• 제목/요약/키워드: Fan xin

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Progress of Study on Mesogen-Jacketed Liquid Crystalline Polymers at Peking University

  • Fan, Xing-He;Chen, Xiao-Fang;Wan, Xin-Hua;Chen, Er-Qiang;Zhou, Qi-Feng
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.90-90
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    • 2006
  • Mesogen-Jacketed Liquid Crystalline Polymers, MJLCPs, are polymers with mesogenic side groups directly attached to main-chains without using flexible connecting spacers and are able to form liquid crystalline structures. Later work on structure-property of the polymers revealed that the side groups are not necessarily mesogenic for the polymers to form a mesophase so long as that the side groups are directly attached to the backbones and the side groups are large enough. Because of its inherent chain stiffness and that the monomers of MJLCPs are readily polymerizable by "living" free radical polymerizations, MJLCP offered a unique handy tool for making block copolymers. In addition, MJLCP offered also new opportunities for novel functional materials.

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Compensation On-line of Errors Caused by Rotor Centrifugal Deformation for a Magnetically Suspended Sensitive Gyroscope

  • Xin, Chao-Jun;Cai, Yuan-Wen;Ren, Yuan;Fan, Ya-Hong
    • Journal of Electrical Engineering and Technology
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    • 제13권2호
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    • pp.1030-1041
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    • 2018
  • The aim of this paper is to design a centrifugal deformation error compensation method with guaranteed performance that allows angular velocity measurement of the magnetically suspended sensitive gyroscopes (MSSGs). The angular velocity measurement principle and the structure of the MSSG are described, and the analytical model of errors caused by MSSG rotor centrifugal deformation is established. Then, an on-line rotor centrifugal deformation error compensation method based on measurement of rotor spinning speed in real-time has been designed. The common issues caused by centrifugal deformation of spinning rotors can be effectively resolved by the proposed method. Comparative experimental results before and after compensation demonstrate the validity and superiority of the error compensation method.

Success and Failure of the Overseas M&A : Cases of Chinese Enterp rises

  • Zhang, Ruo-Nam;Huan, Xin-Gang;Fan, Zhang
    • 동아시아경상학회지
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    • 제3권2호
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    • pp.26-30
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    • 2015
  • Purpose-This paper aims to do research on success and failure of Chinese enterprises and suggest the implications to the Chinese enterprises by comparing the representative examples of Chinese enterprises' overseas M&A. Research Design, Data, and Methodology-This paper selected by six cases of Chinese enterprises' overseas M&A to do the contrast. Results-Consulting company still plays a very important role in Chinese enterprises' overseas M&A because Chinese enterprises' overseas M&A is being placed in growth stage. And how to grasp the development trend of industry accurate and choose the correct target enterprises is a very important issue for Chinese enterprises which can make Chinese enterprises to avoid blind investment. Conclusion-Chinese Enterprises have to evaluate the target enterprise with the aid of authoritative investment and consulting company, focus on training qualified talents and the integration after the M&A when they Overseas M&A in the future.

Real-Time Compensation of Errors Caused by the Flux Density Non-uniformity for a Magnetically Suspended Sensitive Gyroscope

  • Chaojun, Xin;Yuanwen, Cai;Yuan, Ren;Yahong, Fan;Yongzhi, Su
    • Journal of Magnetics
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    • 제22권2호
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    • pp.315-325
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    • 2017
  • Magnetically suspended sensitive gyroscopes (MSSGs) provide an interesting alternative for achieving precious attitude angular measurement. To effectively reduce the measurement error caused by the non-uniformity of the air-gap flux density in a MSSG, this paper proposes a novel compensation method based on measuring and modeling of the air-gap flux density. The angular velocity measurement principle and the structure of the MSSG are described, and then the characteristic of the air-gap flux density has been analyzed in detail. Next, to compensate the flux density distribution error and improve the measurement accuracy of the MSSG, a real-time compensation method based on the online measurement with hall probes is designed. The common issues caused by the non-uniformity of the air-gap flux density can be effectively resolved by the proposed method in high-precision magnetically suspended configurations. Comparative simulation results before and after compensation have verified the effectiveness and superiority of the proposed compensation method.

Algorithm for Detection of Fire Smoke in a Video Based on Wavelet Energy Slope Fitting

  • Zhang, Yi;Wang, Haifeng;Fan, Xin
    • Journal of Information Processing Systems
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    • 제16권3호
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    • pp.557-571
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    • 2020
  • The existing methods for detection of fire smoke in a video easily lead to misjudgment of cloud, fog and moving distractors, such as a moving person, a moving vehicle and other non-smoke moving objects. Therefore, an algorithm for detection of fire smoke in a video based on wavelet energy slope fitting is proposed in this paper. The change in wavelet energy of the moving target foreground is used as the basis, and a time window of 40 continuous frames is set to fit the wavelet energy slope of the suspected area in every 20 frames, thus establishing a wavelet-energy-based smoke judgment criterion. The experimental data show that the algorithm described in this paper not only can detect smoke more quickly and more accurately, but also can effectively avoid the distraction of cloud, fog and moving object and prevent false alarm.

Analysis, Modeling and Compensation of Dynamic Imbalance Error for a Magnetically Suspended Sensitive Gyroscope

  • Xin, Chaojun;Cai, Yuanwen;Ren, Yuan;Fan, Yahong;Xu, Guofeng;Lei, Xu
    • Journal of Magnetics
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    • 제21권4호
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    • pp.529-536
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    • 2016
  • Magnetically suspended sensitive gyroscopes (MSSGs) provide an interesting alternative for achieving precious attitude angular measurement. To effectively reduce the measurement error caused by dynamic imbalance, this paper proposes a novel compensation method based on analysis and modeling of the error for a MSSG. Firstly, the angular velocity measurement principle of the MSSG is described. Then the analytical model of dynamic imbalance error has been established by solving the complex coefficient differential dynamic equations of the rotor. The generation mechanism and changing regularity of the dynamic imbalance error have been revealed. Next, a compensation method is designed to compensate the dynamic imbalance error and improve the measurement accuracy of the MSSG. The common issues caused by dynamic imbalance can be effectively resolved by the proposed method in gyroscopes with a levitating rotor. Comparative simulation results before and after compensation have verified the effectiveness and superiority of the proposed compensation method.

AP-SDN: Action Program enabled Software-Defined Networking Architecture

  • Zheng Zhao;Xiaoya Fan;Xin Xie;Qian Mao;Qi Zhao
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제17권7호
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    • pp.1894-1915
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    • 2023
  • Software-Defined Networking (SDN) offers several advantages in dynamic routing, flexible programmable control and custom application-driven network management. However, the programmability of the data plane in traditional SDN is limited. A network operator cannot change the ability of the data plane and perform complex packet processing on the data plane, which limits the flexibility and extendibility of SDN. In the paper, AP-SDN (Action Program enabled Software-Defined Networking) architecture is proposed, which extends the action set of SDN data plane. In the proposed architecture, a modified Open vSwitch is utilized in the data plane allowing the execution of action programs at runtime, thus enabling complex packet processing. An example action program is also implemented which transparently encrypts traffic for terminals. At last, a prototype system of AP-SDN is developed and experiments show its effectiveness and performance.

DH332, a Synthetic β-Carboline Alkaloid, Inhibits B Cell Lymphoma Growth by Activation of the Caspase Family

  • Gao, Pan;Tao, Ning;Ma, Qin;Fan, Wen-Xi;Ni, Chen;Wang, Hui;Qin, Zhi-Hai
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권9호
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    • pp.3901-3906
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    • 2014
  • Aim: The purpose of this study was to investigate anti-tumor effects and safety of DH332, a new ${\beta}$-carboline alkaloids derivatives in vitro and in vivo. Materials and Methods: The effects of DH332 on human (RAMOS RA.1) and mouse (J558) B lymphoma cell lines were detected using a CCK-8 kit (Cell Counting Kit-8), and apoptosis was detected by flow cytometry with PI/annexinV staining. Western blotting was used to detected caspase-3 and caspase-8. Neurotoxic and anti-tumor effects were evaluated in animal experiments. Results: DH332 exerts a lower neurotoxicity compared with harmine. It also possesses strong antitumor effects against two B cell lymphoma cell lines with low $IC_{50s}$. Moreover, DH332 could inhibit the proliferation and induce the apoptosis of RAMOS RA.1 and J558 cell lines in a dose-dependent manner. Our results suggest that DH332 triggers apoptosis by mainly activating the caspase signaling pathway. In vivo studies of tumor-bearing BALB/c mice showed that DH332 significantly inhibited growth of J558 xenograft tumors. Conclusions: DH332 exerts effective antitumor activity in vitro and in vivo, and has the potential to be a promising drug candidate for lymphoma therapy.

Identification of a Cancer Stem-like Population in the Lewis Lung Cancer Cell Line

  • Zhang, An-Mei;Fan, Ye;Yao, Quan;Ma, Hu;Lin, Sheng;Zhu, Cong-Hui;Wang, Xin-Xin;Liu, Jia;Zhu, Bo;Sun, Jian-Guo;Chen, Zheng-Tang
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권3호
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    • pp.761-766
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    • 2012
  • Objective: Although various human cancer stem cells (CSCs) have been defined, their applications are restricted to immunocompromised models. Developing a novel CSC model which could be used in immunocompetent or transgenic mice is essential for further understanding of the biomolecular characteristics of tumor stem cells. Therefore, in this study, we analyzed murine lung cancer cells for the presence of CSCs. Methods: Side population (SP) cells were isolated by fluorescence activated cell sorting, followed by serum-free medium (SFM) culture, using Lewis lung carcinoma cell (LLC) line. The self-renewal, differentiated progeny, chemosensitivity, and tumorigenic properties in SP and non-SP cells were investigated through in vitro culture and in vivo serial transplantation. Differential expression profiles of stem cell markers were examined by RT-PCR. Results: The SP cell fraction comprised 1.1% of the total LLC population. SP cells were available to grow in SFM, and had significantly enhanced capacity for cell proliferation and colony formation. They were also more resistant to cisplatin in comparison to non-SP cells, and displayed increased tumorigenic ability. Moreover, SP cells showed higher mRNA expression of Oct-4, ABCG2, and CD44. Conclusion: We identified SP cells from a murine lung carcinoma, which possess well-known characteristics of CSCs. Our study established a useful model that should allow investigation of the biological features and pharmacosensitivity of lung CSCs, both in vitro and in syngeneic immunocompetent or transgenic/knockout mice.

Resveratrol Inhibits Oesophageal Adenocarcinoma Cell Proliferation via AMP-activated Protein Kinase Signaling

  • Fan, Guang-Hua;Wang, Zhong-Ming;Yang, Xi;Xu, Li-Ping;Qin, Qin;Zhang, Chi;Ma, Jian-Xin;Cheng, Hong-Yan;Sun, Xin-Chen
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권2호
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    • pp.677-682
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    • 2014
  • Resveratrol has been examined in several model systems for potential effects against cancer. Adenosine monophosphate-activated protein kinase (AMPK) is reported to suppress proliferation in most eukaryocyte cells. Whether resveratrol via AMPK inhibits proliferation of oesophageal adenocarcinoma cells (OAC) is unknown. The aim of this study was to determine the roles of AMPK in the protective effects of resveratrol in OAC proliferation and to elucidate the underlying mechanisms. Treatment of cultured OAC derived from human subjects or cell lines with resveratrol resulted in decreased cell proliferation. Further, inhibition of AMPK by pharmacological reagent or genetical approach abolished resveratrol-suppressed OAC proliferation, reduced the level of $p27^{Kip1}$, a cyclin-dependent kinase inhibitor, and increased the levels of S-phase kinase-associated protein 2 (Skp2) of $p27^{Kip1}$-E3 ubiquitin ligase and 26S proteasome activity reduced by resveratrol. Furthermore, gene silencing of $p27^{Kip1}$ reversed resveratrol-suppressed OAC proliferation. In conclusion, these findings indicate that resveratrol inhibits Skp2-mediated ubiquitylation and 26S proteasome-dependent degradation of $p27^{Kip1}$ via AMPK activation to suppress OAC proliferation.