Metathetic Degradation of Styrene-Butadiene Rubber via Ru-Alkylidene Complex Catalyzed Reaction

Tingting Zou,Bin Jiang,Shaohui Lin,Qinmin Pan 한국고분자학회 2016 폴리머 Vol.40 No.5

Metathetic degradation and functionalization of styrene-butadiene rubber (SBR) were performed with allyl hexanoate, allyl chloroacetate, 5-hexenyl acetate and trifluoroethyl methacrylate as chain transfer agents (CTAs) using Grubbs 2<SUP>nd</SUP> generation catalyst. It has been demonstrated that the catalyst concentration, CTA concentration and reaction time were major factors influencing the molecular weights and polydispersity indices of targeted telechelic SBR oligomers. Well-defined oligomers with molecular weights ranging from 700 to 36600 g mol<SUP>-1</SUP> and polydispersity indices ranging from 1.17 to 4.79 were realized. The structures of the SBR oligomers were determined by FTIR and <SUP>1</SUP>H NMR analyses, which indicated that the functional groups of the CTAs were successfully attached onto the end of the polymer chains. To further investigate the performance of SBR oligomers, differential scanning calorimetry (DSC) analysis was performed, which indicated that the glass transition temperature (Tg) of the metathesis products decreased with longer reaction time.

Fully Distributed Economic Dispatching Methods Based on Alternating Direction Multiplier Method

Linfeng Yang,Tingting Zhang,Guo Chen,Zhenrong Zhang,Jiangyao Luo,Shanshan Pan 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.5

Based on the requirements and characteristics of multi-zone autonomous decision-making in modern power system, fully distributed computing methods are needed to optimize the economic dispatch (ED) problem coordination of multi-regional power system on the basis of constructing decomposition and interaction mechanism. In this paper, four fully distributed methods based on alternating direction method of multipliers (ADMM) are used for solving the ED problem in distributed manner. By duplicating variables, the 2-block classical ADMM can be directly used to solve ED problem fully distributed. The second method is employing ADMM to solve the dual problem of ED in fully distributed manner. N-block methods based on ADMM including Alternating Direction Method with Gaussian back substitution (ADM_G) and Exchange ADMM (E_ADMM) are employed also. These two methods all can solve ED problem in distributed manner. However, the former one cannot be carried out in parallel. In this paper, four fully distributed methods solve the ED problem in distributed collaborative manner. And we also discussed the difference of four algorithms from the aspects of algorithm convergence, calculation speed and parameter change. Some simulation results are reported to test the performance of these distributed algorithms in serial and parallel.

Photodegradation of 17α-ethynylestradiol in nitrate aqueous solutions

Dong Ren,Tingting Bi,Shumei Gao,Xukun Li,Bin Huang,Xuejun Pan 대한환경공학회 2016 Environmental Engineering Research Vol.21 No.2

17α-Ethynylestradiol (Ee₂) has gotten growing concerns due to its widely detected in the environment and high estrogenic potency. However, the knowledge on the photochemical behaviors of Ee₂ in natural waters is still limited. Herein, the photodegradation and estrogenic potency variation of Ee₂ induced by nitrate were studied using a sunlight simulator consisted by a 300 W medium pressure mercury lamp and 290 nm cut-off filters. It was found that Ee₂ could be photodegraded at a rate of 0.0193 h-1 in pure aqueous solutions, and the photodegradation of Ee₂ could be significantly promoted by nitrate. The photodegradation removal rate of Ee₂ was increased from 9% in Milli-Q water to 85% in 2.0 mM nitrate solutions. Reactive species scavenging experiments demonstrated that the photogenerated HO? contributed about 55% to Ee₂ degradation. Fe(III), Cl- and dissolved humic acid (DHA) could inhibit the photodegradation of Ee₂ by competing the incident light and photogenerated HO?, while HCO₃ - had no influence on Ee₂ photodegradation. Ee₂ was determined to be phototransformed into organic chemicals without estrogenic potency by GC-MS and MCF-7 cell proliferation toxicity tests. These findings could extend our knowledge on the photochemical behaviors of steroid estrogens and provide information for ecological risk assessment.

Fully Distributed Economic Dispatching Methods Based on Alternating Direction Multiplier Method

Yang, Linfeng,Zhang, Tingting,Chen, Guo,Zhang, Zhenrong,Luo, Jiangyao,Pan, Shanshan The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.5

Based on the requirements and characteristics of multi-zone autonomous decision-making in modern power system, fully distributed computing methods are needed to optimize the economic dispatch (ED) problem coordination of multi-regional power system on the basis of constructing decomposition and interaction mechanism. In this paper, four fully distributed methods based on alternating direction method of multipliers (ADMM) are used for solving the ED problem in distributed manner. By duplicating variables, the 2-block classical ADMM can be directly used to solve ED problem fully distributed. The second method is employing ADMM to solve the dual problem of ED in fully distributed manner. N-block methods based on ADMM including Alternating Direction Method with Gaussian back substitution (ADM_G) and Exchange ADMM (E_ADMM) are employed also. These two methods all can solve ED problem in distributed manner. However, the former one cannot be carried out in parallel. In this paper, four fully distributed methods solve the ED problem in distributed collaborative manner. And we also discussed the difference of four algorithms from the aspects of algorithm convergence, calculation speed and parameter change. Some simulation results are reported to test the performance of these distributed algorithms in serial and parallel.

Enhanced Coercivity of Sintered NdFeB Magnets Prepared by Dy Addition

Zhang Pengyue,Ge Hong-liang,Pan Minxiang,Wu Qiong,Yang Hangfu,Jiao Zhiwei,Liu Tingting,Fu Rui 한국자기학회 2010 한국자기학회 학술연구발표회 논문개요집 Vol.2010 No.12

An Unambiguous Deterministic Compressed Acquisition Technique for BOC Signal

Xiaoheng Tan,Yan Zhang,Qiang Yan,Tingting Pan,Xiaonan Hu 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.9

The long PN code in a Binary Offset Carrier (BOC) modulated signal has a higher rate than the GPS C/A code, which makes the acquisition process in the new global navigation satellite system (GNSS) much more complex. To achieve a fast acquisition of the GNSS signal with a reduced number of correlators and low computational complexity, a two-stage deterministic compressed (DS) GNSS acquisition technique has been proposed. Nevertheless, the ambiguous threat of BOC signal isn’t taken into account in the DS technique. To eliminate the ambiguity threat in the acquisition process of BOC (m, n) signal, an unambiguous deterministic compressed acquisition is proposed in this paper. The main idea of the proposed technique is to introduce a simplified GRASS algorithm in the second stage measurement. Theoretical analysis and simulation results show that, at the expense of some performance degradation the proposed technique can completely remove the undesired positive side peaks of BOC (m, n) signal, and reduce the chance of false peak acquisition compared with the DS technique.

Sputum Transcriptomics Reveals FCN1+ Macrophage Activation in Mild Eosinophilic Asthma Compared to Non-Asthmatic Eosinophilic Bronchitis

Zhan Wenzhi,Luo Wei,Zhang Yulong,Xiang Keheng,Chen Xiaomei,Shen Shuirong,Huang Chuqing,Xu Tingting,Ding Wenbin,Chen Yuehan,Lin Mingtong,Pan Xinghua,Lai Kefang 대한천식알레르기학회 2024 Allergy, Asthma & Immunology Research Vol.16 No.1

Purpose: Eosinophilic asthma (EA) and non-asthmatic eosinophilic bronchitis (EB) share similar eosinophilic airway inflammation. Unlike EA, EB did not present airway hyperresponsiveness or airflow obstruction. We aimed to compare the mechanism underlying the different manifestations between EA and EB via sputum transcriptomics analysis. Methods: Induced-sputum cells from newly physician-diagnosed EA, EB patients, and healthy controls (HCs) were collected for RNA sequencing. Results: Bulk RNA sequencing was performed using sputum cells from patients with EA (n = 18), EB (n = 15) and HCs (n = 28). Principal component analysis revealed similar gene expression patterns in EA and EB. The most differentially expressed genes in EB compared with HC were also shared by EA, including IL4, IL5 IL13, CLC, CPA3, and DNASE1L3. However, gene set enrichment analysis showed that the signatures regulating macrophage activation were enriched in EA compared to EB. Sputum cells were profiled using single-cell RNA sequencing. FABP4+ macrophages, SPP1+ macrophages, FCN1+ macrophages, dendritic cells, T cells, B cells, mast cells, and epithelial cells were identified based on gene expression profiling. Analysis of cell-cell communication revealed that interactions between FCN1+ macrophages and other cells were higher in EA than in EB. A wealth of transforming growth factor beta (TGF-β) and vascular endothelial growth factor (VEGF) interactions between FCN1+ macrophages and other cells have been shown in EA. The gene expression levels of EREG, TGFBI, and VEGFA in FCN1+ macrophages of EA were significantly higher than those of EB. Furthermore, signatures associated with the response to TGF-β, cellular response to VEGF stimulus and developmental cell growth were enriched in FCN1+ macrophages of EA compared to those of EB. Conclusions: FCN1+ macrophage activation associated with airway remodeling processes was upregulated in EA compared to that in EB, which may contribute to airway hyperresponsiveness and airflow obstruction.