Information entropy-based intention prediction of aerial targets under uncertain and incomplete information

© 2020 by authors. To improve the effectiveness of air combat decision-making systems, target intention has been extensively studied. In general, aerial target intention is composed of attack, surveillance, penetration, feint, defense, reconnaissance, cover and electronic interference and it is related to the state of a target in air combat. Predicting the target intention is helpful to know the target actions in advance. Thus, intention prediction has contributed to lay a solid foundation for air combat decision-making. In this work, an intention prediction method is developed, which combines the advantages of the long short-term memory (LSTM) networks and decision tree. The future state information of a target is predicted based on LSTM networks from real-time series data, and the decision tree technology is utilized to extract rules from uncertain and incomplete priori knowledge. Then, the target intention is obtained from the predicted data by applying the built decision tree. With a simulation example, the results show that the proposed method is effective and feasible for state prediction and intention recognition of aerial targets under uncertain and incomplete information. Furthermore, the proposed method can make contributions in providing direction and aids for subsequent attack decision-makin

Thermodynamic and techno-economic analysis of a direct thermal oil vaporization solar power system

A unique direct thermal oil vaporization solar power system employing cascade organic-steam Rankine cycle is proposed. The oil is a mixture of biphenyl and diphenyl oxide, and it is used for heat transfer, storage and power cycle fluid in the novel system. Stable electricity output and prolonged storage capacity can be facilitated. In the rated mode, the oil is vaporized at 390 °C in the collectors and drives a top turbine. The exhaust heat is used for preheating and evaporating water of the bottom cycle. Meanwhile, the hot oil in a high-temperature tank (HTT) superheats and reheats the generated steam. When the irradiation is insufficient, the heat released by the oil from the HTT to a low-temperature tank drives the bottom cycle. Fundamentals, thermodynamic performance and techno-economic feasibility are elaborated. The results indicate that, compared with the mainstream dual-tank solar power systems, the proposed system has a higher thermal efficiency with a lower water evaporation temperature (42.90% at 260 °C vs. 38.06% at 310 °C) and a larger temperature drop between the two tanks (121 °C vs. 100 °C). The equivalent payback time with respect to the top oil cycle is less than 3 years

Thermo-economic analysis of a novel partial cascade organic-steam Rankine cycle

Conventional heat batteries and concentrated solar power systems adopt subcritical steam Rankine cycles (SRCs) to avoid the technical challenges of supercritical cycles. The water evaporation temperature of 310–337 °C and live steam pressure of 10–14 MPa limit the cycle efficiency (around 42%). This paper proposes a novel partial cascade organic-steam Rankine cycle (ORC-SRC) system to increase the fluid evaporation temperature and thermal efficiency. The ORC-SRC uses a mixture of biphenyl and diphenyl oxide as the top cycle fluid. The mixture absorbs heat from the molten salts and evaporates at about 400 °C to drive a turbine, and then the exhaust vapor releases heat to the bottom SRC. The ORC contributes to saturated steam generation, and molten salts supply the rest heat to the SRC through the steam superheater and reheater. The fundamentals of the system are illustrated, and mathematical models are built. Thermo-economic performance of the system is investigated. The results show that the proposed system significantly increases the average temperature of the power fluid in the heating process, leading to a maximum cycle efficiency of 45.3%. Meanwhile, the moderate live steam pressure of 7.44 MPa in the SRC reduces the leakage loss of the high-pressure turbine and equipment costs. Despite a smaller temperature drop of molten salts during discharge, the equivalent payback period of the ORC-SRC is within 4 years

Effects of Fluorination on Fused Ring Electron Acceptor for Active Layer Morphology, Exciton Dissociation, and Charge Recombination in Organic Solar Cells

Fluorination is one of the effective approaches to alter the organic semiconductor properties that impact the performance of the organic solar cells (OSCs). Positive effects of fluorination are also revealed in the application of fused ring electron acceptors (FREAs). However, in comparison with the efforts allocated to the material designs and power conversion efficiency enhancement, understanding on the excitons and charge carriers' behaviors in high-performing OSCs containing FREAs is limited. Herein, the impact of fluorine substituents on the active layer morphology, and therefore exciton dissociation, charge separation, and charge carriers' recombination processes are examined by fabricating OSCs with PTO2 as the donor and two FREAs, O-IDTT-IC and its fluorinated analogue O-IDTT-4FIC, as the acceptors. With the presence of O-IDTT-4FIC in the devices, it is found that the excitons dissociate more efficiently, and the activation energy required to split the excitons to free charge carriers is much lower; the charge carriers live longer and suffer less extent of trap-assisted recombination; the trap density is 1 order of magnitude lower than that of the nonfluorinated counterpart. Overall, these findings provide information about the complex impacts of FREA fluorination on efficiently performed OSCs

Lead halide–templated crystallization of methylamine-free perovskite for efficient photovoltaic modules

Upscaling efficient and stable perovskite layers is one of the most challenging issues in the commercialization of perovskite solar cells. Here, a lead halide–templated crystallization strategy is developed for printing formamidinium (FA)–cesium (Cs) lead triiodide perovskite films. High-quality large-area films are achieved through controlled nucleation and growth of a lead halide•N-methyl-2-pyrrolidone adduct that can react in situ with embedded FAI/CsI to directly form α-phase perovskite, sidestepping the phase transformation from δ-phase. A nonencapsulated device with 23% efficiency and excellent long-term thermal stability (at 85°C) in ambient air (~80% efficiency retention after 500 hours) is achieved with further addition of potassium hexafluorophosphate. The slot die–printed minimodules achieve champion efficiencies of 20.42% (certified efficiency 19.3%) and 19.54% with an active area of 17.1 and 65.0 square centimeters, respectively

Root-Associated Microbiota Response to Ecological Factors: Role of Soil Acidity in Enhancing Citrus Tolerance to Huanglongbing

peer reviewedThe citrus orchards in southern China are widely threatened by low soil pH and Huanglongbing (HLB) prevalence. Notably, the lime application has been used to optimize soil pH, which is propitious to maintain root health and enhance HLB tolerance of citrus; however, little is known about the interactive effects of soil acidity on the soil properties and root-associated (rhizoplane and endosphere) microbial community of HLB-infected citrus orchard. In this study, the differences in microbial community structures and functions between the acidified and amended soils in the Gannan citrus orchard were investigated, which may represent the response of the host-associated microbiome in diseased roots and rhizoplane to dynamic soil acidity. Our findings demonstrated that the severity of soil acidification and aluminum toxicity was mitigated after soil improvement, accompanied by the increase in root activity and the decrease of HLB pathogen concentration in citrus roots. Additionally, the Illumina sequencing-based community analysis showed that the application of soil amendment enriched functional categories involved in host-microbe interactions and nitrogen and sulfur metabolisms in the HLB-infected citrus rhizoplane; and it also strongly altered root endophytic microbial community diversity and structure, which represented by the enrichment of beneficial microorganisms in diseased roots. These changes in rhizoplane-enriched functional properties and microbial composition may subsequently benefit the plant's health and tolerance to HLB disease. Overall, this study advances our understanding of the important role of root-associated microbiota changes and ecological factors, such as soil acidity, in delaying and alleviating HLB disease.National Key Research and Development Program of Chin

Bearing Fault Diagnosis in the Mixed Domain Based on Crossover-Mutation Chaotic Particle Swarm

The classification frameworks for fault diagnosis of rolling element bearings in rotating machinery are mostly based on analysis in a single time-frequency domain, where sensitive features are not completely extracted. To solve this problem, a new fault diagnosis technique is proposed in the mixed domain, based on the crossover-mutation chaotic particle swarm optimization support vector machine. Firstly, fault features are generated using techniques in the time domain, the frequency domain, and the time-frequency domain. Secondly, the weighted maximum relevance minimum redundancy (WMRMR) algorithm is adopted to reduce the dimension of the feature set and to establish the representative feature set. Thirdly, a new crossover-mutation strategy is suggested to reduce the local minima in optimization, and an optimization disturbance is added. Finally, the support vector machine is optimized using the improved chaotic particle swarm to improve fault classification diagnosis. The effectiveness of the proposed new bearing fault diagnostic technique is verified by experimental tests under different bearing conditions. Test results showed that the bearing fault classification accuracy of CMCPSO-SVM in the mixed domain was much higher than those in a single feature domain

A Pedagogical Approach to Incorporating the Concept of Sustainability into Design-to-Physical-Construction Teaching in Introductory Architectural Design Courses: A Case Study on a Bamboo Construction Project

Sustainable architectural education is offered in colleges and universities all over the world. Studies have emphasized the importance of sustainable architectural education in introductory courses of architecture major programs, but methods and strategies for teaching sustainable architecture at lower levels are scarce. This study focuses on the design-to-physical-construction process and creates a teaching framework that incorporates the concept of sustainable development from the perspectives of sustainable economy, environment and society. Based on the teaching method of learning through the design-to-physical-construction process and referring to the grounded theory, a case study on a bamboo construction project was conducted to explore approaches and strategies of sustainable architectural education in introductory courses. Results reveal that five systems, including the system of sustainable development, consist of a framework that illustrated the teaching effects. Based on the framework, we discovered five factors that should be considered in incorporating the concept of sustainable development into architectural design teaching, including the necessity of conducting sustainable architectural education in introductory courses. This study helps explore the potential role sustainability plays in incorporating interdisciplinary knowledge, connecting specialized knowledge across different program levels, and motivating student learning. It also provides a reference for the practice of sustainable architectural education

A well-balanced strength and electrical conductivity in rolled composite prepared by in-situ TiB2p/Cu composite powder

The TiB2p/Cu composites were prepared by current-assisted vacuum hot pressing (CAVHP) combined with rolling using in-situ spherical TiB2p/Cu composite powder as raw material. The effects of rolling deformation on the microstructure and properties of the sintered TiB2p/Cu composite were investigated. The results show that CAVHP leads to a rapid densification of the composite powder compact, and the subsequent rolling deformation is able to eliminate the unclosed pores and achieve a uniform distribution of TiB2p. The dynamic recrystallization during cold rolling refines the Cu matrix grains to ultrafine grains with an average grain size of 0.47 μm. The cold rolled TiB2p/Cu composite obtains a remarkable comprehensive performance with ultimate tensile strength, yield strength and electrical conductivity of 621 MPa, 567 MPa and 86.3% IACS, respectively. In addition, the strengthening and fracture mechanism of the cold rolled TiB2p/Cu composite are analyzed. This work will explore a new technological solution for the preparation of high-performance Cu matrix composites

Fstl1 Promotes Glioma Growth Through the BMP4/Smad1/5/8 Signaling Pathway

Background: Gliomas result in the highest morbidity and mortality rates of intracranial primary central nervous system tumors because of their aggressive growth characteristics and high postoperative recurrence. They are characterized by genetic instability, intratumoral histopathological variability and unpredictable clinical behavior in patients. Proliferation is a key aspect of the clinical progression of malignant gliomas, complicating complete surgical resection and enabling tumor regrowth and further proliferation of the surviving tumor cells. Methods: The expression of Fstl1 was detected by western blotting and qRT-PCR. We used cell proliferation and colony formation assays to measure proliferation. Then, flow cytometry was used to analyze cell cycle progression. The expression of Fstl1, p-Smad1/5/8 and p21 in GBM tissue sections was evaluated using immunohistochemical staining. Furthermore, we used coimmunoprecipitation (Co-IP) and immunoprecipitation to validate the relationship between Fstl1, BMP4 and BMPR2. Finally, we used orthotopic xenograft studies to measure the growth of tumors in vivo. Results: We found that follistatin-like 1 (Fstl1) was upregulated in high-grade glioma specimens and that its levels correlated with poor prognosis. Fstl1 upregulation increased cell proliferation, colony formation and cell cycle progression, while its knockdown inhibited these processes. Moreover, Fstl1 interacted with bone morphogenetic protein (BMP) 4, but not BMP receptor (BMPR) 2, and competitively inhibited their association. Furthermore, Fstl1 overexpression suppressed the activation of the BMP4/Smad1/5/8 signaling pathway, while BMP4 overexpression reversed this effect. Conclusion: Our study demonstrated that Fstl1 promoted glioma growth through the BMP4/Smad1/5/8 signaling pathway, and these findings suggest potential new glioblastoma treatment strategies