稠油降黏技术应用研究

稠油具有黏度高、流动性差的特点,这是制约稠油开采和集输的主要问题,而解决这一问题的关键是降黏。稠油降黏技术主要包括加热、掺稀、乳化、油溶性降黏剂、水热催化裂化以及微生物降黏、超临界CO2降黏等。通过论述各种降黏技术的降黏机理,分析各种降黏技术的应用特点及存在的问题,选择合适的降黏技术,对稠油的开采和集输具有明显的经济效益。     

稠油降黏技术应用研究

稠油具有黏度高、流动性差的特点。这是制约稠油开采和集输的主要问题,而解决这一问题的关键是降黏。稠油降黏技术主要包括加热、掺稀、乳化、油溶性降黏剂、水热催化裂化以及微生物降黏、超临界CO2降黏等。通过论述各种降黏技术的降黏机理,分析各种降黏技术的应用特点及存在的问题,选择合适的降黏技术,对稠油的开采和集输具有明显的经济效益。     

稠油化学降黏技术的研究进展及发展趋势

总结了稠油化学降黏技术的降黏机理及存在的问题。分析专利申请状况,通过专利申请的时间分布、优先权区域分布、技术功效矩阵等一系列分析讨论,得出稠油降黏技术在未来仍将以乳化降黏和油溶性降黏剂为重心。其中,乳化降黏以开发更加耐温抗盐的表面活性剂为主,其次是尽量降低降黏剂成本;油溶性降黏剂以提高降黏率为主,其次是尽量减少对下游加工的影响。此外,加强降黏机理的认识,实现集成创新和定制开发也是该技术未来发展的可行之路。     

三元复合体系界面黏弹性对残余油乳化作用研究北大核心

分别用不同界面张力和界面扩张黏弹性的三元复合体系进行微观驱替实验,分析油水界面扩张黏弹性、界面张力对残余油乳化的影响。结果表明:界面扩张黏弹性影响残余油的启动和运移,油水界面扩张黏弹性和界面张力存在协同乳化效应;界面张力降低到10-2 mN/m后,界面扩张黏弹性对残余油乳化作用的影响增强;随着界面张力和界面扩张黏弹性的降低,三元复合体系对残余油的乳化作用由乳化油滴向乳化油丝转变。     

三元复合体系界面黏弹性对残余油乳化作用研究

分别用不同界面张力和界面扩张黏弹性的三元复合体系进行微观驱替实验,分析油水界面扩张黏弹性、界面张力对残余油乳化的影响。结果表明:界面扩张黏弹性影响残余油的启动和运移,油水界面扩张黏弹性和界面张力存在协同乳化效应;界面张力降低到10-2 mN/m后,界面扩张黏弹性对残余油乳化作用的影响增强;随着界面张力和界面扩张黏弹性的降低,三元复合体系对残余油的乳化作用由乳化油滴向乳化油丝转变。     

雷管编码图像中的黏连字符分割

以雷管编码识别项目为工程实践案例,提出一种基于最优分割路径的黏连字符分割算法,克服黏连字符对雷管编码识别性能的影响。对输入图像增强并二值化后通过连通域分析提取黏连字符区域,利用垂直投影获得黏连字符的垂直投影直方图,而且同时获得上边界和下边界位置图,分别从中检测局部谷底点并验证其"穿越特性"和"距离特性"得到黏连字符的候选分割点,再按可信度从中选取有效分割点,分别以黏连字符左、右两端为起点向另一端进行字符切分形成两条分割路径,选取方差较小的分割路径作为最优分割路径对黏连字符切分。实验研究表明,该算法能有效克服工业场景中由磨损、划痕、锈迹等造成的金属雷管图像中编码字符黏连问题,比传统算法取得了更好的分割效果和更高的分割准确率。     

路用乳化沥青黏层材料黏附性实验

沥青路面的黏层对于路面路用性能影响很大,用乳化沥青作为黏层材料有一定技术优势。为了减少沥青路面病害,研发沥青路面的黏层沥青材料。为了检验研发的黏层乳化沥青性能,进行材料选择和配合比设计,制备和切割试件,对研发的混合料同时开展了室内实验和现场实验。实验研究表明,6种黏层用乳化沥青材料的室内实验的黏结强度均能达到1.7 MPa左右,满足规范要求,尤其是由于龄期增长,现场实验的拉拔检测结果更好,平均值为2.2 MPa。所研发的乳化沥青路用黏层材料性能优良,为该材料在道路行业的应用和推广提供了技术支持。     

聚合物的黏弹现象及理解——蠕变及应力松弛概念解析

针对《高分子物理》课程中黏弹现象难于理解,作者根据教学经验对聚合物的黏弹性进行解析,通过理论联系实际,让学生加深对黏弹现象的理解,对于提高学生对课程的整体认识,强化学生对课程的理解,取得了良好的教学效果。     

说“粘”道“黏”各有分工

“粘”与“黏”是音义不完全等同的两个字。“黏”音 nian,①像糨糊、胶水等所具有的能使一个物体附着在另一个物体上的性质。如黏液、黏胶。也指具有黏性的。如:黏豆包、黏汗、泥黏雪滑。②特指骈俪文字或近体诗上联对句与下联出句之间的平仄协调。平仄     

不明液体

一滴凉凉的不明液体准确地砸在我的头上,用手一摸——呀!灰黑色、黏黏的。     

高强度SBS复合胶黏剂的固化工业与性能研究

在苯乙烯-丁二烯-苯乙烯三嵌段共聚物（SBS）中添加马来酸酐化聚丁二烯（MLPB）和胺化环氧丁二烯（LCP）可以适当提高胶粘剂的力学性能,其得到的最大拉伸强度分别为2．671MPa和8．652MPa。研究结果表明,温度以及添加胺化LCP和MLPB可以促进胶粘剂中互穿聚合物网络的形成,提高胶粘剂的强度。     

SBS改性沥青性能的研究

对SBS道路沥青改性剂F-420、F-411X、YH-4303进行了沥青改性效果对比评价试验，并对F-420改性沥青进行了道路应用试验。试验结果表明：F-420对沥青的改性效果已达到燕化YH-4303的质量水干，SBSF-420改性沥青高温稳定性能、低温抗开裂性能、抗老化性能等指标均达到部颁标准（JTJ036—1998），同时具有优良的储存稳定性，F-420可以用于生产SBS道路改性沥青。     

Age-related incidence curve of hospitalized Shaken Baby Syndrome cases: convergent evidence for crying as a trigger to shaking

OBJECTIVE: To determine whether there is an age-specific incidence of hospitalized cases of Shaken Baby Syndrome (SBS) that has similar properties to the previously reported "normal crying curve," as a form of indirect evidence that crying is an important stimulus for SBS. DESIGN AND SETTING: The study analyzed cases of Shaken Baby Syndrome by age at hospitalization from hospital discharge data for California hospitals from October 1996 through December 2000. PATIENTS: All cases of children less than 18 months (78 weeks) of age for whom the diagnostic code for Shaken Baby Syndrome (995.55) in the International Classification of Disease, Ninth Edition, Clinical Modification was assigned. RESULTS: There were 273 hospitalizations for SBS. Like the "normal crying curve," the curve of age-specific incidence starts at 2-3 weeks, has a clear peak, and declines to baseline by about 36 weeks of age. In contrast to the normal crying curve that peaks at 5-6 weeks, the peak of SBS hospitalizations occurs at 10-13 weeks. CONCLUSIONS: The age-specific incidence curve of hospitalized SBS cases has a similar starting point and shape to the previously reported normal crying curve but the peak occurs about 4-6 weeks later. Of the likely predisposing causes, this pattern is only consistent with the properties of early crying. There are numerous explanations for the lag in the peaks between crying and SBS hospitalizations, including the possibility of repeat shakings prior to hospitalization. The importance of crying as a stimulus to SBS may provide an opportunity for preventive intervention.     

基于混合水平正交设计的SBS改性沥青储存稳定性研究(英文)

为了研究SBS改性沥青的储存稳定性,将不同SBS改性剂掺量的SBS改性沥青储存于不同条件下.采用混合水平正交设计,选取SBS改性剂掺量、储存时间、储存温度和容器尺寸作为混合水平正交设计OA16(31×44)中的因素.提出用离析软化点差(试样的顶部和底部环与球法软化点差)和平均软化点(试样的顶部和底部环与球法软化点的算术平均值)分别评价在储存期间改性沥青的离析和老化.结果显示,改性沥青的离析和老化随储存温度和储存时间呈现复杂的变化规律.当储存温度从20℃上升到120℃时,离析软化点差变小,当超过120℃时增大,而平均软化点随储存时间的延长而降低.不同储存条件对SBS改性沥青的储存稳定性的影响各有差异.     

I-B型SBS改性道路沥青的中试

通过对SBS改性沥青机理的探讨和中试，分析影响SBS改性效果的因素，提出SBS改性沥青合理的生产工艺流程、适宜的SBS掺加量和工艺控制指标，为改性沥青扩大生产积累经验数据。     

SBS与EVA复合改性沥青的性能研究

本文采用了SBS和EVA作为沥青的改性剂,通过延度、软化点、针入度、抗剥落程度和热损失试验,对改性后沥青的各项指标进行测试,确定SBS和EVA的最佳实验配比.     

Socioeconomic determinants of academic achievement

This study aims to investigate the relationship between academic achievement and the socioeconomic characteristics of elementary school 7th grade students in Burdur. The population of the study are 7th grade students who had education at elementary schools in Burdur in the 2007?C2008 academic year. Two staged sampling was chosen as suitable for the aim of research. In the first stage, settlements were chosen with the random settlement group sampling method. In the second stage, schools in chosen settlements were picked up with the random method considering the number of students who have taken SBS examination. Socioeconomic variables of students generally explain 39.2?% of SBS points of student. When standard beta values are observed, variables which have the most effect on the SBS points of students are: attending a course or having private lessons, father??s education, the average monthly income per capita, attending a course or having private lessons and mother??s education.     

A novel porous silica-zirconia coating for improving bond performance of dental zirconia

Objective:To coat a zirconia surface with silica-zirconia using a dip-coating technique and evaluate its effect on resin-zirconia shear bond strength(SBS).Methods:A silica-zirconia suspension was prepared and used to coat a zirconia surface using a dip-coating technique.One hundred and eighty-nine zirconia disks were divided into three groups according to their different surface treatments(polishing,sandblasting,and silica-zirconia coating).Scanning electron microscopy(SEM),energy dispersive X-ray(EDX),and X-ray diffraction(XRD)were used to analyze the differently treated zirconia surfaces.Different primer treatments(Monobond N,Z-PRIME Plus,and no primer)were also applied to the zirconia surfaces.Subsequently,180 composite resin cylinders(Filtek Z350)were cemented onto the zirconia disks with resin cement(RelyX Ultimate).The SBS was measured after water storage for 24 h or 6 months.The data were analyzed by two-way analysis of variance(ANOVA).Results:SEM and EDX showed that the silica-zirconia coating produced a porous layer with additional Si,and XRD showed that only tetragonal zirconia was on the silica-zirconia-coating surface.Compared with the control group,the resin-zirconia SBSs of the,andblasting group and silica-zirconia-coating group were significantly increased(P<0.05).The silica-zirconia coating followed by the application of Monobond N produced the highest SBS(P<0.05).Water aging significantly reduced the resin-zirconia SBS(P<0.05).Conclusions:Dip-coating with silica-zirconia might be a feasible way to improve resin-zirconia bonding.     

Severe short-bowel syndrome after total small bowel resection

Extensive intestine resection may result in short bowel syndrome (SBS) which is difficult of manage. This study reports a rare SBS case in a 6-year-old boy following resection of total jujunoileum and right colon. Our experience in 4-years follow-up and literature reports on SBS is discussed. The purpose of this study was also to evaluate the nutritional absorptive capacity and intestinal adaptation. In the 15th postoperative month, barium x-ray study showed a significantly extended and enlarged duodenum and colon. The intestinal transit time was prolonged to 22 hours. The absorption rate of palmic acid, glycine and D-xylose had increased from 57%, 50% and 4% respectively in the 15th postoperative month, to 75%, 65% and 6% in the 2nd postoperative year. His absorptive capacity allowed him normal oral feeding and normal school life. Our data confirmed the reports of the colon as an energy-salvage organ, and suggested that it may have some capacity to absorb long-chain fatty acids and amino acids.     

SEVERE SHORT-BOWEL SYNDROME AFTER TOTAL SMALL BOWEL RESECTION

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