Investigation of Rise Time and Overshoot in Pulse Transformers with Different Topologies for Electromagnetic Trigger of SCRs

Lv, Gang,Zeng, Dihui,Zhou, Tong The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.3

This study investigates the influences of different core parameters on the dynamic performances, such as rise time and overshoot, in pulse transformers for the triggering circuit of SCRs. First, a simplified transformer equivalent circuit, which emerges from a standard transformer equivalent circuit, is developed to analyze the step response. Second, the relations between the dynamic performances and the parasitic parameters are calculated by the simplified equivalent circuit. Third, the variations of rise time and overshoot, which are vital to the stability of triggering SCRs, with different core parameters, such as mechanic dimensions and topologies, are comprehensively investigated by analyzing the parasitic parameters. Finally, prototype transformers are fabricated to experimentally validate the analysis. The presented method can practically instruct the design of a pulse transformer for triggering SCRs.

Celebrity Endorsement Problem on Social Media : Formulation, Analysis and Recommendation Algorithm

Lv Hai-xia,Yu Guang,Wu Gang 보안공학연구지원센터(IJUNESST) 2015 International Journal of u- and e- Service, Scienc Vol.8 No.1

In this paper, a new matching recommendation algorithm is proposed to help enterprises find one or more proper celebrities from social media for their product endorsement. The fans group of a celebrity, his impaction value in the social media, as well as the matching degree between the celebrity and the product are selected to measure a celebrity. The attribute similarities between target customers of the product and fans of the celebrity are calculated via the Pearson similarity formula. Then, considering the impaction value of the celebrity and the matching degree of the celebrity and the product which can be accessed on the website or usually available from the enterprise, an evaluation index is proposed. We use some data from Sina Micro-blog, which is the most popular social media platform in China, to show the effectiveness of our proposed matching recommendation algorithm. Moreover, the analysis shows that a particular celebrity may suitable to endorse different product on-line and off-line.

Establishment and Clinical Application of an Electronic Database for Breast Cancer in China

Lv, Yong-Gang,Huang, Mei-Ling,Xiao, Jing-Jing,Ling, Rui Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.2

Purpose: To establish a database for breast cancer patients to save and manage clinical data and to preliminarily investigate its clinical application. Materials and Methods: Information on breast cancer patients hospitalized in our department from 2008.01 to 2013.01 were input into our breast cancer management system. SPSS 16.0 software was used as a convenient reference to evaluate the accuracy of the newly built database. Results: A database of 2403 breast cancer patients was successfully established. Information in the database clearly displayed capabilities of storage, addition, retrieval, statistical analysis and other functions. As the continuously updated database showed, the distribution of age, sex, nationality, allergy history, pausimenia and marriage of patients was identical to that achieved by SPSS analysis, indicating reliable and accurate data analysis. Conclusions: The described database is easy and convenient to operate and manage, and should prove suitable for application in clinical research and treatment.

Effects of age and diet forms on growth-development patterns, serum metabolism indicators, and parameters of body fat deposition in Cherry Valley ducks

Lv Gang,Zeng Qiufeng,Ding Xuemei,Bai Shiping,Zhang Keying 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.2

Objective: This study was conducted to investigate the effects of age and diet forms on growth-development patterns, serum metabolism indicators, and parameters of body fat deposition in Cherry Valley ducks. Methods: According to the hatching age and initial weight, a total of 150 1-day-old male SM3 Cherry Valley ducks were randomly assigned to two diet forms (pellet vs powder form). Each treatment had with 5 replicates per treatment and 15 meat ducks per replicate. The study lasted 42 d, which was divided into two periods (1 to 21 vs 22 to 42 d). Results: Our results showed that compared with powder group, ducks in pellet group had greater growth performance during different period (p<0.05). The inflection point was 24 d and was not numerically affected by diet forms. Increasing age (42 vs 21 d) significantly increased the weight of body fat and hepatic fat metabolism related enzyme activities in ducks (p<0.05), meanwhile, increasing age (42 vs 21 d) improved serum metabolism indicators and decreased mRNA expression levels of fat metabolism-related genes in liver (p<0.05). Ducks fed different diets (pellet vs powder form) increased growth performance as well as the weight of body fat and improved serum metabolism indicators (p<0.05). In addition, interactions were found between age and diet forms on the levels of serum metabolism indicators in ducks (p<0.05). Conclusion: In conclusion, powder feed reduced growth performance of ducks, and the day of inflection point was 24 days old. Ducks with higher age or fed with pellet diet showed higher fat deposition. The effect of age and feed forms on body fat deposition might result from changes in the contents of serum metabolism indicators, key enzyme activity of lipid production, and hepatic gene expressions. Objective: This study was conducted to investigate the effects of age and diet forms on growth-development patterns, serum metabolism indicators, and parameters of body fat deposition in Cherry Valley ducks.Methods: According to the hatching age and initial weight, a total of 150 1-day-old male SM3 Cherry Valley ducks were randomly assigned to two diet forms (pellet vs powder form). Each treatment had with 5 replicates per treatment and 15 meat ducks per replicate. The study lasted 42 d, which was divided into two periods (1 to 21 vs 22 to 42 d).Results: Our results showed that compared with powder group, ducks in pellet group had greater growth performance during different period (p<0.05). The inflection point was 24 d and was not numerically affected by diet forms. Increasing age (42 vs 21 d) significantly increased the weight of body fat and hepatic fat metabolism related enzyme activities in ducks (p<0.05), meanwhile, increasing age (42 vs 21 d) improved serum metabolism indicators and decreased mRNA expression levels of fat metabolism-related genes in liver (p<0.05). Ducks fed different diets (pellet vs powder form) increased growth performance as well as the weight of body fat and improved serum metabolism indicators (p<0.05). In addition, interactions were found between age and diet forms on the levels of serum metabolism indicators in ducks (p<0.05).Conclusion: In conclusion, powder feed reduced growth performance of ducks, and the day of inflection point was 24 days old. Ducks with higher age or fed with pellet diet showed higher fat deposition. The effect of age and feed forms on body fat deposition might result from changes in the contents of serum metabolism indicators, key enzyme activity of lipid production, and hepatic gene expressions.

Investigation of Rise Time and Overshoot in Pulse Transformers with Different Topologies for Electromagnetic Trigger of SCRs

Gang Lv,Dihui Zeng,Tong Zhou 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.3

This study investigates the influences of different core parameters on the dynamic performances, such as rise time and overshoot, in pulse transformers for the triggering circuit of SCRs. First, a simplified transformer equivalent circuit, which emerges from a standard transformer equivalent circuit, is developed to analyze the step response. Second, the relations between the dynamic performances and the parasitic parameters are calculated by the simplified equivalent circuit. Third, the variations of rise time and overshoot, which are vital to the stability of triggering SCRs, with different core parameters, such as mechanic dimensions and topologies, are comprehensively investigated by analyzing the parasitic parameters. Finally, prototype transformers are fabricated to experimentally validate the analysis. The presented method can practically instruct the design of a pulse transformer for triggering SCRs.

Research Articles : Cloning and Characterization of hydroxypyruvate isomerase (EC 5.3.1.22) gene in silkworm Bombyx mori

( Hong Gang Lv ),( Ke Ping Chen ),( Qin Yao ),( Lin Wang ) 한국잠사학회 2008 International Journal of Industrial Entomology Vol.17 No.2

The sequence of hydroxypyruvate isomerase gene was obtained in NCBI. In this study, the hydroxypyruvate isomerase gene of Bombyx.mori was identified and annotated with bioinformatics tools. The result was confirmed by RT-PCR, prokaryotic expression, mass spectrographic analysis and sub-cellular localization. The hydroxypyruvate isomerase cDNA comtains a 783bp ORF, and has 4 exons. The deduced protein has 260 amino acid residues with the predicted molecular weight of 29169.30 Da, isoelectric point of 6.10, and contains conserved PRK09997 and Hfi domains. The hydroxypyruvate isomerases of Nasonia vitripennis and Bombyx mori have a high homology. Through RTPCR analysis, we found that this transcript was present in testis, ovary, blood-lymph, fat body, midgut, silk gland and tuba Malpighii. This protein was located in cytoplasm through immunohistochemistry. We submitted the cloned gene under the accession number EU344910. The enzyme has been classified under accession number EC 5.3.1.22.

Influence of Solution Concentrations on Surface Morphology and Wettability of ZnO Thin Films

Jianguo Lv,Changlong Liu,Feng Wang,Zhitao Zhou,Zhenfa Zi,Yuan Feng,Xiaoshuang Chen,Feng Liu,Gang He,Shiwei Shi,Xueping Song,Zhaoqi Sun 대한금속·재료학회 2013 ELECTRONIC MATERIALS LETTERS Vol.9 No.2

ZnO thin films were grown on silicon substrates using a hydrothermal method. The XRD patterns show that all of the peaks can be attributed to the wurtzite structures of ZnO. The TC value of (002) plane and average crystal size increase first and then decrease with the increase of solution concentration. SEM and AFM results show that many dense hexagonal cylinder particles have been observed on the surface of the thin films, which grown at 0.08 and 0.10 mol/L. The surface roughness of the thin films deposited at 0.06,0.08, 0.10, and 0.12 mol/L are 24.5, 38.3, 32.0, and 39.4 nm, respectively. Surface wettability results show that the preferential orientation along c-axis and surface roughness contribute significantly to the hydrophobicity. The reversible switching between hydrophobicity and hydrophilicity is related to the synergy of the transition of wetting model, surface crystal structure, and surface roughness.

Simulation Analysis of Flexible Track Drilling Machines Based on ADAMS

Zhong-gang Zhu(주중강),Qi Zhang(장기),Jian-Hua Lv(려건화),Zhen Qin(진진),Sung-Ki Lyu(류성기) 한국기계가공학회 2018 한국기계가공학회지 Vol.17 No.5

Flexible track drilling machines are credited with important applications in the area of aircraft manufacturing because of their portability, quick installation capabilities, and high efficiency. However, their structures are special and the constitution principles and motion characteristics are difficult to control, increasing the development costs and research cycle in the context of the technology blockade of foreign companies. The simulation analysis of flexible track drilling machines can be conducted by applying virtual prototypes, shortening the development cycle and reducing the cost. In this paper, a model of a machine is established by using the SolidWorks software and imported into ADAMS to conduct kinematic and dynamic simulation analysis. During the analysis, the feasibility of the configuration is checked, a reasonable driving motion is chosen, potential deficiencies are found, and improvement actions are raised.

Suppression of MED19 expression by shRNA induces inhibition of cell proliferation and tumorigenesis in human prostate cancer cells

( Xin Gang Cui ),( Dan Feng Xu ),( Chao Lv ),( Fa Jun Qu ),( Jin He ),( Ming Chen ),( Yu Shan Liu ),( Yi Gao ),( Jian Ping Che ),( Ya Cheng Yao ),( Hong Yu Yu ) 생화학분자생물학회(구 한국생화학분자생물학회) 2011 BMB Reports Vol.44 No.8

MED19 is a member of the Mediator that plays a key role in the activation and repression of signal transduction or the regulation of transcription in carcinomas. To tested the functional role of MED19 in human prostate cancer, we downregulated MED19 expression in prostate cancer cells (PC-3 and DU145) by lentivirus- mediated short hairpin (shRNA), and analyzed the effect of inhibition of MED19 on prostate cancer cell proliferation and tumorigenesis. The in vitro prostate cancer cell proliferation, colony formation, and in vivo tumor growth in nude mice xenografts was significantly reduced after the downregulation of MED19. Knock- down of MED19 caused S-phase arrest and induced apoptosis via modulation of Bid and Caspase 7. It was suggested that MED19 serves as a novel proliferation regulator that promotes growth of prostate cancer cells. [BMB reports 2011; 44(8): 547-552]

Facile Synthesis of Zn1-xCuxO Nanorods with a Very Broad Visible Band

Jianguo Lv,Changlong Liu,Wanbing Gong,Zhenfa Zi,Xiaoshuang Chen,Kai Huang,Feng Liu,Tao Wang,Gang He,Xueping Song,Zhaoqi Sun 대한금속·재료학회 2012 ELECTRONIC MATERIALS LETTERS Vol.8 No.5

Zn1-xCuxO nanorods with different Cu concentrations are prepared by a hydrothermal method. Bent and aggregated nanorods are obtained, which is attributed to centripetal surface tension of the evaporation and coagulation processes of the water film on the ZnO nanorods. The broad visible band consists of one violet, three blue,and one green emission. The violet emission is due to the transition of electrons from zinc interstitial (Zni)levels to the valance band. The three blue emissions may be attributed to the transition from extended Zni levels, which are slightly below the simple Zni level, to the valance band. The change of the green emission may be the result of competition between oxygen vacancies (VO) and zinc vacancies (VZn).