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Anomaly of the Moist Potential Vorticity Substance with Mass Forcing and Its Application in Diagnosing Mei-Yu Front Rainfall 被引量:1
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作者 ZHOU Yu-Shu ZHU Ke-Feng ZHANG Zhe 《Atmospheric and Oceanic Science Letters》 CSCD 2015年第1期39-44,共6页
The effects of precipitation on the moist potential vorticity substance(MPVS) are investigated by analyzing the MPVS with precipitation mass forcing and its impermeability in daily 1°× 1° data of the Na... The effects of precipitation on the moist potential vorticity substance(MPVS) are investigated by analyzing the MPVS with precipitation mass forcing and its impermeability in daily 1°× 1° data of the National Centers for Environmental Prediction/National Center for Atmospheric Research(NCEP/NCAR) over the Yangtze River Basin from 21 June to 2 July 1999. The results show that the positive MPVS anomalies appear mainly along the Mei-yu front, where the maximum MPVS collocates with the maximum surface rainfall. Rain case diagnoses indicate that the MPVS anomaly may be used as a dynamical signal to detect the location and shift of the rain band when its impermeability is considered. 展开更多
关键词 moist potential VORTICITY substance MASS FORCING i
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Observation on the Clinical Efficacy of Moist Burn Ointment Combined with Rotating Moxibustion in the Treatment of Pressure Ulcers with Deficiency of Qi and Blood
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作者 Song Li Dingxing Zhou 《Journal of Clinical and Nursing Research》 2025年第5期311-318,共8页
Objective:To observe the therapeutic effect of Moist Burn Ointment combined with rotating moxibustion on patients with pressure ulcers and deficiency of both Qi and blood.Methods:40 patients with pressure ulcers and d... Objective:To observe the therapeutic effect of Moist Burn Ointment combined with rotating moxibustion on patients with pressure ulcers and deficiency of both Qi and blood.Methods:40 patients with pressure ulcers and deficiency of both Qi and blood were randomly divided into two groups from July 2024 to November 2025.Group A received Moist Burn Ointment combined with rotating moxibustion,while Group B received Moist Burn Ointment only.Results:Group A showed better efficacy,wound healing time,dressing change frequency,satisfaction,PUSH score,and adverse reaction indicators compared to Group B(P<0.05).Conclusion:The combination of Moist Burn Ointment and rotating moxibustion in the treatment of patients with pressure ulcers and deficiency of both Qi and blood can shorten wound healing time,reduce dressing change frequency,and alleviate the degree of pressure ulcers,which is safe and efficient. 展开更多
关键词 Pressure ulcer Deficiency of both Qi and blood Rotating moxibustion moist Burn Ointment EFFICACY
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Diagnostic Study on the Structural Characteristics of a Typical Mei-yu Front System and Its Maintenance Mechanism 被引量:23
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作者 JIANG Jianying(蒋建莹) +1 位作者 NI Yunqi(倪允琪) 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2004年第5期802-813,共12页
In this paper, a typical mei-yu front process with heavy rainfall from June 12 to 15 in 1998 is analyzed. The results show that the mei-yu front is a front system which consists of an iso-theta(e) dense area with stro... In this paper, a typical mei-yu front process with heavy rainfall from June 12 to 15 in 1998 is analyzed. The results show that the mei-yu front is a front system which consists of an iso-theta(e) dense area with strong horizontal gradient, a deep-convective cloud tower band, a passageway transporting warm and moist air flow from the summer monsoon surge in the mid and low levels to the south of the mei-yu front, and a migrating synoptic scale trough to the north of the mei-yu front, which transports cold and dry air southward in the mid and upper levels. The maintenance of the mei-yu front is realized by: (1) is a positive feedback between the moist physical process enhancing frontogenesis and the development of the strong convective system in front of the mei-yu front; (2) the sustaining system to the north of the mei-yu front which is a migrating synoptic scale trough transporting cold and dry air to the mei-yu front and positive vorticity to the mesoscale system in front of the mei-yu front. 展开更多
关键词 mei-yu front structural characteristics maintenance mechanism moist physical process
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Impacts of Cloud-Induced Mass Forcing on the Development of Moist Potential Vorticity Anomaly During Torrential Rains 被引量:20
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作者 高守亭 周玉淑 +1 位作者 崔晓鹏 戴国平 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2004年第6期923-927,共5页
The impacts of cloud-induced mass forcing on the development of the moist potential vorticity (MPV) anomaly associated with torrential rains are investigated by using NCEP/NCAR 1? × 1? data. The MPV ten... The impacts of cloud-induced mass forcing on the development of the moist potential vorticity (MPV) anomaly associated with torrential rains are investigated by using NCEP/NCAR 1? × 1? data. The MPV tendency equation with the cloud-induced mass forcing is derived, and applied to the torrential rain event over the Changjiang River-Huaihe River Valleys during 26–30 June 1999. The result shows that positive anomalies are located mainly between 850 hPa and 500 hPa, while the maximum MPV, maximum positive tendency of the MPV, and maximum surface rainfall are nearly collocated. The cloud-induced mass forcing contributes to the positive tendency of the moist potential vorticity anomaly. The results indicate that the MPV may be used to track the propagation of rain systems for operational applications. 展开更多
关键词 torrential rain cloud-induced mass forcing moist potential vorticity anomaly
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Diagnostic Analyses and Application of the Moist Ageostrophic Vector Q 被引量:16
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作者 姚秀萍 于玉斌 寿绍文 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2004年第1期96-102,共7页
Considering the main thermal forcing factor, which is critical for the development of synoptic systems, the concept of the moist ageostrophic vector Q is introduced. A formula of the moist ageostrophic Q and the ageos... Considering the main thermal forcing factor, which is critical for the development of synoptic systems, the concept of the moist ageostrophic vector Q is introduced. A formula of the moist ageostrophic Q and the ageostrophic diabatic equation, in which the divergence of the moist ageostrophic Q is taken as a single forcing term, is derived. Meanwhile, the moist ageostrophic Q is applied to diagnose a torrential rain process in North China. The results suggest that the moist ageostrophic Q can clearly reveal the system development during the torrential rain process; the corresponding relationship between the divergence of the moist ageostrophic Q and the rainfall area is better than that of the vertical velocity (w) and the divergence of the dry Q; the 6-h rainfall region can be correctly drawn according to the negative area of the divergence of the moist ageostrophic Q, and its precipitation is positively correlated to the magnitude of the divergence of the moist ageostrophic Q. The research provides valuable information for improving short-term weather forecast. 展开更多
关键词 moist ageostrophic Q diabatic heating effect torrential rain
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Soil Microbial Population Dynamics along a Chronosequence of Moist Evergreen Broad-leaved Forest Succession in Southwestern China 被引量:10
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作者 ZHU Wanze CAI Xiaohu +5 位作者 LIU Xingliang WANG Jinxi CHENG Song ZHANG Xiuyan LI Dengyu LI Maihe 《Journal of Mountain Science》 SCIE CSCD 2010年第4期327-338,共12页
Little is known about whether soil microbial population dynamics are correlated with forest succession.To test the hypotheses that(1) soil microbial composition changes over successional stages,and(2) soil microbial d... Little is known about whether soil microbial population dynamics are correlated with forest succession.To test the hypotheses that(1) soil microbial composition changes over successional stages,and(2) soil microbial diversity is positively correlated with plant species diversity,we determined the soil microbial populations,community composition,and microflora diversity in evergreen broad-leaved forests along a chronosequence of vegetation succession from 5 to 300 years in southwestern China.The soil microbial community was mainly composed of bacteria(87.1-98.7% of the total microorganisms and 10 genera identified),fungi(0.3-4.0%,7 genera),and actinomycetes(2.1-9.1%,8 species and 1 genus).There were significant differences in soil microbial populations among different successional stages and within the four seasons.The seasonal variations of the soil microbial community may be associated with the seasonal changes in environmental conditions.The changes in soil microbial diversity(Shannon-Wiener index) with successional time followed one-humped,convex curves peaked at-100 years since restoration,which is identical with the trends of the aboveground plant diversity.Higher plant diversity resulting in enhanced nutrient flow and root exudation may contribute to positive relationships between the soil microbial diversity and plant diversity.Hence,decreases in soil microbial diversity in the late-successional stages appear to be related to the net loss in species richness that occurs after 100 years since restoration.Our findings confirm the intermediate disturbance hypothesis that suggests diversity peaks at midsuccessional stages. 展开更多
关键词 ACTINOMYCETES Bacteria Fungi Microbial diversity moist evergreen broad-leavedforest Seasonal dynamics
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Study on Moist Potential Vorticity and Symmetric Instabilityduring a Heavy Rain Event Occurred inthe Jiang-Huai Valleys 被引量:15
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作者 寿绍文 李耀辉 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1999年第2期314-321,共8页
In the light of the theory on moist potential vorticity (MPV) investigation was undertaken of the 700 hPa vertical (horizontal) component MP1 (MPV2) for the heavy rain event occurring in July 5–6, 1991. Results show ... In the light of the theory on moist potential vorticity (MPV) investigation was undertaken of the 700 hPa vertical (horizontal) component MP1 (MPV2) for the heavy rain event occurring in July 5–6, 1991. Results show that the distribution features of the two components were closely related to the development of a mesoscale cyclone as a rainstorm-causing weather system in the lower troposphere in such a way that the ambient atmosphere of which MPV1 > 0 and MPV2 < 0 with |MPV1| ≥ |MPV2| favored the genesis of conditional symmetric instability (CSI) and that, as indicated by calculations, a CSI sector was really existent in the lower troposphere during the heavy rain happening and contributed greatly to its development. 展开更多
关键词 Heavy rain moist potential vorticity (MPV) Conditional symmetric instability
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Diagnosis of a Moist Thermodynamic Advection Parameter in Heavy-Rainfall Events 被引量:12
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作者 吴贤笃 冉令坤 楚艳丽 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2011年第4期957-972,共16页
A moist thermodynamic advection parameter, defined as an absolute value of the dot product of hori- zontal gradients of three-dimensional potential temperature advection and general potential temperature, is introduce... A moist thermodynamic advection parameter, defined as an absolute value of the dot product of hori- zontal gradients of three-dimensional potential temperature advection and general potential temperature, is introduced to diagnose frontal heavy rainfall events in the north of China. It is shown that the parameter is closely related to observed 6-h accumulative surface rainfall and simulated cloud hydrometeors. Since the parameter is capable of describing the typical vertical structural characteristics of dynamic, thermodynamic and water vapor fields above a strong precipitation region near the front surface, it may serve as a physical tracker to detect precipitable weather systems near to a front. A tendency equation of the parameter was derived in Cartesian coordinates and calculated with the simulation output data of a heavy rainfall event. Results revealed that the advection of the parameter by the three-dimensional velocity vector, the covariance of potential temperature advection by local change of the velocity vector and general potential temperature, and the interaction between potential temperature advection and the source or sink of general potential temperature, accounted for local change in the parameter. This indicated that the parameter was determined by a combination of dynamic processes and cloud microphysical processes. 展开更多
关键词 moist thermodynamic advection parameter potential temperature advection general potential temperature heavy rainfall event
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Assessment of Several Moist Adiabatic Processes Associated with Convective Energy Calculation 被引量:7
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作者 李耀东 高守亭 刘健文 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2004年第6期941-950,共10页
Several methods dealing with the moist adiabatic process are described in this paper. They are based on static energy conservation, pseudo-equivalent potential temperature conservation, the strict pseudo- adiabati... Several methods dealing with the moist adiabatic process are described in this paper. They are based on static energy conservation, pseudo-equivalent potential temperature conservation, the strict pseudo- adiabatic equation, and the reversible moist adiabatic process, respectively. Convective energy parame- ters, which are closely related to the moist adiabatic process and which re?ect the gravitational e?ects of condensed liquid water, are reintroduced or de?ned, including MCAPE [Modi?ed-CAPE (convective avail- able potential energy)], DCAPE (Downdraft-CAPE), and MDCAPE (Modi?ed-Downdraft-CAPE). Two real case analyses with special attention given to condensed liquid water show that the selection of moist adiabatic process does a?ect the calculated results of CAPE and the gravitational e?ects of condensed liq- uid water are not negligible in severe storms. Intercomparisons of these methods show that static energy conservation is consistent with pseudo-equivalent potential temperature conservation not only in physical properties but also in calculated results, and both are good approximations to the strict pseudo-adiabatic equation. The lapse rate linked with the reversible moist adiabatic process is relatively smaller than that linked with other moist adiabatic processes, especially when considering solidi?cation of liquid water in the reversible adiabatic process. 展开更多
关键词 moist adiabatic processes modified convective available potential energy downdraft con-vective available potential energy modified downdraft convective available potential energy reversible moist adiabatic process liquid water
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A Numerical Study of Mesoscale Vortex Formation in the Midlatitudes:The Role of Moist Processes 被引量:6
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作者 Yongqiang JIANG Yuan WANG +2 位作者 Chaohui CHEN Hongrang HE Hong HUANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2019年第1期65-78,共14页
In this study, a three-dimensional mesoscale model was used to numerically simulate the well-known "98.7" heavy rainfall event that affected the Yangtze Valley in July 1998. Two experiments were conducted to... In this study, a three-dimensional mesoscale model was used to numerically simulate the well-known "98.7" heavy rainfall event that affected the Yangtze Valley in July 1998. Two experiments were conducted to analyze the impact of moist processes on the development of meso-β scale vortices(MβV) and their triggering by mesoscale wind perturbation(MWP). In the experiment in which the latent heat feedback(LHF) scheme was switched off, a stable low-level col field(i.e., saddle field—a region between two lows and two highs in the isobaric surface) formed, and the MWP triggered a weak MβV. However, when the LHF scheme was switched on as the MWP was introduced into the model, the MβV developed quickly and intense rainfall and a mesoscale low-level jet(mLLJ) were generated. The thickness of the air column and average temperature between 400 and 700 hPa decreased without the feedback of latent heat, whereas they increased quickly when the LHF scheme was switched on, with the air pressure falling at low levels but rising at upper levels. A schematic representation of the positive feedbacks among the mesoscale vortex, rainfall, and mLLJ shows that in the initial stage of the MβV, the MWP triggers light rainfall and the latent heat occurs at low levels, which leads to weak convergence and ageostrophic winds. In the mature stage of the MβV, convection extends to the middle-to-upper levels, resulting in an increase in the average temperature and a stretching of the air column. A low-level cyclonic circulation forms under the effect of Coriolis torque, and the m LLJ forms to the southeast of the MβV. 展开更多
关键词 moist process latent heat feedback mesoscale vortex col field
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Treating aplasia cutis congenita in a newborn with the combination of ionic silver dressing and moist exposed burn ointment: A case report 被引量:4
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作者 Guo-Feng Lei Jun-Ping Zhang +6 位作者 Xiao-Bing Wang Xiao-Li You Jin-Ya Gao Xiao-Mei Li Mei-Ling Chen Xiu-Qin Ning Jiang-Li Sun 《World Journal of Clinical Cases》 SCIE 2019年第17期2611-2616,共6页
BACKGROUND Aplasia cutis congenita (ACC) in newborns is a condition in which congenital defects or hypoplasia is present in part of the epidermis,dermis and even subcutaneous tissue (including muscle and bones).First ... BACKGROUND Aplasia cutis congenita (ACC) in newborns is a condition in which congenital defects or hypoplasia is present in part of the epidermis,dermis and even subcutaneous tissue (including muscle and bones).First reported by Cordon in 1767,ACC is a rare disease with a low incidence of 1/100000 to 3/10000.Currently,there are 500 cases reported worldwide.ACC can be accompanied by other malformations.The onset mechanism of the disease remains unknown but is thought to be correlated to factors such as genetics,narrow uterus,foetal skin and amniotic membrane adhesion,use of teratogenic drugs in early pregnancy and viral infection.CASE SUMMARY In August 2018,we treated a newborn with ACC on the left lower limbs using a combination of ionic silver dressing and moist exposed burn ointment (MEBO) and achieved a satisfactory treatment outcome.The skin defects were observed on the external genitals and on areas from the left foot to 3/4 of the upper left side.Subcutaneous tissue and blood vessels were observed in the regions with skin defects.The following treatments were provided.First,the wound was rinsed with 0.9% sodium chloride solution followed by disinfection with povidone-iodine twice.And then MEBO was applied to the wound at a thickness of approximately 1 mm.After applying ionic silver dressing,the wound was covered with sterile gauze.The wound dressing was replaced every 2-3 d.At the 4-mo follow-up,the treatment outcome was satisfactory.There was minimal scar tissue formation,and limb function was not impaired.CONCLUSION The combination of ionic silver dressing and MEBO to ACC is helpful. 展开更多
关键词 APLASIA cutis congenita Newborns IONIC SILVER DRESSING moist EXPOSED burn OINTMENT
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Physical Mechanism of Formation of the Bimodal Structure in the Meiyu Front System 被引量:4
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作者 崔晓鹏 高守亭 +2 位作者 宗志平 刘文明 李小凡 《Chinese Physics Letters》 SCIE CAS CSCD 2005年第12期3218-3220,共3页
The bimodal structure of the Meiyu front system is readdressed after Zhou et al.(2005). The physical mechanism of the formation of the bimodal distribution is discussed. The bimodal structure of the Melyu front syst... The bimodal structure of the Meiyu front system is readdressed after Zhou et al.(2005). The physical mechanism of the formation of the bimodal distribution is discussed. The bimodal structure of the Melyu front system considerably results from atmospheric moisture gradients, though atmospheric temperature gradients are also not negligible. According to the definition of equivalent potential temperature, and by scale analysis, we find that atmospheric equivalent potential temperature gradients, which could be regarded as an indicator of the Meiyu front system, could be mainly attributed to the variations of atmospheric potential temperature gradients with a scaling factor of 1 and moisture gradients multiplied by a scaling factor of an order of about 2.5 × 10^3, which means that small variations of atmospheric moisture gradients could lead to large variations of equivalent potential temperature gradients, and thus large variations of the Meiyu front system. Quantitative diagnostics with a mesoscale simulation data in the vicinity of the Meiyu front system show that moisture gradients contribute to equivalent potential temperature gradients more than potential temperature gradients. 展开更多
关键词 SLANTWISE VORTICITY DEVELOPMENT moist POTENTIAL VORTICITY ASIANSUMMER MONSOON EAST CHINA SEA SCALE STRUCTURE PART II REGION CONVERGENCE TRANSPORT FEATURES
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Structure and regeneration status of Komto Afromontane moist forest, East Wollega Zone, west Ethiopia 被引量:4
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作者 Fekadu Gurmessa Teshome Soromessa Ensermu Kelbessa 《Journal of Forestry Research》 CAS CSCD 2012年第2期205-216,共12页
We conducted a study in Komto Forest in East WoUega Zone, Oromia National Regional State, West Ethiopia for determining vegetation structure and regeneration status in this forest. We systematically sampled 53 quadra... We conducted a study in Komto Forest in East WoUega Zone, Oromia National Regional State, West Ethiopia for determining vegetation structure and regeneration status in this forest. We systematically sampled 53 quadrats (20 m ×20 m) along line transects radiating from the peak of Komto Mountain in eight directions. Vegetation parameters such as DBH, height, seedling and sapling density of woody species, and location and altitude of each quadrat were recorded. In total, 103 woody plant species of 87 genera and 45 families were identified. Analysis of selected tree species revealed different population structures. Generally, the forest was dominated by small trees and shrubs characteristic of secondary regeneration. Observations on the regeneration of the forest indicated that there are woody species that require urgent conservation measures. Based on the results of this study, we recommend detailed ecological studies of various environmental factors such as soil type and properties, and ethnobotanical studies to explore indigenous knowledge on uses of plants. 展开更多
关键词 East Wollega Komto Forest moist montane forest regen- eration status structural analysis
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Tree species diversity and stand structure along major community types in lowland primary and secondary moist deciduous forests in Tripura,Northeast India 被引量:4
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作者 Koushik Majumdar Uma Shankar Badal Kumar Datta 《Journal of Forestry Research》 CAS CSCD 2012年第4期553-568,共16页
Tree species diversity and population structure at different community types were described and analyzed for primary and secondary lowland moist deciduous forests in Tripura. Overall 10,957 individual trees belonging ... Tree species diversity and population structure at different community types were described and analyzed for primary and secondary lowland moist deciduous forests in Tripura. Overall 10,957 individual trees belonging to 46 family, 103 genera and 144 species were counted at ≥30 cm DBH (diameter at breast height) using 28 permanent belt transects with a size of 1 ha (10 m × 1000 m). Four different tree communities were identified. The primary forests was dominated by Shorea robusta (mean density 464.77 trees.ha^-1, 105 species) and Schima wallichii (336.25 trees.ha^-1, 82 species), while the secondary forests was dominated by Tectona grandis (333.88 trees.ha^-1, 105 species) and Hevea brasiliensis (299.67 trees.ha^-1, 82 species). Overall mean basal area in this study was 18.01m2.ha^-1; the maximum value was recorded in primary Shorea forest (26.21 m2.ha^-1). Mean density and diversity indices were differed significantly within four different communities. No significant differences were observed in number of species, genera, family and tree basal cover area. Significant relationships were found between the species richness and different tree population groups across the communities. Results revealed that species diversity and density were increased in those forests due to past disturbances which resulted in slow accumu- lation of native oligarchic small tree species. Seventeen species were recorded with 〈2 individuals of which Saraca asoka (Roxb.) de Wilde and Entada phaseoloides (L.) Men'. etc. extensively used in local ethnomedicinal formulations. The present S. robusta Gaertn dominated forest was recorded richer (105 species) than other reported studies. Moraceae was found more speciose family instead of Papilionaceae and Euphorbiaceae than other Indian moist deciduous forests. Seasonal phenological gap in such moist deciduous forests influenced the population of Trachypithecus pileatus and capped langur. The analysis of FIV suggested a slow trend of shifting the population of Lamiaceae group by Moraceae species in secondary T. grandis L. dominated community. 展开更多
关键词 diversity and stand structure moist deciduous forest species conservation tree community types
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The Impact of Moist Physics on the Sensitive Area Identification for Heavy Rainfall Associated Weather Systems 被引量:3
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作者 Huizhen YU Zhiyong MENG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2022年第5期684-696,共13页
The impact of moist physics on the sensitive areas identified by conditional nonlinear optimal perturbation(CNOP)is examined based on four typical heavy rainfall cases in northern China through performing numerical ex... The impact of moist physics on the sensitive areas identified by conditional nonlinear optimal perturbation(CNOP)is examined based on four typical heavy rainfall cases in northern China through performing numerical experiments with and without moist physics.Results show that the CNOP with moist physics identifies sensitive areas corresponding to both the lower-(850−700 hPa)and upper-level(300−100 hPa)weather systems,while the CNOP without moist physics fails to capture the sensitive areas at lower levels.The reasons for the CNOP peaking at different levels can be explained in both algorithm and physics aspects.Firstly,the gradient of the cost function with respect to initial perturbations peaks at the upper level without moist physics which results in the upper-level peak of the CNOP,while it peaks at both the upper and lower levels with moist physics which results in both the upper-and lower-level peaks of the CNOP.Secondly,the upper-level sensitive area is associated with high baroclinicity,and these dynamic features can be captured by both CNOPs with and without moist physics.The lower-level sensitive area is associated with moist processes,and this thermodynamic feature can be captured only by the CNOP with moist physics.This result demonstrates the important contribution of the initial error of lower-level systems that are related to water vapor transportation to the forecast error of heavy rainfall associated weather systems,which could be an important reference for heavy rainfall observation targeting. 展开更多
关键词 moist physics heavy rainfall sensitive area CNOP
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Application and Characteristic Analysis of the Moist Singular Vector in GRAPES-GEPS 被引量:3
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作者 Jing WANG Bin WANG +3 位作者 Juanjuan LIU Yongzhu LIU Jing CHEN Zhenhua HUO 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2020年第11期1164-1178,共15页
The singular vector(SV)initial perturbation method can capture the fastest-growing initial perturbation in a tangent linear model(TLM).Based on the global tangent linear and adjoint model of GRAPES-GEPS(Global/Regiona... The singular vector(SV)initial perturbation method can capture the fastest-growing initial perturbation in a tangent linear model(TLM).Based on the global tangent linear and adjoint model of GRAPES-GEPS(Global/Regional Assimilation and Prediction System-Global Ensemble Prediction System),some experiments were carried out to analyze the structure of the moist SVs from the perspectives of the energy norm,energy spectrum,and vertical structure.The conclusions are as follows:The evolution of the SVs is synchronous with that of the atmospheric circulation,which is flowdependent.The moist and dry SVs are located in unstable regions at mid-to-high latitudes,but the moist SVs are wider,can contain more small-and medium-scale information,and have more energy than the dry SVs.From the energy spectrum analysis,the energy growth caused by the moist SVs is reflected in the relatively small-scale weather system.In addition,moist SVs can generate perturbations associated with large-scale condensation and precipitation,which is not true for dry SVs.For the ensemble forecasts,the average anomaly correlation coefficient of large-scale circulation is better for the forecast based on moist SVs in the Northern Hemisphere,and the low-level variables forecasted by the moist SVs are also improved,especially in the first 72 h.In addition,the moist SVs respond better to short-term precipitation according to statistical precipitation scores based on 10 cases.The inclusion of the large-scale condensation process in the calculation of SVs can improve the short-term weather prediction effectively. 展开更多
关键词 moist singular vector GRAPES-GEPS adjoint model ensemble prediction
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Sensitivity of Cyclone Tracks to the Initial Moisture Distribution:A Moist Potential Vorticity Perspective 被引量:3
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作者 Zuohao CAO Da-Lin ZHANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2005年第6期807-820,共14页
In this study, the characteristics of moist potential vorticity (MPV) in the vicinity of a surface cyclone center and their physical processes axe investigated. A prognostic equation of surface absolute vorticity is... In this study, the characteristics of moist potential vorticity (MPV) in the vicinity of a surface cyclone center and their physical processes axe investigated. A prognostic equation of surface absolute vorticity is then used to examine the relationship between the cyclone tracks and negative MPV (NMPV) using numerical simulations of the life cycle of an extratropical cyclone. It is shown that the MPV approach developed herein, i.e., by tracing the peak NMPV, can be used to help trace surface cyclones during their development and mature stages. Sensitivity experiments are conducted to investigate the impact of different initial moisture fields on the effectiveness of the MPV approach. It is found that the lifetime of NMPV depends mainly on the initial moisture field, the magnitude of condensational heating, and the advection of NMPV. When NMPV moves into a saturated environment at or near a cyclone center, it can trace better the evolution of the surface cyclone due to the conservative property of MPV. It is also shown that the NMPV generation is closely associated with the coupling of large potential temperature and moisture gradients as a result of frontogenesis processes. Analyses indicate that condensation, confluence and tilting play important but different roles in determining the NMPV generation. NMPV is generated mainly through the changes in the strength of baroclinicity and in the direction of the moisture gradient due to moist and/or dry air mass intrusion into the baroclinic zone. 展开更多
关键词 cyclone tracks moist potential vorticity mid-latitude cyclones
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Effect of moisture and fungal exposure on the mechanical properties of hem-fir plywood 被引量:2
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作者 WANG Wei-hong Scott Kent +2 位作者 Camille Freitag Rorbert J. leichti Jeffrey J. Morrell 《Journal of Forestry Research》 SCIE CAS CSCD 2005年第4期299-300,共2页
Hem-fir plywood were exposed to two brown rot fungi, Gloeophyllum trabeum and Postia placenta, and one white rot fungus, Trametes versicolor, to investigate the effect of fungal decay on mechanical properties of plywo... Hem-fir plywood were exposed to two brown rot fungi, Gloeophyllum trabeum and Postia placenta, and one white rot fungus, Trametes versicolor, to investigate the effect of fungal decay on mechanical properties of plywood. Results showed that modulus of rupture (MOR) and modulus of elasticity (MOE) of hem-fir plywood declined significantly by inoculating fungi, and weight loss of sample had a modest decrease. The fungi also made a greater effect on MOR than on MOE. Of three fungi, Postia placenta caused a most significant weight loss, and Gloeophyllum trabeum resulted in a largest flexural properties loss. Substantial declines in MOR and MOE of hem-fir plywood were also observed when the plywood samples were stored under wet conditions over 15 weeks, even in the absence of fungal attack. 展开更多
关键词 Fungus decay Weight loss Flexural properties moist condition PLYWOOD MOR MOE
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External Heat Transfer in Moist Air and Superheated Steam for Softwood Drying 被引量:2
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作者 PANGShusheng 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2004年第6期762-766,共5页
In kiln drying of softwood timber, external heat and moisture mass transfercoefficients are important in defining boundary temperature and moisture content at the woodsurface. In addition, superheated steam drying of ... In kiln drying of softwood timber, external heat and moisture mass transfercoefficients are important in defining boundary temperature and moisture content at the woodsurface. In addition, superheated steam drying of wood is a promising technology but this has notbeen widely accepted commercially, partially due to the lack of understanding of the dryingphenomena occurred during drying. In this work, experimental investigation was performed to quantifythe heat transfer between wood surface and surrounding moist air or superheated steam. In theexperiment, saturated radiata pine sapwood samples were dried using dry-bulb/wet-bulb temperaturesof 60℃/50℃, 90℃/60℃, 120℃/70℃, 140℃/90℃, 160℃/90℃, 140℃/100℃ and 160℃/100℃. The lasttwo schedules were for superheated steam drying as the wet-bulb temperature was set at 100℃. Thecirculation velocity over the board surface was controlled at 4.2m·s^(-1). Two additional runs(90℃/60℃) using air velocities of 2.4 m·s^(-1) and 4.8 m·s^(-1) were performed to check theeffect of the circulation velocity. During drying, sample weight and temperatures at wood surfaceand different depths were continuously measured. Prom these measurements, changes in woodtemperature and moisture content were calculated and external heat-transfer coefficient wasdetermined for both the moist air and the superheated steam drying. 展开更多
关键词 wood drying external heat transfer coefficient moist air moisture content softwood timber superheated steam
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A Modified Moist Ageostrophic Q Vector 被引量:2
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作者 岳彩军 寿绍文 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2008年第6期1053-1061,共9页
The quasi-geostrophic Q vector is an important rainfall associated with large-scale weather systems diagnostic tool for studying development of surface and is calculated using data at single vertical level. When ageos... The quasi-geostrophic Q vector is an important rainfall associated with large-scale weather systems diagnostic tool for studying development of surface and is calculated using data at single vertical level. When ageostrophic Q vector was introduced, it required data at two vertical levels. In this study, moist ageostrophic Q vector is modified so that it can be calculated using data at a single vertical level. The comparison study between the original and modified moist ageostrophic Q vectors is conducted using the data from 5 to 6 July 1991 during the torrential rainfall event associated with the Changjiang-Huaihe mei-yu front in China. The results reveal that divergences of original and modified moist ageostrophic Q vectors have similar horizontal distributions and their centers are almost located in the precipitation centers. This indicates that modified moist ageostrophic Q vector can be used to diagnose convective development with reasonable accuracy. 展开更多
关键词 moist ageostrophic Q vector MODIFICATION latent heating torrential rainfall associated with mei-yu front
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