最新刊期
卷 59 ， 期 4 ， 2020
- 摘要：In recent years, our team has been committed to the research of new functions of traditional Chinese medicine, and systematically screened Chinese medicines and identified Pithecellobium clypearia with significant antibiotic synergistic effect, which has the potential to be used as an antibiotic adjuvant. In this review, we summarized the current situation of bacterial antibiotic resistance, the research progress of antibiotic adjuvant, and the research progress of Pithecellobium clypearia as antibiotic adjuvant to provide the reference for the further investigation and development of this herbal plant.关键词：multiple antibiotic resistance;antibiotic adjuvant;Pithecellobium clypearia;synergistic effect
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发布时间：2023-11-01
Invited review
- 摘要：Heat shock proteins (HSPs) play important roles in fish stress and immune response, and HSP90-β is an important member of the HSPs family. In the present study, to investigate the possible role of HSP90-β in the immune response, the full-length cDNA sequence of HSP90-β was first cloned from jade perch (Scortum barcoo). The size of the full-length cDNA of jade perch HSP90-β is 2 708 bp, of which 5' UTR is 86 bp, 3' UTR is 444 bp, and ORF is 2 178 bp, which encodes 725 amino acids. The molecular weight of jade perch HSP90-β is predicted as 83 200. And this protein owns five characteristic sequences of the HSP90 family. Moreover, it has no signal peptide and transmembrane domain. Phylogenetic analysis showed that the amino acid sequence identity of jade perch HSP90-β is more than 90% with those of other fishes. Under normal circumstances, the HSP90-β mRNA of jade perch is mainly expressed in the liver. After infection with Streptococcus agalactiae, the HSP90-β mRNA expression decreased first and then increased in liver. Differently, it increased first and then decreased in spleen, head kidney and brain. This result suggests that the HSP90-β may be involved in the immune response elicited by S. agalactiae infection in jade perch.关键词：Scortum barcoo;HSP90-β;molecular cloning;expression analysis
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发布时间：2023-11-01 - 摘要：The mangrove endophytic fungus Aspergillus fumigatus SAS10 from Sonneratia apetala of Dongzhai haror in Hainan was fermented by using rice medium. The extract of fermentation culture was subjected to column chromatography on silica gel, column chromatography on Sephadex LH-20, and semi-preparative HPLC. Seven compounds were obtained.By analyzing mass and NMR spectroscopic data, their structures were identified as aspergyllone (1), (R)-2-(hydroxy(phenyl)methyl)-4H-pyran-4-one (2), carbonarone A (3), campyrone A (4), campyrone C (5), asperfurandione A (6) and dibutylterephthalate (7), respectively. All of compounds obtained are reported firstly from secondary metabolites of the mangrove endophytic fungus Aspergillus fumigatus.关键词：mangrove;endophytic fungus;Aspergillus fumigatus;secondary metabolites;pyrone
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发布时间：2023-11-01 - 摘要：The title reaction was investigated in this paper. The dispersion corrected density functional method (WB97X-D) was applied, together with perturbation theory (MP2 method) and solvation model density (SMD) model based on self consistent reaction field theory. The study showed that benzene ring-H, methylene-H and methenyl-H abstraction by hydroxyl radicals can all induce ibuprofen molecule damage. The calculation of potential energy surface showed that the energy barrier of benzene ring-H abstraction by hydroxyl radicals at different positions was nearly the same with the values of ~123.0 kJ/mol, and the damaged ibuprofen molecule could be repaired. The energy barrier of methylene-H abstraction of hydroxyl radicals at different positions was almost the same, ~100.0 kJ/mol, and the damaged ibuprofen molecule was difficult to be repaired. Furthermore, the energy barrier of methenyl-H abstraction by hydroxyl radicals was 68.4 kJ/mol, and the damaged ibuprofen molecule cannot be repaired. The results showed that the reaction of ibuprofen molecule damage induced by methylene-H abstraction by hydroxyl radicals had an absolute advantage.关键词：ibuprofen;damage;hydroxyl radicals;density functional theory;perturbation theory;energy barrier
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发布时间：2023-11-01 - 摘要：Based on the multiple time scale index of standardization evaporation(SPEI) in the Pearl River basin from 1961 to 2011, the spatial structure distribution and temporal variation characteristics of drought in the Pearl River basin were analyzed by using the methods of rotating empirical orthogonal function decomposition, trend and mutation tests, wavelet spectral and wavelet global coherence spectral analysis. The results show that: 1) The spatial distribution and temporal variation of drought in the Pearl River basin are significantly different in the past 50 years; the number of drought events has been increasing since the 1970s. The duration and intensity of drought events in the Pearl River basin have increased significantly since the 21st century. 2) According to SPEI's REOF spatial decomposition, the Pearl River basin can be divided into 6 spatial modes, and the load centers are located in the south Guizhou and east Yunnan of the Dongjiang river basin in the north Guangxi, the southeast Guangxi, the southwest Guangxi, and the south Guizhou and the east Yunnan, respectively. There is a general drought trend in each region. The southern Guizhou and eastern Yunnan have become the drought center of the Pearl River basin. 3) The wet-dry variation in six zones has an oscillation period of 2-8 year El Nino variation. Some regions show 11 year and 22 year change periods associated with sunspot activities, and the response of each region to ENSO events is significantly different.关键词：the Pearl River basin;standardized precipitation evapotranspiration index;spatial and temporal variation of drought;rotation of empirical orthogonal function;wavelet analysis;wavelet global coherence spectrum
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发布时间：2023-11-01 - 摘要：The industrial spatial differentiation of Guangzhou is analyzed based on the data of surveys of economy in 2008 and 2013, by using factor analysis and clustering analysis. Then the results are compared with previous findings based on similar data in 1996, 2001, and 2004, in order to derive the evolution process and mechanism of the industry in Guangzhou. The results show that: 1) The industry in Guagnzhou showed progresive decline of main urban industrial areas, sluggish differentiation of comprehensive industrial areas, transfer to periphery of special industrial areas, and the upgrading transformation of rural industrial areas. 2) There are five kinds of patterns of the industrial space differentiation process in Guangzhou, which are the declining pattern of the old industrial areas with production factors evacuating, the preserving pattern of the central industrial areas with capital support, the sustained development pattern of the suburban advanced industrial areas with industrial upgrading, the slack pattern of the peripheral comprehensive industrial areas with path dependence, the saltatory pattern of the outer suburban emerging industrial areas relying on large projects. 3) The administrative mechanism, market mechanism and industrial base together contribute to the differentiation patterns in Guangzhou.关键词：industrial area;spatial differentiation;evolution mechanism;Guangzhou
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发布时间：2023-11-01 - 摘要：Taking the soil salinity and corresponding hyperspectral data of the lakeside oasis on the west bank of the Bosten Lake as the research object, the root mean square R, logarithmic lg R, reciprocal 1/R, reciprocal 1/lgR were used to transform the original spectral reflectance. The fractional differentiation was introduced to perform differential preprocessing within 0-2 on the transformed spectral reflectance. The characteristic band through significance test was used to model and verify partial least squares regression. The results show that: 1) The characteristic bands that passed the significance test were mostly 1/R of 691 bands, which was 226 more bands than the original band R. With increasing orders, the number of bands that passed the significance test in each order showed a trend of increasing first and then decreasing. The characteristic bands that passed more were 0.4 and 0.6 orders of 1/R, which were 145 and 150, respectively. 2) The absolute value of the correlation maximum value of the original spectrum R was 2nd order 0.53. The absolute value of the correlation maximum value of the other four mathematical transformations was 0.11-0.16, higher than R. The characteristic bands were mainly concentrated at 600-1 000 nm and 2 020-2 330 nm. 3) The fractional differential of the original spectral R, the root mean square R, the logarithm lgR, the reciprocal 1/R, and the logarithm reciprocal 1/lgR was modeled by partial least squares regression. The model established at 0.2th order of 1/lgR was the best one, with R2C=0.78，RMSEC=1.56，R2V=0.63，RMSEV=1.44.关键词：fractional differential;soil salinity;spectral transformation;partial least squares regression methods;hyperspectral estimation
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发布时间：2023-11-01 - 摘要：In this paper, a modified pseudolinear enhanced phase-locked loop (PL-EPLL) is proposed to improve the performance of PLL synchronization when the power grid is under non-ideal condition, such as disturbances and faults. The modification is based on a timely-decoupling strategy between the estimated phase-angle and the estimated frequency, for which in a designable frequency-locked range, the robustness of frequency synchronization is enhanced and the dynamic performance of PLL is improved. In addition, based on the feature that PL-EPLL has two different phase-locked points, an optimized setting of the initial value of the estimated phase-angle is introduced in this paper, which can statistically improve the start-up speed of the PL-EPLL algorithm. Finally, the feasibility of the proposed method has been verified by simulation and experimental results.关键词：EPLL;PL-EPLL;phase-frequency decoupling;PLL start-up
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发布时间：2023-11-01 - 摘要：Based on sensitivity analysis, by introducing Tikhonov regularization and trust-region restriction, the inverse problem of delayed system - parameter identification is transformed into a normal nonlinear least squares optimization problem with trust region, and a parameter identification method for delayed system based on response sensitivity approach is proposed. A single-degree-of-freedom linear delayed system model is studied and the sensitivity analysis of acceleration is carried out. The numerical simulation of parameter identification shows that the proposed method can effectively identify the parameters of simple delayed system, and has the advantages of high identification accuracy, fast convergence speed and less sensitivity to noise. This numerical example verifies the feasibility and efficiency of the response sensitivity approach in the practical parameter identification of delayed systems.关键词：delay differential equations (DDE);parameter identification;response sensitivity approach;trust-region restriction
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发布时间：2023-11-01 - 摘要：Due to the test errors and the uncertainties of structural parameters, the best local and global solutions are all possible to be the true solution of finite element model updating. To simultaneously obtain the local and global best solutions in model updating, an improved steady state genetic algorithm (ISSGA) is proposed. The proposed ISSGA utilizes a double angle operator to select alternative solutions of the objective function. The solutions are iteratively optimized by defining the solutions pairs, and the global and local best solutions are eventually obtained. Two benchmark functions and model updating of a concrete box girder bridge are employed to validate ISSGA regarding the accuracy, stability and calculation efficiency. In addition, the principle to determine the algorithm parameters is clarified. The results show that the ISSGA can obtain the global and the best local of the objective function at same time. The double angle operator can avoid the omission of the best local. ISSGA provides a possibility to obtain the solution of model updating wi the best justification.关键词：bridge engineering;model updating;steady state genetic algorithm;optimization;multiple solutions problem
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发布时间：2023-11-01 - 摘要：The rapid development of logistics outsourcing has brought new opportunities for the supply chain integration design. This paper proposes a location routing problem planning model with the outsourcing strategy, with the objective to reduce the logistics system cost via partially outsourcing vehicle tasks. Considering the constraints in actual operation such as time windows, and the composition of self-delivery and outsourcing transportation costs, we develop a model to minimize the total cost of the logistics network by a jointly optimizing the distribution of facility locations and vehicle routing decision. The system includes fixed cost of self-vehicle and variable transportation costs, the fixed costs of distribution center construction, and the transportation costs of outsourcing. According to the characteristics of the problem, the hierarchical coding method is designed for genetic algorithm. Through the simulation example, the proposed strategy is compared with the traditional complete self-delivery and outsourcing operation mode. The results show that the proposed strategy could effectively reduce the additional cost of self-delivery and the construction cost of the distribution center, thus reducing the system cost. Our proposed is experimentally proved to reduce the system cost by 8.08% and 25.03% compared to the complete self-delivery and outsourcing operation mode, respectively. Finally, the impact of different outsourcing price on the systematic decisions is investigated by sensitivity analysis.关键词：transportation economy;location routing problem;outsourcing distribution;time window;genetic algorithm
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发布时间：2023-11-01 - 摘要：Single-particle aerosol mass spectrometer (SPAMS) was used to analyze the source features of 3 typical ship emissions in Yantai. The results showed that particle classes emitted by marine diesel oil were mostly composed of organic carbon (OC) and elemental carbon (EC), while those emitted by heavy fuel oil contained larger number of metal-containing particles such as Fe, V, K and Na. V-containing particle classes accounted for the largest proportion in heavy fuel oil emission, and were mainly concentrated in the small particle size range of 0.5-1.1 μm, while the metal-containing particles such as Si, Fe, K, and Pb were mainly distributed in larger size range of 0.8-1.4 μm. Based on the results, the V-containing particles were used as ship-emission tracer to study the impact of ship emissions on the air quality of 5 typical sites in Yantai. The results revealed that the five sites were obviously affected by ship emissions especially in spring and summer. The two sites Parkson Mall and Wanrun Chemical were the closest to the port, and suffered the most from the ship emissions. Under specific conditions in spring and summer, the V-containing particles proportion could reach up to 40%. Based on the statistical data, the PM2.5 emitted from inland and coastal ships in Yantai City were estimated to be 463.6 t in 2017, which was of the same order of magnitude as vehicle emission. Further attention should be paid to the impact of ship exhausts on local air quality.关键词：single particle aerosol mass spectrometry;PM2.5;source profile;V-containing particle;ship emission
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发布时间：2023-11-01 - 摘要：Considering that concrete pavement structure has certain transverse isotropy property due to its formation process and other reasons, in this paper, the dynamic stiffness matrix of deflection basin in frequency domain is obtained by using Fourier integral equation transformation method, and then the dynamic response of deflection basin in time domain under dynamic load of Falling Weight Deflectometer is obtained by using mixed variable algorithm. The algorithm can be expressed analytically in horizontal direction, and precision in computer sense can be achieved by precise integration algorithm in vertical direction. Numerical examples verify the accuracy of the proposed algorithm. On this basis, extensive parametric analysis is carried out for bottom boundary condition of the pavement structure and the transversely isotropic property, so as to provide reliable analysis for engineering practice.关键词：concrete pavement;layered structure;transversal isotropy;dynamic response;the time domain solution
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发布时间：2023-11-01 - 摘要：In order to explore the impact of risk factors, i.e. human, vehicle, road and environment, on bus accident severity, 5 869 bus accidents happening in Guangdong Province during 2008 and 2017 were selected and then divided into 3 categories which were accidents between vehicles, vehicle-pedestrian accidents and single vehicle accidents. Taking accident severity as the dependent variable and selecting age, vehicle maneuver, road alignment, region, lighting condition and accident modalities etc as the independent variables, Logistic models were constructed for comparative analysis. The results show that: The models fit the data properly except the model of single vehicle accidents. The risk factors of bus accident severity had similarities and differences among accidents with different modalities. Vehicle maneuver, road type, region and time were significantly correlated with bus accident severity except in the model of single vehicle accidents. Road alignment only significantly influenced the overall bus accident severity, while type of crash location and holiday only had significant impact on severity of accidents between vehicles. The results can provide references for reducing bus accident severity.关键词：traffic safety;bus transit;accident severity;K-means clustering;Logistic regression model
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发布时间：2023-11-01 - 摘要：In this paper, we study synchronization of a class of fractional-order and integer-order multi-chaotic systems with uncertainties models and external disturbances using self-adaptive sliding mode approach. And the sufficient conditions were arrived for fractional-order and integer- order multi-chaotic systems getting self-adaptive sliding mode synchronization by design sliding mode functions and control laws. Numerical simulation demonstrate the correctness of the conclusion.关键词：self-apaptive;high-order;sliding mode;multi-chaotic
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发布时间：2023-11-01 - 摘要：Let G be a simple graph.An IE-total coloring
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发布时间：2023-11-01 - 摘要：Under the axiomatic assumptions for nonlinear expectations and financial risk measures,the relation between sublinear expectations (Resp. superlinear expectations) and coherent risk measures is obtained, respectively.Furthermore,under a natural continuous assumption for the nonlinear expectations,the relationship between convex expectations (Resp. concave expectations) and convex risk measures is also established,respectively.关键词：nonlinear expectation;sublinear expectation;convex expectation;coherent risk measure;convex risk measure
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发布时间：2023-11-01 -
The generalization of Hermite-Hadamard type fractional integrals inequalities for preinvex functions
摘要：An identity with parameter is constructed via Riemann-Liouville fractional integrals on the invex subset.Using the constructed integral identity as the auxiliary function,some new Hermite-Hadamard type fractional integrals inequalities are derived,whose absolute values of the derivatives of the functions are preinvex.When the parameters are taken some specific values,some integral inequalities with different forms are obtained.关键词：preinvex functions;Hermite-Hadamard type inequalities;Riemann-Liouville fractional integrals;parameter;generalization- 6
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发布时间：2023-11-01 - 摘要：A class of delayed virus infection models with latently infected cells are investigated.The basic reproduction number is defined,and the sufficient conditions for the existence of each feasible equilibrium are given.By using Lyapunov functionals and LaSalle's invariance principle,it is proved that when the basic reproduction number is less than or equal to unity,the infection-free equilibrium is globally asymptotically stable;when the basic reproduction number is greater than unity,the chronic-infection equilibrium is globally asymptotically stable,but the infection-free equilibrium is unstable.The results show that the latently infected delay,the intracellular delay,and virus production period in the model do not affect the global stability of the model,and numerical simulations are carried out to illustrate the theoretical results.关键词：latently infected cells;Beddington-DeAngelis incidence;delay;virus infection model;global stability
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发布时间：2023-11-01
Research articles
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