Hot Deformation Behaviors and Process Parameters Optimization of Low-Density High-Strength Fe–Mn–Al–C Alloy Steel

Peng Wan,Huixiang Yu,Feng Li,Pengfei Gao,Lei Zhang,Zhengzhi Zhao 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.10

The hot deformation behavior of low-density high-strength Fe–Mn–Al–C alloy steel at T = 900-1150 °C and ̇ = 0.01-10 s−1was studied by the Gleeble-3500 thermo-mechanical simulator. The rheological stress curve characteristics of the steel wereanalyzed through experimental data, and a physical constitutive model considering strain coupling was established. At thesame time, the finite element software DEFORM was used to calculate the critical damage value of the steel, and the influenceof T and ̇ on the maximum damage value was considered. By introducing the dimensionless parameter Zener–Hollomon, thecritical damage model was established. Finally, the workability of the steel was evaluated by using the intuitive processingmap technology. The results indicated that Fe–Mn–Al–C alloy steel is a positive strain rate-sensitive and a negative temperature-sensitive material, and the constitutive model considering physical parameters can well predict the rheological stress ofthe steel during hot deformation (R = 0.997). The critical damage factor of Fe–Mn–Al–C alloy steel varies with the changeof T and ̇ , and the range is 0.359-0.535. At the same time, the critical damage factor is more sensitive to ̇ . At a constantT, the damage factor decreases with the increase of ̇ . Based on the Prasad instability criterion, the dynamic material modelprocessing map and the microstructure verification after thermal compression, the rheological instability characteristics ofthe steel are mainly mechanical instability and local plastic flow, and the stable deformation area is mainly characterized bydynamic recrystallization. The optimal hot working process window of the steel is 975-1050 °C/0.01-0.032 s−1.

Insights into chlorantraniliprole resistance of Chilo suppressalis: Expression profiles of ATP-binding cassette transporter genes in strains ranging from low- to high-level resistance

Peng Yingchuan,Zhao Jun,Sun Yang,Wan Peng,Hu Yanyue,Luo Guanghua,Qin Wenjing,Huang Shuijin 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.2

The ATP-binding cassette (ABC) proteins are involved in trans-cellular transport of substances at inverse con centrations. After ABC genes were discovered to be involved in multidrug resistance in humans, increased attention was paid to the role of insect ABC genes in pesticide resistance. Chilo suppressalis, the most important Lepidopteran pest in rice production, has developed resistance to the insecticide chlorantraniliprole. However, few of the ABC genes that contribute to chlorantraniliprole resistance have been studied. Here, 47 genes encoding ABC transporters were identified, including five CsABCA, seven CsABCB, ten CsABCC, two CsABCD, one CsABCE, three CsABCF, 15 CsABCG, and four CsABCH genes. The expression profiles of these transporter genes were determined in three chlorantraniliprole-resistant strains: R1, R2, and HR, with a resistance ratio of 38.8, 110.4, and 249.6, respectively. CsABCA1, -D2, and -H2 were up-regulated in all resistant strains, and the trend in the transcript levels of all 47 CsABC genes fitted a descending curve from R1 to HR. Unexpectedly, CsABCF1, -G11 and -G12 were significantly down-regulated in HR. These results provide new insights into the roles of ABC transporters in chlorantraniliprole resistance in C. suppressalis.

The Effect of Swirling Flow on Elutriation in a Vortexing Fluidized Bed

Wan, Hou Peng,Chyang, Chien Song 한국화학공학회 1999 Korean Journal of Chemical Engineering Vol.16 No.5

The elutriation of fine particles in a vortexing fluidized bed (VFB) was studied by a batch and binary system. The diameter of the coarse particles was 545㎛, and the diameter of the fine particles for the elutriation test was 81, 97, 115, 137, 163, and 193㎛, respectively. It was found that the swirling flow caused by the secondary air injection is the dominating factor to influence the elutriation rates. The effect of primary air velocity, swirling flow, injection angle of secondary air nozzle, and diameter of fine particles on the elutriation rate constant was also studied. The Taguchi experimental method and Regular analysis are used to identify the effects of various operating variables. A correlation was developed to estimate the specific elutriation rate constant (K^*_∞) in the vortexing fluidized bed. The specific elutriation rate constant (K^*_∞) was found to be a function of the primary air velocity, the diameter of fine particles, the secondary air velocity, and the height of secondary air injection.

Hot Deformation Behaviors of Ti-22Al-26Nb-2Ta Alloy Based on GA-LSSVM and 3D Processing Map

Peng Wan,Hang Zou,Kelu Wang,Zhengzhi Zhao 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.10

The thermal compression tests of Ti-22Al-26Nb-2Ta alloy under T = 1173 ~ 1423 K and ̇ = 0.001 ~ 10 s−1 were carried out onthe Gleeble-3500 thermo-mechanical simulator. The flow stress curves were obtained, and the high-temperature rheologicalproperties of the alloy were analyzed. The 3D activation energy maps were calculated and constructed. The least squaressupport vector machine (LSSVM) model of constitutive relation was established, and the penalty coefficient and kernelparameter of the LSSVM model were optimized by genetic algorithm (GA). The constitutive model of the alloy based on theGA-LSSVM algorithm was constructed. The predicted value of the model was also compared with the experimental data. The dynamic material model (DMM) and polar reciprocity model (PRM) were used to establish the 3D processing map ofthe alloy and appropriate thermal processing parameters. Our researches indicated that deformation temperature and strainrate have a great influence on the flow stress of Ti-22Al-26Nb-2Ta alloy. Ti-22Al-26Nb-2Ta alloy is a negative temperaturesensitiveand a positive strain rate-sensitive material. The correlation coefficient of GA-LSSVM algorithm constitutive modelis 0.9922, and the relative error of most samples is within 10%, accounting for 93.18%. The model has high prediction accuracyand strong generalization ability. The DMM processing map based on the Prasad instability criterion is more accurate inoptimizing the processing parameters of the alloy than that of the PRM processing map through analyzing the 3D processingmap and observing the microstructure. The instability modes in the instability region of the alloy mainly include adiabaticshear, crack, and local flow. The 1173 ~ 1273 K/0.001 ~ 0.003 s−1 are the best parameters during the processing of the alloy.

The Construction and Viterbi Decoding of New (2k, k, l) Convolutional Codes

( Wan Quan Peng ),( Cheng Chang Zhang ) 한국정보처리학회 2014 Journal of information processing systems Vol.10 No.1

The free distance of (n, k, l) convolutional codes has some connection with the memory length, which depends on not only l but also on k. To efficiently obtain a large memory length, we have constructed a new class of (2k, k, l) convolutional codes by (2k, k) block codes and (2, 1, l) convolutional codes, and its encoder and generation function are also given in this paper. With the help of some matrix modules, we designed a single structure Viterbi decoder with a parallel capability, obtained a unified and efficient decoding model for (2k, k, l) convolutional codes, and then give a description of the decoding process in detail. By observing the survivor path memory in a matrix viewer, and testing the role of the max module, we implemented a simulation with (2k, k, l) convolutional codes. The results show that many of them are better than conventional (2, 1, l) convolutional codes.

SNPs of Excision Repair Cross Complementing Group 5 and Gastric Cancer Risk in Chinese Populations

Yang, Wan-Guang,Zhang, Shan-Feng,Chen, Ju-Wu,Li, Li,Wang, Wan-Peng,Zhang, Xie-Fu Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.12

We conducted a case-control study to determine the association between several potential SNPs of excision repair cross complementing group 5 (XPG) and gastric cancer susceptibility, and roles of XPG polymorphisms in combination with H.pylori infection in determining risk of gastric cancer. In our study, we collected 337 newly diagnosed gastric cancer cases and 347 health controls. Three SNPs of XPG, rs2296147T>C, rs2094258C>T and rs873601G>A, were genotyped using the Taqman real-time PCR method with a 7900 HT sequence detector system. H. pylori infection was diagnosed by ELISA. By multivariate logistic regression analysis, the rs2296147 CC genotype was associated with a decreased risk of gastric cancer (OR=0.52, 95% CI=0.27-0.97), and rs2094258 TT was associated with elevated risk (OR=2.13, 95% CI=1.22-3.35). Positive H.pylori individuals with rs2094258 TT genotypes demonstrated increased risk of gastric cancer (OR=2.13, 95% CI=1.22-3.35), while rs2296147 CC was associated with lower risk among patients with negative H.pylori (OR=0.45, 95%CI=0.22-0.89). Our findings suggested that XPG polymorphisms might contribute to risk of gastric cancer among Chinese populations, but the effect needs to be further validated by larger sample size studies.

Effect of interaction of operation parameters on elutriation behavior in a vortexing fluidized bed

Hou-Peng Wan,Chien-Song Chyang,Li-Chi Su 한국화학공학회 2007 Korean Journal of Chemical Engineering Vol.24 No.6

RESEARCH PAPERS : The Effect of Swirling Flow on Elutriation in a Vortexing Fluidized Bed

(Hou Peng Wan),(Chien Song Chyang) 한국화학공학회 1999 Korean Journal of Chemical Engineering Vol.16 No.5

The elutriation of fine particles in a vortexing fluidized bed (VFB) was studied by a batch and binary system. The diameter of the coarse particles was 545㎛, and the diameter of the fine particles for the elutriation test was 81, 97, 115, 137, 163, and 193㎛, respectively. It was found that the swirling flow caused by the secondary air injection is the dominating factor to influence the elutriation rates. The effect of primary air velocity, swirling flow, injection angle of secondary air nozzle, and diameter of fine particles on the elutriation rate constant was also studied. The Taguchi experimental method and Regular analysis are used to identify the effects of various operating variables. A correlation was developed to estimate the specific elutriation rate constant (K^*_∞) in the vortexing fluidized bed. The specific elutriation rate constant (K^*_∞) was found to be a function of the primary air velocity, the diameter of fine particles, the secondary air velocity, and the height of secondary air injection.

韓國의 판소리와 中國의 大鼓書

李萬鵬(L? Wan-Peng) 고려대학교 한국학연구소 1996 한국학연구 Vol.8 No.-

High Serum Level of Retinol and α-Tocopherol Affords Protection Against Oral Cancer in a Multiethnic Population

Athirajan, Vimmitra,Razak, Ishak Abdul,Thurairajah, Nalina,Ghani, Wan Maria Nabillah,Ching, Helen-Ng Lee,Yang, Yi-Hsin,Peng, Karen-Ng Lee,Rahman, Zainal Ariff Abdul,Mustafa, Wan Mahadzir Wan,Abraham, Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.19

Background: A comparative cross-sectional study involving oral cancer patients and healthy individuals was designed to investigate associations between retinol, ${\alpha}$-tocopherol and ${\beta}$-carotene with the risk of oral cancer. Materials and Methods: This study included a total of 240 matched cases and controls where subjects were selected from the Malaysian Oral Cancer Database and Tissue Bank System (MOCDTBS). Retinol, ${\alpha}$-tocopherol and ${\beta}$-carotene levels and intake were examined by high-performance liquid chromatography (HPLC) and food frequency questionnaire (FFQ) respectively. Results: It was found that results from the two methods applied did not correlate, so that further analysis was done using the HPLC method utilising blood serum. Serum levels of retinol and ${\alpha}$-tocopherol among cases ($0.177{\pm}0.081$, $1.649{\pm}1.670{\mu}g/ml$) were significantly lower than in controls ($0.264{\pm}0.137$, $3.225{\pm}2.054{\mu}g/ml$) (p<0.005). Although serum level of ${\beta}$-carotene among cases ($0.106{\pm}0.159{\mu}g/ml$) were lower compared to controls ($0.134{\pm}0.131{\mu}g/ml$), statistical significance was not observed. Logistic regression analysis showed that high serum level of retinol (OR=0.501, 95% CI=0.254-0.992, p<0.05) and ${\alpha}$-tocopherol (OR=0.184, 95% CI=0.091-0.370, p<0.05) was significantly related to lower risk of oral cancer, whereas no relationship was observed between ${\beta}$-carotene and oral cancer risk. Conclusions: High serum levels of retinol and ${\alpha}$-tocopherol confer protection against oral cancer risk.