管棚保护下框架桥顶进工程高程控制分析

大直径管棚保护下直接顶进预制箱涵技术是近年来国内发展起来的一种全新的施工技术,但其难度大,理论发展不完善,可借鉴的经验少.依托南昌市新龙岗大道下穿向莆铁路工程,根据实际工程情况建立力学分析模型,计算框架桥下钢管的受力,并根据钢管的受力情况假定钢管为Winkler弹性地基梁,运用弹性地基梁理论建立钢管挠曲微分方程并求解该微分方程,从而计算出框架桥顶进过程中的钢管挠曲变形,进而确定顶进过程中框架桥高程偏差情况.理论分析表明,底排管棚的支撑和引导作用有助于框架桥推进,并能有效遏制框架桥\"栽头\"和\"抬头\"现象,对于现场工程施工具有很好的参考价值.福建省自然科学基金(2014J01208

Tracking of time-varying underwater acoustic channels based on multipath parameter model and hybrid optimization

针对海洋水声信道的稀疏特性,将多径水声信道冲激响应建为一个由各多径分量的时延和幅度组成的多径参数模型.该模型中输入信号向量产生的响应与多径时延参数呈非线性关系,与多径幅度参数呈线性关系.基于此特点,针对海洋水声信道的时变特性,分别采用进化算法和lMS自适应算法对模型中的多径时延和幅度参数进行混合寻优,从而解决时变信道条件下模型参数寻优困难的问题.仿真及海试信道跟踪实验结果表明:采用多径参数模型可降低模型寻优对象的维数,减少运算复杂性,提高估计效率;采用混合优化算法可减少多径参数模型的非线性寻优的复杂度,与进化算法相比,该算法具有更优越的时变信道跟踪性能.As for the structural sparsity of impulse response of an underwater acoustic multipath channel,a multipath parameter model consisting of time delays and amplitudes of multipaths is proposed.The response of the multipath parameter model is nonlinear with the time delay parameters,but linear with the amplitude parameters.Based on this characteristic,as for the time-varying character of the underwater acoustic channel,a novel hybrid optimization method is developed to facilitate the optimization of the parameters of the time varying channel model;that is,the evolutionary algorithm and the least mean square algorithm are applied to address the model's time delay parameters and amplitude parameters,respectively.The results of simulation and sea-trial data demonstrate that the multipath parameter model can decrease the orders of the optimized parameters,reduce computational complexity and improve estimation efficiency.Besides,the hybrid optimization method can reduce the complexity of nonlinear optimization of the multipath parameter model,and compared with the classic evolutionary algorithm,it has a better tracking performance of the time-varying channel.国家自然科学基金资助项目(10704063);福建省高等学校新世纪优秀人才支持计划资助项目(NCETFJ-06XMUCOE

Study on the Characteristics of Loss Ratio and Loading-unloading Response Ratio before Rock Failure

以多种岩石循环加卸载声发射试验为基础,针对岩石损耗比和加卸载响应比特性进行了研究,探索岩石在受载过程中的内部损伤演化和破坏前兆特性。结果表明,在; 循环加卸载下角岩等三种岩石损耗比变化特性一致:低应力水平阶段损耗比较大,呈明显下降趋势;中等应力水平阶段比值下降趋势较平缓;高等应力水平阶段比值; 趋于稳定,在0.08 ~; 0.10时,试样破坏。而钨钼矿等三种岩石加卸载响应比变化特性一致:低应力水平阶段卸载时几乎没有声发射,加卸载响应比较大;中等应力水平阶段卸载时声; 发射较活跃,比值下降至1左右;高等应力水平阶段卸载时声发射很活跃,当比值重新大于1时,试样破坏。试验结果都体现了岩石内部损伤从很小到稳定扩展再到; 不稳定扩展的过程。可见,损耗比和加卸载响应比的变化特性均可用于评价岩石损伤情况,也可用作岩石破坏预测的参考依据。On the basis of the acoustic emission for rock under cyclic loading and; unloading,the characteristics for the loss ratio and loading-unloading; response ratio of rocks is studied,and the evolution of the internal; damage in the course of loading and the precursor characteristics of; failure are explored. The results show that the variation; characteristics of loss ratio of three kinds of rocks like hrnfelswere; are consistent under loading and unloading conditions; The loss ratio is; relatively large in the low stress level stage,and it shows a clear; downward trend. After entering the medium stress level,the ratio; decreases with a relatively flat trend. In higher stress level,the ratio; tends to be stable,and the specimen fails at 0.08~ 0.10. At the same; time,the variation characteristics of loading-unloading response ratio; of three kinds of rocks like tungsten and molybdenum ores are; consistent. There were almost no acoustic emission at the unloading; stage in the low stress level stage,and the loading-unloading response; ratio were relatively large. Acoustic emission was more active at the; unloading stage in the medium stress level,and the ratio dropped to; about 1. In higher stress level,acoustic emission was very active at; unloading stage,and the specimen failed when the ratio increased over 1; again. The results reflect the process of rock internal damage from; small to steady expansion and then to unstable expansion. So the; variation characteristics of loss ratio and loading-unloading response; ration can be used to evaluate the damage of rock,and also can be used; as a reference for prediction of rock failure.国家十二五科技支撑计划项

The Current Situation of Babylonia spp. Farming Industry in Hainan and Prospect Outlook

综述了我国海南省东风螺的养殖历史、养殖产业现状以及存在的问题。针对这些问题,提出了推进海南东风螺产业发展的一些建议。The history,current situation and problems in the farming of Babylonia spp.in Hainan Province were reviewed.Aiming at those problems,several suggestions for promoting Babylonia spp.farming industry development in Hainan were put forward.海洋公益专项(201405020); 2015年海南省科研院所技术开发专项——海南省热带海洋生物资源开发利用创新平台; 南海生物资源开发与利用协同创新中心项

Modeling Influence of Temperature and Salinity on Growth Rate of Larva in Noble Scallop,Chlamys nobilis(Reeve) by Response Surface Methodology(RSM)

采用中心复合设计(CEnTrAl COMPOSITE dESIgn,CCd)的试验设计法研究了温度和盐度2个环境因子对华贵栉孔扇贝幼虫生长的影响。同时采用响应曲面分析法及基于响应曲面基础之上的满意度函数法确立了生长的二次回归方程,同时进行优化处理得到温度与盐度的最佳组合。结果表明,在华贵栉孔扇贝幼虫生长过程中温度与盐度在一定的范围内的互作效应不显著,其中温度效应较为明显。温度对壳长瞬时生长影响的一次项效应和二次项效应均达到显著水平(P<0.000 1)。盐度对壳长瞬时生长影响一次项效应显著(P<0.000 1),然而,盐度对壳长瞬时生长影响的二次项效应达到显著水平(P<0.000 1)。分析响应曲面法优化温度和盐度对华贵栉孔扇贝幼虫壳长瞬时生长率的影响,其结果显示最佳温度与盐度组合为25.33℃与29.42‰,此条件下瞬时生长率为7.91%,其满意度函数值达到85.57%。在生产实践中,严格控制温度和盐度范围,使其在最优值范围内,将会显著提高苗种生产效率。In this study,the combined effects of temperature and salinity on the instantaneous growth rate(IGR) of larva in noble scallop,Chlamys nobilis,was evaluated using the central composite orthogonal quadratic design and the response surface methodology.The results showed that the linear effects of temperature on IGR was statistically highly significant(P<0.000 1);the linear effects of salinity on IGR was significant(P<0.000 1).The interactions between temperature and salinity on IGR was not significant;the quadratic effects of temperature and salinity on the IGR was highly significant(P<0.000 1);temperature was more important in influencing growth of larvaof C.nobilis.By applying the simultaneous optimization technique,the optimum factor combination,i.e.,25.33 ℃ and 29.42‰ was found out,at which the optimal IGR(7.91%)arrived simultaneously,with the desirability value as high as 85.57 %.It is anticipated that application of the optimal temperature-salinity combination to practice would improve the productive efficiency of C.nobilis.国家自然科学基金(31160528); 国家海洋公益性行业科研专项(201405020-5); 海洋公益专项科研基金(201205021); 南海生物资源开发与利用协同创新中

基于真空继电器的选相分合闸控制系统的设计与实现

为减少电力系统中断路器投切开关的分闸燃弧和合闸涌流,设计了一种永磁机构断路器的选相分合闸控制系统.系统通过真空继电器的二级驱动方式保证了机械动作时间可控且离散性小,解决了单级接触器驱动方式的机械动作时间离散性大和单级晶闸管驱动方式的驱动电路复杂性的问题.系统以STM32单片机为控制核心,通过电流突变捕捉时刻算法准确捕捉到分合闸动作完成时刻,进而计算出上一次的分合闸机械动作过程时间,预测出下一次的分合闸机械动作时刻,实现了控制系统根据设定的分合闸相角对断路器准确地进行分相投切控制的功能.控制系统在35kV永磁机构断路器上进行了实验,结果表明分合闸相角最大误差在±3°以内,达到了选相分合闸的精度要求.福建省科技计划项目(2016H6022

DIFFERENCE of SEISMIC BEHAVIOR of HIGH AND LOW CAPS of PILE FOUNDATIONS

对于采用桩基的各类结构,按承台埋没于地基土体与否,可区分之高、低承台桩基形式。在许多实际工程中,因回填土或欠固结土地基的继续沉降,或因土体流变或场地震陷等后沉降效应,均可致使承台与土体接触解除,即先前按设计采用的低承台桩基可能转为高承台形式。在静力条件下,这将导致桩身产生负摩阻力而降低其部分竖向承载能力;然而,在地震作用下,通过开展离心机地震模型试验和AbAQuS计算分析发现:当承台与地基土体脱离时,桩基最大弯矩设计值将会增大,且弯矩有效深度也将变深;并且,基础(承台)周期明显延长,充分表明高、低承台桩基形式地震行为差异迥然,高承台桩基形式较之相应低承台情况更为不利,在抗震设计时应充分予以认识、考虑。The pile foundation could be classified into the high or low types according to the position of cap relative to the surface of grounds.In many engineering practice, the settlement of unconsolidated clay or backfilled soil after construction,the soil rheology or the seismic field subsidence may lead to the separation of the cap from the clay surface, i.e., the cap was embedded originally into clay to a new state of high cap pile foundation.For the static condition,this kind of separation may result in the negative skin friction force along the piles and reduce the vertical bearing capacity of piles.However, under the seismic shaking condition, the centrifuge shaking table experiments and simulation with ABAQUS on both the cases indicated that piles underwent a higher maximum bending moment and a much larger active depth under high cap case than those at low cap case.This suggested that the embedding condition played an important role in the seismic response of pile-cap foundation.It becomes more disadvantageous when the embedding condition of the cap changes from the low cap case to the high cap case.国家自然科学基金资助项目(51209180); 成都理工大学地质灾害防治与地质环境保护国家重点实验室开放基金(SKLGP2012K014); 厦门大学大学生创新创业训练计划项

高效溶藻放线菌BS01发酵培养基及发酵条件优化

从漳江口红树林区采集的沉积物样品中分离到1株放线菌菌株BS01 Brevibacterium sp.,其胞外活性产物对塔玛亚历山大藻Alexandrium tamarense具有明显的溶藻作用。采用单因素及均匀设计,通过摇瓶培养对BS01产溶藻活性物质的发酵培养基及发酵条件进行优化。结果表明,在可溶性淀粉为碳源、硝酸钠为氮源、装液量为40%、起始pH值为7.5、培养温度为28℃、转速为150r.min?1、振荡培养时间为48h的条件时,BS01发酵产物的杀藻活性最强。通过均匀设计进行最佳发酵培养基及培养条件优化的结果为:可溶性淀粉为20g.L?1,硝酸钠为0.5g.L?1,pH为7.7,温度为27.2℃。研究结果为杀藻活性物质高效提取及杀藻机制研究奠定了基础

Study on Rapid Propagation Technique of Leather Corals

[目的]为海洋资源开发和生态环境修复等提供有效途径。[方法]探索肉质软珊瑚的人工快速扩繁方法。[结果]肉质软珊瑚具有快速的修复能力,能很快在肉质层的伤口处形成愈伤组织。通过该方法成功实现了肉质软珊瑚的快速人工扩繁。[结论]肉质软珊瑚内可能含有许多活性物质,具备一定的药物开发潜力。[Objective] The research aimed to provide an effective approach for developing ocean resources and repairing the ecological environment.[Method] The artificial method of rapid propagation of leather coral was explored.[Result] Leather coral was one species of soft corals,which had the properties of rapid regeneration and could develop the callus over the open wound.[Conclusion] Leather corals contained many active substances,so it had some medicinal development potential.2012年海南省科学事业费项目; 国家科技支撑计划项目(2012-BAC18B04-4); 国家海洋公益专项(201405020-5); 海南省科学事业费项目(KYYS-2014-50

红花组分HSYA对人胃腺癌BGC-823移植瘤裸鼠VEGF蛋白、KDR与缺氧诱导因子表达的影响

目的:研究红花组分羟基红花黄色素A(HSYA)对人胃腺癌皮下移植瘤裸鼠血管内皮生长因子(VEGF)蛋白、含激酶插入区受体(KDR)和缺氧诱导因子(HIF-1α)mRNA与蛋白表达的影响。方法:采用BALB/C nu/nu裸小鼠接种人胃腺癌细胞株BGC-823于右前肢腋部皮下建立裸鼠人癌移植瘤模型,随机分为模型组、对照组、HSYA高、低剂量组(0.056g/L、0.028g/L),观察抑瘤作用,酶联免疫吸附测定(ELISA)法检测瘤组织VEGF与HIF-1α蛋白以及血清VEGF蛋白表达;蛋白印迹(Western blotting)法测定瘤组织KDR磷酸化蛋白的表达;实时荧光定量PCR(RTFQ-PCR)法检测瘤组织KDR及HIF-1αmRNA表达。结果:HSYA低剂量组抑瘤明显,该组瘤组织及血清VEGF蛋白表达降低,瘤组织KDR磷酸化蛋白表达减弱,与模型组比较差异明显(P<0.05,P<0.01);HIF-1α蛋白表达较模型组瘤组织明显减少(P<0.01)。KDR mRNA表达与模型组相比减弱,差异有统计学意义(P<0.05)。结论:一定浓度的HSYA抑制肿瘤生长的可能机制与抑制VEGF、HIF-1α蛋白的表达,减弱KDR蛋白磷酸化及其基因表达,从而抑制内皮细胞活化阻碍肿瘤血管新生以及降低肿瘤缺氧微环境对血管生成的诱导有关