Insights into the long-term stability of the magnesia modified H-ZSM-5 as an efficient solid acid for steam reforming of dimethyl ether

The long-term performance of the bifunctional catalyst composed of MgO-modified H-ZSM-5 and Cu/ZnO/Al₂O₃ for steam reforming of dimethyl ether (SRD) is studied under the same conditions. Although the surface chemical state and acid property of 1.55–2.47 wt% MgO modified H-ZSM-5 are almost the same, a significant impact of MgO contents on the stability of the bifunctional catalyst is observed from the 50 h SRD results. The initial dimethyl ether conversion (around 100%) and H₂ yield (∼95%) over the optimal bifunctional catalyst with 2.17 wt% MgO modified H-ZSM-5 is still kept over 90% at 50 h. Combining the characterization data of spent catalysts and SRD results, the synergetic effect between the MgO-modified H-ZSM-5 and Cu/ZnO/Al₂O₃ is rigorously revealed as the key factor in determining the stability of the bifunctional catalyst for SRD. These results demonstrate that MgO-modified H-ZSM-5 is a promising and efficient solid acid for SRD.     

A techno-economic evaluation of the hydrogen production for energy generation using an ethanol fuel processor

The techno-economic analysis of a process to convert ethanol into H₂ to be used as a fuel for PEM fuel cells of H₂-powered cars was done. A plant for H₂ production was simulated using experimental results obtained on monolith reactors for ethanol steam reforming and WGS steps. The steam reforming (Rh/CeSiO₂) and WGS (Pt/ZrO₂) monolith catalysts remained quite stable during long-term startup/shut down cycles, with no carbon deposition. The H₂ production cost was significantly affected by the ethanol price. The monolith catalyst costs contribution was lower than that of conventional reactors. The H₂ production cost obtained using the expensive Brazilian ethanol price (0.81 US$/L ethanol) was US$ 8.87/kg H₂, which is lower than the current market prices (US$ 13.44/kg H₂) practiced at H₂ refueling stations in California. This result showed that this process is economically feasible to provide H₂ as a fuel for H₂-powered cars at competitive costs in refueling stations.     

复杂小断块油藏CO2吞吐工艺技术分析

在总结复杂小断块油田CO2吞吐系列配套技术的基础上，分别从油藏规模、物性、能量等角度剖析了71口吞吐井的实施效果，分析了影响CO2吞吐效果的关键参数，得出了注入量、注入压力、返排速度、吞吐周期等工艺技术参数的取值范围和标准，对提高采收率具有重要意义。     

表面亲油纳米二氧化硅改变岩石表面润湿性的研究

实验研究了注水井增注用的4种商品表面亲油改性纳米二氧化硅改变岩石表面润湿性的能力。kg为0．01～0．1时的胜利义北砂岩岩心，洗油后浸泡在盐水中使表面亲水，注入0．5～3．0PV1．5g／L的纳米二氧化硅柴油悬浮液，静置不同时间，用自吸吸入法测定岩心相对润湿指数W（水、油润湿指数之比）。结果表明,W值随注入量增大按指数关系减小，注入量3PV时达到稳定值，注入量相同时随静置时间（18～40小时）延长而减小；在注入量2PV、静置40小时条件下除829外的3种样品使亲水岩心（W=1．7）变亲油（W〈1．0），俄罗斯产品101效果最好。W=0．5。用光学投影法测量并图示了表面亲水岩石薄片依次浸泡在煤油、纳米二氧化硅柴油悬浮液、盐水中时接触角随浸泡时间的变化。在煤油中，大理石和灰岩表面变亲油，纳米二氧化硅处理使接触角略有增大；在盐水中，经101处理的大理石表面亲油性至少维持500小时，其余样品处理的大理石迅速变为亲水。各种样品处理的亲油灰岩表面在盐水中经过～0～70小时（样品101）先后变为亲水。玻璃表面在煤油中仍亲水。不同纳米二氧化硅处理玻璃的效果各不相同：迅速亲油化（101和727），～60小时后变亲油（829）。接触角增大但仍亲水（902）；处理后的亲油玻璃表面在盐水中迅速变强亲水。纳米二氧化硅不能使石英表面亲油化。图6表4参6。     

中国对虾超声辅助解冻的数值模拟及对蛋白变性的影响

为探究中国对虾超声辅助解冻过程中温度分布和解冻时间的变化规律以及对蛋白变性的影响,采用有限元分析软件COMSOL对超声辅助解冻非稳态过程进行模拟并验证,同时测定解冻后肌原纤维蛋白结构与肌肉热稳定性的变化,旨在建立中国对虾的超声辅助解冻模型,为其解冻工艺的确定提供参考。结果表明：超声辅助解冻时中国对虾中心温度模拟值和实验值的均方根误差（root mean square error,RMSE）为0.943 3 ℃,静水解冻处理组的RMSE为0.907 7 ℃,证明该模型能较好地模拟解冻过程;与静水解冻相比,超声辅助解冻的解冻时间缩短了35.9%,显著提高了解冻速率;解冻后肌球蛋白重链和肌动蛋白没有发生变化,分子质量为70～100 kDa蛋白片段发生一定程度的降解和交联;最大荧光吸收波长无显著变化,但荧光强度增加;超声辅助解冻后肌肉的热稳定性接近鲜样,而静水解冻后肌肉热稳定性变差。综上认为超声辅助解冻是一种高效且有利于保持冷冻中国对虾品质的解冻方法。     

Dopamine D? receptor stimulation of the nucleus accumbens or the medial preoptic area promotes the onset of maternal behavior in pregnancy-terminated rats.

There is good evidence that interference with the mesolimbic dopamine (DA) system results in impaired maternal responding in postpartum female rats. However, whether activation of the mesolimbic DA system is capable of promoting maternal behavior has not been investigated. This study examined whether increasing DA activity in various brain regions of pregnancy-terminated, naive female rats would stimulate the onset of maternal behavior. Experiments 1 and 2 examined the effects of microinjection of various doses (0, 0.2, or 0.5 μg/0.5 μl/side) of a D? DA receptor agonist, SKF 38393, or a D? DA receptor agonist, quinpirole, into the nucleus accumbens (NA) on latency to show full maternal behavior, and Experiment 3 determined the effects of SKF 38393 injection into a control site. Finally, because the medial preoptic area (MPOA) is also important for maternal behavior, receives DA input, and expresses DA receptors, the authors examined whether microinjection of SKF 38393 into MPOA was capable of stimulating the onset of maternal behavior. Results indicated that microinjection of SKF 38393 into either the NA or the MPOA facilitates maternal responding in pregnancy-terminated rats. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

PbS-Sb2S3-FeS三元系在水蒸气气氛下的铅锑分离

在1073K下通过测定三硫化锑和硫化铅的挥发速度,研究了PbS-Sb_2S_3-FeS三元系在水蒸气气氛下的铅锑分离规律。X-射线衍射结果表明,焙砂由PbS、Fe_3O_4、FePb_4Sb_6S_(14)、Pb_5Sb_4S_(11)和FeSb_2O_4组成。当试样中FeS含量在5％～7％时,铅锑分离效果最好。当试样中FeS的含量≥10％时,铅锑分离效果较差,这时过量的FeS会与Sb_2S_3和PbS形成复杂的硫化物(FePb_4Sb_6S_(14)、Pb_5Sb_4S_(11))或被氧化成F4Sb_2O_4,使锑的挥发变得困难,导致残留在焙砂中的锑含量升高。     

塔里木盆地超深层油气藏试油与储层改造技术进展及发展方向

近年来，中国石油塔里木油田公司（以下简称塔里木油田）在塔里木盆地超深层油气勘探陆续取得重大突破。这与其超深层试油与储层改造技术的进步是密不可分的，随着超深井的逐渐增多，试油与储层改造技术仍需要持续升级、完善。为此，通过总结塔里木油田试油与储层改造技术的发展历程，系统梳理了其在超深层油气藏试油与储层改造方面取得的主要技术进展，并结合新的勘探开发形势与要求，指出了塔里木盆地超深层油气藏试油与储层改造技术今后一个时期的发展方向。研究结果表明：①塔里木油田已形成了一系列专项技术——超深高温高压气井安全快速测试技术，超深层、高含硫、缝洞型碳酸盐岩气藏完井试油一体化技术，超深层缝洞型碳酸盐岩储层深度改造技术，以及超深层、高温高压裂缝性致密砂岩气藏储层缝网改造技术，支撑了该盆地超深层油气藏的陆续勘探突破和持续高效开发；②随着油气勘探开发深度领域迈向9 000 m，储层地质条件更加复杂，完井试油与储层改造技术面临着新的技术难题；③今后将围绕“可靠、安全、高效”的目标进行试油完井工具和工艺的持续升级和改进，需要不断完善储层改造地质工程一体化设计、改造工作液和材料以及耐高温高压工具和装备，以支撑精细化缝网体积改造；④新形势下，为了满足井完整性的要求，需要完善相关配套技术，同时建立套管磨损评价与地面管汇剩余寿命检测方法，以保障试油和储层改造工艺的顺利实施。结论认为，该研究成果可以为国内外超深层油气藏的安全高效建井与提产提供借鉴。     

汽轮机真空系统严密性试验过程的动态数值仿真

通过对汽轮机真空系统严密性试验的动态数值仿真 ,分析了凝汽器各运行参数 ,如冷却水温度、冷却水流量、汽轮机排汽量以及抽气器抽空气门关闭速度对真空下降过程和下降速度的影响 ,指出依据真空下降速度很难准确评价真空系统的严密性 ,应该对试验结果进行修正     

Evaluation of control over the microbiological contamination of carcasses in a lamb carcass dressing process operated with or without pasteurizing treatment

The aim of this study was to quantify the hygienic status of a lamb slaughterhouse by means of multivariate statistical analysis, to demonstrate how the microbiological data could be exploited to improve the lamb slaughter process by constructing control charts and to evaluate the potential effect of an intervention step such as steam application on the microbiological quality of lamb carcasses. Results showed that pelt removal and evisceration were hygienically uncontrolled. TVC and Enterobacteriaceae progressively increased from the stage ‘after pelt removal of hind and forelegs/before final pulling’ to the stage ‘after evisceration/before pluck removal’ thus indicating possible deposition of microorganisms during these operations. It seems that the processing stages of freshly produced carcasses were better distinguished by Enterobacteriaceae, with evisceration contributing mostly to the final Enterobacteriaceae counts. Application of steam during the lamb slaughter process reduced microbial counts without adverse effects on the organoleptic characteristics of the carcasses. Moreover, the construction of control charts showed that decontamination with steam contributed to the maintenance of an in control process compared to that before the application of steam, suggesting the potential use of steam as an intervention step during the lamb slaughter process.