Enhancement of Mechanical and Thermal Properties of SU‑8 Photoresist with Multilayer Woven Glass Fabric Based on Micromachining Technology

Wenwen Zhou,Yahui Li,Yunna Sun,Jinyuan Yao,Xutong Song,Guifu Ding 대한금속·재료학회 2020 ELECTRONIC MATERIALS LETTERS Vol.16 No.6

SU-8 photoresist has been more and more widely used as a structural material in micro electromechanical system (MEMS) because of its low cost and excellent biocompatibility. However, the inferior mechanical and thermal performances immensely impinge the reliability of the MEMS device based SU-8 and accordingly restrict its application. Here we report the mechanicaland thermal performance of SU-8 reinforced by the multilayer glass fabric with the MEMS technology. The finite element simulation and specific experiment are conducted, which confirm that the reinforced SU-8 composites have a 281% increase in Young’s modulus and a 64% decrease in coefficient of thermal expansion (CTE) compared with pure SU-8. Additionally,the improved mechanism has also been analyzed, including the excellent interface bonding between the SU-8 and glass fabric, and the high-bond energy of Si–O-Si chain structures in glass fabric. Furthermore, the glass fabric reinforced SU-8 could still possess a high light transmittance to maintain the ability of lithography patterning. Therefore, it is believed thatthe strategy proposed here may satisfy higher requirements of MEMS devices, which guarantees its practical applications in the functional microstructures.

Synthesis and Application of Polyurethane-Modified Silicone as Finishing Agent for Cotton Fabric

Wenwen Lei,Yufa Sun,Bin Huang,Xiangdong Zhou 한국섬유공학회 2018 Fibers and polymers Vol.19 No.5

The polyurethane modified organic silicone (PU-SA) was successfully synthesized via step-by-step polymerization with isophorone diisocyanate (IPDI) and polypropylene glycol (PPG) used as monomers, dibutyltindilaurate (DBTDL) as the catalyst, trimethylolpropane (TMP) and N-methyldiethanolamine (MDEA) as the chain extender, and amino-terminated siloxane (SA) as the blocking agent. The chemical structure of PU-SA was characterized by Fourier transform infrared spectroscopy (FT-IR). X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) showed that PUSA had been successfully finished on the surface. Additionally, the thermogravimetric analysis (TGA) demonstrated that the PU-SA treated fabrics showed low decomposition temperature and slightly high char residue. As a finishing agent, the effect of PU-SA on the handle of cotton fabrics was also studied by using a Kawabata Evaluation System for Fabrics (KES-F). The experimental results found that PU-SA had a significant improvement on the bending properties, surface properties, and compressional properties. Moreover, the mechanical and anti-wrinkle properties of the cotton fabrics were also enhanced.

Effect of Different Storage Temperature on Postharvest Quality of ‘Luo Yang Hong’ Tree Peony Cut Flower

Lin Zhou,PeiYi Jia,WenWen Guo,Li Dong 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

Diversity and Antiaflatoxigenic Activities of Culturable Filamentous Fungi from Deep-Sea Sediments of the South Atlantic Ocean

( Ying Zhou ),( Xiujun Gao ),( Cuijuan Shi ),( Mengying Li ),( Wenwen Jia ),( Zongze Shao ),( Peisheng Yan ) 한국균학회 2021 Mycobiology Vol.49 No.2

Despite recent studies, relatively few are known about the diversity of fungal communities in the deep Atlantic Ocean. In this study, we investigated the diversity of fungal communities in 15 different deep-sea sediments from the South Atlantic Ocean with a culturedependent approach followed by phylogenetic analysis of ITS sequences. A total of 29 fungal strains were isolated from the 15 deep-sea sediments. These strains belong to four fungal genera, including Aspergillus, Cladosporium, Penicillium, and Alternaria. Penicillium, accounting for 44.8% of the total fungal isolates, was a dominant genus. The antiaflatoxigenic activity of these deep-sea fungal isolates was studied. Surprisingly, most of the strains showed moderate to strong antiaflatoxigenic activity. Four isolates, belonging to species of Penicillium polonicum, Penicillium chrysogenum, Aspergillus versicolor, and Cladosporium cladosporioides, could completely inhibit not only the mycelial growth of Aspergillus parasiticus mutant strain NFRI-95, but also the aflatoxin production. To our knowledge, this is the first report to investigate the antiaflatoxigenic activity of culturable deep-sea fungi. Our results provide new insights into the community composition of fungi in the deep South Atlantic Ocean. The high proportion of strains that displayed antiaflatoxigenic activity demonstrates that deep-sea fungi from the Atlantic Ocean are valuable resources for mining bioactive compounds.

Evaluation of the horizontal electric field of the lightning channel with the fast convergent sommerfeld integral tail

Zou, Jun,Zhou, Chenglong,Li, Wenwen,Lee, Jae-bok,Chang, Sughun Emerald Group Publishing Limited 2013 Compel Vol.32 No.6

<B>Purpose</B> - The electromagnetic field radiated from a lightning channel is the excitation for analyzing the field-to-transmission line coupling problem. The purpose of this paper is to propose a novel efficient approach to evaluate the horizontal electric field of the lightning channel expressed by the generalized Sommerfeld integral. <B>Design/methodology/approach</B> - The asymptotic integral is extracted from the original one, which actually makes the Sommerfeld integral tail reach its convergence very quickly. To handle the sharp variance around k0, a closed-form integral, which is obtained by replacing the original kernel with an approximated function, is presented in detail. The numerical examples validated the proposed approach in the both frequency and time domain. <B>Findings</B> - The approach proposed in this paper has been validated by the comparison with results in other papers. The agreement among these results reaches very well, and the approach proposed in this paper is more efficient and easy to implement, especially for the calculation of the tail integral part. <B>Originality/value</B> - In accordance with the numerical experiments, the proposed approach can be served as a qualified candidate in terms of computational efficiency to evaluate the electromagnetic field generated by the lightning channel.

Security Analysis of the Lightweight Cryptosystem TWINE in the Internet of Things

( Wei Li ),( Wenwen Zhang ),( Dawu Gu ),( Zhi Tao ),( Zhihong Zhou ),( Ya Liu ),( Zhiqiang Liu ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.2

The TWINE is a new Generalized Feistel Structure (GFS) lightweight cryptosystem in the Internet of Things. It has 36 rounds and the key lengths support 80 bits and 128 bits, which are flexible to provide security for the RFID, smart cards and other highly-constrained devices. Due to the strong attacking ability, fast speed, simple implementation and other characteristics, the differential fault analysis has become an important method to evaluate the security of lightweight cryptosystems. On the basis of the 4-bit fault model and the differential analysis, we propose an effective differential fault attack on the TWINE cryptosystem. Mathematical analysis and simulating experiments show that the attack could recover its 80-bit and 128-bit secret keys by introducing 8 faulty ciphertexts and 18 faulty ciphertexts on average, respectively. The result in this study describes that the TWINE is vulnerable to differential fault analysis. It will be beneficial to the analysis of the same type of other iterated lightweight cryptosystems in the Internet of Things.

Regional Homogeneity Brain Alterations in Schizophrenia: An Activation Likelihood Estimation Meta-Analysis

Xiaolei Qiu,Wenwen Xu,Rongrong Zhang,Wei Yan,Wenying Ma,Shiping Xie,Min Zhou 대한신경정신의학회 2021 PSYCHIATRY INVESTIGATION Vol.18 No.8

Objective Resting state functional magnetic resonance imaging (rsfMRI) provides a lot of evidence for local abnormal brain activity in schizophrenia, but the results are not consistent. Our aim is to find out the consistent abnormal brain regions of the patients with schizophrenia by using regional homogeneity (ReHo), and indirectly understand the degree of brain damage of the patients with drug-naive first episode schizophrenia (Dn-FES) and chronic schizophrenia. Methods We performed the experiment by activation likelihood estimation (ALE) software to analysis the differences between people with schizophrenia group (all schizophrenia group and chronic schizophrenia group) and healthy controls. Results Thirteen functional imaging studies were included in quantitative meta-analysis. All schizophrenia group showed decreased ReHo in bilateral precentral gyrus (PreCG) and left middle occipital gyrus (MOG), and increased ReHo in bilateral superior frontal gyrus (SFG) and right insula. Chronic schizophrenia group showed decreased ReHo in bilateral MOG, right fusiform gyrus, left PreCG, left cerebellum, right precuneus, left medial frontal gyrus and left anterior cingulate cortex (ACC). No significant increased brain areas were found in patients with chronic schizophrenia. Conclusion Our findings suggest that patients with chronic schizophrenia have more extensive brain damage than FES, which may contribute to our understanding of the progressive pathophysiology of schizophrenia.

Encainide, a class Ic anti-arrhythmic agent, blocks voltage-dependent potassium channels in coronary artery smooth muscle cells

Hongliang Li,Yue Zhou,Yongqi Yang,Yiwen Zha,Bingqian Ye,Seo-Yeong Mun,Wenwen Zhuang,Jingyan Liang,Won Sun Park The Korean Society of Pharmacology 2023 The Korean Journal of Physiology & Pharmacology Vol.27 No.4

Voltage-dependent K⁺ (Kv) channels are widely expressed on vascular smooth muscle cells and regulate vascular tone. Here, we explored the inhibitory effect of encainide, a class Ic anti-arrhythmic agent, on Kv channels of vascular smooth muscle from rabbit coronary arteries. Encainide inhibited Kv channels in a concentration-dependent manner with an IC₅₀ value of 8.91 ± 1.75 μM and Hill coefficient of 0.72 ± 0.06. The application of encainide shifted the activation curve toward a more positive potential without modifying the inactivation curve, suggesting that encainide inhibited Kv channels by altering the gating property of channel activation. The inhibition by encainide was not significantly affected by train pulses (1 and 2 Hz), indicating that the inhibition is not use (state)-dependent. The inhibitory effect of encainide was reduced by pretreatment with the Kv1.5 subtype inhibitor. However, pretreatment with the Kv2.1 subtype inhibitor did not alter the inhibitory effects of encainide on Kv currents. Based on these results, encainide inhibits vascular Kv channels in a concentration-dependent and use (state)-independent manner by altering the voltage sensor of the channels. Furthermore, Kv1.5 is the main Kv subtype involved in the effect of encainide.

Postharvest Behavior and Endogenous Ethylene Pattern of Tree-Peony Cut Flowers

PeiYi Jia,Lin Zhou,WenWen Guo,Li Dong 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

Improved Received Signal Strength Ratio Based High Accuracy Indoor Visible Light Positioning Scheme

Zhijie Luo,JinHua Wang,WenWen Zhao,JianKun Luo,WeiNan Zhang,GuoFu Zhou 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.12

With the increasingly development of Light-emitting Diode (LED) lighting, in this paper, we proposed an Indoor Visible Light Positioning (VLP) Scheme by using visible LED lights for accurate localization. The basic idea of the position scheme is to improve received signal strength ratio algorithm. Received signal strength ratio (RSSR) is the relative ratio of optical powers detected between each LED and optical receiver. In this paper, we introduce concept of multiple LEDs selection to improve RSSR positioning algorithm. By three LEDs are reasonably selected from the multiple LEDs deployed in the room, the positioning accuracy of RSSR is improved. The system can be employed easily because it does not require additional sensors and occlusion problem in visible light would be alleviated. In addition, we performed the simulation experiments, and confirmed the feasibility of our proposed method.