In order to promote the development of winter rapeseed production in double-crop rice area in southern China, two major issues ,i.e. breeding of early-maturing varieties and implementation of mechanical cultivation ,need to be resolved. After nearly five years of systematic research, the research group has successfully bred five new varieties with early-maturing, disease resistance and high oil content successfully, developed a 2BYF(D)-6 type stubble no-tillage multi-seeders for rapeseed for the requirement of rapeseed with tillage free (shallow tillage). Matching with the high-density early-maturing varieties of rapeseeds, a 4YC-200 type rapeseed combine harvester has been developed. At the same time, one-time rapeseed controlled-release fertilizer and ripener are applied and agronomic operation procedures of mechanical cultivation are formed in double rice area in southern China. Test results showed that the income increased to more than 300 yuan per mu by mechanical cultivation of rapeseed. In conclusion, it is effective to reduce rapeseed planting cost, expand cultivation area and improve yield and economic efficiency for rapeseed production via the implementation of integration technologies.
The status of biodiesel industry in U.S.A, EU and China are reviewed. The problems related to the feedstock supply and economic feasibility are discussed. It is proposed that waste vegetable oil and animal fats should be used to speed up the development of biodiesel industry, and simultaneously the utilization of biodiesel and glycerine to produce high-value chemicals should be made to improve the profits.
An engineering survey of the first cable-stayed bridge usingCFRP cables was firstly introduced ; then a three-dimensional computational finite element dynamic model based on beam elements,shell elements and bar elements of above CFRP cable stayedbridge was modeled and a structure dynamic property analysis was put up; lastly a dynamic property test under ambient excitation was put up to analyze the dynamic characteristics of the first cable-stayed bridge using CFRP cables in China, at the same time, a contrast analysis between test results and calculational results of finite element method was presented. The analysis result shows the low order vibratory frequency and mode are basically tallied between test results and calculational results of finite element method. The test and analysis results of this paper could provide reference for dynamic modeling and characteristic analyzing ,seismic and wind loads resistance designing of CFRP cable-stayed bridge,also it could provide reference for the further engineering application of CFRP material used as cables on bridge structure by all means.
Sutong Bridge is the first cable stayed bridge with the span exceeds 1 000 m which located in the mouth of Yangtze River. Its pylon foundation located in the river where the water is deep and current speed is high, and adopted the bored group piles foundation which is the largest group piles foundation. To the group piles foundation with the construction condition of deep water and high speed current, the exactly construction of the steel cofferdam which provided dry condition for the pile caps construction is a problem. This paper discussed the lowering as a whole technology of Sutong Bridge 5 800 t weigh steel cofferdam from 6 respects such as selection of lowering scheme, design, fabrication, lowering techniques, synchronousness controlling and orientation. In which, the design combined the coping of bored piles construction platform with bottom of steel cofferdam, the lowering as a whole techniques, synchronousness controlling and orientation technology are innovation.
The properties of rock dynamics under the commercial nuclear reactor foundation are very important Parameters in ascismic design. The properties of rock dynamics and test method under earthquake loading are analyzed in this paper. From this, the dynamic elastic modulus, poisson' ratio, shear modulus, and triaxial pressure strength of 4 kinds of rock (tuff, tuff sandstone, felsophyre, rhyolite porphyry) have been given by using the RDT-10000 high Pressure triaxial machine. These parameters have been used in the feasibility report and the aseismic design of the Sanmen Nuclear Power Plant.
A three-dimensional numerical model for shallow flow based on a layer-integrated solution method is developed in this paper. The controlled equations are solved using an efficient operator-splitting finite element method on adaptive triangle grids. The experiment data in mending channel flow is selected to verify the proposed model. The simulated results are in satisfactory agreement with the experimental data. Therefore, the present 3D shallow flow model is a robust and efficient tool for simulating the shallow flow hydrodynamics.
Rockburst processes of a circular tunnel are modeled by use of FLAC at different dilation angles. To model the tunnel excavation, a FISH function is written and used to delete the elements in the tunnel. For rock elements exhibiting linear strain-softening behavior beyond the occurrence of failure and then ideal plastic behavior, the failure criterion is a composite Mohr-Coulomb criterion with tension cut-off. The present calculation is divided into three steps. Firstly, a hydrostatic pressure is applied to the plane strain model until a static equilibrium state is reached. Secondly, a tunnel is excavated using the written FISH function. Thirdly, the calculation renews to achieve a new equilibrium state. Results show that with an increase of the dilation angle, the shear band becomes wider; the dog-ear or V-shaped rockburst notch becomes deeper; the number of failed elements is greater and the plastic zone becomes bigger. At lower dilation angles, the apparent strain localization phenomenon is localized at V-shaped notches, the angle between a shear band and the tangential line of the tunnel surface is higher. However, at higher dilation angles, the angle is lower and the apparent strain localization phenomenon is localized at the tunnel surface. The present numerical results about the shear band inclination are consistent with the Roscoe and Arthur theories.
Through systematical research and complex analysis of how the main safety facts affect flow characteristics of oil & gas pipeline, oil & gas pipeline flow assurance is a series of technology which aims to ensure the safe operation of pipeline. The history, current research and future trend of oil & gas pipeline flow assurance are discussed. It is presented that this research field contains four main topics, which include oil rheological research and application, oil & gas pipeline flow improver research, flow characteristics of batch transportation of oil & product oil. The future focus of this research field is presented.
This paper presents the exploration process of expanding cutoff boundary of Tongbai Anpeng bicarbonate mine, and put forward the basic principles of exploring cutoff boundary of mirabilite mine and applied theory, technology and methods of exploring cutoff boundary. This theory, technology, methods are attested practical, the results of expanding cutoff boundary are basically consistent with the development, and thus provided the basis for bicarbonate production and continuing expansion, reducing unnecessary waste and costs.
According to the case of billet heating in a regenerative type heating furnace, the temperature distributing of billet about upper surface, undersurface and center surface in length and width is studied by computational fluid dynamics (CFD)in this article, and the questions of billet such as different temperature of upper surface and undersurface, the higher temperature of foursquare margin and the lower temperature of tapping orifice are put forward. The relation of different thick billet and the heating time is simulated and studied, the result of simulation and the heating time in the actual heating furnace is compared, and the expressions of thickness and heating time is educed by numerical suit, and put into production. The above result of study can offer foundation for the establishment and optimizing of billet heating system.
Physical performances, the limiting oxygen index (LOI), vertical combustion performances (UL94), flame retardant performances, smoke release of bisphenol A diphosphate (BDP), BDP/APP and BDP/SiO2 added in ABS are studied. The experimental results showed that BDP added in phenolic resin (NP) can increase char quality. As BDP/NP= 20 %/5 % was added in ABS, the maximum reduction parameter of physical performances is impact strength, which was reduced by 12.00 %, and the ABS resins passed the UL94V-0 test, LOI reached 29.50 %. CONE data showed that its average heat rate (av-HRR) and peak heat rate (pk-HRR) reduced by 46.40 %and 40.45 %, ignition time(TTI ) increased 30 s, flame growth index(FGI) reduced by 50.75 %, average smoke extinction area(SEA) increased by 31.30 % in 6 minute, char ratio was 7.19 % at 600 ℃. When the BDP/NP /APP=20 %/5 %/5 % was added in ABS, ABS resins passed the UL94V-0 test, LOI reached 31.10 %, its reduction range of impact strength was 36.00 %, av-HRR and pk-HRR reduced by 50.11 %and 55.58 %, TTI increased 35 s, FGI reduced by 64.32 %, av-SEA increased by 11.14 % in 6 minute, char ratio was11.15 % at 600 ℃. Adding BDP//NP / SiO2 =20 %/5 %/7 %BDP into ABS resin, its impact strength increased by 20.00 %, the ABS resins also passed the UL94V-0 test, LOI reached 31.20 %, av-HRR and pk-HRR reduced by 49.45 % and 58.09 %, TTI increased 45 s, FGI reduced by 68.34 %, av-SEA increased by 13.00 % in 6 minute, char ratio was 16.37 % at 600 ℃. ABS resin added BDP/NP (20 %/5 %) and nanometer SiO2(7 %) has the best flame retarded and suppression smoke effect and the smallest influence on physical performances.
In this paper, the safety capability was briefly introduced, the hazard analysis and risk assessment through which the hazard value confirmed and the most important subsystems ascertained was carried through, the safety reliability intending and distributing of subsystems were carried out and the safety designing outline was briefly analyzed. All the above work could provide theoretic foundation for safety reliability designing of hydraulic winder.
Geological prospecting data into three-dimensional system and various three-dimensional modeling methods were used to reason and connect the formation of stratum automatically to generate three-dimensional model of formation. The modeling methods can easily liberate geological workers in the field of water conservancy and hydropower from the heavy geological information access and geological interpretation of the manual labor, thus enhance the speed of three-dimensional stratum modeling and also the quality of construction.
Storage hierarchy oriented DPM, which uses buffer to prolong idle time, can achieve lower power than traditional DPM policies. The paper proposes task information based (TIB) policy for storage hierarchy oriented DPM. TIB subdivides the data access mode of tasks and introduces them into policy by modifying access interface to make prefetching and replacement algorithm more energy aware.
The insulation state of cable can be split into well, bad, worse and fault. The estimation for cable state is a significant topic based on overhaul data, test data and monitor data of the cables. The decision tree is employed to classify the insulation state. The subtrees can be formed by all kinds of data, then the final decision tree is composed of the subtrees, by which the insulation state can be estimated. The application by SPSS with practical data of the cable is carried on. The simulation result for t(he insulation state estimation of cable shows the effectiveness of the approach.
In this paper, the verification system from two aspects was improved. On one hand, we extended MixMax model that the EMD (earth mover's distance) can be applied, which can remove the disturbance of noise; on the other hand, we improved the Tnorm score normalization method based on the EMD. Experimental results show that this method can compensate the speaker-dependent and test-dependent variability, also show a stable performance improvement by decreasing the FA and FR.
To deal with the characters with the strong nonlinear and complex computing of synthetic permeability and burn-through point in the lead-zinc sintering process, an efficient multi-objective particle swarm cooperative optimization algorithm is proposed. Firstly, the multi-objective optimization model for burn-through point and synthetic permeability is established. Secondly, an improved multi-objective particle swarm cooperative optimization algorithm is presented by improving the constraint comparison method and the way of selecting the particles' optima, and using different swarms to optimize corresponding variables respectively. Finally, the proposed multi-objective optimization algorithm is applied to optimize the synthetic permeability and the burn-through point. The simulation results show that the proposed multi-objective optimization algorithm effectively solves the optimization problem of the synthetic permeability and burn-through point.
According to the theory of prior using of new information,based on the research of already existed strengthening buffer operators, some new strengthening buffer operators are established. Meanwhile,their characters are studied. The flaw that the existing strengthening buffer operators can,t fully use new information of the data sequence is overcame. The problem that there are some contradictions between quantitative analysis and qualitative analysis in pretreatment for vibration data sequences is resolved effectively. An example simulation shows, compared with the existing strengthening buffer operators, the kind of new strengthening buffer operators increases the forecast precision of GM(1,1) remarkably.
This Issue
Feb 2010, Volume 12 Issue 2