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61.
62.
CYCLIC DEFORMATION BEHAVIOUR OF Cu SINGLE CRYSTALS ORIENTED FORDOUBLE SLIP Ⅱ. Persistent Slip Bands and Deformation Bands 总被引:1,自引:0,他引:1
用光学显微镜和扫描电镜研究了双滑移取向([034],[117])Cu单晶循环饱和后的表面形貌,塑性分切应变幅(γpl)低于10~(-3)时,[034]晶体表面上要为主滑移系的驻留滑移带(PSBs)占据,次滑移只在边缘区域启动,其PSBs细窄(<1μm),体积百分数在1%以下.γpl>10~(-3)时,次滑移开始在试样的中部启动,同时,表面出现二种贯穿晶体的宏观形变带(DBI,DBII),滑移带在形变带内集中.[117]晶体在γpl=4.4×10~(-4)时,双滑移现象已十分明显.γpl>10~(-3)时,表面也形成与前者相似的形变带.DBI的惯习面与主滑移面平行([034]晶体)或接近([117]晶体),DBII的惯习面则与前者垂直,文章讨论了形变带形成的可能原因. 相似文献
63.
Ling Tan Kipkorir Peter Jing Ren Baoyang Du Xiaojie Hao Yufei Zhao Yu-Fei Song 《Frontiers of Chemical Science and Engineering》2021,15(1):99-108
The rational design of photocatalyst that can effectively reduce CO2 under visible light(l>400 nm),and simultaneously precise control of the products syngas(CO/H2)ratio is highly desirable for the Fischer-Tropsch reaction.In this work,we synthesized a series of CeO2-decorated layered double hydroxides(LDHs,Ce-x)samples for photocatalytic CO2 reduction.It was found that the selectivity and productivity of CO and H2 from photoreduction of CO2 in conjunction with Ru-complex as photosensitizer performed an obvious“volcano-like”trend,with the highest point at Ce-0.15 and the CO/H2 ratio can be widely tunable from 1/7.7 to 1/1.3.Furthermore,compared with LDH,Ce-0.15 also drove photocatalytic CO2 to syngas under 600 nm irradiation.It implied that an optimum amount of CeO2 modifying LDH promoted the photoreduction of CO2 to syngas.This report gives the way to fully utilize the rare earth elements and provides a promising route to enhance the photo-response ability and charge injection efficiency of LDH-based photocatalysts in the synthesis of syngas with a tunable ratio under visible light irradiation. 相似文献
64.
Wenlu Song Rui Huang Hao Guo Chunguang Yin Chuanling Wang Jun Cheng Weijuan Yang 《中国化学工程学报》2021,37(9):114-120
Steam pretreatment was employed to disrupt microalgal cells for lipids extraction.Effects of steam pre-treatment on microstructure of microalgal cells were investigated through scanning electron microscopy(SEM) and transmission electron microscopy (TEM).Effect of treatment on lipid extraction was also stud-ied.Microalgal cell walls were distorted after steam pretreatment due to the hydrolysis of organic macro-molecules contained in cell wall.Maximum curvature was increased from 1.88 × 10-6 m-1 to 1.43 × 10-7 m-1 after treatment with the steam at 130 ℃.The fractal dimension of microalgal cells increased from 1.25 to 1.30 after pretreatment for 15 min,and further increased to 1.47 when the pre-treatment time was increased to 60 min.Increased steam pretreatment temperature and time enhanced the hydrolysis of organic macromolecules,and finally destroyed microalgal cell walls at pretreatment temperature of 130 ℃ and pretreatment time of 60 min.Lipid extracted from wet microalgal was signif-icantly increased (2.1-fold) after pretreatment. 相似文献
65.
Michael Hausmann Martin Falk Charlotte Neitzel Andreas Hofmann Abin Biswas Theresa Gier Iva Falkova Dieter W. Heermann Georg Hildenbrand 《International journal of molecular sciences》2021,22(7)
In cancer therapy, the application of (fractionated) harsh radiation treatment is state of the art for many types of tumors. However, ionizing radiation is a “double-edged sword”—it can kill the tumor but can also promote the selection of radioresistant tumor cell clones or even initiate carcinogenesis in the normal irradiated tissue. Individualized radiotherapy would reduce these risks and boost the treatment, but its development requires a deep understanding of DNA damage and repair processes and the corresponding control mechanisms. DNA double strand breaks (DSBs) and their repair play a critical role in the cellular response to radiation. In previous years, it has become apparent that, beyond genetic and epigenetic determinants, the structural aspects of damaged chromatin (i.e., not only of DSBs themselves but also of the whole damage-surrounding chromatin domains) form another layer of complex DSB regulation. In the present article, we summarize the application of super-resolution single molecule localization microscopy (SMLM) for investigations of these structural aspects with emphasis on the relationship between the nano-architecture of radiation-induced repair foci (IRIFs), represented here by γH2AX foci, and their chromatin environment. Using irradiated HeLa cell cultures as an example, we show repair-dependent rearrangements of damaged chromatin and analyze the architecture of γH2AX repair clusters according to topological similarities. Although HeLa cells are known to have highly aberrant genomes, the topological similarity of γH2AX was high, indicating a functional, presumptively genome type-independent relevance of structural aspects in DSB repair. Remarkably, nano-scaled chromatin rearrangements during repair depended both on the chromatin domain type and the treatment. Based on these results, we demonstrate how the nano-architecture and topology of IRIFs and chromatin can be determined, point to the methodological relevance of SMLM, and discuss the consequences of the observed phenomena for the DSB repair network regulation or, for instance, radiation treatment outcomes. 相似文献
66.
Damien Hunter Kee Heng Navdeep Mann Ravinder Anand-Ivell Richard Ivell 《International journal of molecular sciences》2021,22(8)
Xenobiotic exposure during pregnancy and lactation has been linked to perinatal changes in male reproductive outcomes and other endocrine parameters. This pilot study wished to assess whether brief maternal exposure of rats to xenobiotics dibutyl phthalate (DBP) or diethylstilbestrol (DES) might also cause long-term changes in hypothalamic gene expression or in reproductive behavior of the resulting offspring. Time-mated female Sprague Dawley rats were given either DBP (500 mg/kg body weight, every second day from GD14.5 to PND6), DES (125 µg/kg body weight at GD14.5 and GD16.5 only), or vehicle (n = 8–12 per group) and mild endocrine disruption was confirmed by monitoring postnatal anogenital distance. Hypothalamic RNA from male and female offspring at PND10, PND24 and PND90 was analyzed by qRT-PCR for expression of aromatase, oxytocin, vasopressin, ER-alpha, ER-beta, kisspeptin, and GnRH genes. Reproductive behavior was monitored in male and female offspring from PND60 to PND90. Particularly, DES treatment led to significant changes in hypothalamic gene expression, which for the oxytocin gene was still evident at PND90, as well as in sexual behavior. In conclusion, maternal xenobiotic exposure may not only alter endocrine systems in offspring but, by impacting on brain development at a critical time, can have long-term effects on male or female sexual behavior. 相似文献
67.
68.
摘要:在国内某转炉钢厂采用“留渣 双渣”工艺技术进行脱磷工艺试验。结果表明:随着转炉前期脱磷率不断升高,终点脱磷率不断提高。铁水硅含量对前期脱磷率的影响最大。根据铁水成分,在冶炼前期适当降低供氧强度、降低气固氧比、加入适量石灰及烧结矿,均有利于前期脱磷率的提高。在一倒时每吨钢液加入4~8kg石灰,不影响出钢温度,可提高一倒-终点阶段脱磷率,同时可提高终点脱磷率。从终点的控制效果可知,终点炉渣碱度应保持不小于3.0,炉渣中FeO质量分数在16%~20%,并适当降低终点出钢温度在1610~1630℃,有利于终点脱磷率的提高。通过加强熔池搅拌,促进钢渣反应趋于平衡,有利于终点磷分配比提高,从而可进一步提高终点脱磷率。 相似文献
69.
双滑移取向Cu单晶的循环形变行为──Ⅱ.滑移带和形变带SCIEI 总被引:2,自引:0,他引:2
用光学显微镜和扫描电镜研究了双滑移取向([034],[117])Cu单晶循环饱和后的表面形貌,塑性分切应变幅(γpl)低于10^(-3)时,[034]晶体表面上要为主滑移系的驻留滑移带(PSBs)占据,次滑移只在边缘区域启动,其PSBs细窄(<1μm),体积百分数在1%以下.γpl>10^(-3)时,次滑移开始在试样的中部启动,同时,表面出现二种贯穿晶体的宏观形变带(DBI,DBII),滑移带在形变带内集中.[117]晶体在γpl=4.4×10^(-4)时,双滑移现象已十分明显.γpl>10^(-3)时,表面也形成与前者相似的形变带.DBI的惯习面与主滑移面平行([034]晶体)或接近([117]晶体),DBII的惯习面则与前者垂直,文章讨论了形变带形成的可能原因. 相似文献
70.