The dielectric and electrical modulus properties of Ba(Al0.5Nb0.5)xTi1-xO3 ceramics

R.F. Niu,D.P. Wang,Z.H. Huang,W.T. Wang 한양대학교 청정에너지연구소 2024 Journal of Ceramic Processing Research Vol.25 No.2

In this work, a series of BaTiO3-based ceramic materials, Ba(Al0.5Nb0.5)xTi1-xO3 (x = 0, 0.04, 0.06, 0.08), was synthesized usinga standard solid-state reaction technique. In the temperature range of 100~380 K, the frequency-dependent dielectric andelectrical modulus properties were studied. A colossal dielectric permittivity (>1.5×104) and low dielectric loss (< 0.01) weredemonstrated at the optimal doping concentration x = 0.04. The observed dielectric behavior of Ba(Al0.5Nb0.5)xTi1-xO3 ceramicscan be attributed to the Universal Dielectric Response. The complex electrical modulus spectra indicate a significant decreasein capacitance and permittivity of the grains with increasing co-doping concentration. Our results provide insight into the roleof donor and acceptor co-doping on the properties of BaTiO3-based ceramics, which is important for their use in dielectric andenergy storage applications.

Structure and Magnetic Properties of Cr₂O₃/CrO₂ Nanoparticles Prepared by Reactive Laser Ablation and Oxidation under High Pressure of Oxygen

P. Z. Si,X. L. Wang,X. F. Xiao,H. J. Chen,X. Y. Liu,L. Jiang,J. J. Liu,Z. W. Jiao,H. L. Ge 한국자기학회 2015 Journal of Magnetics Vol.20 No.3

Cr₂O₃ nanoparticles were prepared via one-step reactive laser ablation of Cr in oxygen. The metastable CrO₂ phase was obtained through the subsequent oxidation of Cr₂O₃ nanoparticles under O₂ with gas pressures of up to 40 MPa. The as-prepared Cr₂O₃ nanoparticles are spherical or rectangular in shape with sizes ranging from 20 nm to 50 nm. High oxygen pressure annealing is effective in producing meta-stable CrO₂ from as-dried Cr₂O₃ nanoparticles, and the Cr₂O₃ nanoparticles exhibit a weak ferromagnetic behavior with an exchange bias of up to 11 mT that can be ascribed to the interfacial exchange coupling between uncompensated surface spins and the antiferromagnetic core. The Cr₂O₃/CrO₂ nanoparticles exhibit an enhanced saturation magnetization and a reduced exchange bias with an increasing faction of CrO₂ due to the elimination of uncompensated surface spins over the Cr₂O₃ nanoparticles when exposed to a high pressure of O₂ and/or possible phase segregation that results in a smaller grain size for both Cr₂O₃ and CrO₂.

THE TAOS PROJECT: RESULTS FROM SEVEN YEARS OF SURVEY DATA

Zhang, Z.-W.,Lehner, M. J.,Wang, J.-H.,Wen, C.-Y.,Wang, S.-Y.,King, S.-K.,Granados, Á,. P.,Alcock, C.,Axelrod, T.,Bianco, F. B.,Byun, Y.-I.,Chen, W. P.,Coehlo, N. K.,Cook, K. H.,de Pater, I.,Kim American Institute of Physics 2013 The Astronomical journal Vol.146 No.1

<P>The Taiwanese-American Occultation Survey (TAOS) aims to detect serendipitous occultations of stars by small (~1 km diameter) objects in the Kuiper Belt and beyond. Such events are very rare (<10<SUP>–3</SUP> events per star per year) and short in duration (~200 ms), so many stars must be monitored at a high readout cadence. TAOS monitors typically ~500 stars simultaneously at a 5 Hz readout cadence with four telescopes located at Lulin Observatory in central Taiwan. In this paper, we report the results of the search for small Kuiper Belt objects (KBOs) in seven years of data. No occultation events were found, resulting in a 95% c.l. upper limit on the slope of the faint end of the KBO size distribution of q = 3.34-3.82, depending on the surface density at the break in the size distribution at a diameter of about 90 km.</P>

Effects of Arsenic (As^III) on Lipid Peroxidation, Glutathione Content and Antioxidant Enzymes in Growing Pigs

Wang, L.,Xu, Z.R.,Jia, X.Y.,Jiang, J.F.,Han, X.Y. Asian Australasian Association of Animal Productio 2006 Animal Bioscience Vol.19 No.5

This experiment was conducted to investigate the effect of arsenic ($As^{III}$) on lipid peroxidation, glutathione content and antioxidant enzymes in growing pigs. Ninety-six Duroc-Landrace-Yorkshire crossbred growing pigs (48 barrows and 48 gilts, respectively) were randomly assigned to four groups and each group was randomly assigned to three pens (four barrows and four gilts). The four groups received the same corn-soybean basal diet which was supplemented with 0, 10, 20, 30 mg/kg As respectively. Arsenic was added to the diet in the form of $As_2O_3$. The experiment lasted for seventy-eight days after a seven-day adaptation period. Malondialdehyde (MDA) levels, glutathione (GSH) contents and superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST) activities were analyzed in serum, livers and kidneys of pigs. The results showed that pigs treated with 30 mg As/kg diet had a decreased average daily gain (ADG) (p<0.05) and an increased feed/gain ratio (F/G) (p<0.05) compared to the controls. The levels of MDA significantly increased (p<0.05), and the contents of GSH and the activities of SOD, CAT, GPx, GR and GST significantly decreased (p<0.05) in the pigs fed 30 mg As/kg diet. The results indicated that the mechanism of arsenic-induced oxidative stress in growing pigs involved lipid peroxidation, depletion of glutathione and decreased activities of some enzymes, such as SOD, CAT, GPx, GR and GST, which are associated with free radical metabolism.

On the fatigue performance of Aluminum alloy 2024 scarfed lap joints

Yan, W.Z.,Gao, H.S.,Yuan, X.,Wang, F.S.,Yue, Z.F. Techno-Press 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.44 No.1

A series of fatigue test were carried out on scarfed lap joints (SLJ) using in airfoil siding to explore the effect of structural details, such as rows of rivets, lap angles, on its fatigue performance. Finite element (FE) analysis was employed to explore the effect of lap angle on load transfer and the stress evolution around the rivet hole. At last, the fatigue lives were predicted by nominal stress approach and critical plane approach. Both of the test results and predicted results showed that fatigue life of SLJ was remarkably increased after introducing lap angle into the faying surface. Specimen with the lap angle of $1.68^{\circ}$ exhibits the best fatigue performance in the present study.

Some Factors Affecting Freezing of Boar Semen in 5 ml Maxi-straws

Dai, J.J.,Wu, C.F.,Zhang, Defu,Yin, F.Z.,Zhang, T.Y.,Liu, D.,Wu, H.L.,Li, L.L.,Yang, S.T.,Wang, L. Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.4

A series of experiments were conducted to determine the suitable freezing and thawing temperatures for the freezing of boar semen in 5 ml maxi-straws. The ultrastructure, in vitro fertilization (IVF) and artificial insemination (AI) of frozen-thawed semen were also be evaluated. The 5 cm freezing height gave the best results not only in post-thaw motility rate (54.00%), but also in normal acrosome morphology rate (NAR) (80.23%). There was no significant difference in the post-thaw motility between different thawing temperatures and corresponding thawing times (p>0.05); the group of $52^{\circ}C$ and 25 s gave the highest motility rate (45.00%). As a whole, not only from the motility but also the NAR, thawing at $42^{\circ}C$ was better than the other two treatments. In the freezing packages, 5 ml maxi-straw gave a little lower mobility (40%), viability rate (49.58%), plasma membrane integrity rate (53.91%) and NAR (52.65%) than the 0.25 ml straw, but there was no significant difference between the two straw volumes (p>0.05). The IVF capacity of frozen-thawed semen in this experiment was similar to fresh semen. From ultrastructure observation, the main damage to boar spermatozoa after freezing was seen in the acrosome, such as swelling and formation of vesicles. After AI in recipient Shanghai White sows, frozen-thawed semen from 5 ml maxi-straws and pellets produced 72.2% and 80% conception rate and 7.8 and 8 litter sizes, respectively, and there was no significant difference between the 5 ml maxi-straw and the pellet (p>0.05).

The Additivity of True or Apparent Phosphorus Digestibility Values in Some Feed Ingredients for Growing Pigs

Fang, R.J.,Li, T.J.,Yin, F.G.,Yin, Y.L.,Kong, X.F.,Wang, K.N.,Yuan, Z.,Wu, G.Y.,He, J.H.,Deng, Z.Y.,Fan, M.Z. Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.7

Two experiments were conducted to determine the additivity of apparent or true digestibility of phosphorus (P) in soybean meal (SBM), peas, faba beans, corn, oats, broken rice meal, rough rice meal, buckwheat, and sorghum for growing pigs. Chromic oxide (0.3%) was used as a digestion marker in both experiments. Each experiment lasted for 12 d, which consisted of a 7-d dietary adaptation period followed by a 5-d fecal collection period. Experiment 1 involved 6 diets: the SBM-based control diet; 4 diets with corn, oats, rough rice meal and broken rice meal substituted for SBM; and an additional diet with a representative mixture of the 5 ingredients. In Experiment 2, 6 diets were prepared similarly, except that the tested ingredients besides SBM were faba beans, peas, buckwheat, and sorghum. In each experiment, six barrows with an initial average individual BW of 20.5 kg were fed one of the six diets according to a $6{\times}6$ Latin square design. The apparent and true P digestibility values for the nine tested ingredients were determined by the substitution method. There were no differences (p>0.05) between the determined and the predicted true P digestibility values for the mixture of ingredients in Experiments 1 and 2. However, the determined and the predicted apparent P digestibility values for the mixture of ingredients differed (p = 0.059) in Experiment 1, but not in Experiment 2. These results indicate that true P digestibility values are additive in ingredients containing low levels of phytate phosphorus and anti-nutritional factors, whereas the apparent P digestibility values are not always additive in single feed ingredients for growing pigs.

Effects of Sown Season and Maturity Stage on In vitro Fermentation and In sacco Degradation Characteristics of New Variety Maize Stover

Tang, S.X.,Li, F.W.,Gan, J.,Wang, M.,Zhou, C.S.,Sun, Z.H.,Han, X.F.,Tan, Z.L. Asian Australasian Association of Animal Productio 2011 Animal Bioscience Vol.24 No.6

The effects of seedtime and maturity stage on nutritive value of five maize stover varieties, including conventional maize (Kexiangyu 11, CM), fodder maize (Huqing 1, FM), high oil maize (Gaoyou 115, HOM), sweet maize (Kexiangtianyu 1, SM) and waxy maize (Kexiangluoyu 1, WM), were examined based on chemical composition, in vitro gas production and in situ incubation techniques. Maize stover was sampled at d 17 and d 30 after tasseling, and designated as maturity stage 1 and stage 2, respectively. The average dry matter (DM) organic matter (OM), crude protein (CP) and fiber contents were the greatest for HOM, SM and FM, respectively. CM had the highest in vitro organic matter disappearance (IVOMD) and volatile fatty acid (VFA) concentration. The highest ammonia nitrogen ($NH_3$-N) concentration in the incubation solution, and effective degradability of DM ($ED_{DM}$) and neutral detergent fiber ($ED_{NDF}$) were observed in SM. Advanced maturity stage increased (p<0.05) DM content, $ED_{DM}$ and $ED_{NDF}$, but decreased (p<0.05) OM and CP contents, and decreased (p<0.05) b and a+b values, IVOMD and molar proportion of valerate in the incubation solution for maize stover. Maize sown in summer had greater (p<0.05) OM content, but lower DM, CP, neutral detergent fiber (NDF) and acid detergent fiber (ADF) content compared with maize sown in spring. Maize sown in summer had greater (p<0.001) IVOMD, $NH_3$-N concentration in the incubation solution and $ED_{NDF}$, but lower (p<0.01) ratio of acetate to propionate compared to maize sown in spring. The interaction effect of variety${\times}$seedtime was observed running through almost all chemical composition, in vitro gas production parameters and in situ DM and NDF degradability. The overall results suggested that SM had the highest nutrient quality, and also indicated the possibility of selecting maize variety and seedtime for the utilization of maize stover in ruminants.

Association between Polymorphisms of MSTN and MYF5 Genes and Growth Traits in Three Chinese Cattle Breeds

Zhang, R.F.,Chen, H.,Lei, C.Z.,Zhang, C.L.,Lan, X.Y.,Zhang, Y.D.,Zhang, H.J.,Bao, B.,Niu, H.,Wang, X.Z. Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.12

The objective of this study was to assess the association of polymorphisms in MSTN and MYF5 genes with growth traits in three Chinese cattle breeds. Only one homozygous animal with BB genotype at MSTN locus was observed in Jiaxian population which was at Hardy-Weinberg disequilibrium (p<0.05). The frequencies of allele A at MSTN locus and allele B at MYF5 locus in the three Chinese breeds were 0.9550/0.9730/0.9720 and 0.8275/0.7581/0.7523, respectively. Allele A at MSTN locus and allele B at MYF5 locus were dominant in these three populations. No statistically significant differences in growth traits were observed between the genotypes of the Jiaxian breed at MSTN and MYF5 loci and the Nanyang breed at MYF5 locus. However, there were statistically significant differences between the genotypes at MSTN locus of the Nanyang breed for WH, HG, HGI and HGBLR (p<0.05), and of the Qinchuan breed for BLI (p<0.05). The SNP in MYF5 had significant effects on WH and HHC of Qinchuan animals (p<0.05). These results suggest that MSTN and MYF5 are strong candidate genes that influence growth traits in cattle. Other SNPs of MSTN and MYF5 or other linked genes should also be studied, which could lead to the development of selection plans to improve the performance of Chinese cattle and also promote the breeding of genuine beef cattle in China.

100KW DC Arc Plasma of CVD System for Low Cost Large Area Diamond Film Deposition

Lu, F.X.,Zhong, G.F.,Fu, Y.L.,Wang, J.J.,Tang, W.Z.,Li, G.H.,Lo, T.L.,Zhang, Y.G.,Zang, J.M.,Pan, C.H.,Tang, C.X.,Lu, Y.P. The Korean Ceramic Society 1996 The Korean journal of ceramics Vol.2 No.4

In the present paper, a new type of DC arc plasma torch is disclosed. The principles of the new magnetic and fluid dynamic controlled large orifice long discharge tunnel plasma torch is discussed. Two series of DC Plasma Jet diamond film deposition equipment have been developed. The 20kW Jet equipped with a $\Phi$70 mm orifice torch is capable of deposition diamond films at a growth rate as high as 40$\mu\textrm{m}$/h over a substrate area of $\Phi$65 mm. The 100kW high power Jet which is newly developed based on the experience of the low power model is equipped with a $\Phi$120 mm orifice torch, and is capable of depositing diamond films over a substrate area of $\Phi$110 mm at growth rate as high as 40 $\mu\textrm{m}$/h, and can be operated at gas recycling mode, which allows 95% of the gases be recycled. It is demonstrated that the new type DC plasma torch can be easily scaled up to even higher power Jet. It is estimated that even by the 100kW Jet, the cost for tool grade diamond films can be as low as less than $4/carat.