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91.
创意农业是一项综合性的系统工程,也是对传统农业发展模式的一种创新。在分析主要发达国家创意农业模式、我国创意农业发展现状和山西省创意农业发展状况的基础上,提出了山西省创意农业发展对策建议。  相似文献   
92.
海南民营橡胶产业现状及发展对策   总被引:1,自引:0,他引:1  
简要介绍了海南省民营天然橡胶种植历史,从种植、加工、销售和对农民的增收作用等4个方面概述了海南民营天然橡胶发展现状,剖析了海南民营天然橡胶产业中的优势和存在的主要问题,提出了海南民营天然橡胶发展对策。  相似文献   
93.
New techniques and improvements are required to quantify soil’s chemical and physical properties on production environment, reducing environmental impacts and minimizing soil analysis time. The aim of this study is to evaluate the possibility to estimate the content of silt, sand, clay, total iron and organic matter in soils formed by different lithologies in Parana State, Brazil, using VIS-NIR spectrum associated with Partial Least Square Regression (PLSR). 200 soil samples were collected in an area formed by Lixisols, Cambisols, Ferralsols, Arenosols and Nitisols in a depths of 0–0.2 and 0.2–0.8 m. Spectral readings were obtained in laboratory by FieldSpec 3 JR sensor. The spectral curves of the samples were correlated to the attributes through PLSR. The results obtained for sand in prediction were better when compared to the other attributes, presenting R2 = 0.90, r = 0.95 and RPD = 2.3. Clay and total iron presented satisfactory results, mainly for RPD values, which were above 2.4. Based on the results, it can be concluded that the PLSR technique associated with the spectral response of the soils, was able to estimate sand, clay and total iron with accuracy in a region formed by reworked materials, derived from several lithologies.  相似文献   
94.
Quantitative, qualitative and phenotypic body measurements were determined on Longling Yellow goats in Longling of Yunnan Province in China. Body weight was determined at birth and then at 3, 6, 9, 12, 18, 24, 36, and 48 mon of age. Body measurements traits including height at wither (HW), body length (BL), heart girth (HG), chest depth (CD), and circumference of cannon bone (CCB) were determined at 3, 6, 9, 12, 18, 24, 36, and 48 mon of age. Phenotypic traits including coat colour, horns type, tip horn torsion, nose type, hair on forehead, wattles, ear lobes, black back line, hair on legs, and black hair on belly were determined at 12, 18, 24, 36, and 48 mon of age. Males were heavier (P〈0.01 or P〈0.05) than females; and except for chest depth at 24 mon of age (P 〉 0.05), all other body measurements were also higher (P 〈 0.01 or P 〈 0.05) in males. HW, BL, CD, HG, and BW increased (P 〈 0.01) with age, except for 48 mon of females (P 〉 0.05); while CCB did not always increase with age. HG had the highest correlation (P〈0.01) with body weights of both sexes. No differences were observed between the two sexes in the colour of the coat, horn type, tip horn torsion, nose type, ear lobes, black back line, and black hair on belly. However, differences exist between the two sexes in the presence of hair on forehead, wattles and long hair on legs. The female goats absence of tip horn torsion had positive effect on all variables measured at 36 and 48 mort of age (P〈0.01 or P〈0.05). The presence of wattles was associated with heavier body weights from 18 mort (P〈0.01) of age onward, and also with longer HW, BL and CD (P〈0.01 or P〈0.05) in female goats. Female goats with ear lobes had heavier body weights at 12, 36 and 48 mon (P〈0.01) and longer CCB at 12 and 24 mon of ages (P〈0.05). Hair on legs and black hair on belly only had partly effect body measurements on 12 mon of Longling Yellow female goats. Results of this study provide valuable information that will assist breeders and genetic improvement specialists when conducting selection and preservation programs in Longling Yellow goats in China.  相似文献   
95.
玉米粗缩病发生规律与防控对策   总被引:5,自引:1,他引:4  
近年来,我国北方玉米种植区玉米粗缩病有逐年加重的趋势,给玉米生产带来巨大的损失。本文详细阐述了玉米粗缩病的危害症状及发病规律,分析了玉米粗缩病暴发的主要原因,并提出了综合防控对策。  相似文献   
96.
时间序列的结构分析是深入研究原始序列的重要前提。应用奇异谱分析并以极大熵谱估计为辅助,对我国广义货币供应量M2进行时间序列结构分析,结果显示:改革开放以来,我国广义货币供应量M2除了趋势项外,还具有周期分别约为10年、4~5年和3年,方差解释能力依次为23.22%、7.48%和3.44%的主周期波动成分;所有的周期波动成分的振幅均随时间而增大;长期趋势在改革开放前期增长速度较慢,而在中后期增长速度较快。  相似文献   
97.
提高科技期刊影响力的实证研究   总被引:1,自引:1,他引:0  
以《中国农学通报》为例,从历史积淀、办刊宗旨、主办单位、编辑水平、办刊理念等方面分析了提高科技期刊影响力的基础;论述了增强科技期刊影响力的途径,包括提高稿源水平、办刊质量、编审效率、加强管理与编辑队伍建设,加快与国际接轨。并从载文量、影响因子、即年指标变化、被引频次、基金资助论文率、网络影响力等方面阐述了近年来《中国农学通报》在农业领域影响力的提高情况。  相似文献   
98.
基于支持向量机的云烟87烟叶成熟度高光谱遥感识别   总被引:1,自引:0,他引:1  
利用烟叶光谱反射率数据研究烟叶的成熟度是将高光谱遥感探测技术应用于烟叶成熟采收的前提.对生理成熟期内云烟87的中部叶成熟度进行了研究,研究是从提取和分析烟叶高光谱信息的角度上进行的.基于提取到的反映烟叶成熟度的光谱特征和支持向量机这一基于数据的小样本学习方法,建立了识别烟叶成熟度的数学模型,这个数学模型是由支持向量机生成的2个最优决策超平面,一个将初熟类烟叶和适熟类烟叶分开,另一个将适熟类烟叶和过熟类烟叶分开,且分类精度均在90%以上.  相似文献   
99.
ABSTRACT

Phosphorus (P) determination by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) in soil extracts is affected by copper (Cu) content and may lead to misinterpretation of the results. In this study, Multicomponent Spectral Fitting (MSF) method for the quantitative determination of P in the presence of Cu was tested. Phosphorus determination by UV/Vis molecular absorption spectrometry (COL) was free from copper interference. Phosphorus determination by ICP OES at wavelengths of 213.618 and 214.914 nm without use of MSF were subject to interference when Cu concentration was greater than 1.5 and mg L?1 and 3.5 mg L?1, respectively. When the P: Cu ratio in solution was 1:1 and 2:1, on average, there was no significant difference between the P determined by COL and by ICP-OES using MSF. In matrices containing Cu, it is indicated to use the P spectral line at 214.914 nm because it was less sensitive to Cu concentration than spectral line at 213.618 nm.  相似文献   
100.
发酵测控系统是发酵过程参数智能检测与优化调控的基础,直接影响着发酵过程的控制性能。该文针对L-乳酸发酵过程的智能检测,提出了一种基于智能检测的发酵过程测控系统集成方法,给出了系统的体系结构及实现方法,集成了基于虚拟仪器技术的PXI总线发酵过程智能测控系统,给出了系统的软、硬件设计。该系统通过建立软测量模型,有效地实现了发酵过程不易测量参量的在线估计与控制,为发酵过程提供了一种新的测控系统。试验研究表明,将该系统应用到L-乳酸发酵过程中,通过在线估计葡萄糖液消耗量,实现了L-乳酸发酵过程补料优化控制,乳酸产量提高23%,提高了发酵产物得率。  相似文献   
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