All-optical switching in Pharaonis phoborhodopsin protein molecules

Low-power all-optical switching with pharaonis phoborhodopsin (ppR) protein is demonstrated based on nonlinear excited-state absorption at different wavelengths. A modulating pulsed 532-nm laser beam is shown to switch the transmission of a continuous-wave signal light beam at: 1) 390 nm; 2) 500 nm; 3) 560 nm; and 4) 600 nm, respectively. Simulations based on the rate equation approach considering all seven states in the ppR photocycle are in good agreement with experimental results. It is shown that the switching characteristics at 560 and 600 nm, respectively, can exhibit negative to positive switching. The switching characteristics at 500 nm can be inverted by increasing the signal beam intensity. The profile of switched signal beam is also sensitive to the modulating pulse frequency and signal beam intensity and wavelength. The switching characteristics are also shown to be sensitive to the lifetimes of$mmb pbf pR_bf M$and$mmb pbf pR_bf O$intermediates. The results show the applicability of ppR as a low-power wavelength tunable all-optical switch.     

Contouring controller design for biaxial feed drive systems considering compliance of transmission mechanism

Contouring control is an effective method for computer numerical controlled machining, and various such designs have been proposed to date. However, the compliance of the transmission mechanism is not considered in most existent contouring controller designs. This paper presents a new contouring control system design considering the compliance of a transmission mechanism based on a fourth-order model of feed drive dynamics. First, we present a controller design that enables the controller gain assignment for reducing the error component orthogonal to the desired contour curve, independent of the tangential error component. Although this design provides better control performance with small control input variance, there exists an inherent contour error because of the difficulty in calculating the exact contour error for any contour curve in real time. To address this problem, a reference adjustment method is used to estimate the actual contour error. The effectiveness of the proposed design is experimentally verified by comparing the control performance with a design based on a plant model that neglects the compliance.     

Effective decolorizations and mineralizations of organic dyes over a silver germanium oxide photocatalyst under indoor-illumination irradiation

A silver germanium oxide, Ag₂GeO₃, was developed as a novel photocatalyst for degradation of organic dyes. The chemical composition of the sample was investigated via the SEM/EDX, ICP-AES, and TG-DTA techniques. The general activity of the material was characterized by testing the photodegradations of typical organic dyes, such as Methylene Blue (one of the heteropolyaromatic dyes), Rhodamine B (one of the xanthene dyes), Fuchsin Acid (one of the sulfonic dyes), and Orange II (one of the azoic dyes). All of these dyes were degraded more than 90% within 25 min under the visible-light irradiation of Xe lamp. Besides, with a commercial white fluorescent lamp as testing light source (light intensity, 61 μW/cm²), the efficient decolorizations and mineralizations of the organic dyes were achieved over this material: 79% (90%) of the organic carbon in the Methylene Blue (Rhodamine B) solution was photooxidatized to inorganic carbon forms, when these dyes were totally decolorized. The high performance of this material is due to the photophysical properties of the wide-visible-range absorption and response, and the sufficient oxidative potential of the top of the valence band.     

Production of Propylene from Ethanol Over ZSM-5 Zeolites

In this work, we studied the conversion of ethanol to propylene over ZSM-5 zeolites. The catalytic performance of H-ZSM-5 (Si/Al₂ = 30, 80, and 280) and ZSM-5 (Si/Al₂ = 80) modified with various metals was investigated. H-ZSM-5(Si/Al₂ = 80) afforded high propylene yield, which indicates that a moderate surface acidity favored propylene production. Zr-modified ZSM-5(80) gave the highest yield (32%) of propylene at 773 K. Furthermore, the catalytic stability of the zeolite was improved by the modification of zirconium. The surface acidity and the presence of metal ions played important roles on the production of propylene.     

Operando X-ray Absorption Spectroscopy Study of Pt/γ-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> During the Total Oxidation of C<Subscript>3</Subscript>H<Subscript>6</Subscript>

Operando X-ray absorption fine structure (XAFS) investigations were performed on Pt/γ-Al₂O₃ during the total oxidation of C₃H₆ in reducing and oxidizing atmospheres. Study of the Pt valance state and catalytic conversion behavior as a function of temperature revealed that both the creation of metallic Pt sites and the activation of adsorbed species on Pt are important for the functioning of the catalytic reaction at low temperature.     

Structure–Affinity Relationship Study of Bleomycins and Shble Protein by Use of a Chemical Array

Natural product libraries for SAR studies : We used a chemical array platform to study the SARs of bleomycin (BLM) derivatives and Shble protein. The on‐chip SARs suggested that several domains are important for recognition of BLMs by Shble protein. In particular, the C‐terminal tail and the propionamide moiety in pyrimidoblamic acid (PBA) were shown to be important for the binding.

     

纳米微粒与LCD:一个令人惊奇的世界

把纳米微粒加进液晶显示器(LCD)的主要媒介之中,将引发液晶材料几乎所有的物理性能发生改变,导致工作电压和响应时间均下降。这种技术可能是不需要进行化学分析来提高液晶材料性能的备选方案。     

Suppression of dielectric loss of PPE/HIPS alloys in microwave region by utilization of MgO filler

The high-frequency dielectric, thermal, and mechanical properties of poly(2,6-dimethyl-1,4-phenylene ether)/high-impact polystyrene (PPE/HIPS) alloys compounded with MgO filler were investigated as a function of MgO content. A comparison with isotactic polypropylene/MgO composites was also carried out. Composite samples without voids were successfully prepared by melt-kneading and hot-pressing processes. A reduction of dielectric loss (tan δ) to less than 10⁻³ was achieved by adding 40 vol % of MgO to the PPE/HIPS alloys. The compositional dependencies of the real part of the dielectric constant (ε′), tan δ, and temperature coefficient of ε′ (TCε) showed correspondence with the Bruggeman theory. The decrease in thermal expansion with increasing filler concentration followed the logarithmic rule of mixture. The flexural moduli of the composites increased with MgO loading in accordance with the Nielsen theory. On the other hand, deteriorations were observed in flexural and Charpy impact strengths. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47315.     

Experimental investigation of electrolytic solution for anion exchange membrane water electrolysis

The effect of species and concentration of electrolytic solution on the performance of anion exchange membrane (AEM) water electrolysis is experimentally examined. When potassium hydroxide (KOH) or potassium carbonate (K₂CO₃) solution is applied for the electrolytic solution, electrolysis is successful under mild alkaline conditions, whereas electrolysis with pure water is quite difficult due to the high resistance of the AEM. AEM electrolysis performance with K₂CO₃ solution is superior to that with KOH solution, even at similar pH of around 12. Hydrogen content in the anode gas compartment and relative humidity of produced hydrogen are also measured during the electrolysis.