共查询到19条相似文献，搜索用时 187 毫秒
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作者用Ｆｏｘｐｒｏ语言编写了计算机程序，用来统计分析棉花不同生育时期的棉花株式图，应用该系统能大大提高工作效率和准确性，节省大量时间，并能从调查中获取尽可能多的信息。 相似文献
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对于茶叶企业而言，自身发展需要经济效益的支持，此时销售质量直接决定了企业自身经济效益。一般情况下，茶叶企业管理人员更加重视销售额和成本控制，此过程也是提升企业经济效益的主要途径之一。针对上述内容，茶叶企业需要合理控制成本，才可达成预期经济目标，因此此过程需要应用数学建模思想，从而对茶叶销售中出现的各种问题进行解决，以此达到经济效益最大化的目标。本文对基于数学建模法的茶叶销售方案作出分析，从数学建模内涵和相关优势入手，合理分析茶叶销售的关联性问题，得出茶叶市场特征，最终通过数学建模对销售市场可能的经济效益作出分析，从而提出具体的茶叶销售策略。 相似文献
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我国苎麻育种的成就与问题 总被引：4，自引：1，他引：3
本文从介绍我国近几十年来苎麻育种成就着手，剖析苎麻育种中存在的遗传基础单一、育种手段较落后，品质目标单一和基础理论研究薄弱等问题，并就新技术在苎麻育种上的应用进行探讨。 相似文献
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棉花目标价格补贴政策是我国在农产品领域实施精准化补贴政策的首次尝试。棉花目标价格补贴政策是否充分激发了不同类型棉农生产积极性和提升了棉农的生产性收入，需要对其进行阶段性总结和全面分析，明晰棉花目标价格补贴政策的实施效果和问题，为完善政策提供依据。首先从理论上分析了棉花目标价格补贴政策对棉农收入的影响，然后根据2018年对新疆棉农的实地调研数据，运用普通最小二乘法回归和回归分解法，分析了棉花目标价格补贴政策对棉农收入的效应，并考察了棉花目标价格补贴政策对不同种植规模棉农的影响程度。结果表明：棉花目标价格补贴政策对棉农收入具有显著的促进作用，即棉花目标价格补贴政策的实施可以提升棉农收入；同时，棉花目标价格贴补政策对不同种植规模棉农具有不同的效应，对中小规模种植棉农的影响程度较低，而对大规模种植棉农的影响程度较高。因此，为巩固脱贫攻坚效果，需要稳定新疆棉花目标补贴政策；为避免过度刺激生产和保护生态环境，可以对补贴主体及其补贴面积进行限制。此外，应加大对小规模农户补贴的标准。 相似文献
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中国热带农业科学院试验场职工人数多、类别多、重名多，存在工资及养老金发放时间短、调整数多、操作难度大等问题。本文就如何完善工资及养老金的发放及其审核、复核、审批程序，尽可能确保无差错和及时地发放工资及养老金等问题进行探讨，提出相应的建议。 相似文献
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Miranzadeh MB Heidari M Mesdaghinia AR Younesian M 《Pakistan journal of biological sciences: PJBS》2011,14(1):59-63
The objective of the study is surveying microbial quality of drinking water in Kashan rural areas and determining the rural population that using safe water in terms of microbial quality in second-half of 2008. In this cross-sectional study, microbial quality of water in all rural areas was determined in 3 stages based on 3 parameters as Total Coliforms, Fecal Coliforms and Heterotrophic Plate Count (HPC). The results of this study illustrates that 100.0, 47.71 and 92.99% population in under coverage and non under coverage areas of Kashan Rural Water and Wastewater Company (KRWWC) and all Kashan rural areas, respectively using safe water in terms of Fecal Coliforms and 98.4, 21.2 and 88.00% population in under coverage and non under coverage areas of KRWWC rural areas and all Kashan rural areas, respectively using safe water in terms of Total Coliforms. There is also a meaningful difference in microbial quality between under coverage and non-under coverage rural areas. The results of this study express that the fecal contamination in under coverage rural areas is excellent, but there is a bad condition in non-under coverage areas. Generally, the microbial quality in all Kashan rural areas is approximately equal to national microbial criteria. Its been also illustrated that the role of KRWWC in supplying safe drinking water in terms of microbial quality for rural population is very important. 相似文献
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以灌溉区大田玉米为研究对象,利用Landsat 8TM卫星数据把冠层含水量指数MSI2与温度指数LST结合构建冠层水分温度指数(CTWDI),对研究区2014~2016年大田玉米灌浆期旱情进行监测。结果表明,CTWDI与灌浆期玉米冠层含水量极显著相关(r=0.719**),可以较好地反应灌浆期高覆盖度玉米水分状况。基于CTWDI的灌浆期玉米干旱监测结果与实际情况相符,且Kappa系数均高于57%,改进了玉米生育中后期的旱情监测方法,可以利用CTWDI对灌浆期高覆盖度条件下的玉米进行干旱监测。 相似文献
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Spray applications are most effective when they cover the greatest per unit area, improving target pest control. In order to optimize spray applications, nozzle companies have developed new designs that seek to provide the greatest and most uniform coverage per target unit area. While dual fan nozzles have been examined against single fan nozzles in several studies, there has not been a comprehensive comparison of multiple nominal flow rate and multiple dual fan nozzle types. This study sought to examine pressure, droplet size classification, and nozzle arrangement effects on droplet number density on horizontal artificial collectors using a fixed application rate. The relationship between coverage and nozzle type was significant (P < 0.001) as was the relationship between coverage and pressure (P < 0.001). The 207 kPa pressure resulted in the highest coverage for every nozzle type except the alternating TADFs (ATADF)s. The GAT 11003 resulted in the highest coverage overall with 39.6% at the 207 kPa pressure, followed by the TADF 11005 and TADF 11003 at 38.6% and 38.3% coverage respectively. The effect of pressure was significant for the droplet number density (P < 0.001) as was the effect on droplet number density from nozzle type (P < 0.001). The 414 kPa pressure resulted in the highest droplet number density for all nozzle types except the AITTJ 11003 and the MDD 11004. The GAT 11003 and GAT 11004 produced the highest overall droplet number densities with 73.0 and 72.6 droplets cm2 at the 414 kPa pressure. The GAT 11003 had the greatest droplet number density at every pressure. Nozzle arrangement has a significant effect on spray coverage with asymmetric dual fan nozzles, and it would be recommended to alternate these nozzles on a spray boom to increase coverage especially at higher application speeds. Results from this study show that an applicator can select a coarser droplet size classification without observable loss in coverage, while greatly reducing the drift potential of the application. 相似文献
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利用RADARSAT-2雷达数据与改进的水云模型反演冬小麦叶面积指数 总被引：1，自引：0，他引：1
利用微波遥感反演植被参数往往受到植被分布不均、稀疏植被覆盖、地表裸土等因素影响,导致微波遥感用于农业参数估计的效果不佳。为解决微波遥感反演地表植被参数的问题,本研究在原有的水云模型基础上引入植被覆盖度以及裸土对于雷达后向散射系数的直接作用信息,提出一种改进的水云模型,并充分考虑地表植被的覆盖分布情况,结合地面实测数据及RADARSAT-2雷达数据对改进模型进行验证,然后根据改进模型通过查找表法反演出植被含水量,最后利用叶面积指数与植被含水量的经验关系间接得到叶面积指数的估测值。结果表明,改进的水云模型对后向散射系数的模拟精度比原有的水云模型精度高,模拟的决定系数在HH和VV极化时分别为0.850和0.739,均方根误差分别为0.918dB和1.475dB。由此可见,改进的模型对研究区植被条件更为敏感,能够较好地分离出植被与土壤信息对雷达后向散射系数的影响,同时利用其反演得到的叶面积指数精度较高,决定系数达到0.841,均方根误差为0.233。 相似文献
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桉树人工林间作豆科牧草适应性评价 总被引：3，自引：0，他引：3
桉树人工林单一种植引起植被多样性减少是普遍存在的问题,间作成为恢复与重建桉树林下植被多样性的重要途径。桉树人工林下间作豆科牧草综合评价结果表明GC1581、GC1517、热研10号和热研2号柱花草牧草产草量达296.54~852.08 kg/hm2,耐干旱,旱季牧草产量占年产草量的18.42%~23.95%,在极端干旱条件下仍保持一定的生长和生物量的积累,植株存活率达50.2%~61.9%,间作牧草在桉树行间形成良好的覆盖层,覆盖度达47.083%~79.252%,适应性强。间作可促进林下植被的恢复,进而促进植被多样性的形成,这对增加桉树人工林的群落组成、形成多层次片层结构有积极意义。 相似文献
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