掺硼改性碳化硼陶瓷的研究

以碳化硼粉、无定形硼粉为主要原料,热压烧结制备了B4C陶瓷.研究了不同的硼加入量和烧成温度对样品致密度和力学性能的影响.结果表明,当硼的加入量为11.6wt%时,样品的硬度、断裂韧性、抗弯强度和弹性模量分别达到32.9GPa、3.53MPa·m1/2、544.8MPa和405.3GPa.利用XRD、SEM测试手段对样品的物相组成和显微结构进行了分析.     

一株紫杉醇产生菌发酵条件的初步研究

研究了一株内生真菌Fusarium mairei UH23发酵产紫杉醇的工艺条件。实验结果表明最佳培养条件为:温度26℃,发酵起始pH值7.0,接种量5%,装液量250 mL三角瓶装液60 mL,发酵周期12天。筛选出最佳碳源为葡萄糖,最佳氮源为硝酸铵。在上述条件下发酵,紫杉醇产量达(286.4±20.3)μg/L,较优化前提高10.2%。     

新型污泥吸附材料制备及其对镉、铬吸附行为研究

采用化学活化法,以污水处理厂的剩余污泥为原料,掺杂软锰矿作为造孔剂制备新型污泥吸附材料。研究新型污泥吸附材料对废水中Cd(Ⅱ)、Cr(Ⅲ)的吸附行为。结果表明:新型污泥吸附材料的比表面积比纯污泥吸附材料提高了52.3%。新型吸附材料对Cd(Ⅱ)、Cr(Ⅲ)的吸附容量和吸附能力大小:Cr(Ⅲ)Cd(Ⅱ)。两种金属离子的吸附性能符合二级吸附速率方程,吸附速率:Cd(Ⅱ)Cr(Ⅲ),平衡吸附量:Cd(Ⅱ)Cr(Ⅲ)。对于Cd(Ⅱ),颗粒内扩散过程是该吸附速率的控制步骤,而对于Cr(Ⅲ),颗粒内扩散过程不是吸附速率的控制步骤。     

两种交联氨基淀粉对水中Cu2＋的吸附性能

研究了含C-N键的氨基淀粉（CAS）与含CN键的氨基淀粉（DAS）对重金属离子Cu2＋的吸附性能,包括吸附动力学、吸附等温线和吸附热力学。结果表明CAS比DAS的吸附容量更大,Cu2＋去除率更高;CAS适用的pH为5～7,DAS适用的pH为4～4．5;两者对Cu2＋的吸附均符合拟二级动力学;CAS对Cu2＋等温吸附符合Freundlich型,为非均相表面吸附;DAS吸附则是单层吸附;两种氨基淀粉对Cu2＋的吸附过程均为吸热、熵增、自发的过程。     

悬钩子属植物三萜类化学成分及波谱特征研究进展

对悬钩子属植物中三萜类成分研究进行综述,并对其波谱特征进行归纳总结。从悬钩子属植物中已分离得35个三萜类化合物,其中有9个为齐墩果型,26个为乌索烷型,这些化合物的基本骨架、取代基类型及位置均有其波谱特征。     

Increased Dispersion of Nickel Particles Supported on Activated Carbon by Treating with Methyl Iodide

A novel method dispersing nickel in fine particles on activated carbon (AC) was proposed in this study. The nickel particles with 2.2 nm average diameter supported on AC were obtained through re-dispersing the nickel particles by treating with methyl iodide under atmospheric pressure. High dispersion of nickel particles promoted the activity for methanol vapor-phase carbonylation over Ni/AC catalyst.

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Isothermal melt crystallization and performance evaluation of polylactide/thermoplastic polyester blends with multi‐functional epoxy

A multi‐functional epoxy (ADR) was used to improve compatibilization of poly(lactic acid) (PLA)/ thermoplastic polyester elastomer (TPEE) blends. Influence of ADR on isothermal melt crystallization of the blends was investigated. The results show that isothermal melt crystallization rate of the samples increases with ADR loading. It can be attributed to a nucleation enhancement resulted from an increase of molecular weight and melt viscosity created by the chain extension/branched process of PLA in the presence of ADR. In addition, the maximum crystallinity of the samples shows a decrease with increasing ADR loading because of the chain extended and branched reaction. Quenched and crystallized samples were fabricated using compression molding under different cooling conditions in‐mold. Effects of crystallinity and ADR on mechanical performances of the PLA/TPEE sample were investigated. With increasing the crystallinity, the PLA/TPEE sample shows a marked enhancement in heat resistance. However, the tensile ductility of the crystallized PLA/TPEE sample drastically decreases due to the formation of firm crystal crosslinking and the incompatibility between PLA and TPEE. It is notable that the tensile ductility of the crystallized samples is improved with the introduction of ADR owing to its reactive compatibilization effect. Finally, the crystallized PLA/TPEE/ADR samples with improved heat resistance and relative higher ductility are obtained. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46343.     

Counterion effects of nickel and sodium dodecylbenzene sulfonate adsorption to multiwalled carbon nanotubes in aqueous solution

Batch experiments were conducted to elucidate the adsorption of a widely used anionic surfactant (sodium dodecylbenzene sulfonate (SDBS)) and nickel on multiwalled carbon nanotubes (MWCNTs). Counterion effect on the removal of SDBS and nickel by using MWCNTs was also studied. The microscopic changes of MWCNTs before and after nickel and SDBS adsorption were characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM). X-ray photoelectron spectroscopy (XPS) was performed to study the adsorption mechanism of nickel at a molecular level. The spectroscopic analysis indicated that the adsorption mechanism was mainly attributed to chemical interaction between nickel and the surface functional groups of MWCNTs and surface adsorbed SDBS. The adsorbed SDBS on MWCNTs could lead to the modification of the MWCNT surfaces and partial complexation of nickel with SDBS adsorbed on MWCNTs. MWCNTs are efficient material in the removal of SDBS and nickel from large volume of wastewater.     

Synthesis and characterization of a novel soil stabilizer based on biodegradable poly(aspartic acid) hydrogel

A novel soil stabilizer based on poly-amino acid - polyaspartic acid (PASP) and its copolymer which modified by xanthan gum (XG) was studied to increase soil particle compressive strength and resistance to wind erosion. Due to its unique property, the stabilizer aggregated individual soil particles and formed crust. The sample compressive strength increased from 0.175 to 0.612 MPa and the wind erosion modulus reduced from 22.43 to 10.56 g·m⁻²·min⁻¹ after the 1% PASP hydrogel was applied by 1.67 Lm⁻² (1 cm of crust). The soil water content was higher than the control due to the polymer’s excellent water-retaining property. The polymer had no negative influence on seed germination and growth. The biodegradability experiment showed that PASP was easy to biodegrade and therefore it was safe to apply in the field. This work was presented at 13 ^th YABEC symposium held at Seoul, Korea, October 20–22, 2007.     

影响注塑模内贴标成型因素及产品设计探讨

简介了注塑模内贴标成型原理、工艺和应用发展趋势,根据实际产品的应用案例分析了注塑模内贴标在塑料产品成型过程中的影响因素和工艺要点,提出了模内贴标塑料模具的特点及其设计的一般原则,分析了模内贴标产品的常见缺陷,并给出了改善措施.