Showing papers in "Journal of Heilongjiang Hydraulic Engineering College in 2007"

Study on the Isolation and Growth Condition of Methanogen

Abstract: Two methanogen strains were isolated from methane fermenting liquor by using Hungate obligate anaerobic technique with methanol,formate and acetate as carbon and energy source.They emit blue-green fluorescence when observed by fluorogenic microscope.Their colonies in roll tubes are irregular round and white or a little yellow.In addition,the effect of different pH value and temperature of the growth of the methanogen was studied.The methanogen's optimum growth pH value is 7.0 and can range from 6.5 to 8.0,and the optimum growth temperature is 35 ℃,the results indicated that they were sensitive to the change of pH value and temperature,so a steady circumstance is needed.

Analysis of Seepage Monitoring Model for Earth-rock Dams

Abstract: Seepage monitoring is important for the safety of earth-rock dams and the statistical model plays a vital role in the monitoring processBased on the basic equations of seepage and the definite conditions,the influence factors about effect quantities of seepage monitoring were givenThe analysis method of multiple linear regression is described and an example is employed to indicate that the monitoring model is reasonable

Status Overdraft of Groundwater on Sanjiang Plain(1)

Abstract: Whether the groundwater on Sanjiang Plain is overdraft or not has been in dispute for more than ten yearsAccording to the returns of national and the reclamation area's scientific research during the period of the ninth five-year plan and by analyzing groundwater regime,the author insists that the groundwater of Sanjiang Plain,generally speaking,is not overdraft and still of great developing potencyEspecially for farms on Youyi,Luobei and across-river underground water areasIn some places mentioned above such as Jiansanjiang,although the ground water is not overdraft,more effort should be made in making use of abundant precipitation because the area of paddy field will be greatly extended in futureMore effort should be made in analyzing,researching and calculating possible supplemental recharge recruitment so that the overdraft can be avoidedThe condition that the groundwater is not overdraft is the best affirmation to the returns of national and the reclamation area's scientific research during the period of the ninth five-year plan

Status Analysis of Organic Pollution of Songhua River System

Abstract: The paper analyses the status and the harms of organic pollution of Songhua River system and raises the prevention and countermeasures of organic pollution

Water Saving Control Irrigating Technique of Rice in Cold Regions of Heilongjiang Province

Abstract: With deep research about water-saving control irrigating technique of rice in cold regions,according to control irrigating technique and principle and research achievement having had,through experimental system analysis,model of control irrigation was explored adapting to natural conditions in Heilongjiang cold region,so it provides technical surpport and theory basis for control irrigating technique's spreading and playing an examplary role in large areas.

Control Method of STATCOM Compensated with Three-phase Unbalanced Load

Abstract: The novel control method of STATCOM which could compensate three-phase unbalanced load is proposed.Based on sequence component decomposition and dq decoupling theories,this method could compensate both positive sequence and negative sequence reactive current at the same time,detection process is simplified, the system current achieves three-phase balance.STATCOM mathematical model is set up to derivative the deadbeat STATCOM control model for unbalanced load.Simulation results verify its validity and feasibility.

Application of Gray Connection Analysis on the Groundwater Quality Evaluation in Harbin Urban

Abstract: This article appraises the water quality of Harbin urban by actual ground water sample with application gray connection analytic method,its appraisal result will provide the instruction to the ground water management and the reasonable use

Design of Polarity Reversibility High-voltage Direct-current Generator

Abstract: One kind of high-voltage direct-current generator that is used of the insulation test for HVDC converter transformer is designed in this thesis,this generator can auto compile the range according to the test standard. The basic work principle and several technology keys of this generator is introduced in this thesis,and the main circuit has carried on computer simulation.

Analysis of Volatile Oils of Saponikoviacata in Different Producing Areas

Abstract: The volatile oil extracted from the saponikoviacata in different area by steam distillation and marinate methods were analyzed using GC-MS,and 35 and 43 kinds of chemical compounds of volatile oil were determined,respectively. The main components contain: 2-propenal-3-pheny,Linoleic acid ethyl ester,9,12-Octadecadienoicacid,Apiol,Falcarinol and 1,3-Benzodioxole,methoxy-6-(2-propenyl).Results indicate that chemical constituents of the volatile oil of different production areas as well as different extraction methods varied greatly.

Evaluation of Agricultural Water Consumption in Heilongjiang

Abstract: The point of this article is to evaluating agricultural water according to data that we can get in Heilongjiang ProvinceWith the land use factor equal 07,the agricultural water is 3822～582mm in condition that the area proportion between dry farming and paddy field varied in different years,and the average annual precipitation ranges from 400mm to 600mm in Heilongjiang ProvinceSo potentiality of developing rain supporting agriculture is huge

Investigation on Applying High-order Piezoelectric Effect to Sensors and Actuators

Abstract: The direct and converse piezoelectric effects of the electromechanical coupling process are widely applied to sensor and actuators.But there are some serious problems during application of piezoelectric sensor and actuator,e.g.non-linear problem.Most piezoelectric solids has nonlinear behavior,especially piezoelectric ceramic,its inherent characteristics are non-linear and hysteretic characteristic.In this paper,the nonlinear of piezoelectric solids is discussed,the impaction of high order piezoelectric effect on piezoelectric sensor and actuator is verified through the experiments,the compensation and method of correction are presented.As the result,measurement and control precision of sensor and actuator are improved by applying this theory.

GM(1,1) Model on the Prediction of Project Price Index

Abstract: This paper briefly introduced the suitable conditions for the predicting model,the structure,and test of GM (1,1).The price index predicting model of Heilongjiang project was established.Through model test, the accurate grade of this model on prediction and simulation arrived at grade one.The result shows that the pre- dicting model is credible,and can be used to predict the price index of project accurately and can give necessary advice for cost management.

Vertical Variation Characteristic Analysis of Soil Temperature in the Cold Frozen Soil Area

Abstract: The monthly soil temperature data of Mohe are compiled and analysed from 2000～2005,and the soil temperature observation data at four depth,namely 0 cm,-40 cm,-80 cm and-160 cm,are selected to draw the variation curve of soil temperature in order to find the monthly variation law for soil temperature,variation amplitude,appearing time of maximium,temperature variation amplitude in a year at different depth,and vertical temperature variation gradient of the soil temperature is analysed.The vertical variation and temporal variation law of the soil temperature are studied.It provides reference and foundation for agriculture and construction in frozen area.

Error Analysis of Hydraulic Computation of Open Channel by Use of Manning Equation

Abstract: Discharges are always calculated by average depth instead of hydraulic radius in Manning Equation,in which width and depth ratio is more than 100In this article,adaptable conditions for discharge calculation based on average depth replacing hydraulic radius is proposed after cross-section profile analysis

Study on Adsorption and Release of Heavy Metal in Sediment of Tiebutie Pool in Daqing

Abstract: The paper has made a research on the heavy metals(Cd,Pb,Cu,Zn) content in thesample of Tiebu- tie Pool in Daqing and the adsorption and release characteristics of the sediment to the heavy metals when the en- vironmental elements such as temperature and pH changeThe results show that the heavy metal content in the sample is higher than the normal standardThe amount of adsorption of the sediment to the heavy metals be- comes higher with the increasing of pHWhen pH is higher than 7,the amount of adsorption increases signifi- cantlyThe release of the heavy metals mainly occurs in the acidic area,where pH is lower than 4When pH turns higher,the amount of release becomes smaller immediatelyThe order of the release is ZnCu≥PbCd approximatelyThe result also indicates that the temperature has no significant impact on the adsorption and re- lease of the heavy metals in sediment