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This paper studied the effects of the superheating degree and cooling intensity on the solidification structure of CP 780 slab. The results indicated that the equiaxed crystal ratio decreases with the increase of superheating degree and the cooling intensity. When the superheating degree increases from 15 to 25°C, the equiaxed crystal ratio drops sharply. While the equiaxed crystal ratio decreases slightly with an increasing superheating degree from 25°C to 55°C. It is further revealed that the superheating degree has a greater effect on the equiaxed crystal ratio compared with the influence of cooling intensity. Quantitative analysed the relationship among the equiaxed crystal ratio, the superheating degree and cooling intensity is in line with the Extreme 2D model. The accuracy of the model performance can reach 97.6% when predicting the equiaxed crystal ratio of CSP-CP 780 during CSP process. [ABSTRACT FROM AUTHOR]

A dual‐band terahertz metamaterial absorber using one‐layer periodically patterned hexagon graphene structure is proposed. By periodically loading six graphene stubs to the honeycomb hexagon graphene structure without increase of the overall size, a new high‐frequency absorption peak will be obtained to realize a dual‐band frequency response. By tuning the structural parameters or Fermi energy levels of the presented terahertz metamaterial absorber, both of the two absorption bands will be changed to the required working frequencies for design specifications. Moreover, the proposed terahertz metamaterial absorber has the properties of polarization independence and incident angle insensitivity, which are of great significance in the applications of some detecting and sensing systems. This work will be a good candidate for the design guidance of various metamaterial absorbers using graphene with single or dual absorption bands. [ABSTRACT FROM AUTHOR]

Candida albicans (C. albicans) is a common cause of vulvovaginal candidiasis (VVC). In this paper, the genetic diversity and molecular epidemiology of 173 C. albicans strains were investigated by multilocus sequence typing (MLST). A total of 52 diploid sequence types (DSTs) were recognized, and 27 (51.9%) of which have not been reported in the MLST database. Genotyping was performed on the multiple isolates collected from patients with recurrent VVC (RVVC, referring to VVC which attacks more than 4 times in one year) in different acute infectious phases. The results showed that 59.1% (26/44) of the patients suffered a relapse, with DST 79 (65.4%) as the dominant genotype. The etiology of the remaining 40.9% (18/44) of patients was reinfection, and the main genotypes included DST 79 (33.3%), DST 124 (8.6%) and DST 1895 (8.6%). DST 79 (45%) and DST 1395 (7.5%) were the main isolates of VVC patients, while DST 79 (24.1%), DST 727 (6.9%), DST 732 (6.9%) and DST 1867 (6.9%) were the main types of healthy volunteers. The results of the genotypes between RVVC patients and other groups were statistically different. Furthermore, cluster analysis was carried out on 1468 isolates, among which 1337 were downloaded from the MLST database, 130 were divided into 8 Clades in the present study and the remaining one was taken as a singleton. 92.3% isolates from relapse patients, 58.3% isolates from re-infected patients, 77.5% isolates from VVC patients and 51.7% isolates from volunteers were distributed in Clade 1. The analysis of the genotypes of multiple isolates from RVVC patients further demonstrated that point mutation and loss of heterozygosity contributed to the microevolution of C. albicans. • The etiology of RVVC was reinfection or relapse can be identified by genotyping. • The genotype of relapse RVVC patients was significantly different from other groups(reinfection,VVC and volunteers). • Further demonstrated that point mutation and loss of heterozygosity contributed to the microevolution of C. albicans. [ABSTRACT FROM AUTHOR]

The decrease in mechanical properties of high-strength steel after welding is an important issue affecting the wide application of high-strength steel. Air-hardening steel is a high-strength steel suitable for lower body structural parts such as subframes. Its application process involves welding, hot forming and other processes. The present work investigates the microstructure and mechanical properties of the air-hardening steel laser welded joint that is air-cooled after hot forming in the two-phase zone (800 °C). The microstructure was characterized by electron backscattered diffraction (EBSD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that during hot forming, the welded joint transforms from martensite to ferrite and acicular martensite, and the base metal transforms from ferrite to polygonal martensite and ferrite. The difference in martensite morphology between the welded joint and the base metal is attributed to the nucleation positions of austenite. The structural evolution of the welded joint and the base metal is accompanied with the annihilation and reproduction of dislocations, which results in significant changes in hardness. The hardness value dropped from the highest 430 HV to 271 HV in the welded joint, while increased from the lowest 184 HV to 203 HV in the base metal. After hot forming, the tensile strength of the welded sample is reduced by only 36 MPa, and the total elongation is slightly decreased by about 1.5% compared with the unwelded sample. The welded joint and the base metal have similar plastic deformation capabilities, since the acicular martensite in the welded joint displays good plastic deformation ability, and the dislocation density of the welded joint and the base metal is similar. Overall, the microstructure and dislocation density of the air-hardening steel welded joint after hot forming are similar to those of the base metal, which is responsible for the good mechanical properties of air-hardening steel welded joint. • The rules of microstructure evolution of welded joints during hot forming are proposed. • After hot forming, the strength and plasticity of the welded specimen are basically no loss compared with the unwelded specimen. [ABSTRACT FROM AUTHOR]