STABILITY TEST OF SRC II DISTILLATES BY ESR

The stability of distillates derived from the SRC II coal liquefaction process has been investigated by means of electron spin resonance (e.s.r.). The samples were prepared by storing at room temperature for 8 days in air or in vacuo. The lighter fraction of distillate deteriorated more easily via oxidation than the heavier fraction.     

Transition liquid phase bonding of a Hastelloy X and the bond strength at 1173 K

Transition liquid phase (TLP) bonding has been conducted on a Hastelloy X using amorphous foil filler metals. The inserted fillers were made by rapid solidification of a Ni-15% Cr alloy containing 3 to 5 mass% boron as a melting point depressant. The microstructural change with isothermal bonding time from 2.4 to 38.4 ks was examined in the bond regions by optical microscopy and electron probe microanalysis (EPMA). An assessment of the bond strength was made by stress rupture tests performed at 1173 K. It was found that rupture strain and rupture life increased with increasing bonding time. A bond efficiency greater than 80% was achieved when the bonding time was 38.4 ks.     

High temperature 1H-NMR study of coal and pitch at the early stages of carbonization

The temperature dependence of the ¹H-NMR absorption in coals and pitches have been obtained using a pulsed Fourier transform NMR spectrometer with a high temperature probe. The samples as received were heated in the high temperature probe and NMR spectra were obtained simultaneously. With increasing temperature, the value of the line width at half-height (ΔH_1/2) of a brown coal decreases and then increases rapidly. On the other hand, tar pitch and the γ component of a coal indicate that the values of ΔH_1/2 remain small over a wide temperature range. It is found that there is an excellent relation between the temperature dependence of ΔH_1/2 and the optical texture of the mesophase.     

Theoretische und experimentelle Grundlagen der Erstarrungskinetik von Eisen

Konzentrations- und Temperaturverteilung an der Erstarrungsfront bei normaler Erstarrung und beim Zonenschmelzen. Ableitung der Unterkühlungsgleichung für das Zonenschmelzen an der Erstarrungsfront. Temperaturverlauf in der flüssigen Phase beim Zonenschmelzen in Abhängigkeit von der Erstarrungsgeschwindigkeit zwischen 1,14 cm/h und 34 cm/h. Konzentrationsverteilung für Kohlenstoff, Schwefel, Stickstoff, Sauerstoff, Phosphor und Silicium in den binären und von Kohlenstoff und Schwefel, Kohlenstoff und Stickstoff sowie Schwefel und Stickstoff in den ternären Systemen. Die effektiven Verteilungskoeffizienten k_e und die Stoffübergangskoeffizienten D/ô. Die Gleichgewichtsverteilungskoeffizienten k₀ sowie die Diffusionskoeffizienten. Berechnung des Unterkühlungsverlaufes der Schmelze an der Erstarrungsfront.     

Correlation between menstrual cycle and cognitive performance in a chimpanzee (Pan troglodytes).

Extensive research on human subjects has tried to investigate whether there is a correlation between cognitive performance and the menstrual cycle. Less is known about the relationship between the menstrual cycle and task performance in other cognitive animals. We test whether the secretion of a sex hormone [luteinizing hormone(LH)] influences the performance of cognitive tasks by a female chimpanzee (Pan troglodytes) who is part of a long-term cognition research program. We focus on two cognitive tasks: an “easy task,” which consists of simple numerical ordering, and a “difficult task,” which combines numerical ordering with memorizing the numerals' spatial location. Data on the performance of these cognitive tasks, urine samples, and sexual swelling over six menstrual cycles showed that the chimpanzee's performance accuracy decreased and that the intertrial interval was longer during the LH-surge of the menstrual cycle, but only for the performance of the difficult task. These performance attributes seem to reflect a decrease in attention or motivation during ovulation. In summary, the cognitive performance of a chimpanzee was disturbed by hormonal changes despite her long-term experience in the tasks. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The calibration of Bonner sphere spectrometer

Bonner sphere spectrometer (BSS) is used in radiation protection measurement because of its wide energy range (thermal to MeV) and easy operation. Mitsubishi Heavy Industries (MHI) has used BSS to obtain neutron spectrum and has used the neutron spectrum to estimate neutron dose or induced activity. Calibration of BSS is important to estimate precise neutron dose or induced activity. MHI BSS was calibrated at National Institute of Advanced Industrial Science and Technology (AIST). The calibration results at AIST are in good agreement with calculation results.     

杆状支护系统的耦合模型及应用

锚杆/锚索等杆状支护系统在土木工程界的应用很广。但到目前为止，杆状支护物与被支护体之间的耦合机理却尚未十分清晰，有关支护效果的可靠合理的评价方法也并未成熟。基于Shear-Lag理论，提出一种改良的计算分析方法来描述杆状支护材料、交界面和被支护体之间的耦合作用机理。分析锚杆拉拔试验中由耦合到破坏的整个过程，提出一个计算交界面其实粘结强度的新方法。普通拉拔试验中，交界面的平均剪切强度低于其真实强度。二者的差别受支护杆的锚固长度和试件材料的物理力学性质的影响。若忽略试件材料的变形模量，可能导致试验的计算值与其实强度之间出现很大的偏差。分析不同变形模量试件体的拉拔试验过程，对于软岩支护中金属体的室内拉拔试验，建议试件材料的变形模量和相应的锚固长度。圆形隧道周边锚杆的受力状态分析表明，锚杆受力后存在拉拔区、中性点和锚固区。中性点的位置不但和隧道的几何尺寸有关，还与岩石的物理力学性质有关．计算结果和实测结果进行了对比，二者较为接近。