2010, 28(2):1-5. DOI: 10.3969/j.issn.2095-6002.2010.02.001
Abstract:Using the fiber of Carboxen/PDMS, influences of sample temperature, adsorption time on the number and amount of volatiles identified from lentinus edodes when analyzed by solid phase microextraction (SPME) and GC-MS were investigated. The preferred SPME conditions found were sampling at 60℃ for 45min in which total of forty-three volatiles were identified. The volatiles of great contribution to lentinus edodes flavor included seven oxygen-containing heterocyclics, nine sulfur-containing compounds, five aldehydes, six alcohols and three ketones, where dimethyl dithioether(4.36%), dimethyl trithioether(13.36%),1,2,4-trithiolane(3.70%),1-octen-3-ol(1.11%) were in high amount.
2010, 28(2):6-9. DOI: 10.3969/j.issn.2095-6002.2010.02.002
Abstract:By measuring the antioxidant of sauce residue polypeptide and its MPRS, under the conditions of different DH, conclusion as follow: with concentration increasing, antioxidant both enhanced; DPPH· clearance was not linear with DH; when DH<14.2%, the·OH clearance decreased with the increase of DH; the changing trend of the deoxidization capacity was different , when DH>12.2%, the deoxidization capacity of the sauce residue polypeptide decreased when the DH increased, DH>8.2%,the deoxidization capacity of MRPS was increased the same as DH; Compared with other polypeptides and MPRS, sauce residue polypeptide and its MPRS had high antioxidant and good appropriate value.
2010, 28(2):10-13. DOI: 10.3969/j.issn.2095-6002.2010.02.003
Abstract:Materials are divided into three groups by different maturity, with or without stems of the winter jujube, using infrared CO2 analyzer mensurate the respiration rate changes in different parts of winter jujube, while the winter jujube were completely coated with Vaseline(with stems and peel coated) and semi-coated(with peel coated) and untreated. The results show that: the respiration rate of untreated winter jujube with or without stems has a slow upward trend as winter jujube’s maturity increased; The respiration rate of the winter jujube with stems is significant (P <0.05) compared with that of the winter jujube without stems; the proportion of respiration rate of stems of with stem winter jujube is about 40%,that of peel is about 60% ,so the main respiration channel of winter jujube with stems is the peel; the proportion of respiration rate of stems of without stems winter jujube is about 75%,that of peel is about 25%, so the main respiration channel of winter jujube without stems is the stem; as the winter jujube stems falling off, the main respiration channel may transferred from peel to stem.
2010, 28(2):14-17. DOI: 10.3969/j.issn.2095-6002.2010.02.004
Abstract:Food security is similar to food safety from literal meaning, but their focuses are dissimilar. The paper discusses their key topics and logic relationship from the perspective of social economic evolution. The issue of food security stems from the situation of food shortage, but rationality of food safety is that there are more and more hazard factors in food. They are both difficult problems that the society has to face during the different development periods. Today, market economy system, agricultural technology, and industrial policy have mitigated the situation of food shortage dramatically, however, the measures of pursuing more output and lower cost may bring negative effect on food quality.
2010, 28(2):18-23. DOI: 10.3969/j.issn.2095-6002.2010.02.005
Abstract:By using BTB medium, a heterotrophic nitrification-aerobic denitrifier was isolated from the laboratory SBR reactor fast and efficiently. The strain, coded as WYLW-X06. It was identified as Bacillus cereus according to the analysis of its morphological and physiological features and Biolog system analysis as well as 16S rDNA sequences. The results show that ammonia nitrogen loss through heterotrophic nitrification in the liquid culture medium inoculated with WYLW-X06 reached 97.18% and the removal rate of TN was 96.63%, N2O production was 1.848987mg, the production of N2O-N accounted for 0.572% of the removal TIN.
2010, 28(2):24-29. DOI: 10.3969/j.issn.2095-6002.2010.02.006
Abstract:Adopts the closed sampling method and thermal desorption-GC-MS analysis, Through testing and researching the VOCs released by the three important urban green grass: ryegrass, Kentucky bluegrass and tall fescues, with reclaimed water and clean water irrigating, we can find out the discipline of the VOCs released by the three typical urban green grass and the potential impact on the growth of plant with reclaimed water irrigating. The result shows that, the main VOCs released by the plant under the irrigating of reclaimed water and clean water have the same categories, including the terpenes, the alkanes, the aldehydes, the alcohols, the esters, the acids and the ketones, and have no distinct difference in the discharge amount. Therefore, we can conclude that, it has little impact on the VOCs released by the plant with the reclaimed water irrigating, and it's feasible to irrigate the urban green space with the reclaimed water.
2010, 28(2):30-33. DOI: 10.3969/j.issn.2095-6002.2010.02.007
Abstract:Alkanolamide surfactant is one of the important species in non-ionic surfactant, and has a wide range of applications in the household and industrial production.In the paper, Uniformity experimental design method was investigated to synthesize lauroyl diethanolamine with means of improved one-step synthesis, and analyzed structure and froth properties. The results show that lauroyl diethanolamine optimal synthesis conditions are n(lauric acid)∶n(diethanolamine)=1∶2.2, reaction temperature 159℃, reaction time 3.2 hours, the bubble height of 183.3mm.
2010, 28(2):34-38. DOI: 10.3969/j.issn.2095-6002.2010.02.008
Abstract:The ammonia-nitrogen wastewater treatment process with internal circulation three-phase bio-fluidized bed has big inertia of 1800s and uncertainties. It is a kind of object with complex biological and chemical action and hard to obtain nice characteristics. Take the brief mathematical model to represent the process, study Active-disturbance Rejection Control scheme by simulation to keep ammonia-nitrogen concentration of water out stable and meet the boundary, and save energy by avoiding over-aeration when the outside or internal disturbance exists. Set the output limiter of ADRC and tune parameters of it. It turns out that the system has zero static error and zero overshoot with settling time less than or equal to 2000s when the reference and disturbance input are step. It also shows ADRC has stronger robustness. The performance could overcome the inaccuracy and uncertainty of the object model, thus one-order ADRC is applicable to the ammonia-nitrogen wastewater treatment process with ITFB.
2010, 28(2):39-43. DOI: 10.3969/j.issn.2095-6002.2010.02.009
Abstract:RWP Mobility Model is Widely used in regular MANET research as simulation mobility model, Opportunistic Networks is a branch of MANET, with a characteristic that does not guarantee network topology connectivity, this may lead RWP model not suitable as a simulation model of Opportunistic Networks. In this paper, using concept of average degree and average cluster coefficient in complex network theory, the RWP model simulation data and experimental data are compared and analyzed, and author concludes that when the average degree of RWP model is similar to the experimental data, the clustering coefficient have significant differences, so RWP model is not suited to simulation mobility model of Opportunistic Networks.
2010, 28(2):44-46. DOI: 10.3969/j.issn.2095-6002.2010.02.010
Abstract:Standby power consumption of 3G mobile phone has become a focus of the study. In this paper, a new method on standby power consumption of the WCDMA mobile phone is presented by doing some analysis on important factors of standby current. This method is based on Matlab software platform and BP algorithm is adopted. Besides, some simple analysis is done on the abnormal current data.
2010, 28(2):47-49. DOI: 10.3969/j.issn.2095-6002.2010.02.011
Abstract:The paper proposes a system of safety monitoring based on wireless sensor networks (WSN) under the coal mine. The system can not only monitor the environmental situation in underground coal mines, can collect information on miner's vital signs, and also be provided with self-help function. The system have more reliability and security than the existing systems of safety monitoring under the coal mine.
2010, 28(2):50-54. DOI: 10.3969/j.issn.2095-6002.2010.02.012
Abstract:In order to provide a better train for IT major students and enhance their ability of theory combining with practice, most higher education schools are looking for experimental equipments adapt to their own laboratory conditions and teachers. Ethernet switch practice teaching is an important part of computer network teaching course, so there is being such need, too. Aim at meeting such Ethernet switches' market demand in a university's computer network laboratory, it designed a Miscellaneous Ethernet Switch Simulation Teaching System. Based on an overall consideration of the current stage and development trends of Ethernet switch, system functional requirements and feasibility, it used a three-layer architecture--hardware layer, driver layer and software application layer, and realized using hardware combined with software method. This thesis, using Realtek's Ethernet controller RTL8309SC and TI's single-chip MSP430F149, successfully builds a hardware supporting platform with standard interface, achieve the goal of hardware layer and driver layer. It not only provides a real network environment of good cost performance for users, but also flexibly provides hardware related Ethernet switch teaching experiments as a result of independent researching and development, has a strong practical value.
2010, 28(2):55-59. DOI: 10.3969/j.issn.2095-6002.2010.02.013
Abstract:VBA as the environment of develop software can share the data with other program, this makes connecting and processing more easyily. Using VBA which is embedded in Auto CAD, this paper developed the software for the automatic design of drip irrigation. With this program the users can finish the design work easily. This software contains three modules, knowledge module, calculating module and document module. Through these facilities, the users can finish the work of design. It produces the Excel to transmit the data, which is necessary for the design and choosing equipments. Further more the software provides the ports for exchanging information.
2010, 28(2):60-65. DOI: 10.3969/j.issn.2095-6002.2010.02.014
Abstract:The scheme of high frequency soft-switching electroplate power supply based on TMS320LF2407A with high frequency phase-shifted full bridge ZVS is designed. The 20V/1500A high power switching power supply control circuit and main circuit design process are introduced. The main circuit components are selected and their parameters are calculated. And the communication and network control functions are realized, so that the control system has a higher stability and greater flexibility to adapt to the industrial scene of high-quality switching power supply requirements. This design has a high stability of the fully loaded, and the requirements of industrial production are satisfied.
2010, 28(2):66-70. DOI: 10.3969/j.issn.2095-6002.2010.02.015
Abstract:Aim at the problems about camera calibration for train wheel flange of dynamic testing system,the paper discusses the radial constraint-based camera calibration,chooses the camera calibration which contains distortion factors and developed the method of it by LabVIEW. This method makes use of the LabVIEW graphical development environment, embed core programs written in Matlab, has powerful data processing and nice interactive interface.
2010, 28(2):71-75. DOI: 10.3969/j.issn.2095-6002.2010.02.016
Abstract:On-road tests of three rural vehicles were conducted using SEMTECH-DS. The speed and instantaneous emission concentration data of CO2, CO, NOx and HC were recorded, and the fuel consumption factors were calculated based on carbon balance principle, the average fuel consumption per 100 kilometers is 2.84L and the average fuel-based emission factors of the CO2, CO, NOx and HC are 3022.7g?kg-1, 127.58g?kg-1, 58.05g?kg-1 and 11.35g?kg-1 for the tested rural vehicles, respectively. The relationship between the driving cycle and fuel consumption were analyzed based on the testing data, The results show that, the fuel consumption rate increases with the increase in speed and acceleration; the fuel consumption per 100 kilometers decreases with the increase in speed and increases with the increase in acceleration; the fuel consumption rate and fuel consumption per 100 kilometers are the highest at the acceleration mode, then the cruise mode; in addition, the fuel consumption rate shows a very good correlation with VSP.
2010, 28(2):76-78. DOI: 10.3969/j.issn.2095-6002.2010.02.017
Abstract:In the long-term forecasting work, the original data has the characteristics of randomicity and non-linear movement, and also the capacity of available study samples is small and information is insufficient. The bayesian-regularization neural network possesses the characteristics of strong nonlinear fitting and the capabilities of excellent generalization. Unbiased GM(1,1) can use few data to construct models, it can weaken the randomicity of the original data and strengthen regularity, and also can eliminate the inherent deviation of the conventional GM(1,1) model. Making the best use of the merits of the two, the combined model of unbiased GM(1,1) and bayesian-regularization neural network are constructed and put into real traffic forecasting work. By contrasting with BP network, the result shows that this model is feasible and efficient, the accuracy of forecasting is also increased.
2010, 28(2):79-82. DOI: 10.3969/j.issn.2095-6002.2010.02.018
Abstract:We obtain sufficient conditions for oscillation of all solutions of the impulsive partial difference equation with continuous variable A(x+τ,y)+A(x,y+τ)-A(x,y)+p(x,y)A(x-rτ,y-lτ)=0,x≥x0;y≥y0-τ,x≠xk, A(xk+τ,y)+A(xk,y+τ)-A(xk,y)=bkA(xk,y),y∈［y0-τ,∞),k∈N(1). Where p(x,y)≥0 is continuous on ［x0,∞)×［y0-τ,∞), τ>0, bk are constants, r and l are positive integers, 0≤x0＜x1＜…<xk<… with limk→∞xk=∞.