大断面矩形管廊在无水砂层中顶进施工时,由于砂土流塑性差,掌子面易出现"闭塞"、"喷涌"和"结饼"等不良现象,进而影响施工进度。本文以北京市通州区畅和西路(兆善大街-潞阳大街)大断面矩形顶管施工为工程...大断面矩形管廊在无水砂层中顶进施工时,由于砂土流塑性差,掌子面易出现"闭塞"、"喷涌"和"结饼"等不良现象,进而影响施工进度。本文以北京市通州区畅和西路(兆善大街-潞阳大街)大断面矩形顶管施工为工程依托,开展了掌子面渣土改良试验研究。以不同配比的钠基膨润土、聚丙烯酰胺(PAM)和水作为砂土改良的添加剂,并通过黏度试验和滤失试验对不同配比的改良剂(膨润土添加聚丙烯酰胺)的性能进行了研究,结合改良后渣土的坍落度试验、直剪试验与压缩试验,评价了掌子面渣土的改良效果。研究表明:膨润土添加聚丙烯酰胺对无水砂层的改良效果显著。通过改良剂性能试验,初步筛选出膨润土∶PAM∶水为60︰2︰1000,70︰1.5︰1000,70︰2︰1000和80︰1.5︰1000等4种性能优良的改良剂配比;通过渣土改良效果试验得出,改良剂最优配比膨润土∶PAM∶水为70︰2︰1000,改良剂最优注入比为15%;通过添加改良剂使得改良后渣土的坍落度降低30 mm,黏聚力增加9.3 k Pa,内摩擦角降低6.5°,压缩系数增加0.090 MPa-1,达到了无水砂层土体处于流塑性状态的预期效果,有效降低了大断面矩形管廊侧壁阻力,提高了顶进效率。展开更多
Vanadium dioxide thin films were fabricated through annealing vanadium oxide thin films deposited by dual ion beam sputtering. X-ray diffraction （XRD）, atom force microscopy （AFM）, and Fourier transform infrared s...Vanadium dioxide thin films were fabricated through annealing vanadium oxide thin films deposited by dual ion beam sputtering. X-ray diffraction （XRD）, atom force microscopy （AFM）, and Fourier transform infrared spectrum （FTIR） were employed to measure the crystalline structure, surface morphology, and infrared optical transmittance. The phase transition properties were characterized by transmittance. The results show that the annealed vanadium oxide thin film is composed of monoclinic VO2, with preferred orientation of （011）. The maximum of transmittance change is beyond 65% as the temperature increases from 20 to 80 C. The reversible changes in optical transmittance against temperature were observed. The change rate of transmittance at short wavelength is higher than that at long wavelength at the same temperature across semiconductor-metal phase transition. This phenomenon was discussed using diffraction effect.展开更多
目的:通过整合肺腺癌(lung adenocarcinoma,LUAD)临床信息组、基因组和转录组的多组学信息,构建预后相关风险预测模型,为肺腺癌患者的预后风险预测提供依据。方法:通过肿瘤基因图谱(the cancer genome atlas,TCGA)网站下载522例肺腺癌...目的:通过整合肺腺癌(lung adenocarcinoma,LUAD)临床信息组、基因组和转录组的多组学信息,构建预后相关风险预测模型,为肺腺癌患者的预后风险预测提供依据。方法:通过肿瘤基因图谱(the cancer genome atlas,TCGA)网站下载522例肺腺癌患者数据,完成肺腺癌患者多组学数据库构建。对经过质量控制的数据库,采用Cox比例风险模型评价多组学数据对LUAD预后的影响,构建基于临床信息、基因分型和基因表达多组学信息的预后风险预测模型,并使用受试者工作特征(receiver operating characteristic,ROC)曲线和曲线下面积(area under curve,AUC)评估预后模型风险识别的能力。结果:共386例肺腺癌患者纳入多组学数据库,分别筛选出1个临床信息组、5个基因组单核苷酸多态性(single nucleotide polymorphisms,SNP)和4个转录组mRNA预后相关特征因素与肺腺癌的预后相关。与肺腺癌低风险组相比,高风险组患者较低风险组的预后更差(HR=3.67,95%CI=2.46～5.49,P=1.96×10-10),联合基因组、转录组与临床信息构建多组学预后指数后,其ROC曲线下面积为0.694(95%CI=0.633～0.754)。结论:采用联合临床信息组、基因组和转录组特征的多组学信息构建的预后风险预测指数可有效区分肺腺癌患者预后好坏,其研究结果将为肺腺癌患者的精准治疗提供有效支撑。展开更多
为了解决交换机静态分配给多维信息并且静态配置多维信息,因此流量动态可能导致响应时间长并且导致高维护成本问题,将多维信息SDN数据优化(SDN data optimization for multi-dimensional information,SDOMI)制定为在线优化,以最大限度...为了解决交换机静态分配给多维信息并且静态配置多维信息,因此流量动态可能导致响应时间长并且导致高维护成本问题,将多维信息SDN数据优化(SDN data optimization for multi-dimensional information,SDOMI)制定为在线优化,以最大限度地降低由多维信息集群的响应时间和维护所导致的总成本。通过应用随机固定水平控制(RFHC)框架,将SDOMI分解为一系列稳定的转移匹配问题,保证竞争比率的小损失。由于匹配问题是NP难的,提出了一种关联规则映射算法,它集成了匹配理论和关联规则映射中的关键概念,以有效地解决它。理论分析证明的算法在几十次迭代中收敛于近似最优Nash稳定解,并在多维信息之间实现更好的负载平衡。展开更多
In the surgery of lumbar disc herniation(LDH),the nerve root retractor is used to pull the nerve root to prevent damage.The traditional medical nerve root retractor cannot quantify the force on the nerve root.In order...In the surgery of lumbar disc herniation(LDH),the nerve root retractor is used to pull the nerve root to prevent damage.The traditional medical nerve root retractor cannot quantify the force on the nerve root.In order to improve the nerve root retractor,this paper proposes an intraoperative lumbar neurological force monitoring system.The core module of this system is the improved nerve root retractor equipped with the high density flexible pressure sensor array.The high density microneedle array and multiple pressure detection units are used in the pressure sensor to realise sensitive pressure monitoring in a narrow surgical operation area.The sensing area is 4 mm×17 mm,including 6 detection units.The sensitivity of sensor is 67.30%/N in the range of 0-5 N.This system is used for in vitro animal experiments,which can continuously detect pressure.展开更多
文摘大断面矩形管廊在无水砂层中顶进施工时,由于砂土流塑性差,掌子面易出现"闭塞"、"喷涌"和"结饼"等不良现象,进而影响施工进度。本文以北京市通州区畅和西路(兆善大街-潞阳大街)大断面矩形顶管施工为工程依托,开展了掌子面渣土改良试验研究。以不同配比的钠基膨润土、聚丙烯酰胺(PAM)和水作为砂土改良的添加剂,并通过黏度试验和滤失试验对不同配比的改良剂(膨润土添加聚丙烯酰胺)的性能进行了研究,结合改良后渣土的坍落度试验、直剪试验与压缩试验,评价了掌子面渣土的改良效果。研究表明:膨润土添加聚丙烯酰胺对无水砂层的改良效果显著。通过改良剂性能试验,初步筛选出膨润土∶PAM∶水为60︰2︰1000,70︰1.5︰1000,70︰2︰1000和80︰1.5︰1000等4种性能优良的改良剂配比;通过渣土改良效果试验得出,改良剂最优配比膨润土∶PAM∶水为70︰2︰1000,改良剂最优注入比为15%;通过添加改良剂使得改良后渣土的坍落度降低30 mm,黏聚力增加9.3 k Pa,内摩擦角降低6.5°,压缩系数增加0.090 MPa-1,达到了无水砂层土体处于流塑性状态的预期效果,有效降低了大断面矩形管廊侧壁阻力,提高了顶进效率。
基金supported by the National High-Tech Research and Development Program of China(No.2008AA031401)the National Natural Science Foundation of China (No.60771019)+2 种基金the Natural Science Foundation of Tianjin, China (No.08JCZD-JC17500)the StateKey Lab on Integrated Optoelectronics (No.2010KFB001)The Research Fund for the Doctoral Program of Higher Education of China (No.20100032120029)
文摘Vanadium dioxide thin films were fabricated through annealing vanadium oxide thin films deposited by dual ion beam sputtering. X-ray diffraction （XRD）, atom force microscopy （AFM）, and Fourier transform infrared spectrum （FTIR） were employed to measure the crystalline structure, surface morphology, and infrared optical transmittance. The phase transition properties were characterized by transmittance. The results show that the annealed vanadium oxide thin film is composed of monoclinic VO2, with preferred orientation of （011）. The maximum of transmittance change is beyond 65% as the temperature increases from 20 to 80 C. The reversible changes in optical transmittance against temperature were observed. The change rate of transmittance at short wavelength is higher than that at long wavelength at the same temperature across semiconductor-metal phase transition. This phenomenon was discussed using diffraction effect.
文摘为了解决交换机静态分配给多维信息并且静态配置多维信息,因此流量动态可能导致响应时间长并且导致高维护成本问题,将多维信息SDN数据优化(SDN data optimization for multi-dimensional information,SDOMI)制定为在线优化,以最大限度地降低由多维信息集群的响应时间和维护所导致的总成本。通过应用随机固定水平控制(RFHC)框架,将SDOMI分解为一系列稳定的转移匹配问题,保证竞争比率的小损失。由于匹配问题是NP难的,提出了一种关联规则映射算法,它集成了匹配理论和关联规则映射中的关键概念,以有效地解决它。理论分析证明的算法在几十次迭代中收敛于近似最优Nash稳定解,并在多维信息之间实现更好的负载平衡。
基金the National Key Technologies R&D Program(No.2016YFC0105604)the National Natural Science Foundation of China(No.61474107).
文摘In the surgery of lumbar disc herniation(LDH),the nerve root retractor is used to pull the nerve root to prevent damage.The traditional medical nerve root retractor cannot quantify the force on the nerve root.In order to improve the nerve root retractor,this paper proposes an intraoperative lumbar neurological force monitoring system.The core module of this system is the improved nerve root retractor equipped with the high density flexible pressure sensor array.The high density microneedle array and multiple pressure detection units are used in the pressure sensor to realise sensitive pressure monitoring in a narrow surgical operation area.The sensing area is 4 mm×17 mm,including 6 detection units.The sensitivity of sensor is 67.30%/N in the range of 0-5 N.This system is used for in vitro animal experiments,which can continuously detect pressure.
