检索结果-南通市图书馆

Vegetation Restoration Technique System and Its Ecological Functions of the Degraded Ecosystem in the Arid-Hot Valleys——Taking the Example of Typical Mode in Small Watershed of Yuanmou

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2008年第3期13卷 257-266页

作者： JI Zhonghua LIAO chengfei yang Yanxian FANG Haidong PAN Zhixian SHA Yucang Institute of Tropical Eco-Agricultural Sciences Yunnan Academy ofAgricultural Sciences Yuanmou 651300 Yunnan China

This paper concluded the vegetation restoration technique system in the arid-hot valleys and studied the anti-erosion function, environmental function and biological diversity effects of vegetation restoration on the ecosystem in the arid-hot valleys. The results showed that the soil erodibility decreased significantly after the vegetation restoration. The climate environment of the small watershed had a great improvement after the vegetation restoration, of which the temperature decreased, the humidity increased, the harsh environment of dry and hot in this region changed. The studies of the ecosystem biodiversity were mainly on the analysis of the relations between biodiversity and ecological function of the artificial ecological forest pattern and the natural enclosed treatment mode on the severely of degraded land. It could conclude that the natural enclosed treatment mode is helpful to the biodiversity of the ecosystem and the improvement and stability of the ecosystem, and Leucaena artificial forest restoration pattern reduced the species diversity but optimized the ecological function. Therefore, as to the severely and extremely severely degraded ecosystem in the arid-hot valleys, Leucaena pattern of gully control and natural enclosed treatment mode are the relatively optimal choices.

关键词： vegetation restoration technique system anti-erosion function environmental function biodiversity

Transpiration of the Tamarind Artificial Forest in the Arid-Hot Valleys of Jinshajiang River,Yunnan

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2008年第3期13卷 291-296页

作者： PAN Zhixian LIAO chengfei SHA Yucang yang Yanxian FANG Haidong JI Zhonghua Institute of Tropical Eco-Agricultural Sciences YunnanAcademy of Agricultural Sciences Yuanmou 651300 YunnanChina

The transpiration characteristics of the tamarind artificial forest in the arid-hot valleys of Jinshajiang River, Yunnan were investigated through the measurement of the transpiration rate, stomatal conductance of tamarind leaf and the related envi- ronmental factors. The results showed that the transpiration of the tamarind in the clear sky had the close positive correlations with photosynthetically active radiation and air temperature and negative correlation with atmosphere moisture in the whole growth period. The daily change tendency of the transpiration rate was the similar with stomatal conductance, and the transpiration had the positive correlation with stomatal conductance. The transpiration rate of tamarind was highest in the rainy season of June and July and was relatively low in the drought season of March and April. The transpiration water consumption in rainy season of June and July was obviously higher than that in drought season of March and April. It fully suggested that the tamarind showed very good drought resistance and adaptability to the arid-hot valleys of Yunnan .

关键词： tamarind transpiration rate stomatal conductance transpiration

Landscape Ecological Evaluation on the Artificial Forest of Leucaena leucocephala——Taking the Example of Xiaokua Hill of Yuanmou

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2008年第3期13卷 285-290页

作者： HE Shoujia LIAO chengfei yang Yanxian PAN Zhixian SHA Yucang JI Zhonghua Institute of Tropical Eco-Agricultural Sciences YunnanAcademy of Agricultural Sciences Yuanmou 651300 Yunnan China

Based on the theory of ecology, this article conducted a landscape ecological evaluation on Leucaena leucocephala artificial forest in the add-hot valley, Yuanmou Xiaokua hill, using a combination method of qualitative analysis and landscape comprehensive evaluation. The comprehensive evaluation indexes of landscape include forest coverage, biodiversity, stability, soil erosion, environmental quality, availability, scientific research characteristic, economic benefits. Using AHP （analytical hierarchy process）, determine the grade of ecological evaluation factors and the weight of evaluation index and calculate the CEI （comprehensive evaluation index） on ecological evaluation. Evaluation results showed that the area CEI was 0.714 225, a better quality of the ecological level, but biodiversity indicators was the lowest. To sum up, it was difficult to maintain ecological restoration effectiveness and process but also guarantee a good biodiversity in the add-hot valleys. We must reasonably arrange the alien species and the native species, in order to obtain a stable and sustainable eco-system.

关键词： landscape ecological evaluation arid-hot valley ecological restoration AHP CEI Leucaena leucocephala

HYDRUS-2D simulations of water movement in a drip irrigation system under soilless substrate

在线全文

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2022年第3期15卷 210-216页

作者： Lei Geng Li Li Wei Li chengfei yang Fanjia Meng Key Laboratory of Agricultural Information Acquisition Technology Ministry of Agriculture and Rural AffairsChina Agricultural UniversityBeijing100083China Key Laboratory of Smart Agriculture System Integration Ministry of EducationChina Agricultural UniversityBeijing 100083Chin

A comprehensive understanding of the distribution and water movement of the substrate in root areas is crucial to the design and management of drip irrigation systems,which is a significant step to maximizing crop water use efficiency by understanding the hydrodynamics in soilless *** this study,an improved HYDRUS-2D model by the dynamic root growth model was used to simulate water movement under the condition of drip irrigation and the water uptake process of the root,and then,compared with the observed *** water content under drip irrigation was also measured with the calibrated ECH20-EC5 *** situation of substrate water movement was analyzed under the conditions of different depths,different initial water content,and different irrigation *** substrate water movement under different drip irrigation conditions was *** results showed that incorporating the defined initial and boundary conditions and the hydraulic characteristics of the substrate into the model enabled HYDRUS model to predict the movement and position of water in unsaturated porous media by solving Richards *** drip irrigation,the substrate wetting body was approximately a quarter ellipse,and the water would continue to move to the area where the wetting front did not reach within 1 h after *** simulation results of the improved HYDRUS-2D model agreed well with those observed by the ECH2O-EC5 sensors,and the model could provide a basis for precision irrigation of soilless substrate culture under drip irrigation.

关键词： drip irrigation HYDRUS-2D substrate water movement soilless substrate

Ginsenoside Rg1 improves anti-tumor efficacy of adoptive cell therapy by enhancing T cell effector functions

在线全文

学校读者我要写书评

暂无评论

Blood Science 2023年第3期5卷 170-179页

作者： Yue Liu Lingna An chengfei yang Xiaoqi Wang Ruihao Huang Xi Zhang Medical Center of Hematology Xinqiao HospitalState Key Laboratory of TraumaBurn and Combined InjuryArmy Medical UniversityChongqing 400037China Department of Urology Xinqiao HospitalArmy Military Medical UniversityChongqing 400037China Jinfeng Laboratory Chongqing 401329 China

Adoptive cell therapy(ACT)has emerged with remarkable efficacies for tumor *** antigen receptor(CAR)T cell therapy,as one of most promising ACTs,has achieved prominent effects in treating malignant hematological ***,the insufficient killing activity and limited persistence of T cells in the immunosuppressive tumor microenvironment limit the further application of ACTs for cancer *** studies have focused on improving cytotoxicity and persistence of T cells to achieve improved therapeutic *** this study,we explored the potential function in ACT of ginsenoside Rg1,the main pharmacologically active component of *** introduced Rg1 during the in vitro activation and expansion phase of T cells,and found that Rg1 treatment upregulated two T cell activation markers,CD69 and CD25,while promoting T cell differentiation towards a mature *** sequencing revealed that Rg1 influenced T cell metabolic reprogramming by strengthening mitochondrial *** co-cultured with tumor cells,Rg1-treated T cells showed stronger cytotoxicity than untreated ***,adding Rg1 to the culture endowed CAR-T cells with enhanced anti-tumor *** study suggests that ginsenoside Rg1 provides a potential approach for improving the anti-tumor efficacy of ACT by enhancing T cell effector functions.

关键词： Anti-tumor efficacy Adoptive cell therapy CAR-T Ginsenoside Rg1 Metabolic regulation

基于废旧锂电池回收制备Li_(x)MO(x=0.79,0.30,0.08;M=Ni/Co/Mn)材料作为锂-氧气电池正极催化剂的电化学性能研究

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

化学学报 2022年第9期80卷 1269-1276页

作者：张爽杨成飞杨玉波冯宁宁杨刚苏州大学材料与化学化工学部苏州215006 常熟理工学院江苏省先进材料实验室常熟215500

锂-氧气电池因其超高的理论比容量而受到科研界的广泛关注,但其存在较为严重的充放电极化和较差的循环稳定性等问题,从而极大地限制其商业化进程.因此设计出有效的正极催化剂是解决锂-氧气电池面临的这些棘手问题的必要手段.通过对不同... 详细信息

锂-氧气电池因其超高的理论比容量而受到科研界的广泛关注,但其存在较为严重的充放电极化和较差的循环稳定性等问题,从而极大地限制其商业化进程.因此设计出有效的正极催化剂是解决锂-氧气电池面临的这些棘手问题的必要手段.通过对不同充电状态的废旧锂电池正极进行回收制得三种不同锂含量的多元金属氧化物Li_(x)MO(x=0.79,0.30,0.08;M=Ni/Co/Mn),并分别用作锂-氧气电池正极催化剂.系统研究了Li_(x)MO材料中锂含量及晶体结构对其电化学性能的影响.电化学测试结果表明,与Li_(0.79)MO和Li_(0.08)MO催化剂相比,基于Li_(0.30)MO为正极催化剂的锂-氧气电池在电流密度100 mA·g^(-1)和限定容量800 mAh·g^(-1)的条件下具有较高的放电比容量(14655.9 mAh·g^(-1))、较低的充电电压(3.83 V)和较高的能量转换效率(72.2%).而且该电池体系在充放电循环140圈后充电终止电压仍低于4.3 V.最终认为制得的Li_(0.30)MO材料具有优异的催化性能归因于其稳定的层状-岩盐相复合结构以及结构中富含的氧化镍相和氧空位之间的协同作用.这些优点能够促进放电产物的可逆形成与分解,从而提高锂-氧气电池循环性能.

关键词：废旧锂离子电池锂含量多元金属氧化物正极催化剂锂-氧气电池

基于基质含水率的作物蒸腾量估算与预测模型研究

在线全文

学校读者我要写书评

暂无评论

农业机械学报 2019年第B7期50卷 187-194页

作者：陈士旺李莉杨成飞李文军孟繁佳中国农业大学现代精细农业系统集成研究教育部重点实验室北京100083 中国农业大学农业农村部农业信息获取技术重点实验室北京100083

作物蒸腾作用是基质水分传输的主要驱动力,建立了基于基质含水率变化量的温室番茄作物蒸腾量估算模型和预测模型,并进行对比分析。使用校准后的EC5基质含水率传感器,记录第1次灌溉后与第2次灌溉前基质实时含水率变化量,使用称量法测量... 详细信息

作物蒸腾作用是基质水分传输的主要驱动力,建立了基于基质含水率变化量的温室番茄作物蒸腾量估算模型和预测模型,并进行对比分析。使用校准后的EC5基质含水率传感器,记录第1次灌溉后与第2次灌溉前基质实时含水率变化量,使用称量法测量作物实时蒸腾量。通过基质含水率变化量与基质栽培槽体积的多元线性回归运算,建立番茄单株日蒸腾量估算模型;将基质含水率变化量、空气温度、空气湿度和光照强度作为输入,利用GABP神经网络算法,建立番茄单株日蒸腾量预测模型。将试验所得温室作物日蒸腾量估算模型和预测模型分别与温室作物实际日蒸腾量进行线性回归分析,结果表明,基于基质含水率变化量建立的估算模型在苗期、花期的预测精度分别为0.9729、0.9796,预测模型的预测精度分别为0.9915、0.9890,两者之间差异不大,但估算模型运算速度远高于预测模型的运算速度,估算模型对于温室灌溉管理具有推广应用价值。

关键词：作物蒸腾量基质含水率变化量估算模型预测模型线性回归 GABP神经网络

在线全文

学校读者我要写书评

暂无评论

基于LSTM的温室番茄蒸腾量预测模型研究

农业机械学报 2021年第10期52卷 369-376页

作者：李莉李文军马德新杨成飞孟繁佳中国农业大学农业农村部农业信息获取技术重点实验室北京100083 青岛农业大学山东省智慧农业研究院青岛266109 中国农业大学现代精细农业系统集成研究教育部重点实验室北京100083

作物蒸腾量是指导作物灌溉关键参数之一,实时获取作物蒸腾量,实现按需灌溉是节约用水的有效途径。然而,温室内小气候效应显著,作物蒸腾与环境因子间关系较为复杂,且各环境因子之间相互关联并呈非线性变化。本文以番茄作为研究对象,使用... 详细信息

作物蒸腾量是指导作物灌溉关键参数之一,实时获取作物蒸腾量,实现按需灌溉是节约用水的有效途径。然而,温室内小气候效应显著,作物蒸腾与环境因子间关系较为复杂,且各环境因子之间相互关联并呈非线性变化。本文以番茄作为研究对象,使用称量法测量作物实时蒸腾量,通过布设传感器实时获取温室小气候数据,包括空气温度(Air temperature,AT)、相对湿度(Relative humidity,RH)、光照强度(Light intensity,LI)作为模型的小气候环境输入,冠层相对叶面积指数(Relative leaf area index,RLAI)作为模型的作物生长输入,在此基础上,提出了基于长短期记忆网络(Long short term memory,LSTM)的番茄蒸腾量预测模型。利用该模型对番茄蒸腾量进行预测,并与非线性自回归(Nonlinear autoregressive with exogeneous inputs,NARX)神经网络、Elman神经网络、循环神经网络(Recurrent neural network,RNN)模型进行了对比。试验结果表明,LSTM预测模型决定系数(Determination coefficient,R^(2))与平均绝对误差(Mean absolute error,MAE)分别为0.9925和4.53 g,与NARX神经网络、Elman神经网络、RNN方法进行对比,其决定系数分别提高了8.97%、1.18%和0.82%,其平均绝对误差分别降低了8.16、6.23、0.52 g。本研究所提的预测模型具有较高的预测精度及泛化性能,研究成果可为温室作物需水规律及需水量研究提供参考。

关键词：番茄温室长短期记忆网络蒸腾量预测模型

在线全文

学校读者我要写书评

暂无评论

不同深度基质含水率变化规律与预测模型研究

农业机械学报 2020年第S2期51卷 408-414页

作者：杨成飞和寿星孟繁佳李文军李莉 SIGRIMIS N A 中国农业大学农业农村部农业信息获取技术重点实验室北京100083 云南省农业科学院高山经济植物研究所丽江674199 中国农业大学现代精细农业系统集成研究教育部重点实验室北京100083 雅典农业大学农业工程系雅典11855

为探明不同深度的基质含水率变化规律,使用干燥法分别对多个EC5型传感器进行校准,并将4个传感器分别放置垂向距滴头5、10、15、20 cm 4个不同深度处,测量不同滴头流量及滴灌量条件下垂向基质含水率的变化,建立了不同深度基质含水率预测... 详细信息

为探明不同深度的基质含水率变化规律,使用干燥法分别对多个EC5型传感器进行校准,并将4个传感器分别放置垂向距滴头5、10、15、20 cm 4个不同深度处,测量不同滴头流量及滴灌量条件下垂向基质含水率的变化,建立了不同深度基质含水率预测模型。试验结果表明,在滴灌开始后第1层(距滴头5 cm处)基质含水率最先上升并迅速达到较高水平,滴灌停止后水分将快速扩散至更深基质层,其含水率可提升至根系易利用水平(25.3%及以上),水分快速运移时间持续1 h左右,随着初始基质含水率的降低,在相同滴头流量及灌溉量条件下,水分在垂直方向的运移程度更深,将第1层基质初始含水率、滴灌时间、预测时间、预测层高度差、滴头流量作为输入,利用遗传算法优化的BP神经网络算法与随机森林回归算法(RFR),建立滴灌下基质不同深度含水率预测模型。将试验所预测的滴灌后基质含水率与实际测量的不同深度基质含水率进行对比分析,并对不同预测深度的预测结果进行误差分析,结果表明GABP预测模型及RFR预测模型的R2分别为0.8664、0.9465,即RFR算法建立的预测模型更加精确,并且预测深度越接近于第1层基质预测结果越准确。

关键词：基质含水率滴灌水分运移随机森林预测模型