With the continuous development of petrochemical industry, the demand for titanium heat exchanger is increasing year by year in China. Unlike other material heat exchangers, titanium heat exchangers have strict requirements of gas protection when welding heat exchanger tubes and pipe plate joints.Inert gas protection should be applied to molten pools and welds and heat affected zones at temperatures over 400 ℃. In actual production, this intended purpose was achieved by adding a protective gas nozzle to the tungsten electrodes and adding a gas shield for the tube plates. In the whole welding process, gas shield of tube sheet needs to be moved the tube plate gas protection cover constantly based on the welding position.The process is cumbersome and the production efficiency is low.In this paper, Having used ANSYS Workbench numerical simulation software to simulate the temperature field of joint’s welding process and improving the traditional gas protection measures based on the distribution of temperature field.After the actual welding test,This improved gas protective measure worked well and could be applied to actual production.

Based on the ANSYS platform, the numerical simulates of the temperature field in the welding process of the slurry of the slurry steam generator is carried out to obtain the distribution of the temperature field near the weld. The result of the temperature field is gradually applied to the weld to obtain the distribution of welding residual stress at the pipe head. The simulation results can play a very good role in the detection of the residual stress in the welded parts,which not only greatly saving the welding residual stress testing time, but also on the optimization of the welding process played a good reference value.

Through the expansion joint process,this paper adopts mechanical expansion pipe, hydraulic pipe expander and hydraulic pipe expander to carry out the pipe expansion test by using the expansion process. Expanding test is made by studying the expansion performance with different groove width and the expansion performance with different expanded joint technologies of the expended joint performance under the same groove width, the adaptive expansion technique is determined by comparison. The research results show that the experimental method is reasonable and the data is full and reliable. In order to study the connection between heat exchanger tube and tube plate, cheak the tube expanding quality of expending tube and the expanding character of tube material, determining the best expanding coefficient, testing the surface quality of expanding part and the enclosure character, to provide experimental evidence.

The finite element analysis software ANSYS Workbench is used to analyze the tube shell of shell-and-tube heat exchanger. According to the stress analysis standard JB 4732—1995, the stress intensity of tube sheet under four kinds of transient and steady-state operating conditions which may occur during normal operation, start-up and shutdown are analyzed. The results show that the maximum stress occurs at the junction of the heat exchange tube and the tube sheet and the joint between tube and tube sheet. The main influencing factor of the connection strength between the heat exchange tube and the tube sheet and the connection strength between tube and tube sheet is the pressure load.According to the strength check results, the design of the heat exchanger conforms to the standard of use.

Based on the bow baffle, the same working conditions are set. The FLUENT software is used to simulate the flow and heat transfer performance of the shell, fluid and heat transfer of the three baffle plates of curved, spherical and arched shapes. and the pressure drop and heat transfer coefficient of the shellandtube heat transfer with three types of plate are compared and analyzed. By comparing the heat transfer performance, pressure, temperature and velocity nephograms of the three plate heat transfer, the reasons for the difference in heat transfer performance are analyzed. The research results can provide reference for the design and heat transfer enhancement of the shell and tube heat transfer baffle, which has certain engineering practical significance.

A heat exchanger produced by a company. The tube medium of the heat exchanger is temperature-controlled water, and the shell medium is low-pressure steam. The heat exchange equipment suddenly leaked in less than half a year, causing the equipment to stop. During the maintenance inspection, cracks were found at the tube head of the heat exchange tube, and the cracks were circumferential cracks, and some tubes even broke. Therefore,the chemical composition, hardness, mechanical properties and metallographic structure of the heat transfer tubes were tested and analyzed. The micro-morphology of the crack was observed and analyzed by SEM, and the product of the heat exchange tube fracture was analyzed by EDS spectrometer. The results show that the inclusion is part of the cause of the cracking of heat exchange tube, and the corrosive medium in the heat exchange tube is an important cause of the failure of heat exchange tube. The excessive internal stress in the heat exchange tube is the root cause of the failure of the heat exchange tubes.

Acoustic emission waveform streaming testing technology was adopted to collect acoustic emission waveform streaming signals of rolling bearings under normal conditions and in the case of the failure of outer race, inner race and roller. The relations between frequency characteristics and the signals of acoustic emission waveform streaming were analyzed. Envelope spectrum analysis was adopted to acquire the peak frequency of acoustic emission waveform streaming signals, comparing with the theoretical value of the inherent characteristic frequency of the rolling bearings, under the condition of different faults. The experimental data show that envelope analysis can be carried out for the study of acoustic emission waveform streaming signals of rolling bearing with different kinds of faults and the early diagnosis of rolling bearings with different faults can be realized.

Pipeline crossing structure was very easy to be affected by the settlement of soil along the river, and effective preventive measures should be adopted to effectively prevent the damage to the crossing structure. The finite element model of pipeline crossing structure and soil interaction was established, and the stress change of pipeline span structure with the fixed bracket was established. It was found that the fixed bracket could effectively reduce the stress value of the pipeline when the span structure was affected by the settlement of soil mass, and the installation position of the fixing bracket was more prominent to reduce the stress value of the pipeline span structure. The results could provide a theoretical basis for the safety construction of pipeline crossing structure.

        Tooth-locked quick-opening pressure vessel is widely used. The fast opening structure was an important part of the pressure vessel door opening and closing operation and the meshing degree of the tooth determined the safe of the container's operation. A tooth-meshing autoclave was taken as an example and the finite element analysis was used as a method to carry on the numerical simulation to its meshing tooth in load condition and the strength check to its dangerous path. In the case of the incomplete meshing in the circumferential direction, the incomplete meshing in the radial direction and the combined operation in which the two directions were not fully meshed. According to the analysis results, it could be seen that with the decrease of meshing tooth circumferential or radial meshing degree, the stress increased. Under the dangerous working condition of combined meshing (i.e.circumferential meshing degree was 80%, radial dislocation was 3.0 mm)，the tooth's stress reached the maximum. After the strength check, the primary local membrane stress exceeded the allowable value, so the stress didn't meet the requirements. According to the analysis results, the quick-opening container should be avoided to working with incomplete meshing tooth to ensure the safe use.

      E-commerce enterprise performance was one of the important issues to be considered when they developed to a certain stage, and it was realistic to research enterprise performance. SUNING was taken as an example, the typical E-commerce enterprise, 10 key factors were proposed that affected the performance and converted them into 10 key indicators to study the performance of the E-commerce enterprises. By SPSS19.0 software, the correlation test, descriptive statistics and regression analysis were made based on the 10 indicators, and the conclusion showed that the key factors influenced the E-business enterprise performance. The research conclusion would play a guiding role in the future development of E-commerce enterprises.

Firstly, the ANSYS finite element software was applied to study thermal analysis of the fin-tube with trigonal sections in order to acquire the temperature contours, which showed that at the round of pipe the temperature reached the maximum value from the image. The varied temperature tendency of vertical direction with the fin and axial direction of the pipe were analyzed to get respectively the temperature curve and the temperature contours by definition of the path. What was more, the indirect method was applied for thermal stress analysis at the basis of thermal field in order to require distribution situation of thermal stress by corresponding path. It turned out that thermal stress mainly focused on pipe and the joints of the pipe and fin. At last, according to the analytical and design standard for steel pressured vessels, the assessment of the corresponding stress was analyzed to prove its security in the simulative environment, making the basis of reference for further research.

The freezing-thawing circulation was the most common security problems of buried pipeline in permafrost regions, and it could make pipeline generate additional stress. For the regional with the special structure of topographic, the freezing-thawing circulation would change the original geological characteristics, and caused geological disasters under certain conditions. The stress impact of the pipeline was studied generated by the freezing-thawing landslide because of the melting permafrost. The degree of influence of axial landslide with different displacement on the pipeline was analyzed. The simulation analysis showed that different forms of landslide generated a great impact on the pipelines; furthermore, the effects of stress on the pipeline had a greater impact by changing the location of the landslide. The influence on the pipelines generated by the freezing-thawing landslide were simulated and analyzed ,which could well reflect the changes in stress and provide a theoretical basis for building construction of buried pipelines in the permafrost regions.

The earth's settlement would generate additional stress on pipeline , which was common security problems of buried pipelines. Because of the force of aerial crossing pipeline structure was more complicated, therefore a finite element mechanical model of interactions between the pipeline and soil in acrossing segments of buried pipelines was established, to analysis the changes of the stress in aerial crossing pipeline structure, when aerial crossing pipeline structure used different angles. Further, based on the model, a detailed analysis of the stress changes in the pipeline was obtained, when soil settlement occurred at different locations nearby the acrossing segments. The variation was studied on the relationships of the maximum stress within the pipeline with the position of soil settlement, when the angle between the oblique pipeline of crossing structure and the horizontal direction was 50°, provide a theoretical basis for building construction of buried pipelines.

The moisture content of soil will change when the ambient temperature changes in permafrost, and by this time the internal friction angle, cohesion and severe of permafrost will change accordingly. And for slope segments of buried pipelines, the soil will produce friction on the pipeline along the slope direction with the thawing of permafrost occurrence, to make the pipeline generate the additional tensile stress. Understanding the impact of frozen soil parameters on the pipeline stress correctly was convenient to the analysis of pipeline stress, and it had practical significance for the development of scientific and effective method of preventing damage. When the frozen soil around the buried pipeline of slope section thaws, the degree of influence on pipeline stress with different soil parameter was investigated, and yields the conclusion by the numerical simulation. The results show: when thaw landslide occurs, with the increasing of soil cohesion and weight of soil, the pipeline stress increased; and with the increasing of internal friction angle, the pipeline stress decreased. Moreover, the friction angle of the frozen soil was the most sensitive to the pipeline stress, weight of soil followed, and the influence of permafrost cohesion on pipeline stress was minimal.

Because of the complex terrain in the construction of longdistance buried pipeline, the elbows are widely used in pipeline systems. Due to its specificity in terms of shape and structure, elbows not only can change the axial direction of the pipeline, but also increase the flexibility of the pipeline. However, under the special conditions of environment, bends in the piping system are often the section of concentration of stress. In the certain conditions, plastic deformation occurs at the elbow, which poses a potential threat to the safe operation of pipelines. Through the application of software of finite element analysis, stress at a particular point (elbow) of buried pipeline were numerically calculated and analyzed. By numerical calculation and analysis, when the local pipeline under pressure in the radial direction, the distribution of values of Von Mises stress were obtained at the elbow, in the crossing segment of the buried pipeline. And when the length of the applied load, the bending angle and the radius of curvature of elbow were changed, the influence of the stress of the elbow was also obtained.

The B i 2S r 2C a( C u 1-xMn x) 2O8+δ( x=0、 0. 0 1、 0. 0 2、 0. 0 3)  polycrystalline powders were synthesized by Pechini type solgel method. The changes in structure and electrical properties of B i 2S r 2C a C u 2O8+( abbrev. Bi2212) after Mn doping were investigated. Xray diffraction (XRD) and Fourier Transform Infrared (FT-IR) were employed to investigate the structural change of the samples. Conventional fourprobe method was used to study the electrical properties of samples. The results show that no secondphase diffraction peaks were detected except Bi2212 peaks. The lattice parameters of Bi2212 crystalline were changing with different Mn doping concentration. And the superconducting transition temperature of Bi2212 phase was decreased by about 11 K due to the Mn element introduction into Bi2212 lattice. 

In reference to previous research, the simulation software to simulate overhead gas pipeline leakage diffusion in the flat areas was used and the effects of four different leakage directions and speed on leakage diffusion process were analyzed.The results showed that the risky range of upwind area was bigger than the downwind area near the ground, the higher ground was relatively safe.The risky range of upward natural gas jet was the smallest,the risky ranges of windward and downward jet were the greatest.The impact of wind speed on the risky range of windward jet was less than downward jet.Natural gas leakage in the condition of lower wind speed and calm wind spread wider.The results could be used for the emergency evacuation and rescue of overhead natural gas pipeline leakage in the future.

Taking 67 Ashare listed companies in Shanghai and Shenzhen in the mining industry as samples, the empirical analysis of sample companies social responsibility and corporate performance was done from 2010 to 2012. The conclusions show that a linear relationship between the mining industry social responsibility and corporate performance| the relationship was significantly positive among creditors responsibility, shareholder responsibility, national responsibility and corporate performance| and the relationship was relevant among employee responsibility, social responsibility, environmental responsibility and corporate performance.

Human resources were an essential driving force and a source of economic development. And it was vital to develop human resources to boost a region's economy. Based on analyzing the current situation of human resources development in Qingyuan County, this research's results positively confirmed the findings, defined the strategic position of human resources development, carried out the works to step up the professional quality, vigorously developed education training, promoted the reasonable distribution on human resources, increased employment opportunities, to raised the way of utilization rate human resources. These suggestions and measures could provide some useful reference for economic development and human resource development in other areas.

The Bi2Sr2CaCu2O8+δ(Bi-2212) superconducting powders were synthesized by Pechini method. The samples were prepared with metal nitrates as starting materials, ethylene diamine tetracetic acid (EDTA) as chelating agent and ethylene glycol as cross-linking agent. The effect of EDTA amount, ethylene glycol amount, oil bath temperature and time during gel processes on the crystallnity and superconductivity of Bi-2212 powders were investigated. The X-ray diffraction (XRD) was employed to investigate the phase purity and crystallnity. The resistance measurements were carried out with a conventional four-probe method. The results showed that phase purity is slightly affected by different gel processes. But the crystallnity and electrical conductivity of Bi-2212 phase changes obviously as shown by the XRD patterns and R-T curves. The difference of its critical transition temperature Tc,0 is 7.3 K.

Using furfural as raw material and VB1 as catalyst preparation of furoin was studied through benzoin condensation in the alkaline condition, pH of 9 to 10. The effect of reaction temperature, reaction time and the amount of VB1 were investigated. The optimum reaction conditions are as follows: reaction temperature: 65 ℃, reaction time: 2 h, the amount of VB1 : 8.0 g. The yield of the product reached 82.7%. The product is white needle-like crystals with the melting point of 138 ~ 139 ℃. Structure of objective product was characterized on IR and elementary analyses.

As a newcomer of global oil market, both China and India are confronting with substantial difficulties and intense competition in global expansion of domestic oil companies. However, there are some differences between the two countries' politics and economic systems, and their overseas expansion of petroleum industries shows different characteristics, which provides opportunities for learning from each other. According to the nation oil strategy implementation and internationalization level of enterprises, the advantages and disadvantages of global expansion patterns in China and India's oil industry were analyzed, and the opportunities for the two countries' complementary contributions were discussed. The cooperation prospects of petroleum industry's overseas expansion were described.

The spontaneous combustion of iron sulfides in sour oil tanks is thought to be the main reason to cause fire and explosion accidents in oil tanks. Sulfur hydrogen dissolving in water to form hydro-sulfuric acid reacts with iron to give iron sulfides. The gas of sulfur hydrogen was continuously passed through the water, at a flow rate of 300 mL/min for 6 h, in trigonal beaker contained 8 g iron powder to produce the iron sulfide samples at 25, 50 and 75 ℃ respectively. The deposit was filtered and dried. The reaction product was analyzed by chemical and XRD analysis. The results show the iron sulfide in reaction product is FeS. Air passed through the dry and moist reaction product at a flow rate of 300 mL/min respectively. The experimental results show that all the reaction products are of high spontaneous combustion nature. When sulfuration temperature is increased, the sulfuration reaction rate rose and the spontaneous combustion nature of reaction product are also raised.