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1.
非金属管道因具有优良的耐腐蚀性,在油田得到广泛应用,但其物理机械性能较金属管道差,又限制了在油田的推广,因此有必要对非金属管道的性能进行综合评价,以达到合理选用非金属管道、充分发挥其防腐性能的目的。文章对玻璃钢管、钢骨架复合管、PE内衬管、玻璃釉内衬管和尼龙复合管进行了一年的中试应用及解剖试验评价,认为钢骨架复合管、尼龙复合管的防腐性能及整体性能较好,作为油田集输系统比较适宜的内防腐技术有较好的应用前景;玻璃钢管不适宜在较大压力下应用;PE内衬管防腐性能较好,但内衬与管道的结合力差,玻璃釉内衬管的防腐性能差,二者均不适宜在油田推广应用。 相似文献
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卸荷裂隙在水利水电工程建设中的危害 总被引:3,自引:0,他引:3
卸荷裂隙是对水工建筑物稳定最不利的软弱结构面之一。文中较系统地介绍了这种结构面的特点、分布规律、形成的力学机理、对工程的危害、勘查方法及处理措施。 相似文献
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Te-Yung Fang Pa-Chun Wang Chih-Hsien Liu Mu-Chun Su Shih-Ching Yeh 《Computer methods and programs in biomedicine》2014
Introduction
Virtual reality simulation training may improve knowledge of anatomy and surgical skills. We evaluated a 3-dimensional, haptic, virtual reality temporal bone simulator for dissection training.Methods
The subjects were 7 otolaryngology residents (3 training sessions each) and 7 medical students (1 training session each). The virtual reality temporal bone simulation station included a computer with software that was linked to a force-feedback hand stylus, and the system recorded performance and collisions with vital anatomic structures. Subjects performed virtual reality dissections and completed questionnaires after the training sessions.Results
Residents and students had favorable responses to most questions of the technology acceptance model (TAM) questionnaire. The average TAM scores were above neutral for residents and medical students in all domains, and the average TAM score for residents was significantly higher for the usefulness domain and lower for the playful domain than students. The average satisfaction questionnaire for residents showed that residents had greater overall satisfaction with cadaver temporal bone dissection training than training with the virtual reality simulator or plastic temporal bone. For medical students, the average comprehension score was significantly increased from before to after training for all anatomic structures. Medical students had significantly more collisions with the dura than residents. The residents had similar mean performance scores after the first and third training sessions for all dissection procedures.Discussion
The virtual reality temporal bone simulator provided satisfactory training for otolaryngology residents and medical students. 相似文献5.
为了研究夹层内的血流动力学变化对夹层转归的重要影响,并期望为临床判断主动脉夹层发展及转归提供理论依据,通过3D打印技术制作不同出入口比例及破口大小的B型主动脉夹层模型,对主动脉夹层内血流变化进行模拟,并测量观察主动脉夹层模型假腔内压力变化及流场情况.真腔内固定压力为18.620、21.280 k Pa两组中,不同破口比例的假腔入口压力比普遍均小于夹层模型内其他假腔位置,且压力值低于真腔压力;真腔内压力为23.940 k Pa组中,破口比例为2∶1的夹层模型内假腔压力比较其他破口比例模型的压力比明显升高;所有模型真腔固定水压为21.280、23.940 k Pa下均可观测到同真腔压力下,真腔流速更快,其内部压力低于假腔.同一模型中,假腔压力普遍低于真腔压力;相同压力下,原发破口大的模型假腔流速相对较低,而涡流明显;相同模型相同压力下,假腔流速低于真腔,假腔的涡流更为明显,复杂的涡流和旋动对壁面造成冲击进而使假腔破裂风险增加. 相似文献
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Kamalrulnizam Bin Abu Bakar Fatima Tul Zuhra Babangida Isyaku Fuad A. Ghaleb 《计算机、材料和连续体(英文)》2023,75(1):785-798
The Internet of Medical Things (IoMT) emerges with the vision of the Wireless Body Sensor Network (WBSN) to improve the health monitoring systems and has an enormous impact on the healthcare system for recognizing the levels of risk/severity factors (premature diagnosis, treatment, and supervision of chronic disease i.e., cancer) via wearable/electronic health sensor i.e., wireless endoscopic capsule. However, AI-assisted endoscopy plays a very significant role in the detection of gastric cancer. Convolutional Neural Network (CNN) has been widely used to diagnose gastric cancer based on various feature extraction models, consequently, limiting the identification and categorization performance in terms of cancerous stages and grades associated with each type of gastric cancer. This paper proposed an optimized AI-based approach to diagnose and assess the risk factor of gastric cancer based on its type, stage, and grade in the endoscopic images for smart healthcare applications. The proposed method is categorized into five phases such as image pre-processing, Four-Dimensional (4D) image conversion, image segmentation, K-Nearest Neighbour (K-NN) classification, and multi-grading and staging of image intensities. Moreover, the performance of the proposed method has experimented on two different datasets consisting of color and black and white endoscopic images. The simulation results verified that the proposed approach is capable of perceiving gastric cancer with 88.09% sensitivity, 95.77% specificity, and 96.55% overall accuracy respectively. 相似文献
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大庆油田北三区位于大庆长垣萨尔图油田纯油区内。该区块特高含水期剩余油高度分散,挖潜难度大,各层系间含水差异越来越小,注水低效无效循环越来越严重,过渡带开发效果有待提高。虽然厚油层综合含水高,但剩余油储量大,为下一步的重点挖潜目标,厚油层砂体中高弯曲分流河道砂体所占比重最大。针对高弯曲分流河道,以北三区西部SⅡ1+2b层为例,建立厚油层储层建筑结构(构型)的分布模式,研制储层建筑结构、三维建模及数值模拟的地质解剖、预测和建模数模技术,深化高弯曲分流河道砂体内部建筑结构和剩余油分布的认识,为开发动态分析、剩余油挖潜提供更准确的地质依据。 相似文献
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目的 探讨腔镜下腋窝淋巴结清扫术的安全性、可行性,并对患者术手上肢功能状况进行评价.方法 比较32例乳腺癌腔镜下腋窝淋巴结清扫术(腔镜组)与35例乳腺癌传统腋窝淋巴结清扫术(传统组)的术中出血量、手术时间和淋巴结清扫数目;术后3个月随访上肢情况,比较2组患侧上肢的感觉、运动功能和水肿情况.结果 腔镜组术中出血量为(36.25±6.96)mL,显著少于传统组的(68.29±17.45)mL(P<0.01);腔镜组手术时间为(186.41±13.81)min,显著长于传统组的(158.86±16.09)min(P<0.01);2组手术淋巴结清扫数目差异无统计学意义[(16.00±3.47)枚比(16.86±2.94)枚,P>0.05].术后3个月随访患侧上肢情况,感觉异常、运动受限和上肢水肿发生率腔镜组分别为18.75%、6.25%和9.37%,传统组分别为65.71%、28.57%和28.57%,腔镜组患侧上肢感觉异常、运动受限及上肢水肿者明显少于传统组(P<0.01或P<0.05).结论 腔镜下腋窝淋巴结清扫手术安全、可行,具有微创、美观、上肢功能好等优点. 相似文献