查询词典 weed control

The spraying control system aiming at weed based on machine vision was designed and developed. The index of 2G-R-B is used for segmentation and the method of improved pixel lateral histogram is used for extracting the center of crop row,the method of threthold is also used for identificating between-row weed and BP ANN based on fratal and texture is used for identificating in-row weed. PLC correspondence and performing procedure is desi -gned and developed.

设计和开发了基于机器视觉的麦田除草剂对准喷药控制系统，该系统的视觉子系统首先用过绿的2G-R-B进行植物与土壤背景的分割，其次用改进像素直方图法识别作物中心行，用阈值法识别行间杂草区域，用BP神经网络基于分形和纹理的共同特征识别行内杂草区域，设计并开发了计算机与PLC的通信程序，设计了PLC的运行程序。

The present study investigatated the effect on the diversification of weed community, including weed abundance, dominance, evenness, biomass, and mean height after mulching straw and intercropping white clover in the tea plantation from 2005 to 2006. The results were as follows: 16 families and 31 species were found in total. In April, the dominant species characterized with slow growth, lower biomass, and less than 30 cm height; in July those who grow faster with higher biomass and height became dominant; In September, these malignant communities reduced, while the oxalis and diffusa characterized with lower biomass and low height gradually increased. In the three seasons, the weed abundance, community diversity and evenness increased, and the dominance, the biomass and average height of weeds remarkably reduced after intercropping white clover and muching straw.

结果表明：茶园共有杂草16科31属31种，春季（4月）以生长速度较慢、生物量小、株高在30 cm以下的杂草为主，夏季（7月）以生长快、植株高和生物量大恶性杂草为主，秋季（9月）恶性杂草开始减少，酢浆草、白花蛇舌草等生物量小、株高矮的杂草逐渐增多；稻草覆盖处理茶园春、夏和秋季3个观测时期杂草物种丰富度、多样性、均匀度等指数均高于清耕对照，优势集中性指数低于清耕对照；间种白三叶草处理春、夏和秋季3个观测时期杂草总数量和生物量均显著低于清耕对照，夏、秋季杂草平均株高显著低于清耕对照；稻草覆盖和间种白三叶草处理春季茶芽重和产量显著高于清耕对照，鲜叶中游离氨基酸含量高于清耕对照，茶叶感官评审得分高于清耕对照处理。

The color component of ir was the best for close operation while the other two color component (r+g and r+g+ir) would do a better performance on open operation. Finally, the results of these 3 color components for recognizing weed showed that ir was the best. So, as a conclusion, the color component of ir is best for recognizing weed based on computer vision. Also the operation process for recognizing weed was proposed.6. Supposed an idea on the variable spray mechanism of weedicide.

借助Matlab7.0.1软件对数值量ir和数值组合r+g、r+g+ir进行进一步的分析，在对ir、r+g、r+g+ir图像完成为了去除图像噪声而进行的中值滤波和二值化背景分割后，为消除特定图像细节进行二值形态学操作，通过分别对三个数值量和数值组合的开启和闭合操作结果的比较，发现处理后的数值量ir适合进行闭合操

This weed population had a wider niche breadth, the second widest among 12 major weed populations in weed community, and had bigger niche overlap with Stellaria alsine, Alopecurus acquallis, Malachium aquaticum, Poa annua, Polygonum persicaria and Lapsana apogonoides. In rape, wheat or fallow, B.

在杂草群落中，草的生态位宽度居第2位，说明其有潜在的较强的适应环境的能力；草与雀舌草、看麦娘、牛繁缕、早熟禾、春蓼和稻搓菜等杂草种群的生态位重叠较大，与它们的生态要求比较接近。

Using nuclear DNA C-values for 539 angiosperms in China, we examined the variation of these values among growth forms and taxonomic groups and the relationship of these values with invasiveness. Mean DNA C-value of the 539 angiosperm species was 4.06 pg. Mean DNA C-value was(1) significantly lower for woody species (1.84 pg) than for herbaceous species(5.02 pg);(2) significantly lower for 360 dicots (2.20 pg) than for 179 monocots (7.80 pg);(3) significantly lower for annuals (2.78 pg) than for perennials(6.65 pg);(4) significantly lower for 134 weed species (1.93 pg) than for herbaceous non-weeds (6.75 pg) and for several families that have an unusually high proportion of weed species;(5) significantly lower for 47 exotic weed species (1.76 pg) than for 134 native weeds (1.93 pg), but significantly lower than that of "non-weedy" herbaceous species (6.75 pg);(6) lower for weeds than for "non-weedy" species in same genus or family; and (7) in herbaceous species, generally lower for weedy compared to "non-weedy" species, with some exceptions such as Avena fatua, whose DNA C-value is as high as 14.15 pg, contrarily, and some "non-weedy" herbaceous species in Cruciferae and Cucurbitaceae with very low values.

统计了中国境内有分布的539种被子植物的DNA C-值，分析了它们在不同分类群、生活型、倍性、生活史类型以及在杂草和非杂草类群中的分布情况，主要结果如下：(1)539种被子植物DNA C-值平均为4.06 pg，其中木本植物的DNA C-值平均为1.84 pg，低于草本植物的平均值(5.02 pg)；(2)双子叶植物(360种)的DNA C-值平均为2.20 pg，极明显地小于单子叶植物(179种)的平均值(7.80 pg)；(3)1年生植物的DNA C-值平均为2.78 pg，明显小于多年植物的平均DNA C-值(6.65 pg)；(4)134种杂草的DNA C-值平均为1.93 pg，明显小于非杂草草本植物的平均值(6.75 pg)，含杂草较多的科，平均DNA C-值相对较小；(5)统计的47种入侵杂草的DNA C-值平均为1.76 pg，略小于134种杂草的平均DNA C-值(1.93 pg)，极显著地小于非杂草性草本植物(6.75 pg)；(6)以科为单位，不同科的DNA C-值存在着极大的差异；(7)DNA C-值与染色体倍性的关系并不明显，但是，随着倍性的增加，基因组变小；(8)在同一科、属中，与非杂草相比，典型杂草的DNA C-值往往偏小；(9)总体上杂草或杂草性强的植物，它们的DNA C-值比非杂草性植物的要小。

Variation of important value of dominant weed is that in spring and fall the dominant weed is Viola prionantha while in summer it is Digitaria ischaemum. In general management lawn community it is Leymus secalinus that is the dominant weed in spring and fall and Digitaria ischaemum in summer.

管理水平较差的草坪群落中，春季和秋季是早开堇菜占优势，夏季是止血马唐占优势；管理水平一般的草坪群落中春、秋季节是赖草占优势，夏季也是止血马唐占优势；管理水平较好的草坪群落中整个生长季是鼠掌老鹳草、鹅绒委陵菜、赖草占优势，且以鼠掌老鹳草的优势度最大。

As one kind of the extensive weed killer, Glyphosate is one of the biggest global output agricultural chemical original drug weed killer. It occupies the entire weed killer market 30 % and the first world pesticide sales in continuously many years.

中文摘要嘉磷塞是目前全球产量与使用量最大之杀草剂农药，嘉磷塞作为一种广谱灭生性杀草剂，占整个杀草剂市场总量的30%，连续多年占据世界农药销售额首位。

The results showed that Sigma Broad had a good control of Veronica didyma, Avena fatra, Vicia sativa, Galium aparine.and Rorippa indica., more significant in term of fresh weight control and the inhibition rate of weed height despite less weed control in term of plant number,which maintained a certain number of weeds,due to delayed use.

结果表明，阔世玛对小麦田婆婆纳、野燕麦、大巢菜、猪殃殃、野油菜等单双子叶杂草有较好的防除效果，春季晚用，对杂草的密度防效不佳，小麦田间保留了一定数量的杂草，但对杂草的鲜重防效、株高抑制率显著。

The book is divided into 10 chapters, including discrete and continuous system of PID control system, commonly used digital PID control, Expert PID and fuzzy PID control, neural PID control, genetic algorithm PID control, Multivariable decoupling PID control, several advanced PID control, gray PID control, PID control servo system, PID control in real time, ea

全书共分十章，包括连续系统和离散系统的 PID 控制，常用数字 PID 控制，专家 PID和模糊 PID 控制，神经 PID 控制，遗传算法 PID 控制，多变量解耦 PID 控制，几种先进的PID 控制，灰色 PID 控制，伺服系统 PID 控制，PID 实时控制，每种方法都通过 MATLAB 仿真程序进行了说明。

The development direction changed direction according to the four-wheeler, the domestic and international company changes direction organization to control to the four-wheeler currently main adoption of is a numeral control, this is owing to a lot of advantages of numerical control:the procedure turn a control, the controller carries on the processing of operation and numerical information according to the control regulation designed, mainly passing procedure to carry out, if change control regulation need to change software, but need not change the hardware structure of system: control the accuracy is high, in the emulation the control the system, the accuracy of the controller from the accuracy of the component but settle, numerical controller accuracy from word long decision;Stability good;The software replies to use, needing a hardware environment of using the homology realization in the emulation the system, the numerical controller is a procedure control, the sub- procedure mold piece which need to be designed and write to carry out its model, can immediately carry out several links of functions expediently.

目前各个厂家大多采用的是PLC、单片机应用于四轮转向控制器中，功能基本能够实现，相比较之下，信号处理能力较强的数字信号处理器各方面均性能优于以上三种处理器。DSP是新世纪数字化革命的核心。它是一种独特的微处理器，具有可编程性，且实时运行速度远远超过通用微处理器。强大的数据处理能力和高速的运行速度，是DSP最值得称道的两大特色。DSP芯片是一种特别适合进行数字信号处理的微处理器。它强调运算处理的实时性，因此除了具备普通微处理器所强调的高速运算和控制功能外，主要针对实时数字信号处理，在处理器结构、指令系统和数据流程上做了很大的改动。它具有灵活、精确、可靠性好、体积小、功耗低和易于大规模集成等优点。

Some questions asked by the adjudicators in one English Speaking Contest still run upon me very often.

我参加了一场以"我心中的奥运会"为主题的英语演讲竞赛，其间评判提的几个问题时时萦绕我的心头。

He called InTERActive our most profitable release of the year.

他呼吁互动的我们的最有利可图的释放一年。