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1.
豫北平原土壤养分与施肥状况探析   总被引:2,自引:2,他引:2  
利用全球卫星定位系统(GPS)准确定位,在豫北平原进行网格取样(20km×20km),同时进行农业生产状况和农民施肥习惯调查。土壤样品分析结果表明:豫北平原土壤养分状况整体处于中等水平,土壤有机质、土壤速效磷均处于中高水平,而土壤碱解氮和土壤速效钾处于中低水平。与第二次土壤普查结果相比土壤养分含量有明显变化,土壤有机质、土壤速效磷含量显著提高,而土壤碱解氮、土壤速效钾含量下降。施肥调查表明:90%以上农户采用秸秆还田,重视施用氮、磷肥,而忽视施钾肥,存在所施肥料养分单一、养分配比、施肥方式不合理等问题。豫北平原应重视有机肥施用、推广秸秆还田,注意减少磷肥用量、注重补施钾肥,采用复合和缓/控释氮肥及合理的施氮技术。政府和农业科技部门应重视宣传和加大平衡施肥技术的推广。  相似文献   

2.
Using Designer's Simulation Toolkit DeST h developed by Tsinghua University, research was carried out on the energy consumption of a typical residential building in Ningbo, P. R. China, with a focus on the heat transfer coefficient of external windows facing every direction. Results show that variation of the heat transfer coefficient of external windows in all directions has a substantial effect on energy consumption for heating but little effect on energy consumption for cooling. It is difficult to decrease cooling energy consumption by decreasing the heat transfer coefficient of external windows in summer. The heat transfer coefficient of external windows facing south has a significant effect on building energy consumption, but the windows facing north have less effect, and those facing east and west have the least impact. Decreasing the heat transfer coefficient of external windows facing north and south from 4.7 to 3.2 produces the most favorable performance cost ratio for energy saving investments. Reasons for the decrease in the heat transfer coefficient of external windows leading to increased air conditioning energy consumption were discussed. The conclusions are useful for guiding energy efficient building design in other subtropical cities.  相似文献   

3.
以南美白对虾为试材,研究了不同太阳能干燥量(1、2、3、4kg)对南美白对虾干燥速率、水分活度、硬度、弹性、咀嚼性、色泽、收缩率、复水率等品质特性和干燥能耗的影响。结果表明,干燥量越大,干燥速率越慢,干燥时间越长;不同干燥量干燥初期,南美白对虾的水分活度变化不明显,不同干燥量间差异不明显,当干燥到一定程度(干燥到5h时),不同干燥量下水分活度出现显著差异(P<0.05);干燥量为3kg与4kg时,南美白对虾干燥产品咀嚼性分别为137.41mJ和131.06mJ,显著优于其他干燥量(P<0.05);不同干燥量条件下,南美白对虾干燥后的色泽变化趋势不明显;干燥量3kg与4kg,干燥后的南美白对虾收缩率分别为22%和21.2%,复水率分别为73.0%和76.5%,收缩率显著低于、复水率显著高于其他干燥量(P<0.05);干燥量为3kg,干燥时间为7h时,总干燥能耗最低,为10.25kWh,显著低于其他处理(P<0.05)。干燥量3~4kg时,南美白对虾干燥产品的咀嚼性、色泽、收缩率、复水率等理化特性优于其他干燥量,干燥能耗低,适于干燥南美白对虾产品。  相似文献   

4.
5.
气候变暖已对建筑全生命周期的运行状况产生了不可忽略的影响,准确评估气候变化下的建筑能耗对建筑方案设计和既有建筑的节能改造具有重要意义。进行气候变化下建筑能耗的精确预测,必须拥有未来的逐时气象数据。以寒冷地区北京和夏热冬暖地区广州为研究对象,将挑选的两个城市典型气象年为基线气候,结合全球模式下的预测气象数据,应用变形法修正TMY的气象参数,得到直至本世纪末的10个节点年逐时气象文件,并进行了全年能耗模拟,预估了两个城市的办公建筑在气候变化下建筑能耗的变化趋势。结果表明:在两种预测排放情景下,干球温度、含湿量和太阳辐射均呈增加趋势;北京采暖能耗显著降低、制冷能耗增加,总能耗减少,广州采暖能耗降低、制冷能耗显著增加,总能耗增加。  相似文献   

6.
The internal shading can both impact on the sunshade and indoor daylighting, and work as an indoor heat source by absorbing heat. Presently the evaluation of overall energy efficiency of the internal shading is perceptual and qualitative. Therefore, the tests of the internal surface temperatures of house envelopes and the daylighting illuminance were carried out. It is shown that the surface temperature of interior walls with internal shading are 0.6℃~1℃ lower than those without; however,the surface temperature of internal shading is 3℃~5℃ higher than that of the interior walls. It can be seen that internal shading also forms an indoor heat source. The energy consumption of air-conditioning with internal shading decreases by 17.24% than that without, which indicates the internal shading can certainly reduce the indoor air conditioning load; however, the daylighting illuminance declines by 81%, with the results that the artificial lighting energy consumption is 1.88 times as much as that without the internal shading.  相似文献   

7.
By using the building thermal environment simulation Toolkit DeST to simulation calculation of a residential building in Shanghai,the quantitative relationship between the factors of operation mode of air conditioning affecting the energy consumption of heating and air conditioning in residential buildings has been obtained in this paper,moreover,it has come to a conclusion that the tolerable temperature is superior to control temperature of air conditioning in respect of sensitivity and the living mode of indoor personnel has certain effect on the cold energy consumption.  相似文献   

8.
We introduced a site selection method based on the modified maximum elevation angle intended for mountains possibly affecting the measurement and control of the initial phase in a launching port located in mountainous areas. To use the former analysis results, the method, along the helices whose center is the launcher's project point, analyze each point's visibility on the helices. The visible area can be obtained by comparing the visibility at each moment in the initial phase. Finally, there can be three points in the above visible area with distances longer than required.  相似文献   

9.
The heating and air conditioning energy consumption of residential buildings is influenced by the behavior of indoor living personnel.On the basis of research and analysis,two kinds of calculation modes reflecting the behavior of indoor living personnel are estimated.Under two kinds of different calculation modes,by using the building thermal environment simulation Toolkit DeST to simulate the energy consumption calculation for certain residential building in Shanghai,and the simulation results are compared with the research results.The influence of calculation mode on heating and air conditioning energy consumption of residential buildings in Shanghai is analyzed in this paper.In order to obtain the right simulation calculation method correctly reflecting the energy consumption of residential buildings.This method can be used for analysis and evaluation of heating and air conditioning energy consumption of residential buildings in Shanghai,and it can serve as instruction for right energy design of residence building.  相似文献   

10.
为深入了解长江经济带能源消费与经济增长的关系,本文基于灰色关联分析模型,利用1995-2015年能源消费与经济增长相关数据,对长江经济带能源消费与经济增长的相关性进行实证分析。结果表明: 在能源消费产业中,批发、零售业和住宿、餐饮业能源消费与经济增长的关联度最大,为0.88,农业、工业能源消费与经济增长的关联度最小,分别为0.50、0.52;在能源消费品种中,煤碳消费量与经济增长的关联度相对较小;以天然气和电力为代表的优质能源与经济增长具有显著的关联度。长江经济带应着力调整产业结构、优化能源消费结构,以实现绿色低碳循环发展。  相似文献   

11.
为研究不同含水率对生土材料热工性能及对生土建筑能耗的影响,分别从陕西西安、新疆吐鲁番、西藏拉萨采集当地土样并加工成同一密度级的土坯试件,测试了从绝干到湿饱和状态下各种生土导热系数的变化规律。采用建筑能耗动态模拟结合敏感性分析,研究了上述3种土样在不同含水率下导热系数变化对建筑能耗的影响规律。结果表明,含水率与生土导热系数成线性相关;含水率对生土建筑耗热量的影响具有显著的地域性差异;新疆生土在墙体湿度增大情况下建筑能耗增加幅度最小。  相似文献   

12.
Aimins at the state that present central air- conditioning systems performance in high ineffective energy consumption, this paper studies the reasons of ineffective energy consumption and the key technique to solove the problem. A set of energe saving device for central air - conditioning systems is developed. A system dynamical mathematical model is established in theory, and an optimal performance pattern is fired. The central air - conditioning system can work in the optimal pattern with effective comfortability and saving energy by using. The device may save power rate to 22.6% by survey and may have broad market prospect in the southern area.  相似文献   

13.
银耳热风-微波真空联合干燥工艺优化的研究   总被引:2,自引:0,他引:2  
【研究目的】优化银耳热风-微波真空联合干燥工艺。【方法】以银耳的收缩率、复水比、感官质量以及单位能耗为评价指标,研究热风温度、转换水分含量及微波强度等因素对银耳品质以及干燥能耗的影响;并将较佳的热风-微波真空联合干燥工艺与热风干燥以及微波真空干燥进行比较。【结果】采用前期热风温度70℃,转换水分含量30%,后期微波强度5 W/g的干燥工艺参数,可获得品质较佳的银耳干品,且单位能耗最低,接近于微波真空干燥所需能耗。【结论】热风-微波真空联合干燥可极大地改善银耳干品品质及降低干燥能耗;优化后的工艺参数可为银耳热风-微波真空联合干燥技术的工业化应用提供理论依据。  相似文献   

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