二维编织复合材料管件轴向压缩性能研究

通过优化二维编织复合材料管件复合工艺,制作了碳纤维含量较高的碳纤维复合材料管件,同时对管件进行了轴向压缩性能测试,分析并探讨了编织参数对复合材料管件纤维体积含量及轴向压缩性能的影响。结果表明:优化后的复合工艺可保持复合材料管件纤维体积含量在20%~40%之间,同时使得复合后管件的内径达到一致;在编织速度不变的情况下,随着编织节距的减小,编织角逐渐增加,纤维体积含量逐渐增加,当编织节距减小到一定程度后,纤维体积含量的增加变缓,而轴向压缩强度先升高后降低,当达到最大值时,编织角为46°。     

分子动力学模拟温度对PE–LD零剪切黏度的影响

采用分子动力学方法模拟分析温度(375~550 K)对低密度聚乙烯(PE–LD)零剪切黏度的影响,通过Material Studio 8.0软件构建分子位能模型,施加原子水平模拟研究凝聚态优化的分子力场(COMPASS)力场,经过几何优化、退火处理和动力学弛豫后,运行NPT系综的动力学模拟,进行数据处理。结果表明,PE–LD熔体的黏度随温度升高呈指数递减。从分子链自扩散和自由体积来分析其机理,结果显示,温度的升高,加剧了分子链之间的运动,减少了分子间的缠结,增大了熔体的自由体积,减少了分子间的内摩擦,从而导致黏度下降。     

Determination of Acoustical Parameters of Aqueous Solution of Kolliphors Binary Mixtures Using Density,Speed of Sound,Viscosity, and Surface Tension Measurements

Measurements of density, speed of sound, and surface tension as well as viscosity of aqueous Kolliphor® ELP (ELP) and Kolliphor® RH 40 (RH40) solutions as well as binary mixtures at different surfactant mole fractions were made at 293 K to investigate their aggregation behavior. The free volume, internal pressure, and molar cohesive energy were calculated and compared to the specific acoustic impedance and intermolecular free length to obtain qualitative information about the character of interactions between the surfactant molecules in the mixture through the water phase.     

Evidence for P-Glycoprotein Involvement in Cell Volume Regulation Using Coulter Sizing in Flow Cytometry

The regulation of cell volume is an essential function that is coupled to a variety of physiological processes such as receptor recycling, excitability and contraction, cell proliferation, migration, and programmed cell death. Under stress, cells undergo emergency swelling and respond to such a phenomenon with a regulatory volume decrease (RVD) where they release cellular ions, and other osmolytes as well as a concomitant loss of water. The link between P-glycoprotein, a transmembrane transporter, and cell volume regulation is controversial, and changes in cells volume are measured using microscopy or electrophysiology. For instance, by using the patch-clamp method, our team demonstrated that chloride currents activated in the RVD were more intense and rapid in a breast cancer cell line overexpressing the P-glycoprotein (P-gp). The Cell Lab Quanta SC is a flow cytometry system that simultaneously measures electronic volume, side scatter and three fluorescent colors; altogether this provides unsurpassed population resolution and accurate cell counting. Therefore, here we propose a novel method to follow cellular volume. By using the Coulter-type channel of the cytometer Cell Lab Quanta SC MPL (multi-platform loading), we demonstrated a role for the P-gp during different osmotic treatments, but also a differential activity of the P-gp through the cell cycle. Altogether, our data strongly suggests a role of P-gp in cell volume regulation.     

河道一维非恒定流数值模拟深化研究

传统的河道一维非恒定流数值计算一般采用特征线法和以Preissmann方法为代表的有限差分法.特征线法计算精度比较高,但受时间步长的限制,用于河道一维非恒定流计算时计算效率却不太高.而Preissmann方法相比特征线法计算效率有所提高,但在求解过程中特征量的守恒性却没有做出相应要求.为了兼顾数值计算的效率和特征量的守恒,建立了基于有限体积法的河道一维非恒定流数值计算方法,并分别选取淮河干流洪水和史灌河洪水进行了验证计算,验证计算成果表明所采用的方法特征量守恒性较好,洪峰水位计算值与实测值吻合也较好,可用于河道一维非恒定流计算.     

土方工程量测算方法浅析

随着经济发展速度的不断加快,我国城市化水平得到了飞速提高,各种类型的建筑不断出现,推动了社会的发展和进步。对于大型建筑工程而言,土方工程量的测量是十分重要的,关系着工程整体的施工速度和施工质量。通过对大型土方工程量测算方法进行分析和探讨,希望能为相关工程技术人员提供一些参考。     

多维反滤回灌井室内稳定流试验研究

反滤回灌井是山东胶东半岛地下水回灌中常用的回灌设施,它由普通回灌井和回灌池组成。在分析现有反滤回灌井存在问题的基础上,设计了一组回灌量大,又能防淤积、防低水位污水回灌、抗水流冲刷的多维反滤回灌井,给出了单井回灌量的理论计算公式和计算参数;同时,研制了室内稳定流回灌试验装置,进行了普通回灌井、现有反滤回灌井和多维反滤回灌井的室内稳定流试验研究,得出结论:1同现有反滤回灌井相比,多维反滤回灌井的单井回灌量增加了370%~420%;2多维回灌井口的形状影响单井回灌量,在过水断面面积相同的情况下,圆形多维回灌井口的单井回灌量最大;3初次回灌试验中,单井回灌量最大,随回灌试验次数增加,单井回灌量逐渐减小,并趋向于稳定;4单井回灌量与多维回灌井口过水断面开孔率是一个非线性的关系,20%的过水断面开孔率是适宜的。研究成果对于提高反滤回灌井的回灌能力和定量计算单井回灌量具有重要的现实意义。     

作物可视化中的碰撞检测及响应研究

将碰撞检测与响应技术引入作物可视化生长模拟,针对以NUR13S曲面表示的作物叶片,提出了一种基于曲 面分割技术及混合层次包围盒实现作物叶片间碰撞检测的方法。首先采用节点插入技术分割叶片曲面,然后为分割 后的叶片曲面建立轴向包围盒(AAI313)与固定方向凸包(FDH)的混合层次包围盒树:根节点采用AA1313包围盒,以快 速排除不可能相交的叶片;其它层节点采用FDH包围盒,以保证精确地判定距离较近的叶片间碰撞状态。在此基础 上,根据作物叶片形态变化规律,提出了较合理、有效的冲突响应机制。实例分析表明,所建立的算法可有效地应用于 作物叶片碰撞的模拟实现。