OPTIMUM DESIGN AND NON-LINEAR MODEL OF POWERPLANT HYDRAULIC MOUNT SYSTEM

6-DOF non-linear mechanics model of powerplant hydraulic mount system isestablished. Optimum design of the powerplant hydraulic mount system is made with the hydraulicmount parameters as variables and with uncoupling of energy, rational disposition of naturefrequency and minimum of reactive force at mount's location as objective functions. And based on theoptimum design, software named ODPHMS (optimum design of powerplant hydraulic mount system) used inpowerplant mount system optimum design is developed.

Soil Organic Carbon Stock and Soil Quality under Four Major Agroecosystems in the Eastern Flank of Mount Bambouto (West-Cameroon)

Assessing soil organic carbon stock (SOCS) and soil quality (SQ) helps design better agricultural practices to improve environmental sustainability and productivity. The purpose of the study is to assess SOCS and soil quality SQ in the main agroecosystems (AES) of the eastern flank of Mount Bambouto (West, Cameroon). Using multiple statistics tests and principal component analysis (PCA), SOCS and Soil Quality Index (SQI) were computed for each AES. SOCS and SQI were computed based on soil chemical properties and analysis of variance. Topsoil samples (0 - 30 cm) were collected in a different AES and analyzed in the laboratory. The four AES identified and selected are cultivated land (CL), forest areas (FA), mixed areas (MA), and bush areas (BA). Further, multiple comparison tests were used to compare soils from different AES. PCA was used to select the most appropriate indicators that control SOCS and SQ. Several soil properties showed high to very high coefficient of variation within the AES. Organic matter (OM) was significantly high in FA. SOCS and SQ differ significantly (p = 0.000) between the AES. The study further indicates that the main variables controlling SQ within the eastern flank of Mount Bambouto are OM, pHw, N, C/N, and CEC. While the main soil parameters controlling SOCS are OM, OC, BD, C/N, S, and pHKCl.

Elevational patterns of warming effects on plant community and topsoil properties: focus on subalpine meadows ecosystem

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.

Volcanic Risk Perception and Coping Strategies from Mounts Cameroon and Nyiragongo Eruptions, Central Africa: A Comparative Analysis

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.

Optimization Design and Performance Analysis of Vehicle Powertrain Mounting System

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.

Decoupling Analysis for a Powertrain Mounting System with a Combination of Hydraulic Mounts

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.

Variations of extreme temperature in the Mount Qomolangma region in China during 1971-2020

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.

Cavefish mount a rapid and sustained regenerative response following skeletal muscle injury

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.

Identification of major sources controlling groundwater geochemistry in Mount Makabaï in the Far-North of Cameroon(the northernmost part of the Pan-African Belt)

The present work focuses on the volcanic basement rock geochemistry of Mount Makabaï(MarouaCameroon city)in relation to groundwater geochemistry.Investigations were centered on an approach involving an association of several methods such as geological cartography,hydrogeology,and geochemistry.Three rock samples,four disturbed soil samples,three undisturbed soil samples,and 20 samples of groundwater in 10 wells were collected during fieldwork and prepared for laboratory analyses.Bedrocks exhibit porphyritic,aphyric,and subaphiric textures.The phenocryst phases are mainly olivine,clinopyroxene,and plagioclase.Based on whole rock major element chemical compositions,the Makabaï samples,plotted on Na_(2)O+K_(2)O versus SiO_(2)diagram,are mugearite,hawaiite,and basalt.The ratio of(MgO+CaO)/(Na_(2)O+K_(2)O)exceeds unity and shows dominance of alkaline Earth metals(MgO:2.99-4.48%;CaO:6.19-9.80%)relatively to alkali metals(Na_(2)O:2.27-4.46%;K_(2)O:2.09-2.51%).Exchangeable base contents are high,mostly represented by Ca and Mg,whose contents vary from 14.6 to 35.28 cmol(+)kg^(-1)and from 3.28 to9.48 cmol(+)kg^(-1)respectively.The CECclayis likewise high,fluctuating between 116.80 and181.38 cmol(+)kg^(-1),values in line with the presence of 2:1 clay minerals represented in the study area by montmorillonite.In the water samples,the Ca2+and Na+contents are generally higher than K^(+)and Mg^(2+),reflecting the relative abundance of Na_(2)O and CaO oxides to K_(2)O and MgO oxides in rocks where different waters were sampled.The waters of Makabaï are acidic to neutral(6.3≤pH≤7.4)and weakly to highly mineralized(110.0≤EC≤1190.0μS/cm).Hydro-geochemical classification by using the Piper diagram revealed two water types:(1)CaMg-HCO_(3)(40%)and(2)CaMg-Cl or CaMg-SO4(60%).The average content of ions in all the analyzed samples was HCO_(3)^(-)>>NO_(3)^(-)>SO_(4)^(2-)>Cl-for anions and Ca^(2+)>>Mg^(2+)>Na^(+)>K^(+)for cations.Major mechanisms governing ionic constituents of groundwater in the study area are water-rock interactions,silicate weathering,and ion exchange.

Exploration of the Construction of the National Scenic Byway around Mount Tai

On the basis of traffic,scenic byways can meet tourists’tourism and leisure,catering,accommodation,social,activities,resource protection and so on.In this paper,the concept,functions,characteristics and domestic and foreign research situation of scenic byways were summarized,and the necessity and feasibility of the construction of the national scenic byway around Mount Tai were analyzed.Besides,the route selection,function orientation,construction of supporting facilities,marketing management and construction projects were discussed.Finally,it is pointed out that the construction experience of the national scenic byway around Mount Tai will be used for the construction of national scenic byways in other provinces and autonomous regions,and the national scenic byway around Mount Tai and other national scenic byways will be connected to form the national scenic byway network.It is proposed that relevant departments of the state should formulate national standards,laws and regulations for scenic byways to regulate the construction and development of scenic byways.

Petrochemical Studies of Fouimba and Goma Mounts, Central-West of Cote d’Ivoire: Implication on Petrogenesis Tectonic Setting

Petrogeochemical analysis of mafic rocks of Fouimba and Goma Mount in the Séguéla region (central-western Côte d’Ivoire) is the subject of this study. This analysis combines remote sensing, geophysics, petrography and geochemistry, in order to determine the major characteristics of the mafic formations in the said area, and above all to participate in the detailed mapping of all the Ivorian terrains. The mafic formations encountered in this region are essentially metatonalites to metadiorites, amphibolites, amphibole bearing pyroxenites and porphyry basalts. Chemical analysis indicates that these mafic formations are tonalitic to monzonitic. They are thought to have derived from mantle depleted magmas.

Research on the Exploitation of Study Tour Resources in Mount Taishan

Mount Taishan in Taian Prefecture of Shandong Province has rich study tour resources,but its development efforts are extremely disproportionate to its status as one of the five unique mountains.Through analyzing study tour in the context of its development and study tour resources in Mount Taishan,and based on the in-depth analysis of the existing problems,the proposals for the development of resources were put forward:highlight the main line and enrich the study activities to create study bases around Mount Taishan;improve the study services through the research and development of special products;expand the publicity to promote the educational products and research products.

Mount Taishan:The Supreme of the Five Sacred Mountains

MOUNT Taishan is one of the spiritual symbols of Chinese civilization,and an imperial,ritual place where emperors once paid homage to heaven and earth.Located in the central part of east China’s Shandong Province,Mount Taishan stretches more than 200 kilometers from east to west and 50 kilometers from north to south,with a total area of about 426 square kilometers and a maximum altitude of 1,545 meters.In ancient times.

The Echoes of Ecological Secrets of Mount Qomolangma from Ancient Times

The majestic Mount Qomolangma is the Earth’s highest peak at 8,848 meters above sea level.Located in the Himalaya,it straddles the China-Nepal border.This mighty mountain holds many secrets about the geological history and environmental changes of the Qinghai-Tibetan Plateau.In April 2022,Chinese scientists launched a largescale comprehensive scientific investigation in the Mount Qomolangma region,called the“Earth Summit Mission”.Herein,I am very pleased to recount what occurred to our team’s paleontological field investigation during this scientific endeavor and the one before it.

Ascend Mount Tai to View the World The 37th Mount Tai International Mountain Climbing Festival

From September 3 to 6,"Ascend Mount Tai to View the World"The 37th Mount Tai International Mountain Climbing Festival,jointly sponsored by the Network of International Culturalink Entities of the Ministry of Culture and Tourism,Shandong Provincial Department of Culture and Tourism and the People's Government of Tai'an City,was held in Tai'an City,Shandong Province.

Ascend Mount Tai to View the World

From September 3 to 6,“Ascend Mount Tai to View the World”The 37th Mount Tai International Mountain Climbing Festival,jointly sponsored by the Network of International Culturalink Entities of the Ministry of Culture and Tourism,Shandong Provincial Department of Culture and Tourism and the People's Government of Tai'an City,was held in Tai'an City,Shandong Province.

船载投料系统饲料颗粒流落点预测

【目的】为解决网箱养殖中使用船载投料系统的饲料颗粒流落点控制问题,提出一种用于实时分割饲料颗粒流轨迹并精确预测其落点的方法(MLBP)。【方法】考虑到输料管管内参数及饲料颗粒流出口参数获取难度较大,本研究采用高速相机获取饲料颗粒流轨迹图像,并利用提出的混合网络模型分割饲料颗粒流轨迹,以获取轨迹关键信息;为准确预测饲料颗粒流落点,利用BP神经网络的优势,将轨迹信息及投料口高度作为其输入,实现饲料颗粒流落点的预测。【结果】与相关研究方法对比,结合混合网络模型与BP神经网络的MLBP方法的系统单次运行时间降低95%,同时落点预测准确度达到96%,落点的平均误差范围与平均误差百分比也分别降低32.0%和30.5%。【结论】本研究提出的MLBP方法预测精度及实时性均能满足网箱投饵作业需求,可为相关研究提供参考。

关于压力管道及压力管道元件监管方式的总结与思考

根据现行法规对压力管道、压力管道元件的监管方式进行总结,重点分析了对工厂化预制管段、流量计(壳体)、撬装式承压设备系统和进口压力管道元件的监管。