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The effects of MgO content on the viscosity and melting behaviors of CaO-Al2O3-MgO-FexO-SiO2-K2O slags were studied. The slag samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) to identify precipitated phases during the cooling process. Meanwhile, theoretical calculations on the viscosities, solidus/liquidus temperatures as well as quantities of various precipitated phases from the slag system were also carried out by using the FactSage software, which were compared with the experimental results. The results indicate that the addition of MgO in slag could cause the increase of melting temperature. The relation between viscosities and temperature presents a breakpoint where the viscosity has a rapid rise, and above this transition temperature, MgO content has little effect on the viscosity. The transition temperature increases with the increasing of MgO content. In the process of slag cooling, the crystalline phases are mainly composed of olivine and spinel. From the calculation results, it could be found that the addition of MgO enhances the precipitates of olivine, which makes the viscosity increase suddenly.

The viscosity of solid-containing slags can be calculated using the Roscoe equation combined with the calculation functions of multi-component & multi-phase equilibria and pure-liquid slag's viscosity in FactSage software. An FeO-SiO2-Fe3O4-CaO-Al2O3-MgO system used in copper smelting was studied in this paper. Firstly, the parameters of the Roscoe equation were fitted using the measured viscosities of analogous slag in the literature, and the accuracy of viscosity calculated by the method for this slag system was verified additionally. Then, the effect of slag components' contents on the equilibrium phase-composition and viscosity was investigated based on the calculation model. Accordingly, the reasonable proportions of components in the slag were obtained. When the mass fractions of slag components are FeO 40%~60%, SiO2 25%~40%, Fe3O4 0%~15%, CaO 0%~10%, Al2O3 0%~8%, and MgO 0%~4%, the molten slag with good liquidity and fewer solids can be obtained in the smelting process.

Sclerotinia stem rot is a broad-spectrum threat to rapeseed production, and Brassica juncea contains abundant genetic resources for resistance against Sclerotinia sclerotiorum. Therefore, it is of great significance to carry out screening, localization, and exploration of resistance loci for sclerotinia stem rot in Brassica juncea germplasm resources for the breeding of Sclerotinia-resistant rapeseed. In this study, the S. sclerotiorum resistance of Brassica juncea germplasm resources collected from various regions in Yunnan Province was evaluated under three different growth environments, and a whole-genome association analysis of S. sclerotiorum resistance loci was conducted based on the resequencing data of 91 Brassica juncea germplasm materials. According to the results of leaf identification under in vitro conditions in the three growth environments, one highly resistant germplasm material J7667 and one relatively resistant germplasm material J047 were selected. The resequencing data of the 91 materials were aligned to the reference genome of Brassica juncea for variation detection analysis, resulting in the detection of 11 337 871 SNPs and 40 170 Indels distributed on the 18 chromosomes of Brassica juncea. After data filtering, 403 211 high-quality SNPs were obtained. The phenotypic data of in vitro leaves, in vitro stems, and stem resistance to S. sclerotiorum of the 91 materials under the three growth environments were subjected to whole-genome association analysis using two analysis software, Emmax and Tassel. In the in vitro leaves, both analysis methods identified a total of 62 significantly associated SNP loci with resistance in the three different growth environments, including 23 and 39 significantly associated SNP loci in the Luoping winter sowing and Xiaoshao winter sowing environments, respectively, while no resistance loci were detected in the Xiaoshao summer sowing environment. In the stem of Luoping winter sowing, both methods detected 3 significantly associated SNP loci with resistance, while no significant SNP was detected in the stem of Xiaoshao summer sowing. In the Tassel method, closely located resistance SNP loci were detected on chromosomes A2, A8, and B2 in Luoping winter sowing and Xiaoshao winter sowing, while in the Emmax method, closely located resistance SNP loci were detected on chromosomes B5 and B8 in Luop-ing winter sowing and Xiaoshao winter sowing. In addition, this study mapped the previously identified S. sclerotio-rum resistance QTL loci and the resistance loci identified in this study to the reference genome of Brassica juncea. It was found that the resistance QTL intervals identified in this study (XLRA2-2, XLRA1-4) overlapped with the reported resistance QTL loci Sll2 and qsr10-1, respectively. [ABSTRACT FROM AUTHOR]

To improve seed setting rate and get more seeds in siliques of rapeseed, abortion of ovules and seeds were investigated in 36 DH (double hyploid ) materials under 4 pollinating treatments (open pollination, forced selfing, hybridizing and assisted artificial pollination) . The initial number of ovules, normal mature seeds and abortion seeds were investigated to better understand the abortion period and causes. Statistic results showed that the initial ovule numbers of different materials had highly significantly variation, ranging from 23.05 to 36.15 with an average of 29.48. After maturing, the seeds number in single silique was 8.82 - 26.38, with an average of 16.80. The correlation coefficient between the number of ovules and the number of seeds per siliques was 0.77. Average, 56.19% of the initial ovules could develop into mature seeds and nearly 44% ovules aborted during the seed development. The abortion rate was found to be related to genotype as well. The abortion could be divided into 3 types. They were divided by ovules diameter as : a (less than 0.1 mm), b (between 0.1 - 1.0 mm) and c (embryo abortion). They occurred in all 36 materials under 4 treatments. Type a and b were the main types of ovule (or seed) abortion, with average occurrences of 19. 34% and 7.91% respectively. Type c occurred only 1.54%, which might be related to the ceasing of embryonic developmental. These results indicated that the ovules number was related to genotype, and the abortion occurrence and types were also related to genotype. The cause of abortion might be in stigma development, stigma and pollen recognition, and/or in fertilization and initial embryo development. [ABSTRACT FROM AUTHOR]

Emphasizing the interactions among students makes the collaborative learning accepted as an effective teaching strategy which keeps a balance between the students' emotional development and their academic achievement. The "collaborative-cooperative" learning characterized by "the students' collaboration within and without their study groups" , constitutes an ideal classroom context and generative mechanism for collaborative learning. The adoption of collaborative learning in college classrooms does not only help spread the university spirit of "unremitting learning and seeking for truth" and "incorporating things of diverse nature and cooperating for co-existence" , but also serves as an important way to tap the resources for the education of professional ethics. [ABSTRACT FROM AUTHOR]

The transport mechanism of reverse surface leakage current in the AlGaN/GaN high-electron mobility transistor (HEMT) becomes one of the most important reliability issues with the downscaling of feature size. In this paper, the research results show that the reverse surface leakage current in AlGaN/GaN HEMT with SiN passivation increases with the enhancement of temperature in the range from 298 K to 423 K. Three possible transport mechanisms are proposed and examined to explain the generation of reverse surface leakage current. By comparing the experimental data with the numerical transport models, it is found that neither Fowler–Nordheim tunneling nor Frenkel–Poole emission can describe the transport of reverse surface leakage current. However, good agreement is found between the experimental data and the two-dimensional variable range hopping (2D-VRH) model. Therefore, it is concluded that the reverse surface leakage current is dominated by the electron hopping through the surface states at the barrier layer. Moreover, the activation energy of surface leakage current is extracted, which is around 0.083 eV. Finally, the SiN passivated HEMT with a high Al composition and a thin AlGaN barrier layer is also studied. It is observed that 2D-VRH still dominates the reverse surface leakage current and the activation energy is around 0.10 eV, which demonstrates that the alteration of the AlGaN barrier layer does not affect the transport mechanism of reverse surface leakage current in this paper. [ABSTRACT FROM AUTHOR]

The electron traps in HfO2 are a major concern of the reliability of metal-oxide-semiconductor field effect transistors (MOSFETs) beyond the 30 nm technology generation. In this work, the principle of the discharge-based pulse I–V technique is demonstrated in detail. By using this technique, the thorough energy distribution of electron traps across the 4 nm HfO2 layer is identified, which overcomes the shortcomings of the current techniques. It is observed that there are two peaks in HfO2. The large peak is at around 1.0 eV below the HfO2 conduction band bottom. The small peak is at about 1.43 eV below the HfO2 conduction band bottom. The results provide valuable information for theoretical modeling establishment, fast material assessment and process optimization for MOSFETs with high-k gate dielectrics. [ABSTRACT FROM AUTHOR]

Aim: To perform a meta-analysis to quantitatively summarize the evidence for the association between the Notch signaling pathway and gastric cancer (GC)., Methods: An electronic search of the MEDLINE, EMBASE and Chinese National Knowledge Infrastructure, which contain articles published from 1966 onwards, was conducted to select studies for this meta-analysis., Results: Fifteen studies with a total of 1547 gastric cancer cases and 450 controls were included in this meta-analysis. Overall, the expression of Notch1, Notch2, Delta-like 4 and Hes1 was significantly higher in tumor tissues of GC compared to normal tissues. Specifically, stratified analyses showed that significantly increased expression of Notch1 was associated with non-cardia location, > 5 cm size, diffuse type, positive lymphovascular invasion and distal metastasis. Statistically significant higher expression of Notch3 was found in diffuse type GC. Jagged1 was also significantly over-expressed in diffuse type and poor differentiation type of GC. DLL4 was significantly over-expressed in advanced T stage, N stage and TNM stage in GC patients. However, the stratified analysis showed that there was no statistically significant difference in Hes1 expression between different subgroups. Sporadic reports showed that Notch1 and Jagged1 were independent poor prognostic predictors in GC., Conclusion: The Notch signaling pathway plays an important role in tumor progression of gastric cancer.