[Objective] This study was tween yield-related traits and yield of conducted to understand the relationship be- Yunmai 52 which is a high-quality high-yield multi-resistant new wheat variety, and make contribution of ...[Objective] This study was tween yield-related traits and yield of conducted to understand the relationship be- Yunmai 52 which is a high-quality high-yield multi-resistant new wheat variety, and make contribution of yield-related traits to the yield of Yunmai 52 clear. [Method] Wheat variety regional trial data in Yunnan Province in 2005-2007 were subjected to correlation analysis and path analysis in the paper. [Result] Correlationanalysis showed that the yield of Yunmai 52 was in- very significant positive correlation with spikelet number per ear, maximum tiller number and grains per ear (r=0.726^**, 0.717^** and 0.695^**, respectively), in signif- icant positive correlation with 1 000-grain weight (r=0.491^*), but in significant nega- tive correlation with sterile spikelet number per ear, and in non-significant correlation with basic seedlings, effective ears and percentage of ear bearing tillers. Partial correlation analysis showed that the yield of Yunmai 52 was in very significant posi- tive correlation with spikelet number per ear (r=0.711^**), significant positive correla- tion with 1 000-grain weight (r=0.641 =), but in non-significant correlation with other 6 traits. Path analysis showed that spikelet number per ear (P=-0.595), maximum tiller number (P=0.462) and t 000-grain weight (P=0.263) had more contribution to yield of Yunmai 52. [Conclusion] Therefore, in extension and application of Yunmal 52 that is a high-quality high-yield multi-resistant new wheat variety, supply of fertilizer and water should be increased in tillering stage and jointing stage, to ensure its characteristics of high tilledng ability and large ear, as well as high 1 000-grain weight, and coordinated development of other yield-related traits is beneficial to im- provement of yield of Yunmai 52.展开更多
A located field experiment was carried out to study the effects of different amount of chemical fertilizer usage on rice yield,economic benefits of rice,soil carbon(C) and total nitrogen(TN) under ploughing back o...A located field experiment was carried out to study the effects of different amount of chemical fertilizer usage on rice yield,economic benefits of rice,soil carbon(C) and total nitrogen(TN) under ploughing back of Chinese milk vetch for 5consecutive years.Six treatments were included in the experiment,they are CK(unfertilized),CF(100% chemical fertilizer with the amount of N,P2O5,K2 O being150,75,120 kg/hm^2respectively),A1(22 500 kg/hm^2 Chinese milk vetch and 100%chemical fertilizer),A2(Chinese milk vetch and 80% nitrogen and potassium fertilizer and 100% phosphate fertilizer),A3(Chinese milk vetch and 60% nitrogen and potassium fertilizer and 100% phosphate fertilizer),A4(Chinese milk vetch and 40% nitrogen and potassium fertilizer and 100% phosphate fertilizer).The results were as follows:application of fertilizer could increase the yield of rice,while Chinese milk vetch combined with fertilizer application had a much more increase effect in rice yield.Under the condition of milk vetch application with 22 500 kg/hm^2,the early rice yield of the treatment A1 was significantly increased by 7.7% compared with that of CF.And the yield of treatment A3 was basically identical to or slight increase in comparison with that of CF.Decreasing amount of fertilizers cloud improve output value of rice in the case of the utilization of Chinese milk vetch.The treatment A1 increased output value of rice by 5.92% in comparison of CF,and treatment A2 was by 4.08% in the next.Treatment A4 showed much better effect in increasing soil organic carbon and total nitrogen in the paddy soil than those of treatments applying mineral fertilizer only.There was a significant reduction on soil organic carbon and TN in treatment A2 in comparison with that of CF.In general,amount of application of milk vetch with 22 500 kg/hm^2 could replace chemical fertilizer partially,it also could improve rice yield,decrease the production cost,and raise the utilization efficiency of nutrients.展开更多
In order to investigate the distribution of soil available micronutrients, and provide a theoretical basis for management of fertilizing reasonably on crops, the contents of major and trace elements (P, K, Ca, Mg, Cu...In order to investigate the distribution of soil available micronutrients, and provide a theoretical basis for management of fertilizing reasonably on crops, the contents of major and trace elements (P, K, Ca, Mg, Cu, Fe, Zn, and Mn) in farm- land soil collected from Yunnan Province were determined by inductively coupled plasma-mass spectrometry (ICP-MS), the contents and distribution of major and trace elements were also studied. The results showed that the contents of available P, K were balance, available Ca, Mg were deficient, and available Cu, Fe, Zn, Mn were very plentiful. Major and trace elements distribution of different landform areas were obviously different. The contents of trace elements (Fe, Zn and Mn) of central Yunnan Red Plateau were significantly higher than those of Hengduan Mountains in western Yunnan and those of karst plateau in eastern Yunnan. The contents of available P, K, and Ca gradually declined from west to east, while the content of available Cu rose gradually from west to east. The results are reference value to elements determination and agricultural production in farmland soils.展开更多
[Objective] The effects of ploughing Astragalus sinicus at maturity stage as green manure on paddy soil properties were studied to provide references for ad- vancing the green manure production and field sustainable d...[Objective] The effects of ploughing Astragalus sinicus at maturity stage as green manure on paddy soil properties were studied to provide references for ad- vancing the green manure production and field sustainable development. [Methods] A three-year field positioning experiment was carried out. In the first year, five differ- ent levels (0, 2.81, 5.61, 8.42, 11.23 t/hm~) of Astragalus sinicus ploughed at matu- rity stage were designed. And in the next two years, the amounts of ploughed As- tragalus sinicus at maturity stage were based on the natural growth amounts of As- tragalus sinicus at maturity stage of the former year in each plot field. The yields of Astragalus sinicus at maturity stage were estimated and ploughed directly before rice transplanting. Rice yield, soil nutrients, biological properties and water-stable aggre- gates of paddy fields were measured as well. [Results] The effective panicles and rice yields increased significantly after ploughing Astragalus sinicus at maturity stage. Meanwhile, the organic acid content in paddy field increased and the activities of soil phosphatases, invertase and catalase were higher. The soil dissolved organic carbon also increased with the increasing application of green manure. However, excess amount of green manure inhibited the soil microbial biomass carbon content. The macro aggregates and micro aggregates gathered to middle aggregates. [Conclusion] As green manure, the use of Astragalus sinicus at maturity stage could improve soil physiochemical and biological properties, improve soil fertility and increase rice yield significantly. But the ploughing amount of Astragalus sinicus at maturity stage before rice transplanting should be less than 8.42 t/hm2 (dry weight.展开更多
We have studied the efficiency of energy consumption in the comminution of mica powder with cavitation abrasive water jet technology. The energy required to create new surfaces in the comminution of mica powder with c...We have studied the efficiency of energy consumption in the comminution of mica powder with cavitation abrasive water jet technology. The energy required to create new surfaces in the comminution of mica powder with cavitation abrasive water jet was calculated,in order to estimate its efficiency of energy consumption. The particle size distribution and the specific surface area were measured by applying a JEM-200CX transmission electron microscope and an Autosorb-1 automatic surface area analyzer. The study results show that the efficiency of energy consumed in creating new surface areas is as high as 2.92%,or 4.94% with the aid of cavitation in the comminution of mica powder. This efficiency will decrease with an increase in the number of comminutions. After three comminutions,the efficien-cies will become 1.91% and 2.29% for comminution without cavitation and with cavitation,respectively. The abrasive water jet technology is an effective way for comminution of mica powder.展开更多
The wet canopy evaporation rate (Er) wascalculated by Penman-Monteith combination model based on three assumptions and with meteorological variables 2 m above the canopy inthree stands, dominated by spruce (SF), fir (...The wet canopy evaporation rate (Er) wascalculated by Penman-Monteith combination model based on three assumptions and with meteorological variables 2 m above the canopy inthree stands, dominated by spruce (SF), fir (FF) and birch (BF) trees, respectively[(,)( )]in the subalpineforests in western Sichuan, China over a growingseason. The total amount of the E was 44.5 mm forSF, 88.5 mm for FF and 57.8 mm for BF, accounting for 9.2%, 16.6% and 10.2% of the gross rainfall,respectively, in the measuring period. There was the highest average monthly Er and percentage of E togross rainfall for FF compared with SF and BF.Mean Er was 0.097 mm h-1 (ranging from 0.028 to0.487 mm h-1), 0.242 mm h-1 (from 0.068 to 0.711 mm h-1) and 0.149 mm h-1 (from 0.060 to 0.576 mm h-1for SF, FF and BF, respectively. The highest average monthly Er occurred in June was 0.120 mm h-1 forSF, 0.317 mm h-1 for FF and 0.169 mm h-1 for BF, and the lowest value in October was 0.083 mm h-1 for SF, 0.187 mm h-1 for FF and 0.101 mm h-1 for BF,respectively. The averages of Er from 8:00 to 16:00were significantly higher than those from 0:00 to8:00 and from 16:00 to 0:00 for the three stands. The marked daily and monthly differences of Er were contributable to the variations of solar radiation, air temperature and relative humidity above thecanopy.展开更多
Southeast China has comparable stratus cloud to that over the oceans,especially in the cold seasons(winter and spring),and this cloud has a substantial impact on energy and hydrological cycles.However,uncertainties re...Southeast China has comparable stratus cloud to that over the oceans,especially in the cold seasons(winter and spring),and this cloud has a substantial impact on energy and hydrological cycles.However,uncertainties remain across datasets and simulation results about the long-term trend in low-cloud cover in Southeast China,making it difficult to understand climate change and related physical processes.In this study,multiple datasets and numerical simulations were applied to show that low-cloud cover in Southeast China has gone through two stages since 1980—specifically,a decline and then a rise,with the turning point around 2008.The regional moisture transport plays a crucial role in low-cloud cover changes in the cold seasons and is mainly affected by the Hadley Cell in winter and the Walker Circulation in spring,respectively.The moisture transport was not well simulated in CMIP6 climate models,leading to poor simulation of the low-cloud cover trend in these models.This study provides insights into further understanding the regional climate changes in Southeast China.展开更多
The Cloud Feedback Model Intercomparisons Project (CFMIP) Observation Simulator Package (COSP) is adopted in the Grid-point Atmospheric Model of IAP LASG (GAMIL2) during CFMIP at Phase II to evaluate the model cloud f...The Cloud Feedback Model Intercomparisons Project (CFMIP) Observation Simulator Package (COSP) is adopted in the Grid-point Atmospheric Model of IAP LASG (GAMIL2) during CFMIP at Phase II to evaluate the model cloud fractions in a consistent way with satellite observations. The cloud simulation results embedded in the Atmospheric Model Intercomparison Project (AMIP) control experiment are presented using three satellite simulators: International Satellite Cloud Climatology Project (ISCCP), Moderate Resolution Imaging Spectroradiometer (MODIS), and Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) lidar onboard the Cloud- Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). Overall, GAMIL2 can produce horizontal distributions of the low cloud fraction that are similar to the satellite observations, and its similarities to the observations on different levels are shown in Taylor diagrams. The discrepancies among satellite observations are also shown, which should be considered during evaluation.展开更多
Total Cloud Cover (TCC) over China deter- mined from four climate datasets including the Interna- tional Satellite Cloud Climatology Project (ISCCP), the 40-year Re-Analysis Project of the European Centre for Medi...Total Cloud Cover (TCC) over China deter- mined from four climate datasets including the Interna- tional Satellite Cloud Climatology Project (ISCCP), the 40-year Re-Analysis Project of the European Centre for Medium-Range Weather Forecasts (ERA-40), Climate Research Unit Time Series 3.0 (CRU3), and ground sta- tion datasets are used to show spatial and temporal varia- tion of TCC and their differences. It is demonstrated that the four datasets show similar spatial pattern and seasonal variation. The maximum value is derived from ISCCE TCC value in North China derived from ERA-40 is 50% larger than that from the station dataset; however, the value is 50% less than that in South China. The annual TCC of ISCCP, ERA-40, and ground station datasets shows a decreasing trend during 1984-2002; however, an increasing trend is derived from CRU3. The results of this study imply remarkable differences of TCC derived from surface and satellite observations as well as model simu- lations. The potential effects of these differences on cloud climatology and associated climatic issues should be carefully considered.展开更多
In light of the problems of low-quality and low degree of comprehensive utilization of Guangdong muscovite-type kaolin, the reasons affecting the quality of kaolin were found to be a small amount of maroon powdery goe...In light of the problems of low-quality and low degree of comprehensive utilization of Guangdong muscovite-type kaolin, the reasons affecting the quality of kaolin were found to be a small amount of maroon powdery goethite adhering to the surface of kaolin and minor muscovite affecting the firing whiteness of products. The ores were dealt with by using the new combined process of attritioning-classifieation-bleaching and flotation. The separation of kaolin from muscovite, quartz and feldspar can come true through the new process. The high-quality kaolin with the firing whiteness of 91% can be obtained, and the muscovite is comprehensively recovered by adopting the key technology of flotation. The content of high-purity muscovite produced is over 99%. The muscovite discarded by original process can be comprehensively recovered.展开更多
Cloud distribution characteristics over the Tibetan Plateau in the summer monsoon period simulated by the Australian Community Climate and Earth System Simulator(ACCESS) model are evaluated using COSP [the CFMIP(Cloud...Cloud distribution characteristics over the Tibetan Plateau in the summer monsoon period simulated by the Australian Community Climate and Earth System Simulator(ACCESS) model are evaluated using COSP [the CFMIP(Cloud Feedback Model Intercomparison Project) Observation Simulator Package]. The results show that the ACCESS model simulates less cumulus cloud at atmospheric middle levels when compared with observations from CALIPSO and CloudSat, but more ice cloud at high levels and drizzle drops at low levels. The model also has seasonal biases after the onset of the summer monsoon in May. While observations show that the prevalent high cloud at 9–10 km in spring shifts downward to 7–9 km,the modeled maximum cloud fractions move upward to 12–15 km. The reason for this model deficiency is investigated by comparing model dynamical and thermodynamical fields with those of ERA-Interim. It is found that the lifting effect of the Tibetan Plateau in the ACCESS model is stronger than in ERA-Interim, which means that the vertical velocity in the ACCESS model is stronger and more water vapor is transported to the upper levels of the atmosphere, resulting in more high-level ice clouds and less middle-level cumulus cloud over the Tibetan Plateau. The modeled radiation fields and precipitation are also evaluated against the relevant satellite observations.展开更多
The Chinese Academy of Sciences Flexible Global Ocean-Atmosphere-Land System atmospheric component model(FGOALS-f3-L)participated in Phase 6 of the Coupled Model Intercomparison Project,but its reproducibility of surf...The Chinese Academy of Sciences Flexible Global Ocean-Atmosphere-Land System atmospheric component model(FGOALS-f3-L)participated in Phase 6 of the Coupled Model Intercomparison Project,but its reproducibility of surface temperature(T_(s))over the Tibetan Plateau(TP)as a key climatically sensitive region remains unclear.This study evaluates the capability of FGOALS-f3-L in reproducing the climatological T_(s)over the TP relative to the Climate Forecast System Reanalysis.The results show that FGOALS-f3-L can reasonably capture the spatial pattern of T_(s)but underestimates the annual mean T_(s)for the whole TP.The simulated T_(s)for the whole TP shows a cold bias in winter and spring and a warm bias in summer and autumn.Further quantitative analysis based on the surface energy budget equation shows that the surface albedo feedback(SAF)term strongly contributes to the annual,winter,and spring mean cold bias in the western TP and to the warm bias in the eastern TP.Compared with the SAF term,the surface sensible and latent heat flux terms make nearly opposite contributions to the T_(s)bias and considerably offset the bias due to the SAF term.The cloud radiative forcing term strongly contributes to the annual and seasonal mean weak cold bias in the eastern TP.The longwave radiation term associated with the overestimated water vapor content accounts for a large portion of the warm bias over the whole TP in summer and autumn.Improving land surface and cloud processes in FGOALS-f3-L is critical to reduce the T_(s)bias over the TP.展开更多
基金Supported by National key R&D Projects(2016YFD0101603)National Planning Project Co-supported by Yunnan Province(2014GA016)Science&Technology Specific Project for Benefiting People in China(2014RA056)~~
文摘[Objective] This study was tween yield-related traits and yield of conducted to understand the relationship be- Yunmai 52 which is a high-quality high-yield multi-resistant new wheat variety, and make contribution of yield-related traits to the yield of Yunmai 52 clear. [Method] Wheat variety regional trial data in Yunnan Province in 2005-2007 were subjected to correlation analysis and path analysis in the paper. [Result] Correlationanalysis showed that the yield of Yunmai 52 was in- very significant positive correlation with spikelet number per ear, maximum tiller number and grains per ear (r=0.726^**, 0.717^** and 0.695^**, respectively), in signif- icant positive correlation with 1 000-grain weight (r=0.491^*), but in significant nega- tive correlation with sterile spikelet number per ear, and in non-significant correlation with basic seedlings, effective ears and percentage of ear bearing tillers. Partial correlation analysis showed that the yield of Yunmai 52 was in very significant posi- tive correlation with spikelet number per ear (r=0.711^**), significant positive correla- tion with 1 000-grain weight (r=0.641 =), but in non-significant correlation with other 6 traits. Path analysis showed that spikelet number per ear (P=-0.595), maximum tiller number (P=0.462) and t 000-grain weight (P=0.263) had more contribution to yield of Yunmai 52. [Conclusion] Therefore, in extension and application of Yunmal 52 that is a high-quality high-yield multi-resistant new wheat variety, supply of fertilizer and water should be increased in tillering stage and jointing stage, to ensure its characteristics of high tilledng ability and large ear, as well as high 1 000-grain weight, and coordinated development of other yield-related traits is beneficial to im- provement of yield of Yunmai 52.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201103005-08)National Science and Technology Support Program during the 12thFive-year Plan(2012BAD05B05-3)International Plant Nutrition Institute S&T Program(Hunan-16)~~
文摘A located field experiment was carried out to study the effects of different amount of chemical fertilizer usage on rice yield,economic benefits of rice,soil carbon(C) and total nitrogen(TN) under ploughing back of Chinese milk vetch for 5consecutive years.Six treatments were included in the experiment,they are CK(unfertilized),CF(100% chemical fertilizer with the amount of N,P2O5,K2 O being150,75,120 kg/hm^2respectively),A1(22 500 kg/hm^2 Chinese milk vetch and 100%chemical fertilizer),A2(Chinese milk vetch and 80% nitrogen and potassium fertilizer and 100% phosphate fertilizer),A3(Chinese milk vetch and 60% nitrogen and potassium fertilizer and 100% phosphate fertilizer),A4(Chinese milk vetch and 40% nitrogen and potassium fertilizer and 100% phosphate fertilizer).The results were as follows:application of fertilizer could increase the yield of rice,while Chinese milk vetch combined with fertilizer application had a much more increase effect in rice yield.Under the condition of milk vetch application with 22 500 kg/hm^2,the early rice yield of the treatment A1 was significantly increased by 7.7% compared with that of CF.And the yield of treatment A3 was basically identical to or slight increase in comparison with that of CF.Decreasing amount of fertilizers cloud improve output value of rice in the case of the utilization of Chinese milk vetch.The treatment A1 increased output value of rice by 5.92% in comparison of CF,and treatment A2 was by 4.08% in the next.Treatment A4 showed much better effect in increasing soil organic carbon and total nitrogen in the paddy soil than those of treatments applying mineral fertilizer only.There was a significant reduction on soil organic carbon and TN in treatment A2 in comparison with that of CF.In general,amount of application of milk vetch with 22 500 kg/hm^2 could replace chemical fertilizer partially,it also could improve rice yield,decrease the production cost,and raise the utilization efficiency of nutrients.
基金Supported by National Natural Science Foundation of China(30960179)Program for Innovative Research Team(in Science and Technology)in University of Yunnan Province~~
文摘In order to investigate the distribution of soil available micronutrients, and provide a theoretical basis for management of fertilizing reasonably on crops, the contents of major and trace elements (P, K, Ca, Mg, Cu, Fe, Zn, and Mn) in farm- land soil collected from Yunnan Province were determined by inductively coupled plasma-mass spectrometry (ICP-MS), the contents and distribution of major and trace elements were also studied. The results showed that the contents of available P, K were balance, available Ca, Mg were deficient, and available Cu, Fe, Zn, Mn were very plentiful. Major and trace elements distribution of different landform areas were obviously different. The contents of trace elements (Fe, Zn and Mn) of central Yunnan Red Plateau were significantly higher than those of Hengduan Mountains in western Yunnan and those of karst plateau in eastern Yunnan. The contents of available P, K, and Ca gradually declined from west to east, while the content of available Cu rose gradually from west to east. The results are reference value to elements determination and agricultural production in farmland soils.
基金Supported by the Important Science and Technology Program for Agriculture of Zhejiang Province(2009C2001-TZ)the Taizhou Research and Development of Applied Technology,Zhejiang Province(091TG06)~~
文摘[Objective] The effects of ploughing Astragalus sinicus at maturity stage as green manure on paddy soil properties were studied to provide references for ad- vancing the green manure production and field sustainable development. [Methods] A three-year field positioning experiment was carried out. In the first year, five differ- ent levels (0, 2.81, 5.61, 8.42, 11.23 t/hm~) of Astragalus sinicus ploughed at matu- rity stage were designed. And in the next two years, the amounts of ploughed As- tragalus sinicus at maturity stage were based on the natural growth amounts of As- tragalus sinicus at maturity stage of the former year in each plot field. The yields of Astragalus sinicus at maturity stage were estimated and ploughed directly before rice transplanting. Rice yield, soil nutrients, biological properties and water-stable aggre- gates of paddy fields were measured as well. [Results] The effective panicles and rice yields increased significantly after ploughing Astragalus sinicus at maturity stage. Meanwhile, the organic acid content in paddy field increased and the activities of soil phosphatases, invertase and catalase were higher. The soil dissolved organic carbon also increased with the increasing application of green manure. However, excess amount of green manure inhibited the soil microbial biomass carbon content. The macro aggregates and micro aggregates gathered to middle aggregates. [Conclusion] As green manure, the use of Astragalus sinicus at maturity stage could improve soil physiochemical and biological properties, improve soil fertility and increase rice yield significantly. But the ploughing amount of Astragalus sinicus at maturity stage before rice transplanting should be less than 8.42 t/hm2 (dry weight.
基金The support from both the Research Foundation for Returning Scholars of Chinathe China Postdoctoral Science Foundation
文摘We have studied the efficiency of energy consumption in the comminution of mica powder with cavitation abrasive water jet technology. The energy required to create new surfaces in the comminution of mica powder with cavitation abrasive water jet was calculated,in order to estimate its efficiency of energy consumption. The particle size distribution and the specific surface area were measured by applying a JEM-200CX transmission electron microscope and an Autosorb-1 automatic surface area analyzer. The study results show that the efficiency of energy consumed in creating new surface areas is as high as 2.92%,or 4.94% with the aid of cavitation in the comminution of mica powder. This efficiency will decrease with an increase in the number of comminutions. After three comminutions,the efficien-cies will become 1.91% and 2.29% for comminution without cavitation and with cavitation,respectively. The abrasive water jet technology is an effective way for comminution of mica powder.
基金This work was supported by the China-Finland Cooperation Project“Responses of the Ecosystem Processes of High-Frigid Coniferous Forest to Climate”(No.3021130504)the Key Project of Ecology and Environment in West China,the National Natural Science Foundation of China(NSFC)(No.90202010)“100 Distinguished Experts”Programme of the Chinese Academy of Sciences.Thanks are also given to the staff of the Wanglang Nature Reserve for their kind help.
文摘The wet canopy evaporation rate (Er) wascalculated by Penman-Monteith combination model based on three assumptions and with meteorological variables 2 m above the canopy inthree stands, dominated by spruce (SF), fir (FF) and birch (BF) trees, respectively[(,)( )]in the subalpineforests in western Sichuan, China over a growingseason. The total amount of the E was 44.5 mm forSF, 88.5 mm for FF and 57.8 mm for BF, accounting for 9.2%, 16.6% and 10.2% of the gross rainfall,respectively, in the measuring period. There was the highest average monthly Er and percentage of E togross rainfall for FF compared with SF and BF.Mean Er was 0.097 mm h-1 (ranging from 0.028 to0.487 mm h-1), 0.242 mm h-1 (from 0.068 to 0.711 mm h-1) and 0.149 mm h-1 (from 0.060 to 0.576 mm h-1for SF, FF and BF, respectively. The highest average monthly Er occurred in June was 0.120 mm h-1 forSF, 0.317 mm h-1 for FF and 0.169 mm h-1 for BF, and the lowest value in October was 0.083 mm h-1 for SF, 0.187 mm h-1 for FF and 0.101 mm h-1 for BF,respectively. The averages of Er from 8:00 to 16:00were significantly higher than those from 0:00 to8:00 and from 16:00 to 0:00 for the three stands. The marked daily and monthly differences of Er were contributable to the variations of solar radiation, air temperature and relative humidity above thecanopy.
基金This work was supported by the Ministry of Science and Technology of China[grant number 2017YFA0604002]the National Natural Science Foundation of China[grant numbers 41925023,41575073,41621005,and 91744208]the Collaborative Innovation Center of Climate Change,Jiangsu Province.
文摘Southeast China has comparable stratus cloud to that over the oceans,especially in the cold seasons(winter and spring),and this cloud has a substantial impact on energy and hydrological cycles.However,uncertainties remain across datasets and simulation results about the long-term trend in low-cloud cover in Southeast China,making it difficult to understand climate change and related physical processes.In this study,multiple datasets and numerical simulations were applied to show that low-cloud cover in Southeast China has gone through two stages since 1980—specifically,a decline and then a rise,with the turning point around 2008.The regional moisture transport plays a crucial role in low-cloud cover changes in the cold seasons and is mainly affected by the Hadley Cell in winter and the Walker Circulation in spring,respectively.The moisture transport was not well simulated in CMIP6 climate models,leading to poor simulation of the low-cloud cover trend in these models.This study provides insights into further understanding the regional climate changes in Southeast China.
基金supported by the National High Technology Research and Development Program of China (863 Program) (Grant No. 2010AA012304)the National Basic Research Program of China (973 Program) (Grant No.2010CB951904)+1 种基金the China Meteorological Administration R &D Special Fund for Public Welfare (meteorology) (Grant No.GYHY201006014)the National Natural Science Foundation of China (Grant Nos. 41023002 and 41005053)
文摘The Cloud Feedback Model Intercomparisons Project (CFMIP) Observation Simulator Package (COSP) is adopted in the Grid-point Atmospheric Model of IAP LASG (GAMIL2) during CFMIP at Phase II to evaluate the model cloud fractions in a consistent way with satellite observations. The cloud simulation results embedded in the Atmospheric Model Intercomparison Project (AMIP) control experiment are presented using three satellite simulators: International Satellite Cloud Climatology Project (ISCCP), Moderate Resolution Imaging Spectroradiometer (MODIS), and Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) lidar onboard the Cloud- Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). Overall, GAMIL2 can produce horizontal distributions of the low cloud fraction that are similar to the satellite observations, and its similarities to the observations on different levels are shown in Taylor diagrams. The discrepancies among satellite observations are also shown, which should be considered during evaluation.
基金supported by the "Strategic Priority Research Program" of the Chinese Academy of Sciences(XDA05100300)the National Basic Research Program of China(2013CB955801)the National Natural Science Foundation of China(41175030)
文摘Total Cloud Cover (TCC) over China deter- mined from four climate datasets including the Interna- tional Satellite Cloud Climatology Project (ISCCP), the 40-year Re-Analysis Project of the European Centre for Medium-Range Weather Forecasts (ERA-40), Climate Research Unit Time Series 3.0 (CRU3), and ground sta- tion datasets are used to show spatial and temporal varia- tion of TCC and their differences. It is demonstrated that the four datasets show similar spatial pattern and seasonal variation. The maximum value is derived from ISCCE TCC value in North China derived from ERA-40 is 50% larger than that from the station dataset; however, the value is 50% less than that in South China. The annual TCC of ISCCP, ERA-40, and ground station datasets shows a decreasing trend during 1984-2002; however, an increasing trend is derived from CRU3. The results of this study imply remarkable differences of TCC derived from surface and satellite observations as well as model simu- lations. The potential effects of these differences on cloud climatology and associated climatic issues should be carefully considered.
文摘In light of the problems of low-quality and low degree of comprehensive utilization of Guangdong muscovite-type kaolin, the reasons affecting the quality of kaolin were found to be a small amount of maroon powdery goethite adhering to the surface of kaolin and minor muscovite affecting the firing whiteness of products. The ores were dealt with by using the new combined process of attritioning-classifieation-bleaching and flotation. The separation of kaolin from muscovite, quartz and feldspar can come true through the new process. The high-quality kaolin with the firing whiteness of 91% can be obtained, and the muscovite is comprehensively recovered by adopting the key technology of flotation. The content of high-purity muscovite produced is over 99%. The muscovite discarded by original process can be comprehensively recovered.
基金funded by the Third Scientific Experiment of the Tibetan Plateau (Grant No. GYHY201406001)the National Natural Science Foundation of China (Grant Nos. 41575045, 41205030, and 41175046)the Basic Research Fund of the Chinese Academy of Meteorological Sciences (Grant No. 2017Z013)
文摘Cloud distribution characteristics over the Tibetan Plateau in the summer monsoon period simulated by the Australian Community Climate and Earth System Simulator(ACCESS) model are evaluated using COSP [the CFMIP(Cloud Feedback Model Intercomparison Project) Observation Simulator Package]. The results show that the ACCESS model simulates less cumulus cloud at atmospheric middle levels when compared with observations from CALIPSO and CloudSat, but more ice cloud at high levels and drizzle drops at low levels. The model also has seasonal biases after the onset of the summer monsoon in May. While observations show that the prevalent high cloud at 9–10 km in spring shifts downward to 7–9 km,the modeled maximum cloud fractions move upward to 12–15 km. The reason for this model deficiency is investigated by comparing model dynamical and thermodynamical fields with those of ERA-Interim. It is found that the lifting effect of the Tibetan Plateau in the ACCESS model is stronger than in ERA-Interim, which means that the vertical velocity in the ACCESS model is stronger and more water vapor is transported to the upper levels of the atmosphere, resulting in more high-level ice clouds and less middle-level cumulus cloud over the Tibetan Plateau. The modeled radiation fields and precipitation are also evaluated against the relevant satellite observations.
基金supported by the National Key Research and Development Program of China[grant number 2018YFC1505706]the National Natural Science Foundation of China[grant numbers 91937302,91737306,41975109]the Strategic Priority Research Program of the Chinese Academy of Sciences[grant number XDA17010105]。
文摘The Chinese Academy of Sciences Flexible Global Ocean-Atmosphere-Land System atmospheric component model(FGOALS-f3-L)participated in Phase 6 of the Coupled Model Intercomparison Project,but its reproducibility of surface temperature(T_(s))over the Tibetan Plateau(TP)as a key climatically sensitive region remains unclear.This study evaluates the capability of FGOALS-f3-L in reproducing the climatological T_(s)over the TP relative to the Climate Forecast System Reanalysis.The results show that FGOALS-f3-L can reasonably capture the spatial pattern of T_(s)but underestimates the annual mean T_(s)for the whole TP.The simulated T_(s)for the whole TP shows a cold bias in winter and spring and a warm bias in summer and autumn.Further quantitative analysis based on the surface energy budget equation shows that the surface albedo feedback(SAF)term strongly contributes to the annual,winter,and spring mean cold bias in the western TP and to the warm bias in the eastern TP.Compared with the SAF term,the surface sensible and latent heat flux terms make nearly opposite contributions to the T_(s)bias and considerably offset the bias due to the SAF term.The cloud radiative forcing term strongly contributes to the annual and seasonal mean weak cold bias in the eastern TP.The longwave radiation term associated with the overestimated water vapor content accounts for a large portion of the warm bias over the whole TP in summer and autumn.Improving land surface and cloud processes in FGOALS-f3-L is critical to reduce the T_(s)bias over the TP.