Search

This paper researches the influence rule of unit size on relief amplitude by analyzing relief amplitudes under various statistical units and determines the optimum statistical unit in study area-Chongqing using the correlation between different statistical data. The results show that relief amplitude increased with increasing area of statistical unit, but increasing rate finally becomes stable. When determining the optimum unit using artificial drawing method, the point maintains stable can be found. The optimum unit area is 4km2 of SRTM-DEM data in study area.

The online marking system, which can improve the marking speed and quality, is widely applied in large-scale standardized tests. The P system had great parallelism is applied in the engineering systems just beginning. In this paper, an automatic online marking-management model (AOMMM) based on membrane computing is constructed, which can find marker had quality problems and remind the markers and the leader automatically. According to the basal rules of membrane computing, the management rules of the proposed AOMMM are designed. Through the analysis of the computational time complexity of the proposed model, we find that only three steps (O (1)) are needed to complete the feedback operation. Experimental result shows that the proposed model is appropriate for online marking management. With benefiting from the advantage of membrane system, the proposed OMMAM implements automatic and real time feedback operation.Key-Words: -standardized tests; online marking; error; control; membrane computing; P system; management automation; membrane system

Considering the contact effect between foundation and soil, the dynamic interaction model of tower-foundation-soil coupled system is set up with visco-elastic artificial boundary as the soil boundary. The seismic time history response of a tower-foundation-soil system under three different site conditions is calculated, and compared with the results that do not consider the effect of tower-foundation-soil dynamic interaction. It shows that the displacement of tower and the axial stress of the members substantially increased on soft sites and medium soft sites while no significant change on medium hard sites and hard sites when tower-foundation-soil dynamic interaction is considered. Therefore, it is suggested that the tower-foundation-soil dynamic interaction should be considered in aseismic design of transmission tower on soft sites and medium soft sites.

In this paper the different proportional Pt/Ag on XC-72 carbon are studied to serve as the electro-catalysts of H2O2in acid media. All catalysts are prepared by impregnation reduction method and characterized by XRD and TEM. The electrochemical performance tests are examined by cyclic voltammetry (CV) at 25°C and 30°C, respectively. The results suggest that the peak current density increases with increasing the Ag content in Pt-Ag/C. Attributed to the temperature factor, the electro-catalytic activity of all catalysts at 30°C is better than that of 25°C.

Based on the characteristics of current China's electricity power market, it is necessary to develop the self-regulation system for all market participants. This paper sets up index system based comprehensive risk evaluation for self-regulation construction, which covers market infrastructure stability, schedule fairness,trade compliance, electricity bill settlement risk. The evaluation criterion for each indicator is given afterwards. The key self-regulation information and subsequent trade behavior improvement measures can be attained after making the evaluation by calculating each index value, thus conducive to achieving the power market transaction stability and efficiency.

Because nodes in the loT(Internet of Things) are widely distributed and most of them are unattended, so single node is vulnerable to be attacked and destroyed. Once one node is destroyed or attacked, the whole loT will be faced with tremendous security problems. This paper proposed a Trust Evaluation Model of loT based on AHP and Backward Cloud Model. In the model, in order to be solve the problem that nodes in loT have limited resources, the paper made use of the improved AHP(Analytic Hierarchy Process) and Reverse Cloud Model method, which can work with simple calculation and few resources. In the last, we simulate the method using omnet++ and simulation result show that the model can evaluate the trust value of the malicious node that executes bad communication behaviours fast and also reduce the possibility of wrong judgment.

Concerning the steam-driven induced draft fan renovation tendency in large coal-fired power plants, the economic analysis of steam-driven way is proposed. And based on the 600MW unit of different capacity, the application characteristics are analyzed. As the result, the economic benefit of 600MW subcritical, supercritical and ultra-supercritical units are 6.93×106, 5.14×106 and 3.81×106 RMB, respectively. The lower main steam parameters, the larger economic benefit.

In this study, a combination of a two-step sintering and a particle size gradation technique was used to prepare cermet samples. We focused on the impact of the AlF3 additive on the performance of the cermet. We found that the addition of AlF3 doesnt significantly improve the density and porosity of Ag-NiFe2O4, since the addition of the AlF3 did not reduce the particle size, nor did it promote the tight packing of NiFe2O4 in a spinel-based cermet. However, we did observe a significant enhancement in its conductivity. The sample with 3% additive has the highest conductivity at 22.53S·cm-1 at 900°C, nearly 3.8 times better than the pure sample. An Analysis of the cermet microstructure showed that adding AlF3 can improve wetting between the ceramic phase and the silver metallic phase. It also facilitates the distribution of silver along the contour of the ceramic particles, which contributes to the improved conductivity of the nickel-based cermet.

Fulvic acid solution whose the pH value is at 2.9 and 3.5 is adopted to conduct immersion test of three days cured red clay-cemented soil composite mass. Through monitoring the acid consumption and specimen appearance, the corrosivity and mechanism of red clay-cemented soil composite mass while under the fulvic acid circumstances is studied. It is showed that fulvic acid has some corrosivity to the composite mass. The smaller pH value is, and the more severe corrosivity is. The erosion process can be divided into quick response and stable stages, where the former stage is the primary and the latter is weak.

For analyzing initial moisture content of corn stalks, feed rate, airflow temperature and airflow velocity which affect drying, the experiment bench of air drying was established, industrial analysis, single factor and multi-factors orthogonal experiments for corn stalks were done. The drying curves about various factors were summed up to conclude airflow temperature is the most important factor which affects drying effect.

The problems of the high exhaust gas temperature in the biomass boiler which moves normally are analyzed, and the anti-balance method to get the boiler efficiency is used to get the relationship between the exhaust gas temperature and the boiler efficiency. Greater exhaust gas heat loss, smaller the boiler efficiency. According to 35t/h biomass grate boiler, the factors which affect exhaust gas temperature are analyzed and summarized

To Investigate the Effect of Different Surface Treatments on Push-out Bond Strength of Zirconia Oxide Posts in Root Canals. Sixty Single Rooted Extracted Teeth were Collected and Divided into Two Groups. Custom Milled Zirconium Oxide Posts (Cercon, Degudent, Germany; Cosmopost, Ivoclar, Liechtenstein) were Fabricated. Post Specimens of each Group were Subjected to Different Surface Treatments (n=10): no Treatment (control), Sandblasting then Silane Coating and Silane Application (SB+SC+SI), Sandblasting and Silane Application (SB+SI). all Specimens were Bonded with Relyx Unicem and Horizontally Sectioned into Three Sections and Subjected to a Push-out Test. Data were Analyzed Using Two-way ANOVA. Cercon Recorded Significant Higher Bond Strength than Cosmopost (P＞0.05). Surface Treatments Recorded Higher Values than Control Group, and SB+SC+SI Presented Higher Bond Strength than SB+SI (P＞0.05). there was no Significant Difference among Different Root Regions (P＞0.05). Therefore Cercon May be more Suitable to be Used as Post Materials than Cosmopost. Surface Treatments have Significant Effect on Push-out Bond Strength of Zirconia Oxide Post and SB+SC+SI Group Presents Better Bond Strength than SB+SI Group.

By the use of the experimental system of Impact Rockburst, which was designed by State Key Laboratory for GeoMechanics and Deep Underground Engineering, the stress concentration for orifices in a cubic gypsum specimen subjected to static and dynamic combination loads was studied. The different triaxial precompression was loaded on gypsum specimen, then the dynamic cyclic loading is exerted in the direction of σ1, while the constant stress is exerted in σ2 and σ3. For the stress strain curve, the data of force and displacement were collected by the servo control system in real time. By the strain gauge near the orifices, the strain was recorded by the dynamic strain collecting device, that result in the orifices stress was obtained. In addition, the phenomenon of inner wall of the orifices was real-time photographed. Based on elastic theory and dynamic stress concentration theory, we calculated the stress near the orifices, which keep pace with the results of test.

To Study the Effect of Different Core Thickness on the Flexural Strength of Zirconia and Feldspathic Ceramics. Bilayered Zirconia-Feldspathic Samples of Three Commercial Brands were Made in Three Different Thickness(n=10): 0.5 Mm, 0.8 Mm and 1.0 Mm Respectively. on Zirconia Core Specimens of each Thickness, Feldspathic Dentin Porcelain was Added to Reach a Total Crown Thickness of 2 Mm. Samples were Stored in Artificial Saliva with Neutral Ph for 10 Days at 37°C. Flexural Strength was Conducted with 3-Point Bending Test. Data were Analyzed by One-way ANOVA, and Multiple Comparisons were Performed Using Student-Newman-Keuls Test(α=0.05). the Measurement of 1.0 Mm Group was Higher than the other Groups, and 0.5 Mm Group was the Lowest(P＜0.05), Regardless of any Commercial Brand. Commercial Dental Zirconia Blocks had Varied Flexural Strength, Zirkonzahn Expressed Highest Value in any Thickness Group Compared with the other Materials. Moreover, the Fracture Mode of Zirconia Bilayered Composites was Different in this Study, 0.5 Mm and 0.8 Mm Groups Exhibited Higher Number of Fragments and Appeared to Delamination Compared with 1.0 Mm Group. so we Infer that the Thickness of Core can have an Effect on the Flexural Strength of Bilayered Zirconia-Feldspathic Crown, as well as Different Kinds of Materials.

Based on the implementation of the project of steam induced draft by one factory, heat balance calculation was employed to calculate the coal consumption rate between steam-driven and motor-driven induced draft fans. Besides, an all-purpose economic evaluation method was employed to analyze the investment recovery term and sensitivity of the two plans. The results show that it needs 2.8 years to recover the full cost based on the standard coal price for RMB 900 yuan/t, the electricity price for RMB 0.43 yuan/(kW.h). The evaluation also provided other recovery terms in different electricity price and coal price.

Concerning the steam induced draft fan renovation tendency in large coal-fired power plants, the economic and environmental benefit are analysed for certain 1036MW ultra supercritical units. Under the same generator output, despite the power generation coal consumption for the scheme with steam induced draft fan coal increased, the auxiliary power reduced significantly which results in roughly RMB 10,657 thousands yuan economic saving every year with about 1.9 years payback period of investment. Due to the power supply coal consumption saving, the annual amount of pollutants reduction of CO2, SO2, NO2 and dust are 4440.867, 16.462, 45.514 and 220.829t, respectively.

Silver nanowires in large quantities can be obtained by 5-hydroxy-L-tryptophan through a simple method in the absence of a surfactant and seed. The influences of different experimental parameters on the morphologies of silver nanoproducts in such an environmentally friendly synthesis were investigated. Different molar ratio of reactants which can results different size and shape of silver nanoparticles. The high temperature, the acid or alkaline condition is not to facilitate formation of the nanowires. This simple and eco-friendly preparation method of silver nanowires can decrease the synthetic cost and broaden the research and application areas of silver nanowires.

Pyrite was heat treated on a thermo-gravimetric reactor (TGR) and a drop tube furnace (DTF) in CO2/N2 mixtures with different CO2 concentrations. The effects of CO2 on pyrite transformation were investigated. The reaction products were characterized by XRD and XRF. The results show that, the presence of CO2 can promote pyrite desulfurization and oxidation at 900°C and 1500°C. Pyrite oxidation seems to increase with CO2 concentration. TGR results show that hematite and magnetite are the final iron products at 900°C and higher CO2 concentration. DTF reaction samples generated at 1500°C with the presence of CO2 contain pyrrhotite and magnetite, indicating incompletion of pyrite desulfurization/oxidization due to a short residence time.

Adverse health effects of Fe and S in airborne particulate matter (PM) have been reported. However, little work has been done to characterize Fe and S in PM10 from coal combustion. In this study, a sub-bituminous coal (coal A) and a bituminous coal (coal B) were subjected to combustion in a drop tube furnace under air-and oxy-firing conditions. Size distribution and elemental composition of PM10 (PM with aerodynamic diameter 10 μm) were obtained by low pressure impactor and X-ray fluorescence techniques, respectively. The partitioning characteristics of Fe and S in PM10 were investigated. Data shows that particles of ~0.1μm contains the highest concentration of Fe for both coals under different combustion conditions. The concentration of Fe in the ultrafine particle mode decreases when switching from air combustion to oxy-fuel combustion with 21% O2. It increases when the oxygen concentration increases from 21% to 32% O2 during oxy-fuel combustion. Changing combustion conditions has little effects on Fe partitioning in particles >0.3μm. The concentration of S in PM10 increases with decreasing particle size, but changing combustion conditions have inconclusive influence. Fe and S are dominant elements in ultrafine particles, indicating a greater threat to human health.

The use of coal fly ash for CO2sequestration has been proposed as a promising option for its utilization. However, research is quite necessary for advancing this technology. Indirect carbonation of high-calcium coal fly ash for CO2sequestration was investigated in this study. In these processes, calcium was first extracted from a high-calcium coal fly ash sample with NH4Cl solution. The obtained leachate was subsequently carbonated by bubbling CO2. It was shown that NH4Cl could extract about 35% of the total calcium into the solution under the conditions investigated. The dissolution of calcium is nearly accomplished in half an hour. Further increasing the extraction solution temperature (10-90°C) and the concentration of NH4Cl (0.5-3mol/L) only has subtle positive effects on the calcium extraction efficiency. The carbonation efficiency of the extraction leachate, namely the percentage of the calcium in the solution transformed into calcium carbonates is about 47%. The sharp drop in pH after bubbling CO2due to weak acid buffering capacity of the solution hinders the further precipitation of Ca2+. Calcium carbonate samples with a purity of up to 97% are obtained, meeting the purity requirements for industrial use.

In this paper, a combination of a two-step sintering and a particle size gradation technique was used to prepare cermet samples. The effects of compound additives with various combination of SnO2 and BaO on the performance of cermet were investigated. The results showed that, the performance of cermet could be improved by doping compound additives. The density of cermet sample reached to 5.61g•cm-3, and the porosity fell to 2.01%. Furthermore, we did observe a significant enhancement in its conductivity. The sample with 1% BaO additive has the highest conductivity at 8.02S/cm at 960°C, is increased by about 36% compared with the BaO undoped cermets.

In order to test the photocatalytic activity of Bi20TiO32under different conditions, experiments were done to compare its performance for degrading organic pollutants in water. The results are as following. Higher light intensity will increase the reaction rate. Ions in water will affect adversely the photoreaction. Temperature has little effect on the reaction. High concentration of H2O2helps to degrade organic pollutants in water.

The poor engineering properties of peaty soil are unfavourable for engineering construction. Based on field test datum, the mechanical properties of peaty soil in different buried depth have been analyzed. The result shows that the shear strength of shallowly buried peaty soil reduce gradually with the increase of burial depth, however, which increase gradually along with the depth for deep buried peaty soil. The factors affecting the meso-structure of soil, for example, stress state, the stress history, the stress path, the variation of groundwater, chemical field, biological field and physical field is discussed.

This paper analyzes the connotation of the collective risk in industrial clusters, the conduction elements and the conduction mechanism, then build an enterprise risk conduction mechanism figure, delimits different ways of the collective risk conduction, deepening the understanding of the mechanism of risk conduction in the industrial clusters.

Desulfurization and Denitrification processes in two pulsed discharge plasma systems (NO/SO2/N2/O2/H2O and NO/SOSubscript text2/NSubscript text2/OSubscript text2) were simulated respectively, and then the removal characteristics of these two gas systems were analyzed. The results show that NO can be completely removed when the residence time is close to 1.3 s and SOSubscript text2 removal rate is 61.5% when the residence time reaches 3 s in a system containing water vapor (HSubscript text2O). When the system does not contain water vapor, NO removal rate is still much high, but SOSubscript text2 removal rate is approximately zero. When OSubscript text2 concentration is increased, NO removal velocity will be faster and the peak of the concentration curve of NOSubscript text2 will be higher. NO removing velocity is much faster in a system containing water vapor than that in a system without water vapor when both systems have almost the same OSubscript text2 concentration.

Utilizing multi energy sources synthetically is one of the trends of energy utilization. China has splendid solar energy resource, however, the majority of the electricity production still comes from coal-fired power plants. It is of great necessity to investigate the solar-coal complementary electric generation technology. A 300MW unit thermal-circulation boiler has been studied; calculations about the wall circulation characteristics have been made under 40 conditions. The influence of solar-energy utilization on wall circulation has been analyzed. Calculation and analysis indicated the following: the utilization of solar energy has prominent influences on the steaming point and the under-heating condition of the drum water; the solar energy could be used at high load or low load with the high pressure heaters bypassed conditions, but should not used at 60%-70% load.

Because of discontinuity at threshold, hard threshold de-noising leads to the additional oscillation at threshold when reconstructing the signal, so that the smoothness of the de-noised signal becomes weak; Soft threshold de-noising method can guarantee the good continuity of the signal. However, for the existence of the fixed bias between the estimated threshold and actual threshold, there are also deviations between the reconstructed signal and the actual signal existing deviations too. In this work, by using the high performance DSP as a signal processing tool, we reduced the noise of actual measured vibration signal collected from headstock of CA6140 lathe. By comparing, the result is the same as the noise reduction simulation calculated from MATLAB, which demonstrates the noise reduction effect of wavelet adjustment factor threshold de-noising apparently.

Focuses on the dynamical collapse of large-span spatial structure, this paper uses giant magnetostrictive material as the main component to design a kind of new GMM actuator, which could used in active vibration control of large-span spatial structure. The genetic algorithm has been used to optimize the position of actuators in large-span spatial structure, and the optimization of the results has been analyzed by numerical simulation. The research shows that the GMM actuator has fine actuator effectiv.

L-Tryptophan and 5-Hydroxy-Tryptophan were used to synthesis the plate-like gold particles. The morphology of gold plates can be tunable from several nanometers to dozens of micrometers by changing reaction conditions. High temperature was not only increased the reaction ratio, but also changed the morphology of gold products. The size of gold plate was determined by the molar ratio of tryptophan to HAuCl4. The pH value of HAuCl4also played an important role in the formation of gold plates. One more hydroxyl group in the tryptophan enhanced the reducing ability of tryptophan, which was not suitable for the anisotropic growth.

Different gradation types may have different particle contact behaviors for asphalt mixture, so that it holds diverse pavement performances. The particle contact theory explains the particle contact behaviors law during movement. A particle contact behaviors model was established, which is easy to describe and apply on the spot. A line contact stiffness model was used to simulate particle contact behaviors for gradation types of CA0.2, CA0.4, CA0.6 and CA0.8 when particle of asphalt mixture is moving with dead weight. Their pavement performances were verified with Marshall test, wheel tracking test, gyratory compacting test and the index of potential energy test under optimum asphalt content. Test results show that their service performance is identical to simulation result of particle contact during movement with dead weight. With the help of the research, it can supply some theoretical and applicative bases for an optimum mixture gradation design and indoor gradation simulating design for asphalt mixture.

Based on counter magnetostriction effect the magnetization intensity and stress sensitivity was analyzed for ferromagnetic material. The stress sensitivity of magnetized material was discussed on basis of the law of minimum energy and movement of magnetic domain structure. In accordance with the effect of magnetization intensity from stress the applied stress can lead to movement of domain wall of magnetic domain in the demagnetizing state for ferromagnetic material when the net magnetic moment is equal to zero. Meanwhile easily magnetization axis can be established on known applied stress. Then when ferromagnetic material is forced by the applied stress the magnetization intensity can be changed obviously. It is happened so that magnetic flux is also changed simultaneously. The result shows that real-time strained condition of material can be judged on basis of testing change of magnetic flux. Furthermore the study theory of magnetic nondestructive testing of defect sensibility structure for long span steel structural is obtained through this analysis.

LiFePO4/C cathode materials for lithium ion battery were prepared by solid-state method from using Polystyrene (PS) micro-spheres as new carbon source. The structure, morphology and electrochemical performances of LiFePO4/C were investigated by X-ray diffraction (XRD), scanning electronic morphology (SEM) and galvanostatic charge-discharge tests and cycle voltammetry (CV). The results demonstrate that LiFePO4/C have single olivine type structure with small particle sizes. The electrochemical test results show that the residual carbon produced by the pyrolysis of PS microspheres with functionalized aromatic groups exhibites a better discharge capacity in the LiFePO4/C composite. The LiFePO4/C cathode material with 7 wt% PS delivers an initial discharge capacity of 141mAh/g at 0.1C and between 2.5-4.1V, and displays excellent capacity retention. The composite material exhibited a higher peak intensity and a smaller voltage difference between the oxidation and reduction peak, indicating a good electrochemical reaction reversibility.

Job definition format (JDF) can carry out management and control during the whole printing processes while enterprise resources planning (ERP) system can help enterprises implement supply chain-based integrated management. Base on the analysis of JDF’s and ERP’s identities, according to their adaptability to the printing industry, we designed the combined system model of JDF workflow system and ERP management information system. Under the premise of the most optimal allocation of business resources, production management and information management of the whole printing process from order, production, and enterprise management to the logistics can be obtained.