抗氧化酶促防御系统对白皮松幼苗抗寒性的影响

针对土壤农化分析课的特点,提出了提高该课教师自身的知识修养和实验操作能力具体措施;同时,详细地阐述了土壤农化分析课理论及实验课的授课方式.     

Use of a microwave cavity for sensing dielectric properties ofarbitrarily shaped biological objects

A rectangular waveguide resonator operating in the H₁₀₅ mode at 3.2 GHz is used in determining the change in resonant frequency, ΔF, and the Q factor of the cavity, ΔT , when measured with and without single corn kernels of various shapes and dimensions. By measuring those variables for a kernel oriented in two positions differing by a 90° rotation with respect to the maximum E-field vector, the average values of ΔF and ΔT are found to be independent of shape. The ratio ΔF/ΔT is independent of size and is a function of the material properties (ε'-1)/ε". This function is shown to be related to the material density, moisture content, or other characteristics when all other properties except the one selected remain unchanged     

宽带IP城域网及其应用

文章结合南京电信公众宽带IP城域网的建设，对宽带IP城域网的网络结构、用户接入安全、网络管理和认证计费作了阐述，并简要介绍了应用于宽带IP城域网上的一些业务。     

QQF函数数值计算及图示软件

QQF 软件可以建立不限容量的函数(公式)库,计算和图示库中任一函数在指定范围的数值,并在二维或三维空间显示该函数的图象。软件中使用了特殊的编译技巧,用户能直接以人机对话方式建立和维护自己的函数库,方便地调用其中任何函数。QQF.EXE 可在 IBM—PC及其兼容机上运行。     

Model investigations on the penetration of melts into injection nozzles

The formation of gas bubbles and the penetration behaviour of the liquid into the nozzle against the gas stream were studied in water, water-glycerine mixtures and mercury from bubbling regions to a continuous gas jet region with various nozzle configuration. Measurements were also made with gas and powder injection in the mercury and molten pig iron models. It was observed that the penetration behaviour of the liquids during gas injection depends on the gas flow velocity, the diameter and orientation of the nozzle, the wettability and the density of the liquid. The results of the powder injection showed a lower penetration depth of the liquid into the nozzle than the results for gas only injections. The effect of each influencing factor on the penetration behaviour was shown to be similar in both injection types, with or without powder.     

The effect of non-Gaussian local wind pressures on a side face of a square building

An accurate probabilistic representation of input forces and structural response in the extreme region is essential for the assurance of the safety and reliability of structures subjected to environmental loads. When the loads differ significantly from the Gaussian, they may increase expected damage. The design loads of a cladding glass subjected to the local wind pressures must not exceed the allowable load of a glass panel. The design loads of a cladding glass can be dependent on whether the local wind pressures have a non-Gaussian or Gaussian distribution. In this study, comparing non-Gaussian local wind pressures with Gaussian local wind pressures, and comparing the equivalent 1-min loads of cladding glass subjected to the simulated non-Gaussian local wind pressures with those of cladding glass subjected to the simulated Gaussian local wind pressures are performed to investigate the effect of non-Gaussian local wind pressures on a side face of a square building.     

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在油气田勘探评价和开发阶段，储层研究以建立定量的三维储层地质模型为目标，这是油气勘探开发深入发展的要求，也是储层研究向更高阶段发展的体现。油气藏描述的最终结果是油气藏地质模型，其核心是储层的地质模型，广义的储层模型包括构造模型、储层属性分布模型及流体分布模型，故应用地质、地震、测井、试井等资料建立广义的储层模型的过程实际上就是油气藏描述。在川西新场气田沙溪庙气藏的储层随机建模中，对非连续的类型变量（岩性）和连续的随机变量（储层参数），分别采用了序贯指示模拟方法和序贯高斯模拟方法。首先用序贯指示模拟方法求得砂体的空间展布，然后将泥岩范围屏蔽掉，只在砂岩范围内采用序贯高斯模拟方法对孔、渗、饱等参数进行模拟。应用Jason软件中的随机建模工具，建立了新场气田沙溪庙气藏储层定量的三维储层参数模型，实现了油气勘探开发深入发展的要求，也体现了储层研究向更高阶段的发展。     

Zone-melted unidirectional solidification of particulate dispersed composites

In order to solve the problem of particles settling and agglomeration in front of solidifying interface in unidirectional solidification (UDS) experiments, a zone-melted process has been utilized in this study. The experimental results show that, the melting zone could be kept in 30–40 mm width and the zone melted UDS experiments are realized with Al₂O₃ particle reinforced aluminum-matrix composites. But particle settling still occurs in the liquid, and becomes severe as the particle volume fraction decreases. However, when the volume fraction of the particles is more than 20–22 vol.%, no further settling occurs under a solidification rate of 8–16 mm/h. Investigation on the interaction of particles and solid/liquid interface reveals that the Al₂O₃ particles are rejected into liquid and pushed by the growing solid phase in Al₂O_3(P)/Al and Al₂O_3(P)/Al-0.23wt.%Ce composites. Some particles are mechanically entrapped between cells, and distributed along the crystal grain boundaries.     

Probabilistic failure analysis of a water-cooled tungsten divertor: Impact of embrittlement

Inherent brittleness and neutron embrittlement are critical weaknesses of tungsten for fusion application. Pronounced scattering of the fracture strength of tungsten requires a statistical treatment. Thus, the risk of structural failure of a tungsten component can be estimated only in a probabilistic framework. In this work, we applied a probabilistic failure analysis code STAU to estimate the failure risk of a water-cooled tungsten mono-block divertor component. The STAU code was based on the weakest-link failure theory and linear elastic fracture mechanics. A typical heat flux load being expected for a fusion reactor was considered for the FEM stress analysis. The failure probability was computed considering various mixed-mode fracture criteria. Both the experimentally estimated and hypothetical Weibull parameters were used as material data. In the case of unirradiated tungsten, the failure probability was acceptably small whereas reduced Weibull parameters led to significantly increased failure risk.     

长输管线跨越段管壁皱折原因分析（2）

在文（１）基础上讨论了矩阵方程的迭代处理，并对典型跨越结构在不同载荷条件下位移的内力进行了计算分析，从工程角度按规范进行了稳定性验算及管壁皱折的产生原因分析。结果表明，管壁皱折的产生与输油工艺变化后出站油温提高及输量减少后输送压力降低有关，与固定墩可能产生的轴向位移有关。