最新刊期
卷 49 ， 期 6 ， 2010
- 摘要：The Cmax problem on twogroup jobs with m－2generalpurpose machineries and two specialpurpose machineries that they are the same speed, and the jobs have the setup times and it is no more α time than its processing times is studied. An improved LS algorithm and the upper tight bound performance are given. The ratio of the approximate solution TLS and the best way T*is (1+α)(2-1/m), and it is tight for all α.关键词：heuristic approach;performance indexes;LS algorithm;LPT algorithm;generalpurpose and specialpurpose machinery
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发布时间：2023-12-11 - 摘要：For the inverse source problem where source term is f(t)(x) with f(t) unknown, the solution method similar to the first kind Volterra integral equation is obtained. And stability estimate and numerical examples are given.关键词：illposed problem;inverse source problem;stability estimate
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发布时间：2023-12-11 - 摘要：Let X={a1a2a3…,an} be a finite set and f(n,m) the number of closed family of sets withmelements ofX. Then we show that: For every integer n≥1,f(n,m)=({3n-2nm=24n-2·3n+2nm=35n-5∕2·4n+2·3n-2n-1,m=46n-3·5n+3·4n-3nm=5.关键词：subset;power set;closed family of sets
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发布时间：2023-12-11 - 摘要：A general precise integration method for twopoint boundary value problems of ordinary differential equations is presented. Using the transfer matrix, interval algebraic equations are established and the recursive formulas for interval combination and condensation are derived for various boundary conditions. By utilizing the results of the transfer matrix directly, the process of interval combination and condensation has high efficiency. In addition, the present method has wide application for which can deal with various boundary value problems. Numerical examples show the validity of the present method.关键词：first ordinary differential equations;twopoint boundary value problem;precise integration method;illconditioned equations;recursive algorithm
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发布时间：2023-12-11 - 摘要：A method of smoothing space scattered data by polynomial natural splines is studied. The characteristics and the structure of the solution are given. Numerical examples illustrate the method.关键词：scattered data fitting;polynomial natural spline;smoothing approximation
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发布时间：2023-12-11 - 摘要：A class of KazdanWarner typed equations on noncompact Riemannian manifolds are discussed. Firstly, the existence and uniqueness of longtime solution to the corresponding heat equation with initial condition and Neumann boundary condition are obtained by the exhaustion method and the standard parabolic theory. And then, some uniform estimates of the solution to the heat equation are obtained and the existence and uniqueness of smooth solution to the equations discussed in this paper are gained under suitable conditions.关键词：noncompact Riemannian manifolds;KazdanWarner typed equation;heat equation;exhaustion method
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发布时间：2023-12-11 - 摘要：Considering the power control optimum algorithm presented in the previous work for the uplink channel in the cooperative wireless CDMA network was highcomplexity, a new twophase lowcomplexity power control strategy and optimum algorithm is presented here. In the two phases, the distributed and geometricprogrammingbased power control optimum algorithms are applied respectively. The theoretic analysis and numerical simulation results show that the power control optimum algorithm presented in this paper has less channel information requirement, low computational complexity and fast convergence rate, and it can obtain the global optimal solution.关键词：cooperative communication;Code Division Multiple Access (CDMA);power control
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发布时间：2023-12-11 - 摘要：Combined with Western Tunneling Project from Shenzhen to Hong Kong,the research concerns about deep foundation pit engineering in high fill in the construction of tunnel and municipal road structure Considered complicated geological conditions and asymmetry of composite road structure, a numerical simulation for foundation soil, tunnel structure, PHC group piles, municipal road and high backfilling soil is conducted by nonlinear FEM method. The settlement, horizontal displacement, total displacement and effective stress of composite road structure which is caused by deep foundation pit are discussed. Hence,the classification of controling the stability of composite road structure is proposed, and advances for controling the stability of composite road structure is presented. At the end,the suggested plan is demonstrated. The results show that foundation pit has bigger effect on overlying road structure than tunnel structure. It provides a useful reference for the similar projects.关键词：deep foundation pit;tunnel and municipal road structure;nonlinear FEM method;stability
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发布时间：2023-12-11 - 摘要：Based on doublelayer embankment foundation, the piping outlet particles’ transgression process is simulated using particle discrete element theory. A stratum model around piping outlet is set up by PFC2D(Particle Flow Code in Two Dimension) software, parameters are confirmed with small scale simulate test, linear contact model and parallelbond model are adopted to simulate the contact relationship of clay and sandy soil respectively. Via soilwater coupling, the whole process of piping evolution is presented. Programs based on FISH language are compiled to acquire the loss mass, porosity factor and velocity of flow. Analysis to the results shows that: the simulation phenomena correspond with the macro phenomena of real piping process. As to mesomechanical results, piping particles run out along a zone which has the maximum velocity of flow, the values scatter of velocity follows the tendency of average to local concentration, the separated tiny channels’ occurrence, caused higher velocity and particles around the zone run out rapidly, thus result in the piping zones formation. These results provide practical warranty for the farther research using PFC2D on seepage failure, and thus provide a new approach to analyze piping problem at mesomechanical scale.关键词：piping outlet;discrete element method;model;particle flow;coupling;mesomechanic
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发布时间：2023-12-11 - 摘要：A brief introduction to composite element method (CEM) is given. The finite element model is established by the composite element model for vibration analysis. The lowest few natural frequencies and the associated modeshapes are obtained from generalized eigenvalue analysis.Comparison is made for the results obtained from the CEM, FEM and other analytical methods. It was further verified by the results from ANSYS. The results show that the CEM has the advantages of computational efficiency and high accuracy. Studies indicates that the proposed method has the potential for application in structure vibration analysis.关键词：composite element method;free vibration;beams with variable crosssection;natural frequencies
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发布时间：2023-12-11 - 摘要：Based on the statistic analysis of the installed capacity of built wind farm in China, it is pointed out that the determination of wind farm capacity is mainly affected by political and subjective factors because of lacking technical support. A way of estimating wind farm capacity, ie. considering wake loss, first determining the array of wind turbine generators under the given wind energy resource is presented, then estimating the capacity is determined when the array of wind turbine generators. To do this, the power efficiency of different wind turbines is analyzed, while the concept of reference wind turbine and carries out wake loss experiments using reference wind turbine is introduced. By controlling the average wake loss of wind farm, the array of wind turbines under difference wind velocities is recommended. Using the relationship between the rated power and square of diameter of wind turbine generator, it gives the recommend installation capacity at 50 m height for areas with different wind power density level. The method can provide a reference for determining the installation capacity of wind farm during the early stage of wind farm construction.关键词：wind farm;installed capacity;reference wind turbine generator;array of wind turbine generator;wake loss
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发布时间：2023-12-11 - 摘要：For the reason that the robustness and tamper detection for existing contentbased watermarking algorithms are poor, an image hash watermarking algorithm is proposed based on compressive sensing. It conducts random projection on image using compressive sensing, and gets compressive measurements which represent the content features of image. By the HMAC algorithm, the image digest is generated and embedded into the original image as watermark. When authentication, the watermark is extracted from the tampered image, and random projection on the tampered image is conducted. By comparing the image digests between original and tampered images, the image authentication and tamper detection are implemented. Experimental results show that the proposed algorithm not only has strong robustness and security, but also has good ability of tamper detection.关键词：compressive sensing;content feature;HMAC algorithm;digital watermark;image authentication
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发布时间：2023-12-11 - 摘要：To enhanced robustness and capacity as well as maintains of image transparency of the watermark, a novel watermarking technique combination bit plane is proposed. In this method, carrier image and fingerprint image are decomposed into bit planes after discrete multiwavelet transform(DMWT), respectively. By means of the ranked bitstream of the image subband coefficients using the bit planes combination, the method may adaptively embed hidden fingerprint data into wavelet subband coefficients. Experimentation results shows that the algorithm achieves better tradeoff between invisibility and robustness in various Conditional compression.关键词：bit plane;fingerprint;digital watermark;correlation coefficient
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发布时间：2023-12-11 - 摘要：The noveltert-butylphenyl carbazole derivatives were synthesized by WittigHorner reactions. The chemical structures of the derivatives were determined by1H NMR, IR, MS and EA analyses, and their properties were investigated by UV, PL, TGA, DSC and CV methods. The results showed that ① the synthesized compounds could emit strong fluorescence either in solutions or in solid states and their fluorescent quantum yields ranged from 77% to 54%; ② the compounds possessed high thermal stabilities, and their thermal decomposition temperatures and glass transition temperatures were higher than 470℃ and 220 ℃, respectively;③ their maximum absorption and fluorescence emission wavelengths were related to the linking groups.关键词：organic luminescent materials;tert-butylphenyl carbazole derivatives;high thermal stabilities;high fluorescent quantum yields
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发布时间：2023-12-11 - 摘要：The interactions between N-benzoyl-dehydroabietylamine-7-one (NBDO) and dC6dT6dA6and d(AT)3were studied by ESI-MS analysis. The ［NBDO+DNA-4H］4-complexes ions were investigated by MS/MS method. The results showed that the NBDO could formed noncovalent complexes with dC6dT6dA6d(AT)3and the complexes ions were mainly charged -4. The ［NBDO+DNA-4H］4- ions fragmented at approximately 20% collision energy and all ［NBDO+DNA-4H］4-ions had similar fragmentation mode.关键词：ESI-MS;N-benzoyl-dehydroabietylamine-7-one;DNA;interaction;MS/MS
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发布时间：2023-12-11 - 摘要：According to the orthogonal test Tab. L16(45), the effects of 5 factors (salinity, NH+4-N, NO-2-N, and pH of seawater and quantity of WSSV)with 4 levels on the survival time ofL.vannameiwere investigated. The results indicated that the contribution of those 5 factors to the mean survival time ofL.vannameiwas sequenced as pH>WSSV>NO-2-N>NH+4-N>salinity. The coefficients between the mean survival time ofL.vannameiand WSSV, pH, NO-2-N, and NH+4-N were significant (P<0.01), and the coefficient between the mean survival time ofL.vannameiand salinity was not significant (P>0.05).关键词：Litopenaeus vannamei;white spot syndrome virus (WSSV);physical and chemical factors
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发布时间：2023-12-11 - 摘要：Based on the Support Vector Machine algorithm, the proteinprotein interactions (PPI) networks between Par-4, the cancerrelated apoptosis protein, and related proteins have been built. There are 82 proteins have been predicted interacting with Par-4. The proteins are classified into eight groups by biological functions, which include protein kinase, death receptor associate factor, ubiquitinprotein ligase, special disease associate proteins, DNA replication related proteins, special structure associate protein, regulatory protein and others. Combined with literatures mining and molecular chaperones of Par-4 searching from BOND database, two new signal transduction pathways of Par-4 have been deduced. In this paper, we first discover that Par-4 interacts with a group of ubiquitinproteins. We find that Par-4 has complicated interactions with many proteins. Par-4 plays a major role in some apoptosis pathways.关键词：Par-4;SVM;proteinprotein interactions;apoptosis;signal transduction
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发布时间：2023-12-11 - 摘要：By analyzing the information from marine organisms and their metabolic products, Marine Organism Metabolite Data Center is designed which the information source is from the chemical, biological and pharmacy authority magazine. MOMDC is a nonprofit network database that includes marine biological, metabolic products and biological activity, that consist of about 19 000 marine information.关键词：marine biological;metabolic product;database
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发布时间：2023-12-11 - 摘要：The joint toxicity of PentaBDE (PeBDE) and heavy metals including cadmium(Cd) and copper (Cu) onDaphnia magnawas evaluated on the basis of determining the 48h survival and 21 day reproduction. Fifteen mixture treatments in which the chemicals were at 0, 25, 50, 75, and 100% of their individual median inhibition concentrations and made up to one toxic unit (TU) were applied. The response was classified as additive, greater than additive, or less than additive by comparing the measured TU with one. Based on the survival ofDaphnia magnaadditive responses occurred in the 75% Cd plus 25% PeBDE, 50% Cu plus 50% PeBDE and the 75% Cu plus 25% PeBDE treatments. Greaterthanadditive responses were only found in the 25% Cd plus 75% Cu treatment. For reproduction, additive responses occurred in the 75% Cd plus 25% PeBDE，and 75% Cu plus 25% PeBDE treatments. Lessthanadditive interactions were found in other remaining mixtures. Cu and Cd played a greater role in toxicity than PeBDE did. This may be attributed to the different toxicity mechanism between PeBDE and metals.关键词：ploybrominated diphenyl ethers (PBDEs);heavy metals;combined toxicity;toxic unit
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发布时间：2023-12-11 - 摘要：The dissociation and culture in different artificial cerebrum spinal fluids (ACSF) of facial lobe slice isolated from Southern catfish (Silurus meridionalisChen) are described. To observe the physiological functions in information coding of primary gustatory central neurons and to elaborate the mechanism of information identification in fish, we established the teleost infrared visual patch clamp method. According to experimental requirement, low calcium ACSF contained HEPES, Vc, TU and kynurenic acid could be selected for normal brain slices culture at the temperature of 25 ℃within 2 h. The morphology and electrophysiological characteristics of neurons were observed noninvasively by brain slice patch clamp with infrared videomicroscopy. There were two types of neurons (pyriform and oval neurons) in facial lobe. They all had no or low rate of spontaneous discharges and frequency adaptation. Pyriform neuron had lower membrane resistance but with higher evoked discharge frequency.关键词：Silurus meridionalisChen;artificial cerebrum spinal fluids;brain slice culture;patch clamp
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发布时间：2023-12-11 - 摘要：Three parameter estimation methods of generalized extreme value distribution function were briefly introduced in the paper, which included the maximumlikelihood estimation, the linear moment estimation and the maximum product of spacing estimation. Two demonstration examples including monthly maximum runoff at Makou Station and daily maximum precipitation in Guangzhou over the past years were analyzed by the three parameter estimation methods of GEV distribution. The results indicated that three parameters obtained by three different estimation methods were very close. Several goodness fit tests showed that two examples were obeyed the generalized extreme value distribution. And the designed values predicted by maximum product of spacing estimation were better fitted with the measured values.关键词：generalized extreme value distribution;parameter estimation methods;goodness fit test;demonstration analysis
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发布时间：2023-12-11 - 摘要：Rapid urbanization has caused a series of problems. This paper presents a cellular automaton model based on multicriteria evaluation (MCE-CA) in an attempt to simulate compact urban forms. Local conditions for development and suitability for agriculture are taken into account. The AHP method is used to determine the weights of each factor. Dongguan in Guangdong Province, China, is selected as the case study area. The model is implemented to simulate the urban growth from 2001 to 2005. The simulation result is validated using the observed distribution of urban area in 2005. Then, the urban forms in 2010 and 2020 are predicted based on historical trend. Moreover, the weights of factors are shifted to further simulate the compact urban forms. The comparison between the predicted urban form and the compact urban form in 2020 indicates that the latter significantly prevents the fragmentation of development and reduces the loss of agricultural land of good quality.关键词：cellular automata (CA);compact urban form;Dongguan
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发布时间：2023-12-11 - 摘要：Predicting the size or development tendency of population is a complicated geographical problem. This kind of problem often involves multiple geographical components that interact in a complex way In this article, a new technique based on a gene expression programming (GEP) algorithm is presented, which can be used to address population prediction problems. In the context of GEP algorithm, population prediction problems are formulated by designing encoding strategies, evolutionary operations and fitness function. The population prediction model based on GEP approach is finally constructed and applied to predict population of Dongguan city. Compared with grey model and artificial neural network model, the predicting precision is improved by 18.34% and 30.54%, respectively. GEP model has better accurateness of predicting the size and development tendency of population. It can accurately fit nonlinear population development tendency and avoid overfitting to a certain extent. Gene expression programming algorithm can be used to effectively solve population prediction problems.关键词：gene expression programming;population prediction;temporal series;grey model;artificial neural network
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发布时间：2023-12-11 - 摘要：The background of reservoir operation is becoming complex. The release strategies has to be continuously adjusted to be adaptable for the change of reservoir operation enviroments. In this paper, the complexity of reservoir operation was discussed from the viewpoint of complex adaptive system and the similarity was analyzed between the process of extracting reservoir operating rule and selfadaptive learning of antibody and antigen in human immune system. A reservoir operating rule extraction model based on the co-evolution immune system (CoEISM) is developed and applied to extract the watersupply reservoir operating rule of a water-supply reservoir in North China. The obtained operating rules acquire the identification rate of 92.5% for training samples and 84.4% for testing samples, respectively, which is comparable to that by the RBF. The reseaches indicate that the coevolution artificial immune system is feasible and effective for extracting reservoir operating rule. The obtained rules are easier to be interpreted and can provide more rich decisionmaking information. The selfadaptive adjustment of rules is helpful for decisionmakers to make reseasonable release strategies to fit for environmental changes.关键词：water-supply reservoir;operating rules;co-evolution;artificial immune system
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发布时间：2023-12-11 - 摘要：Different forms of phosphorus have different bioavailability and geochemical behavior. Their contents and distribution contain much environmental geochemistry information. Therefore, researches on geochemical forms of phosphorus have important significance of environmental geochemistry. In this paper, different forms of phosphorus in surface sediments were separated by SEDEX method, and the contents, distribution characteristics, influencing factors of different forms of phosphorus were analyzed. The results indicated that the content of total phosphorus was relatively higher in the surface sediments with an average value of 341.87 mg/kg, in which inorganic phosphorus averaged 290.81 mg/kg, comprising 85.11% of the total phosphorus, and organic phosphorus averaged 51.05 mg/kg. The content of De-P was the highest in all inorganic phofsphorus forms of the surface sediments in the Daya Bay, accounting for 47.67%. Ca-P, the second part of inorganic phosphorus, accounted for 34.79%. Fe-P and Ads-P, the small parts of inorganic phosphorus, accounted for 10.23% and 7.31% respectively. The potential bioavailable phosphorus, including Ads-P, Fe-P and OP, accounted for 29.40%. The contents of different forms of phosphorus in different sites were mainly influenced by terrigenous input, the nature of sediments, etc.关键词：phosphorus form;distribution characteristic;bioavailable phosphorus;surface sediments;Daya Bay
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发布时间：2023-12-11 - 摘要：The membrane electrode assembly (MEA) was constructed with Nafion 112 membrane. TheE-Ipolarization curves and the electrochemical impedance spectrum (EIS) of the proton exchange membrane fuel cell (PEMFC) without external humidification were tested. By comparing with the EIS at 20 ℃ and 55 ℃， the test results indicated that there were obvious difference between Rhfwhich represented the ionic resistance, and Rctwhich corresponded to the charge transfer resistance at these two different temperatures. The values of Rhfunder low current densities were consistent with the ohmic loss in PEMFC. The values of Rhfand Rctincreased with the increasing of the operating temperature when PEMFC was operated at 15 mA·cm-2. The value of Rhfchanged significantly with the increasing of temperature, which was the main factor that caused the breakdown of PEMFC operating over 45 ℃.关键词：PEMFC;electrochemical impedance;current density;temperature
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发布时间：2023-12-11 - 摘要：The technique of mixed fermentation was applied to culture two mangrove endophytic fungi K38 and E33 from the South China Sea Coast. The crude extracts from the fermentation liquids extracted by ethyl acetate showed significant inhibitory activities to several plant pathogens. Five secondary metabolites were isolated from this crude extracts, which did not obtained from these two strains by pure fermentation before. Their structures were elucidated by spectral methods to be deoxyscytalidin（1），2-hydroxy-1-methoxy-3-methylanthracene-9,10-dione(2)，methyl 5butylpicolinate(3)，methyl 5(but3enyl)picolinate(4)，sescandelin（5）. Compound 1,2,3,4 were found in marine fungi for the first time.关键词：mangrove endophytic fungi;mixed fermentation;antifugal activity
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发布时间：2023-12-11 - 摘要：The fatty acids were extracted from a new kelp using alcohol, which were esterified in KOH-CH3OH solution and then analyzed by GC-MS method. The results showed that there were ten polyunsaturated fatty acids (PUFAs) with their contents of 37.98%, including linoleic acid (LA,9.29%), γLinolenic acid (GLA,3.74%), eicosapentaenoic acid (EPA, 1.12%), docosahexenoic acid (DHA, 0.63%), Arachidonic acid (AA, 4.9%). Besides, there were four saturated fatty acids (SFAs) with their contents of 5622%, including palmitic acid 36.23%. This work provided scientific evidence for the deeper exploitation of the new kelp in the biological pharmacy and nourishment fields.关键词：kelp;fatty acid;GC-MS method
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发布时间：2023-12-11 - 摘要：In this paperLonicera hypoglaucaMiq.was identified by TLC，chlorogenic acid and caffeic acid were determined by HPLC. The chromatographic column was Dikma PLATISIL ODS(250 ×4.6 mm，5 μm)，gradient elution with acetonitrile and 0.4% phosphoric acid （pH≈2.5）（12∶88）was applied and the detection wavelength was 327 nm.The recovery of chlorogenic acid was 99.6% with RSD 2.16%，and the recovery of caffeic acid was 101.1% with RSD 3.26%.The established method can be used for quality control ofLonicera hypoglaucaMiq..关键词：Lonicera hypoglaucaMiq.;chlorogenic acid;caffeic acid;TLC;HPLC
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发布时间：2023-12-11 - 摘要：Using the transformation method, the restraint of traditional projection model can be removed. The unconstrained projection model is optimized by artificial fish swarm algorithm and used to calculate the projection vector values of flood. The obtained results are comparable with the actual case. The Shijiao Station of the Beijiang River is taken as an example in this paper. The results indicate that this new model is more effective and reasonable than the traditional method for flood classification. During the period from 1954 to 2006, the flood in 2006 was the biggest one, the floods in 1964, 1966, 1968, 1982, 1994 and 1997 also showed higher intensity. This suggests that the flood situation should not be despised in the Biejiang River. The flood control work should be strengthened in order to ensure the flood control ability of the dike in the Beijiang River.关键词：a non-binding projection pursuit model;artificial fish swarm algorithm;flood intensity
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发布时间：2023-12-11
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