Thermo-mechanical stress analysis of feed-water valves in nuclear power plants

Wen-qing Li,Lei Zhao,Yang Yue,Jia-yi Wu,Zhi-jiang Jin,Jin-yuan Qian 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.3

Feed-water valves (FWVs) are used to regulate the flow rate of water entering steam generators, whichare very important devices in nuclear power plants. Due to the working environment of relatively highpressure and temperature, there is strength failure problem of valve body in some cases. Based on thethermo-fluid-solid coupling model, the valve body stress of the feed-water valve in the opening processis investigated. The flow field characteristics inside the valve and temperature change of the valve bodywith time are studied. The stress analysis of the valve body is carried out considering mechanical stressand thermal stress comprehensively. The results show that the area with relatively high-velocity areamoves gradually from the bottom of the cross section to the top of the cross section with the increase ofthe opening degree. The whole valve body reaches the same temperature of 250C at the time of 1894 s. The maximum stress of the valve body meets the design requirements by stress assessment. This workcan be referred for the design of FWVs and other similar valves.

Differential Impacts on Bacterial Composition and Abundance in Rhizosphere Compartments between Al-Tolerant and Al-Sensitive Soybean Genotypes in Acidic Soil

Wen Zhong-Ling,Yang Min-Kai,Fazal Aliya,Liao Yong-Hui,Cheng Lin-Run,Hua Xiao-Mei,Hu Dong-Qing,Shi Ji-Sen,Yang Rong-Wu,Lu Gui-Hua,Qi Jin-Liang,Zhi Hong,Qian Qiu-Ping,Yang Yong-Hua 한국미생물·생명공학회 2020 Journal of microbiology and biotechnology Vol.30 No.8

In this study, two soybean genotypes, i.e., aluminum-tolerant Baxi 10 (BX10) and aluminumsensitive Bendi 2 (BD2), were used as plant materials and acidic red soil was used as growth medium. The soil layers from the inside to the outside of the root are: rhizospheric soil after washing (WRH), rhizospheric soil after brushing (BRH) and rhizospheric soil at two sides (SRH), respectively. The rhizosphere bacterial communities were analyzed by high-throughput sequencing of V4 hypervariable regions of 16S rRNA gene amplicons via Illumina MiSeq. The results of alpha diversity analysis showed that the BRH and SRH of BX10 were significantly lower in community richness than that of BD2, while the WRH exhibited no significant difference between BX10 and BD2. Among the three sampling compartments of the same soybean genotype, WRH had the lowest community richness and diversity while showing the highest coverage. Beta diversity analysis results displayed no significant difference for any compartment between the two genotypes, or among the three different sampling compartments for any same soybean genotype. However, the relative abundance of major bacterial taxa, specifically nitrogen-fixing and/or aluminum-tolerant bacteria, was significantly different in the compartments of the BRH and/or SRH at phylum and genus levels, indicating genotype-dependent variations in rhizosphere bacterial communities. Strikingly, as compared with BRH and SRH, the WRH within the same genotype (BX10 or BD2) always had an enrichment effect on rhizosphere bacteria associated with nitrogen fixation

Adversarial Attack on DL-based Massive MIMO CSI Feedback

Qing Liu,Jiajia Guo,Chao-Kai Wen,Shi Jin 한국통신학회 2020 Journal of communications and networks Vol.22 No.3

With the increasing application of deep learning (DL) algorithms in wireless communications, the physical layer faces newchallenges caused by adversarial attack. Such attack has significantly affected the neural network in computer vision. We chooseDL-based channel state information (CSI) to show the effect of adversarial attack on DL-based communication system. We presenta practical method to craft white-box adversarial attack on DLbased CSI feedback process. Our simulation results show the destructive effect adversarial attack causes on DL-based CSI feedback by analyzing the performance of normalized mean square error. We also launch a jamming attack for comparison and find thatthe jamming attack could be prevented with certain precautions. As DL algorithm becomes the trend in developing wireless communication, this work raises concerns regarding the security in the useof DL-based algorithms.

The thermal stability of atomic layer deposited HfLaOx: Material and electrical characterization

Wen Yang,Qing-Qing Sun,Run-Chen Fang,Lin Chen,Peng Zhou,Shi-Jin Ding,David Wei Zhang 한국물리학회 2012 Current Applied Physics Vol.12 No.6

HfLaOx based Metaleoxideesemiconductor capacitors were fabricated by atomic layer deposition in this work. The material and electrical properties of the films along with the high temperature thermal treatment were investigated. It was found that samples undergoing annealing at 900 ℃ exhibited the best performance. The film was found to be crystallized to a cubic structure at 900 ℃, and the roughness of the films was estimated to be 0.332 nm. For electrical characterization, the C-V curve of the film is in good agreement with the corresponding simulated curve, and the capacitor does not show any hysteresis. Moreover, the Dit near the center of silicon band gap exhibits lowest value, and it was calculated to be 2.28 × 1011 eV-1 cm-2. HfLaOx based Metaleoxideesemiconductor capacitors were fabricated by atomic layer deposition in this work. The material and electrical properties of the films along with the high temperature thermal treatment were investigated. It was found that samples undergoing annealing at 900 ℃ exhibited the best performance. The film was found to be crystallized to a cubic structure at 900 ℃, and the roughness of the films was estimated to be 0.332 nm. For electrical characterization, the C-V curve of the film is in good agreement with the corresponding simulated curve, and the capacitor does not show any hysteresis. Moreover, the Dit near the center of silicon band gap exhibits lowest value, and it was calculated to be 2.28 × 1011 eV-1 cm-2.

Bond-slip Constitutive Relation between BFRP Bar and Basalt Fiber Recycled-aggregate Concrete

Wen-jing Meng,Hua-xin Liu,Gen-jin Liu,Xiang-qing Kong,Xue-zhi Wang 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.5

In order to investigate the bond stress-slip constitutive relation between BFRP bar and basalt fiber recycled-aggregate concrete, 81 central pullout specimens were tested. Basalt fiber volume percent, fiber length and concrete strength grade were considered to be experimental variables to obtain the bond stress-slip curves. The results showed that adding basalt fiber into recycled-aggregate concrete will reduce the bond stress between BFRP bar and recycled-aggregate concrete but enhance the ductility of bond property; the bond stress increases with the increasing of fiber length and concrete strength grade. The bond stress-slip constitutive model was proposed and the results showed that the model is good in effect of fitting. The constitutive model can reflect the bonding mechanism between BFRP bar and basalt fiber concrete well, it also can provide reference for theoretical analysis and engineering applications of the bond and anchor property between BFRP bars strengthened recycled concrete.

Combination of TEM and 3D Atom Probe Study of Microstructure and Alloy Carbide in a Nb-V Micro-Alloyed Steel Tempered at 650℃

Qing-dong Liu,Wen-qing Liu,Shi-jin Zhao 대한금속·재료학회 2013 METALS AND MATERIALS International Vol.19 No.4

3D atom probe (3DAP) combined with TEM is applied to characterize the nanostructure and composition of coarsening carbides that precipitate in a Nb-V micro-alloyed steel tempered at 650 °C for 4 h. The results indicate that high temperature tempering of the as-quenched lath-like martensitic structures leads to the coarsening of alloyed carbide in the recovered ferritic matrix. TEM characterization and EDS analysis show that the alloy carbides are typically spherical or ellipsoidal and are enriched with V, Nb and Mo. Crystallographic lattice overlap and distortion create a distinct optical Moiré pattern at the carbide/matrix boundary, as observed by HRTEM. 3DAP gives the compositional distribution at atomic scale in the coarsening carbide and the surrounding matrix. Non-carbide-forming elements such as Si and Al are depleted in the carbide and are enriched at the carbide/matrix heterophase interface. Carbide-forming elements such as Mn, V, Mo and Nb distribute heterogeneously in the whole carbide, leading to the formation of a Mn-, V- and Mo-enriched core and Mo-enriched external shell.

Systematic polymorphism analysis of the CYP2C9 gene in Chinese Han and Tibetan populations

Yue-Wen Wang,Xiao-Hong Meng,Wei Yan,Xiao-Qing Zhang,Jin Yang 한국유전학회 2012 Genes & Genomics Vol.34 No.3

Study about polymorphism of the CYP2C9 was not reported in the Chinese Tibetan population and there was no comparison of genetic polymorphism pattern of CYP2C9 between Chinese Han and Tibetan populations. Here we screened the genetic polymorphisms of functional regions of the CYP2C9in 100 unrelated healthy Chinese Han and Tibetan volunteers,respectively, using direct sequencing. A total of 20 variants were detected and there were different distribution of allelic and genotype frequencies, linkage disequilibrium patterns,haplotype structures and htSNPs between the two populations. CYP2C9*3 is a major functional variant of CYP2C9 in the two populations and *11 allele was only detected in Tibetan population. The determined genetic information of CYP2C9in Chinese Han and Tibetan populations might serve as a baseline for larger studies on determining metabolic phenotypes of CYP2C9 substrate drugs and also provide important data for the advance of personalized medicine in Chinese Han and Tibetan populations.

Clinical Application of the Adenosine Triphosphate-based Response Assay in Intravesical Chemotherapy for Superficial Bladder Cancer

Ge, Wen-Qing,Pu, Jin-Xian,Zheng, Shi-Ying Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.2

Objective: To investigate correlations between adenosine triphosphate chemotherapy response assay (ATP-CRA) and clinical outcomes after ATP-CRA-based chemotherapy for drug selection in patients receiving intravesical chemotherapy to prevent recurrence of superficial bladder cancer after surgery. Methods: The chemosensitivities of 12 anticancer drugs were evaluated, including 5-Fu ADM, and EPI, using ATP-CRA and primary tumor cell culture in 54 patients. In addition, a further 58 patients were treated according to clinical experience. Differences in post-chemotherapeutical effects between drug sensitivity assay and experience groups were compared. Results: The evaluable rate of the test was 96.3%, the clinical effective rate was 80.8%, the sensitivity rate was 97.6% (41/42), the specificity was 20%, the total predicting accuracy was 74.3%, the positive predictive value was 83.7% (41/49), the negative predictive value was 66.7% (2/3); in the drug sensitivity test group, the clinical effective rate was 80.8%, the experience group response rate was 63.8%, with a significant difference in clinical effects between the ATP-based sensitivity and experience groups (${\chi}^2$=7.0153, P<0.01). Conclusion: ATP-CRA is a stable, accurate and potentially practical chemosensitivity test providing a predictor of chemotherapeutic response in patients with superficial bladder cancer.

Pd/Ce0.9Cu0.1O1.9-Y2O3 catalysts for catalytic combustion of toluene and ethyl acetate

Xiao-Wen Su,Ling-Yun Jin,Ji-Qing Lu,Meng-Fei Luo 한국공업화학회 2009 Journal of Industrial and Engineering Chemistry Vol.15 No.5

A dual-functional Pd/CuO-CeO2-Y2O3 (Pd/CCY) using CuO-CeO2 as precursor was prepared and tested for catalytic combustion of toluene and ethyl acetate. It was found that the catalyst is much higher active and thermally stable for combustion of both toluene and ethyl acetate, compared with the catalyst prepared with the conventional method. Therefore, the formation of the CuO-CeO2 solid solution before coating is the key to high activity and thermal stability. Moreover, Pd/PdO species are the active phase for oxidation of toluene, while CuO or CuO-CeO2 is responsible for oxidation of ethyl acetate, and the formation of the Pd probably impels the enhancement of activity for the catalyst calcined at 1000℃.

Asiatic Acid Promotes p21^WAF1/CIP1 Protein Stability through Attenuation of NDR1/2 Dependent Phosphorylation of p21^WAF1/CIP1 in HepG2 Human Hepatoma Cells

Chen, Jin-Yuan,Xu, Qing-Wen,Xu, Hong,Huang, Zong-Hai Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.2

Previous studies have suggested anti-tumor effects of asiatic acid in some human cancer cell lines. This agent is reported to increase the levels of $p21^{WAF1/CIP1}$ in human breast cancer cell lines. However, the molecular mechanisms have not been established. Here we report that asiatic acid up-regulates $p21^{WAF1/CIP1}$ protein expression but not the level of $p21^{WAF1/CIP1}$ mRNA in HepG2 human hepatoma cells. Furthermore, we found that the asiatic acid induced increase of $p21^{WAF1/CIP1}$ protein was associated with decreased phosphorylation (ser-146) of $p21^{WAF1/CIP1}$. Knockdown of NDR1/2 kinase, which directly phosphorylates $p21^{WAF1/CIP1}$ protein at ser-146 and enhances its proteasomal degradation, increased the levels of $p21^{WAF1/CIP1}$ protein and eliminated the regulation of $p21^{WAF1/CIP1}$ stability by asiatic acid. At the same time, the expression of NDR1/2 kinase decreased during treatment with asiatic acid in HepG2 cells. Moreover, asiatic acid inhibited the proliferation of HepG2 cells, this being attenuated by knockdown of $p21^{WAF1/CIP1}$. In conclusion, we propose that asiatic acid inhibits the expression NDR1/2 kinase and promotes the stability of $p21^{WAF1/CIP1}$ protein through attenuating NDR1/2 dependent phosphorylation of $p21^{WAF1/CIP1}$ in HepG2 cells.