Globally, white clover（Trifolium repens L.） is commonly infected by plant viruses. It is grown at gardens, roadsides, and public areas as ornamental plants in northern China. Some leaves present disease symptoms tha...Globally, white clover（Trifolium repens L.） is commonly infected by plant viruses. It is grown at gardens, roadsides, and public areas as ornamental plants in northern China. Some leaves present disease symptoms that are similar to those of virus infection. However, to our knowledge, no records are available from China regarding white clover（Trifolium repens L.） virus co-infection. To determine the viral species that infect white clover in China, plant samples with virus disease symptoms were collected and virion morphology and ultrastructure morphology of co-infected plants were observed by electron microscopy; viruses were detected by enzyme linked immunosorbent assay（ELISA） and reverse transcription PCR（RT-PCR）. Virus co-infection was studied by double antibody sandwich enzyme linked immunosorbent assay（DAS-ELISA） and real-time fluorescence quantitative PCR（RT-q PCR） after rub-inoculation of virus-free white clover planted in a growth chamber（25°C） with a photoperiod of 16 h, using single or several purified virions. Results showed that there were six types of symptoms, including those of shrinking mosaic, shrinking and macular mosaic, severe mottle mosaic, yellow macular mosaic, shrinkage chlorisis, and ring plaque and ring stria. The incidence rates for each symptom were 20.93, 1.48, 16.85, 59.07, 1.30, and 0.37%, respectively, based on the field investigation. Two types of viral pathogens were identified as Alfalfa mosaic virus（AMV） and White clover mosaic virus（WCMV）. In mesophyll cells, virus particles with bacilliform virions formed aggregates and linear virions were bundle shaped. The detection rate of AMV was 100% in white clover samples by DAS-ELISA and RT-PCR detection, whereas that of WCMV was 83.33%. The co-infection rate was 83.33%. The relative contents of AMV and WCMV were significantly increased by 5.897-and 3.515-fold upon co-infection, when compared to that with single virus infection. We observed larger starch particles and fewer or collapsed chloroplast 展开更多
A method for using height reassignment to improve the quality of satellite-derived atmospheric motion vectors （AMVs） is presented. The rationale underlying height reassignment is explored, and the technical details ...A method for using height reassignment to improve the quality of satellite-derived atmospheric motion vectors （AMVs） is presented. The rationale underlying height reassignment is explored, and the technical details are studied by applying three height reassignment schemes that use NCEP reanalysis winds. The quality of the AMVs is generally improved following reassignment, although the magnitude of the improve- ment differs according to the scheme applied. Scheme 3 provides the best quality and stability, followed by Scheme 1 and Scheme 2. The negative biases in the zonal components of the AMVs decrease from [ 5, 4] m s^-1 to 〈- 1 m s 1 following reassignment. The meridional components also improve. The AMVs derived from the infrared and water vapor channels improve by 58.7% and 25%, respectively, The feasibility of using Scheme 3 in the operational derivation of AMVs is studied by incorporating the forecast wind field predicted by a T511 medium-range numerical weather prediction （NWP） system. Incorporating the 12-h forecast reduces the negative biases in zonal winds and positive biases in meridional winds retrieved from the water vapor channel, improving the overall quality of the AMVs by 26.7%. Extending the validity period of the forecast field linearly reduces the improvement in retrieved AMVs, but the magnitude of this reduction is small. Incorporating the 120-h forecast field still results in a 13% improvement, although it may eliminate a larger number of AMVs of good quality.展开更多
To identify human thermal comfort in naturally ventilated buildings,the research based on both subjective and objective data was carried out in Chongqing,P. R. China. The characteristics of subjects' clothing regu...To identify human thermal comfort in naturally ventilated buildings,the research based on both subjective and objective data was carried out in Chongqing,P. R. China. The characteristics of subjects' clothing regulation function,changes of actual mean thermal comfort vote (AMV) varying with time and acceptable operative temperature in natural conditions were analyzed. In addition,the indicator actual mean vote-actual percentage dissatisfied (AMV-APD) was used to study the actual dissatisfaction with thermal environment. The results indicate that regulative ability by changing clothing under natural ventilated conditions is very significant but limited simultaneously,about 1.7 ℃ per 0.1 clo. Under naturally ventilated conditions,people may have an acceptable operative temperature of 16-28 ℃. Based on the AMV-APD,the actual minimum percentage dissatisfied can reach 4% at AMV of -0.36.展开更多
基金financial support of the Key Laboratory of Grassland Ecosystem of Ministry of Education of China(CYZS-2011006)
文摘Globally, white clover（Trifolium repens L.） is commonly infected by plant viruses. It is grown at gardens, roadsides, and public areas as ornamental plants in northern China. Some leaves present disease symptoms that are similar to those of virus infection. However, to our knowledge, no records are available from China regarding white clover（Trifolium repens L.） virus co-infection. To determine the viral species that infect white clover in China, plant samples with virus disease symptoms were collected and virion morphology and ultrastructure morphology of co-infected plants were observed by electron microscopy; viruses were detected by enzyme linked immunosorbent assay（ELISA） and reverse transcription PCR（RT-PCR）. Virus co-infection was studied by double antibody sandwich enzyme linked immunosorbent assay（DAS-ELISA） and real-time fluorescence quantitative PCR（RT-q PCR） after rub-inoculation of virus-free white clover planted in a growth chamber（25°C） with a photoperiod of 16 h, using single or several purified virions. Results showed that there were six types of symptoms, including those of shrinking mosaic, shrinking and macular mosaic, severe mottle mosaic, yellow macular mosaic, shrinkage chlorisis, and ring plaque and ring stria. The incidence rates for each symptom were 20.93, 1.48, 16.85, 59.07, 1.30, and 0.37%, respectively, based on the field investigation. Two types of viral pathogens were identified as Alfalfa mosaic virus（AMV） and White clover mosaic virus（WCMV）. In mesophyll cells, virus particles with bacilliform virions formed aggregates and linear virions were bundle shaped. The detection rate of AMV was 100% in white clover samples by DAS-ELISA and RT-PCR detection, whereas that of WCMV was 83.33%. The co-infection rate was 83.33%. The relative contents of AMV and WCMV were significantly increased by 5.897-and 3.515-fold upon co-infection, when compared to that with single virus infection. We observed larger starch particles and fewer or collapsed chloroplast
基金Supported by the National Natural Science Foundation of China (40705037)China Meteorological Administration Special Public Welfare Research Fund (GYHY201206002)
文摘A method for using height reassignment to improve the quality of satellite-derived atmospheric motion vectors （AMVs） is presented. The rationale underlying height reassignment is explored, and the technical details are studied by applying three height reassignment schemes that use NCEP reanalysis winds. The quality of the AMVs is generally improved following reassignment, although the magnitude of the improve- ment differs according to the scheme applied. Scheme 3 provides the best quality and stability, followed by Scheme 1 and Scheme 2. The negative biases in the zonal components of the AMVs decrease from [ 5, 4] m s^-1 to 〈- 1 m s 1 following reassignment. The meridional components also improve. The AMVs derived from the infrared and water vapor channels improve by 58.7% and 25%, respectively, The feasibility of using Scheme 3 in the operational derivation of AMVs is studied by incorporating the forecast wind field predicted by a T511 medium-range numerical weather prediction （NWP） system. Incorporating the 12-h forecast reduces the negative biases in zonal winds and positive biases in meridional winds retrieved from the water vapor channel, improving the overall quality of the AMVs by 26.7%. Extending the validity period of the forecast field linearly reduces the improvement in retrieved AMVs, but the magnitude of this reduction is small. Incorporating the 120-h forecast field still results in a 13% improvement, although it may eliminate a larger number of AMVs of good quality.
基金Projects(50838009, 50678179) supported by the National Natural Science Foundation of ChinaProjects(2006BAJ02A09, 2006BAJ02A13-4) supported by the National Key Technologies R & D Program of ChinaProject(200909A1001) supported by Chongqing University Postgraduates’ Innovative Team Building Project
文摘To identify human thermal comfort in naturally ventilated buildings,the research based on both subjective and objective data was carried out in Chongqing,P. R. China. The characteristics of subjects' clothing regulation function,changes of actual mean thermal comfort vote (AMV) varying with time and acceptable operative temperature in natural conditions were analyzed. In addition,the indicator actual mean vote-actual percentage dissatisfied (AMV-APD) was used to study the actual dissatisfaction with thermal environment. The results indicate that regulative ability by changing clothing under natural ventilated conditions is very significant but limited simultaneously,about 1.7 ℃ per 0.1 clo. Under naturally ventilated conditions,people may have an acceptable operative temperature of 16-28 ℃. Based on the AMV-APD,the actual minimum percentage dissatisfied can reach 4% at AMV of -0.36.
