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This study aims to understand middle and high school students' ecosystem knowledge including knowledge about the food web, food pyramid, and energy flow. The data were collected from 250 middle school and high school students. Students' drawings were used to collect data and coded as correct, wrong, or no answer. Then, students' wrong answers were re-analysed to reveal common problems students had in the ecosystem topic. Findings showed that participants were mainly unsuccessful in their drawings. Only 2% of them could correctly draw food webs, and 10% of the participants could draw food pyramids correctly. Among 250 students, only one student could successfully draw energy flow. Moreover, various problems were identified in students' drawings. For example, 94% of middle school students could not show fungi as decomposers in their food web drawing. Similarly, more than half of all students (67%) placed living organisms in the wrong trophic level when they drew a food pyramid. Likewise, only five high school students used the sun as the starting point of energy flow. Considering the findings, students' ecosystem knowledge is discussed and implications are presented. [ABSTRACT FROM AUTHOR]

Climate change has intensified urban heat risks through extreme heat and heat island effects. Using Fuzhou as a case study, we conducted assessments of heat risk and cool island quality to identify core heat risk sources (CHRSs) and core cold sources (CCSs). Based on the degree of resistance to surface heat transfer, we constructed a comprehensive resistance surface. This was followed by the construction of a composite cooling network using the minimal cumulative resistance and circuit theory models, along with the identification of key nodes to enhance the protection of cool island resources and ensure network stability. Our findings revealed that the central urban area had the highest heat risk, followed by the eastern coastal areas, showing a trend of further expansion towards the southeastern coast. Relatively high-quality cool island resources were distributed in the western mountainous area. We identified 21 CHRSs and 32 CCSs. The composite cooling network included 94 heat transport corridors and 96 cool island synergy corridors, with 148 cooling nodes and 78 barrier nodes. The average land surface temperature of transport and synergy corridors was 27.89°C and 25.34°C, respectively, significantly lower than the high-risk areas (31.14°C). Transport corridors enable heat transfer from CHRSs to CCSs, while synergy corridors can achieve further cooling by enhancing the synergy among cool islands. [ABSTRACT FROM AUTHOR]

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The role of keystone species in maintaining ecosystem stability is a crucial aspect of ecology. Identifying key mammalian species within an ecosystem requires a systematic approach, utilizing criteria and indicators derived from species characteristic variables. This study presents a framework to identify key mammalian species based on various ecological, structural, and functional factors. By developing a mechanistic model of energy flow in food webs and trophic levels, the model aims to pinpoint each species' role in the stability and sustainability of biomass flow within the ecosystem. Known as KVT version 1.0, the model explains the role of each characteristic variable of mammalian species, predicts population growth, elucidates species interactions at trophic levels, and assesses species-specific dietary compositions, including food requirements, reproduction, and activity. Factor analysis of model outputs has produced equations to determine the value of keystone species (Kv), indicating the role of mammalian species in the stability and sustainability of biomass flow in the ecosystem. Keystone species, as identified by this model, are primarily small mammals of the families Muridae, Sciuridae, Tupaiidae, Ptilocercidae, Hystricidae, Viverridae, and Herpestidae, demonstrating omnivorous and herbivorous trophic levels. This model can serve as a valuable framework for conservation management of biodiversity in an ecosystem, with potential for expansion to include characteristics of non-mammalian species in future research. [ABSTRACT FROM AUTHOR]

The high-frequency vibration problem of structures seriously affects the service safety，reliability and comfort of the aircraft. It is of great academic value and engineering significance to predict the high-frequency vibration response of structures efficiently and accurately. The energy finite element method（EFEM）is a new method developed in recent years to predict high-frequency vibration response. It overcomes the shortcomings of traditional methods such as the finite element method（FEM）and the statistical energy analysis（SEA）in predicting highfrequency vibration response. In this paper，the research progress of the energy finite element method in recent years is reviewed. The basic theory of the energy finite element method and its extension and application in enginee ring are elaborated. Studies of the energy finite element method in predicting the high-frequency vibration response of aircraft structures are introduced. In addition，the future directions of the energy finite element method are prospected.

The role of keystone species in maintaining ecosystem stability is a crucial aspect of ecology. Identifying key mammalian species within an ecosystem requires a systematic approach, utilizing criteria and indicators derived from species characteristic variables. This study presents a framework to identify key mammalian species based on various ecological, structural, and functional factors. By developing a mechanistic model of energy flow in food webs and trophic levels, the model aims to pinpoint each species’ role in the stability and sustainability of biomass flow within the ecosystem. Known as KVT version 1.0, the model explains the role of each characteristic variable of mammalian species, predicts population growth, elucidates species interactions at trophic levels, and assesses species-specific dietary compositions, including food requirements, reproduction, and activity. Factor analysis of model outputs has produced equations to determine the value of keystone species (Kv), indicating the role of mammalian species in the stability and sustainability of biomass flow in the ecosystem. Keystone species, as identified by this model, are primarily small mammals of the families Muridae, Sciuridae, Tupaiidae, Ptilocercidae, Hystricidae, Viverridae, and Herpestidae, demonstrating omnivorous and herbivorous trophic levels. This model can serve as a valuable framework for conservation management of biodiversity in an ecosystem, with potential for expansion to include characteristics of non-mammalian species in future research.

This study aimed to assess the roles and contributions of various joint (ankle, knee, hip, shoulder, elbow and wrist) during overhead volleyball passing across different distances. Eight male college volleyball players performed passes into a floating target set at 2.53 meters height from three different distances (2.5, 5 and 7.5 meters) with their feet remaining on the ground. Motion and force data were collected from three successful passes per player. Using inverse dynamics methods, we analyzed kinetic variables at each joint to determine energy generation and transfer. The findings revealed that the energy transfer through the shoulder joint to the arm varied with distance, with significant differences in the upper limb energy generation between the short and medium distances (p < 0.001). The study concluded that precise control and adjustment of the upper limb are crucial for short and medium distance passes, while lower limb contributions, including stabilization and extension play a vital role in executing long-distance passes.

The primary aim of this investigation was to describe the energy flow through the kinetic chain during softball hitting using a segmental power analysis. Twenty-three NCAA Division I collegiate softball athletes (20.4 ± 1.7 yr; 166.7 ± 22.0 cm; 74.9 ± 15.9 kg) performed three maximum effort swings off a stationary tee placed in the middle of the strike zone. Pelvis, trunk, humerus, forearm and hand segment powers were integrated across four phases of the softball swing (load, stride, acceleration, and follow-through). The load and stride phases had low segment energy inflow and outflow values as well as net segment energy flow for all body segments compared to subsequent phases of the swing. The acceleration phase showed large trunk inflow values relative to the pelvis. There was also descriptively larger front compared to back-side upper extremity inflow. Finally, the follow-through phase showed primarily energy outflow for the upper extremity segments likely attributed to slowing down rotation. [ABSTRACT FROM AUTHOR]

Based on the field survey and reference data of the sea area of the Zhongjieshan Islands from 2021 to 2022, the Ecopath model was used to analyze the energy flow structure of the marine ecosystem of the sea area of the Zhongjieshan Islands; the energy structure of the marine ecosystem was divided into 21 functional groups, and its nutrient structure, energy flow, and total system characteristics were analyzed. The results show that the credibility of the model is 0.414, which is at a medium level. The trophic level of each functional group of the ecosystem in the sea area of Zhongjieshan Islands was 1–3.48, the energy flow structure of the system was mainly concentrated in the first five grades, and the trophic level was relatively simple, with the average energy transfer efficiency of the system being 8.11%, the energy flow range being 2.81–13.04%, the energy transfer efficiency of the primary producers of the system being 7.25%, and the energy conversion efficiency of the system debris being 9.12%. The total system throughput was 2125.96 t·km−2; The analysis of the overall characteristics of the ecosystem showed that the system connectance index and the system omnivory index were 0.45 and 0.24, respectively, while the Finn's cycling index was 8.24, the Finn's mean path length of the system was 2.72, and the total primary production/total respiration was 1.71. In this study, the marine ecosystem model of the sea area of the Zhongjieshan Islands was studied to understand the trophic structure and ecosystem status of the sea area, which is conducive to the sustainable utilization and scientific management of fishery resources in the sea area. [ABSTRACT FROM AUTHOR]

Hybrid electric aircraft use traditional engine and electric propulsion combinations to optimize aircraft architecture, improve propulsion efficiency, and reduce fuel consumption. As a new technology, the fuel and energy consumption calculation of hybrid electric aircraft is more complicated than traditional aircraft due to the usage of different energy forms. The purpose of this paper is to develop the analytical method for fuel and energy consumption for hybrid electric aircraft. This paper summarizes the working principle of hybrid electric aircraft, including the system architecture and power conversion mechanism. The calculation of fuel and energy consumption for hybrid electric aircraft is carried out in detail. In order to evaluate large hybrid electric aircraft, the architecture, based on energy flow, is established, and turbofan engine, electrical system, electric duct fan, and aerodynamic model characteristics are established. With a single-aisle aircraft as an example, the fuel and energy consumption under the 800 nautical mile range is performed. It shows that fuel consumption can be reduced by 10% and energy consumption by 4.7% compared with a traditional aircraft. The effects of different range and battery ratios are analyzed. The payload range for the hybrid electric aircraft is analyzed. The results show that even though the hybrid electric aircraft reduces the payload and range, it can significantly reduce fuel and energy consumption. [ABSTRACT FROM AUTHOR]

This paper presents a novel method for generating and shaping reverse energy flow through the interference of light fields from a minimal number of point light sources. Until now, reverse energy flow has only been observed using complex light fields, such as optical vortices or cylindrical vector beams, limiting the formation of reverse energy flow near the optical axis. We demonstrate both analytically and numerically that unbounded regions of reverse energy flow can be achieved with just two point light sources, positioned asymmetrically at specific angles (e.g., 90 or 45 degrees) and with particular polarization states. The results indicate that the relative reverse energy flow can be enhanced by increasing the number of sources to three or four, adjusting their polarization, or introducing a vortex phase singularity. The presence of an initially embedded asymmetry in the fields under consideration leads to the formation of a non-uniform distribution of spin and orbital angular momentum density. Variations in the polarization state, as well as the introduction of a vortex phase singularity, allow for changing the distribution of angular momentum density while maintaining the presence of a reverse energy flow. We also explore the feasibility of implementing the obtained results using sectional phase diffractive optical elements, which will enhance the energy efficiency of the generated fields compared to point sources. [ABSTRACT FROM AUTHOR]

Symbiogenesis has been systematically exploited to understand consciousness as the aggregate of our physiology. The Symbiogenic mechanism for assimilation of factors in the environment formulates the continuum from inside the cell to the Cosmos, both consciousness and cosmology complying with the Laws of Nature. Since Symbiogenesis is 'constructive', whereas eliminating what threatens us is 'destructive', why do we largely practice Symbiogenesis? Hypothetically, Symbiogenesis recursively simulates the monism of our origin, recognizing 'something bigger than ourselves'. That perspective explains many heretofore unexplained aspects of consciousness, such as mind, epigenetic inheritance, physiology, behaviors, social systems, mathematics, the Arts, from an a priori perspective. Moreover, there is an energetic continuum from Newtonian to Quantum Mechanics, opening up to a novel way of understanding the 'true nature of our being', not as 'materialism', but instead being the serial homeostatic control of energy. The latter is consistent with the spirit of Claude Bernard and Walter B. Cannon's perspectives on physiology. Such a paradigm shift is overdue, given that materialism is causing the destruction of the Earth and ourselves. [ABSTRACT FROM AUTHOR]

Performance during the baseball pitch is dependent on the flow of mechanical energy through the kinetic chain. Little is known about energy flow during the pitching motion and it is not known whether patterns of energy flow are related to pitching performance and injury risk. Therefore, the purpose of this study was to quantify energy generation, absorption, and transfer across the shoulder and elbow during the baseball pitch and explore the associations between these energetic measures, pitch speed, and traditional measures of upper extremity joint loading. The kinematics of 40 youth baseball pitchers were measured in a controlled laboratory setting. Energy flow between the thorax, humerus, and forearm was calculated using a segmental power analysis. Regression analyses revealed that pitch speed was best predicted by arm cocking phase shoulder energy transfer to the humerus and peak elbow valgus torque was best predicted by arm acceleration-phase elbow energy transfer to the forearm. Additionally, energy transfer across the shoulder and elbow generally exhibited the strongest correlations to pitch speed and upper extremity joint loads. These data reinforce the importance of energy transfer through the kinetic chain for producing high pitch speeds and provide descriptive data for energy flow during baseball pitching not previously found in the literature. [ABSTRACT FROM AUTHOR]

Climate change has intensified urban heat risks through extreme heat and heat island effects. Using Fuzhou as a case study, we conducted assessments of heat risk and cool island quality to identify core heat risk sources (CHRSs) and core cold sources (CCSs). Based on the degree of resistance to surface heat transfer, we constructed a comprehensive resistance surface. This was followed by the construction of a composite cooling network using the minimal cumulative resistance and circuit theory models, along with the identification of key nodes to enhance the protection of cool island resources and ensure network stability. Our findings revealed that the central urban area had the highest heat risk, followed by the eastern coastal areas, showing a trend of further expansion towards the southeastern coast. Relatively high-quality cool island resources were distributed in the western mountainous area. We identified 21 CHRSs and 32 CCSs. The composite cooling network included 94 heat transport corridors and 96 cool island synergy corridors, with 148 cooling nodes and 78 barrier nodes. The average land surface temperature of transport and synergy corridors was 27.89°C and 25.34°C, respectively, significantly lower than the high-risk areas (31.14°C). Transport corridors enable heat transfer from CHRSs to CCSs, while synergy corridors can achieve further cooling by enhancing the synergy among cool islands.

Abstract Astaxanthin biosynthesis in Haematococcus pluvialis is driven by energy. However, the effect of the flagella-mediated energy-consuming movement process on astaxanthin accumulation has not been well studied. In this study, the profiles of astaxanthin and NADPH contents in combination with the photosynthetic parameters with or without flagella enabled by pH shock were characterized. The results demonstrated that there was no significant alteration in cell morphology, with the exception of the loss of flagella observed in the pH shock treatment group. In contrast, the astaxanthin content in the flagella removal groups was 62.9%, 62.8% and 91.1% higher than that of the control at 4, 8 and 12 h, respectively. Simultaneously, the increased Y(II) and decreased Y(NO) suggest that cells lacking the flagellar movement process may allocate more energy towards astaxanthin biosynthesis. This finding was verified by NADPH analysis, which revealed higher levels in flagella removal cells. These results provide preliminary insights into the underlying mechanism of astaxanthin accumulation enabled by energy reassignment in movement-lacking cells.

Artificial light at night (ALAN) is exerting growing pressure on natural ecosystems, but its impact on biological interactions remains unclear. This study aimed to assess how ALAN influences leaf functional traits and herbivory in two prevalent street tree species (Styphnolobium japonicum (L.) Schott and Fraxinus pennsylvanica) through field surveys and paired experiments in the urban areas of Beijing, China. We found that ALAN led to increased leaf toughness and decreased levels of leaf herbivory. Additionally, ALAN showed species-specific effects on leaf nutrients, size as well as defense substances. The findings illustrate that ALAN can significantly alter some key functional traits and ecological processes (nutrient cycling, energy flow). In general, we suggest that high ALAN intensity will be detrimental to the energy flow from urban plants to higher trophic levels, posing a potential threat to the maintenance of biodiversity (e.g., arthropod diversity, bird diversity) in urban ecosystems. [ABSTRACT FROM AUTHOR]

Astaxanthin biosynthesis in Haematococcus pluvialis is driven by energy. However, the effect of the flagella-mediated energy-consuming movement process on astaxanthin accumulation has not been well studied. In this study, the profiles of astaxanthin and NADPH contents in combination with the photosynthetic parameters with or without flagella enabled by pH shock were characterized. The results demonstrated that there was no significant alteration in cell morphology, with the exception of the loss of flagella observed in the pH shock treatment group. In contrast, the astaxanthin content in the flagella removal groups was 62.9%, 62.8% and 91.1% higher than that of the control at 4, 8 and 12 h, respectively. Simultaneously, the increased Y(II) and decreased Y(NO) suggest that cells lacking the flagellar movement process may allocate more energy towards astaxanthin biosynthesis. This finding was verified by NADPH analysis, which revealed higher levels in flagella removal cells. These results provide preliminary insights into the underlying mechanism of astaxanthin accumulation enabled by energy reassignment in movement-lacking cells. [ABSTRACT FROM AUTHOR]

The membrane structure in aerospace products is hung by cables to construct a microgravity environment during ground testing. The rigid motion and the flexible large deformation of conjoint cable-membrane system are nonlinearly coupled in the dynamic deployment process, in which excessive deformations of membrane caused by inappropriate cable lengths and driving loads are difficult to be predicted. In this paper, a novel analysis method based on energy flow is proposed to reveal the dynamic deployment characteristics of the cable-membrane system. The multibody dynamic model of the flexible cable-membrane system is established by the absolute node coordinate formulation and the coupling effect of rigid motion and flexible large deformation is accurately represented. The connection conditions between the cable and membrane structures at assembly positions are deduced. The formulations for kinetic energy and strain energy are explicitly derived to accurately quantify the energy flow within the system. The accuracy of the dynamic model of the cable-membrane system is verified by experimental validation of the deployment process. The asynchronous folding effect of the membrane array and the lagging traction of the hanging cable during the folding process are analyzed with various driving loads and lengths of hanging cables from the perspective of system energy flow. The correlation between the energy variations of the cable and the membrane is revealed to enable the monitoring of the easily measured cable motion to provide insight into the complex membrane motion, which has significant implications for optimizing system parameters and designing active control strategies for the cable-membrane system. [ABSTRACT FROM AUTHOR]

Based on Kirchhoff thin plate and Mindlin thick plate theories, the vibration and energy flow characteristics of clamped stiffened plate are studied by using the analytical model constructed by finite integral transform method. The results show that the energy flow characteristics of the stiffened plate at the beam/plate coupling interface depend on the position of the rib in the vibration modes of the plate. The effects of shear deformation and rotatory inertia on the energy flow across the beam/plate coupling interface of the stiffened plate are further investigated. It is found that the inclusion of rotatory inertia of the beam and plate in the model only affects the energy flow component controlled by the moment coupling but not that controlled by the shear force coupling. Whilst the inclusion of the shear deformation of the beam and plate mainly causes a decreased amplitude of the energy flow for the mode group where the beam is located away from both the nodal and antinodal lines of modes, in addition to the shear deformation of the plate which also leads to an increased amplitude of the energy flow component controlled by the shear force coupling for the mode group where the beam locates at the antinodal line of modes. The understanding of energy flow characteristics of the stiffened plate at the beam/plate interface is essential to effectively control the noise and vibration problems of structures such as transformer tanks and machine covers. [ABSTRACT FROM AUTHOR]

The evaluation of energy input and output processes in agricultural systems is a crucial method for assessing sustainability levels within these systems. In this research, the investigation focused on the input and output energies and related indices in sunflower farms in Khoy County during the agricultural year 2017–2018. Data were collected from 140 sunflower producers through specialized questionnaires and face-to-face interviews. Additionally, artificial neural networks (ANNs), specifically the multilayer perceptron, were employed to predict the output energy. The results revealed that a substantial portion of the total input energy was attributed to chemical nitrogen fertilizer (43.98%), consumable fuel (25.74%), and machinery (8.42%). The energy efficiency (energy ratio) in these agroecosystems was relatively low, measured at 1.57 for seed and 7.96 for seed and straw. These values should be improved. The energy efficiency in seed production was computed at 0.06 MJ·ha−1, while, for the combined seeds and straw, it was 0.57 MJ·ha−1. In particular, seed energy efficiency represents approximately 11% of the overall biological energy efficiency, highlighting that a substantial 89% of the produced energy is associated with straw. The proper use of this straw is crucial, as its improper handling could lead to a drastic decrease in overall efficiency. Furthermore, the explanatory coefficient (R2) and the mean absolute percentage error (MAPE) to predict the output energy with the best neural network were 0.94, and 1.77 for the training data, 0.97 and 1.55 for the test data, and 0.9 and 2.08 for the validation data, respectively; additionally, 0.97 and 0.42 were obtained by an ANFIS. [ABSTRACT FROM AUTHOR]

Dissection of the matter into its constituents leads us to the smallest particles that we know. These particles form a material structure that is determined by the electromagnetic field generated and carried by those particles. Changes in any of the two major constituents leads to changes in that material system, be it a living organism or a lifeless object. The latter statement carries the mystery of life that is born from a continuous and programmed series of system changes fuelled by an energy source with a yet unknown functioning mechanism. The present work is a theoretical approach towards the understanding and potential discovery of the aforementioned, not-yet-known cellular energetic mechanism. Understanding the energetic basis of intracellular biochemistry is equally important in human and animal therapeutics. Additionally, as all such discoveries offer novel solutions in various fields of the global industry, the final outcome of this theoretical work also brings about the idea of a new discovery in electronics industry. [ABSTRACT FROM AUTHOR]

Animal transport of energy and nutrients through food webs and across ecosystem boundaries is highly dynamic in time and space, challenging our ability to quantify ecological processes. Energy and nutrient flux in individual animals can be measured with data on growth, biochemistry, and trophic ecology, but scaling individual processes up to entire animal communities is inherently difficult. On coral reefs, new frameworks have been developed to predict growth rates, nutrient cycling, micronutrient concentrations, and energy sources in fishes, helping to uncover ecosystem functions and services. Filling data gaps and comparing flux frameworks with existing ecosystem tools will improve quantitative predictions and help ecologists trace energy and nutrient flux in other aquatic systems. The movement of energy and nutrients through ecological communities represents the biological 'pulse' underpinning ecosystem functioning and services. However, energy and nutrient fluxes are inherently difficult to observe, particularly in high-diversity systems such as coral reefs. We review advances in the quantification of fluxes in coral reef fishes, focusing on four key frameworks: demographic modelling, bioenergetics, micronutrients, and compound-specific stable isotope analysis (CSIA). Each framework can be integrated with underwater surveys, enabling researchers to scale organismal processes to ecosystem properties. This has revealed how small fish support biomass turnover, pelagic subsidies sustain fisheries, and fisheries benefit human health. Combining frameworks, closing data gaps, and expansion to other aquatic ecosystems can advance understanding of how fishes contribute to ecosystem functions and services. [ABSTRACT FROM AUTHOR]

Aquaculture supplies high-quality and healthy proteins. With the increasing human demand for aquaculture production, intensive pond aquaculture developed rapidly and results in environmental deterioration. To solve this problem, the eco-substrate (ES), which is the biofilm carrier, has been utilized in aquaculture ponds. Studying the ecological mechanisms of ES from the perspective of the ecosystem may be conducive to the sustainable development of aquaculture. In this study, it was evaluated how ES makes a difference to the trophic structure, energy flow, and system characteristics of two different aquaculture pond ecosystems via the ecopath model. Three aquaculture ponds with ES were designed as the treatment ecosystem and three aquaculture ponds without ES were designed as the control ecosystem. There were 13 and 14 functional groups in the control and treatment ecosystems, respectively. The results showed that (1) the macrozooplankton and microzooplankton showed strong effects on the ecosystem in the keystoneness index; (2) energy transfer pathways in the treatment system with ES increased by 26.23% compared to the control system; (3) the ES improved the utilization rate of detritus, which was 14.91% higher than that of the control ecosystem; (4) the material and energy flow index and network information characteristics demonstrated the ES enhanced the complexity and stability of the treatment system. To improve the energy utilization efficiency, filter feeders can be introduced to ES ponds. Overall, the ES can alter the trophic structure, improve the energy utilization efficiency, and enhance the stability and maturity of aquaculture ecosystems, representing a sustainable practice. Considering the total area of aquaculture ponds on the earth reaching more than 5 million hectares, the application prospect of ES is broad. [ABSTRACT FROM AUTHOR]

Electromagnetic scattering by a sphere is one of the most significant problem in electromagnetics as reported by the optical research community. Based on the framework of generalized Lorenz–Mie theory (GLMT), we investigated the scattering of a Gaussian Beam (a strongly focused basic TEM 00 mode laser beam) by a perfect electromagnetic conductor sphere. The influence of parameters i.e., sphere size parameter, beam waist radius, and beam center coordinate position on the scattering and extinction efficiencies, normalized energy flow, and scattering asymmetry factor is numerically analyzed. On varying the prior mentioned factors, the amplitude of efficiency factors is considerably modified. By increasing the waist radius, the normalized energy flow increases for the PEMC sphere. The investigation of the scattering characteristics for PEMC sphere illuminated by a Gaussian beam can also be extended to study the metamaterial structures. [ABSTRACT FROM AUTHOR]

Substantial research exists on predation and its ecology. Most research has focused on durophagous fishes, brachyuran crabs, and lobsters. Data are lacking, however, on soft-bodied predators like anemones, and their contribution to overall levels of predation remains largely unevaluated. Here, we compared predation rates of the durophagous predator, the crab C. maenas and the soft-bodied predator, the anemone Actinia equina on 15 intertidal shores around Anglesey, north Wales, UK. We employed a novel approach to assess predation based on measuring faecal output from recently collected individuals and converting it to food consumed using absorption efficiencies (AEs) measured using potential prey species inhabiting the same shores. Anemone mean abundance was 8.21 (± 0.27, s.e.) individuals.m−2, whereas for C. maenas it was 0.23 (± 0.02, s.e.) individuals.m−2. AEs when fed mussel tissue, a polychaete worm, or a shrimp were 92.8–94.0% in C. maenas and 40.5–95.8% in A. equina. This difference in values reflected the different feeding modes of the two predators. Unexpectedly, A. equina consumed 3.5–7 times more prey than C. maenas. The consumption of larger amounts of prey by an anemone than the dominant durophagous predator has important consequences for calculating energy flows in food webs, understanding predation controls in assemblages, and potentially for wider predation trends.

This paper explores the generation of coherent electromagnetic energy flows to form a shock wave in free-space as a linear medium. Flows of energies from several waves need to build up coherently to create the wave. In free-space, energy in the propagation direction flows at speed of light and therefore cannot match the required energy accumulation. Electromagnetic waves carrying orbital angular momentum are suggested instead of ordinary plane waves because they have a controllable energy flow in the transverse direction of propagation. Flows of several waves are managed under certain conditions to accumulate energy and create a shock wave in the transverse direction. These conditions must be maintained to preserve the waveform during propagation. Previous studies on acoustical shock waves in a nonlinear medium explained the effect of nonlinear medium on the wave. Nonlinear effects are implemented to create similar propagation conditions in the linear medium and to preserve the waveform. The wave, however, rotates and expands during propagation due to the evolution of its internal energies. Internal energy flows are studied, and an analogy is drawn with flows in fluids. Numerical simulations are conducted to support the theoretical derivations on wave generation and propagation.

Pyrolysis is a mainstream technology for biomass energy utilization, but theoretical simulation, verification feedback on the coordinated pyrolysis process, material conversion rules, and energy efficiency characteristics of multi-source biomass wastes, particularly Chinese medicinal residue, arestill relatively scarce. In this paper, Aspen Plus industrial simulation software with a complete physical property system was used to establish a simulation model for biomass waste pyrolysis to produce carbon, and its reliability was verified. The actual pyrolysis process data of waste pine wood from agricultural forest source were systematically simulated, the material flow and energy flow during the pyrolysis process of the sargentgloryvine stem medicine residue was analyzed, and the conversion efficiency was comprehensively evaluated. The results showed that the energy consumption of the pyrolysis system was 2580.7 MJ/h, and the energy efficiency was 53.0% under the current single waste condition. At temperatures ranging from 500 to 550 ℃, 30%~60% of traditional sargentgloryvine stem medicine residue was simulated to be incorporated into the collaborative pyrolysis, which resulted in optimal material recycling efficiency and energy efficiency. The system′s energy consumption was reduced by 30%~60%, and the energy efficiency of the system increased by 3.0%~6.0%, which could provide scientific basis for the collaborative pyrolysis of Chinese medicine residue.

This study proposed an energy consumption input–output (ECIO) model, which contributed to identifying the roles in energy consumption of all sectors of a certain country or region. Taking all Chinese sectors as an example, this study measured and analyzed the energy consumption flows in all Chinese sectors over 2002–2018 by combining the ECIO model and the modified hypothetical extraction method. The results show that the construction sector was the largest energy receiver in the economic system. Its dependence on other sectors was the strongest and maintained a remarkable growing trend year by year. Specifically, the amounts of energy flow from the other seven sectors to the construction sector in 2002 were 1,128, 2,844, 17,705, 2,556, 524, 2,335, and 579 × 104 tce (1 tce = 29.3 GJ), respectively. They increased to higher amounts of 1,860, 9,061, 74,557, 9,234, 2,865, 10,519, and 3,784 × 104 tce in 2018, respectively. The manufacturing sector as the largest energy supplier was the most dependent on itself, and played the most significant role in China’s economic system. More precisely, the amounts of energy flow from the manufacturing sector to the other six sectors in 2002 were 3,347, 382, 17,705, 3,569, 1,517, and 11,467 × 104 tce respectively. They increased to 3, 434, 1,339, 9,234, 5,885, 3,633, and 38,727 × 104 tce in 2018, respectively. The mining sector has the most paths of energy export for the production and development of other sectors.

Based on the field survey and reference data of the sea area of the Zhongjieshan Islands from 2021 to 2022, the Ecopath model was used to analyze the energy flow structure of the marine ecosystem of the sea area of the Zhongjieshan Islands; the energy structure of the marine ecosystem was divided into 21 functional groups, and its nutrient structure, energy flow, and total system characteristics were analyzed. The results show that the credibility of the model is 0.414, which is at a medium level. The trophic level of each functional group of the ecosystem in the sea area of Zhongjieshan Islands was 1–3.48, the energy flow structure of the system was mainly concentrated in the first five grades, and the trophic level was relatively simple, with the average energy transfer efficiency of the system being 8.11%, the energy flow range being 2.81–13.04%, the energy transfer efficiency of the primary producers of the system being 7.25%, and the energy conversion efficiency of the system debris being 9.12%. The total system throughput was 2125.96 t·km−2; The analysis of the overall characteristics of the ecosystem showed that the system connectance index and the system omnivory index were 0.45 and 0.24, respectively, while the Finn’s cycling index was 8.24, the Finn’s mean path length of the system was 2.72, and the total primary production/total respiration was 1.71. In this study, the marine ecosystem model of the sea area of the Zhongjieshan Islands was studied to understand the trophic structure and ecosystem status of the sea area, which is conducive to the sustainable utilization and scientific management of fishery resources in the sea area.

This paper presents a novel method for generating and shaping reverse energy flow through the interference of light fields from a minimal number of point light sources. Until now, reverse energy flow has only been observed using complex light fields, such as optical vortices or cylindrical vector beams, limiting the formation of reverse energy flow near the optical axis. We demonstrate both analytically and numerically that unbounded regions of reverse energy flow can be achieved with just two point light sources, positioned asymmetrically at specific angles (e.g., 90 or 45 degrees) and with particular polarization states. The results indicate that the relative reverse energy flow can be enhanced by increasing the number of sources to three or four, adjusting their polarization, or introducing a vortex phase singularity. The presence of an initially embedded asymmetry in the fields under consideration leads to the formation of a non-uniform distribution of spin and orbital angular momentum density. Variations in the polarization state, as well as the introduction of a vortex phase singularity, allow for changing the distribution of angular momentum density while maintaining the presence of a reverse energy flow. We also explore the feasibility of implementing the obtained results using sectional phase diffractive optical elements, which will enhance the energy efficiency of the generated fields compared to point sources.

With the increase of new energy penetration, the power balance and frequency stability problems brought by its randomness, intermittency and volatility has become increasingly serious. It is difficult to cope with these problems only by traditional centralized power plants. Flexible resources in the power systems should also bear a part of the responsibility for the balance of power and energy. Virtual power plant (VPP) can aggregate a large number of distributed flexible resources with different characteristics, participate in the electricity markets as a whole and accept the dispatch of the grid, and provide important support for the real-time power balance of the power systems. The development of VPPs should be based on a large number of flexible resources, advanced communication and dispatching/control technologies, and efficient business models and good market policies. The operation of VPPs can be attributed to the energy flow of the energy network, the information interaction of the information network and the value transfer of the value network. Therefore, based on the three-layer network architeciture of “energy-information-value”, the operation modes and control schemes of different types of VPPs were analyzed, and the idea of “three flow separation-convergence” for VPP architecture design was proposed. The findings provide useful guidance for the design, construction and operation of VPPs.

Abstract Aquatic macrophytes are the main autochthonous component of primary production in the Amazon Basin. Floating meadows of these plants support habitats with highly diverse animal communities. Fishes inhabiting these habitats have been assumed to use a broad range of food items and compose a particular food web. We employed carbon (δ13C) and nitrogen (δ15N) stable isotope analysis to draw the trophic structure of these habitats and to trace the energy flow by its trophic levels. Fishes and other animals from 18 independent macrophyte meadows of a floodplain lake of the Solimões River (Amazonia, Brazil) were analyzed. The food web of macrophyte meadows consists of four trophic levels above autotrophic sources. In general, primary consumers exhibited a broader range of food sources than the upper trophic levels. Some fish species depended on a large number of food sources and at the same time are consumed by several predators. The energy transfer from one trophic level to the next was then mainly accomplished by these species concentrating a high-energy flux and acting as hubs in the food web. The broad range of δ13C values observed indicates that the organisms living in the macrophyte meadows utilize a great diversity of autotrophic sources.

Grass carp (Ctenopharyngodon idellus) is the most productive freshwater fish in China, but its traditional aquaculture model still has problems, such as poor water quality and frequent diseases. We have taken monoculture and 80:20 polyculture grass carp ponds as the research object and used EwE software to build the Ecopath model of two ponds. We analyzed and compared the characteristics of ecological structure and energy flow in two ponds. The result showed the highest effective trophic level in the polyculture pond that was higher than that in the monoculture pond, and fish in polyculture had higher EE values which showed the production of fish in polyculture contributed more to the energy conversion efficiency of the ecosystem. Flows into detritus were the largest component of TST both in the two ponds, which accounted for 49.34% and 50.37%. And the average transfer efficiency in monoculture was 13.07%, while that in polyculture was 15.6%. The ascendency/total development capacity (A/TDC) and overhead/total development capacity (O/TDC) were 0.35 and 0.65 both in the two ponds, respectively, which indicated that both systems had a strong anti-perturbation ability, but the stability could be improved. Finn's cycling index (FCI) in polyculture was higher and showed that the polyculture pond was more mature and stable. Unused energy of functional groups will flow to detritus, and that in the monoculture pond was higher, the energy of C. idellus that flowed to detritus in monoculture was 48.17% higher than that in polyculture; unused energy of bacteria and phytoplankton were also high. The result showed that polyculture could improve energy utilization, increase transfer efficiency, and raise the stability of the ecosystem. Grass carp ponds still need to be improved in the aspects of mixed species and energy consumption. It is necessary to improve the ecological and economic benefits of grass carp ponds by optimizing the aquaculture structure and adjusting the aquaculture proportion. [ABSTRACT FROM AUTHOR]

To achieve carbon neutrality and address global energy supply issues by 2050, there is active progress in the industrial sector for waste energy recovery and commercialization projects. It is necessary to consider both the energy recovery efficiency and economic feasibility based on the production volume for the resource utilization of waste energy, along with eco-friendly processing methods. In this study, a waste heat recovery system was designed to recover a large amount of thermal energy from high-temperature exhaust gases of gas engines for power generation by using biogas produced from organic waste in industrial complexes. Types and sizes of components for a waste heat recovery system that were suitable for various engine sizes depending on biogas production were designed, and the energy recovery efficiency was analyzed. The waste heat recovery system consisted of a smoke tube boiler that generated superheated steam at 161 °C under 490 kPa of pressure from the exhaust gas as the heat source, along with two economizers for heating both supply water and hot water. Heat exchangers that were suitable for three different engine sizes were configured, and their performance and energy flow were calculated. In particular, when operating two engines with a power output of 100 kW, the boiler showed the highest steam production efficiency, and the superheated steam production from high-temperature exhaust gas at 600 °C was designed to be 191 kg/h, while hot water at 58 °C was designed to be produced at 1000 kg/h. In addition, further research on the heat exchanger capacity ratio confirmed that it was within a certain range despite the difference in heat exchanger capacity and efficiency depending on the engine size. It was confirmed that the heat exchange capacity ratio of the boiler was important as an optimal-capacity design value for the entire system, as it ranged from 46% to 47% of the total heat exchanger size. [ABSTRACT FROM AUTHOR]

• Controlling region is firstly proposed to analyze the vibration energy flow. • The voltage and temperature controlling regions are determined. • Divergence representation is originally given to locate vibration transmission path. • The effects of voltage and temperature on the stiffness matrix are analyzed. In this study, vibration energy flow (VEF)-controlling regions in a piezoelectric metamaterial plate were determined using the structural intensity method. A finite element model was developed to derive the motion equation of a piezoelectric metamaterial plate in which the stiffness matrix depends on the temperature rise and input voltage. A VEF analysis model was developed to investigate the influence of temperature rise and input voltage on the VEF magnitude and direction based on the structural intensity method. In the numerical calculations, the bandgaps of the finite piezoelectric metamaterial plate agreed well with the band structures, which verified the effectiveness of the finite element model. In the present VEF analysis model, the structural intensity method was developed to investigate the influences of temperature rise and input voltage on the VEF magnitude and direction, and a new representation, called the divergence representation, was proposed to obtain the specific locations of sinks and sources in some complex structures. The numerical results showed that the magnitude of VEF increased with temperature rise or input voltage. The influence of the input voltage on the VEF direction may be offset by the temperature rise, and vice versa. To better analyze the influence of these two parameters, temperature-rise and input voltage-controlling regions were first analyzed. The input voltage played a more important role in controlling the direction of VEF than the temperature rise in the input voltage-controlling region and vice versa. [Display omitted] [ABSTRACT FROM AUTHOR]