Matching Relationship Research Articles

Performance characteristics of a compact self-circulating liquid desiccant air dehumidification system coupled with a heat pump: A comprehensive parametric study

Integration of a heat pump with a liquid desiccant system for air dehumidification has received growing attention in recent years in view of its more compact size and lower electricity consumption. This paper presents a compact combined heat pump and self-circulating liquid desiccant air dehumidification system targeted at small cooling load applications. The compactness lies in the integration of the dehumidifier and evaporator as well as the integration of the regenerator and condenser. Besides, the design of solution self-circulation (SSC) is intended for energy savings and the auxiliaries are employed to help achieve energy matching between the heat pump and the air dehumidification system. First, a comparative study is performed to identify the more energy efficient one of the two strategies for energy matching. Based on this, a thermodynamic model-based parametric study is conducted to investigate the effects of various influencing factors on the energy matching relationship and performance of the proposed system, as well as the energy-saving potential relative to the basic system without SSC. The results show that there exists an optimum solution self-circulation ratio (SCR) to achieve the maximum COP under a given condition. Basically, the proposed system with a proper SCR could yield a significant energy-saving effect regardless of the performance variations under studied operation conditions. It is found that a reduction of 29.68 % in energy consumption and an improvement of 42.20 % in COP are achieved under the ambient condition of 30 ℃ temperature and 20 g/kg humidity ratio. Furthermore, a correlation analysis is used to reveal the association strength and direction between any two main operation and performance parameters. Finally, the heat recovery is proved to effectively reduce the cooling coils load. This paper provides an in-depth understanding of the energy matching relationship and demonstrates the energy-saving performance benefiting from SSC for future practical applications of the proposed system.

Matching relationship research between ore and coke in thermal reserve zone under hydrogen-rich condition

ABSTRACT In this paper, the mathematical relationship between the reduction degree of ore and the reaction rate constant k of FeO was established by experiments. Based on the unreacted core model, the relationship between the gas utilization rate in the thermal reserve zone (TRZ) and k and temperature is derived. The results show that with the decrease of the temperature in the TRZ, the gas utilisation rate increases first and then decreases. With the increase of the reduction degree of raw materials, the gas utilisation rate increases and the peak temperature decreases. With the increase of H2 content, the peak temperature increases. Finally, the relationship between coke reactivity and ore reduction degree and H2 content is: CRI = 164.88 In(RI) – 0.42φ(H2 )% – 696.18. By changing the matching relationship between ore and coke, the gas utilisation rate can be increased by 0.85% and the fuel ratio can be reduced by 5.70 kg·t−1

Study of Contact Pressure Distribution in Bolted Encapsulated Proton Exchange Membrane Fuel Cell Membrane Electrode Assembly

The distribution of contact pressure on the Membrane Electrode Assembly (MEA) significantly affects the performance of a Proton Exchange Membrane Fuel Cell (PEMFC). This paper establishes a PEM fuel cell model to investigate the impact of bolt load and its distribution, sealing gasket hardness, and size on the magnitude and distribution of contact pressure on the MEA during assembly. Thermal–mechanical coupling is employed to simulate the thermal effects resulting from chemical reactions under operational conditions. The findings reveal that there is an extremum of pressure uniformity in the range of 5000 to 6250 N for bolt loads. When the average bolt load is lower than this extremum, altering the distribution of the load can effectively enhance the uniform distribution of contact pressure. Stiffer gaskets reduce the contact pressure on the MEA while increasing the pressure on the gasket itself, resulting in reduced deformation. A rational matching relationship among gaskets, Gas Diffusion Layers (GDLs), and seal grooves is proposed. During operational conditions, thermal effects decrease the sealing performance and also impact the magnitude and distribution of contact pressure on the MEA. These outcomes provide significant guidance for the assembly and performance evaluation of PEMFCs.

Spatial matching relationship between health tourism destinations and population aging in the Yangtze River Delta Urban Agglomeration

In order to address population aging and the healthy China strategy, this paper takes three provinces and one city in the Yangtze River Delta urban agglomeration as the empirical target. Firstly, using the 2010 and 2020 census data, and taking the aging coefficient and the density of the elderly population as the basic research indexes, this paper adopts the center of gravity migration model and the standard deviation ellipse to outline the spatial evolution path of the aging coefficient and the density of the elderly population. Second, using the data of recreational tourism sites in each prefecture-level city of the Yangtze River Delta urban agglomeration from 2016 to 2022, the closest neighbor index is used to judge the overall distribution characteristics of recreational tourism sites, and the judgment results are further verified with the help of Tyson polygonal analysis. Finally, based on the cross-section data of the elderly population in 2020, the spatial distribution of recreation and tourism sites and the elderly population are matched by the geographic concentration index, the center of gravity model and the matching coefficient. The results show that (1) the degree of population aging is deepening, and the characteristics of spatial Agglomeration are obvious, but the development speed among regions is inconsistent; (2) the distribution of health tourism destinations is wide and uneven between regions, showing the characteristics of ‘overall dispersion and local concentration’; (3) the spatial distribution of health tourism destinations and the elderly population shows a certain matching relationship, but the matching degree is not high. With the Yangtze River as the boundary, the distribution of health tourism destinations is ‘high in the south and low in the north’ and assumes a ladder shape from south to north, with obvious regional differences. Overall, health tourism lags behind the development process of aging.

Identification of Bird Habitat Restoration Priorities in a Central Area of a Megacity

Rapid global urbanization has caused habitat degradation and fragmentation, resulting in biodiversity loss and the homogenization of urban species. Birds play a crucial role as biodiversity indicators in urban environments, providing multiple ecosystem services and demonstrating sensitivity to changes in habitat. However, construction activities often disrupt urban bird habitats, leading to a decline in habitat quality. This paper proposes a framework for prioritizing habitat restoration by pinpointing bird hotspots that demand attention and considering the matching relationship between bird richness and habitat quality. Shanghai represents a typical example of the high-density megacities in China, posing a significant challenge for biodiversity conservation efforts. Utilizing the random forest (RF) model, bird richness patterns in central Shanghai were mapped, and bird hotspots were identified by calculating local spatial autocorrelation indices. From this, the habitat quality of hotspot areas was evaluated, and the restoration priority of bird habitats was determined by matching bird richness with habitat quality through z-score standardization. The results were as follows: (1) Outer-ring green spaces, large urban parks, and green areas along coasts or rivers were found to be the most important habitats for bird richness. Notably, forests emerged as a crucial habitat, with approximately 50.68% of the forested areas identified as hotspots. (2) Four habitat restoration types were identified. The high-bird-richness–low-habitat-quality area (HBR-LHQ), mainly consisting of grassland and urban construction land, was identified as a key priority for restoration due to its vulnerability to human activities. (3) The Landscape Shannon’s Diversity Index (SHDI) and Normalized Difference Vegetation Index (NDVI) are considered the most significant factors influencing the bird distribution. Our findings provide a scientifically effective framework for identifying habitat restoration priorities in high-density urban areas.

Optimization of degradable temporary plugging material and experimental study on stability of temporary plugging layer

Temporary plugging technology is an important drilling technique for maintaining wellbore stability and resolving lost circulation problems. The key to its success lies in the use of materials that can form a tight and stable “temporary plugging layer” with certain pressure bearing capacity and a permeability close to zero in the loss channel near the wellbore. Experimental studies have been conducted to develop adhesion formulations for optimal temporary plugging materials, as the matching relationship between particle size and fracture width is critical [(0.5−1)/1]. By measuring the permeability of the temporary plugging layer under varying confining pressure with a soap foam flowmeter, researchers have been able to evaluate the effectiveness, degradation, and dosages of temporary plugging agents. It has been shown that a single-particle material, such as a walnut shell, has a smaller permeability than a hyperfine CaCO3 coated temporary plug layer. The latter, however, is less capable of bearing pressure. By combining different materials, such as walnut shells and hyperfine CaCO3 particles, the researchers were able to create a temporary plug layer that had the lowest permeability and did not change much at variable confining pressures. Its pressure-bearing capacity is strong and the temporary plug works well. Experiments have shown that a ratio of 2:1–3:1 of hyperfine CaCO3 and walnut shell particles work well for plugging a fracture system with particles of size 2–3 times the fracture width. It developed an evaluation method for temporary plugging agents, studied their plugging capability and degradation performance for reservoir conversion, and evaluated degradation performance after successful temporary plugging. The temporary plugging rate of the temporary plugging agent increased from 98.10% to 99.81%, and the maximum temporary plugging pressure is 50.39 MPa, which can be completely reduced at 150°C for 4 h, meeting the technical requirements of “dense temporary plugging, two-way pressure bearing” to some extent.

Chromite-Bearing Peridotite Identification, Based on Spectral Analysis and Machine Learning: A Case Study of the Luobusa Area, Tibet, China

Chromite is a strategic mineral resource for many countries, and chromite deposit occurrences are widespread in the ultramafic rocks of the Yarlung Zangbo ophiolite belt, particularly in the harzburgite unit of the mantle section. Conducting field surveys in complex and poorly accessible terrain is challenging, expensive, and time-consuming. Remote sensing is an advanced method of achieving modern geological work and is a powerful technical means of geological research and mineral exploration. In order to delineate outcrops of chromite-bearing mantle peridotite, the present research study integrates seven image-enhancement techniques, including optimal band combination, decorrelation stretching, band ratio, independent component analysis, principal component analysis, minimum noise fraction, and false color composite, for the interpretation of Landsat8 OLI and WorldView-2 satellite data. This integrated approach allows the effective discrimination of chromite-containing peridotite outcrops in the Luobusa area, Tibet. The interpretation results derived from these integrated image-processing techniques were systematically verified in the field and formed the basis of the feature selection process of different lithologies supported by the support vector machine algorithm. Furthermore, the distribution range of the ferric contamination anomaly is detected through the de-interference abnormal principal component thresholding technique, which shows a high spatial matching relationship with mantle peridotite. This is the first study to utilize Landsat8 OLI and WorldView-2 remote sensing satellite data to explore the largest chromite deposit in China, which enriches the research methods for the chromite deposits in the Luobusa area. Accordingly, the results of this investigation indicate that the integration of information extracted from image-processing algorithms using remote sensing data could be a broadly applicable tool for prospecting chromite ore deposits associated with ophiolitic complexes in mountainous and inaccessible regions such as Tibet’s ophiolitic zones.

Non-linear seepage law and a characterization model of heavy oil-in-water emulsion in porous media

Stable emulsions with different continuous-phase viscosities, dispersed-phase volume fractions, and dispersed droplet sizes were prepared. Seepage experiments using heavy oil-in-water (O/W) emulsion were then conducted in sand packs to analyze the effects of different injection rates, permeabilities, and emulsion characteristics on the seepage law. Finally, an evaluation method for the seepage law was established, and a regression model that considered the factors influencing the non-linear seepage laws was developed using the 1stop software to quantitatively reveal the seepage mechanism. The matching relationship between droplet size and permeability determined the seepage behavior of the O/W emulsion. Emulsions with droplet sizes matched with permeability behaved as a pseudoplastic fluid, with a non-linear flow. With an increase in the dispersed-phase volume fraction, the emulsions displayed a more non-linear behavior due to the accumulated retention and disordered plugging of dispersed droplets. With an increase in the injection rate, the emulsion with a low continuous-phase viscosity had more significant non-linear characteristics than the emulsion with a high continuous-phase viscosity. The correlation of the characterization model was relatively strong under the experimental conditions, with a correlation coefficient of 93.28%. Therefore, the characterization model accurately predicted the effects of the non-linear seepage law for all factors studied.

Spatial heterogeneity analysis of matching degree between endangered plant diversity and ecosystem services in Xishuangbanna.

Biodiversity and ecosystem services (ESs) are closely linked. Human activities have caused critical damage to the habitat and ecosystem function of organisms, leading to decline in global biodiversity and ecosystem services. To ensure sustainable development of local ecological environments, it is critical to analyze the spatial matching degree of biodiversity and ESs and identify ecologically vulnerable areas. Taking Xishuangbanna, southern China, as an example, we constructed a pixel-scale matching degree index to analyze the spatial matching degree of endangered plant diversity (EPD) and four ESs and classified the matching degree into low-low, low-high, high-low, and high-high four types. The results revealed a mismatch relationship of EPD and ESs in more than 70% of areas. Under the influence of altitude and land use/land cover (LULC) type, the matching degree of EPD and ESs showed obvious spatial heterogeneity. In low-altitude areas in the south of Xishuangbanna, EPD and ESs mainly showed mismatch, while high-altitude areas in the west had a better match. Natural forest was the main land cover in which EPD and ESs showed high-high match and its areal proportion was much larger than that of rubber plantation, tea plantation, and cropland. Our findings also stress the need to concentrate conservation efforts on areas exhibiting a low-low match relationship, indicative of potential ecological vulnerability. The pixel-scale spatial matching degree analysis framework developed in this study for EPD and ESs provides high-resolution maps with 30 m × 30 m pixel size, which can support the implementation of ecological protection measures and policy formulation, and has a wide range of applicability. This study provides valuable insights for the sustainable management of biodiversity and ESs, contributing to the strengthening of local ecological environment protection.

Purpurin intercalated layered double hydroxide nanocomposites for improved CO2 visible photocatalytic reduction: Dye-intercalation stabilization and sensitization

Purpurin(pp) can be used as a photosensitive molecule in photocatalytic systems due to its excellent absorption of visible light, but its application is limited due to its poor stability under light. Layered double hydroxides (LDHs) can act as molecular containers due to their interlayer anion exchangeability, introducing target anions into the interlayer of LDHs and improving the instability of anions by utilizing the 2D confinement environment between LDHs layers. A series of co-intercalation materials with different ratios of pp and dodecyl sulfonate (SDS) were prepared through the hydrothermal method in this work, denoted as SDS-pp(x%)/LDHs. Compared with pp, the absorbance retention rate of SDS-pp(x%)/LDHs increased from 12.5% to 90% after 5 h of light exposure. Then its potential application in visible photocatalytic reduction of CO2 was explored. When the intercalation ratio of pp is 3%, the performance is optimal. Compared with ZnAl LDHs, the yield of CO produced by SDS-pp(3%)/LDHs was increased by 12 times and a small amount of 8-electron reduction product CH4 appeared. Through mechanism exploration, the matching energy level relationship between pp and LDHs promotes electron transfer from pp to LDHs. In addition, the catalyst exhibits good cyclic photocatalytic reduction performance for CO2 due to its stable intercalation structure.

New multi-energy sources coupling a low-temperature sustainable central heating system with a multifunctional relay energy station

Due to short cost-effective heat transportation distance, the existing geothermal heating technologies cannot be used to develop the deep hydrothermal type geothermal fields situated far away from urban area. To solve the problem, a new multi-energy source coupling a low-temperature sustainable central heating system with a multifunctional relay energy station is put forward. As for the proposed central heating system, a compression heat pump integrated with a heat exchanger in the heating substation and a gas-fired water/lithium bromide single-effect absorption heat pump in the multifunctional relay energy station are used to lower return temperature of the primary network step by step. The proposed central heating system is analyzed by using thermodynamics and economics, and matching relationships between design temperature of return water and main line length of the primary network are discussed. The studied results indicate that, as for the proposed central heating system, the cost-effective main line length of the primary network can approach 33.8 km, and the optimal design return temperature of the primary network is 23 ℃. Besides, annual coefficient of performance and annual exergy efficiency of the proposed central heating system are about 3.01 and 42.7%, respectively.

Prediction of Marine Thin Shale Gas Reservoir with Seismic Phase-Controlled Nonlinear Stochastic Inversion

Due to the complicated interference sources and low signal-to-noise ratio of seismic records, conventional seismic inversion methods are difficult to accurately identify shale gas reservoirs with a thickness of less than 10 m. This presents great challenges to shale gas exploration and development in China. Seismic phase-controlled nonlinear stochastic inversion (SPCNSI) is related to the heterogeneity of underground media. With the constraints of the stratigraphic sequence or seismic facies models, the minimum value between the seismic model and seismic record can be solved through iterative processes. Based on the solved acoustic velocity in formation, the constraints for SPCNSI can be formed with the matching relationship between target layers and different sequences in three-dimensional space. The prediction resolution of an unconventional reservoir can be effectively improved by combining logging, geological and seismic information. The method is suitable for predicting thin shale gas reservoirs in complex geological structures. In this study, SPCNSI was developed to predict the thin-layer marine shale gas reservoir in the southeast of Chongqing; the horizontal and vertical distribution characteristics were proven in the Longmaxi Formation and the Wufeng Formation; thin layers with a thickness of less than 7 m were also discovered. According to the results, three sets of potential development areas were determined by the inversion method, and the accuracy and reliability of the method were verified by logging and productivity testing.

Regionalization and optimization strategy of ecological management in Xinjiang, China based on supply-demand relationship and spatial flow of ecosystem services.

As an important basis for the optimization of territorial space, ecological management zoning is of great significance for maintaining regional ecological security and promoting the construction of ecological civilization. With 10 ecosystem services, such as wind break and sand fixation, water conservation, and forest and grass supply, we built a supply index system for Xinjiang. Modelling and ecological economics methods were used to quantify ecosystem service supply. Ecosystem service demand of Xinjiang in 2020 was quantitatively assessed by combining land use intensity, population, and economic status. Based on the ecosystem service supply-demand ratio model and quadrant matching method, we explored the matching relationship and spatial differentiation of ecosystem ser-vice supply and demands on the 1 km grid scale. The breaking point formula and field intensity formula were used to evaluate the flow range and intensity of ecosystem services, and then ecological management zones were divided and corresponding control measures were proposed. The results showed obvious spatial differences in the supply and demand of ecosystem services in Xinjiang in 2020. The high-supply areas were mainly distributed in river valleys and along river systems, while the demand was concentrated in oasis-central cities. The overall supply of ecosystem services was less than the demand. The spatial distribution was dominated by low supply-low demand areas and high supply-high demand areas. There were seven output zones of ecosystem services in Xinjiang, namely Fuyun County, Fuhai County, Yizhou District, Shanshan County, Alashankou City, Keping County and Qira County. The rests were input zones. According to the comprehensive analysis, Xinjiang could be divided into five ecological management areas, i.e., mountain ecological barrier area, oasis ecological restoration area, desert ecological improvement area, desert-oasis ecological protection area, and patch ecological transport area.

Optimizing collaborative decision-making of multi-agent resources for large-scale projects: from a matching perspective

PurposeIn recent decades, infrastructure has continued to develop as an important basis for social development and people's lives. Resource management of these large-scale projects has been immensely concerned because dozens of construction enterprises (CEs) often work together. In this situation, resource collaboration among enterprises has become a key measure to ensure project implementation. Thus, this study aims to propose a systematic multi-agent resource collaborative decision-making optimization model for large projects from a matching perspective.Design/methodology/approachThe main contribution of this work was an advancement of the current research by: (1) generalizing the resource matching decision-making problem and quantifying the relationship between CEs. (2) Based on the matching domain, the resource input costs and benefits of each enterprise in the associated group were comprehensively analyzed to build the mathematical model, which also incorporated prospect theory to map more realistic decisions. (3) According to the influencing factors of resource decision-making, such as cost, benefit and attitude of decision-makers, determined the optimal resource input in different situations.FindingsNumerical experiments were used to verify the effectiveness of the multi-agent resource matching decision (MARMD) method in this study. The results indicated that this model could provide guidance for optimal decision-making for each participating enterprise in the resource association group under different situations. And the results showed the psychological preference of decision-makers has an important influence on decision performance.Research limitations/implicationsWhile the MARMD method has been proposed in this research, MARMD still has many limitations. A more detailed matching relationship between different resource types in CEs is still not fully analyzed, and relevant studies about more accurate parameters of decision-makers’ psychological preferences should be conducted in this area in the future.Practical implicationsCompared with traditional projects, large-scale engineering construction has the characteristics of huge resource consumption and more participants. While decision-makers can determine the matching relationship between related enterprises, this is ambiguous and the wider range will vary with more participants or complex environment. The MARMD method provided in this paper is an effective methodological tool with clearer decision-making positioning and stronger actual operability, which could provide references for large-scale project resource management.Social implicationsLarge-scale engineering is complex infrastructure projects that ensure national security, increase economic development, improve people's lives and promote social progress. During the implementation of large-scale projects, CEs realize value-added through resource exchange and integration. Studying the optimal collaborative decision of multi-agent resources from a matching perspective can realize the improvement of resource transformation efficiency and promote the development of large-scale engineering projects.Originality/valueThe current research on engineering resources decision-making lacks a matching relationship, which leads to unclear decision objectives, ambiguous decision processes and poor operability decision methods. To solve these issues, a novel approach was proposed to reveal the decision mechanism of multi-agent resource optimization in large-scale projects. This paper could bring inspiration to the research of large-scale project resource management.

Ultra-low frequency active vibration isolation in high precision equipment with electromagnetic suspension: Analysis and experiment

High performance vibration isolation requirement in the ultra-low frequency band for high precision equipment becomes more and more stringent. An active vibration isolation method is investigated to broaden the frequency band of isolation and improve the performance, in which an electromagnetic suspension is adopted to provide a static lifting force and an active control force. Naturally, the suspension is accompanied by a controllable negative stiffness. Two factors that might cause instability of the suspension system, i.e., the bias current and the base disturbance, are analyzed to give the stable region. The matching relationship between the currents in the upper and lower coils, and the mapping rules among the current, relative displacement, force and stiffness are discussed, respectively. The maximum base disturbance that the system can withstand is analyzed. On the basis of the theoretical analysis, the active position stabilization and vibration control methods are built and the performance is evaluated. Furthermore, experiments were conducted to verify the effectiveness of the active vibration isolation method. Numerical and experimental results demonstrate that the electromagnetic suspension is able to improve the vibration isolation performance in the ultra-low frequency range, where the transmissibility is below 0 dB in the entire frequency band and the initial vibration isolation frequency is less than 1Hz.

Matching degree evaluation between new urbanization and carbon emission system in China: a case study of Anhui Province in China

In order to reveal the relationship between new urbanization and carbon emission to provide reference opinions for the construction of low-carbon urbanization, an evaluation system between new urbanization and carbon emission was constructed. Then their matching degree relationship was analyzed by coupling coordination degree model based on the data from 2012 to 2021 in Anhui Province, and their development trend from 2023 to 2032 was predicted by gray prediction model. The results show that: (1) New urbanization and carbon emission have the co-trend effect, and the consistency of core impact factors is relatively significant. Among them, the level of new urbanization increases from 0.058 in 2012 to 0.699 in 2021 and carbon emission development increases from 0.023 in 2012 to 0.165 in 2021, which both showing an upward trend. Meanwhile, social urbanization and population carbon emission are the core influencing factors. (2) The coupling coordination degree between new urbanization and carbon emission is low, but the synergy trend is optimistic and there is a large room for improvement. Among them, the coupling coordination coefficient of the coupling system rises from 0.136 in 2012 to 1.412 in 2021 (antagonistic phase), and then reaches 0.820 by 2032 (highly coordinated phase) by forecast. It shows that their current development is unbalanced, but the development trend is good, and there is a chance for improvement. This paper deepens the understanding of the logical correlation between new urbanization and carbon emission, and the following views are formed: (1) Low-carbon development is still the mainstream of new urbanization; (2) The coordination development of new urbanization and carbon emission reduction should be strengthened.

Directional policy matrix and cloud model: Theory and application in the evaluation of city-water interaction

The evolution direction of the relationship between city and water determines the healthy prosperity and sustainable development of a city. Scientific evaluation of the matching relationship between water resources and social economy in different cities is the key to analyze the interaction relationship between city and water. Current research on sustainable evaluation of complex systems is dominated by one-dimensional static evaluation, which cannot help find gaps and predict development. Insufficient analysis of the city-water relationship reduces the reference and foresight of policy making. Moreover, conventional methods cannot overcome the uncertainty of the evaluation process. Therefore, this paper constructs a coordinated evaluation model based on directional policy matrix and cloud model, and categorizes cities in different development stages and water resources conditions into the matrix. Based on the analysis of the sources of contradictions in the relationship between city and water for three types of cities, such as cooperative interaction, competitive interaction and conflict interaction, water resources utilization policy and urban development strategy are adjusted accordingly. According to the evaluation results, the single system of the city, such as water resource carrying capacity or economic society level, has a positive development. However, from the point of view of the matching degree of the composite system, the interaction between city and water in most cities is not friendly. Among the cities, leading cities (Guangzhou, Shanghai, Wuhan) and robust cities (Chongqing, Chengdu) have a healthy match between water resources and social economy, and the relationship between city and water is cooperative. In driving cities (Beijing, Tianjin) and restrictive cities (Zhengzhou, Xi 'an), water resources and social economy do not match, and the relationship between city and water exists competition or even conflict. Based on the contradictions of different types of cities, the system in need of improvement and vulnerability indicators, water resources policy and economic society strategy recommendations are given to ensure sustainable development.

Dynamic Matching and Spatial Optimization of Land Use and Resource-Environment Constraints in Typical Regions of the Yellow River Basin in China

Accurately identifying the matching relationships between territorial space evolution and the resources and environment carrying capacity will directly guide the sustainable use of territorial space. Based on the evaluation of the territorial space dynamics of the lower Yellow River, this paper evaluates the suitability of territorial space development by focusing on ecological protection, agricultural development, and urban construction. Specifically, the resources and environment carrying capacity is estimated by identifying and mediating potential conflicts in the development of territorial space. The matching relationship between the evolution of territorial space and the resources and environment carrying capacity is identified using the matching degree model. The results demonstrated that: (1) Between 2000 and 2020, the agricultural space of the lower Yellow River was relatively stable, while the ecological space was generally shrinking, and the urban space continued to increase; (2) The characteristics of suitability for the agricultural development and urban construction of the lower Yellow River are characterized by landform and land-sea differentiation. The carrying scale of resources and the environment is based on agricultural space and is increasing yearly, followed by ecological space, which is gradually decreasing, and urban space, which first increased and then decreased; (3) Between 2000 and 2020, the matching index of the ecological and agricultural space evolution and the resource and environmental carrying capacity in the lower Yellow River exhibited a downward trend, while the regional difference increased. Furthermore, the matching index of urban space and the resources and environment carrying capacity indicated an upward trend, while the regional difference decreased.

Efficient in situ conversion of captured CO2 into fuels enabled by direct solar driven multifunctional calcium looping

Carbon neutrality requires credible action to reduce greenhouse gas emissions and develop clean and renewable energy. The solar driven multifunctional calcium looping (CaL), which integrates CO2 capture, CO2 conversion into fuels, and thermochemical energy storage into a solar driven cycle, tends to be one of the most promising pathways to establish a zero-carbon energy system. However, the progress of this concept remains in the proof-of-principle stage and the research into its magnified operations and underlying fundamental scientific problems is seldom reported. In fact, the thermodynamic and kinetic features of this integrated cycle are intertwined during the solar harvesting, CO2 capture, calcination, and CO2 reduction processes, so that the synergetic manipulation of the reactions becomes vital and challenging. Here, attempts are made to develop the design and regulation scheme for implementing full-scale application according to the research into a preliminarily enlarged operation carried out in a stirred bed reaction system. The kinetic matching relationships between different chemical reactions involving intense heat and mass transfer across the entire solar energy conversion chain are investigated. The average solar absorption of CaCO3 based composite particle material is promoted to 90.9% through doping catalysts into CaCO3. The solar-to-chemical conversion efficiency reaches up to 51.6%. More than 88.2% of the CO2 is converted into syngas in-situ. The high energy conversion efficiency indicates the bright prospect of such a direct solar driven multifunctional CaL system, and the proposed design and enhancement methods are expected to provide theoretical and practical references for its industrialization process.

A folded triboelectric sensor for performance evaluation of shock absorbers in automobile

Recently, pressure sensors for vibration monitoring are widely used in mechanical equipment safety monitoring. Here, we proposed a folded triboelectric nanogenerator (TENG) based on polyether Imide/reduced graphene oxide (PEI/rGO) polymer (PR-TENG) with through-hole structure to harvest mechanical energy and monitor the vibration response of automotive shock absorbers. In this design, the polytetrafluoroethylene film andPEI/rGo (PR) polymer film form the triboelectric pairs. When the mechanical frequency reaches 15 Hz, the output performance of the seven-layer PR-TENG device reaches its maximum at 308 V, 55.2 µA, and 198 nC, respectively. When the external load is 5 MΩ, the output power of seven-layer PR-TENG reaches its maximum value of 3 mW. According to the experimental results, when the space size is 30 mm and the number of working layers is 7, the linearity of vibration amplitude monitoring is the best. In addition, by establishing a fitting curve between multilayer PR-TENG and amplitude, the matching relationship between the test amplitude of TENG and the actual amplitude can be observed. The results indicate that the test results are highly consistent with the actual results, indicating that the multilayer PR-TENG matches the vibration response of the shock absorber. This research will promote the development of automotive vibration sensors.