GPC-GCMS快速测定农产品中的多种残留农药

应用GPC-GCMS在线连接装置，同时分析了97种农药，实现了从样品净化到农药分析完全自动化。提高了分析速度，简化了操作，实现了多种残留农药同时快速分析。     

Worm wheel mechanism with passive rollers

In this study, we developed new worm wheel mechanisms with passive rollers as their teeth and confirmed useful functions of these worm wheels with passive rollers to transmit power from worm gears with higher energy efficiency than ordinary worm wheels. By using passive rollers as their teeth, the developed worm wheels could realize high-power transmission efficiency with rolling frictional resistance instead of sliding frictional resistance. A worm wheel with conical passive rollers and one with disk-shaped passive rollers was fabricated as prototypes and examined in experiments. Smooth back-drivability of the worm wheels with passive rollers, which is difficult to realize with conventional worm wheels, was also demonstrated in the experiments. These serial experiments revealed that the developed worm wheel mechanism with passive rollers can replace conventional worm wheels with the same number of teeth and module in ordinary power transmission mechanisms with worm gearing and realize higher energy efficiency and smooth back-drivability. These features can be very useful to realize safe and soft actuators for automation systems in a human environment.     

Vacancy generation in deformed thin metal

Kiritani found that vacancy clusters of large number density form in f.c.c. thin metal of 100 nm thickness deformed to their fracture. In the present work, a computer simulation of deformation of thin metal is carried out to investigate how vacancies of high concentration generate during a deformation of thin specimens of Al and Cu. A crystal of 4000 atoms whose size is (10a₀ × 10a₀ × 10a₀) is elongated to z-axes. Two modes of simulation are carried out. In the mode 1, surface which are normal to x-axes and y-axes are kept free. In the mode 2, the periodic boundary condition is applied for all surfaces. The mode 2 is equivalent to the deformation of bulk metal. In the simulation of mode 1, the tilting of 1 1 0 atom row initiates on the surface. A tilting of rows to the same direction expands on a (1 1 1) plane and arrives to other side of surface. Dislocations do not form during the tilting. The tilting of atom rows occurs due to easy movement of atoms on surface responding to stress. In highly deformed thin metal, the tilting of atom rows occurs on multi-layers of parallel planes. Subsequently a tilted row split into two rows. A new row initiates by moving an atom on surface to the interstitial position. A transportation of atoms from the normal row to the new row occurs during deformation, which contributes to the reduction of thickness. Vacancies of high concentration are not generated in the case of the mode 1 deformation. In the simulation of the mode 2, the formation of domain in which atom rows tilt to the same direction occurs. At the domain boundary ordered array of atom rows becomes disordered in an instant and grows to a small crack of vacancy cluster. The formation process of vacancy clusters which were observed in deformed thin metal is due to the combination of the processes of the modes 1 and 2.     

The effects of different inorganic salts,buffer systems,and desalting of Varthemia crude water extract on DPPH radical scavenging activity

The DPPH radical-scavenging activity of 25 inorganic salts, two buffer systems, and crude water extract of aerial parts of Varthemia (Varthemia iphionoides) before and after resins purification were investigated. Eight of the 25 inorganic salts tested quenched the DPPH radical colour. Na₂S₂O₃ and FeCl₂ showed markedly high DPPH colour-quenching activity, with inhibition of 65.3% and 47.7% respectively, at a concentration of 10 μg/ml. Four salts slightly increased the intensity of DPPH radical colour. The rest of tested salts, acetate buffer, and phosphate buffer at a concentration less than 0.1 mM did not affect DPPH radical colour. The DPPH radical-scavenging activity of BHT and catechol was considerably affected by the concentration of phosphate buffer (pH 7.0), and by acetate buffer (pH 5.0) at concentrations more than 0.01 mM in the case of BHT only. The DPPH radical-scavenging activity of a crude water extract of aerial parts of Varthemia iphionoides was much higher than that of an extract desalted by cation-exchange resin, indicating that iron ions apparently elevated the DPPH radical-scavenging activity of the extract. Therefore, desalting of plant extracts is important in order to obtain the true value of DPPH radical-scavenging activity.     

Improvement in durability of flexible plastic dye-sensitized solar cell modules

Large-area integrated modules of flexible plastic type dye-sensitized solar cell (DSC) have been fabricated based on polyethylene naphthalate (PEN) film for practical applications such as ubiquitous power sources. From the view point of improving durability, composition of organic solvent-based electrolytes has been investigated. As a result, a plastic DSC module using LiI-free electrolyte maintained its energy conversion efficiency of 2% over 220 h under the accelerated condition of 55 °C and 95% relative humidity.     

Synthesis of chiral side-chain liquid crystalline polyacetylenes bearing succinic acid spacer

A chiral acetylene monomer having a cholesteryl group (PSCh) and novel three types of chiral acetylene monomers having a o-substituted tyrosine methyl ester (PSMY-Rs: –COC₆H₅=PSMY-Bz; –COC₆H₄CN=PSMY-BzCN; –COC₁₂H₉=PSMY-PhBz) as a pendant group were synthesized from 4-oxo-4-(prop-2-ynyloxy)butanoic acid (PS), and polymerized with the rhodium-catalyzed system. Structures and properties of the monomers and the resulting polymers were characterized and evaluated by NMR, IR, GPC, and DSC. In addition, these optical properties were investigated by polarimetric detector and circular dichroism (CD) analyses.     

Effect of Nucleation Temperature on Detecting Molecular Ions and Charged Nanoparticles with a Diethylene Glycol-Based Particle Size Magnifier

The classical nucleation theory predicts that a decrease in nucleation temperature under a constant saturation ratio increases the energy barrier for homogeneous nucleation to occur; therefore lower nucleation temperature would allow higher saturation ratio inside a condensation particle counter (CPC) while suppressing homogenous nucleation of working fluid vapor below a threshold value. On the other hand, the classical theory also predicts that a decrease in nucleation temperature increases the energy barrier for heterogeneous nucleation to occur, which potentially increases the minimum detectable size of CPC. Accordingly, it is important to investigate experimentally whether higher super-saturation under lower nucleation temperature decreases the minimum detectable size or not. Minimum detectable sizes of a diethylene glycol (DEG)-based nanoparticle size magnifier (nano-PSM) developed by Ito et al. (Ito, E., Seto, T., Otani, Y., and Sakurai, H. [2011]. Aerosol Sci. Technol. 45:1250–1259) were investigated at three different nucleation temperatures. Mobility standard molecular ions and mobility-classified silver nanoparticles were used as test aerosol particles. The vapor flux exiting from the evaporator in nano-PSM is accurately controlled using a syringe pump. The temperature of the mixing region and condenser in the nano-PSM is controlled at adiabatic mixing temperature, which we call its nucleation temperature. When the nucleation temperature was set at 16.7, 25.0, and 33.3°C, the minimum detectable mobility diameter values, which were defined at 50% value of counting efficiency curve, were 2.2, 2.9, and 3.0 nm, respectively, indicating that lower nucleation temperature is favorable for detecting smaller sized particles using DEG-based PSM or CPCs.

Copyright 2015 American Association for Aerosol Research     

Preparation of Highly Crystallized Strontium Titanate Powders at Room Temperature

Highly crystallized fine powder of strontium titanate (SrTiO₃) was obtained at room temperature simply by leaving a vial containing the powder mixture of Sr(OH)₂·8H₂O and hydrous titania gel (TiO₂·nH₂O) for 10 d. Solvent and additive(s) used in the conventional low‐temperature process were not used. The crystallinity judged from the FWHM of X‐ray diffraction peak was comparable to that obtained by a solid‐state reaction. To cause the reaction at room temperature, the titania gel had to contain a considerable amount of H₂O (n > 0.97). The reaction is considered to be neutralization of titanic acid [H₄TiO₄ or Ti(OH)₄] and strontium hydroxide (base). Using similar process, highly crystallized BaTiO₃ powder was also obtained at 60°C. In comparison with the formation temperature of BaTiO₃, tolerance factor in the perovskite structure was important for the room‐temperature synthesis of SrTiO₃. SrTiO₃ was hardly obtained at room temperature by the addition of saturated strontium hydroxide solution to the hydrous TiO₂ gel (n = 1.29). Therefore, the reaction seems to proceed in the hydrous titania gel. This process is characterized by three important points; “no solvent”, “no additional reagents”, and above all, “no heating”.     

Experimental analysis in recording transmission and reflection holograms at the same time and location

Holographic recording media with a reflection layer are useful because they make it possible to maintain backward compatibility with CDs and DVDs, and a conventional servo system is easily attachable. The incident beam is fed back to the recording layer by the reflection layer, so there are four beam pairs to record the transmission and reflection holograms. We analyze the basic property of the transmission and reflection holograms and evaluate the problem when the transmission and reflection holograms are recorded at the same time. It is shown that the shrinkage in the photopolymer medium has a different effect on each hologram, so the readout image from the two holograms is misaligned. Those diffraction beams make the interference pattern, and the signal-to-noise ratio (SNR) of the output image decreased. Taking into account the difference in wavelength selectivity between the transmission and the reflection holograms, we propose a way to select one hologram to get the diffraction beam and eliminate the interference pattern using the tuning readout wavelength. By using this method, we can eliminate the diffraction beam from the reflection hologram and keep a high SNR.     

Near-infrared fluorescence probes for enzymes based on binding affinity modulation of squarylium dye scaffold

We present a novel design strategy for near-infrared (NIR) fluorescence probes utilizing dye-protein interaction as a trigger for fluorescence enhancement. The design principle involves modification of a polymethine dye with cleavable functional groups that reduce the dye's protein-binding affinity. When these functional groups are removed by specific interaction with the target enzymes, the dye's protein affinity is restored, protein binding occurs, and the dye's fluorescence is strongly enhanced. To validate this strategy, we first designed and synthesized an alkaline phosphatase (ALP) sensor by introducing phosphate into the squarylium dye scaffold; this sensor was able to detect ALP-labeled secondary antibodies in Western blotting analysis. Second, we synthesized a probe for β-galactosidase (widely used as a reporter of gene expression) by means of β-galactosyl substitution of the squarylium scaffold; this sensor was able to visualize β-galactosidase activity both in vitro and in vivo. Our strategy should be applicable to obtain NIR fluorescence probes for a wide range of target enzymes.