Experimental study on hysteresis phenomena of shock wave structure in an over-expanded axisymmetric jet

In recent studies on two-dimensional supersonic jets, it is reported that the hysteresis phenomenon for the reflection type of shock waves in the jet flow field is occurred under the quasi-steady flow condition and this phenomenon is affected by the transitional pressure ratio between the regular reflection and Mach reflection. However, so far, there are few researches on the hysteresis phenomenon for the transition of shock waves between regular and Mach reflection in over-expanded supersonic jets and the phenomenon has not been investigated satisfactorily. Therefore, the purpose of this study is to clarify the hysteresis phenomena for the reflection type of shock wave in the over-expanded axi-symmetric supersonic jet experimentally, and to discuss the relationship between hysteresis phenomenon and rate of the change of pressure ratio with time. Furthermore, the effect of Mach number at the nozzle exit on hysteresis loop was investigated for two kinds of nozzle.     

Lithium Phenolate Complexes with a Pyridine‐Containing Polymer for Solution‐Processable Electron Injection Layers in PLEDs

A series of (vinylphenyl)pyridine‐based polymer binders, PVPh2Py, PVPh3Py, and PVPh4Py, are designed and synthesized and it is found that mixtures of Liq and the polymers exhibit superior electron injection characteristics as ultrathin (1.6 nm) electron injection layer (EIL) films. They are comparable to those of EILs composed only of Liq. The addition of the polymers does not deteriorate the performance of Liq EILs. Additionally, when the EIL thickness is increased from 1.6 nm to 16 nm, the driving voltages increase and the external quantum efficiencies decrease. The increase in the voltage and decrease in the EQE are suppressed in the device with mixed EILs compared to those observed for the device composed of 100 wt% Liq. Furthermore, the position of the nitrogen in the pyridine ring is considered to influence the electron transport properties of the EILs. The mixing PVPh4Py with Liq improves the driving voltage of the fabricated devices, even with a thick mixed EIL. This reduced dependence of the performance of EILs on their thickness will be advantageous for the coating of large areas using solution processes.     

六角形布置反应堆高保真物理计算方法研究与验证

俄罗斯商用压水堆VVER和大多数实验堆均采用了六角形紧凑型栅格布置,为了实现VVER和六角形实验堆的高保真数值模拟分析,本文基于数值反应堆物理计算程序（NECP-X）开展了六角形堆芯高保真计算方法研究和程序开发。首先,将全局-局部耦合共振自屏计算方法拓展至六角形堆芯,实现六角形堆芯燃料棒的全堆芯高精度共振计算;其次,基于2D/1D耦合输运计算方法研究了六角形堆芯的高保真计算方法;最后,为了提高全堆芯计算的计算效率,研究了基于区域分解松耦合的非结构网格的粗网有限差分（CMFD）加速方法,可以实现以矩形、六角形和其他多边形栅元为基础的pin-by-pin CMFD 加速。为了验证六角形堆芯高保真计算方法的精度和效率,计算了六角形C5G7基准问题,并分析了六角形输运计算方法的计算精度和CMFD方法的加速效果;将NECP-X程序应用于西安脉冲堆的2D全堆芯计算,与蒙特卡罗程序的结果对比表明NECP-X程序计算得到的特征值和功率分布均具有较高精度。因此,本文建立的六角形堆芯高保真计算方法可以应用于六角形堆芯的分析计算。      

一种实时监测系统的体系结构及软件设计

本文介绍了监测点多、面广、距离远、采用无线通讯方式的实时监测系统的体系结构,阐述了其软件结构和功能,讨论了系统实时性、可靠性、灵活扩充性和数据库系统的设计和实现。本文工作对新型实时监测系统的设计与实现有一定参考价值。     

Stabilization of poly(vinyl chloride). X. Synergisms between epoxidized polybutadienes and metal soaps on the stabilization of poly(vinyl chloride)

Effects of epoxidized 1,2- or 1,4-polybutadienes on the zinc stearate/calcium stearate synergetic soap-induced thermal stabilization of poly(vinyl chloride) (PVC) were investigated by colorimetry. The remarkable stabilization effects of epoxidized polybutadienes could not be observed on the PVC films without synergetic soaps, while the stabilization of PVC was markedly enhanced by combined use of epoxidized polybutadienes with synergetic soaps. Excessive coloration of cool color-producing zinc chloride-polyene complexes that were the source of abrupt discoloration of stabilized PVC was retarded by using epoxidized polybutadienes together with synergetic soap. The synergism of epoxidized polybutadienes was enhanced with increasing epoxy contents. Moreover, the effect is also clearly dependent on degree of dispersion of epoxidized polybutadienes in PVC. Further colorimetries, infrared (IR), and X-ray photoelectron spectroscopies on the various PVC-containing epoxidized polybutadienes and zinc chloride indicated that the epoxy groups capture the zinc chloride. The synergistic effect between epoxidized polybutadienes and metal soap was ascribed to epoxidized polybutadienes serving as acceptors for the excessive cool color-producing zinc chloride produced by zinc stearate to retard the abrupt discoloration of stabilized PVC. The plate-out phenomenon appeared during the molding process of PVC-containing epoxy compounds was considerably retarded by epoxidized polybutadienes which modified polyols. The polyol-modifying epoxidized polybutadienes also exhibited a marked effect on PVC stabilization with metal soap.     

Human chymase, an enzyme forming novel bioactive 31-amino acid length endothelins

We report the novel role of human chymase in the production of bioactive 31-amino acid length endothelins (ETs), which may play a role in allergies and vascular diseases. In the bronchi of asthmatic patients, the vascular tissue in atherosclerosis, and the heart muscle in cardiac hypertrophy, both ET-like immunoreactivity and the accumulation of mast cells significantly increase. Chymase from human mast cells selectively cleaves big ET-1, -2 and -3 at their Tyr31-Gly32 bonds, and produces novel bioactive 31-amino acid length ETs, ETs(1-31), without any further degradation products. However, chymases from other species, human cathepsin G, and porcine alpha-chymotrypsin, degrade big ETs. ETs(1-31) at concentrations between 10(-9) M and 10(-7) M exhibited various contractile potencies in rat tracheae and porcine coronary arteries in a dose-dependent manner. Furthermore, ET-1(1-31) at concentrations between 10(-14) M and 10(-10) M caused a significant increase in the intracellular free Ca2+ concentration. The contractile activity of ETs(1-31) may not be the consequence of conversion to the corresponding ETs(1-21) by phosphoramidon-sensitive ET converting enzyme(s) or other chymotrypsin-type proteases and metallo-endopeptidases, because the contractile activity was not significantly inhibited on treatment with inhibitors of these proteases prior to the addition of ET-1(1-31).     

Concentration of cadmium in rice and urinary indicators of renal dysfunction

OBJECTIVES: (1) To examine the relation between concentrations of cadmium (Cd) in rice and urinary concentrations of indicators of renal dysfunction and the prevalence of abnormalities in urine in areas polluted by Cd. (2) To establish the maximum allowable concentration of Cd in rice from these findings. METHODS: The target population consisted of 1703 inhabitants (832 men and 871 women) aged over 50 years who consumed home grown rice and had lived in the same hamlet in areas polluted by Cd in the Kakehashi River basin in Ishikawa Prefecture, Japan for at least 30 years. The correlation coefficients between concentrations of Cd in rice and several urinary substances, the prevalence of abnormalities in urine and sex in hamlets polluted by Cd were calculated. Finally, regression analysis was performed for significant indicators to calculate the maximum allowable concentration of Cd in rice based on values in a control group. CONCLUSIONS: Significant correlations between concentration of Cd in rice and concentrations of urinary beta 2-microglobulin, metallothionein, glucose, and aminonitrogen were established. Similarly, there were significant correlations between concentration of Cd in rice and the prevalence of beta 2-microglobulinuria, metallothioneinuria, glucosuria, proteinuria, proteinuria with glucosuria, and aminonitrogenuria. The highest maximum allowable concentration of Cd in rice calculated for these indicators was 0.34 ppm/l and 0.29 ppm/g creatinine. Both values are lower than 0.4 ppm, the tentative limit prescribed by the Japanese government.     

Investigation of tritrophic interactions in an ecosystem using abstract chemistry

We investigated the population dynamics of a tritrophic interaction mediated by herbivore-induced plant volatiles that attracted carnivorous natural enemies of herbivores. We modeled the system by abstract chemistry, and an abstract rewriting system of multisets (ARMS), and compared the case where plants produced herbivore-induced volatiles with the case where they did not. We found that there was a case where herbivore-induced volatiles that attract carcivores resulted in a population increase of herbivores. This work was presented, in the Sixth International Symposium on Artificial Life and Robotics, Tokyo, Japan, January 15–17, 2001     

Molecular basis of proteolytic activation of Sendai virus infection and the defensive compounds for infection

It has been proposed that the pathogenicity of Sendai virus is primarily determined by a host cellular protease(s) that activates viral infectivity by proteolytic cleavage of envelope fusion glycoproteins. We isolated a trypsin-like serine protease, tryptase Clara, localized in and secreted from Clara cells of the bronchial epithelium of rats. The enzyme specifically cleaved the precursor of fusion glycoprotein F0 of Sendai virus at residue Arg116 in the consensus cleavage motif, Gln(Glu)-X-Arg, resulting in the presentation of the membrane fusion domain in the amino-terminus of the F1 subunit. Administration of an antibody against tryptase Clara in the airway significantly inhibited the activation of progeny virus and multiple cycles of viral replication, thus reducing the mortality rate. These findings indicate that tryptase Clara in the airway is a primary determinant of Sendai virus infection and that proteolytic activation occurs extracellularly. We identified two cellular inhibitory compounds against tryptase Clara in bronchial lavage. One was a mucus protease inhibitor, a major serine protease inhibitor of granulocyte elastase in the lining fluids of the human respiratory tract, and the other was a pulmonary surfactant which may adsorb the enzyme, resulting in its inactivation. These compounds inhibited virus activation by tryptase Clara in vitro and in vivo, but did not themselves affect the hemagglutination and the infectivity of the virus. The functional domain of the mucus protease inhibitor against the enzyme, which is organized in two homologous N- and C-terminal domains, is located in the C-terminal. Administration of these compounds in the airway may be useful for preventing infection with Sendai virus.     

Millimeter wave sensor using cylindrical Luneberg lens with flatsides

The cylindrical lens with flat sides, which has the focal point just on the surface of the lens, is developed by using an artificial low-loss dielectric material, and the design of the lens is also given. The characteristics of the cylindrical lens fabricated in Teflon, and a millimeter-wave sensor, consisting of a millimeter-wave (MMW) antenna mounted at the focus, are also investigated at 40 GHz band. MMW sensors with the beam width of 16° and gain of 15.6 dB were obtained