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Refnement of the supercontinent cycle with Hf, Nd and Sr isotopes

Geoscience Frontiers 2013年第6期4卷 667-680页

作者： Kent c.condie richard c.aster Department of Earth and Environmental Science New Mexico Institute of Mining and Technology Geosciences Department Colorado State University

The combined use of Hf,Nd and Sr isotopes is more useful in understanding the supercontinent cycle than the use of only Hf isotopic data from detrital *** and Nd seawater isotopes,although not as precise as εNd and εHf distributions,also record input from ocean ridge *** detrital zircons where sources cannot be precisely located because of crustal recycling,both the location and tectonic setting often can be constrained for whole-rock Nd isotopic ***,primary zircon sources may not reside on the same continent as derivative detrital zircons due to supercontinent breakup and *** to all of the isotopic studies are geographic sampling biases reflecting outcrop distributions,river system sampling,or geologists,and these may be responsible for most of the decorrelation observed between isotopic *** between 3.5 and 2 Ga based on εHf median values of four detrital zircon databases as well as our compiled εNd database are noisy but uniformly distributed in time,whereas data between 2 and 1 Ga data are more tightly clustered with smaller *** age peaks suggest that both isotopic systems are sampling similar types of *** after 1 Ga and before 3.5 Ga do we see wide variations and significant disagreement between databases,which may partially reflect variations in both the number of sample locations and the number of samples per *** and internal orogens show similar patterns in εNd and εHfwith age suggesting that both juvenile and reworked crustal components are produced in both types of orogens with similar ***,both types of orogens clearly produce more juvenile isotopic signatures in retreating mode than in advancing *** secular changes in εHf and εNd distributions correlate with the supercontinent *** supercontinent breakup is correlated with short-lived decreasing εHf and εNd （≤ 100 Myr） for most supercontinents,there is no isotopic evidence for

关键词： Supercontinent cycle Hf isotopes Nd isotopes collisional orogens Accretionary orogens

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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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Smart cutting Tools and Smart Machining: Development Approaches, and Their Implementation and Application Perspectives

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chinese Journal of Mechanical Engineering 2017年第5期30卷 1162-1176页

作者： Kai cheng Zhi-chao Niu Robin c.Wang richard Rakowski richard Bateman college of Engineering Design and Physical SciencesBrunel University London

Smart machining has tremendous potential and is becoming one of new generation high value precision manufacturing technologies in line with the advance of Industry 4.0 concepts. This paper presents some innovative design concepts and, in particular, the development of four types of smart cutting tools, including a force-based smart cutting tool, a temperature-based internally-cooled cutting tool, a fast tool servo （FTS） and smart collets for ultra- precision and micro manufacturing purposes. Implemen- tation and application perspectives of these smart cutting tools are explored and discussed particularly for smart machining against a number of industrial application requirements. They are contamination-free machining, machining of tool-wear-prone Si-based infra-red devices and medical applications, high speed micro milling and micro drilling, etc. Furthermore, implementation tech- niques are presented focusing on：（a） plug-and-produce design principle and the associated smart control algo- rithms, （b） piezoelectric film and surface acoustic wave transducers to measure cutting forces in process, （c） critical cutting temperature control in real-time machining, （d） in- process calibration through machining trials, （e） FE-based design and analysis of smart cutting tools, and （f） applica- tion exemplars on adaptive smart machining.

关键词： Smart cutting tool Smart machining Fast toolservo (FFS) Precision machining Micro manufacturing Smart tooling

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Transcriptomic biomarkers for predicting response to neoadjuvant treatment in oesophageal cancer

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Gastroenterology Report 2020年第6期8卷 411-424,I0001页

作者： Anita Lavery richard c.Turkington Patrick G Johnston centre for cancer Research Queen’s University BelfastBelfastUK

Oesophageal cancer is a devastating disease with poor outcomes and is the sixth leading cause of cancer death *** the setting of resectable disease,there is clear evidence that neoadjuvant chemotherapy and chemoradiotherapy result in improved ***,only 15%-30%of patients obtain a histopathological response to neoadjuvant therapy,often at the expense of significant *** are no predictive biomarkers in routine clinical use in this setting and the ability to stratify patients for treatment could dramatically improve *** this review,we aim to outline current progress in evaluating predictive transcriptomic biomarkers for neoadjuvant therapy in oesophageal cancer and discuss the challenges facing biomarker development in this *** place these issues in the wider context of recommendations for biomarker development and *** majority of studies focus on messenger RNA(mRNA)and microRNA(miRNA)*** studies report a range of different genes involved in a wide variety of pathways and biological processes,and this is explained to a large extent by the different platforms and analysis methods *** studies are also vastly underpowered so are not suitable for identifying a candidate *** molecular subtypes of oesophageal cancer have been proposed,although little is known about how these relate to clinical *** anticipate that the accumulating wealth of genomic and transcriptomic data and clinical trial collaborations in the coming years will provide unique opportunities to stratify patients in this poor-prognosis disease and recommend that future biomarker development incorporates well-designed retrospective and prospective analyses.

关键词： oesophageal cancer predictive biomarkers chemotherapy radiotherapy gene expression pathological response

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Developing Skin Analogues for a Robotic Octopus

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Journal of Bionic Engineering 2012年第3期9卷 385-390页

作者： Jinping Hou richard H. c. Bonser George Jeronimidis centre for Biomimetics School of Construction Management and Engineering University of Reading Reading RG6 6AY UK School of Engineering and Design Brunel University Uxbridge Middlesex UB8 3PH UK

In order to fabricate a biomimetic skin for an octopus inspired robot, a new process was developed based on mechanical properties measured from real octopus skin. Various knitted nylon textiles were tested and the one of 10-denier nylon was chosen as reinforcement. A combination of Ecoflex 0030 and 0010 silicone rubbers was used as matrix of the composite to obtain the right stiffness for the skin-analogue system. The open mould fabrication process developed allows air bubble to escape easily and the artificial skin produced was thin and waterproof. Material properties of the biomimetic skin were char- acterised using static tensile and instrumented scissors cutting tests. The Young＇s moduli of the artificial skin are 0.08 MPa and 0.13 MPa in the longitudinal and transverse directions, which are much lower than those of the octopus skin. The strength and fracture toughness of the artificial skin, on the other hand are higher than those of real octopus skins. conically-shaped skin prototypes to be used to cover the robotic arm unit were manufactured and tested. The biomimetic skin prototype was stiff enough to maintain it conical shape when filled with water. The driving force for elongation was reduced significantly compared with previous prototypes.

关键词： biomimetic skin artefact octopus robot textile composite

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Design of a Biomimetic Skin for an Octopus-Inspired Robot - Part I： characterising Octopus Skin

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Journal of Bionic Engineering 2011年第3期8卷 288-296页

作者： Jinping Hou richard H. c. Bonser George Jeronimidis centre for Biomimetics School of Construction Management and Engineering University of Reading Reading RG6 6AY UK

Octopus skin samples were tested under quasi-static and scissor cutting conditions to measure the in-plane material prop- erties and fracture toughness. Samples from all eight arms of one octopus were tested statically to investigate how properties vary from arm to arm. Another nine octopus skins were measured to study the influence of body mass on skin properties. In- fluence of specimen location on skin mechanical properties was also studied. Material properties of skin, i.e. the Young＇s modulus, ultimate stress, failure strain and fracture toughness have been plotted against the position of skin along the length of arm or body. Statistical studies were carried out to help analyzing experimental data obtained. Results of this work will be used as guidelines for the design and development of artificial skins for an octopus-inspired robot.

关键词： octopus skin uniaxial tension scissor cutting Young's modulus failure strain fracture toughness

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Design of a Biomimetic Skin for an Octopus-Inspired Robot - Part Ⅱ： Development of the Skin Artefact

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Journal of Bionic Engineering 2011年第3期8卷 297-304页

作者： Jinping Hou richard H. c. Bonser George Jeronimidis centre for Biomimetics School of Construction Management and Engineering UniversiO~ of Reading Reading RG6 6A Y UK

In order to develop skin artefact for an octopus-inspired robot arm, which is designed to be able to elongate 60% of its original length, silicone nlbber and knitted nylon sheet were selected to manufacture an artificial skin, due to their higher elastic strain and high flexibility. Tensile and scissors cutting tests were conducted to characterise the matrix and reinforcing materials and the skin artefact. Material properties of the individual and the composite materials were compared with the measured properties of real octopus skin presented ill Part I. The Young＇s modulus of the skin should be below 20 MPa and the elastic strain range should be over 60%. The fracture toughness should be at least 0.9 kJ.m 2. Tubes made of the skin artefact filled with liquid were tested to study volume change under deformation. Finite element analysis model was developed to simulate the material and arm structure under tensile loading. Results show that the skin artefact developed has similar mechanical properties as the real octopus skin and satisfies all the design specifications of the OcTOPUS robot.

关键词： octopus skin static tensile test toughness skin artefact nylon/silicone composite

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Intraseasonal Variation of Visibility in Hong Kong

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Advances in Atmospheric Sciences 2017年第1期34卷 26-38页

作者： Wen ZHOU richard c.Y.LI Eric c.H.cHOW Guy carpenter Asia-Pacific climate Impact center School of Energy and EnvironmentCity University of Hong KongHong KongChina city University of Hong Kong Shenzhen Research Institute Shenzhen518057China

Visibility is one of the parameters for indicating air pollution. In this study, visibility variation in Hong Kong during summer and winter is investigated. Visibility in Hong Kong has clear intraseasonai variation. Examination of different environmental parameters suggests that the intraseasonal component dominates the overall circulation anomalies in both summer and winter. Associated with the intraseasonal variation of environmental parameters, obvious variation in visibility impair- ment is found in both summer and winter. In summer, local visibility and air quality are found to be significantly affected by the （MJO） and the 10-30-day intraseasonal oscillation （ISO） through modulation of associated atmospheric circulations. In winter, the modulation effects appear to be weaker due to the southward shift of the associated convection. The results in this study highlight the importance of the ISO in contributing to the overall variation in visibility in Hong Kong, and provide useful implications for the development of possible mitigation strategies associated with visibility impairment and air pollution in Hong Kong.

关键词： visibility intraseasonal oscillation air quality Hong Kong

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Influence of Tropical cyclones on Hong Kong Air Quality

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Advances in Atmospheric Sciences 2018年第9期35卷 1177-1188页

作者： Eric c.H.cHOW richard c.Y.LI Wen ZHOU city University of Hong Kong(Shenzhen)Research Institute Shenzhen 518057China Guy carpenter Asia-Pacific climate Impact center School of Energy and Environment City University of Hong KongHong KongChina

Tropical cyclones（Tcs） constitute one of the major atmospheric activities affecting the air quality of the Pearl River Delta region. In this study, the impact of Tcs on air quality in Hong Kong during the Tc active season（July–October） from 2000 to 2015 is investigated. It is found that 57.5% of days with concentration of particulate matter with an aerodynamic diameter 10 μm（PM（10）） above the 90th percentile are related to Tc activity. Tcs in three regions, located to the east, southeast, and southwest of Hong Kong, have obvious impacts on pollutant concentration. When Tcs are located east of Hong Kong near Taiwan, 65.5%/38.7% of the days have high or extremely high PM（10）/ozone（O3） levels, which are associated with northerly wind, sinking motion, and relatively low precipitation. When Tcs are located southeast of Hong Kong, 48.1%/58.2% of the days have high pollution levels, associated mainly with continental air mass transport. When Tcs are south or west of Hong Kong, only 20.8%/16.9% of the days have high PM（10）/O3 levels, and the air quality in Hong Kong is generally good or normal due to Tc-associated precipitation, oceanic air mass transport, and an enhanced rising motion. The higher chance of high O3 days when Tcs are present between Hong Kong and Taiwan, possibly due to lower-than-normal precipitation along the east coast of china under Tc circulation. The results in this study highlight the important influence of Tc position and associated atmospheric circulations on the air quality in Hong Kong.

关键词： PM10 03 air quality HK Tc

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Going visible:high-resolution coherent Raman imaging of cells and tissues

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Light(Science & Applications) 2019年第1期8卷 1089-1090页

作者： richard c.Prince Eric O.Potma Department of Biomedical Engineering University of CaliforniaIrvineCA 92697USA Department of chemistry University of CaliforniaIrvineCA 92697USA

A simple change of light source might prove what is needed for high-resolution label-free mapping of thin biological samples.

关键词： resolution visible coherent

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