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A great thermal divergence in the mantle beginning 2.5 Ga:Geochemical constraints from greenstone basalts and komatiites

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Geoscience Frontiers 2016年第4期7卷 543-553页

作者： kent C.Condie Richard C.Aster Jeroen van Hunen Department of Earth and Environmental Science New Mexico Tech Geosciences Department Colorado State University Department of Earth Sciences University of Durham

Greenstone basalts and komatiites provide a means to track both mantle composition and magma generation temperature with time. Four types of mantle are characterized from incompatible element distributions in basalts and komatiites： depleted, hydrated, enriched and mantle from which komatiites are derived. Our most important observation is the recognition for the first time of what we refer to as a Great Thermal Divergence within the mantle beginning near the end of the Archean, which we ascribe to thermal and convective evolution. Prior to 2.5 Ga, depleted and enriched mantle have indistinguishable thermal histories, whereas at 2.5-2.0 Ga a divergence in mantle magma generation temperature begins between these two types of mantle. Major and incompatible element distributions and calculated magma generation temperatures suggest that Archean enriched mantle did not come from mantle plumes, but was part of an undifferentiated or well-mixed mantle similar in composition to calculated primitive mantle. During this time, however, high-temperature mantle plumes from dominantly depleted sources gave rise to komatiites and associated basalts. Recycling of oceanic crust into the deep mantle after the Archean may have contributed to enrichment ofTi, A1, Ca and Na in basalts derived from enriched mantle sources. After 2.5 Ga, increases in Mg# in basalts from depleted mantle and decreases in Fe and Mn reflect some combination of growing depletion and cooling of depleted mantle with time. A delay in cooling of depleted mantle until after the Archean probably reflects a combination of greater radiogenic heat sources in the Archean mantle and the propagation of plate tectonics after 3 Ga.

关键词： Archean greenstones Mantle thermal evolution Basalts Mantle geochemistry Komatiites

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Engineering a non-model yeast Rhodotorula mucilaginosa for terpenoids synthesis

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Synthetic and Systems Biotechnology 2024年第3期9卷 569-576页

作者： Qiongqiong Chen Liting Lyu Haizhao Xue Aabid Manzoor Shah Zongbao kent Zhao Laboratory of Biotechnology Dalian Institute of Chemical PhysicsCAS457 Zhongshan RoadDalian116023China MOE Key Laboratory of Bio-Intelligent Manufacturing School of BioengineeringDalian University of TechnologyDalian116024China University of Chinese Academy of Sciences 19 Yuquan RoadBeijing100049China

Terpenoids have tremendous biological activities and are widely employed in food,healthcare and pharmaceutical *** synthetic biology to product terpenoids from microbial cell factories presents a promising alternative route compared to conventional methods such as chemical synthesis or *** red yeast Rhodotorula mucilaginosa has been widely studied due to its natural production capacity of carotenoid and lipids,indicating a strong endogenous isoprene pathway with readily available metabolic *** study constructed several engineered strains of *** with the aim of producing different ***α-terpineol was produced by expressing theα-terpineol synthase from Vitis *** titer ofα-terpineol was further enhanced to 0.39 mg/L by overexpressing the endogenous rate-limiting gene of the MVA *** ofα-farnesene synthase from Malus domestica,in combination with MVA pathway rate-limiting gene resulted in significant increase inα-farnesene production,reaching a titer of 822 mg/*** carotenoid degradation productβ-ionone was produced at a titer of 0.87 mg/L by expressing theβ-ionone synthase from Petunia *** study demonstrates the potential of *** as a platform host for the direct biosynthesis of various terpenoids and provides insights for further development of such platforms.

关键词： Rhodotorula mucilaginosa Synthetic biology α-Terpineol β-Ionone α-Farnesene

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On the simulation of shared autonomous micro-mobility

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Communications in Transportation Research 2022年第1期2卷 104-115页

作者： Naroa Coretti Sanchez Inigo Martinez Luis Alonso Pastor kent Larson MIT Media Lab CambridgeMAUSA University of Navarra San SebastianSpain

Fast urbanization and climate change require innovative systems for an efficient movement of people and goods in *** trends towards vehicle-sharing,autonomous vehicles,and the use of micro-mobility systems gain strength,the intersection of these fields appears as an area of great *** could potentially bring the convenience of on-demand mobility into already prevalent shared micro-mobility systems(SMMS),increasing their efficiency and incentivizing more people to use active mobility *** novelty of introducing autonomous driving technology into SMMS and their inherent complexity requires tools to assess and quantify the potential impact of autonomy on fleet performance and user *** paper presents an ad-hoc agentbased simulator for the assessment of the fleet behavior of autonomous SMMS in realistic scenarios,including a rebalancing system based on demand *** also allows comparing its performance to station-based and dockless *** proposed simulation framework is highly configurable and flexible and works with high resolution and precision geospatial *** results of studies carried out with this simulation tool could provide valuable insights for many stakeholders,including vehicle design engineers,fleet operators,city planners,and governments.

关键词： Future mobility Autonomous vehicles Micro-mobility Agent-basedsimulation Multi-agentsystems

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Disbond detection with piezoelectric wafer active sensors in RC structures strengthened with FRP composite overlays

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Earthquake Engineering and Engineering Vibration 2003年第2期2卷 213-223页

作者： Victor Giurgiutiu kent Harries Michael Petrou Joel Bost Josh B.Quattlebaum Department of Mechanical Engineering University of South CarolinaUSA Associate Professor Department of Civil and Environmental Engineering University of South CarolinaUSA Assistant Professor Department of Civil and Environmental Engineering University of South CarolinaUSA Associate Professor Department of Mechanical Engineering University of South CarolinaUSA Undergraduate Research Assistant Department of Civil and Environmental Engineering University of South CarolinaUSA Graduate Research Assistant

The capability of embedded piezoelectric wafer active sensors(PWAS)to perform in-situ nondestructive evaluation(NDE)for structural health monitoring(SHM)of reinforced concrete(RC)structures strengthened with fiber reinforced polymer(FRP)composite overlays is ***,the disbond detection method were developed on coupon specimens consisting of concrete blocks covered with an FRP composite *** was found that the presence of a disbond crack drastically changes the electromecfianical(E/M)impedance spectrum lneasurcd at the PWAS *** spectral changes depend on the distance between the PWAS and the crack ***,large scale experiments were conducted on a RC beam strengthened with carbon fiber reinforced polymer(CFRP)composite *** beam was subject to an accelerated fatigue load regime in a three-point bending configuration up to a total of 807,415 *** these fatigue tests,the CFRP overlay experienced disbonding beginning at about 500,000 *** PWAS were able to detect the disbonding before it could be reliably seen by visual *** correlation between the PWAS readings and the position and extent of disbond damage was *** preliminary results demonstrate the potential of PWAS technology for SHM of RC structures strengthened with FRP composite overlays.

关键词： FRP composite overlays composite strengthening and rehabilitation structural health monitoring piezoelectric wafer active sensors E/M impedance aging infrastructure disbond damage PWAS

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Spectral characteristics of plant communities from salt marshes:A case study from Chongming Dongtan,Yangtze estuary,China

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Frontiers of Environmental Science & Engineering 2008年第2期2卷 187-197页

作者： Liquan ZHANG Zhanguo GAO Richard ARMITAGE Martin kent State Key Laboratory of Estuarine and Coastal Research East China Normal UniversityShanghai 200062China Environment Monitoring Center of Ningbo Ningbo 315012China Research Institute for the Built and Human Environment School of Environment and Life ScienceUniversity of SalfordSalford M54WTUK School of Geography University of PlymouthPlymouth PL48AAUK

The spectral reflectance of recently formed salt marshes at the mouth of the Yangtze River,which are undergoing invasion by Spartina alterniflora,were assessed to determine the potential utility of remotely sensed data in assessing future invasion and changes in species *** a review of published research on remote sensing of salt marshes,53 locations along three transects were sampled for paired data on plant species composition and spectral reflectance using a FieldSpecTM Pro JR Field Portable *** data were processed concerning reflectance,and the averaged reflectance values for each sample were reanalysed to correspond to a 12-waveband bandset of the Compact Airborne Spectral *** spectral data were summarised using principal components analysis(PCA)and the relationships between the vegetation composition,and the PCA axes of spectral data were *** first PCA axis of the reflectance data showed a strong correlation with variability in near infrared reflectance and‘brightness’,while the second axis was correlated with visible reflectance and‘greenness’.Total vegetation cover,vegetation height,and mudflat cover were all significantly related to the first *** implications of this in terms of the ability of remote sensing to distinguish the various salt marsh species and in particular the invasive species *** were *** differences in species with various physiognomies could be recognised but problems occurred in separating early colonising *** from other species at that *** work using multi-seasonal hyperspectral data might assist in solving these problems.

关键词： Chongming Dongtan of China salt marsh vegetation spectroradiometer compact airborne spectral imager(CASI) canopy reflectance indirect ordination

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On the performance of shared autonomous bicycles:A simulation study

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Communications in Transportation Research 2022年第1期2卷 116-151页

作者： Naroa Coretti Sanchez Inigo Martinez Luis Alonso Pastor kent Larson MIT Media Lab CambridgeMAUSA University of Navarra San SebastianSpain

As society faces global challenges such as population growth and climate change,rethinking cities is now more imperative than *** design of cities can not be abstracted from the design of their mobility ***,efficient solutions must be found to transport people and goods throughout the city efficiently and *** autonomous bicycle-sharing system would combine the most relevant benefits of vehicle-sharing,autonomy,and micro-mobility,increasing the efficiency and convenience of bicycle-sharing systems and incentivizing more people to bike and enjoy their cities in an environmentally friendly *** to the novelty of introducing autonomous driving technology into bicycle-sharing systems and their inherent complexity,there is a need to quantify the potential impact of autonomy on fleet performance and user *** paper presents the results of an agent-based simulation that provides an in-depth understanding of the fleet behavior of autonomous bicycle-sharing systems in realistic scenarios,including a rebalancing system based on demand *** addition,this work describes the impact of different parameters on system efficiency and service ***,it quantifies the extent to which an autonomous system would outperform current station-based and dockless bicycle-sharing *** obtained results show that with a fleet size three and a half times smaller than a station-based system and eight times smaller than a dockless system,an autonomous system can improve overall performance and user experience even with no rebalancing.

关键词： Future mobility Bicycle-sharing systems Autonomous vehicles Micro-mobility Agent-based simulation Multi-agent systems

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Effects of deformation twinning on the mechanical properties of biodegradable Zn-Mg alloys

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Bioactive Materials 2019年第1期4卷 8-16页

作者： Shiyang Liu Damon kent Nghiem Doan Matthew Dargusch Gui Wang School of Mechanical and Mining Engineering The University of QueenslandSt Lucia4072Australia Centre for Advanced Materials Processing and Manufacturing(AMPAM) The University of QueenslandSt Lucia4072Australia School of Science and Engineering University of the Sunshine CoastMaroochydoreDC4558Australia ARC Research Hub for Advanced Manufacturing of Medical Devices The University of QueenslandSt Lucia4072Australia School of Dentistry and Oral Health Griffith UniversityGold Coast4215Australia

To satisfy the property requirements for biodegradable medical implants,Zn alloyed with low levels of Mg(≤0.8 wt%)has attracted increased research *** the present study,deformation twinning was observed in tensile tests and twinning appears to have an adverse impact on *** profuse twinning in the as-cast Zn-Mg alloys accelerated crack growth in tension due to twinning impingement which caused local stress concentrations and initiates ***-rolled Zn-Mg alloys have better ductility than their as-cast counterparts due to the inhibition of twinning by the refined Mg2Zn11 intermetallic phase and the finer grain size.

关键词： Biodegradable metals Zn-Mg alloys Deformation twinning Mechanical properties Hot rolling

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RHEOLOGICAL CHARACTERISTICS,POWER CONSUMPTION,MASS AND HEAT,TRANSFER DURING XANTHAN GUM FERMENTATION

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Chinese Journal of Chemical Engineering 1994年第4期2卷 15-27页

作者：赵学明胡宗定 A.W.Nienow C.A.kent S.Chatwin Centre for Biochemical Engineering The University of BirminghamB15 2TTUK

Xanthan gum fermentation is probably the most complex fermentation process in terms ofrheological property variations and associated mixing,power consumption,mass and heat *** order to obtain these data,fermentations of Xanthomonas campestris were carried outon pilot scale bioreactor with different D/T ratios and different feeding strategies(batch andfed-batch).It was discovered that the rheology of xanthan fermentation broth is of paramountimportance to the above *** aerated power consumption and power number are both afunction of aeration rate during the initial stage of the fermentation when the viscosity is low andthe Reynolds number *** when the becames viscous and Reynolds unmber≤10~3,thegas velocity does not show any effect on the power *** oxygen mass transfer coefficientsand the overall heat transfer coefficients are both dependent on the impeller speed,the apparentviscosity of the broth and the D/T *** data taken from practical

关键词： xanthan fermentation rheology power consumption mass transfer heat transfer

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Risk profiles and outcomes of patients receiving antibacterial cardiovascular implantable electronic device envelopes:A retrospective analysis

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World Journal of Cardiology 2022年第3期14卷 177-186页

作者： David A Woodard Grace Kim kent R Nilsson Department of Cardiology Piedmont Heart InstituteAthensGA 30606United States Department of Medicine Augusta University-University of Georgia Medical PartnershipAthensGA 30606United States

BACKGROUND Cardiovascular implantable electronic devices(CIEDs)are implanted in an increasing number of patients each year,which has led to an increase in the risk of CIED *** CIED envelopes locally deliver antibiotics to the implant site over a short-term period and have been shown to reduce the risk of implant site *** envelopes are derived from either biologic or nonbiologic *** is a paucity of data examining patient risk profiles and outcomes from using these envelope materials in the clinical setting and comparing these results to patients receiving no envelope with their CIED *** To evaluate risk profiles and outcomes of patients who underwent CIED procedures with an antibacterial envelope or no *** After obtaining Internal Review Board approval,the records of consecutive patients who underwent a CIED implantation procedure by a single physician between March 2017 and December 2019 were retrospectively collected from our hospital.A total of 248 patients within this period were identified and reviewed through 12 mo of follow *** CIED procedures used either no envelope(n=57),a biologic envelope(CanGaroo®,Aziyo Biologics)that was pre-hydrated by the physician with vancomycin and gentamicin(n=89),or a non-biologic envelope(Tyrx^(TM),Medtronic)that was coated with a resorbable polymer containing the drug substances rifampin and minocycline by the manufacturer(n=102).Patient selection for receiving either no envelope or an envelope(and which envelope to use)was determined by the treating *** analyses were performed between the 3 groups(CanGaroo,Tyrx,and no envelope),and also between the No Envelope and Any Envelope groups by an independent,experienced *** On average,patients who received any envelope(biologic or non-biologic)were younger(70.7±14.0 vs 74.9±10.6,P=0.017),had a greater number of infection risk factors(81.2%vs 49.1%,P<0.001),received more high-

关键词： Cardiovascular implantable electronic device envelope Defibrillator Extracellular matrix Implantable cardioverter-defibrillator Infection Pacemaker

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On the Bifurcations and Multiple Endemic States of a Single Strain HIV Model Dedicated to Professor Toshikazu Sunada on the Occasion of his 60th Birthday

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Acta Mathematicae Applicatae Sinica 2014年第4期30卷 913-930页

作者： Lindley kent M.FAINA Lorna S.ALMOCERA Polly W.SY College of Arts and Sciences University of the Philippines Visayas Natural Sciences and Mathematics Division University of the Philippines VisayasCebu College Institute of Mathematics University of the Philippines

The dynamics of a single strain HIV model is studied. The basic reproduction number R0 used as a bifurcation parameter shows that the system undergoes transcritical and saddle-node bifurcations. The usual threshold unit value of R0 does not completely determine the eradication of the disease in an HIV infected person. In particular, a sub-threshold value Rc is established which determines the system＇s number of endemic states： multiple if Rc 〈 Ro 〈 1, only one if Rc=Ro = 1, and none if R0 〈 Rc 〈 1.

关键词： single strain HIV model multiple endemic states transcritical bifurcation s^idle-node bifurcation hysteresis

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