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The microstructures and thermal stabilities of high silicon aluminum alloys prepared by spray deposition (SD) and subsequent heat treatment were studied. The results indicate that the size of the primary silicon in the deposited ingots is much smaller than that prepared by normal casting. After the subsequent heat treatment, the pores in deposited ingots are disappeared and their density increase to about 100%. While the size and volume fraction of the primary silicon in solidified hypereutectic Al-Si alloy increase with the increasing of silicon content, the corresponding thermal expansion coefficient decreases.

In view of rich resources of corn stalks, cotton stalks forming pellets hot ignition performance, using CFD numerical simulation analysis to study the key parameters of electric ignition such as the surface ignition temperature, air velocity, air flow distribution ratio of influence of hot air outlet temperature. Obtained that increasing electric heating surface temperature, reducing the air flow velocity and convective heat transfer coefficient of the outer tube can significantly improve the ignition temperature of the outlet hot air, the outlet hot air temperature should be higher than 450 °C. Ignition internal and external air passage area ratio affects the allocation of hot air flow, the best area ratio of between 1.8-2.2.

For the operational optimization problem of supply temperature and flow adjustment (known as “quality-quantity” regulation) in district heating system.To meet user needs hot,an operational cost equation of primary network is set up, taking the supply water temperature and the water flux as variables. The optimization objective of this equation is to minimize operational cost.Based on the genetic algorithm,and finally get the optimal water temperature and water flux. Analysis the several regulation of supply water temperature and water flux, finally proposed heating system integrated regulation.

In this paper, we shall first briefly introduce the hydraulic junction of three-sources branched heat-supply network and the related optimization method. It's difficult to guarantee that the system runs in optimal state and it increases energy consumption in the system. In view of this situation this paper proposes a method to find the optimal positions of hydraulic intersections based on analyzing a real heating system with three heat sources in Jining. The optimization objective is to minimize the electric power consumption of circulating water pumps in district heating system. Finally, optimization programs are designed and the optimized results verify the feasibility and validity of the method compared with conventional experience values.

In this paper, we shall discuss the calculate method of heat loss of central heating pipes.the calculation formulas available are too complicated and inconvenienced to analysis the dynamic thermal conditions of heating pipeline. Therefore, this paper presents one order polynomial with least-squares solution, and then establishes linear equations of heating pipeline heat loss that the hot water temperature as a variable alone. It is based on the comparision and analysis of buried hot water heating pipeline heat loss formula. This method will simplify not only the calculation, but also the model of calculation analysis for different diameter, different insulation materials. The result is that the deviation of the formula is caused mainly by the thermal resistance. The relative errors of simplified formula and the selection formulas are less than 3%, which can meet the requirements for engineering applications.

In this paper, three wire structure of the airflow level posture sensor is described. Using ANSYS-FLOTRAN CFD program, the temperature field and the stream field in sensing element of three wire structure and two wire structure under the effect of the different tilt state, has been obtained by a series of procedure, such as model building, meshing, loads applying and equation solving. The results are as follow: In tilt status, the airflow rate difference of three wire structure is nearly five times bigger than two wire structure in the two heat sources. Three wire structure makes heating wire separated from detection wire, solves the contradiction between operating current and output sensitivity, and decrease operating current. The test results show: The compare between three wire structure of the airflow level posture sensor and two wire structure of the airflow level posture sensor is that the sensitivity increases from 10 mV /° to 18mV/°,response time decreases from 100mS to 40mS,operating current decreases from 80mA to 40mA, so three wire structure is better than two wire structure.

The flow and temperature fields caused by point heat source were obtained with the method of FEA (finite element analysis), and the pendulum characteristic of nature convection gas in two-dimensional enclosure with small size was validated and explained. The results are as follow: (1) Whether in horizontal status or in tilting status, under the function of buoyancy lift, the direction of nature convection gas always keeps vertical upwards in two-dimensional enclosure, and it has the pendulum characteristic.(2)The temperatures of two points on the same isotherm are no longer equal. When the tilt angle is 10°, the temperature difference is 20K; when the tilt angle is 20°, the temperature difference is 40K.The tilt angle can be measured by using this characteristic of MEMS airflow level posture sensor.

In this work, cutting experiments were carried out on titanium alloy Ti6Al4V by using single crystal diamond tools to investigate the effects of cutting parameters on machined surface roughness. Experimental results show machined surface roughness decreases with increases in the cutting speed within a limited range, begins to increase as the factors reaches to certain values respectively, and decreases with increases in feed rate. Cutting depth has no significant influence on the machined surface roughness. The results also show that dominant mechanisms of the single crystal diamond tools are abrasive wear and adhesion wear.

In order to compare and research the performance of airflow level posture sensor two wire structure and three-wire structure. By using FLUENT-CFD software, through modeling, meshing, solving and other methods, Respectively, the airflow level posture sensor of two-wire structure and three-wire structure are simulated in the sensitive of the velocity field of different tilt angles and different heat source temperatures. The results showed that the tilt sensitivity to changes of velocity of three-wire structure airflow level posture sensor is 0.3831·10-3m/s/0, and the two-wire structure is 0.2487·10-3 m/s/0, and the measurement range of three-wire structure airflow level posture sensor is 00 to 300, the two-wire structure is 00 to 200. The rate of change of three-wire structure airflow level posture sensor’s sensitive internal velocity difference change with the hot source temperature is 1·10-5m/s/0C, and the two-wire is 3.5·10-5m/s/0C. The performance of three-wire structure airflow level posture sensor in inclination and temperature is better than the two-wire structure’s.

Proposed a two-dimensional air-angular velocity sensor. Dual vertical heat resistance wire, two-dimensional angular velocity sensitive; By simply supported edge piezoelectric pump support to improve the sensitivity of the sensor; Using stacked sheet round table groove type nozzle, improved stability and repeatability of the sensor; Using software compensation processing to improve the temperature performance and linearity of the sensor. Experimental results show that the sensitivity of the sensor improve nearly double, Zero variation decrease from≤10% to≤0.2%, operating temperature extended from-10°C~+40°C to-45°C~+65°C, linearity decrease from≤1% to ≤0.5%, the amount of sensitivity decrease from ≤10% to≤0.6%.

In this day and age, there is a disruptive shift in technology concerning the powerful ability of cloud storage that back up and store large data in the cloud, as well as syncing it across multiple devices automatically, and its drawbacks in data security. This paper mainly presents an overview of cloud storage, highlights many of security issues and vulnerabilities in cloud storage, lists various solutions, and then gives a summary.

This paper presents an investigation of spacing fluctuation characterization (SFC) of Hard Disk Drive (HDD) using thermal asperity (TA) sensor. Firstly, the spacing fluctuation monitored by TA sensor is correlated with that monitored by a Laser Doppler Vibrometer (LDV). Secondly, a series of experiments are conducted to study the factors affecting the spacing fluctuation, including disk distortion, head crown sensitivity, ZH sensitivity. Good disk assembly and small crown sensitivity and ZH sensitivity will be helpful to reduce spacing fluctuation.

The flow distribution of fluidic gyroscope with three different cavities was researched when angular velocity ωi is input. Using Finite element method we calculated two-dimensional flow distribution of fluidic gyroscope with rectangular cavity and two streamlined cavity structures when ωi input. The results show that: with ωi increasing, the fluidic beam centers in three cavities have a more deviation on one side, while in two streamlined cavities it deviates obviously. When ωi is 10rad/s, velocity difference of two thermal wires in streamlined cavity 1 and cavity 2 increase 42.59% and 59.30% respectively compared with rectangular cavity, velocity and y-axial velocity of two thermal wires in streamlined cavity 1 are smaller than rectangular cavity but larger than streamlined cavity 2, but x-axial velocity of two thermal wires in streamlined cavity 1 are smaller than other two cavities, and so is ωi = 15rad/s. It also shows that velocity difference between two thermal wires in streamlined cavity 1 is larger than others, and temperature difference is larger, which can improve the resolution of fluidic gyroscope. This article has laid a theoretical foundation to further enhance performance of fluidic gyroscopes.

The impact that distance between thermal wires and nozzle on flow distribution of fluidic gyroscope with three different cavity structures was researched. Using the Finite element method we calculated the two-dimensional flow distribution of fluidic gyroscope with rectangular cavity and two streamlined cavity structures when the distance d between thermal wires and nozzle is different. The results show that: flow velocity at the outlet in two streamlined cavities is larger than that in rectangular cavity, which is 28.87% and 28.91% of flow velocity at the nozzle respectively; the velocity in the three cavities decrease with d, the velocity in streamlined cavity 1 is always larger than that in streamlined cavity 2. When d = 16mm and 17mm, there are a larger velocity and a smaller x-axial velocity of the fluidic beam center in streamlined cavity 1, and velocity difference of two thermal wires increase, so the resolution of fluidic gyroscope can have an improvement.

The influence of thermal wires position on resolution of fluidic gyroscope with three different cavities was researched. Using Finite element method we calculated two-dimensional flow distribution of fluidic gyroscope with rectangular cavity and two streamlined cavities when the thermal wires are in different positions. As the results shown: define d is the distance between thermal wires and the nozzle along the fluidic beam propagation direction, when d ≥ 13mm, velocity 4SSUM in streamlined cavity 1 is bigger than velocity 2SSUM in streamlined cavity 2. When d >16mm, velocity SX of two streamlined cavities decrease faster than RX of rectangular cavity, which reduce the vortex phenomena in cavity. With the distance away from the center axis of cavity increases, the velocity gradient increases, and increasing the distance between two thermal wires within a certain range can increase velocity difference of two when angular velocity ωi inputs, temperature difference increases, so it increases the resolution of fluidic gyroscopes. This paper has an instructional role on structure optimization and performance improvement of fluidic gyroscopes.

Concentrations of six types of metals (including Cr, Co, Ni, Cu, Zn and Pb) in twelve groundwater samples from two different aquifers (coal bearing and limestone aquifers) in Renlou coal mine in northern Anhui Province, China have been analyzed by using ICP-MS and processed by statistical analysis for tracing their sources. The results indicate that the concentrations of metals are as follows: Cu(6.68 mg/L)> Cr(2.39 mg/L)> Ni(1.03 mg/L)> Zn(0.882 mg/L)> Co(0.569 mg/L)> Pb(0.116 mg/L). Concentrations of Cr, Ni, Cu and Pb are several times (47.8, 51.5, 3.3 and 8.0, respectively) higher than the drinking water standard of WHO, and indicating that these groundwater cannot be used for drinking directly. Two components (eigenvalues higher than one) have been obtained by using factor analysis with a total variance explanation of 88.7%, and two sources for metals in the groundwater have been identified that Cr-Cu and Co-Ni-Pb are originated from different sources. Moreover, the differences of metal concentrations between groundwater in these two aquifers suggest that they can be used for water source discrimination.

Major ion concentrations of twenty groundwater samples from two deep seated aquifers (coal bearing-GC and limestone-LC) are analyzed for identify the differences between them and the source of ions. The results suggest that they are moderate to highly mineralized water with their average TDS values are 2444 (GC) and 1178 (LC) mg/L. LCs show lower Na but much higher Ca and Mg concentrations relative to GCs. Saturation indexes and principle component analysis, as well as mole ratios between Na and Cl, Ca and SO4, Ca and HCO3 indicate that they have multi sources with incorporation of halite and albite for Na, calcite, dolomite and gypsum for Ca, pyrite and gypsum for SO4.

Fine blanking, as an effective and economy metal forming process, can be used for the manufacturing of helical gears with inclined forming movement. In the present study, a reliable three-dimensional (3D) rigid-plastic finite element (FE) model is developed on the DEFORM-3D platform for rotational fine blanking of a helical gear. Based on this FE model, distributions of different field variables such as metal flow velocity, mean stress and effective strain are obtained, and cut surface features and punch stroke curve are predicted. The results achieved in this study can not only evaluate the capabilities of the rotational fine blanking process of a helical gear, but also provide valuable guidelines and a better understanding of the deformation mechanism of this process.

In the tunnel excavation process, often encounter fault belt, soft interlayer and abnormal water-bearing body does not directly predict adverse geological structure, not timely prediction and control these geological disasters will affect the safety of production. In many prediction methods in geophysical technology with nondestructive, accurate, efficient, fast and be recognized, many shot-geophone reflected wave method in different geological conditions on the apparent impedance response, the migrated results can accurately distinguish the lithologic interface, in many projects has been confirmed. The paper introduces the multiple source-detector reflection wave observation system based on, combined with the specific project example, elaborated how the shot-receiver reflected wave method in tunnel face geological disaster prediction in rats.

In this paper, the rule of mixture, which is often used to derive the weld properties from the uniaxial tension test of a subsize welded specimen, was improved by taking the residual welding strain/stress into account and assuming iso-strain increment across the welded specimen. Based on this improved method, hardening data of two different tailor welded blanks were determined. Erichsen cupping tests were performed experimentally and numerically to evaluate the effects of welding residual strain and stress on TWB formability. The results indicate that: (1) the residual strain and stress affect the formality of TWBs to some extent and (2) neglecting the welding residual strain and stress may predict a delayed crack onset and relatively large values in the maximum punch load and Erichsen index.

The aim in this paper is to analyze tooth surface contact stress and transmission errors, verify existence of tooth end effect and discuss symmetry of symmetrical bevel gear differential (SBGD), etc. With this aim, a 3D elastic FE model of SBGD is established under the ANSYS software environment and its meshing characteristic is determined. Starting from here, by analyzing stress and circumferential displacement of tooth, the phenomena of stress concentration is acquired; the distribution of tooth surface contact stress is studied; tooth end effect is confirmed; transmission error is assessed. The analysis is ended by assessing the symmetry of SBGD. Research results provide valuable guidelines for the design of SBGD. The developing model method proposed in this paper makes it possible to study other complex gear mechanisms such as planetary gear system.

Lead concentration of pond sediments near the road, as well as pond sediments far away from roads in a rural area in Sixian County, northern Anhui Province, China, have been analyzed, and the spatial distribution of lead and the index of geo-accumulation have been brought to light. The results indicate that the lead concentrations of pond sediments near the road range from 20 to 34 mg/kg with average= 26.7 mg/kg, whereas pond sediments far away from the road have lower lead concentrations from 20 to 21 mg/kg with average= 20.8 mg/kg. The lead concentration from high to low is Xinji, Gonggou, Dazhuang, Huangwei, Yangzhuang and area far away from the road. A similarity between spatial distributions of lead concentration, index of geo-accumulation (Igeo) and towns (including village and the roads between them) indicates that motor vehicles play important role in controlling the distribution of lead in rural areas.

An experimental program was carried out to obtain the density and compressive strength of lightweight expanded polystyrene (EPS) concretes. Tauchi’s approach was adopted to reduce the numbers of experiment. Four control factors and two responses were used. The results show that EPS dosage had the most significant effect on density and compressive strength. The density value of EPS concrete showed an almost linear decrease as the volume of EPS and W/C parameters increased, but results in a decrease in compressive strength.

The mechanism of effect of the acceleration on acceleration sensor is preliminary elucidated. Using the three-dimensional finite element method, the temperature field in sensing element of the sensor under the effect of the different acceleration have been obtained by a series of procedure , such as model building ,meshing ,loads applying and equation solving. In the process ANSYS2FLOTRAN CFD program is applied. By the numerical results and experiments, the effect of input acceleration on accleration sensor is analogous to the effect of input tilt angle on the sensor, which also will change the temperature of gas flow at two thermal resistors ,so lead to change of the current difference of both thermistor wires, finally the bridge outputs a voltage signal corresponding to the acceleration.

With the method of FEA (finite element analysis), the distribution of temperature field in sense organ at different arrangements of hot-resistances and different accelerations, were obtained by building the three-dimensional model of airflow acceleration sensor’s sense organ.The results are asfollows: When the acceleration is not same, the temperature field distribution near the wires is different; The difference of temperature of 2 symmetry detection thermistors ΔT has also changed. If not beyond the measurement range, The more close to the heat flow center,the greater temperature difference between the two hot-resistances,and the greater output of voltage.

The sensitive mechanism of the airflow tilt sensor was analyzed by finite element method. The streamfield caused by heat source, when the three-dimensional enclosure inclining, has been obtained by a series of procedure,such as model building, meshing, loads applying and equation solving. In the process, ANSYS-FLOTRAN CFD program is employed. In horizontal status, the velocity of gas flow is equal at the two thermistor wires; therefore the current of both wires are also equal and the output of the bridge circuit is zero. In tilting status, the velocity difference of gas flow at the two thermistor wires will change with the tilt angle; therefore lead to changing of the current difference of both wires, the bridge outputs avoltage signal corresponding to the tilt angle. This calculation method provides a new approach to optimization of airflow tilt sensors.

As an important forged part of an automobile, the inner hole of the half-shaft bushing must be formed directly. However, the process requires many steps, and how the forging, or deformation, is spread over the production steps directly affects the die life and forging force required. In this paper, the three steps involved in directly forging a half shaft bushing's inner hole are simulated using the two-dimensional finite element method. Further more, we improve the forging process. From numerical calculation, the improved necessary forging force is found to be only half the original force, and the die life is doubled.