Research on Microstructure and Mechanical Properties of Rheological Die Forging Parts of Al-6.54Zn-2.40Cu-2.35Mg-0.10Zr(-Sc) Alloy

High-strength aluminum alloy (mainly refers to the 7xxx series) is the optimum material for lightweight military equipment. However, this type of aluminum alloy is a wrought aluminum alloy. If it is directly formed by traditional casting methods, there will inevitably be problems such as coarseness, unevenness, looseness, and hot cracking in the structure, which will greatly affect the final performance of the part. Based on the internal cooling with annular electromagnetic stirring (IC-AEMS) method, a new technology of rheological die forging is developed in this paper, and the scale-reduced parts of a brake hub of Al-6.54Zn-2.40Cu-2.35Mg-0.10Zr aluminum alloy were prepared. The influence of IC-AEMS and the addition of rare element Sc on the structure and mechanical properties of the parts was studied. An optical microscope and scanning electron microscope (SEM) were used to observe the microstructure evolution, energy dispersive spectroscopy (EDS) was used to analyze the phase distribution and composition, and the mechanical properties of the parts were tested by uniaxial tensile tests. The results show that the addition of Sc element can effectively refine the grains and improve the strength and elongation of the material; the application of IC-AEMS improves the cooling rate of the melt, increases the effective nucleation rate, and the grains are further refined. Through process optimization, scale-reduced parts of a brake hub with good formability and mechanical properties can be obtained, the ultimate tensile strength is 597.2 ± 3.1 MPa, the yield strength is 517.8 ± 4.3 MPa, and the elongation is 13.7 ± 1.3%.     

Enhanced hydrogen storage properties of 1.1MgH2–2LiNH2–0.1LiBH4 system with LaNi5-based alloy hydrides addition

Significant improvements in the hydrogen sorption properties of the Li–Mg–N–H system have been achieved by adding a small amount of LiBH₄. Herein, the hydrogen storage properties of the 1.1MgH₂–2LiNH₂–0.1LiBH₄ system are further enhanced by addition of LaNi₅-based (LaNi_3.8Al_0.75Mn_0.45, LaNi_4.5Mn_0.5, LaNi₄Co) alloy hydrides. The refinement of the Li–Mg–B–N–H particles and the metathesis reaction are facilitated by adding LaNi₅-based alloy hydrides during the ball milling process. The addition of LaNi₅-based alloy hydrides can enhance the hydrogen sorption kinetics, reduce the dehydrogenation temperature and promote a more thorough dehydrogenation of the Li–Mg–B–N–H system. The LaNi₅-based alloy hydrides are involved in hydrogen de/hydrogenation reaction. Among the three alloys, LaNi_4.5Mn_0.5 makes the most obvious improvement on the reaction kinetics, and the dehydrogenation peak temperature is reduced by 12 °C, while the activation energy is reduced by 11% with 10 wt% LaNi_4.5Mn_0.5 addition. The weakening of the N–H bond and the homogeneous distribution of the LaNi₅-based alloy hydrides in the Li–Mg–B–N–H composite have important roles in the reduction of the desorption barrier and the kinetics enhancement.

The weakening of N–H bond and the homogeneous distribution of LaNi₅-based alloy hydrides in the Li–Mg–B–N–H composite enhance its hydrogen storage properties.     

硝苯地平片薄膜包衣生产工艺研究

目的：研究适合硝苯地平片的薄膜包衣生产工艺方法。方法：用醇溶型薄膜包衣预混剂对该产品片芯进行包衣后,与该产品未包衣片芯同时进行稳定性考察对比。结果：用醇溶型薄膜包衣预混剂对该产品素片进行包衣后,当增重达到3.2%±0.3%时,本品加速试验6个月时的综合质量仍符合中国药典规定,而未包衣的片芯则呈现明显的质量变化。结论：按该工艺生产的硝苯地平片质量稳定可靠,该工艺适合大生产需要。     

新时期医疗废物管理模式的嬗变及发展

<正>《医疗废物管理条例》明确医疗卫生机构在医疗、预防、保健以及其他相关活动中产生的具有直接或者间接感染性、毒性以及其他危害性的废物;2016版《国家危险废物名录》明确指示,医疗废物是一种具有感染性和毒性等特性的危险废物。针对感染性医疗废物(包括锐器)的管理处置,重点解决的难题     

医用热熔胶的研究与应用

BACKGROUND: Hot-melt adhesive is safe and environmental friendly adhesive due to free of solvent, which is particularly suitable for medical applications. OBJECTIVE: To describe the types and characteristics of currently used hot-melt adhesives and to prospect the technical research and development of hot-melt adhesive for polyolefin tubes or catheters as well as to point out the corresponding key points to the hot-melt adhesion. METHODS: Literature search was carried out in SCI, Elsevier, and CNKI with the key words of “hot melt adhesive, medical application” in English and Chinese, respectively, for the initial retrieval of relevant articles or patents published January 1995 to December 2015. RESULTS AND CONCLUSION: To date, the medical hot-melt adhesives reported in the literature could be grouped as amorphous polyolefin, thermoplastic elastomer, acrylic and polyurethane types. The heat resistance of the most of the hot-melt adhesives does not meet the requirement for steam sterilizing process. In the present review, a strategy is proposed to develop a novel hot-melt adhesive which is good for binding polyolefin parts and can undergo the sterilization process. Given this, it is essential to choose a kind of polypropylene random copolymer with a suitable melting point as a substrate. With the aid of an adjuvant agent, therefore, we can develop a novel hot-melt adhesive that exhibits a lower melting point than the polyolefin tube, withstands steam sterilization temperature to ensure that the tube is not deformed during melt adhesion and is not become invalid during sterilization.      

铜绿假单胞菌注射液对多种人恶性肿瘤细胞株的增殖抑制作用

  目的   研究铜绿假单胞菌注射液(PA-MSHA) 在体外对人恶性肿瘤细胞(肝癌BEL-7402、乳腺癌MDA-MB-231、胃癌MKN-45、肺癌A549和结肠癌SW620) 生长状态的影响, 并进行PA-MSHA药物敏感度的比较和分析。   方法  将PA-MSHA (1.8×109/mL) 进行梯度稀释, 在体外分别与5种肿瘤细胞共同培养72 h, 并在显微镜下观察细胞生长和形态变化。用MTT比色法检测细胞的增殖水平, 并计算IC₅₀值。   结果  镜下观察发现, PA-MSHA对5种肿瘤细胞的生长均有显著抑制。MTT法检测显示, PA-MSHA能够有效抑制肿瘤细胞的体外增殖, 并呈现出明显的药物剂量相关性。PA-MSHA对BEL-7402、MDA-MB-231、MKN-45、A549和SW620细胞的IC₅₀值, 分别为2.12×108/mL、1.95×108/mL、2.09×108/mL、1.59×108/mL和1.32×108/mL。   结论  铜绿假单胞菌注射液能够直接抑制人恶性肿瘤细胞的体外增殖, 并且对不同来源的肿瘤细胞具有广谱抑制作用。5种恶性肿瘤细胞对PA-MSHA的药物敏感性依次为: 结肠癌SW620 > 肺癌A549 > 乳腺癌MDA-MB-231 > 胃癌MKN-45 > 肝癌BEL-7402。      

Interfacial Structure of Carbide-Coated Graphite/Al Composites and Its Effect on Thermal Conductivity and Strength

Graphite/Al composites had attracted significant attention for thermal management applications due to their excellent thermal properties. However, the improvement of thermal properties was restricted by the insufficient wettability between graphite and Al. In this study, silicon carbide and titanium carbide coatings have been uniformly coated on the graphite by the reactive sputtering method, and Graphite/Al laminate composites were fabricated by a hot isostatic pressing process to investigate the influence on thermal conductivity and mechanical properties. The results show that carbide coating can effectively improve the interfacial thermal conductance of SiC@Graphite/Al and TiC@Graphite/Al composites by 9.8 times and 3.4 times, respectively. After surface modification, the in-plane thermal conductivity (TC) of the composites with different volume fractions are all exceeding the 90% of the predictions. In comparison, SiC is more conducive to improving the thermal conductivity of composite materials, since the thermal conductivity of the 28.7 vol.% SiC@Graphite/Al reached the highest value of 499 W/m·K, while TiC is favorable for improving the mechanical properties. The finding is beneficial to the understanding of carbide coating engineering in the Graphite/Al composites.     

Porous tantalum structures for bone implants: Fabrication,mechanical and in vitro biological properties

The relatively high cost of manufacturing and the inability to produce modular implants have limited the acceptance of tantalum, in spite of its excellent in vitro and in vivo biocompatibility. In this article, we report how to process Ta to create net-shape porous structures with varying porosity using Laser Engineered Net Shaping (LENS?) for the first time. Porous Ta samples with relative densities between 45% and 73% have been successfully fabricated and characterized for their mechanical properties. In vitro cell materials interactions, using a human fetal osteoblast cell line, have been assessed on these porous Ta structures and compared with porous Ti control samples. The results show that the Young’s modulus of porous Ta can be tailored between 1.5 and 20 GPa by changing the pore volume fraction between 27% and 55%. In vitro biocompatibility in terms of MTT assay and immunochemistry study showed excellent cellular adherence, growth and differentiation with abundant extracellular matrix formation on porous Ta structures compared to porous Ti control. These results indicate that porous Ta structures can promote enhanced/early biological fixation. The enhanced in vitro cell–material interactions on the porous Ta surface are attributed to its chemistry, its high wettability and its greater surface energy relative to porous Ti. Our results show that these laser-processed porous Ta structures can find numerous applications, particularly among older patients, for metallic implants because of their excellent bioactivity.     

纳洛酮在急性有机磷中毒中的综合应用价值研究

目的观察纳洛酮在急性有机磷中毒中的综合应用价值。方法选取2010年9月~2013年4月于本院进行治疗的82例急性有机磷中毒患者为研究对象,将其随机分为对照组（常规治疗方案组）41例和观察组（常规治疗方案加纳洛酮组）41例,对两组中轻度、中度及重度患者的临床总有效率、阿托品化时间、阿托品用量及症状改善时间进行比较。结果观察组的轻度、中度及重度患者的临床总有效率均高于对照组,阿托品化时间、阿托品用量及症状改善时间也明显低于对照组,差异均有统计学意义（P〈0.05）。结论纳洛酮在急性有机磷中毒中的综合应用价值较高,效果好且显效快。