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Tian-Liang Fu,Xiang-Tao Deng,Guo-Huai Liu,Zhao-Dong Wang,Guo-Dong Wang 한국정밀공학회 2016 International Journal of Precision Engineering and Vol.17 No.11
The quenching temperature drop curve for Q345B steel plate with 84 mm and 170 mm thickness was tested to analyze the distributing regularities and influencing factors of cooling speed for ultra-thick steel plate during the jet impinging and quenching process. The influences for temperature drop, temperature gradient and cooling speed were analyzed under the conditions of 60~100 m3/h water amount, 0.4~1.0 MPa water pressure, transient switching of quenching mode and the distribution of heat exchanger. Threedimensional heat anti transfer model, surface heat transfer coefficient model and thermal physical parameter model were built up by finite element and optimization. The results showed that the deviation of calculated and measured values was less than 4% for temperature drop curve model. The cooling speed of vertical section for 84 mm-thick steel plate was approximately proportional to surface heat transfer coefficient. The influence of surface heat transfer to cooling speed became weak when the thickness was increased. The influences of temperature effect when switching different quenching modes and temperature gradient of vertical section to cooling speed were stronger. The minimum value of cooling speed was about 1.0~1.8oC/s, between H/6 and H/3 region. These data provide the key information for increasing the cooling speed and uniformity.
Radiation Hybrid Mapping and mRNA Expression of Chicken N- myc downregulated gene 4
Yong Tian,Li Zhi Lu,Yan Fu,Ai Ping Yuan,Guo Qin Li,Qing Yan Yuan,Zheng Rong Tao,Jin Zhao 한국유전학회 2007 Genes & Genomics Vol.29 No.4
N-myc downregulated gene 4 (NDRG4) is a member of the N-myc downregulated gene family which belongs to the alpha/beta hydrolase superfamily. The protein encoded by this gene is a cytoplasmic protein that may be involved in the regulation of mitogenic signalling in vascular smooth muscle cells. To map NDRG4 gene in chicken chromosome, a 6,000 rads chicken- hamster radiation hybrid panel was used. Primers were designed according to the published human sequence for amplification of chicken NDRG4. We compared the corresponding human mRNA sequence with the predicted coding sequence of chicken NDRG4, and found that the assembled contig shared a high percentage of similarity with that of human gene. PCR of samples from ChickRH6 revealed the locations of NDRG4 to be linked to the maker PARD6G (5 cR away) with a LOD score 20.46. In addition, we detected the mRNA expression and distribution of chicken NDRG4 in various tissues by RT-PCR, and found that NDRG4 was highly expressed in chicken brain and heart, whereas lowly but detectable in thymus. The mRNA expression of this gene in chicken liver, spleen, lung and muscle was rarely detectable under present experimental conditions.
Zhou, Shi-Fu,Shi, Wei-Feng,Meng, Dong,Sun, Chun-Lei,Jin, Jian-Rong,Zhao, Yu-Tian Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4
Objective: To evaluate interoperative radiotherapy after breast conservative surgery in early breast cancer patients in terms of postoperative complications, cosmetic outcome and recurrence events. Methods: From June 2007 to Dec 2011, 143 early breast cancer patients received breast conservative surgery. Seventy-two (study group) received interoperative radiotherapy, compared with 71 patients (control group) given routine radiotherapy. Postoperative complications were evaluated 1 month after surgery; cosmetic outcome was evaluated 1 year postoperatively; recurrence and death events were followed up. Results: The average wound healing time was 13~22 d in the study group and 9~14 d in the control group. In the study group, 2 patients developed lyponecrosis, 16 patients showed wound edema while no such side effects were found in the control group. No infection or hematomas were found in either group. In the study group (59 cases), overall cosmetic outcome in 53 patients was graded as excellent or good, and in 6 as fair or poor. Meanwhile in the control group (56 cases), 42 patients were graded as excellent or good, and 14 as fair or poor (P=0.032). After a follow-up from 3 to 54 months (median: 32 months), two patients (2.78%) in study group developed local relapses, one of them (1.39%) died, 2 patients (2.78%) developed bone metastases. In control group, one patient (1.41%) developed local relapse, 2 patients (2.82%) developed bone metastases, and no one died. Conclusion: Intraoperative radiotherapy is safe and reliable with good cosmetic outcome.
Complete loss distribution model of GaN HEMTs considering the influence of parasitic parameters
Shengwei Gao,Jinrui Tian,Xiaoyu Fu,Yongxiao Li,Bo Wang,Lixia Zhao 전력전자학회 2024 JOURNAL OF POWER ELECTRONICS Vol.24 No.1
When compared with Si-based devices, Gallium Nitride High Electron Mobility Transistors (GaN HEMTs) possess the advantages of lower junction-to-case thermal resistance, smaller on-state resistance, faster switching velocity, and higher switching frequency. These advantages make them a promising power semiconductor device. However, with the enhancement of switching frequencies, the influence of parasitic parameters on switching ringing and the losses of GaN HEMTs are increasingly severe. Thus, it is necessary to predict the loss distribution by establishing an accurate loss model of the switching process. On the premise of considering parasitic inductance, nonlinear junction capacitance, and reverse transfer characteristics, this article proposes a precise switching loss model of GaN HEMTs to predict the loss distribution in the switching process. In addition, it verifies results based on the double pulse test (DPT) circuit, which validates the accuracy of the proposed model. Ultimately, based on the above-mentioned loss model, this article discussed the influence of parasitic capacitance and inductance on the output capacitance loss (Eqoss), the reverse conduction loss (ESD), the opening V-I overlap loss (Eopen), the closing V-I overlap loss (Eclose), and the total loss (Etotal). Then, this article produces an optimizing method to enhance the conversion efficiency of GaN HEMTs in accordance with laboratory findings.
Pan Zhang,Yuetong Zhao,Xiangfeng Tian,Yanxi Ji,Yuxuan Shu,Kun Fu,Dong Fu,Lemeng Wang 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.11
Tetramethylammonium glycine ([N1111][Gly]) can be completely ionized into cation [N1111]+ and anion [Gly] in aqueous solution. The anion contains an amino -NH2 and a carboxyl -COO, both of which can react with hydrogen sulfide (H2S). Therefore, [N1111][Gly] was used to promote the selective absorption of H2S in coke oven gas (COG) by N-methyldiethanolamine (MDEA). The absorption performance and selectivity of H2S in the aqueous solution of MDEA-[N1111][Gly] were investigated. The effects of MDEA mass fraction, [N1111][Gly] mass fraction, temperature, H2S partial pressure and CO2 partial pressure on the absorption capacity and selectivity were clarified. The results showed that an aqueous solution of MDEA-[N1111][Gly] has good selectivity for H2S in COG. The absorption capacity was large and the mass fraction of the solute in the absorbent reached more than 0.55, thereby having outstanding advantages in the aspects of saving energy consumption and operating cost and having a good application potential.
Haowen Zheng,Jun Liu,Ruihong Zhuang,Fu-tian Zhao,Meng-yang Zhen,Yue Wang,Zheng Liu 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.9
The prediction of rock fragmentation is critical to improve the efficiency and economy of blasting excavation. In this study, an attempt is made to predict the entire fragmentation size distribution using a least square support vector machine (LSSVM) model. In addition, three optimization algorithms – the bacterial foraging algorithm (BFO), artificial fish swarm algorithm (AFSA), and adaptive particle swarm optimization (APSO) – were used to determine the appropriate parameters of the LSSVM model. In the constructed LSSVM-BFO, LSSVM-AFSA and LSSVM-APSO models, the hole spacing, row spacing, change per delay and stemming were used as the input parameters, while the statistical rock fragmentation size was assigned as the output. The LSSVM model was also employed as a control group for comparing with the optimized models. The above-mentioned models were trained and tested based on a database comprising of 10 datasets collected from in-site testing of Altashi Water Control Project in China. The performance of the proposed models was compared by several statistical criteria. The viability and efficiency of the LSSVM-BFO model were confirmed with an R2 of 0.9960 and an RMSE of 1.8044, which were better than those of the LSSVM-AFSA, LSSVM-APSO and LSSVM. Last but not least, sensitivity analysis was also executed. The result of sensitivity analysis demonstrated when the size of rock fragmentation of prediction is less 80mm, the most effective parameter will be stemming; otherwise the most effective parameter will be hole spacing.
Yan-Ling Chen,Xian-Guo Guo,Wen-Yu Song,Tian-Guang Ren,Lei Zhang,Rong Fan,Cheng-Fu Zhao,Zhi-Wei Zhang,Wenge Dong,Xiao-Bin Huang,Dao-chao Jin 대한기생충학ㆍ열대의학회 2023 The Korean Journal of Parasitology Vol.61 No.3
Chigger mites are the vector of scrub typhus. This study estimates the infestation status and ecological characteristics of chiggers on the chestnut white-bellied rat Niviventer fulvescens in Southwest China between 2001 and 2019. Chiggers were identified under the microscope, and infestation indices were calculated. The Preston’s log-normal model was used to fit the curve of species abundance distribution. A total of 6,557 chiggers were collected in 136 of 342 N. fulvescens rats, showing high overall infestation indices (prevalence=39.8%, mean abundance=19.2, mean intensity=48.2) and high species diversity (S =100, H’=3.0). Leptotrombidium cangjiangense, Neotrombicula japonica, and Ascoschoengastia sifanga were the three dominant chigger species (constituent ratio=42.9%; 2,736/6,384) and exhibited an aggregated distribution among different rat individuals. We identified 100 chigger species, with 3 of them (Leptotrombidium scutellare, Leptotrombidium wenense, and Leptotrombidium deliense) as the main vectors of scrub typhus in China and nine species as potential vectors of this disease. Disease vector occurrence on N. fulvescens may increase the risk of spreading scrub typhus from rats to humans. Chigger infestation on N. fulvescens varied significantly in different environments. The species abundance distribution showed a log-normal distribution pattern. The estimated number of chigger species on N. fulvescens was 126 species.