检索结果-南通市图书馆

chinese chemical Letters 2012年第5期23卷 569-572页

作者： Seyed Sajad Sajadikhah Malek Taher Maghsoodlou Nourallah Hazeri Sayyed Mostafa Habibi-Khorassani anthony c.willis Department of chemistry The University of Sistan and BaluchestanP.O.Box 98135-674ZahedanIran Research School of chemistry The Australian National UniversityCanberraACT 0200Australia

An efficient green protocol is described for the preparation of highly functionalized piperidines via a one-pot five-component reaction between aromatic aldehydes,anilines andβ-ketoesters in the presence of oxalic acid dihydrate as catalyst in ethanol at ambient *** structure as well as the relative stereochemistry of these compounds was confirmed by single X-ray crystallographic analysis.

关键词： Piperidine Heterocycle Homogeneous catalyst Oxalic acid dihydrate Multi-component reaction

Risk Management——An Industry Approach

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2001年第1期14卷 21-29页

作者： anthony c. HUGGETT Regional Quality Assurance Laboratory

An effective risk management system covering the whole process of food production from “farm to fork” is required by the food industry in order to assure that the food provided to consumers is safe. Food safety and quality assurance begins with the design and development of food products starting with product conceptualisation and continuing with the selection, purchasing, and evaluation of raw materials and with the specifications for processing, packaging and distribution. Within a larger quality management framework a number of tools have been developed by the food industry, which when used in an integrated fashion facilitate the management of food safety. These include good manufacturing practice (GMP), good hygiene practice (GHP) and HAccP (hazard analysis critical control point) as well as quality systems which allow the verification that all factors affecting the safety of a product are under control. Finally, regulations and systems can only function if they are applied. Everyone, from the farmer, the line operator in the manufacturing plant, to the person handling the food in distribution and sales, needs to be aware of his influence with regards safety. The effectiveness of safety awareness programs specific to each area is key to an industry approach to risk management.

关键词： risk management system food industry food safety critical control point quality management quality assurance quality systems raw materials food products in order used in

Impact of vasculature damage on the outcome of spinal cord injury:a novel collagenase-induced model may give new insights into the mechanisms involved

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2014年第20期9卷 1783-1786页

作者： Patrick Losey Daniel c.anthony Experimental Neuropathology Department of PharmacologyUniversity of OxfordOxfordUK

The deleterious effect of vasculature damage on the outcome of spinal cord injury has long been recognized, and numerous clinical studies have shown that the presence of hemorrhage into the spinal cord is directly associated with a poorer neurological outcome. Vascular damage leads to de- creased blood flow to the cord and the release of potentially toxic blood-borne components. Here we consider the mechanisms that may be contributing to hemorrhage-induced damage and discuss the utility of a new model of spinal cord hemorrhage, which was urgently required as most of our current understanding has been extrapolated from intracerebral hemorrhage studies.

关键词： spinal cord injury vasculature hemorrhage animal model collagenase stereotaxic microinjection

Multivariate adaptive regression splines and neural network models for prediction of pile drivability

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2016年第1期7卷 45-52页

作者： Wengang Zhang anthony T.c.Goh School of civil and Environmental Engineering Nanyang Technological UniversitySingapore 639798Singapore

Piles are long, slender structural elements used to transfer the loads from the superstructure through weak strata onto stiffer soils or rocks. For driven piles, the impact of the piling hammer induces compression and tension stresses in the piles. Hence, an important design consideration is to check that the strength of the pile is sufficient to resist the stresses caused by the impact of the pile hammer. Due to its complexity, pile drivability lacks a precise analytical solution with regard to the phenomena *** situations where measured data or numerical hypothetical results are available, neural networks stand out in mapping the nonlinear interactions and relationships between the system’s predictors and dependent responses. In addition, unlike most computational tools, no mathematical relationship assumption between the dependent and independent variables has to be made. Nevertheless, neural networks have been criticized for their long trial-and-error training process since the optimal configuration is not known a priori. This paper investigates the use of a fairly simple nonparametric regression algorithm known as multivariate adaptive regression splines（MARS）, as an alternative to neural networks, to approximate the relationship between the inputs and dependent response, and to mathematically interpret the relationship between the various parameters. In this paper, the Back propagation neural network（BPNN） and MARS models are developed for assessing pile drivability in relation to the prediction of the Maximum compressive stresses（McS）, Maximum tensile stresses（MTS）, and Blow per foot（BPF）. A database of more than four thousand piles is utilized for model development and comparative performance between BPNN and MARS predictions.

关键词： Back propagation neural network Multivariate adaptive regression splines Pile drivability computational efficiency Nonlinearity

Stereoselective Functionalization at c-2 and c-3 of the Gibberellin via an Intramolecular Free Radical cyclization Approach

在线全文

学校读者我要写书评

暂无评论

chinese chemical Letters 2001年第5期12卷 397-398页

作者： An Qi cHEN christine L.willis Department of chemistry Xiamen UniversityXiamen3610052School of ChemistryUniversity of BristolBristolUK BS81TS

Stereoselective functionalization at c-2 and c-3 of the gibberellin skeleton was achieved via an intramolecular free radical cyclization approach using a tethered c-19 halomethyl ester as the radical precursor.

关键词： Gibberellin lactonization free radical cyclization.

Effects of the mass and volume shrinkage of ground chip and pellet particles on drying rates

在线全文

学校读者我要写书评

暂无评论

Particuology 2018年第3期16卷 1-9页

作者： Hamid Rezaei Shahab Sokhansaj c. Jim Lim anthony Lau Xiaotao Bi chemical and Biological Engineering Department University of British Columbia Vancouver BC V6T 1Z3 Canada Environmental Science Division Oak Ridge National Laboratory Oak Ridge TN 37381 USA

The effects of varying the mass and volume of ground chip and pellet particles on the particle drying rate were analyzed. Samples of whole pellets and chips were hammer milled using a 3.2 mm screen and the ground chip and pellet particles were found to have similar size distributions, although the pellet particles were denser and more spherical than the chip particles. Prior to drying, water was added to the particles to obtain 0.10, 0.30, 0.50, 0.70, and 0.90 moisture contents （on a dry mass basis）. The moistened particles were subsequently dried in a constant temperature thin layer dryer set at 50,100, 150, or 200 ~c under dry pure nitrogen, dry compressed air, or atmospheric air. The chip and pellet particles exhibited similar degrees of shrinkage, but the pellet particles underwent a greater reduction in their bulk volume during drying. It appears that the more spherical pellet particles are prone to shrinkage in more than one direction, whereas the needle-like chip particle shrink only in one direction. A variable radius first order drying model was found to fit the experimental data better than a fixed radius model.

关键词： Moisture loss Particle density Ground chip Ground pellet Particle shrinkage Bulk shrinkage

Modern Microalloyed Steels

维普期刊数据库评论

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 Iron and Steel Research International 2011年第S1期18卷 14-21页

作者： Garcia c Issac Suikkanen Pasi P Deardo anthony J Basic Metals Processing Research Institute Department of Mechanical Engineering and Materials ScienceUniversity of PittsburghPittsburghPA 15261USA Department of Mechanical Engineering University of OuluBox 420090014 OuluFinland

The addition of microalloying elements (MAE) to low c-Mn-Si HSLA steels has led to many benefits to the producers,fabricators and *** improvements such as microstructural refinement,higher dislocation and sub-grain boundary densities and finer M-A-c distributions have led to higher strength,improved toughness and better *** improvements can often be traced to the MA *** steels for load-bearing applications,the combination of MAE with hardenability additions (cr,Mo,B,etc.) and lower transformation temperatures has led to much higher strength levels than what were available a few years *** resulting nonpolygonal,bainitic and martensitic ferrite microstructures have not only higher strengths but also adequate levels of improved ductility and *** strip,plate and pipe applications have benefitted from these *** improvements have been found in the microalloyed forging steels,where the change from pearlite-ferrite to bainitic ferrite microstructures has led to higher strengths and improved high-cycle fatigue resistance,with little penalty in ductility and *** the cold rolled gauges,both the so-called Advanced High Strength Steels (DP,TRIP and complex Phase Steels) and the martensitic direct-quenched and press-quenched steels,along with the Interstitial-Free steels,have benefited from MAE additions,especially in the very popular zinc-coated sheet *** paper will briefly review each of these topic areas,and the underlying physical metallurgy will be discussed.

关键词： microalloying vanadium HSLA steels bainite,linepipe thermomechanical processing

Fostering children’s Participation in Disaster Risk Reduction Through Play:A case Study of LEGO and Minecraft

在线全文

学校读者我要写书评

暂无评论

International Journal of Disaster Risk Science 2021年第6期12卷 867-878页

作者： Loïc Le Dé Jc Gaillard anthony Gampell Nickola Loodin Graham Hinchliffe School of Public Health and Interdisciplinary Studies Auckland University of TechnologyManukauAuckland 2025New Zealand School of Environment The University of Auckland.Auckland 1142.New Zealand Unit for Environmental Sciences and Management North-West UniversityPotchefstroom 2520South Africa School of Science.Auckland University of Technology Auckland 1010New Zealand

This article focuses on children’s participation in disaster risk *** draws on a 2018 study done in New Zealand with 33 school children who conducted participatory mapping with LEGO and the video game Minecraft to assess disaster risk in their locality and identify ways to be more *** research involved participatory activities with the children actively involved in the co-design,implementation,and evaluation of the initiative.A focus group discussion was also conducted to assess the project from the viewpoint of the *** results indicate that LEGO and Minecraft are playful tools for children to participate in disaster risk *** research identifies four key elements of genuine children’s participation,including the Participants,Play,the Process,and Power(4 Ps).This framework emphasizes that fostering children’s participation in disaster risk reduction requires focusing on the process through which children gain power to influence decisions that matter to *** process,through play,is child-centered and fosters *** article concludes that Play is essential to ground participation within children’s worldviews and their networks of friends and relatives.

关键词： children's participation Disaster risk reduction New Zealand Participatory game tools

Resistance to the Whitefly Aleurotrachelus socialis(Hemiptera:Aleyrodidae) and SSR Marker Identification in Advanced Populations of the Hybrid Manihot esculenta *** flabellifolia

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2013年第12期12卷 2217-2228页

作者： Arturo carabalí James Montoya-Lerma anthony c Belloti Martin Fregene Gerardo Gallego Deparment of Biology Universidad del Valle International center of Tropical Agriculture (cIAT)

Genes resistant to Aleurotrachelus socialis were transferred to the F 1 from the interspecific hybrid wild species of Manihot flabellifolia to *** and two advanced generations of backcrosses（Bc 1 and Bc 2）.We characterized the resistance of *** transferred to Bc 2 parents（cW67-160,cW67-130,cW67-44）,MTAI-8（Bc 1）,resistant（cMB9B-73） and susceptible（cMB9B-104） genotypes from contrasting pools,and resistant（MEcu-72） and susceptible（cMc-40） *** demography and biology were *** molecular markers associated with a phenotypic response of plant resistance were detected in segregating populations（Bc 2）.Results showed that although female survival time was similar on all hosts,the lowest averages of longevity,fecundity and oviposition rate were observed in the resistant control MEcu- 72,only being significantly similar to the parent *** the Bc 1 and Bc 2 populations were compared,it was found that *** fecundity was eight times lower on cMB9B-73 progeny than on cW67-130,expressing the highest levels of resistance to the *** genotypes of cMB9A and cMB9B family had the best segregation.A total of 486 microsatellite primers were evaluated using bulked segregant analysis（BSA）,11 showed polymorphism between the contrasting pools and only one showed significant differences between resistant and susceptible *** conclusion,fecundity was the parameter that impacted most on the intrinsic rate of *** population growth.

关键词： cassava wild parents interspecific hybrids whitefly resistance BSA

Population increase and changes in behavior and morphology in the critically Endangered Redonda ground lizard(Pholidoscelis atratus)following the successful removal of alien rats and goats

在线全文

学校读者我要写书评

暂无评论

Integrative Zoology 2021年第3期16卷 379-389页

作者： colin M.DONIHUE Jennifer c.DALTRY Shanna cHALLENGER anthony HERREL UMR 7179 c.N.R.S/M.N.H.N. Département Adaptations du VivantParisFrance Department of Biology Washington University in St.LouisSt.LouisMissouriUSA Fauna&Flora International David Attenborough BuildingPembroke StreetCambridgeUK Department of Environment St.John’sAntigua Environmental Awareness Group St.John’sAntigua

Redonda is a small volcanic caribbean island that is home to at least 4 endemic lizard species,including the critically Endangered ground lizard(Pholidoscelis atratus).Black rats(Rattus rattus)and domestic goats(capra hircus)were introduced to the island at some time after its discovery by Europeans in the late *** had a devastating effect on the island,resulting in the loss of nearly all trees and most of the ground *** count surveys of *** in 2012 indicated low densities,and the invasive rats were observed hunting and preying on the *** populations of rats and goats were successfully removed in 2017 as part of an ecological restoration program,and native vegetation and invertebrate populations have increased rapidly *** surveys in 2017,2018,and 2019 show the lizard population has increased by more than *** 2017,as rats and goats were being removed,we evaluated the morphology and escape behavior of this species and repeated these measurements 1 year *** observed that *** had become bolder,with a reduced flight *** also detected changes in limb morphology related to locomotion and suggest possible explanations that will need to be further investigated in the *** results show how the removal of invasive species can rapidly affect lizard population recovery and behavior,potentially restoring island ecosystems to their pre-human interference dynamics.

关键词： Antigua and Barbuda caribbean conservation endangered species invasive alien species island biology Lesser Antilles pest removal