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关键词： 岩石力学   3D打印   脲酶诱导碳酸钙沉积   力学性能   微观结构  

摘要： 3D打印技术在岩石室内试验中以其快速成型、复杂结构复现等优势展现出广阔应用前景,但打印试样的力学性能较差,制约了其工程实际应用。为有效提高3D打印类砂岩试样力学性能,选用GS19型砂与呋喃树脂为基材制备的类砂岩试样为对象,采用不同次数脲酶诱导碳酸钙沉积(enzyme-induced calcium carbonate precipitation,简称EICP)溶液渗透处理,通过单轴压缩试验定量分析其力学性能演化规律,并采用扫描电镜结合能谱与傅里叶变换红外光谱分析从微观尺度揭示脲酶诱导碳酸钙沉积技术的力学增强机制。结果表明:试样抗压强度与弹性模量随渗透次数递增呈现增强特性,经过4次脲酶诱导碳酸钙沉积溶液渗透处理后,试样强度较对照组提升51.92%,弹性模量提升35.57%,同时其破坏模式及裂纹扩展特征与天然弱胶结砂岩相似;从微观结构研究发现,脲酶诱导碳酸钙沉积技术促使试样内部形成“树脂-碳酸钙”复合胶结相,通过增强砂粒间胶结强度,填充孔隙降低结构缺陷的双重作用机制,试样力学性能得到显著提升。研究结果拓展了3D打印技术在岩石试验领域的应用潜力。

关键词： 衰老   血管疾病   症状评估   颈动脉-股动脉脉搏波传导速度   血管舒张   治疗学  

摘要： 随着全球范围内人口老龄化的不断加剧,血管衰老已成为心血管疾病、认知功能障碍以及多器官衰竭的重要病理基础。血管衰老不仅表现为内皮功能障碍、平滑肌细胞表型转化及细胞外基质重构等生物学特征,更与动脉僵硬度增加、血流动力学异常及血管重构密切相关,最终导致动脉硬化、动脉粥样硬化(atherosclerosis,AS),以及心、脑、肾等靶器官受损引起的各种血管退行性疾病如高血压、冠心病、脑卒中、慢性肾脏病等的发生发展[1]。因此,深入解析血管衰老的分子机制、建立精准的评估体系并探索有效的干预策略,已成为当前抗衰老医学与心血管研究的重点方向。

关键词： 川西地区   致密砂岩气   孔隙结构   多重分形维数   非均质性   成岩作用  

摘要： 四川盆地川西地区致密气资源量丰富,但由于川西南部与川西北部储层含气性存在明显差异,制约了天然气的高效勘探开发。为了查明四川盆地川西地区致密储层含气性差异的影响因素,利用多重分形维数理论,结合离心—核磁实验、高压压汞、铸体薄片、扫描电镜、X射线衍射等实验手段,先后明确了川西南地区与川西北地区储层的孔隙结构特征、含气性特征,明确了川西地区储层含气差异性的控制因素。研究结果表明:(1)川西地区孔隙以残余粒间孔为主,川西南地区含气性较差的层位残余粒间孔大部分被碳酸盐胶结,川西北地区孔隙内绿泥石薄膜较发育,含气性较差的储层,被绿泥石堵塞。(2)川西地区储层含气饱和度分布范围为38.79%~56.88%,川西南地区相比川西北地区含气饱和度较低,其值为38.79%。(3)川西北地区储层压实作用强烈,储层减孔率较高,储集空间相对较小,同时,由于储层内部孔径较小部分被绿泥石膜堵塞,也造成储层含气性降低;川西南地区纳米孔隙非均质性较强,天然气运移受阻,其部分储层碳酸盐胶结物发育较多,严重影响储层的二次发育,导致储层内部含气性较差。

关键词： 含油废水   高级氧化   电化学处理   生物强化   膜污染控制   技术耦合   组合工艺处理技术  

摘要： 随着国家工业化的不断发展,石油开采、炼制及石化行业衍生的含油废水已成为水环境治理领域的难点与热点。含油废水组分复杂,含油乳化油、有毒有机污染物、重金属离子及高浓度盐类等多重污染物,不仅对生态系统的稳定性造成严重破坏,更对人类健康构成潜在的威胁。本文系统梳理了近年来含油废水处理技术的发展现状,重点介绍了物理处理技术、化学处理技术、生物处理技术以及组合工艺处理技术等核心技术的机理与发展,明确各技术的优势和适用场景,深入探讨含油废水多技术耦合工艺的前景,以期为石化行业的绿色低碳转型提供理论支撑与技术参考。

关键词： 盐碱   耐盐碱作物   粮食安全  

摘要： 有效利用我国1亿公顷盐碱地是保障粮食安全的有效措施,耐盐碱作物的培育成为解决这一问题的关键途径。通过综合介绍植物耐盐碱机制以及我国在耐盐碱作物培育方面的进展,为耐盐碱作物培育和筛选技术手段应用于中学生物学教学提供参考。

关键词： 活体课程资源   核心素养   中学生物学课程资源建设  

摘要： 活体课程是实现理论与实践结合的关键,本文结合西宁等地区在本土实践上的探索,如资源开发、校园内建设及面临的挑战,介绍了中学生物学活体课程资源的建设,阐述了生物学活体课程资源建设对教师专业发展、学生生物学学科核心素养提升及教学质量提高的系统性意义。

关键词： Nuclear magnetic resonance  

摘要： In order to explore the coupling effect mechanism of saturation and initial damage on the microscopic pore structure and macroscopic physical and mechanical properties of sandstone under freeze-thaw action, firstly, 30 freeze-thaw cycles were carried out on sandstone samples with three damage degrees and five saturation degrees. Secondly, the uniaxial compression test was carried out on the samples after freeze-thaw. Finally, the internal pore structure changes were analyzed by nuclear magnetic resonance(NMR) test. The results show that the elastic modulus and peak strength of frozen-thawed sandstone decrease significantly with the increase of saturation, while the porosity increases gradually with the increase of saturation. When the saturation exceeds the critical value of 50%, the degradation rate of each parameter increases sharply, and the increase of damage further accelerates this trend. Microscopically, the increase of saturation promotes the expansion and connection of micropores and small pores, and gradually forms a network of mesopores, macropores and fissures. Damage significantly enhances the connectivity of the pore system, resulting in a continuous increase in the ratio of mesopores to macropores. The fractal dimension of small pores, mesopores and macropores is negatively correlated with saturation. The increase of damage makes the change of fractal dimension more significant. The total pore fractal dimension has a negative linear correlation with porosity and a positive linear correlation with mechanical parameters. The synergistic effect of saturation and initial damage is the internal mechanism that drives the deterioration of sandstone pore structure and eventually leads to the degradation of rock mass macroscopic properties. © 2026, Central South University. All rights reserved.

关键词： Fracture  

摘要： Objective Geotechnical engineering in cold regions typically involves rock masses containing joints and fractures. During seasonal freeze−thaw cycles, water trapped within these internal structural planes undergoes freezing and thawing, resulting in freeze−thaw damage to the rock mass. This damage leads to the deterioration of mechanical properties and overall structural stability, significantly increasing the risk of engineering accidents. As engineering activities in cold regions continue to expand, the problem of freeze−thaw degradation in fractured rock masses becomes increasingly significant. Therefore, this study investigates the degradation effects and damage mechanisms of saturated fractured rock masses during cyclic freeze−thaw processes at the micromechanical level. The objective is to accurately assess how primary fractures influence the development of secondary fractures during freeze−thaw cycles and to determine whether micromechanical damage alters the loading-fracture characteristics of rock masses. This research provides new insights into the mechanisms of freeze−thaw damage and failure prediction methods for rock slopes in cold regions and advances the interdisciplinary field of rock mechanics and numerical simulation. Methods Fractures within rock masses were connected through rock bridge zones. When external loads caused rock bridge failure, step-like sliding occurred on slopes with discontinuous joints of varying steepness. Therefore, in laboratory experiments, three carefully selected rock specimens with fractures (high dip angle of 75°, low dip angle of 15°, rock bridge length of 15 mm, dip angle of 90°) were subjected to freeze−thaw cycles and uniaxial compression tests after saturation. CT scans were performed on the specimens after they reached predetermined freeze−thaw cycles (0, 15, 30 cycles) or after loading. Using Avizo software, three-dimensional reconstructed images enabled analysis of micro-parameter evolution and quantitative fracta

摘要： 当今世界正经历深刻变革,气候变化加剧、极端天气频发、地区冲突不断、新技术革命兴起,多重因素交织作用下,交通运输系统面临前所未有的不确定性.在这一背景下,如何提升交通运输系统的"韧性"——系统抵御、吸收、适应扰动并快速恢复的能力,已成为交通运输领域研究的重要方向.