Hydrothermal Preparation of Ultrafme Monoclinic ZrO2 Powder

Ultrafine powder of single-phase manoclinic ZrO₂ was prepared by hydrothermal treatments of amorphous hydrated zirconia with 8 wt% KF solution under 100 MPa at 200° to 500°C for 24 h. The process yielded well-crystallized particles 16 nm and 22 nm in size at 200° and 500°C, respectively .     

化学纤维工业和地球环境

从化学纤维工业的回收利用和用于环境保护的化学纤维两个方面综述了日本等国的最新发展情况。对于日本最近比较成功的聚酯回收利用技术进行了比较详细的介绍。并从较宽的视角介绍用于环境保护的化学纤维及其一些最新的技术和产品     

Development and motion control of a biped walking robot based on passive walking theory

This research aims to develop the biped walking robot that can walk on the horizontal ground and improve walking efficiency by utilizing the theory of the passive walking robot, namely the pendulum principle. For that, two motors were installed on the hip of the robot to generate the control torques to perform a walking motion. The computer simulations with dynamic model were carried out to investigate the walking capability of the system. Experimental robot was developed considering the calculated results. The proportional control law was used in walking experiment. The robot can walk on the horizontal ground with the proposed method.     

Tribological characteristics of novel branched perfluoropolyether lubricant films in hard disk drives

In this study, the basic tribological characteristics of novel branched perfluoropolyether (PFPE) lubricant films such as TA-30 and QA-40 were examined. Their surface free energy characteristics and adhesive and friction forces were investigated using an atomic force microscope. The interactions between the lubricant molecules and the water molecules were also examined by monitoring the changes in the contact angle of distilled water on the test lubricant films. The interactive forces such as the adhesive and friction forces of a film that is approximately one monolayer thick were found to be strongly dependent on the conformation of the lubricant molecules on diamond-like carbon thin films. In addition, the TA-30 and QA-40 lubricant molecules appeared to interact with the water molecules more actively than conventional Ztetraol2000 molecules. These results afforded fundamental insight into the tribological performance of novel branched PFPE lubricants in the head-disk interface.     

Optical-fibre scanning near-field optical microscope for cryogenic operation

We have developed a new type of scanning near-field optical microscope (SNOM) utilizing optical fibres. The probe tip is controlled by shear force feedback with a fibre interferometer and signal light is collected directly by a multimode fibre. These features make the SNOM head more compact and less sensitive to vibration. Further advantages of this new type of SNOM are that it obviates the need for optical windows in the cryostat and offers easy optical alignment.     

Chemical force microscopy of self-assembled monolayers on sputtered gold films patterned by phase separation

Patterned self-assembled monolayers (SAMs) were formed on gold films and observed by friction force microscopy (FFM) and adhesive force mapping with pulsed-force mode atomic force microscopy (PFM-AFM). The substrate gold films were prepared by sputtering gold on flat surfaces of osmium-coated cover glass with surface roughness, Ra, of 0.3 nm. The patterned samples with the CH3 and COOH terminated regions were prepared using the Langmuir-Blodgett (LB) method, partial removal of the LB film by ultrasonication, and SAM formation. The CH3 and COOH terminated regions of the patterned SAMs in air and in water were observed by mapping friction and adhesive forces with FFM and PFM-AFM, respectively, using gold-coated AFM tips chemically modified with a thiol compound terminating in CH3 or COOH. The adhesive forces measured in air increased in the order of CH3/CH3, CH3/COOH (or COOH/CH3) and COOH/COOH, while those in water increased in reverse order. The enormous high adhesive force observed in water for CH3/CH3 was attributed to hydrophobic interaction between the CH3 tip and the CH3 terminated sample surface. With CH3 tip, the lower friction force was observed, however, in water on the CH3 terminated region than on the COOH terminated region. This experimental finding raises a question as to what is the effective normal load in friction measurements in water.     

A Support System for Fuzzy Optimum Aseismic Structural Design of Reinforced Concrete Buildings Using Graphical Representation

Abstract: In this paper, a support system of optimum aseismic design is proposed on the basis of fuzzy set theory and a graphical representation method. In optimum aseismic design of buildings, it is necessary to take account of subjective evaluation of users. In this system, a hierarchical model is employed to idealize and model the decision process of optimum aseismic design. By applying fuzzy set theory, this system can take account of subjective evaluation of users. The system is a prototype of an expert system for optimum aseismic design, and its knowledge is compiled interactively as numerical values by the fuzzy confluence rule and membership functions in fuzzy set theory in accordance with the hierarchical model given by users. Knowledge, which is necessary to perform the inference on optimum aseismic design, is acquired interactively. Optimization is performed by fuzzy multiobjective maximizing decision, and the maximum evaluation values of the top attribute can be found. Furthermore, distributions of the grade of membership value in maximizing the decision process are graphically represented, so the user can understand this process easily and intuitively. A case study is carried out for a reinforced concrete typical high school building in Kobe City.     

Involvement of Sac1 phosphoinositide phosphatase in the metabolism of phosphatidylserine in the yeast Saccharomyces cerevisiae

Sac1 is a phosphoinositide phosphatase that preferentially dephosphorylates phosphatidylinositol 4‐phosphate. Mutation of SAC1 causes not only the accumulation of phosphoinositides but also reduction of the phosphatidylserine (PS) level in the yeast Saccharomyces cerevisiae. In this study, we characterized the mechanism underlying the PS reduction in SAC1‐deleted cells. Incorporation of ³²P into PS was significantly delayed in sac1? cells. Such a delay was also observed in SAC1‐ and PS decarboxylase gene‐deleted cells, suggesting that the reduction in the PS level is caused by a reduction in the rate of biosynthesis of PS. A reduction in the PS level was also observed with repression of STT4 encoding phosphatidylinositol 4‐kinase or deletion of VPS34 encoding phophatidylinositol 3‐kinase. However, the combination of mutations of SAC1 and STT4 or VPS34 did not restore the reduced PS level, suggesting that both the synthesis and degradation of phosphoinositides are important for maintenance of the PS level. Finally, we observed an abnormal PS distribution in sac1? cells when a specific probe for PS was expressed. Collectively, these results suggested that Sac1 is involved in the maintenance of a normal rate of biosynthesis and distribution of PS. Copyright © 2014 John Wiley & Sons, Ltd.     

Photoconductive Emission and Detection of Terahertz Pulsed Radiation Using Semiconductors and Semiconductor Devices

Recent studies on the techniques and development of photoconductive (PC) semiconductor devices for efficient generation and detection of terahertz (THz) pulsed radiation are reported. Firstly, the optimization of PC antenna design is discussed. The PC detection of THz pulsed radiation using low-temperature grown GaAs with 1.55-μm wavelength probe is then described. Finally, the enhancement of THz radiation from InSb by using a coupling lens and magnetic field is investigated. These results reveal valuable insights on the design of an efficient, compact, and cost-effective THz time-domain spectroscopy system based on 1.55-μm fs laser sources.