天然橡胶/顺丁橡胶/丁苯橡胶自润滑喷蜡橡胶材料的性能

在天然橡胶(NR)/顺丁橡胶(BR)/丁苯橡胶(SBR)为基体的自润滑喷蜡橡胶材料中加入芥酸酰胺,考察芥酸酰胺作为润滑剂时对NR/BR/SBR自润滑喷蜡橡胶材料的硫化特性、力学性能、门尼黏度、摩擦系数及耐老化性能的影响。结果表明,与未加芥酸酰胺的胶料相比,当芥酸酰胺用量为10份时,胶料转矩减小,焦烧时间和正硫化时间缩短,扯断伸长率从388%增加至523%,拉伸强度降低了21.36%,邵尔A硬度、压缩永久变形分别下降5.56%和8.74%,动、静摩擦系数分别减小23.46%和24.82%,门尼黏度降低20.89%,耐热氧老化性能下降。硫化胶拉伸100%停放5 min后,表面出现明显的白色润滑膜,胶料流动性变好,各组分分散得更均匀,断面更光滑。     

全局力平衡PDC钻头布齿优化设计

针对聚晶金刚石复合片(PDC)钻头在钻井破岩过程中因受力不平衡，导致钻井倾斜、井径扩大、钻头产生横向振动和涡动，造成钻头早期失效的问题，基于已有PDC钻头切削力学知识，构建了PDC钻头弯曲力矩及全局力平衡布齿优化设计模型，并提出模型求解方法。布齿设计实例结果表明，采用全局力平衡布齿设计方法得到的布齿结构可使PDC钻头在不同进尺条件下均能保持全局力平衡状态，尤其低进尺（小于1 mm）时的力平衡状态得到极大改善，提高了PDC钻头的钻井稳定性，对于改善钻头受力、提升钻头使用寿命、提高钻井质量与效率具有重要意义。     

空压机润滑油系统可靠性试验研究

对空压机润滑系统进行分析,提出了一种润滑油压力调节机构,保证了空压机在高油温时油压正常,为空压机运动件提供充分润滑,从而提高空压机运行的可靠性。实验证明了该机构是可靠的,为空压机润滑系统设计提供了参考依据。     

Investigation on the anti-reduction mechanism of Ti4+ in high dielectric constant system Ca0.9La0.067TiO3 by doping with Al2O3

Ca_0.9La_0.067TiO₃ (abbreviated as CLT) ceramics doped with different amount of Al₂O₃ were prepared via the solid state reaction method. The anti-reduction mechanism of Ti⁴⁺ in CLT ceramics was carefully investigated. X-ray diffraction (XRD) was used to analyze the phase composition and lattice structure. Meanwhile, the Rietveld method was taken to calculate the lattice parameters. X-ray photoelectron spectroscopy (XPS) was employed to study the valence variation of Ti ions in CLT ceramics without and with Al₂O₃. The results showed that Al³⁺ substituted for Ti⁴⁺ to form solid solution and the solid solubility limit of Al³⁺ is near 1.11 mol%. Furthermore, the reduction of Ti⁴⁺ in CLT ceramics was restrained by acceptor doping process and the Q × f values of CLT ceramics were improved significantly. The CLT ceramic doped with 1.11 mol% Al₂O₃ exhibited good microwave dielectric properties: ε_r = 141, Q × f = 6848 GHz, τ_f = 576 ppm/°C.     

疏水引力在煤泥浮选过程中的作用机理及应用

为了分析疏水引力在煤泥浮选过程中的作用机理,将-0.074mm的不同密度细粒煤泥混入粗粒煤泥中进行浮选试验,研究不同密度细粒煤泥对可燃体回收率的影响;进行了EDLVO理论计算,分析各作用能的作用效果和疏水引力的成因。结果表明:1.3～1.4 g/cm~3密度级细粒煤泥容易罩盖于粗粒精煤表面疏水部分;水中两个相互接近的疏水表面间的作用以疏水作用为主,疏水引力的产生是由于水中疏水表面相互接近到一定距离时自发形成了纳米气泡桥;浮选调浆的强度应适中,在破坏煤泥颗粒间疏水引力的同时而不破坏煤泥与气泡的附着。     

Test sample allocation method for testability verification test

An extended failure mode effect and criticality analysis (FMECA)-based sample allocation method for testability verification is presented in this study to deal with the poor representativeness of test sample sets and the randomness of the testability evaluation results caused by unreasonable selection of failure samples. First, the fault propagation intensity is introduced as part of the extended information of FMECA, and the sample allocation impact factors of component units and failure modes are determined under this framework. Then, the failure mode similarity and impact factor support are defined, and the game decision method for weighing the relationship between similarity and support is proposed to obtain the weight of failure mode impact factor. Finally, a two-step allocation framework of test samples is formulated to realize the sample allocation of component units and failure modes. This method is applied to the testability verification test of a launch control system. Results show that this method can obtain more representative test samples compared with the traditional sample allocation method while effectively reducing randomness of single testability evaluation result.     

气体裂变产物88Kr半衰期测量

为准确测定气体裂变产物⁸⁸Kr的半衰期，本工作从辐照铀靶中分离得到3个放化纯的⁸⁸Kr气体测量源。以⁸⁵Kr作内标监督源，¹³⁷Cs或⁵⁷Co作外标监督源，使用多个HPGe探测器分别采用单探测器位置接力法和双探测器位置接力法跟踪测量⁸⁸Kr 196.3 keV能量的特征γ射线，跟踪时间均在8个半衰期以上，以获得其半衰期数据。对3次独立测量数据用多种方法进行处理，最终得到⁸⁸Kr半衰期测定结果为（2.796±0.015） h。     

应用M-MIVM预测含钛渣系组元活度

 在钢铁冶炼过程中,随着护炉钛材料和含钛铁矿石的应用,大量的含钛炉渣被生产出来。由于缺少多元含钛渣系的热力学数据,限制了钛资源综合利用技术的深入发展。因此,应用改进的分子相互作用体积模型(M-MIVM(FII)),预测了基础渣系Al₂O₃-CaO-SiO₂、FeO-MnO-SiO₂和含钛渣系FeO-MnO-TiO₂、FeO-SiO₂-TiO₂、MnO-SiO₂-TiO₂、Al₂O₃-CaO-FeO-TiO₂中各组元活度,并与试验值比较。结果表明,M-MIVM(FII)的预测值与试验值符合较好,6个体系总的平均相对误差为11%,该精度处于Turkdogan提出的30%以内的试验误差范围; M-MIVM(FII)在参数拟合与活度预测能力方面均优于MIVM,该模型对多元含钛熔渣体系组元活度具有更好的预测效果。在此基础上,应用M-MIVM(FII)预测Al₂O₃-CaO-SiO₂-TiO₂熔体中TiO₂活度,并分析其影响因素。结果表明,TiO₂活度预测值与试验值吻合良好,且随炉渣碱度、Al₂O₃含量的增加而降低,该规律与试验规律相一致。M-MIVM(FII)仅通过拟合子二元系活度或者直接由无限稀活度系数就能够预测多元熔体的热力学性质。