Editor in chief：朱立光
International standard number：ISSN 1008-1542
Unified domestic issue：CN 13-1225/TS
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2013, 34(1):1-6. DOI: 10.7535/hbkd.2013yx01001
Abstract:By using Avery-Peterson fixed point theorem, the existence of positive solutions of the boundary value problem of impulsive differential equation with sign-changing nonlinearterm was studied.
2013, 34(1):7-14. DOI: 10.7535/hbkd.2013yx01002
Abstract:J．Mawhin coineidence degree theory was used to study two kinds of second order m-point boundary value problems at resonance on infinite interval. By constructing Green function and equipping f with some proper conditions, the existence and uniqueness theorems were established for corresponding boundary value problems.
2013, 34(1):15-17. DOI: 10.7535/hbkd.2013yx01003
Abstract:In this paper, function P(x)=1/(A+Bx)+C is the approximation solution of the ordinary differential equation dy/dx=f(x,y),y(x0)=y0. With the integral applied, a new numerical method of ordinary differential equation is proposed. It is a stable explicit one step method for soving ordinary differential equation. The most impotant thing is that it is stable when the method is applied to the test eqution dy/dx=λy，y(0)=y0(λ<0). The numerical experiments show that the method is effective.
2013, 34(1):18-21. DOI: 10.7535/hbkd.2013yx01004
Abstract:In this paper a two-layer film structure with a resistive film-dielectric layer-total reflection film is provided to completely absorb the incident planely electromagnetic wave by the classical electromagnetic theory. The structure requires that the resistive film and the vacuum wave impedance match, the resistive film's back be lined with lossless media of a quarter wavelength thickness, and the total reflection conductor film should be placed at the bottom of the media. The structure ensures total absorption of the incident electromagnetic wave and can be used for infrared radiometers and stealth materials. The model provides theoretical basis for researching such special functional materials.
2013, 34(1):22-25. DOI: 10.7535/hbkd.2013yx01005
Abstract:There is a relationship between classical physics and special relativity. According to the principle of relativity, Lorentz force formula has the same form in different inertial systems. In this paper Einstein's equation is derived from classical physics without using Lorentz transformation.
2013, 34(1):26-29. DOI: 10.7535/hbkd.2013yx01006
Abstract:Carbon aerogels are prepared by sol-gel process via reaction of resorcinol and formaldehyde with ammonia water as catalyst and afterward ambient drying followed by carbonization. The structure of products is characterized by X-ray diffraction, gas physisorption, scanning electron microscopy and energy spectrum analysis. Results indicte that the carbon aerogels with ammonia as catalyst show a coarser surface, and its specific surface area is about 900 m2/g, presenting continuous granular.
2013, 34(1):30-35. DOI: 10.7535/hbkd.2013yx01007
Abstract:With Artemisia seed polysaccharide powder as raw material, 3-chloro-2-hydroxypropyl-trimethyl ammonium chloride (HAT) as cationic ether and isopropanol as dispersant, cationic Artemisia seed polysaccharide is prepared with catalysis of alkali. Influences of alkalization temperature and time, etherification temperature and time, ratio of alkali to HAT as well as alcohol to distilled water to the final characteristics of cold water solubility and light transmittance of the final product are studied. When the ratio of isopropanol to distilled water is 3.5∶1 and the ratio of NaOH (mol) to cationic ether (mol) is 1.5∶1, the raw material powder is etherified immediately after adding alkali at 60 ℃ for 3.5 h. The result shows that cold water solubility of the product is better than that of the raw material, and light transmission of the product reaches 80%. The structure and thermo stability of the product are characterized by FTIR and DSC.
2013, 34(1):36-39. DOI: 10.7535/hbkd.2013yx01008
Abstract:By means of wet solid phase method，the phase equilibrium relations of Na2SO4-MgSO4-H2O ternary system at 45 ℃ was studied．The dissolution data of ternary system was measured by isothermal solution equilibrium method，and the phase diagram of the ternary system was drawn．The results show that，the ternary system at 45 ℃ phase diagram has five regions．The regions were sodium sulfate pure crystallization region，sodium sulfate and complex salt of bloedite crystallization region，complex salt of bloedite crystallization region，complex salt of bloedite and heptahydrate magnesium sulfate crystallization region，heptahydrate magnesium sulfate crystallization region.
2013, 34(1):40-43. DOI: 10.7535/hbkd.2013yx01009
Abstract:Phnolic wastewater is difficult to handle in coking industry. Lignite Thermal Extraction Residue (LHER) is proposed as adsorbent. The effects of LHER, adsorption time and pH of mimic phenolic solutions on phenol removal are investigated. Results show that the phenol removal can reach 41.85% when 1.0 g LHER is added into the solution at pH 6 for 2 h
2013, 34(1):44-47. DOI: 10.7535/hbkd.2013yx01010
Abstract:An environmental degradable unsaturated polyester amide resin used in putty is synthesized by molten polymerization and the dihydric alcohol is partly replaced by the urea. Its structure is characterized by FT-IR. The effects of the urea's dosage on the mechanical properties of the putty and the hydrolysis property of the resin are studied. The results show that the resin used in putty has preferable combination property and the hydrolysis property is improved when the dihydric alcohol is partly replaced by proper amount of urea.
2013, 34(1):48-53. DOI: 10.7535/hbkd.2013yx01011
Abstract:The germination rate and physiological indices of three cold resistant kernel apricots (Youyi>Baiyubian> Longwangmao) under low temperature stress are studied. And the relationships between these physiological indices and cold resistance of kernel apricots are also analyzed. The results show that the germination rate decreases as the temperature decreases, while the rate of electrolyte leakage, the amounts of soluble sugar and proline and the activity of SOD and POD increase. The results of significant analysis to cold resistant comparison among various kernel apricots show that the rate of electrolyte leakage in branch, the amounts of soluble sugar and proline in epidermis, the activity of POD in xylem and epiderm can be used to assess the cold resistance of kernel apricot except for the activity of SOD. The result of principal component analysis shows that it is reliable to comprehensively evaluate the cold resistance of kernel apricot by using these physiological indices.
2013, 34(1):54-59. DOI: 10.7535/hbkd.2013yx01012
Abstract:Two models of regression equation (RE) and artificial neural network (ANN) are established by analyzing the relationship between the dipine drugs' molecular structure and melting points and compiling the MATLAB program. Selecting 14 dipine drugs as the modeling samples of RE and ANN methods and other 4 dipine drugs for verification, the two models are compared. And results show that the ANN model is more accurate in forecasting the drugs' melting point than the RE method.
2013, 34(1):60-66. DOI: 10.7535/hbkd.2013yx01013
Abstract:The operating process of complex equipment has strong non-linearity, and it is often affected by some unknown factors, bringing much non linear and non gaussion monitoring data, and the calculation time grows up like exponential form as calculated amount increases. If these data are used directly for equipment residual life prediction, it is hard to complete model parameters' estimation and realize equipment's online maintenance. Aiming at settling the above problems, especially for the blindness of kernel function parameters selection in kernel independent component analysis, the kernel function parameters are optimized by particle swarm optimization arithmetic to reduce feature dimension. Finally, the oil monitoring data of self propelled gun engine is used for dimension reduction. Testing results show the feasibility and effects of the proposed method.
2013, 34(1):67-74. DOI: 10.7535/hbkd.2013yx01014
Abstract:Based on DC flow algorithm， the key correlation factors for cascading successive failures are analyzed. Furthermore， with the probability model of hidden failure of relay considered，the sensitive behaviors in cascading successive failures are analyzed, and effects of the key correlation factors on the sensitive behaviors are analyzed. Then，based on the key correlation factors and the sensitive indexes，and from the view of subjecting and actuating，the basic structure and algorithm for distinguishing sensitive areas in power network under the condition of cascading successive failures are proposed. Some examples with IEEE 39 bus test system show the rationality of the algorithm.
2013, 34(1):75-78. DOI: 10.7535/hbkd.2013yx01015
Abstract:SLX-80 cryogenic treatment system is used for cryogenic treatment of 9Cr5MoV steel, and room temperature magnetization of samples is performed in vibrating sample magnetometer option of physics property measurement system (PPMS-VSM). The contents of retained austenite in the samples quenched at 930 ℃, then cryogenic treated at -80 ℃ and -120 ℃ are respectively 13.5%, 11.7% and 10.1%. Compared with cryogenic treatment at -80 ℃, deep cryogenic treatment at -120 ℃ is more effective to reduce the retained austenite in the steel. The maximum hardness of the steel quenched at 950 ℃ is measured to be 65 HRC, while further deep cryogenic treatment at -120 ℃ improves the hardness of steel to 66 HRC. After quenching at 950 ℃ and tempering at 140 ℃, the deep cryogenic treatment at -120 ℃ may enhance the hardness of steel approximately by 1 HRC.
2013, 34(1):79-85. DOI: 10.7535/hbkd.2013yx01016
Abstract:Elemental strain mode difference combined with RBF neural network is proposed to detect the damage of space truss structures. Finite element models of square pyramid space truss and honeycomb shaped triangular pyramid space truss were established. With elemental strain mode difference as criterion, the damage locations of single pole or multi-poles were determined. The damage degrees of the structures were investigated by using RBF neural network. The results show that this method can be used to detect the damage locations and damage degrees of space truss structures。
2013, 34(1):86-90. DOI: 10.7535/hbkd.2013yx01017
Abstract:On the basis of the ratio of electricity consumption to transferred heat quantity (EHR), combined with primary energy consumption rate and propagated in the national building energy efficiency design standard, the index of primary energy consumption ratio of heating supplied (PEHR) is established. According to the requirements of PEHR control index of the absorption heat pump district heating system, the maximum heating range is obtained. The lower limit heating coefficient of the heat pump unit expression is deduced when the absorption heat pump district heating system is more energy-saving than traditional boiler heating system. The results show that when the coefficient of the absorption heat pump is certain, the greater the PEHR control value, the more extensive the reasonable heating range; the larger the area value, the smaller the reasonable heating range. The lower limit of heating coefficient of the absorption heat pump not only increases with the improvement of the thermal efficiency of the boiler, but increases with the increase in the scope of the district heating range. Therefore the smallscale absorption heat pump district heating system is benefit for energy-saving