Microstructure and Texture Evolution of Rolled Plate for Cu–15Cr In-Situ Composite

XuDong Wu,LvQi Zhu,RuiRui Liu,HaiTao Zhou 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.11

The microstructure and texture of different rolling processes in situ Cu–15Cr sheets are studied. The results show that thesecond phase Cr in the material gradually become broken, flattened, merged and homogenized from dendritic state to orientedthin lath. Meanwhile, the texture in distributed copper matrix grains finally forms Brass {110}<112>, Goss {001}<110>and Copper {112}<111> textures along with Cr phase texture of randomly distributed α-fiber (<110> fiber) and γ-fiber(<111> fiber) texture. Based on VPSC (visco-plastic self-consistent model), the texture of cold rolled Cu–15Cr compositeis simulated, and the simulation result indicates that obvious twinning effect in the copper matrix appears with a feature ofa special texture evolution law of Goss.

Genome-wide scan for runs of homozygosity identifies candidate genes in Wannan Black pigs

Wu Xudong,Zhou Ren,Zhang Wei,Cao Bangji,Xia Jingjing,Wang Caiyun,Zhang Xiaodong,ChuMing-Xing,Yin Zongjun,Ding Yueyun 아세아·태평양축산학회 2021 Animal Bioscience Vol.34 No.12

Objective: Runs of homozygosity (ROH) are contiguous lengths of homozygous genotypes that can reveal inbreeding levels, selection pressure, and mating schemes. In this study, ROHs were evaluated in Wannan Black pigs to assess the inbreeding levels and the genome regions with high ROH frequency.Methods: In a previous study, we obtained 501.52 GB of raw data from resequencing (10×) of the genome and identified 21,316,754 single-nucleotide variants in 20 Wannan Black pig samples. We investigated the number, length, and frequency of ROH using resequencing data to characterize the homozygosity in Wannan Black pigs and identified genomic regions with high ROH frequencies.Results: In this work, 1,813 ROHs (837 ROHs in 100 to 500 kb, 449 ROHs in 500 to 1,000 kb, 527 ROHs in >1,000 kb) were identified in all samples, and the average genomic inbreeding coefficient (FROH) in Wannan Black pigs was 0.5234. Sixty-one regions on chromosomes 2, 3, 7, 8, 13, 15, and 16 harbored ROH islands. In total, 105 genes were identified in 42 ROH islands, among which some genes were related to production traits.Conclusion: This is the first study to identify ROH across the genome of Wannan Black pigs, the Chinese native breed of the Anhui province. Overall, Wannan Black pigs have high levels of inbreeding due to the influence of ancient and recent inbreeding due to the genome. These findings are a reliable resource for future studies and contribute to save and use the germplasm resources of Wannan Black pigs. Objective: Runs of homozygosity (ROH) are contiguous lengths of homozygous genotypes that can reveal inbreeding levels, selection pressure, and mating schemes. In this study, ROHs were evaluated in Wannan Black pigs to assess the inbreeding levels and the genome regions with high ROH frequency. Methods: In a previous study, we obtained 501.52 GB of raw data from resequencing (10×) of the genome and identified 21,316,754 single-nucleotide variants in 20 Wannan Black pig samples. We investigated the number, length, and frequency of ROH using resequencing data to characterize the homozygosity in Wannan Black pigs and identified genomic regions with high ROH frequencies. Results: In this work, 1,813 ROHs (837 ROHs in 100 to 500 kb, 449 ROHs in 500 to 1,000 kb, 527 ROHs in >1,000 kb) were identified in all samples, and the average genomic inbreeding coefficient (FROH) in Wannan Black pigs was 0.5234. Sixty-one regions on chromosomes 2, 3, 7, 8, 13, 15, and 16 harbored ROH islands. In total, 105 genes were identified in 42 ROH islands, among which some genes were related to production traits. Conclusion: This is the first study to identify ROH across the genome of Wannan Black pigs, the Chinese native breed of the Anhui province. Overall, Wannan Black pigs have high levels of inbreeding due to the influence of ancient and recent inbreeding due to the genome. These findings are a reliable resource for future studies and contribute to save and use the germplasm resources of Wannan Black pigs.

Thermally Self-Healable Titanium Dioxide/Polyurethane Nanocomposites with Recoverable Mechanical and Dielectric Properties

Xudong Wu,Jingyu Huang,Shuhui Yu,Panpan Ruan,Rong Sun,Ching-Ping Wong 한국고분자학회 2020 Macromolecular Research Vol.28 No.4

Dielectric materials with self-healing property after the occurrence of detrimental events such as tearing or scratch are highly desired, which guarantees reliability and lifetime of the electric and electronic systems. Here, a self-healing covalently bonded titanium dioxide/polyurethane (TiO2/PU) nanocomposite with enhanced dielectric constant was prepared by in-situ polymerization based upon Diels-Alder reaction. The PU prepolymer was prepared from TiO2, poly(tetramethylene glycol) and 4,4-diphenylmethane diisocyanate. Then the linking between the prepolymer and Diels-Alder adducts of bifunctional maleimide blocked by furfuryl alcohol was carried out. The in-situ polymerization method allows the TiO2 filler, the PU polymer matrix, and the DA healing portion to be tightly connected, resulting in a stable nanocomposite system. Due to the reversibility of covalent bonds, the TiO2/PU nanocomposites exhibited thermal self-healing properties after being cut. The dielectric constant and loss, mechanical properties can be effectively restored to their original state after damage.

How Do Microbial Metabolism and New Microbial Legacy Mediate Soil Carbon and Nitrogen Cycling?

Xudong Zhang,Hongbo He,Yeye Wu,Wei Zhang 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Evaluation of Soil Carbon and Nitrogen Transformation by Microbial Metabolism and New Microbial Legacy

Xudong Zhang,Hongbo He,Yeye Wu 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Pore Size Distribution of Cement Mortar Prepared with Crushed Limestone Sand

Xudong Chen,Shengxing Wu,Jikai Zhou 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.2

Recently, the use of crushed sand obtained from limestone-quarried is growing especially in the countries where river sand is not quite available. In the paper, the results from an experimental investigation are presented, which evaluates the pore structure of mortar mixtures where fine aggregate is replaced by Crushed Limestone Sand (CLS). The behavior of pore structure of CLS mortar was compared to that of mortars prepared from Nature River Sand (NRS). A Mercury Porosimeter Intrusion (MIP) is adopted to study the behavior of pore size distribution. Both CLS and NRS mortar with four water-cement ratios and five sand-cement ratios are used to determine pore structure. An analytical model was established to compare changes in pore structure for different water cement ratio and volume of sand, and the model was based on the test results.

Investigation of the Deformation and Failure Characteristics of High-Strength Concrete in Dynamic Splitting Tests

Xudong Chen,Jin Wu,Kai Shang,Yingjie Ning,Lihui Bai 한국콘크리트학회 2022 International Journal of Concrete Structures and M Vol.16 No.6

The dynamic response properties of concrete have been of interest during the use of buildings due to seismic, impact, and explosion events. The splitting Hopkinson lever is a classical device for testing the dynamic mechanical properties of materials. In this paper, dynamic splitting tests on concrete were conducted using it, and a time series predictive computational model for the incident, reflected and transmitted pulses of high-strength concrete specimens at high strain rates was developed, and the extension mechanism of splitting tensile cracks in high-strength concrete was detected and analyzed based on the DIC technique. The results show that: the peak strength of C60 specimens and C80 specimens increased by about 60% and 90%, respectively, from 0.05 MPa to 0.09 MPa in impact strength; the triangular damaged area at the end of the contact surface of the specimen and the rod subjected to high impact pressure increased significantly, the dynamic energy dissipation increased, and the damage degree of the specimens increased; under the action of high strain rate, the brittleness of the concrete specimens with higher strength increased, the damage rate The higher strength concrete specimens have increased brittleness, faster damage rate and higher crack extension under high strain rate. The results of the paper can provide important references for the design of buildings under impact loading.

Effects of the aqueous extract of Schizandra chinensis fruit on ethanol withdrawal-induced anxiety in rats.

Wu, Yiyan,Zhao, Zhenglin,Yang, Yupeng,Yang, Xudong,Jang, Eun Young,Schilaty, Nathan D,Hedges, David M,Kim, Sang Chan,Cho, Il Je,Zhao, Rongjie Chinese Medical Assn 2014 Chinese medical journal : CMJ Vol.127 No.10

<P>We previously demonstrated that the aqueous extract of the Schizandra chinensis fruit (AESC) ameliorated Cd-induced depletion of monoamine neurotransmitters in the brain through antioxidant activity. In the present study, we investigated the effect of AESC on anxiety-like behavior and the levels of norepinephrine and 3-methoxy-4-hydroxy-phenylglycol (a metabolite of norepinephrine) in different brain regions during ethanol withdrawal in rats.</P>

Three-point Bending Behavior and Energy Absorption Capacity of Composite Tube Reinforced by Gradient Braided Structure in Radial Direction

Zhenyu Wu,Yong Shen,Zhongxiang Pan,Xudong Hu 한국섬유공학회 2019 Fibers and polymers Vol.20 No.7

This study aims to investigate the radial gradient structural effect on energy absorption and failure behavior ofbraided composite tubes. Two-layer tubular braided fabrics were fabricated using over-braiding technology with three typesof radial gradient configurations in terms of uninform, descending and ascending pattern. The structure of surface layertouching with indenter roll was found to have a significant role on the bending behavior and failure mode. The compositetube possessing the small angle surface layer tends to fail in top-surface mode characterized by compression damage incontact area between indenter roll and tube. With the increasing of the braiding angle in surface layer, the bottom-surfacefailure mode characterized by penetrating crack in circumferential direction was observed, which accompanies abruptlyloading drop and loss of energy absorption capacity. In addition, the tube in descending gradient pattern contributes to higherflexural modulus and peak load due to high fiber volume fraction, while keeps top-surface failure mode because of loadspreading ability provided by surface layer with small braiding angle. The results show that a proper selection of stackingsequence and braiding angle in multi-layer braided tube is capable of effectively enhancing the energy absorption of tubalstructures under bending load.

Current Sliding Mode Control with a Load Sliding Mode Observer for Permanent Magnet Synchronous Machines

Ningzhi Jin,Xudong Wang,Xiaogang Wu 전력전자학회 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.1

The sliding mode control (SMC) strategy is applied to a permanent magnet synchronous machine vector control system in this study to improve system robustness amid parameter changes and disturbances. In view of the intrinsic chattering of SMC, a current sliding mode control method with a load sliding mode observer is proposed. In this method, a current sliding mode control law based on variable exponent reaching law is deduced to overcome the disadvantage of the regular exponent reaching law being incapable of approaching the origin. A load torque-sliding mode observer with an adaptive switching gain is introduced to observe load disturbance and increase the minimum switching gain with the increase in the range of load disturbance, which intensifies system chattering. The load disturbance observed value is then applied to the output side of the current sliding mode controller as feed-forward compensation. Simulation and experimental results show that the designed method enhances system robustness amid load disturbance and effectively alleviates system chattering.