A.A.A. Saleh
,
X.J. Zhai
,
Y.C. Zhai
,
Y. Fu
,
M.M. Elomella
金属学报(英文版)
Photocatalytic degradations of p-nitrochlorbenzene (p-NCB) with distilled water were
investigated with ZnO crystals (catalyst) of 70nm in diameter under UV irradiation.
The suitable experimental conditions are determined as: ZnO 0.25g, pH 7, p-NCB
concentration 30mg/L. These variables in terms of the degradation rate have been
discussed, which was defined as the rate of the initial degradation to the final degradation of p-NCB. When all of the experimental degradation rate values are plotted as a
function of irradiation time, all of the points appeared on a single line for wide range of
p-NCB degradations. On the basis of these results, it has been concluded that at lower
ZnO catalyst amount, much of the light is transmitted through the slurry in the container beaker, while at higher catalyst amount, all the incident photons are observed
by the slurry. Degradation rates of p-NCB were found to decrease with increasing
solution pH. It has been concluded that the maximum degradation rate values of p-NCB under principally the same experimental conditions mentioned above are 97.4%,
98.8% and 95.5% at 100min respectively. The results suggest that the photocatalytic
degradation is initiated by an oxidation of the p-NCB through ZnO surface-adsorbed
hydroxyl radicals. Absorption spectra are recorded using spectrophotometer before and
after UV-irradiation in the wavelength range 200--400nm at room temperature. It
is found that the variation of irradiation time over the range 20--100min resulted in
change in the form of the spectrum linear absorption and a higher maximum value
will be obtained at longer irradiation time.
关键词:
reactive evaporation method
,
null
,
null
,
null
万小峰
,
张久兴
,
周文元
,
李湘波
,
周美玲
稀有金属材料与工程
研究了FU105大功率广播发射管用碳化镧钼阴极,参照碳化钍钨阴极FU105管的制备工艺,实现了镧钼阴极的碳化以及镧钼阴极FU105管的排气和老炼.通过镧钼阴极FU105管的性能测试,对碳化镧钼阴极的发射能力和稳定性进行了分析.结果认为:FU105管碳化镧钼阴极的发射能力可以达到碳化钍钨阴极的水平,但其稳定性还有待改进.
关键词:
镧钼阴极
,
FU105发射管
,
碳化
,
稀土
钟文远
,
崔永春
,
范春兰
,
胡智兴
,
李玛琳
贵金属
doi:10.3969/j.issn.1004-0676.2004.02.005
为寻求高效低毒的新型顺铂类抗肿瘤药物,用K2PtCl4、乙二胺(en)、氟尿嘧啶(5-Fu)为原料,设计合成了顺铂类似物[pt(en)(5-Fu)2]C12配合物,由元素分析、红外光谱和质谱分析初步证实了其化学结构,用改良MTT、SRB法,选用K562、A549、Bel-7402、BIU-87、Bcap-37细胞株对其进行体外抗肿瘤活性测定.结果表明,所合成的配合物除在浓度为0.01、0.1 μg/mL时对K562细胞株抗肿瘤活性大于顺铂和氟尿嘧啶外,其它情况下的抗肿瘤活性均小于顺铂和氟尿嘧啶.该配合物仍有进一步研究的价值.
关键词:
药学
,
铂(Ⅱ)配合物
,
合成
,
抗肿瘤活性
马宏
,
彭晓东
,
谢卫东
腐蚀学报（英文）
利用对掺法熔铸镁合金AJ61+xY, 研究了合金中相的组成和分布及其在3.5%NaCl溶液中的腐蚀行为. 结果表明, 添加稀土Y使AJ61镁合金的晶粒明显细化,Mg17Al12 相的数量明显减少且由连续网状变成弥散颗粒状分布,沿晶界处生成耐蚀稀土相Al2Y、Al3Y, AJ61镁合金的耐腐蚀性得到明显改善. 耐腐蚀性顺序为:AJ61+1.5%Y>AJ61+2.0%Y>AJ61+1.0%Y>AJ61+0.5%Y.
关键词:
Mg-6Al-1Sr 镁合金
,
yttrium
,
microstructure
,
corrosion resistance
马宏
,
彭晓东
,
谢卫东
腐蚀学报（英文）
利用对掺法熔铸镁合金AJ61++xY,研究了合金中相的组成和分布及其在3.5%NaCl溶液中的腐蚀行为.结果表明,添加稀土Y使AJ61镁合金的晶粒明显细化,Mg17Al12相的数量明显减少且由连续网状变成弥散颗粒状分布,沿晶界处生成耐蚀稀土相Al2Y、Al3Y,AJ61镁合金的耐腐蚀性得到明显改善.耐腐蚀性顺序为:AJ61+1.5%Y＞AJ61+2.0%Y＞AJ61+1.0%Y＞AJ61+0.5%Y.
关键词:
Mg-6Al-1Sr镁合金
,
钇
,
显微组织
,
耐腐蚀
Yan NIU
,
Weitao WU and Chaoliu ZENG (State Key Lab. for Corrosion and Protection
,
Institute of Corrosion and Protection of Metals
,
Chinese Academy of Sciences
,
Shenyang 110015
,
China)F. Gesmundo and F. Viani (Instituto di Chimica
,
Facolta di Ingegneria
,
Un
材料科学技术（英文）
The corrosion of an Fe-based alloy containing 15 wt pct Y in H2-H2S mixtures under 10-3 Pa S2 was studied at 600~800℃ in an attempt to find materials with improved sulphidation resistance with respect to pure Fe. The presence of Y has been shown to be beneflcial, but not sufficient to the level expected. In fact, the alloy is able to form at all tested temperatures an external FeS layer, beneath which a zone containing a mixture of the two sulphides is also present. Thus,Fe can still diffuse through this region to form the outer FeS layer with non-negligible rate. The corrosion rate of Fe is considerably reduced by the Y addition. but the alloy corrodes still much more rapidly than Y. The sulphidation kinetics is generally rather irregular for both the pure metals, while the corrosion rate of the alloy decreases with time and tends to become parabolic after an initial period of 12~17 h. The sulphidation behaviour of the alloys is discussed by taking into account the presence of an intermetallic compound Fe17Y2 and the limited solubility of Y in Fe
关键词:
Transactions of Nonferrous Metals Society of China
The influence of Zr and Y on the cast microstructure of a nickel-based superalloy was investigated by optical microscopy (OM), scanning electron microscopy(SEM), electron probe micro-analysis (EPMA) and X-ray diffraction (XRD). The gamma+gamma' eutectic volume in the superalloy rises notably with the increase of Zr or Y content. Meanwhile, the morphologies of primary MC carbides change from needle and platelet-like to blocky shape with increasing Zr and Y doped. The XRD results show that the primary MC carbide lattice constant increases with Zr and Y additions, and EPMA investigation shows that the platelet-like MC carbides contain primarily Nb and C, while those carbides in blocky shape have 39.2% Zr and 39.6% Nb in average,. These influences on the cast microstructure can be attributed to the atomic size effects of Zr and Y.
关键词:
yttrium;zirconium;carbides;nickel based superalloys;microstructure;solidification;carbide morphology;mechanical-properties;boron;ni3al;yttrium;sulfur
材料科学技术（英文）
The corrosion of an Fe-based alloy containing 15 wt pet Y in H-2-H2S mixtures under 10(-3) Pa S-2 was studied at 600 similar to 800 degrees C in an attempt to find materials with improved sulphidation resistance with respect to pure Fe. The presence of Y has been shown to be beneficial, but not sufficient to the level expected. In fact, the alloy is able to form at all tested temperatures an external FeS layer, beneath which a zone containing a mixture of the two sulphides is also present. Thus, Fe can still diffuse through this region to form the outer FeS layer with non-negligible rate. The corrosion rate of Fe is considerably reduced by the Y addition, but the alloy corrodes still much more rapidly than Y. The sulphidation kinetics is generally rather irregular for both the pure metals, while the corrosion rate of the alloy decreases with time and tends to become parabolic after an initial period of 12 similar to 17 h. The sulphidation behaviour of the alloys is discussed by taking into account the presence of an intermetallic compound Fe17Y2 and the limited solubility of Y in Fe.
关键词:
high-temperature sulfidation;most-reactive component;ni-nb alloys;h2-h2s mixtures;behavior;600-degrees-c-800-degrees-c;oxidation
王永刚
,
何业东
,
朱日彰
中国稀土学报
通过金属蒸汽真空弧离子源(简称MEVVA)方法在Fe3Al表面离子注入Y.在1000°空气中的氧化实验表明,Fe3Al经离子注入Y后,初期氧化速率略有升高,但稳态氧化速率大大降低,氧化膜的塑性和粘附性大大提高,抗氧化性能明显改善.其原因在于注入的Y+在氧化过程中优先氧化,阻碍金属离子向外扩散,促进氧向内传输,改变了氧化膜的形成和生长机制.
关键词:
稀土
,
钇
,
Fe3Al
,
离子注入
,
高温氧化行为
Journal of Materials Research
Based on the best bulk metallic glass (BMG) forming alloy in the Mg-Cu-Y ternary system, we introduced Ag (or Ni) to partially substitute for Cu to improve the glass-forming ability (GFA). The objective of this paper is twofold. First, we illustrate in detail a recently developed search strategy, which was proposed but only briefly outlined in our previous publication [H. Ma, L.L. Shi, J. Xu, Y. Li, and E. Ma: Discovering inch-diameter metallic glasses in three-dimensional composition space. Appl. Phys. Lett. 87, 181915 (2005)]. The protocol to navigate in three-dimensional composition space to land large BMGs is spelled out step-by-step using the pseudo-ternary Mg-(Cu,Ag)-Y as the model system. Second, our ability to locate the best BMG former in the composition tetrahedron allows us to systematically examine, and conclude on, the effects of a given alloying element. The large improvement in glass-forming ability in the Mg-(Cu,Ag)-Y system relative to the based ternary will be contrasted with the reduced glass-forming ability in the Mg-(Cu,Ni)-Y pseudo ternary system. It is demonstrated that the improvement of glass-forming ability requires judicious choice of substitutional alloying elements and concentrations, rather than simple additions of multiple elements assuming the "confusion principle."
关键词:
bulk metallic-glass;shaped copper mold;amorphous-alloys;thermal-stability;ternary-system;casting method;p system;diameter;zr;mm
