Enhancement of Impurity, Machinability and Mechanical Properties in Te-Treated 0Cr18Ni9 Steel

Jian‑bo Xie,Tian Fan,Han Sun,Zhi‑qi Zeng,Jian‑xun Fu 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.6

To enhance the machinability and mechanical properties of 0Cr18Ni9 steel, free-machining element Te was introduced inthis work. By adding various quantities of Te to steel, several machining and tensile tests were carried out. Results show thatwith Te addition of 530 ppm, the number of inclusion sizes below 1 μm disappeared. With raising Te from 360 to 530 ppm,more MnTe–MnS inclusions of 10–40 μm were in spherical shape; above 50 μm2, the ratio of inclusion area at 530 ppmwas greatest among all, and the large-sized inclusions occupied a larger share. Te addition contributed to the surfaces ofmachining steels more smooth. The ultimate tensile strength of steel increased from 399 to 435 MPa. Te resulted in growthof sulfides and improved the machinability of steel.

Distribution of Bi–MnS Inclusions Existing in 1215MS Steels: Correlation with Thermal Physical Coefficient

Jian‑bo Xie,Bei‑bei Liu,Xiang‑yu Wu,Jian‑xun Fu 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.5

This work aims to comprehensively summarize the types and distribution of the isolated Bi particles and MnS inclusions inthe Bi-bearing steels, to study the precipitated behavior of sulfide, and to study the effect of Bi particles on grain sizes andthe volume thermal expansion coefficients of the steels. Results show that the average percentage of the isolated Bi particles,semi-encapsulation, complete encapsulation, back-bridge, tiny encapsulation, cavity bridge Bi–MnS inclusions in the Bibearingsteels was 16.89%, 20.49%, 3.44%, 16.89%, 31.63%, 10.66%, respectively. The average equivalent diameters of thegrains in the 0 ppm, 130 ppm, 240 ppm, 760 ppm, 1200 ppm and 2300 ppm Bi content steels were 20.88, 20.17, 19.54, 18.13,13.98 and 13.25 μm, respectively. The precipitated equilibrium mass concentration product of the MnS (w[Mn]·w[S]) wascalculated to be 1.07, and the solid fraction fS value was 0.61. At 950 °C, the volume thermal expansion coefficient change(ΔVE) in 760 ppm Bi content steel was minimum 4 × 10–10%, while at 461.6 °C the ΔVE was maximum, 0.09%, which meansthat Bi affected the volume thermal expansion of the steel strongest in this temperature range.

Life history responses of the cabbage beetle Colaphellus bowringi to temperature change

Jian‐Jun Tang,Hai-Min HE,Ting GENG,Shu FU,Fang-Sen XUE 한국곤충학회 2016 Entomological Research Vol.46 No.6

Temperature is considered one of the most important mediators of phenotypic plasticity in ectotherms. Here, we investigated life history traits of the cabbage beetle, Colaphellus bowringi Baly (Coleoptera: Chrysomelidae), at a wide range of temperatures (16, 19, 22, 24, 26 and 28°C). The larval and pupal times were significantly decreased with increasing rearing temperature and growth rate was positively correlated with temperature. However, the relationship between body size and rearing temperature in C. bowringi did not follow the temperature–size rule; both males and females reached the highest body weight at 19°C. Females were significantly larger than males at all temperatures. Male pupae lost significantly more weight at metamorphosis compared to females. However, diapausing males gained significantly higher weight after feeding compared to diapausing females at higher temperatures of 22, 24, 26 and 28°C. Body weight tended to decrease with increasing rearing temperature, whereas sexual size dimorphism (SSD) tended to increase with increasing rearing temperature; thus, Rensch's rule is upheld. The degree to which SSD changed with temperature varied with different development stages. SSD was lowest in pupae, highest in newly emerged adults and intermediate in diapausing adults.

DNA methylation and mRNA expression of COL6A3 in antler mesenchyme of female and male reindeer

Jian‑Cheng Zhai,Ruo‑Bing Han,Sheng‑Nan Wang,Qiang‑Hui Wang,Yan‑Ling Xia,Wei‑Shi Liu,Ya‑Jie Yin,He‑Ping Li 한국유전학회 2019 Genes & Genomics Vol.41 No.9

Backgroud Reindeer is the only deer species that both male and female produce antlers, which provides a particularly interesting case in studying the differences between antlers of the two sexes. Alpha 3(VI) Collagen Gene (COL6A3), forms a microfibrillar network associated with the structural integrity and biomechanical properties, has been found to be one of the differentially expressed genes in antler mesenchyme of female and male reindeer. Objective and Methods The promoter sequence of reindeer COL6A3 gene was obtained using the cloning technology and analyzed by the bioinformatics methods. Bisulfite sequencing PCR (BSP) was used to detect the methylation status of the COL6A3 promoter in reindeer antler mesenchyme. Real-time quantitative PCR was used to detect COL6A3 expression in the antler mesenchyme of female and male reindeer. Results Sequence analysis revealed that the reindeer COL6A3 partial promoter sequence was 983 bp including the possible promoter region at + 105 bp to + 155 bp. Homology and phylogenetic analysis indicated that the COL6A3 promoter of reindeer had the closest genetic distance with Bos taurus, Capra hircus and Ovis aries. BSP results indicated that the methylation level of COL6A3 promoter in the female reindeer antler mesenchyme was significantly higher than in the male. Correlating with increased methylation status, we also found that COL6A3 mRNA expression in female reindeer antler mesenchyme was significantly lower than in the male. Conclusion The higher methylation level of the COL6A3 gene in female reindeer antler mesenchyme coincides with decreased COL6A3 mRNA expression, thereby affecting the transposon silencing mechanism and possibly contributing to apparent differences of antlers in female and male reindeer.

Department of Bioengineering

Jian?He Xu 한국생물공학회 2010 한국생물공학회 학술대회 Vol.2010 No.10

長安三階敎寺院與終南山三階敎聖地

李健超 漢陽大學校 民族學硏究所 1994 民族과文化 Vol.2 No.-

韓國學者李수光《芝峰類說》中解杜諸條擧隅析評

광건행 順天鄕大學校 人文科學硏究所 1998 순천향 인문과학논총 Vol.6 No.-

Research on the Strategy of Improving Tourist Satisfaction in the Zushan Scenic Area of Qinhuangdao

Jian Lu(Jian Lu) The International Academy of Global Business and T 2024 Journal of Global Business and Trade Vol.20 No.2

Purpose - With the booming development of the tourism industry, competition among tourist attractions is becoming increasingly fierce. For scenic spots, the level of tourist satisfaction directly affects the popularity of the scenic spot and the economic benefits it can generate. Therefore, improving tourist satisfaction in scenic areas is the key to their development. Design/Methodology/Approach - This article adopts a research method tailored to local conditions. With a full understanding of relevant theories and the Zushan Tourist Scenic Area, domestic and foreign literature and relevant cases are used as references. Findings - Using IPA analysis method to analyze the current situation of tourist satisfaction in Zushan Scenic Area, obtain real and effective data, analyze and propose relevant marketing problems based on this, and finally propose corresponding optimization strategies for this series of marketing problems. Research Implications - Based on theory and practice, this paper reviews and analyzes the existing domestic and foreign literature, which not only enriches the existing research literature, but also provides some enlightenment for future related research. The IPA model and questionnaire survey were used to study the tourist satisfaction in the Zushan Scenic Area of Qinhuangdao. It is of practical significance to have an indepth understanding of the factors affecting tourist satisfaction in the tourism process of Qinhuangdao Zushan Scenic Area, to explore its advantages and disadvantages, and to put forward effective countermeasures and strategies to promote tourism development, so as to improve the tourist satisfaction and tourism market competitiveness of the scenic spot.

Research on the Influencing Factors and Transformation Path of Logistics Enterprise Low-Carbon Performance

Jian Li(Jian Li),Seung-Lin Hong(Seung-Lin Hong) The International Academy of Global Business and T 2023 The International Academy of Global Business and T Vol.19 No.1

Purpose - This study expounds that logistics enterprises should make use of an information-sharing mechanism, benefit distribution mechanism, and government guarantee mechanism to optimize and balance resource allocation with cooperative participants. Design/Methodology/Approach - This study developed a theoretical research model with interface management analysis, interface resource allocation, and interface management measures as independent variables; an interface connection mechanism and collaborative innovation capability as intermediary variables; and the low-carbon performance of enterprises as a dependent variable based on the structural equation model (SEM) and the empirical test, by selecting a certain number of logistics enterprises nationwide as research objects. Findings - This study discloses that elements such as interface management analysis, interface resource allocation, interface management measures, interface connection mechanism, and collaborative innovation capability contribute proportionally to the low-carbon performance of logistics enterprises. Meanwhile, the interface connection mechanism plays an intermediary role in the impact of interface management analysis and interface management measures on the low-carbon performance of enterprises. Research Implications - This study proposes that the collaborative innovation capability of enterprises should be improved through various interface management measures, and that R&D and the application of low-carbon technology and equipment must be accelerated, thus promoting the improvement of the low-carbon performance of enterprises, and enabling a low-carbon transformation in logistics enterprises, and even the whole logistics industry, so as to help achieve the carbon peak and move toward carbon neutrality as soon as possible.

Disruption of ecdysis in Leptinotarsa decemlineata by knockdown of chitin deacetylase 1

Jian-Jian Wu,Li-Li Mu,Zhong-Chao Chen,Kai-Yun Fu,Wen-Chao Guo,Chao Li,Guo-Qing Li 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.2

Chitin deacetylases (CDAs) catalyze N-deacetylation of chitin, a crucial process for chitin modification. In the present paper, LdCDA1 was identified in Leptinotarsa decemlineata. It was copiously expressed in larval foregut, hindgut and epidermis. Just before the molt in the first, second and third larval instars, the mRNA levels of LdCDA1 were high. In the fourth (final)-instar larvae, a peak occurred 4 days after ecdysis. In vivo results revealed that LdCDA1 transcriptionally responded, positively and negatively respectively, to 20-hydroxyecdysone and juvenile hormone titers. Moreover, knockdown of LdCDA1 significantly reduced foliage consumption, lengthened developing period and prevented growth in the final instar larvae. Three distinct lethal phenotypes were noted in the LdCDA1 RNAi larvae. About 30% of the RNAi larvae became moribund and finally died; approximately 50% of deformed pupae died as pharate adults; and around 20% of LdCDA1 depleted pupae finally emerged as abnormal adults and eventually died within 1 week after emergence. Furthermore, chitin content was low and the mRNA levels of five chitin biosynthesis transcripts (LdUAP1, LdUAP2, LdChSAa, LdChSAb and LdChSB) were significantly declined in the LdCDA1 RNAi larvae. In addition, glucose, trehalose and glycogen contents were increased in the LdCDA1 depleted hypomorphs, along with highly expressed genes coding for trehalose and glycogen synthesis enzymes. The findings provide a compelling piece of evidence that CDA1 is critical for chitin deposition in L. decemlineata. Moreover, LdCDA1 may be a potential target for control of the larvae.