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AbstractThe as-quenched microstructures of low-carbon Cu-bearing ferrite steel are investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It is found that the granular bainite formation in Cu-bearing ferrite steel is attributed to a mixed mode of diffusional and displacive mechanisms. Besides, the particle-like or plate-shaped ω phases, along with thin-plate martensites consist of twin, are observed in the Mn1.4Cu-bearing steel, and the orientation relationship is determined as: [2 ?1 ?10]ω // [0 1 1]α and (0 1 ?1 0)ω // (2 ?1 1)α. The ultra-fine or ellipsoidal shaped nanoscale orthorhombic martensite phases, along with laths martensites consist of a high density of dislocations, are observed in the Mn0.66Cu-bearing steel, and the orientation relationship is determined as: [0 1 ?1]o//[?1 1 1]α and (?1 1 1)o//(1 0 1) α. A model is proposed to describe the overall martensite transformation kinetics by taking into account the Mn content, heterogeneity of C content and dislocation reactions play a major role in the subsequent martensite transformation. 相似文献
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Lu Yin Jing Zhu Shengqiu Qu Yifan Li Yuqing Liu Zailiang Yu Fan Yang Ranran Zhang Jiaming Xue Sicheng Huang Weibo Liang 《Electrophoresis》2021,42(19):1928-1935
The Microreader 28A ID System is a new 28-plex genotyping system with 6-dye multiplex amplification, which allows the simultaneous amplification of all 20 Combined DNA Index System (CODIS) core loci (CSF1PO, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D21S11, FGA, TH01, TPOX, vWA, D1S1656, D2S441, D2S1338, D10S1248, D12S391, D19S433, D22S1045), plus five extended STRs loci (D6S1043, Penta D, Penta E, DYS391, SE33), 2 Y-Indels (Rs2032678, Rs771783753), and the amelogenin loci. This system can be used for forensic analyses, such as personal identification, kinship testing, scientific research, database applications, and other aspects of human genetic identification. The validation of the Microreader 28A ID System followed the “Validation Guidelines for DNA Analysis Methods (2016)” described by the Scientific Working Group on DNA Analysis Methods and the regulations published by the China Ministry of Public Security. Our tests included PCR-based studies, sensitivity study, precision and accuracy evaluation, stutter percentage and heterozygous peak height ratio, inhibitor tests, species specificity, and population studies. The validation results suggest that the Microreader 28A ID system is a robust and reliable amplification kit for personal identification, kinship testing, and forensic database applications. 相似文献
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以焦脱镁叶绿酸-a甲酯为起始原料,通过对3-位乙烯基的氧化、格氏反应和E-环的空气氧化和重排在二氢卟吩周环的不同位置上构建酰基结构,利用叶绿素-a衍生物的烷酰基和叶绿素-b的原有甲酰基与丙二腈进行Knoevenagel反应,完成一系列具有长波吸收的β,β-二氰亚甲基叶绿素-a衍生物的合成,并对不同取向的共轭取代基团对大环分子的可见光谱所产生的影响进行了相应的讨论.未见报道的叶绿素-a衍生物均经UV,IR,1H NMR及元素分析证明其结构. 相似文献
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Enzymatic electrosynthesis (EES), combining enzymatic catalysis and electrochemical techniques for the production of desired chemicals, has gained prominence because of its use of clean electrical energy inputs and highly specific enzyme biocatalysts and its capability of performing complicated reactions with high yield. In this review, we summarize the most recent state-of-the-art advances in EES and recognize that the research emphasis has shifted from CO2 reduction to the utilization of N2 and the synthesis of high-value products. Particular attention is given to the energy sources for powering EES, including direct electrical energy, light energy, and chemical energy obtained from self-powered biosystems. Enzyme-based hybrid systems integrated with microbial or chemical approaches are also presented. Finally, key challenges and future directions of EES are discussed briefly. 相似文献
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In this work, the surface characteristics of poly(N-vinyl-2-pyrrolidone) (PNVP)-modified nonwoven fabric (NWF) membranes and the effects of the surface characteristics on the membranes antifouling properties were investigated. Effects of grafting time, grafting temperature, and monomer concentration on the grafting degree of PNVP were systematically investigated. The effect of grafting degree on the surface characteristics was also investigated. Scanning electron microscopy (SEM) was used to characterize the structural and morphological changes on the membrane surface. The water contact angles decreased from 113±1.2° to 52±3°, which means that the hydrophilicity of the modified NWF was enhanced with increasing PNVP grafting degree. The surface free energy was calculated, which showed an increase after modification. Static bovine serum albumin (BSA) adsorption experiments were carried out, which showed a decrease of 82.5%. Permeation experiments of water and supernatant solution of active sludge were carried out to determine the antifouling characteristics against the extracellular polymeric substance. Results demonstrated that the modified NWF had higher permeation fluxes and lower flux loss in comparison with the original NWF. Bacterial adhesion on the membrane surface was largely suppressed after the introduction of PNVP. 相似文献
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Photothermal therapy (PTT) has emerged as one of the promising cancer therapy approaches. As a representative photothermal agent (PTA), magnetite possesses many advantages such as biodegradability and biocompatibility. However, photothermal instability hampers its further application. Herein, we systematically synthesized three kinds of ferrite nanoparticles and detailedly investigated their photothermal effect. Compared with Fe3O4 and MnFe2O4 nanoparticles, ZnFe2O4 nanoparticles exhibited a superior photothermal effect. After preservation for 70 days, the photothermal effect of Fe3O4 and MnFe2O4 nanoparticles observably declined while ZnFe2O4 nanoparticles showed slight decrease. Furthermore, in vitro experiment, ZnFe2O4 nanoparticles showed little toxicity to cells and achieved outstanding effect in killing cancer cells under NIR laser irradiation. Overall, through synthesizing and studying three kinds of ferrite MFe2O4 nanoparticles, we obtained ferrites as PTAs and learned about their changing trend in photothermal effect, expecting it can inspire further exploration of photothermal agents. 相似文献
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Yanzhen Zhang Renjie Ji Baoping Cai Fei Wang Ranran Liu 《Journal of Dispersion Science and Technology》2013,34(12):1700-1707
Adsorption of surfactants at water-oil interfaces is of great importance in the coalescence of drops and stability of emulsions. In this work, we have studied the adsorption of nonionic surfactants Span 80 at water-oil interfaces and its influence on the drop rest phenomenon and W/O emulsion stability in a pulsed DC electrical field. The variation of interfacial tension with the concentration of surfactant was studied and the data were fitted using a surface equation of state derived from the Langmuir adsorption isotherm. A stochastic model for coalescence was used to fit the coalescence time distributions. The significance of the model parameters was discussed. The stability of the emulsion was evaluated by conductivity methods. The researches in this article indicated that both of the rest time distribution of the drops at the interface and stability of the emulsion in the electrical field was significantly affected by surfactant concentration. 相似文献