柴油机自动减压起动装置的有限元分析

分析了柴油机自动减压装置的工作原理,针对在潍柴WP10型柴油机上加装的减压装置,利用Solidworks Simulation对压板进行了静力分析,找出了应力最大的部位和最大值,并按照Von Mises准则,判别压板满足刚度要求。     

海相砂岩油藏水淹层精细表征技术研究与实践

海相水驱砂岩油藏开发后期含水饱和度高,而含水饱和度的影响因素较多,单一的常规含水饱和度模型不能准确反映剩余油的潜力及风险。根据油藏工程动态水相分流量方程理论,并在相渗曲线指数式拟合的基础上,建立了油田含水饱和度与可动含水率的关系式,利用Petrel-RE模拟器将传统方法建立的常规含水饱和度场转化为可动含水率场,形成了水淹储层精细表征技术。     

峡谷和垭口地形风场特征的CFD数值模拟

为获得峡谷和垭口地形的风场特征和典型位置的风加速效应,采用计算流体动力学(CFD)方法进行模拟计算,将计算得到的单山结果与风洞试验及规范进行对比以验证CFD计算的有效性,对峡谷和垭口地形进行数值模拟计算,分析峡谷和垭口在不同山脚间距时的加速效应,针对内侧山脚和山顶处的加速比给出设计建议.研究表明:山顶处加速比最大;山体横风切面的加速效应比顺风切面显著;CFD模拟与风洞试验结果吻合较好;山顶处,垭口地形风加速效应比峡谷和单山都大;内侧山脚加速比随着两山靠近而增大;内侧山脚处,峡谷地形的加速比小于规范下限,垭口地形在山间距小于一半山体底部直径、离山表面高度低于0.4倍山体高度时的加速比大于规范上限;山顶处的加速比在各种工况下均比较接近;不建议将山顶和垭口位置作为构筑物的选址地点.     

用于较大水平位移测量的电阻应变式位移传感器

针对目前位移传感器很难直接测得木结构或木构件在转动中产生较大绝对水平位移的问题,研制了量程为±500 mm的电阻应变式位移传感器（WD位移传感器）,应用正交试验法分析WD位移传感器的影响因素,并对其进行设计与制作,拟合了传感器在不同量程下应变位移的分段函数关系,通过计算得出了WD位移传感器的6种静态参数指标。试验结果表明,WD位移传感器克服了传统电阻应变式位移传感器量程小的问题,解决了木结构或木构件发生非直线运动很难直接测得绝对水平位移的问题,且各静态参数指标良好。     

Numerical Simulation and Analysis of Migration Law of Gas Mixture Using Carbon Dioxide as Cushion Gas in Underground Gas Storage Reservoir

One of the major technical challenges in using carbon dioxide（ CO2） as part of the cushion gas of the underground gas storage reservoir（ UGSR） is the mixture of CO2and natural gas. To decrease the mixing extent and manage the migration of the mixed zone,an understanding of the mechanism of CO2and natural gas mixing and the diffusion of the mixed gas in aquifer is necessary. In this paper,a numerical model based on the three dimensional gas-water two-phase flow theory and gas diffusion theory is developed to understand this mechanism. This model is validated by the actual operational data in Dazhangtuo UGSR in Tianjin City,China.Using the validated model,the mixed characteristic of CO2and natural gas and the migration mechanism of the mixed zone in an underground porous reservoir is further studied. Particularly,the impacts of the following factors on the migration mechanism are studied： the ratio of CO2injection,the reservoir porosity and the initial operating pressure. Based on the results,the optimal CO2injection ratio and an optimal control strategy to manage the migration of the mixed zone are obtained. These results provide technical guides for using CO2as cushion gas for UGSR in real projects.     

Morphology,crystal structure and hydration of calcined and modified anhydrite

The effects of calcination and modification on the morphology （shapes and textures） and crystal structure of anhydrite powders were studied. The results show that, calcination at 100℃ causes anhydrite to disintegrate into smaller crystals, accompanied by a slight in- crease in d-spacing. Without calcination and modification, the solidification time and curing time of anhydrite are 15 and 77 h, respectively. After the treatment, however, the solidification time and curing time are shortened significantly to 9.5 and 14 rain, respectively. The com- pressive and flexural strengths of hydration products made from the treated anhydrite reach 10.2 and 2.0 MPa, respectively. The much shorter solidification and curing time make it possible to use anhydrite as a building and construction material.     

一种改进的ViBe目标检测算法

现有ViBe目标检测算法存在误检率高,得到的结果噪声较大的问题。为此本文提出了一种将判定阈值自适应规则与优化结果反馈机制相结合的改进算法。该算法首先使用样本自身统计值作为阈值进行目标检测;接着对检测结果进行去噪、形态学处理等优化处理;最后将优化后的检测结果反馈给背景模型更新过程使检测更精确。与传统的ViBe算法相比,本文算法可更精确的提取出运动目标,误判率低,过检率较原始算法降低10%-20%。实验结果证明了该算法的有效性。     

沁水盆地郑庄煤层气储层裂隙的测井响应特征

煤层气储层的裂隙发育程度与储层的地球物理测井响应特征相关,通过对沁水盆地郑庄区块80余口井测井资料的分析,总结了地质构造作用及裂隙发育对测井特征的影响,认为研究区识别煤层气储层裂隙的敏感参数依次为体积密度（DEN）、深侧向电阻率（RD）、声波时差（AC）、井径（CAL）、自然伽马（GR）、中子孔隙度（CNL）等,通过判断深、中、浅三个电阻率值的差异识别裂隙发育程度,建立了夹矸层RD≥3000 Ω·m、3000Ω·m＞RD≥1000Ω·m、1000Ω·m＞RD≥500Ω·m、RD＜500Ω·m、及CNL＞ 45％等几种类型的测井响应参数,给出了相应的测井响应示例,为建立研究区的裂隙发育展布提供了参考.     

The relation between the parabolic rate constants for the internal oxidation of binary alloys in terms of weight gain or thickness

A calculation of the parabolic rate law for internal oxidation in binary alloys expressed in terms of weight gain shows that its dependence on the concentration of the most-reactive component is different from that predicted by the classical Wagner treatment for the rate constant expressed in terms of thickness of the internal oxidation zone. It is shown that the ratio between the two rate constants for a given system is a very sensitive function of the concentration of the reactive element in the alloy.     

Mechanical nondiscoloring and antistretching photonic crystal films based on Zn2+ coordination and hydroxypropyl methylcellulose

Mechanical nondiscoloring and antistretching photonic crystal (PC) films, especially those with stable structure colors during deformation, have great potential applications in wearable display devices, decoration, and packaging. Here, PC films with antistretching and invariant structural colors during deformation were prepared, by combining Zn²⁺ coordinated elastic material and hydroxypropyl methylcellulose (HPMC) with polystyrene@silica (PS@SiO₂) colloidal crystals. The PC films release energy by forming local fractures at a microscopic level during the straining process but the lattice spacing and effective refractive index of the local array do not change. According to the Bragg law, the structure color remains unchanged. The introduction of HPMC gave the PC films excellent tensile properties, and the maximum tensile strength reached 10 MPa. And after 100 times of stretching, bending and compression cycles, the structural color remained unchanged.