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机械专业学科竞赛是提升在校工科大学生综合素质、实践能力最有效的方法和手段.文章通过研究高校大学生创新创业能力培养方面的现状,指出了各高校实施创新创业教育过程中遇到的困难和问题,阐述了参加机械专业学科竞赛对促进相关工科专业的学生创新创业能力培养的重要作用,基于实际情况指出了目前各高校都非常重视的学科竞赛及在开展学科竞赛的... 相似文献
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如果创业教育与学生所学的专业不紧密结合，那么创业教育必然与专业课程的学习、专业技能培养以及专业培养目标脱轨，创业教育很可能成为学生专业学习的负担和干扰。如何结合专业进行大学生创业教育？笔者以高校汽车类专业为例，提出了大学生创业教育的一些思考与建议。 相似文献
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随着社会的发展,社会对高校毕业生创新创业能力的需求越来越迫切,"创新创业"课程建设一直是创新创业教育研究的核心,"创新创业"课程建设直接影响了学生创新创业能力的培养,各大高校"创新创业"课程内容、形式丰富多样.基于此,课题组论述了新工科背景下大学生"创新创业"课程建设情况,分析了现有创新创业相关课程建设中存在的问题,并... 相似文献
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近年来,双创教育发展势头强劲,在国家政策、高校改革、企业对接的推动下,学生获得了政策、资金、培训等多方面的资源.服务三农是我国经济发展的重要举措,农村发展、农民脱贫致富、农业产业升级都需要懂农业技术的技能型人才.在当前背景下,涉农高职院校要结合政策导向和经济发展需求培养技能型人才,创业教育改革与专业建设特色密不可分.通过对涉农专业学生的创业教育进行改革创新,旨在培养有服务三农意识的技能型人才. 相似文献
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本文从知识结构、创业能力、创业品格、创业方法四个方面阐述了高职院校工科类专业创新创业人才的培养目标和要求,提出了新时期高职院校工科类专业创新创业人才培养的方法和途径,为构建高职院校工科类专业创新创业人才培养模式提供切实依据,为高职院校完成培养高素质技能型人才的根本任务奠定基础。 相似文献
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工科高职院校将学生成人教育和成才教育有机结合,将学生思想教育和专业教育有机结合,将国家产业战略和教育战略有机结合,积极践行工匠精神,提升学生职业素养,培育未来大国工匠,培养创新创业人才。本文在确立构建工科类高职院校创新创业人才培养模式的基础上,构建由创新创业理论教学方法、创新创业实践教学模式、校企产学研合作教育模式等构成的工科类高职院校创新创业人才培养模式。 相似文献
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新的教育改革发展阶段,随着"互联网+"时代的到来,对高校的创新创业教育发展也有着促进。传统的高校创业教育还有诸多方面有待优化,面对新的时期就要注重创新创业的思想以及和"互联网+"相结合。文章主要就"互联网+"时代高职院校创新创业改革的重要性和创新创业人才培养目标加以阐述,然后对创新创业教育的问题和改革建议详细探究,希望能借助此次对"互联网+"下高职院校创新创业教育改革研究,有助于教学改革目标实现。 相似文献
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国内各高校对创业教育工作从理论上、实践上进行了大量的研究,但是整个的高校创业教育还停留在探索阶段.从规模上来看,高校毕业生创业比例偏低,说明高校创业教育还处于萌芽状态.随着创业型大学的提出,创业教育工作发生了根本性变化.高校通过学校的创业教育课程和创业实践活动,培养学生的创业意识和创业能力. 相似文献
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Production of halophytes using saline waters and soils and feeding them to livestock is one of the most sustainable methods of conservation in desert ecosystems, in addition to accomplishing food production for the people living in these areas. Therefore, to study the possibility of irrigating Kochia (Kochia scoparia L. Schrad) with minimum quantities of highly saline water for use as a fodder crop in arid environments stretching across saline waters, two experiments were carried out in the Research Farm of the Ferdowsi University of Mashhad, Iran. In the salinity experiments, two populations of Kochia, including the Sabzevar and Indian genotypes, were irrigated with ground water having electrical conductivity (EC) of 5, 15, and 20 dS m−1. In the irrigation-treatment experiments, two local populations of Kochia, including Sabzevar and Borujerd, were subjected to four irrigation regimes as follows: complete irrigation (100%), 80%, 60%, and 40% of the water requirements using a saline ground water with EC = 5 dS m−1. Because, the Indian genotype is preferred as an ornamental plant, it is not suitable for increased dry-matter production under high-salinity irrigation water compared to the local genotype (Sabzevar), which is suitable for forage. The Sabzevar genotype produced a large amount of dry matter (7530 kg ha−1), even when irrigated with 20 dS m−1 saline water. The best time for harvesting Kochia for fresh feeding is at the end of flowering (88 days after sowing or DAS), when the biomass is relatively high (6500 kg ha−1) and the leaf-to-shoot ratio, as a quality index, is approximately 50%. The highest green-area index was observed at 15 dS m−1 and decreased at high levels of salinity. Photosynthesis and transpiration rate did not decline significantly with increasing external salinity four weeks after salinization, but increased in both genotypes at 15 dS m−1, indicating that the salinity-tolerance threshold of Kochia for both photosynthesis and transpiration reduction is above this salinity level. The Indian genotype also showed a very low seed yield (210 kg ha−1) at low levels of salinity, whereas Sabzevar produced 1120 kg ha−1 seed under the same conditions. Different irrigation regimes had a significant effect on the biomass and seed production of Kochia. The highest forage yield was obtained from complete irrigation, with 11.1 Mg ha−1 dry material. Sabzevar local population represented a better performance in terms of all characteristics, except accumulation of inflorescence dry matter, and no significant effects were recorded. In conclusion, Kochia's high foliage production capacity in the presence of salinity and limited irrigation make this plant suitable for use as an alternative forage crop in harsh environmental conditions. There is a wide range of intraspecific variation in K. scoparia, but more investigation is needed to introduce it as a cash crop. 相似文献
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Yasar Emekli Ruhi Bastug Dursun Buyuktas Nefise Yasemin Emekli 《Agricultural Water Management》2007,90(3):205-212
This study was conducted to assess crop water stress index (CWSI) of bermudagrass used widely on the recreational sites of the Mediterranean Region and to study the possibilities of utilization of infrared thermometry to schedule irrigation of bermudagrass. Four different irrigation treatments were examined: 100% (I1), 75% (I2), 50% (I3), and 25% (I4) of the evaporation measured in a Class A pan. In addition, a non-irrigated treatment was set up to determine CWSI values. The status of soil water content and pressure was monitored using a neutron probe and tensiometers. Meanwhile the canopy temperature of bermudagrass was measured with the infrared thermometry. The empirical method was used to compute the CWSI values. In this study, the visual quality of bermudagrass was monitored seasonally using a color scale. The best visual quality was obtained from I1 and I2 treatments. Average seasonal CWSI values were determined as 0.086, 0.102, 0.165, and 0.394 for I1, I2, I3, and I4 irrigation treatments, respectively, and 0.899 for non-irrigated plot. An empirical non-linear equation, Qave=1+⌊6[1+(4.853 CWSIave)2.27]−0.559⌋, was deduced by fitting to measured data to find a relation between quality and average seasonal CWSI values. It was concluded that the CWSI could be used as a criterion for irrigation timing of bermudagrass. An acceptable color quality could be sustained seasonally if the CWSI value can be kept about 0.10. 相似文献
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A. Akramkhanov R. Sommer C. Martius J. M. H. Hendrickx P. L. G. Vlek 《Irrigation and Drainage Systems》2008,22(1):115-126
In Khorezm, a district of Uzbekistan situated in the Aral Sea Basin, soil salinization is an important driver of soil degradation
in irrigated agriculture. The main objective of this study was to identify techniques that enable rapid estimation of soil
salinity. Therefore, bulk electrical conductivity of the soil (ECa-meas) was measured with three different devices (2P, 4P, and CM-138) and electrical conductivity of the soil paste (ECp-meas) was measured with the so-called 2XP device. These measurements were compared with independent estimates of ECa-calc and ECp-calc based on laboratory measurements of the saturated extract, ECe, of soil samples from the same sites. Soil salinity could be assessed satisfactorily with all four devices. ECp-meas could be well reproduced by the 2XP device (R
2 = 0.76), whereas ECa-meas estimates using 2P, 4P, and CM-138 in the field were less accurate (R
2 < 0.50). The sensitivity of all devices to the main ions Cl− and Ca2 + suggests that the measuring principles are similar for all instruments. The devices can therefore be used interchangeably.
Field assessment of soil salinity was considerably enhanced by the use of CM-138, because large areas can be quickly assessed,
which may be desirable in spite of the lower accuracy. 相似文献
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Shortage of organic matter hinders agricultural production in the Sahel, and this lack of enough organic matter is more severe for peri-urban horticulture, which depends heavily on it. Alternative sources of organic matter that offer new options for peri-urban horticulture can help reduce the potential for conflict over finite resources between traditional crop production and peri-urban horticulture. Both agronomic and economic evaluations of an organic amendment called heated sewage sludge (HSS) were conducted in the research station of International Crops Research Institute for the Semi-Arid Tropics (ICRISAT)-Niamey, Niger, West Africa. For this study, HSS, a material imported from Japan, applied at a dosage application equivalent to 20.0 kg 100 m−2 on lettuce fields led to production levels as high as those of conventional methods, and the yield became even higher than those of conventional methods when the dosage was increased to 50.0 kg 100 m−2 and 100.0 kg 100 m−2. Even though HSS was imported, its benefits outweighed its cost, as evidenced by the positive net returns. Since profitability in peri-urban horticulture is much higher than that of traditional crop production, the results of this study imply that if adopted, the use of HSS can lead to increased availability of organic matter for traditional cropping systems. 相似文献
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Pierre-Olivier Malaterre 《Irrigation and Drainage Systems》1995,9(4):297-327
This article suggests and defines a characterisation of irrigation canal regulation methods, based on four criteria: considered variables (controlled, measured, and control action variables), logic of control, design method (structure and technique) and field implementation (configuration and device). Depending on the chosen criterion and partition rule, different classifications can be built from this characterisation. In conclusion, a structured characterisation table of the main published canal regulation methods is presented.Abbreviations ASCE
American Society of Civil Engineers
- CACG
Compagnie d'Aménagement des Coteaux de Gascogne
- CARA
Compagnie d'Aménagement Rural d'Aquitaine
- CARDD
Canal Automation for Rapid Demand Deliveries
- CEMAGREF
Centre National du Machinisme Agricole, du Génie Rural, des Eaux et des Forêts
- CNABRL
Compagnie Nationale d'Aménagement du Bas — Rhône Languedoc
- ELFLO
Electronic Filter and Level Offset
- FB
Feedback or closed — loop control
- FB
dn
Feedback or closed-loop downstream control
- FB
mi
Feedback or closed-loop mixed control
- FB
up
Feedback or closed-loop upstream control
- FF
Feedforward or open-loop control
- GPC
Generalised Predictive Control
- LQR
Linear Quadratic Regulator
- MIMO
Multiple Inputs, Multiple Outputs
- nI mO
n Inputs, m Outputs
- P
Perturbation
- P
Estimation of perturbations
- PID
Proportional, Integral, Derivative Controller
- PIR
Contrôleur Proportionnel, Intégral, Retard (PI Delay controller)
- Q
Discharge in the canal
- Q
dn
Downstream discharge in the canal
- Q
in
Intermediate discharge in the canal
- Q
up
Upstream discharge in the canal
- SCP
Société du Canal de Provence
- SISO
Single Input, Single Output
- U
Control action variable
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V
Volume in a canal pool
- V
Elementary control action variable
- w
Regulator gate opening
- Y
Controlled variable
- Y
c
Target controlled variable
- y
Water elevation
- y
dn
Downstream water elevation of the pool (therefore upstream of a regulator)
- y
in
Intermediate water elevation in the pool
- y
up
Upstream water elevation of the pool (therefore downstream of a regulator)
- Z
Measured variable 相似文献
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为探明毕纳1号烟草最适移栽期,研究移栽期对烟草气候斑病的发生和生长的影响。结果表明:适宜的移栽期有利于减轻毕纳1号烟草气候斑病的发生,可改善毕纳1号烟草农艺性状、提高烟叶叶绿素含量,并在一定程度上间接提高烟株抗病性;其中4月27日移栽综合表现最佳,移栽后60 d发病率和病情指数分别为20.10%和2.67,较其他2个移栽期分别显著(P<0.05)降低9.66%～12.12%和1.30～1.61。该结果为毕纳1号烟草适时移栽和气候斑病综合防控提供了技术参考。 相似文献
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E. López-Mata 《Agricultural Water Management》2010,98(1):190-198
There are numerous models capable of simulating crop behavior under different water stress conditions. However, none of them takes into account the effect of irrigation water uniformity on yield. The model developed simulates the uniformity effect on yield and the repercussion on gross margin (GM). The application of the model to a maize crop in Albacete (Spain) indicates that for the same irrigation depth, an increase in uniformity of water in the soil (CU) corresponds to a 4% increase in yield for the common irrigation strategy in the area, and a 6.8% increase in yield for the optimal irrigation schedule established by the model. Values of percentage of adequately irrigated area (a) between 50 and 80% appear to be adequate for values of CU > 80%. This effect has special relevance on the GM mainly when designing the irrigation strategy of areas with limited water resources. This leads to improvement of CU from 75 to 95% for the common irrigation depth applied to maize and may increase GM up to 27%. For small irrigation depths, the effect of CU on GM is reduced. The maximum GM is reached at ETa/ETm < 1 and a <100%. The paper also describes a methodology for determining the most suitable irrigation schedule under regulated deficit irrigation conditions. 相似文献
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We present the results from a sensitivity analysis and a preliminary short-term, site-scale performance assessment of the analytical soil and groundwater nitrate transport RISK-N. The study was carried out in the Central Valley of Chile, on a 2.6 ha corn (Zea mays L.) field underlain by a shallow unconfined aquifer during the cropping season 2000–2001. Nitrogen levels in soils as well as NO3−–N irrigation water and groundwater concentrations were monitored through the crop-growing period, the latter by a network of 16 monitoring wells. A sensitivity analysis shows that both the nitrate flux from the vadose zone and NO3−–N groundwater concentration are mainly influenced by the initial soil nitrogen levels, water input, and soil porosity. Also, simulated groundwater NO3−–N levels are sensitive to changes on the saturated zone denitrification constant. An additional analysis further reveals the significance of the latter parameter, in conjunction with the amount of applied nitrogen fertilizer. We obtained a good agreement between observed average and simulated values. While the model performs well when spatially averaged values are used (root mean square error, RMSE = 1.4 mg l−1 of NO3−–N), the prediction error increases (RMSE = 1.9 mg l−1 of NO3−–N) when the concentration in each well is considered. This fact could be explained by the time and space scale of the experiment and the characteristics of the RISK-N model. The model is easy to use and seems appropriate for mid- and long-term studies of nitrogen contamination in groundwater for agricultural conditions in the Central Valley of Chile and under limited field data availability conditions. However, it needs to be tested for longer periods and under different climatic conditions, soil types, and aquifer characteristics, before its range of applicability can be fully established and recognized. 相似文献
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Improvement of FAO-56 method for olive orchards through sequential assimilation of thermal infrared-based estimates of ET 总被引：1，自引：0，他引：1
The aim of this study is to use the FAO-56-based single crop coefficient approach to estimate actual evapotranspiration (AET) of an olive (Olea europaea L.) orchard in the Mediterranean semi arid region of Tensift-basin (central Morocco) during two consecutive growing seasons (2003 and 2004). The results showed that using crop coefficients Kc suggested by FAO-56 method yielded an AET overestimation by about 18% when compared against eddy covariance measurements. Therefore, the determination of appropriate Kc values is required to accurately estimate crop water requirement of olive orchards in such water scarce area.In this study, after applying the Kc values derived over olive orchard in Spain by Pastor and Orgaz [Pastor, M., Orgaz, F., 1994. Riego deficitario del olivar: los programas de recorte de riego en olivar. Agricultura 746, 768-776 (in Spanish)], a better agreement was observed between measured and simulated AET. The root mean square error (RMSE) was reduced by about 28%, from 0.80 to 0.61 mm/day for 2003 and from 0.93 to 0.69 mm/day for 2004. The used Kc values of olives at three crop growth stages (initial, mid-season and maturity) were 0.65, 0.45, and 0.65, respectively, the mid-season stage value being considerably lower than that suggested by the FAO-56.Despite these improvements in the performance of AET simulations, some discrepancies between measured and simulated AET remained, especially when water stress occurred. These discrepancies were ascribed to the estimation of the stress coefficient Kc To overcome this problem, we assimilated into FAO-56 single source model estimates of AET derived from a simple energy balance model along with thermal infrared observations. The latter were collected with the ASTER sensor in 2003 and from ground-based measurements in 2004. The results showed a clear improvement for FAO-56 performances after assimilation: for 2003 and 2004, the RMSE values between observations and simulations, respectively, dropped down from 0.61 to 0.52 and from 0.69 to 0.46 (corresponding to relative reductions of 15 and 40%, respectively). 相似文献
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对烟苗种植过程中需要人工破膜提出了机械自动化破膜,为实现机械自动化破膜提出3种自动定位烟苗方法,利用双立目视觉机器采取信息图像进行定位破膜;采用3D激光扫描对烟苗进行信息采集定位以及利用精准农业这套整体测控系统全方面定位对这三种方法进行了阐述,并在实际烟草种植破膜过程中对3种方法的优缺点进行比较。 相似文献