Density Functional Theory Study on Triphenylamine-based Dye Sensitizers Containing Different Donor Moieties

Xu, Jie,Wang, Lei,Liang, Guijie,Bai, Zikui,Wang, Luoxin,Xu, Weilin,Shen, Xiaolin Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.9

Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations have been employed to investigate the molecular structures and absorption spectra of two dyes containing diphenylaniline and 4-diphenylamino-diphenylaniline as donor moiety (TPA1 and TPA3). The geometries indicate that the strong conjugation is formed in the dyes. The electronic structures suggest that the intramolecular charge transfer from the donor to the acceptor occurs, and the electron-donating capability of 4-diphenylamino-diphenylaniline is stronger than that of diphenylaniline. The computed highest occupied molecular orbital (HOMO) energy levels are -5.31 and -4.90 eV, while the lowest unoccupied molecular orbital (LUMO) energies are -2.29 and -2.26 eV for TPA1 and TPA3, respectively, revealing that the interfacial charge transfer between the dyes and the semiconductor electrode are electron injection processes from the photon-excited dyes to the semiconductor conduction band. Furthermore, all the experimental absorption bands of TPA1 and TPA3 have been assigned according to the TDDFT calculations.

Novel Structural Composite Yarns Spun with Harmonic Migrations of Filaments

Duo Xu,Hang Fan,Wangwang Yang,Keshuai Liu,Weilin Xu 한국섬유공학회 2022 Fibers and polymers Vol.23 No.6

A novel structural composite yarn was fabricated by periodically forcing filaments with harmonic migrations toenhance the cooperativity between filaments and staple fibers. The geometrical principle of yarn structure variations causedby harmonic migrations of filaments was theoretically analyzed, then demonstrated the influences of filament’s positions ondifferent shapes of the composite spinning-triangle zone. Further, the novel structural composite yarn structure was comparedto the seven models of composite yarns which were established with different filament’s positions, showing a varied filamenthelical structure to capture and then lock internal and external staple fibers, distinguishing that other composite yarns inliterature. Then, a synergetic eccentric device was employed to oscillate two filaments to conduct confirmatory tests. Theonline observations of the dynamic spinning-triangle zone were technically applied to evaluate the filaments’ harmonicmigrations. Furthermore, the yarn structural variations were caused by various geometrical configurations. Experimentalresults exhibited that the novel structural composite yarn had relatively fewer hairiness, medium irregularity, and strengthafter comparisons with other composite yarns. Altogether, the cyclically harmonic migrations of filaments were promising asan efficient and novel method for control the configurations between filaments and staple fibers.

Density Functional Theory Study on Triphenylamine-based Dye Sensitizers Containing Different Donor Moieties

Jie Xu,Lei Wang,Guijie Liang,Zikui Bai,Luoxin Wang,Weilin Xu,Xiaolin Shen 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.9

Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations have been employed to investigate the molecular structures and absorption spectra of two dyes containing diphenylaniline and 4-diphenylamino-diphenylaniline as donor moiety (TPA1 and TPA3). The geometries indicate that the strong conjugation is formed in the dyes. The electronic structures suggest that the intramolecular charge transfer from the donor to the acceptor occurs, and the electron-donating capability of 4-diphenylamino-diphenylaniline is stronger than that of diphenylaniline. The computed highest occupied molecular orbital (HOMO) energy levels are ‒5.31 and ‒4.90 eV, while the lowest unoccupied molecular orbital (LUMO) energies are ‒2.29 and ‒2.26 eV for TPA1 and TPA3, respectively, revealing that the interfacial charge transfer between the dyes and the semiconductor electrode are electron injection processes from the photonexcited dyes to the semiconductor conduction band. Furthermore, all the experimental absorption bands of TPA1 and TPA3 have been assigned according to the TDDFT calculations.

Flow-induced vibrations of three circular cylinders in an equilateral triangular arrangement subjected to cross-flow

Weilin Chen,Chunning Ji,Md. Mahbub Alam,Dong Xu 한국풍공학회 2019 Wind and Structures, An International Journal (WAS Vol.29 No.1

Vortex-induced vibration of three circular cylinders (each of diameter D) in an equilateral triangular arrangement is investigated using the immersed boundary method. The cylinders, with one placed upstream and the other two side-by-side downstream, are free to vibrate in the cross-flow direction. The cylinder center-to-center spacing L is adopted as L/D = 2.0. Other parameters include the Reynolds number Re = 100, mass ratio m* = 2.0, reduced velocity Ur = 2 ~ 15 and damping ratio  = 0. Cylinder vibration responses are dependent on Ur and classified into five regimes, i.e. Regime I (Ur ≤ 3.2), Regime II (3.2 < Ur ≤ 5.0), Regime III (5.0 < Ur ≤ 6.4), Regime IV (6.4 < Ur ≤ 9.2) and Regime V (Ur > 9.2). Different facets of vibration amplitude, hydrodynamic forces, wake patterns and displacement spectra are extracted and presented in detail for each regime.

Intelligent Reconfigurable Surface enhanced Ambient Backscatter Communication enabled Wireless Body Area Network

Zhao Xu,Zang Weilin,Li Ye 한국통신학회 2023 ICT Express Vol.9 No.6

This paper considers an Intelligent Reconfigurable Surface (IRS)-enhanced Ambient Backscatter Communication (AmBC)-enabled Wireless Body Area Network (WBAN) system. We study the Base Station (BS) transmit power minimization problem, where the BS’s transmit beamforming vector and IRS’s reflecting coefficients are jointly optimized, subjected to the Signal-to-Noise Ratio (SNR) requirements of intra-WABN communication and throughput requirement of primary communication. To solve the non-convex problem, a near-optimal algorithm based on Semi-Definite Relaxation (SDR) and Successive Convex Approximation (SCA), and a low complexity algorithm based on IRS elements partition are proposed. Numerical results show that the two proposed algorithms considerably outperform the baseline schemes.

Data-driven Sliding Mode Control for MIMO systems and Its Application on Linear Induction Motors

Dezhi Xu,Xiaoqi Song,Bin Jiang,Weilin Yang,Wenxu Yan 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.7

In this paper, a model free adaptive integral sliding mode constrained control (MFAISMCC) is proposedto maintain the flux linkage of a linear induction motor (LIM) while tracking the speed reference. Firstly, themathematica model of a LIM is given after the electrical analysis. In order to linearize the motor system, thetechnology of compact form dynamic linearzation (CFDL) is applied. Then, the MFAISMCC is proposed basedon the analysed linear model. Furthermore, a novel anti-windup compensator for MIMO systems is proposed incase the actuator is within saturation. The whole closed-system stability is proven by Lyapunov stability method. Finally, some simulation results are given to testify the effectiveness of the proposed method compared with thePID controllers.

Influence of para-orientating Methoxyl Units on the Electronic Structures and Light Absorption Properties of the Triphenylamine-based dyes by DFT Study

Liang, Guijie,Xu, Jie,Xu, Weilin,Wang, Luoxin,Shen, Xiaolin,Yao, Mu Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.7

The geometries, electronic structures and absorption spectra of the two organic triphenylamine-based dyes TA-St-CA and TA-DM-CA, containing identical electron donors and acceptors but the different conjugated bridges, were studied by density functional theory (DFT) at the B3LYP and PBE1PBE levels, respectively. The influence of para-orientating methoxyl units on the electronic structures and light absorption properties of the dyes and the consequent photovoltaic performance of the dye-sensitized solar cells (DSSCs) were investigated in detail. The results indicate that the introduction of the para-orientating methoxyl units into the conjugated bridge induces the increased absorption wavelength as well as the more negative EHOMO corresponding to the bigger driving force $(E_{I^-/I^-_3}-E_{HOMO})$ for dye reduction, which together improve the photovoltaic performance of TA-DM-CA, although there is a decline of the open circuit voltage caused by the more negative $E_{LUMO}$.

Preparation and Dyeing of Superfine Down-powder/Viscose Blend Film

Wang Xin,Xu Weilin,Ke Guizhen The Korean Fiber Society 2006 Fibers and polymers Vol.7 No.3

Superfine down-powder/viscose blend films were prepared and characterized for their dyeing properties. Down-powder with average size of $2.56{\mu}m$ were suspended in viscose dope and blend films were obtained by solution casting. When the blend films were dyed with acid dye, the dye uptake and K/S values increased with the increase in down-powder content. Amino-acid analyses showed that amino acid component of the down were not affected during the film formation, which confirmed the changes of dye uptake and K/S value.

Influence of para-orientating Methoxyl Units on the Electronic Structures and Light Absorption Properties of the Triphenylamine-based dyes by DFT Study

Guijie Liang,Jie Xu,Weilin Xu,Luoxin Wang,Xiaolin Shen,Mu Yao 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.7

The geometries, electronic structures and absorption spectra of the two organic triphenylamine-based dyes TASt-CA and TA-DM-CA, containing identical electron donors and acceptors but the different conjugated bridges, were studied by density functional theory (DFT) at the B3LYP and PBE1PBE levels, respectively. The influence of para-orientating methoxyl units on the electronic structures and light absorption properties of the dyes and the consequent photovoltaic performance of the dye-sensitized solar cells (DSSCs) were investigated in detail. The results indicate that the introduction of the para-orientating methoxyl units into the conjugated bridge induces the increased absorption wavelength as well as the more negative EHOMO corresponding to the bigger driving force (E_I^-/_(I3)^-)− EHOMO) for dye reduction, which together improve the photovoltaic performance of TA-DM-CA, although there is a decline of the open circuit voltage caused by the more negative E_(LUMO).

Efficacy and Safety of a Steroid-Free Immunosuppressive Regimen after Liver Transplantation for Hepatocellular Carcinoma

Qiang Wei,Xiao Xu,Chao Wang,Runzhou Zhuang,Li Zhuang,Lin Zhou,Haiyang Xie,Jian Wu,Min Zhang,Yan Shen,Weilin Wang,Shusen Zheng 거트앤리버 소화기연관학회협의회 2016 Gut and Liver Vol.10 No.4

Background/Aims: We aimed to evaluate the efficacy and safety of an immunosuppressive regimen without steroids after liver transplantation (LT) for hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). Methods: Sixty-six HCC patients who underwent an immunosuppressive regimen without steroids after LT were enrolled in the steroid-free group. The preoperative characteristics and postoperative outcomes of these patients were compared with those of 132 HCC recipients who were placed on an immunosuppressive regimen using steroids (steroid group). The incidence of acute rejection, HBV recurrence, infection, and new-onset diabetes mellitus and the overall and tumor-free survival rates were compared between the two groups. Results: Differences were not observed in the 1-year (83.3% vs 97.0%, p=0.067), 3-year (65.4% vs 75.8%, p=0.067) or 5-year (56.3% vs 70.7%, p=0.067) patient survival rates or in the 1-year (62.1% vs 72.7%, p=0.067), 3-year (49.8% vs 63.6%, p=0.067) or 5-year (48.6% vs 63.6%, p=0.067) tumor-free survival rates between the two groups, respectively. In the steroid-free group, the patients who fulfilled the Milan criteria had higher overall and tumor-free survival rates than those in the steroid group (p<0.001). The prevalence of HBV recurrence (3.0% vs 13.6%, p=0.02) was significantly lower in the steroid-free group compared with the steroid group. Conclusions: After LT, an immunosuppressive regimen without steroids could be a safe and feasible treatment for HBVrelated HCC patients, thus resulting in the reduction of HBV recurrence. Based on the observed survival rates, patients who fulfill the Milan criteria may derive benefits from steroidfree immunosuppression.