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Effects of ultrasonic vibration on plastic deformation of AZ31 during the tensile process

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International Journal of Minerals,Metallurgy and Materials 2011年第1期18卷 70-76页

作者： Tong Wen Li Wei Xia Chen chun-lei pei College of Material Science and Engineering Chongqing University Chongqing 400044 China

An investigation on the plastic behavior of AZ31 magnesium alloy under ultrasonic vibration（with a frequency of 15 kHz and a maximum output of 2 kW） during the process of tension at room temperature was conducted to reveal the volume effect of the vibrated plastic deformation of *** characteristics of mechanical properties and microstructures of AZ31 under routine and vibrated tensile processes with different amplitudes were *** is found that ultrasonic vibration has a remarkable influence on the plastic behavior of AZ31 which can be summarized into two opposite aspects：the softening effect which reduces the flow resistance and improves the plasticity,and the hardening effect which decreases the *** a lower amplitude or vibration energy is applied to the tensile sample,the softening effect dominates,leading to a decrease of AZ31 deformation resistance with an increase of *** the application of a high-vibrating amplitude,the hardening effect dominates,resulting in the decline of plasticity and brittle fracture of the samples.

关键词： ultrasonic effects tensile testing magnesium alloys plastic deformation

The self-assembly of gold nanoparticles in large-pore ordered mesoporous carbons

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Chinese Journal of Chemical Engineering 2022年第1期35卷 420-429页

作者： chun pei Shangjun Chen Rongrong Song Fei Lv Ying Wan Key Laboratory of Resource Chemistry of Ministry of Education Shanghai Key Laboratory of Rare Earth Functional Materialsand Department of ChemistryShanghai Normal UniversityShanghai 200234China

Simple encapsulation of 3 nm gold nanoparticles in ordered mesoporous carbon with large pores of 17 nm and thick pore walls of 16 nm was achieved by a metal–ligand coordination assisted-selfassembly ***-block-polyethylene-oxide(PS-b-PEO)diblock copolymer with a large molecular weight of the PS chain and mercaptopropyltrimethoxysilane were used as the template and the metal ligand,***-angle X-ray scattering,X-ray diffraction,transmission electron microscopy,and X-ray photoelectron spectroscopy showed that monodispersed aggregation-free gold nanoparticles approximately 3 nm in size were partially embedded in the large open pore structure of the ordered mesoporous *** strong coordination between the gold species and the mercapto groups and the thick porous walls increased the dispersion of the gold nanoparticles and essentially inhibited particle aggregation at 600℃.The gold nanoparticles in the ordered mesoporous carbon are active and stable in the reduction of nitroarenes involving bulky molecules using sodium borohydride as a reducing agent under ambient conditions(30℃)in *** large interconnected pore structure facilitates the mass transfer of bulky molecules.

关键词： Gold catalyst Ordered mesoporous carbon Large pores Reduction Nitroarenes

Turning in a Bipedal Robot

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Journal of Bionic Engineering 2013年第3期10卷 292-304页

作者： Jau-Ching Lu Jing-Yi Chen pei-chun Lin Department of Mechanical Engineering National Taiwan University Taipei 106 Taiwan

We report the development of turning behavior on a child-size bipedal robot that addresses two common scenarios： turning in place and simultaneous walking and turning. About turning in place, three strategies are investigated and compared, including body-first, leg-first, and body/leg-simultaneous, These three strategies are used for three actions, respectively： when walking follows turning immediately, when space behind the robot is very tight, and when a large turning angle is desired. Concerning simultaneous walking and turning, the linear inverted pendulum is used as the motion model in the single-leg support phase, and the polynomial-based trajectory is used as the motion model in the double-leg support phase and for smooth motion connectivity to motions in a priori and a posteriori single-leg support phases. Compared to the trajectory generation of ordinary walking, that of simultaneous walking and turning introduces only two extra parameters： one for determining new heading direction and the other for smoothing the Center of Mass （COM） trajectory. The trajectory design methodology is validated in both simulation and experimental environments, and successful robot behavior confirms the effectiveness of the strategy.

关键词： turning biped humanoid trajectory planning robot

Response enhancement of olfactory sensory neurons-based biosensors for odorant detection

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2009年第4期10卷 285-290页

作者： chun-sheng WU pei-hua CHEN Qing YUAN Ping WANG Biosensor National Special Laboratory MOE Key Laboratory of Biomedical Engineering Department of Biomedical Engineering Zhejiang University Hangzhou 310027 China

This paper presents a novel strategy for the response enhancement of olfactory sensory neurons (OSNs)-based biosensors by monitoring the enhancive responses of OSNs to odorants. An OSNs-based biosensor was developed on the basis of the light addressable potentiometric sensor (LAPS), in which rat OSNs were cultured on the surface of LAPS chip and served as sensing elements. LY294002, the specific inhibitor of phosphatidylinositol 3-kinase (PI3K), was used to enhance the responses of OSNs to odorants. The responses of OSNs to odorants with and without the treatment of LY294002 were recorded by LAPS. The results show that the enhancive effect of LY294002 was recorded efficiently by LAPS and the responses of this OSNs-LAPS hybrid biosensor were enhanced by LY294002 by about 1.5-fold. We conclude that this method can enhance the responses of OSNs-LAPS hybrid biosensors, which may provide a novel strategy for the bioelectrical signal monitor of OSNs in biosensors. It is also suggested that this strategy may be applicable to other kinds of OSNs-based biosensors for cellular activity detection, such as microelectrode array (MEA) and field effect transistor (FET).

关键词： Olfactory sensory neurons (OSNs) Response enhancement Light addressable potentiometric sensor (LAPS) Olfactory-based biosensor

Application of Modified Digital Halftoning Techniques to Data Hiding in Personalized Stamps

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仪器仪表学报 2004年第S3期 235-238页

作者： Hsi-chun Wang,pei-Chi Hsiao Department of Graphic Arts and Communications College of Technology National Taiwan Normal University Taipei China Department of Graphic Arts and Communications College of Technology National Taiwan Normal University Taipei China

The objective of this research is to embed information in personalized stamps by modified digital halftoning techniques. The displaced and deformed halftone dots are used to encode data in the personalized stamps. Hidden information can be retrieved by either an optical decoder or digital image processing techniques. The results show that personalized stamps with value-added features like data hiding or digital watermarking can be successfully implemented.

关键词： Digital halftoning Digital watermarking Amplitude modulation (AM)

Synthesis and antitumor activity of nitric oxide releasing derivatives of AT1 antagonist

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Chinese Chemical Letters 2009年第3期20卷 302-305页

作者： Yan chun Zhang Jin pei Zhou Xiao Ming Wu Wei Hong Pan Department of Medicinal Chemistry China Pharmaceutical University Nanjing 210009 China

A series of novel nitric oxide-donating derivatives （7a-e, 8a-e） were synthesized by coupling furoxan and nitric oxide with irbesartan analogue and their cytotoxicity against BEL7402 cells in vitro were evaluated by MTT method. It was found that 8c exhibits the most cytotoxic activities with ICso value of 12.5 μmol/L. The hybrids of AT1 antagonist and nitric oxide donor appear to have beneficial effects on antitumor.

关键词： AT1 antagonist Nitric oxide-donating Antitumor Synthesis

A Bio-Inspired Hopping Kangaroo Robot with an Active Tail

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Journal of Bionic Engineering 2014年第4期11卷 541-555页

作者： Guan-Horng Liu Hou-Yi Lin Huai-Yu Lin Shao-Tuan Chen pei-chun Lin Department of Mechanical Engineering National Taiwan University Taipei 106 Taiwan

Inspired by kangaroo＇s locomotion, we report on developing a kangaroo-style hopping robot. Unlike bipeds, quadrupeds, or hexapods which altemate the legs for forward locomotion, the kangaroo uses both legs synchronously and generates the forward locomotion by continuous hopping behavior, and the tail actively balances the unwanted angular momentum generated by the leg motion. In this work, we generate the Center of Mass （CoM） locomotion of the robot based on the reduced-order Rolling Spring Loaded Inverted Pendulum （R-SLIP） model, for matching the dynamic behavior of the empirical robot legs. In order to compensate the possible body pitch variation, the robot is equipped with an active tail for pitch variation compensation, emulating the balance mechanism of a kangaroo. The robot is empirically built, and various design issues and strategies are addressed. Finally, the experimental evaluation is executed to validate the performance of the kangaroo-style robot with hopping locomotion.

关键词： legged robot kangaroo hopping SLIP tail

KAI1 is a potential target for anti-metastasis in pancreatic cancer cells

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World Journal of Gastroenterology 2008年第7期14卷 1126-1132页

作者： Jian-Hua Xu Xiao-Zhong Guo Li-Nan Ren Li-chun Shao Min-pei Liu Department of Gastroenterology The General Hospital of Shenyang Military Command Shenyang 110016 Liaoning Province China

AIM: To investigate whether KAI1, as a metastasis suppressor gene, is associated with invasive and metastatic ability of pancreatic cancer ***: KAI1 gene was transfected into pancreatic cancer cell line MiaPaCa Ⅱ by liposomes selected with G418. Expression of transfected cells was measured by Western blotting, immunofluorescence and immunocytochemistry. Tumor cell invasion and metastatic ability were detected through gelatinase activity and reconstituted basement membrane (Matrigel) assay. pCMV-KAI1 was directly injected into the heterotopic human pancreatic adenocarcinoma successfully established in the groin of BALB/C nude mice, by subcutaneous injection of MiaPaCa Ⅱ pancreatic cancer cells. The statistical analysis between groups was determined by Student's two tailed t ***: By Western blotting, MiaPaCa Ⅱ cells transfected by KAI1 gene indicated KAI1 expression at approximately 29.1 kDa. Cytoplasm staining was positive and uniformly spread in transfected cancer cells, using immunohistochemistry and immunofluorescence. The most obvious difference was present after 30 h (MiaPaca Ⅱ 43.6 ± 9.42, pCMV-MiaPaca Ⅱ 44.8 ± 8.56, pCMV-KAI1-MiaPaca Ⅱ 22.0 ± 4.69, P < 0.05). Gelatinolysis revealed a wider and clearer band of gelatinolytic activity in non-transfected than in transfected cells (MiaPaCa Ⅱ cells 30.8 ± 0.57, transfected cells 28.1 ± 0.65, P < 0.05). In vivo tumor growth rates of KAI1 transfectants with KAI1-Lipofectamine 1.22 ± 0.31 in A group were lower than control 4.61 ± 1.98 and pCMV-KAI 11.67 ± 0.81. Analyses of metastases with and without KAI1 transfection in mice were different in liver and lung between controls 1.62 ± 0.39, 0.45 ± 0.09, pCMV-KAI 1.01 ± 0.27, 0.33 ± 0.09 and KAI1-Lipofectamine 0.99 ± 0.21, 0.30 ± 0.09 respectively (P < 0.05).CONCLUSION: High expression of KAI1 gene was found in transfected MiaPaCa Ⅱ human pancreatic cancer cells with lower metastatic ability. KAI1 gene plays an important role in inhibiting metastasis of

关键词： KAI1 Pancreatic cancer cell line Transfection Immunocytochemistry Western blotting Immunofluorescence Gelatinolysis

A survey of arsenic and other heavy metals in vegetation from markets or mine tailings

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Journal of Environmental Sciences 2006年第2期18卷 287-291页

作者： LIU Wen-ju Kim Kyoung-woong ZHU Yong-guan LEE Sang-woo CHANG pei-chun Kwak Ji-hyun Department of Environmental Science and Engineering Gwangju Institute of Science and Technology （GIST） Gwangju 500-712 Korea Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China College of Natural Resources and Environment Hebei Agricultural University Baoding 071001 China

This research includes two investigations. The first one is a market basket survey of the levels of arsenic （As） and trace elements in bracken fern （Pteridium aquilinum） originated from three countries： South Korea, China and North Korea. The results showed that the mean As concentrations in stems of samples were significantly higher than those in leaves. As concentrations in all samples did not exceed food safety limits for vegetables. Generally, concentrations of Fe, Mn, Cu and Zn in leaves were higher than those in stems. The second investigation is a survey on the levels of As and other heavy metals in vegetation in the vicinity of Myoungbong mine tailings. The results demonstrated that As, Pb and Cu concentrations and bioaccumulation factors （BCF） in seedlings of the fern（A splenium achilleifolium） were the highest, whereas Marsh horsetail（Equisetum polustre） accumulated the highest levels of Zn. Concentrations of As, Pb, Zn and Cu in vegetable-cress （Lepidium sativum） and the edible herb-aromatic madder （Elasholtzia splendens） were higher than food safety limits. Therefore, a risk assessment of As and other heavy metals in vegetables and herbs on local human health should be conducted in the future.

关键词： arsenic heavy metals ferns bioaccumulation factors