甲醇厂用水系统水平衡测试探讨——以川西北甲醇厂为例

合理、节约用水以及提高水的利用率已经成为目前化工企业面临的重要课题。而水平衡测试正是加强用水管理,最大限度地节约用水和合理用水的一项重要基础工作。通过对甲醇厂用水系统水平衡测试和分析,提出了加强用水管理、完善计量器具、提高循环水浓缩倍数等建议,同时建立了甲醇厂用水技术经济指标。

STUDY ON ARTIFICIAL NEURAL NETWORK FORECASTING METHOD OF WATER CONSUMPTION PER HOUR

An artificial neural network (ANN) short term forecasting model of consumption per hour was built based on seasonality,trend and randomness of a city period of time water consumption series.Different hidden layer nodes,same inputs and forecasting data were selected to train and forecast and then the relative errors were compared so as to confirm the NN structure.A model was set up and used to forecast concretely by Matlab.It is tested by examples and compared with the result of time series trigonometric function analytical method.The result indicates that the prediction errors of NN are small and the velocity of forecasting is fast.It can completely meet the actual needs of the control and run of the water supply system.

渠灌区管道输水灌溉技术研究

通过冶河灌区宜安渠灌区低压管道节水灌溉试验取得的技术研究成果以及经济效益，为在从河道、水库自流引水的渠灌区中推广应用管道节水灌溉技术提供了成功的经验。

Direct Estimation of Nitrogen Gases Emitted from Flooded Soils During Denitrification of Applied Nitrogen

Denitrification losses measured by direct method (measuring the evolution of (N2+N2O)-15N) were compared with the apparent denitrification losses (calculated from the difference between the total N loss and ammonia loss), for fertilizers applied to flooded soils. The direct measured denitrification losses from potassium nitrate were 23.0%, 40.0%, and 63.1-79.7% of applied N in rice field, and in incubations of 7 cm deep layer of soil and 2 cm deep layer of soil, respectively; while the corresponding apparent denitrification losses were 96.0%, 98.4%, and 97.7-97.9%, respectively. In field experiments with urea, the direct measured denitrification losses ranged from 0.1-1.8%, which were much less than the apparent denitrification losses (41.3-45.7%). Such discrepancies were primarily due to the entrapment of the gaseous products of denitrification in the soil as revealed by the facts: (1) stirring the floodwater and the surface soil markedly increased the fluxes of (N2+N2O)-15N from urea or potassium nitrate applied to the flooded rice field, and (2) reducing the pressure in the headspace of the incubation bottle with the 7 cm soil layer during gas sampling decreased the discrepancy between the direct measured and apparent denitrifecation losses from 58.4% to 21.2%. The advantage of reducing the pressure in the headspace is that there is minimal disturbance of the soil. Further testing of this technique in rice field is needed to determine its effectiveness in releasing the entrapped gaseous products of denitrification so that denitrification losses can be quantified directly.

Wavelet Analytical Forecasting Method of Water Consumption

A new method of short-term forecasting for water consumption in municipal supply water networks based on wavelet transformation is introduced. By wavelet decomposing commonly used in the signal field, water consumption per hour is decomposed into many series. Trend item, cycle item and random item are separated from the original time series in this way.Then by analyzing, building a model, forecasting every series and composing the results, the forecasting value of the original consumption is received. Simulation results show that this forecasting method is faster and more accurate, of which the error is less than 2%, indicating that the wavelet analytical method is practicable.

低功耗高性能IC卡水表的研制

本文介绍了一种IC卡水表的研制,主要阐述了如何从硬件和软件两方面出发,做到系统的低功耗和高性能。

Chaotic phenomenon and the maximum predictable time scale of observation series of urban hourly water consumption

The chaotic characteristics and maximum predictable time scale of the observation series of hourly water consumption in Hangzhou were investigated using the advanced algorithm presented here is based on the conventional Wolf's algorithm for the largest Lyapunov exponent. For comparison, the largest Lyapunov exponents of water consumption series with one-hour and 24-hour intervals were calculated respectively. The results indicated that chaotic characteristics obviously exist in the hourly water consumption system; and that observation series with 24-hour interval have longer maximum predictable scale than hourly series. These findings could have significant practical application for better prediction of urban hourly water consumption.

Hydration film measurement on mica and coal surfaces using atomic force microscopy and interfacial interactions

The hydration film on particle surface plays an important role in bubble-particle adhesion in mineral flotation process. The thicknesses of the hydration films on natural hydrophobic coal and hydrophilic mica surfaces were measured directly by atomic force microscopy （AFM） based on the bending mode of the nominal constant compliance regime in AFM force curve in the present study. Surface and solid-liquid interfacial energies were calculated to explain the forming mechanism of the hydration film and atomic force microscopy data. The results show that there are significant differences in the structure and thickness of hydration films on coal and mica surfaces. Hydration film formed on mica surface with the thickness of 22.5 nm. In contrast, the bend was not detected in the nominal constant compliance regime. The van der Waals and polar interactions between both mica and coal and water molecules are characterized by an attractive effect, while the polar attractive free energy between water and mica （-87.36 mN/m） is significantly larger than that between water and coal （-32.89 mN/m）, which leads to a thicker and firmer hydration layer on the mica surface. The interfacial interaction free energy of the coal/water/bubble is greater than that of mica. The polar attractive force is large enough to overcome the repulsive van der Waals force and the low energy barrier of film rupture, achieving coal particle bubble adhesion with a total interfacial free energy of-56.30 mN/m.

Study of non-revenue water status and enforcement measures to reduce water loss:case study in villages of Kermanshah Province of Iran

In this study, the volume and the cash value of water loss, and reduction of water loss as a result of enforcement action during 2011-2013 in the drinking water network of villages in Kermanshah Province, tran, have been investigated. Date collected by referring to the different parts of rural water and waste water company of Kermanshah Province and checklist were completed. The study showed the volume of produced water and sold water has increased and the water loss percentage has decreased. High cost of water production compared to revenue of sold water and water loss resulted in significant detriments in terms of the water production costs. Water loss level decreased from 33% to 30% as result of measures taken to reduce water loss but, it is still 15% higher than the world average level. Also the reduction in number of water resources and increase in the number and volume of reservoirs indicates a lack of water and a growing need. As result of high water loss, waste of costs in the contrast of water production cost and also because physical water loss accounts for most of the water loss of villages, necessary measures can be effective in reducing loss and have economic justification.

Development of a concentration method for detection of tobacco mosaic virus in irrigation water

Tobacco mosaic virus(TMV) causes significant yield loss in susceptible crops irrigated with contaminated water. However, detection of TMV in water is difficult owing to extremely low concentrations of the virus. Here, we developed a simple method for the detection and quantification of TMV in irrigation water. TMV was reliably detected at concentrations as low as 10 viral copies/μL with real-time PCR. The sensitivity of detection was further improved using polyethylene glycol 6000(PEG6000, MW 6000) to concentrate TMV from water samples. Among the 28 samples from Shaanxi Province examined with our method, 17 were tested positive after virus concentration. Infectivity of TMV in the original water sample as well as after concentration was confirmed using PCR. The limiting concentration of TMV in water to re-infect plants was determined as 102 viral copies/mL. The method developed in this study offers a novel approach to detect TMV in irrigation water, and may provide an effective tool to control crop infection.

Time difference based measurement of ultrasonic cavitations in wastewater treatment

Intensity of cavitation is significant in ultrasonic wastewater treatment,but is complicated to measure.A time difference based method of ultrasonic cavitation measurement is proposed.The time differences at different powers of 495 kHz ultrasonic are measured in experiment in comparison with conductimetric method.Simulation results show that time difference and electrical conductivity are both approximately positive proportional to the ultrasonic power.The degradation of PNP solution verifies the availability in wastewater treatment by using ultrasonic.

Micro water dissolution machining principle and its application in ultra-precision processing of KDP optical crystal

In this paper, a micro water dissolution machining （MWDM） principle is proposed for machining potassium dihydrogen phosphate （KDP） crystal using water-in-oil micro-emulsion as an abrasive-free polishing fluid. In addition, two instances of the application of this principle to ultra-precision machining of KDP crystals are presented. Computer-controlled optical surfacing （CCOS） and diamond wire cutting （DWC） process were carried out according to the MWDM principle. In the case of the CCOS technology, it is found that the micro-waviness was removed completely by following the MWDM principle. The surface undulation decreased from 40 nm to less than 10 nm, and the surface root-mean-square （rms） roughness obviously reduced from 8.147 to 2.660 nm. In the case of the DWC process, the surface rms roughness reduced from 8.012 to 2.391 gm, and the cutting efficiency was improved. These results indicate that the MWDM principle can efficiently improve the machining quality of KDP optical crystal and has a great potential to machine water-soluble materials.