A Comparable Study on the Microwave Absorption Properties of Al/Fe/Co Doped OMC/Paraffin Wax Composites

Yanyan Ren,Hongfeng Li,Guanglei Wu,Le Yang,Chenhui Zheng,LIUDING WANG,Fang Ren,Hui Xing,HONGJING WU 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.2

Al/Fe/Co doped ordered mesoporous carbon (OMC) composites have been synthesized by a facile method, and the influence of dopant on the electromagnetic (EM) and microwave absorption properties was investigated in the frequency range of 2–18 GHz. Compared with Fe/Co– OMC composites, the Al–OMC nanocomposite played a great role in adjusting values and frequency dependence of complex permittivity, which gives rise to significant improved microwave absorption and reduced thickness of the corresponding paraffin wax composites. Reflection loss (RL) values less than -5 dB and -10 dB were obtained in the frequency range of 9.2–18 GHz and 10.7–14.7 GHz with a single thickness of 2.00 mm, respectively. Such enhanced EM wave absorption property of the Al–OMC/paraffin wax composite was ascribed to its superior impedance matching characteristic. Thin thickness, broadband absorption microwave absorbers with Al doped OMC nanocomposites were obtained.

Microwave Absorption Properties of Fe-Doped Ordered Mesoporous Carbon (CMK-3)/Silica Matrix Nanocomposites with Magnetic Multi-Resonance Mechanisms

Yanyan Ren,Le Yang,LIUDING WANG,Hui Xing,HONGJING WU 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2015 NANO Vol.10 No.8

Low-density Fe-doped ordered mesoporous carbon (CMK-3)-silica (SBA-15) nanocomposites with different Fe contents have been prepared by a catalytic carbonization procedure followed by high-temperature calcination in N2. From field emission-scanning electron microscope (FE-SEM) and high resolution-transmission electron microscope (HR-TEM) images, it can be concluded that CMK-3 particles are dispersed homogeneously into a silica matrix and form a novel, special and interesting composite nanostructure. The metal species (~18 nm) are dispersed on the surface of frameworks during the catalytic carbonization procedure and endow a magnetic property to the carbon–silica nanocomposites. The optimal reflection loss (RL) calculated from the measured permittivity and permeability is -19 dB at 17.2 GHz for an absorber thickness of 2.00 mm. Moreover, the electromagnetic (EM) wave absorption less than -10 dB is found to exceed 5.76 GHz as the layer thickness is 2.37 mm. The permittivity dispersion behaviors have been explained based on the Cole–Cole model and the conductivity contribution model. A new simple empirical model was also supposed to find the fitted curves of the multi-resonance imaginary permeability spectra of the composites. The EM wave can hardly be reflected on the absorber surface because of a better match between dielectric loss and magnetic loss, which originates from the combination of dielectric carbon–silica and magnetic Fe species.

The Impact of Cultural Differences on Financial Quality in Cross-border Mergers and Acquisitions: A Case Study of SAIC Motor and Ssangyong Motor

Jin, Zheng,Ren, Yanyan,Li, Guangyuan 한중경제문화학회 2016 한중경제문화연구 Vol.6 No.-

This study discusses several issues which are very important in worldwide mergers and acquisitions, such as cultural differences, culture clashes, operating results and financial quality. A case of SAIC Motor's acquisition of Ssangyong Motor is examined. For this study, 20 financial ratios are used to calculate the financial quality of SAIC in the post-acquisition integration. The result shows that cultural differences possibly have a negative effect on post-acquisition integration and cultural clashes are the root cause of the financial quality plummet. The suggestions are also provided that top managers should pay much more attention to the negative effects of cultural clashes and strengthen cultural integration.

Surgical management of inflammatory bowel disease in China: a systematic review of two decades

( Qiao Yu ),( Ren Mao ),( Lei Lian ),( Siew Chien Ng ),( Shenghong Zhang ),( Zhihui Chen ),( Yanyan Zhang ),( Yun Qiu ),( Baili Chen ),( Yao He ),( Zhirong Zeng ),( Shomron Ben-horin ),( Xinming Song 대한장연구학회 2016 Intestinal Research Vol.14 No.4

Background/Aims: The past decades have seen increasing incidence and prevalence of inflammatory bowel disease (IBD) in China. This article aimed to summarize the current status and characteristics of surgical management for IBD in China. Methods: We searched PubMed, Embase, and Chinese databases from January 1, 1990 to July 1, 2014 for all relevant studies on the surgical treatment IBD in China. Eligible studies with sufficient defined variables were further reviewed for primary and secondary outcome measures. Results: A total of 74 studies comprising 2,007 subjects with Crohn`s disease (CD) and 1,085 subjects with ulcerative colitis (UC) were included. The percentage of CD patients misdiagnosed before surgery, including misdiagnosis as appendicitis or UC, was 50.8%±30.9% (578/1,268). The overall postoperative complication rate was 22.3%±13.0% (267/1,501). For studies of UC, the overall postoperative complication rate was 22.2%±27.9% (176/725). In large research centers (n>50 surgical cases), the rates of emergency operations for CD (P =0.032) and in-hospital mortalities resulting from both CD and UC were much lower than those in smaller research centers (n≤50 surgical cases) (P =0.026 and P <0.001, respectively). Regarding the changes in CD and UC surgery over time, postoperative complications (P =0.045 for CD; P =0.020 for UC) and postoperative in-hospital mortality (P =0.0002 for CD; P =0.0160 for UC) both significantly improved after the year 2010. Conclusions: The surgical management of IBD in China has improved over time. However, the rates of misdiagnosis and postoperative complications over the past two decades have remained high. Large research centers were found to have relatively better capacity for surgical management than the smaller ones. Higher quality prospective studies are needed in China. (Intest Res 2016;14:322-332)

Convolutional auto-encoder based multiple description coding network

( Lili Meng ),( Hongfei Li ),( Jia Zhang ),( Yanyan Tan ),( Yuwei Ren ),( Huaxiang Zhang ) 한국인터넷정보학회 2020 KSII Transactions on Internet and Information Syst Vol.14 No.4

When data is transmitted over an unreliable channel, the error of the data packet may result in serious degradation. The multiple description coding (MDC) can solve this problem and save transmission costs. In this paper, we propose a deep multiple description coding network (MDCN) to realize efficient image compression. Firstly, our network framework is based on convolutional auto-encoder (CAE), which include multiple description encoder network (MDEN) and multiple description decoder network (MDDN). Secondly, in order to obtain high-quality reconstructed images at low bit rates, the encoding network and decoding network are integrated into an end-to-end compression framework. Thirdly, the multiple description decoder network includes side decoder network and central decoder network. When the decoder receives only one of the two multiple description code streams, side decoder network is used to obtain side reconstructed image of acceptable quality. When two descriptions are received, the high quality reconstructed image is obtained. In addition, instead of quantization with additive uniform noise, and SSIM loss and distance loss combine to train multiple description encoder networks to ensure that they can share structural information. Experimental results show that the proposed framework performs better than traditional multiple description coding methods.

Nrf2 in adipocytes

Zhendi Wang,Zhuo Zuo,Lu Li,Suping Ren,Tianchang Gao,Jingqi Fu,Yongyong Hou,Yanyan Chen,Jingbo Pi 대한약학회 2020 Archives of Pharmacal Research Vol.43 No.3

White adipocytes play a key role in maintainingwhole body energy homeostasis by forming white adiposetissue (WAT). The impairment of WAT formation or WATdysfunction is clearly associated with severe metabolic disorders. Mature adipocytes are derived from differentiatedpreadipocytes and are pivotal in energy storage and metabolism. Nuclear factor erythroid 2-related factor 2 (Nrf2) isa member of a family of CNC-bZIP proteins which exerttheir transcriptional control on genes harboring antioxidantresponse elements (ARE) in partnership with smallmusculoaponeurotic fibrosarcoma proteins. The activationof Nrf2-ARE coordinated by specific repressor Kelch-likeECH-associated protein 1 (Keap1) regulates networks ofgenes controlling diverse homeostatic processes involvingadaptive antioxidant response and detoxification amongmany other adaptive responses. Interestingly, accumulatingevidence indicates that Nrf2 may act as a transcription factorin regulating the formation and function of adipose tissues,including adipogenesis, lipid metabolism and insulin sensitivity. In this mini-review, an overview on the distinct rolesof Nrf2 in adipocytes is provided. While highlighting the regulatory role of Nrf2 in adipogenesis, recent key findingson Nrf2 in insulin signal transduction and energy metabolismof adipocytes are also summarized.