Effect of focused ion beam sample preparation on the phase composition of zirconia

The investigation of phase transformations in metastable ceramic systems such as zirconia often requires local phase analysis within the areas of interest. Electron backscatter diffraction is a suitable method in combination with focused ion beam sample preparation. The interaction between ion beam and sample has to be carefully considered. In case of metastable Y-PSZ and Mg-PSZ, phase transformations were observed after FIB preparation with 30?kV, 30?nA and 5° incidence angle. Damage was the dominating effect for angles of 72°. The expected local temperature increase due to the ion bombardment with 30?kV and 30?nA is 700?K for ZrO₂. Thus, the observed phase transformations can be explained on the basis of the temperature increase in the corresponding Y-PSZ phase diagram. In case of Mg-PSZ, the transition temperature is 1083?°C. The local temperature increase was obviously lower. The excitation energy for the observed phase transformation was smaller than expected from the phase diagrams of the thermodynamic equilibrium. Using 5?kV, 4.8?nA and 5° incidence angle, no phase transformations and no damage were observed. Thus, these conditions are well suited for the FIB preparation of metastable zirconia.     

用于千兆以太网基带铜缆接收器均衡的甚高频自适应 连续时间Gm-C 二阶带通滤波器的研究和设计

本文设计了用于千兆以太网基带铜缆接收器均衡的甚高频自适应连续时间Gm-C二阶带通滤波器。基于最陡梯度下降算法，带通滤波器的零点在57－340MHz的频率范围内可以自适应地调节，中心频率为1.278GHz。通过外接电阻伺服环路，滤波器中跨导转换器的跨导值不受工艺偏差和温度变化的影响，采用CSMC－HJ0.6μm CMOS工艺器件模型，用Cadence Spectres仿真器仿真了设计的自适应滤波器电路，仿真结果验证了设计原理和设计的电路。系统的最长学习时间为880个参考时钟周期。     

Microstructured and Electro-Assisted High-Temperature Wettability of MgO in Contact with a Silicate Slag-Based on Fayalite

In this work, MgO samples have been microstructured by laser treatment and surfaces with a controlled stripe design have been manufactured. Sessile drop wetting measurements were performed in a special heating microscope by determining horizontal contact angles as well as contact angles as a function of surface inclination angles. In a further step, voltage was applied to ground MgO surfaces and the wetting behavior was registered as a function of the voltage level. Activation energy analysis was conducted for all the experiments.     

The hemostatic system function of patients with severe forms of diphtheria

Hemostasis of 100 patients with severe diphtheria infection was studied throughout the disease. The patients were found to have marked procoagulant, anticoagulant and fibrinolytic disorders. Antithrombogenic activity of the vascular wall was also abnormal. The above impairments correlated with the symptoms severity and are interpreted as DIC syndrome which ran subclinically or as hemorrhagic syndrome. The majority of the patients underwent a hyperhypocoagulant phase of DIC syndrome.     

Effect of freezing rate on the denaturation of myofibrillar proteins

Freezing of bovine muscle has a denaturating effect on myofibrillar proteins, Differ-ential Scanning Calorimetry (DSC) studies of fresh and frozen muscle at different freezing rates show a decrease on denaturation enthalpies; the lower the freezing rate the greater the loss. When measuring the specific areas (ratio between each partial area in cm', and the dry weight of the sample, in mg) of the DSC thermograms, it can be observed that the area ascribed to myosin decreases with freezing, while the area corresponding to actin is not affected. These results are in agreement with the ATPase activity decreases as a consequence of freezing observing higher losses at lower freezing rates. The denaturation observed could be a result of a partial unfolding of the myosin head being more pronounced at low freezing rate.     

0412-1961

TAN Yanchang; HE Bin; ZHAO Yuhua (Northeast Institute of Technology, Shenyang)     

A Novel Vibrating Finger Viscometer for High-Temperature Measurements in Liquid Metals and Alloys

A novel vibrating finger viscometer for high-temperature measurement in liquid metals and alloys up to 1823 K was constructed. The dynamic viscosity (\(\eta \)) of the liquid fluid is measured as a product of \((\rho \cdot \eta )^{0.5}\) and the relative change of the field coil input for a constant amplitude recording at the resonant frequency of the oscillator. The viscometer was calibrated at 298 K using reference silicon oils with varying kinematic viscosities (\(\nu \)), \((0.79\hbox { to } 200)\times 10^{-6}\hbox { m}^{2}\cdot \hbox {s}^{-1}\). In the present study, the viscosity of liquid gold (\(99.99\,\%\) Au), silver (\(99.9\, \%\) Ag), and tin (\(99.9\,\%\) Sn) was measured. The viscosities expressed as an Arrhenius function of temperature are:

$$\begin{aligned} \hbox {for Au:}\quad \quad \hbox {ln }\eta= & {} -0.1990+\frac{2669}{T}\\ \hbox {for Ag:} \quad \quad \hbox {ln }\eta= & {} -0.4631+\frac{2089}{T}\\ \hbox {for Sn:} \quad \quad \hbox {ln }\eta= & {} -0.5472+\frac{671}{T} \end{aligned}$$

The viscosity values are consistent within the range of available literature data.