Mg含量对Al-Cu-Mg合金烧结行为和力学性能的影响(英文)

采用粉末冶金方法制备Al-3Cu-Mg合金,将各合金元素的空气雾化粉末与不同含量的Mg混合,通过控制压制压力分别得到弹性变形、局部塑性变形和塑性变形的粉末样品。确定不同成分合金的烧结温度,使烧结过程中Cu的液相烧结起主导作用。采用光学显微镜和扫描电子显微镜对合金的烧结行为和断口特征进行了分析。烧结后合金的横向断裂强度随Mg含量的增加而减小,Al-3Cu-0.5Mg合金具有适中的横向断裂强度和较高的比强度。     

The Spatial Effects of Antenna Configuration in a Large Area Inductively Coupled Plasma System for Flat Panel Displays

Spatial distributions of plasma parameters such as electron density, electron temperature and electric potential were investigated using a commercial simulation software （COMSOLTM） to predict the effects of antenna configuration in a large area inductively cou- pled plasma （ICP） system for flat panel displays. Nine planar antenna sets were evenly placed above a ceramic window. While the electron density was influenced by both the input current and gas pressure, the electron temperature and electric potential were dominantly affected by the gas pressure.     

金银花乳杆菌发酵凉茶的研制

该研究的目的在于探究植物乳杆菌发酵金银花凉茶的工艺条件。以金银花为原料,通过单因素试验和正交试验,研究植物乳杆菌PMO接种量、发酵温度、发酵时间和糖添加量对金银花凉茶发酵过程的影响,并对发酵工艺条件进行优化。结果表明,植物乳杆菌PMO经过驯化过程,其在金银花凉茶中具有优良的增殖活性;金银花凉茶中绿原酸含量受发酵过程影响较小,始终稳定在29.20 mg/g左右;金银花凉茶最佳发酵工艺条件为植物乳杆菌PMO接种量3%、发酵温度37 ℃、发酵时间14 h、糖添加量7%。     

Anticancer activity of lactoferrin isolated from caprine colostrum on human cancer cell lines

In the present study, lactoferrin was purified from caprine colostrum and its anticancer effects were investigated on various cancer cell lines, including lung, colon, cervix, stomach and breast cancer cells. The caprine lactoferrin (CLF) was purified by ultrafiltration and sequential chromatography using a CM-Sephadex C-50-120 ion-exchange column and affinity chromatography on Hi-Trap^TM Heparin HP. The purified CLF exhibited antiproliferative effects on the five tested cancer cell lines in a dose-dependent manner, with 20–30% survival as compared to the control. Interestingly, the most intense inhibition of cell growth was observed on the ZR-75-1 breast cancer cells (IC₅₀ = 27.5 µg/mL). Our findings suggest, for the first time, that purified CLF from caprine colostrum may constitute a novel anticancer agent for the food industry.     

Simultaneous height and adhesion imaging of antibody-antigen interactions by atomic force microscopy

Specific molecular recognition events, detected by atomic force microscopy (AFM), so far lack the detailed topographical information that is usually observed in AFM. We have modified our AFM such that, in combination with a recently developed method to measure antibody-antigen recognition on the single molecular level (Hinterdorfer, P., W. Baumgartner, H. J. Gruber, K. Schilcher, and H. Schindler, Proc. Natl. Acad. Sci. USA 93:3477-3481 (1996)), it allows imaging of a submonolayer of intercellular adhesion molecule-1 (ICAM-1) in adhesion mode. We demonstrate that for the first time the resolution of the topographical image in adhesion mode is only limited by tip convolution and thus comparable to tapping mode images. This is demonstrated by imaging of individual ICAM-1 antigens in both the tapping mode and the adhesion mode. The contrast in the adhesion image that was measured simultaneously with the topography is caused by recognition between individual antibody-antigen pairs. By comparing the high-resolution height image with the adhesion image, it is possible to show that specific molecular recognition is highly correlated with topography. The stability of the improved microscope enabled imaging with forces as low as 100 pN and ultrafast scan speed of 22 force curves per second. The analysis of force curves showed that reproducible unbinding events on subsequent scan lines could be measured.     

An improved automated fluorimetric method for determination of histamine

The automated continuous flow system for the extraction and fluorimetric analysis of histamine based on the principle of Shore et al. (1959) has been improved. With lower consumption of reagents and further simplification of the working conditions, histamine can be determined quantitatively in a routine fashion in aqueous samples, with or without protein content, up to a concentration of approximately 0.1 ng/ml. The rate of analysis is 30 samples/h.     

Comparison of stability-indicating assay methods: ultraviolet, high pressure liquid chromatography and acid dye

Three techniques--ultraviolet, high pressure liquid chromatography (HPLC) and acid dye--were compared as stability-indicating assay methods. Investigations on six drugs (codeine phosphate, ephedrine hydrochloride, morphine sulfate, procaine hydrochloride, pyrilamine maleate and thiamine hydrochloride) indicate that HPLC is the most reliable method.     

Effect of annealing titanium on in vitro bioactivity

In order to modify titanium surfaces for various biological applications, bioactive and pure titanium oxide thin films were coated on the titanium by thermal oxidation technique. The commercially pure titanium discs after polishing were heated at 500, 550, 600, 650 and 700 °C, respectively, for 10 min in air or in argon. To evaluate the ability of calcium phosphate formation, samples after annealing were soaked in the Eagle's minimum essential medium solution. Surface morphology and chemical composition of the samples before or after immersion were characterized by field emission – scanning electron microscopy and energy dispersive X-ray spectrometry.     

Correlation of microstructure with the hardness and wear resistance of (TiC,SiC)/Ti-6Al-4V surface composites fabricated by high-energy electron-beam irradiation

The correlation of microstructure with the hardness and wear resistance of (TiC,SiC)/Ti-6Al-4V surface composites fabricated by high-energy electron-beam irradiation was investigated in this study. The mixtures of TiC, SiC, or TiC + SiC powders and CaF₂ flux were placed on a Ti-6Al-4V substrate, and then an electron beam was irradiated on these mixtures using an electron-beam accelerator. The surface composite layers of 1.2 to 2.1 mm in thickness were formed without defects and contained a large amount (up to 66 vol pct) of precipitates such as TiC and Ti₅Si₃ in the martensitic matrix. This microstructural modification, including the formation of hard precipitates and a hardened matrix in the surface composite layer, improved the hardness and wear resistance. Particularly in the surface composite fabricated with TiC + SiC powders, the wear resistance was greatly enhanced to a level 25 times higher than that of the Ti alloy substrate, because 66 vol pct of TiC and Ti₅Si₃ was precipitated homogeneously in the hardened martensitic matrix. These findings suggested that high-energy electron-beam irradiation was useful for the development of Ti-based surface composites with improved hardness and wear properties.