组合荷载作用下穿越隧道管道的强度分析

穿越隧道管道跨度较大,受力情况复杂,敷设方式不当很容易导致管道失效。基于非线性有限元方法,建立了穿越隧道管道有限元模型,使用管单元模拟管道,非线性土弹簧模拟管土相互作用。参考实际工程数据,考虑了温度和内压组合荷载的作用,对比计算了不同敷设方式、回填土性质和滑动支撑间距等参数下的管道应力及位移,通过分析得到:直埋敷设能更好地保证管道的安全运行,该敷设条件下管道优先选择用黏土回填并进行夯实;若采用支墩敷设的方式,滑动支撑的间隔应取20 m左右,并且对弯管处管道壁厚进行加厚。研究结果可为穿越隧道管道的敷设设计提供一定的参考。     

提高25t／h沸腾炉出力的措施

通过采用控制给煤粒度、更换不合格风帽、覆盖埋管延伸段受热面的措施后,２５ｔ／ｈ沸腾炉出力明显增加,保证了稳定运行。     

不同地下水埋深条件下农田潜水蒸发规律

汾河灌区作为山西省最大的自流灌区,近年来引用水量不足导致用水供需矛盾突出,文中分析了汾河灌区不同地下水埋深条件下农田潜水蒸发的规律,对今后灌区控制盐碱化的发生起到了重要的作用.     

千米桥奥陶系潜山天然气气源对比

为判明黄骅坳陷千米桥奥陶系潜山天然气藏的气源问题，对大港地区不 同层位烃源岩进行热模拟实验。采用气源综合动态对比思路，根据对模拟得到的产气率、轻烃、轻烃碳同位素的研究，对千米桥奥陶系潜山天然气进行动态气源对比。对比结论：板桥凹陷和歧口凹陷沙三段烃源类均可为千米桥奥陶系潜山供气，认为潜山凝析油主要来源于烃源岩成熟阶段，天然气主要来源于烃源岩高成熟阶段。     

土壤源热泵地埋管换热器传热机制研究

分析了土壤源热泵地埋管换热器与土壤的传热机制,建立了导热机制与渗流传热机制下的地埋管传热模型。在导热与渗流传热机制下,模拟了制冷工况下4×4排列群井的温度分布,提出了群井布置的优化方法。     

瓦斯综合抽放技术在朱庄煤矿的应用

为了更有效解决朱庄煤矿Ⅲ4414综采工作面瓦斯长期超限问题,提出了在该工作面采用包括在采空区上隅角埋管抽放与顶板走向高位钻孔抽放相结合的方法进行瓦斯抽放。通过对采空区抽放埋管位置以及采空区裂隙带的高度分布范围进行分析,确立了最佳抽放埋管位置和终孔位置。瓦斯抽放结果表明:该技术有效地降低了Ⅲ4414综采工作面的瓦斯涌出量,解决了该工作面上隅角瓦斯长期超限问题,使工作面在生产高峰时,上隅角瓦斯体积分数始终控制在0.4%左右,确保了工作面的安全回采。     

埋管灌浆在厚煤层倾斜分层开采中的应用

为了防止厚煤层开采过程中火灾事故的发生,以河滩沟矿为例,介绍了埋管灌浆工艺的技术要点及注意问题。通过在厚煤层倾斜开采中的成功应用,证明了埋管灌浆工艺技术在控制煤层自燃发火方面具有显著作用。     

The Trp-cage: optimizing the stability of a globular miniprotein

The Trp-cage, as the smallest miniprotein, remains the subject of numerous computational and experimental studies of protein folding dynamics and pathways. The original Trp-cage (NLYIQWLKDGGPSSGRPPPS, Tm = 42 degrees C) can be significantly stabilized by mutations; melting points as high as 64 degrees C are reported. In helical portions of the structure, each allowed replacement of Leu, Ile, Lys or Ser residues by Ala results in a 1.5 (+/-0.35) kJ/mol fold stabilization. No changes in structure or fluxionality of the core results upon stabilization. Contrary to the initial hypothesis, specific Pro/Trp interactions are not essential for core formation. The entropic advantage of Pro versus Ala (DeltaDeltaS(U) = 11 +/- 2 J/mol K) was measured at the solvent-exposed P17 site. Pro-Ala mutations at two of the three prolines (P12 and P18) that encage the indole ring result in less fold destabilization (2.3-3.4 kJ/mol). However, a P19A mutation reduces fold stability by 16 kJ/mol reflecting a favorable Y3/P19 interaction as well as Trp burial. The Y3/P19 hydrophobic staple interaction defines the folding motif as an 18-residue unit. Other stabilizing features that have been identified include a solvent-exposed Arg/Asp salt bridge (3.4-6 kJ/mol) and a buried H-bonded Ser side chain ( approximately 10 kJ/mol).     

Buried Interface Passivation: A Key Strategy to Breakthrough the Efficiency of Perovskite Photovoltaics

Owing to the merits of low cost and high power conversion efficiency (PCE), perovskite solar cells (PSCs) have become the best candidate to replace the commonly used silicon solar cells. However, PSCs have been slow to enter the market for a number of reasons, including poor stability, high toxicity, and rigorous preparation process. Passivation strategies including surface passivation and bulk passivation have been successfully applied to improve the device performance of PSCs. The passivation of the defects at the buried interface, which is regarded as a key strategy to breakthrough the device efficiency and stability of PSCs in the future, is ongoing with challenge. Herein, in detail the recent passivation of the buried interface is introduced from three aspects: perovskite layer, buried interlayer, and transport layer. The passivation effect of the buried interface is clearly demonstrated through three categories of salts, organics, and 2D materials. In addition, the transport layer is classified into electron transport layer (ETL) and hole transport layer (HTL). These classifications can help to have a clear understanding of substances which generate passivating effect and guide the continuous promotion of the follow-up buried interface passivating work.     

渤海湾盆地潜山油气藏勘探潜力与方向

渤海湾盆地潜山勘探历经40余年,通过勘探历程与发现规律分析认为,以10年为一个阶段,潜山勘探经历了规模发现阶段、勘探低迷阶段、缓慢发现阶段,目前正处于新的勘探阶段.深层资源研究证实油气资源丰富,潜山勘探具有坚实的资源基础.潜山勘探现状分析表明,潜山类型、潜山勘探层系、勘探深度、不同勘探区域勘探程度等方面存在不均衡现象,并在不均衡中孕育着巨大的勘探潜力.辽河坳陷兴隆台潜山与冀中坳陷牛东深潜山的勘探表明,深层变质岩和碳酸盐岩储层具有较好的储集性能,未来潜山勘探深度将不断加深,4000m以下将成为勘探的热点;潜山类型将由以风化壳型为主向潜山内幕型转变,凹中、凹边隆起(凸起)是内幕潜山勘探的重点;潜山勘探发现具有明显的坳陷接替式,黄骅坳陷、辽河坳陷的滩海以及以往受认识局限制约的低勘探程度区将成为勘探重点.通过勘探程度等条件分析,大兴-固安、曙北-牛心坨、长芦、王官屯-乌马营、燕南、笔架岭、海月等26个潜山带勘探潜力较大.随着工艺技术的进步与成藏认识的提升,潜山勘探必将形成一轮新的规模发现.