Influence of Microstructure Evolution on Mechanical Properties, Wear Resistance and Corrosion Resistance of Ti(C,N)-Based Cermet Tools with Various WC Additions

L. B. Zhao,N. Lin,X. Q. Han,C. Ma,Z. Y. Wang,Y. H. He 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.8

The efects of tungsten carbide addition on the microstructure, mechanical properties and corrosion resistance of Ti(C,N)-based cermets prepared by the sinter-HIP method are investigated through scanning electron microscope, X-ray difraction,electron back scattered difraction, mechanical test and electrochemical method. The results show that the appropriate WCaddition has an important infuence on promoting the formation of core-rim microstructure of cermet, increasing the wettability of ceramic phase and binder phase, and improving the mechanical properties. Ti(C,N)-based cermet with 5 wt% WCaddition has the highest hardness of 92.4 HRA and excellent wear resistance. However, excessive WC addition causes theappearance of slight white core phase containing plenty of W and Ti element in microstructure, which increases the fracturetoughness, and reduces the hardness and wear resistance of cermet. Additionally, the electrochemical result shows that theaddition of 5 wt% WC in cermet has the optimal corrosion resistance in 1 mol/L hydrochloric acid solution.

Effect of night light regimen on growth performance, antioxidant status and health of broiler chickens from 1 to 21 days of age

R.X. Zhao,C.H. Cai,P. Wang,L. Zheng,J.S. Wang,K.X. Li,W. Liu,X.Y. Guo,X. A. Zhan,K.Y. Wang 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.6

Objective: The study was conducted to evaluate the effects of night light regimen on growth performance, antioxidant status and health of Lingnan Yellow broiler chickens from 1 to 21 days of age. Methods: A completely randomized factorial design involved 2 photoperiods (constant lighting [CL], 24 L:0 D and intermittent lighting [INL], 17 L:3 D:1 L:3 D)×2 light intensities (10 lx and 30 lx). A total of one thousand six hundred and eighty 1-d-old Lingnan Yellow broiler chicks were randomly divided into 4 treatments with 6 replicates (70 birds per replicate). The experiment lasted for 21 d. Results: Photoperiods and light intensities had no effect on average daily gain, feed conversion ratio, and mortality of the broiler chickens (p>0.05). The INL had a significant effect on average daily feed intake (p<0.05) of broiler chickens compared with CL. Photoperiod and light intensity had an interactive effect on melatonin (MT) concentration (p<0.05). At CL, reducing light intensity increased MT concentration; INL birds had higher MT but MT concentration was not affected by light intensity. There was an interactive effect on glutathione peroxidase (GPx) and catalase (CAT) in serum and total antioxidant capability (T-AOC) in liver between photoperiod and light intensity. With the decrease of light intensity, the activities of GPx and CAT in serum and T-AOC in liver increased in CL group (p<0.05). Broiler chickens reared under INL had better antioxidant status and 10 lx treatments had higher activities of CAT in serum than 30 lx (p<0.05). Different photoperiods and light intensities had no effect on malondialdehyde. There was an interaction between photoperiod and light intensity on serum creatine kinase (CK) concentration (p<0.05). At CL, the elevated light intensity resulted in an increase in CK content; INL birds had lower CK concentration especially in low light intensity group. Besides, INL and low light intensity significantly reduced the concentration of serum corticosterone and heat shock protein 70 (p<0.05). Serum immunoglobulin M contents were increased in broiler chickens reared under the INL compared with CL group (p<0.05). Conclusion: Results above suggest that the night light regimen of INL and 10 lx could be beneficial to the broiler chickens from 1 to 21 days of age due to the better health status and electricity savings.

Effects of L-tryptophan, Fructan, and Casein on Reducing Ammonia, Hydrogen Sulfide, and Skatole in Fermented Swine Manure

Q.K. Sheng,Z.J. Yang,H.B. Zhao,X.L. Wang,J.F. Guo 아세아·태평양축산학회 2015 Animal Bioscience Vol.28 No.8

The effects of daily dietary Bacillus subtilis (Bs), and adding L-tryptophan, fructan, or casein to fecal fermentation broths were investigated as means to reduce the production of noxious gas during manure fermentation caused by ammonia, hydrogen sulfide (H2S), and 3-methylindole (skatole). Eighty swine (50.0±0.5 kg) were equally apportioned to an experimental group given Bs in daily feed, or a control group without Bs. After 6 weeks, fresh manure was collected from both groups for fermentation studies using a 3×3 orthogonal array, in which tryptophan, casein, and fructan were added at various concentrations. After fermentation, the ammonia, H2S, L-tryptophan, skatole, and microflora were measured. In both groups, L-tryptophan was the principle additive increasing skatole production, with significant correlation (r = 0.9992). L-tryptophan had no effect on the production of ammonia, H2S, or skatole in animals fed Bs. In both groups, fructan was the principle additive that reduced H2S production (r = 0.9981). Fructan and Bs significantly interacted in H2S production (p = 0.014). Casein was the principle additive affecting the concentration of ammonia, only in the control group. Casein and Bs significantly interacted in ammonia production (p = 0.039). The predominant bacteria were Bacillus spp. CWBI B1434 (26%) in the control group, and Streptococcus alactolyticus AF201899 (36%) in the experimental group. In summary, daily dietary Bs reduced ammonia production during fecal fermentation. Lessening L-tryptophan and increasing fructan in the fermentation broth reduced skatole and H2S.

Effects of L-tryptophan, Fructan, and Casein on Reducing Ammonia, Hydrogen Sulfide, and Skatole in Fermented Swine Manure

Sheng, Q.K.,Yang, Z.J.,Zhao, H.B.,Wang, X.L.,Guo, J.F. Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.8

The effects of daily dietary Bacillus subtilis (Bs), and adding L-tryptophan, fructan, or casein to fecal fermentation broths were investigated as means to reduce the production of noxious gas during manure fermentation caused by ammonia, hydrogen sulfide ($H_2S$), and 3-methylindole (skatole). Eighty swine ($50.0{\pm}0.5kg$) were equally apportioned to an experimental group given Bs in daily feed, or a control group without Bs. After 6 weeks, fresh manure was collected from both groups for fermentation studies using a $3{\times}3$ orthogonal array, in which tryptophan, casein, and fructan were added at various concentrations. After fermentation, the ammonia, $H_2S$, L-tryptophan, skatole, and microflora were measured. In both groups, L-tryptophan was the principle additive increasing skatole production, with significant correlation (r = 0.9992). L-tryptophan had no effect on the production of ammonia, $H_2S$, or skatole in animals fed Bs. In both groups, fructan was the principle additive that reduced $H_2S$ production (r = 0.9981). Fructan and Bs significantly interacted in $H_2S$ production (p = 0.014). Casein was the principle additive affecting the concentration of ammonia, only in the control group. Casein and Bs significantly interacted in ammonia production (p = 0.039). The predominant bacteria were Bacillus spp. CWBI B1434 (26%) in the control group, and Streptococcus alactolyticus AF201899 (36%) in the experimental group. In summary, daily dietary Bs reduced ammonia production during fecal fermentation. Lessening L-tryptophan and increasing fructan in the fermentation broth reduced skatole and $H_2S$.

Sex-specific association of X-linked Toll-like receptor 7 (TLR7) with male systemic lupus erythematosus

Shen, N.,Fu, Q.,Deng, Y.,Qian, X.,Zhao, J.,Kaufman, K.M.,Wu, Y.L.,Yu, C.Y.,Tang, Y.,Chen, J.-Y. National Academy of Sciences 2010 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.107 No.36

Effects of Buffer Layer Annealing on ZnO Thin Films Grown by using Atomic Layer Deposition

J. Y. Leem,C. R. Kim,J. H. Heo,C. M. Shin,J. H. Park,T. M. Lee,류혁현,J. H. Chang,C. S. Son,B. C. Shin,W. J. Lee,S. T. Tan,J. L. Zhao,X. W. Sun 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.6

In this study, the effects of buffer layer annealing duration on ZnO thin films deposited by using the remote plasma atomic layer deposition (ALD) method are discussed. ZnO thin films were grown on ZnO-buffer/Si (100) and were annealed for various durations between 0.5 and 60 min. The structural and the optical properties of the ZnO thin films were investigated by using atomic force microscopy, X-ray diffraction, and photoluminescence measurements. The ZnO thin films grown on a rough ZnO buffer layer were found to have high optical quality. The results from this study possibly contribute to advances in ZnO-base LED technologies.

Clarifying the basic phase structure and magnetic behavior of directly quenched (Ce,La)2Fe14B alloys with various Ce/La ratios

X.F. Liao,L.Z. Zhao,J.S. Zhang,G. Ahmed,A.J. Khan,H.X. Zeng,H.Y. Yu,X.C. Zhong,Z.W. Liu,G.Q. Zhang 한국물리학회 2019 Current Applied Physics Vol.19 No.6

To improve the performance/cost ratio of NdFeB based permanent magnets, Ce or/and La substitutions for Nd have been suggested. To better understand the effects of these substitutions, the fundamental behavior of (Ce,La)-Fe-B alloys has to be clearly understood. Here, we reported a systematic investigation on the phase structure, microstructure, and magnetic properties of melt-spun (Ce,La)2Fe14B alloys. The results confirm that partial substitution of Ce by La can effectively enhance the hard magnetism and thermal stability of (Ce1- xLax)2Fe14B alloys, while over 80% La substitution leads to the decomposition of 2:14:1 phase. The lattice parameters a, c and the Curie temperature Tc of 2:14:1 phase increase linearly with the increasing La content. La substitution can effectively refine the grain, resulting in the enhancement of inter-grain exchange coupling. The (Ce0.7La0.3)2Fe14B alloy with a mean grain size of 25 nm exhibits high remanence, maximum energy product and intrinsic coercivity up to 0.69 T, 6.2 MGOe and 217 kA/m, respectively. The present work provides a good understanding on the melt-spun (Ce,La)-Fe-B system for further developing low cost rare earth permanent magnets.

Hyperelasticity of three-dimensional carbon nanotube sponge controlled by the stiffness of covalent junctions

Zhao, W.,Shan, C.,Elias, A.L.,Rajukumar, L.P.,O'Brien, D.J.,Terrones, M.,Wei, B.,Suhr, J.,Lu, X.L. Pergamon Press ; Elsevier Science Ltd 2015 Carbon Vol.95 No.-

To expand the applications of carbon nanotubes (CNTs) at macroscale, a heteroatom doping technique has been employed to fabricate isotropic 3-D CNT architectures by inducing elbow-like covalent junctions into multiwalled CNTs. As the junctions modify the topology of each CNT by favoring the stable bends in CNTs, junction stiffness and the consequence of junction-related morphology changes in sponge's hyperelasticity remain largely elusive. In this study, two types of 3-D multiwalled CNT sponges were fabricated by inducing boron-doped or nitrogen-doped covalent junctions into CNTs. Hyperelastic properties of the sponges were experimentally quantified as the functions of CNT morphology. A novel microstructure informed continuum constitutive law was developed specifically for such isotropic CNT sponges with junctions. Analyzing the experimental data with the new theory demonstrated that, for the first time, the effective modulus of boron-doped junctions (~100 GPa) is higher than that of nitrogen-doped junctions (~20 GPa), and the junction stiffness is a key factor in regulating the hyperelastic compressive modulus of the material. Theoretical analysis further revealed that increased number of junctions and shorter segments on each individual CNT chain would result in stronger hyperelastic 3-D CNT networks. This study has established a fundamental knowledge base to provide guidance for the future design and fabrication of 3-D CNT macrostructures.

Tl2Ba2CaCu2O8 Thin Films on MgO and Sapphire Substrates

X.J. Zhao,S.L. Yan,C. Zhang,E. Chen,L. Fang,L. Ji,Q.L. Xie,S. Li,T.G. Zhou,X. Zhang,X. Zuo,Y.G. Li 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.48 No.5I

High quality Tl2Ba2CaCu2O8(Tl-2212) films were grown on MgO and sapphire substrates with CeO2 buffer layers. The CeO2 buffer layers were prepared by using an in-situ process with RF magnetron sputtering. The Tl-2212 thin films were then fabricated in a two-step process: deposition of the Tl-containing precursor film and low-temperature post-thallination of the precursor film. The resulting Tl-2212 films showed an excellent biaxial texture. The superconducting transition temperatures, Tc’s, of the films on MgO and sapphire were 103.4 and 104.2 K, respectively. The critical current densities Jc at 77 K and zero magnetic field were as high as 2.37 × 106 A/cm2 for the film on MgO and 1.76 × 106 A/cm2 on sapphire. A surface resistance of 725 μ at 10 GHz and 77 K was obtained in the Tl-2212 film on CeO2 buffered sapphire.

Effects of Rice Straw Particle Size on Chewing Activity, Feed Intake, Rumen Fermentation and Digestion in Goats

Zhao, X.G.,Wang, M.,Tan, Z.L.,Tang, S.X.,Sun, Z.H.,Zhou, C.S.,Han, X.F. Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.9

Effects of particle size and physical effective fibre (peNDF) of rice straw in diets on chewing activities, feed intake, flow, site and extent of digestion and rumen fermentation in goats were investigated. A 4${\times}$4 Latin square design was employed using 4 mature Liuyang black goats fitted with permanent ruminal, duodenal, and terminal ileal fistulae. During each of the 4 periods, goats were offered 1 of 4 diets that were similar in nutritional content but varied in particle sizes and peNDF through alteration of the theoretical cut length of rice straw (10, 20, 40, and 80 mm, respectively). Dietary peNDF contents were determined using a sieve for particle separation above 8 mm, and were 17.4, 20.9, 22.5 and 25.4%, respectively. Results showed that increasing the particle size and peNDF significantly (p<0.05) increased the time spent on rumination and chewing activities, duodenal starch digestibility and ruminal pH, and decreased ruminal starch digestibility and $NH_{3}$-N concentration. Intake and total tract digestibility of nutrients (i.e. dry matter, organic matter, and starch) and ruminal fermentation were not affected by the dietary particle size and peNDF. Increased particle size and peNDF did not affect ruminal fibre digestibility, but had a great impact on the intestinal and total tract fibre digestibility. The study suggested that rice straw particle size or dietary peNDF was the important influential factor for chewing activity, intestinal fibre and starch digestibility, and ruminal pH, but had minimal impact on feed intake, duodenal and ileal flow, ruminal and total tract digestibility, and ruminal fermentation.