首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
用1961-2015年贵阳市的地面观测太阳总辐射资料,研究了贵阳市年、季、月的太阳总辐射变化特征,并利用线性及二次拟合回归分析、M-K突变检验和小波变化等方法,验证地面接收太阳总辐射的变化趋势、突变年份和周期变化.结果表明:贵阳市太阳总辐射累年平均年总量为3 721.85 MJ·,1961-1986年总辐射呈明显下降趋势,之后发生逆转,1986-2015年总辐射呈显著上升趋势,总体呈现变暗—变亮的趋势;从四季变化特征来看,春、夏、秋、冬四季的太阳总辐射累年平均值分别为349.27 MJ·、436.89 MJ·、280.31MJ·、174.15 MJ·,地面接收太阳总辐射各季节气候倾向率均为正值,说明各季节接收太阳总辐射都有不同程度的上升;从多年平均各月地面接收太阳总辐射来看,1-5月太阳总辐射逐月上升,在6月有明显的下降,7月、8月达到最高点,之后逐月递减;贵阳市地面接收太阳总辐射在2010年发生突变;太阳总辐射振荡周期为15.6a,现正处于太阳总辐射偏高年份.  相似文献   

2.
为选择更适用的太阳辐射计算模型进行桥梁截面积温度场分析,对国内外不同的太阳辐射计算模型进行归纳总结,主要包括桥梁截面温度场分析中必备的太阳总辐射、太阳直接辐射和太阳散射辐射.对比分析不同数值计算模型之间的异同点及其适用范围.分析发现基于日照时数的日太阳总辐射经验模型ngstr9m-Page模型应用最多,其线性表达式的计算量小且满足精度要求;日太阳总辐射可采用Collares-Pereira and Rabl模型换算为逐时太阳总辐射;逐时太阳直接辐射和逐时太阳散射辐射可分别采用Hottel模型和Liu and Jordan模型进行计算.所总结的逐时太阳辐射计算模型可作为边界条件开展桥梁截面温度场分析.  相似文献   

3.
提出了一个估计各月南向倾斜面太阳总辐射最佳倾角简单表示式,该式表明:太阳赤纬、水平面上太阳总辐射与直接辐射之比以及地面反射率为常数时,最佳倾角随纬度增加而增加而增大,且冬季增大较快;当纬度、太阳 纬和地面反射率不变时,最佳倾角随水平面上辐射经增大而减小,尤其在高纬冬季更加显著;夏季最佳倾角随辐射比的变化较小,这表明一地的辐射状况对该地的坡面最佳倾角有一定的影响,影响程度因季而异。  相似文献   

4.
基于数字高程模型(DEM)数据,综合考虑坡度、坡向、地形遮蔽度等因素,建立了起伏地形下总辐射分布式模型(包括起伏地形下太阳直接辐射、散射辐射和地形反射辐射的分布式模型)。利用1960~2010年数据模拟了福建省旬尺度100 m下的太阳总辐射及其空间分布。结果显示:福建省区域内总辐射平均值绝对误差最大为0. 04 MJ/m~2,平均绝对误差为0. 03 MJ/m~2,平均相对误差为8. 25%,个例年验证平均相对误差为9. 1%;模拟结果表明:福建省总辐射夏季各旬之间变化平缓,实际地形下总辐射受纬度影响没有冬季明显,冬季山地与滨海平原总辐射差异较大;太阳总辐射在局地地形下受坡度坡向影响十分明显,阳坡的辐射量要明显大于阴坡,其中冬季差异最明显;从坡度来看,坡度越大太阳总辐射受坡向的影响越大。  相似文献   

5.
统计了新疆石河子地区1959~2003年太阳总辐射的资料。首先把新疆石河子太阳总辐射资料统一单位,在此基础上用5a滑动平均的统计方法并用最小二乘法建立方程式,计算太阳辐射气候倾向率及日照气候倾向反映太阳辐射的45a变化趋势,用小波分析方法分析太阳总辐射的周期变化规律。结果表明,新疆石河子地区的年日照时数减少,年总辐射量呈显著减少趋势,有11年的周期变化,在1981年左右有突变。初步统计能见度低于10km次数在逐年增多,认为近年来大气混浊度和大气总悬浮粒子浓度的比例增加是引起新疆石河子地区太阳总辐射量下降的原因之一,说明太阳总辐射量的变化与城市发展密切相关。  相似文献   

6.
北疆地区太阳总辐射的时空变化   总被引:1,自引:0,他引:1  
根据1961—2006年北疆4站太阳总辐射气候资料,用气候趋势系数及回归系数研究了太阳总辐射的变化趋势及其时空分布状况,并对影响太阳总辐射的气候因子进行了分析。结果表明,46年间北疆地区的月、季、年太阳总辐射总体均呈现下降趋势,其中太阳年总辐射呈显著下降趋势;太阳总辐射与总、低云量、相对湿度、雨雪日数具有较好的负相关性;造成北疆地区太阳总辐射呈下降趋势的重要气候原因是:平均总、低云量、相对湿度、雨雪日数增加的综合作用。  相似文献   

7.
利用四川省气象站常规观测数据和1∶25万数字高程(DEM)数据,根据地形因子(坡度和坡向)建立太阳辐射分布式模型,计算实际地形下的四川省太阳总辐射时空分布情况;评估分析了能体现太阳能资源的稳定度、资源丰富度、可利用价值等指标.结果表明:四川省复杂地形下的太阳总辐射多年平均年总量为1 800~7 200 MJ/m2,盆地内与高原山地上总辐射值差异较大;总辐射冬季较小,夏季较大,在1981-2010年间降低5%;四川省太阳能资源自西向东规律分布,在太阳能资源稳定且丰富,可利用日数较长,具有开发利用价值的四川省攀西和三州(阿坝州、甘孜州、凉山州)地区可合理利用太阳能资源,在交通不便地区安装小型分布式发电设施;四川省高原和山地以东的盆地地区太阳能资源较差,但仍存在少量太阳能资源丰富地区,有适用中小型分布式发电设施的可能.  相似文献   

8.
当前大部分学者通常只研究太阳辐射大范围区域,对具体地域的研究很少;为此,对河北涞源太阳辐射的时空分布差异及应用可行性进行分析。给出河北莱阳地理位置;太阳辐射数据来源为当地气象站53599。采用Dubayyah太阳辐射估算法对太阳总辐射进行计算,把地表太阳辐射划分成太阳直接辐射、太阳散射辐射和周围地形反射辐射,采用求和方式求出总太阳辐射。给出涞源典型月份太阳直接辐射、散射辐射、周围地形反射辐射和总辐射时空分布差异分析结果,分析了涞源太阳辐射每天不同时段的时间分布差异。对太阳能资源光热转换和光电转换应用可行性进行分析。结果表明:涞源7月太阳辐射值最高,1月太阳辐射值最小,太阳能最佳利用时间为夏季中午;资源应用可行性强。  相似文献   

9.
黄土高原半干旱区地表辐射特征   总被引:9,自引:4,他引:5  
利用兰州大学半干旱气候与环境观测站地表辐射资料,分析了黄土高原半干旱区地表辐射的变化规律,并对该区地表辐射特征、地表反照率的年季变化及其影响机制进行了研究.结果表明:该区全年太阳总辐射较强,年平均值为204.2 W/m2,受地表状况和天气过程等因素影响,年变化表现出不规则或区域性特征.大气和地表对太阳辐射加热的响应需2个月,它们对地表辐射年变化的相对变幅达44.6%和38.9%,比干旱区的(100%)小,这说明该区云量年变化比干旱区的小,且大气和土壤对地表辐射变化的"缓冲"作用更强.反照率的年平均值为0.2432,比荒漠区小;其高值正好对应降雪过程和偏干旱时段,而低值则与降水、连绵阴雨的天气吻合.  相似文献   

10.
利用2012年敦煌云图特征量资料和太阳总辐射逐小时观测资料,研究了敦煌太阳总辐射量与云量、红外亮温、大气可降水、可见光反射率等云图特征量的关系,发现敦煌地区太阳总辐射值的衰减值和总辐射理论值的日变化规律基本一致,敦煌站云图的云量、红外亮温、可见光反射率、大气可降水等特征量和太阳总辐射衰减率具有很好的相关性。进而将云图特征量作为预报因子,利用多元线性回归方程,建立太阳总辐射量统计预报模型。利用2012年敦煌云图特征量资料和太阳总辐射衰减率对方程进行预报效果检验。12个月太阳总辐射衰减率预测结果与实测值变化趋势基本一致,表明基于云图特征量的太阳辐射预报方法具有较好的应用前景。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

20.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号