叠合盆地凸起区多期复杂断裂特征及形成机制——以准噶尔盆地车排子凸起为例

以高精度三维地震资料为基础,结合构造演化恢复和区域构造背景,系统研究了准噶尔盆地车排子凸起断裂分布和形成机制。结果表明,车排子凸起发育深部和浅部2套断裂体系,深部断裂体系和浅部断裂体系分别发育3种断裂样式。车排子凸起共经历5个构造演化阶段,其中,晚二叠世挤压-逆冲控制了深部断裂体系的初始形成,晚侏罗世逆冲-走滑控制了深部断裂体系的最终定型,新近纪叠加掀斜、局部伸展控制了浅部断裂体系的形成。不同断裂体系在油气成藏过程中均起到了重要作用。其中:深部断裂体系的红车断裂是重要的油源断裂,低序级断层控制形成了石炭系火山岩优质储集体;浅部断裂体系使得油气向浅部层系运移调整,同时形成了断块圈闭、断鼻圈闭和断层-岩性圈闭等丰富的圈闭类型。     

A numerical modelling approach to assess the behaviour of underground cavern subjected to blast loads

The paper gives an insight into the behaviour of large underground caverns which are subjected to blast loads. Caverns are generally constructed in hard rock formation which compels us to use blasting methods for the excavation works. Comparative study was done between models with intact rock mass and discontinuities to assess the stability of cavern as a result of blast loads. Numerical modelling was performed with 3 dimensional distinct element code(3 DEC) to analyse the performance of cavern walls in terms of displacement and to compute peak particle velocities(PPV) both around the cavern periphery and at surface of models. Results showed that the velocity wave with higher frequency exhibited large displacements around the periphery of cavern. Computation of PPV showed that model with horizontal joint sets showed lower PPV in comparison to model with intact rock mass. PPV values were also analysed on the surface for model consisting vertical joints spaced at 4 m intervals. Comparative study of PPV on surface vertically above the blast location between models with horizontal joints spaced at 4 m and vertical joints at 4 m intervals were conducted. Results depicted higher magnitudes of PPV for model with vertical joints in comparison to model with horizontal joints.     

CFD Modeling of Active Volume Creation in a Non‐Newtonian Fluid Agitated by Submerged Recirculating Jets

Computational fluid dynamics (CFD) models were employed to investigate flow conditions inside a model reactor in which yield stress non‐Newtonian liquid is mobilized using submerged recirculating jets. The simulation results agree well with the experimental results of active volume in the reactor obtained using flow visualization by the authors in a previous study. The models developed are capable of predicting a critical jet velocity (v_c) that determines the extent of active volume obtained due to jet mixing. The v_c values are influenced both by the rheological properties of the liquid and the nozzle orientation. The liquid with higher effective viscosity leads to higher v_c for a downward facing injection nozzle. However, an upward facing injection nozzle along with a downward facing suction nozzle generates enhanced complementary flow fields which overcome the rheological constraints of the liquid and lead to lower v_c.     

有机激发三重态参与的光化学反应研究进展

光化学反应包括直接光解和间接氧化反应，其中间接氧化反应主要通过活性氧化性物种（reactive oxygen species, ROS）包括单线态氧（¹O₂）、过氧自由基（{\mathrm{O}}_{\mathrm{2}}^{-}）和羟基自由基（·OH）等进行。近年来，有机激发三重态（³C^*）作为一种特殊的氧化剂参与光化学反应引起了广泛关注。本文主要综述了有机三重态光敏剂的形成和光化学反应机制、³C^*参与的环境光化学反应、³C^*自由基寿命、反应速率及稳态浓度测定和激发三重态的应用5个方面，并对未来有机分子激发三重态的研究方向进行了展望，指出³C^*是很多挥发性有机化合物（VOCs）或半/中等挥发性有机化合物（S/IVOCs）在大气中重要的汇，自然水体中溶解性有机质（dissolved organic matter，DOM）的激发三重态（³DOM^*）是污染物降解的主要氧化剂。今后应扩大³C^*与有机物反应的研究范畴，测定不同体系中³C^*的稳态浓度、产生速率（量子产率）等，为污染物治理提供理论依据。     

鄂尔多斯盆地延长气田马家沟组成藏条件分析

鄂尔多斯盆地马家沟组富含天然气,对其成藏条件进行研究,可很好的指导该区域天然气的勘探开发。本文以延长气田为例从烃源岩、储集层、盖层等方面分析了该区域天然气气藏形成的地质条件。     

Effect of spatial constraints on the phase evolution of YFeO3-based nanopowders under heat treatment of glycine-nitrate combustion products

Formation and structural transformations of yttrium orthoferrite crystals have been studied using X-ray diffractometry, Mössbauer spectroscopy and transmission electron microscopy combined with electron microdiffraction. Said processes have been studied under heat treatment of glycine-nitrate combustion products. There have been identified formations of three structural yttrium orthoferrite modifications – amorphized hexagonal <h₁>-YFeO₃ (P6₃cm) and nanocrystalline hexagonal h₂-YFeO₃ (P6₃/mmc), as well as nanocrystalline orthorhombic o-YFeO₃ (Pbnm), which are selectively formed depending on available three-dimensional confinements. Based on the analysis of changes in the fluid and size composition formulation, it has been proposed mechanism for formation and transformation of YFeO₃ nanocrystals, including growth stage of h₂-YFeO₃ crystals due to amorphized phase of <h₁>-YFeO₃ up to critical size of about 15?nm and their subsequent transformation into orthorhombic form o-YFeO₃.     

Distribution of Living Ray Parenchyma Cells and Major Bioactive Compounds During the Heartwood Formation of Taiwania cryptomerioides Hayata

The heartwood of Taiwania (Taiwania cryptomerioides Hayata) has the excellent decay resistance and fascinating color qualities due to the accumulation of bioactive compounds. However, limited information was addressed to the heartwood formation of this species. In this study, we established the distribution of the living ray parenchyma cells and profiled the major bioactive compounds across and along the Taiwania stem. The ray parenchyma cells would die within 1–2 annual rings of the transition zone, which occurs around 8–13 annual rings counted from the cambium. The gradual loss of the starch grains accompanied with the deposition of the colored materials into the cell lumens started from the outer transition zone. The radial distribution of the extractive contents and its signature bioactive compounds across Taiwania stems gradually increased from the transition zone toward the heartwood tissues. The aforementioned properties did not show specific trends along the vertical direction of the Taiwania stems.     

高强度油井管钢中的Nb偏析及形成机制分析

摘要：研究了含Nb高强度油井管钢连铸坯和管材的Nb偏析行为。利用OM、SEM、EDS、EMPA等手段，揭示了含Nb高强度油井管钢连铸圆坯中存在的富Nb、富C点状缺陷及其与管材内壁出现的条带组织中大尺寸NbC的对应关系。从Nb、C元素含量与其固溶度积间的关系分析了Nb的偏析机制。分析认为，大尺寸NbC是由于Nb的分配系数小，在连铸坯凝固后期枝晶间大量富集所形成。经固溶度积计算，富集的Nb含量可高于基体的5.4倍。     

高强铝合金双脉冲VPPA焊缝成形机理

建立双脉冲VPPA(variable polarity plasma arc)焊接系统，进行7A52高强铝合金双脉冲VPPA焊接工艺试验，研究低频脉冲调制叠加高频脉冲对VPPA焊接过程中焊缝成形和焊缝力学性能的影响. 结果表明，低频脉冲周期性振荡液态熔池，可获得表面饱满的鱼鳞纹焊缝；高频脉冲使电弧更为集中，有效地提高了电弧能量密度，穿透力加强；双脉冲耦合振荡加强了对熔池的搅动作用细化了铝合金焊缝晶粒. 焊接接头抗拉强度达到384.13 MPa，相比VPPA焊接接头强度提高了10.21%左右；焊接接头断面收缩率和断后伸长率均有一定程度的提高. 铝合金双脉冲VPPA焊接工艺提高了焊接接头力学性能.