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淡水湿地水文过程控制着湿地植被景观的形成与演变.基于Landsat TM/ETM+遥感影像数据，利用决策树分类法提取鄱阳湖湿地1992、1999、2006、2012年4期景观信息，通过景观格局指数、转移矩阵和质心迁移法对苔草景观的空间变化及其与水文过程关系进行分析.结果表明：研究期间，鄱阳湖湿地秋、冬季苔草景观分布面积受到水位和退水过程的影响，低水位年的中滩位缓慢退水与低滩位快速出露更有利于苔草景观的扩张；苔草景观的空间格局与水位关系密切，在低水位年份，低位洲滩提前出露，苔草景观分布高程较低，部分低位光滩被苔草所侵占，原苔草分布的部分洲滩转变为芦荻景观，景观的破碎化程度较重，在高水位年份，低位洲滩长期被水体淹没，苔草景观分布高程相对较高，部分芦荻分布区被苔草所侵占，而原苔草景观的部分区域转变为水体和光滩，由于该期间苔草主要集中分布在湖周和入湖河口地带的高位洲滩上，其景观破碎化程度较轻；水位年际间的升降变化会影响苔草景观质心位置，年均水位上升引起景观质心发生向湖岸方向推进，而年均水位下降则会导致苔草景观质心向湖心方向转移.

Due to various reasons, there are generally missing data in datasets. Usually the missing data in these incomplete datasets need to be filled. In this paper, the drawbacks of some existing data filling approaches for incomplete information systems are analyzed based on Rough Set theory. Several similarity relation models are discussed and the Valued Limited Tolerance Relation model is proposed. A data filling algorithm based on the Valued Limited Tolerance Relation model is put forward. This approach makes full use of the similarity of objects and selects the object which is the most similar to the incomplete object. More missing data can be filled scientifically. The experimental results show that this approach is effective.

Bioturbation is an important dynamic process in lake sediment.Tubificid worms,widely distributed in Taihu Lake,were selected to study the potential effects of bioturbation on organic phosphorus(P) components and their vertical distribution in sediments.The experiments were performed with the field sediment column under a constant-flow incubation condition in laboratory,while the contents and components of organic P in sediments were analyzed by phosphorus-31 nuclear magnetic resonance spectroscopy(31P-NMR) which is currently a more direct and powerful tool in characterization of organic P forms at the molecular level.The obtained results demonstrated orthophosphate monoesters,phospholipids,DNA,pyrophosphate and phosphonates were the main organic P components.Compared with the control group(no bioturbation of tubificid worms),organic P components in sediments had no significant difference after the bioturbation of tubificid worms,while their vertical distribution changed obviously.The maximum concentration of total P and organic P appeared in the 0—0.5 cm sediment layer,and then decreased sharply downwards in control group,however,the maximum concentration of total P and organic P in sediments with the bioturbation of tubificid worms appeared in the 0.5—1cm sediment layer,their concentration in the 0—0.5 cm sediment layer were lower than that in control group.Based on 31P NMR analysis,the concentration of labile organic P in 0.5—1cm sediment layer with the bioturbation of tubificid worms was reduced significantly,such as DNA,which content was reduced from 11.2 mg/kg to 6.1 mg/kg.In addition,some physical and chemical indexes in sediments were also changed with the bioturbation of tubificid worms,water content,porosity in the 0—4cm sediment layer and alkaline phosphatase activity in the 0—1.5 cm sediment layer were increased significantly.Some research had found that the increase of water content and porosity in sediments can effect the substance release from sediments.In this research,alkaline phosphatase activity was found to be negatively correlated with the concentration of DNA and phospholipids,this indicated that the increasing of alkaline phosphatase activity can accelerate the decomposition of labile organic P,resulting in the decrease of DNA and phospholipids in the upper sediment.

Fishery is one of the main functions of Lake Taihu,which plays an important role in improving the water environment. However,it is also influenced to a large degree by the environmenal change.Recently,the main problems facing the natural fishery in Lake Taihu are the over-intensive catching and irrational utilization of natural resources.This paper,based on the data of many years' catches in Lake Taihu,analyzed the community structure of fishes in Lake Taihu and their succession dynamics.According to the fish yields and compositions in different area of Lake Taihu,the natural fishery characteristics and problems were studied.Some ideas were presented to develop the natural fishery based on the present research,such as controlling the fishing gear specifications and catching intensity,adjusting the catching time,regulating the structure and proportion of stocking fish species and developing lake fishery in a reasonable way.Meanwhile,the potential of natural fishery was analyzed on the basis of present biological resources in Lake Taihu.It suggested that the construction of fishery environment and studies on influence of fishery on water environment should be strengthened for the further development of lake fishery.

Distribution of soluble reactive phosphate (SRP) in pore waters is a sensitive indicator showing geochemical properties of phosphorus in sediments. Concentration of SRP in synthetic solutions was obtained based on the principle of diffusive equilibration in thin films (DET). Analytical procedure generally includes equilibration of the gels in solutions or pore waters, section of the gels after retrieval, back elution of phosphorus in the gels, and analysis of SRP in the eluents. Equilibrium and extraction times were determined at 24h and 16h, respectively, with 0.25mol/L HNO3 used as an extractant. Concentrations of SRP in pore waters of different sediments measured by using the established DET technique agree well with its actual values, and the variations are generally within ±5%. Analytical results for sediment profiles with this technique, which has a vertical resolution at about 3mm, also show comparison with those using sampling techniques of Rhizon and Mini-Peeper. The established DET technique was used to measure SRP profiles in sediments of macrophyte- and algal-dominated regions in Lake Taihu. Peak-shape distribution and horizontal heterogeneity of SRP were observed in macrophyte-dominated region, while an upward and increasing movement of SRP was observed in algal-dominated region with an increase in water temperature.

Bellamya sp.snails are very common in Lake Taihu.The effects of snail(Bellamya sp.) on the growth of Hydrilla verticillata Royle and Elodea nuttalli ST John and dissolved nutrition elements were examined in a labo- ratory.After a week of exposure of snail and aquatic plant in a experiment,increments of the per unit of Hydrilla verticillata Royle in three groups were:H:0.475 g,L:0.106 g,C:0.021 g and increments of the per unit of Elode- a nuttalli ST John were H:0.704 g,L:0.663 g,C:0.478 g respectively.In addition,the change of length and node of Hydrilla verticiUata Royle and Elodea nuttalli ST John with snail were higher than those without snail,It could be concluded that the increase of nutrition by snail in water could stimulate the growth of HydriUa verticiUata Royle and Elodea nuttalli ST John,because the metabolism of Bellamya sp.increased the nutrition of water and the primary productivity of aquatic plant were similar in three situations with the same experiment environment.

In WSNs, routing algorithms need to handle dynamical changes of network topology, extra overhead, energy saving, and other requirements. Therefore, routing in WSNs is an extremely interesting and challenging issue. In this paper, we present a novel bio-inspired trusted routing scheme (B-iTRS) based on ant colony optimization (ACO) and Physarum autonomic optimization (PAO). For trust assessment, B-iTRS monitors neighbors’ behavior in real time, receives feedback from Sink, and then assesses neighbors’ trusts based on the acquired information. For routing scheme, each node finds routes to the Sink based on ACO and PAO. In the process of path finding, B-iTRS senses the load and trust value of each node and then calculates the link load and link trust of the found routes to support the route selection. Moreover, B-iTRS also assesses the route based on PAO to maintain the route table. Simulation results show how B-iTRS can achieve the effective performance compared to existing state-of-the-art algorithms.

To study the factors affecting the nutrient release of Bellamya sp. , laboratory simulation experiments were carried out, and other traits of Bellamya sp. such as the effects of Bellamya spp. on suspended substance in the water column, water transparency and phytoplankton in the system were also investigated. Results showed that temperature and the amount of food had great influence on nutrient release of Bellamya sp. At 15℃, the release rates of ammonia nitrogen and phosphate phosphorus by Bellamya spp. were 55.60(±4. 95 )μg /( g·d ) and 2.073(±0.1203)μg/(g·d), respectively; at 25℃, the release rale of phosphate phosphorus was about 2. 819 (±0.075)μg/(g·d). So the release rate of nutrient increased at an enhanced temperature , meanwhile nutrient release rate of snail eating food was higher than it that eating nothing. Bellamya sp. could increase the transparency of water on a short term, but the release of nutrients increased the contents of nitrogen and phosphorus in water, which in turn accelerated the regeneration of phytoplankton. Bellamya sp. can not control the production of algae completely , but their improving the secchi-disk depth of water is helpful for the growth and restoration of submerged macrophytes. It is suggested that the combination of biomanipulation of snails and restoration of submerged macrophyles will be an important technical way to control the eutrophication and improve water environment.

Accompanying with the speeding up of Internet of things (IOT) construction, the dependability problems become the important factors constraining its all-round development. Based on the multi-level and multidimensional properties of IOT dependability elements, with the overall improving of the dependability index of IOT as the ultimate goal, the dependability elements of the local fine-tuning in each layer, this paper researches the change rule of internal dependability elements in perception layer, network layer and business layer, and adopts perception layer as the example, using the method of linear programming to seek the best proportion of all kinds of dependability elements and the optimal values of the elements, trying to construct a feasible autonomic optimization model for dependability elements of IOT system. Firstly, according to the function features and dependability properties of each layer, and change rules between the dependability index and dependability elements in each layer are analyzed. Secondly, based on the dynamic changes (up or down) of dependability elements in internal environment (that is, three layers in IOT), the ratio relations of dependability elements in each layer are dynamically controlled and adjusted to implement the local optimization, improving the overall autonomic configuration and autonomic adjusting ability of IOT system. At last, example analysis results show that the optimization model proposed in this paper can realize the substantial optimization in each layer of IOT.

The journey accuracy of overhead travelling crane was improved based on error compensation. To begin with analysis of error sources, the holographic error model had been established. As for each error source, the effect had been analyzed to acquire the main error sources which needed to be considered. The error compensation methods corresponding to relevant main error sources had been discussed by different means. The error compensation algorithm that had been designed according to the research results had been applied to compensating journey error of overhead travelling crane. The simulation experiment validated that the algorithm was effective. Through a large number of on-site tests, the maximal error of actual position and ideal position was +2.5(cm), which well satisfied the need of production.

Being an important topic of the knowledge reduction of rough set, the reduction of the decision rules respectively eliminates the redundant attribute values of each decision rule based on rough logic. The definition of the binary discernibility matrix in the incomplete decision system was given by analyzing all kinds of definitions of the binary discernibility matrix. An algorithm for decision rules reduction in incomplete information system was designed based on binary discernibility matrix. This algorithm is suitable for both compatible and incompatible decision table. The correctness of the proposed algorithm was proved by examples and the efficiency was indicated by empirical analysis and applications.