Irradiation-induced microstructure damage in He-irradiated 3C-SiC at 1000℃

The effect of the high-temperature helium irradiation on microstructural evolution of 3C-SiC was investigated by the combination of Raman spectroscopy, conventional transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM). 3C-SiC wafers were irradiated with 130 keV He⁺ ions at fluences of 2 × 10¹⁶ He⁺/cm², 4 × 10¹⁶ He⁺/cm² and 2 × 10¹⁷ He⁺/cm² at 1000℃. Helium bubbles, dislocation loops, and their interaction with the stacking faults were focused on and characterized by TEM. Helium bubbles preferentially nucleate and grow on stacking faults. Bubble links on the (100) plane in 3C-SiC are formed. In addition, stacking faults can effectively trap irradiation-induced lattice defects to enhance their recovery. The type of irradiation-induced lattice defects and elemental distribution are also investigated. The research results are valuable for the 3C-SiC used in the advanced nuclear energy systems.     

低能高通量氦离子辐照下W28Ta28V28Zr8Sc8高熵合金损伤行为研究

采用放电等离子烧结技术制备了W₂₈Ta₂₈V₂₈Zr₈Sc₈高熵合金,研究了高熵合金在低能量、高通量氦离子辐照下的损伤行为。结果表明,在相同He离子辐照参数下,高熵合金表现出比纯W更优异的抗辐照损伤性能。不同He离子能量条件下,高熵合金中出现严重Fuzz结构时的He离子能量阈值远高于纯W。在相同辐照参数下,高熵合金有着明显小于纯W的Fuzz层厚度。W₂₈Ta₂₈V₂₈Zr₈Sc₈高熵合金中不同相区在辐照后表现出不同的表面形貌特点,这与构成相区主要元素的He离子辐照行为有关。通过设计高熵合金的显微组织,可以获得优良的抗辐照材料。     

Matrices pattern using FIB; ‘Out‐of‐the‐box’ way of thinking

Focused ion beam (FIB) is an extremely valuable tool in nanopatterning and nanofabrication for potentially high‐resolution patterning, especially when refers to He ion beam microscopy. The work presented here demonstrates an ‘out‐of‐the‐box’ method of writing using FIB, which enables creating very large matrices, up to the beam‐shift limitation, in short times and with high accuracy unachievable by any other writing technique. The new method allows combining different shapes in nanometric dimensions and high resolutions for wide ranges.     

Ab initio study of helium in Li4SiO4 crystals: Electronic properties,migration, and vacancy capture mechanism

Li₄SiO₄ crystal is a candidate material for tritium breeder material. Vacancy defects and He atoms will be produced in the crystal after neutron irradiation in fusion reactor. In previous research, we learned vacancy defects mainly include V_O⁰, V_O²⁺, and V_Li⁰, meanwhile, He atoms are easy to migrate and aggregate in the crystal. In order to understand the relationship between vacancy defects and He atoms, we use density functional theory (DFT) to study the interaction mechanism between vacancy and He atom. The results show that the local stable sites of He atoms are related to the surrounding charge distribution. V_O²⁺ and V_Li⁰ can capture interstitial He atoms, and it is difficult to escape the vacancies, thereby increasing the nucleation center of He atoms. V_O⁰ promotes the diffusion of He atoms in the interstitial space, which will cause small helium bubbles to merge more easily.     

AVO技术在苏里格气田SQW区块的应用

SQW区块与苏里格气田总体构造特征相似,主要表现为地层平缓,构造圈闭不发育,以岩性气藏为主。由于区内各类岩石速度和密度等参数相互接近,应用传统的波阻抗反演方法难以识别盒8段气层,因此本文选用基于泊松比分析的AVO技术进行储层预测。参考Verm等提出的基于泊松比反射率的AVO技术,在区内利用岩石物理分析建立NI-PR彩色标定图板,通过彩色交会图解释技术分析实际地震道集AVO反演的NI和PR属性,可以获得较准确的含气储层空间展布信息。AVO储层预测结果与研究区内各井盒8段实际情况吻合率达80.5%。     

苏里格气田苏14 井区盒8 段河流相砂体展布与演化规律研究

河流相砂体横向相变快,连续性和连通性差,储层非均质性强,严重影响了河流相储层的开发效果。依据储层沉积学的研究方法,对苏里格气田苏 14 井区盒 8 段河流相砂体展布与演化规律进行了研究。结果表明：苏 14 井区盒 8 段属于早期辫状河沉积向晚期曲流河沉积逐渐转化的沉积背景,其主要沉积微相包括河道滞留沉积、心滩、边滩、决口扇、天然堤、河漫砂及泛滥泥。 受基准面升降与沉积物供应的共同作用,该区河流相砂体演化呈阶段性变化,大致经历了辫状河繁盛发育期、辫-曲共存转化发育期及曲流河繁盛发育期 3 个阶段,其中辫状河繁盛发育期的心滩砂体与辫-曲共存转化发育期的心滩及边滩砂体是主力含气储层。 研究区优质储集砂体的发育受沉积微相展布与基准面旋回的控制。     

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四川油气工业发展史，就是一部科技进步史，为了适应社会主义市场经济体制的要求，必须充分肯定科技进步在四川油气工业发展中的巨大作用，牢固树立依靠科技进步发展四川油气工业的战略思想，确立科技工作的战略地位，抓住机遇，转变观念，切实加强对科技工作的领导，建立新的科技运行机制，增加科技投入，加强新技术开发应用，搞好技术引进和创新，积极开展软科学研究，实行科技进步鼓励政策，进一步调动科技人员的积极性，有效地发     

辽河断陷烃源岩有机地球化学特征

为了研究辽河断陷东、西部凹陷烃源岩地球化学特征的差异及其与油气形成的关系,利用 RockEval 和气相色谱-质谱联用仪（GC-MS）对断陷内古近系沙河街组烃源岩进行了详细的有机地球化学特征研究。 通过对 18 块烃源岩可溶有机质饱和烃进行 GC-MS 测试和生物标志化合物的分析,并分别在东、西部凹陷烃源岩饱和烃馏分 m/z 191 和 m/z 231 质量色谱图中检测到了松香烷和甲基甾烷系列化合物,显示出相同（近）层段烃源岩不同的生物标志化合物特征。 研究结果表明：东、西部凹陷相同（近）层段烃源岩形成的古环境、母源输入等存在显著差异,这可能是造成东、西部凹陷烃源岩差异,并影响辽河断陷东、西部凹陷油气藏差异的重要原因。     

大牛地气田盒1段气层产能主控因素分析

大牛地气田盒1段砂岩厚度大,非均质性较强,气层主控因素多,有效厚度较大,但产能普遍不高,开发地质研究程度有待提高。本文利用测井、薄片鉴定、压汞实验、试井等测试分析资料,对气层四性关系和产能主控因素进行研究,总结分析盒1段高产气层特征与成因,并在分级评价的基础上进行气层纵横向精细刻画。认为盒1段物性、含气性与有效厚度等参数均影响着气层的产能;含气性较差是气层产能普遍不高的主因,岩相与物性、成藏过程的运移通道以及上覆局部封盖层共同控制着气层最后含气丰度,而在沉积微相控制下的砂体展布和后期成岩作用加强的非均质性影响着含气性分布特征。