制备方法对Ce_(0.67)Zr_(0.33)O_2固溶体性能的影响

用氧化共沉淀法、均匀共沉淀法和柠檬酸溶胶-凝胶法制备了Ce_(0.67)Zr_(0.33)O_2固溶体,并将经和900℃焙烧后的固溶体进行了XRD、BET、Raman、H_2-TPR和储氧量(OSC)表征。结果表明,氧化共沉淀法和柠檬酸溶胶-凝胶法制备的Ce_(0.67)Zr_(0.33)O_2固溶体的储氧量、比表面积均高于均匀共沉淀法,且制备的固溶体经900℃焙烧4 h后未出现相分离,具有良好的热稳定性。     

换向脉冲镀金对铍青铜镀厚金层产品存储能力的影响

为提高电镀厚金层的存储性能,采用优化镀层预处理工艺方法,利用换向脉冲电镀技术在铍青铜试件上制备镀厚金层,并研究不同预处理工艺对长时间存储条件下镀层结合力的影响规律;利用X-射线能谱仪研究了优化预处理工艺对存储1~5年后镀厚金层的成分变化规律的影响;利用扫描电子显微镜与能谱仪研究了存储1~5年后镀层与铜基体之间的扩散行为。研究结果表明,换向脉冲电镀厚金层储存5年后,镀铜作为镀金的预镀层,镀层结合力最为优异;换向脉冲电镀厚金层的金原子数分数高于99.9%,镀厚金层具有优异的存储性能,但是镀厚金层界面处存在1.0~1.5μm的相互扩散现象。     

浮顶罐内含蜡原油静态储存中的冷却胶凝规律

将失流点以下的含蜡原油看作是多孔介质体系,以附加比热容法描述蜡的结晶潜热,动量源项方法表征蜡晶网络结构对液态原油的流动阻力,基于有限体积法数值模拟含蜡原油的冷却胶凝过程。结果表明：传热机制和边界条件主导了凝油结构的演变进程。在自然对流作用下,凝油最先在罐底和罐壁所包围的区域内产生,且其始终是罐内胶凝最严重区域。罐顶最先形成完整的凝油层,其发展先后经历了慢速增长和快速增长两个阶段,且其凝油层厚度逐渐趋于均匀分布;其次是罐底,其发展过程与罐顶相反;最后是罐壁,其凝油层的演变具有从罐底沿罐壁向罐顶推进的特点。罐内对流越强,罐顶凝油层的增长速率越缓慢,罐底凝油层的增长速率越快。基于温度场及凝油结构的演变规律,可以将含蜡原油的冷却过程分为3个阶段,即自然对流占主导的第1阶段,导热逐步取代自然对流的第2阶段,及以导热为主导机制、边界条件调控下的第3阶段,同时给出了不同阶段原油温度分布和散热损失规律的细节。     

Improvement of dielectric breakdown strength and energy storage performance in Er2O3–modified 0.95Sr0.7Ba0.3Nb2O6-0.05CaTiO3 lead-free ceramics

In this study, 0.95?Sr_0.7Ba_0.3Nb₂O₆-0.05CaTiO₃-x wt% Er₂O₃ ceramics (SBNCTEx; x?=?0–5) were synthesized using traditional solid-state method, and we investigated the microstructure, energy storage properties as well as the relationship between dielectric breakdown strength and interfacial polarization. As compared with pure 0.95?Sr_0.7Ba_0.3Nb₂O₆-0.05CaTiO₃ ceramics, the Er₂O₃ dopants suppressed the grain growth of SBNCTEx, and the doped ones showed the dense microstructure. The secondary phase was found for x?≥?1 according to the EDS results, and the influence of the secondary phase on relative dielectric breakdown strength has also been studied. The dielectric breakdown strength increased from 18.1?kV/mm to 34.4?kV/mm, which is good for energy storage. The energy storage density of 0.28?J/cm³ and the energy storage efficiency of 91.4% were obtained in the SBNCTE5 ceramics. The results indicate that SBNCTE ceramics can be used as energy storage capacitors.     

Copper substituted nickel ferrite nanoparticles anchored onto the graphene sheets as electrode materials for supercapacitors fabrication

Nickel ferrites with high theoretical capacitance value as compared to the other metal oxides have been applied as electrode material for energy storage devices i.e. batteries and supercapacitors. High tendency towards aggregation and less specific surface area make the metal oxides poor candidate for electrochemical applications. Therefore, the improvements in the electrochemical properties of nickel ferrites (NiFe₂O₄) are required. Here, we report the synthesis of graphene nano-sheets decorated with spherical copper substituted nickel ferrite nanoparticles for supercapacitors electrode fabrication. The copper substituted and unsubstituted NiFe₂O₄ nanoparticles were prepared via wet chemical co-precipitation route. Reduced graphene oxide (rGO) was prepared via well-known Hummer's method. After structural characterization of both ferrite (Ni_1-xCu_xFe₂O₄) nanoparticles and rGO, the ferrite particles were decorated onto the graphene sheets to obtain Ni_1-xCu_xFe₂O₄@rGO nanocomposites. The confirmation of preparation of these nanocomposites was confirmed by scanning electron microscopy (SEM). The electrochemical measurements of nanoparticles and their nanocomposites (Ni_0.9Cu_0.1Fe₂O₄@rGO) confirmed that the nanocomposites due to highly conductive nature and relatively high surface area showed better capacitive behavior as compared to bare nanoparticles. This enhanced electrochemical energy storage properties of nanocomposites were attributed to the graphene and also supported by electrical (I-V) measurements. The cyclic stability experiments results showed ~65% capacitance retention after 1000 cycles. However this retention was enhanced from 65% to 75% for the copper substituted nanoparticles (Ni_0.9Cu_0.1Fe₂O₄) and 65–85% for graphene based composites. All this data suggest that these nanoparticles and their composites can be utilized for supercapacitors electrodes fabrication.     

CO2混合物热物性在CCS研究中的作用:实验数据、理论模型和典型应用

二氧化碳捕集与封存（CCS）各工艺过程的设计、运行都依赖于对CO₂及其混合物热物理性质的深入理解。同时，CCS的规模化发展和商业化进程，对CO₂混合物及其热物性的准确性提出了更高的要求。本文从实验数据、理论模型和典型应用3个方面综述了CO₂及其混合物热物性的发展现状，并尝试对发展趋势进行归纳。在实验研究方面，CO₂混合体系的研究进展视组分不同，差异较大，其中CO₂-N₂、CO₂-CH₄、CO₂-H₂O和CO₂-H₂二元体系已形成较完善的物性数据库，而CO₂-NH₃、CO₂-NO _x 和CO₂-CO体系的物性数据还比较欠缺；在物性估算方面，面向CCS的物性估算模型研究自2008年开始活跃，基于不同理论构架，目前已逐步形成面向CCS的多元化的物性估算体系。物性研究在CCS中的应用主要体现在物性是支撑CCS过程研究的基础，其不准确性在过程模拟或计算中会被“放大”，从而影响过程评估的准确性，本文从物性在循环构建和能效分析中的作用以及CO₂水合物的形成3个方面入手做了说明。文章最后对面向CCS的物性研究趋势进行了梳理，对分子模拟技术、通用性强的物性估算模型和物性在过程设计和循环分析中的角色进行了展望。     

粒径对好氧颗粒污泥储存稳定性的影响

研究了混合粒径与不同粒径好氧颗粒污泥（AGS）在储存过程中的三维结构、质量变化、微生物活性以及理化特性的变化规律。经过室温（16~25℃）下31天的储存,污泥的三维结构均保持较好,未出现明显解体现象。混合粒径的AGS在储存前20天,其质量和比耗氧速率（SOUR）下降缓慢,胞外聚合物（EPS）先减小后上升。20天之后由于厌氧菌在竞争中逐渐占得优势,其质量减小了46.3%,EPS与SOUR分别下降69.0%和72.7%,导致稳定性随之下降。不同粒径AGS经过储存后,其颜色仍为橙黄色且结构完整;1~2mm和3~4mm粒径的AGS质量减小（分别为49.1%和53.9%）较大,且SOUR和EPS下降了亦较大;0.3~1mm粒径的AGS质量减小较少,EPS下降较少,但SOUR下降幅度较大,而2~3mm粒径的质量仅减小了33.7%、SOUR下降幅度最小（39.8%）,EPS下降幅度也相对较小（58.7%）,表明其在储存过程中能保持较好的活性与稳定性。     

含相变材料的定型复合建材储能调温及力学特性

使用微胶囊化和直接吸附法两种方式将相变材料与水泥结合分别制成了含相变微胶囊水泥基复合建材及含相变材料水泥基复合建材,搭建实验测试系统,对复合建材的调温储能特性进行了测试。微胶囊化相变材料和纯相变材料的加入对水泥基建材的微观结构形貌具有较为明显的影响。热重曲线显示纯水泥、相变微胶囊-水泥、相变材料-水泥试样的失重率依次增加,相变微胶囊-水泥式样的稳定性最好;复合成分所占质量分数相同时,相变材料-水泥试块强度略低于相变微胶囊-水泥试块;调温测试表明,在水泥中添加相变微胶囊颗粒或纯相变材料时均具有一定的调温储能功能,能明显减缓水泥基建材的温度在相变温度附近的波动;尽管直接吸附法制备的相变材料-水泥复合建材具有较好的调温性能,但其可循环性较差,伴有刺激性气味逸出,实用性较差。因此相变微胶囊-水泥复合较适宜作为新型建材推广使用。     

Structure variation and energy storage properties of acceptor-modified PBLZST antiferroelectric ceramics

Energy storage capacitors with high recoverable energy density and efficiency are greatly desired in pulse power system. In this study, the energy density and efficiency were enhanced in Mn-modified (Pb_0.93Ba_0.04La_0.02)(Zr_0.65Sn_0.3Ti_0.05)O₃ antiferroelectric ceramics via a conventional solid-state reaction process. The improvement was attributed to the change in the antiferroelectric-to-ferroelectric phase transition electric field (E_F) and the ferroelectric-to-antiferroelectric phase transition electric field (E_A) with a small Mn addition. Mn ions as acceptors, which gave rise to the structure variation, significantly influenced the microstructures, dielectric properties and energy storage performance of the antiferroelectric ceramics. A maximum recoverable energy density of 2.64 J/cm³ with an efficiency of 73% was achieved when x = 0.005, which was 40% higher than that (1.84 J/cm³, 68%) of the pure ceramic counterparts. The results demonstrate that the acceptor modification is an effective way to improve the energy storage density and efficiency of antiferroelectric ceramics by inducing a structure variation and the (Pb_0.93Ba_0.04La_0.02)(Zr_0.65Sn_0.3Ti_0.05)O₃-xMn₂O₃ antiferroelectric ceramics are a promising energy storage material with high-power density.     

油气管道及储运设施安全保障技术发展现状及展望

相比已经完善丰富的开采和勘探技术,油气的运输以及储存却仍然存在不足之处。我国对能源安全提出更加严格要求的同时,对区域经济的发展规划也有足够重视。因此,保障油气管道的安全则成为了我国能源安全战略的重中之重。在阐释油气管道现阶段在储运安全保障技术发展状况的基础上,分析了现存的问题及解决问题的手段,并指出未来可能使用的目标策略,为今后研究者提供一定程度上的借鉴经验。