Diurnal Variations of Summer Precipitation in the Beijing Area and the Possible Effect of Topography and Urbanization

The present study examined the diurnal variations of summer precipitation in the Beijing area by using subdaily precipitation and wind observations. A combined effect of topography and urbanization on the characteristics of diurnal variations was suggested. It was shown that stations located in the plain areaexhibited typical night rain peaks, whereas those in the mountainous area exhibited clear afternoon peaks ofprecipitation diurnal variations. The precipitation peaks were associated with wind fields around the Beijing area, which were found to be highly modulated by mountain-valley circulation and urban-country circulation.The lower-tropospheric wind exhibited a clear diurnal shift in its direction from north at 0800 LST to southat 2000 LST, which reflected mountain-valley circulation. The transitions from valley to mountain windand the opposite generally happened after sunset and sunrise, respectively, and both occurred earlier for thestations located closer to mountains. By comparing the diurnal variations of precipitation at stations in anortheast suburb, an urban area, and a southwest suburb, it was revealed that the northeast suburb grouphad the highest normalized rainfall frequency, but the southwest group had the lowest from late afternoon tolate evening. On the contrary, in the early morning from about 0200 to 1000 LST, the southwest group andurban group had the highest normalized rainfall frequency. This pattern might originate from the combined effects of mountain-valley topography and urbanization.     

Correlation assessment and monitoring of the potential pollutants in the surface sediments of Pyeongchang River, Korea

The study provides a baseline for the assessment of the organic and inorganic pollution specially, heavy metal contamination in the surface sediments of Pyeongchang River,South Korea.The assessment of the study areas was done with respect to metal pollution load,ecological risk and geoaccumulated risk.Based upon the used indices,a priority index(P_index) was used to rank the utmost contaminated sites.Though the concentrations of mercury in all sediments were below the guideline, the significant enriched contamination was observed by all applied indices.As expected,the values of pollution load index（PLI）,ecological risk index（RI） and geoaccumulation risk index(I_geo) demonstrated lower heavy metal contamination in upstream areas compared to the downstream. Admittedly,sediments were unpolluted to slightly-polluted according to PLI while high to extremely high ecological risks were observed in several sediment samples.Furthermore,all the samples were uncontaminated as per I_geo.After simplification of I_geo,the P_index,showed the utmost contaminated sediments with a value of 2.537.Notably,protective measures should be taken to the highly contaminated areas which are prioritized by P_index Admittedly,the maximum concentrations of total organic carbon,total nitrogen,inorganic nitrogen,total phosphorous,inorganic phosphorous,calcium, magnesium,sodium and potassium were significantly observed as 7.8×10⁴,3,185,36,1,032,3.7, 1,5163,2,881,669 and 4,076mg/kg accordingly.     

一株脂肽产生菌发酵参数的响应曲面法优化

从渤海污染土壤中分离的表面活性剂产生菌,经鉴定为Bacillus sp.BO2,该菌在对数生长期产生表面活性剂,至稳定期后可将发酵液的表面张力降低至31.0 mN·m1.初步分析发现其表面活性剂成分为环脂肽,该脂肽在不同温度、盐度、pH条件下有较好的稳定性.进一步采用响应曲面法(RSM),以乳化系数作为响应值来优化菌株BO2产生物表面活性剂培养条件.还通过实验确定碳源(液体石蜡)、NH4NO3、KH2PO4为3个影响表面活性剂产量的显著因素,再进行发酵培养基优化,获得最佳培养基配方.获得的发酵参数为利用该菌株发酵生产生物表面活性剂提供数据,为石油降解菌的应用开发提供了有价值的信息.     

Correlation between Rimjingang belt and Dabie-Sulu orogenic belt

The Dabic-Sulu orogenic belt in central-eastern China is considered as a high-pressure and ultrahighpressure metamorphic belt that demensions are comparatively large,and formed as a result of the colli...     

韩国的乡村林木与农业生物多样性(英文)

韩国的乡村林木处于偏远村庄附近,单独的树木或一片树林,往往构成风水因素。乡村林木也有野生动物生境的功能,有益于农业生物多样性。本文中,乡村林木分为4种类型(天然林、半天然林、半人工林、人工林)23个主要树种(优势种或次优势种)。赤松(Pinus densiflora)在50个地点是优势种,光叶榉(Zelkova serrata)在45个地点为优势种。乡村林木立地植物共分125科、519属、1081种。尽管乡村林木占地面积极小,占100 000 km2韩国国土面积的0.00278%,但这种生态系统具有重要的生物多样性和生境保护功能。乡村林木不仅是保育生物多样性的一个基础,还能为韩国提供生态系统服务。     

Beta Gyres in Global Analysis Fields

A three-component decomposition is applied to global analysis data to show the existence of a beta gyre, which causes Tropical Cyclone (TC) to drift from a large-scale environmental steering current. Analyses from the Global Data Assimilation and Prediction System (GDAPS) of the Korea Meteorological Adminis-tration (KMA), the Global Forecast System (GFS) of NCEP, and the Navy Operational Global Atmospheric Prediction System (NOGAPS) are used in this study. The structure of the beta gyre obtained in our anal...     

Local Meteorological and Synoptic Characteristics of Fogs Formed over Incheon International Airport in the West Coast of Korea

Fogs observed over Incheon international airport (IIA) in the west coast of Korea from January 2002 to August 2006 are classified into categories of coastal fog, cold sea fog, and warm sea fog based on the areal extent of the fogs and the difference between the air temperature (T) and the SST, i.e., cold sea fog if TSST = T-SST>0^oC and warm sea fog if TSST <0^oC. The numbers of coastal, cold, and warm sea fog cases are 64, 26, and 9. Coastal fogs form most frequently in winter, while cold sea fogs occur mostly in summer and warm sea fogs are observed from January to May but not in November and December. On average the air gets colder by 1.6^oC during the three hours leading up to the coastal fog formation, and an additional cooling of 1.1^oC occurs during the fog. The change in the dew point temperature (T_d) is minimal except during the fog (0.6^oC). Decreases in T for the cold and warm sea fogs are relatively smaller. The average T_d is higher than SST during the cold sea fog periods but this T_d is more than 4^oC higher than that for the corresponding non-fog days, suggesting that cold sea fogs be formed by the cooling of already humid air (i.e., T_d>SST). Increases of T_d are significant during the warm sea fog periods (1.4^oC), implying that efficient moisture supply is essential to warm sea fog formation. Four major synoptic patterns are identified in association with the observed fogs. The most frequent is a north Pacific high that accounts for 38% of cases. Surface or upper inversions are present in 77%, 69%, and 81% of the fog periods for coastal, cold, and warm sea fogs, respectively.     

在EBEX-2000实验资料中湍流谱和局地各向同性特征

采用2000年8月在美国加州棉花地两个高度上应用超声三分量仪、快速响应050206 温度和湿度仪进行的EBEX-2000 (International Energy Balance Experiment,2000,EBEX-2000)风速三分量、温度和湿度湍流实验观测数据,计算分析了湍流速度、温度和湿度谱在不同稳定度下的特征.对湍流的局地各向同性进行了讨论并与Kansas和长白山原始森林湍流实验得到的结果进行了比较,得到了一些湍流特征量在不同下垫面情况下的一些有意义的特征.     

中国海—西太平洋莫霍面深度分布特征及其地质意义

中国海—西太平洋位于欧亚板块、印澳板块和太平洋板块的交汇处,构造运动剧烈,地质情况复杂,是认识板块运动、洋陆相互作用、物质交换和能量传递不可多得的窗口,而莫霍面深度对于研究壳幔结构以及深部动力过程有着重要的意义.本文使用最新的覆盖全球的重力和地形数据,收集了深地震测深、多道地震测深等剖面183条,数字化得到2982个控制点,使用带控制点的三维界面反演方法来约束反演过程,得到中国海—西太平洋莫霍面深度,由莫霍面形态分析可知大洋板块的俯冲和印澳板块与欧亚板块的碰撞对西太平洋边缘海的形成演化有着重要作用.结合地热、岩石圈厚度、地震活动等地质地球物理资料,分析得知研究区内各个海域莫霍深度和地壳性质的变化是处于不同构造演化阶段的表现.并在马里亚纳沟弧盆拟合一条重力2.5维剖面,结果表明热物质上涌导致了马里亚纳海槽处地幔密度减小,马里亚纳海槽以及帕里西维拉海盆到西马里亚纳海岭的下地壳高密度异常是由残留的岩浆岩引起的.     

Numerical Study on Air Turbines with Enhanced Techniques for OWC Wave Energy Conversion

In recent years, the oscillating water column (OWC) wave energy converter, which can capture wave energy from the ocean, has been widely applied all over the world. As the essential part of the OWC system, the impulse and Wells turbines are capable of converting the low pressure pneumatic energy into the mechanical shaft power. As an enhanced technique, the design of endplate or ring attached to the blade tip is investigated numerically in this paper. 3D numerical models based on a CFD-software FLUENT 12.0 are established and validated by the corresponding experimental results from the reports of Setoguchi et al. (2004) and Takao et al. (2001). Then the flow fields and non-dimensional evaluating coefficients are calculated and analyzed under steady conditions. Results show that the efficiency of impulse turbine with ring can reach up to 0.49 when φ=1, which is 4% higher than that in the cases for the endplate-type and the original one. And the ring-type Wells turbine with fixed guide vanes shows the best performance with the maximal efficiency of 0.55, which is 22% higher than that of the original one. In addition, the quasi-steady analysis is used to calculate the mean efficiency and output-work of a wave cycle under sinusoidal flow condition. Taking all together, this study provides support for structural optimization of impulse turbine and Wells turbine in the future.