杠杆式气加压摇架的技术进步

为了解决杠杆式气加压摇架存在锁紧定位不稳定、安装调试繁琐,摇架压力不稳定并提高三线平行度等问题,以QYJ30系列摇架为例,对杠杆式气加压摇架在锁紧定位机构、调压机构、三线平行度保证机构、气囊、支杆轴等方面的技术创新进行了详细的论述,通过与老式摇架结构进行对比分析,指出改进后的杠杆式气加压摇架具有安装简单、调试方便、加压稳定、平行度稳定可靠的优点,能适应自动落纱自动清洁并提高成纱质量。     

聚丙烯酸钠缓释作用及其在砂土中吸液性能的探讨

探讨了砂土和溶液中水量、时间、pH值、温度、肥料对聚丙烯酸钠吸液倍率的影响以及聚丙烯酸钠对肥料的缓释作用。实验表明,在砂土中,聚丙烯酸钠的吸液倍率比溶液中降低105g;吸液饱和时间比溶液中延长60min;pH值(4～10),温度(20℃～80℃)对聚丙烯酸钠吸液倍率影响不大;非电解质肥料对吸液倍率影响很小,电解质肥料对吸液倍率影响较大。经过96小时,吸收1.0%KCl和1.0%尿素溶液的聚丙烯酸钠对钾和氮素累积释放率分别不到25.0%和80.0%,说明聚丙烯酸钠对尿素和KCl均有一定的缓释作用。     

两相流安全阀泄放面积的计算

引用API520标准附录D中的方法,计算了两相流情况下安全阀所需的泄放面积;计算实例表明,与国内分别计算汽、液相泄放面积再求和的简化方法相比,该法计算的泄放面积更为保险。     

矿区周边土壤的微生物研究进展

我国多数地区矿产资源的开发都会给生态系统造成严重的破坏,土壤中的微生物活性下降是矿区周边土壤遭到破坏的重要标志之一,同时也是矿区土壤微生物演变的重要因素之一。本文针对矿区周边土壤中解磷微生物的种类和解磷机制进行了综述,还讨论了其作为促进磷酸盐利用率所存在的问题。     

煤与瓦斯突出的预测模型及预测指标

用煤与瓦斯突出的球壳失稳理论分析了影响煤层突出危险性的因素,提出了“理想石门揭煤”的预测模式,研究了这种预测模式的预测指标．实验证明,采用初始释放瓦斯膨胀能和软煤厚度可以准确地预测理想石门揭煤条件下的突出危险性．     

RuFe纳米粒子修饰片状BiVO4协同催化氨硼烷水解产氢

开发高效廉价的催化剂对于清洁能源经济至关重要, 将氨硼烷的催化水解用于氢能源开发前景广阔。本工作首先采用简单回流法制备BiVO₄纳米片, 再通过浸渍还原法制备出Ru/Fe不同摩尔比的RuFe@BiVO₄催化剂, 并在室温下用于催化氨硼烷水解产氢。通过比较载体BiVO₄、Ru@BiVO₄、Fe@BiVO₄、RuFe@BiVO₄以及无载体的RuFe纳米粒子的催化产氢速率发现, 在所有的催化剂中, Ru₁Fe_0.1@BiVO₄具有最高的催化活性, 非贵金属Fe能显著增强Ru的催化性能, 这与RuFe之间强的电子效应以及RuFe纳米粒子与载体BiVO₄间的双功能效应密切相关, 其活化能(E_a)为43.7 kJ·mol^-1, 转化频率(TOF)为205.4 mol_H2·mol_Ru·min^-1。     

Development of a Shape‐Memory Tube to Prevent Vascular Stenosis

Inserting a graft into vessels with different diameters frequently causes severe damage to the host vessels. Poor flow patency is an unresolved issue in grafts, particularly those with diameters less than 6 mm, because of vessel occlusion caused by disturbed blood flow following fast clotting. Herein, successful patency in the deployment of an ≈2 mm diameter graft into a porcine vessel is reported. A new library of property‐tunable shape‐memory polymers that prevent vessel damage by expanding the graft diameter circumferentially upon implantation is presented. The polymers undergo seven consecutive cycles of strain energy‐preserved shape programming. Moreover, the new graft tube, which features a diffuser shape, minimizes disturbed flow formation and prevents thrombosis because its surface is coated with nitric‐oxide‐releasing peptides. Improved patency in a porcine vessel for 18 d is demonstrated while occlusive vascular remodeling occurs. These insights will help advance vascular graft design.     

注塑机拉杆三角螺纹端卸载槽的多目标优化

针对注塑机拉杆三角螺纹在近卸载槽处发生早期断裂的问题，在用ANSYS软件对近卸载槽处三角螺纹进行有限元分析的基础上，就拉杆三角螺纹端卸载槽的几何特性建立参数优化模型，以控制三角螺纹在近卸载槽附近的最大应力、卸载槽的最大应力以及卸载槽加工量最小化为统一的目标函数。通过对拉杆在单向拉伸力作用下的多目标优化，可使拉杆三角螺纹牙根在卸载槽处的最大应力降低55％，在偏载作用下，其最大应力降低21．4％。在单向拉伸力作用下，拉杆卸载槽的最大应力比平均单向拉伸应力提高26．5％，使卸载槽能够较好地发挥其卸载的作用。     

Preparation and Characterization of Chitosan‐Gellan Hybrid Capsules Formed by Self‐Assembly at an Aqueous Solution Interface

Summary: True spherical capsules are formed by electrostatic polysaccharide interaction between chitosan and gellan gum via polyion complex (PIC) formation in aqueous solutions. Dropwise addition of a chitosan solution into the gellan solution gave spherical capsules whose outside surface was gellan and whose inside was chitosan (chitosanⁱⁿ‐gellan^out capsule). Conversely, the addition of gellan into chitosan yields chitosan^out‐gellanⁱⁿ capsules. SEM observation revealed a fibrous network spreading along the capsule membrane of the chitosanⁱⁿ‐gellan^out capsule. The releasing properties of the capsules were examined using low molecular weight substances and high molecular weight proteins. For low molecular weight substances, the releasing kinetics were affected by the attractive and repulsive interactions between the substances and the inside component of the capsule. The molecular weight of the encapsulated substances also affects the releasing kinetics. These results, together with a simple preparation procedure, indicate the applicability of chitosan‐gellan capsules as drug‐carrier materials having a controlling release mechanism. As an application example, preparation of an actually eatable artificial roe was also described.

Illustrative drawing of PIC capsule formation.     

SiO2/Al2O3复合包覆TiH2颗粒的制备及释氢性能的研究

采用非均匀成核法,通过控制滴加反应物的速度、pH值等,实现SiO2和Al2O3在TiH2颗粒表面形核,制备包覆有SiO2和Al2O3的复合型TiH2发泡剂.观察了包覆层形貌,进行了释氢试验.实验结果表明:SiO2/Al2O3包覆层平滑、分布均匀,形成内松外紧的结构,使得释氢时间达到120s.