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1.
The relationship between abrasive concentration, length of oscillating chamber, standoff distance and cutting depth, erosion rate as well as cutting specific energy was investigated by experiments in the submerge and surface conditions. The cutting and erosion capabilities of the pre-mixed abrasive water jet and the pulsed abrasive water jet were analyzed in contrast. It is shown that the maximum cutting depth and erosion rate of the pulsed abrasive water jet are respectively 1.67,1.72 and 1.39, 1.47 than the pre-mixed abrasive water jet in submerge and surface conditions. These results attained from the research are useful to increase the cutting efficiency, decrease the energy ratio and expand the application domains of the abrasive water jet. 相似文献
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The cutting property is studied with the grey theory and method for the premixed abrasive water jet.The relationship between the primary and secondary is obtained about the cutting specific energy influenced by pressure,the standoff distance,the abrasive concentration and transverse velocity.The guidance is provided for further research and pratical application. 相似文献
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Based on references [1, 2, 3], we designed a set of device of the self-excited oscillation cavitating jet. Its cavitation mechanism and the result of jet impact block are analysed. With erosive volume as the object, the effect of the self-excited oscillation cavitating jet is compared with that of conventional continuous jet under the same condition. It is found cxperimeetally that the position of suction air and the air quantities and the geometrical parameters of the device have great effect on the erosive effects of the self-excited oscillation cavitating jet. In certain range of stand off distance, it's not obvious that the erosive effects of the self-excited oscillation cavitating jet changed with stand off distance for pulse cavitating jet and cavitation bubblies and droplet impinging on the target. Compared with continuous jet, the erosive vo-l ume and area of the self-excited oscillation cavitating jet is more than one time larger than the continuous jet. 相似文献
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Abrasive water jets can incise objects with strong rigidity under water. The analytical means of kinetic theory is optimal for theoretical problems of submerged abrasive water jets. The flow characteristics in submerged abrasive water jets were analyzed based on kinetic theory for multiphase flows. The impact characteristics of every phase in submerged abrasive water jets was analyzed and continuity and momentum equations subsequently were developed for solid, gas and liquids in submerged abrasive water jets. It is shown that if the distributing function of every phase were given, the law of its movement could be ascertained. 相似文献
5.
Tang Chuanlin Liao Zhanfang Liu Xueren 《保鲜与加工》1992,(5):96-100
A new pulsed jet device is presented which can produce oscillatory pulsed wafergas jet. This device is used in the erasive experiment on the while sandbrick whose compressive resistance is 30 Mpa. The curves of the erasive effects of the oscillatory pulsed water-gas jet.the oscillatory pulsed jet and the ordinary jet are drawn in order to be compared.which are changed as the distances of the targets are changed. In addition the reason why the erasive effect of the new jet is superior to the other two jets is analyzed. 相似文献
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Aiming at the status quote of long time for methane extraction and slow speed for laneway excavating in coal seams of Liziya south 2JHJ well, abrasive water jet slotting technology is adopted to improve the methane desorption and increase excavating speed in semi-coal laneway. Through analyzing damage model and protection against outburst mechanism, the process of Coal-Rock Mass being cut and fractured is studied. Through lab test on abrasive water jet cutting coal-bed gangue, a new abrasive water jet cutting device is successfully designed and made and all parameters are determined. It is showed that abrasive water jet can cut through a coal-bed gangue with thickness 60~80 mm and uniaxial compressive strength 62 MPa. After cutting coal seams by abrasive water jet, the surface area for methane is enlarged and then coal seams pressure fell rapidly. Therefore the permeability and desorption of coal seams are greatly increased. The results are as follows: the average productivity of single-hole was enhanced by 2.83 times. 相似文献
7.
水稻萌发耐淹性种质资源筛选及QTL定位 总被引：2，自引：0，他引：2
作者用水培的方法研究水稻不同生育期缺磷的影响,结果证明：幼苗期缺磷的影响最显著,表现出生长缓慢,分蘖减少。因此,栽培水稻在幼苗期及分蘖期充分供应磷肥有特别重要意义。 相似文献
8.
黄花倒水莲(Polygala fallax Hemsl)组培快繁技术研究 总被引：1，自引：1，他引：0
以当年生黄花倒水莲幼嫩带腋芽茎段作为外植体,开展组织培养试验研究.结果表明:最佳外植体诱导培养基为1/2 MS+ BA 2.0 mg/L+ NAA 0.1 mg/L,诱导率可达95.1％;最佳增殖培养基为WPM+ BA 1.5 mg/L+ NAA0.1 mg/L,增殖系数为6.12,周期为25 d,不定芽生长状况好;最佳生根培养基为1/2 WPM+ IBA 0.1 mg/L+ ABT0.4 mg/L,生根率为95.67％;以泥炭土∶黄泥土∶珍珠岩(2∶1∶1)为移栽基质,移栽成活率可达92.6％,苗木长势好,叶色绿. 相似文献
9.
The flame ceiling jet is easily formed while the on fire train stops in the tunnel. The iterative formula is derived to calculate the average temperature of the flame ceiling jet when the fire source is set on the center of the train by establishing a one dimensional model of the unit control volume, and the heat exchange is considered among the flame smoke and the wall of the tunnel and the train. Undetermined coefficients in the iterative formula are determined by small scale model experiments with the scale factor of 1:8 and numerical simulation. The calculated values of temperature by the iterative formula are consistent well with the measured values, and the maximum error of calculation is no more than 7%, which indicates that the iterative formula is reliable. The results show that the distributions of the average temperature of flame ceiling jet are in the exponential form, but there are some differences between that above the train and that in the tunnel. Two prediction formulas for the flame ceiling jet average temperature changing along the longitudinal tunnel are obtained by the sub fitting method. The results can provide reference for the alarm parameter selection, device settings in tunnel, safety evacuation of the passenger, as well as the analysis of the destructive effects on the tunnel lining structure caused by tunnel fire. 相似文献
10.
A new type of watering device ,self exited oscillation vortex chamber watering device, is put forward.The jet is controlled by a circular vortex chamber,and self exited oscillation occurs due to a pressure difference between the left and right parts of vortex chamber. By the momentum balance of jet and the masses of air flowing into or out the chamber though air hole,the critical pressure and the time required for reaching the critical pressure can be calculated. This watering device has appropriate size of water drops and uniform water distribution. 相似文献
11.
Investigation and application of jet aeration technology in the oxidation process of desulfurization slurry 
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下载免费PDF全文 The calcium sulfite oxidation rate is an important indicator to judge the efficiency of wet limestone/gypsum flue gas desulfurization process used by high-sulfur-coal power plant. Jet aeration technology which integrates aeration and stir into one apparatus is proposed to implement the forced oxidation of limestone/gypsum flue gas desulfurization in order to improve the oxidation rate. The working principle of jet aeration oxidation in desulfurization slurry is investigated. ANSYS CFX is used to simulate the flow field inside the desulfurization slurry tank and obtain the best installation method of jet aerator which makes the mixing and stirring effect of slurry ideal: 3 jet aerators are uniformly installed at the height of 0.8m up from the bottom of slurry tank with their axis perpendicular to the tank wall. The air suction flowrate of jet aerators is tested under the best installation method in the on-site application test of the X protection company of Chongqing. The oxidation rate of calcium sulfite in desulfurization slurry is also tested by using iodometric method. The results show that the total air suction flowrate of jet aerators is 59.52 m 3/h which meets the requirement of slurry oxidation air quantity and the oxidation rate of calcium sulfite in desulfurization slurry reaches 87.6% after two-hour oxidation by using jet aeration. 相似文献
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普通小麦×东方旱麦草属间杂种长期保存技术及稳定性研究 总被引：3，自引：0，他引：3
对普通小麦×东方旱麦草这一完全不育属间杂种F1的无性系在培养基组成、 外植体大小对诱导率的影响和接种方法等方面进行了系统研究, 建立了对其进行长期保存的技术体系： 选择2n=35的F1正常植株为培养对象, 以1.1～3.0 cm的幼穗为外植体, 剪切足够细碎后接种于MS诱导培养基(MS无机元素+W14有机成分+400 mg/L LH+150 mg/L 相似文献
15.
射流器臭氧—水混合数值模拟及喉管优化 总被引：3，自引：0，他引：3
应用气液两相流动的双流体模型,数值模拟了射流器内臭氧—水的混合过程,得到了喉管内流场的参数分布,揭示了利用射流器进行臭氧—水混合的工作机理,为射流器结构参数优化设计和性能预测提供了有效手段。分析了最优喉管长度与面积比的关系,结果表明：最优喉管长度随着面积比的增大而增长,当面积比为2.25～6.25时,射流器的最佳喉管长度应在5.84～7.47d1之间。 相似文献
16.
乐果在香蕉、土壤中的残留动态及安全性评价 总被引：2，自引：1，他引：1
为了在香蕉上科学、安全地使用乐果,研究了乐果在香蕉和土壤中的残留降解动态。采用气相色谱法和田间试验方法,依据GB/T 5009.20—2003和GB/T 14552—2003对乐果的残留量进行测定,结果表明：在香蕉中,乐果有一定原始沉积量,其残留降解规律符合一级动力学关系,推荐剂量和加倍剂量2种不同处理的降解动态方程分别为C＝1.4009·e-0.2404t、C＝2.2820·e-0.2369t,半衰期(T1/2)分别为2.9、3.0天;在土壤中,乐果的残留降解动态方程为C＝4.5025·e-0.2348t,T1/2为3.0天。距第2次施药后62~66天,最终产品残留量在香蕉及其土壤中均未检出乐果残留量（检出限为0.005 mg/kg）。福建蕉区在香蕉生产上科学合理施用乐果,最终产品质量可符合NY/T 750—2011中规定的MRL要求,同时最终对蕉园土壤环境不会造成污染。 相似文献
17.
西洋杜鹃叶片离体培养及植株再生 总被引：1，自引：0，他引：1
以西洋杜鹃的嫩叶片为外植体,研究了其离体培养和植株再生的过程。结果表明：叶片愈伤组织诱导最佳培养基为Read＋ZT5．0mg／L,可用回归模型y=19．21＋7．32x1来估测西洋杜鹃叶片愈伤组织诱导情况。叶片愈伤组织增殖培养基同初代培养基,继代30d后体积可增为原来的3倍,重量增为原来的2．5～4．5倍。愈伤组织分化的最佳培养基配方为：Read＋ZT1．0mg／L＋NAA0．01mg／L,分化率为87．5％,分化出苗数在12—18株。生根培养基以Read＋IBA1．0mg／L＋NAA2．0mg／L＋ZT 0．2mg／L为好,生根率迭90％以上。炼苗基质选腐殖土：黄沙：珍珠岩：5：1：1为宜,存活率达88．33％。 相似文献
18.
黑木耳漆酶高产菌株的筛选 总被引：3，自引：0，他引：3
为筛选黑木耳漆酶高产菌株以便对黑木耳漆酶酶学性质、基因表达及结构与功能进行研究,从河南省农业科学研究院、河南省生物研究所购得黑木耳菌株10株。首先用含有0.04%愈创木酚的PDA固体培养基进行平板初筛,再进行液体培养基摇瓶培养,ABTS为底物检测酶活进行复筛,对筛选出来的菌株进行Native-PAGE,以判断黑木耳漆酶的同工酶数量。结果发现初筛培养基中,变色圈出现的时间早晚有差异,但一段培养时间后的直径大小差异不大;液体培养筛选得到一个黑木耳漆酶高产菌株地茂1号,其在培养第11天时酶活达到最大值（386.85U/L）;酶活最高峰时取培养液,离心后的粗酶液进行Native-PAGE,底物染色后发现地茂1号粗酶液中含有三种漆酶同工酶。 相似文献
19.
为明确不同胡萝卜素含量及人工饲料制作方法对七星瓢虫幼虫的影响。采用不同浓度的胡萝卜素及其他组分组成的不同状态人工饲料对七星瓢虫幼虫进行饲养,对七星瓢虫幼虫和蛹的发育历期、成蛹率、成虫数量及体重进行评估、分析。结果表明：以50 mg/kg浓度胡萝卜素及其他组分饲养的幼虫的成蛹率为75.00%±5.00%(n=20)、成虫率为71.75%±2.00%(n=20)、幼虫期为(11.68±0.10)天(n=20),显著高于其他浓度胡萝卜素饲养组;体重(0.0325±0.0007) g(n=20)则显著低于其他浓度饲养组,蛹期(3.70±0.11)天(n=20)与其他浓度饲养组相比均无显著性差异。干粉饲料加糖水的组合饲养的七星瓢虫幼虫的蛹期(3.80±0.06)天(n=20)和体重(0.0357±0.0006) g（n=20）与糊状饲料饲养组的蛹期(3.55±0.10)天(n=20)和体重(0.0345±0.0010) g(n=20)没有显著性差异,但干粉饲料加糖水的组合饲养的七星瓢虫幼虫的成蛹率57.50%±2.00%(n=20)和成虫率41.25%±5.00%(n=20)均显著高于糊状饲料饲养七星瓢虫幼虫的成蛹率18.00%±2.00%(n=20)和成虫率17.00%±2.00%(n=20),而幼虫期(9.93±0.17)天(n=20)则显著低于糊状饲料饲养七星瓢虫幼虫的幼虫期(11.68±0.16)天(n=20)。50 mg/kg浓度的胡萝卜素组成的人工饲料饲养七星瓢虫幼虫,其成虫率和成蛹率显著高于其他组合,干粉状人工饲料显著优于糊状人工饲料,研究明确了1组较优的七星瓢虫幼虫饲料及其制作方法。 相似文献
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通过单因素试验和响应面设计对蛹虫草液体深层发酵工艺进行优化。结果显示,最适的碳氮源是葡萄糖和蛋白胨;培养的适宜条件:装液量100 mL,初始pH值5.0,发酵周期为8 d;对于虫草素产量影响最显著的无机盐是FeSO_4。Plackett-Burman设计从8个因子中筛选出4个显著因子,经最陡爬坡和响应面设计,结果表明,葡萄糖31.58 g/L,蛋白胨34.48 g/L,腺嘌呤0.88 g/L,甘氨酸15.48 g/L为发酵培养基的最佳组合;优化条件下,虫草素的产量为917.53 mg/L,生物量为30.06 g/L,较优化前分别提高了108.30%和29.06%。 相似文献