Short-Term Nonlinear Response of Tension Leg Platform in Random Sea Waves

Most of the existing mathematical models for analyzing the dynamic response of TLP are based on explicit or implicit assumptions that motions (translations and rotations) are small magnitude. However, when TLP works in severe adverse conditions, the a priori assumption on small displacements may be inadequate. In such situation, the motions should be regarded as finite magnitude. This paper will study stochastic nonlinear dynamic responses of TLP with finite displacements in random waves. The nonlinearities considered are: large amplitude motions, coupling the six degrees-of-freedom, instantaneous position, instantaneous wet surface, free surface effects and viscous drag force. The nonlinear dynamic responses are calculated by using numerical integration procedure in the time domain. After the time histories of the dynamic responses are obtained, we carry out cycle counting of the stress histories of the tethers with rain-flow counting method to get the stress range distribution

Mechanics of offshore pipelines in several operating states and analyzing software

Offshore pipelines are indispensable structures during the marine petroleum exploitation. There are manifold operation states having to do with pipelines such as in situ operation, span, trenching, pipelaying, lifting of pipe/riser, etc. The behavior of pipelines in one state differs greatly from the others. In addition, the structure configuration, the sea severity, and the seabed soil conditions are complex. Therefore, strength analysis of offshore pipelines becomes a rather difficult and onerous task. Presently, there is a lot of technological difficulty in the course of analysis, among which are not only theoretical problems such as geometric non-linearity and moveable boundary, but also practical problems. To tackle the problems, analytical methods, numerical methods such as FEM and shooting method are adopted respectively and jointly. Based on the theoretical research, integrated software named 'Offshore Pipelines Strength Analysis' is developed. This software can carry through strength analysis of pipelines in different operating state, being up to the requirement of engineers. The theoretical background and interface of the software are presented

Performance Analysis of Chaotic Spread Spectrum CDMA Systems

【中文文摘】混沌序列在具有很好随机性的同时,一些序列还具有KroneckerDelta自相关和近似正交的互相关特点,因此被认为是实现直序扩谱CDMA系统较理想的扩谱序列之一,成为近年来研究的热点。文中从异步DS-CDMA系统的模型入手,分析影响CDMA系统性能的关键问题,说明混沌扩谱CDMA系统的性能优点。为了实现混沌扩谱CDMA系统的数值仿真与性能验证,以切比雪夫映射产生的混沌序列为例进行混沌扩谱CDMA系统的性能分析,并与基于Gold和Kasami两种序列的传统DS-CDMA系统进行比较。 【英文文摘】Chaotic sequence is considered as a good candidate for spread spectrum sequence in CDMA systems because it is characterized by good randomness, Kronecker Delta autocorrelation and orthogonal crosscorrelation. Through asynchronous CDMA system model, the authors analyze the key points of chaotic spread spectrum CDMA system performances,choose Chebyshev map to instantiate the virtue of chaotic sequences and compare with the classic Gold and Kasami sequences.国家自然科学基金项目(60076015);; 福建省自然科学基金项目(A0010019);; 福建省高新技术项

EDA工程建模及其管理方法研究

现代电子设计技术面临着集成电路(IC)芯片设计的复杂度不断增大而产品的研发时限不断缩短的挑战。为了提高芯片质量和设计效率,人们将抽象建模的思想应用于芯片设计和管理,提出结合抽象建模技术的芯片设计方法,并且在大规模芯片设计中采用层次化的分组协作。针对当前电子设计自动化(EDA)技术的发展情况,介绍了一种基于统一建模语言(UML)的芯片设计方法及其相关技术,阐述了目前大型EDA工程所采用的层次化分组协作管理方法的原理,分析其优点和不足,并提出了改进方案

Detection of BCR-ABL fusion gene by multiplex RT-PCR combining with capillary electrophoresis

目的建立多重逆转录-聚合酶链反应(rT-PCr)联合毛细管电泳法检测bCr-Abl融合基因,以期应用于慢性粒细胞白血病(CMl)辅助诊断。方法采用重叠延伸法构建bCr-Abl融合基因阳性模板,设计并优化检测bCr-Abl融合基因的多重rT-PCr联合毛细管电泳体系,对检测体系进行初步的性能评估。结果多重rT-PCr技术检测bCr-Abl融合基因(E1A2、E13A2和E14A2)的最低检测限在102~103拷贝/μl;50例临床确诊CMl的患者应用该法检测bCr-Abl融合基因的阳性率为86.0%,其中E13A2型(20.0%),E14A2型(66.0%);本方法与骨髓细胞培养染色体核型分析相比,阳性符合率为97.6%,阴性符合率为75.0%,总符合率为94.0%,2种方法具有较高的一致性(kAPPA=0.765,P>0.05)。结论成功建立检测bCr-Abl融合基因的多重rTPCr联合毛细管电泳方法。该方法操作简单快捷、特异性好、灵敏度高,适合于临床上CMl的辅助诊断和分子分型。Objective To establish a method for detecting BCR-ABL fusion gene by multiplex reverse transcription polymerase chain reaction( RT-PCR),and to provide a useful tool for chronic myeloid leukemia( CML) auxiliary diagnosis.Methods The construction of BCR-ABL fusion gene as positive template was made by overlap extension method.The method of multiplex RT-PCR combining with capillary electrophoresis was designed and optimized.Its primary performance was evaluated.Results The lower detection limit for BCR-ABL fusion gene( ela2,e13a2 and e14a2) by multiplex RT-PCR was 102-103 copies / μL.The positive rate of this method to detect 50 CML patients was 86.0%( e13a2: 20.0% and e14a2: 66.0%).Compared with the results of chromosome karyotype analysis,the positive coincidence rate was 97.6%,and the negative coincidence rate was 75.0%.The 2 methods have high consistency( Kappa = 0.765,P > 0.05).Conclusions The method of multiplex RT-PCR combining with capillary electrophoresis to detect BCR-ABL fusion gene is simple and rapid with good specificity and sensitivity and is very suitable for the clinical detection of CML.福建省自然科学基金计划资助项目(2012J01414); 厦门市科技局计划项目资助课题(3502Z20113013

明线会车、隧道会车及过隧道时的高速列车动力响应

明线会车、隧道会车和过隧道工况下的气动压力波对高速列车的动力响应和运行安全产生很大影响,本文建立了三辆编组的高速列车动力学模型,通过数值仿真得到了列车在三种工况下的车体所受的气动力,基于数值积分分析了列车的动力响应和脱轨系数。研究发现:明线会车和隧道会车工况相比,车辆的侧向运动相反。明线会车和过隧道时,气动载荷对列车的脱轨系数影响较小,而隧道会车时,气动载荷作用对尾车的安全性影响较大

维生素D及其检测与腺癌

维生素d(VITd)是人体必需的重要物质,其经典生理作用为参与钙磷代谢,维持骨骼代谢平衡。近年来,流行病学调查研究表明,VITd水平与多种腺癌的患病率相关,补充VITd后可降低腺癌的发生和骨转移的发生率。针对乳腺、前列腺、甲状腺等腺癌的研究也发现,VITd通过与其受体结合后,作用于下游靶基因,产生一系列与肿瘤发生、发展相关的生物学效应,预示其在临床肿瘤检验中具有重要意义。国家自然科学基金(81272445); 厦门市科技局国家对台科技合作项目(350Z20121153

Preliminary analysis of newly diagnosed acute myeloid leukemia from 2005 to 2012 in Zhongshan Hospital Xiamen University

目的分析厦门大学附属中山医院近年来急性髓性白血病的发病情况与趋势,从中了解本地区急性髓性白血病的流行趋势,为制定科学的防治方法提供依据。方法回顾性分析2005~2012年厦门大学附属中山医院就诊的初发急性髓性白血病病例资料,统计分析年龄、性别、亚型及疗效的差异。结果新发急性髓性白血病患者的男女比例相当,无差异,25至59岁的中青年为高发病人群,其中35至39岁年龄段最高发,75到79岁出现老年人发病小高峰;M2、M3、M5是发病人数最多的三个亚型,且在未成年人、成年人、老年人不同年龄段组的发病比例有显著差异;2005~2012年新增患者人数具有上升趋势。结论 2005~2012年本院新发急性髓性白血病人数呈上升趋势,不同年龄段新发病例疗效差异显著可能与疾病亚型相关。Objective To explore the morbidity and trend of acute myeloid leukemia of Zhongshan Hospital Xiamen University in recent years, and to provide support for its prevention and intervention.Methods The retrospective analysis of acute myeloid leukemia patient of Zhongshan Hospital Xiamen University from 2005 to 2012 was made to analyze the differences among age, gender, subtype, and curative effect.Results The ratio of newly diagnosed acute myeloid leukemia between male and female was nearly same.The incidence of young and middle aged population between 25 to 59 years old was high.Among them, the highest incidence appeared in people aged 35 to 39.There was a small peak of incidence in old population aged 75 to 79.M2, M3, M5 were the most common subtypes of all patients, and there was a significant difference among age groups of minor, adult, and senior citizens.The newly diagnosed acute myeloid leukemia of each year was upward trend from 2005 to 2012.Conclusion The trend of newly diagnosed acute myeloid leukemia appeared upward.There was a significant difference of curative effects in newly diagnosed group of different ages may be caused by the specific subtype.福建省自然科学基金计划资助项目(2012J01414); 厦门市科技局计划项目资助课题(3502Z20113013); 福建省卫生厅青年课题(2013-2-92

High Aspect Ratio (L/D) Riser Viv Prediction Using Wake Oscillator Model

A two-dimensional (2-D) vortex-induced vibration (VIV) prediction model for high aspect ratio (LID) riser subjected to uniform and sheared flow is studied in this paper. The nonlinear structure equations are considered. The near wake dynamics describing the fluctuating nature of vortex shedding is modeled using classical van der Pol equation. A new approach was applied to calibrate the empirical parameters in the wake oscillator model. Compared the predicted results with the experimental data and computational fluid dynamic (CFD) results. Good agreements are observed. It can be concluded that the present model can be used as simple computational tool in predicting some aspects of VIV of long flexible structures. (C) 2008 Elsevier Ltd. All rights reserved