最新刊期
卷 53 ， 期 1 ， 2014
- 摘要：A discontinuous signum-function-activated (SFA) weights-and-structure-determination (WASD) neuronet model is presented and constructed based on the WASD algorithm. By this algorithm, the optimal weights and structure can be determined effectively. We apply the SFA-WASD neuronet model to XOR (i.e., exclusive or), and detail its performance in the XOR application with various types of disturbance noise considered. Numerical verification results substantiate the validity of the WASD algorithm in determining the optimal weights and structure, as well as the good anti-noise ability of the SFA-WASD neuronet in the XOR application. Moreover, for high-dimension XOR application, the performance comparison is made between the power-functionactivated (PFA) WASD neuronet and the SFA-WASD neuronet. The numerical results verify the superiority of the SFA-WASD neuronet in terms of solving nonlinear problems.关键词：weights-and-structure-determination (WASD)algorithm;discontinuous signum function;neuronet;noise;XOR;high-dimension
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发布时间：2023-12-11 - 摘要：A concrete implementation of a secure obfuscator for a special encrypted ring signature (ERS) functionality is constructed. This ERS functionality is the sequential composition of Waterss ring signature scheme and linear encryption scheme. In the standard model, the proposed obfuscator satisfies average-case virtual black-box property (ACVBP), which guarantees the preservation of the anonymity and unforgeability of the ring signature even if an obfuscated program is given to the adversaries.关键词：virtual black-box property;obfuscation;ring signature
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发布时间：2023-12-11 - 摘要：Based on manyknot splines, a new curves approximation algorithm is proposed in this paper. The algorithm makes use of a hierarchy of control lattices to generate a sequence of functions whose sum approaches the desired approximation function. This algorithm can automatically select the proper control points according to the setting threshold. The satisfactory result is obtained for the fitting of experimental spectroscopic data using the optimization methods of cubic many-knot splines.关键词：many-knot splines;free curves;hierarchical approximation;least square method
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发布时间：2023-12-11 - 摘要：A size-structured two-phase population model with delayed birth process is studied. The well-posedness for this model is established.It is shown that the solution of this model has balanced exponential growth by means of semigroups.关键词：size-structured populations;distributed delay;well-posedness;balanced exponential growth;semigroups
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发布时间：2023-12-11 - 摘要：It is very important for model or function to have exact input parameters. However, the input parameters often have some error in practical application. The parameter error will lead to larger model error in prediction of non-linear model (parameter). Ensemble Kalman filter is introduced into non-linear model (parameter) for parameter estimation. And joint state vector is used to update model parameter and state in the same assimilation time. The method can dynamically adjust model parameters and states according to changing environment by assimilating observation data. And more importantly, it can release the accumulated model error. The method is applied to two-dimension non-linear model which changes with time step. Studies show that the method can obtain ideal results in parameter estimation. It also has good performance in robustness and self-adaption.关键词：nonlinear parameter estimation;data assimilation;ensemble Kalman filter;joint state vector
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发布时间：2023-12-11 - 摘要：The existence of solutions for high-order impulsive boundary value problem of Caputo fractional differential equation in the formDq0+y(t) = A(t,y)y(t)+f(t,y(t),Φy(t),Ψy(t)),t∈［0,1］,q∈(n－1,n),y(i)(0)=0, Δy(i) |t=tk= 0, 1≤i≤n－2,k=1,2,…,p,Δy |t=tk= Ik(y(tk)), Δy(n－1)|t=tk= Jk(y(tk)),k=1,2,…,p,y(0) = y0+ g(y), y(n－1)(1) = y1+∑m－2j=1bjy(n－1)(ξj) is studied. By defining a contraction mapping and using the fixed point theorems, some sufficient conditions for the existence of one unique solution and at least a solution are established. Further, two examples are presented to illustrate the main results respectively.关键词：fractional differential equations;high-order;impulsive;Caputo fractional derivative;fixed point theorems
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发布时间：2023-12-11 - 摘要：Based on decision theory algorithm，the characteristic parameter extraction and automatic identification technology of mixed modulation signal are researched,and then the tree classifier with identification steps which are suitable for mixed modulation signal modulation recognition are put forward. The characteristic vector which are composition of the number of subcarrier signal, envelope variance of mean normalization and algorithm of the statistical value of subcarrier signal instantaneous amplitude distribution area are first used in recognition of outer modulation and inner modulation respectively so as to reduce the noise interference and improve the accuracy of characteristic parameters. The simulation results show that modulation recognition rate is close to 90% under the condition of SNR which is 6 dB and it has a good recognition effect compared with mixed modulation recognition method existing and a broad prospect of application in the management of the mixed signal modulation identification.关键词：tree classifier algorithm;mixed modulation signal;envelope variance of mean normalization;modulation recognition
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发布时间：2023-12-11 - 摘要：A distributed simulation model for CO2heat pump water heater is developed based on SINDA/FLUENT. The static or dynamic start-up and stop procedure are simulated. The characters including temperature and pressure among the system are analyzed. The simulating error is about 10 percent compared with the experiment data. The models can be used for CO2heat pump hot water components design and system optimization.关键词：CO2;heat pump hot water;SINADA/FLUENT;simulation
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发布时间：2023-12-11 - 摘要：Studying the impacts of climate change on water resource can help human beings take measures when facing problems. The results of HadCM3 and 7 meteorological sites’ daily data supplied by China Meteorological Administration in Qiantang River Basin are used to estimate design storms in 2020s under A1B scenario by both dynamic and statistical downscaling methods. The final results show that extreme storms will increase in 2020s under A1B scenario. Besides, the design storms for different return periods calculated through the dynamical method will increase more than those calculated through statistical method.关键词：climate change;downscaling method;PRECIS;LARSWG;precipitation frequency
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发布时间：2023-12-11 - 摘要：For solving the problems of the complexity about feature extraction on largesize image and the loss of feature information, the characteristics of compressive sensing (CS) theory that a small amount of measurements can accurately reconstruct the original signal is used, and a new image retrieval method based on compressive sensing is proposed. First, the wavelet transformation is performed,and the image is divided into blocks. Then,blocked polynomial deterministic measurement matrix and conduct fast CS measurement on blocked image constructed, and very few compressive measurements which represent the image features can be obtained. Finally, we calculate the similarity between the measurement features by weight distance is calculated, so to implement accurate image retrieval. At the same time, it is proved theoretically that the blocked polynomial deterministic measurement matrix is satisfied to the restricted isometric property (RIP). Experimental results show that this method has higher performance on image precision and image recall, and can be applied to massive complex image retrieval.关键词：image retrieval;compressed sensing;measurement matrix;feature extraction;feature matching
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发布时间：2023-12-11 - 摘要：The steadystate spectroscopy and the femtosceond fluorescence upconversion in three kinds of Ga Corroles in toluene and ethanol solvent have been studied. The results show that the effect of the hydroxyl and PTZ substitution on the properties of those Corroles is not significant. In contrast, the blue shifts in absorption spectra, the red shifts in emission spectra and the reduction in fluorescence quantum yield observed when ethanol replaces toluene as a solvent. Moreover, the ultrafast dynamics S2→S1of those Corroles varied significantly in different solvents. Evidently, solvent has a significant effect on those Corroles-energy level structure and optical properties.关键词：Corroles;femtosecond fluorescence upconversion technology;ultrafast dynamics
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发布时间：2023-12-11 - 摘要：As a new solar cell material, further understanding the technology and performance of monolike crystalline silicon solar cells is necessary. Acidic-alkaline texturing of the wafers is discussed，and then the light induced degradation of the solar cells based on conventional process is tested. The mono-like crystalline silicon solar cells show a relatively superior stability with the contrast of monocrystalline and multicrystalline silicon solar cells. Experiments show that mono-like crystalline silicon solar cells have certain advantages and broad prospect.关键词：mono-like crystalline silicon;acidic-alkaline texturing;light induced degradation
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发布时间：2023-12-11 - 摘要：The exact and asymptotic closed-from expressions for the outage probabilities (OPs) of uplink dual-hop cognitive amplify-and-forward (AF) relay cellular networks with opportunistic secondary user (SU) scheduling are investigated. Multiple SUs are involved in this networks.By opportunistically scheduling the best SU to transmit, the performance of uplink cognitive AF relay cellular networks is improved. Simulation results are presented to validate the theoretical analysis.关键词：cognitive cellular networks;relay;spectrum sharing;opportunistic scheduling;outage probability
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发布时间：2023-12-11 - 摘要：Bi1.6La0.4Ti2O7（BLT） thin films were prepared on ITO glass substrates using a chemical solution deposition method. Their structures, dielectric properties, current-voltage I-V curves and optical constants were analyzed. The result of X-ray diffraction (XRD) analysis showed that the thin films annealed at 500, 550 and 600 ℃ for 1h were grown in pyrochlore structure and no secondary phase was detected. Also, the XRD peaks of BLT annealed at 600 ℃ was stronger than those annealed at other temperatures. The dielectric constant and dissipation factor (at 1 kHz) were 114 and 3%, 129 and 3%, 194 and 6%, respectively, for films annealed 500, 550 and 600 ℃. Leakage current densities of BLT thin films versus applied voltage curves suggested that the value of leakage current for films annealed at 600 ℃ was much smaller than those annealed at 500 and 550 ℃. The annealing temperature had little effect on the optical band gap of the films with the values of 3.7 eV. These results indicated that the BLT thin films annealed at 600 ℃ had an excellent property, and they had a potential application in opticoelectric devices.
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发布时间：2023-12-11 - 摘要：Based on the unstructured grid MIKE 3D model with the finite volume method, the 3D tidal and water quality numerical model was used to simulate the marine environmental capacity of COD, DIN and oil in the main discharge areas in the Beibu Gulf Economic Zone, China. Compared with the potential future discharges of these three types of pollutants according to the planning scenario around the Gulf, the available level of marine capacity was also discussed. The results indicated that environmental capacity of COD, DIN and oil in the Gulf were 221 267.1, 23 058 and 5 297.2 t/a, respectively. Due to the good hydrodynamic diffusing condition, the marine environmental capacities of discharge areas in Yangpu and Bohe were relatively large. The environmental capacity of DIN was seriously overloaded, which leaded to 25% and 33% of the discharge areas overloaded in 2015 and 2020, respectively.关键词：Beibu Gulf;marine environmental capacity;numerical model;discharge area
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发布时间：2023-12-11 - 摘要：High performance liquid chromatography (HPLC) was developed for the quantitative analysis of protocatechuic acid (PA) in Spatholobi Caulis (the stem of Suberect spatholobus Dunn.). The preparation method of sample solution was established by optimizing the extraction solvents, methods, times and the sizes of the crude drug. The sample solutions were analyzed using a C18column ( 250 × 4.6 mm，5μm) with CH3CN-φ=0.5% HAc (volumic ratio,10:90) as mobile phase and detected at 260 nm with a flow rate of 1.0 mL·min-1. The crude drug was extracted by boiling water for three times and 1.5 h for each time. The obtained aqueous solution was concentrated and followed by extracted with ethyl acetate for four times. The ethyl acetate layer was concentrated to dryness, and was resolved in methanol-water (volumic ratio,1:1) to give the sample solution previous to HPLC analysis. After systematic method evaluation, the results showed that the linear range was 8.56～214 μg·mL-1 with correlation coefficient R2of 0.999 7; and the average recovery rate was 99.2% with RSD of 2.8%. The contents of PA in marketsold seven batches of Spatholobi Caulis were determined to be in the range of 65.81～122.35 μg·g-1. The established method was accurate and repeatable, which could be used for the quality control of Spatholobi Caulis.关键词：Spatholobi Caulis;Spatholobus suberectus;protocatechuic acid;HPLC
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发布时间：2023-12-11 - 摘要：To continue to study anti-tumour bioactive saponins EtOAc layer from methanol extract of the stem of psychotria sp., four compounds were obtained by all kinds of column chromatography, such as silica gel, Sephdex LH-20, and ODS. Their structures were characterized by spectroscopy including NMR, MS, GCMS analyses, and chemical and the physical methods. The result indicated that they were Psychotrianosides G (1), Ardisianosides D (2),β-amyrin (3), and Stigmasterol3-O-β-D glycosidase(4). Cyclamiretin A (5) was obtained by acid hydrolysis of 2. Psychotrianosides G(1) was firstly obtained as a natural product. The chemical structure of compound (1) was analyzed by 2D NMR firstly. Compounds 1,2,3,4,5 were firstly obtained from genus of psychotria.
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发布时间：2023-12-11 - 摘要：A novel C60-grafted maleic acid copolymer was prepared using C60 and maleic acid. And then the C60-grafted acid copolymer lead salt additives were prepared using C60-grafted maleic acid copolymer and lead nitrate to modify the burning rates of solid propellants. To obtain the higher content of lead in C60-grafted maleic acid copolymer lead salt, the C60-grafted maleic acid copolymer was coordinated in the presence of lead nitrate. The effect of pH, molar ratio of C60-grafted maleic acid copolymer and lead nitrate, reaction temperature and time on the content of lead in the C60-grafted maleic acid copolymer lead salt were investigated by a singlefactor method. The optimum reaction condition of 5609% lead content in C60-grafted maleic acid copolymer lead salt was obtained in pH = 6.92, molar ratio of C60-grafted maleic acid copolymer and lead nitrate 1:7, reaction temperature 30 ℃, and reaction time 2.0 h. The chemical structures of the C60-grafted maleic acid copolymer lead salt were characterized by FT-IR, UV-vis, GPC, AAS, XRD and XPS analyses. The thermal stability of the C60-grafted maleic acid copolymer lead salt was also investigated by DSC, DTA and TG analyses. Three discrete regions of thermal decomposition were observed in the DTA curve at 275, 370 and 462 ℃ respectively. The C60-grafted maleic acid copolymer lead salt had three-steps weight loss, overall weight-loss was 43.6% in the TG curve, which showed good thermal stability.关键词：C60;C60-grafted maleic acid copolymer;C60-grafted maleic acid copolymer lead salt;thermal stability
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发布时间：2023-12-11 - 摘要：Exploring the molecular genetics relationships between Han subpopulations in different administrative regions of China are always noticed by academics. Short tandem repeat (STR) has been often used in molecular genetics studies. The cluster analysis, principal component analysis and MCOA analysis had been used in this paper, we focused on the nine common STR loci (D8S1179, D21S11, D7S820, D3S1358, D13S317, vWA, D18S51, D5S818, FGA) allele frequency data of Han subpopulations from 32 administrative regions in China, in order to initially explore the molecular genetics relationships, the spatial distribution characteristics and distribution pattern of the Chinese Han subpopulations. The studies revealed that the Han nationality could be segregated into two groups which are the Southern and the Northern Han by the Yangtze River. In the Northern areas of China, the Han subpopulations from Shandong and Tianjin have large genetic distance with others; In the Southern areas, the genetic relationships within the Han subpopulations of Hong Kong, Hainan and Guangxi are much closed and greatly different from the others. The Han subpopulation of Xiamen is comparatively closed to Northern Han. Principal component scatter plot reflects that the spatial distribution pattern of Han subpopulations is wide distribution and gathered tightly in small areas in China. The three main factors contributing to the distribution characteristics of Han subpopulations in China are geographic isolation by the Yangtze River, floods in history and the population migration caused by wars or disasters using MCOA analysis method.关键词：STR;MCOA;Han nationality;R
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发布时间：2023-12-11 - 摘要：The genetic relationships among 11 species of Medicago and relative species were studied by using 30 pair of SSR primers and 12 ISSR primers. Based on genetic diversity analysis and UPGMA cluster analysis the results showed that 4 species of subgen. Platycapos were clustered together, related to their similar morphological characteristics; species of subgen. Platycapos were clustered with Trigonella, while T. cancellata were nested in subgen. Platycapos clade; the genetic distances among 3species of M. sativa complex were shortest; M. polymorpha was closer to Trigonella in ISSR results. Thus Trigonella had close genetic relationship with Medicago, especially species of subgen. Platycapos, and relatively farther from other species in Medicago.关键词：Medicago;relative species;microsatellite markers;genetic relationships
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发布时间：2023-12-11 - 摘要：The effects of three Pharmaceuticals and Personal Care Products (PPCPs), namely erythromycin lactobionaten (ETM), diclofenac sodium (DCF) and polyoxyethylene nonylphenol ethers (n=10, NPEO10), on growth and photoystem II (PS II) of Scenedesmus obliquus were investigated. The results showed that the three PPCPs could significantly decrease the growth rate and inhibit the PS II function of the tested algae, among which, ETM was the most toxic, followed by NPEO10 and DCF. However, low concentration (0.05 mg/L) of NPEO10 could promote the growth rate and PS II function of S. obliquus. Analysis of chlorophyll fluorescence transient kinetics showed that ETM induced an inactivation of reaction center and inhibited both donor and acceptor sides of PS II reaction center, however, the other two PPCPs mainly inhibited the electron flow beyond Q-A. Our study suggested that some chlorophyll fluorescence indices are highly sensitive and relatively specific to algal exposure of PPCPs, and may be potentially used as candidate biomarkers for the exposure of PPCPs.关键词：Pharmaceuticals and Personal Care Products;Scenedesmus obliquus;IC 50;chlorophyll fluorescence transient kinetics
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发布时间：2023-12-11 - 摘要：Based on Geographic Information System(GIS), at a 1 km×1 km grid size, by choosing terrain, land cover, climate and water resources as evaluation factors, this paper establishes the human settlement environment model, calculates the human settlement environment index(HEI) of Guangdong, analyses the regional differences of natural suitability of human settlement environment and discusses the suitable and restrictive factors of different regions in Guangdong Province. The results show that: the HEI of Guangdong ranges from 29.6 to 91.2; the natural environment suitability decreases both from the central region to the south and from the central region to the north of Guangdong. Considering area and population, the comparatively suitable region ranks first in both aspects, accounting for 67.46% of the total area and 71.07% of the total population of Guangdong; the common suitable region accounts for 288% of the total area and 21.54% of the total population of Guangdong; the most desirable region -accounts for 2.97% of the total area and 7.32% of the total population of Guangdong; the low suitable region has the lowest percentage in both aspects, with 0.77% of the total area and 0.07% of the population of Guangdong. Salient relief is a common bottleneck of natural suitability for human settlement in northern Guangdong, while surface water shortage and hot climate are the main disadvantages of natural environment suitability in Zhanjiang and Maoming. Sparse vegetation is the main natural restriction to natural suitability of some developed regions in the Pearl River Delta, while most common suitable regions are restricted by two or more natural factors.关键词：Guangdong province;natural suitability of human settlement environment;GIS;terrain;land cover;climate;water resources
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发布时间：2023-12-11 - 摘要：Due to the lack of a clear definition for some key parameters in engineering design specifications, the wrong estimation of earth pressure produced by the inner pit excavation often results in accidents. The existing researches of earth pressure in the passive zone of pit-in-pit have not considered the soil arching effects, which widely exist in geotechnical engineering. As a result, an accurate analysis on passive earth pressure is impossible. In this paper, an earth pressure mechanical model of cohesionless soil is established by presuming the inner pit support structure with large stiffness and very close to the outer pit support structure. Coefficient of earth pressures and the large principal stress rotation angle are obtained by analysing the horizontal earth pressure between two pit supporting structures at a limit state based on soil arching effects, and then the theoretical formulae and the force point are obtained. The case study shows that this method can better reflect the actual situation by analysing horizontal differential elements comparing to the classical earth pressure theory.关键词：pit-in-pit;passive earth pressure;soil arching effects
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发布时间：2023-12-11 - 摘要：The stability and reliability of inversion can be modified and improved by controlling the quality of inversion intermediate results. The reflectivity modeling method and conjugate gradient inversion method are used in this paper. In the process of inversion, the negative gradient is lined up according to the horizontal slowness to form the negative gradient panel in a slowness-depth domain. In the negative gradient panel the gradient represents the contribution provided by data with different incident angles (i.e. different horizontal slowness or ray parameter). Thus, the negative gradient panel has the similar meaning as the common imaging point gather in migration and can be used for tool controlling process of inversion. The roles of quality control that the negative gradient imposed on the process of inversion are discussed from the following aspects: the rationality assessment of the inversion initial value; the correctness evaluation of parameter selection when using three inversion strategies, especifically, the correctness evaluation of the frequency-band selection in frequency-division inversion, the correctness evaluation of the layer segment selection in layer-division inversion, and the correctness evaluation of the slowness components selection in slowness-division inversion. The test using model indicates that the quality control for inversion intermediate results based on negative gradient panel is feasible.关键词：pre-stack inversion;gradient panel;quality control;inversion strategy;waveform inversion
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发布时间：2023-12-11 - 摘要：Based on the fractal theory, the fractal geometry is applied to studying the active faults system in Guangdong Province. Results indicate that the spatial distribution of all faults in Guangdong Province is a distinct fractal set with selfsimilarity in the nonscale range of 12.5-100 km, and the fractal dimension, obtained by the boxcounting method, interprets well the characteristics of the spatial distribution of faults. The fractal dimension of all faults in the study area is 1.582 3, that of the NE faults 1.434 2 and that of the NW faults 1.115 7 and EW faults 1.039 4. The densities of spatial distribution of the NE and the NW faults supplement to each other, indicating the inter-restraint properties of these two groups of faults. Eventually, correlating the isoline maps of fractal dimensions and historical earthquake distribution, it is tried to find out the relationship between the fractal characteristics and seismic activities.关键词：active faults;fractal;box-counting;historical seismic activities;Guangdong province
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发布时间：2023-12-11
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