垂直井两相流动生产测井解释滑动模型

在两相流动模拟实验数据分析的基础上 ,提出油水两相和气液两相流动的滑脱速度的实验关系 ,进而确定垂直井两相流动生产测井解释的滑动模型。现场实际测井资料处理结果表明该模型有很好的应用效果     

GPS在水面流速流向测量中的应用

传统的水面流速流向测量多采用经纬仪交会法,此法需要大量的人力和设备,工作量大且费时。近几年,随着全球定位系统(GPS)的广泛应用和实践,在一定范围内,采用GPS定位法替代经纬仪交会法施测水面流速流向。介绍了GPS定位法的测量原理、设备,以及测量方法。通过对GPS定位法的精度和优缺点的分析,得出采用GPS定位法施测水面流速流向具有较高的推广价值。     

Nondegradative microextrusion of resorbable polyesters for pharmaceutical and biomedical applications: The cases of poly‐lactic‐acid and poly‐caprolactone

In recent years biodegradable polymers, particularly polyesters such as the poly(lactic acid) (PLA) and polycaprolactone (PCL), have gained high interests for their applicability in the biomedical and pharmaceutical fields where they're used for manufacturing various different resorbable devices, from tissue engineering scaffolds to controlled drug release systems. Despite many positive characteristics, processability of these materials still remains a critical issue as they easily tend to degrade during manufacturing. In this article we aimed to assess microextrusion as a nondegradative process for manufacturing PLA and PCL. The results we experimentally obtained, that are hereby presented, set a new point in the on‐going debate on degradation during processing of resorbable polymers as they allow to affirm that microextrusion leaves unmodified molecular weight distributions without producing any evident reductions in mean molecular weight. Microextrusion thus represents a risk‐free high molecular weight polymer processing solution for obtaining nondegraded products within pharmaceutical and biomedical production lines, such as for scaffolds for tissue engineering applications or drug delivery. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Engineering extruded collagen fibers for biomedical applications

Extruded collagen fibers constitute a promising biomimetic scaffold for tissue engineering applications. In this study, we compared the structural, thermal, and mechanical properties of fibers produced from either NaCl or poly(ethylene glycol) with a number-average molecular weight of 8000 (PEG 8K), the only two coagents that have been used in the fabrication process. As novel, we report the fabrication of fibers with properties similar to native or synthetic fibers using other coagents. NaCl derived fibers were characterized by higher thermal stability (p < 0.026), stress (p < 0.001), and modulus (p < 0.0025) values than PEG 8K, whereas the latter yielded more extendable fibers (p < 0.012). Poly(ethylene glycol)s with number-average molecular weights of 200 and 1000 produced fibers with similar mechanical properties (p > 0.05) that were thinner (p < 0.033), stiffer (p < 0.022), and less extendable (p < 0.0002) than those of PEG 8K. Poly(vinyl alcohol) (PVA) with a number-average average molecular weight of 9–10,000 and PEG 8K yielded fibers with similar diameters and stress-at-break values (p > 0.05); however, the poly(ethylene glycol) derived fibers were more extendable (p < 0.0003), whereas the PVA fibers were stiffer (p < 0.029). Gum-arabic- and soluble-starch-derived fibers were of similar tensile strength, extendibility, and stiffness (p > 0.05). In this in vitro study, the thickest (p < 0.011) and the weakest (p < 0.0066) fibers were produced in the presence of sodium sulfate. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

石油套管的壁厚公差对承载能力的影响

石油套管的强度计算是按API标准进行的，它未能反映高强度套管和尺寸公差对抗压溃能力的影响。利用弹塑性力学理论建立理想的石油套管的抗压溃能力计算公式，并考虑套管的壁厚公差对计算公式进行修正。用该方法对受均匀载荷及非均匀载荷作用的套管进行分析，并同有限元计算结果相比，两者十分吻合，说明该方法的有效性。     

用穿透法测量声速时初始点的选择问题

用穿透方法测量岩心或固体的声速时，从测量波形中确定纵波（或横波）的到达时刻（或称初始点）比较困难，当声波的频率比较低时，其误差对测量结果影响比较大。本文用相位分析的方法研究了初始点的选择问题。首先，用各向同性较强、均匀的汉白玉制作标准件，测量其不同传播距离的波形，再用相位补偿的方法得到其传播速度；其次，利用传播速度，可从不同距离的测量波形中确定初始点及其对应的测量系统的时间延迟常数；最后，确定波形的其他位置为初始点时对应的时间延迟常数，因此，我们可以根据实际测量波形的特点选择最佳的初始点，利用其对应的时间延迟常数得到比较精确的声速。模型测量结果表明，初始点位置不同，其对应的测量系统的时间延迟常数也不同，也即测量系统的时间延迟常数是与初始点的选择相对应的。     

樊口大闸加固工程中的爆破振动分析

在考闸墩上爆破开挖出新的闸门槽，在新浇混凝土附近进行底板爆破开挖，爆破振动对闸墩和新浇混凝土的影响值得重视；介绍了在樊口大闸加固工程中的爆破振动观测成果，并对爆破振动特性进行了分析。     

曲柄摇杆机构的三圆图解设计法

这里探讨了对给定行程速比系数K，摇杆摆角ψ，另外再给定摇杆长度l3(机架长度l4)、曲柄长度l1(连杆长度l2)等，找出如何运用辅助圆图解设计曲柄摇杆机构的方法。     

The weight vector theory of Coriolis mass flowmeters

In this paper a fuller and clear derivation of the weight vector theory of Coriolis mass flowmeters is given indicating its potential for the prediction of velocity profile effects in both the traditional kind of meter (vibrating tube) and the compact kind (vibrating element inside a duct).