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Palaeozoic stromatoporoid futures:A discussion of their taxonomy,mineralogy and applications in palaeoecology and palaeoenvironmental analysis

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Journal of Palaeogeography 2013年第2期2卷 163-182页

作者： steve Kershaw Institute for the Environment Halsbury BuildingBrunel UniversityUxbridgeMiddlesexUB8 3PHUK

Palaeozoic stromatoporoids are calcified sponges common between Middle Ordovician and Late Devonian times in reefs and related *** work is well known,but controversial because of conflict between classification schemes based on the calcareous skeleton versus spicules(which are almost completely lacking in Palaeozoic stromatoporoids);however,lower-level taxonomy(at genus-level) of the calcareous skeleton is considered reliable to be applied in palaeobiological *** of stromatoporoid ecology is poorly developed,such that comprehensive information is available for only a few case studies,in some Silurian and Devonian *** an overall understanding of stromatoporoid responses to environmental conditions has not yet been achieved,although stromatoporoids were likely able to deal with fine grained sediment where they mostly *** stromatoporoid genera have only certain growth forms,so future focus on the use of low-level taxonomy in ecological studies,by comprehensive sampling in high-resolution studies,may establish the relationships between stromatoporoids and their *** organisms and growth banding in stromatoporoids are aspects that have great potential in such *** of stromatoporoids remains poorly *** of their apparent state of preservation(ranging from apparently well-preserved to complete loss of calcareous skeleton features) all stromatoporoids are in fact substantially *** underwent a peculiar diagenesis,whereby the calcareous skeleton and gallery cements of all stromatoporoids are overprinted by irregular elongated calcite crystals arranged normal to the growth laminations,most clearly visible in cross-polarized *** cooccur with mollusc shells that are always either fully recrystallized or dissolved(present as internal and external moulds);this difference means that while molluscs are likely under-represented in the fossil record,stromatoproids

关键词： stromatoporoid Palaeozoic palaeoecology taxonomy biomineralogy *

The benefits and dangers of using artificial intelligence in petrophysics

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Artificial Intelligence in Geosciences 2021年第1期2卷 1-10页

作者： steve Cuddy Petrophysicist Petro-InnovationsAberdeenScotlandUnited Kingdom

Artificial Intelligence,or AI,is a method of data analysis that learns from data,identify patterns and makes predictions with the minimal human *** is bringing many benefits to petrophysical *** case studies,this paper describes several successful *** future of AI has even more ***,if used carelessly there are potentially grave consequences.A complex Middle East Carbonate field needed a bespoke shaly water saturation *** was used to‘evolve’an ideal equation,together with field specific saturation and cementation *** UKCS gas field had an‘oil problem’.Here,AI was used to unlock the hidden fluid information in the NMR T1 and T2 spectra and successfully differentiate oil and gas zones in real time.A North Sea field with 30 wells had shear velocity data(Vs)in only 4 *** was required for reservoir modelling and well bore stability *** was used to predict Vs in all 30 *** high vertical resolution data,the Vs predictions were even better than the recorded *** it is not economic to take core data on every well,AI is used to discover the relationships between logs,core,litho-facies and permeability in multi-dimensional data *** a consequence,all wells in a field were populated with these data to build a robust reservoir *** addition,the AI predicted data upscaled correctly unlike many conventional *** gives impressive results when automatically log quality controlling(LQC)and repairing electrical logs for bad hole and sections of missing *** doesn’t require prior knowledge of the petrophysical response equations and is *** are no parameters to pick or cross-plots to *** is very little user intervention and AI avoids the problem of‘garbage in,garbage out’(GIGO),by ignoring noise and *** programs work with an unlimited number of electrical logs,core and gas chromatography data;and don’t‘fall-over’if some of those inp

关键词： Artificial intelligence Fuzzy logic Petrophysics

Introduction to Visual Surveillance of Dynamic Scenes

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自动化学报 2003年第3期29卷 319-320页

作者： steve Maybank DepartmentofComputerScience

Hybrids withouthybridization-can it revolutionize horticulture?

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Horticulture Research 2018年第1期5卷 1-3页

作者： steve van Nocker Michigan State University MichiganUSA

The often-cited idiom“The apple doesn’t fall far from the tree”refers to the occasional striking similarity in appearance or behavior between a human parent and ***,in heterozygous organisms—be it human or apple—strong similarity in multiple traits across generations tends to be the ***,the phenomenon of genetic segregation ensures that off-spring show *** this can be advantageous in nature,it poses numerous problems for horticulture and plant agriculture in general,as the perpetual need to reproduce high-performing hybrids through crossing of parental genotypes,as well as the clonal vegetative propagation of elite hybrid cultivars,involves expensive and time consuming procedures.A recent study by Khanday and colleagues,published 12 December in the journal Nature 1,combined the characterization of a mechanism that triggers embryogenesis in the absence of fertilization。

关键词： culture similarity journal

The Commutator of the Kato Square Root for Second Order Elliptic Operators on R^n

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Acta Mathematica Sinica,English Series 2016年第10期32卷 1121-1144页

作者： Yan Ping CHEN Yong DING steve HOFMANN Department of Applied Mathematics School of Mathematics and PhysicsUniversity of Science and Technology Beijing School of Mathematical Sciences Beijing Normal UniversityLaboratory of Mathematics and Complex Systems(BNU)Ministry of Education Department of Mathematics University of Missouri

Let L = -div（AV） be a second order divergence form elliptic operator, and A be an accretive, n × n matrix with bounded measurable complex coefficients in R^n. We obtain the Lp bounds for the commutator generated by the Kato square root v/L and a Lipschitz function, which recovers a previous result of Calderon, by a different method. In this work, we develop a new theory for the commutators associated to elliptic operators with Lipschitz function. The theory of the commutator with Lipschitz function is distinguished from the analogous elliptic operator theory.

关键词： Commutator Kato square root Lipschitz function elliptic operators

Compacted graphite iron-A material solution for modern diesel engine cylinder blocks and heads

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China Foundry 2009年第3期6卷 241-246页

作者： steve Dawson SinterCast Sweden

The demands for improved fuel economy,performance and emissions continue to pose challenges for engine designers and the materials they choose. This is particularly true for modern diesel engines,where the primary path to achieving improved engine performance and emissions is to increase the Peak Firing Pressure in the combustion chamber. The resulting increase in thermal and mechanical loading has required a change from conventional grey cast iron to Compacted Graphite Iron (CGI) in order to satisfy durability requirements without increasing the size or the weight of the engines. With at least 75% higher tensile strength,45% higher stiffness and approximately double the fatigue strength of conventional grey cast iron,CGI satisfies durability requirements and also provides the dimensional stability required to meet emissions legislation throughout the life of the engine. Currently,there are no CGI diesel engines running on the roads in North America. This is set to change considerably as new commercial vehicle and pick-up SUV diesel engines are launched with CGI cylinder blocks in 2008 and 2009. These initial programs will provide over 2 million CGI diesel engines when ramped to mature volume,potentially accounting for 10%-15% of the North American passenger vehicle fleet within the next four years.

关键词： compacted graphite iron modern diesel engine performance emission cylinder blocks and heads

Projecting the global impact of fossil fuel production from the Former Soviet Union

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International Journal of Coal Science & Technology 2021年第6期8卷 1208-1226页

作者： steve Mohr Jianliang Wang James Ward Damien Giurco The University of Newcastle University DriveCallaghanNSW 2308Australia School of Business Administration China University of PetroleumBeijingChina Engineering and the Environment University of South AustraliaMawson Lakes CampusMawson Lakes BoulevardMawson LakesSA 5095Australia Institute for Sustainable Futures University of Technology SydneyUTS Building 10235 Jones St.UltimoNSW 2007Australia

Detailed projections of the Former Soviet Union(FSU)fossil fuel production has been *** production has been modelled at the region(oblast)level where *** projections were made using the Geologic Resource Supply-Demand Model(GeRS-DeMo).Low,Best Guess and High scenarios were *** fossil fuels are projected to peak between 2027 and 2087 with the range due to spread of Ultimately Recoverable Resources(URR)values *** Best Guess(BG)scenario anticipates FSU will peak in 2087 with production over 170 EJ per *** FSU projections were combined with rest of the world projections(Mohr et al.2015b),the emissions from the High scenario for the world are similar to the IPCC A1 AIM scenario.

关键词： Former Soviet Union Fossil Fuel Production Fossil Fuel Projection

Breeding better cultivars,faster:applications of new technologies for the rapid deployment of superior horticultural tree crops

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Horticulture Research 2014年第1期1卷 198-205页

作者： steve van Nocker Susan E Gardiner Department of Horticulture Michigan State UniversityEast LansingMI 48824 The New Zealand Institute for Plant&Food Research Limited Plant and Food Research Palmerston North Private Bag 11030 Manawatu Mail Centre Palmerston North4442New Zealand

Woody perennial plants,including trees that produce fruits and nuts of horticultural value,typically have long breeding cycles,and development and introduction of improved cultivars by plant breeders may require many breeding cycles and dozens of ***,recent advances in biotechnologies and genomics have the potential to accelerate cultivar development greatly in all *** mini-review summarizes approaches to reduce the number and the duration of breeding cycles for horticultural tree crops,and outlines the challenges that remain to implement these into efficient breeding pipelines.

关键词： cultivar breeding crops

PTOX Mediates Novel Pathways of Electron rransport in Etioplasts of Arabidopsis

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Molecular Plant 2016年第9期9卷 1240-1259页

作者： Sekhar Kambakam Ujjal Bhattacharjee Jacob Petrich steve Rodermel Department of Genetics Development and Cell Biology iowa State University 445 Bessey Hall Ames IA 50011 USA Department of Chemistry Iowa State University Ames IA 50011 USA

The immutans （im） variegation mutant of Arabidopsis defines the gene for PTOX （plastid terminal oxidase）, a versatile plastoquinol oxidase in chloroplast membranes. In this report we used im to gain insight into the function of PTOX in etioplasts of dark-grown seedlings. We discovered that PTOX helps control the redox state of the plastoquinone （PQ） pool in these organelles, and that it plays an essential role in etioplast metabolism by participating in the desaturation reactions of carotenogenesis and in one or more redox pathways mediated by PGR5 （PROTON GRADIENT REGULATION 5） and NDH （NAD（P）H dehydrogenase）, both of which are central players in cyclic electron transport. We propose that these elements couple PTOX with electron flow from NAD（P）H to oxygen, and by analogy to chlororespiration （in chloroplasts） and chromorespiration （in chromoplasts）, we suggest that they define a respiratory process in etioplasts that we have termed ＂etiorespiration＂. We further show that the redox state of the PQ pool in etioplasts might control chlorophyll biosynthesis, perhaps by participating in mechanisms of retrograde （plastid- to-nucleus） signaling that coordinate biosynthetic and photoprotective activities required to poise the etioplast for light development. We conclude that PTOX is an important component of metabolism and redox sensing in etioplasts.

关键词： immutans PTOX etiorespiration phytoene prochlorophyllide retrograde singnaling