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    15 October 2016, Issue 10
      
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  • China Rural Water and Hydropower. 2016, (10):  35-39. 
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    It used constant temperature incubator, urea for fertilizer and sandy loam for soil in the experiment. This experiment studied the dynamic change trend of soil nitrate nitrogen content and used the Logistic growth curve to quantitative describe soil nitrate nitrogen transformation process with time under the condition of constant temperature. The results showed that nitrate nitrogen will be accumulated in the soil with the increase of cultural time, and the nitrate nitrogen accumulation under the high temperature and high nitrogen was obviously higher than that of low temperature and low nitrogen treatment. Soil nitrate nitrogen accumulation can be quantitative described by the Logistic growth curve , and it can be obtained two parameters to quantitative describe nitrification strength: the maximum nitrification rate and period of delay. Maximum nitrification rate ranged from 0.236mg/kg to 0.373 mg/kg and period of delay ranged from 1.05d to 3.15d under different processing conditions. Parameters analysis showed that the nitrification of low temperature and low nitrogen treatment was the slowest, high temperature and high nitrogen treatment was the fastest. Factors of affecting the maximum nitrification rate and period of delay through nonlinear regression analysis have nitrogen、temperature and its coupling effect, and temperature effect reached significant level. It can provide theoretical basis for effective use of soil nitrogen under the condition of constant temperature by the regression model.
  • China Rural Water and Hydropower. 2016, (10):  44-48. 
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    Abstract: Because of huge scale and investment, it is almost impossible that whole country’s small irrigation system funded and implemented by public finance and government, farmer households’ fully participation is the main energy to provide small irrigation services. However, in recent many years, farmer households’ participation willingness was decreasing and made the small irrigation services cannot meet real demands. There have many different factors to affect participation willingness, according to questionnaire survey data analyzing on the total of 3552 valid samples from 21 provinces, it is showed that the factors of agricultural income percent, farmers’ education level, agricultural labor amount, cultivating land amounts, households’ social capital, and irrigation facilities subsidy, are positive correlation with participation willingness, and the factors of present small irrigation facilities amount, agricultural labors’ age, farmers’ trust level to village leaders, are negative correlation with participation willingness. Meanwhile, social gender is also an important factor, it is found that male farmers have higher participation willingness than female.
  • China Rural Water and Hydropower. 2016, (10):  49-52. 
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    In order to study the effects of irrigation depth control on winter wheat root morphology ,In the field of Shanxi conservancy technical college, using soil column cultivation methods to conduct the winter wheat root experiment that measures the root morphology of winter wheat at jointing stage, heading stage, filling stage and maturity stage. The results show that: compared to the ground irrigation methods, depth irrigation methods combined with water contend can promote root depth plunging , improve total root length and weight, and significant effect its vertical distribution of root length and weight density. It improve the whole root biomass by promoting the growth of winter wheat in the lower soil layer. To maturity stage, depth irrigation methods can increase the root depth about 30cm or so, the total root length about 20% or so and the total root weight about 10% or so. But in later growth stages, to the depth irrigation methods, too large irrigation depth would restrain the growth of root in surface soil layer. So it should select the appropriate irrigation depth. In this experiment, to the irrigation depth of 60% and 75% root depth, the overall roots of winter wheat grow well. And it can provide reference for water-saving irrigation of winter wheat in North China.
  • China Rural Water and Hydropower. 2016, (10):  53-55. 
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    Abstract: The animal husbandry in Xinjiang irrigation area due to no electricity supply, so it uses the surface irrigation. Surface irrigation irrigation water more, such as large terrain slope causes a large amount of water loss and soil erosion. Irrigation district of the downstream drainage not free lowland swamp area is increased, the rise of ground water level in soil salinity, abandon the field area expands gradually, the planting area is shrinking, the difficulty of realization of water-saving irrigation projects. In order to solve the above problem, developed a drop of water regulator and the pressure drip irrigation project no electricity filter unit. This paper makes full use of natural terrain, and solved the pressure drip irrigation engineering water filtration, and sand, flushing and washing and so on. Channel water flow at the same time, the regulation of the pool flow, collection of bucket established a balanced relationship between flow and system flow, this paper introduces the system flow calculation method, and for animal husbandry irrigation areas without electricity can provide the theoretical basis for water-saving irrigation technology.
  • China Rural Water and Hydropower. 2016, (10):  59-62. 
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    Greenhouse tomato plants cultivated in buckets with perlite substrate were selected as the experimental crops throughout growth stage. Based on catastrophe theory, the author comprehensively evaluated the irrigation modes coupling with different nutrient solution concentrations and amounts. The experiment set four Hoagland nutrient solution concentrations values (S1: 1/4S, S2: 3/8S, S3: 1/2S, S4: 5/8S) and three dosage values(W1: 1.2ET0, W2:1.0ET0, W3: 0.8ET0) . The results suggested that W3S3 was the most favourable treatment for tomato growth with the purpose of high yield, efficiency and quality. Catastrophe theory could evaluate the irrigation modes objectively with simple calculation and strong practicality, which was a scientific and effective method to evaluate the irrigation mode for greenhouse tomato growth.
  • China Rural Water and Hydropower. 2016, (10):  83-85. 
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    Abstract : This paper introduces a dynamic water diversion open channel area control system. Research on agricultural irrigation and automation technology, hydrolysis of dynamic decoupling control algorithm. The hardware control system of dynamic water diversion on the open channel area that was ganged and cooperative controlled of mechanical and electrical equipment group was designed based on ARM, including wireless communication module, carry water control terminal, water regulating terminal, dynamic water and diversion water terminal, complementary power supply switch control terminal and so on. Development of PC management scheduling software, realize the multipoint cluster alignment coordination control of the terminal. Application experiment was carried out in the irrigation area. The experiment results show that the automatic dynamic water diversion control system on the open channel area runs stably, easy to operation, realizes the dynamic regional irrigation water flow in open channel diversion of information and automation management, greatly improving the efficiency of agricultural water use efficiency and irrigation.
  • China Rural Water and Hydropower. 2016, (10):  86-90. 
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    Recharge well with filter layer is a common device using for recharging groundwater in Shandong Peninsula, and composed of recharge well and recharge pool. By analyzing the problems of existing recharge well with filter layer, three dual?recharge?wells with filter layer were designed, the laboratory steady state flow recharge test device was developed, experimental study was conducted on laboratory steady state flow recharging of the ordinary recharge wells, the existing recharge well with filter layer and three dual recharge wells with filter layer, and the effect of the shape of wellhead on single-well recharge volume was also analyzed, draw the following conclusions: (1) The lower impervious wall of dual recharge wellhead which can prevent inferior water from flowing into aquifer when water level was lower at beginning stage of rainfall flood; covering geomembrane on external wall of dual recharge wellhead which prevent polluted river water from recharging into aquifer. (2) At the same experiment conditions, compared to the existing recharge well with filter layer, the single-well recharge volume of dual recharge wells with filter layer had increased 395%~414%, and the dual recharge wells also had stronger anti-rush capability. (3) The single-well recharge volume of recharge wells with filter layer was the largest in the first test, and decreased with an increased in test times, then tend to be stable. (4) Round dual recharge wellhead had a better inlet flow pattern and a bigger single-well recharge volume compared with square dual recharge wellhead and square table dual recharge wellhead, since the shape of recharge wellhead affected single-well recharge volume
  • China Rural Water and Hydropower. 2016, (10):  100-103. 
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    Aiming at the randomness, nonlinear and fuzziness of daily runoff, sucking up the correlation representing function of mutual information and the nonlinearity approximation capability of RBF neural network, this paper establishes mutual information-based ameliorating the nearest neighbor cluster RBF neural network prediction model. Firstly, utilizing mutual information to filtrate input variable; Secondly, confirming the hidden layer and network parameter using the nearest neighbor cluster. Finally, proceeding runoff prediction using the trained neural network. Taking runoff of Huning hydrometric station which locates on Ya-lung river as example, the result shows that: compared with single RBF neural network model and the modified model, the mutual information-based ameliorating the nearest neighbor cluster RBF neural network prediction model overcomes the drawback of the primary model which doesn't select the input variables, improves prediction accuracy and enhances prediction stability, it provides a new approach for short period runoff prediction.
  • China Rural Water and Hydropower. 2016, (10):  119-122. 
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    In order to optimize the intelligent hydropower plant LCU structure, improve the intelligence degree and reliability,in this paper, on the basis of analysis of the status quo, from the Unit LCU constitute angle data interfaces between method and device, puts forward the intelligent terminal and online monitoring device concept.The method and the advantages of using the intelligent terminal to realize the digital transmission of various types of signals in the hydro generator unit are described in this paper,and discussed the data interface between tthe sequential control device and the other device.Finally, this paper illustrates the realization method of intelligent measurement and control unit main function control in hydropower plant.
  • China Rural Water and Hydropower. 2016, (10):  128-131. 
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    In the second phase of gate slot construction of surge-chamber gate shaft in Jinping-II hydropower station, aiming at current problems of stopping to adjust frequently, spending a lot of resources, slow construction progress and poor safety, which result from adopting traditional structure of the fixed sliding mode, a self-designed adjustable hydromantic elastic slip-form has been developed to construct. The sliding mode adopts the design of whole steel structure and installs guide pulley to solve the deviation problem. And in accordance with the construction condition of high depth (115.3m), an anti-separation concrete feeding system was developed to support the use of it. The construction efficiency, quality and safety of the project were improved and the second phase construction problem of high depth gate slot in gate shaft has been solved. The construction technology has broad application prospects in similar projects in the future.
  • China Rural Water and Hydropower. 2016, (10):  132-133. 
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    After the reform of increasing capacity, big noise and violent vibration was found when the output of unit was bigger than 200kW. Furthermore, it became increasingly serious with the increasing of unit’s output, as a result,the unit cannot run safely. In order to find out the cause, a noise test was carried out on the unit 1. Finally, the root cause leading to big noise and violent vibration was found out that the height of head cover’s strengthen bar was too high. After the reform to head cover’s strengthen bar, the problem was well solved.
  • China Rural Water and Hydropower. 2016, (10):  134-137. 
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    Bulb tubular turbine hydraulic generating unit is a relatively good system for developing and utilizing the hydraulic resources of low water head, with features of high efficiency, small size, simple structure, ease for construction, and small submerging area caused by the reservoir, enabling the system to enjoy very good advantages in the low-water-head section and have a wide range of application in China and other countries. However, while the tubular turbine generating sets are being increasingly used, some problems and defects also come to appear. In this paper, a study is conducted on facture of connecting bolt joining the runner and the main shaft during operation of tubular turbine generating unit, which results in the plant house being flooded and dispensable losses. In order to prevent such case from happening again, a comprehensive analysis is carried out on the cause of the incident, and a series of precautionary measures are suggested for reference of the managers working with similar generating units.
  • China Rural Water and Hydropower. 2016, (10):  141-145. 
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    Abstract: Single-hole, double-hole and multi-hole were perforated on the lower pressure position of a non-symmetrical airfoil NACA2412 to study the effect of cavitation reduction on turbine blades. The software UG, CFX and CFD were used for the process simulation. The effects of these holes were calculated and analyzed by using the RNG double-equation turbulence model and the SIMPLEC algorithm. The influence of hole arrangement on aerofoil cavitation was studied. The results show that when perforating a hole at the position with the lowest pressure on the aerofoil, the pressure above the aerofoil can be increased, and the cavitation can be reduced. The more concentrated the holes are, the more cavitation will be reduced. When perforating holes on the leading side of the aerofoil, the effect of cavitation reduction by one hole with suitable diameter at the point with the lowest pressure is better than that of multi-hole around the point with the lowest pressure.
  • China Rural Water and Hydropower. 2016, (10):  146-150. 
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    The dam monitoring data is limited and the structure is adapted to the risk of deformation in the early impoundment stage. In such a situation, taking advantage of the Grey Theory, Neural Networks and Weighted Markov Chain Theory, a Dam Deformation Monitoring Model based on Gray neural network – Weighted Markov Chain is built to predict a RCC dam horizontal displacement in the early impoundment stage. Results of prediction show that this model solves difficulties the fewer data and greater deformation data volatility to achieve a good fitting and precision.
  • China Rural Water and Hydropower. 2016, (10):  173-178. 
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    In order to optimize impeller geometric parameters of floating water pump, different inner flow field models of different parameters are established based on Pro/E. FLUENT is used to conduct the numerical simulation to discuss the influence of impeller blade numbers, wrapping angles of blade and blade thickness on external characteristics, inner flow fields, blade stresses and velocity distributions of floating water pump. The result shows that, in the same position, the larger blade numbers, the faster velocity of blade surface is. Impeller blade numbers have a great impact on power-flow curve in opposite of efficiency curve. Suitable impeller wrapping angles are required, for which big angles lead to local low pressure on impeller surface and small ones result in a buildup of pressure at the outlet. With the increase of blade numbers, the hump characteristic of efficiency curve is more obvious and high efficiency area moves towards the direction of small flow. Blade thickness has little effect on external characteristics curve. The paper provides certain references for optimization of impeller geometric parameters, coordination of inner flow field distributions and improvement of pump efficiency.
  • China Rural Water and Hydropower. 2016, (10):  186-188. 
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    Because of the operating programs is difficult to choice in the drainage pumping station, on the basis of one pump station’s requirements,have did the test in variable angle adjustment and speed adjustment. The test results shown that the variable angle curve approximate only position change and with a wide range of high efficient area, within a certain range, agree well with the pump speed adjusting performances. By analyzing the test results, summarizes their respective advantages and disadvantages. This paper derived the relationship between the highest efficiency point and speed. Combined with the variable angle adjustment and variable speed adjustment of their respective advantages,Can choose a reasonable operation scheme based on the test result quickly, not only save time and economic, but also safe and efficient.
  • China Rural Water and Hydropower. 2016, (10):  191-195. 
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    In order to investigate the rotor-stator interaction (RSI) between impeller and guide vane for multistage centrifugal pump. Ansys CFX software is adopted to simulate the unsteady flow under multiple operating conditions for a five-stage centrifugal pump, and the pressure fluctuations at monitoring points distributing in four different locations in both the impeller and guide vane passages are obtained under different flow rates. The numerical results were partially confirmed by the experimental results. In general, the fluctuating frequency of each monitoring points is about 560HZ, which is equal to two times of the blades’ passing frequency, and the vibration amplitude is quite large, which means the rotor-stator interaction is strong. The pressure fluctuation around the interface between the impeller and guide vane is maximum, the pressure fluctuation in the guide vane is influenced by the impeller obviously, and the monitoring point away from the exit of the impeller father, the amplitude of pressure fluctuation is smaller. Seen from the frequency spectrogram of the guide vane, the high peak lies at its blades’ passing frequency, which shows that the dominant frequency in the guide vane is the blades’ passing frequency. The fluctuation amplitude is amplified, especially at the lower flow rate. The pressure fluctuation distribution can be an important theoretical basis for designing the low pressure fluctuation multistage centrifugal pumps under multiple operating conditions.
  • China Rural Water and Hydropower. 2016, (10):  200-203. 
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    Two kinds of calcium hypochlorite disinfectant and dosing devices were introduced in this paper, which were respectively calcium hypochlorite tablets and fixed-ratio automatic variable dosing device, calcium hypochlorite cakes and simple soaked variable dosing device. Both of the two above-mentioned solid forms of calcium hypochlorite disinfectant and dosing devices were described thoroughly, including their technical characteristics, working principles, engineering applications and operating results. Besides, their operating costs were measured by theoretical calculation and pilot project observation separately. The results showed that the two kinds of disinfection devices run stable with qualified disinfection results and low cost, so they were both worth popularizing in rural water supply project. The fixed-ratio automatic variable dosing device was suitable for appropriate scale central projects which had good management conditions, as the simple soaked variable dosing device was suitable for small scale central and dispersed projects which had poor management conditions.
  • China Rural Water and Hydropower. 2016, (10):  204-208. 
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    Based on the surveys of fresh water consumption in civil offshore platform, this paper analyzes the relationship among total water consumption, water consumption per capita, fix numbers of person, actual number of person on offshore platform, water consuming points, fraction of supervisor. Finally it gets the useful conclusion. Many methods are used to calculate the water quotas and advanced levels of the platform, such as regression method, quadratic average and probability calculation. Related factors are taken into account, like actual advanced levels in different areas, water saving rate and platform overload rate. A measure in the water scarcity occurred in a Bohai Bay platform proves the feasibility of calculated water saving potential. According to the result of study, the Water Quotas of Offshore platform regression equation is Q=0.146N11.065, the value of Water Quotas is187.7- 213.5 liter per capita per day, related advanced level is 29%-49%, design overload rate is 6.6%, water saving potential is 9.06%, water saving potential.