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Two kinds of Cf/Mullite composites are prepared using S-sol and T-sol through PIP method in the paper. Properties of mechanical and microstructure are studied. The results show that the density of Cf/Mullite composites prepared by S-sol is 1.78 g·cm-3, the porosity is 35.04%, the bending strength reached 109.00 Mpa and the fracture toughness was 8.20 Mpa·m1/2. Through the SEM analysis of the Cf/Mullite composites it can be seen that a weak binding interface was formed. The ductile fracture mechanism is presented in the process of stress, and the fiber extraction is obvious.

The matrix of NZP family ceramics is natrium phosphate zirconium (for short, NZP) . NZP family ceramics have the designabolity of thermal expansion coefficient, and the average thermal expansion coefficient can be changed from negative value to positive value by means of composition adjustment, thus obtaining zero thermal expansion ceramics with good thermal shock resistance. With NZP family ceramics the thermal stress can be effectively reduced and the thermal properties of materials can be enhanced.Therefore, NZP family ceramics have become a hot topic in materials science community in recent years.The calcium phosphate zirconium powder was prepared by coprecipitation method, and NZP family ceramics were prepared after pressing molding and pressureless sintering. The results show that the compressive strength of the prepared NZP family ceramics is 199 MPa and the thermal expansion coefficient is-0.5×10-6/°C at sintering temperature of 1100°C.

In this paper, we added inert filler SiC and ZrC powders in an organic precursor solution to prepare Cf/SiC-ZrC composites. The experiments of three different contents of slurry in the process of impregnation and pyrolysis for Cf/SiC-ZrC composites were studied. The microstructure and composition of Cf/SiC-ZrC composites were analyzed by scanning electron microscope (SEM) equipped with EDS. This study shows that the addition of inorganic powders in an organic precursor solution can shorten the period of preparation of the composite material and improve its strength. When the mass fraction of the inert filler is 15% in an organic precursor solution, the density of the composite material can be increased to 1.9 g·cm-3 rapidly in 8 periods of preparation. Meanwhile, the internal structure of the prepared composite material becomes more compact, and its mechanical properties are excellent.

Carbon/carbon composite of various density were synthesized via chemical vapor infiltration process, and the sedimentary process of pyrolytic carbon were also researched. The density of the sample increased with the extension of growth time. Density change rate of the samples were various at different stages of the growth process, namely pyrolytic carbon of different densities formed at the different stages. It was found that pyrolytic carbon filled the pores of carbon fiber preform, which can help to relieve the interface stress between the fiber and the ceramic substrate. In order to improve the performance of the composite, SiC and ZrC ceramics were introduced into the carbon/carbon composite via polymer infiltration and pyrolysis (PIP) process. The ability of high temperature resistance and oxidation resistance of the composite were strengthened by the PIP process. The bending strength, tensile strength and compressive strength were also increased with the extension of PIP cycle. The C/C-SiC-ZrC composites were obtain through this process, which are useful in various areas.

Great changes have taken place in construction methods of industrial building relative to traditional construction. The cooperation between construction contractors, prefabricated parts suppliers and other materials and equipment suppliers in the supply chain of the industrial building can not be ignored. The evolutionary game theory can be used to explain the dynamic trend of the relationship until it is stable. The evolutionary game theory is applied to study the process and method of cooperative innovation between construction contractor and many subcontractors. Based on evolutionary game theory, the paper discusses the process and method of cooperative innovation between the construction contractors and numerous subcontractors. It focuses on the analysis of the influence of cooperative profit distribution, spillover effect, innovation subsidies and cooperation risk sharing for evolutionary stable strategy. The evolutionary game model of cooperation parties is constructed. The key indexes such as profit, risk loss, distribution of excess income and innovation cost are considered comprehensively. The results show that with the increasing of the spillover effect, innovation cooperation, suppliers’ innovation income and excess returns of cooperation innovation, the system will tend to the stability of cooperation. And with the increasing of the contractor's subsidy coefficient, the innovation cost, cooperation innovation risk cost, the system will tend to uncooperative. There exists an optimal distribution coefficient of excess income, which can strengthen the cooperation willingness of both sides. This study provides a guidance for the cooperative innovation of the supply chain participating parties.

In this paper, using PCS and ZrB2 precursor as raw materials, we prepared Cf/SiC-ZrB2 composites by precursor infiltration and pyrolysis (PIP) process. We studied the solution of different solid content on the influence of porosity and weight gain，and also studied the effect of pressure and other conditions in the process of infiltration. The viscosity of the solution is tested with NDJ-8S digital rotational viscometer. We observed the microstructure of materials through the scanning electron microscope (SEM). The optimum technological parameter was determined by the experiment. The results showed that: a reasonable solution group in relation to the viscosity of the mixed solution，that is the main factor affecting on the performance of the impregnation; The method of vacuum and pressure impregnation can reduce the preparation period and improve material density rapidly. Under the experimental conditions, the best viscosity of the mixed solution is 54.8 mpa•s, the time of vacuum impregnation is 1.5h, and the optimum value of pressure impregnation is 7 MPa.

Silicon carbide possess high performances such as high hardness and strength, oxidation and high temperature resistance, high thermal conductivity and low thermal expansion coefficient. Widely used methods of molding green body for sintered pressureless bonded silicon carbide comprise dry pressing molding and casting molding. The former fails in preparation of complex shapes, while those prepared by casting molding are prone to have defects such as nonuniformity of density and easy cracking. Gel-casting is a net-shape modeling technology caused by the polymerization of organic monomer (acrylamide). The green bodies molded by gel-casting have uniform structure, high density, high strength and machinability. In this study, gel casting molding and pressureless sintering were used to prepare silicon carbide. The effect of the parameters of gel casting and sintering on the microstructure of the obtained silicon carbide was examined

For the problem of the non standard cutter shape cutting edge not smooth transition connection and flank face of cutting tool grinding precision difference, the influence of wheel deformation is analyzed to different grinding linear speed, and the grinding wheel deformation error compensation grinding method is studied in this work. The grinding of annular milling cutter with double-circular-arc is processed in five axis CNC tool grinder. Finally the machining precision of annular milling cutter with double-circular-arc is tested by the tool test center, the result show that the wheel grinding method based on compensation of grinding can realize smooth transition in different parts of cutting edge belt of annular milling cutter with double-circular-arc and flank grinding precision is ensured.

Basedon the present situation of the domestic comprehensive tunneling temporary supporting technology, machine support and temporary support device is researched. This paper is on the basis of the previous design simple optimization.The design enhances temporary support level and improves its ability to support for a long time, in some extent, increases the strength of roof support. The optimization is described in detail.By adding a hydraulic cylinder,it can make each lever own supporting ability and ensure support stability. Organizationstructure and three dimensional graphics are drawn in the paper.The force analysis is carried. Finally appropriate position is determined.

C/C composites have excellent properties, but it will be rapidly oxidized when temperature is above 500 °C, which limits its applications in high temperature environment. In order to improve Anti-oxidation, using CVD method, a SiC coating is prepared on the surface of C/C composites. We have studied the microstructure of the SiC coating, oxidation resistance and high temperature mechanical properties. The results show that SiC coating has excellent oxidation resistance. When coated sample is oxidized at 1500 °C after 50 hours, its oxidation weight loss rate is only 1.45%, and coated samples can still maintain high mechanical properties at 1200 °C.

Cf/SiC composite are widely used in aerospace, chemical industry, traffic, and many other fields because of good mechanical properties, heat resistance, thermal shock resistance and abrasion resistance, corrosion resistance, etc. But its oxidation resistance is poor in the application of high temperature environment. In this paper, high-temperature ceramic coating was prepared on Cf/SiC composites surface through brush painting method and the oxidation resistance of the coating were studied. The coating was tested by XRD, SEM, etc. The results showed that the coating and composite matrix is good combination, at the same time the coating has good oxidation resistance.

The engineering contracting enterprises have the following development obstacles including the lower profit level, malignant competition intensified, the lower financing level and the sole industrial structure. Along with the stern challenge of the climatic change in the whole world, the enterprise must apply the low-carbon thinking to reconstruct operation mode. They should use the diversification strategy to widen the enterprise’s competition channel, strengthen the research and development of low-carbon technology to promote the competition level and apply the measures of the high-quality personnel training and the technical science and technology to impetus the management mechanism innovation. These measures provide the highly effective realization path for the enterprise’s sustainable development.

At present, China is in a critical period of energy restructuring. Renewable energy industry bear to ensure national energy security and achieve the historic task of energy for sustainable development. To speed up technological innovation of renewable energy industry has been a priority. Conducting systematic research of renewable energy technologies selected, not only can grasp the advantages of renewable energy resources, a clear direction of development of industrial technology, but also to enrich and improve the industrial technology innovation management theory and methods to make a positive contribution. This paper established a renewable three-dimensional evaluation model of industrial technology development (technology needs dimension, technology dimension and the supply of integrated environmental dimensions) ,and took Beijing as an example to calculate the Beijing photovoltaic, wind power, biomass and small hydro renewable energy generation technology evaluation results.

Based on the depth analysis of the related literature and the present situation of energy consumption of Beijing’s carbon emissions, through the MATLAB programming on the Lagrange interpolation algorithm, the paper predicts the carbon emissions from energy consumption in Beijing’s economic growth. According to the relevant historical and predicted data, the paper examines the process of Carbon Emission Trend of energy consumption in Beijing. The results show that: Beijing carbon emissions showed "Y=X3" type growth. Combining the current situation, the paper analyzes the results, and finally provides decision support to the government, to promote the relationship between economic growth and energy consumption of carbon emissions in Beijing city into the inverted "U" trend.

The objective of this study is employing acoustic coagulation to induce agglomeration of fine and ultrafine particles after wet flue gas desulfurization (WFGD) and analyzing its effectiveness and characteristic based on numerical simulation. Matters such as calcium sulfate and calcium sulfite in WFGD can form very fine particles. Smoluchoski’s equation is employed as the simulating model. Orthokinetic coagulation, hydrodynamic coagulation and Brownian coagulation are taken into account to form the agglomeration kernel. An improved sectional arithmetic is introduced to achieve sectional size adjusting automatically according to the mass concentration of particles, so that section size is fine where the mass concentration is large to guarantee computational accuracy, but coarse where the mass concentration is small to save computation time. Besides, mass conservation rate is introduced to estimate the calculation error in the compute of mass concentration. Simulation results show that the overall number concentration decreased more than 40% after acoustic wave acting on the flue gas for 2 second; Increasing sound intensity level (SIL) is more effective to coagulation than increasing frequency; There exists an optimal acoustic wave frequency within 1500~2000Hz; Coarse particles are more sensitive to acoustic wave frequency than fine particles.

Cf/SiC composites were fabricated by chemical vapor infiltration with CH3SiCl3 as precursor and H2 as carrier gas. The carbon preform was noodled by continuous carbon fiber and network tires layer. The screws were processed with Cf/SiC composites by diamond tool. The mechanical properties of screws were studied in this paper. Results show that the tensile and double shear strength reach separately 128.15 Mpa and 58Mpa. The microstructure of fracture surfaces from tensile and shear test were analysized.

Cf/SiC-ZrB2 composites were fabricated by chemical vapor infiltration and precursor infiltration pyrolysis. Specimens were then tested for mechanical properties , thermo-physical properties and microstructure. Results show flexural strength, tensile strength and compressive strength reach 430MPa,120 MPa and 365 Mpa, respectively. The mechanical properties at high temperature were tested. And the fractograph and microstructure of composites were analysized.

A new aroylhydrazone compound of 4-hydroxybenzaldehyde benzoyl hydrazone was synthesized through the condensation of 4-hydroxybenzaldehyde and benzoyl hydrazine. The crystal structure was determined by single-crystal X-ray diffraction. It crystallizes in the orthorhombic system, space group Pbca with a=1.5514(3) nm, b=0.9318(16) nm, c=2.2921(4)nm, β=90.00o, Z=8, V=3.3137(10)nm3. Its crystal structure was determined and refined to a final R=0.0567 for 2725 independent reflections. The intermolecular hydrogen bonding interactions, C-O...N and O-H...O-C, connect the molecules into a layered network structure. The compound showed broad spectrum activity against S. aureus, E. Coli and P. Aeruginosa. The compound has the higher activity for Escherichia coli.

Electro-hydraulic control system of hydraulic support in addition to being able to control the basic movements of hydraulic support, also can work for signal acquisition of mining environment, including pressure of column pressure, displacement of push lutetium and pull support etc. The electro-hydraulic control system is presented in this paper, on the basis of the original control function added signal acquisition module, and designed the hardware and software.

As economic globalization and information technology integration, it brings a great deal of changes and challenges to enterprise business and management. This research is aimed at establish a reasonable configurations among schedule, cost and quality of power construction projects in China and draw up a standardization process to enterprise management. According to a detailed joint analysis of the process efficiency and resource matching condition with Date Envelopment Analysis (DEA) method, we formulate two models including CCR and BBC. Then we select 12 power construction projects as samples, give a data verification, and find a correlation among schedule, cost, quality and project achievement. At the end of paper, we give an objective evaluation to it, and analysis the shortcomings and insufficiency of this research.

The performance of a dual and multi-stage treatment system which was made up of two-stage whole stillage anaerobic fermentation (WSAF), an internal circulation reactor (IC), an anoxic/aerobic reactor (A/O) and a biological aerated filter (BAF), was investigated for the treatment of complex chemical wastewater with an influent chemical oxygen demand (COD) concentration of 700-55,000 mg/L. According to different wastewater sources and qualities, different types of wastewater were inputted into the treatment system. More than 95% of CODCr and suspended substance (SS) could be removed by anaerobic treatment. Approximately 4% of CODCr and SS could be removed during the phases of A/O and BAF. The highest values of CODCr, BOD5, NH3-N and SS in the treated effluent were 87.0, 19.7, 14.5 and 38.0 mg/L, respectively.

In recent years, internal control system aroused wide attention from scholars at home and abroad and company's internal control is the core issue of Enterprise management. Mainly from the ERP and internal control theory perspective, this paper explored to melt ERP ideas into the company's internal control system and internal control systems were evaluated both from the qualitative and quantitative ways. The author analyzed the weight and evaluation value of index with AHP and fuzzy comprehensive evaluation method to explain the result of the internal control system of power supply enterprise after implementing ERP system.

At present, the bud type rings are widely used in the hydraulic cylinder piston rod seal, but there is no corresponding detection method to measure the contact stress when the seals are in the dynamic sealing condition. However, the contact stress is very important for analyzing the performance of the seals. A method for measuring the contact stress is presented in this paper, and the design of major parts of the test cylinder and the selection of seals are emphatically introduced.

A new performance test system is presented in this paper, as we all known, hydraulic support is the most important equipment in mechanized coal mining. Electric hydraulic valve, as the key components, consist of electromagnetic pilot valve and mechanical valve bodies. When electromagnetic pilot valve hasnt enough driving force, precursor core wont work normally. The test stand can measure relationship between displacement and force of electromagnetic pilot valve. First of all, electric hydraulic valve is introduced simply, then detailed designing process. The test Bench includes measurement and control system, as well as working theory.

The power system is facing line losses, low voltage level and some other issues, this article begin with the point of the reactive power optimization, and through with the improved PSO algorithm, we find a way to reduce the line network loss.

Pyrolysis of sewage sludge for the fixed bed were investigated at different final temperatures (300-900 °C) to acquire distribution and characteristics of pyrolysis products. The mass balance was established on base of continuous on-line measurement of gases and integration of gas compounds to give a more accurate reflection on the yields distribution. It was observed that at low temperatures the liquid was the main product with maximum yield of 57 wt%(daf) at 500°C and the gas composition was mainly CO2. Under the condition of a higher pyrolysis temperature (above 600°C), secondary reaction occurred among phase of solid, liquid and gas and generated more CO and H2. From the perspective of energy utilization and accumulation of heavy metals, a lower temperature no more than 600°C is suitable for sewage sludge pyrolysis.

With the growing tension of the energy resources, energy risk has become the core of common concern. In this paper, the definition and the cause of energy risk analysis, combined with the analytic hierarchy process (AHP) construct the comprehensive risk-based energy industry index system. According to the viewpoint of information theory, the entropy method to calculate the objective factors, to measure the information content of the Beijing Energy Risk indicators inexact. By visual comparison of each indicator entropy, research the impact of various indicators of system.

The bidding decision-making of power plant was a complicated system engineering which had high complexity and real-time, so power plant must rely on the support of information technology to complete the bidding. Therefore, how to use all kinds of advanced information technologies had become one of topics which broad power enterprises must face. This paper established a kind of intelligent decision support system (IDSS) which was based on multi-agent intelligent decision support system and combined with the data warehouse, data mining and on-line analysis processing. Compared with the former information management, IDSS had so many advantages in auxiliary support for decision-making. If it was applied to power plant bidding strategies or other semi-structural and unstructured problems in power market, it would provide good auxiliary support for them.

Vehicle routing problem (VRP) is a kind of NP combination problem. In order to overcome PSOs premature convergence, a Cloud Particle Swarm Optimization (CPSO) is put forward, it uses the randomicity and stable tendentiousness characteristics of cloud model, adopts different inertia weight generating methods in different groups, the searching ability of the algorithm in local and overall situation is balanced effectively. In the paper, the algorithm is used to solve VRP, a kind of new particles coding method is established and the solution algorithm is developed. The simulation results prove that the algorithm has more search speed and stronger optimization ability than GA and the PSO algorithm.

As the development of Internet, E-commerce gradually becomes a new form of business activities; the security of the traditional cryptographic technique application method is under threat too. Not only domestic scholars but also foreign scholars are all devoting themselves to study the solutions faced to business application. Using cryptographic technique with E-commerce to the application of cryptographic technique and the development of E-commerce is very important to practical significance. This paper studied the security problems of e-commerce transactions and analyzed solutions combining the password techniques from the technology angle; moreover aimed at characteristics of E-commerce and the existing problems. The paper uses digital signature technology integration and digital signature design method to put forward the digital signature which is new and original. The E-commerce applies the digital signature to solve security work.

In web2.0 era, tag marks that users have become from passive consumers into active information creators. Users can create and use any tags which represent their will freely on the Internet; they can also share all kinds of tags which other users have created. At the same time, personalized information recommendation can solve the problem of the flood of information, so how to conduct personalized information recommendation based on tags has become the focus of many scholars. This paper summarized three categories about the information recommendation model based on tags: Graph theory- based model, Tensor-based model and Topic-based model, then the author put forward the defects of the existing model and the problems that need to be solved in the future, such as how to reduce noise, how to use social network analysis method to study social tag system and so on.

With the construction of smart grid, an increasing number of resources of smart grid knowledge base inevitably lead to the information island of power system and low utilization ratio of power system knowledge. Introduced the ontology for knowledge representation of Smart Grid domain and constructed a repository to be shared by each application software system. It can enhance the power system simulation and analysis capabilities of the complex state of the Smart Grid. At present, Smart Grid lacks of researches on knowledge applications based on ontology technology. This paper introduces some typical applications based on ontology, elaborates the application status of the ontology in power system. According to the ontology technology applied to typical domains, it looks forward to the direction of ontology-based applications in power system.

In order to improve the knock diagnosis accuracy, knock tests were carried out on a gasoline engine, and the slight knock characteristics from vibration signals of the gasoline engine were extracted by wavelet transform method. Making use of sub-band signals which were generated by wavelet transform of vibration signals as the style signals, 23 time-domain parameters were studied by using rough set theory, and the redundant relationship of the various parameters for describing the knock characteristic was revealed. Finally, the best parameters combination of peak-to-peak value, mean amplitude and mean value was put forward as the knock indicators. The result shows that the indicators obtained by rough set theory can diagnose slight knock combustion, and the diagnostic accuracy is better than single indicator determination knock method.

The melting point of zirconium diboride is up to 3245 ° C. It is concerned widespread as a high-temperature structural materials because of high melting point, high hardness, excellent electrical conductivity and good thermal conductivity. In this paper zirconium diboride powder was prepared by the carbothermic reduction and precursor pyrolysis. XRD, SEM and DTA were used to characterize the performance of the two powders. Results show that the median diameter of zirconium diboride powder prepared by solid phase is about 6μm, round in shape, is not conducive to the sintering. Zirconium diboride powder prepared by precursor pyrolysis is massive, which is deposited by the layers of zirconium diboride crystals.

Vehicle emissions and their control (VEC) is an important course for majors about automobiles, such as vehicle engineering, Automobile Service Engineering and thermal energy and power engineering. In order to meet the development of automobile technology and culture the corresponding talents, the teaching method should be reformed and innovated. In this paper, the difficulties in VEC course teaching were summarized and analyzed, and the countermeasures and suggestions were put forward. The course content was redesigned and the laboratory experiment was re-arranged. The innovation training program of students was put forward. Some pedagogical techniques and evaluation methods for VEC course were proposed.

With the widespread use of information systems, traditional manual audit approach cannot adapt to the quick development of information technologies. It has drawbacks of high cost, inefficiency, big risk, poor quality, etc. Computer-assisted audit and its applications are studied in this paper. Firstly, comparative analysis between traditional manual audit and computer-assisted audit is conducted. Then the flow of data-oriented computer-assisted audit is presented and the implementation steps are detailed. Finally, the applications of computer-assisted audit are discussed in four practical audit cases of information systems, i.e. hospital information system, electrical police management system, local taxation management information system and medical insurance fund management information system. And the corresponding audit results are given. The practical audit cases show that computer-assisted audit can expand the audit scope and perform deeper data analysis, thus cutting down the cost and risk of audit while improving efficiency and quality of audit. Therefore, it can effectively help auditors to perform information systems audit.

Nitrogen-doped mesoporous carbon materials have been synthesized by using melamine-formaldehyde resin as carbon precursor and SBA-15 as a removable template. The structure of the materials was investigated by X-ray diffraction, BET specific surface area analysis, Fourier transform infrared spectroscopy, and thermogravimetric analysis. X-ray and BET studies confirmed that a pore nanostructure is inherited from the silica templates. Fourier transform infrared spectroscopy analysis showed N atoms are strongly bonded in the carbon structure in heterocycles or nitrile functions. These mesoporous nitrogen-doped carbon materials exhibits textural properties with BET surface areas ranging between 400 and 600 m2/g and uniform pore size(3.9 nm). The mechanism of carbonization process is studied by thermogravimetric analysis. The ratio of melamine/formaldehyde plays an important role during the carbonization process for the surface areas and textural properties, and element analysis reveals that the nitrogen content of the mesoporous carbon materials is as high as 10wt%.

Large-sized, crack-free silica monoliths have been fabricated by a fast and convenient way via EISA method using P123 as soft template and 1-hexadecyl-3-methylimidazolium bromide (［C16mim］Br) as additive. The hydrogen bonds formed between ILs and the silano groups of silica gel play crucial roles in the form of the bulk, transparent silica monolith. The mesoporous structure onion-like carbon monoliths were prepared with the transparent silica monolith as template via the nanocasting technique. The mesoporous silica and carbon monoliths have been characterized by the XRD, HRTEM, N2sorption and elemental analysis. The results reveal that pore diameter of the mesoporous carbon about 3.47nm, and the specific surface area of carbon with a nitrogen content of 4.2%, can be tuned from 408.2-629.0m2/g. HRTEM shows that this carbon material with nanoonions structure.

ZrB2-20%volSiC ceramic composites with different volume of BN short fiber were fabricated by the hot-pressing sintering under 2000°C. The content of BN short fiber changed from 0 to 15vol%. The density, flexural strength, fracture toughness and thermal expansions coefficient were studied. The microstructures of the samples were observed by scanning electron microscopy. The results show that the introducing of BN short fiber into the ZrB2-20%volSiC lead to a serious of change to the mechanical properties of the ceramic. When the content of the BN short fiber is 10vol%, the flexural strength and fracture toughness reach 422.1MPa and 6.15 MPa•m 1/2 respectively. And the mechanism of the increasing toughness was studied.

The ZrB2-SiC composite ceramic was prepared using Al2O3 and Y2O3 as additives through pressureless sintering under 1800°C. The electrical and mechanical properties were studied with the different mass ratio of ZrB2 and SiC. The microstructure and phase transformation of the ZrB2-SiC composites ceramic were characterized by scanning electron microscopy. Results show that the densities of the samples are decreased with the decrease of the mass ratio of ZrB2 and SiC while the resistivities are increased. When the mass ratio of ZrB2 and SiC is 4 the resistivity reaches 14μΩ•mm while the density is 4.85g/cm3. When the mass ratio of ZrB2 and SiC is13:7, the flexural strength reaches the max value and toughness reaches the minimum value. The flexural strength reaches 233Mpa and the toughness reaches 4.51 Mpa• m 1/2. The changes of the properties of the ceramic were analyzed through the microstructure and the conduction mechanism was studied.

The hydrophobic aerogel heating-insulating composite ceramic was fabricated in the way of constant pressure. The properties of the ceramic were attributed through FT-IR and energy spectrum. The microstructure and phase transformation of the insulation composites ceramic was characterized by scanning electron microscopy. The results show that after compositing with aerogel the coefficient of heat conductivity of the heat-insulating ceramic decreases forty-sixty percent and the compressive strength increases a hundred percent. There is little change to the tensile-strength. The holes of the ceramic are full of aero gel particles whose grain size is ten-twenty μm and the distribution of pore size is ten-seventy nm. After heating at 400°C for 12 minutes by quartz lamp on the surface of the ceramic which the thick of it is 8mm, the temperature of the other side increases 10°C .When the thick of the ceramic is 16mm, the temperature of the other side remains unchanged. The ceramic has excellent heating-insulting property.

It is difficult to detect critical knock for a gasoline engine by the common method of knock diagnosis. In this paper, a new approach is presented to detect critical knock for gasoline engines. Based on this approach knock diagnosis consists of four steps. Firstly, discrete wavelet transform (DWT) is chosen as a pre-processor for a neural network to extract knock characteristic signals; Secondly, four characteristic factors are selected and calculated from knock characteristic signals; Thirdly, degree of memberships of the characteristic factors are calculated as the input and output of the neural network; and finally a RBF(Radial Basis Function) neural network is chosen, trained and applied to detect critical knock. Knock experiments were performed on a gasoline engine, and the application of the presented approach was studied. The results show that the presented method is practicable and can be applied to control the ignition of a gasoline engine working under critical knock which is admitted as an improved state of engine performance.

Brushless Doubly-fed Machine (BDFM) is a new inverter-driven induction motor, and it has broad prospects in wind power generation. This paper analyses the structure and VSCF electricity generating principle of a cascade Brushless Doubly fed Wind Power Generator, deduces the BDFG’s mathematical model, The variable structure control (VSC) was used to the active and reactive power decoupling control of the BDFM, analysis the relation of electromagnetism and energy balance .Finally, simulation and analysis of the whole system and control strategy are carried through in matlab/simulink soft. According to these results, the correct of parameters and simulation model for BDFM is proved.

Polyurethane (PU) with mixed poly(ethylene glycol) / poly(ε-caprolactone) (PEG/PCL) soft segments is a representatively kind of degradable polyurethane material. Polyurethane foams (PUF) with mixed PEG/PCL soft segments were synthesized by using one pot method, and their mechanical and dynamic mechanical properties were investigated. Influences of PEG/PCL weight ratio and molecular weight of soft segments on PUF's mechanical and dynamic mechanical properties were studied. The results showed that: with increasing content of PCL, PUF's tensile strength, elongation at break, stress at certain tensile/compressive strain and storage modulus increased gradually; with increasing molecular weight of soft segment, PUF's elongation at break increased, but tensile strength, stress at certain tensile/compressive strain and storage modulus all decreased accordingly; glass transition temperature (Tg) of PUF with various soft segments decreased according to the following sequence: PEG-400, PCL-210N, PEG-1000 and PTMG1000; loss factor of PUF with PEG/PCL mixed soft segments was higher than that of PUF with individual PEG or PCL soft segments.

ZrB2-SiC and ZrB2-SiC-C ultra-high temperature ceramics (UHTCs) were fabricated by pressureless sintering under an argon atmosphere. The mass and linear ablation rates were tested in an oxyacetylene flame with high velocity. The microstructure and phase transformation of the ZrB2-based UHTCs were characterized by scanning electron microscopy along with energy dispersive spectrometry. Results show that the UHTCs have excellent properties of ablation resistance at ultra-high temperature. The values of mass and linear ablation rates were lower in the ZrB2-SiC UHTCs than those measured for ZrB2-SiC-C. The effect of C addition on the ablation resistant was not obvious but it influenced the microstructure of the ZrB2-SiC UHTCs. And the ablation resistant mechanisms of ZrB2-based UHTCs were discussed according to microstructure analysis.

With AlN, Al2O3 and Al powders as starting materials, ALON powders were prepared by high temperature solid state reaction at 1650°C, 1750°C and 1850°C respectively. Nitrogen gas at 1atm was selected as reaction atmosphere. X-ray diffraction analysis and scanning electron microscope analysis were carried out for the as-prepared ALON powders. In this paper, single-component γ-ALON porous materials were obtained at temperatures below 1800 degree with void ratio more than 75%, which is prone to be grinded to powders less than 1μm and applicable for the preparation of transparent ceramics. Aluminum oxynitride spinel γ-ALON transparent ceramics were successfully obtained with the as-prepared ALON powders. The volume density of the transparent ceramics was 3.67g/cm2, which is 99.3 percent of the theoretical density of γ-ALON materials. The bending strength of the transparent ceramics was 296MPa and the transmittance was about 75% in the wavelength range of 1.2 to 5.3μm.