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61.
《岩石力学与岩土工程学报(英文版)》2020,12(5):943-959
In this study, servo-controlled biaxial compression tests were conducted on marble specimens to investigate their failure characteristics and fracturing process. The complete stress–strain curves were obtained, and the three-dimensional (3D) features of the failure surfaces were acquired by 3D laser scanning. Acoustic emission (AE) monitoring and moment tensor (MT) analysis were used in combination to better understand the fracturing mechanism of marble under biaxial compression. It was noted that a type of 3D stepwise cracking behaviour occurred on the fracturing surfaces of the examined specimens. The stress dropped multiple times, and a repeated fracturing mode corresponding to the repeated stress drops in the post-peak regime was observed. Three substages, i.e. stress stabilisation, stress decrease and stress increase, were identified for a single fracturing mode. Then quantitative and statistical analyses of the fracturing process at each substage were discussed. Based on the testing results, it was found that at the stress stabilisation substage, the proportion of mixed-mode fractures increased. At the stress decrease substage, the proportion of mixed-mode fractures decreased, and the tensile or shear fractures increased. At the stress increase substage, the proportion of mixed-mode or tensile fractures decreased, and the shear fractures increased. Finally, a conceptual model for the stepwise crack formation was proposed. 相似文献
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设计并实现了一种基于电话通道的家用电器遥控装置。该装置采用单片机智能控制,利用不同的提示音达到对不同操作的提示和受控方状态的信息反馈,从而使操作者能及时了解受控方信息,使产品达到交互式与智能化。经过实际测试:该装置经济、可靠,符合未来家电的智能化发展方向,具有一定的实用价值。 相似文献
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基于三菱FXIN_40MT可编程控制器设计抢答器模块,使可编程控制器实训台功能更强,能完成丰富多彩且具有不同专业特色的实训项目。针对FXIN_40MT的输出点不够,采用软硬件结合的设计方案节省I/O点;针对模块电路体积的尺寸要求,采用FXIN_40MT的可编程元件特殊辅助继电器M8013编程为倒计时电路提供秒时钟信号、利用特殊辅助继电器M8011编程为超时语音报警电路提供100Hz的输入信号简化硬件电路以减小模块体积;采用顺序控制编程方法编写抢答器的指令表程序。电路具有抢答选手编号显示功能、抢答倒计时功能和答题超时语音声光报警功能.答题时间可在0~99s范围内设置,抢答器具有小于15ms分辨率。 相似文献
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文章根据电话监控与监管的要求,设计和简化了共用串口的数据采集与数据通信电路,DTMF输出信号耦合电路和摘挂机检测与模拟摘挂机电路。通过反复的实验和分析,实现了来电号码的检测和状态检测,同时还能检测并线电话的主叫号码以及进行主叫状态的检测,上位机还可以发送控制指令拨打指定号码。本系统具有完善的功能和精简的电路结构,是一个经济、实用电话监控系统。 相似文献
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Margarita Alfimova Nikolay Kondratyev Galina Korovaitseva Tatyana Lezheiko Victoria Plakunova Marina Gabaeva Vera Golimbet 《International journal of molecular sciences》2022,23(20)
As genetic and environmental influences on schizophrenia might converge on DNA methylation (DNAm) within loci which are both associated with the disease and implicated in response to environmental stress, we examined whether DNAm within CYP17A1, a hypothalamus–pituitary–adrenal axis gene which is situated within the schizophrenia risk locus 10q24.32, would mediate genetic and environmental effects on stress-related schizophrenia symptoms. DNAm within an exonic–intronic fragment of CYP17A1 was assessed in the blood of 66 schizophrenia patients and 63 controls using single-molecule real-time bisulfite sequencing. Additionally, the VNTR polymorphism of the AS3MT gene, a plausible causal variant within the 10q24.32 locus, was genotyped in extended patient and control samples (n = 700). The effects of local haplotype, VNTR and a polyenviromic risk score (PERS) on DNAm, episodic verbal memory, executive functions, depression, and suicidality of patients were assessed. Haplotype and PERS differentially influenced DNAm at four variably methylated sites identified within the fragment, with stochastic, additive, and allele-specific effects being found. An allele-specific DNAm at CpG-SNP rs3781286 mediated the relationship between the local haplotype and verbal fluency. Our findings do not confirm that the interrogated DNA fragment is a place where genetic and environmental risk factors converge to influence schizophrenia symptoms through DNAm. 相似文献