岩溶区某锰矿尾矿回填区地下水环境数值模拟预测

针对岩溶区某锰矿尾矿回填区渗漏污染地下水问题进行影响预测,运用数值模拟方法,模拟了污染物在岩溶含水层中的时空分布情况。结果表明:在30年的模拟期内,污染物在回填区下游的最大迁移距离为300m,有9个地下水保护目标受到影响,包括分散式饮用水源井及泉水,但未影响到回填区北部的集中式饮用水源保护区。研究结果可为岩溶区的地下水污染预测提供一定的借鉴。     

老旧煤矿健康老龄化环境建设路径分析

被关闭的低效率老旧煤矿,作为很多退休煤矿职工的家庭所在地,依然担负着为其提供正常生活条件和养老功能的任务。为了营造煤炭企业退休职工适老环境,对老旧煤矿健康老龄化环境建设路径进行了探讨。在分析健康老龄化的普遍性问题后,从公共服务、卫生健康服务、认同感、原有养老模式等方面论述了老旧煤矿存在的具体问题;针对现状及问题,从理顺养老服务管理机制和合理确定具体任务目标两方面提出了对策与建议。     

Robust Mapping for Mobile Robot Based on Immobile Area Grid Map Considering Potential Moving Objects

Mobile robots need Simultaneous Localization and Mapping (SLAM) for autonomous movement in human living environments. The occupancy grid map used in SLAM is a conventional method which makes a map by an occupancy probability in each grid. This method renews a map based on whether an object is observed or not. In order to remove moving objects from a map, an additional method is required. However, conventional methods deal only with actually moving objects, and potential moving objects (e.g., standing humans) are mapped as static objects. Furthermore, only binary states, used or not used, are given to each object in map updating. This paper proposes the immobility area grid map to represent a map by an immobility probability in each grid. The proposed method renews a map based on the identification of observed objects by a robot's sensors, in addition to whether an object is observed or not. We introduce the map update parameter, which is set adaptively from the certainty of identification result of the object. Observed objects can take continuous states, truly static—unknown—truly moving, according to the parameter value. Potential moving objects are not mapped if the parameter takes values corresponding to moving objects. The experimental results show robust mapping in dynamic environments including potential moving objects.     

四川矿区典型煤层地应力场瓦斯渗透性规律实验研究

在深部开采或复杂地质条件下,地应力对煤岩渗透率的影响明显,进而影响煤矿瓦斯抽采的效果。对四川矿区不同典型煤层条件下的原煤进行了实验研究,分析矿区典型地应力特征条件下煤岩渗透率的变化规律,拟合了煤岩渗透率与有效应力的函数关系模型。研究发现:煤岩的渗透率与有效应力呈规律性的反比例关系,并存在拐点。这一发现为该矿区根据地应力条件进行煤层强化增透措施选取提供了依据,该研究成果在四川矿区白皎煤矿的保护层开采应用中取得了较好的效果,瓦斯抽采效果良好。     

Differences between internal and external hydrogen effects on slow strain rate tensile test of iron-based superalloy A286

To investigate the evaluation method of hydrogen compatibility of A286 superalloy in high pressure hydrogen gas, SSRT tests of hydrogen-charged specimens were conducted at ambient temperature at various strain rates. The relative reduction in area (RRA), one of the ductility parameters, was determined. The hydrogen content in the hydrogen-charged specimen was the same as the equilibrium hydrogen content on the specimen surface at 150 °C in 70 MPa hydrogen gas. The strain rate dependence of RRA was smaller than that of RRA obtained in 70 MPa hydrogen gas at 150 °C. All the hydrogen-charged specimens showed slip-plane fractures in the grains in their cores. However, the specimens in 70 MPa hydrogen gas at 150 °C showed fracture surfaces morphology ranging from dimples to quasi-cleavages and intergranular fractures with decreasing strain rate. These dissimilarities are expected to arise from differences in the hydrogen concentration behaviors of the specimens during the deformation process.     

A graphical method of presenting property rights,building types,and residential behaviors: A case study of Xiaoxihu historic area,Nanjing

One of the main reasons for the decline of urban historic areas in China is the co-existence of multiple property rights. It also deeply affects conservation and regeneration practice. This paper aims to propose a graphical method that illustrates the association between property rights, space, and resident behavior. Based on typological maps and justified graphs, a three-step method was proposed to visualize the relationships between these three elements. The final graph and quantitative data were used to observe the evolution of the courtyard building from a diachronic perspective, as well as to compare the residential behavior in different types from a synchronic perspective. The results show that following the subdivision of property rights, the building layout become more diverse due to various illegal additions, while the residential behavior within different building types tends to be consistent. Moreover, the study observed the traditional Chinese courtyard buildings’ adaptability. The findings contribute to understand the evolution of Chinese urban historic areas and internal motivation, and provide guidance for the conservation and regeneration practice.     

Oxygen vacancies as a link between the grain growth and grain boundary conductivity anomalies in titanium-rich strontium titanate

Titanium-rich (Sr/Ti?=?0.995) strontium titanate (ST) ceramics, air-sintered in a temperature range of 1400–1625?°C, were reported to possess anomalies in the grain growth and analogous anomalies in the grain boundary (GB) conductivity activation energy. However, these two interface-related phenomena, occurring at GBs, could not be associated with each other using a simple “brick-layer” model. In this work we revise the topic and advocate that the deviation from the model comes from the oxygen vacancies localized at GBs of the rapidly-cooled ST ceramics. To verify this, we annealed the ceramics in oxygen and performed their systematic and comparative analysis using impedance spectroscopy. A levelling-off in the GB conductivity activation energy, which increases for ≤1.24?eV, and a four-fold decrease in the GB permittivity are observed after annealing. Thus, we confirm a key role of oxygen vacancies in relation between the grain growth and GB conductivity anomalies of as-sintered Ti-rich ST ceramics.     

Mullite-bonded SiC-whisker-reinforced SiC matrix composites: Preparation,characterization, and toughening mechanisms

A novel mullite-bonded SiC-whisker-reinforced SiC matrix composite (SiCw/SiC, SiC whisker-to-SiC powder mass ratio of 1:9) was designed and successfully prepared. Before preparing the composite, the inexpensive lab-made SiCw was first modified by an oxidation/leaching process and then coated with Al₂O₃. The kinetics results indicate that the oxidation process can be described by improved shrinking-cylinder models. The aspect ratio of SiCw improved after modification. Subsequently, raw materials with a SiC–SiO₂–Al₂O₃ triple-layered structure were obtained after the Al₂O₃-coating process and used as feedstocks during the subsequent hot-pressing sintering. Finally, the characterization of the composites indicates that the mullite-bonded sample performs better (relative density of 93.8?±?1.4%, flexural strength of 533.3?±?18.2?MPa, fracture toughness of 13.6?±?2.1?MPa?m^1/2, and Vickers hardness of 20.6?±?2.5?GPa) than the reference sample without the mullite interface. The improved toughness could essentially be attributed to the moderately strong interface bonding and effective load transfer effects of the mullite interface.     

四川盆地高石梯-磨溪地区下二叠统气源示踪

以天然气、烃源岩及储层沥青的地球化学特征为主要依据,通过天然气-天然气、储层沥青-烃源岩、天然气-烃源岩3个方面对比,深入探讨四川盆地高石梯-磨溪地区下二叠统天然气来源。研究表明,四川盆地高石梯-磨溪地区下二叠统天然气主要来源于筇竹寺组泥岩。其5项证据分别为:下二叠统天然气乙烷碳同位素小于-30.5‰,甲、乙烷碳同位素倒转是由高演化程度烃源岩所致;多数下二叠统天然气与龙王庙组天然气特征最为相似;GS18,NC1井下二叠统天然气特征与寒武系相似,说明上下层气源一致;高石梯-磨溪地区下二叠统储层沥青地球化学特征与筇竹寺组泥岩最为相似;筇竹寺组泥岩主要为下二叠统供气,这一认识符合干酪根油气生成理论和同位素分馏规律。     

矿井顶板水探测方法及富水区成因分析

某矿1303工作面为三采区首采工作面，顶板含水层主要为第四系含水层、K₁₀和K₈砂岩裂隙含水层。为了解顶板K₁₀和K₈砂岩裂隙含水层的富水性，在1303工作面运输巷布置了覆盖全工作面的10个钻场（46个顶板探放水钻孔）进行探测，结合地表钻孔的顶板覆岩规律以及抽水试验结果可知，K₁₀和K₈砂岩裂隙含水层属于弱富水含水层，在2号钻场和8号钻场周边局部存在局部富水区；局部富水区均与构造有关，2号钻场位于背斜翼部，8号钻场位于向斜轴部，而背斜翼部和向斜轴部易出现砂岩裂隙带，成为地下水的富集区。