Analysis of reservoir water quality using fuzzy synthetic evaluation

A general methodology for fuzzy synthetic evaluation is developed and illustrated with a case study of trophic status assessment for Fei-Tsui Reservoir in Taiwan. The historical data base was collected from the management agency of Fei-Tsui Reservoir from 1987 to 1996. In fuzzy synthetic evaluation, the classification is determined by a matrix operation of the weighted vector with the fuzzy evaluation matrix. After all individual membership functions of evaluated factors have been determined, the fuzzy evaluation matrix can be established. The weighted vector is determined by the analytic hierarchy process method (AHP). The results of this investigation show that the long-term change of water quality and the overturn phenomena cannot be observed with the Carlson index from 1987 to 1992 but is expressed by fuzzy synthetic evaluation. Fuzzy synthetic evaluation is better suited than the Carlson index to rating the trophic status of self-sustaining lakes. Interpretation of the results can provide valuable information to decision makers and aid reservoir management.     

Periodic orbits based on geometric structure of center manifold around Lagrange points

This study proposes an analytical method that determines the center manifold and identifies the reduced system on the center manifold. The proposed method expresses the center manifold through general equations containing only state variables, and not functions with respect to time. This is the so-called geometric structure of the center manifold. The location of periodic or quasi-periodic orbits is identified after the geometric structure of the center manifold is determined. The reduced system on the center manifold is described using ordinary differential equations, so that periodic or quasi-periodic orbits can be computed by numerically integrating the reduced system. The results indicate that the analytical method proposed in this study has higher precision compared with the Lindstedt-Poincaré method of the same order.     

Remote Sensing of Eupatorium Adenophorum Spreng Based on HJ-A Satellite Data

In the southwest of China, one of the greatest threats to local ecosystem is the area expansion of an invasive species, i.e., Eupatorium adenophorum Spreng (EAS). In this study, the remote-sensing technology was used to detect and map the spatial distribution of EAS in Guizhou Province, China. A series of vegetation indices, including normalized difference vegetation index (NDVI), simple ratio index (SRI) and atmospherically resistant vegetation index (ARVI), were used to identify EAS from HJ-A Chninese satellite data. According to the analysis results of fieldworks from March 21 to 22, 2009, it was found that the vegetation index of {1.9589 ≤ SRI ≤ 4.1095}∩{0.2359 ≤ ARVI ≤ 0.5193} was the optimal remote-sensing parameter for identifying EAS from HJ-A data. According to the spatial distribution of EAS estimated from HJ-A data, it was found that EAS was rather more in southwest of Guizhou Province than in northeast. EAS became sparse from southwest to northeast gradually, and the central Guizhou Province was the ecological corridor linking EAS in southwest to that in northeast. By comparison with validated data collected by the government of Guizhou Province, it was found that the uncertainty of remote-sensing method was 18.52%, 29.31%, 8.77% and 9.46% in grassland, forest, farmland and others respectively, and the mean uncertainty was 13.29%. Owing to the lower height of EAS than many plants in forest, the uncertainty of EAS was the greatest in forest than that in grassland, farmland and so on.     

ESR dating of Pleistocene archaeological localities of the Nihewan Basin,North China – Preliminary results

The well-developed, late Cenozoic Nihewan Beds in northern China are amongst the most famous and well-preserved Quaternary strata in East Asia. The Nihewan Basin is also well-known for its mammalian fossils and stone artifacts, which document early human settlements in high northern latitudes (around 40°N). It is a key geological place to study palaeoenvironments and ancient human activities due to the excellent age-control of the formation by palaeomagnetism. In the present paper, the sediments of two Paleolithic sites were dated using the ESR signals of the titanium center in quartz. In order to check the reliability of our analytical procedures, a reference sample collected near the Brunhes/Matuyama (B/M) boundary at the Donggutuo site was firstly analyzed, yielding an age of 750 ± 88 ka. Then, three samples collected from the Dongpo site were analyzed by the same procedures. Our ESR results indicate that the age of the Dongpo cultural layer ranges between 304 ± 12 ka and 333 ± 23 ka, with an average of approximately 321 ± 15 ka.     

Dipole tilt controls bow shock location and flaring angle

The dipole tilt angle has been found to affect Earth’s bow shock. This work presents a quantitative relationship between the dipole tilt angle and the bow shock location and flaring angle. We collected a large data set of bow shock crossings from four different satellites (IMP 8, Geotail, Magion 4, and Cluster), including some recent crossings obtained during 2012–2013. The results from a statistical analysis demonstrate that: (1) the subsolar standoff distance increases but the flaring angle decreases with increasing dipole tilt angle; (2) when the dipole tilt angle changes sign from negative to positive, the dayside bow shock moves toward Earth and the shift can be as much as 2.29 R _E, during which the flaring angle increases; and (3) the shape of bow shock in the northern and southern hemispheres differs. For the northern hemisphere bow shock, with increasing positive/negative dipole tilt angle, the flaring angle increases/decreases. While for the southern hemisphere, the trend is the opposite; with increasing positive/negative dipole tilt angle, the flaring angle decreases/increases. These results are helpful for future bow shock modeling that needs to include the effects of dipole tilt angle.     

关于我国电力建设问题

本文在分析我国能源资源分布特点,总结过去电力建设经验的基础上,通过水、火电全面经济效益比较,认为,在我国具体的国情和国力条件下,今后必须贯彻优先开发水能的方针,并提出了因地制宜发展水电建设应注意做好的四项工作。     

TL dating of loess in China

TL ages of 56 loess samples collected from Xinjiang and the middle reaches of the Yellow River were determined by using fine-grained quartz and man-made light source bleaching techniques.The results indicate that :1.The well-preserved loess sections in Xinjiang began depositing 400000 a ago.The loess/paleosol series may be comparable with that observed in the middle reaches of the Yellow River but the depositing time was probably delayed by 30000-50000a.2.The bottom boundary age of the Malan loess varies from one place to another.The TL dates can be divided into two group:70000-130000 a and 30000-50000 a.The TL data are con-sistent with the appearance of two warmer climate periods since the Pleistocene,indicating obvious regional differences in stratigraphic development of loess,i.e.,paleosol occurred in the warm climate period in the same location,but loess was deposited in other locations.The initial age of loess deposition tends to become older from west to east and from south to north .In contrast ,the cold cli-matic belt showed an opposite trend.The TL ages of loess provide strong evidence for the Quaternary stratigraphy throughout geological times and the shift tendency of climatic belt.3.The depositing rate of the Malan loess along the middle reaches of the Yellow River varies from place to place but the TL age shows a linear relationship with the depositing thickness.The de-positing rate of loess in the north is higher than that in the south,suggesting that loess materials are derived from desert areas of northern China.     

高应变法在判定大直径灌注桩缺陷中的应用

测试数据准确可靠的高应变法检测,能够定量分析基桩缺陷,准确判定缺陷位置。通过工程桩的低应变法和高应变法对桩身完整性判定分析的工程实例,结合钻芯法验证,总结高应变法在不同情况下对桩身完整性的评定。