碱性矿化水灌溉对土壤溶质运移的影响

经过连续几年的灌溉试验可知,应用2.5 g稬-1以下的低矿化水灌溉是安全的,超过此值土壤积盐和碱化明显。灌溉后,土壤中溶质运移受多因素影响。在阳离子分布中,水平方向Na+随灌溉水矿化度增大而增多,Ca2+、Mg2+变化不大;土壤剖面上,从表层至60 cm土层,先以Ca2+、Mg2+为主,过渡到Na+、Ca2+、Mg2+共同占优,再发展为以Na+占优。阴离子的分布中,水平方向,随灌溉水矿化度增大HCO3-增多;土壤剖面上,从表向里,先以Cl-或SO42-为主,过渡到C1-、SO42-、HCO3-均分局面,再发展以HCO3-占优。灌溉后土壤pH值在0~20 cm变化不明显,大于20 cm土层有一定增加。土壤中的SAR和ESP均以大于1.5 g稬-1的碱性低矿化水灌溉后增加明显,碱化层由下向上抬升,小麦田碱化速度快于玉米田。

Structure-activity relationship of surfactant for preparing DMFC anodic catalyst

Three kinds of surfactants as stabilizer were applied to the preparation of electrocatalysts for direct methanol fuel cell (DMFC). The catalysts have been characterized by examining their catalytic activities, morphologies and particle sizes by means of cyclic voltammetry, chronoamperometry, X-ray diffraction and transmission electron microscopy (TEM). It is found that the surfactants with different structures have a significantly influence on the catalyst shape and activity. The catalysts prepared with non-ionic surfactants as the stabilizer show higher activity for direct oxidation of methanol. The structure-activity relationship (SAR) analysis has been explored and the effect of hydrophile-lipophile balance (HLB value) has also been discussed.

STUDY ON STRUCTURE-ACTIVITY-RELATIONSHIPS OF ORGANIC-COMPOUNDS - 3 NEW TOPOLOGICAL INDEXES AND THEIR APPLICATIONS

In this paper, three new topological indices, A(x1), A(x2), and A(x3), have been developed for use in multivariate analysis in structure-property relationship (SPR) and structure-activity relationship (SAR) studies. Good results have been obtained by using them to predict the physical and chemical properties and biological activities of some organic compounds.

Near-Space Wide-Swath Radar Imaging With Multiaperture Antenna

Near-space, defined as the altitude region between 20 and 100 km, offers many capabilities that are not accessible for low Earth-orbit (LEO) satellites or airplanes because it is above storm and not constrained by orbital mechanics and high fuel consumption. Hence, a high flying speed can be obtained for the maneuvering vehicles operating in near-space. This offers a promising solution to simultaneous high-resolution and wide-swath synthetic aperture radar (SAR) imaging. As such, one near-space wide-swath SAR imaging technique is presented in this letter. The system configuration, signal model, and imaging scheme are described. An example near-space SAR system is designed, and its imaging performance is analyzed. Simulation results show that near-space maneuvering vehicle SAR indeed seems to be a promising solution to wide-swath SAR imaging.

On the nonlinear integral transform of an ocean wave spectrum into an along-track interferometric synthetic aperture radar image spectrum

We present a new nonlinear integral transform relating the ocean wave spectrum to the along-track interferometric synthetic aperture radar (AT-INSAR) image spectrum. The AT-INSAR, which is a synthetic aperture radar (SAR) employing two antennas displaced along the platform's flight direction, is considered to be a better instrument for imaging ocean waves than the SAR. This is because the AT-INSAR yields the phase spectrum and not only the amplitude spectrum as with the conventional SAR. While the SAR and AT-INSAR amplitude spectra depend strongly on the modulation of the normalized radar cross section (NRCS) by the long ocean waves, which is poorly known, the phase spectrum depends only weakly on this modulation. By measuring the phase difference between the signals received by both antennas, AT-INSAR measures the radial component of the orbital velocity associated with the ocean waves, which is related to the ocean wave height field by a well-known transfer function. The nonlinear integral transform derived in this paper differs from the one previously derived by Bao et al. [1999] by an additional term containing the derivative of the radial component of the orbital velocity associated with the long ocean waves. By carrying out numerical simulations, we show that, in general, this additional term cannot be neglected. Furthermore, we present two new quasi-linear approximations to the nonlinear integral transform relating the ocean wave spectrum to the AT-INSAR phase spectrum.

Ocean wave imaging mechanism by imaging radar

Analytical representations of the high frequency spectra of ocean wave and its variation due to the variation of ocean surface current are derived from the wave-number spectrum balance equation. The ocean surface imaging formulation of real aperture radar (RAR) is given using electromagnetic wave backscattering theory of ocean surface and the modulations of ocean surface winds, currents and their variations to RAR are described. A general representation of the phase modulation induced by the ocean surface motion is derived according to standard synthetic aperture radar (SAR) imaging theory. The detectability of ocean current and sea bottom topography by imaging radar is discussed. The results constitute the theoretical basis for detecting ocean wave fields, ocean surface winds, ocean surface current fields, sea bottom topography, internal wave and so on.

A parametric method of retrieving ocean wave spectra from synthetic aperture radar images

A parametric method that extracts the ocean wave directional spectra from synthetic aperture radar (SAR) image is presented. The 180 degrees ambiguity of SAR image and the loss of information beyond the azimuthal cutoff can be overcome with this method. The ocean wave spectra can be obtained from SAR image directly by using iteration inversion mapping method with forward nonlinear mapping. Some numerical experiments have been made by using ERS-1 satellite SAR imagette data. The ocean wave direction retrieved from SAR imagette data is in agreement with the wind direction from the scatterometer data.

Numerical simulation and validation of ocean waves measured by an Along-Track Interferometric Synthetic Aperture Radar

A new nonlinear integral transform of ocean wave spectra into Along-Track Interferometric Synthetic Aperture Radar (ATI-SAR) image spectra is described. ATI-SAR phase image spectra are calculated for various sea states and radar configurations based on the nonlinear integral transform. The numerical simulations show that the slant range to velocity ratio (R/V), significant wave height to ocean wavelength ratio (H-s/lambda), the baseline (2B) and incident angle (theta) affect ATI-SAR imaging. The ATI-SAR imaging theory is validated by means of Two X-band, HH-polarized ATI-SAR phase images of ocean waves and eight C-band, HH-polarized ATI-SAR phase image spectra of ocean waves. It is shown that ATI-SAR phase image spectra are in agreement with those calculated by forward mapping in situ directional wave spectra collected simultaneously with available ATI-SAR observations. ATI-SAR spectral correlation coefficients between observed and simulated are greater than 0.6 and are not sensitive to the degree of nonlinearity. However, the ATI-SAR phase image spectral turns towards the range direction, even if the real ocean wave direction is 30 degrees. It is also shown that the ATI-SAR imaging mechanism is significantly affected by the degree of velocity bunching nonlinearity, especially for high values of R/V and H-s/lambda.

南海西北部陆架潮频内波生成过程的数值模拟

我国南海海水运动复杂、海底地形多变，是内波的多发区域。目前关于南海内波的报道、观测和研究主要集中在Luzon海峡到南海东北部东沙群岛附近海域。2005年4月16日始，中国科学院海洋研究所和中国海洋石油总公司联合在海南岛东部的文昌站进行了为期近半年的连续定点海洋调查，观测资料清楚地表明，这一海域陆架上长期存在着比较规则的潮频内波现象。 从航天图片和SAR卫星图片上捕捉到的信息来看，南海西北部陆架上（文昌站附近海域）有些潮频内波并非从Luzon海峡传播而来，而极有可能是局地正压潮与陆坡作用生成的。本文用数值模拟的方法来证明这一观点。 首先，我们从Reynolds方程组出发，用差分方法和有限元方法建立了一个连续层结海水中正压潮与海底地形相互作用生成潮频内波的二维非线性数值模式。我们用该模式研究了正压潮流流经下降地形、上升地形、凸起地形、凹陷地形等几种典型的海底地形时生成内波的过程，探讨了该数值模式中各个参数对生成内波的影响。 然后，我们从文昌站海洋科学调查的温盐深数据资料中提取了该海区的密度、跃层厚度和强度等海洋环境参数；用调和分析法从海流流速、流向数据中提取了正压潮潮流成分及各潮流分量的速度、振幅、方向等与数值模式相关的信息。我们把这些从实测资料中提取出的海洋环境和潮流信息应用到内波生成的非线性数值模式中，模拟了文昌站附近海域正压潮流与陆坡作用生成内波的过程。模拟结果表明，南海局地潮流与陆坡作用足以生成能够被SAR捕捉到的大振幅内波。从而我们可以断定，南海西北部陆架上有些潮频内波是天文潮与陆坡作用生成，然后传播到陆架上的。

合成孔径雷达提取海面风、浪信息研究

传统海洋测量方法例如岸基观测站、船只和浮标等方式只能对海面进行单点观测，存在很多不足之处：观测点少，只能获得有限的点的资料，无法得到大范围的海面信息；费用较高，无法大范围的密集观测；传统方法受天气影响较大，无法长时间的连续观测；星载合成孔径雷达能全天候、全天时、高分辨率对海面成像，能实现多波段、多极化、多视角得观测海面，提供大范围、高精度的实时动态海面信息。同时，这种全天候、全天时和高分辨率观测海洋的优势是可见光和红外传感器所没有的。总之研究如何从SAR影像中有效地获取海面信息具有重要的科学和实用意义。 自从1978年Seasat卫星发射以来SAR图像就广泛的应用于海洋要素的反演如海面风场、波高、平均周期。其中对海面风场的反演研究的最多，一般的方法是首先对SAR图像进行快速傅立叶变换得到SAR图像谱，通过图像谱的峰值信息能够得到具有180°模糊的风向，利用SAR图像的条纹或者浮标等外部信息来消除180°模糊确定风向，其次把风向和图像的正交后向散射截面数值(NRCS)带入经验函数CMOD4通过迭代计算得到风速。这种方法得到的海面风场需要外部信息的辅助，不利于大范围的业务化的反演海面风场。因此本文试图直接通过SAR图像来反演海面风场而不利用其他外部信息的帮助。2002年3月1日发射的ENVISAT卫星所获得的ASAR图像具有不同于ERS系列的SAR图像的新特点：不同入射角的情况下获得ASAR图片、双极化数据以及可以获得更宽的带幅的图像。双极化数据可以同时地提供同极化和交错极化的影像，两种极化的数据能够增加分辨目标的能力和提供目标更多的信息，这方面的优势也使得利用双极化的数据来消除SAR图像反演风场中的180º模糊问题提供了可能。本文推导了利用双极化的ASAR图像反演海面风场的新函数，该函数是在同极化和交错极化函数的基础上推导出来的，有效的消除了只用一副ASAR图片反演风场所固有的180º模糊现象。风速和风向的反演结果与Quikscat数据之间的均方根误差分别为0.53 m/s和2.21º。该方法与传统方法的比较可以看出新方法与浮标数据以及Quikscat数据符合的更好。 利用SAR图像来反演海浪的波高也是一个研究的比较多的领域。比较传统的方法是由SAR图像得到的海浪谱计算出波高，目前国际上比较流行的SAR图像反演海浪谱的模式有两种：一种是Hasselmann（1991）提出的在Max－Planck Institute（MPI）发展起来的方法，Hasselmann（1996）进行了改进和完善。另一种是Mastenbroek和de Valk（2000）提出的半参数化反演方法。这两种方法的最主要的缺点就是需要引进外部信息(WAM模式结果或者散射计的风的信息)来消除图像所固有的180°方向模糊问题。而本文应用的经验函数方法(CWAVE)不需要引进任何外部信息而直接得到海浪的重要参数－有效波高(Hs)，输入该经验函数的参数主要有：波模式图像的雷达截面、图像方差以及由SAR谱得到的20个参数。这些参数的选择是通过逐步回归方法进行筛选的。CWAVE经验函数的系数是通过6000幅全球分布的ERS-2波模式的图像谱拟合同时同地点的WAM模式结果得到的。利用CWAVE经验函数反演了1998年9月到2000年11月两年多的全球接近一百万的ERS-2 SAR图像的有效波高，利用NOAA浮标数据对反演结果进行了验证，他们之间的相关系数为0.83, 均方根误差为0.61m，偏差为0.02 m；反演结果也与欧洲中长期预报中心(ECMWF)的ERA-40有效波高资料和高度计资料进行了比较，结果表明该方法是通过SAR图像反演Hs的一种有效方法。 SAR的反演结果也应用于有效波高的非线性统计分布的研究。结合动力学和随机统计学原理推导了海面高度、波高和有效波高的非线性统计分布，同时利用了NOAA浮标数据、华师大的波高数据以及SAR的有效波高数据分别对推导出的非线性统计分布函数进行了检验。 SAR的结果也用来反演新的风浪成长关系： ，与已有的风浪成长关系的比较表明该成长关系与已有的结果比较一致。

基于微波图像的辽东湾海冰典型要素信息提取

业务化海冰遥感监测的要素主要包括海冰类型、海冰厚度和海冰范围（冰缘线）。本文针对辽东湾海冰的特点，结合星载合成孔径雷达（SAR）、机载微波辐射计（ABMR）和星载微波辐射计遥感图像观测辽东湾海冰，发展海冰要素探测算法，提取海冰类型、海冰厚度和冰缘线信息。 海冰类型SAR信息提取方面，首先分析了双极化ENVISAT ASAR数据不同极化方式的海冰探测能力。然后利用SAR图像，结合同步TM数据和航空照片，开展辽东湾地区不同类型海冰的电磁特性研究。研究结果表明，SAR图像可较好地区分沿岸固定冰、平整冰和碎冰堆积区，但在探测初生冰方面并不可靠，探测结果与海冰生长阶段以及海冰周围环境条件有关。根据SAR图像中海冰类型的分析，将PCNN神经网络用于海冰SAR图像的分割和海冰分类，并对PCNN做了简化和改进。经SAR图像分类结果测试，简化和改进后的PCNN可较好地区分SAR图像中的海冰类型。通过分析了PCNN网络各参数对SAR图像分割结果的影响，指出了各参数的取值范围，并在此基础上建立了基于PCNN神经网络的海冰SAR图像半自动分类判读系统。 海冰厚度机载微波辐射计信息提取方面，推导了非相干模式的ABMR海冰厚度反演模型，并首次得到了模型中高阶亮温辐射项的计算表达式。通过对模型的分析，指出ABMR只能测量一定范围内的海冰厚度。其中，最大海冰探测厚度不仅决定于ABMR的波长，而且还受到仪器精度的限制；最小海冰探测厚度只与仪器的波长有关。在此基础上，定量计算了我国几种常用波长ABMR的海冰厚度探测范围。并结合辽东湾海冰冰情等级，指出适合不同海冰冰情等级的ABMR的选择。最后分析了海冰厚度反演模型的影响因素和模型的适应范围。 海冰边缘线星载微波辐射计信息提取方面，首次将PSSM算法用于AMSR数据，提取辽东湾海冰边缘线信息，可得到空间分辨率为2.5km、重复周期为1d的辽东湾海冰边缘线信息。通过提取结果与Jason-1高度计和SAR探测海冰边缘线的比较，验证了PSSM方法探测辽东湾海冰边缘线的有效性。 论文的最后对全文做了总结，并提出和讨论了需要进一步开展的工作。

干涉合成孔径雷达海浪遥感理论与应用研究

干涉合成孔径雷达 (Interferometric Synthetic Aperture Radar，InSAR) 是以合成孔径雷达复数据提取的相位为信息源获取地表三维信息和海表散射体运动信息的新型微波成像雷达。 InSAR通过两幅天线同时观测 (单轨模式)，或两次近平行的观测 (重复轨道模式)，获取地面或海面同一景观的复图像对。20世纪90年代以来，InSAR陆地和海洋研究成为微波遥感的热点，广泛应用于地表变形监测、南极冰流测量、地面或海面慢速运动目标检测等领域。 近年来，国际上逐渐应用机载顺轨或交轨干涉合成孔径雷达进行海表面流速测量以及海面波成像机制研究。相对于传统单天线合成孔径雷达 (Synthetic Aperture Radar, SAR)，双天线干涉合成孔径雷达 (InSAR) 测量海表面波有着独特的优势： (1) InSAR复图像的相位近似正比于海面散射体的径向速度，这种内在的成像机制提供了直接测量海表面动态运动的机会。 (2) 真实孔径雷达调制传递函数几乎对InSAR相位图像没有影响，而对传统SAR图像影响较大。 基于干涉合成孔径雷达测量海浪的优势，本文做了一些干涉合成孔径雷达海浪遥感理论与应用研究工作，主要内容大致可归纳如下： (1)基于新建立的顺轨干涉合成孔径雷达 (Along-Track Interferometric Synthetic Aperture Radar，ATI-SAR) 相位谱与海浪谱之间的非线性映射关系，通过数值模拟研究了不同雷达参数和海况参数对应的ATI-SAR相位谱。数值模拟结果表明：距离速度比率、雷达入射角、天线间距和有效波高和波长比率是影响ATI-SAR海浪成像的重要因素。进一步，利用机载X波段水平极化相位图像和机载C波段水平极化相位图像谱结合方向波骑士浮标测量的海浪方向谱验证了ATI-SAR相位谱与海浪谱之间的非线性映射关系。结果显示用前向映射关系计算的相位谱与实际观测的相位谱较为一致，二者相关系数总体大于0.6，而且对成像非线性不敏感. (2)建立了包含海表面高度和速度聚束的交轨干涉合成孔径雷达 (Across-Track Interferometric Synthetic Aperture Radar，XTI-SAR) 涌浪干涉相位模型，得到了涌浪成像的解析表达式，进一步研究了XTI-SAR沿方位向传播的涌浪成像机制。定义二次谐波振幅与基波振幅比率来表征成像非线性，通过比较XTI-SAR和ATI-SAR相位的二阶调和分量，分析不同海况和干涉SAR参数情况下的数值模拟，结果表明：当速度聚束弱时，XTI-SAR相位比ATI-SAR相位具有较强的非线性，ATI-SAR比XTI-SAR更适合测量海浪。当速度聚束强时，XTI-SAR相位比ATI-SAR相位具有较弱的非线性，XTI-SAR比ATI-SAR更适合测量海浪。 (3)基于包含海表面高度和速度聚束的交轨干涉合成孔径雷达 (XTI-SAR) 涌浪干涉相位模型，结合多维高斯变量的特征函数方法建立了新的XTI-SAR相位谱与海浪谱非线性积分变换。新积分变换不同于Bao (1999) 建立的积分变换，两者形式上区别在于新积分变换中包含了长波径向轨道速度一阶倒数项。数值模拟显示：通常情况下，长波径向轨道速度一阶倒数项不能忽略。进一步，我们针对不同雷达参数和海况结合新非线积分变换对XTI-SAR海浪成像进行了数值模拟，结果表明：同顺轨干涉合成孔径雷达 (ATI-SAR) 海浪成像一致，距离速度比率 和有效波高与波长比率 是影响XTI-SAR海浪成像的重要因子。 (4)基于新的ATI-SAR相位谱与海浪谱之间的非线性映射关系，发展了利用ATI-SAR相位图像反演海浪方向谱的参数化反演模式，并由此得到海浪波长、波向和有效波高。反演结果与现场浮标观测结果比较一致。相对于其它反演模式，参数化反演模式的优点在于：(1) 不需要任何附加信息如初猜海浪谱、散射计提供的风速风向等信息。 (2) 不需要对相位图像进行辐射定标，可以由反演的海浪谱直接计算有效波高。(3) 反演结束后还可以得到成像区域的局地风速信息。因此，参数化反演模式可以实现风、浪信息的联合反演。

多因素对海洋上混合层深度影响的数值模拟

海洋上混合层深度（MLD）是刻画海洋上混合层的一个非常重要的物理参量，MLD的准确确定对人们了解上层海洋动力学、热力学等具有重要的科学意义和实用价值。本文概述了影响MLD的几个主要因素，介绍了MLD的定义方法和主要的两类混合层模型。利用2001年月平均资料，分析了中国南海海表风应力、净热通量、蒸发、降雨及蒸降差的时、空分布变化规律。采用国外先进的MITgcm模式及考虑了非局地作用影响的KPP垂直混合模型，通过改变模式的上边界强迫条件，进行了海表风应力、海表净热通量、蒸降差对MLD影响的敏感性分析，结果表明MLD对海表风应力变化最为敏感。 通过网格嵌套方法，采用MITgcm模式及分辨率为1/4°×1/4°的强迫场资料对南海进行数值模拟，分析了海表温度、盐度、流场及混合层深度的时、空分布特征变化规律，探讨了海表风应力、净热通量、蒸降差对海洋上混合层深度的影响。通过模拟结果与实测资料的比较，同时也表明MITgcm模式应用于中国南海区域范围的MLD数值模拟研究是可行的。 基于考虑了地转和均匀背景流场影响的两层流体界面内波频散关系模型，得到一种新的利用SAR遥感图像反演混合层深度的方法。利用该方法对南海北部SAR内波图像进行了MLD的实例反演研究，并和时空同步的CTD资料进行了对比，结果表明考虑地转和均匀背景流场影响的MLD反演算法更为合理，为更准确地利用SAR图像遥感反演混合层深度奠定了基础。

双模式相关技术研究与实现

文中研究的相关跟踪技术主要应用于飞航导弹的末制导。现阶段，激光制导技术、GPS制导技术、合成孔径雷达（SAR）制导技术在我国的实际应用还不成熟，传统的电视、红外制导技术仍然具有很强的生命力，因而，基于可见光的视频相关跟踪技术具有重要的研究价值。本文主要论述的两种相关算法是：多灰度点相关（MPC）、区域模板相关（RTC）。其中多点相关（MPC）算法的跟踪灵敏度高，定位精度好，硬件实现比较方便，实时性能好；区域模板相关算法（RTC），在图像的匹配过程中，不仅考虑了目标区域的灰度特征，而且兼顾了区域里多灰度层次的位置特征、面积特征，算法具有很好的鲁棒性。文中深入研究了两种相关跟踪算法，并针对它们在实际应用中的不足，提出了有效的改善措施。最后，本文对两种相关跟踪算法进行了初步融合，一是：通过粗匹配、精匹配过程来选取目标跟踪点；二是：提出了一种度量模板更新的能量准则函数。大量的仿真实验结果表明：改进后的两种相关跟踪技术可以较好地完成一些复杂背景下的目标跟踪任务，两种算法的有效结合又进一步提高了目标跟踪的稳定性能和可靠性能。本文研究的一些相关跟踪技术已经运用到实际工程项目中。

释光测年实验室的建立与沉积物释光测年技术研究

The main research projects reported in this paper are the establishment of a luminescence (OSL/TL) dating laboratory in The Institute of Geology and Geophysics, CAS, and studies on OSL dating technique and protocol of sediments from North China. These projects have been suggested in order to fit in with the needs of research developments in environmental changes, in particular the aridity and desertification in North China. A new luminescence dating laboratory in which there are a Rise TL/OSL-DA-15B/C reader with Sr-90 beta source, a set of Little More Tape 9022 alpha and beta irradiators, three set of Daybreak 583 intelligent alpha counters and sample preparation system has been set up in the Institute in June 2001. The courses of the establishment of a new laboratory involved a series of technical works, besides making a suitable choice of the equipment, as follows: installing and testing TL/OSL reader, calibrating the dose rate of the beta and alpha sources in the irradiators with the standard sources, testing and calibrating the count rates of the thick source alpha counting in the alpha counters with a standard sample, and then dating of the know age samples to check and examine the OSL/TL dating system. All data obtained from above calibrations and tests show that the established OSL/TL system, including the used equipment in it, can be used to determine age of the geological and archaeological samples with an error of equivalent dose (De) of less than 5%. The OSL dates of several sediment samples obtained from the system are good agreement with those from the OSL dating laboratory in Hong Kong University and ~(14)C dates within 1 - 2 standard deviations. The studies on OSL dating technique and protocol of sediment samples being in progress involve the De determinations with single aliquot regeneration (SAR) (Murray and Wintle, 2000) of the coarse grain quartz from sand dune samples and comparison of the De determinations obtained from SAR with those measured by using multiple aliquot regeneration of loess fine grains. The preliminary results from these research works are shown as follows. The very low natural equivalent dose (De) of about 0.012 - 0.03 Gy, corresponding age of less than 10 years, for BLSL (blue light stimulated luminescence) of the coarse grain quartz from modern sand dune samples in Horqin sand fields has been determined with both the SAR and multiple aliquot regeneration (MAR) techniques. This imply that the BLSL signal zeroing of the quartz could be reached before burying of the sand in Horqin sand fields. The De values and ages of the coarse grain quartz measured with SAR protocol are in good agreement with those obtained from multiple aliquot technique for the modern sand dune samples, but the errors of De from the MAR is greater than those from the SAR. This may imply that the higher precision of age determination for younger sand dune samples could be achieved with the SAR of coarse grain quartz. The MAR combining with "Australian Slide method" may be a perfect choice for De measurements of loess fine grain samples on the basis of analysis of De values obtained from the SAR and from the MAR. The former can be employed to obtain a reliable age estimate of loess sample as older as approximately SO ka BR There is a great difference between De determinations from the (post-IR) OSL of the SAR (Roberts and Wintle, 2001) and those from independent or expected estimates for the older samples. However, the age estimates obtained from the (post-IR) OSL of the SAR are mostly closed to the independent age determinations for the younger (age less than 10 ka) fine grain samples. It may be suggested that the (post-IR) OSL of the SAR protocol of the fine grain fraction would be a suitable choice to dating of the younger samples, but may be unsuitable for the older samples.