汉中市人工流水和仿生态养殖大鲵肌肉营养成分研究

本研究分别提取了人工流水养殖和仿生态养殖4育龄大鲵肌肉,测定其营养元素、氨基酸含量及矿物质含量。结果表明,仿生态养殖大鲵较人工流水饲养大鲵肌肉更具开发价值。仿生态养殖大鲵肌肉的平均粗蛋白含量比人工流水养殖大鲵高4.19%;仿生态养殖大鲵肌肉含有大量优质蛋白,EAA/TAA较人工流水养殖大鲵高11.39%,且矿物质含量丰富。

文蛤人工流水催产试验

近年来随着国内外海产品需求量的增加,文蛤的价格不断升高,其采捕强度也逐年加大,加之围埝养虾及盐业的生产,文蛤资源受到严重损害。为尽快恢复文蛤资源,发展文蛤人工增养殖,1991年我站承担了河北省水产局下达的“文蛤室内人工育苗技术试验研究”项目,目前。

人工饲料袋装无菌流水养蚕设计模式

随着中国加入WTO,中国蚕丝业经历了几起几落的波折后,又开始活跃起来."入世"给中国蚕丝业带来了希望,西部大开发又给四川蚕业注入了活力,新一轮蚕桑基地建设的热潮正在四川形成.

Design of Constructed Wetland for Treatment of Tailwater from Wastewater Treatment Plant

In this study, the project of constructed wetland for treatment of tailwater from the wastewater treatment plant in Wudang Mountain was taken as an example, and the technological processes, pollution load, wetland bed structure, bed filler, selection of plants and hydraulic conditions of the subsurface flow constructed wetland were discussed. A subsurface flow constructed wetland, which covered an area of 7 227 m^2 was finally designed. It could treat 7 000 m^3 of tailwater from the wastewater treatment plant a day. In addition, the system could reduce the emission of COD, BODs, TN, TP and NH3-N by 25.55, 25.55, 12.78, 1.28 and 17.89 t respectively a day. The outlet water was proved to reach the Standard A of the first class in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant （GB 18918-2002）.

Study on the Floating Plant Climatic Adaptation of Undercurrent Constructed Wetland in North China

[Objective] The aim was to choose appropriate floating plant in the wetland in the north China.[Method] Pistia stratiotes L.,Eichhornia crassipes,and Hydrocharis dubia（Bl.） Backer were planted in the aquatic biological pool of constructed subsurface flow wetland system in the reservoir.Through filed investigation,the growth of the three kinds of plants was studied and their adaptability to the northern climate was concluded.[Result] Judging from the growth speed and state of the three kinds of floating plants,the biological characteristic of Pistia stratiotes L.can perfectly adapt the environment in the pool in the reservoir,followed by the Eichhornia crassipes.The growth state of the Hydrocharis dubia（Bl.） Backer was the worst one and it can not adapt to the north environment.[Conclusion] It provided references for the choice of artificial floating plant in the north area.

Effects of Hydraulic Loading of Vertical Flow Constructed Wetland Clogging

[Objective] The aim was to al eviate the constructed wetland clogging problems and to explore to the effects of hydraulic loading on wetland clogging. [Method] The experiment, through artificial soil columns, simulated vertical flow arti-ficial wetland, set four hydraulic load level at 50, 100, 150 and 200 cm/d, to identify the impact of hydraulic loading on wetland clogging and to explore the factors run-ning threshold. [Result] The results show that the different levels of hydraulic loading have greater impact; in the constructed wetland clogging process under high hy-draulic loading of 200 cm/d, the effective life was only six months, and the single factor can be speculated that the threshold of the hydraulic load should be at 100-150 cm/d; system can last for six months at low hydraulic loading and last for three months at medium hydraulic load. [Conclusion] The research provides references for wetland clogging experiments in future.

Performance of Subsurface Constructed Wetland in River Rehabilitation

[ Objective] This study was to research the treatment effect of different media in undercurrent wetland on contamination, so as to pro- vide reference for rehabitating water body of river along small towns. [ Method ] Three different media of gravel, cobblestone and shale were used to rehabilitate water quality of contaminated river. [ Result ] Gravel, cobblestone and shale all performed well in removing TN, TP and CODw,, in contaminated water, of which gravel stuffed undercurrent wetland run best, averagely removing 49.4% TN, 34.7% and 48. 5% COD~, respectively. [ Conclusion] Undercurrent constructed wetland can effectively improve the water quality of contaminated river, and it is cheaper in cost and simpler in operation, thus suitable for generalizing in small towns of China.

Efficiency and mechanism of pretreatment on water supply in reservoirs of Yellow River by subsurface constructed wetlands

In order to improve the source water quality of drinking water and mitigate the load of drinking water treatment plant, a pilot test was conducted with integrated horizontal flow constructed wetlands to pretreat the water supply in the reservoirs of Yellow River. Resuhs show that under the hydraulic loading rate of 4 m^3/（ m^2 · d）, the average removal rates of chemical oxygen demand （COD）, total nitrogen （TN）, ammonium nitrogen （ NH4 ^＋ - N）, nitrate nitrogen （ NO3 ^- - N）, nitrite - nitrogen （ NO2^ - - N） and total phosphorus （TP） in the horizontal flow constructed wetlands are 49. 68% , 53.01%, 48.48%, 53.61% , 62. 57% and 49. 56%, re- spectively. The study on purifying mechanism of the constructed wetlands indicates that the disposal of contamination by subsurface wetlands is the combined actions of physical chemistry, plants and microorganism.

Artificial neural network approach for rheological characteristics of coal-water slurry using microwave pre-treatment

Detailed experimental investigations were carried out for microwave pre-treatment of high ash Indian coal at high power level(900 W) in microwave oven. The microwave exposure times were fixed at60 s and 120 s. A rheology characteristic for microwave pre-treatment of coal-water slurry(CWS) was performed in an online Bohlin viscometer. The non-Newtonian character of the slurry follows the rheological model of Ostwald de Waele. The values of n and k vary from 0.31 to 0.64 and 0.19 to 0.81 Pa·sn,respectively. This paper presents an artificial neural network(ANN) model to predict the effects of operational parameters on apparent viscosity of CWS. A 4-2-1 topology with Levenberg-Marquardt training algorithm(trainlm) was selected as the controlled ANN. Mean squared error(MSE) of 0.002 and coefficient of multiple determinations(R^2) of 0.99 were obtained for the outperforming model. The promising values of correlation coefficient further confirm the robustness and satisfactory performance of the proposed ANN model.

Application of ANNs Model with the SDSM for the Hydrological Trend Prediction in the Sub-catchment of Kurau River, Malaysia

The paper describes the application of SDSM （statistical downscaling model） and ANNs （artificial neural networks） models for prediction of the hydrological trend due to the climate-change. The SDSM has been calibrated and generated for the possible future scenarios of meteorological variables, which are temperature and rainfall by using GCMs （global climate models）. The GCM used is SRES A2. The downscaled meteorological variables corresponding to SDSM were then used as input to the ANNs model calibrated with observed station data to simulate the corresponding future streamflow changes in the sub-catchment of Kurau River. This study has discovered the hydrological trend over the catchment. The projected monthly streamflow has shown a decreasing trend due to the increase in the, mean of temperature for overall months, except the month of August and November.

A pilot study on wastewater treatment by constructed wetlands with high dissolved oxygen vegetated submerged bed

It is necessary to treat wastewater in a more environment-friendly fashion.Vegetated submerge bed constructed wetlands (CWs) has become the focus of the research in this field. In this paper, the overall capacity of vertical subsurface flow CWs in the removal of pollutants from municipal wastewater effluent and the effects of the depth of vegetated submerged bed on the removal efficiency were studied. The results showed that the COD, NH+4-N and TN could be removed effectively in the vertical subsurface flow CWs and the best efficiency was obtained from the 10 cm run. However, the TP removal was not effective in all vertical CWs. A shallow depth of vegetated submerged bed may avoid the risk of substrate plugging effectively, and may keep a stable operation of CWs in long term. Decreasing the depth of vegetated submerged bed could create a sufficient aerobic circumstance in which the concentration of DO (dissolved oxygen) in bed was super saturation.

Research progress in artificial upwelling and its potential environmental effects

Artificial upwelling, as a geoengineering tool, has received worldwide attention because it may actualize ocean fertilization in a sustainable way, which could potentially alleviate the pressures on the fish stocks and human-driven climate change in the ocean. We reviewed the current knowledge on the development of an artificial upwelling system and its potential environmental effects. Special attention was given to the research progress on the air-lift concept artificial upwelling by Zhejiang University. The research on artificial upwelling over the past few decades has generated a range of devices that have been successfully applied in the field for months. Based on field experiments and the associated modeling results, part of them reported positive effects on increasing primary production and enhancing CO2 sequestration. However, as a significant disturbance to the environment, especially for large-scale applications, the uncertainties related to the potential effects on ecosystem remain unsolved. Zhejiang University has overcome the technical challenges in designing and fabricating a robust and high efficiency artificial upwelling device which has been examined in two field experiments in Qiandao Lake and one sea trial in the East China Sea. It was investigated that cold and hypoxic deep ocean water(DOW) could be uplifted to the euphotic layer, which could potentially change the nutrient distribution and adjust the N/P ratio. Both simulation and field experiments results confirmed that utilizing self-powered energy to inject compressed air to uplift DOW was a valid and efficient method. Therefore, further field-based research on artificial upwelling, especially for long-term field research is required to test the scientific hypothesis.

Deposition rate and interaction of human-riverine from height increase and permanent function of an 1180 years weir in Southeast China

This paper is to present an efficient approach to enriching the quantification model of human-riverine interactions and its anthropogenic impact by a retrospective study on one of the four most famous historical hydraulic projects in China,the Tuoshan Weir.It was constructed in 833 AD and had trajectories of natural resilience and hydraulic engineering maturity more than thousand years.Extensive historical data and maturation procedure of the hydraulic system were used judiciously to examine the spatial patterns of the long-term water conservancy system with agriculture,urbanization and civilization of Ningbo City in Zhejiang Province,Southeast China.Interaction framework is assessed from historical perspective and the deposition rate(DR)is calculated by analyzing the continuous increase of the Tuoshan Weir height.The results show that the declining DR during the 1180 years guaranteed the beneficial role the Tuoshan Weir played in spite of some negative river responses caused by the increase of sediment deposition and decrease of fresh water-retention capacity.The following up revamped workings and well matured hydraulic system around the Tuoshan Weir also contribute a lot to the designed mission of the weir.We conclude that hydraulic system maturation is very important for the proper function and life span of huge hydraulic projects.