基于米兰科维奇理论的湖相细粒沉积岩高频层序定量划分

湖相的细粒沉积同时具有高度的连续性和分辨率,其忠实地记录了湖泊流域的气候和环境变化的信息,由于沉积过程的稳定性,使得这种湖相细粒沉积成为米兰科维奇旋回分析的理想载体,而米兰科维奇理论的时间内涵是进行高频旋回划分和对比有效手段,可以提高地层划分的时间分辨率,是传统层序地层学的有力补充。精确识别米氏旋回是湖相细粒沉积岩高频层序划分的基础,约束沉积速率的变化是米氏旋回识别的关键。针对陆相沉积地层相变快、非均质性强等特点,以磁化率作为替代性指标,引入进化谐波（EHA）和平均频谱拟合差（ASM）分析技术,约束纵向上沉积速率的变化,更精确识别米兰科维奇旋回信号。结合高分辨率层序地层学基准面旋回理论,四级层序与中期基准面旋回对应,时间量化为405 kyr;五级层序与短期基准面旋回对应,时间量化为100 kyr;六级层序与超短期基准面旋回对应,时间量化为40 kyr,最终分别以长偏心率、短偏心率和斜率周期曲线作为四级、五级和六级层序划分的参考曲线,实现湖相细粒沉积岩高频层序定量划分。     

鄂尔多斯盆地延长组7段致密油地质工程一体化解决方案——针对科学布井和高效钻井

鄂尔多斯盆地陇东地区长7致密油储层主要为重力流砂体沉积,砂体的分布在垂向和横向上均复杂多变,单砂体厚度薄,对高效钻井和生产提出了挑战。文章提出了一套利用近钻头随钻测量技术等多学科知识相结合的地质工程一体化方法。在综合地质研究的基础上,建立三维精细地质、油藏和地质力学模型,进行钻井位置优选、工厂化平台设计、钻井作业实施和地质导向方案优化,使井轨迹设计科学合理,钻井过程中提高砂体钻遇率,同时保证后期生产阶段较高的单井产量与井区的最终长期累计产量。研究结果表明:研究区的优质储层主要为碎屑流的块状砂岩,提高钻遇率的核心在于利用实时传输随钻测量数据,综合分析钻、测、录数据,确定钻头在沉积旋回的位置,从而确定地质导向作业方案。在该方法指导下实施的两口水平井钻井作业,油层钻遇率较周边井钻遇率提高5%~10%;通过早期基于地质模型和地质力学模型基础上的数值模拟,结合钻井和生产实践科学布井,最终选定400m为研究区最佳水平井井距。     

油气管道缺陷漏磁检测有限元模拟

为了研究油气管道缺陷的漏磁信号特征,基于漏磁检测技术基本原理,采用有限元方法,应用ANSYS软件对含裂纹和气孔缺陷管道磁化后产生的漏磁场进行模拟仿真,得到了描述漏磁场特征的磁通密度径向和轴向分布曲线。通过改变裂纹和气孔的尺寸,得出这两种缺陷形式不同尺寸下的漏磁场分布规律。结果表明,随着裂纹深度增加,磁通密度径向、轴向分量的峰值强度均明显增大;在距管壁表面相同深度下,气孔缺陷磁通密度的峰值随孔径增加而显著增大;相同孔径时,气孔距表面越近,漏磁信号越强。为管道漏磁检测过程中的裂纹和气孔缺陷的特征识别提供了理论基础和实践依据。     

低渗透储层试井资料二次解释与应用

坪桥长6油藏属典型的低渗裂缝油藏,历经三十余年注水开发,开发矛盾表现为孔渗区单井产能低,递减快,裂缝区主向井快速水淹,侧向井见效慢。     

205/75R17.5 16PR全钢载重子午线轮胎的设计

介绍205/75R17.5 16PR全钢载重子午线轮胎的设计。结构设计：外直径　750 mm,断面宽　210 mm,行驶面宽度　165 mm,行驶面弧度高　6 mm,胎圈着合直径　443.5 mm,胎圈着合宽度　165 mm,断面水平轴位置（H1/H2）　1.036,胎面为4条纵向花纹沟设计,花纹深度　12 mm,花纹饱和度　77%,花纹周节数　89。施工设计：双复合挤出胎面,胎体采用3＋9×0.22＋0.15HT钢丝帘线,1#和2#带束层采用3×0.20＋6×0.35HT钢丝帘线,3#带束层采用5×0.30HI钢丝帘线,0°带束层采用3×7×0.20HE钢丝帘线;采用一次法胶囊成型机成型,蒸锅式硫化机硫化。成品性能试验结果表明,轮胎充气外缘尺寸、强度性能、耐久性能和高速性能满足相关国家标准或企业标准要求。     

Multi-component yttrium aluminosilicate (YAS) fiber prepared by melt-in-tube method for stable single-frequency laser

The multi-component glass fibers have demonstrated their unique advantages in the application of single-frequency lasers due to their higher solubility of rare-earth ions and thus a higher gain per unit length in a compact fiber laser cavity. In this study, multi-component yttrium aluminosilicate (YAS) fiber with high doping concentration of Yb³⁺ was prepared by the “melt-in-tube” (MIT) method. A unit-length gain of 3 dB/cm was obtained in a 4.4 cm-long YAS fiber, the laser output slope efficiency reached 23.8% in a 10 cm-long Yb:YAS fiber. Single-frequency laser operation was achieved in a 1.7-cm-long Yb:YAS active fiber. To the best of our knowledge, this is the first demonstration of single-frequency laser with this YAS glass fiber as gain medium. The novel multi-component YAS fiber can be applied as a new gain material to realize single-frequency fiber laser.     

Preparation of highly phenol substituted bio-oil–phenol–formaldehyde adhesives with enhanced bonding performance using furfural as crosslinking agent

Highly phenol substituted bio-oil–phenol–formaldehyde (BPF) adhesives were prepared via the phenolization-copolymerization method, in which furfural was used as a novel crosslinking agent to improve the bonding performance. The effects of bio-oil percentage, furfural content, curing temperature, and pressure on the performance of BPF adhesives have been studied in detail. A BPF adhesive with 75% bio-oil percentage and 15% furfural loading (named 75BPF_15) was synthesized, which was cured at 180 °C and 4 MPa. Compared to the conventional phenol–formaldehyde adhesive, the wet tensile strength of 75BPF_15 adhesive reached 2.84 MPa, which was significantly higher than the 1.54 MPa of PF. A possible mechanism of BPF adhesives crosslinked with furfural is proposed. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 46995.     

Hydrogels based on chitosan in tissue regeneration: How do they work? A mini review

The repair of tissue defects after injury is of significant clinical and research importance. A variety of chitosan-based hydrogels have been investigated and applied to address this problem. By using different synthetic methods, the hydrogels exhibit distinct physical properties, including porosity, adhesion, and stiffness. These properties are considered important factors affecting cell proliferation and tissue regeneration. Meanwhile, drug delivery and cell delivery are the two main strategies to improve the therapeutic effects of chitosan-based hydrogels, but the choices of cells or drugs are quite varied and largely depend on the specificity of the treated tissues. The present review summarizes the physicochemical properties of chitosan-based hydrogels and their influences on cells, and lists specific ways to promote the tissue regeneration in different systems of the human body. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47235.     

Core‐shell structured Al/PVDF nanocomposites with high dielectric permittivity but low loss and enhanced thermal conductivity

Surface modification of core‐shell structured Al (Al@Al₂O₃) nanoparticles was performed using γ‐(Aminopropyl)‐triethoxysilane (APS) and dopamine (DA), respectively, and the microstructures, dielectric properties and thermal conductivities of the Al/poly(vinylidene fluoride) (PVDF) nanocomposites were investigated. Both DA and APS enhance the interfacial bonding strength between the fillers and the matrix, leading to homogeneous dispersion of Al nanoparticles in PVDF matrix. Compared with raw Al nanoparticles, surface‐treated Al/PVDF exhibit much higher dielectric permittivity due to the enhanced interfacial interactions between the two components, whereas, the dielectric loss and electric conductivity of the nanocomposites still remain at rather low levels owing to the insulating alumina shell preventing effectively core Al from direct contact. The dynamic dielectric properties results reveal that dielectric constant and loss increase with temperature due to the gradually enhanced mobility of molecular chain segments of PVDF for the raw Al/PVDF and treated Al/PVDF nanocomposites. Additionally, the PVDF nanocomposites with Al treated with APS and DA show enhanced thermal conductivities compared with raw Al/PVDF under the same filler loading because of reduced thermal interfacial resistance promoting phonon transfer across the interfaces. POLYM. ENG. SCI., 59:103–111, 2019. © 2018 Society of Plastics Engineers