Stable Tetrabenzo-Chichibabin’s Hydrocarbons: Tunable Ground State and Unusual Transition between Their Closed-Shell and Open-Shell Resonance Forms

Zeng, Zebing,Sung, Young Mo,Bao, Nina,Tan, Davin,Lee, Richmond,Zafra, José,L.,Lee, Byung Sun,Ishida, Masatoshi,Ding, Jun,Ló,pez Navarrete, Juan T.,Li, Yuan,Zeng, Wangdong,Kim, Dongho,Huang American Chemical Society 2012 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.134 No.35

<P>Stable open-shell polycyclic aromatic hydrocarbons (PAHs) are of fundamental interest due to their unique electronic, optical, and magnetic properties and promising applications in materials sciences. Chichibabin’s hydrocarbon as a classical open-shell PAH has been investigated for a long time. However, most of the studies are complicated by their inherent high reactivity. In this work, two new stable benzannulated Chichibabin’s hydrocarbons <B>1-CS</B> and <B>2-OS</B> were prepared, and their electronic structure and geometry in the ground state were studied by various experiments (steady-state and transient absorption spectra, NMR, electron spin resonance (ESR), superconducting quantum interference device (SQUID), FT Raman, X-ray crystallographic etc.) and density function theory (DFT) calculations. <B>1-CS</B> and <B>2-OS</B> exhibited tunable ground states, with a closed-shell quinoidal structure for <B>1-CS</B> and an open-shell biradical form for <B>2-OS</B>. Their corresponding excited-state forms <B>1-OS</B> and <B>2-CS</B> were also chemically approached and showed different decay processes. The biradical <B>1-OS</B> displayed an unusually slow decay to the ground state (<B>1-CS</B>) due to a large energy barrier (95 ± 2.5 kJ/mol) arising from severe steric hindrance during the transition from an orthogonal biradical form to a butterfly-like quinoidal form. The quick transition from the quinoidal <B>2-CS</B> (excited state) to the orthogonal biradicaloid <B>2-OS</B> (ground state) happened during the attempted synthesis of <B>2-CS</B>. Compounds <B>1-CS</B> and <B>2-OS</B> can be oxidized into stable dications by FeCl<SUB>3</SUB> and/or concentrated H<SUB>2</SUB>SO<SUB>4</SUB>. The open-shell <B>2-OS</B> also exhibited a large two-photon absorption (TPA) cross section (760 GM at 1200 nm).</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2012/jacsat.2012.134.issue-35/ja3050579/production/images/medium/ja-2012-050579_0017.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja3050579'>ACS Electronic Supporting Info</A></P>

Pushing Extended <i>p</i>-Quinodimethanes to the Limit: Stable Tetracyano-oligo(<i>N</i>-annulated perylene)quinodimethanes with Tunable Ground States

Zeng, Zebing,Ishida, Masatoshi,Zafra, José,L.,Zhu, Xiaojian,Sung, Young Mo,Bao, Nina,Webster, Richard D.,Lee, Byung Sun,Li, Run-Wei,Zeng, Wangdong,Li, Yuan,Chi, Chunyan,Navarrete, Juan T. Lo American Chemical Society 2013 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.135 No.16

<P><I>p</I>-Quinodimethane (<I>p</I>-QDM) is a fundamental building block for the design of π-conjugated systems with low band gap and open-shell biradical character. However, synthesis of extended <I>p</I>-QDMs has usually suffered from their intrinsic high reactivity and poor solubility. In this work, benzannulation together with terminal cyano-substitution was demonstrated to be an efficient approach for the synthesis of a series of soluble and stable tetracyano-oligo(<I>N</I>-annulated perylene)quinodimethanes <B><I>n</I>Per-CN</B> (<I>n</I> = 1–6), with the longest molecule having 12 <I>para</I>-linked benzenoid rings! The geometry and electronic structures of these oligomers were investigated by steady-state and transient absorption spectroscopy, nuclear magnetic resonance, electron spin resonance, superconducting quantum interference device, and FT Raman spectroscopy assisted by density functional theory calculations. They showed tunable ground states, varying from a closed-shell quinoidal structure for monomer, to a singlet biradical for dimer, trimer, and tetramer, and to a triplet biradical for pentamer and hexamer. Large two-photon absorption cross-section values were observed in the near-infrared range, which also exhibited a clear chain-length dependence.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2013/jacsat.2013.135.issue-16/ja402467y/production/images/medium/ja-2013-02467y_0010.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja402467y'>ACS Electronic Supporting Info</A></P>

NUMERICAL SIMULATION AND PREDICTION OF NEGATIVE STORM SURGE IN THE YANGTZE RIVER ESTUARY

Zeng Hao Qin,Yi Hong Duan,De Bao Hu,Mao Xing Gong 한국해안해양공학회 1999 학술강연회 발표논문초록집 Vol.1 No.1

An attempt is made by using both statistical model and multi-layer simplified ECOM-Si model with temperature and salinity effects neglected to investigate numerically the negative storm surge (SS) in the Yangtze River estuary. An operational system for predicting the negative SS are constructed in conjunction of ECOM-Si model with the operational limited-area fine-mesh numerical weather prediction (NWP) model developed by the Shanghai Typhoon Institute(STI).To test the reliability of ECOM-Si model and to understand the computational feature of the model in simulating sea surface elevation, both semi-diurnal tide computation at the river mouth tidal station and numerical SS simulations under the action of idealized easterly and westerly winds are completed. Based on these experiments, a series of negative SS simulations induced by the cold wave, tropical and extratropical cyclones are carried out respectively, in which the objective analysis data of atmospheric forcings on the sea surface are offered by STI NWP model. Case experiments show that the predicted peak negative SS are coincident with the real ones and the phase differences between them are within a acceptable limit. The system is hopeful in operational use for predicting negative SS in the Yangtze River estuary.

The Effect of Herb-Partition Moxibustion on Toll-like Receptor 4 in Rabbit Aorta during Atherosclerosis

Zeng-Hui Yue,Xin-Qun He,Xiao-Rong Chang,Jian-Ling Yuan,Bao-Sheng Yu,Mi Liu,Ling Fu,Liang Zhang,Li-Chao Shang 사단법인약침학회 2012 Journal of Acupuncture & Meridian Studies Vol.5 No.2

Objective: To explore the mechanism of Toll-like receptor (TLR4) inhibition in the delay of formation of atherosclerosis by herb-partition moxibustion. Method: Seventy-five rabbits were randomly assigned to one of five groups: blank, atherosclerosis (AS) model, direct moxibustion, herb-partition moxibustion, and drug treatment. With the exception of the blank group, all rabbits were given a high-fat diet in addition to immunologic injury to create the AS model. The experiments were carried out for 16 weeks, at which time the aorta was removed from each rabbit. Immunohistochemical methods were used to detect the gray level of the aortic TLR4 to observe the immunologic competence of its antigens. Fluorescent quantitative polymerase chain reaction was used to detect the expression of TLR4 messenger RNA (mRNA) in the aorta. Results: The gray-scale value of TLR4 and the TLR4 mRNA expression significantly decreased (p < 0.05) in the direct moxibustion, herb-partition moxibustion, and drug treatment groups. Furthermore, the effects of the herb-partition moxibustion and drug treatment were superior to those of the direct moxibustion. Conclusion: Herb-partition moxibustion inhibits aortic TLR4 activity and mRNA expression,showing that herb-partition moxibustion delays the formation of atherosclerosis through the inhibition of TLR4 expression.

DYNAMICS OF AN ACTIVELY GUIDED TRACK INSPECTION VEHICLE

Zeng, C.C.,Bao, J.H.,Zhang, J.W.,Li, X.H. The Korean Society of Automotive Engineers 2006 International journal of automotive technology Vol.7 No.7

The lateral dynamic behaviours of a track inspection vehicle with laterally guided system are studied for the safety and comfort. A 10-DOF dynamic model is proposed counting for lateral and yaw motions. The equations for motions of the vehicle running on curved tracks at a constant speed are presented. It is shown by simulation that lateral guiding forces applied to the guiding wheels on the inner side of the track increase in a larger scale in comparison with those on the outer side when the vehicle passes through curved tracks with cant, and the front guiding spring forces is larger than the rears. Lateral vibrations due to yaw motions of the vehicle take place when the vehicle runs through curved tracks. Finally, effect of the lateral guidance on the vehicle dynamics is also examined and advantages of such a guiding system are discussed in some details. An optimal guided control is applied to restrain the lateral and yaw motions. The comparisons between the active and passive guidance explain the effect of the active control approaches.

Turning on the biradical state of tetracyano-perylene and quaterrylenequinodimethanes by incorporation of additional thiophene rings

Zeng, Z.,Lee, S.,Zafra, J.,Ishida, M.,Bao, N.,Webster, R.,LopezNavarrete, J.,Ding, J.,Casado, J.,Kim, D. THE ROYAL SOCIETY OF CHEMISTRY 2014 Chemical Science Vol.5 No.8

A Novel Impedance Measurement Method for Three-Phase Power Electronic Systems

Qingyu Dou,Zeng Liu,Jinjun Liu,Weihan Bao 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

Power electronic systems could be unstable due to the interaction between converters. Impedance-based stability analysis is an effective approach to predict stability and to provide design criteria. Therefore significant are impedance measurement techniques, which have been well established for DC systems, but need to be improved for AC systems nevertheless. This paper proposes a novel AC impedance measurement method which injects bipolar pulse at current zero-crossing point. Compared with existing methods, it enhances accuracy and reduces distortion. Simulation and experimental results demonstrate the effectiveness of the novel method.

DYNAMICS OF AN ACTIVELY GUIDED TRACK INSPECTION VEHICLE

C. C. ZENG,J. H. BAO,J. W. ZHANG,X. H. LI 한국자동차공학회 2006 International journal of automotive technology Vol.7 No.7

The lateral dynamic behaviours of a track inspection vehicle with laterally guided system are studied for the safety and comfort. A 10-DOF dynamic model is proposed counting for lateral and yaw motions. The equations for motions of the vehicle running on curved tracks at a constant speed are presented. It is shown by simulation that lateral guiding forces applied to the guiding wheels on the inner side of the track increase in a larger scale in comparison with those on the outer side when the vehicle passes through curved tracks with cant, and the front guiding spring forces is larger than the rears. Lateral vibrations due to yaw motions of the vehicle take place when the vehicle runs through curved tracks. Finally, effect of the lateral guidance on the vehicle dynamics is also examined and advantages of such a guiding system are discussed in some details. An optimal guided control is applied to restrain the lateral and yaw motions. The comparisons between the active and passive guidance explain the effect of the active control approaches.

Outcomes of Microendoscopic Discectomy and Percutaneous Transforaminal Endoscopic Discectomy for the Treatment of Lumbar Disc Herniation: A Comparative Retrospective Study

Arjun Sinkemani,Xin Hong,Zeng-Xin Gao,Su-Yang Zhuang,Zan-Li Jiang,Shao-Dong Zhang,Jun-Ping Bao,Lei Zhu,Pei Zhang,Xin-Hui Xie,Feng Wang,Xiao-Tao Wu 대한척추외과학회 2015 Asian Spine Journal Vol.9 No.6

Study Design: Retrospective, case control evaluation of 86 patients who underwent microendoscopic discectomy (MED) and percutaneous transforaminal endoscopic discectomy (PTED) for the treatment of lumbar disc herniation (LDH). Purpose: To evaluate the safety and the outcomes of MED and PTED for the treatment of LDH. Overview of Literature: MED and PTED are minimally invasive surgical techniques for lower back pain. Studies to date have shown that MED and PTED are safe and effective treatment modalities for LDH. Methods: A retrospective study was performed in patients with LDH treated with MED (n=50) and transforaminal endoscopic discectomy (PTED; n=36) in our hospital. All patients were followed-up with self-evaluation questionnaires, Oswestry disability index (ODI), medical outcomes study 36-item short form health survey and MacNab criteria. All the patients in both groups were followed up to 12 months after the operation. Results: ODI questionnaire responses were not statistically different between the MED and PTED groups (53.00 vs. 48.72) before treatment. Average scores and minimal disability after 5 days to 12 months of follow-up were 4.96 in the MED group and 3.61 in the PTED group. According to MacNab criteria, 92.0% of the MED group and 94.4% of the PTED group had excellent or good results with no significant difference. Conclusions: There was no significant difference between MED and PTED outcomes. Further large-scale, randomized studies with long-term follow-up are needed.

Prognostic Evaluation of Categorical Platelet-based Indices Using Clustering Methods Based on the Monte Carlo Comparison for Hepatocellular Carcinoma

Guo, Pi,Shen, Shun-Li,Zhang, Qin,Zeng, Fang-Fang,Zhang, Wang-Jian,Hu, Xiao-Min,Zhang, Ding-Mei,Peng, Bao-Gang,Hao, Yuan-Tao Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.14

Objectives: To evaluate the performance of clustering methods used in the prognostic assessment of categorical clinical data for hepatocellular carcinoma (HCC) patients in China, and establish a predictable prognostic nomogram for clinical decisions. Materials and Methods: A total of 332 newly diagnosed HCC patients treated with hepatic resection during 2006-2009 were enrolled. Patients were regularly followed up at outpatient clinics. Clustering methods including the Average linkage, k-modes, fuzzy k-modes, PAM, CLARA, protocluster, and ROCK were compared by Monte Carlo simulation, and the optimal method was applied to investigate the clustering pattern of the indices including platelet count, platelet/lymphocyte ratio (PLR) and serum aspartate aminotransferase activity/platelet count ratio index (APRI). Then the clustering variable, age group, tumor size, number of tumor and vascular invasion were studied in a multivariable Cox regression model. A prognostic nomogram was constructed for clinical decisions. Results: The ROCK was best in both the overlapping and non-overlapping cases performed to assess the prognostic value of platelet-based indices. Patients with categorical platelet-based indices significantly split across two clusters, and those with high values, had a high risk of HCC recurrence (hazard ratio [HR] 1.42, 95% CI 1.09-1.86; p<0.01). Tumor size, number of tumor and blood vessel invasion were also associated with high risk of HCC recurrence (all p< 0.01). The nomogram well predicted HCC patient survival at 3 and 5 years. Conclusions: A cluster of platelet-based indices combined with other clinical covariates could be used for prognosis evaluation in HCC.