Direction of pressure wave propagation during combustion-induced rapid phase transition

In the work presented in this paper, the propagation direction of the pressure waves generated during combustion-induced Rapid Phase Transition (cRPT) was investigated. To this end, explosion tests were performed for CH₄/O₂/N₂/CO₂ mixtures in a tubular reactor. Ignition was provided at the top or at the bottom of the vessel. Pressure time histories were recorded by two transducers positioned one at the top and the other one at the bottom.Results have shown that the preferential direction for the pressure waves is that of the flame propagation. When the cRPT phenomenon is weak, an over-adiabatic pressure peak (of around 10–20 bar) can be measured by only one transducer and, in particular, by the transducer far away from the ignition point. Conversely, when the cRPT phenomenon becomes severe, over-adiabatic peaks (as high as 250 bar) can be detected even by the other transducer. Such peaks are the result of separate cRPT events that occur very close to the transducers and, thus, are not damped along the vessel length. In spite of the fact that the upward flame propagation is faster, the cRPT phenomenon is more severe in the case of downward flame propagation.     

Synthesis of TiO2 visible light catalysts with controllable crystalline phase and morphology from Ti-bearing electric arc furnace molten slag

TiO₂ visible light catalysts with different crystalline phases and morphologies were synthesized from titanium-bearing electric arc furnace molten slag (Ti-bearing EAF slag) by using a simple acidolysis process. The effects of the pH of the HCl solution, liquid to solid ratio (R_L/S, HCl solution to the residue ratio, mL/g) and acidolysis time on the micro-morphology and crystalline phase of as-prepared TiO₂ photocatalysts were systematically investigated. The results indicated that with decreasing pH in the HCl solution and increasing R_L/S, the crystalline phase and micro-morphology of the obtained TiO₂ nanostructures tended to transform from anatase type TiO₂ with spherical nanoparticle structures to rutile type TiO₂ with needle-like nanorod structures. The acidolysis time had little influence on the crystalline phase but great impact on the size of the obtained TiO₂. The growth mechanism of TiO₂ from Ti-bearing EAF slag during the acidolysis process was also discussed. In addition, the influence of R_L/S on the photocatalytic properties of the synthesized nanostructured TiO₂ was studied. The results showed that the photodegradation efficiency for Rhodamine B solution could reach 91.00% in 120 min when the R_L/S was controlled at 50:1.     

苯并[a]蒽与肺表面活性剂混合磷脂的相互作用

为探究多环芳烃对肺表面活性物质（PS）膜的影响,选取1,2-二棕榈酰-sn-甘油-3-磷酸胆碱（DPPC）和1-棕榈酰-2-油酰-sn-甘油-3-磷酸胆碱（POPC）混合磷脂为PS模型,研究了苯并[a]蒽与DPPC/POPC混合磷脂的界面化学相互作用.结果表明,苯并[a]蒽对DPPC/POPC混合膜的相变影响显著,会削弱膜的抗形变能力、干扰膜分子的致密有序排列,这一不利影响随POPC占比增多更加明显.DPPC/POPC混合磷脂胶束会包裹苯并[a]蒽对其产生增溶作用,当DPPC浓度为200mg/L时,苯并[a]蒽的表观溶解度接近水溶液的3倍且POPC含量增加会促进胶束的分散使增溶更显著.苯并[a]蒽与DPPC/POPC混合磷脂的相互作用既抑制PS的生理功能,又会影响苯并[a]蒽的溶解迁移,进一步增加苯并[a]蒽的暴露风险.同时生理条件变化引起PS组分的改变可能导致苯并[a]蒽潜在毒性的差异,对患有相关肺部疾病的人群造成的肺损伤可能更严重.     

基于贮存剖面的弹上电子部件可靠性分析

目的 提高弹上电子部件贮存可靠性预测的准确度,提出基于贮存剖面的弹上电子部件可靠性分析方法。方法 在分析弹上电子部件贮存剖面及环境条件的基础上,将弹上电子部件视为多阶段任务系统,引入贝叶斯分析,采用分阶段建模方法,针对各阶段相关性和失效率的不同,基于累积损伤模型,构建弹上电子部件贮存寿命周期内的可靠性模型。结果 相比于洞库贮存、值班等单一环境条件下的可靠性预测,基于贮存剖面综合环境下的可靠性预测结果的准确性更高,且随着贮存时间的增长,优势更明显。结论 该方法立足于实际贮存剖面,分析结果更符合弹上电子部件的应用实际,也为其他弹上部件的可靠性分析提供了一种有效途径。     

固相萃取剂在富集检测极性有机污染物领域的应用研究进展

介绍了常用固相萃取剂的类型与适用范围,综述了近年来在极性有机污染物富集检测中获得应用的新型固相萃取剂,包括具有高比表面积和亲水表面的聚合物萃取剂,以及利用分子印迹和免疫亲和技术制备的新型萃取剂。     

白腐真菌生物过滤塔处理氯苯气体的研究

以竹子为填料,构建新型的白腐真菌Phanerochaete chrysosporium生物过滤塔,考察该过滤塔在不同操作条件下对氯苯的去除性能.结果表明,白腐真菌生物过滤塔对氯苯表现出较好的去除效果,在进口浓度200～1 500 mg/m3,空塔停留时间122 s的条件下,最大去除率接近80%,平均去除率约50%.过滤塔的去除速率与进口负荷和去除率有关,在进口浓度500～1 500mg/m3,流量0.5 m3/h的条件下,最大去除速率可达94 g/(m3·h),平均去除速率为60 g/(m3·h).过滤塔去除速率对进口负荷变化的响应幅度与流量有关,在低流量条件下随进口负荷的变化率较大.过滤塔中氯苯浓度的沿程分布呈现出非线性下降的特征,造成这一现象的原因可能与过滤塔内生物量的分布情况有关.     

特大型现代化矿井高压漏电保护系统的研制

本文介绍一特大型现代化矿井的高压漏电保护系统。该保护系统能集中监护地面变电所６段母线６４路馈出线、井下中央变电所８段母线４８路馈出线，以及井筒中的四对并联下井电缆；具有自动选线、选相、声光报警、数字显示、自动记录及自检演示等功能；还能区分永久性漏电和瞬间性漏电。     

不同生长期的Pseudomonas putida 5-x细胞对工业废水中Cu2+的吸附

研究了不同生长阶段的Cu^2 吸附细菌Pseudomonas-putida5-x对Cu^2 的吸附容量。结果表明在低硫培养基中，当P.putida 5-x细胞生长刚进入对数生长期时，单位细胞对Cu^2 的吸附溶量最低。而当生长进入稳定生长期的后期或死亡期的早期时，单位细胞对Cu^2 的吸附量最大。实验结果还表明，高浓度的Cu^2 对对数期细胞的吸附能力有一定的抑制，而对死亡期的细胞影响较小。早期 研究已证明细胞对重金属离子的吸附和细胞表面某些对重金属离子具有亲和性的功能基团（如某些膜蛋白及羰基化合物）有关。利用透视电子显微镜观察了不同生长阶段的细胞表面结构及对铜离子的吸附效果，发现生长后期细胞表面吸附有较多的Cu^2 ，这表明生长后期的细胞表面可能含有较多的这类功能基团。     

藻细胞不同生长阶段的海泡石凝聚除藻性能

对铜绿微囊藻(Microcystis aeruginosa 469)的4个不同生长阶段:延迟末期,对数中期,对数末期和衰老初期的表面疏水性(疏水分配法)和表面电性(Zeta电位)进行了测定,并利用0.2 g/L的海泡石进行了凝聚除藻性能实验.结果显示以上4个生长阶段的藻细胞表面疏水性平均为:64%, 48%, 58%和70%,而凝聚沉降60 min后的藻细胞去除效率为:97%, 87%, 81%和99%,表明藻细胞表面疏水性与粘土凝聚性能之间有较好的相关性(R＝0.7～0.8),但与表面电性的关系不大.M.A.469各个生长阶段的表面疏水性和凝聚性能的强弱顺序可依次确定为:衰老期>延迟期>对数增长期.