共查询到20条相似文献，搜索用时 15 毫秒
1.
Shuqing HAO Hongwei HUANG KunYIN .School of Civil Engineering Tongji University Shanghai China.College of Construction Engineering Jilin University Changchun China 《东北亚地学研究》2008,11(1):37-41
By using fluent fluid engineer emulator software to simulate negative pressure formed inside the injector added in the reverse-circulation sampling drilling bit, at six angles of 15, 30, 45, 60, 75 and 90 degrees. The pressure distributing nephogram and the corresponding numerical value gotten compared with the experiment data received by an injector with 6 angles designed by emulation the conclusion. It has been found that the two values are coincident essentially. The article shows that using emulator technology to design optimizely is credible and simple. The cost is low and the design cycle is short compared with the method through experience and test. 相似文献
2.
赵秀娟 《东北石油大学学报》2012,(6):59-64,9,10
为了对大庆油田水驱油藏层系井网进行优化调整和剩余油挖潜,研究特高含水期多井系统井间干扰规律,应用势的迭加原理分析3口井的激动井产量、距离及相互位置对观察井(油井)产量和压力的影响.结果表明,当激动井是油井时,激动井产量越大,与观察井距离越近,激动井之间距离越远,观察井产量越小,压力恢复越低;当激动井是水井时,激动井注水量越大,与观察井距离越近,激动井之间距离越远,观察井产量越大,压力恢复越高.在采用均匀井网时,油井间的影响使观察井产量降低、压力下降;注水井的影响使观察井产量上升、压力升高.特高含水期剩余油分布零散,采用均匀井网可以有效挖潜剩余油,可以通过注水调整观察井产量和压力,均匀井网更有利于提高油田注水开发效果. 相似文献
3.
定义了一种简单的高级语言--Min-B语言和一个虚拟的简单计算机的机器语言VSML,详细阐述了一个能够将Min-B语言源程序转换成VSML目标程序的编译器的设计思路和实现方法,并简要介绍了能够运行VSML的计算机仿真器simpleMachine的设计方法. 相似文献
4.
龚一光 《成都信息工程学院学报》2000,15(3):248-254
提出了一种在AT89C5 1仿真板上实现编程器来替代专门的编程器 ,分析了AT89C5 1芯片进行编程的方法 ,并详细阐述了硬件和软件的实现。 相似文献
5.
介绍一种新型气象参数测量仪的主要技术指标和功能特点.该仪器使用了高准确度的HD9008TR温湿度传感器、MS5534C气压传感器,采用先进的电子线路设计,具有准确度高、稳定性好、可扩展性强、性能价格比高等特点,满足常规气象监测. 相似文献
6.
李学波 《大地测量与地球动力学》2022,42(2):119-124
通过分析铅电极和固体不极化电极测量的地电场变化特征、地面场与区域气压及测向与附近断裂走向的关系等发现:1)2种地电场与断裂走向近垂直的测向日变幅相对较小,与断裂走向近平行的测向日变幅相对较大;2)活动断裂附近,基于铅电极测量的地电场有气压非周期变化形态,且各测向地电场和气压变化的相关性与测向和附近断裂走向的夹角有关,夹... 相似文献
7.
CO2地质封存是减少CO2向大气排放,缓解温室效应的有效手段之一。由于构造和成岩作用,倾斜地层在自然界中普遍存在,研究倾斜地层对CO2封存量及安全性的影响具有实际意义。依托新疆准噶尔盆地阜康凹陷某CO2地质封存示范工程,采用数值模拟方法,分析了中高渗CO2储层地层倾角变化对CO2地质封存过程的影响。结果表明:CO2注入将导致近井区域地层压力显著升高;中高渗倾斜地层与水平地层相比,在地层压力分布、CO2侧向运移距离、CO2注入速率和总封存量等方面均存在明显差异。相比于水平地层,由于地层倾角的存在,倾斜地层压力呈不对称分布,CO2侧向运移距离显著加大。倾斜地层中压力传递和消散过程与水平地层差异显著,受此影响,倾斜地层与水平地层CO2的总注入量差值随时间呈非单调性变化。在注入初期,倾斜地层CO2的总注入量小于水平地层,随着注入时间延长,倾斜地层CO2的总注入量逐渐接近并超过水平地层;注入20年后,相较于水平地层,倾斜地层倾角越大越有助于增加CO2的总注入量,这一研究结果与前人基于低渗倾斜地层的研究结论正好相反。地层倾角的存在会促进CO2向浅部运移,倾角越大,CO2向浅部含水层和大气泄露的风险越大。因此,在CO2地质封存场地选址中,应充分考虑倾斜地层对封存效率及安全性的影响。 相似文献
8.
The destructiveness of impulse waves generated by landslides(IWL) originates from the wave's movement and load, wherein the impulse wave's load is the major cause of sub-aerial building damage and casualties. In this study, an experiment involving 16 groups of physical tests for the wave pressure generated by a landslide was designed, consisting of 4 sets of IWL and 4 opposite bank slope angles. A high-frequency strain system was used to measure the total pressure of the impulse wave in a water tank. The tests showed that the dynamic pressure caused by the IWL can be divided into two types: impact pressure generated by the jetflow and the pulsating pressure caused by the wave. Under the same impulse wave conditions, the maximum run-up becomes smaller as the opposite bank's slope angle increases, and the jetflow maximum impact pressure experienced by the opposite bank increases, while the maximum pulsating pressure caused by the impulse wave is slightly decreased. Different from previous studies, the spatial maximum pressure distributions of the wave generated by landslide were concluded that the position of the maximum pulsating pressure appears adjacent to the still water surface, and the overall spatial distribution pattern of maximum wave pressure is presented as an inclined "M" shape.Meanwhile, this study is the first to quantitatively analyzed that impact pressure has a very short action time, is even 7 times of the pulse pressure value, and there is a simple mathematical linear relationship between the two. Currently, some wave-load formulas for wind waves and tides are not applicable to calculating the loads of IWL. Research on the load of IWL will explain the hazard of impulse wave very clearly, and will greatly contribute to hazard prevention, mitigation and risk assessment work associated with IWL. 相似文献
9.
利用对偶四元数能同时描述旋转矩阵和平移向量的优势,提出一种适用于大角度的三维空间坐标转换参数求解模型。该模型解决了传统算法不适用于大旋角的问题,可以直接解算坐标转换参数,且无需迭代初始值。通过模拟数据进行仿真实验表明,该方法无需线性化,计算简便,验证了该方法的正确性与有效性。 相似文献
10.
包括恐龙化石在内的古生物化石是重要的地质遗迹,是研究生物进化的最重要资料。该文从物理力学角度,通过数值试验模拟分析围压和轴压作用下对恐龙化石强度和破坏特性的影响效果。试验结果表明:不同埋深时围压对含有不同角度裂隙化石应力影响较大,随着埋深增加,含有裂隙化石的应力大幅增大。在围压与轴压共同作用时,埋深对开裂角的影响较小,而随埋深增大时极限载荷也随之增大。同时,在不同埋深下开裂角随裂隙角度的变化趋势一致,均随着裂隙角度的增大而减小;而极限载荷随裂隙角度的变化趋势一致。 相似文献
11.
针对传统控制系统鲁棒控制器阶数较高的缺陷,提出一种具有阶次限制的鲁棒控制器设计方法.利用Ne-vanlinna-Pick插值方法,将鲁棒控制器设计问题转化为求解非线性方程的根,避免选择H∞控制中加权函数.基于同伦法设计低阶鲁棒控制器,通过仿真实验研究该鲁棒控制器下的阶跃响应,以及存在外部干扰时系统的控制性能及干扰抑制能力,并与传统滞后超前校正方法进行比较.结果表明:该控制器不仅能够在保证跟踪精度前提下具有较强干扰抑制能力,而且当系统存在不确定性时,闭环控制系统具有很好的鲁棒性. 相似文献
12.
Foam is used widely in underbalanced drilling for oil and gas exploration to improve well perfor-mance.Accurate prediction of the cutting transport and pressure loss in the foam drilling is an important way to prevent stuck pipe,lost circulation and to increase the rate of penetration(ROP).In foam drilling,the cuttings transport quality may be defined in terms of cuttings consistency and downhole pressure loss,which are controlled by many factors.Therefore,it is very difficult to establish the mathematical equation that reflects nonlinear relationship among various factors.The field and experimental measurements of these parameters are time consuming and costly.In this study,the authors suggest a cuttings transport mathematical modeling using BPN(back propagation network),RBFN(radial basis function network)and GRNN(general regression neural network)based on various experiment data of cuttings transport of previous researchers and compared the result with experiment data.Results of this study show that the GRNN has a correlation coefficient of 0.99962 and an average error of 0.15 in training datasets,and a correlation coefficient of 0.99881 and an average error of 0.612 in testing datasets,which has higher accuracy and faster training velocity than the BP network or RBFN network.GRNN can be used in many mathematical problems for accurate estimation of cuttings consistency and downhole pressure loss instead of field and experimental measurements for hydraulic design in foam drilling operation. 相似文献
13.
Landsat遥感影像正规化处理的模型比较研究 总被引：2，自引：0，他引：2
徐涵秋 《地球信息科学学报》2008,10(3):294-301
卫星遥感影像在接收的过程中由于受到许多因素的干扰,使影像的质量受到一定程度的影响。而不同时相的影像也会因为成像时光照和大气条件的不同而出现差异。因此,在使用遥感影像之前往往需要进行必要的辐射校正。目前,主要用于辐射校正的两种基于影像的正规化模型分别是Markham和Irish等人提出的校正日照差异的正规化模型(ICM)和美国尤他州立大学遥感和地理信息系统实验室新近提出的日照大气综合校正模型(IACM/IACMt)。本文以三对不同时相的Landsat TM/ETM+影像为例,利用不变特征地物法求出各影像的相对噪音、RMSE和斜率,并用这些指标来对模型进行定量对比和评价。结果表明,当不同时相影像之间的季相、太阳天顶角和大气条件有较大差别时,经过正规化处理的遥感影像的噪音和RMSE比未经正规化处理的影像得以明显降低,且斜率更接近于1,镶嵌接缝淡化,效果更好。但如果遥感影像之间的季相一致、成像时的太阳天顶角接近,且影像晴空无云的话,则经过正规化处理的影像和未经该处理的影像之间的区别并不大。就正规化模型之间的对比而言,当影像无明显的大气影响时,ICM要好于IACM;但当受到明显的大气影响时,带有τ值的IACMt模型更好。 相似文献
14.
《中国海洋大学学报(英文版)》2015,(6)
Wave pressure on the wet surface of a V-shaped floating breakwater in random seas is investigated. Considering the diffraction effect, the unit velocity potential caused by the single regular waves around the breakwater is solved using the finite-depth Green function and boundary element method, in which the Green function is solved by integral method. The Response-Amplitude Operator(RAO) of wave pressure is acquired according to the Longuet-Higgins' wave model and the linear Bernoulli equation. Furthermore, the wave pressure's response spectrum is calculated according to the wave spectrum by discretizing the frequency domain. The wave pressure's characteristic value corresponding to certain cumulative probability is determined according to the Rayleigh distribution of wave heights. The numerical results and field test results are compared, which indicates that the wave pressure calculated in random seas agrees with that of field measurements. It is found that the bigger angle between legs will cause the bigger pressure response, while the increase in leg length does not influence the pressure significantly. The pressure at the side of head sea is larger than that of back waves. When the incident wave angle changes from 0? to 90?, the pressure at the side of back waves decreases clearly, while at the side of head sea, the situation is more complicated and there seems no obvious tendency. The concentration of wave energy around low frequency(long wavelength) will induce bigger wave pressure, and more attention should be paid to this situation for the structure safety. 相似文献
15.
《中国海洋大学学报(英文版)》2015,(4)
China's newly enacted Breakwater Design Specifications(JTS154-2011) explicitly state that breakwaters with water depths greater than 20 m are categorized as deep-water breakwaters, and emphasize that design principles, methods and construction requirements are different from those of common shallow water breakwaters. However, the specifications do not make any mention of how to choose wave force calculation methods of deep-water breakwaters. To study the feasibility of different formulae for wave force estimation of deep water combined breakwaters, the wave force calculated by the Sainflou's, Goda's, modified Goda's and specifications' methods are compared for various water depths and wave heights in this paper. The calculated results are also compared with experimental data. The total horizontal forcing and the pattern of pressure distributions are presented. Comparisons show that the wave pressure distributions by the four methods are similar, but the total horizontal forces are different. The results obtained by the Goda's method and the specified formulae are much closer to the experimental data. As for the wave force estimation for the deepwater mixed embankment foundation bed parapet, the Goda's formula is applied in the case with a water depth of less than 42 m. The Specifications method is suitable for standing waves. In the wave force estimates of breastworks, Sainflou's and the modified Gaoda's formulae are no longer applicable for the foundation bed of mixed embankment. 相似文献
16.
【目的】从亲疏水特征的角度对贝壳各层次结构中的界面进行分析探讨。【方法】采用接触角测量仪对贝壳的中维界面、无机文石及无机方解石进行水接触角测量。【结果】贝壳内表面的水接触角普遍大于90°,其中最大值为113°,最小值为91°;贝壳表壳层内表面边缘位置的水接触角平均值为67°,内部位置的水接触角平均值为112°;无机文石及无机方解石平整表面的水接触角均小于90°,其平均值分别为50°、49°。【结论】贝壳内表面具有疏水性,即有机质层具有疏水性;由于具有亲水特征的文石及方解石为贝壳矿物的主要成分,说明贝壳矿物结构具有亲水性;贝壳表壳层内表面边缘呈现亲水特征,内部呈现疏水特征。 相似文献
17.
Usually the water head of the pumped storage hydro-plant is high, generally up to 400-500 m, therefore the rock mass under the high-pressure bifurcation pipe have to bear as high as millions Pascal water pressure, in according with the requirements of high water head pumped storage hydro-plant should be 1.2 times of the water head special high-pressure packer permeability test compared with normal to test the permeability of rock and rock cleavage pressure value. The test results on the choice of design options often play a decisive role. Based on the engineering practice, the authors studied the drillhole high-pressure packer permeability test in the pumped storage hydro-plant's underground powerhouse, by the analysis of test results, this article offers a demonstration of the deformation of rock fracture witch under building in the condition of high-pressure water head, it provides a more detailed engineering geological background. 相似文献
18.
Measuring the internal velocity of debris flows using impact pressure detecting in the flume experiment 总被引：2，自引：0，他引：2
Sergey CHERNOMORETS 《山地科学学报》2011,8(2):109-116
Measuring the internal velocity of debris flows is very important for debris flow dynamics research and designing debris flow control works. However, there is no appropriate method for measuring the internal velocity because of the destructive power of debris flow process. In this paper, we address this problem by using the relationship between velocity and kinetic pressure, as described by surface velocity and surface kinetic pressure data. Kinetic pressure is the difference of impact pressure and static pressure. The former is detected by force sensors installed in the flow direction at the sampling section. Observations show that static pressure can be computed using the formula for static water pressure by simply substituting water density for debris flow density. We describe the relationship between surface velocity and surface kinetic pressure using data from seven laboratory flume experiments. It is consistent with the relationship for single phase flow, which is the measurement principle of the Pitot tube. 相似文献
19.
LUO Chunhong ZHENG Zhichuan CAO Pinlu College of Construction Engineering Jilin University Changchun China 《东北亚地学研究》2009,12(1):36-39
The authors tested the percussion-extruding Down-the-hole （DTH）hammer bit with five different structures and mainly analyzed the drilling mechanism between conical bit and stepped bit. In addition, aiming at ＂the pile effect＂ in combination with the advantage＇ of stepped bit, we design a new cam spinning bit and test it outdoors. The result shows that using cam spinning bit can solve the problem of ＂the pile effect＂, which can also obtain higher drilling efficiency than using conical bit in high confining pressure strata. It is characterized by novel structure and high drilling speed as well as good guiding, and it is significant for improving efficiency in percussion-extruding drilling technique. 相似文献
20.
在双天线GNSS/MEMS组合测姿中,低精度、低成本的MEMS加速度计输出通常包含比较大的噪声,导致由加速度计调平计算得到的水平角观测值精度较低,影响组合测姿的精度和可靠性。不同于传统的时域降噪方法,从频域的角度出发,根据实际车载运动中加速度计输出具有因汽车固有结构产生的高频振动噪声的特点,利用滑动窗口的Butterworth低通滤波器平滑加速度计输出。动态车载实验结果表明,该滤波器降噪效果明显。与滤波前相比,水平角观测值精度提升了约4倍,达到(0.643°,0.546°)。在此基础上,滤波后组合测姿精度也从(0.124°,0.738°,0.532°)提升到(0.122°,0.074°,0.052°),其中水平角精度提升了大约一个数量级,滤波后的测姿结果更加准确可靠。 相似文献