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阐述了日光节能温室建设的技术发展及机理,介绍了高寒地区日光节能温室的建设方法和技术要求,提出了发展日光节能温室的研究方向。  相似文献   

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This paper reports a study on the solar and thermal radiative environment inside a plastic film cladded tunnel type greenhouse.In the day-time the net radiation is found to be strongly correlated to the incoming solar radiation, in analogy to what is known to occur over open ground. At night, a simple radiation budget model is effective in relating the net radiation to the radiometric properties and temperature of the surfaces which form the envelope of the greenhouse and the external (atmospheric and terrestrial) radiation fluxes.  相似文献   

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温室内光照环境对作物生长有重要影响,然而受温室形状、方位、覆盖材料、天气等各因素的影响,温室内光分布一直是研究的难点。该文提出基于计算机视觉技术和基于图像的光照技术来采集温室内真实环境的光分布,通过高动态范围图像的制作,以及从图像中的光源信息的提取,得到温室内光分布的辐射度图,该图能够真实反映不同天气情况下以及一天中不同时刻、不同方向的光照强度分布,能较好地模拟场景周围的自然光照。该研究将为温室内复杂光源分布的获取和作物冠层顶部入射辐射的研究提供准确的光照模型。  相似文献   

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基于Web的温室作物模拟系统的实现   总被引:4,自引:3,他引:4  
基于Web技术、OOP(面向对象设计)思想,根据作物生长发育模型特点,提出了计算机模拟系统的结构设计方案,并采用ASP.NET技术规范和Visual C#程序语言,初步实现了一个基于Web技术远程调用的温室作物生长发育计算机模拟系统,该系统目前可对番茄和黄瓜等温室作物光合作用、干物质积累与分配等过程进行模拟与分析。  相似文献   

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该文主要根据温室控制的特点,介绍了一套基于485总线分布式智能温室环境控制系统.其中包括系统的构成,硬件结构,传感器的选择和软件的各种功能.  相似文献   

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Abstract

Global climate change is one of the most important issues of contemporary environmental safety. A scientific consensus is forming that the emissions of greenhouse gases, including carbon dioxide, nitrous oxide and methane, from anthropogenic activities may play a key role in elevating the global temperatures. Quantifying soil greenhouse gas emissions is an essential task for understanding the atmospheric impacts of anthropogenic activities in terrestrial ecosystems. In most soils, production or consumption of the three major greenhouse gases is regulated by interactions among soil redox potential, carbon source and electron acceptors. Two classical formulas, the Nernst equation and the Michaelis–Menten equation, describe the microorganism-mediated redox reactions from aspects of thermodynamics and reaction kinetics, respectively. The two equations are functions of a series of environmental factors (e.g. temperature, moisture, pH, Eh) that are regulated by a few ecological drivers, such as climate, soil properties, vegetation and anthropogenic activity. Given the complexity of greenhouse gas production in soils, process-based models are required to interpret, integrate and predict the intricate relationships among the gas emissions, the environmental factors and the ecological drivers. This paper reviews the scientific basis underlying the modeling of greenhouse gas emissions from terrestrial soils. A case study is reported to demonstrate how a biogeochemical model can be used to predict the impacts of alternative management practices on greenhouse gas emissions from rice paddies.  相似文献   

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Soil cultivation changes and usage of agricultural wastes can have profound impacts on greenhouse gas (GHG) emission from soil. In this study, the effects of soil cultivation and organic amendment on GHG emission were investigated using aerobic incubation. Surface soil (0–20 cm) from (1) rice–legume consecutive rotation (Rice) and (2) recently (<3 years) converted from rice field to plastic-covered intensive vegetable and flower production (VegC) were collected in Kunming, P.R. China. Rose (Rosa rugosa Thunb.) residues and cattle manure were applied at 5% by weight. Results indicated that N2O and CO2 fluxes were significantly influenced by soil cultivation, organic amendment, incubation time and their interaction (p <0.05). Applying cattle manure increased, while rose residue decreased, cumulative N2O emissions from soil (84 days). Rose residue application significantly increased cumulative CO2 emissions with peak values of 6371 (Rice) and 7481 mg kg?1 (VegC), followed by cattle manure addition figure of 2265 (VegC) and 3581 mg kg?1 (Rice). Both were significantly higher (p <0.05) than the un-amended Control at 709 (VegC) and 904 mg kg?1 (Rice). Our study demonstrates that a low C/N ratio in cattle manure is better than a high C/N ratio in rose residue in regard to reducing the global warming potential of agricultural soil.  相似文献   

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通过室内培养试验研究生物炭及生物硝化抑制剂添加对黄土区设施菜地土壤N2O和CO2排放的影响,并与化学合成硝化抑制剂作对比。试验设置6个处理:不施肥(CK)、施氮(N)、施氮+生物炭(N+BC)、施  相似文献   

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The Framework Convention on Climate Change separately recognizes sources and sinks of greenhouse gases and provides incentives to establish C offset projects to help meet the goal of stabilizing emissions. Forest systems provide multiple opportunities to offset or stabilize greenhouse emissions through a reduction in deforestation (C sources), expansion of existing forests (CO2 sinks) or production of biofuels (offset fossil fuel combustion). Attributes and dimensions of eight forest-sector C offset projects, established over the past three years, were examined. The projects, mostly established or sponsored by US or European electric utilities, propose to conserve/sequester over 30 × 106 Mg C in forest systems at an initial cost of $1 to 30 Mg C. Given the relative novelty and complexity of forest sector C offset projects, a number of biogeochemical, institutional, socio-economic, monitoring, and regulatory issues merit analysis before the long-term potential and cost effectiveness of this greenhouse gas stabilization approach can be determined.  相似文献   

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After 1989, the use of potassium (K) mineral fertilizers in the Czech Republic dropped from ~55 kg K ha?1 to a mean rate of ~6.5 kg in the last decade. In order to test alternative solutions for K fertilization, the trioctahedral mica mineral zinnwaldite (8% K), orthoclase (10% K) and waste mica from Cínovec (Kru?né Hory Mts/Erzgebirge, Czech Republic), consisting primarily of zinnwaldite, were applied as the only K sources for spring barley. The minerals were treated in three different types of high-energy mills under different working conditions. Application rates in the range 139–820 mg K kg?1 were tested in quartz sand cultures. In all treatments, plant growth, total plant biomass and the K content in the plant tissues increased in the order zinnwaldite > waste mica > orthoclase. K fractionation and K plant uptake were significantly influenced by the milling method used. The effect of 195 mg K kg?1 as zinnwaldite on K uptake from K-depleted soils was positive; however, it was smaller than in sand cultures because of the relatively high content of non-exchangeable K in the soils. Direct use of waste mica as a K fertilizer is limited by the increased fluorine and heavy metal content.  相似文献   

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Abstract

To optimize the nutrient management of upland rice production on tropical ferralsols, a greenhouse experiment was established using the multi-nutrient omission approach. A reciprocal soil origin-rice cultivar transplant experiment was also conducted to better understand the relative contributions of the soil origin and the rice cultivar in rice nutrient limitation. We tested the deficiency of seven major and secondary nutrients [nitrogen (N), phosphorus (P), potassium (K), sulfur (S), calcium (Ca), magnesium (Mg), and silicon (Si)] and a solution of six micronutrients (B, Mn, Cu, Co, Na, Mo) likely to limit the growth of two upland rice cultivars, Chhomrong Dan and Nerica 4, on two Ferralsols from the highlands of Madagascar. We found severe multiple nutrient deficiencies. For both cultivars, P, Ca, N, Mg omission significantly depressed the shoot and root dry biomass and their amounts in plant tissues. However, the main limiting nutrients were not the same in both soils. We conclude that the multinutrient deficiencies observed for rice growth in the Ferralsols are site-specific, even though P limitation appears to be in common, and requires a holistic consideration of the mineral fertility, including micronutrients.  相似文献   

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本试验以金太阳和骆驼黄杏为试材,对设施栽培杏树果实与新梢生长发育和花芽分化进程进行了研究.结果表明设施中的两个杏品种,不论是正常区还是高温区,果实的纵横径生长都呈"双S"生长曲线,但是高温区的果实纵横径的生长量高于常温区.设施条件下金太阳杏树的新梢生长的快速生长出现次数没有改变,与露地杏树相同均为三次,但生长速率大,维持时间长,出现的时间也与露地不同.设施杏树果实与新梢之间在生长时间上存在有交替现象.设施内金太阳杏的花芽形态分化进程从5月20日开始到10月下旬结束.  相似文献   

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中国设施农业经过几年快速膨胀后,逐步开始走向稳定发展,提高质量、降低成本、增强市场竞争力,已成为行业发展的急需,相应对设施、设备和技术的规范化要求也提上了议事日程.本文在回顾我国设施农业发展历程的同时,重点综述了温室标准化的发展过程、取得的成就和存在的问题,旨在为我国今后温室行业标准化发展再上新台阶准备条件.  相似文献   

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保护性耕作对温室效应的影响   总被引:15,自引:2,他引:13  
农业是非常重要的温室气体排放源,而不合理的农田管理措施强化了农田排放源的特征,同时弱化了吸收汇的作用。保护性耕作对温室效应的影响来自两方面,一方面是免耕减少了农田CO2排放,对CH4和N2O排放的影响不明确;另一方面是秸秆还田以后部分秸秆C以气体形式释放进入大气,增加了农田CO2、CH4排放,但秸秆还田相对其他用途提高了土壤固碳潜力,减少了总的温室气体排放量。通过耕作与秸秆管理对温室气体排放资料的整理分析,指明保护性耕作是一种有利于减少温室效应的农田管理措施,为保护性耕作的温室效应研究提供借鉴。  相似文献   

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Although extracellular proteins may play an important role in the soil environment, these proteins are difficult to isolate because they are immediately degraded by soil microbes, or become associated with clay mineral and humic substances. We developed a method of isolating extracellular proteins from greenhouse soils. Phosphate buffer (pH 6.0) was used to extract protein from soil. A phosphate buffer with higher pH was not recommended because it extracted a large amount of non-proteinaceous organic matter as well as protein and, as a result, the extracted protein was difficult to separate by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE). After removing cells by filtration, proteins dissolved in the soil extract were recovered by precipitation with 5% trichloroacetic acid (TCA) and isolated by SDS-PAGE. Proteins were detected in 10 of 32 soil samples derived from different greenhouses and the protein bands ranged in apparent molecular mass from 35 to 68 kDa, suggesting that some of soils derived from greenhouse culture contained significant amounts of a specific protein soluble in 67 mM phosphate buffer (pH 6.0). N-terminal amino acid sequence of one of the isolated proteins was found to be a homologue of thermostable cellulase produced by the genus Humicola, a thermophilic fungus.  相似文献   

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