基于独立组分分析和BP神经网络的可见/ 近红外光谱稻谷年份的鉴别

建立了一种基于独立组分分析的可见/近红外光谱反射技术快速鉴别稻谷年份的新方法.首先用独立组分分析方法获取不同年份稻谷的可见/近红外光谱载荷图,将载荷图中相关性最大的波段(特征波段)作为人工神经网络的输入建立稻谷年份的鉴别模型.每个年份40个样本,3个年份共120个样本用来建立BP神经网络模型,剩余的3个年份各20个样本用于预测.预测的结果表明,准确率达到100%.同时通过独立组分分析,得到了稻谷主要成分对应的敏感波段.说明本文提出的基于独立组分分析的方法具有很好的鉴别效果,为稻谷的年份鉴别提供了一种新方法.     

Reversible Molecular Rearrangement of Slightly Acid-treated Starches

The reersible association and dissociation of starch chain populations obtained from acid-treated starches (ATSs) was investigated. Potato starch, both nonglutinous and glutinous rice starches and sago starch were suspended in 15% sulfuric acid until 1% hydroysis occured. These ATSs had relative molecular weight ranges of 25,00–29,000 daltons. In water, about half the molecules were reconstituted into large aggregates of a few million daltons. This change in molecular size depended on presence of potassium chloride. It was not observed in debranched samples. The aggregates showed a clear endothermic peak on a DSC curve. Thus, the reversibly rearranging starch chain populations were not linear, but were branched and had some type of ordered structure.     

基于激光诱导击穿光谱积分信号的水稻种子鉴别研究

基于LIBS技术结合BP神经网络技术,对6类水稻种子进行类型鉴别研究.对水稻种子的LIBS全谱和分段光谱进行积分,再输入BP神经网络,得到:全谱积分前的识别率为81.02％,积分后识别率为93.40％,识别率提高12.38％;分段光谱积分后识别效果较好的是中心波长为405 nm、570 nm、810 nm的光谱,将这三...     

空时编码在莱斯信道下精确成对误码率公式

文中针对研究空时编码误码率的需要,得出了空时编码系统在莱斯信道下新的精确的误码率公式,该式可以看作是把现有的结果从瑞利信道推广到了莱斯信道。     

5种稻田突眼隐翅虫触角感器的超微结构研究

本文利用扫描电镜对小黑突眼隐翅虫Stenus melanarius、瘦突眼隐翅虫S.tenuipes、黑胫足突眼隐翅虫S.macies、虎突眼隐翅虫S.cicindeloides和阑氏突眼隐翅虫S.lewisius等5种稻田突眼隐翅虫雌、雄成虫的触角感器进行了观察和比较研究.结果表明,5种突眼隐翅虫的触角感器类型基本相同,均有5种感器,其中毛形感器和锥形感器又分为3个亚型:即B?hm氏鬃毛、毛形感器(毛形感器1、毛形感器2、毛形感器3)、刺形感器、锥形感器(锥形感器1、锥形感器2、锥形感器3)和栓锥形感器,同种感器形态相似;各种感器在触角上的分布相对稳定,具有一定规律;感器的分布、数量在种间及雌、雄两性间无显著差异.因此,触角感器可能不宜作为突眼隐翅虫种类鉴定的依据之一.     

一种区域分离方法及其在米粒检测中的应用

针对计算机视觉技术中米粒靠接在一起不利于大米的分级检测,采用图像处理分离靠接在一起的米粒融合区域,提出了基于扫描式区域增长的区域分离方法。该方法充分利用了单个米粒图像区域为凸性区域这一几何特点,通过区域增长的方法在图像中寻找由凸性米粒靠接在一起所形成的融合凹性区,并从凹处将融合区域分离开来。由于利用了米粒区域的几何特征来分离融合米粒区域,因此分离工作的自适应性强。大米垩白粒率的检测实验结果表明：该方法分离融合米粒区域的成功率达到了100％,而且检测结果与人工检测结果基本一致。     

Lowland rice response to potassium fertilization and its effect on N and P uptake

Not much is known about the response of lowland rice to K fertilization under Brazilian conditions. A field experiment was conducted during four consecutive years to determine the response of three lowland rice (Oryza sativa L.) cultivars to K fertilization on a Low Humic Gley soil. In the first two years, K was broadcast at rates of 0, 42, 84, 126, and 168 kg K ha^–1. In the last two years K rates were reduced to 0, 25, 50, 75, and 100 kg K ha^–1 and applied in a band. Potassium significantly (P < 0.01) increased grain yields but the response varied from cultivar to cultivar and year to year. Yield responses to K fertilization were superimposed on a general trend of increasing grain yields across the four growing seasons. Mean grain yields increased 14.3% with broadcast application of K in the first two years and 10.4% with banded application of K in the last two years when compared to the control treatments. Extractable soil K increased with K application rate and decreased with soil depth. Potassium was rapidly removed from the soil and yearly broadcast or banded application of K can be expected to result in a significant increase in grain yield of lowland rice in these soils.     

Effect of steam distillate extract of resistant wild riceOryza officinalis on behavior of brown planthopperNilaparvata lugens (Stal) (Homoptera: Delphacidae)

Rice plant volatiles extracted as steam distillates significantly affected the behavior of the brown planthopperNilaparvata lugens (Stal). In a choice test, significantly more females settled and fed on tillers of a susceptible rice variety, Taichung Native 1 (TN 1), sprayed with acetone or untreated TN 1 plants than on TN 1 tillers sprayed with the extracts of resistant wild riceOryza officinalis. O. officinalis steam distillate was highly toxic to first-instar nymphs ofN. lugens. Ingestion and assimilation of food by females was significantly reduced on TN 1 plants sprayed withO. officinalis distillate compared to TN 1 plants sprayed with acetone. Application of0. officinalis distillate on TN 1 plants adversely affected hatchability of eggs ofN. lugens.     

Heat-induced Gels of Rice Globulin: Comparison of Gel Properties with Soybean and Sesame Globulins

The hardness and water-holding ability of rice globulin gels were intermediate between those of gels of soybean and sesame globulins. Scanning electron micrographs showed that rice globulin gel had a rough network structure composed of small globular particles of protein aggregates. Effects of various reagents on solubilization of proteins from the three gel types were compared. Disulfide bonds and hydrophobic interactions contributed mainly to the stability of rice globulin gels. The contributions of disulfide bonds to both the formation and stability of rice globulin gels were greater than for sesame globulin gels.     

紫外照射对留胚米稳定性的影响

为了提高留胚米的稳定性,采用紫外照射对留胚米进行稳定化处理。采用单因素实验及响应面分析研究紫外照射对留胚米脂肪酶灭活率的影响,同时考察留胚米水分损失率、碎米率和爆腰率的变化。结果表明:紫外照射最佳条件是照射时间11.50 min,照射距离为4.5 cm,初始含水量13%,此时脂肪酶灭活率66.73%、且碎米率增加0.12%、爆腰率增加1.63%、水分散失率增加0.38%,处于可以接受范围内,因此可以选为紫外照射稳定留胚米的工艺参数。