TRANSIENT ELECTROMAGNETIC RESPONSE OF A SPHERE IN A LAYERED MEDIUM*     

T. LEE 《Geophysical Prospecting》1975,23(3):492-512

The Galerkin method of solving integral equations is well suited to the solution of the integral equations describing the transient response of a sphere embedded in a layered medium, which is excited by a large co-axial loop. The transient response is calculated by transforming the steady state solutions obtained in the frequency domain. The analysis shows that the scattering matrix is extremely diagonally dominant and the maximum number of modes required to obtain convergence does not rapidly increase with frequency. The number of modes required is about eight. This type of scattering matrix can be taken to be an expression of the principle of elementary superposition. This principle is reflected in the decay curves. These show that the early part of the decay curves asymptotically approach the decay curves to be expected for a layered structure without the sphere. The slope of the latter stages of the decay curve gives a decay constant that is the same as was obtained for spheres in free space excited by planar or dipolar sources. The point of departure in time of these curves from the layered ground curves is delayed either by placing the sphere at a greater depth or by placing a more conductive overburden above the sphere.  相似文献   

RANK-ORDER ANALYSIS FOR ROBUST MULTIRESPONSE,MULTIBLOCK COMPARISONS:EVALUATION OF HERBICIDE INTERACTIONS     

DAVID LEE DUEWER  ROBERT D.CLARK 《地理学报(英文版)》1991,(6)

Studies of interactions among bioactive compounds are often difficult to interpret unambiguously.A priori assumptions about the nature of such interactions can seriously distort analysis of the data.Byapplying a rank order analysis appropriate to the naturally ordinal scale of response to xenobiotic insult,several co-herbicides were successfully identified from among numerous candidates in an experimentinvolving multiple blocks,rates and species.Moreover,underlying herbicide interactions weresubstantiated and identified which were not apparent by more traditional parametric analysis.  相似文献   

Bottom-current deposits in the Miocene–Pliocene Misaki Formation, Izu forearc area, Japan     

INTAE  LEE & YUJIRO  OGAWA 《Island Arc》1998,7(3):315-329

Sedimentary structures in the middle–late Miocene to early Pliocene Misaki Formation, Miura Group, Miura Peninsula, Central Japan, were studied, and paleocurrent data were interpreted as the result of deep-sea bottom-current flow. These current data were further compared with present-day bottom currents in the northwestern Pacific region. The Misaki Formation is thought to be a forearc deposit within the Izu oceanic arc, and is composed of thick volcaniclastic beds interbedded with siliceous biogenic clayey sediments. Sedimentary structures showing paleocurrent directions are involved in the upper part of the volcaniclastic beds, in the pumiceous beds just above the volcaniclastic beds, and in the pelagic sediments. Based on paleomagnetic data suggesting considerable rotation of the beds, all the current directions were reconstructed to their original orientation. The paleocurrents are summarized into the following three groups. The first group in the volcaniclastic beds indicates southeast-directed paleocurrent directions. The second group in the upper parts of volcaniclastic beds and in some pumiceous beds exhibits a southwest- and northeast-directed paleoflow. The third group usually observed in the pumiceous beds with parallel lamination displays a northwest- or southeast-directed paleocurrent. The origin of each group's paleoflow direction is attributed to turbidity current, internal tidal current, and contour current influences, respectively. Present-day observations of the deep-sea northwest Pacific suggest that most of the bottom-current indicators in the Misaki Formation are related to North Pacific Deep Water, possibly Antarctic Bottom Water as well as a combination of tidal and local effects. It is concluded that the beds of the Misaki Formation were deposited in the proto-Sagami basin ca 9 Ma and were formed under weak bottom currents in a wide and flat basin during colder climatic conditions, whereas the beds dated at ca 6 Ma were deposited under strong bottom-current flow, and were then accreted to the Honshu arc.  相似文献   

Sensitivity of Snowfall Characteristics to Meteorological Conditions in the Yeongdong Region of Korea     

Yoo-Jun KIM  So-Ra IN  Hae-Min KIM  Jin-Hwa LEE  Kyu Rang KIM  Seungbum KIM  Byung-Gon KIM 《大气科学进展》2021,38(3):413-429

This study investigates the characteristics of cold clouds and snowfall in both the Yeongdong coastal and mountainous regions under different meteorological conditions based on the integration of numerical modeling and three-hourly rawinsonde observations with snow crystal photographs for a snowfall event that occurred on 29?30 January 2016.We found that rimed particles predominantly observed turned into dendrite particles in the latter period of the episode when the 850 hPa temperature decreased at the coastal site,whereas the snow crystal habits at the mountainous site were largely needle or rimed needle.Rawinsonde soundings showed a well-defined,two-layered cloud structure along with distinctive wind-directional shear,and an inversion in the equivalent potential temperature above the low-level cloud layer.The first experiment with a decrease in lower-layer temperature showed that the low-level cloud thickness was reduced to less than 1.5 km,and the accumulated precipitation was decreased by 87%compared with the control experiment.The difference in precipitation amount between the single-layered experiment and control experiment(two-layered)was not so significant to attribute it to the effect of the seeder?feeder mechanism.The precipitation in the last experiment by weakening winddirectional shear was increased by 1.4 times greater than the control experiment specifically at the coastal site,with graupel particles accounting for the highest proportion(~62%).The current results would improve snowfall forecasts in complicated geographical environments such as Yeongdong in terms of snow crystal habit as well as snowfall amount in both time and space domains.  相似文献   

Erratum to: Observational Study of Surface Wind along a Sloping Surface over Mountainous Terrain during Winter     

Young-Hee LEE  Gyuwon LEE  Sangwon JOO  Kwang-Deuk AHN 《大气科学进展》2022,39(10):1787-1787

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Growth and photosynthesis of Chlorella strains from polar,temperate and tropical freshwater environments under temperature stress     

Kok-Keong LEE  Phaik-Eem LIM  Sze-Wan POONG  Chiew-Yen WONG  Siew-Moi PHANG  John BEARDALL 《中国海洋湖沼学报》2018,(4)

Elevated temperatures as a consequence of global warming have significant impacts on the adaptation and survival of microalgae which are important primary producers in many ecosystems. The impact of temperature on the photosynthesis of microalgae is of great interest as the primary production of algal biomass is strongly dependent on the photosynthetic rates in a dynamic environment. Here, we examine the effects of elevated temperature on Chlorella strains originating from different latitudes, namely Antarctic, Arctic, temperate and tropical regions. Chlorophyll fluorescence was used to assess the photosynthetic responses of the microalgae. Rapid light curves(RLCs) and maximum quantum yield( F_v/F_m) were recorded. The results showed that Chlorella originating from different latitudes portrayed different growth trends and photosynthetic performance. The Chlorella genus is eurythermal, with a broad temperature tolerance range, but with strain-specific characteristics. However, there was a large overlap between the tolerance range of the four strains due to their "eurythermal adaptivity". Changes in the photosynthetic parameters indicated temperature stress. The ability of the four strains to reactivate photosynthesis after inhibition of photosynthesis under high temperatures was also studied. The Chlorella strains were shown to recover in terms of photosynthesis and growth(measured as Chl a) when they were returned to their ambient temperatures. Polar strains showed faster recovery in their optimal temperature compared to that under the ambient temperature from which they were isolated.  相似文献   

Late Pleistocene–Holocene records from Lake Ulaan,southern Mongolia: implications for east Asian palaeomonsoonal climate changes     

MIN KYUNG LEE  YONG IL LEE  HYOUN SOO LIM  JAE IL LEE  HO IL YOON 《第四纪科学杂志》2013,28(4):370-378

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Dynamic simulation model of vertical infiltration of water in soil     

J. LEE 《水文科学杂志》2013,58(3):290-292

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Development of Precise Geoid Model for the Establishment of Consistent Height System in Geoga Grand Bridge Construction Area     

Dong-Ha LEE  Hong-Sic YUN  He HUANG 《中国海洋工程》2009,23(4):679-694

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基于两种半分析算法的水体吸收系数反演   总被引：1，自引：0，他引：1  

汪文琦  董强  商少凌  吴璟瑜  李忠平 《热带海洋学报》2009,28(5):35-42

本文基于42组不同年份不同季节获得的遥感反射率、水体各组分吸收系数的实测数据，对QAA（Quasi-Analytical Algorithm）和GSM（Garver-Siegel-Maritorena）算法在寡营养的南海和富营养的福建沿岸两种不同类型水体的吸收系数反演进行了检验。以水样测量值为参考，两种算法在本研究水体中的反演成效与他人在其它水域的研究结果相当。QAA算法在南海的反演成效高于福建沿岸水体。对于443 nm的总吸收系数（a443 ），南海的对数均方根误差（RMSE ）为0.046，平均相对误差为7.9%，对数平均偏差为0；福建沿岸水体的对数均方根误差（RMSE ）为0.194，平均相对误差为30.6%，对数平均偏差为-0.167 。GSM算法在两类水体的反演成效类似，A443 之RMSE和平均相对误差，南海分别为0.161和27.7%，福建沿岸分别为0.149和32.1%，但从A443的对数平均偏差值看，其在南海反演值低于实测值（对数平均偏差为-0.142 ），在福建沿岸则略呈高于实测值（对数平均偏差为0.016）。两种算法中的部分经验参数与实测值之间的差异是产生反演误差的主要原因，为了提高反演精度，对算法中经验参数的更进一步区域化调整可能是必要的。  相似文献