Abstract:In order to understand the toxic effects of the pollution by organophosphorus pesticide as acephate on the local aquatic sensitive species as Scenedesmus obliquus,under laboratory conditions,based on the static toxicity test,the acute toxic effects of acephate on Scenedesmus obliquus for 96 hours were investigated in this paper.And based on the acute test,the chronic experiments including the 14 days changes of chlorophyll a,soluble protein and MDA in Scenedesmus obliquus were analyzed.It shows that:the 96 h EC₅₀of acephate is 482.9 mg/L,which belongs to the low-toxic pesticide and the growth of Scenedesmus obliquus could be promoted with 1 mg/L of acephate;no significant effect is showed on the photosynthesis of Scenedesmus obliquus,but the toxic effects are exposed by acephate through interfering the algae's metabolic activities and causing membrane lipid peroxidation;the soluble protein and MDA could be used as valid biological markers for evaluating the toxicity of pesticide.The results in this paper could be considered as the theoretical basis for protecting local aquatic sensitive species and establishing the criterion on safe use of pesticide.

Abstract:Landfill methane emission is an important source of anthropogenic greenhouse gases.Its influence on the increasing global greenhouse gas emissions in the entire atmosphere which cause climate effects can not be ignored and it is a serious problem of public nuisance that needs to be solved urgently in the modernization process of the world.The paper summarizes the related formative factors of methane,the present status of waste disposal and methane emission reduction technologies at home and abroad.Methane production is affected by waste characteristics,moisture content,temperature,pH,time,leachate levels and other factors in landfill.The current landfill methane emission reduction technologies include the in situ reduction technique,resource utilization and end control technology.The landfill can achieve the goal of methane emission reduction from the combined effect of various aspects.

Abstract:To the soil microorganisms,soil nutrient and soil soluble salt of Yulin aerial seeding forest as the object of study,research on the variation law of forest soil soluble salt and the correlation to soil nutrient and microorganism,in order to provide a theoretical basis for the sustainable utilization of water resources and the improvement of forestation effect by aerial seeding effect.The results show that the study area soil genus sulfate type,soil layer distribution is not significant,the soil is still at the primary stage of development.In the soil surface,moderate reduction of chlorine ion can promote the growth of bacteria in soil.Soil salt and nutrient correlation is not obvious,appropriate concentration of potassium ions increase can be benefit to fungus survival and biomass accumulation.While additional 1 gram of potassium ions the number of fungi will increase by almost 14 in 1 kg.In the soil layer of 0-40 cm,soluble salt presents surface aggregation phenomenon in the uplink process,meanwhile,the salt present surface aggregation phenomenon in the middle of soil layer.The increasing of Na⁺ and HCO₃^- contents is favorable to the increase of total soil nitrogen content and the HCO₃^- is of the most obvious influence in the bottom of soil layer.

Abstract:An exploratory study of anti-wear and friction reduction properties was carried out on the long grinding conditions to investigate the effect of copper nanoparticles as lubricant additive on the vehicle gear oil 500SN.Lubricant performances were tested at different burden and mass percentage of metal nanoparticles under the condition of 1200r/min and 2h.When the burden is 98N and the mass percentage of copper nanoparticles is 0.05%,the property of anti-wear and antifriction of the lubricant oil can be significantly improved,with the wear scar diameter being reduced by 18.1% and the friction coefficient being reduced by 13.6%.When the burden is changed to 392N,the anti-wear performance of the lubricant oil can also be improved with the mass percentage of copper nanoparticles varied from 0.05% to 0.7%,while the capacity of anti-wear and antifriction decreases for the copper nanoparticles as the mass percentage of metal nanoparticles increases.Thus the best percentage of copper nanoparticles as lubricant additive is 0.05% in mass percentage.

Abstract:A review on the previous literature of Little Ice Age is made,and the temperature and precipitation data from National Oceanic and Atmospheric Administration are compared and analyzed to discuss the regional climate characteristics in China during the Little Ice Age.Results show that Little Ice Age were found in all parts of China in the proxy record,with regional difference in start/end time,duration period,and temperature/humidity condition.The Little Ice Age in China is characterized by a moving trend from west to east in start time,or alternatively,from Qinghai-Xizang plateau to North China and then to east China.As for the climatic condition,the eastern monsoon region is generally cold and dry,while the western monsoon region is cold and humid during the Little Ice Age.

Abstract:The distribution characteristics of heat island intensity was obtained after surface temperature inversion through the use of Landsat TM/ETM+ data,then the contrast of surface temperature spatial distribution was analyzed combined with the underlying surface land cover types in sample areas.The result indicates that there existed obvious heat island effect in Nanchang,and the surface temperature gradually decreased from city center to suburban.The surface temperature was closely related to the nature of the underlying surface.The research results have important reference value to improve ecological environment and slow down the heat island effect for Nanchang.

Abstract:In this article,a complete thunderstorm electrification model is proposed by adding the aerosol module to the existing two-dimensional thunderstorm electrification model.The SEET case is used to discuss the effect of different aerosol concentration on the electric charge of various particles in thunderstorm cloud.The result shows that a good positive correlation exists between the aerosol concentration and maximum charge density/quantity carried by particles like the cloud droplet,graupel grain,hail or raindrop in the thunderstorm cloud,and the increase of the aerosol particle concentration will bring forward the time of the charges brought by the raindrop to reach its peak.

Abstract:For characteristics and requirements of data acquiring in large-scale unattended automatic weather monitoring,the design on acquiring system of surge meteorological data are given,and the key technologies are discussed in depth based on wireless communication network.By analyzing the structure of data transmission protocol and its disadvantages in the system,a reliable application protocol is designed based on UDP and its working principle and reliability are discussed in detail,and the instability of the wireless data transmission is solved.For real time receiving and concurrent processing of surge meteorological data,by making use of multi-threading technology and large-scale communication events response technology,the data reception thread pool is constructed and realized.Through the introduction of data partition management concept,a concurrent processing data buffer is planned and excogitated,which can solve the problems such as data loss,data blocking and low efficiency in data processing.The system is tested and applied to real weather operation,and its performance shows that this system can acquire real time surge meteorological data efficiently and reliably.The system meets the current needs of the weather operation and is adaptable to the development of future weather operation.

Abstract:In order to overcome the shortcomings of slow convergence speed and large steady-state error of Constant Modulus Algorithm(CMA),on the basis of analysis of constant modulus blind equalization algorithm based on variable segment error function,a constant modulus blind equalization algorithm based upon dynamic variable segment error function(DVSCMA) was proposed.The blind equalization algorithm adjusts the section position of the error function dynamically by using the Mean Square Error (MSE),and the characteristics of the error function is changing in the balancing process with the MSE,which enables the error model and the transmit signal model to match continuously,thus accelerate the convergence speed and reduce the steady state error.The new algorithm is simulated by using mixed-phase and minimum phase of underwater acoustic channel.The simulation results demonstrate that the proposed algorithm has significantly faster convergence rate and lower steady-state mean square error compared with the CMA for the mixed-phase of underwater acoustic channel,while the new algorithm has significantly lower steady-state mean square error and very close convergence rate compared with the CMA for the minimum phase of underwater acoustic channel.

Abstract:S-boxes bring the only nonlinearity to symmetric ciphers and strengthen their cryptographic security.A detailed analysis of the cryptographic properties of S-boxes in several symmetric ciphers,such as AES,SEED,Camellia and SMS4,is made in this paper.The algebraic properties and the Boolean functions of S-boxes are well investigated.Then the attack capability resisting to differential cryptanalysis and linear cryptanalysis are provided.At last,the security of AES,SEED,Camellia and SMS4 is revealed by comparing the advantages and disadvantages of the S-boxes used in these symmetric ciphers.

Abstract:In order to enhance the practical and operational performance,a method based on PCA-LINMAP-FCE for maintainability evaluation is proposed.Combining PCA-LINMAP with fuzzy comprehensive evaluation,the provided approach evaluates the maintainability quantitatively and qualitatively on the basis of a simplified evaluation index system.Experimental results show that this high operational method reduces the arbitrary of subjective evaluation effectively.It is useful for maintenance personnel and designer to get acquainted with influencing factors of maintainability,and supply decision-making information for scientific design and implementation of maintaining scheme.

Abstract:This paper uses the method of gray relation analysis to find out the change point for time series of meteorological factors and energy consumption in Beijing from 1980 to 2010.The meteorological factors include average temperature,precipitation and sunshine hour\soutet al.It is shown that the change point of Beijing's energy consumption series occurs in 1993 and 1997,while the change points of the meteorological factors occurs in period from 1993 to 2000.Especially,the change point of average temperature,sunshine hour and energy consumption sequences occur in the same period exactly.Furthermore,meteorological factors have the extremely close relationship with energy consumption in Beijing.In a word,according to the local climate conditions,the government could arrange the strategy of energy resource development accurately.

Abstract:China is one of the countries which have the most earthquake disasters in the world,to evaluate the losses of earthquake therefore has important social and economic value.This paper focuses on the assessment of economic losses of earthquake disasters,which is divided into two parts,namely direct economic loss and indirect economic loss.Firstly,K-S test is used to determine the distribution of the annual earthquake losses in China,and the monthly frequency of earthquake is calculated and fitted.Secondly,grey clustering method and principal component analysis(PCA) are applied for direct economic loss rating and indirect economic loss rating,respectively.Finally,the economic losses due to the earthquakes happened during 2006-2009 in China are evaluated,and eight earthquakes are rated based on the comprehensive economic loss.

Abstract:Refraction is the main characteristic when electromagnetic wave propagates through ionosphere,which is mainly determined by the free electrons in ionosphere.In this paper the relationship between the refractive index(n),the electron concentration(N_e) and the altitude(h) is analyzed,and numerical simulations are taken on the refractive index and the electron concentration relating to the altitude.We contrast the simulated altitudinal profile of critical frequency and the actual altitudinal profile of critical frequency,and the results show that at high ionosphere,the simulations are roughly in agreement with the actual measurements,while at the lower ionosphere the simulations deviate from the measurements by reason of nonlinear relationship and existence of E_s layer.