Subjects: Materials Science >> Materials Science (General) submitted time 2017-03-31 Cooperative journals: 《金属学报》
Abstract：文利用定量逐层研磨和计算机辅助重建及可视化技术，并结合电子背散射衍射技术(EBSD)，研究了Hi-B钢二次再结晶退火初期不同取向晶粒的三维形貌.研究表明Goss晶粒主要呈现出“塔状”,黄铜晶粒则类似“上大下小”倒锥状，{411}晶粒也表现为“塔状”和倒锥状.而{111}取向晶粒形貌各异，没有一致性.与其它取向晶粒相比，Goss晶粒在三维尺度上没有尺寸优势，Goss晶粒异常长大前，其长大主要受曲率控制.
Subjects: Physics >> Nuclear Physics submitted time 2024-03-11
Abstract： Fusion triple product represents a crucial parameter for evaluating the potential of self-sustained fusion nuclear reactions. It employs the product of three physical properties: the fuel nuclei number density ($n$), plasma confinement time ($τ_ mathrm{E}$) and fuel temperature ($T$) to establish a condition for assessing the feasibility of achieving self-sustained nuclear fusion. This study considers a fusion reaction system using $^{6}$Li-D as nuclear fuel, neglects cyclotron radiation, incorporates the impact of relativistic effects on bremsstrahlung radiation and the impact of recycled energy on the energy gain factor $Q$. Based on this foundation, the minimum triple product ($n_ mathrm{i}Tτ_ mathrm{E}$= SI{4.9e23}{ per cubic meter kilo electronvolt second}) is calculated for the $^{6}$Li-D reaction to yield energy gain of Q=1. These results show that although the $^{6}$Li-D fusion reaction can achieve a positive energy gain but the condition required for the $^6$Li-D fusion reaction is more difficult than the D-T fusion reaction.
Subjects: Biology >> Botany >> Applied botany submitted time 2021-07-20 Cooperative journals: 《广西植物》
Abstract： Endophytic fungi in medicinal plants have the capacity to produce bioactive compounds whose features have great identity or similarity with the phytohosts. Since Asclepias curassavica has been known to possess a broad range of biological activities, we sought to obtain the active endophytic fungi from this plant. We performed the study followed the idea of “ethnic drug-endophytic fungi-active ingredients”, and thereafter we examined the bio-activities of fungal metabolites from 168 strains of endophytic fungi isolated from A. curassavica. To evaluate the activities of anti-tumor, anti-inflammatory, anti-α-glucosidase and antioxidant in these fungi, the ethyl acetate extracts from fermentation broth of endophytic fungi were first determined using the methods of SRB, Griess, PNPG and DPPH, respectively. Furthermore, we identified the bioactive fungal strains with conserved ITS sequencing. Our results reveal 22 in 168 isolated strains have variable biological activities; and of which 9 strains have obvious antitumor effect with the IC50 values of 0.1 - 40 μg·mL-1. Further, the strain MJF-53 display prominent inhibitory effect on the release of both NO and IL-1β in Raw264.7 cell line by LPS- induction under the concentration of 2.5 μg·mL-1. There were 7 strains showing α-glucosidase inhibitory activity with the IC50 values ranging from 1.0 to 4.0 mg·mL-1, Especially, the inhibitory activity of MYF-16 and MYF-55 are close to acarbose; 19 endophytic fungi have different degrees of DPPH radical scavenging activities, among which MYF-9, MYF-19 and MJF-84 show moderate antioxidant activity with IC50 values of 13.562, 17.776 and 12.395 μg·mL-1 respectively; The ITS identification show that the 22 active strains are mainly distribute in six genera: Alternaria, Colletotrichum, Fusarium, Diaporthe, Talaromyces and Neofusicoccum. This study shows that the bioactivities of the endophytic fungi from A. curassavica are diverse, which lays a foundation for exploring new potential natural anti-tumor, anti-inflammatory, hypoglycemic and antioxidant compounds from the endophytic fungi of A. curassavica.
Subjects: Physics >> Nuclear Physics submitted time 2023-09-04 Cooperative journals: 《核技术》
Abstract： Supernovae are the most gorgeous fireworks that people can observe in the universe. Their explosion can produce a maximum luminosity 10 billion times that of the Sun, helping scientists see farther. Type Ia supernovae can be used as a standard candle to facilitate measurement of the distance between galaxies in the universe. A supernova explosion will also propel a large number of heavy elements into interstellar space, which is a major driving force for the chemical evolution of galaxies. In addition, supernovae are crucial to the origin of elements in the Milky Way, the formation of the structure of the solar system, and the evolution of life on the Earth. The study of supernovae will further enrich our understanding of the universe and help us solve the mysteries of the expansion of the universe, the generation of heavy elements, and the origin of life. At present, scientists predict that the next supernova will explode at any time, and preparations are in progress for observing the coming supernova.
Hits
Hits
Downloads
Comment
YES