Search

Shale oil and gas resources are abundant in the Chang 7 shale of the Yanchang Formation in Ordos Basin. To determine the characteristics and influencing factors of hydrocarbon generation evolution of the Chang 7 shale, a series of thermal simulation experiments were conducted on low‐maturity shale and kerogen samples. The results indicate that the maximum yield of shale oil are 294.5 and 304.3 mg/g TOC for kerogen sample at heating rates of 20 and 2°C/h, and the corresponding experimental temperatures are 360.2°C and 408.0°C, respectively. The utilization of lower heating rates is favourable for shale oil generation and it is recommended to employ a lower heating rate during in situ heating processes to maximize the economic benefits. The formation of crude oil cracking gas begins when simulating temperature exceeds 528.0°C (Easy Ro 2.6%) at a heating rate of 20°C/h and 480.0°C (Easy Ro 2.5%) at a heating rate of 2°C/h, as indicated by the carbon isotopic composition of gaseous hydrocarbons. The maximum oil production rate of the rock powder sample is 159.8 mg/g TOC, which is lower than that of the kerogen sample. It suggests that certain minerals in the Chang 7 shale may impede hydrocarbon generation. After the addition of pyrite, the highest yield of shale oil is 213.96 mg/g TOC, 33.9% higher than the yield of the original rock powder sample, reflecting the positive catalytic effect of pyrite on hydrocarbon generation of Chang 7 shale. Under geologic conditions, pyrite catalytic hydrocarbon generation may act primarily on the migration of organic matter by macromolecules, which considerably increases the probability of direct contact between pyrite and organic matter. Therefore, the organic‐rich shale with high pyrite content in Chang 7 member is the preferred target for in situ conversion of shale oil and gas in the Ordos Basin. [ABSTRACT FROM AUTHOR]

Exploration and development effects of Lucaogou Formation laminated shale are not ideal in the Santanghu Basin, and the reasons are not clear. Therefore, in this study, laminated and massive shales were systematically sampled, and experiments of cryogenic adsorption of nitrogen and multi‐dimensional nuclear magnetic resonance comparison were carried out. The results show that Lucaogou Formation shale is rich in volcanic ash and low content of clay, which can be divided into tuff, dolomite, tuffaceous dolomite, dolomitic tuff, and other lithologic types. The laminar structure is developed in tuffaceous dolomite and dolomitic tuff. The pores of Lucaogou Formation shale with a diameter of more than 10 nm can be used as an effective storage space for movable oil. The oil saturation and mobile oil ratio of laminated shale are lower than that of massive shale. Movable oil is controlled by carbonate content, and the higher the content, the higher the proportion of movable oil. Millimetre laminae are rich in organic matter and have poor interlaminar pore connectivity, which leads to strong adsorption capacity for oil. Therefore, the migration of oil between laminae is blocked, and oil mainly distributes or migrates in the bedding plane between laminae in laminated shale, which cannot be used as favourable reservoirs. [ABSTRACT FROM AUTHOR]

This letter presents a design method of resistance reactance hybrid continuous power amplifier based on reconfigurable devices and CG2H40010F. The power amplifier combines resistive‐reactive inverse F‐class power amplifier (RRIFPA), resistive‐reactive J‐class power amplifier (RRJPA), and resistive‐reactive F class power amplifier (RRFPA). We utilize the principle of low‐pass filters to control the impedance of multi‐frequency harmonics, and use the reconfigurable device SMP1345‐079LF to expand the bandwidth of the power amplifier. This article designs and produces a 1–4 GHz broadband power amplifier. The simulation and measurement results show that within the entire frequency range of 1–4 GHz, the Drain efficiency is between 53.6 and 72.1% $ \% $, the output power is between 40.1 and 42.6 dBm, the gain is between 10.1 and 12.6 dB, and the relative bandwidth is up to 120% $ \% $. [ABSTRACT FROM AUTHOR]

BACKGROUND: Spatial‐explicit weed information is critical for controlling weed infestation and reducing corn yield losses. The development of unmanned aerial vehicle (UAV)‐based remote sensing presents an unprecedented opportunity for efficient, timely weed mapping. Spectral, textural, and structural measurements have been used for weed mapping, whereas thermal measurements—for example, canopy temperature (CT)—were seldom considered and used. In this study, we quantified the optimal combination of spectral, textural, structural, and CT measurements based on different machine‐learning algorithms for weed mapping. RESULTS: CT improved weed‐mapping accuracies as complementary information for spectral, textural, and structural features (up to 5% and 0.051 improvements in overall accuracy [OA] and Marco‐F1, respectively). The fusion of textural, structural, and thermal features achieved the best performance in weed mapping (OA = 96.4%, Marco‐F1 = 0.964), followed by the fusion of structural and thermal features (OA = 93.6%, Marco‐F1 = 0.936). The Support Vector Machine‐based model achieved the best performance in weed mapping, with 3.5% and 7.1% improvements in OA and 0.036 and 0.071 in Marco‐F1 respectively, compared with the best models of Random Forest and Naïve Bayes Classifier. CONCLUSION: Thermal measurement can complement other types of remote‐sensing measurements and improve the weed‐mapping accuracy within the data‐fusion framework. Importantly, integrating textural, structural, and thermal features achieved the best performance for weed mapping. Our study provides a novel method for weed mapping using UAV‐based multisource remote sensing measurements, which is critical for ensuring crop production in precision agriculture. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

ABSTRACT In this study, poly(styrene-maleic anhydride) functionalized graphene oxide (SMAFG) was fabricated with in situ polymerization. The sample was characterized with Raman spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy, and ultraviolet-visible absorption. The results of the experiments show that the thermal stability of SMAFG was improved significantly, and it also possessed a good dispersion in N,N-dimethylformamide, N,N-dimethylacetamide, aniline, and certain organic solvents. The calculated Hildebrand parameter of SMAFG was 23.8 MPa1/2. This new method will broaden the applications of graphene, and the experiment showed that it could effectively improve the strength of polyamide 6 (PA6) compared with the pure PA6 fiber. The tensile strength of the SMAFG/PA6 composite fiber improved 29%, and the Young's modulus improved 33%, so this kind of functionalized graphene oxide can be used in the preparation of polymeric composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41987. [ABSTRACT FROM AUTHOR]