摘要 :
Simulation technology has been widely used in the aerospace field due to its economical and rapid nature. The simulation technology based on STKX not only inherits the professionalism and fidelity of STK (Satellite Tool Kit), but ...
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Simulation technology has been widely used in the aerospace field due to its economical and rapid nature. The simulation technology based on STKX not only inherits the professionalism and fidelity of STK (Satellite Tool Kit), but also can be seamlessly integrated into the software, which has become a key technology in the simulation research in the aerospace field. The agile satellite is a kind of satellite that can observe the ground target quickly and flexibly. It is of great significance to guarantee modern agriculture, disaster prevention and reduction, resource investigation, environmental protection and national security in China. This article takes the agile satellite ground observation imaging as the engineering background, expounds the basic principles of STKX technology, explains the engineering and technical issues such as the creation of satellites, cameras and observation targets in scene simulation, and uses Cesium to demonstrate simulation effect of ground observation imaging. It aims to provide reference for the engineering application of STKX technology.
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摘要 :
Simulation technology has been widely used in the aerospace field due to its economical and rapid nature. The simulation technology based on STKX not only inherits the professionalism and fidelity of STK (Satellite Tool Kit), but ...
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Simulation technology has been widely used in the aerospace field due to its economical and rapid nature. The simulation technology based on STKX not only inherits the professionalism and fidelity of STK (Satellite Tool Kit), but also can be seamlessly integrated into the software, which has become a key technology in the simulation research in the aerospace field. The agile satellite is a kind of satellite that can observe the ground target quickly and flexibly. It is of great significance to guarantee modern agriculture, disaster prevention and reduction, resource investigation, environmental protection and national security in China. This article takes the agile satellite ground observation imaging as the engineering background, expounds the basic principles of STKX technology, explains the engineering and technical issues such as the creation of satellites, cameras and observation targets in scene simulation, and uses Cesium to demonstrate simulation effect of ground observation imaging. It aims to provide reference for the engineering application of STKX technology.
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A fingerprinting is related to cryptographic hash functions. In contrast to cryptographic hash functions this robust digest is sensitive only to perceptual change. Minor changes, which are not affecting the perception, do not resu...
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A fingerprinting is related to cryptographic hash functions. In contrast to cryptographic hash functions this robust digest is sensitive only to perceptual change. Minor changes, which are not affecting the perception, do not result in a different fingerprint. This technique is used in content-based retrieval, content monitoring, and content filtering. In this paper we present a cumulant-based image fingerprinting method. Cumulants are typically used in signal processing and image processing, e.g. for blind source separation or Independent Component Analysis (ICA). From an image with reduced dimensions we calculate cumulants as an initial feature vector. This feature vector is transformed into an image fingerprint. The theoretical advantages of cumulants are verified in experiments evaluating robustness (e.g. against operations like lossy compression, scaling and cropping) and discriminability. The results show an improved performance our method in comparison to existing methods.
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摘要 :
A fingerprinting is related to cryptographic hash functions. In contrast to cryptographic hash functions this robust digest is sensitive only to perceptual change. Minor changes, which are not affecting the perception, do not resu...
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A fingerprinting is related to cryptographic hash functions. In contrast to cryptographic hash functions this robust digest is sensitive only to perceptual change. Minor changes, which are not affecting the perception, do not result in a different fingerprint. This technique is used in content-based retrieval, content monitoring, and content filtering. In this paper we present a cumulant-based image fingerprinting method. Cumulants are typically used in signal processing and image processing, e.g. for blind source separation or Independent Component Analysis (ICA). From an image with reduced dimensions we calculate cumulants as an initial feature vector. This feature vector is transformed into an image fingerprint. The theoretical advantages of cumulants are verified in experiments evaluating robustness (e.g. against operations like lossy compression, scaling and cropping) and discriminability. The results show an improved performance our method in comparison to existing methods.
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A delayed cross linked gel profile control agent is used to plug high permeable formations. Also, well nutrient fluid and microbes are injected with 50% of the heavy residual oil, after polymer flooding, in order to improve oil re...
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A delayed cross linked gel profile control agent is used to plug high permeable formations. Also, well nutrient fluid and microbes are injected with 50% of the heavy residual oil, after polymer flooding, in order to improve oil recovery due to the complex environment of oil reservoirs. Four strains of polycyclic aromatic hydrocarbon-degrading bacteria are selected from oilfield produced water with a high efficiency. Two of the four strains, namely BISYX17 and BISYX14, are new. Polycyclic aromatic hydrocarbon-degrading bacteria have high growth activity and they are able to reach a maximum stain concentration after being cultured 4 to 8 days, using phenanthrene as their sole carbon source. They are able to effectively degrade heavy hydrocarbon with a phenanthrene degradation rate of up to 80%, after the sample is cultured for seven days. Strain BISYX7 has the strongest phenanthrene -degrading ability, with a maximum degradation percentage of 89.89%. The strains are capable of producing dioxygenase to open rings of polycyclic aromatic hydrocarbon. The dioxygenase activity, produced by BISYX17, is able to reach 40.2 IU/mg, which is higher than the enzyme activities of a wild strain. This shows the strain has excellent potential to produce enzymes. Enzymes, produced by metabolism, have a direct degradation rate of 68% on crude oil. A core displacement simulation experiment indicates a profile control oil-displacing system is able to improve crude oil recovery efficiency by 17%, after polymer flooding. Thus, the system has excellent application potential for residual oil recovery.
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摘要 :
A delayed cross linked gel profile control agent is used to plug high permeable formations. Also, well nutrient fluid and microbes are injected with 50% of the heavy residual oil, after polymer flooding, in order to improve oil re...
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A delayed cross linked gel profile control agent is used to plug high permeable formations. Also, well nutrient fluid and microbes are injected with 50% of the heavy residual oil, after polymer flooding, in order to improve oil recovery due to the complex environment of oil reservoirs. Four strains of polycyclic aromatic hydrocarbon-degrading bacteria are selected from oilfield produced water with a high efficiency. Two of the four strains, namely BISYX17 and BISYX14, are new. Polycyclic aromatic hydrocarbon-degrading bacteria have high growth activity and they are able to reach a maximum stain concentration after being cultured 4 to 8 days, using phenanthrene as their sole carbon source. They are able to effectively degrade heavy hydrocarbon with a phenanthrene degradation rate of up to 80%, after the sample is cultured for seven days. Strain BISYX7 has the strongest phenanthrene -degrading ability, with a maximum degradation percentage of 89.89%. The strains are capable of producing dioxygenase to open rings of polycyclic aromatic hydrocarbon. The dioxygenase activity, produced by BISYX17, is able to reach 40.2 IU/mg, which is higher than the enzyme activities of a wild strain. This shows the strain has excellent potential to produce enzymes. Enzymes, produced by metabolism, have a direct degradation rate of 68% on crude oil. A core displacement simulation experiment indicates a profile control oil-displacing system is able to improve crude oil recovery efficiency by 17%, after polymer flooding. Thus, the system has excellent application potential for residual oil recovery.
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Two strains of bacteria degrading polycyclic aromatic hydrocarbons (PAHs) were isolated using enrichment cultures of various heavy crude oil samples obtained from the Dagang Oilfield. The strains, namely S17 and S28, are able to d...
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Two strains of bacteria degrading polycyclic aromatic hydrocarbons (PAHs) were isolated using enrichment cultures of various heavy crude oil samples obtained from the Dagang Oilfield. The strains, namely S17 and S28, are able to degrade crude oil using phenanthrene as the sole carbon and energy source. The crude oil composition analysis indicates both strains are able to degrade heavy hydrocarbon components in crude oil. Then, the viscosities of heavy crude oil with S17 and S28 were decreased, and the surface tension between fermentative fluid and air were also decreased. The core flooding tests demonstrated that the fermentation broth, containing the two strains, can improve the residual oil recovery ratio by approximately 12.26% after polymer flooding.
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Culture-based techniques were applied to analyze the diversity of indigenous microbial communities in the Qinghai middle salinity petroleum reservoir (QH-MSPR). The results of the most probable number (MPN) method indicated there ...
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Culture-based techniques were applied to analyze the diversity of indigenous microbial communities in the Qinghai middle salinity petroleum reservoir (QH-MSPR). The results of the most probable number (MPN) method indicated there was an abundance of indigenous microbes (10~5-10~6MPN/ml). Two isolations (BIOS682) from the QH-MSPR were identified as Brevibacillus agri and Brevibacillus levickii. The study showed that BIOS682 enhanced the degradation rate of Huatugou crude oil. The viscosity and freezing point of crude oil after treatment by BIOS682 were all decreased. The results of TLC and FTIR spectrum analysis of the biosurfactant produced by BIOS682 indicated that it was identical to that of lipopeptide. The core-flooding tests showed that the incremental oil recoveries were 7.05-10.15%. Thus, BIOS682 may provide a viable application of microbial enhanced oil recovery (MEOR).
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Thermochromatium tepidum (TTP) is a themophilic purple sulfur photosynthetic bacterium of which light-harvesting 1 reaction center (LH1RC) complexes exhibit an unusual LH1 Qy absorption at 915 nm and thermal resistance relative to...
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Thermochromatium tepidum (TTP) is a themophilic purple sulfur photosynthetic bacterium of which light-harvesting 1 reaction center (LH1RC) complexes exhibit an unusual LH1 Qy absorption at 915 nm and thermal resistance relative to those of mesophilic counterparts. Recently, we demonstrated that these unique properties were regulated by an inorganic cofactor, Ca2+. Wild-type TTP cells grew anaerobically at 50 ℃ in a culture medium containing a small amount of CaCl2. When Ca2+ was removed from the medium or replaced with other metal cations, the photosynthetic growth was largely suppressed, however, only Sr2+ was biofunctionally replaceable with Ca2+. The resulting Sr2+-substituted TTP (Sr2+TTP) cells showed different spectral properties compared with the native ones in the LH1 Qy region. The LH1RC complex purified from Sr2+-TTP cells exhibited its Qy maximum at 888 nm (B888). Depletion of Sr2+ from the B888 species induced a blue-shift of the LH1 Qy peak and decreased the thermal stability. Upon the Sr2+-reconstitution, the LH1-RC recovered its thermal stability and Qy peak position depending on the Sr2+-concentration with an approximately 104 M-1 of binding constant. This is the first evidence for a functional LH1-variant which was prepared by the biosynthetic metal substitution.
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Recent investigations of the microbial communities in an oil reservoir using culture-independent molecular techniques has indicated that this environment contains many uncultured assemblages, and that the cultured bacteria may rep...
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Recent investigations of the microbial communities in an oil reservoir using culture-independent molecular techniques has indicated that this environment contains many uncultured assemblages, and that the cultured bacteria may represent very minor components of the true microbial diversity.In this study, 16S rDNA based PCR amplification and denaturing gradient gel electrophoresis (PCR-DGGE) was used to monitor the microbial diversity in an injection well (12#9-11) and two related production wells (12#9-9S、13#11-8) in the KELAMAYI oilfield（Xin Jiang Autonomous Region）.The DGGE gel profiles showed significant difference between the microbial community structure of injection and production wells.The bacterial species richness in the injection well was higher than those of the production ones.Unweighted Pair Group Method Clustering (UPGMC) showed the similarity between the injection well and two production wells was 30% and 20% respectively, whereas the similarity between the two production wells was 54%.In addition, the dominant bands in the DGGE gel were excised and analyzed by nucleotide sequence analysis.This analysis of 10 excised bands showed that the dominant microorganisms in all samples had high sequence identity with rRNA genes from uncultured bacteria in the GenBank database (NCBI).Nine sequences of excised band were affiliated with α, γ, δ,ε-Proteobacteria, and one was related to Bacteroides.Two bands exhibited 100% identity to sequences of Pseudomonas stutzeri and Aminobacter sp.cox, respectively.Three bands showed relatively low identity (92% to 93%) to cultured bacteria in the GenBank database, indicating possible new taxa.This work analyzed the composition of the microbial community in KELAMAYI oilfield, which provides important data which may facilitate the isolation of new bacteria from this special underground environment.It also provides useful information for understanding the mechanism of MEOR and applying MEOR in practical oil production in KELAMAYI oilfield.
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