The precise point positioning requires high quality of observation data, and all kinds of errors must be accurately corrected. In order to clarify the influence of error models on positioning accuracy and realize PPP more accurately, on the basis of the non-ionosphere observation model, six MGEX stations are selected, the precision ephemeris provided by the global analysis center and the troposphere model of the RTKLIB are adopted to realize the post-processing PPP resolution. Then the convergence curve and positioning error are evaluated. Simulation results show that there are more than 6 satellites, and DOP value is less than 3, so the data quality of MGEX station is better. The average positioning accuracy of east, north and sky are counted. Compared with two precise ephemerises IGS(International GNSS Service) and JPL(Jet Propulsion Laboratory), the difference of positioning accuracy between the two precise ephemeris are 0.18 %,0.53 % and 2.31 % respectively in static PPP, and 6.23 %, 10.50 % and 9.91 % respectively in dynamic PPP. In static PPP, the average positioning accuracy of the Saastamoinen model is 2.213 cm, 0.209 cm and 0.533 cm, while the average positioning accuracy of the Estimate ZTD model is 0.553 cm, 0.101 cm and 0.27 cm, which is 300.6 %, 114.88 %, 97.22 % higher than that of Saastamoinen, respectively. In dynaminc PPP, the average positioning accuracy of the Saastamoinen model is 6.368 cm, 23.683 cm, and 68.043 cm respectively, while the average positioning accuracy of the Estimate ZTD model is 9.243 cm, 5.741 cm, and 14.553 cm, which is 300.6 %, 114.88 % and 97.22 % higher than that of Saastamoinen, respectively.
In order to effectively carry out disaster relief work to guarantee the material supply for disaster areas,considering the periodicity of emergency rescue and uncertainty of demand scenarios,the supplier location and relief allocation problem is studied,with combination of multi-period,multi-supplier,multi-disaster area,multi-relief and multi-vehicle. A stochastic programming model is built in order to minimize the summation of construction cost and transportation cost. A hierarchical genetic algorithm is designed to solve the model,to make decision about multi-period save point location and relief materials flow. Considering the effects of parameters on the solutions,three experiments are performed and analyzed. Finally a numerical example is presented to verify the feasibility of the developed model and the algorithm,in which the decisions of multi-period save point location and transportation of relief supplies in each period of a week after disaster are made,and the influence of parameters on the solutions under uncertain scenarios is analyzed.
In order to study the deformation control and prediction of RC columns by adjusting stirrup configuration,a bending shear test was carried out on six specimens of RC column with the same main reinforcement but different stirrup configuration and stirrup ratio. The load-deformation relationship and the performance of the specimen in the range of R = 1 /50 were analyzed,and the deformation of the ultimate limit states was discussed. The ultimate bearing capacity and the stability of the specimen under repeated loading are influenced obviously by the stirrup configuration at the end of the specimen. The specimens with the same deformation angle but different stirrup configuration have a large difference on strength retrogression when they are under the repeated loading. The deformation mainly concentrates at both ends of the specimens where the stirrup is dense,and the location where rotation angle is larger has the next most concentrated deformation. Increasing the density of the stirrup at the end of pillars can control the development of cracks and the shear deformation,and the fact that the displacement vectors of all monitoring sites have the trend of directing from the location with dense stirrup to that with non-dense stirrup can be learned by the distribution of the displacement vectors.
s:There is a complex relation between delay and timing control design at signalized inter-section. The present delay acquisition methods were analyzed. Using the measured real-time cycle delay and considering the traffic flow, the K-nearest neighbor algorithm was used to obtain the next cycle delay, and the forecasted delay was employed to study, the timing optimization of the next cy-cle. Based on an example in VISSIM simulation platform, it is proved that the optimization method described in the paper can decrease the intersection delay by 13. 52%. Therefore, this method has potential applicability to signalized intersection control optimization in the future.
To control a small spark ignition( SI) engine electronically, an electronic control system was designed to reduce the emissions, improve its power and economy. By Using Freescales’ micro-controller MC9S12XEP100 and MC33812 controller chip, the electronic control unit(ECU)hardware circuit of microcontroller unit( MCU) control module, the power management module, the input ad-justment module, the output driver module and the controller area network ( CAN) communication module were designed. The board support package was written by C language. The fuel injection and ignition signals were tested and analyzed to complete the bench test by using an engine 168F. The test results showed that the rated power was increased by 7. 6%, the minimum effective fuel con-sumption was decreased by 7. 9% and the maximum torque of engine could reach to 11. 15 N·m, which was increased by 2. 3%. According to the United States Environmental Protection Agency ( EPA) regulation of the small non-road SI engine, the emission of CO was 259. 18 g/( kW·h) and the emission of HC+NOx was 8. 05 g/( kW·h) , both of which were decreased. The electronic con-trolled engine can meet the limitation of EPA phaseⅢstandards and the electronic controlled system was qualified.
To study the tensile properties of sprayed FRP,13 groups of specimens were tested for their tensile properties,and the index of stress-strain curve,tensile strength,elastic modulus,elongation and other mechanical properties were analyzed. Influence of fiber type,resin type,fiber volume fraction,fiber length,specimen thickness and other factors on the mechanical properties of sprayed FRP was studied. The results show that the effect of fiber type and resin type on the tensile properties of sprayed FRP is very obvious; that,when the fiber volume fraction is 20% ~ 25% and the fiber length is 40 mm,sprayed FRP demonstrates better mechanical properties; that the mechanical properties of sprayed FRP specimens cannot be effectively enhanced with the increase of the thickness of specimens,and the sprayed FRP should not be too thick. In order to obtain better mechanical properties,sprayed FRP had better be produced by carbon fiber sprayed yarn and vinyl ester resin,the volume ratio and length of fiber should be limited to a certain range,and the thickness of the material should not be too thick.
[Objective]To investigate the curative effects and its mechanism of extracts in vine of Luffa on the treatment of allergic rhinitis. [Methods] The mice model of allergic rhinitis were induced by ovalbumin and Al(OH)3so as to observe the symptoms of the mice and pathological changes of nasal mucosal morphology and to detect the histamine content and eosinophils of the nasal mucosa in the serum after 10 days of drenching corresponding drugs.[Results]The extracts in vine of Luffa can effectively change pathological alteration of nasal mucosa in rhinitis mice and reduce histamine levels and eosinophils of the nasal mucosa in the serum so as to cure rhinitis.[Conclusion]The functional mechanism of vine of Luffa in treating rhinitis can be achieved through decreasing histamine and eosnophils.
The use of limited capital to control risk under the expected return condition is one of the purpose of investment,assuming that investors are risk averse. CVaR was used as a method to measure a portfolio risk. A portfolio model with typical transaction cost was constructed under the cost constraint condition and the CVaR as an objective function,and the algorithm steps of solving the model are provided. The empirical analysis of the historical data of China's stock market is carried out to verify the validity of the model.
In order to solve the problem of the dual clutch automatic transmission assemble module difficult to manufacture,a new technology scheme of separated layout-dual clutch automatic transmission was proposed. And the structure characteristics and working principle of the scheme were analyzed. The dynamic model of the transmission was established. And the transmission main parameter was designed based on the vehicle parameters requirements. The vehicle power transmission system model was established and the vehicle performance was simulated by the AVL Cruise simulation software. The simulation results indicated that compared with the ordinary dual clutch transmission,this type of transmission not only met the vehicle design requirements,but also improved the performance within 2. 5% in the maximum speed,maximum climb angle,acceleration time,cycle fuel consumption. Therefore,the dual clutch module of the separated layout-dual clutch automatic transmission can overcome the defect of the dual clutch transmission assemble module difficult to manufacture,and has good application value.
To know more about the development level of logistics and improve the development of logistics in western provinces and municipality, this paper does empirical study on the logistics efficiency of the 11 western provinces and municipality in the year of 2009-2010 under the constraints of the carbon emissions with the three-stage DEA. It is found that the external environmental factors affect the western logistics efficiency significantly;and the third stage logistics efficiency value of western provinces and municipality changes a lot. Inner Mongolia Autonomous Region, Guizhou province, Ningxia Hui Autonomous Region are at the effective forefront; efficiency values of Yunnan and Sichuan provinces are below the average;the efficiency value of the rest increases in various degrees. Finally some constructive suggestions are proposed from the respect of environmental variables and efficiency values.
[Objective]To conduct preliminary study on quality standards of Jasminum nervosum Lour.(Oleaceae).[Methods]Preliminary tests and TLC identification for the chemical constituents of Jasminum nervosum Lour. were performed.Determination of moisture, total ash,acid insoluble ash and extractives in Jasminum nervosum Lour. was studied based on appendix of Chinese Pharmacopoeia,published in 2010.[Results]Its chemical constituents were initially determined and TLC identification were established. Meanwhile, the limit of moisture, total ash, acid insoluble ashand extractives in Jasminum nervosum Lour. were determined. [Conclusion]The established methods can provide the experimental foundation to formulate the quality standards for Jasminum nervosum Lour..
In order to mimic the catalytic activity cavacity of cytochrome P-450 enzyme and display the best catalytic performance of the supported iron tetrakis ( p-sulphophenyl) porphyrin( Fe TPPSO3 H) , nano porous chitosan( np-CTS) was used to graft the metalloporphyrins by ionic bonds, forming an iron tetrakis ( p-sulphophenyl) porphyrin grafted to nano porous chitosan ( Fe TPPSO3-H3+N-np-CTS). The mimicking catalyst material was charactierized by UV-Vis and FT-IR spectra, X-ray dif-fraction(XRD) pattern, Thermoanalyser(TG), Bmnauer Enmet Teller(BET)surface area analysis and Scaning Electron Microscope ( SEM). The catalytic performance for ethylbenzene oxidation over the Fe TPPSO3-H3+N-np-CTS was studied. The experimental results indicate that the only amount of 1 mg Fe TPPSO3 H grafted in np-CTS, the such supported catalyst can be reused for 4 times in the ethylbenzene oxidation, on everage, with 43. 27% of ethylbenzene conversion, 27. 88% of yields and 64. 31% of selectivity(alcohol and ketone), and the catalyst turnover number of 3. 40 ×106, under the optimal reaction conditions of 140 ℃ and 0. 8 MPa oxygen pressure. Compared with the yields of main products from the oxidation of ethylbenzene over the correspongding Fe TPPSO3-H3+N-nonp-CTS and Fe TPPSO3 H, those from the Fe TPPSO3-H3+N-np-CTS have elevated 6. 16% and 1. 15%, respectively. It shows that the catalyst material has a better catalytic performance.
Optimization of a China Stage V diesel engine combustion system were carried out on a heavy-duty diesel engine, which has met the China Ⅳ emission standards under the condition of without the after-treatment device in order to meet the much more stringent emission regulations. Test results showed that, in most operation conditions, the joint operating point between diesel en-gine and the supercharger (2TC2) where the flow area of low pressure compressor is smaller, mov-ing in the direction of high pressure ratio and equivalent flow, can obviously increase intake pressure and air-fuel ratio, and effectively improve the trade-off relationships of NOx-Soot and NOx-BSFC (Brake Specific Fuel Combustion). Combustion chamber (SF4) where reentrant down 1 mm based on the original combustion chamber ( SF1 ) , can enhance airflow motion in cylinder, and increase the mixing uniformity and the mixing rate of fuel and gas. BSFC and Soot can be decreased and keep the maximum in-cylinder pressure in the reasonable range at the same time. With retarded injection timing, the combustion phase delay, Soot emissions decrease, and BSFC increase. The Soot emis-sions rise, however, when the injection timing delayed too much. Increasing the pressure of injec-tion can reduce Soot and BSFC simultaneously at the high speed conditions. However, Soot and BSFC is increase with the increasing of the injection pressure at low speed and high load conditions. By using proper interval between main and post, injection can improve emissions. The test results showed that NOx and Soot emission are 1. 799 g/( kW·h) and 0. 015 g/( kW·h) respectively, which both under the limit value of the China Stage V emission regulations. Meanwhile, BSFC can be reach 211. 6 g/( kW·h) . The optimized combustion chamber has the ability to meet the China Stage V emissions standard while reducing the requirement of exhaust after-treatment devices.
To mimic the catalytic cavity site of Cytochrome P- 450 enzyme,promoting the activity of chitosan grafted manganese tetra( p-carboxylphenyl) porphyrin( Mn TCPP). Nan-porous chitosan( np-CTS) was prepared by freeze drying method,to which was the Mn TCPP grafted by acylation,forming biomimetic catalytic material,Mn TCPP / np-CTS. Non-porous chitosan grafted manganese tetra( p-carboxylphenyl) porphyrin( Mn TCPP / nonp-CTS) was prepared by a similar procedure. The materials were characterized by UV-Vis and FT-IR spectra,X-ray diffraction( XRD) pattern,thermoanalyser( TG) and transmission electron microscope( SEM). The materials were used as a catalyst for an oxidation of ethylbenzene. The experimental results show that under an optimum oxidation conditions( 145 ℃ and 0. 8 MPa),the catalytic actvitiy of Mn TCPP / np-CTS was 26% greater thanthat of Mn TCPP / nonp-CTS,the yields( keton and alcohol) of ethylbenzene oxidation over the former was 38% greater than that over the latter. This indicates that the nano cavity in CTS benifite to fully displaying the catalytic activity of the CTS-grafted Mn TCPP and elevating the catalytic efficency of the biomimetic catalytic material.
In order to make full use of recycled aggregate, 20 specimens with circular and square cross sections were designed to be tested, and the dosage of silica powder and content of steel fiber were regarded as the major variable parameters. Through the experiment, the entire compress process and failure modes of all specimens were observed, and load-strain curves of the specimens were obtained. The test results indicate that the ultimate axial load and corresponding strain of the concrete-filled steel tube columns would decrease after the replacement of natural coarse aggregate with 100% recycled coarse aggregate. The filling effect and pozzolanic action of silica powder and the confinement effect of steel fiber could be used to improve the performance of concrete-filled steel tube columns with 100% recycled coarse aggregate, and the performance of modified columns was i- <br> dentical to that of common columns. The column with 10% cement replaced by silica powder and 1. 5%volume fraction of steel fiber has a higher ultimate axial load than that of common columns. In addition, the applicability of present theory and formula from different codes to calculate the bearing capacity of the specimens was obtained based on the comparison of calculated results. The results obtained by EC4 are more close to the experimental results.
A voltage regulation system based on the simplified emotion control of static synchronous compensator( STATCOM) is designed to maintain a constant terminal voltage of self-excited induction generator under loading conditions. The proposed control strategy can overcome the shortcomings of excessive emotional control parameters of emotional control by eliminating the orbitofrontal cortex and hiding the reward signal. At the same time,it can also avoid the difficulties of parameter tuning and the poor adaptive ability of conventional PID control. Finally,the control system is verified on the d SPACE platform. The results show that the proposed approach can improve loading capacity of SEIG effectively. And it has faster voltage response speed and better robustness.
In order to study the vibration control of nonlinear vehicle suspension,an optimal control method is presented by using control parameters and applied to the control of nonlinear vibration of vehicle suspension system. The nonlinear dynamic and math model of two degree-of-freedom suspension system is built and the linear control parameters of velocity and displacement are applied. The amplitude-frequency response is obtained by averaging method. The following analysis of the effects of excitation amplitude,nonlinear degree and the control parameters on resonance amplitude are studied. The suspension system stability is analyzed,and the range of control parameters is gained on the condition of stable solution of the system. Taking the attenuation rate and vibration energy of suspension system as objective functions and the stable control parameters as constraint conditions,the optimal control parameters are calculated by the optimization method. The results show that the nonlinear vibration characteristic of vehicle suspension is influenced by the amplitude of excitationand the nonlinear degree of the system. The control parameter of velocity plays the main control role. The peak amplitude of suspension vibration can be suppressed about 88% when the optimal values of two control parameters are obtained by comparing with no control parameters,and the nonlinear characteristics can be eliminated. Finally,a simulation example validated the correctness and effectiveness of the results.
In order to realize the real-time online monitoring the road header's cutting tooth wear in the cutting process,by using the PLC as the data acquisition and processing core,road header's current signal,vibration signal and acoustic emission signal separately for the real-time in the tunneling process were detected,and the exact amount value of cutting tooth wear after decision was got by using the fuzzy information fusion method to realize fuzzy and fuzzy rules the characteristics of the signal and the solution of fuzzy query processing. The test results show that the cutting tooth wear value which was tested by monitoring system based on fuzzy information fusion and that of measured data were well coincide with each other,the error in the range of 8%,there are high precision and reliability.
In this paper,a modified search direction with backtracking line search method for symmetric nonlinear equations is presented. Furthermore,the proposed method not only possesses descent property but also owns global convergence in mild conditions. The numerical results indicate that the presented method is effective for the given problems.
In this study,a new bioflocculant-producing strain C412 was isolated from soil samples. The isolated strain was derived amyloliquefaciens bacillus via characteristics of morphology as well as biochemical and physiological analyses and the comparison of 16 S r DNA sequencing. 16 S r DNA nucleotide sequencing analyses revealed that the strain C412 was closely related with the amyloliquefaciens bacillus with 99% similarity. Culture conditions optimization for strain C412,including culture time,carbon sources,nitrogen sources and metal ions on bioflocculant production and biomass was investigated by single factor test. The best carbon and nitrogen sources for producing flocculation were soluble starch and beef extract,respectively. The fermentation kinetics analysis showed that strain C412 reached the highest values of biomass production and flocculating activity( 95. 53%) in 17 h. These results indicated that the optimal medium for bioflocculant production was15 g / L soluble starch,1 g / L beef extract,3 g / L( NH4)2SO4,1 g /L Na Cl,5 g /L K2HPO4,2 g /L KH2PO4,0. 05 g /L Mg SO4·6H2O( p H = 7). Infrared spectrophotometry analysis indicated that this bioflocculant contained hydroxyl,amino,carbonyl,and methoxyl groups in its structure and thesegroups were beneficial for flocculation process. This study indicated this bioflocculant was applicable under wide range p H condition between 4 and 13 and had heat resisting property between 4 and 60℃). Further study on its flocculation properties and culture scaling-up process are in progress with the purpose of enhancing the yield of bioflocculant and realize its industrial utilization.
