Experimental study on calculation of hydro-geological parameters for unsteady flow

After the linear analytical method of unsteady flow theory is further improved, an innovative and faster algorithm is introduced. The water storage in a confined aquifer is derived from the water transmissivity coefficient and the water-pressure conductivity coefficient. The water transmissivity coefficient is approximated by a Taylorseries expansion of drawdown, and the water-pressure conductivity coefficient is obtained by the average drawdown. In this algorithm, the distance of the observation points from the pumping well must be short. When the distance is as short as the radius of the main pumping well, the data of the drawdown difference between the sidewall and the center of pumping well are difficult to measure, but the same results can be achieved based on the assumption that the drawdown difference approximates to the drawdown of the observation wells at a radial distance from the pumping well according to the algorithm. Without the help of charts, this algorithm is more concise and efficient, which has been verified by the test of water pumping project in Tianjin Binhai International Airport.     

NUMERICAL INVESTIGATION ON THE PHASE CHANGE OF WATER-SATURATED POROUS MEDIA WITH THERMOSYPHON

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流动注射仪法与传统方法测定土壤全磷的比较

利用流动注射分析仪法和传统的钼蓝比色法、钼黄比色法分析比较采自全国30个地区的33个土壤样品全磷含量的测定结果,为利用流动注射分析仪法快速有效地测定土壤磷含量的可靠性提供依据。结果表明:3种方法测定结果的平均变异系数,流动注射分析法(3.119%)钼蓝比色法(3.985%)钼黄比色法(4.203%);流动注射分析仪法的分析结果与钼蓝比色法、钼黄比色法测定结果间的相关性分别为0.997 1和0.987 0,均达到极显著性的正相关;3种方法的回收率均在95.0%～105.0%,符合分析要求。研究结果表明,流动注射分析仪法可用于土壤全磷含量的测定,其结果与传统方法相一致。     

工业用水总硬度在线检测方法探索

将流动注射技术应用于水中总硬度的分析,并在各种实验条件下研究相关因素的影响.在EDTA浓度为0.02 mol/L时,检测范围能满足国标要求的5～1000 mg/L测量范围,能够很好地应用于炼钢厂中生产用水、锅炉水的总硬度的在线测定.     

低渗透储层裂缝方位综合分析方法研究

在对低渗透油田的开发以及注水的深入研究中,发现在有些注水井井区内,部分注水井尽管生产正常,但对应的油井一直没有见效,储层裂缝则成为说明这些注水井井区无效（或低效）注水的重要依据,而有效识别裂缝则成为至关重要的问题。文章介绍了裂缝识别的几个方法,包括见水动态分析法、注入压力动态分析法、微地震裂缝检测和同位素示踪剂法。     

U形渠道断面流速分布规律试验研究

U形渠道是灌区广泛推广的灌溉渠道，其具有占地面积少、水头损失小等特点。但U形渠道流速分布规律及其流量测量仍处于研究阶段。对灌区计划用水、科学用水和节约水资源等工作造成了很大的影响，因此U形渠道测流技术是亟待解决的问题。本文从试验的角度使用断面测流方法，针对三种不同规格的U形渠道测量断面，运用数学拟合方法，探求其流速分布规律，并分析出了相应的U形渠道过水断面流量的积分求和公式，以求对以后的U形渠道量水工作有所帮助。     

液体饱和蒸汽压测定实验的改进

针对目前静态法测定液体饱和蒸汽压实验中饱和蒸汽压数值读取不合理,汽液两相未充分平衡等问题,改变传统的调整U型管两端液面等高后再读取数字压力计的方法。改进后的实验装置只需在U型管的两侧标上刻度,待系统恒温、汽-液充分平衡后,读取数字压力计的数值、温度以及U型管两端液面的高度差就可得到该温度下的液体饱和蒸汽压。该方法可解决静态法测定液体饱和蒸汽压实验中调整U型管两端液面等高耗时,空气容易倒灌的问题。     

水闸泵站自动检测系统的设计

设计了一种新型水闸泵站自动检测系统,以电场传感器MC33794为核心,应用微控制器MC9S12DJ128组成了智能自动检测系统.它克服了目前一些注水泵机组因无监控系统,致使水泵抽空、电机和泵轴承以及轴瓦过热烧损、泵体振动过大等事故时有发生的缺点,提高了水闸泵站自动监测系统的自动化管理水平,确保了系统的安全性和可靠性.     

煤层注水技术的应用

回采工作面通过采用煤层注水挤排瓦斯,降低了回采工作面在割煤期间粉尘量,改善了工作面及上风巷恶劣环境,降低了回采时瓦斯涌出量,使工作面回风流瓦斯浓度小于临界状态,提高了回采工作面生产率,煤层注水工作面得以开展。     

新型连续注射水相法合成CdS量子点

基于连续注射进样系统,研究了水溶性CdS量子点的合成方法。结果表明连续注射技术可实现对反应物比例的精确控制,从而快速确定最佳反应物比例,所制得CdS量子点荧光特性较为稳定。激发波长范围为340—360nm,且在480～510nm的宽波长范围有强烈荧光发射。在最佳反应物比例为nc1：nTCA：ns=1．00：1．15：0．90时,最大荧光发射波长为504nm。CdS量子点的荧光显微成像表明其水溶液分散性良好。     

长武县机井配套潜水电泵综合装置技术改造研究

长武县机井配套潜水电泵选型不当,剩余扬程多,致使装置运行工况点偏离高效区较远,低效高耗;为此,组织人员,对试区机组进行现场抽水测试,根据额定扬程与选用扬程的差值大小,选择了三种潜水电泵综合装置技术改造方法：维修保养;变级改造,同时维修保养;变径改造,同时维修保养。试区采取综合措施改造后,流量平均由29.45 m3/h提高到32.88 m3/h,能源单耗平均由10.53 kWh/（kt.m）降低到6.62 kWh/（kt.m）,综合装置效率由28.59%提高到41.90%,节能32.1%。     

Mitigation of soil liquefaction using microbially induced desaturation

Soil liquefaction can cause disastrous consequences to buildings and human lives. Regular countermeasures against soil liquefaction are often overly expensive for normal buildings and structures. This could be the major reason that liquefaction induced damage is still widely encountered in large- and mid-size earthquakes in recent years. In this paper, a new method for the mitigation of soil liquefaction using the microbially induced soil desaturation is proposed and tested. The desaturation effect in soil is achieved by the generation of nitrogen gas produced from the microbial denitrification process. Some major issues related to this method are experimentally investigated. These include soil desaturation procedures, shapes and distribution of gas bubbles in soil, mechanical responses and liquefaction resistance of desaturated soils, and stability of gas in soils. The desaturation treatment of soils is made simply by introducing denitrifying bacteria and a desaturation solution into soil pores by mixing, flushing, or injection. The degree of saturation can be reduced as the microbial reaction proceeds. Experimental results show that the final degree of saturation is related to the initial nitrate concentration added to the soil: the higher the concentration of nitrate in the desaturation solution, the lower the degree of saturation that can be achieved. The existence of gas bubbles in soil is evidenced by computer tomography (CT) technology. The CT images reveal that gas is in the form of small pockets which has a size a little larger than the mean size of sand grains. It is shown in the shaking table tests that microbially induced desaturation can effectively improve the liquefaction resistance of soil by showing a much lower pore pressure generation, much smaller volumetric strain, and much smaller settlement of the structure in desaturated soil, as compared with those in saturated soil. Triaxial consolidated undrained tests reveal that the desaturation treatment of soil can improve the undrained shear strength of loose sand. The stability of gas is tested under hydrostatic and water flow conditions. The gas phase is stable under the hydrostatic condition, but unstable under water flow conditions. So measures ought to be taken to prevent steady flow in practice.     

磁悬浮控制技术在非圆镗削加工中的应用

为了实现非圆异形孔的镗削加工,借鉴了主动磁悬浮控制技术。针对径向异形孔的加工特点,对磁悬浮主轴进行了运动学分析,建立了描述其运动的综合机电方程,并在工作点上进行了线性化处理。为了实现磁悬浮主轴的径向微动控制,采用了增益调度自适应控制算法。以某型号活塞的销孔加工为例进行了镗削试验,结果表明,通过控制磁悬浮主轴的旋转轴心沿设定的轨迹移动,能够实现椭圆异形孔的加工,并且能够获得高的加工精度和表面粗糙度。     

浅谈欧阳修咏物词对前代文学意象的继承

欧阳修的咏物词透露着他浓厚的主体意识或主观情感,但这种主体意识或主观情感明显地带有传统色彩.这与他在咏物时积极继承传统意象有关.他以菊象征清贵品质,以莲表达相思爱情,以蝶讽刺滥情,都有他源于传统又高于传统的地方.     

压裂作业中多层压裂液返排计算

水力压裂过程中,布砂成功与否和压裂液返排控制有着直接的关系。而目前压裂液返排的研究主要集中在定性分析上,很少有定量的计算。且油田经常采用经济性较强的分层压裂,其压裂液返排的检测和控制,以及其模型和计算关系到水力压裂施工最终导流效果。通过建立压裂液由储层向裂缝,由裂缝向井筒以及井筒中的流动模型,并通过无因次简化数学模型来定量的计算多层压裂液的返排。以压裂液单层裂缝返排模型作为多层返排模型的基础,考虑了井口压力随时间引起压裂液返排比的变化,并利用VB程序编制双层压裂液返排模型,利用实例来计算其返排比。从而可推广到多储层返排应用中。     

微波消解流动注射法测定水中总磷

利用微波炉消解水样,采用流动注射分析技术,建立了测定水中总磷的快速分析方法.通过优化实验条件,检出限为0.025mg/L.应用于河水样的测定,结果令人满意.     

Experiments and sensitivity analyses for heat transfer in a meter-scale regularly fractured granite model with water flow

Experiments of saturated water flow and heat transfer were conducted for a meter-scale model of regularly fractured granite. The fractured rock model (height 1502.5 mm, width 904 mm, and thickness 300 mm), embedded with two vertical and two horizontal fractures of pre-set apertures, was constructed using 18 pieces of intact granite. The granite was taken from a site currently being investigated for a high-level nuclear waste repository in China. The experiments involved different heat source temperatures and vertical water fluxes in the embedded fractures either open or filled with sand. A finite difference scheme and computer code for calculation of water flow and heat transfer in regularly fractured rocks was developed, verified against both the experimental data and calculations from the TOUGH2 code, and employed for parametric sensitivity analyses. The experiments revealed that, among other things, the temperature distribution was influenced by water flow in the fractures, especially the water flow in the vertical fracture adjacent to the heat source, and that the heat conduction between the neighboring rock blocks in the model with sand-filled fractures was enhanced by the sand, with larger range of influence of the heat source and longer time for approaching asymptotic steady-state than those of the model with open fractures. The temperatures from the experiments were in general slightly smaller than those from the numerical calculations, probably due to the fact that a certain amount of outward heat transfer at the model perimeter was unavoidable in the experiments. The parametric sensitivity analyses indicated that the temperature distribution was highly sensitive to water flow in the fractures, and the water temperature in the vertical fracture adjacent to the heat source was rather insensitive to water flow in other fractures.     

基于仿水流算法的最短路径问题求解

使用传统算法求解最短路径问题时,收敛速度慢,且求得的路径并不是所有行程的最短路径。为此文章提出一种求解最短路径问题的仿水流算法。该算法结合水流量局部更新和全局动态更新,能够动态调配水流量值,避免算法陷入停滞状态;局部搜索中,对于更优路径的水流使用2-opt方法进行搜索,以此提高收敛速度。仿真实验验证了该算法的有效性,与其他算法相比,仿水流算法收敛速度快,收敛精度高,鲁棒性好,所求的最短路径明显优于传统算法。     

基于奇异值分解的电网潮流转移模式研究

针对电网潮流转移场景下支路传输功率和电网节点注入功率之间的关联作用关系,提出了一种分析节点注入功率模式的方法。根据支路传输功率和电网节点注入功率之间的关联作用关系矩阵,利用矩阵奇异值分解,将节点注入功率分解为各种模式;在此基础上,进一步分析节点注入功率的各种模式的表现形式并进行算例分析。算例分析初步表明,在节点注入功率模式的各种表现形式中,比较常见的是以部分奇异值为主导的作用模式,在实际分析和处理中,把握这样的主导模式,将有利于进一步的分析和预防潮流转移引起的不利后果。     

英国新大学运动及其对我国应用型本科教育的启示

19世纪之前,以牛津、剑桥为代表的传统英式大学拒绝降低门户开展技术教育。随着资产阶级革命的胜利和工业革命的推动,英国经济社会对技术型、应用型人才的需求大增,新大学运动由此应运而生。英国新大学运动的发展对我国开展应用型本科教育有如下启示:大学的内在逻辑是一切大学的准则,外延式发展是大学改革的可信赖路径,在秉持传统的同时不应囿于传统。