从汶川M_S 8.0地震到九寨沟M_S 7.0地震：青藏高原东缘大震前重力变化     

祝意青  刘芳  徐云马 《地震地磁观测与研究》2021,42(2):108-109

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T213L31全球中期数值天气预报系统2m温度预报误差源分析   总被引：9，自引：0，他引：9  

佟华  姚明明  王雨  陈起英  管成功 《气象》2006,32(2):52-57

T213L31全球中期数值天气预报系统的2m温度预报存在系统性偏低的问题，对业务预报影响很大，针对这一问题就产生原因对模式系统进行分析定位。经过一系列分析，通过对模式地形高度与观测站地形高度的比较，以及通过采用欧洲中心与国家气象中心的陆面过程初值得到的2m温度的比较，认为2m温度的误差是由于模式地形高度与实际地形高度存在较大差异以及2m温度预报对陆面过程所需的初值如土壤湿度等的敏感而实际采用特定值代替初始场的不科学性造成的。  相似文献   

安徽柯村A型花岗岩岩墙群地质地球化学特征及构造环境   总被引：4，自引：0，他引：4  

钟华明 《安徽地质》1997,(2)

柯村岩墙群岩石具文象结构，地球化学上具富硅、富碱、富Ｇａ、Ｚｒ、Ｎｂ、Ｆ，低铝、贫水和Ｂａ、Ｓｒ特征。在多种判别图上，均投影在Ａ型花岗岩区。根据岩石地球化学特征和产出构造环境分析，柯村岩墙群属非造山区裂图１柯村碱性花岗岩岩墙群地质略图Ｆｉｇ．１Ｔｈｅａｌｋａｌｉｎｅｇｒａｎｉｔｅｄｙｋｅｃｌｕｓｔｅｒ，Ｋｅｃｕｎ．谷Ａ型花岗岩。  相似文献   

2021年中国龙卷活动及灾情特征     

植江玲  黄先香  白兰强  蔡康龙  李彩玲  李兆明  张晶晶  关良  盛杰  周康辉  徐纵横  何秋蕊  麦文强  彭斯琪 《气象科学进展》2022,(1):26-36

2021年中国经确认的龙卷天气过程有39次,总计58个龙卷,其中EF2级或以上强度龙卷数量16个,EF3级龙卷6个,EF2级和EF3级龙卷数量明显多于2004—2013年的龙卷记录年平均值.龙卷发生在4—10月,其中7月最多.龙卷共导致23人死亡、470多人受伤.龙卷的地理分布呈现出北多南少的特征.有55个龙卷为西风带...  相似文献   

Current structure and its variation in the equatorial area of the western north Pacific Ocean     

Guan Bingxian 《中国海洋湖沼学报》1986,4(3):239-255

Based on the current measurement data from the R/V Ryofu Maru of JMA in the equatorial area along 137°E (1972–83) and 155°E (1972–79) the structures of the zonal velocity of the Equatorial Undercurrent (EUC) and the North Equatorial Countercurrent (NECC) and their variations are systematically analyzed in detail. At 155°E, the current at the equator and 100–300 m depth was a typical eastward EUC, it intensified in 1973–75, i.e., in the non-El Niño period. While the corresponding current at 137°E was mostly westward, and the origin of the EUC shifted to north of the equator around 0.5–1.5°N owing to the influence of the New Guinea Coast. The EUC origin disappeared in early July, 1982. Comparing with the EUC disappearance at 159°W, the average speed of an eastward travelling wave would be～1.1m/s. The velocity core of the NECC at 137°E generally shifted northward in winter and southward in summer, and was stronger in summer and weaker in winter. The fluctuations of the NECC were closely related to those of the wind stress curl over the region 2–10°N, 160°E–150°W.  相似文献   

A note on the deep circulation in the area east of Taiwan and the Philippines   总被引：1，自引：0，他引：1  

Guan Bingxian 《中国海洋湖沼学报》1990,8(2):167-176

The deep water (1000–3000 m) circulation in the area east of Taiwan and the Philippines has been little studied. Moriyasu (1972) and Reid (1981) discussed the 3000 db surface (3000/1200 db) and 2000 db surface (2000/3500 db) circulations of the Philippine Sea Basin, respectively. They both showed that there may be a northward current close to the western margin of the Sea Basin. Recent analyses of two sets of deep sea hydrographic data yielded quite different results, i. e., at deep waters in the area east of Taiwan and the Philippines southward countercurrents flow under the upper northward currents. The possible causative mechanism of these southward deep countercurrents is the blocking effects of the submarine ridge east of Suao and of the Ryukyu Islands Shelf on the northward flowing upper currents. The above-mentioned preliminary deductions were wholely based on consideration of the relative geostrophic current and calculation, though the reference surface (3500 db) was very deep. It is suggested that direct measurements of the deep currents in the study area are needed to verify these results. Contribution No. 1750 from the Institute of Oceanology, Academia Sinica. This paper was presented at the PRC/USA Symposium on Western Pacific Air-Sea Interaction (Nov., 1988, Beijing). This project was supported by the National Natural Science Foundation of China.  相似文献   

A note on circulation of the East China Sea   总被引：1，自引：0，他引：1  

Guan Bingxian  Mao Hanli 《中国海洋湖沼学报》1982,1(1):5-16

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Spatial weighting functions: transient hydraulic tests and heterogeneous media     

Molz FJ  Guan J  Wang J 《Ground water》2005,43(2):215-221

To improve understanding of property measurements in heterogeneous media, an energy-based weighting function concept is developed. In (assumed) homogeneous media, the instrument spatial weighting function (ISWF) depends only on the energy dissipation distribution set up by the measurement procedure and it reduces to simply inverse sample volume (uniform weighting) for 1-D parallel flow case (ideal permeameter). For 1-D transient flow in homogeneous media, such as with slug tests, the ISWF varies with position and time, with 95% of the total weighting contained within 115 well radii, even late in the test. In the heterogeneous case, the determination of the ISWF is connected to the problem of determining an equivalent hydraulic conductivity (K), where the criterion for equivalence is based on equal energy dissipation rate rather than equal volume discharge. The discharge-based equivalent K (K(E)) and the energy-based equivalent K in heterogeneous media (K(eh)) are not equal in general, with K(eh) typically above the nodal arithmetic mean K. The possibly more fundamental problem is that as one makes K measurements in heterogeneous media at different locations or on different cores of heterogeneous materials, the ISWF will be heterogeneity dependent, implying that the averaging process resulting in the equivalent K value also varies with position. If the testing procedure is transient, then the averaging process varies with time. This suggests a fundamental ambiguity in the interpretation of hydraulic conductivity measurements in heterogeneous media that may impact how we approach modeling and prediction in a practical sense (Molz 2003). Further research is suggested.  相似文献   

威特DI2002测距仪性能及其与ME－3000反射镜匹配研究     

巩守文  祝意青  任道胜 《大地测量与地球动力学》1995,(2)

本文通过对威特ＤＩ２００２测距仪性能的测试。发现影响测距精度的主要因素是ＧＲＴ１０－ＧＰＨ１Ａ的反射镜系统。威特ＤＩ２００２测距仪匹配ＭＥ－３０００反射镜后，需加两项改正，但观测精度显著提高，实测表明达到与ＭＥ－３０００测距仪相同的精度。  相似文献   

BIOMONITORING OF AMBIENT CONCENTRATIONS OF CADMIUM, COPPER, I,EAD AND ZINC IN THE COASTAL WETLAND WATER BY USING GILLS OF THE GREEN- LIPPED MUSSEL PERNA VIRIDIS     

Chee Kong Yap Ahmad Ismail Abdul Rahim Ismail Soon Guan Tan 《湿地科学》2006,4(4):247-252

The distribution and concentrations of Cd, Cu, Pb and Zn were determined in the gills and remaining soft tissues of Perna viridis collected from 12 geographical sites （ 10 from the west and 2 from the east coastal waters） of Peninsular Malaysia. All samples showed that the levels of Cd, Pb and Zn were generally higher in the gill than those in the remaining soft tissues. These results could be due to the fact that gills are the first organ of metal accumulation and larger surface area with mucus sheets in the organ. Since the mussel gill is a better accumulator of Cd, Pb and Zn of ambient seawater than remaining soft tissue, it is a potential indicator of ambient levels of dissolved metals in the ambient seawater. However, further validations based on laboratory conditions are needed.  相似文献