Metallic glasses were potentially industrial materials due to their excellent properties, such as high specific strength and high corrosion resistance. However, glass-forming ability (GFA) limited their applications greatly. Some key theories and parameters associated with GFA of metallic glasses were reviewed, expecting present new insights and developing bulk metallic glasses.
The calix[4] arene Mannich base was synthesized and characterized by nuclear magnetic resonance. The electrochemical behavior of compound a1（An acidic salt of the calix[4] arene Mannich base (dimethylamine)）and compound b1（An acidic salt of calix[4] arene Mannich base (diethylamine)）was studied by cyclic voltammetry, single potential step time current method, time keeping method and conventional pulse polarography (voltammetry) with CH3COOH—CH3COONa as buffer solution. The result shows that there is an irreversible oxidation peak in a scan potential of -0.5 V to 1.5 V. The oxidation peak potentials are 0.92 V and 0.89 V respectively. The peak current and peak potential of the oxidation peak are linear with the scanning rate. The formation of oxidation peak is controlled by diffusion. The activation energy of the reaction is 11.62 kJ/mol and 13.35 kJ/mol respectively.
With CTAB as template, the β/MCM-41 micro-mesoporous composite molecular sieve has been synthesized by self-assembly of the zeolite structure fragments and the structural units obtained by alkali-treated β zeolite, and the effects of the alkali solution concentration, CTAB dosage in the synthesis process of β/MCM-41 was investigated. The β/MCM-41 composite molecular sieve with well long-range order can be synthesized under the optimum conditions: The solution concentration of NaOH is 1.5 mol/L and the mass fraction of CTAB is 10%. Then the Ce-β/MCM-41 composite molecular sieve doped skeleton with rare earth metal Ce was synthesized and the effect of Ce doping amount (Ce/β=0.03, 0.08) on Ce-β/MCM-41 was investigated. The result shows that the 0.03-Ce-β/MCM-41 had a well long-range order. The effect of acetylation reaction conditions on the yield of p-MOAP was investigated by using 0.03-Ce-β/MCM-41 as a catalyst in a fixed bed. The single-factor experiments showes that the 4.0 h p-MOAP yield is 58.6% under the conditions: The velocity of the reactants flow is 65 mL/h, the LHSV is 6.5 h-1, reaction temperature is 140 ℃ and n(AN)/n(AA)=6.0.
A new type Mannich base was developed by the reaction of binary copolymer AM/C9 synthesized from C9 petroleum fractions with acrylamide as raw materials. The effects of reaction time, reaction temperature, pH of solution and ratio of aldehyde were studied. The apparent viscosity of Mannich was characterized by IR spectroscopy and its structure is characterized. Finally, the performance of the product is analyzed. The results show that the optimum reaction conditions were as follows: The reaction time is 4 h, the reaction temperature is 70 ℃, the pH is 9 and the ratio of dimethylamine to formaldehyde was 1.5. The result of infrared spectrum characterization shows that the product has been synthesized. Synthetic Mannich base has higher viscosity, temperature and salt tolerance compared with traditional HPAM.
The natural gas project supported by CNOOC Ningbo Daxie Petrochemical Co., Ltd. distillate comprehensive utilization project was not synchronized with the start of the project due to external reasons, and there was a risk of lagging behind the start of the project. Starting with the difficulties faced by the start-up process, this study uses propane purchased from outside, self-produced liquefied gas, DCC-produced propane as an alternative medium for natural gas and raw materials for hydrogen production, and adds vehicle propane as the carburetor and LPG tank area to the hydrogen supply process. In the reforming and wax oil hydrogenation installations, 2×5 t/h and 5 t/h liquid hydrocarbon carburetors were added separately to achieve the start of natural gasfree operation, and optimization suggestions were made for the design of the fuel gas pipeline network for refineries.
Photoinduced ATRP is a controlled radical polymerization in the presence of UV/visible light and can be used to synthesize functional polymer materials which can control the molecular structure. The polymerization kinetics was studied by changing illumination time, intensity and frequency of the light source. The amount of transition metal catalyst in photo-induced ATRP polymerization is reduced to less than 100 μg/g, which makes industrial application of controlled free radical technology possible. In this paper, the research progress of direct/indirect light-induced atom transfer radical polymerization (ATRP) is reviewed from the aspects of light source, catalyst, ligand and initiator.
The paper introduces the structure and composition of zeolite molecular sieves, and it elaborates the property of zeolite molecular sieves. In this paper, the performance of the adsorption and diffusion of substances in zeolite molecular sieves is reviewed, and the paper lists the main methods of measuring the performance of molecular sieve's adsorption and diffusion coefficients. It also introduces the adsorption and diffusion of different types of molecular sieves. In the present study, each method of measuring the adsorption performance of zeolite molecular sieves has certain applicable conditions. Due to the difference of measurement mechanism, boundary conditions and assumptions, the diffusion coefficients obtained by different methods are also different. Therefore, the appropriate measurement method will be selected according to the actual experimental situation. As different molecular sieves have different substrates suitable for adsorption, it has different application values.
The MEH-PPV electroluminescent materials were synthesized by the dehalogenation condensation method using potassium t-butoxide as the catalyst and tetrahydrofuran as the solvent. The effects of reaction temperature, reaction time, catalyst, solvent and other conditions were studied in details. The synthesis of MEH-PPV requires no heating and the yield is good when THF as the solvent in room temperature. And no gelation appeared during the reaction. The relative molecular mass of MEH-PPV could be controlled well by adding p-methoxyphenol in the reaction system.
The objective optimization function was set by the summary of the insulation materials' annual sharing cost and the annual heat losing cost after insulation and the calculating model of buried hot oil pipelines' insulation economical thickness was given. The model included the burying depth's influences on around pipelines ambient temperature, the heat transfer coefficient of the outer wall insulation, and the overall heat transfer coefficient. With the help of C# programming language, a computer program was developed to optimize the thickness of insulation layer of buried hot oil pipeline with EXCEL to work out economic evaluation procedures, combining with examples of calculation. The results showed that: The determination of buried hot oil pipeline insulation thickness would have some impact on the economic benefits of the project, and it should take the double requirements into account determining the thickness on both technology and economy. That could provide a theoretical reference to the hot oil transportation construction's optimizing design.
Optimizing the storage and transportation logistics system focus on the optimization of the oil supply chain. It is necessary to take into account the cost of each link in the process of oil logistics, and to formulate the optimization scheme according to the actual needs of the enterprise itself. Based on the related theories of oil storage and logistics, combined with practical production situation of a transfer oil terminal, the existing storage and transportation facilities, such as tanks, cranes and loading systems, are optimized and integrated, and mathematical models are established to optimize the distribution and transportation problems so as to reduce operating costs and bring more economic benefits for the enterprises.
With the rapid development of national economy in our country, the demand of oil and gas, as a representative of the major energy, continued to increase, and the security risks of long distance oil and gas pipelines also caused people's attention. Especially, the pipeline leakage deflagration happened from time to time in recent years, which caused not only great economic losses of the people's lives and property, also caused the ecological environment pollution and destruction. Therefore the leak detection of intelligent and efficient positioning method was applied to oil and it was critical for gas pipelines in a timely manner to prevent secondary disasters. The main cause of pipeline leak was analyzed, several kinds of leak detection methods used on the pipeline at present were summarized, and the method of negative pressure wave and flow balance method was dopt in crude oil pipeline leak detection experiments. The experimental results showed that the method could monitor oil pipeline leak in real time, especially small slow leakage, meanwhile could accurately locate the leak point.
The mixed mode Ⅰ-Ⅱ crack propagation behaviors when KⅠ=KⅡ were studied based on the geometrical modeling for stress singularity boundary multi-direction cracking, the energy release rate and the energy-based driving force of crack side-branching and kinking had been established, and the critical initiation angle or the critical stress intensity factor had also been calculated. The prediction of critical crack kinking angle by the present theory had a good agreement with 2024-T3, and the deviation was estimated to be 8.9% when compared with En3B and Al.
This paper analyzes the problem of lines duplication, overlap and discontinuity in the application of AutoCAD. And it also proposes a method of automatic elimination of duplication, overlap and discontinuity by using the VisualLISP language embedded in AutoCAD system. After the processing, the engineering drawings can avoid linear problems which do not conformity to the requirements of the national standard, and can also avoid the complex work of manually modifying on the complicated lines. The processing of repetition elimination in sheet cutting diagram is possible to extend the life of the laser cutting head and the cutting accuracy of the spare part. After the computer graphics repeating the eliminate processing, it can effectively improve the recognition rate of computer graphics automatic scoring system.
A numerical study was conducted for the research of the fiber coalescence separation flow field.The results show that the pressure field of the fiber coalescence separator shows a slowly decreasing distribution from front to back. The pressure decreases with the increase of thickness. The coalescence pressure drop increases linearly with the increase of flow velocity and thickness. With the increase of porosity, the velocity distribution of the fiber coalescence separator is symmetrical. When the fluid flows into the fiber layer, The maximum velocity occurs in the fiber gap. The distribution of velocity in the fiber gap presents a “M” shape.
The expansion dryer was the critical equipment for the finishing unit of rubber plant. It could take off 90% moisture in the rubber melt. The flow behavior of rubber melts in the channel of the expansion dryer was analyzed by FLUENT. Observing the nephogram of the distribution of rubber melts speeds and stress nephogram, the flow rule of rubber melts in the expansion dryer was analyzed. The following research directions were indicated.
Because there is a large error defect of predicting the severe fluctuating fire data by traditional grey forecasting model, the article expends the original data sequence of grey prediction model using Taylor formula and expends Lagrange type remainder, which modified the traditional grey forecasting model and improved the traditional grey prediction algorithm. The article used Matlab software to program, and used the traditional gray prediction algorithm and improved gray prediction algorithm,respectively.Then the article selected three sets of data to predict aiming at the mini zone bathtub shape fire accident. As the results show that: modified grey forecasting model prediction curve gives satisfactory accuracy comparing to the characteristic of bathtub curve, which has a high consistency with the original data.And the poor quality, large error and low accuracy is improved. Compared with the traditional grey prediction model, the error of the improved grey prediction model has reduced 86.59%, 55.32%, and 55.70%, respectively. The prediction results of the improved grey prediction model can meet the requirements in three aspects: accuracy, relative error and correlation.
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.
In previous image watermarking methods, an encoded host image and a watermark image are usually directly added.Therefore, the two images have cross-talk in the decryption step.In order to eliminate this effect，a new method based on digital holography interferometry is proposed,in which all the image pixels of the two sets of holograms resulted from two hidden images are rearranged and integrated into one set of composite holograms with a random scattering matrix (RSM)．In decryption the use of this matrix can ensure the exact retrieval of each hologram，and then the perfect reconstruction of each image without cross-talk noise can be achieved．In the decryption process, the use of RSM can ensure the accurate recovery of each holographic image, so as to achieve a perfect reconstruction of no crosstalk noise in each image. The computer simulation is performed using phase-shift interference and double random phase encoding techniques to verify the feasibility of the method , its robustness to occlusion and additional noise.this method is suitable for 2D and 3D images, and the additional RSM can also provide a higher level of security as a key.
