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1.
To characterize the mechanical properties of thin films,an improved blister method is proposed,which combines a digital speckle correlation method with the blister test.Based on this method,an experimental setup is developed to measure Young’s modulus,residual stress,and interfacial adhesion energy of an electroplated nickel flm.The results show that the improved blister method has the advantage of a high accuracy full-field measurement with the simple operation and low requirement on environments,which can be used to characterize the mechanical properties of films with various scales from laboratorial to industrial applications.  相似文献   

2.
The Knowledge Map (KM) concept, which was derived from the Fuzzy Cognitive Map (FCM), is used to describe and manage knowledge. KM provides insight into the interdependencies and uncertainties contained in the system. This paper uses a model-free method to mine KMs in historical data to analyze component stock corporations of the Shanghai Stock 50 index. The analyses use static and time-domain analyses. The results indicate that a knowledge map is useful for representing knowledge and for monitoring the health of companies. Furthermore, sudden changes of the key features of the KMs should be taken seriously by policymakers as an alarm of a crisis.  相似文献   

3.
《矿物冶金与材料学报》2020,27(8):1021-1035
Mine closure is associated with many negative impacts on society and the environment. If these effects are not rationally addressed, they would pose risks of mine closure. Thus, a risk management method is needed to mitigate these adverse impacts and address mine-closure issues. An integral framework for mine-closure risk management that includes risk assessment and risk treatment was proposed. Given the fuzziness and randomness of the transformation between qualitative and quantitative knowledge in the risk assessment process, a novel risk assessment method based on the cloud model was presented, which fully considers the uncertainty in risks themselves and in the reasoning process. Closed mine reutilization is an effective risk treatment option in response to the identified high risks, but it requires selecting optimal reutilization strategies for the successful implementation of the reuse plan. To this end, a hybrid semi-quantitative decision method is proposed to optimize decision-making. The results of a case study showed that this risk management methodology can help budget planning for risk treatment and provide an instructional framework to effectively reduce the negative effects of closed mines.  相似文献   

4.
Multi-traveling salesman problem(MTSP) is an extension of traveling salesman problem,which is a famous NP hard problem,and can be used to solve many real world problems,such as railway transportation,routing and pipeline laying.In this paper,we analyze the general properties of MTSP,and find that the multiple depots and closed paths in the graph is a big issue for MTSP.Thus,a novel method is presented to solve it.We transform a complicated graph into a simplified one firstly,then an effective algorithm is proposed to solve the MTSP based on the simplified results.In addition,we also propose a method to optimize the general results by using 2-OPT.Simulation results show that our method can find the global solution for MTSP efficiently.  相似文献   

5.
The boundary element theory together with the optimization method is used to calculate the driving voltage weighting vector of a conformal array of underwater acoustic projecting transducers to obtain a low-sidelobe beampattern. At first, the relationship between the acoustic radiated field and the vibra- tion velocity of the array is formulated from the boundary element equation when the boundary im- pedance of the array baffle is specified. Then, the mutual impedance matrix of the array is calculated, and the relationship between the driving voltage and the vibration velocity of the transducers is pre- sented based on the equivalent circuit principle. At last, the driving voltage weighting vector of the array is calculated through an optimization method to obtain a low-sidelobe projecting beampattern. Computer simulation is conducted for a 14-element conformal array. An experiment has been carried out to measure the radiation directivity of the array in an anechoic water tank. The calculated and the experimental results show that the proposed method accounts for the acoustic effect of the baffle and the mutual interactions among transducers successfully and obtain a low-sidelobe projecting beam- pattern, and at the same time provide the largest amplitude of pressure in the axial direction when the maximum amplitude of the driving voltage weighting vectors keeps unchanged.  相似文献   

6.
Evidence shows that biological systems are composed of separable functional modules. Identifying protein complexes is essential for understanding the principles of cellular functions. Many methods have been proposed to mine protein complexes from protein-protein interaction networks. However, the performances of these algorithms are not good enough since the protein-protein interactions detected from experiments are not complete and have noise. This paper presents an analysis of the topological properties of protein complexes to show that although proteins from the same complex are more highly connected than proteins from different complexes, many protein complexes are not very dense (density 0.8). A method is then given to mine protein complexes that are relatively dense (density 0.4). In the first step, a topology property is used to identify proteins that are probably in a same complex. Then, a possible boundary is calculated based on a minimum vertex cut for the protein complex. The final complex is formed by the proteins within the boundary. The method is validated on a yeast protein-protein interaction network. The results show that this method has better performance in terms of sensitivity and specificity compared with other methods. The functional consistency is also good.  相似文献   

7.
Non-Mendelian segregation of markers, known as distorted segregation, is a common biological phenomenon. Although segregation distortion affects the estimation of map distances and the results of quantitative trait loci (QTL) mapping, the effects of distorted markers are often ignored in the construction of linkage maps and in QTL mapping. Recently, we have developed a multipoint method via a Hidden Markov chain method to reconstruct linkage maps in an F2 population that corrects for bias of map distances between distorted markers. In this article, the method is extended to cover backcross, doubled haploid and recombinant inbred line (RIL) populations. The results from simulated experiments show that: (1) the degree that two linked segregation distortion loci (SDL) affect the estimation of map distances increases as SDL heritability and interval length between adjacent markers increase, whereas sample size has little effect on the bias; (2) two linked SDL result in the underesti- mation of linkage distances for most cases, overestimation for an additive model with opposite additive effects, and unbiased estimation for an epistatic model with negative additive-by-additive effects; (3) the proposed method can obtain the unbiased estimation of linkage distance. This new method was applied to a rice RIL population with severely distorted segregation to reconstruct the linkage maps, and a bootstrap method was used to obtain 95% confidence intervals of map distances. The results from real data analysis further demonstrate the utility of our method, which provides a foundation for the inheritance analysis of quantitative and viability traits.  相似文献   

8.
Ag@Pt core-shell nanoparticles (Ag@Pt NPs) were prepared by a co-reduction method. Pt nanocapsules with diameters of less than 10 nm were obtained by an electrochemical method. Cyclic voltammetry (CV) scanning was used to cavitate the Ag@Pt NPs, and the morphology, structure, and cavitation conditions were studied. The results indicate that the effective cavitation conditions to obtain Pt nanoparticles from Ag@Pt NPs are a scanning voltage of 0 to 0.8 V and continuous CV scanning over 2 h. This cavitation method is also applicable for the syntheses of Ir, Ru, and Ru-Pt nanocapsules.  相似文献   

9.
In this paper, the physical basis and application conditions of the entransy theory are reviewed and discussed. Entransy can be obtained from the analogy between heat and electrical conductions. It is a state value and the‘‘potential energy’’ of heat. From the viewpoint of thermomass, it reflects the thermal energy of the thermomass in an object. Furthermore, it was also related to the microstate number and is a single value function of the microstate number. The concepts of entransy, entransy flux and entransy dissipation can be used to express the least action of heat transfer. The entransy balance equations for heat transfer and thermodynamic processes and their applications to thermal systems are also reviewed. The differences between the entransy theory, constructal theory, entropy generation minimization, exergy analyses method, principle of uniformity of temperature difference field and field synergy(coordination) principle are also discussed. The entransy theory is different from the other discussed theories. The limitations of the entransy theory are also discussed.  相似文献   

10.
The common method classifying tactile qualities of fabrics is indirectly based on their difference of purely mechanical and physical properties. When human skin slides across fabric surfaces, the friction interaction between fabrics and skin will occur and trigger the cutaneouS tactile receptors, which are responsible for perceived tactile sensation. By the extracted features from friction- induced vibration signals, this paper presents an anthropomorphic classification method classifying tactile qualities of fabrics. The friction-induced vibration signals are recorded by a three-axis accelerator sensor, and the entice testing procedure is conducted in an anthropomorphic way to obtain vibration signals. The fast Fourier transform (FFT) is applied to analyzing the recoded signals, and then the classification features are extracted from the FFT data by the neurophysiological properties of tactile receptors. The extracted features are used to classify fabric samples by the softness sensation and the roughness sensation, respectively, and the classification performance is checked by a comparison with those in a sensory evaluation procedure. The results showed that the anthropomorphic objective classification method was precise and efficient to clarify tactile qualities of woven fabrics.  相似文献   

11.
Engineering-oriented simulations of quantum mechanical tunneling are often based on density-gradient(DG) theory.This paper presents an analytical solution to the DG equation for quantum tunneling through an ultra-thin oxide in a MOS capacitor with an n+ poly-silicon gate obtained using the method of matched asymptotic expansions.Tunneling boundary conditions extend the approximation into the entire region of the poly-silicon gate,oxide barrier,and substrate.An analytical solution in the form of an asymptotic series is obtained in each region by treating each part of the domain as a separate singular perturbation problem.The solutions are then combined through ’matching’ to obtain an approximate solution for the whole domain.Analytical formulae are given for the electrostatic potential and the electron density profiles.The results capture the features of the quantum effects which are quite different from classical physics predictions.The analytical results compare well with exact numerical solutions over a broad range of voltages and different oxide thicknesses.The analytical results predict the enhancement of the quantum tunneling effect as the oxide thickness is reduced.  相似文献   

12.
A method to determine optimum production is presented. First, based on analysis of various geological, technological and economic factors that influence the determination of underground mine capacity, a feasible range of production capacity is selected. Second, by means of scale economic theory and depletion feature of mineral resounce, an economicmathematical model that aimed at maximum net profit in the whole life of mine is developed to optimum production. The model was tested in a undergrond mine.  相似文献   

13.
Danckwert‘s method was used to determine the specific interfacial area, a, and the individual mass transfer coefficient, κL, during absorption of CO2 in a bubble column with an anionic surfactant in the carbonate-bicarbonate buffer solution and NaAsO2 as catalyst, the presence of which decreases the specific interracial area and the individual mass transfer coefficient. The specific interfacial area and the individual mass transfer coefficient increase with increasing superficial gas velocity. The specific interfacial area decreases whereas the individual mass transfer coefficient increases with increasing temperature. The results of experiments were used to determine the dependence of a, κL, and κLa on the surface tension, the temperature of the absorption phase, and the superficial velocity of the gas. The calculated results from the correlation were found to be within 10% deviation from the actual experimental results.  相似文献   

14.
Yima Coal Corporation is considering to adopt highwall mining method with auger machine to recover coal from north surface pit that has reached final highwall position. The major geomechanical issues associated with auger mining are highwall and pillar stability. Based on the field investigation and laboratory test results of mechanical parameters, numerical modeling is carried out to assess the stability of highwall and pillar. Field measurements of highwall deformation have been used to validate and ensure the confidence for the development of realistic models. The results of numerical modeling show that the mining method is feasible for mining the seam of 10 m thickness in north surface coal mine.  相似文献   

15.
Cross-correlating traffic flow data at different intersections in an urban transportation network is important for understanding the collective behavior of constituents in a complex system and for predicting the risk of network-wide congestion. In this work, a Random Matrix Theory (RMT) based method is used to describe the collective behavior from massive traffic data sets. Nonrandom correlations between traffic flow series recorded in the Beijing road network occur both with and without detrending. The effect of the traffic load on the correlation patterns of network-wide traffic flows is analyzed using the RMT analysis of a simulated data set collected from Paramics. The RMT analysis is also used to evaluate the impact of incidents on the network-wide traffic status. Cluster analysis is used to find the largest cluster in the network which indicates the critical congestion caused by the incident. All the results show that RMT analyses are an effective method for investigating systematic interactions in urban transportation systems.  相似文献   

16.
Quick detection of a small initial fault is important for an induction motor to prevent a consequent large fault.The mathematical model with basic motor equations among voltages,currents,and fluxes is analyzed and the motor model equations are described.The fault related features are extracted.An immune memory dynamic clonal strategy (IMDCS) system is applied to detecting the stator faults of induction motor.Four features are obtained from the induction motor,and then these features are given to the IMDCS system.After the motor condition has been learned by the IMDCS system,the memory set obtained in the training stage can be used to detect any fault.The proposed method is experimentally implemented on the induction motor,and the experimental results show the applicability and effectiveness of the proposed method to the diagnosis of stator winding turn faults in induction motors.  相似文献   

17.
In this paper,the adaptive lifting scheme (ALS) and local gradient maps (LGM) are proposed to isolate the transient feature components from the gearbox vibration signals. Based on entropy minimization rule,the ALS is employed to change properties of an initial wavelet and design adaptive wavelet. Then LGM is applied to characterize the transient feature components in detail signal of decomposition results using ALS. In the present studies, the orthogonal Daubechies 4 (Db 4) wavelet is used as the initial wavelet. The proposed method is applied to both simulated signals and vibration signals acquired from a gearbox for periodic impulses detection. The two conventional methods (cepstrum analysis and Hilbert envelope analysis) and the orthogonal Db4 wavelet are also used to analyze the same signals for comparison. The results demonstrate that the proposed method is more effective in extracting transient components from noisy signals.  相似文献   

18.
To help comfort for an amputee, it is important to understand the load distribution between the residual limb and the prosthetic socket for a prosthetic socket system. An interfacial stress sensor was presented which was capable of measuring compressive pressure and shear stress simultaneously. A mathematical model was built and an experiment was conducted to obtain the transfer function of interfacial stress sensor to compressive pressure. The results show that the sensor is capable of measuring a range of 30-217 kPa compressive pressure with a relative error of 32.15% in lower range and 6.22% in upper range.  相似文献   

19.
The lignite pre-drying process plays an important role in modern lignite power plants and the fluidized bed dryer with internal heat utilization is a promising drying method which has both high efficiency and cost-effectiveness. After conducting an in-depth analysis of a typical lignite pre-drying power plant, this work proposed a novel lignite pre-drying system with low-grade heat integration. Through system integration, the low-temperature evaporation of the lignite was recovered to heat the combustion air, while the residual heat from the flue gases was used to heat the feed or condensed water, thereby saving a portion of heat from the steam bleeds of the high and intermediate pressure turbines. The results for a 1,000 MW lignite-fired power plant showed that, the proposed pre-drying system could yield an increase in net plant efficiency of approximately 3.6 % points and a reduction in the cost of electricity of $1.83/(MW h). The thermodynamic and economic performances were each superior to those of the existing pre-drying system, convincingly demonstrating that the research of this paper may provide a promising integrated lignite pre-drying method for the next-generation of lignite-fired power plants.  相似文献   

20.
Ruin Probability in Linear Time Series Model   总被引:1,自引:0,他引:1  
This paper analyzes a continuous time risk model with a linear model used to model the claim process. The time is discretized stochastically using the times when claims occur, using Doob‘s stopping time theorem and martingale inequalities to obtain expressions for the ruin probability as well as both exponential and non-exponential upper bounds for the ruin probability for an infinite time horizon. Numerical results are included to illustrate the accuracy of the non-exponential bound.  相似文献   

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