نتایج جستجو برای: fishing crafts

تعداد نتایج: 15317  

2018
Jennifer C Selgrath Sarah E Gergel Amanda C J Vincent

Locally sustainable resource extraction activities, at times, transform into ecologically detrimental enterprises. Understanding such transitions is a primary challenge for conservation and management of many ecosystems. In marine systems, over-exploitation of small-scale fisheries creates problems such as reduced biodiversity and lower catches. However, long-term documentation of how governanc...

Journal: :The Journal of organic chemistry 2007
Changkun Li Jianbo Wang

The BF3.OEt2-catalyzed Friedel-Crafts propargylation of aromatic compounds with O-propargyl trichloroacetimidates is highly efficient and affords 1,3-diarylpropyne derivatives in good yields.

Journal: :Journal of African Studies 1984

Journal: :Educación Química 2012

This paper used the Data Envelopment Analysis (DEA) to measure the technical efficiency of fishing vessels in Haizhou Bay, and then used the Tobit regression to define its influencing factors. This study shows that the overall fishing capacity utilization of fishing vessels at present is very low which indicates that there is a serious waste of resources problem in Haizhou Bay. Specifically, th...

2017
Nina G Schmidt Tea Pavkov-Keller Nina Richter Birgit Wiltschi Karl Gruber Wolfgang Kroutil

The Friedel-Crafts acylation is commonly used for the synthesis of aryl ketones, and a biocatalytic version, which may benefit from the chemo- and regioselectivity of enzymes, has not yet been introduced. Described here is a bacterial acyltransferase which can catalyze Friedel-Crafts C-acylation of phenolic substrates in buffer without the need of CoA-activated reagents. Conversions reach up to...

Journal: :Journal of the American Chemical Society 2007
Sandra Lee David W C MacMillan

Over the last 8 years, our laboratory has developed the concept of iminium catalysis, a mode of LUMO-lowering activation that has enabled the invention of a large number of enantioselective organocatalytic transformations including Diels-Alder cycloadditions, Friedel-Crafts alkylations, Mukaiyama-Michael additions, hydrogenations, and heteroconjugate additions.1 Central to the utility of this t...

Journal: :بهره برداری و پرورش آبزیان 0
افشین عادلی دانشگاه گرگان ارغوان معماری -

abstract nowadays, the management of water resources by planning through appropriate site selection, fish species storage and selection, enforcement and providing various side services has become a profitable, entrepreneurial and fun process. survey and usage of development of fee-fishing experience in the world wide represent a model in order to a better economical and fun plan offers and envi...

2016
João C. Ferreira Serge Lage Iola Pinto Nuno Antunes

— This paper discusses the results of an applied research on the fishing activity based on a monitor system developed by a company and fishing reports produced at the end of each fishing activity. Due to economic interests combined with fishing limitations there is a natural tendency for wrong reporting. We apply Data Mining (DM) methodologies to find fishing patterns. These DM techniques in SQ...

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