Three-dimensional acoustic sound field reproduction based on hybrid combination of multiple parametric loudspeakers and electrodynamic subwoofer

Auditory Mixed Reality (MR) systems that reproduce Three-Dimensional (3-D) acoustic sound fields have recently become a research focus because the combination of visual and auditory MR systems can achieve a greater sense of presence than conventional visual MR systems. General auditory MR systems usually use a headphone-based system with a Head-Related Transfer Function (HRTF), which is a major system for reproducing 3-D acoustic sound fields. However, the localization accuracy of sound images with a HRTF depends on the individual. On the other hand, we have already proposed a system for reproducing a 3-D acoustic sound field with parametric loudspeakers instead of headphones. The 3-D acoustic sound field reproduced by this system has achieved a highly accurate localization of sound images. However, one problem is that it is difficult to reproduce lower frequency sounds using parametric loudspeakers, which causes a poorer sound quality. We tried to accomplish a greater sense of presence for 3-D acoustic sound fields based on a hybrid combination of an electrodynamic subwoofer and the parametric loudspeakers by improving the sound quality. Sound images were formed at the target location using the parametric loudspeakers, and a lower frequency sound was compensated for by using the electrodynamic subwoofer. Subjective evaluation experiments were conducted to verify the effectiveness of the proposed system. We confirmed the improved sound quality while maintaining a higher accuracy of sound image localization by using the proposed system. We also confirmed the optimum parameters of the proposed system to achieve a greater sense of presence.     

Synthesis of 5'-terminal capped oligonucleotides using O-N phosphoryl migration of phosphoramidite derivatives

Trivalent phosphoramidite derivatives could be readily converted by reacting with 1-hydroxy-7-azabenzotriazole to phosphotriester intermediates; these intermediates reacted smoothly with phosphorylated compounds to give pyrophosphate derivatives. This new phosphorylation approach enabled a facile and rapid synthesis of 5'-adenylated DNA oligomers (A(5')ppDNA) on resins using a silyl-type linker. Our new approach could be applied to the synthesis of a 2'-OMe-RNA oligomer containing the 5'-terminal 2,2,7-trimethylguanosine cap structure.     

白烟灰的物相分析及酸浸脱砷工艺

白烟灰因其含有砷等有毒化合物,其安全堆存是冶金企业面临的难题。 对白烟灰进行物相分析是处理该烟灰,使其达到环保要求堆存的重要依据。 采用X射线光电子能谱(XPS)和X射线粉末衍射(XRD)研究了河南某企业白烟灰的物相组成及化学结合状态,确定其所含化学成分及元素含量。 结果表明,样品中元素As相对含量高达20.99%,其中11%以游离态As₂O₃形式存在,其余以PbAs₂O₆形式存在。 样品中还含有少量的Cu、Pb、Zn等金属及其氧化物。 根据被测样品物相组成,提出了一种氧化酸浸脱砷的方法,并确定了最佳脱砷工艺,在最佳工艺条件下,砷的浸出率高达97.1%,高于文献报道的砷的浸出率。     

Analysis of human tear proteins by two-dimensional electrophoresis.

Human tear proteins in the conjunctival sac were separated on the basis of the differences in their isoelectric points and molecular weights using micro two-dimensional electrophoresis combined with immunoblotting. The two-dimensional electrophoretic patterns of tear proteins from patients with conjunctivitis were compared with those from normal individuals. We also measured integrated intensities of seven protein spots, lactoferrin (LF), albumin and five specific tear proteins (STP), to examine differences in the amounts of these proteins in tears from normal individuals of different sexes. In the tears from patients with conjunctivitis, secretory immunoglobulin A (IgA), LF and STP spots were stained more weakly, whereas the albumin spot was stained more strongly as compared with those from normal individuals. Furthermore, haptoglobin and IgG spots appeared in the tears from patients with conjunctivitis. These were more prominent in the tears from patients with severe conjunctivitis. There were significant differences in the amounts of LF and two kinds of STPs in the different sexes. The amounts of these proteins were larger in females.     

Prodrugs of 9-benzyl-8-hydroxy-2-(2-hydroxyethylthio)adenine: potent interferon inducing agents in monkeys

In order to improve the oral bioavailability of 9-benzyl-8-hydroxy-2-(2-hydroxyethylthio)adenine (SM-295072), a potent interferon (IFN) inducing agent, we synthesized prodrugs of it by utilizing the hydroxy groups at the C(2)-side chain and/or the C(8)-position. The carbonate prodrug at the C(8)-position was more effective than that at the C(2)-side chain for oral absorption in rats. Among the compounds prepared, compound 6 demonstrated the most preferable prodrug properties, and the maximum plasma concentration of 6 was approximately 4-fold higher than that of SM-295072. Furthermore, compound 6 was dose-dependently absorbed in monkeys by oral administration, and exhibited a potent IFN-inducting activity that correlated well with its plasma drug concentration.     

Synthesis and electrochemical performance of LiCr x Mn2-xO4(x=0,0.02,0.05,0.08,0.10) powders by ultrasonic coprecipitation

LiCr _x Mn_2-x O₄(x=0, 0.02, 0.05, 0.08, 0.10) compounds with a spinel crystal structure have been prepared by a novel ultrasonic co-precipitation method. The effects of the calcination temperature and the citric acid-to-metal ion molar ratio (R) on powder characteristics and electrochemical performance are evaluated. It is found that the optimum R and sintering temperature for LiCr _x Mn_2-x O₄ materials by the ultrasonic co-precipitation method are R= 5/6 and 800°C, respectively. The calcined powders are loosely bound agglomerates of abnormally coarsened particles with a narrow range of particle sizes. The effect of Cr doping was also explored. Electrochemical studies show that optimum materials synthesized by the ultrasonic co-precipitation method demonstrate good cycling performance.