Pole Region Research Articles

Highly Sensitive Chemiresistive H2S Detection at Subzero Temperature over the Sb-Doped SnO2@g-C3N4 Heterojunctions under UV Illumination.

NASA has detected H2S in the persistently shadowed region of the lunar South Pole through NIR and UV/vis spectroscopy remotely, but in situ detection is generally considered to be more accurate and convincing. However, subzero temperatures in space drastically reduce chemisorbed oxygen ions for gas sensing reactions, making gas sensing at subzero temperature something that has rarely been attempted. Herein, we report an in situ semiconductor H2S gas sensor assisted by UV illumination at subzero temperature. We constructed a g-C3N4 network to wrap the porous Sb doped SnO2 microspheres to form type II heterojunctions, which facilitate the separation and transport of photoinduced charge carriers under UV irradiation. This UV-driven technique affords the gas sensor a fast response time of 14 s and a response value of 20.1 toward 2 ppm H2S at -20 °C, realizing the sensitive response of the semiconductor gas sensor at subzero temperature for the first time. Both the experimental observations and theoretical calculation results provide evidence that UV irradiation and the formation of type II heterojunctions together promote the performance at subzero temperature. This work fills the gap of semiconductor gas sensors working at subzero temperature and suggests a feasible method for deep space gas detection.

Modulations of right hemisphere connectivity in young children relates to the perception of spoken words

The early school years shape a young brain's capability to comprehend and contextualize words within milliseconds of exposure. Parsing word sounds (phonological interpretation) and word recognition (enabling semantic interpretation) are integral to this process. Yet little is known about the causal mechanisms of cortical activity during these early developmental stages. In this study, we aimed to explore these causal mechanisms via dynamic causal modelling of event-related potentials (ERPs) acquired from 30 typically developing children (ages 6–8 years) as they completed a spoken word-picture matching task. Source reconstruction of high-density electroencephalography (128 channels) was used to ascertain differences in whole-brain cortical activity during semantically “congruent” and “incongruent” conditions. Source activations analyzed during the N400 ERP window identified significant regions-of-interest (pFWE<.05) localized primarily in the right hemisphere when contrasting congruent and incongruent word-picture stimuli. Dynamic causal models (DCMs) were tested on source activations in the fusiform gyrus (rFusi), inferior parietal lobule (rIPL), inferior temporal gyrus (rITG) and superior frontal gyrus (rSFG). DCM results indicated that a fully connected bidirectional model with self-(inhibiting) connections over rFusi, rIPL and rSFG provided the highest model evidence, based on exceedance probabilities derived from Bayesian statistical inferences. Connectivity parameters of rITG and rSFG regions from the winning DCM were negatively correlated with behavioural measures of receptive vocabulary and phonological memory (pFDR<.05), such that lower scores on these assessments corresponded with increased connectivity between temporal pole and anterior frontal regions. The findings suggest that children with lower language processing skills required increased recruitment of right hemisphere frontal/temporal areas during task performance.

Sustainable Development Strategies of Eco-Tourism in the Third Pole Based on Environmental Carrying Capacity Assessment Study

The rich natural resources and multi-ethnic cultural characteristics of the third pole region have created a good foundation for its development of ecotourism. However, the sustainable development of the third Pole ecotourism still needs to be explored on the basis of environmental carrying capacity assessment. Starting from the perspective of tourism environmental carrying capacity, this paper takes the third pillar as the research area, adopts the methods of desktop research, survey and interview, literature search, etc. Based on the construction of environmental carrying capacity model, carries out data analysis from four aspects: ecology, resource space, residents&amp;#39; psychology and social economy. The results showed that the other three carrying capacity levels were higher except for the social and economic carrying capacity. Therefore, it can be concluded that the third pole region is suitable for the development of ecotourism, but due to the low socio-economic carrying capacity, the development of ecotourism should be guided and regulated to some extent, and it is necessary to formulate a strategy suitable for the sustainable development of ecotourism in the third pole.

Electrophysiological correlates of distance and direction processing during cognitive map retrieval: A source analysis.

The cognitive map is an internal representation of the environment and allows us to navigate through familiar environments. It preserves the distances and directions between landmarks which help us orient ourselves in our surroundings. The aim of our task was to understand the role played by theta waves in the cognitive map and especially how the cognitive map is recalled and how the manipulation of distances and directions occurs within the cognitive map. In order to investigate the neural correlates of the cognitive map, we used the Cognitive Map Recall Test, in which 33 participants had to estimate distances and directions between familiar landmarks tailored to their own knowledge. We examined the role of theta waves in the cognitive map, as well as the brain regions that generated them. To that aim, we performed electroencephalographic source imaging while focusing on frequency spectral analysis. We observed increases of theta amplitude in the frontal, temporal, parahippocampal gyri and temporal poles during the recall of the cognitive map. We also found increases of theta amplitude in the temporal pole and retrosplenial cortex during manipulation of directions. Overall, direction processing induces higher theta amplitude than distance processing, especially in the temporal lobe, and higher theta amplitude during recall compared to manipulation, except in the retrosplenial cortex where this pattern was reversed. We reveal the role of theta waves as a marker of directional processing in the retrosplenial cortex and the temporal poles during the manipulation of spatial information. Increases in theta waves in frontal, parahippocampal, temporal and temporal pole regions appear to be markers of working memory and cognitive map recall. Therefore, our Cognitive Map Recall Test could be useful for testing directional difficulties in patients. Our work also shows that there are two distinct parts to the cognitive map test: recall and manipulation of spatial information. This is often considered as two similar processes in the literature, but our work demonstrates that these processes could be different, with theta waves from different brain regions contributing to either recall or manipulation; this should be considered in future studies.

Displacement of the South Pole from 2006 to 2021: Role of sea ice and Antarctic surface temperature

The effect of global warming on the southern polar regions necessitates careful monitoring of glacier deformations and their movements, as well as an understanding of atmospheric physics. For this purpose, the yearly movements of UNAVCO stations-South Pole Station (AMU2) (winter-summer) and other stations in the South Pole region have been observed in this paper for about a fifteen-year period (2006–2021). In addition, the area differences of the Antarctic continent due to seasonal changes (winter-summer) between 1980 and 2021 were investigated in this study. Moreover, the height values of the stations on the Antarctic continent were observed seasonally. The subglacial lakes in the Antarctic continent cause the differences in the height values as a result of the seasonal changes. A decrease in sea ice of 0.91 million km2 for the winter season and 0.55 million km2 for the summer season during a 41-year period has been determined for four sectors of the Antarctic continent. The temperature changes on the Antarctic continent in the summer and winter seasons (2005–2022) were also evaluated in this paper. Air temperature increases was apparent especially in the Antarctic Peninsula, East Antarctic and West Antarctic coasts. The Weddell Sea and the Amundsen Sea regions have had the most sea ice loss, each with 1.24 million km2. On the other hand, it can be observed that the East Antarctic sector has expanded by 0.32 million km2.

TPHiPr: a long-term (1979–2020) high-accuracy precipitation dataset (1∕30°, daily) for the Third Pole region based on high-resolution atmospheric modeling and dense observations

Abstract. Reliable precipitation data are highly necessary for geoscience research in the Third Pole (TP) region but still lacking, due to the complex terrain and high spatial variability of precipitation here. Accordingly, this study produces a long-term (1979–2020) high-resolution (1/30∘, daily) precipitation dataset (TPHiPr) for the TP by merging the atmospheric simulation-based ERA5_CNN with gauge observations from more than 9000 rain gauges, using the climatologically aided interpolation and random forest methods. Validation shows that TPHiPr is generally unbiased and has a root mean square error of 5.0 mm d−1, a correlation of 0.76 and a critical success index of 0.61 with respect to 197 independent rain gauges in the TP, demonstrating that this dataset is remarkably better than the widely used datasets, including the latest generation of reanalysis (ERA5-Land), the state-of-the-art satellite-based dataset (IMERG) and the multi-source merging datasets (MSWEP v2 and AERA5-Asia). Moreover, TPHiPr can better detect precipitation extremes compared with these widely used datasets. Overall, this study provides a new precipitation dataset with high accuracy for the TP, which may have broad applications in meteorological, hydrological and ecological studies. The produced dataset can be accessed via https://doi.org/10.11888/Atmos.tpdc.272763 (Yang and Jiang, 2022).

Evaluation of renal cortical echogenicity in healthy cats using anisotropic backscatter artifacts and echogenicity differences among internal organs

Background Renal cortical anisotropic backscatter artifact (CABA) is a hyperechoic region of the renal poles where the insonation of sound beams is perpendicular to the renal tubules within the renal cortex. Aims To determine whether renal CABA can be observed in healthy cats and to compare the echogenicity of renal CABA with that of the spleen and liver. Material and methods Images of the spleen, liver, kidneys, and urinary bladder were acquired from 30 clinically healthy cats with renal CABA. Echogenicity differences among organs and echo scores within urine were recorded and analyzed. All ultrasound images were acquired using a 7.2–14-MHz linear transducer. Univariate logistic regression was used to assess the associations between the presence of renal CABA and various variables. Results The prevalence of the renal CABA was 86.7% (26/30) and 93.3% (28/30) according to different observers. The reproducibility of renal CABA is substantial to excellent. The renal CABA echogenicity was greater or equal to the spleen and greater than the hepatic echogenicity in 90.0% of cats (27/30). For comparison with the spleen and liver, there were three and six combinations of echogenicity differences using the CABA and non-CABA regions, respectively. The renal cortical echogenicity in the CABA region was higher than the liver in all subjects. Renal CABA was not associated with age, body weight, gender, body condition score, or lipid droplets in the urinary bladder. Conclusion Renal CABA was present in most healthy cats and could be used for echogenicity comparisons with the liver and spleen.

ЕКОНОМІКО-ПРАВОВИЙ АСПЕКТ ОЦІНЮВАННЯ РЕЗУЛЬТАТИВНОСТІ Й ЕФЕКТИВНОСТІ РОЗБУДОВИ ФУНКЦІОНАЛЬНИХ ТИПІВ ТЕРИТОРІЙ УКРАЇНИ

Обґрунтовано економіко-правове забезпечення оцінювання соціально-економічної результативності й ефективності розбудови функціональних типів територій України. В умовах повномасштабної війни норми державної регіональної політики розробляються з використанням територіально орієнтованого і безпекового підходів, що передбачає визначення таких функціональних типів територій, як території відновлення, території з особливими умовами для розвитку, регіональні полюси зростання, території сталого розвитку. Віднесення макро- і мікрорегіонів, територіальних громад до того чи іншого функціонального типу територій залежить від показників їх соціально-економічного становища, з огляду на що їх когерентність встановлено за допомогою матричного підходу. Розроблено матрицю оцінки результативності й ефективності розбудови функціональних типів територій України і треки їх розвитку (повний і короткі). Зауважено про появу потенційно небезпечних територій і територій тимчасового невідновлення. Запропоновано два ключових індикатори для попереднього віднесення макро- і мікрорегіонів, територіальних громад до того чи іншого функціонального типу територій: коефіцієнт доцільності розбудови (відновлення і розвитку) територій після війни і коефіцієнт зменшення населення регіону або територіальної громади через війну. Для розбудови регіонів і територіальних громад передбачаються розроблення і реалізація програм комплексного відновлення регіону (області) й територій територіальних громад. Виокремлено індикатори (показники, характеристики), які відображають специфіку руйнувань, обґрунтовують доцільність і можливість відновлення територій у контексті програм їх комплексного відродження на основі чинного законодавства. Наголошено, що при цьому доречно визначити кількісні й якісні показники оцінки результативності та ефективності розбудови функціональних типів територій України з урахуванням впливу війни.

Optimal control of satellite system model using Linear Matrix inequality approach

In this paper, a robust control strategy has been proposed for the satellite attitude control system, namely, ℋ∞ with regional pole constraints. This design method has been applied to eliminate the effects of disturbances and uncertainties, which are inevitable in aerospace applications. A convex optimization approach using Linear Matrix Inequalities (LMIs) has been utilized in this work. The concept of LMI region constraints have been used to guarantee the closed-loop poles lie within a defined region in the complex plane, which helps improve performance in addition to the robustness properties. Therefore, the designed controller can be viewed as a multi-objective controller that guarantees both robustness and performance. Simulation results demonstrate that the developed controller (ℋ∞ with LMI region constraint) performs better than only ℋ∞ and pole placement controllers, in terms of disturbance attenuation, transient response, and control effort.

Optimal multi-site selection for a PV-based lunar settlement based on a novel method to estimate sun illumination profiles

Recently, space organizations have considered the Moon to host lunar bases. Such bases require power and energy to function. However, the efficient and safe use of the energy resources on the Moon is a huge challenge. Space photovoltaic (PV) power systems are appealing technologies due to their maturity and high solar energy availability at some locations on the Moon. The effectiveness of these PV systems depends on their selenographic location, which might necessitate the deployment of energy storage technologies to cover the base’s energy demand. Some analysts have proposed the installation of PV modules on kilometers-tall towers near the lunar poles to harvest more solar energy and limit the need for energy storage systems (ESSs). Alternatively, this paper proposes to harvest the energy from multiple sites in the lunar South Pole region using a novel technique to compute the Sun illumination profile and the LOLA topographic databases to compute the terrain elevations. The proposed algorithm seeks the most optimal configuration of sites and tower heights to minimize the longest night period and total distance between the sites. This study assesses groups of 1 to 6 sites assuming the use of towers having heights of 10, 100, and 500 [m]. The time horizon for the analysis is one Axial Precession Cycle, which is approximately 18.6 years. According to the results, a system of two sites with a separation of 42.05 [km] and towers of 500 [m] height has a maximum darkness period of only 3 [h] while another solution proposes a system of three sites with towers of 10 [m] that removes the need of EES (solar eclipse periods by the Earth are not considered). The proposed technique is suitable for engineering applications, such as base planning and operation management.

Driving Fatigue Effects on Cross-Frequency Phase Synchrony Embedding in Multilayer Brain Network

Driver fatigue has been intensively investigated for recent decades, nevertheless the underlying neural mechanism remains unclear. This study explored the cross-frequency coupling (CFC) between slow and fast oscillations in a multilayer brain network description of the functional brain network. Specifically, we compared the topological characteristics of the CFC embedded multilayer brain networks in the vigilant and fatigue states. From the 24-channel EEG recorded on 20 subjects, we found that the CFC of the fatigue state was elevated, especially in the beta-gamma coupling and in the frontal pole, frontal, and parietal regions. Results also revealed profound differences in the topology of the multilayer brain network between the vigilant and fatigue states, particularly the significant increases in the global and local efficiencies of the multilayer network in the fatigue state that were closely related to the behavioral performance, i.e., the reaction time. What is more, a graph neural network (GNN) was developed for imitating the features of the within-frequency sub-networks diffused through the CFC to detect fatigue with a satisfactory classification accuracy (96.23%). The proposed approach could enhance our understanding about neural coordination across frequencies in driver fatigue and would facilitate the fatigue-related studies for a better understanding about the underlying mechanism and ultimately a traffic accident reduction.

Prospective Longitudinal Perfusion in Probable Alzheimer's Disease Correlated with Atrophy in Temporal Lobe.

Reduced cerebral blood flow (CBF) in the temporoparietal region and gray matter volumes (GMVs) in the temporal lobe were previously reported in patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD). However, the temporal relationship between reductions in CBF and GMVs requires further investigation. This study sought to determine if reduced CBF is associated with reduced GMVs, or vice versa. Data came from 148 volunteers of the Cardiovascular Health Study Cognition Study (CHS-CS), including 58 normal controls (NC), 50 MCI, and 40 AD who had perfusion and structural MRIs during 2002-2003 (Time 2). Sixty-three of the 148 volunteers had follow-up perfusion and structural MRIs (Time 3). Forty out of the 63 volunteers received prior structural MRIs during 1997-1999 (Time 1). The relationships between GMVs and subsequent CBF changes, and between CBF and subsequent GMV changes were investigated. At Time 2, we observed smaller GMVs (p<0.05) in the temporal pole region in AD compared to NC and MCI. We also found associations between: (1) temporal pole GMVs at Time 2 and subsequent declines in CBF in this region (p=0.0014) and in the temporoparietal region (p=0.0032); (2) hippocampal GMVs at Time 2 and subsequent declines in CBF in the temporoparietal region (p=0.012); and (3) temporal pole CBF at Time 2 and subsequent changes in GMV in this region (p = 0.011). Therefore, hypoperfusion in the temporal pole may be an early event driving its atrophy. Perfusion declines in the temporoparietal and temporal pole follow atrophy in this temporal pole region.

Human amygdala compared to orbitofrontal cortex connectivity, and emotion.

The amygdala and orbitofrontal cortex have been implicated in emotion. To understand these regions better in humans, their effective connectivity with 360 cortical regions was measured in 171 humans from the Human Connectome Project, and complemented with functional connectivity and diffusion tractography. The human amygdala has effective connectivity from few cortical regions compared to the orbitofrontal cortex: primarily from auditory cortex A5 and the related superior temporal gyrus and temporal pole regions; the piriform (olfactory) cortex; the lateral orbitofrontal cortex 47m; somatosensory cortex; the hippocampus, entorhinal cortex, perirhinal cortex, and parahippocampal TF; and from the cholinergic nucleus basalis. The amygdala has effective connectivity to the hippocampus, entorhinal and perirhinal cortex; to the temporal pole; and to the lateral orbitofrontal cortex. The orbitofrontal cortex has effective connectivity from gustatory, olfactory, and temporal visual, auditory and pole cortex, and to the pregenual anterior and posterior cingulate cortex, hippocampal system, and prefrontal cortex, and provides for rewards and punishers to be used in reported emotions, and memory and navigation to goals. Given the paucity of amygdalo-neocortical connectivity in humans, it is proposed that the human amygdala is involved primarily in autonomic and conditioned responses via brainstem connectivity, rather than in reported (declarative) emotion.

Atmospheric and Surface Processes, and Feedback Mechanisms Determining Arctic Amplification: A Review of First Results and Prospects of the (AC)3 Project

Abstract Mechanisms behind the phenomenon of Arctic amplification are widely discussed. To contribute to this debate, the (AC)3 project was established in 2016 (www.ac3-tr.de/). It comprises modeling and data analysis efforts as well as observational elements. The project has assembled a wealth of ground-based, airborne, shipborne, and satellite data of physical, chemical, and meteorological properties of the Arctic atmosphere, cryosphere, and upper ocean that are available for the Arctic climate research community. Short-term changes and indications of long-term trends in Arctic climate parameters have been detected using existing and new data. For example, a distinct atmospheric moistening, an increase of regional storm activities, an amplified winter warming in the Svalbard and North Pole regions, and a decrease of sea ice thickness in the Fram Strait and of snow depth on sea ice have been identified. A positive trend of tropospheric bromine monoxide (BrO) column densities during polar spring was verified. Local marine/biogenic sources for cloud condensation nuclei and ice nucleating particles were found. Atmospheric–ocean and radiative transfer models were advanced by applying new parameterizations of surface albedo, cloud droplet activation, convective plumes and related processes over leads, and turbulent transfer coefficients for stable surface layers. Four modes of the surface radiative energy budget were explored and reproduced by simulations. To advance the future synthesis of the results, cross-cutting activities are being developed aiming to answer key questions in four focus areas: lapse rate feedback, surface processes, Arctic mixed-phase clouds, and airmass transport and transformation.

Molecular Dynamics Study on the Structure-Property Relationship of Self-Assembled Gear-Shaped Amphiphile Molecules with/without Methyl Groups.

Gaining insight into the encapsulation mechanism is important for controlling the encapsulation rate toward the self-assembly of gear-shaped amphiphile molecules (GSAs). To this aim, we conducted molecular dynamics (MD) simulations for three different hexameric nanocubes (1612+, 2612+, and 3612+) of GSAs (12+, 22+, and 32+, respectively) to elucidate the quantitative structure-property relationship between the stability of the nanocubes and the rate of encapsulation of a guest molecule. The 12+, 22+, and 32+ monomers differ from each other in the number of methyl groups, having three, zero, and two methyl groups, respectively. The 3612+ hexamer has methyl groups only on the equatorial region. In the cases of the simulations of 1612+ and 3612+, the cubic structures are maintained due to a tight triple-π stacking around the equator region. Meanwhile, 2612+ deforms easily due to the occurrence of a large fluctuation. These results indicate that the methyl groups on the equator are crucial to stabilize the nanocubes. The encapsulation of an iodide ion as a guest molecule is revealed to occur through the pole region via a gap that is easily formed in the nanocubes without methyl groups on the poles. Our study clearly suggests that self-assembled nanocubes can be designed to attain a specific stability and encapsulation efficiency simultaneously.

The Distribution and Accessibility of Geologic Targets near the Lunar South Pole and Candidate Artemis Landing Sites

Transformative lunar science will be driven by the accessibility, recovery, and return to Earth of geological specimens. Isolated boulders, rock exposures, and rocky craters at the lunar south pole all provide opportunities for geologic characterization and sampling of the lunar crust. Here, we present the results of orbital geological mapping of the region surrounding the south pole using Lunar Reconnaissance Orbiter Narrow Angle Camera images (0.5–2 m pixel−1). We mapped the distribution of isolated boulders (86,896), rocky craters (3556), and rock exposures (7553) around potential Artemis landing sites 001 and 004 (NASA 2020), which are within or near one of the Artemis III candidate landing regions. We found that boulder abundance decreases with increasing distance from the rim of Shackleton crater. From that correlation, we infer that most of the boulders and rock exposures near Shackleton were deposited as ejecta by the Shackleton impact, and by later the reworking of that material during smaller impact events. We additionally assessed the accessibility of the mapped features, and documented geologic targets located on shallow (<15°) slopes, including those on the Shackleton crater rim and on the “Connecting Ridge” between Shackleton and Henson crater. Such targets could be sampled by a future mission to the lunar south pole region. Our catalog of mapped features is made available to the lunar community.

Towards Ensemble-Based Kilometer-Scale Climate Simulations over the Third Pole Region

The Tibetan Plateau and its surrounding mountains have an average elevation of 4,400 m and a glaciated area of $$\sim $$ 100,000 $$\hbox {km}^{2}$$ giving it the name “Third Pole (TP) region”. The TP is the headwater of many major rivers in Asia that provide fresh water to hundreds of millions of people. Climate change is altering the energy and water cycle of the TP at a record pace but the future of this region is highly uncertain due to major challenges in simulating weather and climate processes in this complex area. The Convection-Permitting Third Pole (CPTP) project is a Coordinated Regional Downscaling Experiment (CORDEX) Flagship Pilot Study (FPS) that aims to revolutionize our understanding of climate change impacts on the TP through ensemble-based, kilometer-scale climate modeling. Here we present the experimental design and first results from multi-model, multi-physics ensemble simulations of three case studies. The five participating modeling systems show high performance across a range of meteorological situations and are close to having ”observational quality” in simulating precipitation and near-surface temperature. This is partly due to the large differences between observational datasets in this region, which are the leading source of uncertainty in model evaluations. However, a systematic cold bias above 2000 m exists in most modeling systems. Model physics sensitivity tests performed with the Weather Research and Forecasting (WRF) model show that planetary boundary layer (PBL) physics and microphysics contribute equally to model uncertainties. Additionally, larger domains result in better model performance. We conclude by describing high-priority research needs and the next steps in the CPTP project.

Examining Spatio-Temporal Dynamics of Ecological Quality in the Pan-Third Pole Region in the Past 20 Years

Examining the ecology quality of the Pan-Third Pole region has implications for global environmental change and sustainable development. However, spatio-temporal evolution of ecological quality in this region is still lacking. In this study, 65 countries of the Pan-Third Pole region were selected. A comprehensive evaluation index system of ecological quality was constructed using a dataset containing remote sensing, ecological environment and socio-economic data to spatially quantify the ecological quality, as well as its change from 2000 to 2020. The results displayed that the average ecological quality of the Pan-Third Pole region was at a moderate level of 0.53. Spatially, the excellent ecological quality regions were mainly concentrated in East Asian countries, while the severe quality regions were located in the Middle East. From 2000–2020, areas with improved ecological changes accounted for 38.48% of the total area, and 10.66% of the total area experienced a decline; specifically, European countries had a large proportion of improved ecological quality areas, while East Asian countries had a significantly larger proportion of declining ecological quality areas. We also found that ecosystem changes and human activities had an influence on ecological quality in the Pan-Third Pole region. This study provides an important empirical study on ecosystem services in the region.

Air Pollutant Emissions from Residential Solid Fuel Combustion in the Pan-Third Pole Region.

As the largest emission source in the Pan-Third Pole region, residential solid fuel combustion gains increasing public concern regarding air pollution-associated health impacts. This study firstly developed emission inventories by combining energy statistics, fuel-mix survey, and detailed emission factors considering different fuel types, stove types, and altitudes, and we achieved full regional coverage and increased spatial resolution from 9 × 9 km to 1 km × 1 km. Total CO2, CO, PM2.5, SO2, and NOx emissions (coefficient of variation) were estimated to be 823 Mt (24%), 53 Mt (28%), 4525 kt (48%), 1388 kt (55%), and 1275 kt (46%) in 2020. India, Pakistan, and Bangladesh combined contributed 73, 57, 65, 67, and 69% of total CO2, CO, PM2.5, SO2, and NOx emissions, respectively, due to the large population. The Qinghai-Tibet Plateau had the second-highest emission intensity, mainly due to the high fuel consumption per capita. Unlike the emissions of the Pan-Third Pole in existing Asian inventories, dung cake combustion dominated total PM2.5, SO2, and NOx emissions rather than firewood combustion with proportions of 54, 70, and 67%, respectively. The effect of altitude on combustion efficiencies increased PM2.5 emissions by about 21% from the region. The method and results can provide technical guidance for emission inventory refinement in the Pan-Third Pole and other regions.

Fuzzy model based fault estimation and fault tolerant control for flexible spacecraft with unmeasurable vibration modes

This paper investigates the problem of anti-disturbance fault estimation and attitude tracking fault tolerant control for a flexible spacecraft subject to actuator faults, external disturbances, input saturation, and configuration misalignment. Different form the traditional methods, both the nonlinear dynamics subsystem and attitude control system are reconstructed into Takagi–Sugeno fuzzy models, where partial nonlinear term is remained to assist the design of fuzzy controller. A fuzzy fault estimation observer with proportional–integral adaptive laws is first designed. Without measuring any dynamic information of flexible appendages, estimated values of unknown actuator faults and vibration disturbances of flexible appendages can be obtained simultaneously. This is the most important advantage of the proposed fault estimation scheme over the previous methods. Then, a fuzzy sliding mode fault tolerant control scheme, based on fewer fuzzy rules and less computational burden, is developed under the framework of feedback linearisation and feedforward compensation. The actuator faults and vibration disturbances are counteracted in real time. Regional pole placement and virtual controller with input saturation are adopted to tune the control input and avoid the radical control torque scheduling. Finally, numerical simulations are given to illustrate the validity of the proposed fault estimation and fault tolerant control strategies.