2,149 research outputs found

    Selection method modelling and matching rule for rated power of prime motor used by beam pumping units

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    The energy consumption of prime motors used in oilfields is the one-third of the total energy consumption of beam pumping unit wells. In order to keep initiating and operating the prime motor smoothly and safely, its actual rated power is high much more than the needed. With the intention of improving the efficiency of the prime motor and decreasing the cost of rod-pumping, a set of rated power calculated methods and a set of matching templates was built up under the regarding conditions such as the changing rule of the system load, the heating of the prime motor and the overload torque in the initiate processing. The tested data indicated that, after replacing the prime motor with lower power, the active power, the inactive power and the suspended polished-rod load were all decreased substantially

    N-(4-Amino­phen­yl)-1,8-naphthalimide hemihydrate

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    The title compound, C18H12N2O2·0.5H2O, was prepared by the reaction of 1,4-phenyl­enediamine with 1,8-naphthalic anhydride in refluxing dimethyl­formamide. The structure is stabilized by N—H⋯O and O—H⋯O hydrogen bonds. There are π–π stacking inter­actions [centroid-centroid distances of 3.718 (2), 3.510 (2) and 3.546 (2) Å] and C—H⋯π inter­actions between the mol­ecules. The water molecule lies on a twofold rotation axis. Its two H atoms are disordered equally over two positions

    A Numerical Study On The Indoor Thermal Environment Served By A Novel Air Source Heat Pump Powered Bed-Based Space Heating (ASHP-BBSH) System

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    A numerical study on the indoor thermal environment served a novel air source heat pump powered bed-based space radiation heating (ASHP-BBSH) system is reported in this paper. This novel system combines the merits from a Chinese Kang, or a heated bed, widely used in northern rural China and a standard ASHP system, which can provide localized space heating via both convection and radiation to maintain a comfortable indoor thermal environment, at reduced energy use. In this novel bed-based system, a bed is heated and thus used as a radiator for providing space heating at both daytime and nighttime. In this paper, firstly, a numerical model for a bedroom with a heated bed was firstly built and a manikin with simplified dimensions and physiological shape sitting on the heated bed has been added to the numerical model. Secondly, using the model, the relationships between indoor thermal environment and a number of influencing factors, including the bed surface temperature and heating area were numerically studied. Thirdly, a comparison between the novel system and a standard ASHP system was numerically conducted to demonstrate the advantages of the novel bed-based space heating system. The numerical results show that compared with a standard ASHP system, a better thermal comfort level and higher energy saving potential can be achieved by applying the ASHP-BBSH system. Necessary parameters for the system design and operation in the follow-up experimental work were provided

    DNMT3a in the hippocampal CA1 is crucial in the acquisition of morphine self‐administration in rats

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    Drug‐reinforced excessive operant responding is one fundamental feature of long-lasting addiction‐like behaviors and relapse in animals. However, the transcriptional regulatory mechanisms responsible for the persistent drug‐specific (not natural rewards) operant behavior are not entirely clear. In this study, we demonstrate a key role for one of the de novo DNA methyltransferase, DNMT3a, in the acquisition of morphine self‐administration (SA) in rats. The expression of DNMT3a in the hippocampal CA1 region but not in the nucleus accumbens shell was significantly up‐regulated after 1‐ and 7‐day morphine SA (0.3 mg/kg/infusion) but not after the yoked morphine injection. On the other hand, saccharin SA did not affect the expression of DNMT3a or DNMT3b. DNMT inhibitor 5‐aza‐2‐deoxycytidine (5‐aza) microinjected into the hippocampal CA1 significantly attenuated the acquisition of morphine SA. Knockdown of DNMT3a also impaired the ability to acquire the morphine SA. Overall, these findings suggest that DNMT3a in the hippocampus plays an important role in the acquisition of morphine SA and may be a valid target to prevent the development of morphine addiction. Includes Supplemental informatio

    A Few-Shot Learning-Based Siamese Capsule Network for Intrusion Detection with Imbalanced Training Data

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    Network intrusion detection remains one of the major challenges in cybersecurity. In recent years, many machine-learning-based methods have been designed to capture the dynamic and complex intrusion patterns to improve the performance of intrusion detection systems. However, two issues, including imbalanced training data and new unknown attacks, still hinder the development of a reliable network intrusion detection system. In this paper, we propose a novel few-shot learning-based Siamese capsule network to tackle the scarcity of abnormal network traffic training data and enhance the detection of unknown attacks. In specific, the well-designed deep learning network excels at capturing dynamic relationships across traffic features. In addition, an unsupervised subtype sampling scheme is seamlessly integrated with the Siamese network to improve the detection of network intrusion attacks under the circumstance of imbalanced training data. Experimental results have demonstrated that the metric learning framework is more suitable to extract subtle and distinctive features to identify both known and unknown attacks after the sampling scheme compared to other supervised learning methods. Compared to the state-of-the-art methods, our proposed method achieves superior performance to effectively detect both types of attacks

    Improving mobility of silicon metal-oxide-semiconductor devices for quantum dots by high vacuum activation annealing

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    To improve mobility of fabricated silicon metal-oxide-semiconductor (MOS) quantum devices, forming gas annealing is a common method used to mitigate the effects of disorder at the Si/SiO2 interface. However, the importance of activation annealing is usually ignored. Here, we show that a high vacuum environment for implantation activation is beneficial for improving mobility compared to nitrogen atmosphere. Low-temperature transport measurements of Hall bars show that peak mobility can be improved by a factor of two, reaching 1.5 m^2/(Vs) using high vacuum annealing during implantation activation. Moreover, the charge stability diagram of a single quantum dot is mapped, with no visible disturbance caused by disorder, suggesting possibility of fabricating high-quality quantum dots on commercial wafers. Our results may provide valuable insights into device optimization in silicon-based quantum computing.Comment: 13 pages, 4 figure
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