The problem of control input saturation and measurement uncertainties in spacecraft attitude control systems is investigated in this paper. Asymmetric limitation of the control torque and additive ...attitude measurement errors are considered in the backstepping attitude controller design. Stable antiwindup compensator is employed to handle the adverse effect of input saturation. The additive attitude measurement errors, external disturbances, and parametric uncertainties are compensated by the outputs of stable nonlinear disturbance observers in the robust controller design. The tuning conditions of controller parameters are derived based on the Lyapunov analysis, and it is proved that attitude, angular velocity, saturation compensator states, and disturbance observer states converge to small neighborhoods of zero. Simulation results illustrate the effectiveness of the proposed control approach.
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► The cathode active materials LiCoO
2 from spent lithium-ion batteries peeled completely from aluminum foils by vacuum pyrolysis and hydrometallurgical process. ► The aluminum foils ...were excellent without damage after vacuum pyrolysis. ► The pyrolysis products organic fluorine compounds from organic electrolyte and binder were collected and enriched. ► High leaching efficiencies of cobalt and lithium were obtained with H
2SO
4 and H
2O
2.
Spent lithium-ion batteries contain lots of strategic resources such as cobalt and lithium together with other hazardous materials, which are considered as an attractive secondary resource and environmental contaminant. In this work, a novel process involving vacuum pyrolysis and hydrometallurgical technique was developed for the combined recovery of cobalt and lithium from spent lithium-ion batteries. The results of vacuum pyrolysis of cathode material showed that the cathode powder composing of LiCoO
2 and CoO peeled completely from aluminum foils under the following experimental conditions: temperature of 600
°C, vacuum evaporation time of 30
min, and residual gas pressure of 1.0
kPa. Over 99% of cobalt and lithium could be recovered from peeled cobalt lithium oxides with 2
M sulfuric acid leaching solution at 80
°C and solid/liquid ratio of 50
g
L
−1 for 60
min. This technology offers an efficient way to recycle valuable materials from spent lithium-ion batteries, and it is feasible to scale up and help to reduce the environmental pollution of spent lithium-ion batteries.
Melatonin (N‐acetyl‐5‐methoxytryptamine) is an important biological hormone in many abiotic stress responses and developmental processes. In this study, the protective roles of melatonin were ...investigated by measuring the antioxidant defense system and photosynthetic characteristics in maize under salt stress. The results indicated that NaCl treatment led to the decrease in plant growth, chlorophyll contents and photochemical activity of photosystem II (PSII). However, the levels of reactive oxygen species increased significantly under salt stress. Meanwhile, we found that application of exogenous melatonin alleviated reactive oxygen species burst and protected the photosynthetic activity in maize seedlings under salt stress through the activation of antioxidant enzymes. In addition, 100 μM melatonin‐treated plants showed high photosynthetic efficiency and salinity. Immunoblotting analysis of PSII proteins showed that melatonin application alleviated the decline of 34 kDa PSII reaction center protein (D1) and the increase of PSII subunit S protein. Taken together, our study promotes more comprehensive understanding in the protective effects of exogenous melatonin in maize under salt stress, and it may be involved in activation of antioxidant enzymes and regulation of PSII proteins.
This study explores the reform of the modularized course “Cultivation Technology of Northern Daoji Medicinal Herbs” in the context of the new version of the “Good Agricultural Practice for the ...Production of Chinese Medicinal Herbs” (GAP). The research methods include skill mapping and knowledge structure analysis, formal context theory, ensemble and analytic models, and learning path planning algorithms based on KL dispersion and matrix eigenvector similarity. These methods aim to construct course knowledge structures, clarify teaching and learning priorities, and generate personalized learning paths. RESULTS SURFACE: The established course knowledge network reveals the relationship between knowledge points through skill mapping and knowledge structure analysis. The network density is 0.0624, indicating fewer connections between knowledge points. The course contains 68 knowledge and skill points, among which the Degree of centrality of the skill node “Dewhead Cultivation” is the largest. Based on the analyzed knowledge networks and learning paths, the course was divided into several modules, each tailored to specific teaching objectives and students’ learning needs. Through the effective integration of skill mapping and knowledge structure, the modularized curriculum reform of “Cultivation Technology of Northern Medicinal Herbs” in the context of the new GAP not only improves the quality of teaching, but also meets the personalized learning needs of the students, and provides a new direction for future education.
With rapid advances of perovskite light-emitting diodes (PeLEDs), the large-scale fabrication of patterned PeLEDs towards display panels is of increasing importance. However, most state-of-the-art ...PeLEDs are fabricated by solution-processed techniques, which are difficult to simultaneously achieve high-resolution pixels and large-scale production. To this end, we construct efficient CsPbBr
PeLEDs employing a vacuum deposition technique, which has been demonstrated as the most successful route for commercial organic LED displays. By carefully controlling the strength of the spatial confinement in CsPbBr
film, its radiative recombination is greatly enhanced while the nonradiative recombination is suppressed. As a result, the external quantum efficiency (EQE) of thermally evaporated PeLED reaches 8.0%, a record for vacuum processed PeLEDs. Benefitting from the excellent uniformity and scalability of the thermal evaporation, we demonstrate PeLED with a functional area up to 40.2 cm
and a peak EQE of 7.1%, representing one of the most efficient large-area PeLEDs. We further achieve high-resolution patterned perovskite film with 100 μm pixels using fine metal masks, laying the foundation for potential display applications. We believe the strategy of confinement strength regulation in thermally evaporated perovskites provides an effective way to process high-efficiency and large-area PeLEDs towards commercial display panels.
This paper presents a six-degree-of-freedom relative motion control method for autonomous spacecraft rendezvous and proximity operations subject to input saturation, full-state constraint, kinematic ...coupling, parametric uncertainty, and matched and mismatched disturbances. Relative rotational and relative translational controllers are developed separately based on a unified adaptive backstepping technique. Both element-wise and norm-wise adaptive estimation techniques are used for handling parametric uncertainties, kinematic couplings, and matched and mismatched disturbances, where the bounds of disturbances are unknown. Two auxiliary design systems are employed to deal with input saturation in the relative rotational and relative translational control designs, and the stability of the saturated control solution is verified. Full-state constraint of the relative pose motion is handled by using barrier Lyapunov functions while achieving a satisfactory control performance. All signals in the closed-loop system are guaranteed to be uniformly ultimately bounded, and the relative motion states are all restricted within the known constraints. Compared with the previous control designs of spacecraft rendezvous and proximity operations, the proposed control strategy in this paper can simultaneously deal with input saturation, full-state constraint, kinematic coupling, parametric uncertainty, and matched and mismatched disturbances. Experimental simulation results validate the performance and robustness improvement of the proposed control strategy.
It has been well established that the TMEM106B gene rs1990622 variant was a frontotemporal dementia (FTD) risk factor. Until recently, growing evidence highlights the role of TMEM106B in Alzheimer's ...disease (AD). However, it remains largely unclear about the role of rs1990622 variant in AD.
Here, we conducted comprehensive analyses including genetic association study, gene expression analysis, eQTLs analysis, and colocalization analysis. In stage 1, we conducted a genetic association analysis of rs1990622 using large-scale genome-wide association study (GWAS) datasets from International Genomics of Alzheimer's Project (21,982 AD and 41,944 cognitively normal controls) and UK Biobank (314,278 participants). In stage 2, we performed a gene expression analysis of TMEM106B in 49 different human tissues using the gene expression data in GTEx. In stage 3, we performed an expression quantitative trait loci (eQTLs) analysis using multiple datasets from UKBEC, GTEx, and Mayo RNAseq Study. In stage 4, we performed a colocalization analysis to provide evidence of the AD GWAS and eQTLs pair influencing both AD and the TMEM106B expression at a particular region.
We found (1) rs1990622 variant T allele contributed to AD risk. A sex-specific analysis in UK Biobank further indicated that rs1990622 T allele only contributed to increased AD risk in females, but not in males; (2) TMEM106B showed different expression in different human brain tissues especially high expression in cerebellum; (3) rs1990622 variant could regulate the expression of TMEM106B in human brain tissues, which vary considerably in different disease statuses, the mean ages at death, the percents of females, and the different descents of the selected donors; (4) colocalization analysis provided suggestive evidence that the same variant contributed to AD risk and TMEM106B expression in cerebellum.
Our comprehensive analyses highlighted the role of FTD rs1990622 variant in AD risk. This cross-disease approach may delineate disease-specific and common features, which will be important for both diagnostic and therapeutic development purposes. Meanwhile, these findings highlight the importance to better understand TMEM106B function and dysfunction in the context of normal aging and neurodegenerative diseases.
The problem of six-degrees-of-freedom (6-DOF) relative motion control is investigated for spacecraft close proximity maneuvers with input saturation and model uncertainties. A nonlinear disturbance ...observer is developed to estimate the lumped disturbance that comprises the effects of parametric uncertainties, measurement uncertainties, kinematic couplings, and external environment disturbances, while a linear compensator system is incorporated into the controller design to deal with the control input saturation. A 6-DOF robust state feedback saturated controller is designed for relative position tracking and attitude synchronization simultaneously, and the same is augmented by the linear saturation compensator and nonlinear disturbance observer to compensate the control input saturation effect and model uncertainties, respectively. Rigorous stability of the closed-loop system with the proposed control method is established under mild assumptions, and it is proven that the relative position and the relative attitude converge to a small neighborhood of zero. Numerical simulation result demonstrates the effectiveness of the proposed controller designing method.
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