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478篇 您的检索式:作者名="Hewitt J"
    题名 作者 年代 出处 被引量
1喷雾助剂类型及浓度对喷头雾化效果影响显示文摘为达到农药减施增效的目的,助剂逐渐成为农药喷洒过程中必不可少的部分,其效果及浓度直接影响着施药过程中农药利用率。为探索不同助剂及浓度对喷头雾化效果的影响,该文利用激光粒度仪比较分析了IDK120-025型和LU120-015型喷头喷施不同浓度典型增效剂意欧、减量增产助剂激健、尿素时,其雾滴体积中径及雾滴分布相对跨度差异。两款喷头应用广泛,喷雾角度相同、喷腔雾化结构相异。结果表明:3种助剂溶液对IDK120-025型喷头的影响效果相比于LU120-015型喷头更为显著,但是LU120-015喷头喷雾雾滴均匀性较优于IDK120-025。激健溶液配比为1:3 000时,在0.4 MPa喷雾压力条件下,与水相比可将IDK喷头雾滴体积中径增加20.43%,粒径分布相对跨度减小1.74%;意欧溶液配比为1:2 000时,在0.4MPa喷雾压力条件下,与水相比可将IDK喷头雾滴体积中径增加11.10%,粒径分布相对跨度减小8.86%;意欧溶液配比1:3 000时,在0.2 MPa喷雾压力条件下,与水相比可将LU喷头雾滴体积中径减小5.99%,粒径分布相对跨度增大1.56%;尿素溶液在配比1:2 000时,在0.4 MPa喷雾压力条件下,与水相比可将IDK喷头雾滴体积中径增加16.92%,粒径分布相对跨度减小6.92%。该试验可为田间农药施用中助剂及喷头的选择提供依据,为进一步研究喷头及助剂提供数据基础。张瑞瑞 张真 徐刚 陈立平 Andrew J Hewitt 2018农业工程学报2018,34,20:25
2脉宽调制变量控制喷头雾化性能及风洞环境雾滴沉积特性显示文摘脉宽调制(pulse width modulation, PWM)技术是实现变量喷雾的重要手段,其工作参数与环境条件决定着施药的精准性。为探究PWM变量喷头雾化及风洞环境沉积特性,该文研制了脉宽调制变量喷雾系统,以农业施药常用空心圆锥雾化喷头喷雾的雾化、沉积特性为研究对象,在IEA-II型常规风速风洞内,通过点阵式放置电容式雾滴沉积传感器测定计算雾滴沉积与沉积评价指数(deposition evaluation index,DEIX),并利用Spraytec雾滴粒径仪测试其雾滴体积中径(volume median diameter,VMD)和雾滴相对分布跨度(relative span,RS)。试验结果表明:占空比在10%~40%间,随占空比增大,雾滴体积中径呈减小趋势,与占空比10%时相比,占空比40%时的雾滴体积中径下降了7.9%;PWM占空比60%时分布跨度最小,较占空比20%时雾滴分布跨度下降9.52%,雾滴谱最窄,获得的雾滴粒径分布最集中。雾滴沉积方面,风速1 m/s条件下,雾滴主要沉积在距喷头3.3 m内,此范围内沉积量占总沉积量的95.7%,当风速超过3 m/s时,在气流作用下,雾滴沉降距离增大,导致雾滴运动偏离施药靶标区域。PWM占空比增加,雾滴沉积评价指数DEIX值降低,雾滴的飘移率增大;相同工况下,风速及喷头高度越大,DEIX越小,施药雾滴越易飘移。该研究可为农业田间实际生产中脉宽调制变量施药技术应用及其工况参数的选择提供依据,为PWM变量调节装置的进一步优化提供研究基础。张瑞瑞 李龙龙 付旺 陈立平 伊铜川 唐青 Andrew J Hewitt 2019农业工程学报2019,35,3:17
3'Twin Copper Source' growth of metal-organic framework membrane- Cu3(BTC)2 with high permeability and selectivity for recyeling H2 显示文摘Guo H L Zhu G Hewitt I J Qiu S 2009Journal of American Chemical Society2009,131,20:1
4Determination of hydroxyl radical concentration in environmental using electron spin resonance显示文摘Stokes N J Tanner B J Hewitt C N 1994Chemosphere1994,28,5:1
5The impact of residual coagulant on downstream treatment process 显示文摘Lees E J Noble B Hewitt R 2001Environment Technology2001,22,1:1
6Clinical presentation and pre-mortem diagnosis of variant Creutzfeldt-Jakob disease associated with blood transfusion: a case report显示文摘Stephen J Wroe Suvankar Pal Durrenajaf Siddique Harpreet Hyare Rebecca Macfarlane Susan Joiner Jacqueline M Linehan Sebastian Brandner Jonathan DF Wadsworth Patricia Hewitt John Collinge 2006The Lancet2006,,9552:1
7Droplet size spectra classification categories in aerial application scenarios显示文摘Hewitt A J 2008Crop Protection2008,27,9:1
8Synoptic Inventory of Riparian Ecosystems:the Utility of Landsat Thematic Mapper Data 显示文摘Hewitt M J 1990Forest Ecology and Management1990,,3334:1
9Resolution of quantitative into Mendelian factors by usinga complete RFLP linkage map显示文摘Paterson A H Landon E S Hewitt J D 1988Nature1988,335,:1
10A model for prediction of fume formation rate in gas metal arc welding (CMAW) , globular and spray modes, DC electrode positive 显示文摘Dennis J H Hewitt P J Redding C A J 2001Occupational Hygiene Society2001,45,2:1
11Studies with tissue cultures of the Chinese herbal plant, Tripterygium wilfordii isolation of metabolites of interest in rheumatoid arthritis, immunosuppression, and male contraceptive activity显示文摘Kutney J P Hewitt G M Lee G 1992Can J Chem1992,70,5:1
12Electrochemistry of in Sb as a Li insertion host:problems and prospects显示文摘HEWITT K C BEAULIEU L Y DAHN J R 2001J Electrochem Soc2001,148,:1
13Advanced cycles and re- placement working fluids in heat pumps 显示文摘Hewitt N J McMuUan J T 2001Applied thermal engineering2001,,21:1
14A comparison of initial spray characteristics produced by agricultural nozzles显示文摘Dorr G J Hewitt A J Adkins S W 2013Crop Protection2013,53,11:1
15A test of the humped-back theory of species richness in new zealand native forest显示文摘Wilson J B Allen R B Hewitt A E 1996New Zealand Journal of Ecology1996,20,:1
16Glycophorin A mutations and risk of secondary leukaemia in patients treated for childhood acute lymphoblastic leukaemia显示文摘 Hewitt M Mott MG 1996Br J Haematol1996,93,:1
17Resolution of quantitative traits into Mendelian factors by using a comp lete linkagemap of restriction fragment length polymorphisms 显示文摘Paterson A H Lander E S Hewitt J D 1988Nature1988,335,:1
18Deter- mination of hydroxyl radical concentration in envi- ronmental using electron spin resonance显示文摘STOKES N J TABNER B J HEWITT C N 1994Chemo- sphere1994,28,5:1
19The dynamic properties of unidirectional carbon and glass fiber-reinforced plastics in torsion and flexure显示文摘Adams R D Fox Mao Flood R J L Hewitt R L 1969Journal of Composite Material1969,3,:1
20Induction of ovulation in women undergoing assisted reproductive techniques: recombinant human FSH (follitropin alpha) versus highly purified urinary FSH (urofollitropin HP)显示文摘Lenton E Soltan A Hewitt J 2000Hum Reprod2000,15,5:1
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