Manufacturing process of bezel frame for strength-reinforced TFT LCD module by progressive hemming of SUS304 stainless steel sheet

In this study, the design procedure for a progressive multi-hemming forming process has been proposed for manufacturing bezel frames for strength-reinforced TFT LCD (Thin-film-transistor liquid-crystal display) modules. First, a strength analysis was performed using Finite element (FE) simulations to determine the minimum number of required folding edges. Subsequently, anoother FE analysis was carried out in order to investigate the effects of the process parameters on the dimensional accuracy of the bezel frame and to design the progressive hemming process. The analytical results were validated by hemming experiments performed using SUS304 stainless steel with a thickness of 0.3 mm. Finally, the quality of the bezel frame was estimated through measurements of its dimensional accuracy and bending stiffness. From the experimental results, it was confirmed that a bezel frame with a height distribution of 1.5±0.05 mm and a respectable bending stiffness of 70 N/mm could be manufactured using the proposed process.     

Analysis of performance for centrifugal steam compressor

In this study, mean streamline and Computational fluid dynamics (CFD) analyses were performed to investigate the performance of a small centrifugal steam compressor using a latent heat recovery technology. The results from both analysis methods showed good agreement. The compression ratio and efficiency of steam were found to be related with those of air by comparing the compression performances of both gases. Thus, the compression performance of steam could be predicted by the compression performance of air using the developed dimensionless parameters.     

Pruning deep convolutional neural networks for efficient edge computing in condition assessment of infrastructures

Health monitoring of civil infrastructures is a key application of Internet of things (IoT), while edge computing is an important component of IoT. In this context, swarms of autonomous inspection robots, which can replace current manual inspections, are examples of edge devices. Incorporation of pretrained deep learning algorithms into these robots for autonomous damage detection is a challenging problem since these devices are typically limited in computing and memory resources. This study introduces a solution based on network pruning using Taylor expansion to utilize pretrained deep convolutional neural networks for efficient edge computing and incorporation into inspection robots. Results from comprehensive experiments on two pretrained networks (i.e., VGG16 and ResNet18) and two types of prevalent surface defects (i.e., crack and corrosion) are presented and discussed in detail with respect to performance, memory demands, and the inference time for damage detection. It is shown that the proposed approach significantly enhances resource efficiency without decreasing damage detection performance.     

Quality assurance of Chinese herbal medicines: Procedure for multiple‐herb extraction

A quality assurance (QA) procedure for multiple‐herb extraction, which takes into account the existence of common chemical markers and multiple‐herb‐extraction effects, has been developed for producing Chinese herbal medicines (CHMs) of consistent quality. The experimental method for determining related correlation function of the multiple‐herb‐extraction effect was designed. A systematic solution strategy was also developed to appropriately decompose the multiple‐herb extraction system into several subsystems for obtaining solution(s) and determining the overall behavior of the system. An example of QA of Danshen–Gegen (DG) decoction was used to demonstrate the QA procedure. An H9c2 cell assay was used to test the efficacy of consistent quality DG decoctions prepared by different herb combinations with different material costs of herbs. It was observed that a multiple‐herb‐extraction effect was present in the aqueous extraction of Danshensu and this effect was depended on the extraction solvent. The possible mechanism of this multiple‐herb‐extraction effect in the aqueous DG extraction was speculated to be the change of initial pH value of the aqueous extraction solvent by an unknown component from Gegen. The experimental chemical marker concentrations fell within ±10% of the specified chemical marker compositions by using the amount of herb from each herb class as predicted by the QA model. Furthermore, an H9c2 cell assay was used to test the efficacy of three consistent quality DG extracts, which were produced by different herb combinations with different material costs of herbs. The results showed that the three DG extracts provided consistent biological efficacy against menadione‐induced toxicity. This study extended a recently developed QA procedure of single‐herb extraction to multiple‐herb extraction. It provides a solution of QA in extraction, which is one of the most important unresolved problems in the modernization of traditional Chinese medicines. With this modified model and the companion experiments, the amount of herbs needed from different quality classes to produce a multiple‐herb formula CHM product decoction with consistent quality can be exactly determined. © 2014 American Institute of Chemical Engineers AIChE J 60: 4014–4026, 2014     

Palladium‐Catalyzed Construction of Spirooxindoles by Arylative Cyclization of 3‐(γ,δ‐Disubstituted)allylidene‐2‐Oxindoles

The palladium‐catalyzed, one‐pot arylative cyclization of 3‐(γ,δ‐disubstituted)allylidene‐2‐oxindoles afforded spirodihydronaphthalene‐2‐oxindole frameworks via an oxidative Heck arylation (Fujiwara–Moritani reaction), an allylic palladium migration, and an aryl C H bond functionalization/arylation cascade of reactions. This is a first example of the palladium‐catalyzed oxidative arylation and an aryl C H bond functionalization/arylation cascade reaction which involves an electrophilic arylative quenching of a π‐allylpalladium intermediate and a regio‐controlled aryl C H bond activation assisted by a weak palladium‐arene interaction.

     

Morphological core/shell structure and dispersion stability of water-dispersible copolyester graft polymerized with acrylic acid and ethyl acrylate

Anionic water-dispersible copolyester was prepared by the polycondensation of dimethyl isophathalate (DMI)/5-sodium sulfo dimethyl isophathalate (DMS) with ethylene glycol (EG)/ diethylene glycol (DEG) to synthesize water-dispersible copolyester-g-AA/EAs by chemical method. In the case of graft polymerization of AA/EA onto DMI/DMS/EG/DEG copolyester does not. This is a result of the core/shell structure that was ascertained by the graft yield and the zeta potential of copolyester-g-AA/EAs. It appears that grafted AA/EA exists at the surface of copolyester-g-AA/EA particles, and the backbone polymer, i.e., DMI/DMS/EG/DEG copolyester, exists in the inner phase of the copolyester, -g-AA/EA particles. The complete solubility of copolyester-g-AA/EAs in 1N NaOH aqueous solution seems to come mainly from the electrostatic repulsion between  COOs that are present at the surface of copolyester-g-AA/EA particles due to AA grafting and  OHs that are present at the dispersion medium due to NaOH decomposition and which cause the hydrolytic breakage and consequently the coagulation of copolyesters in alkaline medium. © 1996 John Wiley & Sons, Inc.     

The effect of pyrolysis on the mechanical properties and microstructure of carbon fiber-reinforced and stabilized fiber-reinforced phenolic resins for carbon/carbon composites

Carbon/carbon composites were prepared with phenol-formaldehyde resin, one kind of commercial carbon fiber, and a stabilized fiber that was developed in our laboratory. The effect of pyrolysis on the microstructure, fracture behavior, and flexural strength of the composites during the carbonization process was studied. During the pyrolysis of the composites a chemical reaction at the fiber/resin interface apparently took place. A thermogravimetry (TG) study indicated that the use of stabilized fiber reinforced composites inhibited decomposition reactions and thermal fragmentation in the matrix resin, and reduced the weight loss of the final composites. The X-ray reflection of the resin and the two composites showed a reflection appearing at 2θ ≈ 12° when the samples were carbonized above 600°C. The intensity of this reflection in the composites made with stabilized fiber was higher than that of the composite made with carbon fiber. Because of the formation of strong bonding in the fiber-matrix interface, the composites made with stabilized fiber showed catastrophic failure and low flexural strength below carbonization temperatures of 600°C. Above 600°C, the flexural strength of the composites increased with an increase in the carbonization temperatures, even if the fracture behaviors showed catastrophic failure. The flexural strength of the composites made with carbon fiber showed pseudo-plastic patterns and debonding with very little fiber pullout. Above 800°C, these composites showed a catastrophic failure and smooth failure surfaces. During pyrolysis the flexural strength decreased with an increase in the carbonization temperature.     

Influence of Nb5+ ions on phase transitions and polar disorder above TC in PbZrO3 studied by Raman spectroscopy

Micro-Raman light scattering experiments on PbZrO₃ (PZO) single crystal doped with Nb⁵⁺ have been investigated. Special attention was paid to the paraelectric (PE) phase in which nominally forbidden first-order Raman spectra were detected at temperatures far above the phase transition T_C. Complex Raman spectra were observed in the vicinity of three structural phase transitions. These results mainly from the coexistence of phases with different symmetries in a wide temperature range below T_C. The Raman measurements have been compared with dielectric and optical observations and proved that polar nanoregions in a centrosymmetric lattice appear well above T_C. It was shown that doping ABO₃ perovskites with heterovalent ions like Nb⁵⁺ unbalances charge neutrality of the lattice and strongly extends the temperature range of polar regions. The investigations performed point out that in the PE matrix the interaction between electrons and lattice vibrations, as recently suggested for pure PZO, plays an important role.     

填充了碳纳米管的连续纳米纤维的静电纺丝

<正>尽管在单壁碳纳米管(SWNTs)的合成和表征方面已经取得了重大进展,但还有一重大挑战,即寻找一条有效途径来接通纳米管及工程材料和结构之间的尺寸和性能的通道。为了将SWNT的超性能转化到中型和大型结构中,人们已经花费了很大精力来开发线性和平面SWNT组件。本文描述的静电