Composite fibers of La0.5Sr0.5CoO3-δ-LaSrCoO4±δ with high catalytic activity toward oxygen reduction reaction

To promote catalytic activity toward oxygen-reduction reaction in the intermediate temperature solid-oxide fuel cells, we prepared a dual-phase composite cathode material 75 mol%La0.5Sr0.5CoO_3-δ-LaSrCoO_4±δ with a fibrous structure via one-pot electrospinning of a polymer containing solution. We then investigated the micro-structure and electrochemical performance of this fibrous composite. The results confirm that the fibrous composite is composed of intimately mixed nano-crystalline grains and that the compositional phases are compatible with each other. Compared with the corresponding single-phase fibers, the nano-crystalline size of the composite is more stable, and the fine nano-crystalline grains are more resistant to growth and coarsening, indicating the mutual dispersion and suppression between the constituent phases. Furthermore, compared with the corresponding single-phase fibers, the electrochemical performance of this fibrous composite cathode is more favorable. At 800 °C, its area specific resistance (ASR) is as low as 0.03 Ω cm², and maximum output power density is as high as 960 mW cm⁻², which is achieved from an electrolyte-supported single cell that was developed using this cathode. After aging this cathode for a long time, ASR is less worsened and the output power density decreases only slightly, indicating that the prolonged electrochemical performance in the running cells is more stable.     

港里矿软破围岩采矿的分析与研究

港里矿围岩软弱破碎，随开采深度延伸，地压显现越来越剧烈，严重影响港里矿正常回采。为研究港里矿软破围岩采矿，分析了影响采矿正常进行的因素和机理，调整采矿的顺序，使港里矿软破围岩采矿的困难得到根本扭转，保证了采矿生产的正常进行，选择围岩稳固及充分卸压部位布置斜坡道和联巷、优先回采围岩破碎的高应力区是地压管理的关键问题。     

瑞木矿区配矿实践

通过对品位高低不同的矿石按比例进行互相搭配,尽量使之混合均匀调配成满足矿山生产矿石指标要求,降低损失率、提高回收率。     

Fabrication of a double-layered Co-Mn-O spinel coating on stainless steel via the double glow plasma alloying process and preoxidation treatment as SOFC interconnect

To improve oxidation resistance, prevent Cr evaporation and maintain appropriate electrical conductivity of AISI 430 stainless steel (430 SS) as the solid oxide fuel cells' (SOFCs) interconnect, a double-layered Co-Mn-O spinel coating is fabricated successfully on 430 SS via a simple double glow plasma alloying process (DGPA) followed by heating in the air (preoxidation treatment). The double-layered Co-Mn-O spinel coating is composed of a thick MnCo₂O₄ spinel outlayer and a thin mutual-diffused (MnCoFe)₃O₄ oxide innerlayer. The isothermal and cyclic oxidation measurements are used to investigate the oxidation resistance, and the ASR test is performed to evaluate the conductivity for the coated and uncoated specimens. The coated specimen has a lower oxidation kinetics rate constant (9.0929 × 10⁻⁴ mg² cm⁻⁴ h⁻¹) than the uncoated one (1.900 × 10⁻³ mg² cm⁻⁴ h⁻¹) and the weight gain of the coated specimen (0.84 mg cm⁻²) is less than that of bare steel (1.29 mg cm⁻²) after 750 h oxidation. Meanwhile, the coated specimen holds a lower area specific resistance (0.029 Ω cm²) compared to the uncoated one (2.28 Ω cm²) after 408 h oxidation. Furthermore, the compact Co-Mn-O spinel coating can effectively impede Cr-volatilization. Additionally, the probable mechanism of the Co-Mn alloy conversion into spinel and the electronic conduction behavior in the spinel are discussed. The effects of mutual-diffused oxide innerlayer on oxidation behavior and conductivity are investigated.     

天荣矿二2煤储层物性及特征

煤储层物性及特征是煤层气地质理论的重要内容，加强其研究对提高煤层气勘探开发成效至关重要。基于天荣矿地质、煤层气勘探及相关测试等资料，采用地质与煤层气地质理论对该矿二₂煤储层物性及特征进行了研究。结果表明:天荣矿二₂煤层物理性质良好，生烃物质丰富；煤层含煤性、稳定性、可采性好，煤层气含量和纯度高，可为煤层气开发提供良好对象和气源条件；煤变质程度高，煤中裂隙相对发育，但其渗透性整体较差，渗透率分异显著且普遍低下；煤储层能量较强且分异显著，煤储层压力状态为欠压—超压型，并以正常—超压煤储层压力状态为主，有利于煤层气高产富集。     

不同类型液体水化作用下海相页岩巴西劈裂破坏特征

为了研究不同类型液体水化作用对页岩内部裂缝形态、岩石抗拉强度和巴西劈裂张性破坏模式的影响,选取昭通国家级页岩气示范区下志留统龙马溪组页岩气储层岩心,采用清水及滑溜水分别进行了水化预处理,通过CT扫描对比了页岩中裂缝结构的变化;然后开展巴西劈裂试验,研究了水化预处理后页岩试件抗拉强度及张性破坏模式;在此基础上,选取研究区内的两口水平井,在其压裂施工现场开展了水化预处理先导性试验。研究结果表明:①相同时间内,自发渗吸过程清水水化作用对海相页岩裂缝复杂程度的提升效果优于滑溜水;②清水表面张力更大且黏度更低,清水水化作用不仅能够促使原始裂缝延伸,还能诱发新的微细裂缝或分支缝,而滑溜水水化则以促使原始裂缝扩展为主;③水化作用使海相页岩发生损伤,其抗拉强度降低,经过清水、滑溜水水化预处理后的页岩试件抗拉强度相对未水化试件分别降低了35.6%和18.1%;④根据主裂缝延伸形态将页岩水化后巴西劈裂张性破坏模式分为阶梯形、折线形、分支形和弧形4种或是其相互组合,而未水化页岩张性破坏模式仅为直线形;⑤水化作用能有效提升海相页岩压裂裂缝复杂程度,建议在施工条件允许的情况下,射孔后在限压范围内高排量注入一定量清水并关井直至主压裂施工开始,为了降低主压裂施工难度,可以通过"低砂浓度、长段塞"泵注的策略来满足设计加砂量。     

25%小偏置碰撞策略及测试评估研究

随着汽车事故的增加,且小重叠碰撞事故死亡率居高不下,小偏置碰撞试验逐渐成为焦点。基于IIHS公布的最新车辆碰撞试验结果,统计超过100余款不同类型的25%小偏置碰撞车辆,建立碰撞转角与碰撞区域的数学模型,将25%小偏置碰撞归结为三种不同的碰撞策略,分别是吸能策略、掠过策略和掠过与吸能策略;并进行试验验证,对三种策略的优缺点进行分析。结果表明,小偏置碰撞试验可运用合理的碰撞策略达到法规要求,对25%小偏置碰撞试验具有一定的参考价值。     

Sputtered Fe1·5CoNi0.5 coating: An improved protective coating for SOFC interconnect applications

In an attempt to optimize the properties of FeCoNi coating for planar solid oxide fuel cell (SOFC) interconnect application, the coating composition is modified by increasing the ratio of Fe/Ni. An Fe_1·5CoNi_0.5 (Fe:Co:Ni = 1.5:1:0.5, atomic ratio) metallic coating is fabricated on SUS 430 stainless steel by magnetron sputtering, followed by oxidation in air at 800°C. The Fe_1·5CoNi_0.5 coating is thermally converted to (Fe,Co,Ni)₃O₄ and (Fe,Co,Mn,Ni)₃O₄ without (Ni,Co)O particles. After oxidation for 1680 h, no further migration of Cr is detected in the thermally converted coating region. A low oxidation rate of 5.9 × 10^?14 g² cm^?4 s^?1 and area specific resistance of 12.64 mΩ·cm² is obtained for Fe_1·5CoNi_0.5 coated steels.     

甘肃靖远宝积山矿区煤层气成藏条件研究

甘肃靖远宝积山矿区煤层埋深小于1500m的煤层气地质资源量98．28×10^8m^3，且具有煤层厚度大、层数多，埋藏浅、含气量较高、水动力径流条件差、顶底板岩性封盖性能较好和发育复式向斜构造等条件，利于区域内煤层气的富集成藏。     

铁法矿区地面垂直采空区井技术

基于对低透气性煤层顶板受采动影响下的移动规律的研究，铁法矿区于1994年通过联合国UNDP项目率先在国内应用地面垂直采空区钻井进行了技术示范。通过对已经施工的21口采空区钻井的应用和研究，铁法矿区对于采空区钻井的布孔原则和理论方面取得了丰富的经验和成果，大量的实践也证明了地面垂直采空区钻井技术在低透气性煤层，尤其在煤层群开采时，是最有效的煤层气开发技术之一。