Using the conductor surface function, the Laplace equation is transformed into the integral operation, and the potential expression is obtained which is generally established in the no charge region. Then the electric field distribution between two confocal parabolic conductor plates is calculated by the boundary condition, and equations of the electric field line is given.
With the rapid advancement of hydrologic informatization in Zhejiang province, the type, structure and volume of hydrological data are continuously enriched and developed. Traditional single-structured data storage and management methods cannot meet the requirements of the information-based society, hence not suitable today. This research adopts advanced technologies such as distributed data acquisition, intelligent data filtering and big data storage to build a hydrologic cloud data center in Zhejiang province. Based on the big data cloud platform technology, the cloud data center integrates various types of distributed multi-source heterogeneous hydrological data. It not only supports quality control, deep mining and efficient sharing of hydrological data, but enriches the resource sample of hydrological information and expands the depth and breadth of hydrological services. With the improved data mining and analysis efficiency, the cloud data center lays a solid foundation for modernization of water conser
In order to improve tannin extraction from longan callus, the effects of ethanol concentration, ultrasonic power and extraction time on the extraction of tannin were studied by ultrasound-assisted extraction. The tannin extraction procedure specification was then established using response surface methodology. The results show that optimized extraction of tannin (7.53 mg·g－1) could be obtained under the condition of ethanol concentration 61%, ultrasonic power 140 W, extraction time 54 min and extraction temperature 60 ℃.
Based on the shrimps data (species, numbers and weights) collected in the Jiushan Islands waters in November (autumn) 2015 and February (winter), May (spring) and August (summer) of 2016, we jointly apply the quantitative and qualitative methods, including the index of relative importance (IRI), redundancy analysis (RDA), W-statistics, RDA ordination and abundance-biomass comparison curve (ABC curve), to explore the relationship between shrimps community and marine environment. The Results show that there are 16 warm-temperate and warm-water species in total captured in the investigated area, belonging to 8 families and 12 genera; The relative shrimp resources vary with season, shrimp biomass in spring and autumn are higher compared to that in summer and winter. Dominant species (IRI > 100 0) vary with season as well: Exopalaemon annandalei and Palaemon gravieri are dominant species in autumn. RDA ordination result shows that the bottom seawater temperature is the major impact factor (r2 = 0.726 2，P = 0.001)
Cochlear sensory hair cells, as auditory mechanoreceptor, are the linchpin of our senses of hearing. The inability of the mammalian inner ear to regenerate lost hair cells is the major reason for the hearing disorder or permanent hearing loss. So elucidating the mechanisms of the mammalian inner ear development will be useful for testing potential inner ear therapies. Transcription factor Math1 plays an important role in the process of the hair cells development and regeneration. This paper provides an overview of the functions of Math1 and its related genes or signaling pathways in this process.
The positive definite solutions of a class of nonlinear matrix equation X+∑i=1mAi*X-1Ai-∑j=1nBj*X-1Bj=Q are addressed. Some sufficient conditions for the existence and uniqueness of the positive definite solution to such equations are established. An iterative method for the unique positive definite solution is provided. Perturbation analysis is also conducted. An estimation bound and the explicit expression of Rice condition number of the unique positive definite solution are derived. Several numerical examples are given to illustrate the effectiveness of the above theoretical results.
The hazard prediction is a worldwide problem. Exploiting the seismic data of all the earthquakes with MW≥5.8 since 1966 of Pakistan, this paper analyses their space-time symmetry by using the butterfly structure and disaster statistics calculation method based on the commensurability theory and symmetry principle. According to the law of space rotation in the epicenter and the characteristic of the epicenter migration pattern of the adjacent space wired， the trend judgement for the location of next earthquake can be made: (1) the commensurability of Pakistan historical earthquake of MW≥5.8 is good, the signal for an earthquake in 2018 and 2019 is strong; (2) a MW≥5.8 earthquake is likely to happen in 70.9°E～77.7°E，31.5°N～37°N of Pakistan according to the spatial characteristics of earthquake epicenter position; (3) most MW≥5.8 earthquakes happened during the stage when the number of sunspots declines, which offers a further evidence for the next earthquake in 2018 and 2019 in the region. This study provides a
The physical unclonable function (PUF) takes advantage of the inherent biases in semiconductor fabrication processes to produce unique and stable response results, which produces integrated circuit chips non-clonable safety. A new structure of D flip-flop based PUF is presented. This PUF takes advantage of the random distribution of D flip-flops' setup time to generate PUF responses. And, the differential approach of D flip-flops pairs is proposed to improve the accuracy of PUF. According to the statistic results, several near-ideal characteristics of this kind of PUF are disclosed. Compared with mainstream PUFs, D flip-flop based PUF obviously improves the uniqueness of PUF designs.
Taking the Yulin city, an energy exploitation area of northern Shaanxi province as the sample area, and based on the relative statistical data from 1990 to 2015, this paper makes an intensive analysis on the change trend of the three industrial structures, the direction and speed of industrial structure transformation and upgrade as well as its economic effects by using the methods of lead coefficient of industrial structure, More value, Lilien index and Shift-share analysis. The results show that: During the period from 1990 to 2015, the main features of industrial structure evolution exhibited "double inflection point", and the industrial structure was not coordinated with the employment structure. The primary and the tertiary industry were lagged behind, while the secondary industry achieved advanced development. Then a fast industrial structure transformation and upgrade were conducted, due to the effective policies of the national government. The contribution to economic effects was more from the interna
The title reaction is studied by using the B3LYP method of density functional theory, the MP2 method of perturbation theory and the SMD model method based on self-consistent reaction field (SCRF) theory. The research shows that there are two channels a and b in the optical isomer reaction of α-Ala. In channel a, the proton is transferred from the side of the α-carbon to the other side with the amino as the bridge after the carboxyl anti-isomeric using water clusters as medium, and hydroxyl radicals of water clusters can damage the α-Ala. In channel b, the transfer of proton from chiral carbon to amino groups is coordinated with the anti-isomerism of carboxyl groups with water clusters as medium. The potential energy surface calculation shows that the energy barrier of rate-limiting step is 113.37 kJ·mol－1 with three water molecule clusters as hydrogen transfer agents in channel a, while the hydroxyl groups reduce the barrier to 64.45 kJ·mol－1 in water liquid environment. In channel b, the energy barrier of ra
In this work, we propose a divergence measure between two Gaussian covariance matrices, the SΣ divergence, which allows one to evaluate the global effects of small and large changes in the network parameters. We discuss some theoretical properties of SΣ divergence, including the positive definiteness, symmetry, triangular inequality constraints and show that it is a metric in the space of positive definite matrices. Then, we apply it to the task of sensitivity analysis in Gaussian Bayesian networks. The results obtained by SΣ divergence are almost completely consistent with those obtained by the KL and Bhattacharyya divergences, but the amount of computation is reduced greatly.
This study deals with the issue of designing the sensing matrix for a compressed sensing system. With the given dictionary, a ETF-based （Equiangular Tight Frame） measure matrix designing method use the sensing matrix rather than a measure matrix, so does the spare signal recovery process. A novel conjugate gradient method for sensing matrix optimization is proposed in this paper. The proposed method is simple, and the result is consistent with the target Gram matrix. Simulation results show the advantage of the novel sensing matrix optimization method in theoretical analysis, real image application and algorithmic effectiveness.
Current research on point clouds organization pays little attention to the performance characteristics of mobile devices. An integrated spatial index is proposed for online visualization of geo-scene point clouds on mobile devices. First, the index adopts an improved KD-tree which accounts for the network bandwidth and rendering performance of mobile terminal to implement a balanced division and coding of point clouds. Then, it builds a LOD model of point clouds and uses an improved Octree to organize the LOD models. Finally, the code of the improved KD-tree is concatenated with the improved Octree to form an optimized index structure of . The proposed index supports LOD-based rendering, determination of spatial relations from data blocks and multi-threading data query. Experiments and analysis show that: compared to the traditional indexes of point clouds, this index has a stable construction efficiency and excellent performance of spatial query. It provides reliable data supp
In parks, schools, shopping centers and other crowded places，security incidents are likely to happen in cases of the earthquake, fire and similar accidents. Identifying people's state is of great significance for the arrangement of rescue resources to reduce the casualties. To detect and judge the potential crowd emergencies, this paper proposes an effective algorithm, which is based on optical flow and information entropy of the surveillance video. By adopting LK optical flow algorithm, we extract the feature points of moving objects in the video, thereby obtaining their location, speed and acceleration information. According to acceleration, we can determine whether there are crowd emergencies.Besides, the entropy is calculated through distribution of velocity vector to identify if there is a chaos happening in the video. Compared with the other methods, this algorithm can accurately detect the crowd emergencies, and analyze the state of the crowd. The algorithm is suitable to deal with environment with dif
The image features of density function f(t) and failure rate function λ(t) at the peak and around the median β are studied for two-parameter BS fatigue life distribution. Meanwhile, a general conclusion for identifying image feature of failure rate function is proposed.
This paper presents a study on the Ding graded projective (injective) R-modules and strong Ding graded projective (injective) R-modules over a graded ring R. It is proved that the class of the Ding graded projective (injective) modules over any graded ring is projectively (injectively) resoluble.Some characterizations of these modules are discussed. Some relations between strongly Ding graded projective (injective) R-modules and Ding graded projective (injective) R-modules are listed. Finally, the relation between strong Ding graded projective (injective) R-modules and ungraded strong Ding projective (injective) R-modules is also studied. It is proved that for finite group graded ring R, if M is a strong Ding projective (injective) R-modules, then F(M) is a strong Ding graded projective (injective), and if N is a strong Ding graded projective (injective) R-modules, then U(N) is a strong Ding projective (injective).
Remote sensing thematic system is used for image loading, analyzing, thematic extracting, drawing, and it is widely used in various industries. In order to develop a customizable remote sensing thematic system with dynamic, real-time and extensible module configuration, a component-based design framework of remote sensing thematic system was proposed. Following the framework, the thematic system was divided into functional components and container components, with the properties of the components and the relations between the components prespecified. An XML document was then used to describe the system and could be parsed to the thematic system. At last, a software design platform was developed. Some thematic systems customized by this platform have been applied in relevant departments. This framework provides a new design mode for software development which makes it convenience for using remote sensing data in multiple industries and reduces repetitive development of software.
Noticing the shortcomings of Wolf Pack Algorithm(WPA), such as too many parameters, predetermined step length and fixed scouting direction, a wolf pack algorithm based on adaptive step length and regulable scouting direction, named Modified Adaptive and Changed Scouting Direction Wolf Pack Algorithm(MACWPA) is proposed. It makes modifications on the step length of the three major processes, namely scouting behavior, summoning behavior and beleaguering behavior, and adopts tentative direction of scouting behavior, providing wolf pack more artificial intelligence. Each wolf is able to adjust its step length as well as scouting direction according to the leader wolf's position, which simplifies parameter set up, accelerates the convergence speed and improves the optimization precision. Simulation results show that the optimization precision for low dimensional unimodal function is greatly improved by MACWPA compared with WPA. It also improves the optimization precision of high dimensional multimodal function.
The conformations of ring polymer chain and the aggregation behavior of nanoparticle in nanocomposites are investigated by coarse-grained molecular dynamics.Nanoparticles exhibit three dispersion-aggregation states:contact aggregation,dispersion and tele bridging aggregation,which are consistent with the theoretical results.By altering the stiffness of ring chain,three typical conformations are obtained:middle adsorption,saddle-shaped adsorption and obit-shaped adsorption.The increasing of ring chain stiffness is benefit for the dispersion of nanoparticle in nanocomposites.
In terms of the problem of ranking decision making unit (DMU) in data envelopment analysis, an evaluation approach based on cross ranking matrix of DMUs is established. On the basis of neutral cross efficiency, this matrix can be obtained from relative ordinal in the corresponding cross efficiency. Then, the sum of efficiencies for each DMU on different sequences can be gained by aggregating the self-and peer-evaluation values. Next, a linear programming model is established, and the DMUs are ranked according to the results of this model. The proposed method is applied to the efficiency evaluation of several experimental demonstration centers in Fuzhou University town. The result shows that our model works better than CCR and NCE in distinguishing the performances of DMUs.