PPV/PVA/ZnO nanocomposite prepared by complex precursor method and its photovoltaic application

Mingqing Wang,Yanqing Lian,Xiaogong Wang 한국물리학회 2009 Current Applied Physics Vol.9 No.1

In this article, we describe a new method to prepare a ZnO and conjugated polymer nanocomposite and its application in bulk-heterojunction solar cells. The composite was composed of zinc oxide (ZnO) and poly(phenylene vinylene)/poly(vinyl alcohol) (PPV/PVA). For the preparation, the composite was prepared first through the complex reaction between Zn2+ ion and –OH of the PVA–PPV precursor by simply mixing zinc salts and a PVA–PPV precursor aqueous solution at 70℃. By addition of a concentrated aqueous ammonia into the system, highly regular Zn(OH)2 nanodots were formed and dispersed in the PVA/PPV precusor mixed solution. The PVA/PPV precursor can well bind Zn2+ ion through complex interaction, so act as a template to direct the distribution of ZnO in the process. The nanocomposite films were finally obtained by solution casting and subsequently treated by heating samples at 160 ℃ for 6 h. TEM observations showed that ZnO nanodots uniformly dispersed in PVA–PPV mixtures. The resulting nanocomposite films possess a large interfacial area between the electron donor and acceptor of the bulk-heterojunction. Improved charge seperation and collection are evidenced by the large photoluminescence intensity difference between pure PPV and composites films, which result in the increase in both open circuit voltage and short circuit current of the hybrid solar cells. In this article, we describe a new method to prepare a ZnO and conjugated polymer nanocomposite and its application in bulk-heterojunction solar cells. The composite was composed of zinc oxide (ZnO) and poly(phenylene vinylene)/poly(vinyl alcohol) (PPV/PVA). For the preparation, the composite was prepared first through the complex reaction between Zn2+ ion and –OH of the PVA–PPV precursor by simply mixing zinc salts and a PVA–PPV precursor aqueous solution at 70℃. By addition of a concentrated aqueous ammonia into the system, highly regular Zn(OH)2 nanodots were formed and dispersed in the PVA/PPV precusor mixed solution. The PVA/PPV precursor can well bind Zn2+ ion through complex interaction, so act as a template to direct the distribution of ZnO in the process. The nanocomposite films were finally obtained by solution casting and subsequently treated by heating samples at 160 ℃ for 6 h. TEM observations showed that ZnO nanodots uniformly dispersed in PVA–PPV mixtures. The resulting nanocomposite films possess a large interfacial area between the electron donor and acceptor of the bulk-heterojunction. Improved charge seperation and collection are evidenced by the large photoluminescence intensity difference between pure PPV and composites films, which result in the increase in both open circuit voltage and short circuit current of the hybrid solar cells.

Expression of Bacillus subtilis proBA Genes and Reduction of Feedback Inhibition of Proline Synthesis Increases Proline Production and Confers Osmotolerance in Transgenic Arabidopsis

Chen, Mingqing,Wei, Hongbo,Cao, JunWei,Liu, Ruijie,Wang, Youliang,Zheng, Congyi Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.3

Proline accumulation has been shown to correlate with tolerance to drought and salt stresses in plants. We attempt to introduce the wild-type, mutant, and fusion proBA genes derived from Bacillus subtilis into Arabidopsis thaliana under the control of a strong promoter cauliflower mosaic virus 35S (CaMV35S). The transgenic plants produced higher level of free proline than control and the overproduction of proline resulted in the increased tolerance to osmotic stress in transgenic plants. Besides, the mutation in proBA genes, which were proved to lead $\alpha$-glutamyl kinase ($\alpha$-GK) reduces sensitivity to the end-product inhibition and the fusion of proB and proA also result in increasing proline production and confer osmotolerance in transgenic lines.

Observer-based Admissible Control for Singular Delta Operator Systems

Xin-zhuang Dong,Mingqing Xiao,Yushun Wang,Wenxue He 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10

This paper studies the problem of designing an observer-based admissible controller for singular delta operator systems. Sufficient conditions are provided for the existence of an asymptotical and physically realizable observer. Then an observer-based admissible controller is obtained in terms of strict linear matrix inequalities. The corresponding gain matrices appeared in our proposed approach can be constructed through the feasible solutions of a set of linear matrix inequalities. Some numerical examples are presented to demonstrate the theoretical outcomes of the paper.

Novel Prognostic Nomograms for Hepatocellular Carcinoma Patients with Microvascular Invasion: Experience from a Single Center

Liangliang Xu,Lian Li,Peng Wang,Ming Zhang,Yanfang Zhang,Xiangyong Hao,Lvnan Yan,Bo Li,Tianfu Wen,Mingqing Xu 거트앤리버 소화기연관학회협의회 2019 Gut and Liver Vol.13 No.6

Background/Aims: Microvascular invasion (MVI) is an established risk factor for hepatocellular carcinoma (HCC). However, prediction models that specifically focus on the individual prognoses of HCC patients with MVI is lacking. Methods: A total of 385 HCC patients with MVI were randomly assigned to training and validation cohorts in a 2:1 ratio. The outcomes were disease-free survival (DFS) and overall survival (OS). Prognostic nomograms were established based on the results of multivariate analyses. The concordance index (C-index), calibration plots and Kaplan-Meier curves were employed to evaluate the accuracy, calibration and discriminatory ability of the models. Results: The independent risk factors for both DFS and OS included age, tumor size, tumor number, the presence of gross vascular invasion, and the presence of Glisson’s capsule invasion. The platelet-tolymphocyte ratio was another risk factor for OS. On the basis of these predictors, two nomograms for DFS and OS were constructed. The C-index values of the nomograms for DFS and OS were 0.712 (95% confidence interval [CI], 0.679 to 0.745; p<0.001) and 0.698 (95% CI, 0.657 to 0.739; p<0.001), respectively, in the training cohort and 0.704 (95% CI, 0.650 to 0.708; p<0.001) and 0.673 (95% CI, 0.607 to 0.739; p<0.001), respectively, in the validation cohort. The calibration curves showed optimal agreement between the predicted and observed survival rates. The Kaplan-Meier curves suggested that these two nomograms had satisfactory discriminatory abilities. Conclusions: These novel predictive models have satisfactory accuracy and discriminatory abilities in predicting the prognosis of HCC patients with MVI after hepatectomy.

A theoretical study for high-performance inverted p-i-n architecture perovskite solar cells with cuprous iodide as hole transport material

Syed Zulqarnain Haider,Hafeez Anwar,Sehrish Manzoor,Ahmad G. Ismail,Mingqing Wang 한국물리학회 2020 Current Applied Physics Vol.20 No.9

Inverted perovskite solar cells (p-i-n PSCs) have been fascinated due to rapid progress of performance in recent years. PEDOT:PSS is commonly used hole transport material (HTM) in p-i-n PSCs having hygroscopic and acidic nature that leads towards poor performance of device. Therefore, it is necessary to replace PEDOT:PSS with stable HTM. In this paper, theoretical study is carried out to investigate physical parameters that can affect the performance of p-i-n PSCs with copper iodide (CuI) as HTM. These parameters include the effect of doping density of electron transport material (ETM), absorber and HTM as well as defect density and thickness of absorber on the performance of p-i-n PSCs. Hole mobility and thickness of HTM are also investigated. It is found that performance of p-i-n PSCs is strongly dependent on defect density and thickness of absorber. Upon final optimization, device attains PCE of more than 21% which is encouraging.

Fatty Acid Biosynthesis in Eukaryotic Photosynthetic Microalgae: Identification of a Microsomal Delta 12 Desaturase in Chlamydomonas reinhardtii

Xiaoyuan Chi,Xiaowen Zhang,Xiangyu Guan,Ling Ding,Youxun Li,Mingqing Wang,Hanzhi Lin,Song Qin 한국미생물학회 2008 The journal of microbiology Vol.46 No.2

Polyunsaturated fatty acids (PUFAs) are important components of infant and adult nutrition because they serve as structural elements of cell membranes. Fatty acid desaturases are responsible for the insertion of double bonds into pre-formed fatty acid chains in reactions that require oxygen and reducing equivalents. In this study, the genome-wide characterization of the fatty acid desaturases from seven eukaryotic photosynthetic microalgae was undertaken according to the conserved histidine-rich motifs and phylogenetic profiles. Analysis of these genomes provided insight into the origin and evolution of the pathway of fatty acid biosynthesis in eukaryotic plants. In addition, the candidate enzyme from Chlamydomonas reinhardtii with the highest similarity to the microsomal Δ12 desaturase of Chlorella vulgaris was isolated, and its function was verified by heterologous expression in yeast (Saccharomyces cerevisiae).

Crystallization and melting behavior of polypropylene in b-PP/polyamide 6 blends containing PP-g-MA

Zhidan Lin,Zixian Guan,Baofeng Xu,Chao Chen,Guangheng Guo,Jiaxian Zhou,Jiaming Xian,Lin Cao,Yueliang Wang,Mingqing Li,Wei Li 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.2

In this research, we used a twin-screw extruder to melt and blend PP-g-MA compatibilizer with bpolypropylene (PP)/polyamide 6 (PA6). The influences of the PA6 and PP-g-MA contents in PP/PA6 blends on crystallization and melting behavior of PP phase and morphology were investigated. The results showed that, when PP-g-MA copolymer was added to the b form of nucleated PP/PA6 blends, the anhydride groups in PP-g-MA and PA6 terminal amine groups react to form PP-g-PA graft copolymer in a two-phase interface. This reduces the interfacial tension, improves the interfacial adhesion, and reduces the size of PA6 domains in the blend. The generated PP-g-PA graft copolymer wrapped PA6 phase and buried the anhydride groups of PP-g-MA. When the proportion of PP-g-MA and PA6 was between 0.5 and 0.75, there was no longer interfering to the formation of b-crystals in the PP phase. The content of bcrystal of PP phase in blends was found to reach as large as 85.9%.