The distinctive conditions present on the north and south slopes of Mount Qomolangma,along with the intricate variations in the underlying surfaces,result in notable variations in the surface energy flux patterns of t...The distinctive conditions present on the north and south slopes of Mount Qomolangma,along with the intricate variations in the underlying surfaces,result in notable variations in the surface energy flux patterns of the two slopes.In this paper,data from TESEBS(Topographical Enhanced Surface Energy Balance System),remote sensing data from eight cloud-free scenarios,and observational data from nine stations are utilized to examine the fluctuations in the surface heat flux on both slopes.The inclusion of MCD43A3 satellite data enhances the surface albedo,contributing to more accurate simulation outcomes.The model results are validated using observational data.The RMSEs of the net radiation,ground heat,sensible heat,and latent heat flux are 40.73,17.09,33.26,and 30.91 W m^(−2),respectively.The net radiation flux is greater on the south slope and exhibits a rapid decline from summer to autumn.Due to the influence of the monsoon,on the north slope,the maximum sensible heat flux occurs in the pre-monsoon period in summer and the maximum latent heat flux occurs during the monsoon.The south slope experiences the highest latent heat flux in summer.The dominant flux on the north slope is sensible heat,while it is latent heat on the south slope.The seasonal variations in the ground heat flux are more pronounced on the south slope than on the north slope.Except in summer,the ground heat flux on the north slope surpasses that on the south slope.展开更多
The continuous pursuit for a better quality of life promotes continuous advancements in intelligent technology.Flexible wearable and implantable bioelectronics have emerged as an innovative complement to rigid materia...The continuous pursuit for a better quality of life promotes continuous advancements in intelligent technology.Flexible wearable and implantable bioelectronics have emerged as an innovative complement to rigid material-based electronic devices[1-3].Due to their distinct advantages in terms of ductile,ultrathin,and biocompatible features,these elastic and soft bioelectronic devices can be seamlessly mounted onto various real or artificial tissues and organs.展开更多
The integration of artificial intelli-gence(AI)into chemical engineering marks a transformative era,redefin-ing traditional methodologies with AI-driven approaches.AI has emerged as a powerful ally in tackling complex...The integration of artificial intelli-gence(AI)into chemical engineering marks a transformative era,redefin-ing traditional methodologies with AI-driven approaches.AI has emerged as a powerful ally in tackling complex problems once considered insur-mountable.As chemical engineering grapples with increasingly complex systems and stringent sustainability targets,AI sets the stage for a new generation of solutions.展开更多
This paper presents a systematic methodology for analyzing and optimizing an innovative antenna mount designed for phased array antennas, implemented through a novel 2-PSS&1-RR circular-rail parallel mechanism. In...This paper presents a systematic methodology for analyzing and optimizing an innovative antenna mount designed for phased array antennas, implemented through a novel 2-PSS&1-RR circular-rail parallel mechanism. Initially, a comparative motion analysis between the 3D model of the mount and its full-scale prototype is conducted to validate effectiveness. Given the inherent complexity, a kinematic mapping model is established between the mount and the crank-slider linkage, providing a guiding framework for subsequent analysis and optimization. Guided by this model, feasible inverse and forward solutions are derived, enabling precise identification of stiffness singularities. The concept of singularity distance is thus introduced to reflect the structural stiffness of the mount. Subsequently, also guided by the mapping model, a heuristic algorithm incorporating two backtracking procedures is developed to reduce the mount's mass. Additionally, a parametric finite-element model is employed to explore the relation between singularity distance and structural stiffness. The results indicate a significant reduction(about 16%) in the antenna mount's mass through the developed algorithm, while highlighting the singularity distance as an effective stiffness indicator for this type of antenna mount.展开更多
The main aim of this study is to explain periglacial processes on the summits of Mount Honaz(2571 m a.s.l.),define periglacial landforms,and determine the relationships between morphometric features and topographic fa...The main aim of this study is to explain periglacial processes on the summits of Mount Honaz(2571 m a.s.l.),define periglacial landforms,and determine the relationships between morphometric features and topographic factors.Mud circles,stony earth circles,non sorted steps,and non sorted stripes were identified on the summits of Mount Honaz.Pearson's correlation coefficient(r)and linear regression analyses were performed by taking metric measurements from 125 periglacial landforms to describe their morphometric features(length,width,height)of periglacial landforms and explain the relationships between them and topographic factors(elevation,slope).To explain the relationships between periglacial landforms and soil properties,soil samples from 11 periglacial landforms were taken and analysed.Periglacial landforms,which continue to develop on the summits of Mount Honaz today,have been evaluated with present climate data.Analysis of soil samples indicates a notable impact of parent material on the genesis of periglacial landforms.The high ratio of organic matter in mud circle and non sorted step landforms and the high lime ratio in stony earth circle landforms prove a strong relationship between the formation mechanisms of landforms and the soil properties.Furthermore,it is consistent with the findings obtained from the analysis that severe periglacial processes and washing and scavenging events are experienced more on the northern slopes.展开更多
Climate warming profoundly affects plant biodiversity, community productivity, and soil properties in alpine and subalpine grassland ecosystems. However, these effects are poorly understood across elevational gradient...Climate warming profoundly affects plant biodiversity, community productivity, and soil properties in alpine and subalpine grassland ecosystems. However, these effects are poorly understood across elevational gradients in subalpine meadow ecosystems. To reveal the elevational patterns of warming effects on plant biodiversity, community structure, productivity, and soil properties, we conducted a warming experiment using open-top chambers from August 2019 to August 2022 at high(2764 m a. s. l.), medium(2631 m a. s. l.), and low(2544 m a. s. l.) elevational gradients on a subalpine meadow slope of Mount Wutai, Northern China. Our results showed that three years of warming significantly increased topsoil temperature but significantly decreased topsoil moisture at all elevations(P<0.05), and the percentage of increasing temperature and decreasing moisture both gradually raised with elevation lifting. Warming-induced decreasing proportions of soil organic carbon(SOC, by 19.24%), and total nitrogen(TN, by 24.56%) were the greatest at high elevational gradients. Experimental warming did not affect topsoil C: N, p H, NO_(3)^(-)-N, or NH_(4)^(+)-N at the three elevational gradients. Warming significantly increased species richness(P<0.01) and Shannon-Weiner index(P<0.05) at low elevational gradients but significantly decreased belowground biomass(P<0.05) at a depth of 0–10 cm at three elevational gradients. Warming caused significant increases in the aboveground biomass in the three elevational plots. Warming significantly increased the aboveground biomass of graminoids in medium(by 92.47%) and low(by 98.25%) elevational gradients, that of sedges in high(by 72.44%) and medium(by 57.16%) elevational plots, and that of forbs in high(by 75.88%), medium(by 34.38%), and low(by 74.95%) elevational plots. Species richness had significant linear correlations with SOC, TN, and C: N(P<0.05), but significant nonlinear responses to soil temperature and soil moisture in the warmed treatment(P<0.05). The warmed aboveground biomass had a significant nonlinear response to soil temperature and significant linear responses to soil moisture(P<0.05). This study provided evidence that altitude is a factor in sensitivity to climate warming, and these different parameters(e.g., plant species richness, Shannon-Weiner index, soil temperature, soil moisture, SOC, and TN) can be used to measure this sensitivity.展开更多
The impact of structural stiffness on optical axis deviation poses a significant challenge in the design of equatorial telescope structures.A comprehensive analysis during the design process can reduce the reliance of...The impact of structural stiffness on optical axis deviation poses a significant challenge in the design of equatorial telescope structures.A comprehensive analysis during the design process can reduce the reliance of a telescope on advanced control technologies,thereby improving its economic feasibility.Although full-system finite element analyses are reliable,they are encumbered by significant time requirements and limitations in covering all possible telescope orientations.Therefore,we propose an efficient and comprehensive analytical method to evaluate the optical axis deviation of equatorial telescopes across a full range of angles.To address the challenge of ensuring that the analysis covers all possible positions of an equatorial telescope,based on a model from SiTian project,we analyze the optical axis deviations caused by the fork arm at 25 different angles and then use fitting methods to obtain results for all angles.Based on the analysis results of the optical axis deviation caused by the stiffness of the optical tube in the horizontal position,we derive the results for the tube at any position using geometric relationships.Finally,we calculate the coupling factors and combine these impacts.Furthermore,we identify six discrete feature points to reflect possible telescope orientations and conduct comprehensive finite element analyses.The results are in alignment with those acquired through a comprehensive computational approach.展开更多
Ash-rich pyroclastic flows from the cataclysmic eruption of Mount Mazama (~7700 yr. B. P.), Cascade volcanic arc, Oregon, entered and blocked the narrow, bedrock-lined canyon of the Williamson River approximately 35 t...Ash-rich pyroclastic flows from the cataclysmic eruption of Mount Mazama (~7700 yr. B. P.), Cascade volcanic arc, Oregon, entered and blocked the narrow, bedrock-lined canyon of the Williamson River approximately 35 to 44 km from the source volcano. The blockage impounded a body of water which then released producing four stratigraphic units in the downstream debris fan. The four stratigraphic units are a boulder core comprised of locally sourced bedrock boulders and three sand-rich units including a fine-grained sand unit, a sandy pumice gravel (±basalt/hydrovolcanic tuff) unit, and a pumice pebble-bearing, crystal-rich sand unit. Hand-drilled auger holes up to ~1.6 m deep were used to obtain samples of the sand-rich units. Units were delimited using surface and down-hole observations, composition and texture, estimated density, statistical parameters of grain size, and vertical and lateral distribution of properties. Overtopping followed by rapid incision into the ash-rich pyroclastic flows progressively cleared the canyon, but a bedrock knickpoint near the head of the canyon limited the volume of debris available for transport to about 0.04 km<sup>3</sup> to 0.08 km<sup>3</sup>. Co-deposition of bedrock boulders and lithic-rich sand was followed by rapid deposition with minimal reworking of remobilized pyroclastics. Continued draining of the impounded lake sent hyperconcentrated flows onto the debris fan depositing pumice-rich gravels that graded upward to crystal-rich sands.展开更多
Amid gloomy forecasts for the global economy in 2024,news of China’s 5.2 percent GDP growth in 2023 was a shot in the arm for a world still beset with regional conflicts,lackluster economic recovery,and mounting geop...Amid gloomy forecasts for the global economy in 2024,news of China’s 5.2 percent GDP growth in 2023 was a shot in the arm for a world still beset with regional conflicts,lackluster economic recovery,and mounting geopolitical tension.But despite this outstanding economic performance,dire predictions,and assumptions that China’s economy is on the verge of collapse continued to dominate some Western media portals.Certain Western media obstinately dwell on the so-called economic“strains”on China’s economy,despite evidence to the contrary in the National Bureau of Statistics(NBS)of China’s January 17 release of this data.展开更多
Captain Qomolangma Director:Wu Xi Length:One Episode Producer:Mountain Climbing Films,Emei Film Group Broadcasting Platforms:Migu Video,bilibili Sula Wangping was born in a small village at the foot of Mount San’ao i...Captain Qomolangma Director:Wu Xi Length:One Episode Producer:Mountain Climbing Films,Emei Film Group Broadcasting Platforms:Migu Video,bilibili Sula Wangping was born in a small village at the foot of Mount San’ao in southeastern China’s Sichuan Province.More than 20 years ago,he participated in an expedition to San’ao with China’s national mountaineering team.Being amazed by the grandeur of the snow-capped mountain and obssessed with the exhilaration of climbing,he decided to pursue climbing as a professional career.In June 2019,he led eight amateur mountaineers to the summit of Mount Qomolangma.After overcoming hardships in extreme cold conditions,they became the world’s first team to reach the top of the mountain in 2019.展开更多
The presented research illustrates the applicability and productiveness of the systematic literature review methodology, a non-empirical methodology in the geological sciences, particularly volcanology. The systematic...The presented research illustrates the applicability and productiveness of the systematic literature review methodology, a non-empirical methodology in the geological sciences, particularly volcanology. The systematic literature review methodology is a replicable, rigorous, and transparent methodology for synthesizing existing literature to answer questions on a specific topic. The synthesis allows for knowledge consolidation, such as identifying knowledge gaps. In our illustration of this methodology, we focused on the expanding knowledge about the magma pathway at Mount Cameroon, one of Africa’s active volcanoes. Our synthesis of the relevant international geoscience research literature is based on the framework of knowledge about the magma pathway beneath a typical basaltic volcano. The framework has three primary components: magma supply, storage, and transport to erupting vents. Across these components is a total of twelve secondary components. The result is a previously non-existent and fragmented overall understanding of the magma pathway at Mount Cameroon. The gaps in the understanding (such as in the magma supply rates, timescales of chamber processes, and magma ascent rates) may be addressed in future research. Another key implication of the presented research lies in the proof of concept of the systematic literature review methodology as an applicable qualitative research methodology in the study of volcanoes.展开更多
Approximately 2,000,000 people are exposed to volcanic risks in communities situated at the flanks of Mounts Cameroon (MC) and Nyiragongo (MN) volcanoes in Central Africa. This study therefore sought to investigate ri...Approximately 2,000,000 people are exposed to volcanic risks in communities situated at the flanks of Mounts Cameroon (MC) and Nyiragongo (MN) volcanoes in Central Africa. This study therefore sought to investigate risk perception from four previous eruptions of MC, namely the 1959, 1982, 1999, and 2000 eruptions;and two previous eruptions of MN: 1977 and 2002. The study was initiated with co-design workshops held with major stakeholders in the cities of Buea and Goma at the flanks of MC and MN, respectively, in 2017, to develop the research objectives for the study. A non-random questionnaire survey was later conducted within 14 and 15 communities in Buea and Goma respectively, on the effects, perceived risks, and coping strategies for the chosen eruptions. Three age groups (18 - 30, 31 - 45 and >45 years) and gender (male and female) were considered. The population at the flanks of both volcanoes cited scientific and indigenous factors to be responsible for eruptions from these volcanoes. At MC and MN, ≥45% of the sampled participants (with a higher female population) perceived that the sampled eruptions posed a very high risk to the population. In terms of the effects, the age group of 18 - 30 was the least knowledgeable. In terms of direct effect on persons, over 90% of participants at MC and MN attested that they were overcome by fear/panic. On measures to cope with any likely eruption, the following order was established at the flanks of both volcanoes: sensitization of population, use of religious (prayers) and of traditional/indigenous strategies. In terms of future coping strategies, while the males at MC maintained sensitization as the favourite option, 62% of the males at MN opted for traditional/indigenous strategies. The female population at both MC and MN showed a higher preference for religious strategies like prayers.展开更多
When talking about rich places on the Qinghai-Xizang Plateau,we should not ignore Lhodrak in Shannan.With the popularity of Mount Kula Kangri,Lhodrak has become famous for its high mountains,lakes,and glaciers in the ...When talking about rich places on the Qinghai-Xizang Plateau,we should not ignore Lhodrak in Shannan.With the popularity of Mount Kula Kangri,Lhodrak has become famous for its high mountains,lakes,and glaciers in the Himalayas Mountains like"a place in the clouds".展开更多
Lakes that resemble mirrors and jade,ancient temples,and Mount Qomolangma soaring into the clouds...If you want to experience the unique folk culture of Xizang,you can head west to Xigaze,the hometown of Mount Qomolan...Lakes that resemble mirrors and jade,ancient temples,and Mount Qomolangma soaring into the clouds...If you want to experience the unique folk culture of Xizang,you can head west to Xigaze,the hometown of Mount Qomolangma.展开更多
Mount Fanjing Mount Fanjing,located in the eastern Guizhou Province of China,is the highest peak of the Wuling Mountains.Spanning altitude between 500 metres to 2,570 metres above sea level and covering an area of ove...Mount Fanjing Mount Fanjing,located in the eastern Guizhou Province of China,is the highest peak of the Wuling Mountains.Spanning altitude between 500 metres to 2,570 metres above sea level and covering an area of over 775 square km,it emerges as an island of metamorphic rock amid a sea of karst.Established as a nature reserve in 1978 and later designated as a UNESCO Biosphere Reserve in 1986,Mount Fanjing earned further recognition as a UNESCO World Heritage Site in 2018.Mount Fanjing is much taller than it is wide,a vertical pinnacle that resembles a pencil standing on a desk.To reach the top,visitors have to ascend more than 8,000 steps or take a cable car ride up from the road below.展开更多
South Korea's Jeju Island has a lot of natural beauty.Millions of people visit the island each year.Climbing Mount Hallasan is a popular activity.At 1,950 meters,it's the highest mountain in South Korea.It is ...South Korea's Jeju Island has a lot of natural beauty.Millions of people visit the island each year.Climbing Mount Hallasan is a popular activity.At 1,950 meters,it's the highest mountain in South Korea.It is possible to hike all the way to the top and back in one day.展开更多
According to observational daily temperature data from the meteorological stations during 1971-2020,the variations of the extreme temperature event in the Mount Qomolangma(also known as Mount Everest) region in China ...According to observational daily temperature data from the meteorological stations during 1971-2020,the variations of the extreme temperature event in the Mount Qomolangma(also known as Mount Everest) region in China have been analyzed using statistical methods.The extreme temperature indices recommended by the World Meteorological Organization are selected to describe the extreme temperature event.The RClimDEX 1.0 software is used to calculate the extreme temperature indices.There are no tropical nights,and just three summer days at the last 50 years.The frost days are the main extreme temperature events all year round.The temperature in the north slope is more extreme than that in the south slope of the Mount Qomolangma.There is remarkable decadal variation for the extreme temperature indices except diurnal temperature range.There are the warm extremes increasing,however,the cold extremes decreasing with the decadal lapse,which is more remarkable into the 21^(th) century.The tendencies for the extreme temperature indices in the north slope are consistent with those in the south slope.There are statistically significant trends for most extreme temperature indices during the study period.It shows that the warm extremes would be more prominent in the future with the global continued warming.The abrupt changes of the extreme temperature index have occurred mainly in the 20^(th) century especially from the mid to late 1980s and 1990s.The periodic changes in the south slope do not synchronize those in the north slope for the most extreme temperature indices.It is different for most extreme temperature indices between the south and north slope,which has demonstrated that the regional or local changes are not neglectable for extreme temperature research.The results of this study are also the consistent response of extreme temperature event to the global warming.展开更多
Field surveys and empirical integrated methods are commonly used in the ecological research to understand the altitudinal pattern of plant diversity of mountains.However,few studies have compared the differences betwe...Field surveys and empirical integrated methods are commonly used in the ecological research to understand the altitudinal pattern of plant diversity of mountains.However,few studies have compared the differences between the two methods on the same scale.Here,we addressed and compared the altitudinal patterns of species richness(SR),phylogenetic diversity(PD),the standardized effect size of phylogenetic diversity(PDses)and mean phylogenetic distance(MPDses)of about 580 angiosperms growing on Mount Kenya from two independent datasets:one is based on our several times field surveys in this mountain and another one is based on empirical data integrated from literatures.We found that the altitudinal diversity patterns of field surveys dataset were consistent with the empirical integrated dataset.Both SR and PD showed hump-shaped patterns along the altitude,and both PDses and MPDses showed monotonically decreasing patterns along the altitude.The ratio of diversity between field surveys dataset and empirical integrated dataset were gradually increase along the altitude.Our research provides new insight for understanding the altitudinal diversity patterns of plants of a tropical mountain.展开更多
Dear Editor,Physical injury and tissue damage are prevalent throughout the animal kingdom,with the ability to regenerate quickly and efficiently providing a selective advantage.In most vertebrates,skeletal muscle poss...Dear Editor,Physical injury and tissue damage are prevalent throughout the animal kingdom,with the ability to regenerate quickly and efficiently providing a selective advantage.In most vertebrates,skeletal muscle possesses a remarkable ability to regenerate,making it a valuable model for investigating the cellular processes underpinning tissue regeneration.Following damage,skeletal muscle mounts a complex regenerative cascade centered around dedicated muscle stem cells,i.e.,satellite cells.These satellite cells are,in turn,regulated by both resident and infiltrating innate immune cells of myeloid lineage,which play a crucial role in activating and guiding the transition of satellite cells towards maturation(Chen et al.,2020;Tidball,2017;Tidball&Villalta,2010).While critical for muscle regeneration,the innate immune system is energetically costly,resulting in many species decreasing immune investment under nutrient-limited environments.Whether this reduced investment results in a decreased capacity to mount a regenerative response following tissue damage remains unclear.Here,we utilized an emerging evolutionary model,the Mexican tetra(Astyanax mexicanus),to investigate the consequences of shifts in immune system investment on skeletal muscle regeneration.展开更多
K-Ar dating of synkinematic illite is increasingly recognized as a central method to constrain the timing of shallow crustal faulting.Methods of efficient sample preparation and quantitative identification of illite p...K-Ar dating of synkinematic illite is increasingly recognized as a central method to constrain the timing of shallow crustal faulting.Methods of efficient sample preparation and quantitative identification of illite polytypes are critical to acquiring K-Ar isotope data for authigenic clays.In this respect,we compared the commonly used clay size separation method through centrifugation with vacuum filtration technology,showing that the former is prone to extract fractions with finer particle sizes under similar conditions,thus improving the error in the authigenic end-member age.Additionally,we demonstrated that the side-packed mounting method for X-ray diffraction analysis can significantly enhance the randomness in powder samples,thus improving the quantification accuracy compared with the front-packed and back-packed methods.The validity of our quantification method was confirmed by comparing Profex■modeling patterns with a suite of synthetic mixtures of known compositions,yielding an average analytical error of 3%.Dating results of these artificial mixtures and the reference materials indicated that a large range in percentages of detrital illite and a sufficient amount of age data will produce reliable results for ages of both extrapolated end-members.However,if the range is limited,the extrapolated age close to those of datasets is still reliable.展开更多
基金financially supported by the National Natural Science Foundation of China[grant number 42230610]the Second Tibetan Plateau Scientific Expedition and Research(STEP)program[grant number 2019QZKK0103]+1 种基金the Natural Science Foundation of Sichuan Province[grant number 2022NSFSC0217]the Scientific Research Project of Chengdu University of Information Technology[grant number KYTZ201721].
文摘The distinctive conditions present on the north and south slopes of Mount Qomolangma,along with the intricate variations in the underlying surfaces,result in notable variations in the surface energy flux patterns of the two slopes.In this paper,data from TESEBS(Topographical Enhanced Surface Energy Balance System),remote sensing data from eight cloud-free scenarios,and observational data from nine stations are utilized to examine the fluctuations in the surface heat flux on both slopes.The inclusion of MCD43A3 satellite data enhances the surface albedo,contributing to more accurate simulation outcomes.The model results are validated using observational data.The RMSEs of the net radiation,ground heat,sensible heat,and latent heat flux are 40.73,17.09,33.26,and 30.91 W m^(−2),respectively.The net radiation flux is greater on the south slope and exhibits a rapid decline from summer to autumn.Due to the influence of the monsoon,on the north slope,the maximum sensible heat flux occurs in the pre-monsoon period in summer and the maximum latent heat flux occurs during the monsoon.The south slope experiences the highest latent heat flux in summer.The dominant flux on the north slope is sensible heat,while it is latent heat on the south slope.The seasonal variations in the ground heat flux are more pronounced on the south slope than on the north slope.Except in summer,the ground heat flux on the north slope surpasses that on the south slope.
文摘The continuous pursuit for a better quality of life promotes continuous advancements in intelligent technology.Flexible wearable and implantable bioelectronics have emerged as an innovative complement to rigid material-based electronic devices[1-3].Due to their distinct advantages in terms of ductile,ultrathin,and biocompatible features,these elastic and soft bioelectronic devices can be seamlessly mounted onto various real or artificial tissues and organs.
文摘The integration of artificial intelli-gence(AI)into chemical engineering marks a transformative era,redefin-ing traditional methodologies with AI-driven approaches.AI has emerged as a powerful ally in tackling complex problems once considered insur-mountable.As chemical engineering grapples with increasingly complex systems and stringent sustainability targets,AI sets the stage for a new generation of solutions.
基金financed by the National Key Research and Development Program of China,High efficiency space satellite charging system based on microwave wireless energy transfer technology(Grant No.2021YFB3900304)。
文摘This paper presents a systematic methodology for analyzing and optimizing an innovative antenna mount designed for phased array antennas, implemented through a novel 2-PSS&1-RR circular-rail parallel mechanism. Initially, a comparative motion analysis between the 3D model of the mount and its full-scale prototype is conducted to validate effectiveness. Given the inherent complexity, a kinematic mapping model is established between the mount and the crank-slider linkage, providing a guiding framework for subsequent analysis and optimization. Guided by this model, feasible inverse and forward solutions are derived, enabling precise identification of stiffness singularities. The concept of singularity distance is thus introduced to reflect the structural stiffness of the mount. Subsequently, also guided by the mapping model, a heuristic algorithm incorporating two backtracking procedures is developed to reduce the mount's mass. Additionally, a parametric finite-element model is employed to explore the relation between singularity distance and structural stiffness. The results indicate a significant reduction(about 16%) in the antenna mount's mass through the developed algorithm, while highlighting the singularity distance as an effective stiffness indicator for this type of antenna mount.
基金produced from the responsible author's master's thesis titled“Periglacial geomorphology of Mount Honaz(Denizli)”,prepared at BilecikŞeyh Edebali University,Social Sciences Institute in 2019.
文摘The main aim of this study is to explain periglacial processes on the summits of Mount Honaz(2571 m a.s.l.),define periglacial landforms,and determine the relationships between morphometric features and topographic factors.Mud circles,stony earth circles,non sorted steps,and non sorted stripes were identified on the summits of Mount Honaz.Pearson's correlation coefficient(r)and linear regression analyses were performed by taking metric measurements from 125 periglacial landforms to describe their morphometric features(length,width,height)of periglacial landforms and explain the relationships between them and topographic factors(elevation,slope).To explain the relationships between periglacial landforms and soil properties,soil samples from 11 periglacial landforms were taken and analysed.Periglacial landforms,which continue to develop on the summits of Mount Honaz today,have been evaluated with present climate data.Analysis of soil samples indicates a notable impact of parent material on the genesis of periglacial landforms.The high ratio of organic matter in mud circle and non sorted step landforms and the high lime ratio in stony earth circle landforms prove a strong relationship between the formation mechanisms of landforms and the soil properties.Furthermore,it is consistent with the findings obtained from the analysis that severe periglacial processes and washing and scavenging events are experienced more on the northern slopes.
基金carried out in the framework of the 1331 Project of Cultural Ecology Collaborative Innovation Center in Wutai Mountain (00000342)co-financed by Program for the Philosophy and Social Sciences Research of Higher Learning Institutions of Shanxi (2022J027)+1 种基金Applied Basic Research Project of Shanxi Province (202203021221225)Basic Research Project of Xinzhou Science and Technology Bureau (20230501)。
文摘Climate warming profoundly affects plant biodiversity, community productivity, and soil properties in alpine and subalpine grassland ecosystems. However, these effects are poorly understood across elevational gradients in subalpine meadow ecosystems. To reveal the elevational patterns of warming effects on plant biodiversity, community structure, productivity, and soil properties, we conducted a warming experiment using open-top chambers from August 2019 to August 2022 at high(2764 m a. s. l.), medium(2631 m a. s. l.), and low(2544 m a. s. l.) elevational gradients on a subalpine meadow slope of Mount Wutai, Northern China. Our results showed that three years of warming significantly increased topsoil temperature but significantly decreased topsoil moisture at all elevations(P<0.05), and the percentage of increasing temperature and decreasing moisture both gradually raised with elevation lifting. Warming-induced decreasing proportions of soil organic carbon(SOC, by 19.24%), and total nitrogen(TN, by 24.56%) were the greatest at high elevational gradients. Experimental warming did not affect topsoil C: N, p H, NO_(3)^(-)-N, or NH_(4)^(+)-N at the three elevational gradients. Warming significantly increased species richness(P<0.01) and Shannon-Weiner index(P<0.05) at low elevational gradients but significantly decreased belowground biomass(P<0.05) at a depth of 0–10 cm at three elevational gradients. Warming caused significant increases in the aboveground biomass in the three elevational plots. Warming significantly increased the aboveground biomass of graminoids in medium(by 92.47%) and low(by 98.25%) elevational gradients, that of sedges in high(by 72.44%) and medium(by 57.16%) elevational plots, and that of forbs in high(by 75.88%), medium(by 34.38%), and low(by 74.95%) elevational plots. Species richness had significant linear correlations with SOC, TN, and C: N(P<0.05), but significant nonlinear responses to soil temperature and soil moisture in the warmed treatment(P<0.05). The warmed aboveground biomass had a significant nonlinear response to soil temperature and significant linear responses to soil moisture(P<0.05). This study provided evidence that altitude is a factor in sensitivity to climate warming, and these different parameters(e.g., plant species richness, Shannon-Weiner index, soil temperature, soil moisture, SOC, and TN) can be used to measure this sensitivity.
文摘The impact of structural stiffness on optical axis deviation poses a significant challenge in the design of equatorial telescope structures.A comprehensive analysis during the design process can reduce the reliance of a telescope on advanced control technologies,thereby improving its economic feasibility.Although full-system finite element analyses are reliable,they are encumbered by significant time requirements and limitations in covering all possible telescope orientations.Therefore,we propose an efficient and comprehensive analytical method to evaluate the optical axis deviation of equatorial telescopes across a full range of angles.To address the challenge of ensuring that the analysis covers all possible positions of an equatorial telescope,based on a model from SiTian project,we analyze the optical axis deviations caused by the fork arm at 25 different angles and then use fitting methods to obtain results for all angles.Based on the analysis results of the optical axis deviation caused by the stiffness of the optical tube in the horizontal position,we derive the results for the tube at any position using geometric relationships.Finally,we calculate the coupling factors and combine these impacts.Furthermore,we identify six discrete feature points to reflect possible telescope orientations and conduct comprehensive finite element analyses.The results are in alignment with those acquired through a comprehensive computational approach.
文摘Ash-rich pyroclastic flows from the cataclysmic eruption of Mount Mazama (~7700 yr. B. P.), Cascade volcanic arc, Oregon, entered and blocked the narrow, bedrock-lined canyon of the Williamson River approximately 35 to 44 km from the source volcano. The blockage impounded a body of water which then released producing four stratigraphic units in the downstream debris fan. The four stratigraphic units are a boulder core comprised of locally sourced bedrock boulders and three sand-rich units including a fine-grained sand unit, a sandy pumice gravel (±basalt/hydrovolcanic tuff) unit, and a pumice pebble-bearing, crystal-rich sand unit. Hand-drilled auger holes up to ~1.6 m deep were used to obtain samples of the sand-rich units. Units were delimited using surface and down-hole observations, composition and texture, estimated density, statistical parameters of grain size, and vertical and lateral distribution of properties. Overtopping followed by rapid incision into the ash-rich pyroclastic flows progressively cleared the canyon, but a bedrock knickpoint near the head of the canyon limited the volume of debris available for transport to about 0.04 km<sup>3</sup> to 0.08 km<sup>3</sup>. Co-deposition of bedrock boulders and lithic-rich sand was followed by rapid deposition with minimal reworking of remobilized pyroclastics. Continued draining of the impounded lake sent hyperconcentrated flows onto the debris fan depositing pumice-rich gravels that graded upward to crystal-rich sands.
文摘Amid gloomy forecasts for the global economy in 2024,news of China’s 5.2 percent GDP growth in 2023 was a shot in the arm for a world still beset with regional conflicts,lackluster economic recovery,and mounting geopolitical tension.But despite this outstanding economic performance,dire predictions,and assumptions that China’s economy is on the verge of collapse continued to dominate some Western media portals.Certain Western media obstinately dwell on the so-called economic“strains”on China’s economy,despite evidence to the contrary in the National Bureau of Statistics(NBS)of China’s January 17 release of this data.
文摘Captain Qomolangma Director:Wu Xi Length:One Episode Producer:Mountain Climbing Films,Emei Film Group Broadcasting Platforms:Migu Video,bilibili Sula Wangping was born in a small village at the foot of Mount San’ao in southeastern China’s Sichuan Province.More than 20 years ago,he participated in an expedition to San’ao with China’s national mountaineering team.Being amazed by the grandeur of the snow-capped mountain and obssessed with the exhilaration of climbing,he decided to pursue climbing as a professional career.In June 2019,he led eight amateur mountaineers to the summit of Mount Qomolangma.After overcoming hardships in extreme cold conditions,they became the world’s first team to reach the top of the mountain in 2019.
文摘The presented research illustrates the applicability and productiveness of the systematic literature review methodology, a non-empirical methodology in the geological sciences, particularly volcanology. The systematic literature review methodology is a replicable, rigorous, and transparent methodology for synthesizing existing literature to answer questions on a specific topic. The synthesis allows for knowledge consolidation, such as identifying knowledge gaps. In our illustration of this methodology, we focused on the expanding knowledge about the magma pathway at Mount Cameroon, one of Africa’s active volcanoes. Our synthesis of the relevant international geoscience research literature is based on the framework of knowledge about the magma pathway beneath a typical basaltic volcano. The framework has three primary components: magma supply, storage, and transport to erupting vents. Across these components is a total of twelve secondary components. The result is a previously non-existent and fragmented overall understanding of the magma pathway at Mount Cameroon. The gaps in the understanding (such as in the magma supply rates, timescales of chamber processes, and magma ascent rates) may be addressed in future research. Another key implication of the presented research lies in the proof of concept of the systematic literature review methodology as an applicable qualitative research methodology in the study of volcanoes.
文摘Approximately 2,000,000 people are exposed to volcanic risks in communities situated at the flanks of Mounts Cameroon (MC) and Nyiragongo (MN) volcanoes in Central Africa. This study therefore sought to investigate risk perception from four previous eruptions of MC, namely the 1959, 1982, 1999, and 2000 eruptions;and two previous eruptions of MN: 1977 and 2002. The study was initiated with co-design workshops held with major stakeholders in the cities of Buea and Goma at the flanks of MC and MN, respectively, in 2017, to develop the research objectives for the study. A non-random questionnaire survey was later conducted within 14 and 15 communities in Buea and Goma respectively, on the effects, perceived risks, and coping strategies for the chosen eruptions. Three age groups (18 - 30, 31 - 45 and >45 years) and gender (male and female) were considered. The population at the flanks of both volcanoes cited scientific and indigenous factors to be responsible for eruptions from these volcanoes. At MC and MN, ≥45% of the sampled participants (with a higher female population) perceived that the sampled eruptions posed a very high risk to the population. In terms of the effects, the age group of 18 - 30 was the least knowledgeable. In terms of direct effect on persons, over 90% of participants at MC and MN attested that they were overcome by fear/panic. On measures to cope with any likely eruption, the following order was established at the flanks of both volcanoes: sensitization of population, use of religious (prayers) and of traditional/indigenous strategies. In terms of future coping strategies, while the males at MC maintained sensitization as the favourite option, 62% of the males at MN opted for traditional/indigenous strategies. The female population at both MC and MN showed a higher preference for religious strategies like prayers.
文摘When talking about rich places on the Qinghai-Xizang Plateau,we should not ignore Lhodrak in Shannan.With the popularity of Mount Kula Kangri,Lhodrak has become famous for its high mountains,lakes,and glaciers in the Himalayas Mountains like"a place in the clouds".
文摘Lakes that resemble mirrors and jade,ancient temples,and Mount Qomolangma soaring into the clouds...If you want to experience the unique folk culture of Xizang,you can head west to Xigaze,the hometown of Mount Qomolangma.
文摘Mount Fanjing Mount Fanjing,located in the eastern Guizhou Province of China,is the highest peak of the Wuling Mountains.Spanning altitude between 500 metres to 2,570 metres above sea level and covering an area of over 775 square km,it emerges as an island of metamorphic rock amid a sea of karst.Established as a nature reserve in 1978 and later designated as a UNESCO Biosphere Reserve in 1986,Mount Fanjing earned further recognition as a UNESCO World Heritage Site in 2018.Mount Fanjing is much taller than it is wide,a vertical pinnacle that resembles a pencil standing on a desk.To reach the top,visitors have to ascend more than 8,000 steps or take a cable car ride up from the road below.
文摘South Korea's Jeju Island has a lot of natural beauty.Millions of people visit the island each year.Climbing Mount Hallasan is a popular activity.At 1,950 meters,it's the highest mountain in South Korea.It is possible to hike all the way to the top and back in one day.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research (STEP) program (Grant No. 2019QZKK0105)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA19070401)。
文摘According to observational daily temperature data from the meteorological stations during 1971-2020,the variations of the extreme temperature event in the Mount Qomolangma(also known as Mount Everest) region in China have been analyzed using statistical methods.The extreme temperature indices recommended by the World Meteorological Organization are selected to describe the extreme temperature event.The RClimDEX 1.0 software is used to calculate the extreme temperature indices.There are no tropical nights,and just three summer days at the last 50 years.The frost days are the main extreme temperature events all year round.The temperature in the north slope is more extreme than that in the south slope of the Mount Qomolangma.There is remarkable decadal variation for the extreme temperature indices except diurnal temperature range.There are the warm extremes increasing,however,the cold extremes decreasing with the decadal lapse,which is more remarkable into the 21^(th) century.The tendencies for the extreme temperature indices in the north slope are consistent with those in the south slope.There are statistically significant trends for most extreme temperature indices during the study period.It shows that the warm extremes would be more prominent in the future with the global continued warming.The abrupt changes of the extreme temperature index have occurred mainly in the 20^(th) century especially from the mid to late 1980s and 1990s.The periodic changes in the south slope do not synchronize those in the north slope for the most extreme temperature indices.It is different for most extreme temperature indices between the south and north slope,which has demonstrated that the regional or local changes are not neglectable for extreme temperature research.The results of this study are also the consistent response of extreme temperature event to the global warming.
基金financially supported by National Natural Science Foundation of China(32260046 and 31800176)the Sino-Africa Joint Research Centre(Y323771W07 and SAJC201322)。
文摘Field surveys and empirical integrated methods are commonly used in the ecological research to understand the altitudinal pattern of plant diversity of mountains.However,few studies have compared the differences between the two methods on the same scale.Here,we addressed and compared the altitudinal patterns of species richness(SR),phylogenetic diversity(PD),the standardized effect size of phylogenetic diversity(PDses)and mean phylogenetic distance(MPDses)of about 580 angiosperms growing on Mount Kenya from two independent datasets:one is based on our several times field surveys in this mountain and another one is based on empirical data integrated from literatures.We found that the altitudinal diversity patterns of field surveys dataset were consistent with the empirical integrated dataset.Both SR and PD showed hump-shaped patterns along the altitude,and both PDses and MPDses showed monotonically decreasing patterns along the altitude.The ratio of diversity between field surveys dataset and empirical integrated dataset were gradually increase along the altitude.Our research provides new insight for understanding the altitudinal diversity patterns of plants of a tropical mountain.
基金supported by institutional funding from the Stowers Institute for Medical Research,NIH Grant 1DP2AG071466-01,NIH Grant R01 GM127872,NSF IOS-1933428NSF EDGE Award 1923372。
文摘Dear Editor,Physical injury and tissue damage are prevalent throughout the animal kingdom,with the ability to regenerate quickly and efficiently providing a selective advantage.In most vertebrates,skeletal muscle possesses a remarkable ability to regenerate,making it a valuable model for investigating the cellular processes underpinning tissue regeneration.Following damage,skeletal muscle mounts a complex regenerative cascade centered around dedicated muscle stem cells,i.e.,satellite cells.These satellite cells are,in turn,regulated by both resident and infiltrating innate immune cells of myeloid lineage,which play a crucial role in activating and guiding the transition of satellite cells towards maturation(Chen et al.,2020;Tidball,2017;Tidball&Villalta,2010).While critical for muscle regeneration,the innate immune system is energetically costly,resulting in many species decreasing immune investment under nutrient-limited environments.Whether this reduced investment results in a decreased capacity to mount a regenerative response following tissue damage remains unclear.Here,we utilized an emerging evolutionary model,the Mexican tetra(Astyanax mexicanus),to investigate the consequences of shifts in immune system investment on skeletal muscle regeneration.
基金funded by the National Natural Science Foundation of China(Nos.42072240 and 41602218)Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(No.GML2019ZD0201)the Fund from the Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources,Chinese Academy of Geological Sciences(Nos.J1901-30 and J1908)。
文摘K-Ar dating of synkinematic illite is increasingly recognized as a central method to constrain the timing of shallow crustal faulting.Methods of efficient sample preparation and quantitative identification of illite polytypes are critical to acquiring K-Ar isotope data for authigenic clays.In this respect,we compared the commonly used clay size separation method through centrifugation with vacuum filtration technology,showing that the former is prone to extract fractions with finer particle sizes under similar conditions,thus improving the error in the authigenic end-member age.Additionally,we demonstrated that the side-packed mounting method for X-ray diffraction analysis can significantly enhance the randomness in powder samples,thus improving the quantification accuracy compared with the front-packed and back-packed methods.The validity of our quantification method was confirmed by comparing Profex■modeling patterns with a suite of synthetic mixtures of known compositions,yielding an average analytical error of 3%.Dating results of these artificial mixtures and the reference materials indicated that a large range in percentages of detrital illite and a sufficient amount of age data will produce reliable results for ages of both extrapolated end-members.However,if the range is limited,the extrapolated age close to those of datasets is still reliable.