Effect of Prior Microstructures on Cementite Dissolution Behavior During Subcritical Annealing of High Carbon Steels

Xiao‑Yu Zhao,Xian‑Ming Zhao,Chun‑Yu Dong,Yang Yang,Huai‑Bin Han 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.6

The variation of the morphology and distribution of cementite particles in different prior structures with spheroidizingannealing process has been proceeded in this paper. It is found that the dissolution and coarsening progresses of variousinitial structures in spheroidizing annealing process are quite asynchronous due to the different interlamellar spacing. Thedissolution rate of degenerated pearlite (D-P) with finer interlamellar spacing is faster. The granular cementite in the spheroidizedmicrostructure is fine, uniform and dense. The mean diameter of spherical cementite is refined to 233 nm. However,the initial structure of degenerated pearlite (D-P) is highly sensitive to the austenitization temperature. The cementite iseasy to be coarsened under high austenitizing temperature. The coarsening is accompanied by the gradual increase of theCr content in the cementite, which increases the stability of the cementite. Therefore, the optimal austenitizing temperaturefor degenerated pearlite (D-P) is suggested to be 770 °C.

Transcriptome profiling of rubber tree (Hevea brasiliensis) discovers candidate regulators of the cold stress respo

Xiao‑Xiao Gong,Bing‑Yu Yan,Jin Hu,Cui‑Ping Yang,Yi‑Jian Li,Jin‑Ping Liu,Wen‑Bin Liao 한국유전학회 2018 Genes & Genomics Vol.40 No.11

Tropical plant rubber tree (Hevea brasiliensis) is the sole source of commercial natural rubber and low-temperature stress is the most important limiting factor for its cultivation. To characterize the gene expression profiles of H. brasiliensis under the cold stress and discover the key cold stress-induced genes. Three cDNA libraries, CT (control), LT2 (cold treatment at 4 °C for 2 h) and LT24 (cold treatment at 4 °C for 24 h) were constructed for RNA sequencing (RNA-Seq) and gene expression profiling. Quantitative real time PCR (qRT-PCR) was conducted to validate the RNA-Seq and gene differentially expression results. A total of 1457 and 2328 differentially expressed genes (DEGs) in LT2 and LT24 compared with CT were respectively detected. Most significantly enriched KEGG pathways included flavonoid biosynthesis, phenylpropanoid biosynthesis, plant hormone signal transduction, cutin, suberine and wax biosynthesis, Pentose and glucuronate interconversions, phenylalanine metabolism and starch and sucrose metabolism. A total of 239 transcription factors (TFs) were differentially expressed following 2 h or/and 24 h of cold treatment. Cold-response transcription factor families included ARR-B, B3, BES1, bHLH, C2H, CO-like, Dof, ERF, FAR1, G2-like, GRAS, GRF, HD-ZIP, HSF, LBD, MIKC-MADS, M-type MADS, MYB, MYB-related, NAC, RAV, SRS, TALE, TCP, Trihelix, WOX, WRKY, YABBY and ZF-HD. The genome-wide transcriptional response of rubber tree to the cold treatments were determined and a large number of DEGs were characterized including 239 transcription factors, providing important clues for further elucidation of the mechanisms of cold stress responses in rubber tree.

Effect of Different Cooling Rates in High Rheological Rate Forming Process on Mechanical Properties of Zr57Cu20Al10Ni8Ag5 Bulk Metallic Glass

Xiao‑Bo Mei,Bao‑Chuan Liu,Wei Jiang,Quan Xu,Qi‑Dong Zhang,Yu‑Bai Ma,Fang‑Qiu Zu 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.9

The influence of cooling rates on the mechanical properties of a Zr-based bulk metallic glass prepared with high rheologicalrate forming (HRRF) was investigated and compared with traditional suction cast methods. Amorphous samples of Zr57Cu-20Ni8Al10Ag5 were prepared in copper molds with different sizes in order to obtain different cooling rates for both HRRFand traditional cast methods. These specimens were subjected to compression experiments, including microhardness testing,X-ray diffraction testing and differential scanning calorimetry analysis. The results indicate that the plasticity of the samplesformed by HRRF are higher than that of the as-cast ones at the same cooling rates, while the microhardness manifests theopposite principle. As the cooling rate increases further, the difference in plasticity further increases between two methods,indicating that the plasticity of metallic glasses is more sensitive to cooling rates during the HRRF process. At the core ofthis phenomenon is the fact that HRRF methods can introduce more free volume into glasses than traditional cast methodswith an elevated cooling rate are able to.

Axial Resistance of Bored Piles Socketed into Soft Rock

Xiao-yu Chen,Ming-yi Zhang,Xiao-yu Bai 대한토목학회 2019 KSCE Journal of Civil Engineering Vol.23 No.1

Three fully-instrumented full-scale static load tests were conducted on three 0.8-m-diameter bored piles socketed at 3.2 m deep into argillaceous siltstone (1.6 and 1.6 deep into strong and medium decomposed siltstones, respectively) in Qingdao, China. About 50% of head load was transmitted and supported by base resistance at the end of the tests. Totally 53 test piles socketed into soft rock with unconfined compressive strength less than 20 MPa in Qingdao were reviewed. The measured side resistance along shaft socked into rock was compared with prediction using empirical methods in literatures based on database from Qingdao projects.

Cloning and Characterization of a Novel Mannanase from Paenibacillus sp. BME-14

( Xiao Yu Fu ),( Xiao Luo Huang ),( Peng Fu Liu ),( Ling Lin ),( Gao Bing Wu ),( Chan Juan Li ),( Chun Fang Feng ),( Yu Zhi Hong ) 한국미생물 · 생명공학회 2010 Journal of microbiology and biotechnology Vol.20 No.3

Taguchi Approach for Anti-heat Stress Prescription Compatibility in Mice Spleen Lymphocytes In Vitro

Xiao-yu Zhu,Gui-lin Cheng,Feng-hua Liu,Jin Yu,Yu-jie Wang,Tong-quan Yu,Jian-qin Xu,Ming Wang 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.7

Heat stress (HS) may induce immunosuppression as well as inhibit the proliferation of lymphocytes. This study evaluated the effects on immune function of our prescription on splenic lymphocytes under HS as well as its compatibility. The effects of four herbal extracts from Agastache rugosa, Atractylodes lancea, Cortex Phellodendri, and Gypsum Fibrosum on heat treated splenic lymphocytes were investigated and the compatibility of the prescription was also explored by using the Taguchi method. This study revealed changes in proliferation by traditional Chinese medicines of splenic lymphocytes after HS. Proliferation in the HS group was significantly lower than the control group. Under HS, the effects of higher concentrations of Agastache rugosa (100 and 200 μg/mL), Atractylodes lancea (100 and 200 μg/mL), Cortex Phellodendri (50 and 100 μg/mL) and Gypsum Fibrosum (100 and 200 μg/mL) caused a significant increase on ConA/LPS-induced proliferation of lymphocytes than lower concentrations. We, therefore, conclude that the prescription of traditional Chinese medicines may recover splenic lymphocytes from the immunosuppression induced by HS. The Taguchi design, which allows rapid and high efficiency for the selection of the best conditions for our prescription on HS-treated splenic lymphocytes, demonstrated that Agastache rugosa (200 μg/mL), Atractylodes lancea (200 μg/mL), Cortex Phellodendri (100 μg/mL) and Gypsum Fibrosum (100 μg/mL)were the optimal conditions for the prescription. The validation experiment confirmed that our composition in optimum extraction conditions enhanced effects on ConA or LPS-stimulated lymphocytes under HS. The results showed that the Taguchi optimization approach is a suitable method for optimization of the composition of prescription.

Research on Aesthetic Preferences for Transparency and Glossiness in Optical Phenomena-Focused on Evolutionary Aesthetics-

Xiao, Xiao Yu(샤오샤오유),Cho, Taig Youn(조택연) 한국디자인문화학회 2023 한국디자인문화학회지 Vol.29 No.4

투명도와 광택도는 대부분 함께 일어나는 광학 특성이다. 그리고 이 두 가지 물리적 특성은 심미 경험에 영향을 미칠 수 있다. 사람들이 선호하는 투명도와 광택을 가진 시각, 제품, 건축, 공간 디자인은 긍정적인 의미를 갖다. 본 논문은 광학 이론을 기반으로 광학적 성질이 어떻게 시각적으로 처리되는지를 분석한다. 그리고 진화 미학을 기반으로 광학이 정의한 투명도와 광택의 미적 선호 반응이 어떻게 작동하는지 설명한다. 본 연구에서는 광택에 대한 심미적 선호가 물표면의 반짝임이 가진 광택을 단서로 맑은 물을 찾는 의지에서 비롯될 수 있음을 제시하였다. 또한 투명성에 대한 심미적 선호는 다당류가 가수분해되어 달콤함이 증가할 때 나타나는 반투명한 시각적 자극에서 잘 익은 과일을 고르는 것에서 비롯될 수 있음을 발견했다. 또한 본 연구는 이를 통해 투명도와 광택의 정도가 미적 선호에 영향을 미칠 수 있음을 발견했다. 이를 검증하기 위해 투명도와 광택에 반응서 느끼는 호감의 행동학적 실험을 진행하였다. 실험에 참여한 피험자의 행동 분석에서 투명도와 광택에 대한 심미적 선호가 보편적이며, 더 높은 투명도와 선명한 광택 또한 강한 미적 선호 반응을 보였다. 그 결과 높은 투명도와 선명한 광택이 함께 작용하여 일어나는 심미적 선호가 가장 강렬하다는 결과를 보여준다. 본 연구의 목표는 투명도와 광택에 대한 심미적 선호 반응의 구조를 탐구하고, 이를 행동학적으로 검증해, 더 심미적 선호를 이끄는 투명도와 광택의 정도, 그리고 두시각 자극의 조합 방식을 발견하여 디자인에 적용할 수 있는 이론적 근거를 제공하는 것이다. Transparency and glossiness are optical properties that are usually associated with each other, and both of these physical characteristics can influence people’s aesthetic experiences. Visuals, products, architecture, and spatial design that possess transparency and glossiness are generally viewed positively. This article analyzes how visual processing of optical properties is based on optical theory and explains how aesthetic preferences for transparency and glossiness, as defined optically, operate from an evolutionary aesthetic perspective. This research suggests that the aesthetic preference for glossiness may stem from a desire for clear water, which can be inferred from the shimmering on the water’s surface. Furthermore, the preference for transparency may be rooted in the selection of ripe fruits from translucent visual stimuli, possibly associated with an increase in sweetness resulting from the breakdown of polysaccharides. Additionally, the study finds that the degree of transparency and glossiness can influence aesthetic preferences. To validate this point, behavioral experiments on preferences for transparency and glossiness were conducted. Behavioral analysis of the participants in the experiments revealed that aesthetic preferences for transparency and glossiness are widespread, with higher transparency and a clearer gloss eliciting stronger aesthetic preference responses. This suggests that the most pronounced aesthetic preference responses occur when high transparency and a bright gloss work together. The goal of this study is to explore the structure of aesthetic preference responses for transparency and glossiness, validate them behaviorally, and discover further combinations of transparency and glossiness levels, as well as the ways in which these two visual stimuli induce aesthetic preferences, to provide a theoretical basis for design applications.

Microstructure evolution and effect on deuterium retention in oxide dispersion strengthened tungsten during He⁺ irradiation

Ding, Xiao-Yu,Xu, Qiu,Zhu, Xiao-yong,Luo, Lai-Ma,Huang, Jian-Jun,Yu, Bin,Gao, Xiang,Li, Jian-Gang,Wu, Yu-Cheng Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.12

Oxide dispersion-strengthened materials W-1wt%Pr₂O₃ and W-1wt%La₂O₃ were synthesized by wet chemical method and spark plasma sintering. The field emission scanning electron microscopy (FE-SEM) analysis, XRD and Vickers microhardness measurements were conducted to characterize the samples. The irradiations were carried out with a 5 keV helium ion beam to fluences up to 5.0 × 10²¹ ions/m² under 600 ℃ using the low-energy ion irradiation system. Transmission electron microscopy (TEM) study was performed to investigate the microstructural evolution in W-1wt%Pr₂O₃ and W-1wt%La₂O₃. At 1.0 × 10²⁰ He⁺/m², the average loops size of the W-1wt%Pr₂O₃ was 4.3 nm, much lower than W-1wt% La₂O₃ of 8.5 nm. However, helium bubbles were not observed throughout in both doped W materials. The effects of pre-irradiation with 1.0 × 10²¹ He⁺/m² on trapping of injected deuterium in doped W was studied by thermal desorption spectrometry (TDS) technique using quadrupole mass spectrometer. Compared with the samples without He⁺ pre-irradiation, deuterium (D) retention of doped W materials increased after He⁺ irradiation, whose retention was unsaturated at the damage level of 1.0 × 10²²D₂⁺/m². The present results implied that irradiation effect of He⁺ ions must be taken into account to evaluate the deuterium retention in fusion material applications.

Improvement of Tautomycin Production in Streptomyces spiroverticillatus by Feeding Glucose and Maleic Anhydride

Xiao-Long Chen,Yu-Hua Xu,Yu-Guo Zheng,Yin-Chu Shen 한국생물공학회 2010 Biotechnology and Bioprocess Engineering Vol.15 No.6

Optimization of the feeding process for tautomycin production by Streptomyces spiroverticillatus was performed using glucose and/or maleic anhydride. The feeding of glucose was based on the reducing sugar content (lower than 8 g/L) at a cultivation time of 40 h. After addition of 2% (w/v) glucose, the biomass increased from 21 to 28 g/L, and that of tautomycin from 572.06 to 837.6mg/L. Moreover, 1723.1 mg/L of tautomycin (increased by 201.21%) was obtained by feeding 0.2% (w/v) maleic anhydride solution at a pH between 4 and 7 in the broth. For the experiments in the 15 L fermentor, tautomycin content reached its highest level (1714.7 mg/L), which was 199.7% higher than that of control by feeding both glucose and maleic anhydride.

Porous Carbon Particles Derived from Natural Peanut Shells as Lithium Ion Battery Anode and Its Electrochemical Properties

Xiao-Yu Cao,Shuangqiang Chen,왕과시우 대한금속·재료학회 2014 ELECTRONIC MATERIALS LETTERS Vol.10 No.4

Abandoned peanut shells, a common farm waste, have caused tremendous environmental pollution and huge waste deposits through burned and buried disposal approaches. In targeting to enhance the potential value of peanut shells and discover a new alternative candidate for lithium ion batteries, we adopted an easy to scale-up and highly repeated method to treat fresh and dry peanut shells via acid-treatment and pyrolysis, making porous structures on carbonized peanut shells. The pyrolysis process transformed the peanut shells to porous carbon (PC) materials in a quartz tube furnace at a series of temperatures from 500°C to 700°C in N2 under the condition of 40°C gradient temperatures with a heating rate of 2°C min−1. Scanning electron microscopy (SEM) images show that the irregular porous structures and hundreds of micropores are distributed on the PC materials. The cyclic voltammogram (CV) test and particle size analysis are employed to investigate their characteristics of voltammetry and particle size distribution. PC material obtained at 620°C (PC-620) exhibited good particle distribution, porous structure and less agglomerated particles. When applied as anode materials in lithium ion batteries, the PC-620 electrode displayed the high reversible capacity of 608 mAh g–1. Moreover, the cycling performance of PC-620 was the most stable, with a high Coulombic efficiency of 98.9% at the 20th cycle, demonstrating a reversible capacity of 418 mAh g–1, which is higher than the theoretical capacity of graphite. Most importantly, the PC materials harvested from the wastes of natural resources are turned into valuable electrode materials for the high demand energy storage devices, which can significantly reduce severe environmental pollution and alleviate an energy shortage.