茶树的光合作用是其基本生理过程之一,快速评估其光合作用速率能够为茶树的水分控制提供重要依据。该研究构建了茶树物联网环境信息监测系统,通过设置100%、85%、70%、55%土壤持水量的4组水分胁迫梯度,实现对茶树生长环境和生理参数的采...茶树的光合作用是其基本生理过程之一,快速评估其光合作用速率能够为茶树的水分控制提供重要依据。该研究构建了茶树物联网环境信息监测系统,通过设置100%、85%、70%、55%土壤持水量的4组水分胁迫梯度,实现对茶树生长环境和生理参数的采集,建立了茶树水分胁迫指数(Crop Water Stress Index,CWSI)模型以量化茶树的水分胁迫程度,并研究茶树净光合作用速率(NetPhotosyntheticRate,Pn)的变化特点。在此基础上,构建了基于物联网和深度长短期记忆(Deep Long Short-term Memory,Deep-LSTM)的茶树净光合作用速率动态预测模型,将不同水分处理下的茶树生长环境参数、冠层温度和CSWI作为输入特征,构建多层LSTM单元形成深度LSTM网络,实现特征提取,并引入全连接层实现降维,对茶树在不同水分胁迫程度下的Pn进行预测,计算模型的均方根误差(RMSE)和决定系数(R^(2))以评估其性能表现,并与经典的反向传播神经网络(Back Propagation Neural Network,BPNN)模型进行了性能对比。结果表明,茶树物联网环境信息监测系统能够有效获取其环境参数。茶树冠气温差下限与饱和水汽压差的线性方程拟合度为0.866。Deep-LSTM模型对100%、85%、70%、55%土壤持水量的水分处理下的光合作用速率的预测的RMSE分别为0.304、0.280、0.157和0.160μmol/m^(2)·s;其R^(2)分别为0.846、0.875、0.893和0.954,而BPNN模型的RMSE分别为0.980、0.897、0.633、0.417μmol/m^(2)·s,R^(2)分别为0.516、0.355、0.315、0.432,表明Deep-LSTM模型能够有效预测茶树的Pn,同时其性能好于BPNN模型。该研究可为快速评估茶树光合作用速率提供可行的方法,并为利用水分胁迫和光合作用指定茶树亏缺灌溉策略提供数据支持。展开更多
To study the molecular characteristics of Chlamydia trachomatis, the major outer membrane protein gene(omp A) of C. trachomatis from primary school students with trachoma residing in the Qinghai Tibetan area was seque...To study the molecular characteristics of Chlamydia trachomatis, the major outer membrane protein gene(omp A) of C. trachomatis from primary school students with trachoma residing in the Qinghai Tibetan area was sequenced and compared with the same serotype in Gen Bank. In Jianshetang Primary School and Galeng Central Primary School in the Galeng Tibetan Township of Qinghai Haidong Sala Autonomous County, scraped samples were collected from the upper tarsal conjunctiva and lower conjunctival sac of both eyes of 45 students with trachoma, stored at 4°C, and transported to Beijing Tongren Hospital by air within 24 h. The samples were screened for C. trachomatis by real-time PCR. The omp A gene from the C. trachomatis-positive samples was amplified by nested PCR. The serotype was confirmed by National Center for Biotechnology Information(NCBI) BLAST search and homology analysis. The entire omp A gene sequence was compared with the corresponding gene sequences of serotype B strains available in Gen Bank. Of the 45 students aged 6–13 years with trachoma, 26 C. trachomatis-positive students were identified by the initial real-time PCR screening(average age,(9.09±1.63) years; sex ratio, 1.0), accounting for 57.78%(26/45). The cycle threshold values for real-time PCR were 16.79–37.77. Half(13/26) of C. trachomatis-positive students had a bacterial copy number of >105. The compliance rate of the omp A gene sequences with the C. trachomatis serotype B strains in Gen Bank was up to 99%. Two novel genetic mutations were found when the omp A gene was compared with those of the 11 serotype B strains in Gen Bank. The two non-synonymous mutations were located at(i) position 271 in the second constant domain, an adenine(A) to guanine(G) substitution(ACT?GCT), changing the amino acid at position 91 from threonine to alanine(Thr?Ala) in all 26 strains; and(ii) position 887 in the fourth variable domain, a cytosine(C) to thymine(T) substitution(GCA?GTA), changing the amino acid at residue 296 from alanine to valine(Ala?Val) in展开更多
The spouted-fluidized bed is modified from the classical fluidized bed device,which combines the features of spouted and fluidized beds.In the present work,the performance of oxy-fuel spouted-fluidized bed combustion ...The spouted-fluidized bed is modified from the classical fluidized bed device,which combines the features of spouted and fluidized beds.In the present work,the performance of oxy-fuel spouted-fluidized bed combustion with under bed feeding and its effect on NO emission were systematically investigated.The results revealed that it was feasible to use a spouted-fluidized bed combustor for oxy-fuel combustion with real flue gas recycling.The transition from air combustion to oxy-fuel combustion was smooth and the concentration of CO_(2) in the flue gas could be as high as 90%steadily(dry base).Increasing the reaction temperature exhibited a negative effect on NO emission.Compared with that under the shallow bed,the concentration of NO in the flue gas was lower under the deep bed condition.Besides,the utilization of crush particles was favorable for suppressing NO emission because of the promoted mixing between coal particles and solid bed materials.Furthermore,the addition of limestone was proven to undesirably increase the NO emission during oxy-fuel spouted-fluidized bed combustion.展开更多
文摘茶树的光合作用是其基本生理过程之一,快速评估其光合作用速率能够为茶树的水分控制提供重要依据。该研究构建了茶树物联网环境信息监测系统,通过设置100%、85%、70%、55%土壤持水量的4组水分胁迫梯度,实现对茶树生长环境和生理参数的采集,建立了茶树水分胁迫指数(Crop Water Stress Index,CWSI)模型以量化茶树的水分胁迫程度,并研究茶树净光合作用速率(NetPhotosyntheticRate,Pn)的变化特点。在此基础上,构建了基于物联网和深度长短期记忆(Deep Long Short-term Memory,Deep-LSTM)的茶树净光合作用速率动态预测模型,将不同水分处理下的茶树生长环境参数、冠层温度和CSWI作为输入特征,构建多层LSTM单元形成深度LSTM网络,实现特征提取,并引入全连接层实现降维,对茶树在不同水分胁迫程度下的Pn进行预测,计算模型的均方根误差(RMSE)和决定系数(R^(2))以评估其性能表现,并与经典的反向传播神经网络(Back Propagation Neural Network,BPNN)模型进行了性能对比。结果表明,茶树物联网环境信息监测系统能够有效获取其环境参数。茶树冠气温差下限与饱和水汽压差的线性方程拟合度为0.866。Deep-LSTM模型对100%、85%、70%、55%土壤持水量的水分处理下的光合作用速率的预测的RMSE分别为0.304、0.280、0.157和0.160μmol/m^(2)·s;其R^(2)分别为0.846、0.875、0.893和0.954,而BPNN模型的RMSE分别为0.980、0.897、0.633、0.417μmol/m^(2)·s,R^(2)分别为0.516、0.355、0.315、0.432,表明Deep-LSTM模型能够有效预测茶树的Pn,同时其性能好于BPNN模型。该研究可为快速评估茶树光合作用速率提供可行的方法,并为利用水分胁迫和光合作用指定茶树亏缺灌溉策略提供数据支持。
文摘To study the molecular characteristics of Chlamydia trachomatis, the major outer membrane protein gene(omp A) of C. trachomatis from primary school students with trachoma residing in the Qinghai Tibetan area was sequenced and compared with the same serotype in Gen Bank. In Jianshetang Primary School and Galeng Central Primary School in the Galeng Tibetan Township of Qinghai Haidong Sala Autonomous County, scraped samples were collected from the upper tarsal conjunctiva and lower conjunctival sac of both eyes of 45 students with trachoma, stored at 4°C, and transported to Beijing Tongren Hospital by air within 24 h. The samples were screened for C. trachomatis by real-time PCR. The omp A gene from the C. trachomatis-positive samples was amplified by nested PCR. The serotype was confirmed by National Center for Biotechnology Information(NCBI) BLAST search and homology analysis. The entire omp A gene sequence was compared with the corresponding gene sequences of serotype B strains available in Gen Bank. Of the 45 students aged 6–13 years with trachoma, 26 C. trachomatis-positive students were identified by the initial real-time PCR screening(average age,(9.09±1.63) years; sex ratio, 1.0), accounting for 57.78%(26/45). The cycle threshold values for real-time PCR were 16.79–37.77. Half(13/26) of C. trachomatis-positive students had a bacterial copy number of >105. The compliance rate of the omp A gene sequences with the C. trachomatis serotype B strains in Gen Bank was up to 99%. Two novel genetic mutations were found when the omp A gene was compared with those of the 11 serotype B strains in Gen Bank. The two non-synonymous mutations were located at(i) position 271 in the second constant domain, an adenine(A) to guanine(G) substitution(ACT?GCT), changing the amino acid at position 91 from threonine to alanine(Thr?Ala) in all 26 strains; and(ii) position 887 in the fourth variable domain, a cytosine(C) to thymine(T) substitution(GCA?GTA), changing the amino acid at residue 296 from alanine to valine(Ala?Val) in
基金supported by the National Natural Science Foundation of China(No.51806220,51922040)China Postdoctoral Science Foundation Funded Project(No2019M660594)+1 种基金Grants from Fok Ying Tung Education Foundation(161051)Fundamental Research Funds for the Central Universities(No.2019QN003,2020DF01,2018ZD08)。
文摘The spouted-fluidized bed is modified from the classical fluidized bed device,which combines the features of spouted and fluidized beds.In the present work,the performance of oxy-fuel spouted-fluidized bed combustion with under bed feeding and its effect on NO emission were systematically investigated.The results revealed that it was feasible to use a spouted-fluidized bed combustor for oxy-fuel combustion with real flue gas recycling.The transition from air combustion to oxy-fuel combustion was smooth and the concentration of CO_(2) in the flue gas could be as high as 90%steadily(dry base).Increasing the reaction temperature exhibited a negative effect on NO emission.Compared with that under the shallow bed,the concentration of NO in the flue gas was lower under the deep bed condition.Besides,the utilization of crush particles was favorable for suppressing NO emission because of the promoted mixing between coal particles and solid bed materials.Furthermore,the addition of limestone was proven to undesirably increase the NO emission during oxy-fuel spouted-fluidized bed combustion.
