134 research outputs found

    Multilingual Text Detection with Nonlinear Neural Network

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    Multilingual text detection in natural scenes is still a challenging task in computer vision. In this paper, we apply an unsupervised learning algorithm to learn language-independent stroke feature and combine unsupervised stroke feature learning and automatically multilayer feature extraction to improve the representational power of text feature. We also develop a novel nonlinear network based on traditional Convolutional Neural Network that is able to detect multilingual text regions in the images. The proposed method is evaluated on standard benchmarks and multilingual dataset and demonstrates improvement over the previous work

    Research on One Novel Logging Interpretation Method of CBM Reservoir

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    Coalbed methane (CBM) is a kind of natural gas which is stored in the micropores and fractures of the “coal seam” and has not been transported out of the source rock. Conventional logging technology plays an important role in coalbed methane exploration and development. By analyzing the response characteristics of conventional logging of coalbed methane, coal bearing strata are accurately determined. Two methods of statistical model and volume model are established to analyze and calculate industrial components. Based on the study of adsorption isotherm and correlation between logging parameters and coal core gas content, the calculation method of coal seam gas content is determined In practices, the calculation accuracy of industrial components and gas content of coal seam has been significantly improved. Abstract: coalbed methane (CBM) is a kind of natural gas which is stored in the micropores and fractures of “coal seam” and has not been transported out of the source rock. Conventional logging technology plays an important role in coalbed methane exploration and development. By analyzing the response characteristics of conventional logging of coalbed methane, coal bearing strata are accurately determined. Two methods of statistical model and volume model are established to analyze and calculate industrial components. Based on the study of adsorption isotherm and correlation between logging parameters and coal core gas content, the calculation method of coal seam gas content is determined In practice, the calculation accuracy of industrial components and gas content of coal seam has been significantly improved

    Dynamic Simulation of Deposition Processes of Spacecraft Molecular Contamination

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    Accurate simulation and calculation of the deposition of outgassing molecule can shorten the cycle and reduce the cost of vacuum tests on satellites. It also provides a reference for contamination protection design by systems engineers. In this study, the molecular outgassing, transport and deposition processes were simulated by diffusion theory, the angle coefficient method, and the first-order desorption equation, respectively. The simulation results were consistent with the test data trends, but deviated from the test values. Given the effect of initial molecular outgassing rate, diffusion coefficient and residence time on the deposition mass, it was surmised that considering the molecular species and the weight mass rate would improve the calculation result. These considerations indeed improved the numerical simulations of high-vacuum contamination

    The effects of new urbanization pilot city policies on urban innovation: Evidence from China

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    The new urbanization city pilot policy is China’s most recent policy on urban urbanization. This paper uses new urbanization pilot policies as a quasi-natural experiment to empirically test the impact of new urbanization pilot policies on urban innovation through the difference-in-differences (DID) method using panel data from 199 cities in China from 2011 to 2019. The results show that: (1) The new urbanization city pilot policy has significantly enhanced urban innovation. (2) The theoretical mechanism test shows that the pilot policy of new urbanization promotes urban innovation through the level of human capital. (3) The results of the heterogeneity analysis show that the new urbanization pilot policies have obvious city-level heterogeneity and regional heterogeneity on the improvement of urban innovation levels. The impact effect of new urbanization pilot policies is higher in first-tier and second-tier cities than in fourth-tier and fifth-tier cities; the effect of new urbanization pilot policies is higher in western regions than in eastern and middle regions.National Natural Science Foundation of Chin

    Controlled Synthesis of Hierarchically Assembled Porous ZnO Microspheres with Enhanced Gas-Sensing Properties

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    The ZnO microspheres constructed by porous nanosheets were successfully synthesized by calcinating zinc hydroxide carbonate (ZHC) microspheres obtained by a sample hydrothermal method. The samples were characterized in detail with scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and thermogravimetric and differential scanning calorimetry (TG-DSC). The results indicated that the prepared ZnO microspheres were well crystalline with wurtzite hexagonal phase. The effects of reaction time, temperature, the amount of trisodium citrate, and urea on the morphology of ZnO microspheres were studied. The formation mechanism of porous ZnO microspheres was discussed. Furthermore, the gas-sensing properties for detection of organic gas of the prepared porous ZnO microspheres were investigated. The results indicated that the prepared porous ZnO microspheres exhibited high gas-sensing properties for detection of ethanol gas

    Effect of Cooking Temperature on Protein Oxidation and in Vitro Digestive Properties of Yak Meat

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    The digestibility of myofibrillar proteins (MP) extracted from yak meat cooked to different internal temperatures of (40, 50, 60, 70 and 80 ℃) was determined during in vitro gastrointestinal digestion, and total carbonyl content, total sulfhydryl content and Schiff base content before and after digestion were measured. Ultraviolet (UV) absorption spectroscopy, endogenous fluorescence spectroscopy and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were used to investigate the oxidation and digestion patterns of yak meat proteins during gastrointestinal digestion. The results showed that total protease hydrolysis of MP from yak meat cooked to 60 ℃ was the highest after simulated gastric and intestinal digestion (88.64%). The rates of pepsin hydrolysis and total protease hydrolysis of MP from yak meat cooked to 80 ℃ decreased by 34.10% and 22.47%, respectively, and the rate of trypsin hydrolysis increased by 75.34% compared with MP from raw yak meat. The total carbonyl content after simulated gastric and intestinal digestion increased by 81.42% and 77.40%, respectively, and the total sulfhydryl content decreased by 30.02% and 36.43%, respectively, compared with raw MP. With an increase in cooking temperature, the Schiff base content gradually increased, the UV absorbance was significantly enhanced, and the endogenous fluorescence intensity was significantly reduced. The SDS-PAGE patterns showed that the protein bands were severely degraded and even disappeared after digestion. It was found that the digestibility of MP from yak meat cooked to 60 ℃ was the highest. The degree of protein oxidation in yak meat cooked to 80 ℃ was the strongest and increased during gastrointestinal digestion

    Petrology and geochemistry of the high-sulphur coals from the Upper Permian carbonate coal measures in the Heshan Coalfield, southern China

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    The Heshan coals, with very high organic sulphur content, are found in the Upper Permian marine carbonate successions Heshan Formation) in the Heshan Coalfield, central Guangxi, southern China. The petrography, mineralogy, and geochemistry of coals and non-coal partings from the Suhe and Lilan coal mines of the Heshan Coalfield have been investigated using proximate, petrographic, inductively coupled plasma mass spectrometry (ICP-MS), X-ray fluorescence (XRF), X-ray diffraction (XRD), and scanning electron microscopy with an energy-dispersive X-ray (SEM-EDX) techniques. The sulphur content in the coals (with ash less than 50%) ranges from 5.3% to 11.6%, of which more than 90% is organic sulphur, reflecting a strong marine water influence on the palaeomire. The high vitrinite reflectance (1.89–2.18%Romax) indicates that the coals in the Heshan Coalfield are mainly low-volatile bituminous coal. Microscopic observation has revealed that the coal is mainly composed of vitrinite and inertinite macerals with relatively low TPI and high GI values, suggesting an unusual, strongly alkaline palaeomire, with high pH. XRD analysis plus optical and scanning electron microscopy show that the minerals in these coals are mainly quartz, calcite, dolomite, kaolinite, illite, and pyrite, although marcasite, strengite, and feldspar, as well as some oxidised weathering products such as gypsum, are also present. Most trace elements in the Heshan coals are enriched with respect to their world mean, with Mo, U, and W highly enriched, more than 10 times their world means. The trace elements are believed to be associated either with organic compounds (Mo and U) or minerals such as aluminium–iron-silicates (Sc, Ge, and Bi), aluminium-silicates (Cs, Be, Th, Pb, Ga, and REE), iron-phosphates (Zn, Rb, and Zr), iron-sulphides (As, Cd, Cr, Cu, Ni, Tl, and V), and carbonates (Sr, Mn, and W). Abnormally high organic sulphur content, high ash yields, relatively high GI values, very low TPI values, very high U contents, and very low Th/U ratios suggest that the Heshan coals accumulated in low-lying, marine-influenced palaeomires, developed on carbonate platforms. Many of these characteristics have also been recorded in the Tertiary coals of the circum-Mediterranean coal basins, where no marine influence is present. The similarities are thought to be produced by strongly alkaline groundwater chemistry, common to both environments

    Effect of Aurantii Fructus Immaturus Flavonoid on the Contraction of Isolated Gastric Smooth Muscle Strips in Rats

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    This study was designed to investigate the effect of Aurantii fructus immaturus flavonoid (AFIF) on the contraction of isolated gastric smooth muscle in rats and explore its underlying mechanisms. Isolated antral longitudinal smooth muscle strip (ALSMS) and pyloric circular smooth muscle strip (PCSMS) of rats were suspended in tissue chambers. The responses of ALSMS and PCSMS to administration of AFIF were observed. Cyclic guanosine monophosphate (cGMP) and protein kinase G (PKG) levels of PCSMS were measured by ELISA kits. In this study, AFIF showed no significant effect on ALSMS contraction, but it dose-dependently reduced the mean contraction amplitude of PCSMS. When the concentration of AFIF reached 3000 g/mL, 6000 g/mL, and 10000 g/mL, its inhibitory effect on PCSMS contraction was significant. This effect of AFIF was weakened in Ca 2+ -rich environment. And N -nitro-L-arginine methyl (L-NAME), the inhibitor of nitric oxide synthase (NOS), significantly inhibited AFIF's action in comparison with control ( < 0.05). After incubation with AFIF for 30 min, levels of cGMP and PKG in PCSMS were significantly increased compared with control ( < 0.05). Our results suggest that AFIF has a dose-dependent diastolic effect on PCSMS in rats, which may be related to the regulatory pathway of NO/cGMP/PKG/Ca 2+
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