重力无阀滤池处理能力降低原因分析及措施

针对气化循环水系统重力无阀滤池在运行过程中处理能力降低的现象,从滤池跑砂、结泥球及进水分配槽溅水严重等方面进行分析,通过清理滤砂,检修设备及仪表等措施,提高重力无阀滤池的处理能力。     

不同类型电涡流探头对核电站传热管胀管过渡段缺陷的定位准确性研究

为了更有效和可靠地检测出胀管过渡区出现的缺陷,分析了3种不同类型的涡流探头特性,然后通过一系列试验,对不同探头在传热管胀管过渡段上的缺陷识别并进行准确定位能力进行了对比测试,获得了相关的定位准确性数据,掌握了胀管过渡段缺陷定位技术及其精度范围,能够进一步提高对胀管过渡段上的缺陷的准确判别能力。     

Hybrid photocatalytic H2 evolution systems containing xanthene dyes and inorganic nickel based catalysts

The application of nickel based earth abundant inorganic solids as catalysts in xanthene dye sensitized systems was evaluated for photocatalytic H₂ production from water. The introduction of heterogeneous nanoparticles into molecular systems as catalysts is the conceptual begin to broaden the construction of photocatalytic H₂ production systems. A series of Ni based inorganic nanoparticles, including Ni metal, NiO, NiS and NiSe, are capable of producing H₂ from triethanolamine sacrificial aqueous solution when photosensitized by xanthene dyes. NiS catalysts synthesized from different methods were also evaluated for H₂ production performance. The best H₂ production result is obtained with the use of Erythrosin Y as the photosensitizer and NiS synthesized in ethylene glycol as the catalyst. This system is active even under photons with wavelengths longer than 520 nm with a H₂ production of 2.5 mmol within 26 h of irradiation from a 300 W Xenon lamp. Meanwhile, it can generate over 4.2 mmol of H₂ within 16 h of irradiation with a 440 nm long-pass cut-off filter. Within the visible light range we examined, the highest quantum efficiency is around 15% at 520 nm. The high activity of NiS could be contributed by its high electrochemical activity, metallic nature, unsaturated Ni environment and suitable Fermi energy level. These hybrid systems consist of earth abundant elements, and the catalyst is photostable and recyclable compared to homogeneous metal complex catalyst.     

Selective elution of tea catechins and caffeine from polyvinylpolypyrrolidone

Desorption of catechins and caffeine from polyvinylpolypyrrolidone (PVPP) was comprehensively investigated. The result showed that caffeine could easily be desorbed from PVPP by the tested solvents except n‐hexane, while catechins could only be thoroughly done by dimethyl sulphoxide (DMSO) and N, N‐dimethylformamide (DMF). Excellent desorption efficiency of DMSO and DMF might be attributed to their high dipole moments and H‐bond potentials. Addition of ethanol was recommended considering the elution efficiency and fluidity, but ethanol volume should be <40% (v/v) for DMSO or 20% (v/v) for DMF. Desorption would get to equilibrium within 1 h and followed the pseudo‐second‐order model. Caffeine and catechins could be separately desorbed through two‐stage elution procedure, that is, water or 20% aqueous ethanol for desorbing caffeine and part of nongalloylated catechins and DMSO/ethanol (8/2, v/v) for eluting the remaining catechins. Highly purified catechins (~95%) with high level (~70%) galloylated catechins would be achieved when the desorption procedure was applied in column chromatograph.     

可溶性盐复分解法碳酸钙制备影响因素研究

采用可溶性盐复分解法进行碳酸钙合成影响因素及其机理的研究。以正交试验法对合成温度、pH值、反应物浓度在碳酸钙合成中的影响进行探索,验证了温度以及pH值在合成反应中对产物晶型、形貌以及尺度有显著影响;使用周期键链理论(PBC)讨论了碳酸钙晶体方解石/文石共生现象;研究观察Mg2+对碳酸钙合成的影响,Mg2+作为能够稳定无定形碳酸钙前驱体(ACC)的金属离子,大量存在时碳酸钙形貌随nMg/nCa增大而变化,同时颗粒尺度变小。     

超大直径太阳定位热力系统的施工应用

采用BIM技术模拟安装,改进施工工艺,钢梁提前预制等多种技术措施,解决安装精度要求高,高空环境复杂,多专业交叉的施工难题。将超大直径(88m直径)太阳定位热力系统安装在高空屋面上,实现太阳能集采系统对于太阳方位角进行360°全面跟踪,工程应用在国内尚属首例,可为其他相关工程提供借鉴与参考。     

Temperature stable 0.35Ag2MoO4-0.65Ag0.5Bi0.5MoO4 microwave dielectric ceramics with ultra-low sintering temperatures

In this study, the novel temperature-stable (1-x)Ag₂MoO₄-xAg_0.5Bi_0.5MoO₄ microwave dielectric ceramics were prepared by a modified solid-state reaction method. The phase composition, microstructures and microwave dielectric properties of the (1-x)Ag₂MoO₄-xAg_0.5Bi_0.5MoO₄ ceramics were investigated. All the compounds can be sintered well at ultra-low temperatures (<540 °C). The XRD and SEM analysis indicate that the Ag₂MoO₄ and the Ag_0.5Bi_0.5MoO₄ can coexist with each other. When x = 0.65, the ceramics exhibit the best microwave dielectric properties with a relative permittivity of 23.9, a Q × f value of 16,200 GHz (at 7.3 GHz) and a near-zero TCF value of -2.4 ppm/°C at 520 °C. The results indicate that temperature-stable (1-x)Ag₂MoO₄-xAg_0.5Bi_0.5MoO₄ ceramics are promising candidates for low temperature co-fired ceramics (LTCC) applications.     

碳纳米管作为新型催化材料的发展

纳米材料真正作为研究领域的历史至今还不到一个世纪,在这不到一世纪时间里,纳米材料在人们越来越炽热的关注中飞速发展。作为纳米材料,其粒子由于尺寸的微观性,以及量子力学的出现,便具有了一些特殊的性质,包括量子尺寸效应、小尺寸效应、表面效应以及宏观量子隧道效应。在石油化工领域,催化剂是整个行业的命脉之一,而纳米材料由于其特殊的性质,使其在催化材料方面也开始逐渐崭露头角,并被专业人士视为富有前景的新型催化材料。本文中将以碳纳米管(CNTs)为例着重介绍其作为催化材料的发展进程并进行展望。