动态水声环境不确定性的预报与估计

水声环境具有强烈的时空易变性,为了解其变化中的规律和产生的不确定性,将POM海洋数值模型和水声传播模型FOR3D进行耦合,建立海洋—声学耦合数值模式。对海区的温盐等环境参数和水下声场进行预报,给出了典型断面的温度垂直结构、实验海区声速剖面和传播损失。同时,采用集合卡尔曼滤波(EnKF)方法结合海洋—声学耦合数值模式分析了水声环境的不确定性,对不同深度与频率下,传播损失的均值与满足90%的可能区间进行了计算,同时给出了不同点声速、传播损失、声纳作用距离的不确定性直方图。和实验数据的对比结果表明该方法具有较高的有效性,能对水声环境的不确定性进行合理的预报与估计。     

~(159)TbII超精细结构光谱测量

利用具有光谱高分辨和选择性激发等特点的共线快离子束激光光谱学方法研究了159Tb II亚稳态 4 f95 d7H08和激发态 4 f96 p3 / 2 ( 1 5 /2 ,3/2 )的超精细结构光谱 ,所有光谱线可以很好地分辨 ;并由实验测量到的高分辨超精细结构光谱 ,给出了相应能级的超精细结构常数     

脂酸调合漆配方的优化设计

本文应用混合型正交设计方法，对哈尔滨油漆厂生产的脂酸调合漆配方进行了优化．设计，提高了产品质量，降低了成本，收到了显著的经济效益．     

Inner Surface Modification of a Tube by Magnetic Glow-Arc Plasma Source Ion Implantation

A new method named the magnetic glow-arc plasma source ion implantation （MGA-PSⅡ） is proposed for inner surface modification of tubes. In MGA-PSⅡ, under the control of an axial magnetic field, which is generated by an electric coil around the tube sample, glow arc plasma moves spirally into the tube from its two ends. A negative voltage applied on the tube realized its inner surface implantation. Titanium nitride （TIN） films are prepared on the inner surface of a stainless steel tube in diameter 90mm and length 600mm. Hardness tests show that the hardness at the tube centre is up to 20 GPa. XRD, XPS and AES analyses demonstrate that good quality of TiN films can be achieved.     

中子星周围发现时空扭曲

宇宙中密度最大的可观测物体——中子星周围发现了爱因斯坦所预测的时空扭曲。密歇根大学和美国国家航空航天管理局（NASA）的天文学家说，这种扭曲表现为中子星周围含铁气体快速旋转所造成的模糊线路。这个发现还可用于测定中子星的体积限度。     

Measurement of hyperfine structure and isotope shifts in the 580.56nm line of 142－145,146,148,150Nd+

Isotope shifts and hyperfine spectrum of singly ionized neodymium ion was measured by collinear fast-ion-beam laser spectroscopy. The hyperfine A constants and B constants are obtained for the (23230)9/2^0 level and 4f^45d ^6K9/2 level, respectively. The optical isotope shifts between seven isotopes in the 580.56 nm of^142-145,146,148,150Nd^ line are determined. The configuration admixtures for (23230)9/2^0 level were quantitatively analysed to be 4f^46p, 4f^35d^2, and 4f^35d6p with mixing coefficients of 67%, 5%, and 28%, respectively.     

用亚图参数与回归技术估计和预测烷烃的核磁共振碳谱

系统研究了分子建模在波谱分析中的应用.采用多元线性回归算法(MLR)估计和预测了60余种烷烃的碳谱化学位移.烷烃中碳原子由十余种对应于所谓根亚树的相嵌频率描述子所决定.这些描述子等于由2~5个碳原子组成的更小结构骨架组成.说明了所用描述子作为很有用的工具可适当地描述烷烃中碳所处微观环境.同时还比较了与神经网络的计算结果.     

层流预混气体多棱火焰燃烧现象的分析

在一定条件下,层流预混气体燃烧过程中可清晰地观察到多棱火焰现象。本文从燃料浓度、温度对燃烧速度、气流速度的影响出发,推导出了火焰面变化随空气消耗系数的关系式,并得出了形成多棱火焰现象的条件为:Kx<0。用该式判断的丁烷层流预混气体燃烧的多棱火焰区与实验结果基本吻合。     

Behaviour of Self-Standing CVD Diamond Film with Different Dominant Crystalline Surfaces in Thermal-Iron Plate Polishing

Self-standing CVD diamond films with different dominant crystalline surfaces are polished by the thermal-iron plate polishing method. The influence of the dominant crystalline surfaces on polishing etfficiency is investigated by measuring the removal rate and final roughness. The smallest rms roughness of 0.14 μm is measured with smallest removal rate in the films with the initial （220） dominant crystalline surface. Activation energy for the polishing is analysed by the Arrhenius relation. It is found that the values are 170kJ/mol, 222kJ/mol and 214kJ/mol for the film with three different dominant crystalline surfaces. Based on these values, the polishing cause is regarded as the graphitization-controlling process. In the experiment, we find that transformation of the dominant crystalline surfaces from （111） to （220） always appears in the polishing process when we polish the （111） dominant surface.     

上期《问题思考》解答

1.二者弹簧秤的读数一样。因在图1(b)中上磁环受到其本身的重力和下磁环对它磁性斥力的作用。当二力平衡时,上磁环就悬浮在空中不动。根据牛顿第三定律,下磁环也受到上磁环的磁性斥力,其大小刚好等于上磁环的重量。故图1(b)的情形与图1(a)一样,弹簧秤的读数都是两磁环重量之和。如果我们用手往上托图1(b)中的上磁环,则因两环距离加大,磁斥力减小,弹簧秤示数变小;同理,下压图1(b)中的上磁环时,弹簧秤的示数将变大。(刘贵兴) 2.参见本期罗维治、朱久运《电磁感应中的“佯谬”与电磁感应定律的表述》一文。 3.车头开动后,先是自己作加速运动,走…