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C_6F_6^+→C_6F_5^++F气相单分子分解及碰撞诱导分解反应研究
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作者 王建华 X.D.Zhou +1 位作者 a.k.shukla J.H.Futrell 《化学学报》 SCIE CAS CSCD 北大核心 1999年第9期1009-1013,共5页
用质量分析离子动能谱(MIKES)研究了C_6F_6^+→C_6F_5^++F的气相单分子分解及其与Ar和He的碰撞诱导分解(CID)反应.实验结果表明,C_5F_6^+在电离室中获得足够能量而被激发到某一长效激发态,而CID是诱导其分解的必要步骤,且该分解过程有... 用质量分析离子动能谱(MIKES)研究了C_6F_6^+→C_6F_5^++F的气相单分子分解及其与Ar和He的碰撞诱导分解(CID)反应.实验结果表明,C_5F_6^+在电离室中获得足够能量而被激发到某一长效激发态,而CID是诱导其分解的必要步骤,且该分解过程有两条能量不同的反应途径.当碰撞气体为Ar时,两条途径所对应的能量变化分别为0eV和+9.8eV(将多余能量转化为动能),而当碰撞气体为He时,则分别为0eV和-17eV(将多余能量转化为内能).CID/Ar诱导该长效激发态在C—F键断裂之前将多余能量转化为动能,而在CID/He中则将多余能量转化为内能. 展开更多
关键词 六氟代苯 单分子分解 CID MIKES 碰撞诱导分解
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低压低成本滴灌系统的设计、构造与评估(摘选)
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作者 D.N.Sah R.C.Purohit +2 位作者 Virendra Kumar a.k.shukla S.K.Jain 《农业工程》 2011年第2期111-113,共3页
使用当地产材料,包括KB管、KB压力脚踏泵、带有微型管的压力桶以及医用输液管开发了手动控制低压低成本(LPLC)滴灌系统。对该装置进行了田间试验,并且针对西红柿与椰菜,对该系统的各种独立参数,如营养生长、水力性能、农作物需水量、水... 使用当地产材料,包括KB管、KB压力脚踏泵、带有微型管的压力桶以及医用输液管开发了手动控制低压低成本(LPLC)滴灌系统。对该装置进行了田间试验,并且针对西红柿与椰菜,对该系统的各种独立参数,如营养生长、水力性能、农作物需水量、水分利用效率以及经济成本从不同方面进行了评估。该系统的投资回收期为1个季度,效益成本比为1·59~5·31。该滴灌系统具有方便适用、经济实惠、拆装灵活、易学易用以及较低运作与维护成本的优点,对于小地块农户来说是一个不错的选择。 展开更多
关键词 低压低成本滴灌系统 医用滴头 可分割 营养生长参数
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Total and Extractable Manganese and Iron in Some Cultivated Acid Soils of India:Status,Distribution and Relationship with Some Soil Properties 被引量:1
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作者 S.K.BEHERA a.k.shukla 《Pedosphere》 SCIE CAS CSCD 2014年第2期196-208,共13页
A total of 400 surface soil (0-15 cm) samples were collected from cultivated soils representing four soil series, namely, Hariharapur, Debatoli, Rajpora and Neeleswaram in Orissa, Jharkhand, Himachal Pradesh and Ker... A total of 400 surface soil (0-15 cm) samples were collected from cultivated soils representing four soil series, namely, Hariharapur, Debatoli, Rajpora and Neeleswaram in Orissa, Jharkhand, Himachal Pradesh and Kerala states of India, respectively, and were analyzed to measure the contents of total and extractable Mn and Fe, to establish the relationship among total and extractable Mn and Fe and soil properties, and to characterize the spatial distribution pattern of Mn and Fe in some cultivated acid soils of India. The contents of total as well as extractable Mn and Fe varied widely with extractants and soil series. However, the amounts of Mn or Fe extracted by diethylene triamine penta-acetic acid (DTPA), Mehlich 1, Mehlich 3, 0.1 mol L-1 HC1 and ammonium bicarbonate DTPA (ABDTPA) were significantly correlated with each other (P 〈 0.01). Based on the DTPA-extractable contents and the critical limits (2 mg Mn kg-1 soil and 4.5 mg Fe kg-1 soil) published in the literature, Mn and Fe deficiencies were observed in 7% 23% and 1%-3% of the soil samples, respectively. The content of soil organic carbon (SOC) had greater influence on total and DTPA-extractable Fe than did soil pH. Geostatistical analysis revealed that total and DTPA-extractable Mn and Fe contents in the acid soils were influenced by soil pH, SOC content, and exchangeable cations like potassium, calcium and magnesium. Spatial distribution maps of total and DTPA-extractable Mn and Fe in soil indicated different distribution patterns. 展开更多
关键词 MICRONUTRIENTS EXTRACTANT geostatistical analysis spatial variability
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Assessment of ecosystem services of rice farms in eastern India
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作者 A.K.Nayak Md Shahid +11 位作者 A.D.Nayak B.Dhal K.C.Moharana B.Mondal R.Tripathi S.D.Mohapatra P.Bhattacharyya N.N.Jambhulkar a.k.shukla Nuala Fitton Pete Smith H.Pathak 《Ecological Processes》 SCIE EI 2019年第1期435-450,共16页
Background:Rice is a major cereal crop and staple food of eastern India,and most farmers depend solely on rice for their livelihood.Rice farming provides both tangible and non-tangible benefits to ecosystems which nee... Background:Rice is a major cereal crop and staple food of eastern India,and most farmers depend solely on rice for their livelihood.Rice farming provides both tangible and non-tangible benefits to ecosystems which need to be maintained and enhanced.These benefits are provided through ecosystem services(ES)that include both marketable and non-marketable.Methods:In this study,the rice farms in eastern India were valued by quantifying the economic value of the services under conventional method of rice cultivation and the gap of ecosystem services value and farm income per unit area were assessed.A stratified random sampling technique was used in this study for selection of agro-climatic zones,districts,blocks,gram panchayat,and study units(households).Soil sampling was also performed for assessing the regulating services(biocontrol of pests,carbon flow,soil erosion,nitrogen fixation),provisioning services(food and by-products),and supporting services(soil fertility,hydrological flow,nutrient cycling,and soil formation).Results:The results indicated that the total economic value of ecosystem services ranged from US$1238 to 1688 ha−1 year−1.The marketed(primary production)and non-marketed ecosystem services values ranged from 66–89 to 11–34%of the total,respectively.Valuation of some of the ecosystem services such as cultural services,biodiversity,and gas regulation,which may play a significant role in total ecosystem services,has not been made due to non-availability of data and appropriate methodology for rice ecosystem.Different values of parameters can explain the variability in ecosystem services among the agro-climatic zones in eastern India.Clustering of locations based on variability of ecosystem services helps in identifying intervention points for sustaining and improving ecosystem services,while permitting sustainable agro-ecological intensification.The highest total economic gap between ES value and farm income was found in the north central plateau zone(US$1063 ha−1 year−1)and the lowest in the north western plateau zone(US$670 ha−1 year−1).Conclusion:We suggest various measures to reduce the economic gap,including payments for ecosystem services for rice farming for sustainability of the ecosystem and agricultural development,while ensuring reliable farm income. 展开更多
关键词 Ecosystem services Rice farming Economic gap Payment for ecosystem services(PES)
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