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Huai-feng Peng Gang-qiang Kong Han-long Liu Hossam Abuel-Naga Yao-hu Hao 《浙江大学学报(A卷英文版)》2018,19(8):638-649
This paper presents the experimental results of small-scale model tests of an instrumented floating energy pile group in which the piles were embedded in dry medium-dense sand and subjected to the seasonal temperature pattern of the city of Nanjing in China. The study also included a model test to assess the effect of including nonthermal piles on the thermo-mechanical behaviour of the floating energy pile group. For comparison, a model test of a single floating energy pile embedded in the same soil and subjected to a similar temperature pattern was also conducted. The results show that the thermo-mechanical behaviour of an energy pile group is different from that of a single energy pile in terms of the thermally induced change in axial pile stress and the displacement of the pile top and tip. This difference in behaviour could be explained by the higher lateral confining pressure expected on a single pile than on a pile in a group due to pile interaction effects, which could lead to different end restraint boundary conditions. We conclude that the thermo-mechanical behaviour of an energy pile is controlled mainly by the end restraint boundary conditions. 相似文献
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ISMAIL I.A. AMIN Mohammed DIAB Hossam 《浙江大学学报(A卷英文版)》2006,7(12):2022-2030
INTRODUCTION Owing to the advance in network technology, information security is an increasingly important problem. Popular application of multimedia tech- nology and increasingly transmission ability of net- work gradually leads us to acquire information di- rectly and clearly through images. Hence, data secu- rity has become a critical and imperative issue. Hill cipher is a block cipher that has several advantages such as disguising letter frequencies of the plaintext, its simplicity be… 相似文献
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Faten Zahran Ramzy Rashed Mohamed Omran Hossam Darwish Arafa Belal 《Indian journal of clinical biochemistry : IJCB》2021,36(3):319
A metabolomic study for determination of certain urinary metabolomes, 1-methyladenosine (1-MA), 1-methylguanosine (1-MG), and 8-hydroxy-2′ deoxyguanosine (8-OHdG) in urine specimens of breast cancer patients. The accuracy of these metabolites and their combined score with cancer antigen 15-3 (CA15-3) was developed to improve the early detection of breast cancer. This study recruited 52 healthy individuals, 47 benign breast tumors, and 167 malignant breast tumor patients. Urine samples were handled to adjust the creatinine concentrations to 8 mg/dL (0.7 mmol/L) and analyzed using GC–MS to detect and quantify the selected urinary metabolomes in urine samples of all participants. The accuracy of individual urinary metabolomes and their combination with CA15-3 were evaluated using multivariate statistical analysis. The cutoff value of CA15-3 was 32.5 U/mL. Cutoff values of 1-MA, 1-MG, and 8-OHdG were 2.19, 2.1, and 7.3 µmol/mmol creatinine, respectively. The concentrations of 1-MA, 1-MG, and 8-OHdG were significantly higher in breast cancer patients, especially in the early-stage. The combination of three urinary metabolomes with CA15-3 improves the diagnostic sensitivity of breast cancer. For the combined score, the area under the curve (AUC) value of combined score ranged from 0.820 to 0.950, with high accuracy, ranged from 77.0 to 95.5%. The most significant AUC (0.973), sensitivity (90.1%), selectivity (94.0%) was recorded at comparing the healthy control with the early-stage of malignant breast cancer. In conclusion, the combination of three urinary metabolomes with serum CA15-3 improves the diagnostic sensitivity of breast cancer. 相似文献
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Miri Barak Abeer Watted Hossam Haick 《Assessment & Evaluation in Higher Education》2020,45(2):212-223
AbstractThe goal of this study was to establish the validity and reliability of a self-report tool for assessing individual differences in innovative thinking, based on a modification of the ‘innovative behavior scale’. A five-stage study was conducted among engineering students worldwide, who enrolled in a massive open online course in Nanotechnology and Nanosensors. Content validity was established by a panel of experts in engineering education. Construct validity was established through exploratory and confirmatory factor analysis, indicating a four-factor solution with 13 items loaded above critical level. Known-groups validity revealed differences among learners with distinct expertise. The scale’s stability across populations and over time was confirmed, providing there has been no intentional intervention. Finally, the scale’s concurrent validity was reinforced through data triangulation with actual practice - the fabrication of innovative nanosensors. 相似文献
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目的:能量桩在工作状态下的热力学响应十分复杂,同时受到桩顶荷载、桩侧摩擦以及温度等多重因素的影响。当群桩中出现部分能量桩不工作时,将造成上部结构的额外应力与变形。因此,本文重点探讨摩擦型能量桩群桩中部分能量桩在加热制冷作用下的热力学响应,并与单桩的热力学效应进行对比分析。创新点:1.通过建立摩擦型能量桩群桩模型试验,探讨桩侧摩擦对能量桩群桩的影响规律;2.利用能量桩群桩与单桩对比,揭示能量桩群桩与单桩热力响应特性的区别;3.揭示部分能量桩加热制冷作用对能量桩群桩的影响机理。方法:1.建立摩擦型能量桩群桩及单桩的模型试验;2.将能量桩群桩与单桩进行对比,研究能量桩群桩与单桩热力响应特性的区别;3.进行能量桩群桩部分加热制冷试验。结论:1.对于长期工作的能量群桩,可以将其视为一个长宽高与整个群桩相同的热交换体,其表面温度与群桩的平均表面温度一致。2.能量桩单桩在加热过程中,由于桩底受到的限制较大,所以桩顶位移大于桩底位移。3.能量桩单桩在制冷过程中,由于土体及桩体收缩,会出现明显的下沉。4.能量桩群桩桩帽在加热过程中,桩帽的位移与群桩的上半部分长度相关;在本文的试验中,由于群桩上半部分受土的限制较小,因此其位移与桩自由膨胀的位移一样。5.能量桩群桩在制冷期间,群桩的下沉量级要比单桩的大。6.在制冷过程中,能量桩群桩在群桩效应作用下,内部桩的桩底热位移较大。7.能量桩群桩在部分加热的情况下,会出现不均匀沉降,且在加热期间,沉降主要受到不工作桩的牵制影响;而在制冷期间,沉降主要受工作桩的下沉影响。8.摩擦型能量桩的热引起的桩身轴力是与桩侧的土压力大小相关的;由于群桩在群桩效应作用下,桩侧土压力要小于单桩,因此群桩的热引起的桩身轴力要大于单桩。 相似文献
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OBJECTIVE: The goal of the study was to investigate whether maltreated children differ from nonmaltreated children with regard to their social skills and play behaviors. METHOD: The social skills and free-play behaviors of 30 3- to 5-year-old maltreated and nonmaltreated children were compared. Fifteen children with a range of maltreatment experiences drawn from a hospital-based therapeutic nursery treatment program and 15 demographically similar children drawn from a home-based Head Start program participated in the study. All children were of low socioeconomic status. Children's free-play peer interactions were videotaped during the first 3 months of attendance in either program and analyzed along social and cognitive dimensions. Teachers and therapists rated children's social skills in peer interactions. RESULTS: Maltreated children were found to have significantly poorer skill in initiating interactions with peers and maintaining self-control, as well as a greater number of problem behaviors. Significant differences were not found between groups with regard to social participation or cognitive level of play. Significant correlations of moderate strength were found between social participation in play and social skills for the sample as a whole: total social skills score was positively related to interactive play, and negatively related to solitary play. CONCLUSION: The results suggest that the experience of maltreatment has a negative impact on children's developing interpersonal skills above and beyond the influence of factors associated with low socioeconomic status and other environmental stressors. 相似文献
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本文介绍了海湾大学医学科学学院成立24年来的教育经验,包括学院的规划与发展、课程设置及跨国协作等.希望其先进教学方法、理念能够进一步推动我国医学教育的发展. 相似文献