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311.
一、前言根据《清洁空气法修正案》中“防止空气质量严重恶化”条款的规定,在一些重大的排放设施建成以前,要履行排放量批准手续,即对这些设施的大气质量影响作出预评价,因此,对大气质量模拟模式提出了更高要求。为了在模式的使用方面做到较为统一,1978  相似文献   
312.
1.引言在过去的十年间,气象研究技术的发展已导致了采集及检验有关环境大气参数的数值信息系统的应用。因此,目前已有可能把数据的获取及处理工作全部实现自动化。  相似文献   
313.
THE PERMIAN SYSTEM OF THE NUJIANG—LANCANGJIANG—JINSHAJIANG AREA, SOUTHWESTERN CHINA  相似文献   
314.
A Metallogenic Model of Gold Deposits of the Jiaodong Granite-Greenstone Belt   总被引:34,自引:0,他引:34  
An analysis of trace elements and isotopic geochemistry suggest that the ore-forming materials of gold deposits in the Jiaodong granite-greenstone belt have multiple sources, especially the mantle source. Seismic wave, magnetic and gravity fields show that the crust-mantle structure and its coupling mechanism are the fundamental dynamic causes for the exchange and accumulation of materials and energy in the metallogenic system. Considering the evolution history of the structural setting, the tectono-metallogenic dynamics model of the area can be summarized as follows: (1) occurrence of the greenstone belt during the Archean-Proterozoic-the embryonic form of Au-source system; (2) stable tectonic setting in the Paleozoic-an intermittence in gold mineralization; (3) intensive activation and reformation of the greenstone belt in the Mesozoic-tectono-mineralization and tectono-diagensis; (4) posthumous structural activity in the Cenozoic-destruction of orebodies in the later stage. In the middle and late Ind  相似文献   
315.
最近的许多地震动预测方程(GMPE)都使用上30m土层的平均剪切波速度Vs30表示场地效应。然而,在一些研究发现V鹦。是表征场地效应合理参数的同时,另一些研究则给出了相反的证据。本研究使用日本的大地震动数据集对这两个场地效应参数的预测能力进行系统的比较。采用该方法的基础是使用场地周期(Ts,4倍剪切波从基岩到地表的走时)或Vs30对经验模拟场地效应的标准偏差和放大比振幅进行比较。模拟的场地效应除了包括地震动预测方程的场地效应项,还特别包括KiK-net台网的地表与井下记录之间的场地放大比。就KiK—net台网数据而言,对Ts〉0.6s的土层场地,Ts被确定是比Vs。。好的预测参数;而对T。〈0.6s的场地,这两个参数对放大比产生了相似的变异性。在所有场地类别的多数周期上,由地震动预测方程获得的场地效应,Vs30和Ts在统计上相等;而在一些谱周期上,Vs30产生了比Ts小的变异性。KiK-net台网地表一井下记录与地震动预测方程结果的矛盾可能由地震动预测方程中包括震源变异性、路径变异性和场地变异性的大变异性所致。相比之下,KiK-net台网地表一井下数据对的变异性小多了。虽然VS30。和Ts对地震动预测方程的数据产生了统计上相似的标准偏差,但瓦仍然获得了比Vs30更好的中值放大比。  相似文献   
316.
Before the 1980s, El Ni?o was believed as the sea surface warming along the coast of Peru in South America. As the positive anomaly strengths, the warm water expands westward along the equator to form large area of anomalous high sea surface temperature. Rasmusson and Carpenter (1982) summarized the de-velopment process of the sea surface warm water and the corresponding wind field[1] during ENSO cylce. However, this canonical El Ni?o was questioned by 1982-1983 warm episode and later dat…  相似文献   
317.
The three-dimensional nonlinear quasi-geostrophic potential vorticity equation is reduced to a linear form in the stream function in spherical coordinates for the permanent wave solutions consisting of zonal wavenumbers from 0 to n and rn vertical components with a given degree n. This equation is solved by treating the coefficient of the Coriolis parameter square in the equation as the eigenvalue both for sinusoidal and hyperbolic variations in vertical direction. It is found that these solutions can represent the observed long term flow patterns at the surface and aloft over the globe closely. In addition, the sinusoidal vertical solutions with large eigenvalue G are trapped in low latitude, and the scales of these trapped modes are longer than 10 deg. lat. even for the top layer of the ocean and hence they are much larger than that given by the equatorial β-plane solutions. Therefore such baroclinic disturb-ances in the ocean can easily interact with those in the atmosphere.Solutions of the shallow water potential vorticity equation are treated in a similar manner but with the effective depth H = RT / g taken as limited within a small range for the atmosphere.The propagation of the flow energy of the wave packet consisting of more than one degree is found to be along the great circle around the globe both for barotropic and for baroclinic flows in the atmosphere.  相似文献   
318.
The absorption properties of the water vapor continuum and a number of weak bands for H2O, O2, CO2, CO, N2O, CH4, and O3 in the solar spectrum are incorporated into the Fu-Liou radiation parameterization program by using the correlated k-distribution method (CKD) for the sorting of absorption lines. The overlap absorption of the H2O lines and the H2O continuum (2500-14500 cm-1) are treated by taking the two gases as a single-mixture gas in transmittance calculations. Furthermore, in order to optimize the computation efforts, CO2 and CH4 in the spectral region 2850-5250 cm-1 are taken as a new single-mixture gas as well. For overlap involving other absorption lines in the Fu-Liou spectral bands, the authors adopt the multiplication rule for transmittance computations under which the absorption spectra for two gases are assumed to be uncorrelated. Compared to the line-by-line (LBL) computation, it is shown that the errors in fluxes introduced by these two approaches within the context of the CKD method are small and less than 0.48% for the H2O line and continuum in the 2500-14500 cm-1 solar spectral region, -1% for H2O (line) H2O (continuum) CO2 CH4 in the spectral region 2850-5250 cm-1, and -1.5% for H2O (line) H2O (continuum) O2 in the 7700-14500 cm-1 spectral region. Analysis also demonstrates that the multiplication rule over a spectral interval as wide as 6800 cm-1 can produce acceptable errors with a maximum percentage value of about 2% in reference to the LBL calculation. Addition of the preceding gases increases the absorption of solar radiation under all sky conditions. For clear sky, the increase in instantaneous solar absorption is about 9%-13% (~12 W m~2) among which the H2O continuum produces the largest increase, while the contributions from O2 and CO2 rank second and third, respectively. In cloudy sky, the addition of absorption amounts to about 6-9 W m-2. The new, improved program with the incorporation of the preceding gases produces a smaller solar absorption in clouds due to the reduced solar flux reaching the cloud top.  相似文献   
319.
This article reviews Fuqing ZHANG’s contributions to mesoscale atmospheric science,from research to mentoring to academic service,over his 20-year career.His fundamental scientific contributions on predictability,data assimilation,and dynamics of high impact weather,especially gravity waves and tropical cyclones,are highlighted.His extremely generous efforts to efficiently transmit to the community new scientific knowledge and ideas through mentoring,interacting,workshop organizing,and reviewing are summarized.Special appreciation is given to his tremendous contributions to the development of mesoscale meteorology in China and the education of Chinese graduate students and young scientists.  相似文献   
320.
利用平面照相法,以江苏南热发电有限责任公司#Q2号烟囱为研究对象,进行了500次拍摄,通过风向风速、云量、太阳高度角等气象数据,确定了不同稳定度下南京北郊大气扩散参数的特征。与P-G扩散曲线对比发现,在强不稳定A、弱不稳定C、中性D层结中,南京北郊的大气垂直扩散参数在距离排放源200 m范围内更不稳定,而在200—1000 m范围内更稳定。其中,不稳定B层结的扩散曲线与P-G扩散曲线一致,较稳定E、稳定F层结出现于白天的频率很低。对比垂直扩散参数幂函数表达式σ_z=γx~α的系数值γ和α,本研究中α值分别比国家标准增加了28. 6%(A层结)、56. 4%(C层结)、30. 4%(D层结),而B层结的α值却比国家标准减少了22. 9%。此外,通过高斯扩散公式计算得到SO_2和NO_X扩散到观测点的浓度,发现该计算值仅占气象楼污染气体监测平台实测SO_2和NO_X浓度的0. 82%和0. 69%。结合风场发现,SO_2和NO_X实测值受观测点东部工业污染物排放的叠加效应影响较大。其中,NO_X的实测值在受到偏东风和偏南风的影响时具有较大值,且在0. 5~1. 5 m·s~(-1)的较弱风速影响时,NO_X的实测值将达到60μg·m~(-3)以上。  相似文献   
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