Nineteen early mature varieties of winter rape and one spring rape variety were sowed in different plots separately at 10 d interval. The growth and development characteristics of early mature variety of winter rape were explored. Results indicate: The complete growth period of early mature variety of winter rape should be approximately 180 days. Both springness and weak response to photoperiod should be their good trait for early mature variety of winter rape. Sowing time would be in late October. And in that sowing time early flowering than normal can be prevented, and also maturity rapseed can be expect in next year' late April. Early mature variety excels in growth properties than the faintly winter varieties, which belong to medium mature rapeseed, and the former gets the seedling stage around 40 days, budding stage around 70 days, flowering stage around 40 days and ripening stage around 30 days. Days from seedling to end of flower are positively correlation with days from seedling to ripening (r≥0.90). 5 Spring rape varieties from Qinghai is weak in response to photoperiod and can be used as early mature variety of winter rape, but long elapse rosette period and flowering stage more concentrated type are much better.
Aiming at the domestic eco-compensation work and the implementation of eco-compensation policy on the Three Gorges reservoir area, the eco compensation effects and the problems in recent years were analyzed. Based on the advanced experience at home and abroad, the actual situation of the Three Gorges reservoir area was discussed, and some suggestion to further develop the eco-compensation policy, system and mechanism of the Three Gorges reservoir area was proposed.
This paper presents a new method for the system identification of channel roughness for the water diversion projects. According to the principle of hydraulics, established the relationship among channel roughness, rough height ks and hydraulic radius R, and deduce the linear model by means of the mathematical transformation to make use of the least square method for the identification. Finally, based on the prototype observation data from the south to north water diversion project and considering the influence of channel section shapes, bottom slopes and lengths etc, a universal formula is obtained for calculation of channel roughness by the system identification.
The ultra-small spacing tunnel of Jiaozhou Bay seabed tunnel in Qingdao is took for example; the surrounding rock pressure features and support force are analyzed through the field measurement. Results show that the surrounding rock pressure and support force of the after-excavation tunnel are larger than others of the tunnel. This result is different from the theoretical predictions and experimental results of most of the small spacing symmetry tunnel. To alleviate these problems effectively, support parameters are adjusted opportunely; the radial support capacity of the after-excavation tunnel is enhanced, and reinforcement measures of rock pillar are made at the same time. The monitoring results show that the stability of the after-construction tunnel has been effectively controlled, which provides useful reference for the design and construction of similar tunnels with small spacing.
The reasonable water pressure upon lining determination is the key to structure design of subsea tunnel. The analytic method calculation formula of outside pressure upon lining of circular subsea tunnel was derived with complex function and groundwater dynamic theory. It was verified that the calculation formula is high precision and extensive applicability by lots of contrast. Results of model tests showed that under the condition of fully closed, the pressure on lining could not be reduced; the water pressure would significantly reduce if the water of the tunnel was drained, and it would be presented linear decreasing with the increase of the water discharge. Lining external water pressure formula under limited drainage was established, and it was also verified by field tests. The research results were applied in the first subsea tunnel in China, Xiang'an Subsea Tunnel, which is built in Xiamen. And it provided key technique parameter to determination of support structure design and programme of blocking water by grouting, following the principle plugging dominantly and limited drainage. The field application obtained good results. Research results would have certain reference significance to the following subsea tunnel.
On the distance science review of the Lushan region, the particular researched for the geologic stratum section of Late Quaternary Period in the Lushan Dajiaochang area. This introduced or with the ancient terrestrial magnetism, and electronics spin resonance (ESR) and 36Cl, and luminescence dating etc. of various instrument of the dating method are analysis, they constituted the whole geologic strata of the complete section from the series age data that since 400 Ka.B.P., there be opposite to with it identified out the Biwa-III (320 Ka.B.P.) event, and the Biwa-II (260 Ka.B.P.) event, and the Biwa-I (180 Ka.B.P.) event (the molest influence of the iron dish is scarcity), and the Blake (100 Ka.B.P.) event, and the Laschamp (20 Ka.B.P.) event (the activity influence of the surface layer is not growth) etc. of events of ancient terrestrial magnetism. That also combined the layer sequence geologic strata and the layer type characteristics and sink to cumulate the sediment environment, by early to night for thedivided to 4 developmentic gyrational stages the section geologic strata: the I stage is climate period of the glacial epoch (400~200 Ka.B.P.), the II stage is climate period of the interglacial epoch (200~100 Ka.B.P.), the III stage is climate period of the glacial marginal epoch (100~10 Ka.B.P.), the IV stage is climate period of the post glacial epoch (10~0 Ka.B.P.).
When the bridge structure stability safety factor of the first type is 4, the research that whether the structure reliability index will reach target reliability index under the more-likely-to-happen collapse situation of the second type is necessary. The stability calculations of the first and the second type are made respectively for single layer and single span rigid frame bridge. Based on the critical load obtained from the stability calculation of the first type, the stability safety factor of the first type is taken as 4, and the first order reliability method is used to program and calculate the reliability index. Then, the load effect under the stability reliability index calculation of the first type and the critical load of the second type are employed to calculate the reliability index of the second type. The evaluation of structure stability safety factor is discussed according to reliability index. Based on the discussion above, parameter analysis of the stable critical loads of two types is made, and the influence of critical load change on reliability index is researched. The result shows that stability analysis should identify collapse state; when the stability safety index of the first type is 4, and the structure has the collapse of the second type, the reliability index cannot ensure to reach the target reliability index under some situations.
Taking the Hesheng Bridge as the prototype, a health-diagnosis-oriented concrete cable-stayed model bridge was designed and made with a scale of 1∶15 based on similarity theory, problems and solutions were analyzed in model design process. The initial finite element model(FEM) of prototype and model bridge were established and the baseline FEM were computed after model updating. The static and dynamic characteristic similarity of the model and prototype bridge was analyzed at undamaged and damage states. The results show that after a variety of simplifications and treatments, the static and dynamic characteristic and damage characteristic of model and prototype bridge still have a good similarity. The method can provide a reference for the model design of concrete cable stayed bridge.
Aiming at widespread presence of expansive soil which canbe obtained in the project from Xiaoxita to Yaqueling first-class highway rebuilding engineering in Yichang City of Hubei Province and weathered sand which can be made full use of locally, many experiments were made. Compaction experiments and expansibility index indoor experiments of undisturbed expansive soil and expansive soil mixed with sand range from 10 % to 50 % were made. Through the test of undisturbed expansive soil mixed with different content of weathered sand, it was found that undisturbed expansive soil mixed with weathered sand can change the expansive soil water characteristics and compaction characteristics. Undisturbed expansive soil mixed with different content of weathered sand can influence the expansibility of the expansive soil index and significantly inhibit the expansibility of the expansive soil and reach the standard of roadbed filler.
The photovoltaic(PV) shed system structure and design in detail with the present of its actual photos were described. The shed is 50 m long and 5.5 m wide and capable of parking 18 cars. Under the control of system intellectual controller, the power produced by PV from sunlight will charge the parking electric vehicle (EV) car prior to charge the storage battery, charge the storage battery prior to grid power at last, and charge the EV by utility grid while on a cloudy or rainy day.
The remarkable development of science and technology speeds up the development of the deeper oil and gas field offshore via subsea production system. In order to optimize the reservoir, the well fluid to be monitored and measured to get enough information transmitted to the topside being processed and analysis. Recent years there are more and more subsea multiphase flow meters installed and being in operation. The principles of multiphase flow measurement are introduced and other factors relevant to the measurement scope, installation location and the communication are discussed. The feasibility of cases is also presented and it is helpful for the selection of subsea multiphase flow meters installation.
The Laser Doppler Velocimetry (LDV) or Adaptive Phase Doppler Velocimetry (APV) system was used to study the water mist flow field under longitudinal ventilation. The water mist characteristics: mean velocity, volume mean size and volume flux were obtained. The results indicate that in the same cross section mean velocity of water mist increases as airflow velocity increases, but displays as two step linear fitting. Experiments deepened the understanding of the mechanics of water mist induced by a jet and provided better conditions for experiment of water mist induced by flame in the next step.
Water mist technology provides efficient firefighting performance while there is still room for improvement, so varieties of additives have been studied recent years both abroad and domestic. The self-made additives are used to compare the firefighting performance of diesel and heptane fire in open space. By adjusting the concentration of substance in the additives and conducting the experiment under the pressure of 0.3 MPa, 0.5 MPa and 0.7 MPa, extinguishing time, flame shape and temperature are measured in the experiment. Through the experiments using different fuels, it can be found when the fuel is heptane who has a lower ignition point and a higher evaporation, the water mist additives can still significantly improve the firefighting performance. According to the data based on different concentrations of fluorinated surfactants, we can see fluorinated surfactants are the main substance to prove the performances by changing physical property of water mist. Maximize fire performance proportion of the additives are find by experiments results.
Aiming at the characteristic of the formation water of Huaqing Chang 6 reservoir and taking the comprehensive foaming ability as evaluation index, 6 foaming agents were optimized. ZY-1 foaming agent was the optimal foaming agent, and the optimal foaming agent concentration and foam stabilizer concentration were 0.5 % and 764 mg/L respectively. On the basis of the foaming agent optimization result, using parallel cores with approximate permeability contrast，CO2 foam flooding experiment was simulated through 2 injection way. The experiment result showed that underground foaming way, CO2 and the foaming agent injected alternately, had higher plugging differential pressure and better displacement efficiency. The optimal injection slug combination was first 0.2 PV (pore volume) foaming agent solution and then 0.4 PV CO2 gas, and the total injected volume was 0.6 PV.
Grains in the slurry enter into cutting area by steel wire with a certain speed and remove the workpiece material in the free brasive wire sawing. Multi-strands wire is made by metal wires and has many grooves in the surface compared with steel wire. Therefore it can carry more grains into cutting area and improve the slicing efficiency. In this paper, optical glass K9 were cut by multi strands wire (0.25 mm) and steel wire (0.25 mm).The results show that multi strands wire is better than steel wire in slicing efficiency and surface roughness, but the kerf loss is wider than steel wire under the same process conditions.
It was found that there were badly oxidation phenomena in a superheater and a evaporator of CEFR's steam generators when they were being installed. So a static immersion test had been finished firstly by the sodium technology department of CEFR to investigate how to removing the rust from the CEFR's steam generators. But the site condition of CEFR's steam generators can not achieve the ndition of the means of removing rust only by static immersion. We decided to do the test of removing rust by flowing sodium of the samples of CEFR’ s steam generators to investigate behavior of the oxidation surface of CEFR's steam generators in the flowing sodium. The test would provide the testing foundation for the work of removing rust by flowing sodium on CEFR site. The test has utilized a mini-loop of sodium—“sodium loop for characteristic test of PEC's electromagnetism pump ” and simulated the work condition of CEFR's steam generators. Through the comparison between the photos of the samples which are before and after the test, the results about effect of removing rust of the samples under different conditions have been reached. These would provide the esting foundation for the work of removing rust by flowing sodium of CEFR’s steam generators.
In the printed circuit board defect inspection based on AOI, there are some dislocate deviation between sample PCB image and the PCB image, which make the need of the image registration to be processed. First of all, define the sample image edge point concept according to the PCB line features, formulate the edge points sampling rules. Then, in the view of the PCB image, propose the registration intensity evaluation based on the sample edge points, and establish of evaluation model and fast algorithm for registration. Finally, through the PCB registration experiment and plenty of application testing, prove that the alignment intensity evaluation model can accurately describe the alignment level for the sample PCB image and the tested PCB image, which can provide reliable migration parameters for the defects search for later period.
The optimal equilibrium between the multiple objectives of construction projects is a significant aspect of project management research, which has seen rapid development in recent years, gaining a bunch of fruitful achievements. In this paper, a review is provided for the multiobjective tradeoff research of construction projects based on literature review. Models under deterministic conditions and nondeterministic conditions are investigated and summarized. Some suggestions on the possible direction for future research are included considering the algorithms adopted in the problem solution. This paper aims at providing a review of the achievements in this area so far and keeping track of the ongoing research topics so as to give certain indications for research that follows.