检索结果-南通市图书馆

Animal Nutrition 2024年第1期16卷 288-298页

作者： robert J.Moore School of Science RMIT UniversityBundooraVictoria 3083Australia

The global trend towards raising broiler chickens without the use of in-feed antibiotics(IFAs)means that there is an ongoing need to develop alternative treatments capable of delivering the benefits that IFAs previously *** supported the productivity performance of chickens and played a key role in maintaining their *** enteritis(NE)is an important disease of broilers that affects health,productivity,and welfare,and was previously well controlled by ***,with the reduction in IFA use,NE is resurgent in some *** and various feed additives,including pre-,pro-,and postbiotics,phytobiotics,fatty acids,and phage therapies have been introduced as alternative methods of NE *** some of these feed additives have specific activity against the NE pathogen,Clostridium perfringens,most have the more general goal of reinforcing gut *** reviews of the effects of many of these feed additives on gut health have been published ***,rather than cover previously well reviewed areas of research this review focuses on the challenges and pitfalls in undertaking experimental assessment of alternative NE treatments and translating laboratory research to real world commercial production *** review is based on the author's particular experience,reading,thoughts,and analysis of the available information and inevitably presents a particular understanding that is likely to be at odds with others thinking on these *** is put forward to stimulate thinking and discussion on the issues covered.

关键词： Necrotic enteritis Clostridium perfringens Vaccines Feed additive Farm management

Hydrologic Time Scale:A Fundamental Stream Characteristic

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2022年第5期33卷 1291-1297页

作者： robert E.Criss Department of Earth and Planetary Sciences Washington University in St.LouisSt.LouisMO63130USA

A new,fundamental catchment attribute called the hydrologic time scaleτgoverns the rate of delivery of runoff to a particular site,and is equal to∫Qdt/∫|dQ|,where Q is discharge and t is *** value ofτfor any gauged site is readily calculated from tabulated discharge data by replacing the integrals with *** quantity,coupled with the square root of catchment area,√A,form a coordinate pair that embodies the characteristic time and length scales for any catchment,which govern its flow *** fitting constants used in several unit hydrograph models are simple multiples ofτ,so knowledge ofτallows rapid calibration of these models for the particular site,facilitating flow prediction from rainfall *** ofτreflect many different landscape attributes,but for multiple sub-basins in watersheds with homogeneous land use and lithologic conditions,they correlate linearly with √*** ratio √A/τprovides a characteristic velocity that is high for channelized,floodprone rivers,for flashy urban streams with high impervious cover,and for sites downstream of hydropower *** with low velocities are resistant to flooding,as their landscapes have a greater ability to delay the delivery of runoff by retention,detention,and infiltration into the groundwater system.

关键词： unit hydrograph time constant flash floods impervious cover urban streams flashiness hydrogeology

A radical reinterpretation of the growth and form of the stromatolite Conophyton lituus(Maslov)from evidence of syngenetic biofilm mineralisation

在线全文

学校读者我要写书评

暂无评论

Journal of Palaeogeography 2022年第1期11卷 69-84页

作者： robert V.Burne Research School of Earth Sciences The Australian National University CanberraACT 0200Australia School of Earth and Environmental Sciences The University of QueenslandBrisbaneQLD 4072Australia

Conophyton(Maslov)is a cylindroidal stromatolite form-genus characterized by nested conical ***-preserved Conophyton,up to 4 m tall and with basal diameters of up to 50 cm,are exposed in the Proterozoic Atar Formation of Mauritania,where many occur together,in growth position,as fields of individual columns spaced between 5 and 70 cm *** uniformity of these forms and their regular distribution suggest that they grew in quiet-water environments below wave *** for their penecontemporaneous organomineralization is indicated by nearby toppled examples of undeformed Conophyton forms alongside eroded lithified Conophyton fragments in carbonate *** characteristics of Conophyton have been used to classify the structures-the form of the lamination and the nature of its axial structure.A mathematical/physical model provides an explanation for the growth pattern of *** predicts that coniform structures with thickened axial zones form when upward organic growth of a biofilm moderately exceeds the rate of its *** varying characteristics of these features between different forms of Conophyton are thought to reflect biomineralization of the decaying biofilm rather than differences in the composition of microbial communities.A modern example of a syngenetic mineralization process capable of producing similar structures has been observed in the contemporary sediments of Lake Preston,Western Australia,where benthic microbial mats are being transformed into coniform lithified *** initial biomineralization of the coniform mat forms magnesium silicate that first coats and permineralizes web-like microbial extracellular polymeric substances(EPS)and then coalesces into a uniform mass that provides mechanical strength to the *** a later stage,massive carbonate crystal growth occurs that over-prints much of this texture,leaving only small,remnant areas of the magnesium silicate *** fossil Conophyton are composed o

关键词： Conophyton Morphogenesis Proterozoic Stromatolite Microbialite Mineralisation Biofilm Lake Clifton Lake Preston Maslov

Investigating the raveling test for full-depth reclamation

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2018年第2期12卷 222-226页

作者： robert HILL Andrew BRAHAM Department of Civil Engineering University of Arkansas Fayetteville AR 72701 USA

Full-Depth Reclamation （FDR） is a sustainable method of building pavement structure compared to more traditional rehabilitation methods. Traffic is generally returned to an FDR project before a surface course is applied, as water in the FDR needs time to evaporate from the structure. This should not be done too quickly or raveling occurs. Currently, there is no test to quantify the timing of return to traffic. In this study, the ＂Raveling test of cold mixed bituminous emulsion samples＂（ASTM D7196） was used to compare asphalt emulsion and asphalt foam FDR. Asphalt emulsion samples were cured at ambient and 40℃ temperatures, while asphalt foam samples were cured at ambient temperatures. Raveling test data was collected from 0 to 48 hours of curing, however, samples were often not able to withstand fifteen minutes of testing. Therefore, the ＂time lasted＂（the time the raveling head loses contact with the surface of the sample） was recorded. In general, the asphalt emulsion samples that were cured in the oven at 40℃ had a longer time lasted and showed higher potential for determination of return to traffic. In addition, the asphalt emulsion samples had a longer time lasted than the asphalt foam samples at ambient temperatures.

关键词： raveling full depth reclamation

The Orosirian(1800–2050 Ma)plate tectonic episode:Key for reconstructing the Proterozoic tectonic record

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2023年第3期14卷 1-9页

作者： robert J.Stern Geosciences Dept. U Texas at DallasRichardsonTX 75083-0688United States

Eight lines of evidence indicate that the Orosirian Period in mid-Paleoproterozoic time was characterized by plate tectonics:ophiolites,low T/P metamorphism including eclogites,passive margin formation,tall mountains,paleomagnetic constraints,ore deposits,abundant S-type granites,and seismic images of paleo-subduction *** plate tectonic episode occurred about 1 billion years earlier than the present plate tectonic episode began in Neoproterozoic *** two plate tectonic episodes bracket the‘Boring Billion’,which may have been a protracted single lid tectonic episode that began when the supercontinent Nuna or Columbia *** of multiple lines of evidence for Orosirian plate tectonics demonstrates that Earth’s tectonic style can be reconstructed with some confidence back to at least Early Paleoproterozoic time,and thus the absence of compelling evidence for Mesoproterozoic plate tectonics is not obvious due to poor preservation.A tectono-magmatic lull2.3 Ga suggests an earlier episode of single lid *** for two episodes of plate tectonics and two episodes of single lid tectonics indicates that Earth switched between single lid and plate tectonics multiple times during the last 2.4 Ga.

关键词： Plate tectonics Single lid tectonics Urey ratio Paleoproterozoic

The Climate Change Imperative to Transform Disaster Risk Management

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Disaster Risk Science 2020年第2期11卷 152-154页

作者： robert Glasser Australian Strategic Policy Institute CanberraAustralia

This year the international community marks the fifth anniversary of the Sendai Framework for Disaster Risk Reduction 2015–2030 (SFDRR), in which countries committed to curbing the impact of natural and human-caused ... 详细信息

关键词： Climate anniversary committed

Innovations in Agriculture and Food Supply in Response to the COVID-19 Pandemic

在线全文

学校读者我要写书评

暂无评论

Molecular Plant 2020年第8期13卷 1095-1097页

作者： robert Henry Queensland Alliance for Agriculture and Food Innovation University of QueenslandBrisbaneQLD 4072 Australia

In human history,the long-term expansion of populations has been limited by the availability of food and constraints of disease(Diamond,1997).The domestication of plants and animals has facilitated the development of human societies,and the resulting larger human populations have increased the risk of major disease outbreaks(pandemics).The recent COVID-19 pandemic resulted from the emergence of a disease caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).This has caused major disruption to economic activity with severe restrictions on international *** impact on agriculture and global food security will be complex(Torero,2020),and many of the consequences are yet to be identified and understood(Jámbor et al.,2020).Despite growing stocks of foods such as cereals(FAO,2020),it has been estimated that the number of people facing a food crisis will grow from 135 million to 265 million by the end of 2020(Anthem,2020;Figure 1).The pandemic has added to the food security challenges posed by climate change and major conflicts,both of which have been major factors contributing to recent food *** scientists need to determine how investment in innovation needs to change in response to the *** about shortages of labor and food safety will intensify efforts to use automation at all stages in the food production system to ensure supply.

关键词： Figure travel consequences

INTRODUCING BIOMASS ENERGY AT FERRUM COLLEGE:THE CHALLENGE OF INTRODUCING NEW TECHNOLOGY

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Green Building 2014年第4期9卷 43-59页

作者： robert Bryant Ascent Energy

Ferrum College and English Biomass Partners have been working together for nearly five years to design,build,and operate a biomass plant that will provide almost all of the thermal energy and a portion of electricity requirements for the *** biomass plant began full operation in *** is the story of what they have *** new technologies into existing systems to achieve strategic sustainability goals often create unexpected challenges that threaten hoped for benefits and leave participants wondering what went *** even projects that present these challenges are also great sources of encouragement and *** projects begin with a focus on the promise of a particular technology,(in this case using biomass for fuel),and while the prospects can be exciting,it can obscure the hard work of preparing the existing system for ***,the“systems”that frequently present the most difficulty are the human systems and behaviors that influence *** these are not well-understood or documented they are“uncovered”during *** purpose of this article is to identify critical success factors and provide insight about processes that enhance the likelihood of success.

关键词： biomass plant thermal energy college sustainability district heating alternative biomass fuels forest sustainability

CCA-secure unidirectional proxy re-encryption in the adaptive corruption model without random oracles

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2010年第3期53卷 593-606页

作者： DENG robert School of Information Systems Singapore Management University

Up to now, it is still an open question of how to construct a chosen-ciphertext secure unidirectional proxy re-encryption scheme in the adaptive corruption model. To address this problem, we propose a new unidirectional proxy re-encryption scheme, and prove its chosen-ciphertext security in the adaptive corruption model without random oracles. Compared with the best known unidirectional proxy re-encryption scheme proposed by Libert and Vergnaud in PKC’08, our scheme enjoys the advantages of both higher efficiency and stronger security.

关键词： unidirectional proxy re-encryption adaptive corruption model chosen-ciphertext attack

Simulation of blood flow in a small-diameter vascular graft model with a swirl (spiral) flow guider

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2008年第10期51卷 913-921页

作者： robert GUIDOIN Department of Surgery Laval University and Quebec Biomaterials Institute CHUQQuebec G1K7P4

Small-diameter vascular grafts are in large demand for coronary and peripheral bypass procedures, but present products still fail in long-term clinical application. In the present communication, a new type of small-diameter graft with a swirl flow guider was proposed to improve graft patency rate. Flow pattern in the graft was simulated numerically and compared with that in a conventional graft. The numerical results revealed that the swirl flow guider could indeed make the blood flow rotate in the new graft. The swirling flow distal to the flow guider significantly altered the flow pattern in the new graft and the ve- locity profiles were re-distributed. Due to the swirling flow, the blood velocity near the vessel wall and wall shear rate were greatly enhanced. We believe that the increased blood velocity near the wall and the wall shear rate can impede the occurrence of acute thrombus formation and intimal hyperplasia, hence can improve the graft patency rate for long-term clinical use.

关键词： arterial prosthesis acute thrombus formation flow simulation swirling (spiral) flow