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1.
濮阳市最高气温和最低气温非对称变化趋势分析   总被引:2,自引:1,他引:1  
提要:运用1960-2008年以来濮阳逐月和年平均最高、平均最低以及平均气温和相应的极端气温资料,借助线性分析和年代跃变分析的方法,研究其长期变化趋势和年际变化,结果表明:濮阳的夏季平均最高气温呈下降趋势、冬季最低气温和年平均气温呈现明显上升趋势,冬季增温主要在夜间,夏季降温主要在白天。全年的平均增温主要是由冬季夜间引起的。  相似文献   

2.
Since 1988, air temperature, humidity, air quality, noise level and intensity of illumination in lots of dancing halls in China have been investigated and tested. This paper introduces the present situation of indoor environment and air conditioning systems in dancing halls of China. The design indexes of cooling load for room and ontside air are recommended. The reasons for indoor environment deterioration have been found out. From the actual situation of China, the ways for imoroving indoor environment and approach of energy conservation in air conditioning systems are explored.  相似文献   

3.
1953—2010年安康市气温变化特征分析   总被引:2,自引:0,他引:2  
气温变化特征是全球气候变化研究中的一个至关重要的课题, 其研究对生态环境建设与保护、农业生产以及气象灾害的防灾减灾等具有重要意义。笔者以安康市为研究对象, 采用 1953—2010年逐日及年平均气温数据作为基础资料, 运用气候倾向率、 滑动平均法、 M-K趋势检验和突变分析方法对安康市年均气温和各季节气温的变化特征进行分析。结果表明:(1) 安康市近 60年来年平均气温呈上升趋势, 气温倾向率为 0.05℃/10 a, 并经历 “暖-冷-暖” 3个时期, 20世纪 60年代中期之前为偏暖期, 60年代中期到 90年代中期为偏冷期, 之后为偏暖期;(2) 年平均气温的年代际变化表现出 “缓慢上升-显著下降-显著上升” 的特征, 20世纪 80年代为低温期, 但未出现明显的突变点;(3) 安康市冬、 春、 秋 3个季节呈增温趋势, 20世纪90年代后为偏暖期, 且冬春2季增温明显, 秋季次之; 夏季呈降温趋势, 20世纪70年代中期以后降温趋势明显, 进入偏冷期;(4) 夏冬2季平均气温在近60年间存在明显的突变点, 突变时间分别为 1974年和 1991年, 但春秋 2季气温没有出现明显的突变。总体而言, 安康市近 60年来冬春 2季增温明显, 夏季呈降温趋势, 表现出 “冬春变暖、 夏季变凉” 的特征。  相似文献   

4.
人工环境实验室对温度的控制精度低于工艺性环境要求,但冬季若采用分体式空调制热模式控制,实验室温度的波动范围过大,影响采集实验数据的准确性。提出冬季采用空调制冷模式联合电取暖器稳定人工环境实验室内温度的新方法,在背景实验中将新方法和传统空调制热温度控制方法进行对比,结果表明:采用新方法能大幅度提高人工环境实验房间温度的稳定性。为对新方法中空调的设定制冷温度与电取暖器功率匹配问题做进一步研究而进行探究试验,实验结果表明:空调制冷量Q1、测试房间热负荷Q2、电取暖器功率Q3和测试房间其他设备功率Q4存在匹配关系,当空调设定温度相同时,|Q1+Q2-Q3-Q4|值越小,人工环境实验室内温度波动频率越稳定,振幅越小。  相似文献   

5.
选取两栋条件相同的高大平房仓,分别采用离心风机和轴流风机在冬季对库存小麦进行降温通风试验,并对通风前后的粮食温度、水分变化情况进行比较,同时分析两种通风方式的经济效益。通过试验研究得出,冬季在我国北方地区,可适时利用轴流风机对储存粮食进行降温保水通风,既可减少因通风所产生的粮食水分损耗,提高经济效益,又可以达到较理想的降温目的。  相似文献   

6.
辽宁省近53年冬季气温变化特征分析   总被引:1,自引:0,他引:1  
为准确预测辽宁冬季气候,进而达到对冬季设施农业等方面服务的目的,根据辽宁省53个气象观测站1961—2014年逐月的平均气温资料,利用滑动T检验方法、Mann-Kendall检验方法、最大熵谱方法以及Morlet小波分析等方法,分析了1961—2013年辽宁省冬季平均气温的变化特征。结果表明:近53年辽宁省冬季平均气温时间序列呈显著的线性递增趋势,与全球气候变暖趋势相一致。但值得注意的是,近几年辽宁出现了气温偏低的情况;辽宁省冬季平均气温在1985—1986年前后发生了1次明显突变,之前气温以偏低为主,之后开始显著增温。辽宁省冬季平均气温的主要周期为准3~5年周期和17年周期。采用新资料得到的辽宁冬季气温变化特征与采用旧资料的情况略有差异。  相似文献   

7.
An attempt has been made to work out a simple and reliable method of fast frost resistance evaluation of winter oilseed rape using in vitro cultures. In winter rape cv. Górczański, there was investigated cold acclimation ability of hypocotyle sections from 5-days old seedlings and also of callus tissue formed on these sections after subsequent 4 weeks growth on induction medium. It has been found that hypocotyle sections are unable to cold-acclimate. Winter rape calli acclimated well and optimum conditions for acclimation is fortnight's growth at +2°C. Exposure to light during hardening was not necessary for acquiring maximum resistance. On five winter rape cultivars freezing tests were performed using the best cold acclimation conditions. The differences in resistance between hypocotyle sections did not match the differences in field survival or frost resistance of whole plants. As distinct from hypocotyle sections callus tissue appeared to be suitable for evaluation of frost resistance. However, to ensure the objectiveness of assessment in this method is not so easy. The testing temperature must be chosen carefully, because the results can be reliable only at sufficiently low temperature. For correct estimation of the frost resistance level, it is possible to use both the decrease of triphenyltetrazolium chloride reduction rate during freezing and the increase of callus dry weight during 14 days after freezing.
(Abbreviations: BAP — 6-Benzylaminopurine; 2,4-D — 2,4-dichlorophenoxyacetic acid; LT50 — temperature at which 50 % of the plants (or plant material) has been frost killed; MS(0.5;2) — Moorashige and Skoog Basic Medium with addition of 0.5 mg 2.4-D and 2 mg BAP; PPFD — photosynthetic photon flux density; TTC — 2,3,5 triphenyltetrazolium chloride)  相似文献   

8.
Ventilation design is the difficulty of transformer room design. Temperature field and velocity field in a transformer room was simulated by CFD method . By comparing simulation value with the experimental value in related document , the effectiveness of the mathematical model was verified. Based on it, an indoor substation transformer built was taken as the simulation object, then designed and simulated six kinds of ventilation condition by changing the location and area of air inlet, focused on the influence of air inlet on the ventilation effect by comparing the temperature field ,velocity field and temperature characteristic value in different condition. The simulation results show that when air inlet area is fixed, the air inlet should be arranged in the radiator side and its center height should be controlled in the radiator center height or slightly offset position, it should not be higher than the radiator. When the air inlet location is fixed, air inlet area should be increased along the high direction to improve ventilation effect. The conclusions can provide technical support for the ventilation design of transformer room.  相似文献   

9.
开花期干旱胁迫对鲜食糯玉米产量和品质的影响   总被引:4,自引:0,他引:4  
为探明开花期(抽雄吐丝期)干旱胁迫对鲜食糯玉米(吐丝后23 d采收)产量和品质的影响, 以苏玉糯5号和渝糯7号为试材, 采用负水头供水控水盆栽装置控制土壤含水量, 设置开花期正常供水(土壤相对含水量80%)和干旱胁迫(土壤相对含水量60%) 2个处理, 研究干旱胁迫对鲜食糯玉米产量(鲜果穗和鲜籽粒)、籽粒组分、糊化和热力学特性的影响。结果表明, 开花期干旱胁迫减少籽粒数量、降低籽粒重量、缩小籽粒体积, 导致鲜果穗和鲜籽粒产量损失。开花期干旱胁迫下鲜食期籽粒淀粉含量升高, 但对于蛋白质含量渝糯7号降低, 苏玉糯5号变化不显著。蛋白质组分中, 对球蛋白含量影响不显著, 清蛋白、谷蛋白和醇溶蛋白均显著降低。开花期干旱胁迫显著降低淀粉粒平均粒径。碘结合力2015年度显著下降, 2014年度受干旱影响不显著。开花期干旱胁迫下籽粒峰值黏度、谷值黏度和终值黏度在苏玉糯5号中降低, 在渝糯7号中升高。开花期干旱胁迫下两品种峰值温度降低, 回生热焓值和回生值升高, 而热焓值仅渝糯7号在2014年度升高。总之, 开花期干旱降低糯玉米鲜果穗和鲜籽粒产量, 增加籽粒淀粉含量, 降低籽粒蛋白质含量、淀粉粒径和支链淀粉中长链比例, 进而使籽粒回生增加, 但糊化黏度两品种表现不同(渝糯7号升高, 苏玉糯5号下降)。  相似文献   

10.
农产品热泵烘房温度场均匀性是影响农产品干燥品质的重要因素。本文选用5HGR-35型农产品热泵烘房,通过交互式CAD/CAM系统(UG)软件建立热泵烘房3D模型,运用理论分析与计算流体动力学(Computational fluid dynamics,CFD)模拟相结合的方法,研究其内部温度场分布情况,对现有结构烘房的温度场建模模拟,分析模拟结果并对现有结构进行优化。通过模拟得出结论:送风速度越大,烘房内热空气更新越快,换热效果越好。综合温度场分布以及农产品烘干要求,烘房内合理的送风速度为11 m/s左右;在11 m/s风速下,烘房空载时在15 min左右达到设定温度(65℃);小推车设计高度加大300~310 mm烘房内部温度场更均匀;烘房顶部均匀加入3块长×宽×高=2900 mm×20 mm×300 mm的挡板,可以使烘房内部温度场更均匀;小推车与烘房之间及相互之间保持30 mm左右间隙摆放更有利于烘房内部温度场的分布;验证试验中,模拟温度与实测温度吻合性良好。上述结论对烘房的进一步优化设计具有一定的指导意义。  相似文献   

11.
为进一步了解气候变化背景下黄土高原丘陵红枣种植区气温变化特征及其影响,为红枣产业发展提供科学依据。利用红枣种植区1971—2010年气温资料,采用线性倾向估计、Mann-Kendal法、滑动T检验和Morlet小波分析等方法,研究了该区域年、季平均气温以及年极端最高最低气温的演变特征。结果显示:近40年红枣种植区年平均气温和年极端最高气温显著上升,年极端最低气温下降;四季中冬季增温最明显,其次是春季、夏季、秋季。气温在20世纪80—90年代发生突变,冬季气温突变出现最早,其次为年、春季、夏季气温,年极端最高气温。气温主要存在31年左右的周期。空间分布上具有南高北低、西高东低的特征。气温升高对红枣物候期、产量、病虫害等方面均产生一定影响。  相似文献   

12.
Increasing climatic variability is projected to affect large‐scale atmospheric circulation, triggers and exacerbates more extreme weather events, including winter warming and more frequent extreme low temperatures in spring. Historical data from 1961–2000 indicate these temperature fluctuations may seriously affect grain yield of winter wheat crops. In this study, a field air temperature control system (FATC) was used to simulate the winter warming, spring cold and freezing events in the field experiment in 2010–2011 to explore their impacts on growth and yield of winter wheat. Eight elite wheat varieties released during 1961–2000 were included and four temperature scenarios were applied, including late spring freeze alone, winter warming + late spring freeze, early spring cold + late spring freeze and the normal temperature condition as control. Winter warming combined with late spring freeze significantly decreased tiller survival rate, leaf photosynthetic rate and leaf growth in wheat plants, and reduced the spike number and kernel number per spike, and the final grain yield. In contrast, the wheat plants experienced early spring cold had higher tiller survival rate, leaf photosynthetic capacity and sugar accumulation and improved tolerance to the late spring freeze, resulting in less yield loss, as compared with those without experiencing early spring cold. Both the meta‐analyses and the field experimental data demonstrated that the effects of later spring freeze stress on wheat yield were exacerbated by winter warming but were extenuated by early spring cold events. Therefore, it is important to consider the characteristics of temperature fluctuations during winter to spring for precise evaluation of climate change effects on wheat production.  相似文献   

13.
使用4种不同的风机组合方式,对通风前后的降温效果,水分损失情况及能耗情况进行对比分析,结合华南地区气候特点,对高大浅圆仓通风性能进行探索。结果表明:1.1 kW轴流风机不能够满足高大浅圆仓冬季通风降温的需要;5.5 kW小功率离心风机的降温效果优于22 kW大功率离心风机;但从华南地区气候特点考虑,大功率离心风机在高大浅圆仓冬季通风降温上存在一定的优越性。  相似文献   

14.
The passive solar house is one of the effective techniques to decrease the energy consumption of buildings. In this paper, the ventilation performance of synthetic solar house with sunshine room has been analyzed, while it is used as auxiliary ventilation in summer. The mean temperature of air in this room is calculated through the model of heat transfer of solar room, and then the auxiliary ventilation quantity is calculated. It is concluded that the capacity of auxiliary ventilation of synthetic solar house can meet the fresh air demand of common residential construction, but if there are more ventilation quantity needed the capacity of auxiliary ventilation of synthetic solar house is insufficient. The simulation calculation provides the necessary theoretical basis for the further theoretical and experimental research on synthetic solar house.  相似文献   

15.
低温送风空调系统引进新型冰蓄冷设备,采用正丁烷作为制冷剂,制冷剂与水直接接触,换热更强烈且稳定。为了研究该系统相应㶲损因素条件下的节能薄弱环节,实现系统性能优化,基于该系统及各表冷器㶲分析模型,分析了热湿比、新风比、送风温差等㶲损因素对系统㶲效率和各表冷器㶲损率的影响。结果表明:当热湿比变化时,处理二次混风的表冷器㶲损率随之呈正比变化,其他表冷器㶲损率及系统㶲效率随之呈反比变化;当新风比变化时,处理新风的两级表冷器㶲损率随之呈正比变化,其他表冷器㶲损率及系统㶲效率随之呈反比变化;当送风温差变化时,处理一次回风的表冷器㶲损率随之呈正比变化,其他表冷器㶲损率及系统㶲效率随之呈反比变化。  相似文献   

16.
This paper presents a passive dehumidifying solar houase(PDSH),with combination of the Trombe wall and the dehumidifying air layer.For the envelopment of PDSH a porous slab with salt soluiton is inserted into the air layer of Trombe wall.This slab can absorb moisture at inner side and release moisture at outer side.The PDSH wall can dehumidify the room during the outer air layer open in summer and have heatstoring during the outer air layer shut in winter.It is an important character for the Trombe wall.So,the PDSH wall can be applied to insulation and heatstore,or dehumidifying and cooling.Therefore,the PDSH wall can be adopted everywhere in the world.  相似文献   

17.
重庆村镇空气源热泵供暖系统夜间性能实测分析   总被引:1,自引:0,他引:1  
针对重庆山地村镇迫切的供暖需求,选取该地区典型村镇搭建了空气源热泵供暖系统实验平台,分析了空气源热泵系统性能影响因素,并从供回水温度、系统耗电量、供热量、性能系数COP等角度对运行过程中的阶段特性(启动、稳定运行及全阶段)进行阐述,发现系统在3个阶段特点差异很大:启动阶段初始温度对COP影响较为明显,除霜时系统性能下降25%;稳定阶段特性与初始温度无关,室外条件较好时,降低设定温度,COP提高明显;总体来看,启动阶段COP最高,全阶段次之,稳定阶段COP最低。  相似文献   

18.
Fuzzy PID controller was applied in variable air volume system. The task was to control the temperature of supply air and the temperature of air conditioned room (the return air temperature) close to their respective targets. The fuzzy PID control system of supply air temperature and return air temperature was designed respectively. The supply air temperature was controlled through adjusting the valve opening of chilled water. And the indoor temperature was controlled through adjusting the rotational speed of variable frequency ventilator. The supply air temperature and the indoor temperature (return air temperature) were controlled online by fuzzy PID controller. Thus, it was shown that the design of fuzzy PID controller was reasonable and the effect of fuzzy PID control was well.  相似文献   

19.
This paper points out the problems in air conditioning and the urgent need in energy saving. By observations and analyses, it shows that the idea of making use of natural resources to improve the indoor air may date back to ancient times. This paper also examines the feasibility of taking advantage of dry or wet bulb temperature, solar energy, underground rock etc. to regulate the room temperature. Finally, it concludes that the above mentioned old idea has such characteristics as energy saving, low cost and less pollution. Therefore, it is a good green plan in energy saving air conditioning.  相似文献   

20.
海水养殖与气象Ⅱ——惠东石斑鱼寒害对气候变暖的响应   总被引:1,自引:1,他引:0  
冬季低温常给水产养殖造成严重损失,制约了渔业生产发展。本研究揭示了石斑鱼寒害变化特征及其对气候变暖响应规律,分析结果可以指导石斑鱼养殖确定合理的放养时段、评估寒害风险,同时为水产养殖业及政府部门制定防寒减灾决策提供科学依据。利用惠东2011年海水养殖试验点冬季逐日海温及对应气温资料,采用逐步回归分析构建了冬季海温预报方程,代入惠东气象站逐日气象资料得到对应1971—2012年冬季逐日海温资料,根据试验测得的石斑鱼寒害指标,分析了惠东石斑鱼养殖冬季寒害变化特征。结果表明:近42年来惠东地区石斑鱼冬季寒害日数略有减少,大石斑鱼寒害日数多于中石斑鱼,大石斑鱼寒害发生逐日概率有一个升降的变化过程,高发时段为1月1日—2月15日。在未来气候变暖水温升高1℃的情景下,石斑鱼冬季寒害逐日概率显著降低,大石斑鱼平均冬季寒害发生时段显著缩短。平均初寒日期由变暖前的1月4日推迟到变暖后的1月15日,平均终寒日期由变暖前的2月7日提前到变暖后的2月3日。  相似文献   

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