The design strategies for powertrain mounting systems play an important role in the reduction of vehicular vibration and noise. As stiffness and damping elements connecting the transmission system and vehicle body, th...The design strategies for powertrain mounting systems play an important role in the reduction of vehicular vibration and noise. As stiffness and damping elements connecting the transmission system and vehicle body, the rubber mount exhibits better vibration isolation performance than the rigid connection. This paper presents a complete design process of the mounting system, including the vibration decoupling, vibration simulation analysis, topology optimization, and experimental verification. Based on the 6?degrees?of?freedom vibration coupling model of the powertrain mounting system, an optimization algorithm is used to extract the best design parameters of each mount, thus rendering the mounting system fully decoupled and the natural frequency well configured, and the optimal parameters are used to design the mounting system. Subsequently, vibration simulation analysis is applied to the mounting system, considering both transmission and road excitations. According to the results of finite element analysis, the topological structure of the metal frame of the front mount is optimized to improve the strength and dynamic characteristics of the mounting system. Finally, the vibration bench test is used to verify the availability of the optimization design with the analysis of acceleration response and vibration transmissibility of the mounting system. The results show that the vibration isolation performance of the mounting system can be improved effectively using the vibration optimal decoupling method, and the structural modification of the metal frame can well promote the dynamic characteristics of the mounting system.展开更多
The content of this subject research is to conduct optimization for engine mounting system, and through optimization, it can make the vibration between engine and vehicle body achieve a minimum, using Adams software f...The content of this subject research is to conduct optimization for engine mounting system, and through optimization, it can make the vibration between engine and vehicle body achieve a minimum, using Adams software for simulation. It studies the isolation vibration of the engine mounting system and conducts goal optimization for fixed frequency. This paper uses two methods for optimization. One is to use the rational allocation of fixed frequency to optimize the fixed frequency, and the other is to use energy decoupling method to optimize the fixed frequency. It uses Adams software for simulation of the optimized fixed frequency and conducts comparison of simulated results. The simulated results show that the optimized energy distribution situation almost achieves 90%. Compared with original data, decoupling degree also has a very great improvement, illustrating that the optimized data has greater effect for the isolated vibration of engine, in order to further verify the feasibility of optimization design method.展开更多
The existing torque roll axis(TRA) decoupling theories for a powertrain mounting system assume that the stiffness and viscous damping properties are constant. However, real-life mounts exhibit considerable spectrally ...The existing torque roll axis(TRA) decoupling theories for a powertrain mounting system assume that the stiffness and viscous damping properties are constant. However, real-life mounts exhibit considerable spectrally varying stiffness and damping characteristics, and the influence of the spectrally-varying properties of the hydraulic mounts on the powertrain system cannot be ignored. To overcome the deficiency, an analytical quasi-linear model of the hydraulic mount and the coupled properties of the powertrain and hydraulic mounts system are formulated. The influence of the hydraulic mounts on the TRA decoupling of a powertrain system is analytically examined in terms of eigensolutions, frequency, and impulse responses, and then a new analytical axiom is proposed based on the TRA decoupling indices. With the experimental setup of a fixed decoupler hydraulic mount in the context of non-resonant dynamic stiffness testing procedure, the quasi-linear model of the hydraulic mount is verified by comparing the predictions with the measurement. And the quasi-linear formulation of the coupled system is also verified by comparing the frequency responses with the numerical results obtained by the direct inversion method. Finally, the mounting system with a combination of hydraulic mounts is redesigned in terms of the stiffness, damping and mount locations by satisfying the new axiom. The frequency and time domain results of the redesigned system demonstrate that the torque roll axis of the redesigned powertrain mounting system is indeed decoupled in the presence of hydraulic mounts (given oscillating torque or impulsive torque excitation). The proposed research provides an important basis and method for the research on a powertrain system with spectrally-varying mount properties, especially for the TRA decoupling.展开更多
In this study,a hybrid uncertainties-based analysis and optimization method is presented for the designs of the powertrain mounting system(PMS)involving mixed uncertainties.In the presented method,the PMS parameters w...In this study,a hybrid uncertainties-based analysis and optimization method is presented for the designs of the powertrain mounting system(PMS)involving mixed uncertainties.In the presented method,the PMS parameters with sufficient data are treated as random variables,while those with limited information are defined as interval variables.Then,an uncertainty-based analysis method called as hybrid interval-random perturbation-central difference method(HIRP-CDM),is proposed to compute the hybrid interval-random outputs of the inherent characteristics of the PMS in concerned directions.In addition,the hybrid interval-random-Monte Carlo method(HIR-MCM)is developed to verify the computational accuracy of HIRP-CDM.Next,an optimization model mixed uncertainties is built up for the PMS design based on HIRP-CDM,in which the hybrid intervalrandom outputs of the concerned inherent characteristics are adopted to construct the design objective and constrains.The complex optimization problem can be effectively settled by means of HIRP-CDM.The effectiveness of the presented method is verified by a numerical example.展开更多
To achieve the goal that China and Nepal jointly announce the new height of Mount Qomolangma(MQ),the campaign of Qomolangma Height Survey(QHS)was carried out from 2019 to 2020.A high precision geoid model realizing th...To achieve the goal that China and Nepal jointly announce the new height of Mount Qomolangma(MQ),the campaign of Qomolangma Height Survey(QHS)was carried out from 2019 to 2020.A high precision geoid model realizing the common height datum for both sides is necessary for determining the unique height of MQ.However,high altitude and rugged topography make it extremely difficult to conduct terrestrial gravity measurements in this region,the accuracy of geoid model is restricted by terrestrial gravity data gaps.In the campaign of 2020 QHS,the airborne gravity survey was carried out over MQ and its surrounding areas,the airborne gravity data covering an area of 12,700 km^(2) were successfully collected.For the first time,the high precision observations of terrestrial gravity and BeiDou Navigation Satellite System(BDS)at the peak of MQ were collected.These datasets pave the way for the precise determination of the orthometric height of MQ.According to the definition of the International Height Reference System(IHRS),we developed the IHRS-based gravimetric quasigeoid model by combining the airborne and terrestrial gravity data.Validations against highly accurate GNSS leveling data at 61 benchmarks demonstrate that the accuracy of the quasigeoid model is 3.8 cm,and the addition of airborne gravity data improves the accuracy by 51.3%.Based on the IHRS,the final orthometric height of the snow surface of the peak of MQ is determined to be 8848.86 m.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 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
On January 15,the launch ceremony of 2025“One River,One Family”Spring Festival cultural series in Laos was held in the Lao capital of Vientiane.Distinguished vips present at and addressing the ceremony included Vi...On January 15,the launch ceremony of 2025“One River,One Family”Spring Festival cultural series in Laos was held in the Lao capital of Vientiane.Distinguished vips present at and addressing the ceremony included Vilavone Phanhthavong,deputy head of the Publicity and Training Board of the Lao People’s Revolutionary Party(LPRP)Central Committee,Vansay Tavinyan,deputy head of the Publicity and Training Board of the LPRP Central Committee and editor-in-chief of Pasaxon newspaper,Savankhone Razmountry,president of the Lao Journalists’Association.展开更多
The Shiquanhe River,like a dynamic young man,roars all the way from the glacial lake on the northern side of Mount Gang Rinpoche to the Shiquanhe river basin.There,the water gradually slows and kindly moistens the sur...The Shiquanhe River,like a dynamic young man,roars all the way from the glacial lake on the northern side of Mount Gang Rinpoche to the Shiquanhe river basin.There,the water gradually slows and kindly moistens the surrounding grasslands,presenting a lush and picturesque landscape.展开更多
As 2025 unfolds,global economic growth remains lackluster,protectionism is intensifying,and key markets are grappling with weak growth prospects and mounting debt burdens.As the external environment grows ever more un...As 2025 unfolds,global economic growth remains lackluster,protectionism is intensifying,and key markets are grappling with weak growth prospects and mounting debt burdens.As the external environment grows ever more uncertain and unstable,China is poised at a pivotal crossroads in its economic transformation.展开更多
For decades,antigen presentation on major histocompatibility complex class I for T cell-mediated immunity has been considered the primary function of proteasome-derived peptides1,2.However,whether the products of prot...For decades,antigen presentation on major histocompatibility complex class I for T cell-mediated immunity has been considered the primary function of proteasome-derived peptides1,2.However,whether the products of proteasomal degradation play additional parts in mounting immune responses remains unknown.Antimicrobial peptides serve as a first line of defence against invading pathogens before the adaptive immune system responds.Although the protective function of antimicrobial peptides across numerous tissues is well established,the cellular mechanisms underlying their generation are not fully understood.Here we uncover a role for proteasomes in the constitutive and bacterial-induced generation of defence peptides that impede bacterial growth both in vitro and in vivo by disrupting bacterial membranes.In silico prediction of proteome-wide proteasomal cleavage identified hundreds of thousands of potential proteasome-derived defence peptides with cationic properties that may be generated en route to degradation to act as a first line of defence.展开更多
Same-sex mounts provide male juvenile golden snub-nosed monkeys(Rhinopithecus roxellana)with opportunities to practice heterosexual copulatory skills and are often followed by grooming(post-mounting grooming,PMG).We h...Same-sex mounts provide male juvenile golden snub-nosed monkeys(Rhinopithecus roxellana)with opportunities to practice heterosexual copulatory skills and are often followed by grooming(post-mounting grooming,PMG).We hypothesized that juveniles acted as the mountee and provided mounting opportunities to receive grooming from their peer mounter.Here,we observed same-sex mounts among male juveniles(N=5)in a captive group of R.roxellana in Shanghai Wild Animal Park,China,from November 2014 to June 2015.Among 1,044 mounts recorded,45.40% were accompanied by PMG initiated by the mounter and only 3.74% were followed by PMG initiated by the mountee.Mountees were more likely to receive PMG when they performed a mounting solicitation than when they did not,or when they were mounted for a longer time(even if they did not solicit).Over a long timeframe(1 month),mountee’s tended to choose partners who groomed them more often than others after mounting,regardless of how long the grooming lasted.However,whether the mounter groomed the mountee did not predict the mounting direction in their subsequent mount.Our results suggest that,in the context of same-sex mounts,juveniles provide mounting opportunities to receive grooming from peers on a long-term,rather than on a short-term basis.This study provides the first evidence that juveniles’same-sex mounting strategy may be associated with the grooming market in nonhuman primates,which necessitates further investigation with large free-ranging groups due to the limited sample size of individuals and the captive setting of the current study.展开更多
The government work report demonstrates China’s resolve and confidence to surmount all difficulties to break new ground amidst profound changes.AS an important window into China’s economic policy direction,the signi...The government work report demonstrates China’s resolve and confidence to surmount all difficulties to break new ground amidst profound changes.AS an important window into China’s economic policy direction,the significance of the“two sessions”becomes even more prominent in a time of increasing geopolitical tension.展开更多
Shanxi,where the essence of its mountains and rivers converge,is a treasure trove of cultural and travel marvels.In the timeless embrace of ancient Pingyao,the legacy of Jin merchants echoes through the ages.The Yunga...Shanxi,where the essence of its mountains and rivers converge,is a treasure trove of cultural and travel marvels.In the timeless embrace of ancient Pingyao,the legacy of Jin merchants echoes through the ages.The Yungang Grottoes,with their solemn Buddhas,stand as timeless sentinels,whispering tales of a millennium's passage.On the sacred slopes of Mount Wutai,the air is scented with incense,and the tranquil spirit of Zen envelops the misty landscape.Journey back to the heart of the Three Jins,where the aroma of aged vinegar lingers in the air,and hidden vistas reveal their profound beauty.Here,you will discover a charm and character like no other,as the spirit of the land unveils its unique poetic elegance and grace.展开更多
Plato’s grave柏拉图的坟墓In 79 AD,Mount Vesuvius covered the Herculaneum scrolls^(1).Scientists now use smart tools to read them,learning about Plato’s life,death at 81,and where he was buried^(2).This discovery tea...Plato’s grave柏拉图的坟墓In 79 AD,Mount Vesuvius covered the Herculaneum scrolls^(1).Scientists now use smart tools to read them,learning about Plato’s life,death at 81,and where he was buried^(2).This discovery teaches us more about the past.展开更多
The optical absorption of large molecular compounds HULIS(humic-like substances)can significantly impact the aerosol light absorption and radiative forcing,influencing cloud condensation nuclei formation and thus the ...The optical absorption of large molecular compounds HULIS(humic-like substances)can significantly impact the aerosol light absorption and radiative forcing,influencing cloud condensation nuclei formation and thus the climate and atmospheric environment.This study collected aerosol(PM_(2.5))samples from the summit of Mount Tai in North China to investigate the concentration,molecular composition,and optical properties of HULIS.The average concentration of HULIS in the PM_(2.5) in this study was 1.26±0.54μg/m^(3),comprising for 56%of the water-soluble organic carbon(WSOC),with levels lower than urban areas but higher than other mountainous regions.Mass spectrometry revealed that CHO and CHON components,with high aromaticity and phenolic groups,are major contributors to absorption and fluorescence.These results indicate that HULIS is mainly composed of lignin and proteins/amino sugars,derived from combustion and secondary formation,and possesses a high light absorption capacity(withMAE365(mass absorption efficiency)and AAE(A˚ngstrom exponent)indices of 0.62m^(2)/g and 4.99,respectively).Parallel factor analysis identified three fluorescence components of HULIS,with proportions of 60.8%for less oxygen humic-like substances,21.0%for high oxygen humic-like substances,and 18.2%for protein-like substances.Our study highlights the significance of the light-absorbing capacity and secondary formation of HULIS at Mount Tai,laying the groundwork for investigation into the climate effects,formation mechanisms,and sources of HULIS generation.展开更多
Aerosol category and its physicochemical properties are key factors influencing its climate and environmental effects.To further enhance our understanding of aerosols in the Himalayas-Tibetan Plateau region,atmospheri...Aerosol category and its physicochemical properties are key factors influencing its climate and environmental effects.To further enhance our understanding of aerosols in the Himalayas-Tibetan Plateau region,atmospheric particulate matter samples were collected at three different altitudes on Mount Qomolangma(Everest).Using an automated scanning electron microscope system,the composition,size,and morphology of 52,349 particles were analyzed.The average mass concentrations of PM_(1),PM_(2.5),and PM_(10)were 0.678,5.054,and 16.698μg/m^(3),respectively.Aluminosilicate particles dominated the samples,accounting for 71.5%to 82.8%of PM_(10)mass and 34.7%to 62.4%of the particle number.Quartz particles,carbonate particles,metal oxides,and sulfates were also observed at different periods.Carbonaceous particles made up a significant portion of aerosols,comprising 2.1%to 9.7%of PM_(10)mass and 10.4%to 45.4%of particle number,with their concentration showing an upward trend with altitude.Small amounts of tar ball particles and fly ash particles were also observed,providing direct evidence of anthropogenic influences on high-altitude regions,even at altitudes exceeding 6000 m.The size distribution and abundance of different particle categories were closely related to the transport trajectories of air masses.The morphology of different particle categories varied,with fly ash particles mainly spherical and carbonaceous particles exhibiting higher irregularity.展开更多
Mount Tai Scenic Area has achieved certain results in the construction of accessible tourism facilities,realizing the exploration of digital and intelligent transformation in traditional mountain scenic areas.In this ...Mount Tai Scenic Area has achieved certain results in the construction of accessible tourism facilities,realizing the exploration of digital and intelligent transformation in traditional mountain scenic areas.In this study,using questionnaire surveys and in-depth interviews,the development of accessible tourism in Mount Tai Scenic Area was investigated and analyzed.Some countermeasures were put forward,including strengthening information guidance services,enhancing awareness and skills in accessibility services,improving feedback mechanisms for continuous refinement,and strengthening collaborations in the fields of the disabled and accessibility development,aiming to further promote humanistic care and enhance service satisfaction at the scenic area.展开更多
Over the past decades,the expansion of natu-ral secondary forests has played a crucial role in offsetting the loss of primary forests and combating climate change.Despite this,there is a gap in our understanding of ho...Over the past decades,the expansion of natu-ral secondary forests has played a crucial role in offsetting the loss of primary forests and combating climate change.Despite this,there is a gap in our understanding of how tree species’growth and mortality patterns vary with eleva-tion in these secondary forests.In this study,we analyzed data from two censuses(spanning a five-year interval)conducted in both evergreen broadleaved forests(EBF)and temperate coniferous forests(TCF),which have been recovering for half a century,across elevation gradients in a subtropical mountain region,Mount Wuyi,China.The results indicated that the relative growth rate(RGR)of EBF(0.028±0.001 cm·cm^(-1)·a^(-1))and the mortality rate(MR)(20.03%±1.70%)were 27.3%and 16.4%higher,respec-tively,than those of TCF.Interestingly,the trade-off between RGR and MR in EBF weakened as elevation increased,a trend not observed in TCF.Conversely,TCF consistently showed a stronger trade-off between RGR and MR compared to EBF.Generalized linear mixed models revealed that ele-vation influences RGR both directly and indirectly through its interactions with slope,crown competition index(CCI),and tree canopy height(CH).However,tree mortality did not show a significant correlation with elevation.Additionally,DBH significantly influenced both tree growth and mortal-ity,whereas and CH and CCI had opposite effects on tree growth between EBF and TCF.Our study underscores the importance of elevation in shaping the population dynamics and the biomass carbon sink balance of mountain forests.These insights enhance our understanding of tree species’life strategies,enabling more accurate predictions of forest dynamics and their response to environmental changes.展开更多
Indian Pilgrimage in China's Xizang to Resume This Summer Indian pilgrimage to Mount Gang Rinpoche and Lake Mapham Yutso in the Xizang Autonomous Region will resume this summer as agreed between the two countries,...Indian Pilgrimage in China's Xizang to Resume This Summer Indian pilgrimage to Mount Gang Rinpoche and Lake Mapham Yutso in the Xizang Autonomous Region will resume this summer as agreed between the two countries,according to China's Foreign Ministry.Mount Gang Rinpoche and Lake Mapham Yutso are the sacred mountain and lake for believers of several religions,including Tibetan Buddhism and Hinduism,and thus the pilgrimage is an important part of the cultural and people-to-people exchange between China and India.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.51375047,51775040)
文摘The design strategies for powertrain mounting systems play an important role in the reduction of vehicular vibration and noise. As stiffness and damping elements connecting the transmission system and vehicle body, the rubber mount exhibits better vibration isolation performance than the rigid connection. This paper presents a complete design process of the mounting system, including the vibration decoupling, vibration simulation analysis, topology optimization, and experimental verification. Based on the 6?degrees?of?freedom vibration coupling model of the powertrain mounting system, an optimization algorithm is used to extract the best design parameters of each mount, thus rendering the mounting system fully decoupled and the natural frequency well configured, and the optimal parameters are used to design the mounting system. Subsequently, vibration simulation analysis is applied to the mounting system, considering both transmission and road excitations. According to the results of finite element analysis, the topological structure of the metal frame of the front mount is optimized to improve the strength and dynamic characteristics of the mounting system. Finally, the vibration bench test is used to verify the availability of the optimization design with the analysis of acceleration response and vibration transmissibility of the mounting system. The results show that the vibration isolation performance of the mounting system can be improved effectively using the vibration optimal decoupling method, and the structural modification of the metal frame can well promote the dynamic characteristics of the mounting system.
文摘The content of this subject research is to conduct optimization for engine mounting system, and through optimization, it can make the vibration between engine and vehicle body achieve a minimum, using Adams software for simulation. It studies the isolation vibration of the engine mounting system and conducts goal optimization for fixed frequency. This paper uses two methods for optimization. One is to use the rational allocation of fixed frequency to optimize the fixed frequency, and the other is to use energy decoupling method to optimize the fixed frequency. It uses Adams software for simulation of the optimized fixed frequency and conducts comparison of simulated results. The simulated results show that the optimized energy distribution situation almost achieves 90%. Compared with original data, decoupling degree also has a very great improvement, illustrating that the optimized data has greater effect for the isolated vibration of engine, in order to further verify the feasibility of optimization design method.
基金supported by National Natural Science Foundation of China (Grant Nos. 51075112, 51175135)Fundamental Research Funds for the Central Universities of China (Grant Nos. 2012HGBZ0618,2013HGBH0008)
文摘The existing torque roll axis(TRA) decoupling theories for a powertrain mounting system assume that the stiffness and viscous damping properties are constant. However, real-life mounts exhibit considerable spectrally varying stiffness and damping characteristics, and the influence of the spectrally-varying properties of the hydraulic mounts on the powertrain system cannot be ignored. To overcome the deficiency, an analytical quasi-linear model of the hydraulic mount and the coupled properties of the powertrain and hydraulic mounts system are formulated. The influence of the hydraulic mounts on the TRA decoupling of a powertrain system is analytically examined in terms of eigensolutions, frequency, and impulse responses, and then a new analytical axiom is proposed based on the TRA decoupling indices. With the experimental setup of a fixed decoupler hydraulic mount in the context of non-resonant dynamic stiffness testing procedure, the quasi-linear model of the hydraulic mount is verified by comparing the predictions with the measurement. And the quasi-linear formulation of the coupled system is also verified by comparing the frequency responses with the numerical results obtained by the direct inversion method. Finally, the mounting system with a combination of hydraulic mounts is redesigned in terms of the stiffness, damping and mount locations by satisfying the new axiom. The frequency and time domain results of the redesigned system demonstrate that the torque roll axis of the redesigned powertrain mounting system is indeed decoupled in the presence of hydraulic mounts (given oscillating torque or impulsive torque excitation). The proposed research provides an important basis and method for the research on a powertrain system with spectrally-varying mount properties, especially for the TRA decoupling.
基金supported by the National Natural Science Foundation of China(Grant Nos.51605167,51975217)the Science and Technology Program of Guangzhou,China(Grant No.201804010092)the Fundamental Research Funds for the Central Universities,SCUT(Grant No.2019MS058).
文摘In this study,a hybrid uncertainties-based analysis and optimization method is presented for the designs of the powertrain mounting system(PMS)involving mixed uncertainties.In the presented method,the PMS parameters with sufficient data are treated as random variables,while those with limited information are defined as interval variables.Then,an uncertainty-based analysis method called as hybrid interval-random perturbation-central difference method(HIRP-CDM),is proposed to compute the hybrid interval-random outputs of the inherent characteristics of the PMS in concerned directions.In addition,the hybrid interval-random-Monte Carlo method(HIR-MCM)is developed to verify the computational accuracy of HIRP-CDM.Next,an optimization model mixed uncertainties is built up for the PMS design based on HIRP-CDM,in which the hybrid intervalrandom outputs of the concerned inherent characteristics are adopted to construct the design objective and constrains.The complex optimization problem can be effectively settled by means of HIRP-CDM.The effectiveness of the presented method is verified by a numerical example.
基金supported by the National Natural Science Foundation of China[grant numbers 41974010,42074020]the basic scientific research operating program of Chinese Academy of Surveying and Mapping。
文摘To achieve the goal that China and Nepal jointly announce the new height of Mount Qomolangma(MQ),the campaign of Qomolangma Height Survey(QHS)was carried out from 2019 to 2020.A high precision geoid model realizing the common height datum for both sides is necessary for determining the unique height of MQ.However,high altitude and rugged topography make it extremely difficult to conduct terrestrial gravity measurements in this region,the accuracy of geoid model is restricted by terrestrial gravity data gaps.In the campaign of 2020 QHS,the airborne gravity survey was carried out over MQ and its surrounding areas,the airborne gravity data covering an area of 12,700 km^(2) were successfully collected.For the first time,the high precision observations of terrestrial gravity and BeiDou Navigation Satellite System(BDS)at the peak of MQ were collected.These datasets pave the way for the precise determination of the orthometric height of MQ.According to the definition of the International Height Reference System(IHRS),we developed the IHRS-based gravimetric quasigeoid model by combining the airborne and terrestrial gravity data.Validations against highly accurate GNSS leveling data at 61 benchmarks demonstrate that the accuracy of the quasigeoid model is 3.8 cm,and the addition of airborne gravity data improves the accuracy by 51.3%.Based on the IHRS,the final orthometric height of the snow surface of the peak of MQ is determined to be 8848.86 m.
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 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On January 15,the launch ceremony of 2025“One River,One Family”Spring Festival cultural series in Laos was held in the Lao capital of Vientiane.Distinguished vips present at and addressing the ceremony included Vilavone Phanhthavong,deputy head of the Publicity and Training Board of the Lao People’s Revolutionary Party(LPRP)Central Committee,Vansay Tavinyan,deputy head of the Publicity and Training Board of the LPRP Central Committee and editor-in-chief of Pasaxon newspaper,Savankhone Razmountry,president of the Lao Journalists’Association.
文摘The Shiquanhe River,like a dynamic young man,roars all the way from the glacial lake on the northern side of Mount Gang Rinpoche to the Shiquanhe river basin.There,the water gradually slows and kindly moistens the surrounding grasslands,presenting a lush and picturesque landscape.
文摘As 2025 unfolds,global economic growth remains lackluster,protectionism is intensifying,and key markets are grappling with weak growth prospects and mounting debt burdens.As the external environment grows ever more uncertain and unstable,China is poised at a pivotal crossroads in its economic transformation.
文摘For decades,antigen presentation on major histocompatibility complex class I for T cell-mediated immunity has been considered the primary function of proteasome-derived peptides1,2.However,whether the products of proteasomal degradation play additional parts in mounting immune responses remains unknown.Antimicrobial peptides serve as a first line of defence against invading pathogens before the adaptive immune system responds.Although the protective function of antimicrobial peptides across numerous tissues is well established,the cellular mechanisms underlying their generation are not fully understood.Here we uncover a role for proteasomes in the constitutive and bacterial-induced generation of defence peptides that impede bacterial growth both in vitro and in vivo by disrupting bacterial membranes.In silico prediction of proteome-wide proteasomal cleavage identified hundreds of thousands of potential proteasome-derived defence peptides with cationic properties that may be generated en route to degradation to act as a first line of defence.
基金financially supported by the National Natural Science Foundation of China(31901083,31872250,and 31401985)the China Postdoctoral Science Foundation(2019M663796).
文摘Same-sex mounts provide male juvenile golden snub-nosed monkeys(Rhinopithecus roxellana)with opportunities to practice heterosexual copulatory skills and are often followed by grooming(post-mounting grooming,PMG).We hypothesized that juveniles acted as the mountee and provided mounting opportunities to receive grooming from their peer mounter.Here,we observed same-sex mounts among male juveniles(N=5)in a captive group of R.roxellana in Shanghai Wild Animal Park,China,from November 2014 to June 2015.Among 1,044 mounts recorded,45.40% were accompanied by PMG initiated by the mounter and only 3.74% were followed by PMG initiated by the mountee.Mountees were more likely to receive PMG when they performed a mounting solicitation than when they did not,or when they were mounted for a longer time(even if they did not solicit).Over a long timeframe(1 month),mountee’s tended to choose partners who groomed them more often than others after mounting,regardless of how long the grooming lasted.However,whether the mounter groomed the mountee did not predict the mounting direction in their subsequent mount.Our results suggest that,in the context of same-sex mounts,juveniles provide mounting opportunities to receive grooming from peers on a long-term,rather than on a short-term basis.This study provides the first evidence that juveniles’same-sex mounting strategy may be associated with the grooming market in nonhuman primates,which necessitates further investigation with large free-ranging groups due to the limited sample size of individuals and the captive setting of the current study.
文摘The government work report demonstrates China’s resolve and confidence to surmount all difficulties to break new ground amidst profound changes.AS an important window into China’s economic policy direction,the significance of the“two sessions”becomes even more prominent in a time of increasing geopolitical tension.
文摘Shanxi,where the essence of its mountains and rivers converge,is a treasure trove of cultural and travel marvels.In the timeless embrace of ancient Pingyao,the legacy of Jin merchants echoes through the ages.The Yungang Grottoes,with their solemn Buddhas,stand as timeless sentinels,whispering tales of a millennium's passage.On the sacred slopes of Mount Wutai,the air is scented with incense,and the tranquil spirit of Zen envelops the misty landscape.Journey back to the heart of the Three Jins,where the aroma of aged vinegar lingers in the air,and hidden vistas reveal their profound beauty.Here,you will discover a charm and character like no other,as the spirit of the land unveils its unique poetic elegance and grace.
文摘Plato’s grave柏拉图的坟墓In 79 AD,Mount Vesuvius covered the Herculaneum scrolls^(1).Scientists now use smart tools to read them,learning about Plato’s life,death at 81,and where he was buried^(2).This discovery teaches us more about the past.
基金supported by the National Natural Science Foundation of China(Nos.22176112 and 42307134)the Natural Science Foundation of Shandong Province(No.ZR2021MD028)the Natural Science Foundation of Qingdao(No.23–2-1–74-zyyd-jch).
文摘The optical absorption of large molecular compounds HULIS(humic-like substances)can significantly impact the aerosol light absorption and radiative forcing,influencing cloud condensation nuclei formation and thus the climate and atmospheric environment.This study collected aerosol(PM_(2.5))samples from the summit of Mount Tai in North China to investigate the concentration,molecular composition,and optical properties of HULIS.The average concentration of HULIS in the PM_(2.5) in this study was 1.26±0.54μg/m^(3),comprising for 56%of the water-soluble organic carbon(WSOC),with levels lower than urban areas but higher than other mountainous regions.Mass spectrometry revealed that CHO and CHON components,with high aromaticity and phenolic groups,are major contributors to absorption and fluorescence.These results indicate that HULIS is mainly composed of lignin and proteins/amino sugars,derived from combustion and secondary formation,and possesses a high light absorption capacity(withMAE365(mass absorption efficiency)and AAE(A˚ngstrom exponent)indices of 0.62m^(2)/g and 4.99,respectively).Parallel factor analysis identified three fluorescence components of HULIS,with proportions of 60.8%for less oxygen humic-like substances,21.0%for high oxygen humic-like substances,and 18.2%for protein-like substances.Our study highlights the significance of the light-absorbing capacity and secondary formation of HULIS at Mount Tai,laying the groundwork for investigation into the climate effects,formation mechanisms,and sources of HULIS generation.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(No.2019QZKK0106)the Basic Research Fund of CAMS(Nos.2023Z004 and 2023Z015).
文摘Aerosol category and its physicochemical properties are key factors influencing its climate and environmental effects.To further enhance our understanding of aerosols in the Himalayas-Tibetan Plateau region,atmospheric particulate matter samples were collected at three different altitudes on Mount Qomolangma(Everest).Using an automated scanning electron microscope system,the composition,size,and morphology of 52,349 particles were analyzed.The average mass concentrations of PM_(1),PM_(2.5),and PM_(10)were 0.678,5.054,and 16.698μg/m^(3),respectively.Aluminosilicate particles dominated the samples,accounting for 71.5%to 82.8%of PM_(10)mass and 34.7%to 62.4%of the particle number.Quartz particles,carbonate particles,metal oxides,and sulfates were also observed at different periods.Carbonaceous particles made up a significant portion of aerosols,comprising 2.1%to 9.7%of PM_(10)mass and 10.4%to 45.4%of particle number,with their concentration showing an upward trend with altitude.Small amounts of tar ball particles and fly ash particles were also observed,providing direct evidence of anthropogenic influences on high-altitude regions,even at altitudes exceeding 6000 m.The size distribution and abundance of different particle categories were closely related to the transport trajectories of air masses.The morphology of different particle categories varied,with fly ash particles mainly spherical and carbonaceous particles exhibiting higher irregularity.
基金Sponsored by Tai’an Science and Technology Innovation Development Project(Policy Guidance Category)(2024ZC042)Research Project of Inner Mongolia Autonomous Region Center for the Theoretical System of Socialism with Chinese Characteristics(2024ZZB018).
文摘Mount Tai Scenic Area has achieved certain results in the construction of accessible tourism facilities,realizing the exploration of digital and intelligent transformation in traditional mountain scenic areas.In this study,using questionnaire surveys and in-depth interviews,the development of accessible tourism in Mount Tai Scenic Area was investigated and analyzed.Some countermeasures were put forward,including strengthening information guidance services,enhancing awareness and skills in accessibility services,improving feedback mechanisms for continuous refinement,and strengthening collaborations in the fields of the disabled and accessibility development,aiming to further promote humanistic care and enhance service satisfaction at the scenic area.
基金funded by the National Natural Science Foundation of China(Grant No.32271872).
文摘Over the past decades,the expansion of natu-ral secondary forests has played a crucial role in offsetting the loss of primary forests and combating climate change.Despite this,there is a gap in our understanding of how tree species’growth and mortality patterns vary with eleva-tion in these secondary forests.In this study,we analyzed data from two censuses(spanning a five-year interval)conducted in both evergreen broadleaved forests(EBF)and temperate coniferous forests(TCF),which have been recovering for half a century,across elevation gradients in a subtropical mountain region,Mount Wuyi,China.The results indicated that the relative growth rate(RGR)of EBF(0.028±0.001 cm·cm^(-1)·a^(-1))and the mortality rate(MR)(20.03%±1.70%)were 27.3%and 16.4%higher,respec-tively,than those of TCF.Interestingly,the trade-off between RGR and MR in EBF weakened as elevation increased,a trend not observed in TCF.Conversely,TCF consistently showed a stronger trade-off between RGR and MR compared to EBF.Generalized linear mixed models revealed that ele-vation influences RGR both directly and indirectly through its interactions with slope,crown competition index(CCI),and tree canopy height(CH).However,tree mortality did not show a significant correlation with elevation.Additionally,DBH significantly influenced both tree growth and mortal-ity,whereas and CH and CCI had opposite effects on tree growth between EBF and TCF.Our study underscores the importance of elevation in shaping the population dynamics and the biomass carbon sink balance of mountain forests.These insights enhance our understanding of tree species’life strategies,enabling more accurate predictions of forest dynamics and their response to environmental changes.
文摘Indian Pilgrimage in China's Xizang to Resume This Summer Indian pilgrimage to Mount Gang Rinpoche and Lake Mapham Yutso in the Xizang Autonomous Region will resume this summer as agreed between the two countries,according to China's Foreign Ministry.Mount Gang Rinpoche and Lake Mapham Yutso are the sacred mountain and lake for believers of several religions,including Tibetan Buddhism and Hinduism,and thus the pilgrimage is an important part of the cultural and people-to-people exchange between China and India.
