水分活度仪测定稻谷吸附与解吸等温线

稻谷吸附与解吸等温线是稻谷干燥、贮藏的重要参数。试验研究了用水分活度仪测定稻谷吸附与解吸等温线方法，并由所测数据，计算机绘出等温线曲线。对测试过程中，物料在测试环境中的Ａｗ值平衡时间和平衡速率进行了数学分析。

CONSERVATIVE DIFFERENCE SCHEME BASED ON NUMERICAL ANALYSIS FOR NONLINEAR SCHRDINGER EQUATION WITH WAVE OPERATOR

A new conservative finite difference scheme is presented based on the numerical analysis for an initialboundary value problem of a class of Schroedinger equation with the wave operator. The scheme can be linear and implicit or explicit based on the parameter choice. The initial value after discretization has second-order accuracy that is consistent with the scheme accuracy. The existence and the uniqueness of the difference solution are proved. Based on the priori estimates and an inequality about norms, the stability and the convergence of difference solutions with the second-order are proved in the energy norm. Experimental results demonstrate the efficiency of the new scheme.

A method for absorption compensation based on adaptive molecular decomposition

In this paper,we present a new method for seismic stratigraphic absorption compensation based on the adaptive molecular decomposition.Using this method,we can remove most of the effects resulting from wavelets truncation and interference which usually exist in the common time-frequency absorption compensation method.Based on the assumption that the amplitude spectrum of the source wavelet is smooth,we first construct a set of adaptive Gabor frames based on the time-variant properties of the seismic signal to transform the signal into the time-frequency domain and then extract the slowly varying component（the wavelet＇s time-varying amplitude spectrum） in each window in the timefrequency domain.Then we invert the absorption compensation filter parameters with an objective function defined using the correlation coefficients in each window to get the corresponding compensation filters.Finally,we use these filters to compensate the timefrequency spectrum in each window and then transform the time-frequency spectrum to the time domain to obtain the absorption-compensated signal.By using adaptive molecular decomposition,this method can adapt to isolated and overlapped seismic signals from the complex layers in the inhomogeneous viscoelastic medium.The viability of the method is verified by synthetic and real data sets.

Determination of Chromium and Zinc in Soil by Microwave Digestion and Flame Atomic Absorption Spectrometry

[Objective] The aim was to develop a rapid, simple method for determination of chromium and zinc in soil samples by flame atomic absorption spectrometry.[Method] The method for determination of Cr and Zn in soil by combined flame atomic absorption spectrometry and microwave digestion was used. [Result] The concentration curve was linear within the range of 0-0.8 mg/L for Cr and 0-0.8 mg/L for Zn, the detection limits of Cr and Zn was 0.0025 mg/L and 0.002 3 mg/L, respectively. Recoveries of 102.4%-103.2% for Cr and 97.7%-98.3% for Zn were obtained for there soil samples. [Conclusion] The proposed method has the advantages of simple operation, high sensitivity, and high efficiency; it was successfully used for determination of Cr and Zn in soil samples.

Determination of Mg Content in Crayfishby Microwave Digestion-Flame Atomic Absorption Spectrometry

[Objective] This study was conducted to investigate the Mg level in cray- fish. [Method] Microwave digestion was applied to treat crayfish sample, Mg content in which was then determined by flame atomic absorption spectrometry, and recov- ery test and the determination of standards were also performed. [Result] This method was used for the detection of Mg in crayfish, obtaining satisfactory effect. The sample recoveries were in the range of 90.0%-110%, and the detection limit was 0.8 mg/kg. [Conclusion] The method is rapid, simple, accurate and reliable, worth extending.

Determination of Cadmium and Lead in Sugarcane by Graphite Furnace Atomic Absorption Spectrometer with Zeeman Correction

[Objective] The aim was to develop a rapid,simple method for determination of cadmium and lead in sugarcane samples by graphite furnace atomic absorption spectrometry.[Method] The method for determination of Cd and Pb in sugarcane by combined graphite furnace atomic absorption spectrometry and microwave digestion was used.[Result] The concentration curve was linear within the range of 0-0.80 μg/L the detection limits of Cd and Pb was 0.015 and 0.030 μg/L,respectively.The precision for elevenfold determination of Cd and of Pb at the 0.40 μg/L level were 1.8% and 2.3%（RSD）,respectively.Recoveries of 96.7%-98.2% for Cd and 104.6%-106.7% for Pb were obtained for two sugarcane samples and one certified reference material.[Conclusion] The proposed method has the advantages of simple operation,high sensitivity,and high efficiency;it was successfully used for determination of Cd and Pb in sugarcane samples.

Numerical simulation of concrete shrinkage based on heat and moisture transfer in porous medium

To simulate the concrete shrinkage in varying temperature and moisture environments, a simulate procedure comprising an analytical process and a finite element analysis is proposed based on the coupled partial differential equations describing heat and moisture transfer in a porous medium. Using the Laplace transformation method and transfer function to simplify and solve the coupled equations in Laplace domain, the moisture and temperature distribution in time domain are obtained by inverse Laplace transformation. The shrinkage deformations of concrete are numerically simulated by the finite element method （FEM） based on the obtained temperature and moisture distribution. This approach avoids the complex eigenvalues, coupling difficulty and low accuracy found in other solving methods, and also effectively calculates the moisture induced shrinkage which is almost impossible using familiar FEM software. The validity of the simulation procedure is verified by Hundt＇s test data. The results reveal that the proposed approach can be considered a reliable and efficient method to simulate the coupling moisture and temperature shrinkage of concrete.

Current efficiency of recycling aluminum from aluminum scraps by electrolysis

Extracting aluminum from aluminum alloys in AlCl3-NaCl molten salts was investigated. Al coating was deposited on the copper cathode by the method of direct current deposition using aluminum alloys as anode. The purity of the deposited aluminum is about 99.7% with the energy consumption of 3-9 kW＆#183;h per kg Al, and the current efficiency is 44%-64% when the deposition process is carried out under 100 mA/cm2 for 4 h at 170 ＆#176;C. The effects of experimental parameters, such as molar ratio of AlCl3 to NaCl, cathodic current density and electrolysis time, on the current efficiency were studied. The molar ratio of AlCl3 to NaCl has little effect on the current efficiency, and the increase of deposition temperature is beneficial to the increase of current efficiency. However, the increase of current density or electrolysis time results in the decrease of current efficiency. The decrease of current efficiency is mainly related to the formation of dendritic or powder deposit of aluminum which is easy to fall into the electrolyte.

Strong visible absorption and excellent photocatalytic performance of brown TiO_2 nanoparticles synthesized using one-step low-temperature process

particle size （5.0 nm）, large specific surface area （213.45 m1 2/g）, and efficient response to broadband light over the entire ultraviolet-visible spectrum with a narrow band gap of 1.84 eV. In addition, TiO2 -180℃ exhibited the optimal reaction rate constant for the degradation of methylene blue （0.08287 mg/（Lmin））, which is six times higher than that of the mixed rutile/anatase phase TiO2 photocatalytic standard P25 （0.01342 mg/（L min））. Furthermore, cycling photodegradation ex-periments confirmed the stability and reusability of this catalyst. The unique physicochemical properties resulting from the low-temperature preparation of TiO2 -180℃, including its broadband visible absorption associated with a high concentration of oxygen vacancies, large surface area, and enriched surface -OH/H2O may be responsible for this excellent photocatalytic performance. The use of as-prepared TiO2 -180℃ for practical applications is expected after further optimization.

Comparative studies on hydrometallurgical treatment of smelted low-grade electronic scraps for selective copper recovery

A comparison of three hydrometallurgical methods for selective recovery of copper from low-grade electric and electronic wastes was reported. Scraps were smelted to produce Cu？Zn？Sn？Ag alloy. Multiphase material was analyzed by SEM？EDS and XRD. The alloy was dissolved anodically with simultaneous metal electrodeposition using ammoniacal and sulfuric acid solutions or leached in ammonia？ammonium sulfate solution and then copper electrowinning was carried out. This resulted in the separation of metals, where lead, silver and tin accumulated mainly in the slimes, while copper was transferred to the electrolyte and then recovered on the cathode. The best conditions of the alloy treatment were obtained in the sulfuric acid, where the final product was metal of high purity （99% Cu） at the current efficiency of 90%. Ammoniacal leaching of the alloy led to the accumulation of copper ions in the electrolyte and further metal electrowinning, but the rate of the spontaneous dissolution was low. Anodic dissolution of the alloy in the ammonia？ammonium sulfate solution led to the unfavorable distribution of metals among the slime, electrolyte and cathodic deposit.

Dissociation Dynamics of Nitrous Oxide from Jet-cooling Absorption Spectrum in 142.5-147.5 nm

The absorption spectrum of the C1Ⅱ state of N2O molecule in the wavelength range of 142.5-147.5 nm has been measured under the jet-cooled condition, and the clear spectral features are displayed. A vibrational progression is observed with a frequency interval of about 500 cm-1. With the aid of potential energy surfaces （PES） of the low-lying electronic states of N2O, the vibrational progression is assigned as the bending mode of the repulsive C1Ⅱ state. From the Fourier transformation analysis, the recurrence period of the periodic orbit near the transition state region is derived to be 65 fs. Through the least-square Lorentzian fitting, the lifetimes of the resonance levels are estimated from their profile widths to be about 20 fs, which is shorter than the recurrence period. Therefore, a new explanation is suggested for the observed diffuse spectral structure, based on the behavior of dissociating N20 on PES of the C1Ⅱ state in the present excitation energy range.

Effect of Inoculation with Effective Microorganisms and Leachate Recycle on Degradation of Municipal Refuse

Biodegradation of waste in landfill is a slow process requiring decades for completion. Accelerated degradation of municipal refuse in modulated landfill environments may alleviate or eliminate pollution to the land, water and air. In this work, nineteen effective microorganisms (EMs) were isolated from old landfill refuse by enrichment culturing techniques and used for the inoculum of municipal refuse. The preliminary experiments demonstrate that a combination of EMs inoculation in landfill with leachate recycle resulted in increased rates of decomposition and faster process stability. The concentrations of COD, VFA and SO4^2- in digester with EMs inoculation and leachate recycle decreased more rapidly than others. Gas production from digester with EMs inoculation and leachate recycle commenced around 32 days, which is a week shorter than with leachate recycle only. And peak cumulative gas production was obtained much earlier in digester with EMs inoculation and leachate recycle (150 days) compared to 180 days with leachate recycle only. Moreover, in the first two months, the rate of settlement in digester with EMs inoculation and leachate recycle was more rapid than others.

Recovery of carbon and cryolite from spent pot lining of aluminium reduction cells by chemical leaching

A two-step alkaline-acidic leaching process was conducted to separate the cryolite from spent pot lining and to purify the carbon. The influencing factors of temperature, time, and the ratio of liquid to solid in alkaline and acidic leaching were investigated. The results show that the recovery of soluble compounds of Na3AlF6 and Al2O3 dissolving into the solution during the NaOH leaching is 65.0%,and the purity of carbon reaches 72.7%. During the next step of HCl leaching, the recovery of soluble compounds of CaF2 and NaAl11O17 dissolving into the HCl solution is 96.2%, and the carbon purity increases to 96.4%. By mixing the acidic leaching solution and the alkaline leaching solution, the cryolite precipitates under a suitable conditions of pH value 9 at 70 °C for 2 h. The cryolite precipitating rate is 95.6%, and the purity of Na3AlF6 obtained is 96.4%.

A Method to Prove Convergence of Some Nonlinear Differential Equation's Form Solution

A method to prove the convergence of some nonlinear differential equation’s from solu tion and its existance.

Convergence on Finite Difference Solution for Semilinear Wave Equation in One Space Variable

In this paper,the convergence and stability of the ’Leap-frog’ finite difference scheme for the semilinear wave equation are proved by using of the bounded extensive method under more generalized condition for the nonlinear term. The more complex standard a priori estimates are avoided so that the theoretical results are complemented for the scheme which was presented by Perring and Skyrne (1962).

Inorganic Carbon Parameters Responding to Summer Hypoxia Outside the Changjiang Estuary and the Related Implications

The eutrophication, hypoxia and coastal acidification are attracting more and more attention. In this study, inorganic carbon parameters, including dissolved inorganic carbon （DIC）, total alkalinity （TA） and calculated partial pressure of CO2 （pCO2）, obtained from a summer cruise in August, 2009, were used to investigate their integrated response to biological processes accompanying the oxygen depletion in the areas off the Changjiang Estuary. According to the observations, the typical hypoxia occurred in the bottom water just outside the Changjiang Estuary with Dissolved Oxygen （DO） lower than 2.00 mg L^-1. The biological uptake in the surface water and the decomposition of organic matter in the bottom water were fully coupled with each other. The high concentration of Chl_a （Chl_a = 10.9μgL^-1） and DO （9.25 mgL^-1）, profoundly decreased DIC concentration 0828 μmolkg^-1） and elevated pH （8.42） was observed in the surface water. The correspondingly increased DIC and depletion of oxygen were observed in the bottom water. The semi-quantitative analysis proved that the locally-produced phytoplankton, determined by primary productivity, was deposited to the bottom and contributed about 76% of total amount of the organic carbon decomposition in the bottom. However, in the bottom hypoxia （DO = 2.05 mgL^-1） area observed in the Southern Zhejiang coastal water, the responding patterns of inorganic carbon parameters deviated from the previous one. The expanding of Changjiang Diluted Water （CDW）, the adding of Hangzhou Bay water （with high DIC concentration） and Coastal Current together modify the DIC background value in this area, and the local degeneration and upwelling process may also help to offset the local DIC removed by net biological uptake in surface water. In addition when the mixing occurring in autumn, which may break the summer stratification, the excess release of high DIC in the bottom water to the subsurface water could have an important influence on coastal acidification and the CO2 uptake capacity in this area.

Two-grid method for characteristic mixed finite-element solutions of nonlinear convection-diffusion equations

A two-grid method for solving nonlinear convection-dominated diffusion equations is presented. The method use discretizations based on a characteristic mixed finite-element method and give the linearization for nonlinear systems by two steps. The error analysis shows that the two-grid scheme combined with the characteristic mixed finite-element method can decrease numerical oscillation caused by dominated convections and solve nonlinear advection-dominated diffusion problems efficiently.

Construction of LDPC Codes for the Layered Decoding Algorithm

Abstract： The layered decoding algorithm has been widely used in the implementation of Low Density Parity Check （LDPC） decoders, due to its high convergence speed. However, the pipeline operation of the layered decoder may introduce memory access conflicts, which heavily deteriorates the decoder throughput. To essentially deal with the issue of memory access conflicts,

A robust predictive tool for estimating CO2 solubility in potassium based amino acid salt solutions

The acid gas absorption in four potassium based amino acid salt solutions was predicted using artificial neural network(ANN). Two hundred fifty-five experimental data points for CO_2 absorption in the four potassium based amino acid salt solutions containing potassium lysinate, potassium prolinate, potassium glycinate, and potassium taurate were used in this modeling. Amine salt solution's type, temperature, equilibrium partial pressure of acid gas, the molar concentration of the solution, molecular weight, and the boiling point were considered as inputs to ANN to prognosticate the capacity of amino acid salt solution to absorb acid gas. Regression analysis was employed to assess the performance of the network. Levenberg–Marquardt back-propagation algorithm was used to train the optimal ANN with 5:12:1 architecture. The model findings indicated that the proposed ANN has the capability to predict precisely the absorption of acid gases in various amino acid salt solutions with Mean Square Error(MSE) value of 0.0011, the Average Absolute Relative Deviation(AARD) percent of 5.54%,and the correlation coefficient(R^2) of 0.9828.

The isolation of prophyra-334 from marine algae and its UV-absorption behavior

Prophyra-334 was prepared by methanol extraction and HPLC methods from marine algae （dried laver）. It is a sunscreen compound that has good absorption of ultraviolet radiations in the wavelength ranges of 200-400 nm. The absorption maximum wavelength of prophyra-334 is at 334 nm, so defined the name. The molar extinction coefficient （ε） of prophyra-334 in aqueous solution at 334 nm wavelength is 4.23×10^4. The absorption of prophyra-334 in organic solvents differs in aqueous solutions. In polar organic solvents, the absorption maximum wavelength of prophyra-334 has a slight shift toward longer wavelength compared with that in pure water. On the contrary, in inert non-polar organic solvents, the absorption maximum wavelength and the shape of absorption spectra of prophyra-334 are changed. The effects of organic solvents on prophyra-334 stability suggested that： （1） the absorbance of prophyra-334 in water is generally constant at temperature of 60℃ in 24 h, meaning that prophyra-334 is quite stable in water; （2） the absorbance of prophyra-334 in ethanol and hexane decreases at the same condition. The stability of prophyra-334 in organic solvents is less than that in aqueous solution. In benzene, the prophyra-334 is very instable.