检索结果-南通市图书馆

Probing the interaction between asphaltene-wax and its effects on the crystallization behavior of waxes in heavy oil via molecular dynamics simulation

引用

Petroleum Science 2024年第4期21卷 2839-2848页

作者： yong Hu Xi Lu Hai-Bo Wang Ji-Chao Fang Yi-Ning Wu jian Fang Sun SINOPEC Petroleum Exploration and Production Research Institute Shandong Key Laboratory of Oilfield Chemistry School of Petroleum Engineering China University of Petroleum (East China)

High content of asphaltenes and waxes leads to the high pour point and the poor flowability of heavy oil,which is adverse to its efficient development and its transportation in *** the interaction mechanism between asphaltene-wax is crucial to solve these problems,but it is still *** this paper,molecular dynamics simulation was used to investigate the interaction between asphaltenewax and its effects on the crystallization behavior of waxes in heavy *** show that molecules in pure wax are arranged in a paralleled *** wax molecules in heavy oil,which are close to the surface of asphaltene aggregates,are bent and arranged *** the mass fraction of asphaltenes in asphaltene-wax system(ωasp) is 0-25 wt%,the attraction among wax molecules decreases and the bend degree of wax molecules increases with the increase of ω*** ωaspincreases from 0 to 25 wt%,and the attraction between asphaltene-wax is stronger than that among *** causes that the wax precipitation point changes from 353 to 333 *** the ωaspincreases to 50 wt%,wax molecules are more dispersed owing to the steric hindrance of asphaltene aggregates,and the interaction among wax molecules transforms from attraction to *** causes that the ordered crystal structure of waxes can't be formed at normal ***,the asphaltene,with the higher molecular weight or the more hetero atoms,has more obvious inhibition to the formation of wax ***,resins also have an obvious inhibition on the wax crystal due to the formation of asphalteneresin aggregates with a larger *** results reveal the interaction mechanism between asphaltene-wax,and provide useful guidelines for the development of heavy oil.

关键词： Heavy oil Interaction mechanism Asphaltenes Waxes Molecular dynamics

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Development and validation of a nomogram model for predicting the risk of gallstone recurrence after gallbladder-preserving surgery

引用

Hepatobiliary & Pancreatic Diseases International 2024年第3期23卷 288-292页

作者： Peng Liu yong-Wei Chen Che Liu Yin-Tao Wu Wen-Chao Zhao jian-yong Zhu Yang An Nian-Xin Xia Faculty of Hepato-Pancreato-Biliary Surgery the First Medical CenterChinese PLA General HospitalBeijing 100853China Institute of Hepatobiliary Surgery of Chinese PLA Beijing 100853China Key Laboratory of Digital Hepetobiliary Surgery of Chinese PLA Beijing 100853China

Background:The high incidence of gallstone recurrence was a major concern for laparoscopic gallbladderpreserving *** study aimed to investigate the risk factors for gallstone recurrence after gallbladder-preserving surgery and to establish an individualized nomogram model to predict the risk of gallstone ***:The clinicopathological and follow-up data of 183 patients who were initially diagnosed with gallstones and treated with gallbladder-preserving surgery at our hospital from January 2012 to January 2019 were retrospectively *** independent predictive factors for gallstone recurrence following gallbladder-preserving surgery were identified by multivariate logistic regression analysis.A nomogram model for the prediction of gallstone recurrence was constructed based on the selected *** C-index,receiver operating characteristic(ROC)curve and calibration curve were used to evaluate the predictive power of the nomogram model for gallstone ***:During the follow-up period,a total of 65 patients experienced gallstone recurrence,and the recurrence rate was 35.5%.Multivariate logistic regression analysis revealed that the course of gallstones>2 years[odds ratio(OR)=2.567,95%confidence interval(CI):1.270-5.187,P=0.009],symptomatic gallstones(OR=2.589,95%CI:1.059-6.329,P=0.037),multiple gallstones(OR=2.436,95%CI:1.133-5.237,P=0.023),history of acute cholecystitis(OR=2.778,95%CI:1.178-6.549,P=0.020)and a greasy diet(OR=2.319,95%CI:1.186-4.535,P=0.014)were independent risk factors for gallstone recurrence after gallbladder-preserving surgery.A nomogram model for predicting the recurrence of gallstones was established based on the above five *** results showed that the C-index of the nomogram model was 0.692,suggesting it was valuable to predict gallstone ***,the calibration curve showed good consistency between the predicted probability and actual ***:The nomogram model for

关键词： Gallstone Gallbladder-preserving surgery Recurrence Risk factors Nomogram

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Microfacies and diagenetic alteration in a semi-deep to deep lacustrine shale: The Yanchang Formation in the Ordos Basin, China

引用

Petroleum Science 2024年第3期21卷 1524-1538页

作者： Bin Bai Jing-Yue Hao Ling fu Yu-Xi Liu jian-Peng Wang Lan Wang Kevin GTaylor Lin Ma PetroChina Research Institute of Petroleum Exploration and Development Beijing100083China Department of Earth and Environmental Sciences University of ManchesterM139PLUK College of Earth Sciences Jilin UniversityChangchun130061jilinChina Department of Chemical Engineering University of ManchesterM139PLUK

The mineralogical development and diagenetic sequence of lacustrine shales in the Chang 7 Member of the Yanchang Formation in the Ordos Basin are detailed studied.A model of their depositional system and a diagenetic diagram are proposed in this *** detailed petrographic,mineralogical,and elemental analyses,four distinct shale types are identified:argillaceous shale,siliceous shale,calcareous shale,and carbonate,clay,and silt-bearing *** main diagenetic process in argillaceous shale is the transformation of illite to smectite,negatively impacting shale *** shale undergoes carbonate cementation and quartz dissolution,contributing to increased porosity,particularly in *** shale experiences diagenesis characterised by carbonate formation and dissolution,with a prevalence of *** carbonate,clay,and silt-bearing shale,the dissolution of K-feldspar contributes to illitization of *** shale,characterised by more clay minerals and lower mesopore volume,is identified as a potential hydrocarbon *** shale,with the highest pore volume and abundant inter-mineral pores,emerges as a promising shale oil *** findings contribute to a comprehensive understanding of shale properties,aiding in the prediction of shale oil exploration potential in the studied area.

关键词： Ordos Basin Yanchang Formation Chang 7 Member Diagenesis Microfacies

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

New insights into the interactions between the gut microbiota and the inflammatory response to ulcerative colitis in a mouse model of dextran sodium sulfate and possible mechanisms of action for treatment with PE&AFWE

引用

Animal Models and Experimental Medicine 2024年第2期7卷 83-97页

作者： Qianhui fu Xiaoqin Ma Shuchun Li Mengni Shi Tianyuan Song jian Cui Key Laboratory of Ethnomedicine of Ministry of Education School of PharmacyMinzu University of ChinaBeijingChina

Background:Inflammatory bowel disease(IBD),comprising Crohn's disease(CD)and ulcerative colitis(UC),is a heterogeneous state of chronic intestinal *** innate immunity,including innate immune cells,defends against pathogens and excessive entry of gut microbiota,while preserving immune tolerance to resident intestinal microbiota,and may be characterized by its capacity to produce a rapid and nonspecific *** association between microbiota dysbiosis and the pathogenesis of IBD is complex and *** the intestinal ecosystem is in dysbiosis,the reduced abundance and diversity of intestinal gut microbiota make the host more vulnerable to the attack of exogenous and endogenous pathogenic gut *** aim of our study was to comprehensively assess the relationship between microbial populations within UC,the signaling pathways of pathogenic gut microbe therein and the inflammatory response,as well as to understand the effects of using PE&AFWE(poppy extract[Papaver nudicaule L.]and Artemisia frigida ***)on UC ***:A UC mouse model was established by inducing SPF-grade C57BL/6 mice using dextrose sodium sulfate(DSS).Based on metagenomic sequencing to characterize the gut microbiome,the relationship between gut microbiota dysbiosis and gut microbiota was further studied using random forest and Bayesian network analysis methods,as well as histopathological ***:(1)We found that the 5 gut microbiota with the highest relative abundance of inflammatory bowel disease UC model gut microbiota were consistent with the top 5 ranked natural *** were three types of abundance changes in the model groups:increases(Chlamydiae/Proteobacteria and Deferribacteres),decreases(Firmicutes),and no significant changes(Bacteroidetes).The UC model group was significantly different from the control group,with 1308 differentially expressed species with abundance changes greater than or equal to 2-fold.(2)The proportion

关键词： Arachidonic acid metabolism Gut microbiota Microbial dysbiosis Proteobacteria

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Petrogenesis and Economic Potential of the Sangong MaficUltramafic Intrusion in the Eastern Tianshan, Central Asian Orogenic Belt: Constraints from Mineral, Whole-Rock, and PGE Geochemistry

引用

Journal of Earth Science 2024年第3期35卷 850-865页

作者： Guochao Zhou Yuwang Wang Jingbin Wang Yu Shi Hongjing Xie Dedong Li yong fu Pan Wu College of Resources and Environmental Engineering Guizhou UniversityGuiyang 550012China Technic Research Center for Deep Resources Exploration in Non-ferrous Metal Mines Beijing Institute of Geology for Mineral Resources Co.Ltd.Beijing 100012China Sino-Zijin Resources Ltd. Beijing 100012China State Key Laboratory of Nuclear and Environment East China University of TechnologyNanchang 330013China

The Sangong Cu-Ni sulfide mineralized mafic-ultramafic intrusion is located on the southern margin of the Bogeda-Harlik belt,eastern Tianshan,*** intrusion is a well-differentiated complex and is comprised of leucogabbro,gabbro,olivine gabbro,Pl-bearing peridotite,and Pl-bearing *** Pl-bearing pyroxenite hosts both irregularly disseminated sulfide and round droplet *** intrusive rocks have a wide range of SiO_(2)(42.1 wt.%-50.48 wt.%)and MgO(6.21 wt.%-22.11 wt.%),and are enriched in light rare earth elements(LREE),large-ion lithophile elements(LILE;e.g.,Rb,Ba,Sr,and Pb),and palladium platinum group elements(PPGE)but depleted in high-field-strength elements(HFSE;e.g.,Nb,Ta,and Ti)and iridium PGEs(IPGE).These geochemical characteristics indicate that the Sangong mafic-ultramafic intrusion was derived from high degree of partial melting of depleted mantle and interacted with subduction-related *** low Pd/Ir(3.21-27.44)but high Ni/Cu(1.64-24.16)ratios,combined with the olivine crystals with low Fo(60.88-78.65)and Ni(54.99 ppm-1688.87 ppm)concentrations suggest that the parental magma of the Sangong intrusion were likely high MgO basaltic in composition that experienced extensive evolution prior *** Ce/Pb ratios(5.8-13.6)and Nb/U ratios(11.6-30.3)of the intrusive rocks all range between MORB and crustal values,the Nb/Yb and Th/Yb values are close to the lower crust values,together with the low Se/S ratios[(17-100)×10^(-6))]suggest that the magma experienced assimilation not only in mantle source but also in conduit,but the degree of crustal contamination is *** Cu/Pd ratios of the rocks range from 3.9×10^(4) to 10.8×10^(4),and the Cu/Zr ratios of Pl-bearing pyroxenite in the Sangong intrusion are>1,combined with the presence of sulfide droplets in the Pl-bearing pyroxenite,indicating the parental magma experienced sulfide saturation and the economical ore bodies may present in the depth of the ***,gi

关键词： Sangong mafic-ultramafic intrusion deposits geochemistry PGE economic potential eastern Tianshan.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Pathogen-induced methylglyoxal negatively regulates rice bacterial blight resistance by inhibiting OsCDR1 protease activity

引用

Molecular Plant 2024年第2期17卷 325-341页

作者： Zheng-Wei fu jian-Hui Li Xiang Gao Shi-Jia Wang Ting-Ting Yuan Ying-Tang Lu State Key Laboratory of Hybrid Rice College of Life SciencesRenmin Hospital of Wuhan UniversityWuhan UniversityWuhan 430072China Key Laboratory of Biology and Genetic Improvement of OilCrops Ministry of Agriculture and Rural AffairsOilCrops Research Institute of the Chinese Academy of Agricultural SciencesWuhan 430062China

Xanthomonas oryzae ***(Xoo)causes bacterial blight(BB),a globally devastating disease of rice(Oryza sativa)that is responsible for significant crop *** and sugar metabolites are important for pathogen infection,providing energy and regulating events associated with defense responses;howev-er,the mechanisms by which they regulate such events in BB are *** an inevitable sugar metabolite,methylglyoxal(MG)is involved in plant growth and responses to various abiotic stresses,but the underlying mechanisms remain *** and how MG functions in plant biotic stress responses is almost completely ***,we report that the Xoo strain PXO99 induces OsWRKY62.1 to repress transcrip-tion of OsGLY Il genes by directly binding to their promoters,resulting in overaccumulation of *** negatively regulates rice resistance against Pxo99:osglyll2 mutants with higher MG levels are more sus-ceptible to the pathogen,whereas OsGLYIl2-overexpressing plants with lower MG content show greater resistance than the wild *** of OsGLYll2 to prevent excessive MG accumulation confers broad-spectrum resistance against the biotrophic bacterial pathogens Xoo and Xanthomonas oryzae *** and the necrotrophic fungal pathogen Rhizoctonia solani,which causes rice sheath *** evidence shows that MG reduces rice resistance against PXO99 through CONSTITUTIVE DISEASE RESISTANCE 1(OsCDR1).MGmodifies the Arg97 residue of OsCDR1to inhibit its aspartic protease activ-ity,which is essential for OsCDR1-enhanced *** together,these findings illustrate how Xoo promotes infection by hijacking a sugar metabolite in the host plant.

关键词： Oryza sativa bacterial blight OsWRKY62.1 methylglyoxal OsCDR1

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Jetting of a near-wall cavitation bubble induced by another tandem bubble

引用

Journal of Hydrodynamics 2024年第3期36卷 444-456页

作者： Hui Han Jing-zhu Wang jian-lin Huang Peng-bo Bai yong-gang Chen Yi-wei Wang Key Laboratory for Mechanics in Fluid Solid Coupling Systems Institute of MechanicsChinese Academy of SciencesBeijing100190China School of Engineering Science University of Chinese Academy of SciencesBeijing100049China Guangdong Aerospace Research Academy Guangzhou511458China School of future Technology University of Chinese Academy of SciencesBeijing100049China jianghuai Advance Technology Center Hefei230088China

Double bubbles near a rigid wall surface collapse to produce a significant jet impact,with potential applications in surface cleaning and ultrasonic ***,the dynamic behaviors of near-wall bubbles remain *** this study,we investigate the jetting of a near-wall bubble induced by another tandem *** define two dimensionless standoff distances,γ_(1),γ_(2),to represent the distances from the center of the near-wall bubble to the rigid wall and the center of controlling bubble to the center of the near-wall bubble,*** observations reveal three distinct jetting regimes for the near-wall bubble:transferred jetting,double jetting,and directed *** further investigate the jetting mechanism,numerical simulations are conducted using the compressibleInterFoam solver in the open-source framework of OpenFOAM.A detailed analysis shows that the transferred jet flow is caused by the pinch-off resulting from the axial contraction velocity at the lower end of the near-wall bubble being greater than the vertical contraction velocity,leading to a maximum jet velocity of 682.58 m/*** the case of double jetting,intense stretching between the controlling bubble and the wall leads to a pinch-off and a double jetting with a maximum velocity of 1096.29 m/*** directed jet flow is caused by the downward movement of the high-pressure region generated by the premature collapse of the controlling bubble,with the maximum jet velocity reaching 444.62 m/s.

关键词： Jetting of near-wall bubble controlling bubble impact velocity

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

活化海泡石对苯酚的吸附研究

引用

环境科学与技术 2006年第7期29卷 73-74页

作者：肖秋国付勇坚湖南科技大学化学化工学院湘潭400201

海泡石经酸活化,在300℃焙烧,比表面积增加,吸附效果明显增强。通过实验,研究了焙烧温度、溶液pH值以及不同活化酸对吸附效果的影响。同时研究了活化海泡石对苯酚吸附动力学特性,及其脱附再生性能。并与活性炭对苯酚的吸附效果进行了比... 详细信息

海泡石经酸活化,在300℃焙烧,比表面积增加,吸附效果明显增强。通过实验,研究了焙烧温度、溶液pH值以及不同活化酸对吸附效果的影响。同时研究了活化海泡石对苯酚吸附动力学特性,及其脱附再生性能。并与活性炭对苯酚的吸附效果进行了比较,虽然其吸附性能较差,但具有良好的脱附再生性能,并且再生方法简单,在含酚废水的处理方面,海泡石可以作为一种新型的廉价的吸附剂。

关键词：海泡石活化苯酚吸附

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

利多卡因两种给药途径对兔蛛网膜下腔出血的脑保护作用

引用

四川大学学报（医学版） 2017年第1期48卷 120-123页

作者：施贤清符永健郑丽蓉贵州省人民医院ICU 贵阳550002 贵州医科大学研究生院贵阳550002

目的比较利多卡因两种给药途径对蛛网膜下腔出血(SAH)的脑保护作用。方法 40只新西兰大白兔随机分为假手术(sham)组、SAH模型组(SAH组)、利多卡因静脉治疗组(L1组)及利多卡因枕大池治疗组(L2组),每组各10只。麻醉下采用自体动脉血注入... 详细信息

目的比较利多卡因两种给药途径对蛛网膜下腔出血(SAH)的脑保护作用。方法 40只新西兰大白兔随机分为假手术(sham)组、SAH模型组(SAH组)、利多卡因静脉治疗组(L1组)及利多卡因枕大池治疗组(L2组),每组各10只。麻醉下采用自体动脉血注入枕大池制备SAH模型,sham组注入等量生理盐水(NS);30min后sham组、SAH组及L1组的动物,再次从枕大池注入0.3mL NS,L1组同时静脉给予0.3mL 2%利多卡因治疗,L2组从枕大池注入0.3mL 2%利多卡因治疗。所有动物72h后处死。分别于造模型前、治疗后72h采用ELISA法检测血清白介素-6(IL-6)水平;72h后取脑基底动脉以及海马组织行常规HE染色及C-fos免疫组化染色,测定基底动脉腔面积(AA)和直径(AD)、海马正常神经元密度(NNDHP)、C-fos阳性细胞数目(CCPHP)。结果各组动物造模前血清IL-6水平差异均无统计学意义(P>0.05),治疗后72h各组IL-6水平均较术前高(P<0.05),SAH及L1组高于sham组和L2组(P<0.05)。SAH及L1组基底动脉的AA、AD及海马NNDHP比假手术sham组和L2组减少(P<0.05),而SAH及L1组海马CCPHP比sham组和L2组增多(P<0.05)。结论同剂量利多卡因经枕大池注入比静脉注入对兔蛛网膜下腔出血的脑保护效果好。

关键词：给药途径利多卡因蛛网膜下腔出血脑保护

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Optimization of the co-closing law of guide vanes and blades for bulb turbines based on CFD

引用

Journal of Hydrodynamics 2024年第2期36卷 363-377页

作者： Hui Liu Yun-fa Lin yong-guang Cheng Song Xue Mao-jia Tang jian Zhang Jia-yi Fan State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan430072China Dongfang Electric Machinery Co. Ltd.Deyang618000China

The load rejection transient process of bulb turbine units is critical to safety of hydropower stations,and determining appropriate closing laws of guide vanes(GVs)and runner blades(RBs)for this process is of *** this study,we proposed a procedure to optimize the co-closing law of GVs and RBs by using computational fluid dynamics(CFD),combined with the design of experiment(DOE)method,approximation model,and genetic optimization *** sensitivity of closing law parameters on the histories of head,speed,and thrust was analyzed,and a two-stage GVs’closing law associating with a linear RBs’closing law was *** results show that GVs dominate the transient characteristics by controlling the change of *** GVs’first-stage closing speed while shortening first-stage closing time can not only significantly reduce the maximum rotational speed but also suppress the water hammer pressure;slowing GVs’second-stage closing speed is conducive to controlling the maximum reverse axial *** directly affect the runner *** RBs’closing speed can further reduce the rotational speed and the maximum reverse axial *** safety margin of each control parameter,flow patterns,and pressure pulsations of a practical hydropower station were all improved after optimization,demonstrating the effectiveness of this method.

关键词： Bulb turbine load rejection transient process double regulation closing law optimization computational fluid dynamics(CFD)

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：