Mapping QTLs for mineral accumulation and shoot dry biomass under different Zn nutritional conditions in Chinese cabbage ( Brassica rapa L. ssp. pekinensis )

Abstract Chinese cabbage (Brassica rapa L. ssp. pekinensis) is one of the most important vegetables in China. Genetic dissection of leaf mineral accumulation and tolerance to Zn stress is important for the improvement of the nutritional quality of Chinese cabbage by breeding. A mapping population with 183 doubled haploid (DH) lines was used to study the genetics of mineral accumulation and the growth response to Zn. The genetic map was constructed based on 203 AFLPs, 58 SSRs, 22 SRAPs and four ESTPs. The concentration of 11 minerals was determined in leaves for 142 DH lines grown in an open field. In addition shoot dry biomass (SDB) under normal, deficient and excessive Zn nutritional conditions were investigated in hydroponics experiments. Ten QTLs, each explaining 11.1¿17.1% of the Na, Mg, P, Al, Fe, Mn, Zn and Sr concentration variance, were identified by multiple-QTL model (MQM) mapping. One common QTL was found affecting SDB under normal, deficient and excessive Zn nutritional conditions. An additional QTL was detected for SDB under Zn excess stress only. These results offer insights into the genetic basis of leaf mineral accumulation and plant growth under Zn stress conditions in Chinese cabbag

Superradiance of low density Frenkel excitons in a crystal slab of three-level atoms: Quantum interference effect

We systematically study the fluorescence of low density Frenkel excitons in a crystal slab containing $N_T$ V-type three-level atoms. Based on symmetric quasi-spin realization of SU(3) in large $N$ limit, the two-mode exciton operators are invoked to depict various collective excitations of the collection of these V-type atoms starting from their ground state. By making use of the rotating wave approximation, the light intensity of radiation for the single lattice layer is investigated in detail. As a quantum coherence effect, the quantum beat phenomenon is discussed in detail for different initial excitonic states. We also test the above results analytically without the consideration of the rotating wave approximation and the self-interaction of radiance field is also included.Comment: 18pages, 17 figures. Resubmit to Phys. Rev.

Thermal Fatigue Life Prediction of Ventilation Air Methane Oxidation Bed

Thermal flow-reversal oxidation is the main technology that can effectively reduce emissions of ventilation air methane. As the core component of coal mine ventilation oxidation devices, honeycomb ceramic oxidation beds play a decisive role in the functionality of these devices. The thermal fatigue properties of mullite ceramic – which is commonly used in oxidation beds – was tested in the present research. Then, the service life of the oxidation bed was predicted according to the intensity attenuation law and the thermal fatigue experimental data. The results of the fatigue experiment indicated that in general, the bending strength of mullite ceramics decreases as thermal shocks increase. At higher temperature differences, the bending strength decreased at greater rates. At the temperature differences between 600 and 800°C, the bending strength initially declined. Then, after reaching a certain value, it remained unchanged for a while before declining again. The results of the equation that was developed from intensity attenuation theory and the thermal fatigue experimental data indicate that the thermal fatigue life of an oxidation bed is about 1–8 months. The predicted result is consistent with actual working conditions

Structure and properties of composite Ni–Co–Mn coatings on metal interconnects by electrodeposition

In order to obtain the high conductivity values and wide spinel stability region for solid oxide fuel cell interconnect, several multilayer Ni, Co and Mn coatings are electroplated and then oxidized in air to form spinel oxide layers. Potentiodynamic polarization curves in different simple solutions are tested to analyze the deposition behavior of Co and Mn. Microstructures and compositions of Ni–Co–Mn multi-layers by adjusting the thickness and deposition parameters are analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that area specific resistance value of sample B–Ni/Co after oxidation at 750 °C for 500h is the lowest among the coatings, and the resistance values at 700 °C and 800 °C are 35.3 and 31.7 mΩ‧cm2, respectively. When the Ni transition layer in the vicinity of coating/substrate interface is thick, it will lead to the outward diffusion and aggregation of element Fe to form Fe-rich oxide intermediate layer, which will affect the high-temperature performance of the coating. Pure Co and CoMn alloy coatings with a certain thickness can effectively prevent the inward diffusion of oxygen and the outward diffusion of Fe and Cr at high temperature. The thin Ni transition layer combined with the thick Co layer or CoMn layer has the best element diffusion inhibition and high temperature electrical properties during the long-term high-temperature oxidation process

Elemental and Sr–Nd–Pb isotope geochemistry of the Cenozoic basalts in Southeast China : insights into their mantle sources and melting processes.

We analyzed whole-rock major and trace elements and Sr–Nd–Pb isotopes of the Cenozoic basalts in Southeast China to investigate their mantle source characteristics and melting process. These basalts are spatially associated with three extensional fault systems parallel to the coast line. After correction for the effect of olivine microlites on bulk-rock compositions and the effect of crystal fractionation, we obtained primitive melt compositions for these samples. These primitive melts show increasing SiO2, Al2O3 but decreasing FeO, MgO, TiO2, P2O5, CaO and CaO/Al2O3 from the interior to the coast. Such spatial variations of major element abundances and ratios are consistent with a combined effect of fertile source compositional variation and increasing extent and decreasing pressure of decompression melting from beneath the thick lithosphere in the interior to beneath the thin lithosphere in the coast. These basalts are characterized by incompatible element enrichment but varying extent of isotopic depletion. This element-isotope decoupling is most consistent with recent mantle source enrichment by means of low-degree melt metasomatism that elevated incompatible element abundances without yet having adequate time for isotopic ingrowth in the mantle source regions. Furthermore, Sr and Nd isotope ratios show significant correlations with Nb/Th, Nb/La, Sr/Sr⁎ and Eu/Eu⁎, which substantiates the presence of recycled upper continental crustal material in the mantle sources of these basalts. Pb isotope ratios also exhibit spatial variation, increasing from the interior to the coastal area. The significant correlations of major element abundances with Pb isotope ratios indicate that the Pb isotope variations also result from varied extent and pressure of decompression melting. We conclude that the elevated Pb isotope ratios from the interior to coast are consistent with increasing extent of decompression melting of the incompatible element depleted mantle matrix, which hosts enriched Pb isotope compositions

Applying Bayesian Neural Networks to Separate Neutrino Events from Backgrounds in Reactor Neutrino Experiments

A toy detector has been designed to simulate central detectors in reactor neutrino experiments in the paper. The samples of neutrino events and three major backgrounds from the Monte-Carlo simulation of the toy detector are generated in the signal region. The Bayesian Neural Networks(BNN) are applied to separate neutrino events from backgrounds in reactor neutrino experiments. As a result, the most neutrino events and uncorrelated background events in the signal region can be identified with BNN, and the part events each of the fast neutron and $^{8}$He/$^{9}$Li backgrounds in the signal region can be identified with BNN. Then, the signal to noise ratio in the signal region is enhanced with BNN. The neutrino discrimination increases with the increase of the neutrino rate in the training sample. However, the background discriminations decrease with the decrease of the background rate in the training sample.Comment: 9 pages, 1 figures, 1 tabl