http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Microstructural Stability and Creep Performance of a Novel Low-Cost Single Crystal Superalloy
Z. H. Tan,X. G. Wang,Y. L. Du,Y. M. Li,Y. H. Yang,J. L. Liu,J. D. Liu,J. G. Li,Y. Z. Zhou,X. F. Sun 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7
The increasing pursuit of advanced aero-engines with lower ratio between the cost and performance has greatly promotedthe demanding of single crystal superalloys characterized by low cost and outstanding temperature capability. In this study,a novel low-cost single crystal superalloy was designed and the creep tests as well as micro-characterization were carried outon the experimental alloy. The results illustrated that the novel single crystal alloy exhibited an ideal microstructural stabilitywithout precipitating TCP phases, after long-term thermal exposure at the ultimate service temperature of third generationsingle crystal superalloys. Moreover, the experimental alloy with only 3 wt% Re addition demonstrated remarkable creepresistance and maintained a very low minimum creep rate at 1100 °C/137 MPa and 1120 °C/137 MPa, while the accumulationand coalescence of micro-pores had eventually led to the alloy fracture. Apart from that, the compact interfacial dislocationnetworks the 2nd γ′ phase were observed after high-temperature creep rupture, and the typical a < 010 > superdislocationswith relatively poor mobility was found at 1120 °C. At 760 °C/800 MPa, both the minimum creep velocity and entire creepstain was increased evidently, however, the ultimate creep rupture life of the alloy had still reached 200 h. The correspondingdeformation mechanism was identified as the combination of superdislocation pairs shearing and a/3 < 121 > partial dislocationcutting the γ′ phase with a SISF being generated. In general, the novel single crystal alloy characterized by remarkablemechanical properties and cost reduction possesses a great potential for future application in the advanced aircraft engines.
Masters, D.G.,Purser, D.B.,Yu, S.X.,Wang, Z.S.,Yang, R.Z.,Liu, N.,Lu, D.X.,Wu, L.H.,Ren, J.K.,Li, G.H. Asian Australasian Association of Animal Productio 1993 Animal Bioscience Vol.6 No.1
This study determined the macro-mineral levels in plants and sheep, at different times during the year, at three farms in northern China. Samples of plants, animal tissues and faeces were collected at 5 to 8 times during the year from each site. They were analysed for calcium, sodium, phosphorus, magnesium and potassium. Sodium concentrations in plants were below those recommended for optimum animal production at all sites for all or part of the year (0.01-1.66 g/kg DM). Low concentrations of sodium in faeces were measured and signs of sodium deficiency (soil ingestion) were observed on one farm. There were seasonal trends in other mineral levels in plants and animals. Plants were lowest in potassium (2.3-13.4 g/kg DM), magnesium (1.28-4.82 g/kg DM) and phosphorus (0.24-1.62 g/kg DM) in winter and spring. However, high levels of these elements were supplied in the feed supplements used at this time of the year. During the periods of rapid pasture growth, in summer and autumn, supplements of feed and salt are often not provide even though pasture concentrations of phosphorus and sodium are low. It may be at these times that sheep will be most susceptible to deficiencies of these elements.
Zhao, Z.L.,Kim, S.C.,Zhang, J.,Liu, H.F.,Lee, B.H.,Jang, E.Y.,Lee, C.W.,Cho, I.J.,An, W.G.,Yang, C.H.,Kim, Y.W.,Zhao, R.J.,Wu, Y.Y. Elsevier Science B.V., Amsterdam 2016 JOURNAL OF ACUPUNCTURE AND MERIDIAN STUDIES Vol.9 No.1
A previous study demonstrated that acupuncture at ST36 (Zu-San-Li) attenuates ethanol withdrawal (EW)-induced hyperactivation of the hypothalamic-pituitary-adrenal axis in rats. The current study investigated the involvement of hypothalamic norepinephrine (NE) in that process. Rats were intraperitoneally treated with 3 g/kg/d of ethanol or saline for 28 days. After 24 hours of EW, acupuncture was applied to rats at bilateral ST36 points or at nonacupoints (tail) for 1 minute. A high-performance liquid chromatography analysis showed that EW significantly increased both the NE and the 3-methoxy-4-hydroxy-phenylglycol (MHPG) levels in the hypothalamic paraventricular nucleus (PVN). Western blot analysis also revealed that EW markedly elevated the phosphorylation rates of tyrosine hydroxylase (TH), but spared TH protein expression in the PVN. However, acupuncture at ST36, but not at nonacupoints, greatly inhibited the increase in the hypothalamic NE, MHPG, and phosphorylation rates of TH. Additionally, postacupuncture infusion of NE into the PVN significantly attenuated the inhibitory effects of acupuncture at ST36 on the oversecretion of plasma corticosterone during EW. These results suggest that acupuncture at ST36 inhibits EW-induced hyperactivation of the hypothalamic NEergic system to produce therapeutic effects on the hypothalamic-pituitary-adrenal axis.
G. Z. YANG,H. CUI,C. X. WANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2011 NANO Vol.6 No.5
Density-controlled single-crystalline β-SiC nanotubes were successfully synthesized on a large scale by adding Zn into the system via direct thermal evaporation of C60 onto silicon wafers at 1290°C. Interestingly, no Zn elements can be detected in the final products. However, the addition of Zn power is important because without Zn, density-controlled SiC nanotubes cannot be observed in our experiment. On the basis of the results, a possible growth mechanism was proposed to illustrate the role that Zn played in the growth process. The field emission and hydrophobic performances show strong dependence on the densities of as-synthesized β-SiC nanotubes. The density-controlled β-SiC nanotubes with tunable field emission and hydrophobic properties may have potential in the future of nanotechnology.
Inbreeding and Genetic Diversity in Three Imported Swine Breeds in China Using Pedigree Data
Tang, G.Q.,Xue, J.,Lian, M.J.,Yang, R.F.,Liu, T.F.,Zeng, Z.Y.,Jiang, A.A.,Jiang, Y.Z.,Zhu, L.,Bai, L.,Wang, Z.,Li, X.W. Asian Australasian Association of Animal Productio 2013 Animal Bioscience Vol.26 No.6
The accumulation of inbreeding and the loss of genetic diversity is a potential problem in the modern swine breeds in China. Therefore, the purpose of this study was to analyze the pedigrees of Chinese Duroc (CD), Landrace (CL) and Yorkshire (CY) swine to estimate the past and current rates of inbreeding, and to identify the main causes of genetic diversity loss. Pedigree files from CD, CL and CY containing, 4529, 16,776 and 22,600 records, respectively, were analyzed. Pedigree completeness indexes of the three breeds, accounting for one generation back, were 83.72, 93.93 and 93.59%, respectively. The estimated average annual inbreeding rates for CD, CL and CY in recent three years were 0.21, 0.19 and 0.13%, respectively. The estimated average percentage of genetic diversity loss within each breed in recent three years was about 8.92, 2.19, and 3.36%, respectively. The average relative proportion of genetic diversity loss due to unequal contributions of founders in CD, CL and CY was 69.09, 57.95 and 60.57%, and due to random genetic drift was 30.91, 42.05 and 39.43%, respectively. The estimated current effective population size for CD, CL and CY was 76, 117 and 202, respectively. Therefore, CD has been found to have lost considerable genetic diversity, demanding priority for optimizing the selection and mating to control future coancestry and inbreeding. Unequal contribution of founders was a major cause of genetic diversity loss in Chinese swine breeds and random genetic drift also showed substantial impact on the loss of diversity.
Masters, D.G.,Purser, D.B.,Yu, S.X.,Wang, Z.S.,Yang, R.Z.,Liu, N.,Lu, D.X.,Wu, L.H.,Ren, J.K.,Li, G.H. Asian Australasian Association of Animal Productio 1993 Animal Bioscience Vol.6 No.1
This study determined the concentrations of micro-minerals in pastures, in feed supplements and in grazing, reproducing ewes, at different times during the year, at three farms in Northern China. Samples were collected 5 to 8 times during the year and analysed for selenium, copper, iron, molybdenum and zinc. On two farms selenium concentrations in both pastures and animal tissues were low for part of the year. The lowest concentrations in pasture (< $30{\mu}g/kg$ DM) and liver (< $100{\mu}g/kg$ wet weight) indicated that productivity of the sheep may be reduced by a deficiency of this element. On one farm copper concentrations in the lever were in the liver were in the deficient range (< $5{\mu}g/kg$ wet weight) for part of the year. It is likely that this is a result of high intakes of iron from pasture (up to 4.5 g Fe/kg DM) and soil, as indicated by high concentrations of iron in faeces (up to 7 g Fe/kg DM). Molybdenum intake is unlikely to have had much influence on copper absorption because pasture concentrations of this element were not unusually high (1 to 5 mg/kg DM). Zinc in pastures on two farms was below 10 mg/kg DM for part of the year. On one of these farms, the concentration of zinc in faeces was below 30 mg/kg DM throughout the year and this is consistent with zinc intakes of 7 to 15 mg/kg. Despite these low intakes, the concentratons of zinc in plasma were consistently above deficient levels. No clinical signs of deficiencies of any of the elements studied were observed.
Liu, L.,Yang, Z.B.,Yang, W.R.,Jiang, S.Z.,Zhang, G.G. Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.4
Alfalfa (Medicago sativa L) is a high-quality forage for ruminants and the main stem is the dominant morphological component contributing to the forage nutritive value in mature alfalfa forage. Shearing force, a fracturing property of plant stem, is an important indictor of forage value. The objectives of this study were to investigate the effects of morphological characteristic on shearing force, the relationship between shearing force and chemical composition, and the relationship between shearing force and in situ digestibility of alfalfa stem. The results showed that linear density (weight per unit length of stem) was more important than chemical composition in affecting shearing force. There was a positive relationship between lignin content and shearing force (r = 0.78). Correlations were not found between shearing force and other chemical components such as neutral detergent fiber (NDF), acid detergent fiber (ADF), cellulose and hemicelluloses. In situ digestibility (of dry matter and NDF) was related to shearing force. A negative correlation was found between shearing force and dry matter (DM) digestibility (r = -0.70), and there was also a negative correlation between shearing force and NDF digestibility (r = -0.87). When shearing force was standardized for stem diameter or stem linear density, the relationship between shearing force and digestibility was consistent regardless of stem diameter and stem linear density. Shearing force was significantly correlated with lignin content and in situ digestibility (of DM and NDF), and was a more direct indicator for estimating forage nutritive value related to animal performance, so it can be used to predict the forage value of alfalfa.
PRODUCTION FROM FINE WOOL SHEEP IN THREE AREAS IN NORTHERN CHINA
Masters, D.G.,Purser, D.B.,Yu, S.X.,Wang, Z.S.,Yang, R.Z.,Liu, N.,Wang, X.L.,Lu, D.X.,Wu, L.H.,Rong, W.H.,Ren, J.K.,Li, G.H. Asian Australasian Association of Animal Productio 1990 Animal Bioscience Vol.3 No.4
The seasonal changes in production, the systems of management and the seasonal climatic and feeding conditions are described for three farms representative of the major areas for growing fine-wool sheep in northern China. At all farms, summer and autumn were seasons of rapid liveweight gain and wool growth. In the winter and spring, during lactation, liveweight declined wool growth decreased by approximately 70%, and fibre diameter by 4 to 8 microns. The wool produced was characterized by a very low clean wool yield (39-51%). Greasy fleece weights ranged from 4.5 to 8.0 kg and average diameter of wool fibres from 20.5 to 23 microns. The number of lambs born per 100 ewes mated ranged from 79 to 95, lamb weights ranged from 3.8 to 4.5 kg, and weaning weights ranged from 17 to 25 kg. Overall, the patterns of sheep production were similar to those found in seasonally arid environments (such as in the mediterranean climatic zone). Yield of clean wool and therefore clean fleece weights were far below those in most other fine-wool producing areas of the world.