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.
A mass proportion paraffin and microcrystalline wax was adopted as raw material, and under certain conditions catalyzed oxidation reaction took place, a sample which qualify and performance similar to that of natural carnauba wax was obtained. By using oxidation wax as experimental material and water as solvent, under the surfactants’action, after the reaction of emulsification, polishing and decontaminating wax for leather was prepared. Then some factor's effects on stability of emulsifying wax, such as emulsifier type, quantity, stirring speed, emulsifying time and emulsifying temperature were discussed. The results show that when the dosage of oxidation wax: the mass fraction of auxiliary,emulsifier and emulsifier is 1∶0.3∶0.000 2, emulsifying time is 20 min, stirring speed is 500～1 000 r/min, emulsifying temperature is 85～90 ℃, the wax for leather whose feature is well-distributed, well function and low cost which compared with the natural carnauba wax is obtained.
The two-dimensional nonisothermal injection filling process of Polypropene melt was simulated using Polyflow software. The distributions of velocity, pressure, temperature and shear rate for polypropene melt in injection filling in the mould cavity were analyzed. Results show that changes of every physical variable in injection filling in the mould cavity are even. The temperature of the flow front is higher and the pressure is the least. The melt average pressure and temperature at different time were also analyzed. The melt average pressure increases while the melt average temperature decreases with the time. The effect of different injection temperatures to the flow fields of melt in the mould cavity was studied. The higher injection temperature can increase the melt average temperature and decrease the average pressure, which can decrease the viscosity and improve the flow. Numerical results are of great significance for injection machine mold design and injection molding processing parameter selection.
The sulfides in catalytic cracking gasoline of No.2 oil refinery of Funshun were oxidized effectively with hydrogen peroxide in the presence of formic acid was investigated. The volumic fraction of oxidant, volumic ratio of formic acid and hydrogen peroxide, reaction temperature and reaction time was investigated. The optimal reaction conditions are that volumic fraction of oxidant is 6%，volumic ratio of formic acid and hydrogen peroxide is 3.5∶1，reaction temperature is 45 ℃ and reaction time is 60 min. Under the optimal tconditions, desulfurization rate of catalytic cracking gasoline is 76.4%.
The acylation of tert-butanol with acetic anhydride was studied by using polyaniline doped with iodine as catalysts. The effects of reaction temperature, time, the mass fraction of catalysts and molar ratio of acetic anhydride to tert-butanol on the yields of tert-butyl acetate were investigated. The experiment results shows that polyaniline doped with iodine has a good catalytic activity. The optimum reaction conditions for this reaction are a molar ratio of 1∶1 of acetic anhydride to tert-butanol, the mass fraction of polyaniline doped with iodine 7.0%, 55 ℃ for 6 h. At this time, the yield of tert-butyl acetate is 87.6%. The product is colorless and transparent and characterized by IR.
Catalytic oxidation is a non-HDS technology to remove sulfur compounds from diesel fuel. On the basis of catalytic oxidation and solvent extraction, ultrasound irradiation was introduced to provide energy for the reaction， which developed a completely new diesel oil oxidative desulfurization technology. The sulfides in Liaohe straight-run diesel fuel had been oxidized to sulfones with H2O2-formic acid as oxidant system was used in the process, the effects of reaction temperature, time and volumic ratio of oxidant and oil were investigated. The results show：under the condition of an ultrasonic frequency of 28 kHz|ultrasonic power of 200 W|the volumic ratio of H2O2 to formic acid 1∶1|extraction solvents N, N-dimethylformamide (DMF)|an extraction time of 10 min and the volumic ratio of extraction solvent to oil is 1∶2, its proper conditions are as follows: volumic ratio of oxidant to oil is 1∶10|reaction temperature is 50 ℃|oxidation time is 10 min|the rate of desulfurization is 87.8%.
The catalytic performance of self- developed non-hydrogen-dewaxing catalyst (FC-DB) was evaluated, and the hydrocracking tail oil was used as feed stock. The influence of reaction temperature and space velocity on the yield and pouring point of base oil was investigated. The relationships between yield, pouring point and operation conditions were determined by polynary quadratic regression, and the optimum operation conditions were determined by non-linear programming. The reaction temperature is 400 ℃ and space velocity is 1.2 h-1. At this time, the yield and pouring point of base oil respectively are 92.53% and -20 ℃, approximately dropping 53 ℃. The qualify of base oil obtained under above optimum operation conditions was analyzed, and the base oil can be used as premium lubricant base oil because of its high viscosity index, low pouring point, acidity and residue carbon.
The decomposition of micro crystallite cellulose was investigated by hydrothermal reaction in tube batch reactor. The effect of temperature, time, and oxidant on the TOC and reducing sugar were researched. The results indicate that the TOC and the yield of reducing sugar increase with increasing temperature. The TOC and the yield of reducing sugar increase at first and then declined with the increasing time and hydrogen peroxide. The organic acid, including formic acid, acetic acid, lactic acid, oxalic acid, propenoic acid, propionic acid, malonic acid, maleic acid, succinic acid, were obtained by hydrothermal decomposition. At the same time, dihydroxyacetone, pyruvaldehyde and 5-hydroxymethyl-2-furaldehyde were also produced. The HPLC analysis show that the intermediate product and the unstable organic acid are oxidized finally into formic acid and acetic acid.
The naphthalene phase spectrophotometer was used to determinate the micro aluminum in polypropylene resin samples with Chrome azurol S(CAS) as chromatogenic agent. Then the experimental conditions were carefully investigated by adding masking agent CyDTA-Mn with masked ions. The results indicate that when CAS, emulsifier OP, CTMBA and buffer solution, Al(Ⅲ) react with CAS, the complex compound form, which has maximum absorption wavelength at 680 nm. The reaction finished instantly, then kept 8.5 h. Under the optimum conditions, the linearity range of Al is 0～9.3 μg, the linearity coefficient is 0.999 2 and the apparent molar absorption coefficient is 8.98×104 L/(mol•cm). The polypropylene resin was analyzed. The average recovery rate of the artificial synthetic sample is 96.94%, the average recovery rate is 89.32%～102.70%, and the analytical result RSD is 2.63% .
It was introduced that the influence and mechanics of anti-welding procedure on corrosion resistance of the different materials such as Q235 steel,16MnR steel and 20g steel in the acidic and alkali solutions. This method is to carry on the heat treatment for each kind of material sample, and use the cooling medium to cool the welding joint rapidly, in order to obtain the negative temperature departure that is opposite to the welding temperature field，and relieve the residual stresses produced in the welding process. Q235 steel and 16MnR steel which are processed by 350℃ anti-welding procedure, compared with the unprocessed samples, the corrosion rate in the acidic solution reduces 66.1％and 67.9% respectively. The results show that the anti-welding procedure relieves effectively the welding line residual stresses and slows up the stress corrosion rate. This method can be applied to the welding structures which are required to prevent the stress corrosion.
Using finite element method, nonlinear stress, such as contact borderline and large deformation of C seal ring in high-pressure quickly opening blind plate, was analyzed. Through modeling and analyzing computing with ANSYS, contact deformation, contact stress and its distribution characteristics were obtained. And also, distribution law of contact pressure between seal ring and barrel of blind plate, and relationship between distribution and medium were gained. Furthermore, seal ability of C compound structure’s servo seal ring was effectively analyzed.
The test piece which was made from metal material such as 16MnR, Q235 and 20g was processed using anti-welding-heating treatment. The stress and fatigue was tested for the processed piece. Through the data analysis, it was obtained that anti-welding-heating treatment is a kind of effective technology about adjusting the welding residual stress, which can decrease the welding residual tensile stress of the metal material. If the difference in temperature is big enough, a bidirectional compress residual stress layer will be formed on the processed metals surface, which can improve fatigue resistance ability of metal material.
According to the pipes’ vibration phenomenon of the vacuum hermetic closure system in ketone-benzol-dewaxing plant of No.2 Refinery in PetroChina Fushun Petrochemical Company，the researchers used the Bently velocity sensor and the rotatory state test and fault diagnosis CAMD-6100 to detect the vibration of pipelines in vacuum compressor J-6/3, then some important data and conclusions were obtained. It indicates that vibration of equilibrium pipe with more elbows is vigorous and the vibration of the pipe near motivation is much more vigorous. Through simplifying pipeline system, a dynamics pattern of equilibrium pipes was established. The software ANSYS was adopted to analyze system characteristic value, characteristic vector and vibration pattern. It is found that certain-order intrinsic frequency of pipelines is exactly near diploid frequency of motivation, which approves the deduction. In the premise of analyzing vibratory spectrums of pipes and vibration causes, improved measures were taken, such as changing space distribution of the pipelines, adding equipments of vibration reduction and altering system’s stiffness matrix, to alleviate vibration of pipelines. Service life of pipelines is prolonged and product safety is promoted.
A lot of design data are described in the form of curves in engineering design. Solubility curve is one of typical engineering curves and has the characteristics of engineering curves. Solubility curve was taken for an example. Methods of data sampling, data extraction, data sorting and storage of curves were put forward, and recognition of curves was realized during data extraction. Meanwhile, data sampling of curves were fitted by using Cardinal curve. Furthermore, digitizing of engineering curves was performed by using parabolic interpolation.
Given a sequence X={x1,x2,…,xn} with n non-negative numbers and a positive integer k≤n, the linear partition problem requires to partition X into k or less than k subsequences, so as to minimize the maximum sum of elements over all subsequences. The known best algorithm for this problem is a dynamic programming algorithm with time complexity O(kn2) and space complexity O(kn). By using the properties of the non-negative sequence, an improved algorithm with time complexity O(knlogn) and space complexity O(n) was given.
It is required that conventional instrument control system should be rebuilt in the atmospheric-vacuum distillation unit in the petrochemical enterprise. Current situation in communication signal category between all kinds of sensors and input devices in the control room was described. Adapting to development that computer control technique is widely used to automation system of petrochemical enterprises, industrial IT Freelance 2000 DCS was adopted to implement production process’ automation controlling of the atmospheric-vacuum distillation unit. According to practical needs of units and safety and stabilization requests of system, DCS’s software and hardware frame were determined. A configuration control plan, which advanced computer control algorithm was applied to the typical control loop of the unit, was described. Finally, installation request for DCS was given. The system can reduce error and promote control precision.
Struts is a classic framework based on the MVC model, which integrates Java Servlets, Java ServerPages, self-defining tag and message resources into a whole framework. The software thinking of 3G communication of support services based on struts framework was discussed. According to the work principle of struts, the detailed design and implement were completed by using some software such as Windows 2000, SQL Server 2000, Tomcat 5.0 and JDK development environment. The advantages of the struts and website establishment were presented through detailed codes.
A detection method of foamed slag height based on computer vision was put forth. The image of self-made foamed slag in high temperature stove was gathered several times in laboratory，and the digital image was processed by computer. The contour line of foamed dreg was displayed in real-time on CRT monitor in the form of black and white image. According to the calibration tail of contour background，the actual height of foamed slag in stove can be observed directly. Compared with the experimental results of several kinds of traditional edge detection algorithms, it approves that this edge detection method has better immunity and adaptability.
On the basis of the browser/server application environment, uploading varied files and convenient management of upload files has become one of the problems of file management applications. The program of file upload without components was designed by using Java I/O flow. The operation of uploading files includes interfaces of submission, process and management of upload files. Upload files are able to be directly stored in the appointed catalog, and upload files can be managed through database. The implement principle of upload files using Java I/O flow and database management method were discussed. And detailed solutions and implement methods were given.
Genetic algorithm neural networks is a method that uses genetic algorithms to optimize connection right value to replace gradient decrease method. Joining the simulation annealing algorithm in the evolution process of the genetic algorithm, it has the global optimum and local search capability. At the same time, it can not only enhance the rate and efficiency of algorithmic constringency, but also effectively avoid appearing precocity and plunging into local optimum. The method can completely satisfy the accuracy and speed’s requirements of the real-time system. It was studied that genetic algorithm neural networks joining simulation annealing arithmetic operators after reproduction, crossover or mutation, and was compared their performance of optimize in the genetic neural networks.
According to committed XPath Expression (XPE) by users, an XPE access controlling method was presented by using XACT technique. A briefly authorized auto-XPE was directly obtained in XACT, which enhances safety requirements of querying XML document message. Compared with the DOM tree searching method, the XPE access controlling method can greatly decrease the number of the nodes which are accessed by XML document, and promote the authorized searching efficiency of XML document.
In e-commerce times, it is important for an e-commerce website whether it can provide better personality and individuality services for customers. An adaptive recommend framework was presented and accuracy of recommendation was improved through combining some basic recommendation algorithms. Average method and grouping adjustment method were given to solve combination problems of these basic algorithms. The experiment shows that the two methods have well recommend results. The framework can avoid defects of single algorithm, and it is more suitable for recommend application of e-commerce.
The concepts of local (α,β)-diagonally dominant matrix were introduced. Under the condition of local (α,β)-diagonally dominant matrix with a nonzero elements chain, by constructing a positive diagonal matrix [WTHX]X[WTBZ], the conclusion that [WTHX]B=AX[WTBZ] was α-diagonally dominant matrix with a nonzero elements chain was presented, and a criterion for nonsingular [WTHX]H[WTBZ]-matrix was obtained. The outcome implies that the extended local (α,β)-diagonally dominant concept is a development for matrix's diagonally dominance's theory, and a strong tool for researching [WTHX]H[WTBZ]-matrix and [WTHX]M[WTBZ]-matrix.
Let [WTHX]A[WTBX]=(aij)∈Cn×n, [WTBZ]if there exists[WTBX] α[WTBZ]∈（0，1）, which can make[WTBX] |aiiajj|≥（RiRj）α（SiSj）1-α[WTBZ] be right for[WTBX] i≠j（i，j∈N={1，2，…，n}）, [WTBZ]then [WTHX]A[WTBZ] is called an α-doubly diagonally dominant matrix. First it is extended the concept to generalized α-doubly diagonally dominant matrix, and obtained a new necessary and sufficient condition for [WTHX]A[WTBZ] to be generalized α-doubly diagonally dominant matrices, improving and generalizing the related results. This result enriches and improves the theory of α-doubly diagonally dominant matrices.
The thesis states the characteristics of the provincial foundation and analyzes the characteristics of current evaluating model of achievements and effects of provincial science and technology foundation (PSTF for short). It probed the feasibility of evaluating the entire process from the study of the PSTF items to its application and some related influential aspects and analyzed the connotation. The creation of PSTF evaluating system structure of the entire process promote popularize science and standardization of the evaluating system of achievements and effects of local science and technology foundation items. It provides a scientific foundation to the government to make strategic decisions.
Taking 48 Chinese IT listed companies as samples, the mutual relationship between capital structure and performance was studied by using correlation analysis and multivariate linear regression analysis methods. It indicates that asset-liability ratio is correlated evidently negatively with profit rate of assets and yield rate of net assets, and long term asset-liability ratio is correlated remarkably positively to profit rate of main business.
It proves that the absolute value and square sequences of GARCH process are pairwise PQD sequences. The pairwise positive quadrant dependent property of GARCH model was discussed. Some inequalities of sums of GARCH modelwhich are consistent with conditional heteroskedasticity property of GARCH process is obtained. It is reasonable that using the GARCH model to describe the volatility cluster phenomenon of finance time sequences.
