An analytic expression for wind-velocity profile within the saltation layer

The vertical wind-velocity profile within the saltation layer is investigated theoretically. New equations for the fluid shear stress distribution in the saltation layer and the velocity profile affected by saltation are derived. The dependence of the velocity profile on the threshold shear velocity, the vertical variations of sand grain velocity, the vertical sand-mass-flux distribution, and the fluid shear stress within the saltation are demonstrated. Velocity profiles with or without Bagnold's focus are predicted. These velocity profiles are not very sensitive to the vertical distribution of sand-mass flux. Predicted velocity profiles are compared with profiles measured in the wind tunnel, and satisfactory agreement has been achieved.     

粘土中氯离子的测定方法改进实验

针对目前国内测定粘土中的氯离子采用碱熔分解、硫氰酸汞比色法所存在的问题，进行了改进实验。采用硝酸溶解样品，有效地消除了S^2-对Cl^-的干扰，用洗涤好的滤纸过滤，在硝酸酸度为1．0mol／L条件下，用硫氰酸汞显色测定，达到了好的效果，提高了方法的精密度，完全能达到水泥原料的规定要求。该方法操作简便、快速、实用，适宜大批量样品的分析测试。     

论项目管理承包模式的进度控制

本文通过对PMC项目阶段的划分、进度控制管理的特点、进度控制影响因素等方面的分析．浅谈一点在PMC项目中应如何采取有效的措施搞好进度控制．实现项目目标的体会。     

A landslide susceptibility model using the Analytical Hierarchy Process method and multivariate statistics in perialpine Slovenia

Landslides cause damage to property and unfortunately pose a threat even to human lives. Good landslide susceptibility, hazard, and risk models could help mitigate or even avoid the unwanted consequences resulted from such hillslope mass movements. For the purpose of landslide susceptibility assessment the study area in the central Slovenia was divided to 78 365 slope units, for which 24 statistical variables were calculated. For the land-use and vegetation data, multi-spectral high-resolution images were merged using Principal Component Analysis method and classified with an unsupervised classification. Using multivariate statistical analysis (factor analysis), the interactions between factors and landslide distribution were tested, and the importance of individual factors for landslide occurrence was defined. The results show that the slope, the lithology, the terrain roughness, and the cover type play important roles in landslide susceptibility. The importance of other spatial factors varies depending on the landslide type. Based on the statistical results several landslide susceptibility models were developed using the Analytical Hierarchy Process method. These models gave very different results, with a prediction error ranging from 4.3% to 73%. As a final result of the research, the weights of important spatial factors from the best models were derived with the AHP method. Using probability measures, potentially hazardous areas were located in relation to population and road distribution, and hazard classes were assessed.     

Design, analysis, and inference for studies comparing thematic accuracy of classified remotely sensed data: a special case of map comparison

Assessing thematic map accuracy is a special type of map comparison that is frequently applied to remote sensing classification problems. For map comparisons in the accuracy assessment setting, one map represents the classified output and the other map represents the true or “reference” condition. Several articles in this special issue describe state-of-the-art map comparison analysis tools that could serve to quantify accuracy of a single map. However, accuracy assessment objectives generally extend beyond describing accuracy of a single map to comparing accuracy of several maps. Consequently, interest focuses on comparing map comparison measures when these measures are used to represent accuracy. The virtual workshop emphasizes the analysis component of map comparisons, but it is also important to examine the underlying study designs generating the data input into these analyses. The study designs for accuracy comparisons implemented in remote sensing practice often investigate only a single test site, thus limiting our ability to generalize the results of these accuracy comparisons. Map accuracy comparison studies can be designed to provide stronger generalizations by incorporating experimental design principles such as replication and blocking, and identifying an experimental unit appropriate for the application. It is also important to recognize the role of statistical hypothesis testing and inference for different objectives that motivate map accuracy comparisons. Deciding which of two maps to use for a particular site can be addressed by enumerative inference and does not require hypothesis testing. For the objective of a more general comparison of classification procedures, analytic inference is appropriate and hypothesis testing plays a more prominent role.     

江西省数字化雷达回波拼图技术方法的研究

介绍了江西省数字化雷达回波拼图的技术方法。该方法主要包括回波资料的预处理、拼图投影处理。它具有资料同一性、准确性好、方便灵活、适合业务使用等特点。     

荒漠化及其系统过程

荒漠化是全球重大的社会经济和环境问题。本文通过分析荒漠化及其系统过程认为，荒漠化是在土地利用系统中由于不合理的土地利用方式造成植被覆盖度下降，并通过一系列反馈机制形成的土地退化过程。由于系统内植被破坏对土壤侵蚀存在放大效应，应注重对我国南方山地丘陵水蚀荒漠化的研究。     

Arsenic — a Review. Part II: Oxidation of Arsenic and its Removal in Water Treatment

In natural waters arsenic normally occurs in the oxidation states +III (arsenite) and +V (arsenate). The removal of As(III) is more difficult than the removal of As(V). Therefore, As(III) has to be oxidized to As(V) prior to its removal. The oxidation in the presence of air or pure oxygen is slow. The oxidation rate can be increased by ozone, chlorine, hypochlorite, chlorine dioxide, or H₂O₂. The oxidation of As(III) is also possible in the presence of manganese oxide coated sands or by advanced oxidation processes. Arsenic can be removed from waters by coprecipitation with Fe(OH)₃, MnO₂ or during water softening. Fixed‐bed filters have successfully been applied for the removal of arsenic.The effectiveness of arsenic removal was tested in the presence of adsorbents such as FeOOH, activated alumina, ferruginous manganese ore, granular activated carbon, or natural zeolites. Other removal technologies are anion exchange, electrocoagulation, and membrane filtration by ultrafiltration, nanofiltration or reverse osmosis.     

简论资源、环境与经济间可持续发展关系

资源学、环境学与经济学是相对独立的学科，但它们之间又具有密切的内部联系。资源（自然资源）、经济和环境是现代社会发展中的三个重要方面。本文试图用综合发展的观点，分析资源、环境、经济三者之间的相互矛盾、相互依赖、相互影响、相互作用的规律，论述处理好资源、环境与经济相互协调、发展的关系。这也是社会经济可持续发展的时代要求。     

江西省丹霞地貌分布特征及旅游开发初步评价

江西省分布有123处丹霞地貌,丹霞地貌旅游资源十分丰富。简述了丹霞地貌的分布特征,对其地质成因进行了简要分析。利用层次分析法建立了丹霞地貌旅游资源开发评价的目标评价体系结构,通过模糊赋分法对江西省丹霞地貌主要景区进行初步的定量评价,根据评价结果提出了合理开发该省丹霞地貌旅游资源的几点建议。