共查询到20条相似文献，搜索用时 609 毫秒
1.
In this paper, the design and verification process of an automobile-engine-fan control system on chip （SoC） are introduced. The SoC system, SHU-MV08, reuses four new intellectual property （IP） cores and the design flow is accomplished with 0.35 btm chartered CMOS technology. Some special functions of IP cores, the detailed integration scheme of four IP cores, and the verification method of the entire SoC are presented. To settle the verification problems brought by analog IP cores, NanoSim based chip-level mixed-signal verification method is introduced. The verification time is greatly reduced and the first tape-out achieves success which proves the validity of our design. 相似文献
2.
Internal exposure of university students to polycyclic aromatic hydrocarbons(PAHs)was assessed through urinary PAHs metabolites. Eight monohydroxylated PAHs(OH-PAHs)were detected with high performance liquid chromatography (HPLC). The detectable frequencies were 59%-100% for different analytes. Major components in the subjects‘ urine were 2-hydroxynaphthalene(2-OHNap, 0.60 μg/mmol creatinine), followed by hydroxyphenanthrene(ΣOH-Phe, 0.38 μg/mmol cre-atinine)and 2-hydroxyfluorene(2-OHFlu, 0.25 μg/mmol creatinine). Excretion of 1-hydroxypyrene(1-OHPyr, 0.08 μg/mmol creatinine)was almost one order of magnitude lower than the 2-OHNap level in the urine samples. Phenanthrene can be metabolized to five monohydroxy metabolites in human urine. In the present study, 1-or 9-hydroxyphenanthrene(1-or9-OHPhe)was the dominant component(79%), followed by 2-+3-OHPhe(18%)and 4-OHPhe(3%). The study indicates that 1-OHPyr may not be a good marker for total PAHs exposure, and monitoring of 2-OHNap, 2-OHFlu, 1-or 9-OHPhe and 1-OHPyr as multiple biomarkers are more suitable than only using 1-OHPyr. The levels of OH-PAHs detected in urines of students living in Shanghai are higher those of people in other countries or regions. The concentrations of urine OH-PAHs are directly related to the exposure to PAHs in the environment, indicating that Shanghai residents are at high health risk. 相似文献
3.
A color-intensity feature extraction method is proposed aimed at supplementing conventional image hashing algorithms that only consider intensity of the image. An image is mapped to a set of blocks represented by their dominant colors and average intensities. The dominant color is defined by hue and saturation with the hue value adjusted to make the principal colors more uniformly distributed. The average intensity is extracted from the Y component in the YCbCr space. By quantizing the color and intensity components, a feature vector is formed in a cylindrical coordinate system for each image block, which may be used to generate an intermediate hash. Euclidean distance is modified and a similarity metric introduced to measure the degree of similarity between images in terms of the color-intensity features. This is used to validate effectiveness of the proposed feature vector. Experiments show that the color-intensity feature is robust to normal image processing while sensitive to malicious alteration, in particular, color modification. 相似文献
4.
A series of polysulfonamide （PSA）/TiO 2 modifier nano-composite films were successfully prepared by in-situ polymerization at a low temperature based on 4, 4-diaminodiphenylsulfone and terephthaloyl chloride in the common solvent N, N-dimethylacetamide （DMAc）. It was shown that the nano particles were well dispersed in the polymer substrate. Mean-while, PSA/TiO 2 /modifier composites exhibited good UV-resistant properties and mechanical properties. In addition, the composites’ heat stability improved. These prepared composites are promising in preparing spinning solution and might have potential application in heat-resistant fiber. 相似文献
5.
Instead of manual polishing work for aluminum wheel hub （hub） surface, a new planetary scroll surface polishing method based on the rotation and revolution of hub in abrasives is presented in this paper. Since conventional barrel rotation polishing mode is unsatisfactory, shorter polishing period and lower energy consumption are expected. The surface polishing mechanism of the proposed method is ghen introduced. The influence of cutting velocity, cutting angle, abrasive on surface polishing quality and efficiency, as well as the correlation of the revolution velocity and the rotation velocity of hub are discussed. Experimental results show that high surface polishing quality and efficiency can be achieved with the new polishing method implying that a dustless clean working environment is realized. 相似文献
6.
This paper presents a rheology-based approach to animate realistic face model. The dynamic and biorheological
characteristics of the force member (muscles) and stressed member (face) are considered. The stressed face can be modeled
as viscoelastic bodies with the Hooke bodies and Newton bodies connected in a composite series-parallel manner. Then, the
stress-strain relationship is derived, and the constitutive equations established. Using these constitutive equations, the face
model can be animated with the force generated by muscles. Experimental results show that this method can realistically
simulate the mechanical properties and motion characteristics of human face, and performance of this method is satisfactory. 相似文献
characteristics of the force member (muscles) and stressed member (face) are considered. The stressed face can be modeled
as viscoelastic bodies with the Hooke bodies and Newton bodies connected in a composite series-parallel manner. Then, the
stress-strain relationship is derived, and the constitutive equations established. Using these constitutive equations, the face
model can be animated with the force generated by muscles. Experimental results show that this method can realistically
simulate the mechanical properties and motion characteristics of human face, and performance of this method is satisfactory. 相似文献
7.
Oil spills may considerably damage sensitive coastal wetlands. The phytoremediation potential and restoration of a dominant coastal marsh plant, Cyperus rotundus, for diesel pollutant and its phytoremediation effectiveness were investigated in this open-air pot experiment. Cyperus rotundus was transplanted into soil contaminated with diesel at concentrations of 1 000, 5 000, 10 000, 15 000, 20 000 mg/kg. In order to better elucidate the biochemical and physiological responses to diesel pollutants, activity of the antioxidant enzymes peroxidase （POD）, catalase （CAT） and ascorbic acid oxidase （AAO） were determined in the plant tissue after 50 d treatment at the levels mentioned above. The results showed that CAT and AAO of stem and leaf exhibited peak enzyme activities on 15 000 mg/kg soil and 10 000 mg/kg soil respectively, and declined at higher concentrations. Additionally, the increment of biomass and the content of soluble protein, as well as chlorophyll content were affected by diesel. The highest restoration effectiveness appeared at the level of 5 000 mg/kg. Collectively, Cyperus rotundus is a potential plant which can be used for restoring the diesel-contaminated soil. 相似文献
8.
β-TCP ceramic scaffolds were fabricated with selective laser sintering(SLS)in this work. Carbon nanotubes(CNTs)were mixed with porous β-TCP matrix to enhance the mechanical performance of the bone tissue engineering scaffolds. Scaffold reconstruction and microstructure analysis were fulfilled based on micro-computed tomography(Micro-CT)scanning data.Results show that the strength of scaffold mixed with 0.2% CNTs reaches 0.819 MPa which has been improved by 85.7% compared with that without CNTs. Micro-CT analysis shows that the scaffold has a good interconnectivity, and pore size mainly distributes in the two regions of 60-340 μm and 500 620 μm. 相似文献
9.
The element-free Galerkin method is proposed to solve free vibration of rectangular plates with finite interior elastic point supports and elastically restrained edges.Based on the extended Hamilton＇s principle for the elastic dynamics system,the dimensionless equations of motion of rectangular plates with finite interior elastic point supports and the edge elastically restrained are established using the element-free Galerkin method.Through numerical calculation,curves of the natural frequency of thin plates with three edges simply supported and one edge elastically restrained,and three edges clamped and the other edge elastically restrained versus the spring constant,locations of elastic point support and the elastic stiffness of edge elastically restrained are obtained.Effects of elastic point supports and edge elastically restrained on the free vibration characteristics of the thin plates are analyzed. 相似文献
10.
To solve the Fredholm integral equations of the second kind, a new notion of the least-squares orthogonal polyno- mials of function-valued Pade-type approximation is introduced. On the basis of the error formula, the least-squares function： valued Pad＆type approximation is constructed. Their existence and uniqueness are studied. A recursive computation formula of the least-squares function-valued Padetype approximation is given. In the end, an example is given to show that the method is effective and stable. 相似文献
11.
A new customization approach based on support vector regression (SVR) is proposed to obtain individual headrelated
impulse response (HRIR) without complex measurement and special equipment. Principal component analysis (PCA) is
first applied to obtain a few principal components and corresponding weight vectors correlated with individual anthropometric
parameters. Then the weight vectors act as output of the nonlinear regression model. Some measured anthropometric
parameters are selected as input of the model according to the correlation coefficients between the parameters and the weight
vectors. After the regression model is learned from the training data, the individual HRIR can be predicted based on the
measured anthropometric parameters. Compared with a back-propagation neural network (BPNN) for nonlinear regression,
better generalization and prediction performance for small training samples can be obtained using the proposed PCA-SVR
algorithm. 相似文献
impulse response (HRIR) without complex measurement and special equipment. Principal component analysis (PCA) is
first applied to obtain a few principal components and corresponding weight vectors correlated with individual anthropometric
parameters. Then the weight vectors act as output of the nonlinear regression model. Some measured anthropometric
parameters are selected as input of the model according to the correlation coefficients between the parameters and the weight
vectors. After the regression model is learned from the training data, the individual HRIR can be predicted based on the
measured anthropometric parameters. Compared with a back-propagation neural network (BPNN) for nonlinear regression,
better generalization and prediction performance for small training samples can be obtained using the proposed PCA-SVR
algorithm. 相似文献
12.
The coal tar was qualitative and quantitative anMyzed by gas chromatography （GC） method. 74 components were identified exactly by gas chromatographY-mass spectrometry （GC-MS）. 31 components （37%） were quantitatively analyzed by gas chromatography-flame ionization detector （GC-FID）. The linearity, accuracy, precision, limit of detection （LOD） and limit of quantitative （LOQ） determination were inspected. The scope of quantitative analysis by CC was discussed. The experimental results of thermogravimetric analysis （TGA） proved that GC quantitative analysis of the coal tar was reliable. 相似文献
13.
According to the principles of simultaneous equilibrium and electronic charge neutrality, the thermodynamics of Zn（II）-NaOH-H2O system was studied in this paper. Varying the concentration of sodium hydroxide, in range of 0- 400 g/L, the distribution law of all zinc species and the mathematical model of equilibrium concentration of zinc in the system were obtained. The relative errors between theoretic calculation and the experimental values of total concentration of zinc were analyzed, and the absolute average error is only 0.129 8%. The mathematical model and the thermodynamic data are believable. 相似文献
14.
Nano-manipulation technology is an emerging field in the development of modern science and technology. Atomic force microscope （AFM）, a sharp weapon for nano imaging and nanomanipulation, which is honored as ＂eye＂ and ＂hand＂ of nano-technology. However, due to the hysteresis, creep and other nonlinearity of piezoelectric ceramics tube （PZT） as well as the probe＇s tip deviations caused by cantilever deformation, AFM has larger error of relative displacement between probe and sample, which creates enormous inconvenience to the nano-manipulation and repositioning. As to improve positioning accuracy, this dissertation presents a novel AFM＇s X-Y dimensional nano-positioning control system with large-scale based on H∞ control. Through careful research on variety of influence factors on AFM＇s precise nano-manipulation, a composite control strategy based on feedforward compensation control of cantilever probe tip＇s offset and H∞ control of piezoelectric scanner is presented in this paper. In the end, simulation results can also testify the tracking ability and better nano-positioning performance of the system. 相似文献
15.
利用广义Riccati变换和不等式技巧,给出了一类时间尺度上二阶非线性时滞动力方程解的一个新的振动准则.该结果不仅推广和改进了已有文献的有关结果,而且在时间尺度上统一了二阶非线性时滞微分方程和二阶非线性时滞差分方程的振动性. 相似文献
16.
Gas chromatography （GC） analysis of sulfer dioxide is challenging because SO2 is a highly mobile and chemically active molecule. For the conventional GC method with flame photometric detector （FPD） and direct-injection, it is often ineffective particularly when the SO2 level is as low as on the trace level. In this paper, a modified GC system integrated with an adsorption-desorption device was developed to detect the trace SO2 impurity in H2 fuel. Adsorbent GDX-502 is used in the adsorber to adsorb/collect SO2 from the sample gas and desorb/release it in a concentrated flow so that the conventional GC at downstream could detect it with an acceptable accuracy. 相似文献
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Let G = （V,A） be a digraph.A set T of vertices of G is a twin dominating set of G if for every vertex v ∈ V ／ T.There exist u,w ∈ T （possibly u = w） such that （u,v）,（v,w） ∈ A.The twin domination number γ＊（G） of G is the cardinality of a minimum twin dominating set of G.In this paper we consider the twin domination number in generalized Kautz digraphs GK（n,d）.In these digraphs,we establish bounds on the twin domination number and give a sufficient condition for the twin domination number attaining the lower bound.We give the exact values of the twin domination numbers by constructing minimum twin dominating sets for some special generalized Kautz digraphs. 相似文献
20.
Numerical simulation on dense gas-particle riser flow 总被引：1，自引：0，他引：1
A turbulence gas-solid model that combines Eulerian approach and Lagrangian approach is formulated, which takes inter-particle
interaction into consideration on the base of kinetic theory. The numerical algorithm is included. Comparison of the model
results with the experimental results of Miller and Gidaspow (1992) showed good agreement.
Project(59425004) supported by NSFC. 相似文献