濮阳3286m岩盐勘探深井高密度钻井液工艺

濮阳岩盐普查项目ZK0401孔设计孔深3280 m。在该孔钻探取心施工中,结合地层水敏性、地层压力及地温特点,试验采用了耐高温、高密度饱和盐水钻井液,并配以适宜取心钻探工艺,成功地实施了连续岩盐取心,实际终孔孔深3286 m,收到了良好的效果。重点介绍了钻井液体系配方的优选及钻井液工艺技术措施。     

10.6 μm脉冲激光对多晶硅探测器干扰损伤实验

用10.6 μm脉冲CO2激光辐照多晶硅光电探测器,进行了干扰与损伤阈值实验研究,得到了对多晶硅探测器的干扰、损伤阈值;分析了不同干扰能量的干扰效果,研究了干扰损伤机理,依据受干扰程度对干扰等级进行了划分;通过干扰激光能量与干扰光斑面积的关系,重度饱和后探测器随时间恢复情况,探讨了各干扰等级下10.6 μm脉冲激光对红外成像系统的干扰效果。     

一种基于Ad Hoc网络的协作MAC方案

在 IEEE 802.11b MAC层协议的研究基础上,提出了一种基于无线Ad Hoc网络的最佳中继选择策略,该策略综合考虑瞬时信道信息和节点剩余能量,能够有效防止信道条件好的节点的过度使用,并能保证系统高吞吐量。文中以饱和吞吐量和网络生存时间为性能指标,对新算法和以往协作MAC算法进行仿真和比较,结果表明新算法在网络吞吐量下降不明显的情况下,能大大增加网络生存时间。     

Analytical evaluation of different carbon sources and growth stimulators on the biomass and lipid production of Chlorella vulgaris – Implications for biofuels

The key challenges in lipid production from marine microalgae include the selection of appropriate strain, optimization of the culture conditions and enhancement of biolipid yield. This study is aimed at evaluating the optimal harvest time and effect of chlorella growth factor (CGF) extract, carbon sources and phytohormones on the biomass and lipid production in Chlorella vulgaris. CGF, extracted using hot water from Chlorella has been reported to possess various medicinal properties. However, in the present study, for the first time in C. vulgaris, CGF was found as a best growth stimulator by enhancing the biomass level (1.208 kg m⁻³) significantly on day 5. Gibberellin and citrate augmented the biomass by 0.935 kg m⁻³ and 1.025 kg m⁻³. Combination of CGF and phytohormones were more effective than CGF and carbon sources. Analysis of fatty acid methyl esters indicated that the ratio of saturated to unsaturated fatty acids is higher in cytokinin, abscisic acid and CGF, and are also rich in short chain carbon atoms, ideal criteria for biodiesel. Nitrogen starvation favoured synthesis of more unsaturated fatty acids than saturated. This study shows that CGF enhances the biomass and lipid significantly and thus can be used for large scale biomass production.     

MPEG修饰的纳米氧化铁粒子的合成及清洗工艺

以MPEG为溶剂、还原剂及修饰剂,Fe(acac)3为铁源,通过高温热分解法制备了超顺磁性氧化铁纳米粒子(SPIONs).采用饱和食盐水清洗方法对合成的粒子进行收集,经透析除去其表面残留的NaCl.采用XRD,TEM,HRTEM,SQUID,ICP MS,TGA,FT IR,纳米粒度与Zeta电位分析仪对样品进行表征.结果表明:经透析处理后氧化铁的质量分数为NaCl的6.9×104倍,制备的SPIONs具有高的结晶度及单分散性,在300K下,具有超顺磁性,饱和磁化强度为53.7A· m2·kg-1;具有惰性端基的MPEG修饰于SPIONs表面,为其提供了良好的水分散性.采用盐桥法萃取清洗工艺可清除过量的MPEG,有利于SPIONs更好的应用在生物医学领域.     

Non-axisymmetric Biot consolidation analysis of multi-layered saturated poroelastic materials with anisotropic permeability

To start with, an analytical layer-element (i.e., a symmetric stiffness matrix), which describes the relationship between the generalized displacements and the stress levels of a layer subjected to non-axisymmetric loading, is exactly derived in the transformed domain by the application of a Laplace–Hankel transform with respect to variables t and r, a Fourier expansion with respect to variable θ, and a Laplace transform and its inversion with respect to variable z, based on the governing equations of Biot’s consolidation of multi-layered saturated poroelastic materials with anisotropic permeability. The analytical layer-element experiences considerable improvement in computation efficiency and stability, since it only contains negative exponential functions in its elements. In addition, a global stiffness matrix for multi-layered saturated poroelastic media is obtained by assembling the interrelated layer-elements based on the continuity conditions between adjacent layers. By introducing the boundary conditions and solving the global stiffness matrix, the solutions in the Laplace–Hankel transformed domain are obtained, and the final solutions can be recovered by a numerical inversion of the Laplace–Hankel transform. Finally, numerical examples are presented to verify the theory and to study the effect of the property of anisotropic permeability on vertical displacements and excess pore pressure. The calculation results show that the property of anisotropic permeability has a great influence on the process of consolidation.     

冻融循环作用下饱和砂岩损伤扩展模型研究

首先分析饱和砂岩所经历的冻融作用的特点,认为冻融作用是一种低周疲劳荷载,且砂岩冻融循环作用下的受力状态可简化为单向拉伸荷载的循环作用。基于以上分析,在疲劳损伤理论的基础上,建立砂岩在冻融循环作用下的损伤演化方程。同时,通过对饱和砂岩冻融循环过程中的物理性质的观测,及对砂岩自身结构特点的分析,选取砂岩的开孔隙率作为损伤变量。之后通过试验数据对所建立的损伤模型进行验证,并探讨损伤方程中各参数的确定方法。经过验证,该损伤模型能较好地反映饱和砂岩在冻融循环作用下的损伤扩展规律,可以为相关的研究提供参考。     

磷石膏尾矿坝渗流场与稳定性分析

针对大峪口磷石膏尾矿坝的实际情况,设定多种运行工况。运用饱和-非饱和渗流理论,分析磷石膏尾矿坝在各种工况下的渗流场。渗流场分析结果表明,干滩长度变化以及排渗垫层的淤堵程度对浸润线的影响十分明显,干滩长度越长,坝体浸润线越低;排渗垫层淤堵越重,浸润线越高。在渗流场分析的基础上,运用饱和-非饱和边坡稳定性分析方法,对坝体进行稳定性分析,得出不同工况下坝坡的安全系数。坝坡稳定性分析结果表明,在当前实际运行坝高180m时,最小安全系数为2.27,坝体是稳定的。不同工况下的安全系数均满足技术规程的规定。     

单轴压缩下饱水裂隙砂岩体积效应的试验研究

为研究水和岩样体积对砂岩物理力学及变形特性的影响,采用MTS815型岩石力学测试系统,对干燥和饱水状态下的3种不同体积(高径比2∶ 1)完整和裂隙砂岩进行单轴压缩试验。结果表明:完整和裂隙砂岩的孔隙率与饱和吸水率与岩样体积成正比;干燥和饱水的完整与裂隙砂岩单轴抗压强度均随体积增大而小幅降低;砂岩弹性模量和变形模量与岩样体积呈负相关,且水降低了砂岩的弹性模量与变形模量;干燥砂岩的泊松比随岩样体积增加而增大,而饱水砂岩则随岩样体积先增加,后稳定;干燥的完整和裂隙砂岩的宏观破坏形式由小尺寸的轴向多劈裂面破坏逐渐转变为大尺寸的单一剪切破坏,水的存在对岩样单轴压缩破坏形态没有明显影响。     

饱和细砂的动力反应及其中的弹性体波

该文通过室内试验揭示了饱和细砂在动荷载作用下的液化—析水—再固结动力反应过程 ,试验测得的超静孔隙水压力—时间关系曲线定量地反映了超静孔隙水压力的产生、发展和消散规律。试验结果和理论分析表明 ,动荷载作用下饱和细砂中存在着三种弹性体波———第一压缩波 (P1 波 )、第二压缩波 (P2 波 )和剪切波 (S波 )。