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Patricia Flores Damián Poggi Stella Maris García Marcela Catraro 《International Journal of Fruit Science》2017,17(1):29-40
The objective of this work was to quantify changes in the germination capacity of Juglans nigra seeds following storage and then artificial stratification. Seeds were stored at 5 and –20 °C under 5% and 14% internal moisture content (IMC) for 0, 8, 10, and 12 months under conditions with oxygen or under vacuum. Germination percentage (GP) was affected by storage temperature, IMC, and storage period. Seeds stored with 5% IMC succeeded in germinating regardless of the temperature. Seeds stored with 14% IMC did not germinate (–20 °C) or germinated during storage (5 °C). The GP was reduced with the time of storage in seeds at –20 °C and 5% IMC and this effect was avoided in storage under vacuum. In conclusion, the germination capacity of black walnut seeds did not change for up to 12 months at low above-zero temperature and low IMC (5 °C, 5% IMC), being the most cost-effective alternative for long-term storage of black walnut seeds in commercial nurseries. Vacuum storage avoided the decrease of around 50% in average germination capacity of seeds stored for a year at –20 °C. 相似文献
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为满足季节性冻土地区越冬期间储水灌溉管理的需求,基于山西省汾河灌区季节性冻土的冬季大田土壤水分入渗试验,得到了120组Philip入渗模型参数实测样本,借助MATLAB软件,建立了以土壤温度、有机质质量分数、土壤含水率、土壤体积质量、物理性黏粒量为输入因子、以Philip入渗模型参数吸渗率和稳渗率为输出因子的多元非线性传输函数模型,并用实测资料对该模型进行了精度检验。结果表明,预测参数的相对误差均小于11%,预报精度在可接受范围之内。 相似文献
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This paper describes a prototype of a portable rainfall simulator that can simulate a wide range of rainfall intensities with a kinetic energy similar to that of natural rainfall and, more innovatively, provide simultaneous or independent simulations of rainfall and overland flow at the microplot scale (0.70 m2 ). The design of the rotating shutter disc makes possible a wide range of rainfall intensities, from 30 to 155 mm/h without changing nozzle type or working pressure. Overland flow intensity can be adjusted from 94 to 573 mm/h depending on nozzle type and working pressure. The flow is applied on the upper side of the experimental plot. The Christiansen coefficient of uniformity of the simulated rainfall varied between 81.4 and 85.1%, and the calculated kinetic energy was >90% the kinetic energy of corresponding natural rain. Special attention was paid to portability. Stainless steel was used whenever possible and the equipment was constructed in modules so that it could easily be dismantled and carried by two people. A telescopic-type frame allows operation on sloping ground. 相似文献
85.
Amrakh I. Mamedov Benayahu Bar‐Yosef Irit Levkovich Rivka Rosenberg Avner Silber Pinchas Fine Guy J. Levy 《Land Degradation \u0026amp; Development》2016,27(6):1629-1639
Application of organic wastes to cultivated lands can replace mineral fertilizers but may also alter soil physical properties and enhance pollution potential. The objective of this study was to investigate the effects of biosolids [composted manure (MC) and activated sludge (AS)] and specific biosolid component [orthophosphate (OP), phytic acid (PA) and humic acid (HA)] application on soils differing in texture [loamy‐sand (Ramat‐HaKovesh, RH), loam (Gilat, GL) and clay (Bet‐Dagan, BD)], infiltration rate, runoff volume and soil sediment loss. The soils were packed in erosion boxes (400 × 200 × 40 mm) and subjected to six consecutive simulated rainstorms, each of 186 mm deionized water. The results showed that runoff volume and sediment loss from untreated soils increased with increasing clay contents. In treated soils, the response to AS application differed from the response to other amendments; in the BD clay and GL loam, it was the only amendment that caused a decrease in sediment removed by runoff. In the RH loamy‐sand, all amendments reduced the final infiltration rate, but only AS and HA increased the measured runoff. It is proposed that the difference in the response of the soils to the amendments is associated with the soil's ability to attenuate changes in the negative charge on the clay edges following the increase in the specific adsorption of charged anions, thus controlling clay swelling and maintaining aggregate integrity. The effects of amending soils with a source of organic matter in order to control runoff and soil erosion are not straight forward and depend on soil and amendment properties. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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为了研究提取方法对饲用苎麻绿原酸和总黄酮提取效益的影响,笔者采用真空冷冻干燥和热风干燥2种不同的干燥提取方法,对‘湘饲苎X1’和宁远苎麻的各部位器官进行了绿原酸和总黄酮的定量提取。分析得率差异表明:无论是绿原酸还是总黄酮,‘湘饲苎X1’和宁远苎麻不同部位器官的测定含量,均表现为真空冷冻干燥样品明显高于热风干燥。在真空冷冻条件下,‘湘饲苎X1’的营养根、叶片、地下茎和茎的绿原酸测定含量提高幅度都大于100%,各器官总黄酮测定含量提高幅度也超过了1倍,且茎提高了6.08倍。宁远苎麻在真空冷冻干条件下,叶、地下茎、营养根、茎中绿原酸和总黄酮测定含量也都大幅提高。由此可见,在饲用苎麻药理成分含量的提取工艺上,真空冷冻干燥方式明显优于热风干燥方式。 相似文献
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Solar energy sourcei s regenerative source,reasonable use of it is an effective way to solve the problem of exiguousness of the traditional energy. But the usage of the solar energy is limited. To achieve the satisfactory effect, we must use a reasonable system style combined with the traditional energy. Through the application of swimming pool heating with solar energy. It is pointed out that more attention should be puid to reason dispose the collectors,store up heating tank,assistant thermal resource and dependable auto control. Solar energy can take place of the traditional energy, it is obviously that the solar energy can save the money and the energy and protect the environment. 相似文献