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Drag reduction behavior of hydrolyzed polyacrylamide/xanthan gum mixed polymer solutions

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Petroleum Science 2017年第2期14卷 412-423页

作者： Mehdi Habibpour peter e. clark School of Chemical engineering Oklahoma State University Stillwater OK 74078 USA

Partially hydrolyzed polyacrylamide（HPAM）as the main component of slickwater fracturing fluid is a shear-sensitive polymer,which suffers from mechanical degradation at turbulent flow *** different concentrations of HPAM as well as mixtures of polyacrylamide/xanthan gum were prepared to investigate the possibility of improving shear stability of *** reduction（DR）measurements were performed in a closed flow *** HPAM solutions,the extent of DR increased from 30%to67%with increasing HPAM concentration from 100 to1000 *** the HPAM solutions suffered from mechanical degradation and loss of DR efficiency over the shearing *** indicated that the resistance to shear degradation increased with increasing polymer *** efficiency of 600 wppm xanthan gum（XG）was 38%,indicating that XG was not as good a drag reducer as *** with only 6%DR decline,XG solution exhibited a better shear stability compared to HPAM *** HPAM/XG solutions initially exhibited greater DR（40%and 55%）compared to XG,but due to shear degradation,DR%dropped for HPAM/XG *** to 200 wppm HPAM solution,addition of XG did not improve the drag reduction efficiency of HPAM/XG mixed solutions though XG slightly improved the resistance against mechanical degradation in HPAM/XG mixed polymer solutions.

关键词： Slickwater Polyacrylamide Xanthan gum Drag reduction Shear stability

Late Paleozoic–early Mesozoic tectonic evolution of the Zongwulong Shan-Qinghai Nanshan tectonic belt in the northern Qaidam continent， northern Tibet

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Journal of earth Science 2025年

作者： Yonghui Zhao Chen Wu Jie Li peter J.Haproff Lin Ding State Key Laboratory of Tibetan Plateau earth System and Resources environment (TPeSRe)， Institute of Tibetan Plateau Research， Chinese Academy of Sciences University of Chinese Academy of Sciences Chongqing Key Laboratory of Complex Oil and Gas Field exploration and Development， Chongqing University of Science and Technology Department of earth and Ocean Sciences， University of North Carolina Wilmington

The Zongwulong Shan-Qinghai Nanshan tectonic belt of the northern Tibet Plateau experienced a protracted tectonic history， including the openings and closures of the Proto- and Paleo-Tethyan Oceans. Although the tectonic belt has been extensively studied， details regarding the tectonic processes involved in its development remain controversial. To better constrain the tectonic processes of this tectonic belt， we conducted detailed field geological mapping， zircon U-Pb geochronology， and whole-rock geochemical and Sr-Nd isotopic analyses. Our results show that intrusive rocks in the tectonic belt crystallized in ca. 292–233 Ma， perhaps in an arc/subduction setting. Geochemical and Sr-Nd isotopic data suggest that early Permian–late Triassic ultramafic-intermediate intrusions were sourced from the enriched mantle， whereas intermediate-acidic rocks were sourced from mixed crust-mantle. We present the tectonic model that involves: (1) early Devonian–early Permian intracontinental extension occurred in the northern margin of the Qaidam continent (ca. 416 Ma–292 Ma); (2) early Permian–late Triassic northward subduction of the Paleo-Tethyan Ocean resulted in arc magmatism (ca. 292 Ma–233 Ma); and (3) subsequent late Triassic intracontinental extension (ca. 233 Ma–215 Ma). Our results suggest that the late Paleozoic–early Mesozoic development of the Zongwulong Shan-Qinghai Nanshan was related to the opening， subduction， and slab retreat of the Paleo-Tethyan Ocean， which has key implications for the tectonic evolution of the northern Tibetan Plateau.

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Immunohistochemical assessment of NY-eSO-1 expression in esophageal adenocarcinoma resection specimens

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World Journal of Gastroenterology 2014年第14期20卷 4011-4016页

作者： Stephen J Hayes Keng Ngee Hng peter clark Fiona Thistlethwaite Robert e Hawkins Yeng Ang Department of Histopathology Salford Royal NHS Foundation Trust Faculty of Medical and Human Sciences University of Manchester Department of Gastroenterology Salford Royal NHS Foundation Trust Department of Medical Oncology The Christie NHS Foundation Trust Department of Medical Oncology Paterson Institute of Cancer ResearchUniversity of Manchester

AIM: To assess NY-eSO-1 expression in a cohort of esophageal adenocarcinomas.

关键词： esophageal adenocarcinoma Immunohistochemistry NY-eSO-1 Stem cells Vesicle trafficking

Learning causality and causality-related learning:some recent progress

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National Science Review 2018年第1期5卷 26-29页

作者： Kun Zhang Bernhard Scholkopf peter Spirtes clark Glymour Department of Philosophy Carnegie Mellon University Max Planck Institute for Intelligent Systems

INTRODUCTION Causality is a fiundamental notion in science,and plays an important role in explanation,prediction,decision making and ***,with the rapidaccumulation of huge volumes of data,it is even more desirable to abstract causal knowledge from ***,such data are usually time series measured over a relatively long time period or ag-

关键词： Learning causality and causality-related learning:some recent progress FCI

Low temperature microwave-assisted vs conventional pyrolysis of various biomass feedstocks

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Journal of Natural Gas Chemistry 2012年第3期21卷 270-274页

作者： peter Shuttleworth Vitaliy Budarin Mark Gronnow James H.clark Rafael Luque Green Chemistry Centre of excellence University of YorkHeslingtonYO10 5DD YorkUK Departamento de Química Orgnica Universidad de CórdobaCampus de Excelencia Agroalimentario ceiA3Edif icio Marie Curie(C-3)Ctra Nnal IVKm 396E-14014CórdobaSpain

A comparison between conventional pyrolysis and a novel developed low-temperature microwave-assisted pyrolysis methodology has been performed for the valorisation of a range of biomass feedstocks including waste residues. Microwave pyrolysis was found to efficiently deliver comparable evolution of bio-gases in the system as compared with conventional pyrolysis at significantly reduced temperatures （120-180 ℃vs 250-400 ℃）. The gas obtained from microwave-assisted pyrolysis was found to contain CO2, CH4 and CO as major components as well

关键词： microwave-assisted pyrolysis biomass valorisation gas production

Reappraising the P-T evolution of the Rogaland-Vest Agder Sector,southwestern Norway

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Geoscience Frontiers 2017年第1期8卷 1-14页

作者： eleanore Blereau Tim e.Johnson Chris clark Richard J.M.Taylor peter D.Kinny Martin Hand Department of Applied Geology The Institute for Geoscience Research(TIGeR)Curtin University Centre for Tectonics Resources and Exploration(TRaX)School of Earth and Environmental SciencesUniversity of Adelaide

The Rogaland-Vest Agder Sector of southwestern Norway comprises high-grade metamorphic rocks intruded by voluminous plutonic bodies that include the ~1000 km^2 Rogaland Igneous Complex（RIC）.New petrographic observations and thermodynamic phase equilibria modelling of three metapelitic samples collected at various distances（30 km,10 km and ~ 10 m） from one of the main bodies of RIC anorthosite were undertaken to assess two alternative P-T-t models for the metamorphic evolution of the *** results are consistent with a revised two-phase *** metamorphism followed a clockwise P-T path reaching peak conditions of ~ 850-950 ℃ and ~7-8 kbar at ~1035 Ma followed by high-temperature decompression to ~5 kbar at ~950 Ma,and resulted in extensive anatexis and melt loss to produce highly residual *** emplacement of the RIC at ~930 Ma caused regional-scale contact metamorphism that affected country rocks 10 km or more from their contact with the *** thermal overprint is expressed in the sample proximal to the anorthosite by replacement of sillimanite by coarse intergrowths of cordierite plus spinel and growth of a second generation of garnet,and in the intermediate（10 km） sample by replacement of sapphirine by coarse intergrowths of cordierite,spinel and *** formation of late biotite in the intermediate sample may suggest the rocks retained small quantities of melt produced by regional metamorphism and remained at temperatures above the solidus for up to 100 *** results are more consistent with an accretionary rather than a collisional model for the Sveconorwegian Orogen.

关键词： UHTPhase equilibria modellingRogaland Igneous ComplexTHeRMOCALCSveconorwegian Orogen

electrically pumped quantum-dot lasersgrownon 300 mm patterned Si photonic wafers

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Light(Science & Applications) 2022年第11期11卷 2698-2705页

作者： Chen Shang Kaiyin Feng eamonn THughes Andrew clark Mukul Debnath Rosalyn Koscica Gerald Leake Joshua Herman David Harame peter Ludewig Yating Wan John e.Bowers Materials Department University of California Santa BarbaraSanta BarbaraCA 93106USA Department of electrical and Computer engineering University of California Santa BarbaraSanta BarbaraCA 93106USA OQe IncGreensboroNC 27409USA RF SUNY Polytechnic Institute AlbanyNY 12203USA NAsPIII/NV GmbH MarburgGermany

Monolithic integration of quantum dot(QD)gain materials onto Si photonic platforms via direct epitaxial growth is a promising solution for on-chip light *** developments have demonstrated superior device reliability in blanket hetero-epitaxy ofⅡ-Ⅴdevices on Si at elevated ***,thick,defect management epi designs prevent vertical light coupling from the gain region to the Si-on-lnsulator ***,we demonstrate the frst electrically pumped QD lasers grown by molecular beam epitaxy on a 300 mm patterned(001)Si wafer with a buttcoupled *** growth and fabrication challenges imposed by the template architecture have been resolved,contributing to continuous wave lasing to 60℃and a maximum double-side output power of 126.6 mW at 20℃with a double-side wall-plug efficiency of 8.6%.The potential for robust on-chip laser operation and effcient lowloss light coupling to Si photonic circuits makes this heteroepitaxial integration platform on Si promising for scalable and low-cost mass production.

关键词： pumped quantum coupling

Blind spots in climate finance for innovation peter WARReN

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Advances in Climate Change Research 2020年第1期11卷 60-64页

作者： peter WARReN School of Public Policy University College London(UCL)LondonWCIH 9QUUK

International climate finance is a sub-set of green finance and refers to investments specifically in climate change mitigation and adaptation activities,which primarily involve public finance and the leveraging of private finance in developing *** addition to continued international support for scaling low carbon solutions and facilitating replicability in developing countries,there remains an important need to increase the amount of climate finance provided to innovation,particularly demonstration(for technology innovation)and pilot implementation(for policy innovation),and to channel a greater proportion of Official Development Assistance(ODA)to‘hard-to-abate'areas,such as industrial decarbonisation,international transport and cross-sectoral issues like cooling and behavioural insights,to accelerate the commercialisation and implementation of technological,linancial and policy solutions to contribute to meeting the Paris Agreement's goal of limiting global warming to‘well-below'2℃ in these *** research,development and demonstration(RD&D)support with technical assistance is important in providing the route to obtain wider donor finance(concessional finance)and private finance to enable deployment through scalability and replicability.

关键词： Climate finance Climate policy Paris Agreement Official development assistance Industrial decarbonisation Sustainable cooling Behavioural insights International transport

Diverse plant mixtures sustain a greater arbuscular mycorrhizal fungi spore viability than monocultures after 12 years

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Journal of Plant ecology 2020年第4期13卷 478-488页

作者： peter Dietrich Christiane Roscher Adam Thomas clark Nico eisenhauer Bernhard Schmid Cameron Wagg Institute of ecology and evolution Friedrich-Schiller-University JenaDornburger Strasse 15907743 JenaGermany Department of evolutionary Biology and environmental Studies University of ZurichWinterthurerstrasse 1908057 ZurichSwitzerland Department of Physiological Diversity UFZHelmholtz Centre for Environmental ResearchPermoserstrasse 1504318 LeipzigGermany German Centre of Integrative Biodiversity Research(iDiv)Halle-Jena-Leipzig Deutscher Platz 5e04103 LeipzigGermany Institute of Biology Leipzig UniversityDeutscher Platz 5e04103 LeipzigGermany Department of Geography University of ZurichWinterthurerstrasse 1908057 ZurichSwitzerland Fredericton Research and Development Center Agriculture and Agri-Food Canada850 Lincoln RoadFrederictonNew Brunswick E3B 1P9Canada

Aims Intensive land management practices can compromise soil biodiversity,thus jeopardizing long-term soil *** mycorrhizal fungi(AMF)play a pivotal role in promoting soil productivity through obligate symbiotic associations with ***,it is not clear how properties of plant communities,especially species richness and composition influence the viability of AMF populations in *** Here we test whether monocultures of eight plant species from different plant functional groups,or a diverse mixture of plant species,maintain more viable AMF *** address this question,we extracted AMF spores from 12-year old plant monocultures and mixtures and paired single AMF spores with single plants in a factorial design crossing AMF spore origin with plant species *** Findings AMF spores from diverse plant mixtures were more successful at colonizing multiple plant species and plant individuals than AMF spores from plant ***,we found evidence that AMF spores originating from diverse mixtures more strongly increased biomass than AMF from monocultures in the legume Trifolium repens *** viability and ability to interact with many plant species were greater when AMF spores originated from 12-year old mixtures than *** results show for the first time that diverse plant communities can sustain AMF viability in soils and demonstrate the potential of diverse plant communities to maintain viable AMF propagules that are a key component to soil health and productivity.

关键词： aboveground–belowground interactions biodiversity biomass production mutualism plant–AMF interaction root colonization