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991.
稻壳热解制备纳米二氧化硅   总被引:3,自引:0,他引:3  
以稻壳为原料,通过热解法制备SiO2纳米粉体.试验在热解温度520℃,保温2.5 h的条件下,成功地制备出了具有纳米尺寸的SiO2颗粒.采用SEM和ZRD对SiO2微观结构进行表征,结果表明:所制的SiO2纳米粉体为无定性结构、颗粒均匀、分散性好、平均粒径为80 nm左右.  相似文献   
992.
塔河油田油藏属古岩溶缝洞型碳酸盐岩油藏,非均质性强,储集体空间分布具有不连续性。裂缝是主要的渗流通道,将溶 洞连通,而流体又主要储存在溶洞中,储层中流体流动复杂。传统试井解释方法难以正确描述储层特征和流体流动规律,针对缝 洞型油藏地质特征,把储层视为离散介质进行处理,建立了离散介质数值试井解释方法,解释结果更符合缝洞型储层的真实地 质特征,能更好地描述缝洞型油藏结构。根据离散数值试井分析与地质认识结合,划分出塔河油田碳酸盐岩5种典型油藏类型 和解释溶洞大小、溶洞距离等关键油藏参数,试井解释成果能有效指导注水井优选、注水参数优化及配套生产措施制定,对碳酸 盐岩缝洞型油藏提高采收率具有重要意义。  相似文献   
993.
根据太阳能混合吸收式制冷循环的特点,提出一种可用于该循环的新型高效蓄能系统。分析该系统的工作原理及特性,并与传统的蓄热方式和蓄冷方式蓄能系统进行性能比较分析,在相同蓄冷量情况下,新型蓄能系统的蓄能体积是传统系统蓄能体积的1/10以下,从而为促进蓄能装置小型化、推动小型太阳能空调的商品化提供理论依据。  相似文献   
994.
This paper presents a method to determine the safety threshold of bridge pier settlement in high-speed railways.An analytical expression of the mapping relationship between the pier settlement and the rail deformation is derived theoretically for the double block ballastless track-bridge system.By adopting the superposition of the track random irregularity and the rail deformation caused by the pier settlement as the excitation inputs,the variations of vehicle dynamics indices with pier settlement are comparatively analyzed.Then,the safety threshold of the bridge pier settlement is obtained according to the limit of vehicle running safety and ride comfort indices of the high-speed trains.Results show that the dynamics indices of different trains have different sensitivities to the pier settlement,and the train CRH2C is the most sensitive one among all the types of Chinese high-speed trains.When passing through the bridges in common span with pier settlement at the speed of 250–350 km/h,the trains suffer the low-frequency excitations,and the vertical acceleration of car body is most sensitive to the pier settlement of all the dynamics indices.When the car body vertical acceleration just exceeds the allowable limit,the critical settlement value is 23.4 mm,which is much bigger than the pier differential settlement limit in the current code for Chinese high-speed railways.  相似文献   
995.
In this work, we have employed melamine, cyanuric acid and thymine to fabricate triazine-based carbon nitrides (CNs) by supramolecular approach. The resultant CNs possess large specific surface area, hierarchical porous structure, better light absorption capacity and high separation rate of photoinduced carriers. Then, the photocatalytic reduction and oxidation performance has been evaluated. The obtained CNs exhibit enhanced photocatalytic reduction performance on water splitting to H2, the largest hydrogen evolution rate can reach 8466.3 μmol g?1 h?1, which is 81.9 times as high as that of bulk CN. Simultaneously, the porous CNs show excellent photocatalytic reduction ability on the conversion of CO2 to H2, CO and CH4. Of particular interest is that they have high selectivity for CO. It’s worth noting that the porous CNs also possess outstanding photocatalytic oxidation ability on high concentration nitric oxide (NO), and the highest NO conversion rate can reach 79.3% under visible light. The enhanced photocatalytic performance for the multifunctional porous CN can be ascribed to the synergic effect of large specific surface area, strong light absorption capacity and fast separation of photoinduced electron–hole pairs. Finally, the photocatalytic reduction and oxidation mechanism of the porous CN is also proposed and discussed.  相似文献   
996.
王桂琴  陆平 《化工科技》1998,6(2):41-46
利用高效液相色谱、红外光谱等分析测试手段,对盐酸苯海拉明中存在的各种杂质进行了全面剖析,并对各杂质含量进行了定量测定,阐述了影响产品水溶液澄明度的原因。这一剖析结果对产品的生产工艺及质量控制均有重要的指导意义。  相似文献   
997.
998.
Our objective is to develop a rapid and sensitive assay based on magnetic beads to detect the concentration of influenza H3N2. The possibility of using variable domain heavy-chain antibodies (nanobody) as diagnostic tools for influenza H3N2 was investigated. A healthy camel was immunized with inactivated influenza H3N2. A nanobody library of 8 × 108 clones was constructed and phage displayed. After three successive biopanning steps, H3N2-specific nanobodies were successfully isolated, expressed in Escherichia coli, and purified. Sequence analysis of the nanobodies revealed that we possessed four classes of nanobodies against H3N2. Two nanobodies were further used to prepare our rapid diagnostic kit. Biotinylated nanobody was effectively immobilized onto the surface of streptavidin magnetic beads. The modified magnetic beads with nanobody capture specifically influenza H3N2 and can still be recognized by nanobodies conjugated to horseradish peroxidase (HRP) conjugates. Under optimized conditions, the present immunoassay exhibited a relatively high sensitive detection with a limit of 50 ng/mL. In conclusion, by combining magnetic beads with specific nanobodies, this assay provides a promising influenza detection assay to develop a potential rapid, sensitive, and low-cost diagnostic tool to screen for influenza infections.  相似文献   
999.
Modified BET model and Do and Do (D.D.) model were chosen to interpret the desorption process of water on hard and soft lignites. The organic and inorganic hydrophilic sites were determined by X-ray photoelectron spectroscopy and X-Ray fluorescence spectroscopy. From the modified BET model, only a small part of hydrophilic sites (HSs) acted as effective primary sites due to space restraint, intramolecular hydrogen bond and maybe more than one hydrophilic site connecting with one water molecule. From the D.D. model, the total adsorption sites (St) of Loy Yang lignite (LY) is 18.7 mmol/g, which is higher than that of Shengli (SL) 17.0 mmol/g in spite of lower primary sites, and the saturation concentration of water (qus) in the micropore of LY is 33.7 mmol/g, which is much higher than that of SL (12.5 mmol/g). So the high moisture-holding capacity of LY is mainly determined by the high St and qus, and not the primary sites. The size of water clusters entering the micropores is 7 for SL and 6 for LY, which is related to relative location of HS. When dewatered, the higher total sites density and smaller water cluster size of LY both implied higher dewatering energy.  相似文献   
1000.
万世强  白康林 《贵州化工》1999,24(2):46-48,57
合成塔出口气锅炉给水换热器防爆隔膜板裂,上封头泄漏引起着火,对事故的应急处理,中修消缺处理方法及现场光刀机设计作了介绍。  相似文献   
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