Inspired by the integrated guidance and control design for endo-atmospheric aircraft,the integrated position and attitude control of spacecraft has attracted increasing attention and gradually induced a wide variety o...
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Inspired by the integrated guidance and control design for endo-atmospheric aircraft,the integrated position and attitude control of spacecraft has attracted increasing attention and gradually induced a wide variety of study results in last over two decades,fully incorporating control requirements and actuator characteristics of space *** paper presents a novel and comprehensive survey to the coupled position and attitude motions of spacecraft from the perspective of dynamics and *** this end,a systematic analysis is firstly conducted in details to show the position and attitude mutual couplings of ***,in terms of the time discrepancy between spacecraft position and attitude motions,space missions can be categorized into two types:space proximity operation and space orbital *** on this classification,the studies on the coupled dynamic modeling and the integrated control design for position and attitude motions of spacecraft are sequentially summarized and *** the one hand,various coupled position and dynamic formulations of spacecraft based on various mathematical tools are reviewed and compared from five aspects,including mission applicability,modeling simplicity,physical clearance,information matching and *** the other hand,the development of the integrated position and attitude control of spacecraft is analyzed for two space missions,and especially,five distinctive development trends are captured for space operation ***,insightful prospects on future development of the integrated position and attitude control technology of spacecraft are proposed,pointing out current primary technical issues and possible feasible solutions.
The use of biodiesel mixtures has become a part of everyday life. The current implementation of B7 biodiesel at the pump and the premise that the near future will make B20 biodiesel compulsory leads to the necessity o...
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The identification of intercepted radio fuze modulation types is a prerequisite for decision-making in interference ***,the electromagnetic environment of modern battlefields is complex,and the signal-to-noise ratio(S...
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The identification of intercepted radio fuze modulation types is a prerequisite for decision-making in interference ***,the electromagnetic environment of modern battlefields is complex,and the signal-to-noise ratio(SNR)of such environments is usually low,which makes it difficult to implement accurate recognition of radio *** solve the above problem,a radio fuze automatic modulation recognition(AMR)method for low-SNR environments is ***,an adaptive denoising algorithm based on data rearrangement and the two-dimensional(2D)fast Fourier transform(FFT)(DR2D)is used to reduce the noise of the intercepted radio fuze intermediate frequency(IF)***,the textural features of the denoised IF signal rearranged data matrix are extracted from the statistical indicator vectors of gray-level cooccurrence matrices(GLCMs),and support vector machines(SVMs)are used for *** DR2D-based adaptive denoising algorithm achieves an average correlation coefficient of more than 0.76 for ten fuze types under SNRs of-10 d B and above,which is higher than that of other typical *** trained SVM classification model achieves an average recognition accuracy of more than 96%on seven modulation types and recognition accuracies of more than 94%on each modulation type under SNRs of-12 d B and above,which represents a good AMR performance of radio fuzes under low SNRs.
Trehalose production via a one-step enzymatic route using trehalose synthase(TreS)holds significant promise for industrial-scale applications due to its simplicity and utilization of low-cost ***,the development of a ...
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Trehalose production via a one-step enzymatic route using trehalose synthase(TreS)holds significant promise for industrial-scale applications due to its simplicity and utilization of low-cost ***,the development of a robust whole-cell biocatalyst expressing TreS remains crucial for enabling practical and economically viable *** this study,a high-sugar tolerant strain of *** was screened and employed as a host cell for the cell surface display of TreS from Acidiplasma *** resultant strain,*** I3A,exhibited remarkable surface displayed TreS activity of 3358 U/g CDW and achieved approximately 64%trehalose yield(10.8 g/L/h productivity)from ***,no glucose by-product was observed during trehalose *** *** I3A cells exhibited reusability for up to 12 cycles leading to potential cost reduction of trehalose ***,our study demonstrated the development of a high-sugar tolerant *** strain expressing TreS on its surface as a whole-cell biocatalyst for efficient and economical trehalose production with potential applications in the food and pharmaceutical industries.
The effective utilization of accumulated forestry science papers is of paramount significance in enhancing our understanding of the current state of forests and the formulation of strategies for forest environmental p...
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In the domain of data governance,crimes involving virtual currencies have emerged as an integral concern that cannot be *** address challenges such as the difficulty of evidence col-lection and the low probability of ...
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In the domain of data governance,crimes involving virtual currencies have emerged as an integral concern that cannot be *** address challenges such as the difficulty of evidence col-lection and the low probability of recovering stolen funds in virtual currency crimes,this paper proposes a new mechanism for the electronic storage and retrieval of evidence using blockchain technology,elab-orating on its core steps and underlying ***,from the perspective of virtual currency transaction intermediaries,this study employs game theory to analyze the issue,constructing replicator dynamics equations,solving for the Jacobian matrix,and exploring the direction of game evolution and the factors influencing the decision-making of the *** analysis demonstrates that the decision-making of virtual currency criminals is impacted by this electronic evidence mechanism,which can deter illicit intermediaries from assisting in money laundering activities,thereby reducing the fea-sibility of committing crimes with virtual ***,the paper offers policy recommendations to enhance the implement ability of the evidence storage and retrieval mechanism in regulating virtual currency crimes.
Lithium-ion (Li-ion) batteries are widely used in the automotive industry and energy storage systems due to their high power and energy density, long cycle life, and low self-discharge. However, they still experience ...
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We analyze the socio-economic development of Macau after the return to Chinese sovereignty from the three dimensions of sustainability (economy, society, and environment). Macau's economy has both high growth and ...
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In general, majority of MOFs are powder, which limit their applications. In this study, the highly stable Zr-based MOF-808 and its thiol-modified MOF-808-SH were selected as precursors, and then they were wrapped by s...
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In general, majority of MOFs are powder, which limit their applications. In this study, the highly stable Zr-based MOF-808 and its thiol-modified MOF-808-SH were selected as precursors, and then they were wrapped by sodium alginate hydrogel via a dripping strategy. Based on these, MOF/hydrogel composite beads（Alg-MOF-808, AlgMOF-808-SH） with 3D network structure were prepared successfully. Due to its excellent adsorption properties and easy recovery, they were employed as effective environmental functional materials for the adsorption of Hg（Ⅱ）. The adsorption capacities of Hg（Ⅱ） were 170.52 mg·g-1and 221.73 mg·g-1respectively and they can achieve adsorption equilibrium in a short time. The adsorption stability of Alg-MOF-808-SH was studied at different p H as well. In addition, the removal efficiency of composite beads for Hg（Ⅱ） was almost unaffected by other coexisting ions, displaying good adsorption selectivity. Furthermore, the removal efficiency only decreased by 10.4% after 5 cycles, indicating that the as-prepared materials have high recycling efficiency. The results demonstrated that the MOF/hydrogel composite beads have a certain application potential for mercury removal in actual wastewater.
The automatic colorization of anime line drawings is a challenging problem in production *** advances in deep neural networks have addressed this problem;however,collectingmany images of colorization targets in novel ...
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The automatic colorization of anime line drawings is a challenging problem in production *** advances in deep neural networks have addressed this problem;however,collectingmany images of colorization targets in novel anime work before the colorization process starts leads to chicken-and-egg problems and has become an obstacle to using them in production *** overcome this obstacle,we propose a new patch-based learning method for few-shot anime-style *** learning method adopts an efficient patch sampling technique with position embedding according to the characteristics of anime line *** also present a continuous learning strategy that continuously updates our colorization model using new samples colorized by human *** advantage of our method is that it can learn our colorization model from scratch or pre-trained weights using only a few pre-and post-colorized line drawings that are created by artists in their usual colorization ***,our method can be easily incorporated within existing production *** quantitatively demonstrate that our colorizationmethod outperforms state-of-the-art methods.
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