Line Matching Based on Characteristic Ratio Invariants of Collinear Points

2012 ◽  
Author(s):  
Jielin Zhang ◽  
Qianqian Zhao ◽  
Xin Fan ◽  
Zhongxuan Luo
Keyword(s):  
Characteristic Ratio

scholarly journals Spatial and Temporal Distribution Characteristics and Source Apportionment of VOCs in Lianyungang City in 2018

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1598
Author(s):  
Cheng Chen ◽  
Lingrui Wang ◽  
Yunjiang Zhang ◽  
Shanshan Zheng ◽  
Lili Tang
Keyword(s):  
Urban Area ◽  
Sampling Site ◽  
Industrial Area ◽  
Suburban Area ◽  
Vehicle Exhaust ◽  
Characteristic Ratio ◽  
Industrial Emission ◽  
Industrial Areas ◽  
Suburban Areas ◽  
Fuel Evaporation

From April to September 2018, five sampling sites were selected in Lianyungang City for volatile organic compounds (VOCs) analysis, including two sampling sites in the urban area (Lianyungang City Environmental Monitoring Supersite and Mine Design Institute), one sampling site in the industrial area (Deyuan Pharmaceutical Factory), and two sampling sites from the suburb (Hugou Management Office and YuehaiLou). The results showed that the mean VOCs concentration followed this pattern: industrial area (36.06 ± 12.2 µg m−3) > urban area (33.47 ± 13.0 µg m−3) > suburban area (27.68 ± 9.8 µg m−3). The seasonal variation of the VOCs trend in the urban and suburban areas was relatively consistent, which was different from that in industrial areas. The concentration levels of VOCs components in urban and industrial areas were relatively close, which were significantly higher than that in suburban areas. The possible sources and relative importance of VOCs in Lianyungang City atmosphere were measured by the characteristic ratio of toluene/benzene (T/B), ethane/acetylene (E/E) and isopentane/TVOCs. The contribution of traffic sources to the VOCs in Lianyungang City was significant (T/B ~ 2), and there were obvious aging phenomena in the five sampling sites (E/E > 4). The ratio of isopentane/TVOCs in the contribution of gasoline volatilization sources in urban and suburban areas was significantly bigger than that in industrial areas. According to the maximum incremental reactivity (MIR) method, aromatics (40.32–58.09%) contributed the most to ozone formation potential (OFP) at the five sampling sites. The top 10 OFP species showed that controlling n-hexane and aromatics, such as benzene, toluene, xylene, and trimethylbenzene in Lianyungang City can effectively control ozone generation. Nineteen typical VOCs components were selected and the sources of VOCs from five sampling points were analyzed by the principal component analysis (PCA) model. The sources of VOCs in different areas in Lianyungang were relatively consistent. Five sources were analyzed at the two sampling sites in the urban area: industrial emission + plants, vehicle exhaust, fuel evaporation, combustion and industrial raw materials. Four sources were analyzed in the industrial area: industrial emission + plants, vehicle exhaust, fuel evaporation and combustion. Five sources were analyzed at the two sampling sites in the suburban area: industrial emission + plants, vehicle exhaust, fuel evaporation, combustion and solvent usage.

scholarly journals Subduction of non-Newtonian plates: Thin-sheet dynamics of slab necking and breakoff

2019 ◽  
Author(s):  
Neil M Ribe ◽  
Bingrui Xu
Keyword(s):  
Convergence Rate ◽  
Initial Period ◽  
Thin Sheet ◽  
Boundary Integral ◽  
Dislocation Creep ◽  
Diffusion Creep ◽  
Characteristic Ratio ◽  
Lithospheric Thinning ◽  
Slab Breakoff ◽  
Stress Resultant

Summary We use a hybrid boundary-integral/thin-sheet (‘BITS’) model to investigate the subduction of 2-D viscous sheets with composite diffusion creep/dislocation creep rheology, with a focus on the conditions required for slab necking and breakoff. To validate the model, we show that its predictions of the sinking speed of the slab follow a universal scaling law identical to one previously derived for purely Newtonian sheets. We obtain analytical expressions for the fiber stress resultant and bending moment of the sheet during deformation by pure stretching and pure bending, respectively, and show that the non-Newtonian dislocation creep component of the rheology significantly weakens the sheet for both types of deformation. We solve the BITS equations for two distinct situations: “free” subduction, in which the slab pulls an attached negatively buoyant plate without hindrance; and “arrested” subduction that slows or stops when a positively buoyant (continental) portion of the attached plate arrives at the trench. Strong lithospheric thinning is difficult to obtain in free subduction and requires dominantly non-Newtonian rheology, i.e. large (>5) values of the characteristic ratio λ of the Newtonian to the non-Newtonian viscosity. However, during arrested subduction strong thinning leading to breakoff occurs for much lower values of λ, and the point of maximum thinning is at shallower depths. These results are explained by a one-dimensional viscous dripping model (‘DRIP’) of a vertical slab with a composite rheology and an arbitrary kinematically prescribed time-dependent convergence rate U0(t). By injecting into DRIP convergence histories predicted by BITS, we find that DRIP reproduces closely the results of the more complicated BITS model. The DRIP model shows that the convergence rate controls slab breakoff in two distinct ways. On the one hand, the rate of lithospheric thinning is proportional to the accumulated convergence, i.e., the time integral of U0(t). The breakoff depth, on the other hand, is controlled by the convergence rate history, being shallower when U0 rapidly decreases (arrested subduction) after an initial period of oceanic subduction.

scholarly journals Demodulation Technique Based on Laser Interference for Weak Photo-Acoustic Signals on Water Surface

2018 ◽  
Vol 8 (12) ◽  
pp. 2423 ◽  
Author(s):  
Xiaolin Zhang ◽  
Hongjie Mao ◽  
Wenyan Tang
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
High Frequency ◽  
Water Surface ◽  
Processing System ◽  
Detection Accuracy ◽  
Laser Interference ◽  
Characteristic Ratio ◽  
Frequency Detection ◽  
Interference Signals

To detect underwater sound-generating targets, a water surface acoustic wave laser interference and signal demodulation technique is proposed in this paper. The underlying principle of this technique involves casting a laser beam onto the water surface disturbed by an underwater acoustic source and creating interference between lights reflected by the surface and reference lights. A data acquisition and processing system was employed to obtain water surface acoustic wave information from the interference signals by means of demodulation, thus allowing detection of the underwater target. For the purpose of this study, an interference detection platform was set up in an optical dark chamber. High-frequency water surface fluctuations were introduced in the reference optical path as the phase generated carriers to create laser interference signals in two different paths, which received demodulation based on an improved arc tangent demodulation algorithm and characteristic ratio algorithm, respectively, in view of their different frequencies. Water surface wave information was then derived from such low-frequency and high-frequency signals. According to test results, in the frequency range of 200 Hz–10 kHz, the frequency detection accuracy was better than 1 Hz. The amplitude measurements exhibited high repeatability, with a standard deviation lower than 2.5 nm. The theory proposed in this paper is therefore experimentally verified with good results.

Transient Response Control of Two-Mass System via Polynomial Approach

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Yue Qiao ◽  
Junyi Cao ◽  
Chengbin Ma
Keyword(s):  
Time Constant ◽  
Transient Response ◽  
Controller Design ◽  
Polynomial Method ◽  
Transient Responses ◽  
Mass System ◽  
Response Control ◽  
Characteristic Ratio ◽  
Starting Point ◽  
Generalized Time

This paper discusses the application of polynomial method in the transient response control of a benchmark two-mass system. It is shown that transient responses can be directly addressed by specifying the so-called characteristic ratios and the generalized time constant. The nominal characteristic ratio assignment (CRA) is a good starting point for controller design. And the characteristic ratios with lower indices have a more dominant influence. Two practical low-order control configurations, the integral-proportional (IP) and modified-integral-proportional-derivative (m-IPD) controllers are designed. The primary design strategy of the controllers is to guarantee the lower-index characteristic ratios to be equal to their nominal values, while the higher-index characteristic ratios are determined by the interaction with the generalized time constant and the limits imposed by zeros, a specific control configuration, etc. The demonstrated relationship between the transient responses and the assignments of characteristic ratios and generalized time constant in simulation and experiments explains the effectiveness of the polynomial-method-based controller design.

Calculation of the Characteristic Ratio of Randomly Coiled Poly(L-proline)

1975 ◽  
Vol 8 (5) ◽  
pp. 623-631 ◽  
Author(s):  
Seiji Tanaka ◽  
Harold A. Scheraga
Keyword(s):  
Characteristic Ratio

Characteristic Ratio and Plateau Modulus of 1,2-Polybutadiene. A Comparison with Other Rubbers

1990 ◽  
Vol 63 (5) ◽  
pp. 734-746 ◽  
Author(s):  
Jacques Roovers ◽  
Paul M. Toporowski
Keyword(s):  
Molecular Weight ◽  
Star Polymer ◽  
Dilute Solution ◽  
Plateau Modulus ◽  
Characteristic Ratio ◽  
Polymer Systems ◽  
Dilute Solution Properties ◽  
Linear Viscoelastic ◽  
Low Levels

Abstract In the course of work on linear and ring polybutadienes with 62% 1,2 units, a number of discrepancies were noted with data on polybutadienes of various microstructure available in the literature. For example, GNο=870 kPa for our 62% 1,2-polybutadiene. This is larger than GNο=730 kPa for a 56% 1,2-polybutadiene and GNο=550 kPa for a 78% 1,2-polybutadiene sample. The cis : trans ratio of our 62% 1,2-polybutadiene, prepared with potassium counterion, is 1 : 4, On the other hand, the cis : trans ratio of 62% 1,2-polybutadiene prepared with a modified Li catalyst is estimated to be 1 : 2. It is conceivable that the different cis : trans ratio leads to different properties at constant 1,2 content. Nevertheless, the low levels of both the cis and the trans units are not expected to cause more than minor differences in the properties of the polybutadienes. Correct values for GNο of model polymers are important for the study of the influence of the chemical structure on the melt characteristics of a polymer. For this reason, it was thought useful to reinvestigate 1,2-polybutadiene itself in some detail. The synthesis of narrow molecular-weight distribution 1,2-polybutadiene by anionic polymerization techniques has been described recently. The dilute-solution properties of 1,2-polybutadiene has been investigated. The melt rheology of two 1,2-polybutadiene samples have been studied, but no systematic study of the molecular-weight dependence of the melt properties was made. 1,2-Polybutadiene has been used as a component in block copolymers with 1,4-polybutadiene. These studies have permitted an investigation of the phase behavior of two rubbery blocks at room temperature. Poly(l,4-butadiene-graft-l,2-butadiene)s with well-defined composition and architecture have also been prepared. Hydrosilylated 1,2-polybutadiene has found use as the coupling agent for multiarm star polymer, and this method can easily be extended to the preparation of poly( l,2-butadiene-graft-l,4-butadiene). Hydrogenated 1,2-polybutadienes are prepared as model polymers for poly(l-butene). The synthesis and characterization of a series of 1,2-polybutadienes are described here. Special attention is given to low-molecular-weight polymers. The linear viscoelastic properties of the melts are also described. In the discussion, the relation between the characteristic ratio, C∞, and the plateau modulus, GNο, of a number of model polymer systems is explored.

A mathematical model for the wet-spinning process

1993 ◽  
Vol 4 (4) ◽  
pp. 341-360 ◽  
Author(s):  
H. Ockendon ◽  
E. L. Terrill
Keyword(s):  
Mathematical Model ◽  
Fluid Flow ◽  
Hydrodynamic Force ◽  
Wet Spinning ◽  
Fluid Inertia ◽  
Spreading Process ◽  
Characteristic Ratio ◽  
Spin Bath ◽  
Spinning Process ◽  
Two Parameters

A mathematical model for the hydrodynamic flow and fibre deflections in a wet-spinning process is presented. The model is characterized by two parameters: α which is a characteristic ratio of the hydrodynamic force to the tension force acting on a fibre, and β which is a characteristic ratio of the fibre drag to the fluid inertia. The model is applied to three situations: (i) the spin bath of the process where α ≪ 1 and β ≫ 1, (ii) the preheat bath where α is order 1 and β ≫ 1, (iii) a fibre spreading process where α is order 1 and β is order 1 or smaller. In each case, analytical results are obtained for the fluid flow and fibre deflections and compared with experiment.

Characteristic Ratio-Independent Arterial Stiffness-Based Blood Pressure Estimation

2017 ◽  
Vol 21 (5) ◽  
pp. 1263-1270 ◽  
Author(s):  
Seddigheh Baktash ◽  
Mohamad Forouzanfar ◽  
Izmail Batkin ◽  
Miodrag Bolic ◽  
Voicu Z. Groza ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Arterial Stiffness ◽  
Characteristic Ratio ◽  
Pressure Estimation ◽  
Blood Pressure Estimation
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