YSM压力数显变送器

我厂是国家机械部定点生产企业,有30多年的历史,是国内大规模生产测压仪表的主要厂家。重点生产Y40～Y250—0.1～250MPa各种规格的压力表。近几年来相继开发了几十种新产品。其中YSM压力数显变送器是一种机电一体化新型二次仪表。与差动远传压力表配套后,可用于电力、化工、冶金、供水等工艺过程的气态、液态的介质压力测量。除就地压力显示外,还能连续输出与被测压力成线性关系的0～10mA(或4～20mA)信号和记录。

用压力幂数法预测油井的产量

文中简介了不同压力条件下的压力幂数法预测产量公式的导出、预测步骤,以及转抽和调参的预测实例。通过对大庆油田61口井的预测实践表明,该方法与PI-IPR法及相对采油指数法比较,平均误差较小,按其预测产量结果选泵和调参效果较好。

有杆泵井抽油参数的优化设计

有杆泵井抽油参数的优化设计方法较多,大庆油田在对图表法和API法分析研究的基础上,获得了几种新的设计方法,其中以双幂双模法为最佳。双幂双模法是通过4个环节来进行优化设计的方法,双幂就是用压力幂数法预测产量和计算地层压力;双模就是用模拟示功图法计算最大负荷、最大扭矩等参数,用模糊数学法优选泵径、冲程、冲数等参数。本文详细介绍了双幂双模法的设计内容,计算方法和应用效果。

储层流体流态判定方法研究

以低渗透油田的开发实践为背景,应用雷诺数法和压力数法综合判断地层流体渗流特征,指出了判定达西流非达西流的临界雷诺数和临界压力数,从而判断出地层流体渗流特征。

Icon memory research under different time pressures and icon quantities based on event-related potential

In order to obtain related brain electrical components and neural bases of physiology assessment of icon elements in a digital human-computer interface the modified sample-delay matching task experimental paradigm is used under different time pressures 4 000 and 2 000 ms and different icon quantities three five and ten icons on icon memory based on event-related potential ERP technology.Experimental results demonstrate that P300 has significant volatility changes and the maximum amplitude around the middle line of the parietal area PZ and P200 has obvious volatility changes around the middle line of the frontal and central area FCZ during icon cognition.P300 and P200 amplitudes increase as tasks become more difficult.Thus P300 latency is positively correlated with task difficulty. ERP research on the characteristics of icon memory will be an important reference standard in guiding user neurocognitive behavior and physiology assessment on interface usability.

Numerical Simulation of Extrusion Pressure in the Process of Hydrostatic Extrusion

In order to study the laws of the extrusion pressure changing with the extrusion parameters in the process of hydrostatic extrusion for the tungsten alloys, the large deformation elasto plastic theory and the software of ANSYS 5 5 are used to carry out the numerical simulation research. The laws of the extrusion pressure changing with the extrusion parameters, such as the die angle, extrusion ratio, and friction coefficient, are obtained. The simulation results are in good agreement with the experimental ones, and the simulated results are believable.

Forming defects in aluminum alloy hot stamping of side-door impact beam

The forming defects, including thinning, rupture, wrinkling and springback, usually arising in producing a side-door impact beam, were investigated by trial and numerical simulation. A temperature-related constitutive model specific to the temperature range from 350 °C to 500 °C was established and used for the numerical simulation. The trial and numerical simulation were conducted to clarify the quantitative characteristics of forming defects and to analyze the effects of process parameters on the forming defects. Results show that the rupture situation is ameliorated and the springback is eliminated in the aluminum alloy hot stamping. The wrinkling severity decreases with increasing blank holder force (BHF), but the BHF greater than 15 kN causes the rupture at the deepest drawing position of workpiece. The forming defects are avoided with lubricant in the feasible ranges of process parameters: the BHF of 3 to 5 kN and the stamping speed of 50 to 200 mm/s.

A general method to calculate passive earth pressure on rigid retaining wall for all displacement modes

A general analytical method to calculate the passive rigid retaining wall pressure was deduced considering all displacement modes. First, the general displacement mode function was setup, then the hypotheses were made that the lateral passive pressure is linear to the corresponding horizontal displacement and the soil behind retaining wall is composed of a set of springs and ideal rigid plasticity body, the general analytical method was proposed to calculate the passive rigid retaining wall pressure based on Coulomb theory. The analytical results show that the resultant forces of the passive earth pressure are equal to those of Coulomb＇s theory, but the distribution of the passive pressure and the position of the resultant force depend on the passive displacement mode parameter, and the former is a parabolic function of the soil depth. The analytical results are also in good agreement with the experimental ones.

Geostress measurements near fault areas using borehole stress-relief method

To minimize negative effects of geostress distribution on mining safety near the fault areas, the UPM40 triaxial geostress testing system was introduced to conduct in-situ geostress measurements at three sites and nine points by the borehole stress-relief method. The results of strain?confining pressure curves show that rock masses at the three measuring sites exhibit comprehensive linear elasticity in spite of various fissures or cracks within rocks. Horizontal and vertical stress components distribute discrepantly near the fault areas, and the maximum lateral pressure coefficient is as high as 6.15. The maximum principle stress ranges from 8.01 to 14.93 MPa, and stress directions are in the range of N78.07°W?N17.55°W. Geostresses near fault areas are dominated by the horizontal tectonic stresses, while the lower values, compared to those under similar geological conditions are due to stress release by the fault. Additionally, the fault and shear stress nearby are partially responsible for asymmetric elongation and southwesterly migration of orebodies.

Magnetic force distribution and deformation law of sheet using uniform pressure electromagnetic actuator

The distribution of magnetic forces and current on sheet and coil was analyzed in detail according to the structural parameter of the coil which was invalid.The result shows that the current direction based on simulation result agrees with the principles of uniform pressure electromagnetic actuator.The reason for coil failure was proposed.Then the magnetic forces on the sheet were input into an explicit finite element software ANSYS/LS-DYNA to analyze the deformation law of the sheet.

MATHEMATICAL MODEL OF ~4He QUANTUM INTERFEROMETER GYROSCOPE

The mathematical model of 4He quantum interferometer gyroscope is presented. The model includes the driven equation, the current equation and the position equation. Therefore, it can sufficiently describe the gyro- scope system. The driven equation shows the thermally driven gyroscope can work for a long time but the pres- sure driven one cannot. From the current equation, the superfluid currents passing through the weak link contain the AC currents which show the rotation flux, and other currents caused by drive. As shown in the position equa- tion, the displacement of diaphragm is the only detectable parameter in the gyroscope system. The model is tested by the simulations based on experimental parameters, and can be used to research performance of the gyroscope and analyse the gyroscope error.

增加LKJ总风缸欠压报警控制功能 提高列车运行安全可靠性

正机车空气制动系统直接关系到机车的运行安全,是机车的重要组成部分,其中机车总风缸的作用是确保制动系统内有充足的压力空气,总风缸压力由机车上的压力控制器自动控制,必须控制在750～900kPa。当总风缸内的压缩空气由于某种原因不能得到补充时,压力会开始下降,使列车管压力不能得到保证。而现行的列车运行监控装置(LKJ)控制模式只有列车管欠压报警功能。

A new method to construct reservoir capillary pressure curves using NMR log data and its application

By analyzing hundreds of capillary pressure curves, the controlling factors of shape and type of capillary pressure curves are found and a novel method is presented to construct capillary pressure curves by using reservoir permeability and a synthesized index. The accuracy of this new method is verified by mercury-injection experiments. Considering the limited quantity of capillary pressure data, a new method is developed to extract the Swanson parameter from the NMR T2 distribution and estimate reservoir permeability. Integrating with NMR total porosity, reservoir capillary pressure curves can be constructed to evaluate reservoir pore structure in the intervals with NMR log data. An in-situ example of evaluating reservoir pore structure using the capillary pressure curves by this new method is presented. The result shows that it accurately detects the change in reservoir pore structure as a function of depth.

Determination of undrained shear strength using piezocone penetration test in clayey soil for bridge foundation

In order to obtain the reasonable undrained shear strength Su for geotechnical analyses of bridge foundations in Yangtze River floodplain clayey soils, a site-specific study is conducted using the imported piezocone penetration test （CPTu） with dissipation phases at the Fourth Nanjing Yangtze River Bridge construction sites. Taking the values of Su from laboratory tests as references, several existing Su-predicted methods based on CPTu are compared and evaluated. To verify the presented cone factor Nk, additional test sites are selected and examined. The results show that the values of cone factors such as Nkt, Nke, and Nau, depend on the shear test mode and disturbance. Generally, the values of Nke show more scattering than those of Nkt and N△u. For the stratified and layered sediments of the Yangtze River floodplain, it is recommended using the net cone resistance qT to estimate Su and the preliminary cone factor values Nkt are from 7 to 16, with an average of 11. It is also confirmed that the CPTu test, as a new technique in site characterization, can present reasonable parameters for bridge foundations.

长期穿高跟鞋 会导致骨关节炎

美国爱荷华州立大学的研究人员通过研究穿着高跟鞋走路时下肢关节受到的压力影响发现,穿这些漂亮的高跟鞋会对身体有一些冲击力,对膝盖内部造成巨大的压力,长期如此会导致关节退化。

Nephelauxetic-Effect in DMS Zn_(1-x)Co_xSe and Effect of Pressure on Nephelauxetic-Effect

Based on the 3D electron's radial wave function of Co 2+ free ion,a Nephelauxetic effect modifying factor to modify the radial wave function is introduced when Co 2+ cations are put into the crystal field of Zn 1-x Co x Se.With the modified wave functions,the optical transitions for Zn 1-x Co x Se crystals are calculated.Moreover,based on the first principle of physics,the influences of high pressure to the Nephelauxetic effect modifying factor is considered,and the high pressure blue shift for the Zn 1-x Co x Se crystal absorption spectra are calculated and a shift rate of d E /d p =0 45meV/GPa is obtained.

Research on Volume Identification with the Method of Discharging at the Velocity of Sound

The method of volume identification in pneumatics was studied through theoretical analysis and experimental investigation. Regarding discharging from a container as a thermodynamic process with invariable index the dependence of the container’s volume on the pressure in the container and the index, during discharging at the velocity of sound, is deduced. Then through a lot of experiments, the value of index n of the process is found with a given precision and a specified volume range. Furthermore, the feasibility and practicability of this method are verified by experiments.

EFFECT OF WALL FUNC TION IN NUMERICAL STUDY ON TURBULENT IMPINGING JET

A low Reynolds number k-ε model is used in the numeri cal study on a circular semi-confined turbulent impinging jet . The result is c ompared with that of the standard k-ε model and a refined k-ε mode l, which re-consi-dered the fluctuating pressure diffusion term in the dissipa tion rate equation (ε-equation) through modeling. It shows that the low Re ynolds number k-ε model and the standard k-ε model yield very poor performance, while the predicting ability of the refined k-ε model is mu ch improved , especially for the turbulent kinetic energy k. So it can be co ncluded that the poor performance of the standard k-ε model is owing to t he incorrect considering the effect of the fluctuating pressure diffusion term r ather than the use of the wall function near the wall just as presumed in the re ference.

NUMERICAL PREDICTION OF AIRCRAFT HYDRAULIC SYSTEM BASED ON THERMAL DYNAMIC ANALYSIS

A mathematical model of principal elements of the aircraft hydraulic system is presented based on the heat transfer theory. The dynamic heat transfer process of the hydraulic oil and the pump shells within an aircraft hydraulic system are analyzed by the difference method. A kind of means for the prediction to variational trends of the aircraft hydraulic system temperature is provided during operation. The numerical prediction and simulation under the operational conditions are presented for ground trial running and the decelerated operation in flight. Computational results show that there is a good coincidence between the experimental data and the numerical predictions.

STUDY ON VIBRATION REDUCTION BEHAVIOR FOR THE HYDRAULIC ENGINE MOUNT

In this paper,the metal hydraulic engine mount (HEM) with the orifice is presented,the construction of HEM is consist of hydraulic cylinder and the spring on the bottom,its mechanical model is given and dynamics equations are set up with considering kinematics conditions and continuous of fluid,the dynamics behavior of HEM including dynamic stiffness of fluid and transferability of HEM are studied here.The example of hydraulic engine mount is calculated,it is shown that the vibration reduction performance of the hydraulic engine mount of this paper is better.The analysis method of vibration reduction behavior for HEM in this paper can be used in designing of the reduction vibration devices and the HEM in this paper can be used in the practical engineering for reduction vibration.