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Molecular characterization of polar heteroatom species in oilsands bitumen-derived vacuum residue fractions by Fourier transform ion cyclotron resonance mass spectrometry

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Petroleum Science 2019年第5期16卷 1196-1207页

作者： Fang Zheng Warren chung Eusebio Palmisano Dahai Dong Quan Shi Zhiming Xu Keng h.chung State Key Laboratory of heavy Oil Processing China University of PetroleumBeijing 102249China Well Resources Inc EdmontonCanada Cenovus Energy Inc CalgaryCanada Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of SciencesQingdao 266101China

A Canadian in situ oilsands bitumen-derived vacuum residue(VR)was subjected to supercritical fluid extraction and fractionation(SFEF)into 13 extractable fractions and an unextractable end-cut and characterized by positive-and negative-ion electrospray ionization(ESI)Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS).The results of negative-ion ESI FT-ICR MS showed that the N1 class species was the most abundant and the multifunctional group compounds,such as N1 O1,N1 O2,N1 S1,N1 S2,and N2 class species became abundant as the SFEF fraction became *** positive-ion ESI mode,the relative abundance of N1 class species decreased gradually in the heavy SFEF fractions while that of multifunctional group compounds *** relative abundance of N4 V1 O1 increased dramatically in heavy fractions and the *** distributions of polar heteroatom species of VR derived from oilsands bitumen were similar with those of VR derived from the Venezuela Orinoco extra heavy oil.

关键词： Molecular characterization Canadian oilsands bitumen SFEF ESI FT-ICR MS

Subchronic Oral Toxicity of Pyridostigmine Bromide in Rats

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Biomedical and Environmental Sciences 1991年第3期4卷 283-289页

作者： B.S.LEVINE R.LONG h.chung Department of Pharmacology University of Illinois at Chicago Chicago IL 60680Pathology Associates Inc. Chicago IL 60616Walter Reed Army Institute of Research WashingtonDC 20307

This study evaluated the oral toxicity of pyridostigmine bromide in Sprague-Dawley rats when administered for 13 weeks by daily gavage. Groups of 10 rats/sex received doses of 0, 5, 15, 30, or 60 mg/kg/day. Toxicity was limited to exaggerated cholinergic stimulation at doses of 15 mg/kg/day or greater. Significant findings included tremors and inhibition of RBC acetylcholinesterase. Thus, 5 mg/kg/day of pyridostigmine bromide appears to be the no observed toxic effect level under the conditions of the present investigation.

关键词： Subchronic Oral Toxicity of Pyridostigmine Bromide in Rats

Factors that affect heart rate variability following acute resistance exercise:A systematic review and meta-analysis

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Journal of Sport and health Science 2022年第3期11卷 376-392页

作者： Sajith U.Marasingha-Arachchige JacoboÁ.Rubio-Arias Pedro E.Alcaraz Linda h.chung UCAM Research Center for high Performance Sport Catholic University of MurciaMurcia 30107Spain LFE Research Group Department of Health and Human PerformanceFaculty of Physical Activity and Sport Science-INEFUniversidad Politécnica de MadridMadrid 28040Spain Faculty of Sport Catholic University of MurciaMurcia 30107Spain

Background:There is controversial evidence regarding the effect of acute resistance exercise(ARE) on heart rate variability(hRV) parameters,which indicates the activities of the cardiac autonomic nervous *** aim of this study was to perform a systematic review and meta-analysis of the literature on the effect of ARE on hRV parameters and identify its possible moderating ***:The PubMed-Medline,Web of Science,SPORTDiscus,and Cochrane Library databases were *** Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA) declaration was followed,and the methodological quality of the studies was *** level of significance was set at p≤***-six studies met the inclusion *** effect analyses between pre-and post-test interventions demonstrated an increase in normalized units low frequency(p high frequency ratio(p he normal-to-normal(NN)interval(p he successive differences(p high frequency(p healthy individuals range:15 ± 1 to 48 ± 2 years;mean ± SD).Results:There were differences between the subgroups in the number of sets used in an exercise(p=0.05) for root mean square of the successive differences,as well as for exercise intensity(p=0.01) and rest between sets(p=0.05) for normalized units high ***,there were differences between the subgroups in training volume for root mean square of the successive differences(p=0.01),normalized units high frequency(p=0.003) and normalized units low frequency(p=0.02).Conclusion:Overall,there was a withdrawal of cardiac parasympathetic and activation of cardiac sympathetic modulations following ARE,and th

关键词： Cardiac Parasympathetic Sympathetic

Accurate identification of glass crystallization helps in selecting high electronic conductivity materials

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Progress in Natural Science:Materials International 2024年第3期34卷 503-511页

作者： Fanhou Kong Shuli Li Suoqi Zhao huiwen Li Lin Li Zhenting Zang Rui Zhang hongrui Liu Lehan Wang Changjiu Li Keng h.chung Dongying Key Laboratory of New Energy Materials and Devices & School of Chemical Engineering Shandong Institute of Petroleum and Chemical Technology Special Glass Key Lab of hainan Province & State Key Laboratory of Marine Resource Utilization in South China Sea Hainan University

Though the current research on vanadium-based glass electrodes has made great progress, the conductivity theory of V-based glasses has not been obviously improved and crystals cannot be positioned precisely. The changes in the valence state of V3+, V4+and V5+are regulated by the strong reducing agent Fe2P to realize valence bond transformation of the amorphous electrode, explore the redox process of multi-electron reactions and further optimize the conductivity of electrode materials. VPFe2 and VPFe3 precipitate VO2crystals and VPFe4 precipitates VO2and V6O11crystals. Electron back-scattered diffraction was used to accurately identify the distribution and specific positions of both types of crystals. V6O11crystals exhibit a strong texture according to pole figure and inverse pole figure. XPS reveals that Fe2P and V2O5, undergo a redox reaction during the hightemperature melting process, where V5+is reduced to V4+and V3+and V4+renders a positive influence on conductivity. The addition of Fe2P increases the content of V4+in the glass and VPFe3 glass contains the highest content of V4+, leading to the highest electronic conductivity. V2O5transforms into VO2crystals and VO2transforms into V6O11with the increase of Fe2P content. The type of nanocrystal precipitation in glass affects electronic conductivity.

关键词： Electron back-scattered diffraction Electronic conductivity Glass crystallization Multi-electron reactions V2O5

用于制备聚氨酯纳米复合物的高岭石粒子的表征(英文)

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无机化学学报 2003年第11期19卷 1261-1265页

作者：李再峰王义银 Luba S.Kotlyar Keng h.chung 青岛科技大学化学与分子工程学院青岛266042 西安交通大学管理学院西安710049 ICPET National Research Council1200 Montreal RoadOttawaOntario Syncrude Canada Ltd. Edmonton Research Centre9421-17th AvenueEdmontonAlberta

Clay such as kaolinite, is commonly used as an additive to modify the thermal properties of polymer. In this paper, the morphology, composition, shape and structure of kaolinite was characterized by various advanced techniques. The TEM/ EDX data showed that the kaolinite had a larger particle size and a Si/Al ratio of 1.8. The individual particle of kaolinite was a single crystalline. TEM also showed that these particles were always stacked together due to the presence of electrostatic cohesive energy and hydrogen bond between plaletes. The PAS FTIR spectra showed that no absorbance of hydroxyl group for hydration water in hydrogen bond region or at 1650cm- 1 was observed at room temperature. It meant a little ability to adsorb water for kaolinite particle. Kaolinite clay also showed no change for its PAS FTIR spectra with increasing temperature. The TGA results revealed that kaolinite almost doesn′ t lose weight at 60℃ due to loss of dehydration of absorbed water, however, it will decomposed around 510℃ and lose its hydroxyl functional group in the form of water (dehydroxylation). The result is consistent with that of PAS FTIR analysis. This suggests that the structural hydroxyl group on the surface of individual kaolinite clay particle is very stable below 500℃ , and the kaolinite composed polymer could be got by the reaction of its stable structural hydroxyl group with isocynate group of polyurethane prepolymer.

关键词：制备聚氨酯纳米复合聚合物高岭石粒子表征

Molecular composition of naphthenic acids in a Chinese heavy crude oil and their impacts on oil viscosity

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Petroleum Science 2023年第2期20卷 1225-1230页

作者： Qian-hui Zhao Shuai M Jian-Xun Wu Wei-Feng Chang Sheng-Fei Zhang Xin-Ge Sun Bing Zhou Zeng-Min Lun Keng h.chung Quan Shi State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development Sinopec Petroleum Exploration and Production Research InstituteBeijing 100083China State Key Laboratory of heavy Oil Processing Petroleum Molecular Engineering Center(PMEC)China University of PetroleumBeijing 102249China Research Institute of Petroleum Exploration and Development CNPCBeijing 100083China Xinjiang Oilfield Company CNPCKaramayXinjiang 834000China Well Resources Inc. EdmontonCanada

Most heavy crude oils underwent biodegradation and generated a significant amount of naphthenic acids. Naphthenic acids are polar compounds with the carboxylic group and are considered as a major factor affecting the oil viscosity. however, the relationship between the molecular composition of naphthenic acids and oil viscosity is not well understood. This study examined a “clean” heavy oil with low contents of heteroatoms but had a high content of naphthenic acids. Naphthenic acids were fractionated by distillation and caustic extraction. The molecular composition was characterized by high-resolution Orbitrap mass spectrometry. It was found that the 2- and 3-ring naphthenic monoacids with 15–35 carbon atoms are dominant components of the acid fractions;the caustic extraction is capable of isolating naphthenic acids with less than 35 carbons, which is equivalent to the upper limit of the distillable components, but not those in the residue fraction;the total acid number of the heavy distillates is higher than that of the residue fraction;the viscosity of the distillation fraction increases exponentially with an increased boiling point of the distillates. Blending experiments indicates that there is a strong correlation between the oil viscosity and acids content, although the acid content is only a few percent of the total oil.

关键词： heavy crude oil Viscosity high-resolution mass spectrometer Naphthenic acid

Athabasca油砂沥青中重组分的分子模拟

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化工学报 2003年第1期54卷 9-17页

作者：高金森徐春明 Luba S.KOTLYAR Keng h.chung 石油大学重质油加工国家重点实验室北京102249 加拿大国家研究院加拿大合成油有限公司埃德蒙顿研究中心

利用分子模拟技术对加拿大Athabasca油砂沥青超临界萃取分馏残渣组分的化学分子结构进行了研究 ,首先选用长度不同的桥链构建了其三维平均结构 ,然后采用分子力学 (MM)和分子动力学 (MD)方法得到能量最低也即最稳定的构象 .研究发现 ,... 详细信息

利用分子模拟技术对加拿大Athabasca油砂沥青超临界萃取分馏残渣组分的化学分子结构进行了研究 ,首先选用长度不同的桥链构建了其三维平均结构 ,然后采用分子力学 (MM)和分子动力学 (MD)方法得到能量最低也即最稳定的构象 .研究发现 ,即使分子的二维结构相同 ,其三维结构差别也很大 ,由此可见仅用二维模型来表征重质油大分子的结构和物理化学性质远远不够 .另外 ,分子模拟还可以预测沥青质残渣中最有可能存在的桥链长度 .Athabasca沥青残渣组分中长度为C5到C7的桥链存在的可能性最大 ,而C1和C2桥链则由于其总能量相对较高。

关键词： Athabasca油砂沥青分子模拟重组分分子结构分子力学分子动力学超临界萃取分馏残渣

产前日粮碳水化合物来源和莫能菌素对经产奶牛围产期代谢和泌乳的影响

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中国畜牧兽医 2008年第10期35卷 95-95页

作者： Y.-h.chung 张春林

选用85头经产荷斯坦奶牛随机设计,评估产前碳水化合物来源及莫能菌素对围产期奶牛干物质采食量、血液参数和泌乳性能的影响。日粮处理按照2×2阶乘排列设计,包括传统的干奶料(CONV)和不含有草料纤维来源的干奶料(NFFS),补充或不补充330 ... 详细信息

选用85头经产荷斯坦奶牛随机设计,评估产前碳水化合物来源及莫能菌素对围产期奶牛干物质采食量、血液参数和泌乳性能的影响。日粮处理按照2×2阶乘排列设计,包括传统的干奶料(CONV)和不含有草料纤维来源的干奶料(NFFS),补充或不补充330 mg/d.头莫能菌素。CONV日粮包括70%的草料,NFFS日粮28%的草料用棉籽壳和大豆壳替代。在整个干奶期(产前60 d)饲喂试验日粮(CONV和NFFS)。在预期产犊日期之前的28 d开始每天追加一次莫能菌素直到分娩。分娩后,所有奶牛饲喂相同的泌乳期奶牛料。结果发现,在妊娠的最后28 d,与饲喂CONV日粮相比,饲喂NFFS产前日粮干物质采食量(15.8 vs 11.9 kg/d)、干物质采食量体重百分比(2.1%vs1.6%体重)、血糖(67.4 vs 64.6 mg/dl)和血清胰岛素浓度(0.59 vs 0.45 ng/ml)更高,非酯化脂肪酸浓度(185 vs 245μEq/L)较低。在泌乳的前56 d,产前ChO、莫能菌素或两者混合效应对平均产奶量或乳成分没有明显的影响。但随着时间的延长,产前碳水化合物来源有影响产奶量的趋势。产前28 d补给莫能菌素对围产期产奶量没有影响。产前日粮对产后干物质采食量、血糖、非酯化脂肪酸、胰岛素浓度或肝脏甘油三酯没有影响。研究结果表明,在干奶期日粮中用NFFS部分替换传统日粮碳水化合物提高或维持了产前干物质采食量,因此增强了分娩前代谢水平。产前更高的干物质采食量可能潜在增加泌乳早期的产奶量。

关键词：非草料纤维来源莫能菌素产前饲喂围产期代谢

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过瘤胃胆碱和丙二醇对早期断奶荷斯坦奶牛采食量和血液参数的影响

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饲料与畜牧（新饲料） 2009年第6期 63-63页

作者：刘冰 Y.-h.chung N.E.Brown C.M.Martinez T.W.Cassidy G.A.Varga

采用6×6拉丁方设计同时进行三个试验来研究添加丙二醇干品对干物质摄入量、产奶量和血液参数的影响。丙二醇的添加方式分为两种：与全混日粮混合或直接喷洒在日粮表面（对照1）；日粮中胆碱和丙二醇的添加按照2×2因子设计（对照2）；... 详细信息

采用6×6拉丁方设计同时进行三个试验来研究添加丙二醇干品对干物质摄入量、产奶量和血液参数的影响。丙二醇的添加方式分为两种：与全混日粮混合或直接喷洒在日粮表面（对照1）；日粮中胆碱和丙二醇的添加按照2×2因子设计（对照2）；或者增加日粮中胆碱含量（对照3）。6头经产荷斯坦奶牛泌乳41d左右。

关键词：过瘤胃胆碱丙二醇干品采食量血液参数