采茶机、轻修剪机最佳刀、机速度     

金心怡 《福建农林大学学报(自然科学版)》1993,(4)

茶叶采、剪机械的刀、机速度关系到机采和机剪的作业质量、生产率、油耗以及机子的使用寿命,在使用中应正确掌握,本文从切割器的切割图人手,对国内常见的8种机型逐一进行刀机速比分析,通过实验测定和灰色综合评判,确定出机采和机剪的最佳刀、机速度。  相似文献   

辽宁兴城种子园油松高生长的预估模式     

姚丽华 《北京林业大学学报》1988,10(1):49-54

本文应用灰色系统理论,以辽宁兴城油松种子园内1977—1984年12个无性系的平均单株年生长量为基础,与该地6个气象因子分别计算了关联度。从这些数据中按水分和热量择取关联度较大的相对湿度和气温,建立了线性静态模式,并用残差模型作修正,得到下列模式; X_1~(0)(t)=70.214-0.975X_2~(0)(t)+2.335X_3~(0)(t)经检验,模式的平均误差为5％  相似文献   

Soundscape effects on visiting experience in city park: A case study in Fuzhou,China     

《Urban Forestry & Urban Greening》2018

The main objective of this study was to reveal the relationships between sound/soundscape perception and public visiting experience in city parks, based on a questionnaire survey of 146 park users in West Lake park in Fuzhou, China. The results indicated that, the three visiting experience indicators, i.e., soundscape tranquil degree (STD), landscape aesthetic degree (LAD) and visiting satisfaction degree (VSD) were positively related with each other, and LAD (correlation coefficients = 0.728, p < 0.01) was more associated with VSD than STD (correlation coefficients = 0.565, p < 0.01). Perception of certain individual sounds was found in close relationships with the three indicators. Specifically, STD showed the most significant relationships with harmonious degree of individual sounds, where perception of traffic sounds showed the most negative effects, while perception of music related sounds and water sound showed positive effects. LAD was more associated with perceived occurrences of individual sounds, where traffic sounds and music related sounds showed the most significant effects again. Both perceived occurrences and dominant degree of individual sounds showed the most and equal relationships with VSD. Specifically, mechanical sounds showed the most negative effects, and dog barking showed significant negative effects too, while music related sounds could be the only kind of sound positively contributed to VSD. Social/demographical/behavioral factors and visit motivations all showed significant relationships with individual sound perception and visiting experience. Considering the effects of all associated factors, key factors were detected for each of the visiting experience indicators. All the three visiting experience indicators showed negative relationships with certain traffic sounds, while tree rustling sound was the only sound showing positive relationship with STD. Age was the most important social/demographical/behavioral factor showing positive relationships with LAD and VSD. The research results provided theoretical references for management and design of soundscapes to contribute to more satisfied experiences in city parks.  相似文献   

Study on the Characteristics and Interrelationship of Plant Community and Soil in Degraded Alpine Meadow北大核心CSCD     

She Y.-D.  Yang X.-Y.  Ma L.  Zhang Z.-H.  Wang D.-J.  Huang X.-T.  Ma Z.  Yao B.-Q.  Zhou H.-K. 《草地学报》2019,(1):61-71

To explore the changes of vegetation and soil characteristics and their relationships in the alpine meadow at different stages of degradation, the plant biomass, species diversity index, soil nutrient, soil physical and chemical properties were measured by the combination of field sample survey and laboratory analysis. The results showed that vegetation coverage, above ground and below ground biomass decreased from slight to severe degradation, the species diversity index, Shannon-wiener diversity index, Evenness index and Simpson index of vegetation community all showed a decreasing trend, and the soil nutrient and physical and chemical properties tended to deteriorate, the decrease of soil moisture and the increase of soil bulk density led to the decrease of biomass. The interaction and interaction between biomass and soil properties can change plant community composition and soil properties and reduce soil nutrient loss in the moderate degradation stage, improving the stability of plant community structure and increasing the diversity of plant community will be beneficial to the restoration of degraded alpine meadow. This study will help to clarify the degradation pattern of alpine meadow in different degradation stages, and provide a scientific basis and theoretical basis for restoring degraded alpine meadow. © 2019 Authors. All rights reserved.  相似文献   

甘肃牧区牧民对草原生态补奖政策满意度研究     

王丽佳  刘兴元 《草业学报》2019,28(4):1-11

在中国政府致力于完善草原生态补奖机制的背景下,如何权衡牧民禁牧减畜与收入减少之间的矛盾,提高牧民对政策的满意度,是完善草原生态补奖政策亟须解决的关键科学问题。第一轮草原生态补偿政策实施期(2011-2015年)已结束,第二期(2016-2020年)已经开始,评估牧民对第一期补偿政策的满意度,对完善第二期草原生态补偿机制具有重要的借鉴意义。本研究以甘南、肃南和天祝500户牧户为调查对象,采用探索性因子分析,选取牧民社会经济特征、牧民对草原生态补奖政策的感知质量和感知价值3个潜变量,构建牧民对草原生态补偿政策满意度结构方程模型。结果显示,牧民受教育水平越高,获得的草原生态补奖额度越高,其对草原生态补奖政策的满意度也越高。牧民生活与放牧地区自然灾害发生情况,以及水质和水量的下降情况从侧面反映该地区草原生态环境情况。因此,本研究从完善牧区教育机制,强化草原生态补奖政策配套措施建设,鼓励牧民对草场进行科学管理等方面提出增强牧民对草原生态补奖政策满意度的建议。  相似文献   

甘南地区饲用型小黑麦草产量及营养品质研究     

代寒凌  田新会  杜文华  吴建平 《草原与草坪》2019,39(2):66-72

以饲用型小黑麦品系C35为试材,黑麦品系C39和当地种植的燕麦品种(岷县燕麦)为对照,对3种牧草4个刈割期(抽穗期、开花期、灌浆期、乳熟期)的草产量、营养价值和干物质消化率进行了测定分析,并运用灰色关联度法进行了综合评价。结果表明:乳熟期小黑麦,黑麦和燕麦的平均干草产量最高,抽穗期CP含量和干物质消化率最高,株高,NDF含量和ADF含量最低。小黑麦的平均干草产量和营养品质显著高于燕麦,虽然干草产量与黑麦无显著差异,但CP含量显著高于黑麦,NDF和ADF含量显著低于黑麦。综合评价,3种牧草最佳刈割时期均为乳熟期,乳熟期的灰色关联度排序为γi(小黑麦)>γi(黑麦)>γi(燕麦);小黑麦品系C35在该地区具有较高的生产性能和营养品质,具有明显区域优势,适于推广种植。  相似文献   

高寒草甸退化对优势物种根际土壤微生物量及酶活性的影响     

马源  张德罡  周恒  周会程  陈建纲 《草原与草坪》2019,39(4):44-52

以祁连山东缘的4个不同退化程度(未退化、轻度退化、中度退化、重度退化)高寒草甸为研究对象,测定分析了高寒草甸退化对优势物种和土壤理化性质的影响,以及不同退化程度优势物种对根际土壤和非根际土壤中3大类微生物的数量、微生物生物量(碳、氮、磷)的含量以及酶活性的影响。结果表明:(1)随高寒草甸退化程度的加剧,植物群落多样性呈下降趋势,土壤中有机碳、全氮、全磷和速效磷的含量呈逐渐降低的趋势;(2)随退化程度的加剧,根际和非根际土壤中3大类微生物的数量呈逐渐降低的趋势,并且不同退化程度下根际和非根际土壤中微生物的数量均表现为,细菌>放线菌>真菌;(3)随退化程度的加剧,根际和非根际土壤中微生物生物MBC,MBN和MNP的含量和土壤蔗糖酶、蛋白酶、脲酶、过氧化氢酶的活性均呈逐渐降低的趋势,并且土壤中微生物生物量的含量和土壤酶的活性均表现为根际土壤高于非根际土壤。  相似文献   

14个紫花苜蓿品种草产量及营养品质的综合评价     

李岩  徐智明  李争艳  李杨 《草原与草坪》2019,39(4):85-91

为筛选出适宜安徽江淮地区种植的优势品种,对来自美国的14个紫花苜蓿品种进行了连续3年的田间引种比较试验,利用方差分析和灰色关联度分析,综合评价了不同苜蓿品种连续种植3年的草产量及营养品质。结果表明:鲜干草产量,正道440表现最好,均值分别为2.61kg/m^2和0.61kg/m^2,中性洗涤纤维含量、酸性洗涤纤维含量表现较好,均值分别为42%和32.5%。但其粗蛋白含量较低,仅为16.5%;正道656,354和903等品种在粗蛋白含量、中性洗涤纤维含量、酸性洗涤纤维含量等方面表现突出,品质较好,其中,354的鲜干草产量表现也很突出,正道656次之。经过灰色关联度综合评价后,正道656最接近理想品种,其草产量及营养品质的均值分别为:鲜草产量2.1kg/m^2、干草产量0.47kg/m^2、粗蛋白20.4%、中性洗涤纤维35.0%、酸性洗涤纤维26.3%,其次较突出的品种依次是正道440、354、525、903,以上5个品种均适宜在当地推广种植。  相似文献   

农作物病害流行程度划分标准的方法探讨     

刘万才 《中国植保导刊》2001,(6):10-12

农作物病害流行程度划分标准是确定病害流行轻重的主要依据.在研究分析当前病害流行程度划分标准存在问题的基础上,提出病害流行程度划分标准应该由多项指标改为一项指标,分别以相应行政区域的加权病情指数或虫口密度来表示,并给出了其测算方法.同时提出行政区域范围的大小不同,病害流行程度分级标准的指标不同.行政区域小,分级指标值大;行政区域大,分级指标值小.从而解决了目前实际工作中病害流行程度分级标准不规范的问题.  相似文献   

The Effect of Treatment With Ulocladium Atrum on Botrytis Cinerea-attack of Geranium (Pelargonium Zonale) Stock Plants and Cuttings     

M. Gerlagh  J.J. Amsing  W.M.L. Molhoek  A.I. Bosker-van Zessen  C.H. Lombaers-van Der Plas  J. Köhl 《European journal of plant pathology / European Foundation for Plant Pathology》2001,107(4):377-386

In two successive seasons, the effect of treatment of geranium stock plants with the competitive saprophytic fungus Ulocladium atrum as a biocontrol agent against Botrytis cinerea was compared to a fungicide treatment with Euparene M. B. cinerea incidence and severity on the stock plants, B. cinerea spore load in the air around stock plants and death of cuttings due to B. cinerea were scored. B. cinerea incidence and severity were much stronger in the second than the first experiment. This was quantitatively expressed by higher numbers of conidia of B. cinerea monitored in the second than the first year, both on necrotic (a maximum for the control of 27.5 × 10⁶ spores per sample - all necrotic leaves of five plants - in experiment 1 against 86 × 10⁶ in experiment 2) and green leaves, but numbers of conidia of B. cinerea recovered from the air were only slightly different. The death rate of cuttings was moderate in the first and extremely high in the second experiment. For the fungicide treatment, maximum sample values of 7% and 76% of 6-week old cuttings were killed in the first and the second experiment respectively. Treatment with U. atrum was effective in reducing all parameters studied. With the exception of the spore load of B. cinerea in the air and the success of cuttings, the effect of U. atrum varied from as good as the fungicide to half as effective. In the first trial, only Euparene M reduced spore load in the air, in the second trial only U. atrum consistently did so. In the first trial U. atrum reduced death of 4-week old cuttings, though less than fungicide (1.2, 20 and 38% killed with fungicide treatment, U. atrum treatment and control respectively). In the second trial only the fungicide reduced loss of cuttings. The impact of the data on the integration of U. atrum in a control system of B. cinerea in geranium is discussed.  相似文献