Effect of nitrocarburizing on sulphide layer during nitrocarburizing-sulphurating treatment

Compared with the single sulphurating treatment, the duplex treatment of nitrocarburizing-sulphurating can more effectively improve the properties of steel such as friction-reducing, wear resistance and anti-scuffing. Under the same processing parameters, the sulphide layers were fabricated on the surface of CrMoCu alloy cast iron by single ion-sulphurating treatment and nitrocarburizing-sulphurating duplex treatment, respectively. Through the analysis of the sulphide, the effect of the nitrocarburizing on the fabrication of the sulphide layer was investigated. And the result shows that the fabrication of sulphide layer is promoted by the nitrocarburizing treatment.     

五坐标数控快锻机的液压系统设计

对63MN五坐标数控快锻机在自由锻和恒温锻不同的工艺过程进行分析,根据压机设备压力高、流量大的特点,进行系统的优化设计。并对降低噪声、抗污染、保证系统可靠性、实现系统的高精度、高响应等要求,提出了合理的设计方案。     

升温速率对金属熔化和过热的影响

采用分子动力学方法和QSC(Quantum Sutton-Chen)力场研究了升温速率对金属银和金属铅的熔化和过热行为的影响。研究结果表明，升温速率对金属银和铅的熔化和过热行为有很大影响，随着升温速率的升高，金属的熔点有所升高。高的升温速率会导致金属体系内部无序化程度增加，降低了熔化相变的能垒。升温速率导致的银和铅完美晶体的过热极限分别为1450K和800K。     

交通事故后的交通运行风险状态等级预测方法

以事故数据为基础研究事后风险状态,建立了基于改进深度森林算法的交通运行风险状态等级预测模型.首先分析了事故特征重要度,建立了基于极端梯度提升算法的事故特征筛选机制,引入贝叶斯参数寻优和十折交叉验证法实现了深度森林模型的超参数优化;同时设计了循环多粒度扫描方法和加权级联森林结构,获取了交通运行风险状态等级与事故特征的映射...     

铁尾矿为原料微波法制备介孔分子筛

以鞍山铁尾矿为硅源,CTAB为模板剂,采用微波辐照法合成出全硅介孔分子筛MCM-41。用N2低温吸附、FT-IR、XRD和TEM等表征手段考察了其比表面积、孔径分布、晶体形貌等特性。结果表明:微波辐射法合成的MCM-41分子筛诱导期极短,晶化速度很快,具有典型的按六方对称性排列的孔道结构,FT-IR证明了分子筛具有硅氧四面体骨架。     

虎拟变量法求抗震结构的变形能力可靠度

在考虑地震地面运动加速度及结构参数随机性的基础上,利用虚拟变量法来求抗震结构的形能力可靠度,给出了弹性范围内的基本公式和求解步骤。方法能综合反映地震动及结构参数随机性的影响,计算较为简便。     

Stable sodium metal anode enhanced by advanced electrolytes with SbF3 additive

The practical application of sodium metal batteries (SMBs) is hampered due to the inferior interfacial stability between Na metal and conventional electrolytes....     

多弧离子镀与磁控溅射共沉积TiN/TiCN多层膜的高温抗氧化性能

TiN/TiCN多层膜的高温抗氧化性研究对于扩大其应用领域具有重要作用,但目前鲜见相关报道。采用多弧离子镀与磁控溅射技术以不同调制周期在304不锈钢表面共沉积TiN/TiCN多层膜。采用XRD、XPS、倒置显微镜及高温氧化试验研究了多层膜的高温抗氧化行为。结果表明:TiN/TiCN多层膜表面光滑平整、均匀致密,薄膜主要为具有Ti-(C,N)键的fcc-TiN结构;随着调制周期的减小,TiN/TiCN多层膜生长取向发生转变,且具有(111)晶面生长织构;随着氧化温度的升高,多层膜的显微硬度逐渐降低,氧化增重速率不断增大,且在700℃之后变化速率较快,薄膜的开始氧化温度约为750℃;随着调制周期的减小,多层膜TiN与TiCN界面层数量增多,促使晶粒细化,提高了其致密性,还隔断了缺陷贯穿薄膜的连续性,显著降低了薄膜的孔隙率,致使O原子扩散困难,增强了薄膜的高温抗氧化性能。     

Studied on a novel human keratinocyte membrane delivery system in vitro

The culture of keratinocytes on flexible membranes has been proposed as a means to simplify, accelerate and improve the efficiency with which proliferating cells are delivered to full thickness or non-healing skin defects. The purpose of this article was to study the ability of chitosan-gelatin manbranes to facilitate the growth of human keratinocytes. The membranes with different chitosan contents were studied. The surface properties of chitosan-gelatin membranes were investigate by SEM, and water contact angle test. The mechanical property of the membranes was tested. Data implied that gelatin could make the membranes more flexible and hydrophilic than chitosan membranes, which may regulate the seeded cells behavior. Loading human keratinocytes on chitosan-gelatin membranes, cells attachment, spread, and growth were investigated by light microscopy, SEM, and MTT test. The results suggested that the adhesion and proliferation of keratinocytes seeded on chitosan-gelatin membranes were same as on tissue culture plate, in which gelatin could modify the interaction between keratinocytes and chitosan membranes. Therefore, chitosan-gelatin membrane is a good candidate for keratinocytes delivery system.