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WP30-6属于折射式微喷头,由铜合金或铝合金制成。喷嘴直径1.4-5.0mm共分八档,流量0.17-1.32m~3/h射程2.35-6.54m,工作压力150-300kPa,喷灌强度=9.64mm/h。 相似文献
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中国对虾与缢蛏投饵混养的实验研究 总被引:8,自引:2,他引:6
在4 个50 m × 50 m ×18 m 的陆基围隔中分别放入缢蛏 ( Sinonovacula constricta) 0 ,250 , 375 和500 只( 0 , 10 ,15 和20 只/ m 2) , 壳长为 540 cm ±035 c m , 再放入等量 (6 尾/ m 2) 的中国对虾 ( Penaeus chinensis) , 体长为285 cm ±016 c m 。投饵饲养3 个月结果表明, 缢蛏放养密度为20 只/ m 2 时, 对虾的成活率 (740 % ) 和产量 (4136 kg/h m 2) 最高, 分别比单养对虾的成活率(650 % ) 和产量 (3054 kg/h m 2) 高138 % 和354 % , 氮的绝对利用率提高了53 % 。缢蛏密度为10 只/ m 2 时, 其成活率和产量最高, 为904 % 和316 kg/h m 2 ; 密度为20 只/ m 2 时, 降至 782 % 和92 kg/h m 2。本系统中对虾的生产潜力为124 g/ ( m 2·d) , 缢蛏的极限配养量为1500 kg/h m 2 左右。 相似文献
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提出通过变圆心途径实现非圆形喷洒域喷头的构想 ,研究了实现这一构想的数学原理 ;以近似正方形喷洒域为重点 ,对水质点的运动轨迹和运动速度、喷灌强度和喷灌均匀度进行了计算机模拟和计算 ;提出了实现非圆形喷洒域的结构设想。结果表明 :运用双圆周复合运动可较简单地实现非圆形喷洒域 ;近似正方形喷洒域的点喷灌强度取决于喷头单向喷洒时的线喷灌强度函数。 相似文献
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研究了在硫酸环境中8-羟基喹啉对碘催化亚砷酸与硫酸铈氧化还原反应的抑制作用及其动力学条件。据此建立了动力学的直接光度法测定痕量8-羟基喹啉的新方法。结果表明,在0225mol/LH2SO4,000125mol/LAs2O3,0001mol/LCe(SO4)2,001mg/LI,05g/LNaCl环境中测定8-羟基喹啉,其线性范围为0020~027mg/L,表观摩尔吸光系数为27×105L·mol1·cm1,Sandel灵敏度为0538μg/cm2。用本法对药物硫酸羟基喹啉钾中的8-羟基喹啉含量的测定,结果满意。 相似文献
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采用滤纸法测定。试验表明喷洒水裂散的程度不仅与喷头的工作压力、喷嘴直径有关,且与喷洒水射流的雷诺数有关。提出常用旋转式喷头喷洒水滴沿程分布特性,喷洒水滴以累计水量为60%~70%的上限水滴直径作为旋转式喷头喷洒水滴代表性直径。给出了砂土、砂壤土、壤土、壤粘土和粘土在不同喷水定额下的允许喷灌强度,供修改GBJ85-85参考。 相似文献
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美洲斑潜蝇幼虫龄期划分的研究 总被引:4,自引:0,他引:4
运用测定幼虫口钩、头咽骨长度的方法,推断美洲斑潜蝇幼虫期共有3龄。1~3龄幼虫口钩长度分别为:2202±014μm,3792±013μm,6701±015μm,头咽骨长度分别为8424±0.13μm,14072+016μm,21435±014μm,1~3龄幼虫体长×宽分别为:047mm×018mm,124mm×045mm,251mm×085mm,虫道在上下龄分界处有明显加宽,此方法可快速划分龄期,为适龄防治提供理论依据。 相似文献
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川中丘区川单15高产综合栽培技术研究初报 总被引:6,自引:0,他引:6
运用三因素五水平二次正交旋转组合试验设计方法,研究了川中丘区川单15播种期、种植密度和氮化肥用量对产量及其主要经济性状的影响,并建立了相应的数学模型,得出在直播条件下产量60t/hm2以上的高产栽培技术方案为:播种期4月6日~17日、种植密度61~66株/m2,氮化肥用量250~300kg/hm2。 相似文献
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采用反向高效液相色谱法, 研究了罗美沙星在健康鸡体内的药动学与生物利用度。结果表明, 鸡静注罗美沙星后的ci- ti数据符合二室开放模型, 其主要动力学参数如下: tt/2α056±012h, t1/β769±079 h, Vd216±035 L/kg, C L B020±003 L/kg·h, A U C 5219±899 ug/m L·h。鸡内服、肌注罗美沙星c1- t1 数据, 均符合有吸收因素二室模型, 内服的主要动力学参数如下: t1/2ka118±014 h、t1/2α245±046 h、t1/2β1721±158 h、 A U C 3878±633 ug/m L·h、tmax316+ 023 h、 Cm ax206±043 ug/m L、 F7431% ; 肌注的主要动力学参数是: t1/2ka067±012 h、t1/2α130±023 h、t1/2β1152±102h、 A U C 4315±204 ug/m L·h、tm ax176±020 h、 Cmax460±ug/m L、 F8268% 。本文还就罗美沙星的临床应用进行了药动学评价。 相似文献
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The objective of this research was to assess the effect of soil cracks on soil moisture distribution under various sprinkler
irrigation applications and to identify the optimal irrigation strategy that enhances soil moisture distribution and reduces
water drainage for the upper soil layer 0–250 mm. The assessment was made for six irrigation events: the first two were for 10 and 46 mm water applications using a hand shift-set
sprinkler system. The second set was for 43 and 19 mm water applications using the lateral move system with fixed sprayer
heads and the third pair of events were for 43 and 32 mm water applications using the lateral move system with rotating sprinklers.
The experiments were conducted on two adjacent fields at the University of Queensland, Gatton, Australia. Each field was divided
into 2 m × 2 m grids that covered 62 sampling locations. For each event, the initial soil moisture content (SMC) was measured
at each sampling location before irrigation. After irrigation, catch can readings were recorded for each sampling location.
After 12 h overnight, the second set of soil moisture measurements was taken at each location. The area1 distribution of SMC
for the studied applications was quantified. An attempt was made to identify the relationship between the applied water uniformity
using catch cans and the soil moisture uniformity using gravimetric water content measurements. The study also took into consideration
variables that could affect the soil physical and hydrological properties including the field slope, the soil texture, the
infiltration rate, the salt content and the soil organic matter content of the two fields. Since the soils were cracking clay
Vertisols, further analyses were conducted on the crack dynamics, size and distribution using image analysis techniques. The
research findings demonstrated that the cracks were the main contributors to water drainage below 250 mm soil depth due to
the micro-run off from the crust surface to the cracks. The cracks ranged from a few millimeters to more than 40 mm in width.
It was observed that the cracks which were wider than 15 mm remained open after irrigation for the specified application rates.
Improving the irrigation system application uniformity did not always result in higher uniformity of the surface SMC (0–250 mm).
The event that best enhanced soil moisture distribution and thus improved soil moisture recharging was observed after the
sixth irrigation event when the field received 32 mm water application. The soil was at a relatively high initial SMC of 25%,
(which represented 43.3% of the plant available water range) and the sprinkler water uniformity was rather high above 87%
Christiansen coefficient of uniformity (CUc). At this SMC, the extent of soil cracking is limited. 相似文献
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中药材种植基地的喷灌系统,要求既满足灌溉需要又不影响中药材收获对象的产量和质量。结合中药材喷灌工程实例,阐述了管道布置、喷头选择、喷头间距和支管间距的确定、主管与支管的管径计算、管道水头损失计算、喷灌强度计算、水泵选配等喷灌设计方法以及开挖管道沟、安装管道和立杆、安装水泵和控制系统、安装喷头等施工过程和注意事项,全部设计安装过程为大面积生产基地的基础农业设施建设提供了参考。 相似文献
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不同灌溉方式对香蕉产量和品质的影响 总被引:4,自引:0,他引:4
采用大田试验方法,研究了滴灌、漫灌、微喷灌3种灌溉方式对香蕉产量及品质的影响。结果表明,香蕉产量以微喷灌处理最高,分别比漫灌和滴灌处理增产2.3%和4.3%;漫灌处理的香蕉总糖、维生素C含量均显著高于滴灌和微喷灌处理,微喷灌处理的维生素C含量显著高于滴灌处理;可食率以微喷灌处理最高,漫灌处理最低,3种灌溉方式之间差异均显著;干物质含量以微喷灌处理最高,滴灌处理最低,二者间差异显著。在香蕉约100d的生长期内,微喷灌处理的用水量比漫灌少约19%。综合来看,在3种灌溉方式中,微喷灌是在最适宜于香蕉的方式。 相似文献
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试验以辣椒"农大7923"为研究对象,对其在不同滴灌施肥强度下的生物学性状、产量等做了试验。试验结果表明:在试验条件下,辣椒生产最适宜的滴灌施肥强度为全生育期滴灌施肥10次,每次滴施肥水混合液施用量为12 m3/667 m2,即每次施肥量6.00 kg/667 m2(纯养分),此滴灌施肥强度下辣椒的生物学性状、产量都有一定提高。 相似文献
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冬小麦氮素吸收及产量对喷灌施肥均匀性的响应 总被引:9,自引:1,他引:9
为了为喷灌均匀系数设计标准的制订提供更充分的依据,分别于2002~2003和2003~2004年度在北京进行了喷灌施肥均匀系数和施肥量对冬小麦氮素吸收量和产量影响的田间试验。试验中生育期平均喷灌均匀系数变化范围为72%~84%。除了基肥外,其它肥料利用喷灌系统施入,生育期平均喷灌施肥均匀系数变化范围为71%~85%,喷灌施肥量的变化范围为0~180kgN/hm2。试验结果指出,在所研究的均匀系数范围内,均匀系数对氮素吸收量和产量的影响不明显。施肥量对冬小麦产量的影响不明显,但秸秆全氮含量和氮素吸收量均随施肥量的增加呈现出增加趋势。本研究结果表明,对华北平原的冬小麦喷灌来说,目前我国采用的喷灌均匀系数不小于75%的设计标准不会对氮素吸收量和产量造成负面影响。 相似文献
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