Practical Calculation Method for the Short‑Circuit Current of Power Grids with High Temperature Superconducting Fault Current Limiters

Hai‑feng Hong,Meng‑ze Yu,Xiao‑hui Zhang,Jia‑jia Huan,Yu Sui,Xian‑xian Pan 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.2

With the expansion of the power grid scale and the enhancement of network structure interconnection, the short-circuit current of power grids is increasingly close to the upper capacity limit of circuit breakers. The fault current limiter is efective in suppressing the short-circuit current of power grids, and with the mature development of superconducting technology, high-temperature superconducting fault current limiters (HTS-FCLs) have been widely used in power grids. Due to the nonlinear impedance–current characteristic of HTS-FCLs, the traditional short-circuit current calculation method is inapplicable to power grids with HTS-FCLs. First, based on the establishment of the electromechanical transient model and the short-circuit calculation model, the short-circuit current calculation procedure for power grids with HTS-FCLs is proposed. Second, the calculation methods for three-phase and single-phase short-circuit currents at the substation bus in power grids with HTS-FCLs are analyzed. Finally, three-phase and single-phase short-circuit currents at the 500 kV Xijiang substation bus in the Guangdong power grid are calculated as the study case. Simulation results show that compared with the situation where there is no HTS-FCL installed, the short-circuit current on the 500 kV bus decreases from 65.34 to 58.31 kA in terms of the three-phase short-circuit fault, and decreases from 54.56 to 46.62 kA in terms of the single-phase short-circuit fault, thus verifying the efectiveness and practicability of HTS-FCLs in suppressing the short-circuit current, which is signifcant for the safe, stable and reliable operation of the power grid.

Molecular Cloning and Characterization of a cis-Epoxysuccinate Hydrolase from Bordetella sp. BK-52

( Hai Feng Pan ),( Wen Na Bao ),( Zhi Peng Xie ),( Jian Guo Zhang ),( Yong Quan Li ) 한국미생물 · 생명공학회 2010 Journal of microbiology and biotechnology Vol.20 No.4

Association Between the FAS/FASL Polymorphisms and Gastric Cancer Risk: A Meta-Analysis

Tian, Jing,Pan, Feng,Li, Jing,Ma, Yan,Cen, Han,Pan, Hai-Feng,Pan, Yue-Yin,Ye, Dong-Qing Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.3

Objective: FAS/FASL gene promoter polymorphisms have been repeatedly associated with gastric cancer risk, but findings are inconclusive across studies. To address a more precise estimation of the relationship, a meta-analysis was performed. Methods: Data were collected from the Pubmed, Medline and EMBASE databases, with the last report up to 1 December, 2011. Crude ORs with 95% CIs were used to assess the strength of the association by (1) the additive, (2) the codominant, (3) the dominant, and (4) the recessive models. Results: A total of seven studies, including six studies on FAS -1377G>A polymorphism, five studies on FAS -670A>G polymorphism, and six studies on FASL -844T>C polymorphism, were identified in the current meta-analysis. Overall, an association of FAS -1377G>A (AA versus GG: OR = 1.313, 95% CI = 1.045-1.650, Ph = 0.347, $I^2$ = 10.8) and FASL -844T>C (CC versus TT: OR = 1.352, 95% CI = 1.043-1.752, Ph = 0.461, $I^2$ = 0.0) polymorphisms with gastric cancer was found in the codominant model. However, we did not detect any association between gastric cancer and the FAS -670A>G polymorphism. In the subgroup analysis by ethnicity, similar elevated risks were also observed in Asian population for FAS -1377G>A (AA versus GG: OR = 1.309, 95% CI = 1.041-1.646, Ph = 0.240, $I^2$ = 27.3) and FASL -844T>C (CC versus TT: OR = 1.420, 95% CI = 1.081-1.865, Ph = 0.524, $I^2$ = 0.0) polymorphisms. Conclusions: This meta-analysis indicated that FAS -1377G>A and FASL -844T>C polymorphisms might be associated with gastric cancer risk.

Development and Evaluation of a Patient-Reported Outcome (PRO) Scale for Breast Cancer

Zhang, Jun,Yao, Yu-Feng,Zha, Xiao-Ming,Pan, Li-Qun,Bian, Wei-He,Tang, Jin Hai Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.18

Background: This study was guided by principles of the theoretical system of evidence-based medicine. In particular, when searching for evidence of breast cancer, a measuring scale is an instrument for evaluating curative effects in accordance with the laws and characteristics of medicine and exploring the establishment of a system for medically assessing curative effects. At present, there exist few tools for evaluating curative effects. Patient-reported outcomes (PROs) refer to outcomes directly reported by patients (without input or explanations from doctors or other intermediaries) with respect to all aspects of their health. Data obtained from PROs provide evidence of treatment effects. Materials and Methods: In accordance with the tenets of theoretical medicine and ancient medical theory regarding breast cancer, principles for developing a PRO scale were established, and a theoretical model was developed and a literature review was performed, items from this pool were combined and split, and an initial scale was constructed. After a pilot survey and additional modifications, a pre-questionnaire scale was formed and used in a field investigation. After the application of statistical methods, the item pool was used to create a formal scale. The reliability, validity and feasibility of this formal scale were then assessed. Results: In a clinical investigation, 479 responses were recovered, with an acceptance rate of 95%. a combination of various methods was employed, and the items that were selected by all methods or more than half of the methods were employed in the questionnaire. In these cases, the screening methods were combined with certain features of the item, A total of four domains and 38 items were reserved. The reliability analysis indicated that the PRO scale was relatively reliable. Conclusions: Scientific assessment proved that the proposed scale exhibited good reliability and validity. This scale was readily accepted and could be used to assess the curative effects of medical therapy. However, given the limited scope of this investigation, the capacity for adapting this scale to incorporate other theories could not be determined.

Synthesis and characterization of monodisperse yttrium aluminum garnet (YAG) micro-crystals with rhombic dodecahedron

Xu, Tao,Yuan, Rui,Xu, Peng-Cheng,Pan, Dong-Jie,Yang, Woochul,Guo, Hai-Bo,Shen, Yu-Fang,Hu, Jian-Feng,Zhang, Zhi-Jun,Zhao, Jing-Tai Elsevier 2018 Journal of alloys and compounds Vol.762 No.-

<P><B>Abstract</B></P> <P>Uniform, monodisperse yttrium aluminum garnet (YAG) rhombic dodecahedron micro-crystals were synthesized using coprecipitation and hydrothermal methods. The Na<SUB>2</SUB>SO<SUB>4</SUB> as a surfactant was helpful in improving the dispersity of the crystallites and forming well-faceted, micro-sized dodecahedral YAG crystallites. The effect of the reaction time and the solvent has also been studied. The crystal growth mechanism called dissolution/crystallization was determined by analyzing the experimental and simulated results. And the specific well-developed crystal facets in the {110} family have been demonstrated by the theoretical calculation. A higher integrated emission intensity can be achieved for the YAG:Ce crystallites by improving the phase purity, morphology with better developed dodecahedrons, and dispersion. Furthermore, a rather high luminous efficacy (LE = 104.14 lm/W) for the white LED fabricated using the YAG:Ce<SUP>3+</SUP> phosphor prepared in this work was realized. The correlation between the crystal growth, morphology and luminescence properties of YAG crystallites has been established, which exhibits a great importance for the synthesis and application of mono-dispersed YAG crystallites.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Uniform and monodisperse YAG rhombic dodecahedron micro-crystals were synthesized. </LI> <LI> The growth mechanism of YAG rhombic dodecahedron was studied through experimental and computational simulation. </LI> <LI> The correlation between the crystal growth, morphology and luminescence of YAG crystallites was established. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Correlation of CT Perfusion Images with VEGF Expression in Solitary Brain Metastases

Zhang, Jian-Hua,Wang, Ming-Sheng,Pan, Hai-Hong,Li, Shu-Feng,Wang, Zhong-Qiu,Chen, Wang-Sheng Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4

Objectives: To obtain permeability surface (PS) values using multi-slice helical CT perfusion imaging and to evaluate the spatial distribution correlation between PS values and vascular endothelial growth factor (VEGF) expression in solitary brain metastases. Methods: Imaging was performed on 21 patients, PS values being calculated from the central, border and peripheral parts of tumours. VEGF expression was determined by immunohistochemical staining. Results: Rim enhancement was found in 16 cases, the border of the tumour featuring PS elevation with high VEGF expression in 13 cases. In the 5 cases with nodular enhancement, the border and the central part had high permeability and VEGF expression was high in all cases, the correlation being significant (P<0.01). Conclusion: VEGF expression in brain metastases positively correlates with PS values from CT perfusion imaging, so that the latter can be used in the surveillance of angiogenic activity in brain metastases.

Research Paper : Influences of long-term different types of fertilization on weed community biodiversity in rice paddy fields

( Kai Yuan Wan ),( Yong Tao ),( Ru Hai Li ),( Jun Feng Pan ),( Lei Lei Tang ),( Fang Chen ) 한국잡초학회 2012 Weed Biology and Management Vol.12 No.1

In order to provide a scientific basis for developing integrated weed management strategies in rice paddy fields, this study investigated the influences of different types of fertilization on weed biodiversity. The experiment was conducted at Long-term-located Monitoring Station for Soil Fertility, Agricultural Science Academy, of Jiangxi Province, China. Five fertilization treatments were set: no fertilization (NOF), PK, NP, NK, and NPK. The results showed that the influence of different fertilization treatments on weed community traits followed the models PK > NOF > NK > NP > NPK for species richness, PK > NOF > NK > NP > NPK for species diversity, NPK > NP > NK > NOF > PK for community dominance, and PK > NOF > NK > NP > NPK for community evenness. Under NPK (i.e. balanced fertilization), the weed species diversity and richness and weed community evenness were the lowest. The principal component analysis showed that the weed community was divided into three groups: (i) NK and a part of NOF; (ii) NP and NPK; and (iii) PK and NOF. The correlation analysis indicated that the influence of each macro-element on the weed community followed the model N > P > K. The organic content in the paddy soil might have played an equally important role with the amount of available N in determining the weed community`s characteristics. Regarding the way by which N, P, and K influenced the weed community, the amount of available P and K mainly influenced the organic content, while the amount of available N influenced both the organic content and light transmittance within the canopy, thereby enhancing the capacity of rice to compete with weeds.

Ordered Morphologies on the Binary Blend of Diblock Copolymers Film Induced by Nanoparticles

Min-Na Sun,Jin-Jun Zhang,Jun-Xing Pan,Bao-Feng Wang,Hai-Shun Wu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.1

In this study, we investigate the ordered morphologies on the binary blend of diblock copolymers film induced by the mobile wettable nanoparticles on the substrate. The film forms highly ordered microphase and macrophase morphologies. We constructed the phase diagram, which suggests that the ordered-striped macrophase structures are due to the competition equilibrium of the wetting strength and the chemical potential amplitude upon the nanoparticles. The morphologies of the binary blend film form the striped pattern of different periods with the changing oscillation period of the chemical potential. The short-range interaction between monomers only alters the microphase structures. We analyzed the variation in the interfacial energy, the wetting energy and the particles/substrate's coupling energy on different morphologies. The results provide a new control mechanism to stabilize the ordered microphase and macrophase structures within the copolymer blend film.

5,10-Methylenetetrahydrofolate Reductase Polymorphisms and Colon Cancer Risk: a Meta-analysis

Fang, Xin-Yu,Xu, Wang-Dong,Huang, Qian,Yang, Xiao-Ke,Liu, Yan-Yan,Leng, Rui-Xue,Pan, Hai-Feng,Ye, Dong-Qing Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.19

Previous studies investigating the association between 5,10-methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and colon cancer risk have generated conflicting results. The aim of our meta-analysis was to clarify the precise association. A systematic literature search was conducted to identify all relevant studies. Pooled odds ratio (ORs) with 95% confidence interval (CI) were used to estimate the strength of the association. In this meta-analysis, a total of 13 articles, involving 5,386 cases and 8,017 controls met the inclusion criteria. Overall, a significant association was found between colon cancer risk and the MTHFR C667 polymorphism (TT vs CC+CT: OR=0.79; 95%CI=0.65-0.96; p=0.017). Stratification by ethnicity revealed that MTHFRC667 was associated with colon cancer risk in the non-Asian group (TT vs CC+CT:OR=0.77, 95%CI=0.68-0.89, p=0.000; TT vs CC: OR=0.84, 95%CI=0.73-0.97, p=0.016). Stratification by source of control indicated that MTHFR C667 also correlated with colon cancer risk in the population-based subgroup (TT vs CC: OR=0.85, 95%CI=0.74-0.97, p=0.017; TT vs CC+CT: OR=0.78, 95%CI=0.68-0.89, p=0.000) and hospital-based subgroup (TT vs CC+CT: OR=0.65, 95%CI=0.49-0.86, p=0.003). However, risk was significantly increased for MTHFR A1298C polymorphisms and colon cancer risk in hospital-based studies (C vs A: OR=1.52, 95%CI=1.26-1.83, p=0.000; CC+AC vs AA: OR=1.93, 95%CI=1.47-2.49, p=0.000) but reduced in population-based studies (CC vs AA: OR=0.83, 95%CI=0.70-0.99, p=0.042). In conclusion, the results of our meta-analysis suggest that the MTHFR C667 polymorphism is associated with reduced colon cancer risk, especially for non-Asian populations.