Identification of rice chromosome segment substitution line Z322-1-10 and mapping QTLs for agronomic traits from the F₃ population

Chromosome segment substitution lines (CSSLs) are powerful tools to combine naturally occurring genetic variants with favorable alleles in the same genetic backgrounds of elite cultivars. An elite CSSL Z322-1-10 was identified from advanced backcrosses between a japonica cultivar Nipponbare and an elite indica restorer Xihui 18 by SSR marker-assisted selection (MAS). The Z322-1-10 line carries five substitution segments distributed on chromosomes 1, 2, 5, 6 and 10 with an average length of 4.80 Mb. Spikilets per panicle, 1000-grain weight, grain length in the Z322-1-10 line are significantly higher than those in Nipponbare. Quantitative trait loci (QTLs) were identified and mapped for nine agronomic traits in an F3 population derived from the cross between Nipponbare and Z322-1-10 using the restricted maximum likelihood (REML) method in the HPMIXED procedure of SAS. We detected 13 QTLs whose effect ranging from 2.45% to 44.17% in terms of phenotypic variance explained. Of the 13 loci detected, three are major QTL (qGL1, qGW5-1 and qRLW5-1) and they explain 34.68%, 44.17% and 33.05% of the phenotypic variance. The qGL1 locus controls grain length with a typical Mendelian dominance inheritance of 3:1 ratio for long grain to short grain. The already cloned QTL qGW5-1 is linked with a minor QTL for grain width qGW5-2 (13.01%) in the same substitution segment. Similarly, the previously reported qRLW5-1 is also linked with a minor QTL qRLW5-2. Not only the study is important for fine mapping and cloning of the gene qGL1, but also has a great potential for molecular breeding

Effect of the Surface Texture on Laser Joining of a Carbon Fiber-Reinforced Thermosetting Plastic and Stainless Steel

A carbon fiber-reinforced thermosetting plastic and stainless steel were joined by the fiber laser. The surface texture effect on the joint was investigated. The abrasive paper scratching is shown to form single directional striae on stainless steel with intermittent ridges. Laser texture processing creates uniformly distributed microdimples and ridges, which forms a rectangular cellular structure. This processing can improve the fluidity of molten polyphenylene sulfite during laser joining. Laser scanning on stainless steel results in the formation of fusion and heat-affected zones. In the heat-affected zone, lathy ferrite is located along the boundary, while in the fusion zone, ferrite forms the skeletal structure and separates austenite into a cellular structure. The surface texture modification can contribute to the adhesive strength between stainless steel and polyphenylene sulfite through on enlarged contact surface area by forming striae, microdimples, and ridges. As compared to the abrasive paper scratching, the stainless steel/plastic joint with laser texture processing exhibits a higher shear strength.Реактопласт, армированный углеродным волокном, и нержавеющую сталь соединяли с помощью волоконного лазера. Изучено влияние текстуры поверхности на качество соединения. Показано, что царапание абразивной бумагой поверхности нержавеющей стали вызывает появление отдельных направленных бороздок, перемежающихся выступами. Лазерная обработка текстуры приводит к возникновению равномерно распределенных микролунок и выступов, образующих прямоугольную ячеистую структуру. Такая обработка может улучшать текучесть полифениленсульфитного расплава при лазерном соединении. Лазерное сканирование поверхности нержавеющей стали приводит к образованию зон проплавления и термического влияния. В зоне термического влияния игольчатый феррит располагается вдоль границы, тогда как в зоне проплавления он образует скелетную структуру и выделяет аустенит в ячеистую структуру. Модификация текстуры поверхности увеличивает прочность сцепления между нержавеющей сталью и полифениленсульфитом за счет расширения площади поверхности контакта вследствие образования бороздок, микролунок и выступов. Соединение нержавеющая сталь реактопласт после лазерной обработки текстуры по сравнению с царапанием обладает более высоким сопротивлением сдвигу.Реактопласт, армований вуглецевим волокном, і нержавіючу сталь з'єднували за допомогою волоконного лазера. Вивчено вплив текстури поверхні на якість з'єднання. Показано, що дряпання абразивним папером поверхні нержавіючої сталі викликає поява окремих спрямованих борозенок, що перемежовуються виступами. Лазерна обробка текстури призводить до виникнення рівномірно розподілених мікролунок і виступів, що утворюють прямокутну комірчасту структуру. Така обробка може покращувати плинність поліфеніленсульфітного розплаву при лазерному з'єднанні. Лазерне сканування поверхні нержавіючої сталі призводить до утворення зон проплавления і термічного впливу. У зоні термічного впливу голчастий ферит розташовується уздовж кордону, тоді як в зоні проплавлення він утворює кісткову структуру і виділяє аустенит в пористу структуру. Модифікація текстури поверхні збільшує міцність зчеплення між нержавіючої сталлю і поліфеніленсульфітом за рахунок розширення площі поверхні контакту внаслідок утворення борозенок, мікролунок і виступів. З'єднання нержавіюча сталь-реактопласти після лазерної обробки текстури в порівнянні з дряпанням володіє більш високим опором зсуву

Determination of plastic properties using instrumented indentation test with hybrid particle swarm optimization

Instrumented indentation test is a promising non-destructive method to determine mechanical properties. This paper proposes a new approach to determine the plastic properties of bulk metal materials (including yield stress, strain-hardening exponent (n) and strain-hardening rate (K)), which couples an experimental load-displacement curve with finite element method. The load–displacement curve was obtained from continuous instrumented indentation test. Then a hybrid particle swarm optimization was employed to minimize the deviation between experimental and simulated load-displacement curves. As a combination of particle swarm optimization and simulated annealing, the simulated annealing particle swarm optimization is an economical and effective algorithm to identify plastic parameters. It was observed that the maximum error of strain-hardening rate extracted from the macro indentation test was 8.2 percent contrast to that determined by the conventional tensile test, and the maximum error of strain-hardening exponent was 4.7% respectively

Effects of Sc and Zr on the texture and mechanical anisotropy of high strength Al - Zn - Mg alloy sheets

Texture, mechanical anisotropy and microstructure of aged Al–Zn–Mg, Al–Zn–Mg–0.1Sc–0.1Zr and Al–Zn–Mg–0.25Sc–0.1Zr (wt.%) alloy sheets were investigated by tensile tests and electron microscopy. Sc and Zr additions do not change the texture of homogenized and cold rolled alloys, but transfer the cube texture of the aged Al–Zn–Mg alloy into -fiber rolling texture. With increasing Sc and Zr additions, the strength significantly increases, and mechanical anisotropy is enhanced. The strength is highest parallel to the rolling direction, whereas it is lowest at a 45° angle to the rolling direction. The higher strength is mainly due to grain boundary strengthening and precipitation strengthening caused by Al₃ScxZr₁₋x nano-particles. The stronger mechanical anisotropy is ascribed to the rolling texture, due to the inhibitory effect of Al₃ScxZr₁₋x on recrystallization. A new model was successfully established to reveal the interrelation between Sc and Zr additions, texture and yield strength anisotropy of Al–Zn–Mg sheets

Hot Extrusion Effect on the Microstructure and Mechanical Properties of a Mg–Y–Nd–Zr Alloy

A Mg–Y–Nd–Zr alloy was prepared by casting and hot extrusion. The microstructure and mechanical properties of OM, SEM, XRD, TEM, and tensile tests were investigated with casting and hot extruded alloys. The results demonstrate that in a casting Mg–Y–Nd–Zr alloy, the α-Mg matrix is separated into the cell structure by a discontinuously distributed coarse Mg₂₄Y₅/α-Mg eutectic structure and fine Mg₁₂Nd particles.Сплав Mg-Y-Nd-Zr получен литьем и горячей экструзией. Исследованы микроструктура и механические свойства литейного и экструзионного сплавов с помощью оптической, сканирующей электронной, просвечивающей электронной микроскопии, рентгенографии и испытаний на растяжение. Показано, что матрица α-Mg в литейном сплаве превращается в ячеистую структуру за счет образования дискретно распределенной крупной эвтектики Mg₂₄Y₅ и мелких частиц Mg₁₂Nd/α-Mg

Phylogenetic analyses of four Chinese endemic wheat landraces based on two single copy genes

Chinese endemic wheat landraces possess unique morphological features and desirable traits, useful for wheat breeding. It is important to clarify the relationship among these landraces. In this study, 21 accessions of the four Chinese endemic wheat landrace species were investigated using single-copy genes encoding plastid Acetyl-CoA carboxylase (Acc-1) and 3-phosphoglycerate kinase (Pgk-1) in order to estimate their phylogenetic relationship. Phylogenetic trees were constructed using maximum parsimony (MP), maximum likelihood (ML) and Bayesian, and TCS network and gene flow values. The A and B genome sequences from the Pgk-1 loci indicated that three accessions of Triticum petropavlovskyi were clustered into the same subclade, and the T. aestivum ssp. tibetanum and the Sichuan white wheat accessions were grouped into a separate subclade. Based on the Acc-1 gene, T. aestivum ssp. tibetanum and T. aestivum ssp. yunnanense were grouped into one subclade in the A genome; the B genome from T. petropavlovskyi and T. aestivum ssp. tibetanum, and the Sichuan white wheat complex and T. aestivum ssp. tibetanum were grouped in the same clades. The D genome of T. aestivum ssp. yunnanense clustered with T. petropavlovskyi. Our findings suggested that (1) T. petropavlovskyi is distantly related to the Sichuan white wheat complex; (2) T. petropavlovskyi, T. aestivum ssp. tibetanum and T. aestivum ssp. yunnanense are closely related; (3) T. aestivum ssp. tibetanum is closely related to T. aestivum ssp. yunnanense and the Sichuan white wheat complex; and (4) T. aestivum ssp. tibetanum may be an ancestor of Chinese endemic wheat landraces

Exploration of hyperfine interaction between constituent quarks via eta productions

In this work, the different exchange freedom, one gluon, one pion or Goldstone boson, in constituent quark model is investigated, which is responsible to the hyperfine interaction between constituent quarks, via the combined analysis of the eta production processes, $\pi^{-}p\rightarrow\eta n$ and $\gamma p\rightarrow\eta p$. With the Goldstone-boson exchange, as well as the one-gluon or one-pion exchange, both the spectrum and observables, such as, the differential cross section and polarized beam asymmetry, are fitted to the suggested values of Particle Data Group and the experimental data. The first two types of exchange freedoms give acceptable description of the spectrum and observables while the one pion exchange can not describe the observables and spectrum simultaneously, so can be excluded. The experimental data for the two processes considered here strongly support the mixing angles for two lowest S11 sates and D13 states as about -30 and 6 degree respectively.Comment: 7 pages, 4 figures, 4 table

Cross Section Measurements of Charged Pion Photoproduction in Hydrogen and Deuterium from 1.1 to 5.5 GeV

The differential cross section for the gamma +n --> pi- + p and the gamma + p --> pi+ n processes were measured at Jefferson Lab. The photon energies ranged from 1.1 to 5.5 GeV, corresponding to center-of-mass energies from 1.7 to 3.4 GeV. The pion center-of-mass angles varied from 50 degree to 110 degree. The pi- and pi+ photoproduction data both exhibit a global scaling behavior at high energies and high transverse momenta, consistent with the constituent counting rule prediction and the existing pi+ data. The data suggest possible substructure of the scaling behavior, which might be oscillations around the scaling value. The data show an enhancement in the scaled cross section at center-of-mass energy near 2.2 GeV. The differential cross section ratios at high energies and high transverse momenta can be described by calculations based on one-hard-gluon-exchange diagrams.Comment: 18 pages, 19 figure

Measurements of the observed cross sections for exclusive light hadron production in e^+e^- annihilation at \sqrt{s}= 3.773 and 3.650 GeV

By analyzing the data sets of 17.3 pb$^{-1}$ taken at $\sqrt{s}=3.773$ GeV and 6.5 pb$^{-1}$ taken at $\sqrt{s}=3.650$ GeV with the BESII detector at the BEPC collider, we have measured the observed cross sections for 12 exclusive light hadron final states produced in $e^+e^-$ annihilation at the two energy points. We have also set the upper limits on the observed cross sections and the branching fractions for $\psi(3770)$ decay to these final states at 90% C.L.Comment: 8 pages, 5 figur

Search for the Rare Decays J/Psi --> Ds- e+ nu_e, J/Psi --> D- e+ nu_e, and J/Psi --> D0bar e+ e-

We report on a search for the decays J/Psi --> Ds- e+ nu_e + c.c., J/Psi --> D- e+ nu_e + c.c., and J/Psi --> D0bar e+ e- + c.c. in a sample of 5.8 * 10^7 J/Psi events collected with the BESII detector at the BEPC. No excess of signal above background is observed, and 90% confidence level upper limits on the branching fractions are set: B(J/Psi --> Ds- e+ nu_e + c.c.)<4.8*10^-5, B(J/Psi --> D- e+ nu_e + c.c.) D0bar e+ e- + c.c.)<1.1*10^-5Comment: 10 pages, 4 figure