WAVELENGTH POSITIONING ERRORS AND TRUE DETECTION LIMIT IN RELATION TO MULTICOMPONENT ANALYSIS TECHNIQUES FOR THE CORRECTION OF LINE INTERFERENCES IN INDUCTIVELY COUPLED PLASMA ATOMIC EMISSION-SPECTROMETRY

The present paper deals with the evaluation of the relative error (DELTA(A)) in estimated analyte concentrations originating from the wavelength positioning error in a sample scan when multicomponent analysis (MCA) techniques are used for correcting line interferences in inductively coupled plasma atomic emission spectrometry. In the theoretical part, a quantitative relation of DELTA(A) with the extent of line overlap, bandwidth and the magnitude of the positioning error is developed under the assumption of Gaussian line profiles. The measurements of eleven samples covering various typical line interferences showed that the calculated DELTA(A) generally agrees well with the experimental one. An expression of the true detection limit associated with MCA techniques was thus formulated. With MCA techniques, the determination of the analyte and interferent concentrations depend on each other while with conventional correction techniques, such as the three-point method, the estimate of interfering signals is independent of the analyte signals. Therefore. a given positioning error results in a larger DELTA(A) and hence a higher true detection limit in the case of MCA techniques than that in the case of conventional correction methods. although the latter could be a reasonable approximation of the former when the peak distance expressed in the effective width of the interfering line is larger than 0.4. In the light of the effect of wavelength positioning errors, MCA techniques have no advantages over conventional correction methods unless the former can bring an essential reduction ot the positioning error.

EVALUATION OF THE RELIABILITY OF KALMAN FILTERING RESULTS IN INDUCTIVELY COUPLED PLASMA ATOMIC EMISSION-SPECTROMETRY

This paper deals with the evaluation of the reliability of the analytical results obtained by Kalman filtering. Two criteria for evaluation were compared: one is based on the autocorrelation analysis of the innovation sequence, the so-called NAC criterion; the other is the innovations number, which actually is the autocorrelation coefficient of the innovation sequence at the initial wavelength. Both criteria allow compensation for the wavelength positioning errors in spectral scans, but there exists a difference in the way they work. The NAC criterion can provide information about the reliability of an individual result, which is very useful for the indication of unmodelled emissions, while the innovations number should be incorporated with the normalization of the innovations or seek the help of the sequence itself for the same purpose. The major limitation of the NAC criterion is that it does not allow the theoretical modelling of continuous backgrounds, which, however, is convenient in practical analysis and can be taken with the innovations number criterion.

He, Ne and Ar isotopic composition of Fe-Mn crusts from the western and central Pacific Ocean and implications for their genesis

The noble gas nuclide abundances and isotopic ratios of the upmost layer of Fe-Mn crusts from the western and central Pacific Ocean have been determined. The results indicate that the He and Ar nuclide abundances and isotopic ratios can be classified into two types: low He-3/He-4 type and high He-3/He-4 type. The low He-3/He-4 type is characterized by high He-4 abundances of 191x10(-9) cm(3.)STP(.)g(-1) on average, with variable He-4, Ne-20 and Ar-40 abundances in the range (42.8-421)x10(-9) cm(3.)STP(.)g(-1), (5.40-141)x10(-9)cm(3.)STP(.)g(-1), and (773-10976)x10(-9) cm(3.)STP(.)g(-1), respectively. The high He-3/He-4 samples are characterized by low He-4 abundances of 11.7x10(-9) cm(3.)STP(.)g(-1) on average, with He-4, Ne-20 and Ar-40 abundances in the range of (7.57-17.4)x10(-9) cm(3.)STP(.)g(-1), (110.4-25.5)x10(-9) cm(3.)STP(.)g(-1) and (5354-9050)x10(-9) cm(3.)STP(.)g(-1), respectively. The low He-3/He-4 samples have He-3/He-4 ratios (with RIRA ratios of 2.04-2.92) which are lower than those of MORB (R/R-A=8 +/- 1) and Ar-40/Ar-36 ratios (447-543) which are higher than those of air (295.5). The high He-3/He-4 samples have He-3/He-4 ratios (with R/R-A ratios of 10.4-12.0) slightly higher than those of MORB (R/R-A=8 +/- 1) and Ar-40/Ar-36 ratios (293-299) very similar to those of air (295.5). The Ne isotopic ratios (Ne-20/Ne-22 and Ne-21/Ne-22 ratios of 10.3-10.9 and 0.02774-0.03039, respectively) and the Ar-38/Ar-36 ratios (0.1886-0.1963) have narrow ranges which are very similar to those of air (the Ne-20/Ne-22, Ne-21/Ne-22, Ar-38/Ar-36 ratios of 9.80, 0.029 and 0.187, respectively), and cannot be differentiated into different groups. The noble gas nuclide abundances and isotopic ratios, together with their regional variability, suggest that the noble gases in the Fe-Mn crusts originate primarily from the lower mantle. The low He-3/He-4 type and high He-3/He-4 type samples have noble gas characteristics similar to those of HIMU (High U/Pb Mantle)- and EM (Enriched Mantle)-type mantle material, respectively. The low He-3/He-4 type samples with HIMU-type noble gas isotopic ratios occur in the Magellan Seamounts, Marcus-Wake Seamounts, Marshall Island Chain and the Mid-Pacific Seamounts whereas the high He-3/He-4 type samples with EM-type noble gas isotopic ratios occur in the Line Island Chain. This difference in noble gas characteristics of these crust types implies that the Magellan Seamounts, Marcus-Wake Seamounts, Marshall Island Chain, and the Mid-Pacific Seamounts originated from HIMU-type lower mantle material whereas the Line Island Chain originated from EM-type lower mantle material. This finding is consistent with variations in the Pb-isotope and trace element signatures in the seamount lavas. Differences in the mantle surce may therefore be responsible for variations in the noble gas abundances and isotopic ratios in the Fe-Mn crusts. Mantle degassing appears to be the principal factor controlling noble gas isotopic abundances in Fe-Mn crusts. Decay of radioactive isotopes has a negligible influence on the nuclide abundances and isotopic ratios of noble gases in these crusts on the timescale of their formation.

Impact of difference accuracy on computational properties of vertical grids for a nonhydrostatic model

Starting from nonhydrostatic Boussinesq approximation equations, a general method is introduced to deduce the dispersion relationships. A comparative investigation is performed on inertia-gravity wave with horizontal lengths of 100, 10 and 1 km. These are examined using the second-order central difference scheme and the fourth-order compact difference scheme on vertical grids that are currently available from the perspectives of frequency, horizontal and vertical component of group velocity. These findings are compared to analytical solutions. The obtained results suggest that whether for the second-order central difference scheme or for the fourth-order compact difference scheme, Charny-Phillips and Lorenz ( L) grids are suitable for studying waves at the above-mentioned horizontal scales; the Lorenz time-staggered and Charny-Phillips time staggered (CPTS) grids are applicable only to the horizontal scales of less than 10 km, and N grid ( unstaggered grid) is unsuitable for simulating waves at any horizontal scale. Furthermore, by using fourth-order compact difference scheme with higher difference precision, the errors of frequency and group velocity in horizontal and vertical directions produced on all vertical grids in describing the waves with horizontal lengths of 1, 10 and 100 km cannot inevitably be decreased. So in developing a numerical model, the higher-order finite difference scheme, like fourth-order compact difference scheme, should be avoided as much as possible, typically on L and CPTS grids, since it will not only take many efforts to design program but also make the calculated group velocity in horizontal and vertical directions even worse in accuracy.

Impact of spatial resolution and spatial difference accuracy on the performance of Arakawa A-D grids

This paper alms at illustrating the impact of spatial difference scheme and spatial resolution on the performance of Arakawa A-D grids in physical space. Linear shallow water equations are discretized and forecasted on Arakawa A-D grids for 120-minute using the ordinary second-order (M and fourth-order (C4) finite difference schemes with the grid spacing being 100 km, 10 km and I km, respectively. Then the forecasted results are compared with the exact solution, the result indicates that when the grid spacing is I kin, the inertial gravity wave can be simulated on any grid with the same results from C2 scheme or C4 scheme, namely the impact of variable configuration is neglectable; while the inertial gravity wave is simulated with lengthened grid spacing, the effects of different variable configurations are different. However, whether for C2 scheme or for C4 scheme, the RMS is minimal (maximal) on C (D) grid. At the same time it is also shown that when the difference accuracy increases from C2 scheme to C4 scheme, the resulted forecasts do not uniformly decrease, which is validated by the change of the group A velocity relative error from C2 scheme to C4 scheme. Therefore, the impact of the grid spacing is more important than that of the difference accuracy on the performance of Arakawa A-D grid.

A HYBRID METHOD OF FRACTIONAL STEPS WITH PREDICTOR-CORRECTOR DIFFERENCE-PSEUDOSPECTRUM FOR NUMERICAL-SOLUTION OF THE CONVECTION-DOMINATED FLOW PROBLEMS

A fractional-step method of predictor-corrector difference-pseudospectrum with unconditional L(2)-stability and exponential convergence is presented. The stability and convergence of this method is strictly proved mathematically for a nonlinear convection-dominated flow. The error estimation is given and the superiority of this method is verified by numerical test.

淤泥质潮滩地貌的遥感研究－以苏北辐射沙洲海岸为例

本文以具有典型特征的苏北淤泥质潮滩海岸作为研究区，利用1975-2003年间14景覆盖该地区的Landsat和SPOT卫星影像作为主要数据源，结合地面调查和验证工作，在遥感影像处理和地理信息系统分析技术的支持下，对区内潮滩、岸线、水边线和盐沼植被等进行遥感解译，分析苏北辐射沙脊群和沿岸地貌的空间分布特征和动态演变趋势。研究结果表明：苏北辐射沙脊群海域的潮汐水位过程的不同步现象普遍存在，限制了常规遥感数据在苏北潮滩地貌研究中的适用范围和解译精度；在人工判别的辅助下，多光谱遥感的非监督分类方法可以有效解译淤泥质潮滩的水边线；利用修改型土壤调整植被指数（MSAVI）可以较好地提取潮滩上的盐沼植被信息；苏北沿岸潮滩的快速淤长促进了盐沼植被带向海侧快速扩展，近年来持续的潮滩围垦工程则不断从陆侧侵占盐沼植被带，使盐沼植被带宽度减小乃至消失；在大规模人类活动和自然条件的共同影响下，苏北辐射沙脊群海岸的岸线发育趋于平直化，无序的潮滩围垦项目使得可垦滩地资源被过度消耗；1975～2002年间，研究区北部和南部沿岸的高潮滩整体上处于淤长状态，中部沿岸潮滩和离岸沙洲高潮滩则被大面积侵蚀；1999年以来，研究区内低潮滩部位开始形成有序排列的滩面地物，并表现出逐年大面积蔓延的趋势，可能是滩涂紫菜养殖区扩展的结果。

Assessing the potential of VEGETATION sensor data for mapping snow and ice cover: a Normalized Difference Snow and Ice Index

The VEGETATION (VGT) sensor in SPOT 4 has four spectral bands that are equivalent to Landsat Thematic Mapper (TM) bands (blue, red, near-infrared and mid-infrared spectral bands) and provides daily images of the global land surface at a 1-km spatial resolution. We propose a new index for identifying and mapping of snow ice cover, namely the Normalized Difference Snow/Ice Index (NDSII), which uses reflectance values of red and mid-infrared spectral bands of Landsat TM and VGT. For Landsat TM data, NDSII is calculated as NDSIITM =(TM3 -TM5)/(TM3 +TM5); for VGT data, NDSII is calculated as NDSIIVGT =(B2- MIR)/(B2 + MIR). As a case study we used a Landsat TM image that covers the eastern part of the Qilian mountain range in the Qinghai-Xizang (Tibetan) plateau of China. NDSIITM gave similar estimates of the area and spatial distribution of snow/ice cover to the Normalized Difference Snow Index (NDSI=(TM2-TM5)/(TM2+TM5)) which has been proposed by Hall et al. The results indicated that the VGT sensor might have the potential for operational monitoring and mapping of snow/ice cover from regional to global scales, when using NDSIIVGT.

基于超短基线的缆控水下机器人动力定位

动力定位 (DynamicPositioning(DP) )技术是水下机器人的关键技术之一。因此针对当前动力定位主要在缆控水下机器人 (ROV)中应用的情况 ,给出了ROV动力定位技术的实施方法。通过声学定位技术确定ROV的坐标 ,计算出与期望位姿的差 ,将其作为神经网络控制器的输入量来控制ROV ,从而进行动力定位。同时还重点研究了ROV动力定位中的主要研究内容即水声定位技术和定位控制技术的构建。

含激电信息的人工源频率域电磁法正演研究——大功率人工固定源极低频电磁法激电效应预研究

ABSTRACT Base on Dias-model, this paper study the forward modeling to IP response with MT souece and CSAMT source with the author’s program，that is to provide the theoretical basis for extracting the IP information from the far field, near field and transition field in extremely low frequency electromagnetic sounding with artificial strong fixed source signal. The outline of the paper is as follows. Firstly, review the history of the complex-resistivity-model, and analyses the bases for choosing Dias model; meanwhile, effects and responses of each parameter in Dias model are analyses. Afterward, study the forward modeling to 1D layered model with MT source, numerically simulate the IP effects of classic geoelectric objects; Find the clear anomaly and relationship between the peak value of the amplitude anomaly ratio and phase anomaly difference with and without IP parameters to be considered within a frequency range. On the basis of the modeling of MT, Study the CSAMT modeling with a dipole-source, obtain the anomaly responses and the relationship between anomaly and characters of object. Base on the infinite line source, study the 2D IP effect of geoelectric objects with 2D modeling. Calculate the response with different source distance, object depth and different wall rock resistivity systemically. Finally, conclude the viewpoints and give the discussion of the result, and point out the lack of this research also.

Millstone Hill电离层F层等效风场的气候学研究

Neutral winds and electric fields in the ionospheric F layer play important roles in the variations of the ionosphere, and also affect the thermospheric circulation via the close coupling between the ionosphere and the thermosphere. By now, the neutral winds and electric drifts are generally observed with ground-based Fabry-Perot interferometers (FPI) and incoherent scatter radars (ISR), rockets, and satellite-borne instrument. Based on the servo theory, the ionospheric equivalent winds, which include the information of both the neutral winds and electric fields, can be derived from these characteristic parameters observed by ionosondes. This indirect derivation has potential values in climatological researches and space weather forecast. With the data set of the incoherent scatter radar observations at Millstone Hill, USA, from 1976 to 2006, we statistically analyzed the climatological variations of the vertical component of the equivalent winds (VEWs) over Millstone Hill, which are derived from the ionospheric key parameters (the peak electron number density and peak height of the F2 layer, NmF2 and hmF2) on the basis of the servo theory, Liu's method, and measurements from the ion line-of-sight velocity as well. The main results of this analysis are summarized as follows: (1) The values of VEWs over Millstone Hill during nighttime are stronger than in the daytime, and the upward drift dominates most of the day. In 1993, Hagan found that the component of the neutral winds in the magnetic meridion in daytime is weaker than during nighttime under both solar maximum and minimum conditions; he also found that the equatorward winds dominate most of the day. Both results suggest that the thermosphere in Millstone Hill is modulated by the aurorally driven high-latitude circulation cell; that is, during geomagnetic quiet periods, the average auroral activity is strong enough to drive thermospheric circulation equatorward for most of the day at Millstone Hill. Moreover, since ion drag is the strongest during daytime when F region densities are enhanced by photoionization, the wind speeds are smaller during the daytime than in the nighttime. (2) There is equinoctial symmetry in VEWs at Millstone Hill. The amplitudes and phases of VEWs in spring are quite similar to those in autumn. In contrast, the nighttime upward drift in winter is weaker than in summer and the difference becomes more significant with increasing solar activity. This solstice asymmetry indicates that, the aurorally driven circulation in the northern hemisphere at Millstone Hill latitude is weaker in winter due to arctic darkness, because the subsolar point is in the southern hemisphere. (3) The comparison of the VEWs derived from three methods, i.e., the servo theory, Liu's method, and the ISR ion line-of-sight velocity measurements, indicates that the amplitudes and main phase tendencies of these VEWs accord well with each other during nighttime hours. However, the case in the daytime is relatively worse. This daytime discrepancy can be explained in terms of the effects of photochemical processes and the choices of the servo constants. A larger servo constant gives a stronger plasma drift in daytime. Therefore, this study tells how important to choose a suitable constant for deriving VEWs at Millstone Hill.

河流成因储层沉积微相与剩余油分布及形成机理研究

Based on the study of fluvial sandstone reservoir in upper of Guantao group in Gudao and Gudong oilfields, this paper first introduces A.D.Miall's(1996a) architectural-element analysis method that was summarized from ground outcrop scale into the reservoir formation research of the study area, more subtly divides sedimentary microfacies and establishes sedimentary model of research area.on this base, this paper summarizes the laws of residual oil distribution of fluvial formation and the control effect of sedimentary microfacies to residual oil distribution, and reveals residual oil formation mechanism. These results have been applied to residual oil production, and the economic effect is good. This paper will be useful for residual oil research and production and enhancement of oil recovery in similar reservoir. The major conclusions of this paper are as follows. 1. Using the architectural-element analysis method to the core data, a interfacial division scheme of the first to the dixth scale is established for the studied fluvial formation. 2.Seven architectural-elements are divided in upper of Guantao group of study area. The sandstone group 5～1+2 of Neogene upper Gutao group belongs to high sinuous fine grain meandering river, and the sandstone group 6 is sandy braided river. 3. Inter layer, the residual oil saturation of "non-main layer" is higher than "main layer", but the residual recoverable reserve of former is larger. Therefore, "main layer" is the main body of residual oil distribution. The upper and middle part of inner layer has lower permeability and strong seeping resistance. Addition to gravity effect in process of driving, its driving efficiency is low; residual oil saturation is high. Because of controlling of inside non-permeable interlayer or sedimentary construction, the residual oil saturation of non-driving or lower driving efficiency position also is high. On plane, the position of high residual oil saturation mostly is at element LV, CS, CH (FF), FF etc, Which has lower porosity and permeability, as well as lens sand-body and sand-body edge that is not controlled by well-net, non-perfect area of injection and production, lower press difference resort area of inter-well diffiuent-line and shelter from fault, local high position of small structure. 4.Microscopic residual oil mainly includes the non-moved oil in the structure of fine pore network, oil in fine pore and path, oil segment in pore and path vertical to flow direction, oil spot or oil film in big pore, residual oil in non-connective pore. 5.The most essential and internal controlling factor of fluvial formation residual oil distribution is sedimentary microfacies. Status of injection and production is the exterior controlling factor of residual oil distribution. 6. The controlling effect of formation sedimentary microfacies to residual oil distribution indicates inter-layer vertical sedimentary facies change in scale of injection and production layer-series, planar sedimentary face change and inner-layer vertical sedimentary rhythm and interbed in single layer to residual oil distribution. 7. It is difficult to clear up the inter-layer difference in scale of injection and production layer-series. The using status of minor layer is not good and its residual oil saturation is high relatively. It is obvious that inter-layer vertical sedimentary facies changes control inter-layer residual oil distribution at the same or similar conditions of injection and production. For fluvial formation, this vertical sedimentary facies change mainly is positive gyration. Namely, from down to top, channel sediment (element CHL, LA) changes into over-bank sediment (element LV, CR, CS). 8. In water-injection developing process of transverse connecting fluvial sandstone oil formation, injection water always comes into channel nearby, and breaks through along channel and orientation of high pressure gradient, does not expand into side of channel until pressure gradient of channel orientation changes into low. It brings about that water-driving status of over-bank sedimentary element formation (LV, CR, CS) is not good, residual oil saturation is high. In non-connective abandoned channel element (CH) formation with channel, because this reverse is difficult to control by injection and production well-series, its using status is not good, even terribly not good, residual oil is enrichment. 9. The rhythm and sedimentary structure, sedimentary facies change in single sand body brings about vertical changes of formation character, growth character of inner layer interbed. These are important factor of controlling and affecting vertical water spread volume and inner layer residual oil forming and distribution in single sand body. Positive rhythm, is the principal part of fluvial sandstone inner layer sedimentary rhythm. Namely, from down to upside, rock grain granularity changes from coarse to fine, seeping ability changes from strong to feebleness. It brings about that water-driving status of inner layer upside is not good, residual oil saturation is high. Inner layer interbed has different degree affecting and controlling effect to seeping of oil and water. Its affecting degree lies on interbed thickness, extending scale, position, and jeted segment of production or injection well. The effect of interbed at upside of oil formation to oil and water seeping is less; the effect of interbed at middle of oil formation to oil and water seeping is more. 10. Indoor experiment and research indicate that wettability, permeability step, vertical permeability, position of Kmax and ratio of oil viscousity and water viscousity all have great effect on the water-driving recovery ratio. 11. Microscopic residual oil distribution is affected and controlled by formation pore network structure, pressure field distribution, and oil characteristic. 12.The residual oil forming mechanism: the over-bank sedimentary element and upper part of a positive rhythm sandstone have fine pore and throat network, permeability is low, displacement pressure of pore and throat is high. The water-driving power usually falls short of displacement pressure that brings about injection water does not spread into these pore and throat network, thereby immovable oil area, namely residual oil, is formed. At underside of channel sedimentary element and positive rhythm sandstone, porosity and permeability is relatively high, connecting degree of pore and throat is high, displacement pressure of pore and throat is low. Thereby injection water is easy to enter into pore and throat, driving oil in them. Because the pore space is irregular, the surface of pore wall is coarse and non-flat. That the oil locate on concave hole of pore wall and the dead angle of pore, and the oil attaches on surface of pore wall by surface tension, are difficult to be peeled off, becoming water-driving residual oil (remaining oil). On the other hand, Because flowing section lessens, flowing resistance increase, action of capillary fore, or seeping speed decreases at process of transfer at pass narrow throat path in the course carried by driving water. The "oil drop", "oil bead", or "oil segment" peeled off by driving water is difficult to carry and to drive out by water at less pressure difference. Thereby they are enclosed in pore to form discontinuous residual oil. 13.This results described above have been applied in nine develop blocks of Gudao and Gudong oilfield. Its applying effect is marked through local injection production adjustment, deploying replacement well, repair hole, replacement envelop, block off water and profile control etc. Relative method and technology can be applied to other oil production area of Shengli oilfield, and obtain better economic and societal effect.