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The onset of surface-enhanced Raman scattering for single-particle detection of submicroplastics

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Journal of Environmental Sciences 2022年第11期34卷 58-64页

作者： Cheng-Hao Lee james Kar-Hei Fang Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic UniversityKowloonHong Kong SARChina Institute of Textiles and Clothing The Hong Kong Polytechnic UniversityKowloonHong Kong SARChina Research Institute for Future Food The Hong Kong Polytechnic UniversityKowloonHong Kong SARChina State Key Laboratory of Marine Pollution City University of Hong KongKowloonHong Kong SARChina

Microplastics represent an emerging environmental problem worldwide, raising ecological and food safety concerns. Compared to microplastics, there is growing evidence of an even higher abundance of submicro-and nanoplastics in the environment, but a reliable monitoring method for detecting these smaller-sized plastics is lacking. Herein we presented the application of surface-enhanced Raman scattering(SERS) for this purpose. Particles of polystyrene(PS;600 nm) were used as the probe analyte. Gold nanourchins(Au NU;50 nm),i.e. urchin-shaped nanoparticles with irregular spikes around the core, were used as the SERS-active substrate. The effectiveness of SERS on PS was evaluated at a single-particle level with different numbers of Au NU in order to determine the minimum conditions required for the onset of the SERS effect. Our findings suggest that SERS of a single particle of PS can be induced by as few as 1–5 particles of Au NU, and that the use of excitation wavelength at 785 nm is appropriate to meet the red-shifted surface plasmon resonance of Au NU upon aggregation. These specifications provide additional information for the development of SERS-based tools for detecting plastic particles < 1 μm in food and environmental samples.

关键词： Microplastics Nanoplastics Gold nanourchins SERS Food contamination

A“Sequential Design of Simulations”approach for exploiting and calibrating discrete element simulations of cohesive powders

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Frontiers of Chemical Science and Engineering 2022年第6期16卷 874-885页

作者： Xizhong Chen Chunlei Pei james A.Elliott Department of Materials Science and Metallurgy University of CambridgeCambridge CB3 OFSUK Process and Chemical Engineering School of EngineeringUniversity College CorkCork T12 K8AFIreland Department of Chemical and Biological Engineering The University of SheffieldSheffield S102TNUK Key Laboratory for Green Chemical Technology of Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China

The flow behaviours of cohesive particles in the ring shear test were simulated and examined using discrete element method guided by a design of experiments methodology.A full factorial design was used as a screening design to reveal the effects of material properties of *** augmented design extending the screening design to a response surface design was constructed to establish the relations between macroscopic shear stresses and particle *** is found that the powder flow in the shear cell can be classified into four *** stress is found to be sensitive to particle friction coefficient,surface energy and Young’s modulus.A considerable fluctuation of shear stress is observed in high friction and low cohesion *** high cohesion regime,Young’s modulus appears to have a more significant effect on the shear stress at the point of incipient flow than the shear stress during the pre-shear *** predictions from response surface designs were validated and compared with shear stresses measured from the Schulze ring shear *** is found that simulations and experiments showed excellent agreement under a variety of consolidation conditions,which verifies the advantages and feasibility of using the proposed“Sequential Design of Simulations”approach.

关键词： discrete element method cohesive materials parameter calibration ring shear cell design of experiments

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[美]詹姆斯·赖特诗选

扬子江（诗刊） 2024年第3期 61-63页

作者：詹姆斯·赖特张文武(译) 不详

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缓解住房抵押贷款市场风险的宏观审慎政策

中国金融 2024年第2期 21-24页

作者：亚历山德拉·瓦拉迪詹姆斯·瓦德尔张林(译) 英格兰银行宏观金融风险局《中国金融》编辑部

英格兰银行金融政策委员会推出两项管控抵押贷款的政策工具,防止放贷机构降低审贷标准以及高负债家庭数量上升所引发的住房市场风险在英国,负责制定住房金融政策工具的宏观审慎监管机构是英格兰银行金融政策委员会(Financial Policy Com... 详细信息

英格兰银行金融政策委员会推出两项管控抵押贷款的政策工具,防止放贷机构降低审贷标准以及高负债家庭数量上升所引发的住房市场风险在英国,负责制定住房金融政策工具的宏观审慎监管机构是英格兰银行金融政策委员会(Financial Policy Committee,FPC)。FPC的主要职责是确保英国金融体系具备抵御各种风险的韧性,其中包括抵御来自英国抵押贷款市场的风险(注:本文的“抵押贷款”均指住房抵押贷款)。英格兰银行应对这些风险的政策工具十分丰富,既有针对购房自住抵押贷款的工具,也有针对购房出租抵押贷款的工具。

关键词：英格兰银行抵押贷款宏观审慎政策放贷机构住房市场高负债宏观审慎监管金融体系

Design of soft magnetic materials

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npj Computational Materials 2022年第1期8卷 17-26页

作者： Ananya Renuka Balakrishna Richard D.james Aerospace and Mechanical Engineering University of Southern CaliforniaLos AngelesCA90089USA Aerospace and Engineering Mechanics University of MinnesotaMinneapolisMN55455USA

We present a strategy for the design of ferromagnetic materials with exceptionally low magnetic hysteresis,quantified by *** this strategy,we use a micromagnetic algorithm that we have developed in previous research and which has been validated by its success in solving the“Permalloy Problem”—the well-known difficulty of predicting the composition 78.5%Ni of the lowest coercivity in the Fe–Ni system—and by the insight it provides into the“Coercivity Paradox”of ***,the design strategy predicts that cubic materials with large saturation magnetization ms and large magnetocrystalline anisotropy constant κ_(1) will have low coercivity on the order of that of Permalloy,as long as the magnetostriction constantsλ_(100),λ_(111)are tuned to special *** explicit prediction for a cubic material with low coercivity is the dimensionless number(c_(11)−c_(12))λ_(100)^(2)/(2_(κ_(1)))=81 for〈100〉easy *** results would seem to have broad potential application,especially to magnetic materials of interest in energy research.

关键词： magnetic cubic exceptional

Emergency Logistics Management for Hazardous Materials with Demand Uncertainty and Link Unavailability

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Journal of Systems Science and Systems Engineering 2023年第2期32卷 175-205页

作者： Ginger Y.Ke james H.Bookbinder Faculty of Business Administration Memorial University of NewfoundlandSt.John’sNewfoundland and LabradorA1B 3X5Canada Department of Management Sciences University of WaterlooWaterlooOntarioN2L 3G1Canada

Due to its harmful nature,any incident associated with hazardous material(hazmat)may cause tremendous impacts on the surrounding people and the *** on the incident involving this specific type of good,we develop a reliable and robust emergency logistics network that considers both demand uncertainty and possible unavailability of particular links.A time-based risk measure is carefully designed upon the traditional risk assessment to reflect the stakeholder’s sensitivity to risk over response *** disruption and uncertainty are modeled as two sets of scenarios which are integrated into a bi-objective robust model to evaluate the trade-offs between risk and *** effectiveness of the emergency response can be assured by expenditures that add extra capacities to certain links or establish additional facilities that aid recovery from *** apply our model and approach to a real-world network in Guangdong *** results reveal the necessity of embedding consideration of uncertainty and unreliability into emergency network design problems;outline the importance of hedging against unpredictability by system redundancies;and indicate the impact of stakeholder’s orientation towards cost and risk on the location,allocation,and routing decisions in hazmat emergency response.

关键词： Emergency response hazardous materials robust optimization link disruption emergency demand uncertainty

Habit(Extract)/William james

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英语学习 2022年第4期 59-62,72页

作者： William james 不详

Think about the following questions,and write down your answers before reading the essay.(1)What is the habit you want to remove most?When did you get into it?What have you done to remove it?Have you succeeded?(2)What... 详细信息

关键词： remove get think

Abiotic and biotic constituents of oil sands process-affected waters

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Journal of Environmental Sciences 2023年第5期127卷 169-186页

作者： Nora A.S.Hussain james L.Stafford Department of Biological Sciences University of AlbertaEdmontonAlberta T6G 2N8Canada

The oil sands in Northern Alberta are the largest oil sands in the world,providing an important economic resource for the Canadian energy *** extraction of petroleum in the oil sands begins with the addition of hot water to the bituminous sediment,generating oil sands process-affected water(OSPW),which is acutely toxic to *** of litres of OSPW are stored on oil sands mining leased sites in man-made reservoirs called tailings *** the volume of OSPW increases,concerns arise regarding the reclamation and eventual release of this water back into the *** is composed of a complex and heterogeneous mix of components that vary based on factors such as company extraction techniques,age of the water,location,and bitumen ore ***,the effective remediation of OSPW requires the consideration of abiotic and biotic constituents within it to understand short and long term effects of treatments *** review summarizes selected chemicals and organisms in these waters and their interactions to provide a holistic perspective on the physiochemical and microbial dynamics underpinning OSPW.

关键词： OSPW toxicants Reclamation Tailings ponds Remediation Microbial AOPs Bioremediation

Matrilinear hierarchy in the American black bear (Ursus americanus)

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Integrative Zoology 2022年第1期17卷 139-155页

作者： Benjamin KILHAM james R.SPOTILA Kilham Bear Center LymeNew HampshireUSA Department of Biodiversity Earth and Environmental ScienceDrexel UniversityPhiladelphiaPennsylvaniaUSA

The American black bear(Ursus americanus)was long thought to be solitary and its social organization has not been well ***,we present new data on black bear social *** objectives of the study were to make detailed observations of the behavior of wild black bears to determine their social interactions and *** tested whether black bears interacted socially beyond mating and competing for resources,if black bears tracked relationships and interacted regularly even when resources were not limited,and whether the social structure of a population of black bears was based on a matrilinear *** collected data by direct observation of bears from 1993 to *** of 1210 social interactions at a provisioning site indicated that females compete and form matrilinear *** bears established a hierarchy for food,control of space,and control of younger *** interaction scent marking took place,which suggested that dominant females were conditioning subordinates to their scent *** behavior occurred between related and unrelated bears and helped to establish the social structure of the bear *** on our data,human–bear conflicts can be reduced by behavioral modifications by humans when they encounter *** of bear behavior and the matrilinear hierarchy provide a basis for non-lethal management of bears that find themselves in a bear–human conflict situation.

关键词： bear matrilinear hierarchy New Hampshire rank social behavior Ursus