最新刊期
卷 52 ， 期 6 ， 2013
- 摘要：The existing geodesic distance transform algorithms consider the influence of obstacles, but the calculated distances have errors. A bruteforce algorithm is suggested for accurate geodesic distance transform in a space with obstacles in this paper. It takes the convex corners on obstacles as relay sources to calculate the length of the shortest passable path from foreground pixels to background pixels behind the obstacles. The relay sources of this algorithm lie on the shortest passable paths from foreground pixels to background pixels, and thus distance errors are avoided, better than other relay sources suggested in the existing geodesic distance transform algorithms. Experimental results show that there is no distance error in the new algorithm, and it is applicable for distance transform in space with obstacles in any shapes.关键词：obstacle space;geodesic distance;distance transform;visibility
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发布时间：2023-12-11 - 摘要：Incremental updating is one of the most frequently used methods in spatial databases updating and the detection of changed objects is the crucial technology. Change detection is of great significance for improving the efficiency of spatial database updating. This paper refines the object-traversing method and proposes a new change detection method based on quad-tree. Considering the principle of spatial index, this method divides the region of the corresponding layers based on quad-tree. By calculating the vertex-edge changed index of the objects in the region, this method can evaluate the changed situation of the region. The method can filter out the unchanged areas and rapidly locate the change areas in an iterative way. The experimental result showed that this method can reach high computational efficiency and properly recognize the change information. Comparing with the traditional change detection algorithm, this method can improve the efficiency of GIS database updating significantly.关键词：change detection;quad-tree;incremental updating
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发布时间：2023-12-11 - 摘要：The Pearl River Estuary region is densely covered with rivers. Affected by runoff, tide and other natural factors and human activities, the salinity change process during salt water intrusion period is extremely complex. With the data of salinity from Guangchang Station and tidal range from Sanzao Station, the period features of salinity change and the correlation between tides and salinity change in Modaomen waterway were studied using wavelet analysis. The results show significant correlation between salinity change and tides in the cycle of 15 days. Phase difference is about 60°~90°, that means salinity changes ahead of tidal process about 2.5~3.75 days.关键词：the Pearl River estuary;salinity changes;tidal process;delay correlation
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发布时间：2023-12-11 - 摘要：Three zenith hydrostatic delay (ZHD) models of Saastamoinen, Hopfield and Black are adjusted by using sounding data and GPS/MET observations from Nanchang and Ganzhou in 2010. These adjusted ZHD models not only reduce the model bias, but also improve the accuracy of ZHD. Compared with old ZHD models, the improved ZHD models are much closer to the sounding observations because they yield smaller bias and standard deviation from sounding data. Based on the GPS PW from Hopfield ZHD model (which has minimum bias), the typhoon “Haikui” was analyzed during 7-11 August 2012 when it influenced northeast of Jiangxi. Results showed that the precipitation occurred two hours after GPS PW exceeding 60 mm, became much heavy when GPS PW was high and finally came to the end when the GPS PW was less than 60 mm. In this paper, the variation of GPS PW in Jingdezhen located northeast of Jiangxi was diagnosed using water-vapor budget equation. Results showed that in the early stage of typhoon's influence on Jiangxi，the specific humidity advection was the main cause for the increase of GPS PW. In the middle stage, the specific humidity advection weakened and the convergence of horizontal wind became the main cause for the increase and maintenance of GPS PW. In the late stage, the convergence of horizontal wind reduced rapidly and the water vapor consumed by rainfall was the main reason for the decrease of GPS PW.
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发布时间：2023-12-11 - 摘要：By using functions of the form H(t,s,t0) and a generalized Riccati transformation technique, new Kamenevtype oscillation criteria are established for second-order nonlinear dynamic equations on time scales of the form (p(t)ψ(x(t))xΔ(t))Δ+f(t,x(σ(t)))=0关键词：second-order nonlinear dynamic equations on time scales;Kamenev-type;oscillation criteria;generalized Riccati technique
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发布时间：2023-12-11 - 摘要：Using linear-quadratic control theory, a stochastic differential game problem between investor and market with liability is investigated, in which the liability process is assumed to be a geometric Brownian motion and completely correlated with stock prices, with the market as the hypothetical counterpart and the investor as the leader of game. Under exponential utility and power utility, optimal investment strategies and optimal market strategies as well as the closed form expression of the value function are obtained. Though further analyzing of the results, some explanations in economic are given.关键词：stochastic differential games;linear-quadratic control;liability;exponential utility;power utility
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发布时间：2023-12-11 - 摘要：For iterative method to solving the linear system Ax=b in the preconditioned, on the basis of selecting the preconditioned factors in the past by using matrix iterative analysis and comparison theorems, two types of the split form with parameters are given. The new splitting methods not only can make the SOR iterative method convergence, but also can make the convergence rate better than the general preconditioned SOR method, and finally find the optimal values of the parameters.关键词：precondition;convergence;the SOR iteration method;M-matrix
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发布时间：2023-12-11 - 摘要：Temporal reasoning is an important research direction of Artificial Intelligence (AI). Disjunctive temporal problem (DTP) is an expressive quantitative temporal model which is widely used in automated planning and scheduling and is therefore being well studied. The definition of weak implication and weakly evolutional disjunctive temporal network (WEDTN) is proposed. Based on the WEDTN structure a visual DTP solver TRSE is designed. The demonstration reveals that the visualization based on WEDTN better facilitates the understanding and discovery of DTP solving algorithm and the impact of structural information on that than usual search tree based visualization.关键词：artificial intelligence;temporal reasoning;disjunctive temporal problem (DTP);constraint satisfaction problem (CSP);weakly evolutional disjunctive temporal network (WEDTN)
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发布时间：2023-12-11 - 摘要：For a class of complex cubic Lotka-Volterra systems with a 4 : -5 resonant singular point, the sufficient conditions for integrability are obtained through the computation of the first eight generalized singular point values. All these conditions are verified by constructing integrating factors or formal first integrals.
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发布时间：2023-12-11 - 摘要：The projective control of the complex system model by using the generalized control method is investigated,and it proves the globally stable condition of the error system. Numerical simulation verifies the feasibility and effectiveness of the method.关键词：complex system model;generalized control;stability
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发布时间：2023-12-11 - 摘要：Solar cells under uniform and non-uniform illumination show different features.The results of Matlab Simulink simulations of solar cell under uniform and non-uniform illumination are presented respectively. And MPPT technology is analysized on the basis of the characteristic curve obtained. SAA(Simulate Anneal Arithmetic) is applied in incremental conductance to improve the tracking precision of the MPPT under non-uniform illumination. Finally, a simulation of SAA is conducted and compared to the result of the simulation using incremental conductance and global MPPT. The results indicate that incremental conductance join with SAA can accurately track the maximum power point of PV array under nonuniform illumination, stabilizing the MPPT control.关键词：photovoltaic;maximum power point tracking;non-uniform illumination;incremental conductance algorithm;SAA
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发布时间：2023-12-11 -
Study on Technology of the Sinking Pipe by the Method of Autoclaved Aerated Concrete Replacement Mud
摘要：In the deep hole of gas pumping, double plugs buoyancy method is used to install mine gas pipe. Because velocity of exhausting the pressure air in two plugs is difficulty controlled and there is large pressure difference between internal and external gas pipe, sometimes the pipe is collapsed and mud sprays out the pipe, at last the sinking pipe is failure. Based on the above reasons, the buoyancy method of sinking pipe is put forward filling of the autoclaved aerated concrete blocks used for floating pipes. In the experiment, the autoclaved aerated concrete blocks are put in the pressure tank, and then confining pressure strength of the AAC is 6 MPa which is associated with 500 m depth under the mud and the volume change rate of the AAC, which should not be considered in the application, is also measured to be 1.68% while the density of the AAC is 660 kg/m3. Field application shows that the pipe filling of autoclaved aerated concrete blocks reduce the load of the rig. For the pressure between internal and external gas pipe is equal, what the collapse of the pipe is completely avoided and that pipe wall becomes thinner brings obvious economic benefit.关键词：gas drainage pipe;technology of sinking pipe by buoyancy;autoclaved aerated concrete column;replacement of mud;oil pressure experiment in the pressure tank- 549
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发布时间：2023-12-11 - 摘要：In order to provide real-time communication in wireless multimedia sensor networks (WMSNs), the QoS supported routing algorithm is addressed. Theoretically, data aggregation is defined and its advantages in QoS routing are introduced. Based on it, a least energy realtime routing algorithm (LERTR) is presented to construct the delay-constrained routing tree in WMSNs. In LERTR, a least energy routing tree is constructed by average distance heuristic (ADH) , and then, if the path delay can't meet the delay upper bound, a shortest delay path which is computed by Dijkstra's algorithm will be merged into the existing routing tree to meet the delay upper bound. Finally, the simulation results verify the correctness of the algorithm in some degree.关键词：WMSNs;routing algorithm;data aggregation;real-time;least energy consumption
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发布时间：2023-12-11 - 摘要：The interface plays an important role in the macro-mechanical properties of SFRC (Steel Fiber Reinforced Concrete), especially the interface layer between the steel fiber and concrete matrix.The pull-out numerical models with or without aggregates have been established, then the effect of matrix strength on pullout properties of single fiber and the influence of aggregate have been studied. The results indicate that the higher the matrix strength, the larger the peak load of specimen and the higher the interfacial bond strength, but the pull-out toughness decreases. The variation of matrix strength has little impact upon the damage process of pullout procedure. The specimen with concrete matrix is more sensitive to the changes of matrix strength compared with cement.关键词：interface;single fiber pullout;matrix strength;aggregate;bond strength;pullout toughness
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发布时间：2023-12-11 - 摘要：The normal distribution assumption of measured results in the Lamb waves-based damage detection work was studied. Through the analysis of the results of numerical simulations, it was proved that the distribution of the arriving time measured by using threshold method was still not a topical normal distribution even under ideal Gaussian white noise. Therefore, the new algorithm of non-parametric statistics was introduced to give the accurate estimate about the distribution. The damage detection numerical result shows that the using of the correct probability density function of the measurement results have a direct impact on the damage location detection accuracy.关键词：lamb waves;damage detection;probability density function;measurement error
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发布时间：2023-12-11 - 摘要：In order to obtain high performance PP composites using high toughness β-PP, the β-PP composites were prepared by PP filled nano-CaCO3(CC) supported β-nucleating agent (β-CC),CC and micro-CaCO3(MC).The result of differential scanning calorimetry indicated that the crystallization peak temperatures of PP increased by adding MC, the crystallization peak temperatures of β-CC filled PP composites were higher than those of composites filled by MC and CC, and the heterogeneous nucleation of β-CC was higher than those of MC and CC for iPP crystallization. The results on wide-angle X-ray diffraction analysis demonstrated that the MC and CC filled iPP composites mainly formed α-crystal, and the β-CC filled composites mainly formed βcrystal. The β-iPP composites with high filler could be prepared by adding β-CC into iPP matrix.关键词：isotactic polypropylene;CaCO3;β-nucleation;crystallization;melting behavior
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发布时间：2023-12-11 - 摘要：Ethidium bromide（EB）was used as molecule probe, the interaction between β-cyclodextrin-4-Benzyloxypheno (β-CD-PBP) and herring-sperm DNA was studied in physiological buffer solution (pH=7.4) by fluorescence spectroscopy, thermodynamic analysis and viscosity method. Based on the mole ratio method and linear method, the parameters were determined as follows: the binding rationβ-CD: nPBP =1 : 1 and binding constantKf= 7.39×103L·mol-1. The binding ratio was nDNA: nβ-CD-PBP =1 : 9, the thermodynamic perameters were ΔrHmθ＝1.44×105J/mol，ΔrGmθ300.15K＝－1.97×104J/mol，ΔrSmθ＝549.32 J/(mol·K), ΔrSmθwas the primary driven power of this interaction, the binding constants were K300.15K=2.86×103L/mol，K310.15K=2.69×104L/mol. These results indicated that the interaction between β-CD-PBP and herring-sperm DNA belonged to electrostatic and part intercalation.
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发布时间：2023-12-11 - 摘要：In order to conduct cleaner production audit for enterprises belonging to nocleaner production standard industry, a factor analysis framework combined with qualitative and quantitative method was proposed in this study. As a demonstration, an optical glass lens manufacturer was audited for cleaner production using the factor analysis method and the traditional cleaner production audit (CPA) method respectively. The result showed that, comparing with the traditional CPA method, using the factor analysis method could reduce CPA time by 40% and CPA cost by 32%, but obtain 97-90% audit benefits. This work provided a new approach and idea for cleaner production audit in nostandard industry.关键词：cleaner production;audit;methods;nocleaner production standard;factor analysis method
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发布时间：2023-12-11 - 摘要：Six Rhodiola crenulata samples collected from different places in Tibet were extracted by methanol and analyzed using UPLC-ESI-MS/MS in negative-ion mode. In addition to 12 compounds identified based on quasi-molecular ion and MS2 fragment ions, the differences of the relative content of related compounds were compared. The results showed that there were obvious differences in the composition of identified compounds in herbs with different collection places.关键词：Rhodiola crenulata;UPLC-ESI-MS/MS;chemical composition;Salidroside;flavone
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发布时间：2023-12-11 - 摘要：After the samples were extracted by ethyl acetate, the supernatant were cleansed by acidic alumina and extracted by potassium carbonate. The extracts were then reacted with acetic anhydride. The products were detected by gas chromatography with ECD detector via an external standard method following being extracted by n-hexane. The linearity of three compounds were held in 5~100 μg/L, with correlation coefficient R2> 0.999. The detection limits for the GC method (S/N=3) of the nitrophenolate were 5 μg/kg. The tests for recovery were carried by addition of standard at concentration of 10~100 μg/kg. The result indicated that the residue content of p-nitrophenol sodium, o-nitrophenol sodium and 2-methoxy-5-nitropenolate sodium were 86.4%~ 89.6%, 82.8%~ 84.3% and 89.9%~ 92.2%，respectively, while the relative standard deviations were less than 15%. This method can be used to determine the residue content of nitrophenolate in edible portion of fish and shrimp.关键词：Gas chromatography;fish;shrimp;sodium nitrophenolate;residue
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发布时间：2023-12-11 - 摘要：The quality standard for Hongzhu Capsule (Citrus Grandis active fraction) was established. Naringin and rhoifolin were identified by TLC．The TLC identification was specific．The assays of the total flavonoids were determined by UV. The linear range of flavonoids was from 0～27 μg/mL ( r=0.999 8) with an average recovery of 99.63% ( RSD was 1.95%，n=9)．Naringin was determined by HPLC.The linear range of naringin was from 0.201 2～2.012 0 μg ( r=0.999 9) with an average recovery of 97.92%(RSD was 2.80%，n=9)．The methods in quality standard were simple， accurate and reproducible. The established standard can be used for quality control of Hongzhu Capsule.关键词：Hongzhu capsule;TLC;UV;HPLC;naringin;quality standard
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发布时间：2023-12-11 - 摘要：Bacillus thuringiensis is widely used for pest control. However, the fermentation production of this bacterium was severely influenced by the ramdom outbreak of lysogenic phage from B. thuringiensisIn the present study, a novel bacteriophage MZTP02 was isolated from industrial 〖WTBX〗B. thuringiensis strain MZ1 and sequenced for tmp gene encoding tail tape measure protein. By assisting and control the tail packaging of bacteriophage, the protein is an essential component to help phage attach to the host for successful infection. By PCR, tmp gene was amplified from the genome DNA of MZTP02 and cloned into pQE30 and expressed in M15. The TMP protein of 35 000 was obtained and purified by Ni-NTA column. Using the purified TMP protein as the immunogen, polyclonal serum was raised in the New Zealand rabbit. Western blot analysis of TMP proteins expressed in prokaryotic cells demonstrated a polypeptide with size of 35 000 which was in agreement with the predicted size of this protein. Results of plaque formation of phage after TMP antiserum treatment showed a negative relationship to the concentration of antiserum when the concentration of multiplicity of infection (m.o.i) was less than 1, e.g. the titers were 1×105pfu/mL and 2×103pfu/mL when a degnized amounts of phage were mixed with TMP antiserum with concentration of 25 μg/mL and 250 μg/mL respectively. This result indicated that TMP antiserum can combine with TMP protein, and then depress the phage titer.关键词：Bacillus thuringiensis;lysogenic bacteriophage;tmp gene;prokaryotic expression;packaging
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发布时间：2023-12-11 - 摘要：Many plants of genus Pellionia (Urticaceae) are with wild vegetable high quality. P. scabra is used widely in Mount Dayaoshan of Guangxi Province and Mount Yaoshan of Guangdong Province. In this paper, the nutritional components of P. scabra were analyzed by using the national standard methods of food detection and instrumental analytical methods such as IRIS Advantage (HR) and Amino Acid Analyzer. The results show that the stem and leaf of P. scabra contain crude protein 3.21g, crude fat 1.27 g, total sugar 2.19 g, energy 33.03×4.19 J in every 100 g fresh weight and contain Ca 4 178.13 mg, P 381.05mg, Ｋ 6 116.78 mg, Na 35.10 mg, Mg 1 236.73 mg, Fe 53.81 mg and Cu 2.88 mg in every 1 kg fresh weight.The content of 17 amino acids determinated includes 7 essential amino acids accounts for 14.36% of the dry weight. Comparing with other common vegetables, the Pellionia scabra could be considered as a kind of wild vegetable with higher nutritious value, abundant nutritional components, mineral element and amino acids.关键词：wild vegetable;Pellionia scabra;nutritional components;mineral element;amino acid
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发布时间：2023-12-11 - 摘要：The aim of the present study is to verify whether roflumilast attenuates PQinduced injury and fibrosis in lung, liver and kidney tissues of mice. Mice are pretreated with PQ of 20 mg/kg (ip.), and then dealt with roflumilast or dexamethasone 5 mg/(kg·d) for 21 days. The tissues of lung, liver and kidney are surgically separated and immersed in 10% neutral formalin. The injury and fibrosis in tissues of lung, liver and kidney are observed by H&E staining and Masson staining. The results show that PQ (20 mg/kg, ip.) induces remarkable toxicity and fibrosis in tissues of lung, liver and kidney. Roflumilast (5 mg/kg per day for 21 days) treatment reduces PQinduced injury and fibrosis in tissues of lung, liver and kidney, which is superior to dexamethasone. So, roflumilast attenuates PQinduced injury and fibrosis in tissues of lung, liver and kidney of mice.关键词：roflumilast;injury;fibrosis;paraquat;mice
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发布时间：2023-12-11 - 摘要：The northwest area provides ideal situation for installing PV power systems with its rich solar resource and open area, such as Gobi desert. A prototype of a shaded photovoltaic module is presented. And then, the typical shading types are concluded, which is classified as front row shading, vegetation, wire poles and distribution rooms and birds dropping after longtime surveys and observation. The shading effects caused by some particular obstacles are measured and analyzed according to the field test on a 20-MW PV system. Reduction of the I-V and P-V characteristic has been observed and compared with the theoretical value.In the end, some suggestions on dealing with these shading problems in the installation and operation of the PV system are proposed.关键词：shading effects;output characteristic;grid-connected;solar farm
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发布时间：2023-12-11 - 摘要：Deletion-correcting codes of mixed length are considered. By applying directed pairwise balanced design, it is proved that for all positive integers v, v≥4and v〖JB({〗8,9〖JB)}〗and possibly v≠14, there exists T(2,{4,5,6},v)－codes. The bound of T(2,{4,5,6},v)－codes is also investigated.关键词：deletion-correcting code;perfect deletioncorrecting code;mixed length;directed pairwise balanced design
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发布时间：2023-12-11 - 摘要：Let G=(V,E) be a graph, a function f:V→{－1,1} is said to be a cycle signed domination function (CSDF) of G if ∑v∈V(C)f(v)≥1 holds for any induced cycle C of G,where the cycle signed domination number of G is defined as γsc(G)=min{∑v∈V f(v)f is a CSDF of G}.Some lower bounds of the cycle signed domination number of a graph are obtained, and all graphs G with δ≥2 and γsc(G)=4－|V(G)| are characterized.关键词：graph;signed domination;cycle signed domination function;cycle signed domination number
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发布时间：2023-12-11
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