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1.
Distilled fractions of a coal-derived liquid from the H-Coal process were upgraded to diesel fuel by catalytic hydrotreatment. The total hydrotreated products were distilled into naphtha (<180°C) and diesel fuel fractions (>180°C) and the diesel fractions were analysed for hydrocarbon-type composition, hydrogen content and some diesel fuel properties. GC—MS-analyses were carried out on the hydrocarbon-type fractions to identify individual chemical compounds. To investigate the effect of different distillation cut points on diesel fuel yield and properties, cut points for one hydrotreated product were varied. The diesel fuel cetane numbers were correlated with percentage hydrogen, total aromatics and saturates. Cetane numbers above 40 were obtained for diesel fuels containing (i) more than 75% saturates, (ii) less than 15% total aromatics and (iii) a hydrogen content above 12.8%. Compounds identified by GC—MS-analyses (in the diesel fractions) were typical aromatic and cycloparaffin compounds. Normal-and iso-paraffin compounds were not detected. By varying the distillation cut point from 135 to 180°C, the cetane number of the residual diesel fraction improved from 37 to 44. This increase is ascribed to the removal of aromatic compounds in the 135–180°C boiling point range. 相似文献
2.
Failure to establish agreed-upon criteria by which to measure and identify online video game addiction has resulted in a lack of reliable evidence of the actual percentage of individuals who are pathologically dependent. Building upon prior research, the present study sought to better determine the magnitude of pathological online video game play using a distinction between core and peripheral criteria for behavioral addiction. Preferences and perceptions towards online video games and addiction were also examined to better understand players’ habits. A questionnaire was administered to 1332 South Korean students across 11 high schools and 1 middle school in an area surrounding the capital of Seoul. Using a monothetic and a polythetic classification system, findings showed rates ranging between 1.7% and 25.5%, with a 2.7% addiction rate when distinguishing core from peripheral criteria. These results may suggest that online video game addiction rates in intense gaming cultures such as South Korea are not as high as otherwise believed. The findings will be of assistance to educators, policymakers, clinicians, and researchers in understanding the challenges in deriving meaningful video game addiction prevalence rates, and thus being able to better separate reality from conjecture with regard to the notion of pathological game play. 相似文献
3.
WANG ChengHai CUI Yang & JIN ShuangLong Key Laboratory for Semi-Arid Climate Change of the Ministry of Education College of Atmospheric Sciences Lanzhou University Lanzhou China National Climate Center China Meteorological Administration Beijing 《中国科学:技术科学(英文版)》2011,(2)
The interaction between the low-frequency atmospheric oscillation(Madden-Julian Oscillation,MJO) and the diabatic heating over the Qinghai-Xizang Plateau(QXP) from March to June is analyzed.The results show that there are respectively two and one wave trains around the QXP during the onset of the South China Sea monsoon in strong and weak monsoon years.The locations and strength of the wave train propagation differ between the strong and weak monsoon years.Because diabatic heating of the QXP prevents the lo... 相似文献
4.
Amer Jassin Al-Khafaji Mohammed Hail Hakimi Ahmed Askar Najaf 《Egyptian Journal of Petroleum》2018,27(1):117-130
Seven crude oils from Cretaceous Mishrif reservoir rocks in the southern Mesopotamian Basin, South Iraq were studied to describe oil characteristics, providing information on the source of organic matter input and the genetic link between oils and their potential source rock in the basin. This study is based on biomarker and non-biomarker analyses performed on oil samples. The analysed oils are aromatic intermediate oils as indicated by high aromatic hydrocarbon fractions with more that 50%. These oils are also characterized by high sulfur and trace metal (Ni, V) contents and relatively low API gravity values (19.0–27.2° API). The results of this study indicate that these oils were derived from a marine carbonate source rocks bearing Type II-S kerogen that were deposited under sulphate-reducing conditions. This is primary achieved from their biomarkers and bulk carbon isotope and inorganic element contents (i.e., S, Ni and V). The absence of 18a (H)-oleanane biomarker also suggests a source age older than Late Cretaceous. The biomarker characteristics of these oils are consistent with those of the Late Jurassic to Early Cretaceous source rocks in the basin. However, biomarker maturity data also indicate that the oils were generated from early maturity source rocks. This appears to result from the type of kerogen of the source rock, characterized by a high-S kerogen (Type II-S). 相似文献
5.
南水北调调蓄工程经济性的探讨 总被引:1,自引:0,他引:1
用于调节南水北调工程来水的有两类水库,在这两类水库中,一类为已建水库,位于南水北调中线以西较高位置,叫做“高库”,例如黄壁庄水库;另一类为拟建水库,位于中线以东平原洼地,也叫“低库”,以大浪淀水库为例.技术经济指标分析表明,第一类水库的供水成本明显小于后者,故得出如下结论:利用某些已建“高库”的闲置库容调节南水北调来水可能是经济的. 相似文献
6.
7.
Fusarium oxysporum was isolated from roots of declining grapevines of cv Semillon ( Vitis vinifera L.) in the Hunter Valley, New South Wales. The pathogenicity of the fungus was confirmed by infecting grapevines growing in the glasshouse with material obtained from roots of field-grown vines. The symptoms of the infection on the plants and the effect of the fungus on the roots are described. 相似文献
8.
9.
Debarun Dutta Timothy Zhao Kai Bing Cheah Larke Holmlund Mark D.P. Willcox 《Contact lens & anterior eye》2017,40(3):175-183
Purpose
To determine the antimicrobial activity of the melimine derived peptide Mel4 against Delftia, Stenotrophomonas, Elizabethkingia, Burkholderia and to investigate biocompatibility of Mel4 as an antimicrobial coating on contact lenses in animals and humans.Methods
In vitro antimicrobial activity of Mel4 was determined against the four Gram negative bacteria by investigating growth curves for 24 h followed by viable counts to determine the minimum inhibitory concentration (MIC). Contact lenses were coated by covalently binding Mel4, characterized by amino acid analysis, and were investigated for changes in lens parameters. Safety of Mel-4 coated lenses were determined in a rabbit model of daily contralateral wear. A prospective, randomised, double-masked, contralateral, 1week daily wear human clinical trial was used to evaluate subjective responses and ocular physiology.Results
Mel4 was active against all the bacteria tested (MIC50 ranged from 31–1000 μg ml?1) and produced an antimicrobial surface on contact lenses. Mel4-coating resulted hydrophilic surface without any significant change in contact lens parameters, and showed no signs of cytotoxicity or ocular irritation during rabbit wear. During human clinical trial, there were no differences between Mel4 coated and uncoated contact lenses in lens performance indicators and ocular signs such as corneal fluorescein staining. Mel4 and control uncoated lenses had no differences in ocular symptoms during lens wear.Conclusion
Mel4 has achieved antimicrobial activity against variety of Gram negative bacteria that are often resistant to the action of cationic peptides and have been implicated in contact lens related adverse events. Mel4-coated contact lenses were safe to wear. 相似文献10.
超临界CO_2从南海翡翠贻贝中萃取EPA和DHA的研究 总被引:6,自引:0,他引:6
用超临界CO2对南海翡翠贻贝中萃取二十碳五烯酸(EPA)和二十二碳六烯酸(DHA)工艺进行了研究,得出其最佳工艺条件为:压力35MPa,温度35℃,CO2用量2ml/g料,尿素用量为乙酯量的10%。乙酯的萃取率达到61.5%。EPA和DHA乙酯总含量(w)达到2832%。 相似文献