A novel mechanism of cochlear excitation during simultaneous stimulation and pressure relief through the round window

The round window (RW) membrane provides pressure relief when the cochlea is excited by sound. Here, we report measurements of cochlear function from guinea pigs when the cochlea was stimulated at acoustic frequencies by movements of a miniature magnet which partially occluded the RW. Maximum cochlear sensitivity, corresponding to subnanometre magnet displacements at neural thresholds, was observed for frequencies around 20 kHz, which is similar to that for acoustic stimulation. Neural response latencies to acoustic and RW stimulation were similar and taken to indicate that both means of stimulation resulted in the generation of conventional travelling waves along the cochlear partition. It was concluded that the relatively high impedance of the ossicles, as seen from the cochlea, enabled the region of the RW not occluded by the magnet, to act as a pressure shunt during RW stimulation. We propose that travelling waves, similar to those owing to acoustic far-field pressure changes, are driven by a jet-like, near-field component of a complex pressure field, which is generated by the magnetically vibrated RW. Outcomes of research described here are theoretical and practical design principles for the development of new types of hearing aids, which use near-field, RW excitation of the cochlea.     

SPS烧结层状TiB2／BN陶瓷的界面研究

本文采用放电等离子烧结(SPS)技术烧结层状TiB2/BN陶瓷，研究其界面结合的性质和状况。并讨论了当夹层厚度不同的时候，界面结合的不同机制。     

煤沥青中五种有毒成分对人的影响及其防治

简单介绍了煤焦油中的苯、萘、蒽、苯并（a）芘和苯酚所具有的不同毒性，针对这五种物质应采用的预防和急救措施，以保护工人的健康与生命安全。     

Microstructure refinement of alumina: Optimisation by gas pressure sintering process

This paper investigates densification and grain growth evolutions during gas pressure sintering of alumina. Isothermal sintering runs are performed under different nitrogen pressures: atmospheric pressure and 2 MPa. Experimental data are fitted thanks to constitutive laws in order to understand nitrogen pressure effect on densification and grain growth mechanisms of a fine-grained alumina. An optimal run of densification is proposed as an application of these results.     

Website browsing aid: A navigation graph-based recommendation system

Websites nowadays are an important and popular source of publicly available information. However, due to their exploding scale and complexity, overcoming information overload to find relevant information is a major challenge. In addition to website maps and search engines, self-adaptive websites or websites with intelligent navigation aid are very useful tools in addressing this issue. In this paper, a navigation graph-based recommendation system is proposed, in which the navigation patterns of previous website visitors are utilized to provide recommendations for newcomers. The performance of the proposed recommendation algorithm is tested using the data collected from a real world website. Experimental results reveal that the proposed system can yield satisfactory recommendations, especially to the visitors in their early navigation steps.     

Preparation of polycrystalline BaTi2O5 ferroelectric ceramics

Polycrystalline BaTi₂O₅ (BT₂) was prepared by solid state sintering in air using BaCO₃ and TiO₂ as starting materials. A rod-like BT₂ sintered bodies in a single phase were obtained above 1025 °C by adding 5 wt.% B₂O₃. The densification of BT₂ sintered bodies decreased with increasing sintering temperature. The maximum permittivity of BT₂ sintered body was 640 at the Curie temperature (T_c) of 461 °C and the frequency of 100 kHz. The addition of B₂O₃ was effective to obtain BT₂ in a single phase at low temperatures with elongated microstructure and to improve the permittivity, indicating the formation of preferred orientation at low temperature was related with liquid-phase sintering mechanism.     

两性聚丙烯酰胺的合成与助滤性能研究

通过自由基溶液聚合，以丙烯酰胺、丙烯酸钠及２－丙烯酸亚胺基－２－甲基丙烷三甲基氯化铵为单体合成了两性聚丙烯酰胺，与结构相似的阳离子，阴离子和非离子聚丙烯酰胺对比研究了助滤性能，同时研究了助滤剂用量，溶液ｐＨ值等因素对助滤效果的影响。     

Influence of erbia or europia doping on crystal structure and microstructure of ceria–zirconia (CZ) solid solutions

In this study we have prepared three zirconia–ceria compositions, namely 12, 50 and 80 mole% CeO₂. Along with each pure ceria–zirconia composition we have prepared two parallel erbia- or europia-doped materials in which 0.5 mole% of each of the two starting oxides is replaced by 1 mole erbia or europia.     

Advanced indium-tin oxide ceramics for sputtering targets

Indium-tin oxide (ITO) ceramic sputtering targets are widely used in formation of electrically conductive transparent thin films for electrodes in flat panel displays, solar cells, antistatic films and others, and which are commonly produced by a conventional dc magnetron sputtering process. The ceramic targets should be of high purity with a uniform microcrystalline structure and should possess high density and high electrical conductivity. In the present work, the challenges of the ceramic composition (e.g. the ratio of In₂O₃ and SnO₂) and manufacturing are considered; they include the use of high quality starting materials, particularly In₂O₃ powders with respect to purity, morphology and sinterability, manufacturing routes and sintering process. Positive experience in the development and manufacturing of ITO ceramic planar sputtering targets using in-house prepared In₂O₃ powders is reported. ITO ceramic tiles with areas up to 1500–1700 cm² and densities of 99+% of TD are manufactured. Physical properties of the ITO ceramics and sputtered films have been studied.     

Answer to the remarks on superconductivity in PdH

In this paper, the effect of heating rate on the microwave sintered 90W–7Ni–3Fe heavy alloys was investigated, with the heating rate in the range from 10 to 112 °C/min. When the alloys were sintered at the heating rate from 20 to 105 °C/min, they exhibit excellent properties with the relative density over 99%, tensile strength between 850 and 922 MPa and elongation around 20%. It has been shown that a faster heating rate results in smaller W grain size and larger W–W contiguity. The heating rate of 80 °C/min has the best combination of the microstructure and mechanical performance. Sintering under an optimized condition leads to the enhanced mechanical properties of 1020 MPa in tensile strength and 21% in elongation.