Synthesis of Polymeric Phthalocyanine Sulfonate Photosensitizer and Its Photodegradation on Rhodamine B in Aqueous Medium

Peng Zhao,우재완,박용성,Yenan Song,Fushi Zhang 한국고분자학회 2010 Macromolecular Research Vol.18 No.5

Novel phthalocyanine sulfonate (H2PPcSx) was synthesized from the sulfonation of a steric polymeric phthalocyanine and investigated as a photocatalyst in a homogenous system. The molecular weight of H2PPcSx was characterized as 9213-11692 by MALDI-TOF MS, classified as an oligomer with a 14-18 degree of polymerization. The electronic spectrum indicated a less aggregative tendency of H2PPCSx than the usual monomeric phthalocyanine photocatalyst. Efficient photodegradation of butyl Rhodamine B (bu Rh B) catalyzed by H2PPcSx was achieved in a homogenous solution; the spectral character indicated that decomposition occurred on the benzene ring in the Rh B molecular. For a 50 mg L-1 bu Rh B solution, the percentage degradation reached 95% in 4 h using 100 mg H2PPcSx as a photocatalyst. A mechanism involving the participation of both singlet oxygen and radicals was established for the photodegradation.

Opportunistic Routing for Bandwidth-Sensitive Traffic in Wireless Networks with Lossy Links

Peng Zhao,Xinyu Yang 한국통신학회 2016 Journal of communications and networks Vol.18 No.5

Opportunistic routing (OR) has been proposed as a vi-able approach to improve the performance of wireless multihopnetworks with lossy links. However, the exponential growth ofthe bandwidth-sensitivemobile traffic (e.g.,mobile video streamingand online gaming) poses a great challenge to the performance ofOR in term of bandwidth guarantee. To solve this problem, a novelmechanism is proposed to opportunistically forwarding data pack-ets and provide bandwidth guarantee for the bandwidth-sensitivetraffic. The proposal exploits the broadcast characteristic of wire-less transmission and reduces the negative effect of wireless lossylinks. First, the expected available bandwidth (EAB) and the ex-pected transmission cost (ETC) under OR are estimated basedon the local available bandwidth, link delivery probability, for-warding candidates, and prioritization policy. Then, the policiesfor determining and prioritizing the forwarding candidates is de-vised by considering the bandwidth and transmission cost. Finally,bandwidth-aware routing algorithm is proposed to opportunisti-cally delivery data packets; meanwhile, admission control is ap-plied to admit or reject traffic flows for bandwidth guarantee. Ex-tensive simulation results show that our proposal consistently out-performs other existing opportunistic routing schemes in providingperformance guarantee.

On the No-Fault Insurance Movement in the United States and Its Inspiration for the Legislative Model of China’s Compulsory Traffic Insurance

ZHAO, PENG-JU(조평주),ZANG ZHEN(장전) 동아대학교 법학연구소 2023 國際去來와 法 Vol.- No.40

The popularity of automobiles has led to frequent traffic accidents, and the defects of the traditional automobile liability insurance have become increasingly apparent. The victims burden of proof in a traffic accident makes it hard for the victim to obtain relief in time. Consequently, the no-fault insurance movement began in the United States in the 1960s and 1970s. American scholars hoped that in the field of automobile insurance, like workers’ insurance, third-party insurance can be replaced by first-party insurance, making the traditional automobile liability insurance get rid of the shackles of tort liability. Yet, things backfired. The no-fault movement finally went nowhere under the opposition from various forces. Not only did it fail to be widely implemented in the United States, but the goal of making victims receive timely and effective relief to reduce lawsuits was not fully realized. But it cannot be denied that the no-fault movement still has a huge impact on the field of automobile liability insurance. The current circumstance of Chinas compulsory traffic insurance is highly similar to that of the United States in the 1960s and 1970s, and the existing compulsory traffic insurance system is also inspired by no-fault insurance to a certain extent. However, owing to the lack of recognition of the difference between no-fault insurance and no-fault liability, the legislative model of China’s compulsory traffic insurance is not no-fault insurance and is significantly different from traditional automobile liability insurance, forming a unique mixed legislative system. This model directly results in the confusion of the legal system of Chinas compulsory traffic insurance. Besides, because there are many problems in the scope of victim protection and the sub-item limit of liability in Chinas compulsory traffic insurance, the revision of Chinas compulsory traffic insurance is imperative. In this regard, the author holds that by reflecting on the no-fault insurance movement in the United States, the future reforms of Chinas compulsory traffic insurance should take “compulsory” as its core and strict liability its basis to build a legal system of compulsory traffic insurance that is in line with Chinas own reality. What’s more, in order to effectively protect victims and address the problems brought about by self-driving vehicles, China’s compulsory traffic insurance should also expand its protection objects, change the accident sub-item limit to the victim general limit system, and improve the system of the victim’s direct claim right.

Microscopic Study on the Mechanism of Tool Bond Wear in Cutting Ni–Fe-Cr-Co–Cu Series Nickel-Base Superalloy

Zhao Peng Hao,Xue Han,Yi Hang Fan,Zai Zhen Lou 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.4

In the process of nickel-based alloy machining, chips are easy to bond on the tool surface, which weaken the tool performance and make the tool wear. Therefore, it is very important to study the mechanism of tool bond wear in the process of nickel-based superalloy machining. In order to reflect the wear process of the tool from the perspective of micro cutting, the molecular dynamics simulation model for cutting Ni–Fe-Cr-Co–Cu nickel-based alloy with SiC tool was established. The Morse potential functions between the tool and workpiece are calculated, and the simulation results are analyzed visually. It is found that the bond wear is the main wear form of tool in the process of cutting nickel-based alloy, and the wear processes are divided into three stages: contact, adhesion and shedding. The stress and strain in the cutting area are calculated and it is found that the bond occurs when the tool-workpiece extrusion is strong. Through the calculation of radial distribution function and formation energy, it is found that Ni-Si compound is formed on the tool surface, and the newly generated Ni-Si compound reduces the tool performance compared with the silicon carbide structure. This study provides a more complete microscopic explanation of the tool wear mechanism, which is helpful to find a method to prolong tool life.

Inhibitory Effects of Syk Transfection on Lung Cancer Cell Invasion

Peng, Chuan-Liang,Zhang, Ying,Sun, Qi-Feng,Zhao, Yun-Peng,Hao, Ying-Tao,Zhao, Xiao-Gang,Cong, Bo Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.5

Objective: Spleen tyrosine kinase (Syk) is closely related to tumor invasion and metastasis, and has been shown to have potential inhibitory effects in tumors. In this study, we constructed a eukaryotic expression vector for Syk and analyzed its effects on invasive ability of the A549 non-small cell lung cancer cell line in vitro. Methods: A fragment of Syk was obtained by RT-PCR from human lung cancer cells and cloned into the expression vector pLNCXSyk. After restriction endonuclease digestion, PCR and DNA sequencing confirmation, the recombinant Syk expression plasmid was transfected into A549 human lung cancer cells using lipofectamine protocols. After selection, the cells stably expressed Syk. Detection of Syk expression of the cells by RT-PCR, and invasive ability were examined. Results: The eukaryotic expression plamid pLNCXSyk was constructed and expressed stably in the A549 human lung cancer cells. The RT-PCR results showed that Syk mRNA expression was upregulated significantly (P<0.05). Lower invasion through a basal membrane were apparent after transfection (P<0.05). Conclusions: A eukaryotic expression plasmid to cause Syk expression in lung cancer cells can obviously inhibit their invasive ability in vitro.

First-principles study of the switching characteristics of the 15,16-dinitrile DDP/CPD-based optical molecular switch with carbon nanotube electrodes

Peng Zhao,Chang-feng Fang,Yi-ming Wang,Ya-xi Zhai,De-sheng Liu 한국물리학회 2009 Current Applied Physics Vol.9 No.6

We have studied the switching characteristics of an optical molecular switch based on the 15,16-dinitrile dihydropyrene/cyclophanediene (DDP/CPD) molecule with two single-walled carbon nanotube (SWCNT) electrodes using first-principles transport calculations. It is shown that the DDP shows an overall higher conductance than the CPD at low bias which is independently of the SWCNT chirality. Meantime, the conductance of the molecular switch can be tuned by the chirality of the SWCNT. We have studied the switching characteristics of an optical molecular switch based on the 15,16-dinitrile dihydropyrene/cyclophanediene (DDP/CPD) molecule with two single-walled carbon nanotube (SWCNT) electrodes using first-principles transport calculations. It is shown that the DDP shows an overall higher conductance than the CPD at low bias which is independently of the SWCNT chirality. Meantime, the conductance of the molecular switch can be tuned by the chirality of the SWCNT.

Anti-proliferation Effects of Interferon-gamma on Gastric Cancer Cells

Zhao, Ying-Hui,Wang, Tao,Yu, Guang-Fu,Zhuang, Dong-Ming,Zhang, Zhong,Zhang, Hong-Xin,Zhao, Da-Peng,Yu, Ai-Lian Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.9

IFN-${\gamma}$ plays an indirect anti-cancer role through the immune system but may have direct negative effects on cancer cells. It regulates the viability of gastric cancer cells, so we examined whether it affects their proliferation and how that might be brought about. We exposed AGS, HGC-27 and GES-1 gastric cancer cell lines to IFN-${\gamma}$ and found significantly reduced colony formation ability. Flow cytometry revealed no effect of IFN-${\gamma}$ on apoptosis of cell lines and no effect on cell aging as assessed by ${\beta}$-gal staining. Microarray assay revealed that IFN-${\gamma}$ changed the mRNA expression of genes related to the cell cycle and cell proliferation and migration, as well as chemokines and chemokine receptors, and immunity-related genes. Finally, flow cytometry revealed that IFN-${\gamma}$ arrested the cells in the G1/S phase. IFN-${\gamma}$ may slow proliferation of some gastric cancer cells by affecting the cell cycle to play a negative role in the development of gastric cancer.

Mechanical properties and cushioning mechanism of shear thickening fluid

Peng Zhao,Qian Chen,Xue Gao,Zhaoyong Wu 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.11

Shear thickening fluid (STF) is one type of dispersed system with rapidly changing rheological properties under an impulse load. The apparent viscosity of such a suspension system changes dramatically under high-speed impact, and the system can even change from suspension to quasi-solid. Once the load is removed, the STF will quickly return to its original state. In this paper, a mechanical model based on a particle-jammed model and added mass was proposed by calculating the acceleration response of the impact bar, and the local hardening phenomenon of STF in the low-speed impact test was interpreted. Then with the low-speed impact test, the rheological properties of STF in the cushioning process were recorded by a high-speed camera. Meanwhile, a comparison was made with the cushioning efficiency of AV-200, a closed-cell foam material, by using the force-displacement curve. Finally, based on the constitutive relation of STF and by using the fluid-solid coupling method in the FEM, the lowspeed impact test of STF was analyzed to obtain more comprehensive dynamic characteristics. The acceleration response obtained in the test was consistent with the theoretical results, which further verified the rationality and effectiveness of the theoretical model. Compared with AV-200, STF has a cushioning efficiency of 50 %-60 %, and its cushioning performance was superior to AV-200. Starting with the rheological cloud map of STF and the acceleration response of the impact bar by the numerical model, a comparison was made with the results of low-speed impact test, and a good agreement is observed.

온도에 의한 황산적늑대거미(거미목: 늑대거미과)의 성장과 생식에 관한 연구

Peng Y.J.Z.Zhao,J.P.Kim 외1명 한국거미연구소 1998 한국거미 Vol.14 No.2

Opportunistic Routing for Bandwidth-Sensitive Traffic in Wireless Networks with Lossy Links

Zhao, Peng,Yang, Xinyu The Korea Institute of Information and Commucation 2016 Journal of communications and networks Vol.18 No.5

Opportunistic routing (OR) has been proposed as a viable approach to improve the performance of wireless multihop networks with lossy links. However, the exponential growth of the bandwidth-sensitive mobile traffic (e.g., mobile video streaming and online gaming) poses a great challenge to the performance of OR in term of bandwidth guarantee. To solve this problem, a novel mechanism is proposed to opportunistically forwarding data packets and provide bandwidth guarantee for the bandwidth-sensitive traffic. The proposal exploits the broadcast characteristic of wireless transmission and reduces the negative effect of wireless lossy links. First, the expected available bandwidth (EAB) and the expected transmission cost (ETC) under OR are estimated based on the local available bandwidth, link delivery probability, forwarding candidates, and prioritization policy. Then, the policies for determining and prioritizing the forwarding candidates is devised by considering the bandwidth and transmission cost. Finally, bandwidth-aware routing algorithm is proposed to opportunistically delivery data packets; meanwhile, admission control is applied to admit or reject traffic flows for bandwidth guarantee. Extensive simulation results show that our proposal consistently outperforms other existing opportunistic routing schemes in providing performance guarantee.