedical applications. The proposed deformation treatments can be useful for the construction of the MI sensitive elements with a new type of the responses.     

Magnetic anisotropy of amorphous (Fe1−x Co x )78Si10B12 alloys

In order to better understand the problem of magnetic anisotropy in amorphous alloys produced by a rapidly quenching technique, in-plane magnetic anisotropy of amorphous (Fe_1−x Co _x (₇₈Si₁₀B₁₂ alloys was measured by means of a torque magnetometer using a disk specimen made from the amorphous alloy ribbon. The amorphous ribbons were prepared by a single roller type quenching apparatus. It was found that the anisotropy had mostly twofold symmetry in all the alloy cases, and that the concentrationx dependence of the anisotropy constant behaved differently from that of the magnetostriction. Moreover, the anisotropy did not disappear by subsequent annealing at high temperatures where the internal stress relief and the crystallization were completed.     

静高压下非晶(Fe0.99,Mo0.01)78Si9B13合金晶化过程的热力学研究

 在600~930 K，常压到7 GPa的范围内，对非晶(Fe_0.99,Mo_0.01)₇₈Si₉B₁₃合金等温等压退火30 min。实验表明：其晶化产物α-Fe(Mo, Si)、Fe₃B和Fe₂B相的析出与所加压力密切相关。压力使非晶(Fe_0.99,Mo_0.01)₇₈Si₉B₁₃合金的晶化温度和亚稳Fe₃B相的析出温度下降，在一定的压力和温度下，亚稳Fe₃B相将向稳定Fe₂B相转变，其转变温度随压力而变化。还对非晶(Fe_0.99,Mo_0.01)₇₈Si₉B₁₃合金的晶化和亚稳Fe₃B到稳定Fe₂B转变的热力学机制进行了讨论，并给出Fe₃B向Fe₂B的相转变方程。     

非晶铁基合金中两类不同的压磁效应

 本文详细介绍了在0.000 1~2.3 GPa流体静压力下测量三种非晶合金饱和磁感应强度B_s和最大磁导率μ_max的实验方法。实验结果表明：三种非晶合金受压后B_s和μ_max表现各异，可归为两大类。（1）第一类压磁效应：总趋势是B_s和μ_max都随压力增加而下降，但在几个压力区B_s反常增高。如Fe₇₅Ni₅Si₅B₁₅非晶合金B_s随压力增加均匀下降，(Fe_0.85Co_0.15)Cu_0.4Si_4.4B_13.2非晶合金的B_s随压力增加降—升—再降。（2）第二类压磁效应，如Fe_78.75Cu_1.25Si₅B₁₅非晶合金的B_s和μ_max随压力增加都有未见报导过的微弱升高。分别结合局域电子模型的交换作用理论和巡游电子模型的刚带理论进行了讨论。     

流体静高压原位磁测量的误差研究（二）──退磁场的影响

 为了探讨流体静高压原位磁测量中退磁场的影响有多大？分别选用6种不同片数（n＝1、3、5、7、10、13）的非晶Fe_46.3Co_0.03Ni_46.5Si_3.75V_0.92B_2.5合金薄带样品，先后放进13层密绕直螺线管初级线圈内，采用工业频率400 Hz去测量和比较其磁化曲线、磁导率曲线和起始磁化曲线。研究表明：（1）样品片数越多，退磁场的影响越大，导致μ_m和μ_i出现惊人的测量误差，以1片（μ_m＝4 430，μ_i＝3 396）为最准。（2）随着样品片数的增多，测量饱和磁感应强度B_s＝0.837～0.762T，表明受退磁场影响较小。（3）若要减小退磁场误差，可将样品做得更薄，如0.2 μm薄膜。（4）若要彻底消除退磁场误差，必须采用闭合磁路，如用非晶合金薄带卷成的圆环。     

Influence of structural defects on the magnetization process in high-magnetic fields in the Fe61Co10Y8Nb1B20 alloy in the form of ribbons and plates

Amorphous samples of the Fe₆₁Co₁₀Y₈Nb₁B₂₀ alloy in the form of a ribbon with thickness of approximately 30 μm and in the form of a plate with thickness of 0.5 mm have been investigated. Plates were obtained by a suction-casting method, and ribbons by a single roller melt-spinning method. Microstructural studies, using X-ray spectroscopy, confirmed that samples in the as-quenched state were fully amorphous. Measurements carried out using a vibrating sample magnetometer allowed values of coercivity and saturation magnetization to be obtained; it also facilitated the estimation of size and nature of structural defects in the investigated samples. All of the investigated samples of this alloy in the as-quenched state have high values of saturation magnetization of greater than 1.25 T.     

流体静高压原位磁测量的误差研究（三）——综合兼顾两种影响

 先后选用1至3片非晶Fe_46.3Co_0.03Ni_46.5Si_3.75V_0.92B_2.5合金薄带作样品,插入13层密绕直螺线管内,分别在高静水压容器内和其他四种不同环境中测量它们的磁化曲线、磁导率曲线和起始磁化曲线,再次研究了初级线圈采用多层直螺线管对铁镍合金样品的误差。（１）实验结果表明：既存在样品材料被磁化而形成的退磁场H',也存在漏磁通引起周围铁器磁化而形成的退磁场H'。（２）为了缩小H'的影响,只用1片非晶合金薄带作样品时,H'的影响变得严重,导致μ_m和μ_i出现惊人的误差：Δμ_m/μ_m=50%,Δμ_i/μ_i＝104%。（３）为了综合兼顾这两种影响,采用3片非晶合金薄带作样品时,虽然H'的影响增大一点,但是H'的影响被更多地削弱,所以环境磁化引起的误差反而减小：Δμ_m/μ_m=29%,Δμ_i/μ_i＝15.5%。     

Effect of thermophysical factors and magnetic field on the composition and optical properties of the surface of ribbons of amorphous cobalt- and iron-based alloys

Ellipsometric measurements of the surface of ribbons of amorphous Co₅₉Fe₅Ni₁₀Si₁₁B₁₅ and Fe₆₁Co₂₀Si₅B₁₄ alloys before and after thermal and laser treatments and Auger analysis of their surface layers have been performed in order to determine the character of changes in the composition of these layers after the noted treatments. It is found that magnetostriction significantly affects the processes of modification of the atomic structure of the surface layer of ribbons of amorphous iron-or cobalt-based alloys and formation of a microrelief of their surface from the noncontacting side after cryogenic treatments under the same conditions. Specifically, magnetostriction is characteristic of amorphous iron-based alloys and is responsible for the optical anisotropy induced in the skin layer. It is established that annealing of ribbons of a Co-based amorphous alloy, even at the temperature T = 425°C, changes the character of the spectral dependence of the IR optical conductivity of this alloy to that described by the Drude relation. This change fixes the beginning of ordering of the atomic structure of the surface layer of the material with the formation of microscopic crystallization regions.     

Effect of Zr Addition on Glass-Forming Ability and Magnetic Properties of Fe-Nd-Al-B Alloys Prepared by Suction Casting

The microstructure and magnetic behaviors of the Fe-Nd-Al-B alloys prepared by suction casting with zirconium addition are investigated. With the small amount of zirconium addition, the magnetic properties of the alloys change from hard magnetic property to soft magnetic property. The proper addition of Zr （6%） not only improves the glass forming ability, but also suppresses the crystallization. From the scanning electron microscopy of the [（Fe0.53Nd0.37 Al0.10 ）0.96B0.04]94Zr6 alloy and the local average elemental compositions determined using energy dispersive spectroscopy analysis, the amorphous phase with a composition of Fe47Nd38Al12Zra in the alloy can be observed. The bulk amorphous Fe47Nd38Al12Zr3 alloy is prepared by suction casting exhibiting good glassforming ability and soft magnetic behavior.