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Carbazole compounds are widely used in determining the direction of petroleum migration, but the effect of thermal maturity on carbazoles is still ambiguity. In this paper, using compaction pyrolysis simulation experiments, artificial mature samples with vitrinite reflectance (Ro) range from 0.38 to 3.0% were acquired. And the content and composition change characteristics of carbazole compounds were analyzed in coal source rocks. The experimental results showed that thermal maturity controls the generation of a large amount of carbazole compounds in coal rocks. Compared with the low mature stage, the content of carbazole compounds was about 10–100 times higher in the mature stage. With the increasing maturity, in the coal sample, the content of carbazole compounds showed a trend of first increasing and then decreasing. In derivatives of carbazole, the corresponding maturity for the maximum generation of ethylcarbazole (EC), dimethylcarbazole (DMCA), methylcarbazole (MCA), carbazole (CA) and benzocarbazole (BCA) performed the increasing sequence. With the increasing maturity, the relative abundance of 2-MCA, 1,7-DMCA and benzo[a]carbazole increased with the increasing maturity, while 4-MCA, 1,4-DMCA and benzo[c]carbazole gradually decreased. Benzocarbazole ratio [a]/[a] +[ c] varies only in a narrow range 0.36–0.61 in the entire maturity range, suggesting limited maturity dependence. The experimental conclusion provides more theoretical basis for future geochemical analysis using carbazole compounds. [ABSTRACT FROM AUTHOR]

Normal-pressure shale gas reservoirs are widely distributed in south-eastern Chongqing and show good potential for resource exploration. This paper reports the organic matter (OM), physical, and pore characteristics, mineral composition, and gas content of representative shale samples from the Upper Ordovician Wufeng Formation and Member 1 of the Lower Silurian Longmaxi Formation (Long 1 Member). Microscopic pores within different shale layers of the Long 1 Member were classified, quantitatively evaluated, and their development mechanisms were systematically studied. We found that OM characteristics, mineral composition, and pore type were the main factors affecting the enrichment and preservation of shale gas. The characteristics of the Long 1 Member are mainly controlled by changes in the sedimentary environment. There are evident differences in total organic carbon content and mineral composition vertically, leading to a variable distribution of pores across different layers. Organic matter abundance controls the degree of OM pore development, while clay minerals abundance control the development of clay mineral-related pores. Total organic carbon content generally controls the porosity of the Long 1 Member, but clay minerals also play a role in OM-poor layers. Pore connectivity and permeability are influenced by the development of pores associated with brittle minerals. We propose a microscopic pore development model for the different layers. Combining geochemical data and this pore development model, layers 1–4 are considered to be excellent shale gas preservation and enrichment reservoirs. Poor preservation conditions in layers 5–7 result in high levels of shale gas escape. Layers 8–9 possess a better sealing condition compared with layers 5'-7 and are conducive to the enrichment and preservation of shale gas, and can thus be used as future potential target strata. This research provides a theoretical basis for exploring and evaluating shale gas potential in the studied region or other complex normal-pressure shale blocks. [ABSTRACT FROM AUTHOR]

Deformation of coals under tectonic movements could cause reduction of mechanical strength and enhancement of gas adsorption, which might result in coal and gas outburst, and cause safety and environmental issues. In this study, geophysical characteristics of coals with various structures were investigated with a special emphasis on characterization of pore size distribution, rock mechanical strength, acoustic emission, resistivity and acoustic velocity of anthracites with three types of structures in the Qinshui Basin, north China. The studied No. 3 coal seam developed three types of structures, namely undeformed coal, cataclastic coal, and granular coal. Petrographic observations under scanning electron microscope and pore size distribution using N2 and CO2 adsorption of anthracites of three types show that the undeformed coal consists of primary micropores, and cataclastic coal is mainly composed of mesopores and well-connected fractures. In comparison, granular coal has the least mesopores. Rock mechanical strength, acoustic emission, resistivity and acoustic velocity of coals with three structure types were investigated under uniaxial and triaxial compression. With increasing degree of deformation of anthracites, compression strength, Young's modulus, density, acoustic emission counting and acoustic velocity decreases, while resistivity increases. We suggest that the evolution of pore size distribution of anthracites with increasing degree of deformation contributed to variations of geophysical characteristics of coals with different structures to some extent. [ABSTRACT FROM AUTHOR]

In order to study the geochemical characteristics of fine-grained sedimentary rocks and clarify its relationship with the tight oil reservoir, the Chang7 Member of Triassic Yanchang Formation in Longdong area was taken as an example to be studied by rock pyrolysis, isotopic determination, maceral analysis, gas chromatography and gas chromatography–mass spectrometry. Lacustrine organic-rich fine-grained sedimentary rocks can be divided into organic-rich shale and organic-rich mudstone according to their lithology and texture. The results show that the organic-rich shale was deposited in a quiet and anoxic deep lacustrine environment, the organic matter was of high abundance and mainly sourced from plankton and benthic algae (type I–II1). Organic-rich mudstone mainly deposited in the semi-deep lacustrine environment, where the water was relatively shallow and the salinity was low, the organic matter was of low abundance and came from the mixed source of plankton and terrestrial clastic (type II1–II2). The Chang7 tight oil is widely distributed in the turbidite sand bodies, and it was mainly sourced from the Chang7 organic-rich shale. [ABSTRACT FROM AUTHOR]

The capability of manipulating objects based on vision system are essential to robotic applications. For a vision system, high accuracy and robustness is vital. However, due to external environment and interference influences, as well as to lighting conditions influences, the most existing image-based vision system are limited in applications. In this context, a novel and robust data-driven vision system for recognizing different types of objects in various external situations has been presented in this paper. The system consists of three parts, namely, integrated module based on X2 Ultra-wideband (UWB) radar, deep learning (DL) module and robot controller. Specifically, the introduction of X2 UWB radar aims to (1) capture and process radar echo signals of different objects in various environments; (2) extract Range-Doppler power spectrograms from the processed signals accurately. The second part combines the DL algorithm to take the spectrograms as the input from the former to realize object classification. And the last part is used to control the behavior of the robot based on the classification results. The experimental results show that the proposed vision system achieves very reliable performance in recognizing six types of objects in four kinds of external environment and lighting conditions with three deep learning network models. Besides, by experimental data comparison, the performance of the proposed system achieves higher than that of the image-based system in the same poor conditions and ResNet is the optimal model for our proposed system in all conditions. [ABSTRACT FROM AUTHOR]

A multiuser multiple-input-single-output simultaneous wireless information and power transfer downlink system with imperfect channel is considered. This paper maximizes the worst-case harvested energy of all users and maintains the signal-to-interference and noise ratio requirement. The unknown channel estimate error is assumed within a certain range. Under the assumption, beamforming vector optimization is formulated as a semi-definite programming problem transformed by S-Procedure method. Using semidefinite relaxation technique, an optimal beamforming vector is obtained for the multi-antenna transmitter. The robustness and effectiveness of our proposed algorithm are provided by the simulation results compared with the non-robust design. [ABSTRACT FROM AUTHOR]

In this paper, we first analyze the scalability and programming network architectures for Internet of things (IoT) in industries. Then, a representational state transfer(REST) framework for IoT based on software defined network (SDN) is proposed. Based on the proposed framework, control plane model and data plane model for IoT are proposed. In addition, a gateway model is provided to evaluate the proposed framework and use case results show that the proposed architectures are good for raw sensor data collecting. This framework provides a sharing mechanism for IoT in the modern manufacturing. [ABSTRACT FROM AUTHOR]

A multi-cell multi-input multi-output energy-harvesting network for factory-of-things is considered, where the control panel and smart devices are equipped with multiple antennas. Simultaneous wireless information and power transfer can deliver radio frequency energy for devices in the network, thus formulating the issue of quality of service(QoS). Each cell composes of one control panel and several smart devices where the process of SWIPT causes interference to each other, leading to a complicated non-convex problem. In order to solve it, the linear beamformers and receivers have been designed to maintain the QoS by minimizing the interference. Based on the minimum mean-square-error criterion, an joint controller-device design in which the control panels and smart devices would satisfy the transmit power constraints and the receiving energy bound is proposed. Numerical results of MSE uncover good performance of our proposed algorithm in this network. [ABSTRACT FROM AUTHOR]

Solid and hollow CoO nanospheres were synthesized by solvothermal method with oleic acid as reactant and SiO as template. Each sample of high-purity CoO was characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy and X-ray photoelectron energy spectroscopy, respectively. Both solid and hollow CoO nanospheres as anode for lithium-ion battery were tested by galvanostatic discharge-charge experiments. The first discharge capacity of 1598 and 1640 mAh g was obtained at 0.1 C for solid and hollow CoO nanospheres, respectively. Hollow CoO nanospheres showed better cycle performance. [ABSTRACT FROM AUTHOR]

Forty-six crude oil samples were selected from the Ordovician in the northwestern part of the Tahe oilfield for detailed molecular geochemical and isotopic analysis, including group compositions, carbon-hydrogen isotopes and gas chromatograms of saturated hydrocarbons, as well as the characteristics of terpane, sterane and other biomarkers, indicating that crude oils are of the same origin from different districts in the Tahe oilfield and were derived from the same source kitchen (or oil source formation), i.e., mainly stemming from marine hydrocarbons. Detailed studies of oil physical properties of 25-honpane revealed that such oils have heavy or thick oil qualities due to biodegradation. Comprehensive assessment in terms of five maturity parameters shows that the oils from the Ordovician with R values varying from 0.80% to 1.59% are widely distributed in the northwest of the Tahe oilfield. [ABSTRACT FROM AUTHOR]

In the future time the exploration of marine oil and gas will be one of the significant domains in China. In this paper the biomarker assemblage characteristics of oilshow in the Nanlinghu Formation of the Majiashan profile, which is located in Chaoxian County, south of Anhui Province, are described in the light of gas chromatography/mass spectrometric (GCMS) analysis on the qualitative and quantitative basis. Based on the investigation of the biomarker assemblage characteristics of possible source rocks developed in the area studied, a conclusion is drawn that the oilshow was generated from the Nanlinghu Formation source rocks (abbreviated as T1 n), instead of the Qixia Formation source rocks (abbreviated as P1 q). It is pointed out that the T1 n is of strong potential for future oil exploration, and therefore much attention should be paid to it. [ABSTRACT FROM AUTHOR]

The geochemical characteristics of natural gases discovered in the Bozhong Depression are systematically described in this paper. The natural gases are composed mainly of hydrocarbon gases. Natural gases occurring in the Paleogene and older reservoirs are wet gases, whereas those in the Neogene reservoirs are dry gases. Methane and ethane in the gases are significantly different in carbon isotopic composition. The methane carbon isotopic composition of the gases in structure BZ28-1 and the ethane carbon isotopic composition of the gases in structure QHD30-1 are characterized by the heaviest values, respectively. The natural gases are in the mature to highly mature stages. The hydrocarbon gases are of organic origin and can be classified as oil-type gases, coal-derived gases and mixed gases with the third one accounting for the major portion. [ABSTRACT FROM AUTHOR]

Gas chromatography fingerprint technique has the advantages of fast performance and low cost. It can be used to conduct analysis without interruption either in the field or at laboratory. This technique has been used successfully in such cases that conventional production logging techniques are powerless. Taking low-concentration anthracene as internal standard, we calculated the absolute concentrations of fingerprints, initially made some experiments directly on biodegradation of crude oils, and calculated production allocation in the Gudong Oil field. Compared with the production logging, this method has made up for the deficiencies of the former GC fingerprint technique. It will find wide applications in monitoring the trend of production in various oil-fields. [ABSTRACT FROM AUTHOR]

Field and laboratory analyses of carbonate rock samples from the Qiangtang Basin, Tibet, indicate that carbonate source rocks are mainly developed in the Middle Jurassic Xiali Formation and Upper Jurassic Suowa Formation. Comprehensive studies showed that the Suowa Formation carbonate source rocks have a favorable hydrocarbon-generating potential. The abundance of organic matter in the carbonate rocks is controlled mainly by sedimentary environment and inorganic compounds in the rocks, which is higher in the restricted platform facies than in the open platform facies. Organic carbon contents decrease with increasing CaO contents in the source rocks. [ABSTRACT FROM AUTHOR]

Oil samples from the Bongor Basin, SW Chad have been geochemically characterized to investigate the biodegradation influence on alkylphenanthrenes. Concentrations of C0–3-alkylphenanthrenes (C0–3Ps) increase markedly after level 6 biodegradation due to the removal of other vulnerable components, decrease sharply after level 7 biodegradation and approach to absence at level 8. Phenanthrene appears to have higher ability to resist biodegradation than C1–3Ps at certain biodegradation levels (≤level 7) due to demethylation, which has been inferred as a possible reaction process during biodegradation of the aromatic hydrocarbons. The enrichment of non-alkylated phenanthrene in biodegraded oils makes biodegradation assessment complicated on the basis of alkylphenanthrene distributions. Individual isomers in alkylphenanthrenes exhibit variable ability to resist biodegradation influence. While certain isomers do show higher ability to resist biodegradation than others, no uniform biodegradation sequence can be established. Meanwhile, the biodegradation susceptibility between hopanes and alkylphenanthrenes varies greatly in different samples. The biodegradation systematics of alkylphenanthrenes proves to be highly complex, which may be indicative of the multiple charges and mixing during biodegradation. [ABSTRACT FROM AUTHOR]

A simultaneous wireless information and power transfer system in interference channels of multi-users is considered. In this system, each transmitter sends one data stream to its targeted receiver, which causes interference to other receivers. Since all transmitter-receiver links want to maximize their own average transmission rate, a power allocation problem under the transmit power constraints and the energy-harvesting constraints is developed. To solve this problem, we propose a game theory framework. Then, we convert the game into a variational inequalities problem by establishing the connection between game theory and variational inequalities and solve the variational inequalities problem. Through theoretical analysis, the existence and uniqueness of Nash equilibrium are both guaranteed by the theory of variational inequalities. A distributed iterative alternating optimization water-filling algorithm is derived, which is proved to converge. Numerical results show that the proposed algorithm reaches fast convergence and achieves a higher sum rate than the unaided scheme. [ABSTRACT FROM AUTHOR]

This paper discussed the direction of secondary migration of oil in the No. 6 area of the Melut Basin by making use of nitrogen compounds as secondary oil migration tracers. From the results, we have found that the occurrence and compositional characteristics of isomeric-nitrogen compounds in crude oil precisely manifest the fractionation effect of oil migration: with increasing secondary migration distance, the absolute concentrations tend to decrease, and the ratio of nitrogen-shielded isomers to nitrogen exposed isomers tends to increase. It is considered that the main direction of oil migration in the No. 6 area of the Melut Basin is from north to south. [ABSTRACT FROM AUTHOR]