Unified SVPWM Strategy for Post-fault Three-level NPC Voltage Source Inverters

Qingli Deng,Xinglai Ge 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Eight switch three-phase inverters (ESTPIs) are the reconfigured topologies of the three-level neutralpoint-clamped (NPC) inverter with a failure leg. This failure leads to different topologies of ESTPIs, which can be controlled by different space vector pulse width modulation (SVPWM) strategies. By analyzing the relationship of three SVPWM strategies for different ESTPIs, a unified coordinate transformation is proposed, which can make one of the three SVPWM strategies be a unified control strategy of ESTPIs. And the unified coordinate transformation is suited for two different SVPWM strategies for ESTPIs. Consequently, the unified strategy not only simplifies the control strategy, but also makes the fault tolerant control strategy more flexible. Simulation and hardware-in-the-loop (HIL) test results have shown the validity and feasibility of the proposed unified SVPWM strategies.

Investigation on the Preparation and Adsorption Performance of Bamboo Fiber Based Activated Carbon

Qing Zhang,Yue Zeng,Xiuyun Xiao,Penghu Deng,Qing He,Tonghua Zhang 한국섬유공학회 2019 Fibers and polymers Vol.20 No.2

In this work, an approach was explored to make natural fiber based activated carbon with high adsorption capacity for treating dyeing wastewater. Bamboo fiber based activated carbon (BFAC) was prepared by bamboo fiber extracted from bamboo strips by extracting technique. An orthogonal experiment was carried out to obtain optimum preparation condition for the best dye adsorption. The microstructures of BFAC were characterized by scanning electron microscopy, N2 adsorption-desorption analysis, X-ray diffraction, and Fourier transform infrared spectroscopy. Adsorption mechanism of BFAC to methylene blue (MB) was studied and the adsorption isotherm followed the Langmuir model, with maximum monolayer adsorption capacity of 651.7 mg g-1. The adsorption kinetic was better described by the pseudo-second-order model. Microstructure characterization showed lots of opened pores and cracks with different size on BFAC, with Brunauer-Emmett-Teller (BET) surface area of 1370 m2 g-1 and total pore volume of 0.9411 cm3 g-1. The analysis indicated that cellulose crystal of bamboo fiber was severely destroyed in the preparation process, which could contribute to the formation of pores. Moreover, -OH and -C=O functional groups on BFAC are beneficial for adsorbing MB in aqueous solution. As a result, adopting bamboo fiber may help form BFAC with high BET surface area, which proved to be an effective idea to prepare activated carbon with high adsorption performance.

폴리프로필렌/폴리아미드 엘라스토머 블렌드

Qing Sheng Liu,Yan Xu,Hong Xia Zhang,Yu Hao Li,Bing Yao Deng 한국고분자학회 2014 폴리머 Vol.38 No.5

The polypropylene/polyamide elastomer (PP/PAE) blends were prepared by melt mixing. PP and PAE in PP/PAE were immiscible completely. The size of PAE domains was large and the clear gap in the interface between PP and PAE existed, which did not meet the conditions enhancing toughness of polymers by elastomer. Therefore, maleic anhydride grafted polypropylene (MP) was used to improve the miscibility between PP and PAE. The miscibility between PP and PAE was improved and the size of dispersed phase PAE decreased by introducing MP. The crystallization of PP became easier by introducing PAE as a nucleating agent. With the increase of PAE content, the melt-crystallization temperatures of PP components in PP/PAE/MP blends increased gradually. The melt-crystallization of the polytetramethyleneoxide segment of PAE component in PP/PAE blends were hampered by PP component. In addition, PAE can enhance significantly the toughness of PP, and the tensile strength and modulus did not decrease.

Meta-analysis of the CYP1A2 -163C>A Polymorphism and Lung Cancer Risk

Deng, Sheng-Qiong,Zeng, Xian-Tao,Wang, Yun,Ke, Qing,Xu, Qiong-Li Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.5

Many published studies have concerned associations between the CYP1A2 -163 C>A polymorphism and risk of lung cancer, but the results have been inconsistent. Therefore, we performed a meta-analysis to obtain a more precise estimate. We searched the PubMed database up to March 1, 2013 for relevant cohort and case-control studies. Supplementary search was conducted manually by searching the references of the included studies and relevant meta-analyses. A meta-analysis was performed using RevMan 5.2 software for calculation of pooled odds ratios (ORs) and relevant 95% confidence intervals (CIs) after data extraction. Finally, seven case-control studies and one nested case-control study involving 1,675 lung cancer patients and 2,393 controls were included. The meta-analysis showed that there was no association of CYP1A2 -163 C>A polymorphism with risk of lung cancer overall [(OR=0.89, 95%CI= 0.74-1.07) for C vs. A; (OR=0.73, 95%CI= 0.50-1.07) for AA vs. CC ; (OR=0.82, 95%CI= 0.62-1.09) for AC vs. CC; (OR=0.79, 95%CI= 0.58-1.07) for (AC+AA) vs. CC; and (OR=0.87, 95%CI= 0.67-1.13) for AA vs. (CC+AC)]. Subgroup analysis indicated that there was an associationbetween CYP1A2 -163C>A polymorphism and lung cancer risk for population-based controls, a trend risk for SCCL (squamous cell carcinoma of lung) and Caucasians. These results suggested that -163 C>A polymorphism is likely to be associated with risk of lung cancer compared with population-based controls.

Mesoporous CexZr1−xO2 solid solutions supported CuO nanocatalysts for toluene total oxidation

Qing-Fang Deng,Tie-Zhen Ren,Bao Agula,Yuping Liu,Zhong-Yong Yuan 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.5

Mesoporous CexZr1 xO2 solid solutions were prepared by the surfactant-assisted method and used as support of CuO nanocatalysts for catalytic total oxidation of toluene. The prepared CuO/CexZr1 xO2 catalysts have a wormhole-like mesoporous structure with high surface area and uniform pore size distribution, and the CuO nanoparticles were highly dispersed on the surface of CexZr1 xO2. The doping of ZrO2 in CeO2 promotes the dispersion of active copper species and enhances the reducibility of copper species. The effect of Ce/Zr ratio, calcination temperature and CuO loading amount on the catalytic performance of CuO/CexZr1 xO2 was investigated in detail. The 400 ℃-calcined 8%CuO/Ce0.8Zr0.2O2 catalyst exhibits the highest activity with the complete toluene conversion temperature of 275 ℃ at the condition of GHSH = 33,000 h-1 and the toluene concentration of 4400 ppm. The interfacial interaction between CuO and the CexZr1 xO2 support, highly dispersed CuO nanoparticles and the nature of the support contribute to the high catalytic activity of mesoporous CuO/CexZr1 xO2 nanocatalysts.

Production of Recombinant Humanized Anti-HBsAg Fab Fragment from Pichia pastoris by Fermentation

Deng, Ning,Xiang, Junjian,Zhang, Qing,Xiong, Sheng,Chen, Wenyin,Rao, Guirong,Wang, Xunzhang Korean Society for Biochemistry and Molecular Biol 2005 Journal of biochemistry and molecular biology Vol.38 No.3

In this report, we describe the high-yield secretory expression of the recombinant human anti-HBsAg Fab fragment from Pichia pastoris that was achieved by co-integration of the genes encoding the heavy and light chains (both under the control of alcohol oxidase promoter) into the genome of the yeast cells. The fed-batch fermentations were carried out in a 5 L scale. Both chains of the Fab were successfully expressed upon methanol induction. The absorbance ($OD_{600}$) of the broth can reach 350~500 at the end of fed-batch phase. After the induction, the expression level of the recombinant Fab (soluble) reached 420~458 mg/L. The recombinant Fab fragment was purified from the crude culture supernatant by ion exchange chromatography and the purity of the recombinant Fab fragment was over 95%. The affinity activities of the crude fermentation supernatant and the purified Fab were analyzed by indirect ELISA, which showed that the purified recombinant Fab fragment had high affinity activity with hepatitis B surface antigen.

Design and Synthesis of Pyrazolyl Thiosemicarbazones as New Anticonvulsants

Deng, Xian Qing,Song, Ming Xia Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.9

A series of pyrazolyl thiosemicarbazone derivatives were synthesized and evaluated for their anticonvulsant activity using the maximal electroshock (MES) method. Interestingly, all compounds prepared showed long duration of protection effect in the MES screens. Among them, compound 5b was considered as the most promising one with an $ED_{50}$ value of 47.3 mg/kg, and a PI value of 4.8, which was superior to phenobarbital and valproate in the aspect of safety. Furthermore, compound 5b showed protection against seizures induced by pentylenetetrazole suggesting that compound 5b may exert anticonvulsant activity through GABA-mediated mechanisms.

THE ENVIRONMENTAL DEPENDENCE OF THE FRACTION OF 'UNCONVENTIONAL' GALAXIES: FAINT RED AND LUMINOUS BLUE

Deng, Xin-Fa,Zhang, Fuyang,Song, Jun,Chen, Yi-Qing,Jiang, Peng The Korean Astronomical Society 2012 Journal of The Korean Astronomical Society Vol.45 No.3

Using the volume-limited Main galaxy sample constructed from the Sloan Digital Sky Survey Data Release 7 (SDSS DR7), we explore the environmental dependence of the fraction of 'unconventional' galaxies: luminous blue and faint red. It is found that the fraction of faint red increases apparently with increasing local density, and the fraction of luminous blue declines substantially with increasing local density, which shows that there is an environmental dependence for color beyond that for luminosity.

Comparative Serum Proteomic Analysis of Serum Diagnosis Proteins of Colorectal Cancer Based on Magnetic Bead Separation and MALDI-TOF Mass Spectrometry

Deng, Bao-Guo,Yao, Jin-Hua,Liu, Qing-Yin,Feng, Xian-Jun,Liu, Dong,Zhao, Li,Tu, Bin,Yang, Fan Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.10

Background: At present, the diagnosis of colorectal cancer (CRC) requires a colorectal biopsy which is an invasive procedure. We undertook this pilot study to develop an alternative method and potential new biomarkers for diagnosis, and validated a set of well-integrated tools called ClinProt to investigate the serum peptidome in CRC patients. Methods: Fasting blood samples from 67 patients diagnosed with CRC by histological diagnosis, 55 patients diagnosed with colorectal adenoma by biopsy, and 65 healthy volunteers were collected. Division was into a model construction group and an external validation group randomly. The present work focused on serum proteomic analysis of model construction group by ClinProt Kit combined with mass spectrometry. This approach allowed construction of a peptide pattern able to differentiate the studied populations. An external validation group was used to verify the diagnostic capability of the peptidome pattern blindly. An immunoassay method was used to determine serum CEA of CRC and controls. Results: The results showed 59 differential peptide peaks in CRC, colorectal adenoma and health volunteers. A genetic algorithm was used to set up the classification models. Four of the identified peaks at m/z 797, 810, 4078 and 5343 were used to construct peptidome patterns, achieving an accuracy of 100% (> CEA, P<0.05). Furthermore, the peptidome patterns could differentiate the validation group with high accuracy close to 100%. Conclusions: Our results showed that proteomic analysis of serum with MALDI-TOF MS is a fast and reproducible approach, which may provide a novel approach to screening for CRC.

Analysis of thermally induced vibration of cable-beam structures

Deng, Han-Qing,Li, Tuan-Jie,Xue, Bi-Jie,Wang, Zuo-Wei Techno-Press 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.3

Cable-beam structures characterized by variable stiffness nonlinearities are widely found in various structural engineering applications, for example in space deployable structures. Space deployable structures in orbit experience both high temperature caused by sun's radiation and low temperature by Earth's umbral shadow. The space temperature difference is above 300K at the moment of exiting or entering Earth's umbral shadow, which results in structural thermally induced vibration. To understand the thermally induced oscillations, the analytical expression of Boley parameter of cable-beam structures is firstly deduced. Then, the thermally induced vibration of cable-beam structures is analyzed using finite element method to verify the effectiveness of Boley parameter. Finally, by analyzing the obtained numerical results and the corresponding Boley parameters, it can be concluded that the derived expression of Boley parameter is valid to evaluate the occurrence conditions of thermally induced vibration of cable-beam structures and the key parameters influencing structural thermal flutter are the cable stiffness and thickness of beams.