超高速粒子碰撞的Swift,Lawrence RJ模型的改进

改进了描述弹丸与带缓冲板的靶板间超高速碰撞现象的Ｓｗｉｆｔ，Ｌａｗｒｅｎｃｅ ＲＪ计算模型，使该模型增加了确定靶板上受到碎片云团碰撞部分的范围大小及计算碎片云团碰撞靶板上各占的速度和质量面积密度两项新功能。     

压裂用自主存储式电子压力计的设计

新研制的自主存储式电子压力计将人工神经网络技术融入井下仪器,使井下仪器能自主识别压裂作业过程,保证在实际压裂作业时间段缩短采样和数据存储周期,实行加密采样、存储,确保采集和存储的数据能"采全、录准"。进行了电子压力计的硬件设计及软件流程设计,硬件部分的核心是单片机和时钟控制电路。室内及现场试验表明,系统工作可靠,使用简便,重复性好,满足压裂作业环境下的井下测试要求;系统可方便地实现与射流、压裂、射流泵速排等工艺的多联作作业,与其他管柱连接方便,下井、起出管柱无挂、卡现象。     

青岛海湾大桥大直径旋挖钻孔灌注桩施工技术

青岛海湾大桥大沽河航道桥采用φ2.5m桩基,为目前国内海上直径最大的群桩基础.根据桥位处地质条件复杂、桩径大、海上施工条件复杂等情况,其海上钻孔灌注桩均采取搭设工作平台进行施工.介绍了海上钻孔平台搭设、旋挖机钻进及泥浆护壁成孔施工工艺.较之传统的回转钻机和冲击反循环钻机钻进,旋挖钻进工艺提高了成孔效率和成孔质量,同时拓宽了旋挖钻机的应用领域.     

耐酸耐氧双歧杆菌突变株的选育与冷冻浓缩发酵剂的制备

应用紫外线、60Co辐照育种,选育出1株耐酸、耐氧的长双歧杆菌突变株GKSW1101.该菌株在pH4.5的液体培养基中,37.5℃培养24h,活菌数达到4.2×108cfu/mL.采用加碱中和保持培养液pH6.0～6.进行发酵,在4℃、6000r/min离心15min收集菌体,添加脱脂奶粉、甘油、蔗糖,L-半胱氨酸盐酸盐为冷冻保护剂,-25℃冷冻保藏,制备成双歧杆菌冷冻浓缩发酵剂,活菌数达到2.4×1010.cfu/g,-25℃贮存3个月后,活菌存活率为50%.     

Facile preparation of low swelling,high strength,self-healing and pH-responsive hydrogels based on the triple-network structure

A polyacrylic acid(PAA)/gelatin(Gela)/polyvinyl alcohol(PVA)hydrogel was prepared by copolymerization,cooling,and freezing/thawing methods.This triplenetwork(TN)structure hydrogel displayed superior mechanical properties,low swelling ratio and self-healing properties,The superior mechanical properties are attributed to the triple helix association of Gela and PVA crystallites by reversible hydrogen bonding.The characterization results indicated that the fracture stress and the strain were 808 kPa and 370% respectively,while the compression strength could reach 4443 kPa and the compressive modulus was up to 39 MPa under the deformation of 90%.The hydrogen bonding in PVA contributed to maintain and improve the self-healing ability of hydrogels.Every type of hydrogels exhibited a higher swelling ratio under alkaline conditions,and the swelling ratios of PAA,PAA/PVA and PAA/Gela hydrogels were 27.71,12.30 and 9.09,respectively.The PAA/Gela/PVA TN hydrogel showed the lowest swelling ratio(6.57)among these hydrogels.These results indicate that the novel TN hydrogels possess good environmental adaptability and have potential applications in the biomedical engineering and sensor field.     

Dielectric performance and conductive mechanism of KNN-based ceramics prepared via sol–gel core–shell process

Journal of Materials Science: Materials in Electronics - 0.95(Li0.02Na0.50K0.48)(Nb0.95Sb0.05)O3–0.05AgTaO3@BaZrO3 (LNKNbSAT@BZ) lead-free ceramics were prepared via a sol–gel...     

PARAMETRIC MATCHING SELECTION OF MULTI-MEDIUM COUPLING SHOCK ABSORBER

To achieve the dual demand of resisting violent impact and attenuating vibration in vibration-impact-safety of protection for precision equipment such as MEMS packaging system, a theoretical mathematical model of multi-medium coupling shock absorber is presented. The coupling of quadratic damping, linear damping, Coulomb damping and nonlinear spring are considered in the model. The approximate theoretical calculating formulae are deduced by introducing transformation-tactics. The contrasts between the analytical results and numerical integration results are developed. The resisting impact characteristics of the model are also analyzed in progress. In the meantime, the optimum model of the parameters matching selection for design of the shock absorber is built. The example design is illustrated to confirm the validity of the modeling method and the theoretical solution.     

弧齿锥齿轮三维接触应力的有限元——线性规划法求解及分析

采用有限元—线性规划法对弧齿锥齿轮的三维接触应力进行了计算和分析,在对载荷分布不加任何假设的条件下,先粗划轮齿网格,然后再在可能的接触点域细划网格,线性规划法求出了接触区域的载荷分布,有限元法求出了接触区内的接触应力分布.     

原料组份对土质相似材料力学特性影响的试验研究

研制适合的相似材料对地质力学模型试验的顺利开展具有重要意义。通过直剪试验、无侧限抗压强度试验和室内三轴试验获得了一种软质土类材料的基本物理力学性质,借助扫描电镜对其微观形貌特征进行了分析,研究了原料组份对该材料强度特性、受力过程及破坏特征的影响规律。结果表明:原料组份变化对相似材料的物理力学参数及力学特性影响显著,洗衣液在软质土类相似材料中的应用效果较好,能够对材料的力学特性进行稳定调节,石膏、重晶石粉和膨润土均为调节材料密度的重要控制变量;洗衣液和水对材料力学参数及应力-应变曲线特征的影响最大,膨润土在材料表观特征、受力过程、破坏特征方面影响较为明显。试验结果为进一步研究地质力学模型试验中土质相似材料的力学特性和制备工作提供了参考。     

基于应变评价边坡-地基失稳的过程控制

传统的边坡监测手段主要是监测局部区域的水平位移, 然而应力和应变指标可更直观体现边坡的实时状态。根据光纤传感分布式监测技术的原理, 建立了边坡-地基数值模型, 采用水平应变的评价指标, 对其变形失稳过程开展了研究。结果表明:在加载过程中, 相对于水平位移指标, 边坡内部的水平应变指标可以更好地体现边坡的变形失稳过程并能够预测实际破坏的滑动面。坡体内部设置的6条水平测线中最大水平应变与稳定性系数呈较好的对数关系, 通过比较, 建议主要对坡中区域进行布线监控。此外, 引入水平应变加速度指标, 得到了与边坡稳定性系数的关系, 并可预测边坡-地基的稳定性劣化趋势, 进而实现过程控制。