508 research outputs found
AN ANALYSIS OF THE EFFECT OF FOOTBALL ON THE MENTAL AND EMOTIONAL STRESS INDUCED BY COLLEGE STUDENTS’ EXERCISE
The Main Progress of Perovskite Solar Cells in 2020–2021
Perovskite solar cells (PSCs) emerging as a promising photovoltaic technology with high efficiency and low manufacturing cost have attracted the attention from all over the world. Both the efficiency and stability of PSCs have increased steadily in recent years, and the research on reducing lead leakage and developing eco-friendly lead-free perovskites pushes forward the commercialization of PSCs step by step. This review summarizes the main progress of PSCs in 2020 and 2021 from the aspects of efficiency, stability, perovskite-based tandem devices, and lead-free PSCs. Moreover, a brief discussion on the development of PSC modules and its challenges toward practical application is provided
Structural variation and introgression from wild populations in East Asian cattle genomes confer adaptation to local environment
BACKGROUND: Structural variations (SVs) in individual genomes are major determinants of complex traits, including adaptability to environmental variables. The Mongolian and Hainan cattle breeds in East Asia are of taurine and indicine origins that have evolved to adapt to cold and hot environments, respectively. However, few studies have investigated SVs in East Asian cattle genomes and their roles in environmental adaptation, and little is known about adaptively introgressed SVs in East Asian cattle. RESULTS: In this study, we examine the roles of SVs in the climate adaptation of these two cattle lineages by generating highly contiguous chromosome-scale genome assemblies. Comparison of the two assemblies along with 18 Mongolian and Hainan cattle genomes obtained by long-read sequencing data provides a catalog of 123,898 nonredundant SVs. Several SVs detected from long reads are in exons of genes associated with epidermal differentiation, skin barrier, and bovine tuberculosis resistance. Functional investigations show that a 108-bp exonic insertion in SPN may affect the uptake of Mycobacterium tuberculosis by macrophages, which might contribute to the low susceptibility of Hainan cattle to bovine tuberculosis. Genotyping of 373 whole genomes from 39 breeds identifies 2610 SVs that are differentiated along a "north-south" gradient in China and overlap with 862 related genes that are enriched in pathways related to environmental adaptation. We identify 1457 Chinese indicine-stratified SVs that possibly originate from banteng and are frequent in Chinese indicine cattle. CONCLUSIONS: Our findings highlight the unique contribution of SVs in East Asian cattle to environmental adaptation and disease resistance
AN ANALYSIS OF THE EFFECT OF FOOTBALL ON THE MENTAL AND EMOTIONAL STRESS INDUCED BY COLLEGE STUDENTS’ EXERCISE
Bi-Objective Optimization and Emergy Analysis of Multi-Distributed Energy System Considering Shared Energy Storage
Shared energy storage (SES) provides a solution for breaking the poor techno-economic performance of independent energy storage used in renewable energy networks. This paper proposes a multi-distributed energy system (MDES) driven by several heterogeneous energy sources considering SES, where bi-objective optimization and emergy analysis methods are used for the system’s optimal capacity planning and operating scheduling considering economic, environmental, and sustainable performances, and Nash bargaining is adopted for the reasonable distribution of benefits of MDES. Then, an energy system composed of four different DESs (distributed energy system) considering one Shared Energy Storage Operator (SESO) is taken as an example for further study, namely one to four shared energy storage multi-energy systems, where MDES with and without SESO are compared. The results reveal that the operation cost of MDES considering SESO and Nash bargaining is reduced by 3.03%, while all the distributed energy systems have lower operating costs, and SESO has an additional income of $142.4/day. Correspondingly, the emergy yield ratio, emergy sustainability index, and emergy investment ratio of the corresponding system increase by 5.15%, 3.83%, and 9.94%, respectively, wherein the environmental load rate increases by 1.67% because of the greater consumption reduction of renewable resources than that of non-renewable resources under the premise of reduced emergy consumption
Cost-Performance Analysis of Perovskite Solar Modules
99 p. // 15 - 29 : 0015El proceso de mantenimiento en una empresa garantiza la efectividad y eficiencia
de las maquinas de tracción instaladas por la empresa Andino, un estudio detallado
del histórico de fallas causadas por esta empresa, permitió estipular el método de
mantenimiento que mejor se ajustara a las necesidades de la empresa, diseñando
para ella un modelo de mantenimiento preventivo.
La causa del retiro de aproximadamente el 7% de clientes en el último año,
despertó una gran preocupación, aplicando herramientas como diagrama de causa
efecto se encontró que las causas fueron las abundantes fallas en las máquinas de
tracción y métodos para mantenerlas por efecto de su funcionamiento, por ello se
generan nuevos elementos de control de tiempos de uso, como es la adaptación de
un Horómetro para cada máquina de tracción, que aporta al personal de
mantenimiento un dato real del uso y de esta manera los tiempos más apropiados
para generar visitas de mantenimiento preventivo, reduciendo de manera
sustancial los tiempos de parada de las máquinas y daños mayores en las mismas,
se reduce también las horas hombre de los mecánicos, lo que se traduce en mayor
eficiencia y satisfacción para el cliente
Ferromagnetic Property and Synthesis of Onion-Like Fullerenes by Chemical Vapor Deposition Using Fe and Co Catalysts Supported on NaCl
Metal-encapsulating onion-like fullerenes (M@OLFs) were synthesized by CVD at relatively low temperature (420C∘) using Fe and Co nanoparticles impregnated into NaCl as catalyst. The morphology and structure of the products were characterized by field emission scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. The results show that Fe@OLFs and Co@OLFs with stacked graphitic fragments were prepared using Fe/NaCl or Co/NaCl as catalysts; after Co@OLFs were immersed in concentrated HCl for 48 hours, Co nanoparticles encapsulated by carbon shells were not removed, meaning that carbon shells can protect the encapsulated Co cores against environmental degradation. The coercivity value (750.23 Oe) of Co@OLFs showed an obvious magnetic property
Measurement of Cavity Loss and Quasi-Fermi-Level Separation for Fabry-Perot Semiconductor Lasers
A fitting process is used to measure the cavity loss and the quasi-Fermi-level separation for Fabry- Perot semiconductor lasers. From the amplified spontaneous emission (ASE) spectrum, the gain spectrum and single-pass ASE obtained by the Cassidy method are applied in the fitting process. For a 1550nm quantum well InGaAsP ridge waveguide laser, the cavity loss of about ~24cm~(-1) is obtained
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