对NOAA／AVHRR通道反照率和植被指数的大气影响订正试验

在利用大气窗区进行遥感时,大气成分对辐射的吸收和散射作用造成辐射消弱,从而影响气象卫星（AVHRR）两个通道（可见光和近红外）反演地表反照率值及其差和比的植被指数值。在选取实测卫星资料对其作预处理并考虑仪器定标衰减作用后,利用LOWTRAN－7大气辐射传输模式对卫星资料进行大气订正的探讨,指出气溶胶、水汽等大气参数是订正计算中的敏感因子。       

Chemical alternation of waters in the Kuroshio/Oyashio Interfrontal Zone

An intensive survey has been conducted of the distributions of some chemical properties (dissolved oxygen, nutrients and carbonate properties) in the Kuroshio/Oyashio Interfrontal Zone. Many low-salinity water patches were found down to depths of 640 m. Each chemical property also showed anomalies in these patches, but the degree of variation showed a low correlation with salinity. This may be due to the high variability of biological processes in the surface waters where these patches are formed. Vertical profiles of the chemical properties were also observed along the Kuroshio extension axis from 140.50°E to 146.75°E. The concentrations of nutrients and total carbonate (TC) in the water having densities greater than σ_θ=26.60 can be regarded as being formed by the isopycnal mixing of the Kuroshio component water and Oyashio component water and biological degradation within the density surfaces. This implies that the transport of chemical properties by the diapycnal mixing is negligible in these density layers in the K/O zone.     

Short-term variabilities of upper ocean current in the warm pool region during TOGA/COARE IOP

Oceanic current data in the warm pool region of the western equatorial Pacific measured by upward-looking moored Acoustic Doppler Current Profilers at two equatorial sites (147°E and 154°E) and two off-equatorial sites (2°N and 2°S, 156°E) during TOGA/COARE Intensive Observing Period (IOP) from November 1992 to February 1993 are used to examine short-term variabilities in the upper layer above 160–240 m. In time series of the zonal and meridional currents in many layers, spectral peaks are found at periods around 2 days and 4 days in addition to high energies in a period range longer than 10 days. The signal with the period of about 2 days has significantly high energies at all sites, and its magnitude is higher for the meridional current than for the zonal one. This signal is especially active in the first half of IOP from November to December in 1992. In this period, the quasi-2-day signal in the current field is coherent between northern (2°N) and southern (2°S) stations, but it has no evident relationship with that in the surface wind field around the stations. The quasi-4-day signal with the period of about 4 days has highest energies in layers above 160 m at the southern station, and is coherent between northern and southern stations. Besides, the signal at the station of 2°S has a significantly high coherence with that in the wind at the southern station, suggesting that it is a local phenomenon.     

加卸载响应比的数值模拟

用数值模型来模拟和验证加卸载响应比（ＬＵＲＲＬｏａｄ／Ｕｎｌｏａｄ　ＲｅｓｐｏｎｓｅＲａｔｉｏ）理论．编制非均匀各向异性材料宏细观损伤破坏程序,模拟固体材料在损伤破坏时的加卸载过程,证实了加卸载响应比理论的正确性．结果表明,ＬＵＲＲ这一反映地球介质临近破坏的指标,也可以用来预测材料的破坏．同时讨论了一些参数（如均匀程度和脆性程序）对ＬＵＲＲ的影响,发现材料越呈脆性,或越均匀,ＬＵＲＲ值上升得越晚,曲线越陡．该结果对用ＬＵＲＲ指标预测地震具有一定启发．     

Geomagnetic paleosecular variation at Hawaii around 3 Ma from a sequence of 107 lava flows at Kaena Point (Oahu)

We have sampled a sequence of 107 lava flows in the Waianae series on Oahu, Hawaii, in two separate stretches. The first (51 flows) at Kaena Point extends from sea level to an altitude of 190 m, and the second (56 flows) follows the Satellite Tracking Station road from 218 m to 360 m above sea level. Thermal and af demagnetization yield very similar results, and reveal only normal polarities. K/Ar dating at five different horizons combined with the paleomagnetic results indicate that the sequence was emplaced entirely in the normal polarity interval between the Upper Mammoth and the Lower Kaena polarity transitions (3.22–3.11 Ma). Some of the flows are serially correlated. Filtering does not, however, drastically affect the final results. Inclinations are shallower than those expected from a centered dipole field. Although large (13°), the inclination anomaly is consistent with results from other sites at the same latitude. The scatter of the VGPs about the geographic pole is consistent with available data from other regions at similar latitudes. The scatter of the directions is also consistent with the predictions of recent statistical models of paleosecular variation. Therefore, these results do not support the hypothesis of a Pacific dipole window.     

A record of changing redox conditions in the northern Peru Basin during the Late Quaternary deduced from Mn/Fe and growth rate variations in two diagenetic manganese nodules

Two diagenetic manganese nodules from the Peru Basin were investigated by thermal ionization mass spectrometry and high resolution alpha spectrometry for uranium and thorium. The TIMS concentrations for nodule 62KD (63KG) vary as follows: 0.12–1.01 ppb (0.06–0.59) ²³⁰Th, 0.51–1.98 ppm (0.43–1.40) ²³²Th, 0.13–0.80 ppb (0.09–0.49) ²³⁴U, and 1.95–13.47 ppm (1.66–8.24) ²³⁸U. Both nodules have average growth rates of 110 mm per million years. However, from the variations of excess ²³⁰Th with depth we estimate partial accumulation rates which range from 50 to 400 mm per million years. The δ²³⁴U dating method cannot be applied due to remobilization of U from the sediment and subsequent incorporation into the nodules' crystal lattice, reflected by decay corrected δ²³⁴U values far above the ocean water value. Sections of fast nodule growth are related to those layers having high Mn/Fe ratios (up to 200) and higher densities. As a possible explanation we develop a scenario that describes similar glacial/interglacial trends in both nodules as a record of regional changes of sediment and/or deep water chemistry.     

A Comparison of Growth Biomarkers for Assessing Sublethal Effects of Cadmium on a Marine Gastropod, Nassarius festivus

The effect of cadmium on the growth of an intertidal marine gastropod, Nassarius festivus, was investigated using a number of biomarkers namely conventional measurements in terms of increase in shell length or body weight, scope for growth (SfG) and RNA/DNA ratio. After eight days of cadmium exposure, the no observable effect concentration (NOEC) and lowest observable effect concentration (LOEC) for the rate of increase in wet weight were 1.00 and 1.38 mg/l, respectively, while those for shell length did not show any significant difference from the control until day 16. After 16 days of cadmium exposure, the LOEC for both shell length and wet weight measurements was 0.22 mg/l. The 8-day SfG test was sensitive to cadmium stress, showing a significant decrease at 0.16 mg/l cadmium when compared to the control. The NOEC and LOEC of RNA/DNA ratio determination were 0.52 and 0.93 mg/l, respectively. An assessment based on sensitivity and technical complexity suggests that Scope for Growth is the most sensitive growth biomarker, followed by the RNA/DNA ratio, and then the conventional growth measurement based on shell size and body weight.     

深部地震资料的处理和解释方法

深部地震资料的处理类似于油气地震资料,但也有其自身的一些特点。在水平叠加处理前后,分别使用强有力的去噪和归位处理技术是获取高质量深部地震剖面的保证。在深地震时间剖面上,强能量条带的分布是大地构造格架的反映。综合测区重磁电等物化探资料进行解释,有利于提高解释精度和进一步探讨造山带的构造演化     

GIS中多用户环境下数据共享一致性问题研究

讨论了GIS中多用户环境下数据一致性问题,着重研究了由于某个用户修改其他用户已读数据所产生的不一致以及由于用户UNDO/REDO后产生的不一致。对于前者,本文提出了一种“通知-重读”法。     

应用中间件技术的土地管理信息系统的研究

介绍了中间件技术原理,说明了SDE在系统中的工作原理,并以南海市国主管理信息系统的设计与实现为例,介绍了应用中间件技术的GIS的研究与实践。