Phase formations and tunable red luminescence of Na₂CaMg_1−<i>x</i>Mn_<i>x</i>(PO₄)₂ (<i>x</i> = 0.05–1.0)

Lü,, Juan,Du, Fuping,Zhu, Rui,Huang, Yanlin,Seo, Hyo Jin Royal Society of Chemistry 2011 Journal of materials chemistry Vol.21 No.41

<P>Mn<SUP>2+</SUP>-doped phosphates Na<SUB>2</SUB>CaMg<SUB>1−<I>x</I></SUB>Mn<SUB><I>x</I></SUB>(PO<SUB>4</SUB>)<SUB>2</SUB> (<I>x</I> = 0.05–1.0) were prepared by conventional solid-state reaction. X-ray powder diffraction (XRD), the emission and excitation spectra, and decay measurements were employed to characterize the synthesized phosphors. The XRD patterns show that Na<SUB>2</SUB>CaMg<SUB>1−<I>x</I></SUB>Mn<SUB><I>x</I></SUB>(PO<SUB>4</SUB>)<SUB>2</SUB> (<I>x</I> = 0.05–0.3) forms the single low temperature monoclinic phase α-Na<SUB>2</SUB>CaMg(PO<SUB>4</SUB>)<SUB>2</SUB> with the crystal group of <I>P</I>2<SUB>1</SUB>/<I>c</I> (No.14). The heavily Mn<SUP>2+</SUP>-doped Na<SUB>2</SUB>CaMg<SUB>1−<I>x</I></SUB>Mn<SUB><I>x</I></SUB>(PO<SUB>4</SUB>)<SUB>2</SUB> (<I>x</I> = 0.6–1.0) crystallizes in the single high-temperature trigonal phase of β-Na<SUB>2</SUB>CaMg(PO<SUB>4</SUB>)<SUB>2</SUB> with space-group <I>P</I>3̄<I>m</I>1 (No. 164). The members with <I>x</I> = 0.3–0.5 form a series of solid solutions containing two distinct phases, α- and β-Na<SUB>2</SUB>CaMg(PO<SUB>4</SUB>)<SUB>2</SUB>. The dependence of luminescence spectra on the Mn<SUP>2+</SUP>-doping concentration in Na<SUB>2</SUB>CaMg<SUB>1−<I>x</I></SUB>Mn<SUB><I>x</I></SUB>(PO<SUB>4</SUB>)<SUB>2</SUB> (<I>x</I> = 0.05–1.0) was investigated. The great red-shift of Mn<SUP>2+</SUP> emission with increasing Mn<SUP>2+</SUP>-concentration in Na<SUB>2</SUB>CaMg(PO<SUB>4</SUB>)<SUB>2</SUB> were observed. The results are discussed in relation with the detailed crystal structure and the spectral analyses. The CIE coordinates and the luminescence decay (lifetimes) of Mn<SUP>2+</SUP> ions were discussed in order to further investigate the potential applications.</P> <P>Graphic Abstract</P><P>Na<SUB>2</SUB>CaMg<SUB>1−<I>x</I></SUB>Mn<SUB><I>x</I></SUB>(PO<SUB>4</SUB>)<SUB>2</SUB> demonstrates the low-temperature monoclinic α-phase to the high-temperature trigonal β-phase transition and the red-shift of luminescence wavelength with increasing Mn<SUP>2+</SUP>-doping (<I>x</I> = 0.05–1.0). <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1jm12854j'> </P>

AN INVESTIGATION OF IMMUNIZATION AGAINST SOMATOSTATIN BY MEASURING ANTIBODY TITRES, SOMATOSTATIN AND SOMATOTROPIN PROFILES IN GILTS

Du, Z.L.,Hacker, R.R. Asian Australasian Association of Animal Productio 1993 Animal Bioscience Vol.6 No.2

The effect of active immunization against porcine somatostatin (SRIF-14) on somatostation and somatotropin secretion profile in 18 gilts was investigated. Gilts were assigned to the following treatments: control (sham injection, n = 6); bovine serum albumin (BSA) (injection of BSA with bacterial protein adjuvant, n = 6); SRIF (injection of BSA-SRIF-14 conjugate with bacterial protein adjuvant n = 6). Serum SRIF and pST were assayed from the blood samples taken on day 7 after the last immunization injection. Anti-SRIF antibody titres were assayed in weekly samples two weeks after the initial immunization to one week after the last immunization. Results revealed that the immunization protocol used in the present investigation failed to produce antibodies capable of neutralizing endogenous somatostatin. In addition, the porcine somatotropin assay revealed no significant differences in baseline pST concentration, mean peak amplitude and number of peaks during a 24 h secretory period among SRIF, BSA and control treatment. There were also no differences in SRIF baseline concentration, peak amplitude, and number of peaks during a 24 h secretory period among any of the three treatments. Circulating concentrations of pST and pSRIF were highly correlated (r = -0.09). Furthermore, anti-SRIF antibody titre was not detected in the serum of the gilts actively immunized against SRIF. These data, collectively, suggest that the protocol employed in the present investigation for active immunization against SRIF is not an effective method for changing SRIF and pST secretion profiles of the gilt and thus to enhance performance.

AN INVESTIGATION OF IMMUNIZATION AGAINST SOMATOSTATIN BY MEASURING GROWTH AND CARCASS PARAMETERS IN GILTS

Du, Z.L.,Hacker, R.R. Asian Australasian Association of Animal Productio 1992 Animal Bioscience Vol.5 No.4

To investigate the effects of immunization against somatostatin (SRIF) on growth rate, feed efficiency and carcass quality; forth-eight Yorkshire gilts ($age=37.5{\pm}4.3d,\;wt=8.2{\pm}1.6kg$) were randomly assigned to one of the following three treatments (1) control, (2) bovine serum albumin (BSA) and (3) SRIF. Cyclic SRIF was conjugated to BSA as the antigen containing 1 mg of SRIF diluted in 3 ml of saline. The conjugate was injected subsutaneously together with bacterial cell protein (BP) adjuvant on both sides of the neck of each gilt as the initial injection with three subsequent booster injections. Throughout the experiment all pigs were fed ad libitum a corn-soy diet containing 20% protein. Body weight and feed intake were measured on a weekly basis. All pigs in the experiment were slaughtered when they approached 101 kg body weight on the weekly weigh day. After slaughter, carcass parameters were analyzed to assess carcass quality. Results revealed that there were no differences among SRIF, BSA and control treatments for average daily gain, feed efficiency and feed intake during the first 5 wk of the experiment and from 6 wk to slaughter. The results for carcass analysis indicated that active immunization against SRIF had no effect on fat content, lean yield, water content and Canadian carcass index These data, collectively, suggest that the protocol employed in the present investigation for active immunization against SRIF is not an effective method for the enhancement of pig growth and improvement of feed efficiency and carcass quality.

Research on air diversion channel of air-cooled gasoline engine cylinder head and simulation of fluid- solid coupling heat transfer

Du B. C.,Tang G. Z.,Zhang L.,Zhong L.,Deng T.,Yi Y. L. 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.11

In view of the problem that local temperature of the original cylinder head is on the high side, an innovative cooling air diversion channel is proposed. The cooling air diversion channel introduces cool air into the cylinder head to forcedly cool the cylinder head. Furthermore, the multiple guide plates are set to reasonably distribute cold air in the air diversion channel. In addition, appropriately increase the length of the fins to cooling the whole cylinder head. The fluid-solid coupling three-dimensional simulation technology is adopted to analyze the impact of the new air diversion channel on the heat dissipation of cylinder head. Finally, the optimal scheme is defined to fabricate the prototype. Simulations results show that the above improvements make the temperature in the high temperature region effectively decrease, and the cooling performance of whole cylinder head is enhanced. In the optimal improvement scheme, the highest temperature of cylinder head decrease by 23 K. Furthermore, the prototype was fabricated according to the optimal scheme. The experimental results show that the temperature of the improved cylinder head decreased effectively, and the highest temperature decreased by 20.4 K. The simulation results are in agreement with the experimental results, and the maximum error is less than 5 percent.

Optimal Design for Marker-assisted Gene Pyramiding in Cross Population

Xu, L.Y.,Zhao, F.P.,Sheng, X.H.,Ren, H.X.,Zhang, L.,Wei, C.H.,Du, L.X. Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.6

Marker-assisted gene pyramiding aims to produce individuals with superior economic traits according to the optimal breeding scheme which involves selecting a series of favorite target alleles after cross of base populations and pyramiding them into a single genotype. Inspired by the science of evolutionary computation, we used the metaphor of hill-climbing to model the dynamic behavior of gene pyramiding. In consideration of the traditional cross program of animals along with the features of animal segregating populations, four types of cross programs and two types of selection strategies for gene pyramiding are performed from a practical perspective. Two population cross for pyramiding two genes (denoted II), three population cascading cross for pyramiding three genes(denoted III), four population symmetry (denoted IIII-S) and cascading cross for pyramiding four genes (denoted IIII-C), and various schemes (denoted cross program-A-E) are designed for each cross program given different levels of initial favorite allele frequencies, base population sizes and trait heritabilities. The process of gene pyramiding breeding for various schemes are simulated and compared based on the population hamming distance, average superior genotype frequencies and average phenotypic values. By simulation, the results show that the larger base population size and the higher the initial favorite allele frequency the higher the efficiency of gene pyramiding. Parents cross order is shown to be the most important factor in a cascading cross, but has no significant influence on the symmetric cross. The results also show that genotypic selection strategy is superior to phenotypic selection in accelerating gene pyramiding. Moreover, the method and corresponding software was used to compare different cross schemes and selection strategies.

Thermoelectric performance of quaternary Mg2(1+x)Si0.2Ge0.1Sn0.7 (0.06 ≤ x ≤ 0.12) solid solutions with band convergence

Z.L. Du,H.L. Gao,J.L. Cui 한국물리학회 2015 Current Applied Physics Vol.15 No.7

The study of Mg2Si based thermoelectric materials has received widespread attention. In this research, quaternary Mg2(1+x)(Si0.2Ge0.1Sn0.7)0.99Sb0.01 (0.06 ≤ x ≤ 0.12) solid solutions with an optimized Sb doping were prepared by B2O3 flux method combined with spark plasma sintering (SPS) technique. The Seebeck coefficient, electrical conductivity and thermal conductivity were measured as a function of Mg excess between 300 K and 780 K. The electron concentration, electrical conductivity and lattice thermal conductivity increase while the Seebeck coefficient decreases with increasing magnesium excess content. The electron effective mass enhancement for x ≥ 0.08 suggests the conduction band convergence of Mg2Si0.2Ge0.1Sn0.7. Mg2.16(Si0.2Ge0.1Sn0.7)0.99Sb0.01 with a maximum dimensionless figure of merit of 0.94 at 780 K stand out as one of the best materials for intermediate temperature applications, providing a good nontoxic alternative to PbTe.

Detection of 881^A→881^G Mutation in Tyrosinase Gene and Associations with the Black Ear Coat Color in Rabbits

Jiang, Y.L.,Fan, X.Z.,Lu, Z.X.,Tang, H.,Xu, J.-Q.,Du, L.-X. Asian Australasian Association of Animal Productio 2002 Animal Bioscience Vol.15 No.10

The tyrosinase gene was selected as a candidate for uncovering genetic mechanism causing 'black ear' coat color in rabbits. A PCR-SSCP detection method was established for the $881^A{\rightarrow}881^G$ mutation located in the central region of the tyrosinase gene between the CuA and CuB binding region signatures, and this was confirmed by sequencing and alignment. Fully consistent associations between the SNP and 'black ear' coat color were observed by analysis in a "black ear" pedigree and on 61 unrelated individuals. This SNP can serve as a molecular marker for use in "back ear" wool rabbit breeding.

Associations of T→A Mutation in the Promoter Region of Myostatin Gene with Birth Weight in Yorkshire Pigs

Jiang, Y-L,Li, N,Fan, X-Z,Xiao, L-R,Xiang, R-L,Hu, X-X,Du, L-X,Wu, C-X Asian Australasian Association of Animal Productio 2002 Animal Bioscience Vol.15 No.11

A T$\longrightarrow$A mutation in the promoter region of porcine myostatin (MSTN) gene has been identified in our previous work. This study analyzed the associations of the myostatin genotypes (TT, TA) caused by this mutation with birth weigh in Yorkshire pigs. Data from 211 unrelated individuals were collected three times from one breeding farm. Detections of the mutation were carried out by PCR-RFLPs approach. The effects of MSTN genotypes (TT and TA) on birth weight were compared by least square means. The results showed that for birth weight of Yorkshire pigs, individuals with TA genotype were significantly higher than those with TT genotype (p<0.05), and the birth weight for pigs with TA genotype were 1.37 kg in average but only 1.25 kg for pigs with TT genotype, indicating a positive effect of birth weight for A allele.

Research on the Influencing Factors of Cross-border E-commerce Business Incubation from the Perspective of School-enterprise Cooperation

Zheng, S.L,Du L,Zhou Y.W. 한국지능정보시스템학회 2022 한국지능정보시스템학회 학술대회논문집 Vol.2022 No.6

Along with the Internet economy developing entrepreneurship has become the good choice of college students. However, there are still many problems. School-enterprise cooperation provides a new direction for training students to conduct cross-border e-commerce entrepreneurship. Based on the triple helix theory, it is found that conditions of incubator, school-enterprise cooperation degree, entrepreneurship education and entrepreneurial environment of universities directly affect the success rate of incubator of cross-border e-commerce entrepreneurial projects.

Precision Measurement of Cosmic-Ray Nitrogen and its Primary and Secondary Components with the Alpha Magnetic Spectrometer on the International Space Station

Aguilar, M.,Ali Cavasonza, L.,Alpat, B.,Ambrosi, G.,Arruda, L.,Attig, N.,Aupetit, S.,Azzarello, P.,Bachlechner, A.,Barao, F.,Barrau, A.,Barrin, L.,Bartoloni, A.,Basara, L.,Baş,eğ,mez-du Pree American Physical Society 2018 Physical review letters Vol.121 No.5