The Effects of Terrain Slope and Orientation on Different Weather Processes in China under Different Model Resolutions          下载免费PDF全文

HUANG Danqing  QIAN Yongfu 《Acta Meteorologica Sinica》2009,23(5):617-628

Currently, short wave radiation at the ground surface (GSW) is calculated under the assumption of a horizontal surface. This method of estimating the GSW may lead to considerable errors when the model resolution becomes higher and the model terrain becomes steeper. In this paper, to improve the short wave solar radiation simulations, a terrain slope and orientation parameterization has been implemented into the non-hydrostatic mesoscale model GRAPES (Global/Regional Assimilation and Prediction System). The effects of the terrain slope and orientation on different short range weather processes in China under different model resolutions are simulated and discussed. In the simulations, topography height is taken from NCEP(National Centers for Environmental Prediction) with a resolution of 1 km, and the slope and orientation of terrain are calculated using different staggering schemes and under di erent weather conditions. The results show that when the model resolution is low (30 and 60 km) and the slope of terrain is not large, the influence of the slope and orientation of terrain on the GSW is not evident; otherwise, however, it is not negligible. Under high model resolutions (3 and 6 km), the increase (decrease) of simulated precipitation corresponds to the decrease (increase) of the GSW induced by the slope effect, and the variations of precipitation are usually ranged between －5 and 5 mm. Under the high resolution, the surface temperature and heat fluxes are strongly correlated to each other and the high correlation exists mostly in the complex terrain regions. The changes of the GSW, precipitation, surface temperature, and heat fluxes induced by the e ects of the terrain slope and orientation are more obvious in mountainous regions, due to the alternations in the atmospheric circulation. It is found as well that under the weather condition of less cloud and less precipitation, the effects of the terrain slope and orientation can be more realistically seen. Therefore, the terrain slope and orientation can usually be neglected in numerical models when the horizontal model resolution is low and the slopes are moderate, but should be taken into account when the model resolution becomes high and the terrain is steep and undulating.  相似文献   

The Effects of Terrain Slope and Orientation on Different Weather Processes in China under Different Model Resolutions          下载免费PDF全文

黄丹青  钱永甫 《Acta Meteorologica Sinica》2009,23(5):617-628

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墙面太阳辐照的理论计算与模式估计——以上海为例   总被引：7，自引：0，他引：7  

朱志辉 《地理学报》1987,(1)

倾斜面和墙面的太阳辐射和日照状况对于农林生态、建筑环境工程以及城市气候研究具有重要意义。为了充分利用水平面日照与日射的丰富资料以得到倾斜面和墙面相应变量的细致分布规律,本文将理论计算与模式估计相结合的方法具体应用到一个平原城市(上海)。在倾斜面直接辐射计算中,本文以倾斜面与水平面天文辐射月值的比值(R_b)取代各月代表日的(R_(bo))在倾斜面日照时间的估计中,本文提出利用水平面日照百分率的简单方法。在倾斜面辐射与日照的时空分布规律方面主要突出其随方位与随季节(月份)的变化。 作为例子,本文计算分析了上海市每月各方位墙面上的天文辐射与可能日照时间,对相应的实际日照时间进行了估计。并在计算给出的(R_b)值的基础上,利用散射辐射各向同性与非各向同性模式研究了上海各月墙面直接辐射与总辐射随方位的变化特征。  相似文献   

Study of Absorption Properties of Modified Zeolites     

R.G. Gevorkyan  H.H. Sargsyan  G.G. Karamyan  Y.M. Keheyan  H.N. Yeritsyan  A.S. Hovhannesyan  A.A. Sahakyan 《Chemie der Erde / Geochemistry》2002,62(3):237-242

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Radiation-induced decomposition of U(VI) phases to nanocrystals of UO₂     

Satoshi Utsunomiya  Lu-Min Wang 《Earth and Planetary Science Letters》2005,240(2):521-528

U⁶⁺-phases are common alteration products, under oxidizing conditions, of uraninite and the UO₂ in spent nuclear fuel. These U⁶⁺-phases are subjected to a radiation field caused by the α-decay of U, or in the case of spent nuclear fuel, incorporated actinides, such as ²³⁹Pu and ²³⁷Np. In order to evaluate the effects of α-decay events on the stability of the U⁶⁺-phases, we report, for the first time, the results of ion beam irradiations (1.0 MeV Kr²⁺) of U⁶⁺-phases. The heavy-particle irradiations are used to simulate the ballistic interactions of the recoil-nucleus of an α-decay event with the surrounding structure. The Kr²⁺-irradiation decomposed the U⁶⁺-phases to UO₂ nanocrystals at doses as low as 0.006 displacements per atom (dpa). U⁶⁺-phases accumulate substantial radiation doses (∼1.0 displacement per atom) within 100,000 yr if the concentration of incorporated ²³⁹Pu is as high as 1 wt.%. Similar nanocrystals of UO₂ were observed in samples from the natural fission reactors at Oklo, Gabon. Multiple cycles of radiation-induced decomposition to UO₂ followed by alteration to U⁶⁺-phases provide a mechanism for the remobilization of incorporated radionuclides.  相似文献   

饱和度对玄武岩微波响应的影响试验研究     

高峰  熊鑫  熊信  周科平 《岩土力学》2022,43(Z2):43-51

岩石的微波处理效果受诸多因素影响,其中水是一种良好的吸波介质,能提高岩石的微波吸收能力。为探索饱和度对微波照射后岩石响应特征的影响效果,以不同饱和度的玄武岩试样为研究对象,以升温特性、波速与孔隙度变化以及动态抗拉强度等为参考指标,开展了3 kW功率微波照射的破岩试验。从细观与宏观角度的分析结果表明：（1）水的存在影响了微波照射过程中岩样的升温特性,照射的前15 s内,饱和度低于75%组明显促进了升温速率,而饱和度达到100%则作用相反,升温速率低于干燥组;15～30 s随着含水率的减少与蒸发吸热,含水试样升温速率降低;30～45 s内水分蒸发完毕,含水试样的升温速率接近干燥试样。（2）饱和度差异导致玄武岩在微波照射后发生不同程度的波速与孔隙率的变化,波速降幅范围为8.18%～17%,孔隙率增长范围为18.71%～43.65%,损伤效果并未随饱和度升高而增强。（3）同样照射条件下,50%饱和度组在蒸汽压力和热应力共同作用下快速达到强度极限,试样直接发生破坏。其余组试样大多未发生明显细观损伤,最终动态抗拉强度差距不明显。  相似文献   

渤海海面太阳辐照强度的观测分析与计算方法研究   总被引：8，自引：2，他引：8  

张新玲  郭心顺  吴增茂  由建华  闫丽风 《海洋学报》2001,23(2):46-51

对渤海海面(1998-09-24～10-07和1999-04-28～05-11)实测太阳辐射日总量同云量的关系和春、秋季的对比关系及其与插值计算出的晴日太阳辐射日总量的关系进行了分析,并同烟台(福山)测站的结果进行了对比分析.通过分析发现,渤海海面太阳辐射日总量春季远大于秋季,其无云条件下的太阳辐射日总量与插值计算出的晴日太阳辐射日总量的差异秋季大于春季.分析表明,海陆温差引起的海面大气垂直输送与水汽物的产生是造成这种差异的主要原因.采用经验公式对渤海海面太阳辐射日总量进行计算,计算结果与实测结果具有较好的一致性.结果表明所用经验公式及推算出的参数适合于春、秋季渤海海面太阳辐照度的计算.  相似文献   

非开挖地下管线铺设施工方法     

邓洪超  郑午 《世界地质》1997,16(1):92-96

铺设地下管线大都采用开挖路面的方法,这样做的结果是破坏了街路的完整性,影响交通与城市面貌,采用“非开挖地下管线铺设方法”施工可以避免为铺设地下管线而开挖街路。损伤路面、影响交通。它包括以下三种方法：挤密导孔－拉削扩孔方法,小断面挖掘液面送管方法,地下夯管方法。  相似文献   

水下激光通讯发射接收系统   总被引：1，自引：0，他引：1  

黄晓圣  王汝霖  徐仁声  刘金涛 《中国海洋大学学报(自然科学版)》1998,(4)

报导了可用于水下激光通讯的由８９ｃ５１单片机控制的全双工水下激光通讯系统实验装置。系统能有效的消除水下背景光的影响,并具有３～４个数量级动态范围的自动增益放大能力以更有效地接收水下激光通讯信号。能在水下以较高的数据传输率传递信息,数据传输率可以用软件调整,最大数据传输率为１９．２ｋＢｉｔｓ／ｓ。  相似文献   

近距离照射联合贻贝提取物对荷瘤鼠治疗效果的研究   总被引：1，自引：0，他引：1  

李翊  毛文君  王海青 《海洋科学》1999,23(3):63-66

观察了近距离照射联合贻贝提取物对Ｕ１４鼠免疫功能的影响,以期探讨贻贝提取物在放射治疗中的作用。结果表明,贻贝提取物使荷瘤鼠因近距离照射而下降的免疫指标明显回升,包括脾脏ＮＫ细胞杀伤活性,丝裂原诱发的淋巴细胞转化强度和外周血白细胞总数及脾指数,亦有效增强放疗的治疗效果。  相似文献