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Stefan Cenkowski Digvir S. Jayas James K. Daun 《Journal of the science of food and agriculture》1993,63(4):377-383
The presence of green seeds in canola arises primarily from the common practice of swathing the crop prematurely in order to hasten the harvesting process and reduce the shattering losses. The purpose of this study was to determine the effects of plant maturity, swathing and duration of swathing on moisture and chlorophyll contents of canola seeds (Brassica napus L cv Westar), and to determine the effect of canola conditioning with air at 25·C and 90% RH on chlorophyll content. A standing crop of canola with 50% to 10% (w/w) seed moisture content was sampled at regular intervals in two consecutive harvest years (1989 and 1990). Canola was also swathed at three different stages of maturity, and seeds were checked for chlorophyll at 2-3 day intervals and compared with chlorophyll contents of seed from standing crop. Samples were conditioned in a thin layer with air at 25·C and 90% RH for 24 h, and chlorophyll was determined before and after conditioning. The chlorophyll of seeds decreased exponentially with a decrease in moisture content. Conditioning canola seeds decreased chlorophyll content by an average of 16% (SD = ± 12%). 相似文献
54.
基于甲基异丁基甲酮于稀盐酸介质中定量地萃取Zn ̄(2+)与CNS ̄-形成的络阴离子。从而达到与共存的锰、镍、铝、铬的完全分离。在有氟化物、硫脲存在时Fe ̄(3+)、Cn ̄(2+)和Ag ̄+也不被萃取。有机相中的锌于PH5.5“六胺”缓冲介质中返萃取回水相,用EDTA滴定。在文中给定的条件下锌的一次被萃取率可达99%以上,成功地解决了锰铜基高阻尼合金中共存离子对锌量测定的干扰问题。 相似文献
55.
Development of a recurrent Sigma-Pi neural network rainfall forecasting system in Hong Kong 总被引:1,自引:1,他引:0
At the moment, weather forecasting is still an art — the experience and intuition of forecasters play a significant role in determining the quality of forecasting. This paper describes the development of a new approach to rainfall forecasting using neural networks. It deals with the extraction of information from radar images and an evaluation of past rain gauge records to provide shortterm rainfall forecasting. All of the meteorological data were provided by the Royal Observatory of Hong Kong (ROHK). Preprocessing procedures were essential for this neural network rainfall forecasting. The forecast of the rainfall was performed every half an hour so that a storm warning signal can be delivered to the public in advance. The network architecture is based on a recurrent Sigma-Pi network. The results are very promising, and this neural-based rainfall forecasting system is capable of providing a rain storm warning signal to the Hong Kong public one hour ahead. 相似文献
56.
本文介绍的基于信息的智能控制理论的发展过程,主要分为智能控制的信息指标和智能控制的信息结构分析两部分,文中在最后对这套理论可能的发展方向进行了探讨。 相似文献
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Management of multidimensional discrete data 总被引:1,自引:0,他引:1
Peter Baumann Ph.D. 《The VLDB Journal The International Journal on Very Large Data Bases》1994,3(4):401-444
Spatial database management involves two main categories of data: vector and raster data. The former has received a lot of in-depth investigation; the latter still lacks a sound framework. Current DBMSs either regard raster data as pure byte sequences where the DBMS has no knowledge about the underlying semantics, or they do not complement array structures with storage mechanisms suitable for huge arrays, or they are designed as specialized systems with sophisticated imaging functionality, but no general database capabilities (e.g., a query language). Many types of array data will require database support in the future, notably 2-D images, audio data and general signal-time series (1-D), animations (3-D), static or time-variant voxel fields (3-D and 4-D), and the ISO/IEC PIKS (Programmer's Imaging Kernel System) BasicImage type (5-D). In this article, we propose a comprehensive support ofmultidimensional discrete data (MDD) in databases, including operations on arrays of arbitrary size over arbitrary data types. A set of requirements is developed, a small set of language constructs is proposed (based on a formal algebraic semantics), and a novel MDD architecture is outlined to provide the basis for efficient MDD query evaluation. 相似文献
59.
抗震结构变形能力可靠度的时程分析方法 总被引:3,自引:1,他引:2
采用可靠指标β来度量抗震结构可靠度.取结构失效准则为:地震作用下结构层间位移响应超越结构层间位移能力限值.将时程分析方法与JC方法结合,建立了计算抗震结构变形能力可靠指标β的时程分析方法. 相似文献
60.