THE EFFECT OF LESSER HIMALAYAN CALC-SILICATES ON THE ~(87)Sr/~(86)Sr OF THE BHOTE KOSI RIVER OF NEPAL—IMPLICATIONS FOR HIMALAYAN WEATHERING, THE MARINE ~(87)Sr/~(86)Sr RECORD AND GLOBAL CLIMATE

THE EFFECT OF LESSER HIMALAYAN CALC-SILICATES ON THE ~(87)Sr/~(86)Sr OF THE BHOTE KOSI RIVER OF NEPAL—IMPLICATIONS FOR HIMALAYAN WEATHERING, THE MARINE ~(87)Sr/~(86)Sr RECORD AND GLOBAL CLIMATE1　VeizerJ .AnnuRevEPS ,1989,17:141～ 16 8. 2　KrishnaswamiS ,etal.EPSL ,1992 ,10 9:2 43～ 2 5 3. 3　EdmondJM .Science ,1992 ,2 5 8:15 94～ 15 97. 4　DerryLA .France LanordCEPSL ,1996 ,142 :5 9～ 74. 5　QuadeJ ,eta…     

油田注水开发中后期注水井调剖经济有效的方法

在任何水驱项目中，注水井调剖一直是一个富有挑战性的难题。面在多层，非均质性油藏里，调剖问题尤为严重。本文讨论了Ｌ．Ａ盆地中两上油田调剖所用的几种方法，包括所用方法的详细情况以及所得到的结果。     

Comparability of bioaccumulation within the sanddab guild in coastal Southern California

Most assessments of fish contamination in Southern California use ecologically different species from different sites. Use of ecologically similar species (a guild) might provide better assessments of fish contamination across different sites and depths. In July-August 1997, we collected samples of four sanddab guild species at 22 sites where species pairs co-occurred and determined total DDT concentrations in homogenized whole fish composites. Log-transformed DDT concentrations were highly correlated among all species pairs within this guild. All relationships were linear over the range observed, with slopes not statistically different from unity. The variability in response among species was about four times the variability encountered among replicates within species, but 15 times smaller than the variability among sites. Together, these results suggest that the sanddab guild, widespread on soft bottoms of the Southern California coastal shelf, can be used as a "superspecies" in bathymetrically diverse regional assessments of fish tissue contamination.     

The Rest-Frame Optical Spectrum of MS 1512-cB58

Moderate-resolution, near-IR spectroscopy of MS 1512-cB58 is presented, obtained during commissioning of the near-infrared spectrometer (NIRSPEC) on the Keck II telescope. The strong lensing of this z=2.72 galaxy by the foreground cluster MS 1512+36 makes it the best candidate for detailed study of the rest-frame optical properties of Lyman-break galaxies. In 80 minutes of on-source integration, we have detected Halpha, [N ii] lambdalambda6583, 6548, [O i] lambda6300, He i lambda5876, [O iii] lambdalambda5007, 4959, Hbeta, Hgamma, [O ii] lambda3727, and a strong continuum signal in the range of 1.29-2.46 μm. A redshift of z=2.7290+/-0.0007 is inferred from the emission lines, in contrast to the z=2.7233 calculated from UV observations of interstellar absorption lines. Using the Balmer line ratios, we find an extinction of E(B-V) = 0.27. Using the line strengths, we infer a star formation rate (SFR) of 620+/-18 M middle dot in circle yr-1 (H0=75, q0=0.1, and Lambda=0), which is a factor of 2 higher than that measured from narrowband imaging observations of the galaxy but is a factor of almost 4 lower than the SFR inferred from the UV continuum luminosity. The width of the Balmer lines yields a mass of Mvir=1.2x1010 M middle dot in circle. We find that the oxygen abundance is 13 solar, in good agreement with other estimates of the metallicity. However, we infer a high nitrogen abundance, which may argue for the presence of an older stellar population.     

电阻负载偶极天线辐射图形的数值研究

通过计算得出了低损耗介电半空间上的有限体积电阻负载水平电偶极的远场辐射图形，这些图形是由瞬变无穷小偶极单元的计算结果叠加而成的，其中每个单元的瞬变波形是由严格的稳态解合成的，每个偶极单元电流激发是一个半周正弦平方波形，这种波以变速沿偶极单元传播。假定天线端点无反射，电流半周期的时间长度控制着瞬变辐射变形主波的全部时间，偶极激发电流的振幅是由模拟电阻负载的余弦分布决定的，瞬变辐射图形与稳态偶极图形的     

The high-latitude cloud MBM 7. I. H I and CO observations

The high-latitude cloud (HLC) MBM 7 has been observed in the 21 cm H I line and the 12CO(1-0) and 13CO(1-0) lines with similar spatial resolutions. The data reveal a total mass approximately 30 M solar for MBM 7 and a complex morphology. The cloud consists of a cold dense core of 5 M solar surrounded by atomic and molecular gas with about 25 M solar, which is embedded in hotter and more diffuse H I gas. We derive a total column density N(H I + 2H2) of 1 x 10(21) cm-2 toward the center and 1 x 10(20) cm-3 toward the envelope of MBM 7. The CO line indicates the existence of dense cores [n(H2) > or = 2000 cm-3] of size (FWHM) approximately 0.5 pc. The morphology suggests shock compression from the southwest direction, which can form molecular cores along the direction perpendicular to the H I distribution. The H I cloud extends to the northeast, and the velocity gradient appears to be about 2.8 km s-1 pc-1 in this direction, which indicates a systematic outward motion which will disrupt the cloud in approximately 10(6) yr. The observed large line widths of approximately 2 km s-1 for CO suggest that turbulent motions exist in the cloud, and hydrodynamical turbulence may dominate the line broadening. Considering the energy and pressure of MBM 7, the dense cores appear not to be bound by gravity, and the whole cloud including the dense cores seem to be expanding. The distance to HLCs suggest that they belong to the galactic plane, since the scale height of the cloud is < or approximately equal to 100 pc. Compared to the more familiar dense dark clouds, HLCs may differ only in their small mass and low density, with their proximity reducing the filling factor and enhancing the contrast of the core and envelope structure.     

A comparison of plastic and plankton in the north Pacific central gyre

The potential for ingestion of plastic particles by open ocean filter feeders was assessed by measuring the relative abundance and mass of neustonic plastic and zooplankton in surface waters under the central atmospheric high-pressure cells of the North Pacific Ocean. Neuston samples were collected at 11 random sites, using a manta trawl lined with 333 u mesh. The abundance and mass of neustonic plastic was the largest recorded anywhere in the Pacific Ocean at 334 271 pieces km² and 5114 g km², respectively. Plankton abundance was approximately five times higher than that of plastic, but the mass of plastic was approximately six times that of plankton. The most frequently sampled types of identifiable plastic were thin films, polypropylene/monofilament line and unidentified plastic, most of which were miscellaneous fragments. Cumulatively, these three types accounted for 98% of the total number of plastic pieces.     

Poverty,development and patterns of rural male outmigration in Uttar Pradesh

This paper indexes rural male out-migration and explains changing intensity patterns in Uttar Pradesh, India, since 1961. The sex ratio among non-migrants serves as an indicator of regional variations in rural out-migration. The paper highlights 2 population divergence zones in the underdeveloped Northern hilly and Eastern plain regions. The process of infrastructural development combined with cultural factors and inadequate employment opportunities seem to stimulate rural outmigration. Regional imbalance in economic development seems to be working as a suction economic system. The developed regions in India are utilizing the labor force of backward areas. The number of districts of high and moderately high rural male outmigration has increased, reflecting a wider gap between individual income and regional inequality. Unless the process is reversed in favor of rural areas, strategies for development will only work in capitalistic frameworks which serve the interests of developed regions.