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Molecular composition of naph.h.nic acids in a Ch.nese h.avy crude oil and th.ir impacts on oil viscosity

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

作者： Qian-h.i Zh.o Sh.ai M Jian-Xun Wu Wei-Feng Ch.ng Sh.ng-Fei Zh.ng Xin-Ge Sun Bing Zh.u Zeng-Min Lun Keng h.chung Quan Sh. State Key Laboratory of Sh.le Oil and Gas Enrich.ent Mech.nisms and Effective Development Sinopec Petroleum Exploration and Production Research InstituteBeijing 100083China State Key Laboratory of h.avy 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 h.avy crude oils underwent biodegradation and generated a significant amount of naph.h.nic acids. Naph.h.nic acids are polar compounds with.th. carboxylic group and are considered as a major factor affecting th. oil viscosity. h.wever, th. relationsh.p between th. molecular composition of naph.h.nic acids and oil viscosity is not well understood. Th.s study examined a “clean” h.avy oil with.low contents of h.teroatoms but h.d a h.gh.content of naph.h.nic acids. Naph.h.nic acids were fractionated by distillation and caustic extraction. Th. molecular composition was ch.racterized by h.gh.resolution Orbitrap mass spectrometry. It was found th.t th. 2- and 3-ring naph.h.nic monoacids with.15–35 carbon atoms are dominant components of th. acid fractions;th. caustic extraction is capable of isolating naph.h.nic acids with.less th.n 35 carbons, wh.ch.is equivalent to th. upper limit of th. distillable components, but not th.se in th. residue fraction;th. total acid number of th. h.avy distillates is h.gh.r th.n th.t of th. residue fraction;th. viscosity of th. distillation fraction increases exponentially with.an increased boiling point of th. distillates. Blending experiments indicates th.t th.re is a strong correlation between th. oil viscosity and acids content, alth.ugh.th. acid content is only a few percent of th. total oil.

关键词： h.avy crude oil Viscosity h.gh.resolution mass spectrometer Naph.h.nic acid

Video Traces for Network Performance Evaluation 2007

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Clinical application and management of temporary mech.nical circulatory support:A clinical consensus

2007年

作者： Patrick Seeling frank h. P. Fitzek Martin Reisslein

来源：畅想之星图书光盘版（南... 评论

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Ch.nese Medical Journal 2024年第10期137卷 1135-1139页

作者： Nianguo Dong Liangwan Ch.n Xin Ch.n h.ish.n Wang Yingbin Xiao Xianqiang Wang Jinsong h.ang Yang Yan Pramod Bonde Neel Sodh. Pavan Atluri Juan Pablo Maureira AndréVincentelli Masanobu Yanase Yixuan Wang h.itao Zh.ng Xiaotong h.u Yosh.juki Takami Pascal Leprince Th.erry Folliguet frank W Sellke Ch.nese Society for Th.racic and Cardiovascular Surgery Ch.nese Association of Cardiovascular Surgeons Cardiac Critical Care Professional Committee of Ch.nese Medical Association Ch.nese Society of Extracorporeal Life Support European Society of Cardiovascular and Endovascular Surgery French.Society of Th.racic and Cardiovascular Surgery Japanese Society for Cardiovascular Surgery Japanese Society of Artificial Organs Department of Cardiovascular Surgery Union Hospital of Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubei 430022China Department of Cardiovascular Surgery Fujian Medical University Union HospitalFuzhouFujian 350000China Department of Th.racic and Cardiovascular Surgery Nanjing First HospitalNanjing Medical UniversityNanjingJiangsu 210000China Department of Cardiovascular Surgery General Hospital of Northern Theater CommandShenyangLiaoning 110000China Department of Cardiovascular Surgery Xinqiao HospitalThird Military Medical UniversityChongqing 400037 China Department of Cardiovascular Surgery Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100000 China Department of Cardiovascular Surgery Guangdong Provincial Cardiovascular InstituteGuangdong General HospitalGuangdong Academy of Medical SciencesGuangzhouGuangdong 510000 China Department of Cardiovascular Surgery First Affiliated Hospital of Xi’an Jiaotong UniversityXi’anShaanxi 710061China Department of Cardiac Surgery Yale School of Medicine330 Cedar St204 BoardmanNew HavenCT 06510USA Department of Cardioth.racic Surgery Alpert Medical SchoolBrown University Rhode Island HospitalProvidenceRI 02912USA Department of Cardiovascular Surgery Department of SurgeryUniversity of PennsylvaniaPhiladelphiaPA 19113USA Department of Cardiovascular Surgery and Transplantation University Hospital of NancyUniversity of LorraineVandoeuvre-lès-Nancy 54500France Department of Cardiovascular Surgery University Hospital of LilleUniversity of LilleLille 59037France Department of Cardiology Fujita Health University School of MedicineToyoakeAichi 470-1192Japan Department of Adult Surgical Intensive Care Unit Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100000China Department of Cardiac Intensive Care Beijing Institute of HeartLung and B

Temporary mech.nical circulatory support(tMCS)plays a pivotal role in managing severe or refractory cardiogenic sh.ck(CS),furnish.ng essential h.modynamic support,and sustaining organ perfusion from h.urs to weeks,or to even *** th. past decade,th. utilization of tMCS h.s witnessed a signicant increase in American and European *** in Asia,th. newly developed concepts and devices constituting tMCS h.ve also made rapid ***,th. absence of a consensus or standardized guidelines,especially for th. Asian population considering inh.rited polymorph.sm,is *** address th.s knowledge gap,eigh. associations/societies and experts in th.seld came up with.th. present consensus after repeated discussions,more specically for th. Asian *** compreh.nsively elucidates th. commonly employed tMCS devices,criteria for patient selection,indications and contraindications,clinical management,and th. optimal timing for implantation and *** goal of th.s statement is to promote th. standardized application of tMCS and make reasonable decisions in clinical ***-length.version of th. consensus can be seen in Supplementary File,h.tp://***/CM9/B883.

关键词： application statement discussions

ON INVENTORY STRATEGIES OF ONLINE RETAILERS

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Journal of Systems Science and Systems Engineering 2005年第1期14卷 52-72页

作者： frank Y. Ch.N S. h. h.M Ch.ryl h. SIM Department of System Engineering and Engineering Management Th. Ch.nese University of h.ng Kong Hong Kong NUSBusiness Sch.ol The National University of Singapore 1 Business Link Singapore 117592 National Library Board of Singapore Singapore

Th.s study focuses on inventory strategies of Internet retailers (etailers). Th. etailer faces options of h.lding h.r own inventory or outsourcing th.ough.th. th.rd party(ies). We assess etailer inventory strategies th.ough.math.matical modeling and numerical experiments. Wh.n ordering and h.lding h.r own stock, th. etailer h.s full control of th. order fulfillment process but bears th. inventory-related risk. Wh.n outsourcing stock, etailer’s orders may not get an equal priority as for th.se of th. th.rd party’s own. Built upon simple operations research.models, th. numerical experiments suggest th.t th. etailer is better off relying on oth.rs to fulfill orders if h.r demand (profit margin) is low, but sh.uld revert to th. strategy of maintaining h.r own inventory if h.r sales volume (profit margin) is relatively h.gh. Oth.r factors are also investigated. Th.se findings seem to confirm wh.t are being practiced in th. industry.

关键词： Electronic commerce e-retailer fulfillment inventory

Optimal concentration of mesench.mal stem cells for fracture h.aling in a rat model with.long bone fracture

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World Journal of Stem Cells 2022年第12期14卷 839-850页

作者： Myung-Seo Kim h.un-Ju chung Kang-Il Kim Department of Orth.paedic Surgery School of MedicineKyung Hee University and Kyung Hee University Hospital at GangdongSeoul 05278South Korea Department of Core Research.Laboratory Clinical Research InstituteKyung Hee University Hospital at GangdongSeoul 05278South Korea

BACKGROUND Th.re is still no consensus on wh.ch.concentration of mesench.mal stem cells(MSCs)to use for promoting fracture h.aling in a rat model of long bone *** To assess th. optimal concentration of MSCs for promoting fracture h.aling in a rat *** Wistar rats were divided into four groups according to MSC concentrations:Normal saline(C),2.5×10^(6)(L),5.0×10^(6)(M),and 10.0×10^(6)(h.*** MSCs were injected directly into th. fracture *** rats were sacrificed at 2 and 6 wk *** bone formation[bone volume(BV)and percentage BV(PBV)]was evaluated using micro-computed tomograph.(CT).h.stological analysis was performed to evaluate fracture h.aling *** protein expression of factors related to MSC migration[stromal cell-derived factor 1(SDF-1),transforming growth.factor-beta 1(TGF-β1)]and angiogenesis[vascular endoth.lial growth.factor(VEGF)]was evaluated using western blot *** expression of cytokines associated with.osteogenesis[bone morph.genetic protein-2(BMP-2),TGF-β1 and VEGF]was evaluated using real-time polymerase ch.in *** Micro-CT sh.wed th.t BV and PBV was significantly increased in groups M and h.compared to th.t in group C at 6 wk post-fracture(P=0.040,P=0.009;P=0.004,P=0.001,respectively).Significantly more cartilaginous tissue and immature bone were formed in groups M and h.th.n in group C at 2 and 6 wk post-fracture(P=0.018,P=0.010;P=0.032,P=0.050,respectively).At 2 wk post fracture,SDF-1,TGF-β1 and VEGF expression were significantly h.gh.r in groups M and h.th.n in group L(P=0.031,P=0.014;Ph.gh.r in groups M and h.th.n in group C at 6 wk postfracture(P=0.037,P=0.038;P=0.021,P=0.010).Compared to group L,TGF-β1 expression was significantly h.gh.r in groups h.P=0.016).Th.re were no significant differences in expression levels of ch.mokines related to MSC migration,angiogenesis and cytokines associated

关键词： Rat model Femoral sh.ft fracture Mesench.mal stem cells Direct injection Optimal concentration Fracture h.aling

Ch.racterization of h.avy petroleum fraction by positive-ion electrospray ionization FT-ICR mass spectrometry and collision induced dissociation: Bond dissociation beh.vior and aromatic ring arch.tecture of basic nitrogen compounds

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Science Ch.na Ch.mistry 2013年第7期56卷 874-882页

作者： Zh.NG LinZh.u Zh.NG Yah. Zh.O SuoQi XU Ch.nMing chung Keng h. Sh. Quan State Key Laboratory of h.avy Oil Processing China University of Petroleum

Th.s paper examined th. bond dissociation beh.vior and aromatic ring arch.tecture of basic nitrogen compounds in Sudan h.avy petroleum fraction. Both.broadband and quadrupole isolation modes positive-ion electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) coupled with.collision induced dissociation (CID) tech.iques were used to ch.racterize a low sulfur crude oil derived vacuum residuum (VR). Th. appropriate CID operating condition was selected by comparing th. molecular weigh. distributions of th. basic nitrogen compounds under various CID operating conditions. Both.oddand even-electron fragment ions were observed from th. mass spectrum, indicating th.t th. h.terolytic and h.molytic bond cleavages occurred simultaneously during th. CID process. Th. odd-electron fragment ions were predominant in each.class species, indicating preferential h.terolytic bond cleavages. At th. optimal CID condition, th. alkyl groups decomposed deeply and just left th. aromatic cores of th. nitrogen compounds. No significant variation in double bond equivalent (DBE) value was observed between th. fragment and parent ions, revealing th.t th. domination of single core structure.

关键词：碱性氮化合物碰撞诱导解离电喷雾电离石油馏分分离行为环结构正离子质谱法

Significant Lifetime Enh.ncement in QLEDs by Reducing Interfacial Ch.rge Accumulation via Fluorine Incorporation in th. ZnO Electron Transport Layer

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Nano-Micro Letters 2022年第12期14卷 432-446页

作者： Dong Seob chung Tyler Davidson-h.ll Giovanni Cotella Quan Lyu Peter Ch.n h.ny Aziz Department of Electrical and Computer Engineering Waterloo Institute for NanotechnologyUniversity of Waterloo200 University Avenue WestWaterlooON N2L 3G1Canada Ipswich.Research.Centre Huawei Technologies Research&Development(UK)Ltd.Phoenix House(B55)Adastral ParkIpswich IP53REUK Ottawa IC Laboratory Huawei Canada19 Allstate ParkwayMarkhamON L3R 5B4Canada

ZnO nanoparticles are widely used for th. electron transport layers(ETLs)of quantum dots ligh. emitting devices(QLEDs).In th.s work we sh.w th.t incorporating fluorine(F)into th. ZnO ETL results in significant enh.ncement in device electroluminescence stability,leading to LT50 at 100 cd m^(−2) of 2,370,000 h.in red QLED,47X longer th.n th. control devices.X-ray ph.to-electron spectroscopy,time-of-fligh. secondary ion mass spectroscopy,ph.toluminescence and electrical measurements sh.w th.t th. F passivates oxygen vacancies and reduces electron traps in *** ph.toluminescence versus bias measurements and capacitance-voltage-luminance measurements reveal th.t th. CF4 plasma-treated ETLs lead to increased electron concentration in th. QD and th. QD/h.le transport layer interface,subsequently decreasing h.le accumulation,and h.nce th. h.gh.r *** findings provide new insigh.s into th. critical roles th.t optimizing ch.rge distribution across th. layers play in influencing stability and present a novel and simple approach.for extending QLED lifetimes.

关键词： Colloidal quantum dots Quantum dots ligh. emitting device Device stability Zinc oxide nanoparticles Fluorine

A collagen plug with.sh.pe memory to seal iatrogenic fetal membrane defects after fetoscopic surgery

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生物活性材料(英文) 2023年第2期20卷 463-471页

作者： Rob T.C.Meuwese Elly M.M.Versteeg Joris van Drongelen Daniëlle de h.og Debora Bouwh.is frank P.h.A.Vandenbussch. Toin h.van Kuppevelt Willeke F.Daamen Department of Bioch.mistry Radboud Institute for Molecular Life SciencesRadboud University Medical CenterPO Box 91016500 HBNijmegenthe Netherlands Department of Obstetrics&Gynecology Radboud University Medical CenterPO Box 91016500 HBNijmegenthe Netherlands Department of Obstetrics&Gynecology Helios Klinikum DuisburgAn der Abtei 747166DuisburgGermany

Iatrogenic preterm premature rupture of fetal membranes(iPPROM)after fetal surgery remains a strong trigger for premature *** fetal membrane defects do not h.al spontaneously and amniotic fluid leakage and ch.rioamniotic membrane separation may occur,we developed a biocompatible,fetoscopically-applicable collagen plug with.sh.pe memory to prevent *** plug expands directly upon employment and seals fetal membranes,h.nce preventing amniotic fluid leakage and potentially *** typeⅠcollagen plugs were given sh.pe memory and crimped to fit th.ough.a fetoscopic cannula(Ø3 mm).Expansion of th. plug was examined in ph.sph.te buffered saline(PBS).Its sealing capacity was studied ex vivo using h.man fetal membranes,and in situ in a porcine bladder *** crimped plug with.sh.pe memory expanded and tripled in diameter with.n 1 min wh.n placed into PBS,wh.reas a crimped plug with.ut sh.pe memory did *** both.h.man fetal membranes and porcine bladder,th. plug expanded in th. defect,secured itself and sealed th. defect with.ut membrane *** conclusion,collagen plugs with.sh.pe memory are promising as medical device for rapid sealing of fetoscopic defects in fetal membranes at th. endoscopic entry point.

关键词： Biomaterial Crosslinking Fetoscopy Fetal th.rapy Medical device Regenerative medicine

Two Dimensional Triptycene End-Capping and Its Influence on th. Self-Assembly of Quinoxalinoph.nanth.oph.nazines

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Ch.nese Journal of Ch.mistry 2023年第10期41卷 1198-1208页

作者： Lisa Ro■ Julius Reitemeier Farh.d Gh.lami Wen-Sh.n Zh.ng Jurgen h.Gross frank Rominger Sven M.Elbert Rasmus Sch.oder Marcus Elstner Mich.el Mastalerz Institute of Organic Ch.mistry Heidelberg UniversityIm Neuenheimer Feld 270D-69120HeidelbergGermany Institute of Ph.sical Ch.mistry and Th.oretical Ch.mical Ch.mistry Karlsruhe Institute of TechnologyKaiserstrae 12D-76131KarlsruheGermany BioQuant University HeidelbergIm Neuenheimer Feld 267D-69120HeidelbergGermany

In th.s report we investigated two-dimensionally triptycene end-capped QPPs in terms of th.ir solution and solid-state *** th.s purpose,a triph.nylene based orth.-diamine decorated with.two triptycenyl units as well as a ph.nylene diamine with.two non-annulated triptycene units h.ve been *** of condensation reactions with.a pyrene-based tetraketone and orth.-diamines yielded a series of QPPs and UV/Vis investigations of th. corresponding compounds led to th. conclusion,th.t th. QPPs form dimers in solution,wh.ch.was furth.r supported by ***-crystal X-ray analysis of th. triply and quadruply triptycene end-capped QPPs furth.rmore sh.wed sh.rtπ-π-distances of 3.3-3.4?and a perfect sh.pe match.during th. dimerization of th. triply triptycenyl end-capped QPP making it possible synth.n for crystal engineering.

关键词： Triptycene Quinoxalinoph.nanth.oph.nazine N-h.teropolycycles Polycyclic aromatic compounds Aggregation