Effect of Main Parameters on Cutting of the Pulsed Abrasive Water Jet

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.     

The Grey Related Degree Analysis of the Cutting for the Premixed Abrasive Water Jet

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.     

Theoretically Investigation of Dynamic Characteristics of Spherical Bubble Collapse in Pulsed Abrasive Water Jet

This paper theoretically investigates the characteristics of cavitating bubbles in the pulsed abrasive water jet(PAWJ) and establishes the dynamic equations of cavitating bubbles. The effects of abrasive diameter and density on the spherical bubble collapse are also analyzed. It is found that the change of abrasive diameter rarely affects the bubble collapse when the abrasive diameter and density are small whereas the smaller abrasive greatly blocks the bubble collapse when the abrasive diameter and density are comparably big. It is also shown that when the abrasive density is increased, the fluid viscosity rises, and the kinetic energy of the abrasives near the collapsed bubble is enhanced and meanwhile the intensity of cavitating erosion is weakened.     

Study and Application on the Abrasive Grinding Properties of Precision Abrasive Belt

The characteristics of work piece's surface under precision abrasive belt grinding are analyzed.A comprehensive understanding of the reason of low roughness value's surface is found out,which the edge of grain formed compact and crossed micro grinding marks that can compensate for the inconsistence of grinding mark's height in single grinding direction.The grinding test of gear shaft is done for the sake of doing research on the main factors of surface roughness in grinding quenching stainless steel.The results indicate that decreasing the vertical pressure is beneficial to(reduce) surface roughness of work piece,and the surface roughness also can reach the requirement of precision processing when steadily grinding.     

Effects of Wave Speed on Frequencies of the Self excited Oscillation Pulsed Abrasive Water Jets

The effects of cavitation and abrasive acceleration in the self excited oscillation pulsed abrasive water jets are directly determined by its oscillating frequencies, so the wave speed in the jets and its effects on pulsed frequencies are discussed. The numerical results show that the oscillating frequencies of the jets increase obviously with decreasing wave speed, and the abrasive parameters have almost no effects on the wave speed, whereas the exit of air in fluid has significant consequences on the wave speed.It was found that these conclusions were applicable for design the nozzle of the jets.     

Experimental Study on Cone Water Jet

The model of conical membrane atomization for cone water jet is presented. The atomizational ability and dust-laying effect for water jet are investigated experimentally. Some results are useful for dust-laying and fire-extinguishing researchers and designers.     

An Experimental Study of the Optimal Jet Position on Water Jet Assisted Drag Bit During Rock Cutting

The tests for the effects of jet position on drag bit cutting process were described. The influence of jet position on rock chips formed ahead of bit was analyzed. And the effects of cutting depth,bit velocity on bit force reductions were discussed. One of the most interesting results is that the water jet has the largest effect on drag bit forces when it is directed towards the center beneath drag bit.     

Studies on Dust-Laying with Swirl-Water Jet

The main optimum parameters of laying dust for mine is introduced in this pa-per.The related parameters of laying dust with swirl,pulsed and ordinary water jet are analysed re-spectively at different water pressures.     

Analysis of the Kinetic Theory of Submerged Abrasive Water Jets

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.     

Effect of Deflection Characters on Self oscillating Water Jet

The deflective mechanism of the oscillating water jet is analyzed and the effects of jet deflection on the self oscillating water jet are investigated. It is experimentally shown that the deflective angle may reach 9.53 degree, the pressure fluctuation is more intensive and more regular and the jet can efficiently eliminate the water cushion effect and increase the ability in cutting.     

前混合磨料射流磨料速度测试的新方法

前混合磨料射流超强的打击力主要是由高速磨料群提供的,因此,磨料速度测试是磨料打击力分布规律等研究的基础。针对传统研究方法的不足之处,笔者提出采用PIV技术结合自主编程设计的磨料中心识别程序,实现非接触式测试手段下磨料速度测试实验研究,并利用该方法简要分析了喷嘴结构对磨料速度的影响。结果表明,在一定范围内增加直线段长度有利于提高喷嘴出口处磨料的速度,表明在喷嘴直线段末端磨料依然处于明显的加速状态;增加收敛段长度对提高喷嘴出口处磨料速度有一定的作用,但磨料速度增幅不大;收敛角较大时,液相在收敛段前半段加速缓慢而在后半段过于剧烈,因磨料颗粒加速滞后于液相的原因导致喷嘴出口处磨料速度降低。     

Predictive Analysis of Water Environment Quality in Aha Reservoir

ased on the average depth's momentum equation of two dimension which observe the momentum conservation,the numerical simulation of velocity distribution in aha reservoir is presented. According to the property of pollutant while they are in convective diffusion or transplant and degradation, the model simulates organics convective diffusion and heavy metal transplantion. In the end, some forecast are presented for typical organics and heavy metal pollutant at abundant season and medium season in the future of ten years and some proposal are given for dispose.     

Effect of the Parameters of the Collimating Pipe on the Efficiency of Cutting Rock of Collimated Abrasive Water Jets

This paper applies economy principle to analyzing the principal agent model between client and property management company, the model is applied to putting forward three kinds of solutions contributing to solving the problems in present expenses collection of property management company.     

Experimental Study on Shear Strength of High Strength Concrete Columns

On basis of the experiment on sixteen high strength concrete columns, their shear behaviors are analysed. The effects of shear-span ratio and axial compression ratio on failure behavior, cracking shear and shear strength are analysed. The authors have discussed the suitability of the design equations for shear strength in the code. This experimental study on shear strength of high strength concrete frame columns is the first one in this field at home and the results can be served as reference for the code of high strength concrete design.     

A Study on the Social Sateguard System for Centralized Processing the Flammable Wastes as Substitute Fuel in Cementklin

The paper proposes to use the synthesis effect of commercial,technical and eraluational subsystems to establish the operational model of centralized process of flammable harmful wastes as substitute fuel in cementklin,and points out the method to establish social safeguard system on the basis of developing, maituining, protesting functions, and provide demonstration, conception and design for converting harmful wastes into harmless and resourceful sources in proctice.     

Research of Application About Environment Dredging on River and Reservoir with Water Jet Airlift

Being established in the thought of environment dredging, the crafts flow of water jet airlift dredging and treating of surplus water as well as circle using of mud polluted have been analysed following the status in quo of pollution of the fiver and reservoir. Definitely, it has been pointed out that the total of mud will be reduced with the technique of dehydration so as to reduce the volume of mud stack. At the same ring the surplus water. The mud which had been treated can be time, it will be reduced for pollution secondly by treaused as soil of fiver or gardens or road for the recycle. Then, the parameter and efficiency of production in HuaXi river valley integration treating project have been expatiated particularly in environment dredging. It indicates the new way for environment dredging in river and reservoir at the mountainous area.     

水葫芦厌氧发酵实验及其产气模型研究

水葫芦是厌氧发酵制沼气的一种良好原料。本文以水葫芦为唯一底料进行厌氧发酵制沼气实验,研究其发酵过程的产气特性,并建立两阶段模型分析水葫芦厌氧发酵的产气过程。结果显示：水葫芦厌氧发酵产气潜力约为500 mL/gTS;两阶段模型与发酵实验过程基本吻合,模型误差小于10%。     

Comparative Study on the Effect of Water Stress on the Photosynthesis and Water Relations of Triticale, Rye and Wheat

An attempt was made to investigate the effect of water stress treatment on the components of photosynthesis and water relations of triticale ( Triticale octoploide ), Russian rye ( Secale cereale ) and wheat, ( Triticum aestivum var. Sonalika ). The results revealed that there was no significant adverse effect of water stress on the photosynthesis of triticale compared to wheat and rye. The maintenance of photosynthetic productivity under water stress in triticale has been accomplished by (a) reduction in water loss by stomatal behaviour and (b) by maintenance of water uptake through continued transpirational flow. Both these mechanisms served to maintain high water potential as stress occures. This ameliorates the onset of stress and helps to maintain photosynthesis. The rye also consists of another type of adaptability to drought through significant recovery of photosynthesis and chlorophyll development on reirrigation particularly at post-anthesis stage, when other species failed to recover. However, in wheat Sonalika both these adaptive characteristics did not exist in such intensity.     

酸性电解水的稳定性研究

在酸性电解水的稳定性研究中,开机后酸性氧化电位水生成器仅需制水2 min,可得到理化性质稳定的酸性电解水;酸性电解水的理化指标受电流影响,随着电流的增加,ORP与ACC呈上升趋势(p<0.05),pH值呈下降趋势(p<0.05);光照条件、密封情况、贮藏温度、贮藏时间等因素对酸性电解水ORP,ACC,pH值的稳定性有较大影响,室内封口避光条件有利于酸性电解水的贮藏。     

旱塬区不同地带耕地土壤水分动态变化研究

为探明土壤水分在不同地带的变化特征,于2011年10、11月和2012年2—5月采集渭南塬耕地以及渭河边附近耕地的土壤样本进行了土壤水分含量的测定分析。研究结果表明：由于降水和地下水位等因素的影响,渭河附近耕地含水量大于塬上耕地,渭河附近耕地含水量变化大于塬上耕地。2011年10、11月和2012年2月由于受冬季气候的影响,土壤含水量较高,而2012年3、4和5月受春旱的影响,土壤含水量数值偏低。