H. R. Hou
,
Q. Y. Liu
,
Q. A. Chen and H. Dong Division of Structural Materials
,
Central Iron & Steel Research Institute
,
Beijing 100081
,
China
金属学报(英文版)
Heavy deformation and controlled cooling is one of the most effective effective ways for grain refinement in HSIA steels. In this paper, experimental specimens are prepared with a commercial linepipe steel grade X65, and the chemical compositions are (wt% ): Fe-0.094C-1.42Mn-0. 29Si-0. 045Nb-0. 008Ti. After heavy deformation with 80% reduction in non-recrystallization range of austenite, and at controlled cooling rates from 2K/s to 64K/s, the grain sizes vary from 9.55μm to 1.06μm.It is shown by the results that a linear relationship still remains between the yield strength and reciprocal of square root of ferrite grain size as grain size is refined to 1m.The ultra-fine grains might be dynam- ically formed through the deformation-induced transformation when reduction is large enough.The grain sizes decrease when the cooling rates increase.When the cooling rates increase over 10K/s, the grain sizes are rarely changed. The particles distribute on grain boundaries, sub-grain boundaries, deformed bands and within the ferrite grains.
关键词:
microalloyed steel
,
null
,
null
,
null
杨慧芬
,
唐琼瑶
,
王传龙
,
张露
,
李甜
中国有色金属学报
为考察红城红球菌(Rhodococcus erythropolis,R. erythropolis)作为赤铁矿捕收剂使用的可能性及效果,对R. erythropolis形貌、细胞壁成分及其吸附前后赤铁矿、石英表面电性、疏水性进行分析,对赤铁矿、石英单矿物以及赤铁矿与石英矿1:1(质量比)混合矿进行浮选实验,对其在赤铁矿表面的吸附状况及吸附机理进行研究.结果表明,杆状R. erythropolis表面既含有非极性基团,又含有极性基团,使得其表面具有较高的负电性和较强的疏水性,因而对赤铁矿的吸附作用明显大于对石英的吸附作用.当以此细菌为捕收剂、在溶液 pH 值为6、R. erythropolis用量为75 mg/L时,赤铁矿的回收率为89.68%,而石英的回收率仅为26.25%.混合矿经过一次浮选,可获得铁品位和回收率分别为50.08%和76.41%的铁精矿.R. erythropolis在赤铁矿表面发生复杂的化学吸附且使赤铁矿颗粒形成疏水絮团,从而证实R. erythropolis可作为赤铁矿的捕收剂使用.
关键词:
R. erythropolis
,
微生物
,
赤铁矿
,
石英
,
吸附
,
絮团
,
捕收剂
陶明
,
熊伟
,
陈华
,
李贤均
催化学报
合成了(R,R)-1,2-二苯基乙二胺((R,R)-DPEN)、钌和三苯基膦的三元配合物RuCl2[P(C6H5)3]2-(R,R)-DPEN,并将其用于萘乙酮的不对称加氢反应.考察了碱/催化剂的摩尔比、反应温度和氢气压力等对催化活性和对映选择性的影响.结果表明,多种因素对反应的转化率和对映选择性均有影响.在萘乙酮:(CH3)3COK:催化剂摩尔比为50 000:450:1,氢气压力为4 MPa,反应温度为25℃的条件下,反应16 h时,萘乙酮生成α-萘乙醇的产率和对映选择性分别达到了100%和83%.
关键词:
钌膦配合物
,
手性二胺
,
萘乙酮
,
不对称催化加氢
,
α-萘乙醇
,
对映选择性
秦鹏
,
李萍
,
侯天宇
,
赵杰
,
李廷举
材料工程
doi:10.11868/j.issn.1001-4381.2016.11.015
基于对影响非线超声性检测因素的探讨，考察了应用非线性检测无损评价H R3C烟侧腐蚀的可行性。结果表明：脉冲激励串个数 n≤2df／c ，加汉宁窗有助于降低系统干扰，此外，样品表面粗糙度对非线性系数β产生显著的影响。随腐蚀时间的延长，非线性系数呈现阶段性的递增趋势。腐蚀初期（腐蚀时间在50h以内），非线性系数增幅不足20％；然而，腐蚀至150h ，非线性系数显著增加；相对于未腐蚀样品，腐蚀200h时的非线性系数增幅达260％。非线性系数的单调变化与腐蚀损伤的加剧相一致，因此，应用超声非线性无损评价 H R3C的烟侧腐蚀是可行的。
关键词:
非线性超声检测
,
非线性系数
,
烟侧腐蚀
杨敏
,
常海萍
,
毛军逵
工程热物理学报
本文实验研究了离心力场下细微封闭循环通道中,以H2O和氟利昂R12为热驱动介质的热驱动流动规律和换热特性,重点分析了热驱动换热技果随Ra数Ro数的变化规律以及冷却效果.实验结果表明:在热流密度和旋转速度相同的条件下,采用介质R12可以获得较高的半均换热系数,冷却效果也优于以H2O为介质的冷却效果.最后建立了两种介质条件下相应的准则关系式.
关键词:
热驱动
,
热驱动介质
,
细微通道
,
旋转
,
换热系数
刘欢
,
严凯
,
晏井利
,
薛烽
,
孙甲鹏
,
江静华
,
马爱斌
中国有色金属学报(英文版)
doi:10.1016/S1003-6326(17)60007-4
为了揭示14H相的形成机理，制备并研究了18R LPSO单相Mg?Y?Zn(简称S18)合金经773 K退火100 h的显微组织演变。结果表明：铸态S18合金主要由18R相组成(其体积分数高于93%)，并含有少量的W相和α-Mg相。退火时，S18合金中的18R相保持稳定，未转变成14H LPSO结构。然而，在α-Mg相内部形成了14H层片相，其尺寸和体积分数随着退火时间的延长不断增大。TEM分析表明，14H相在α-Mg内基面堆垛层错区域独立形核。14H层片的增厚生长是界面控制过程，与基面台阶的形成密切联系。而14H层片的伸长生长属于扩散控制，与溶质元素的扩散有关。该18R单相合金中14H相的形成机理可通过反应式α-Mg'→α-Mg +14H表示。
关键词:
Mg-Y-Zn合金
,
18R LPSO相
,
14H LPSO相
,
高温退火
,
显微组织演变
Journal of Solid State Chemistry
The subsolidus phase relations of R2O3-CaO-CuO ternary systems (R = Nd, Sm, Gd, Tm) have been investigated by X-ray powder diffraction. All samples were synthesized at about 950degrees in air. There exists a ternary compound Ca14-xRxCu24O41 (x = 4 for R = Nd, Gd and x = 5 for R = Sm) and a ternary solid solution Ca2+xR2-xCu5O10 (R = Nd, Sm, Gd, Tm) with a wide composition range Deltax of about 0.6. The compound Ca14-xRxCu24O41 possesses a layered orthorhombic structure and is isostructural to Sr14-xCaxCu24O41. The lattice parameters a and c of the compound are basically independent of the ionic radius of R, while the lattice parameter b and unit-cell volume V decrease substantially with the decrease of the ionic radii of R. The Ca2+xR2-xCu5O10 solid solution is isostructural to Ca2+xY2-xCu5O10, the structure of which is based on an orthorhombic "NaCuO2-type" subcell containing infinite one-dimensional chains of edge-shared square planar cuprate groups crosslinked by the layered cations Ca and R that locate in the inter-chain tunnels. (C) 2002 Elsevier Science (USA). All rights reserved.
关键词:
R2O3-CaO-CuO (R = Nd, Sm, Gd, Tm) systems;phase relations;Ca10R4Cu24O41 (R = Nd, Sm, Gd) structure;Ca2+xR2-xCu5O10 (R = Nd, Sm,;Gd, Tm) structure;ternary-system;approximately 950-degrees-c;high-pressure;superconductivity;diagram;air;er;compatibilities;property;oxide
Chemical Physics Letters
The relationship between the local structure and EPR spectrum is studied by diagonalizing the complete energy matrices for Mn(2+) in a trigonal ligand-field. The results show that the degree of distortion increases with temperature increasing whether it is compressed or elongate distortion, and the distorted tendency of the local structure is different according to the sign of D. Meanwhile, the distortion of Cd(BF(4))(2)center dot 6H(2)O:Mn(2+) system is more sensitive to temperature than that of ZnSnF(6)center dot 6H(2)O:Mn(2+) system. Moreover, the EPR parameter D is closely associated with the local structure parameters R and h while (a - F) is mainly concerned with R. (C) 2010 Elsevier B. V. All rights reserved.
关键词:
single-crystals;optical-absorption;phase-transitions;mn2+;field;ions;resonance;spectra;relaxation;fe-3+
Journal of Applied Physics
Samples of R2Fe17C(y)N(x) (R = Y, Sm, Er, Tm) were prepared by arc melting appropriate amount of R, Fe, and C, vacuum annealing at 1373 K and finally annealing at 740 K in nitrogen for 10 h. The magnetic properties of these compounds were investigated by means of ac initial susceptibility, magnetization measurements, and x-ray diffraction. The thermal stability of the nitride phase was studied by differential scanning calorimetry. It was found that, when heated above 600 K, R2Fe17C(y)N(x) irreversibly decomposes N which is irrespective of the carbon concentration and rare-earth element. The Curie temperatures of R2Fe17C(y)N(x) are independent of the carbon concentration and are approximately 400 K higher than those of the corresponding pure R2Fe17 compounds. However, the Curie temperatures cannot be correlated to the composition x of the initial R2Fe17C(y)N(x) compounds at room temperature because some N was lost during the heating to T(c). In the Er and Tm compounds spin reorientation transitions were found, marking the change of the easy magnetization direction from the c axis to the basal plane with increasing temperature. The Tm compounds show an additional magnetic transition at low temperatures (below 40 K). A coexistence of the hexagonal and the rhombohedral structural modifications was found in Er2Fe17C(y)N(x) when y < 1.5, characterized by two different spin reorientation temperatures. The anisotropy fields of Sm2Fe17C(y)N(x) are higher than that of Sm2Fe17N(x). Indications of a magnetic phase transition were found also in Sm2Fe17C0.7N(x) and Sm2Fe17C0.9N(x).
关键词:
magnetocrystalline anisotropy;carbides;alloys
E. El Ouariachi
金属学报(英文版)
Rosmarinus officinalis essential oil obtained by hydrodistillation was tested as corrosion inhibitor of steel in 0.5~M H2SO4 using weight loss measurements, and electrochemical polarisation methods. Results obtained indicate that the corrosion rate is reduced and R.officinalis oil adsorbs on the metal surface and then inhibits corrosion process. Its inhibition efficiency increases with oil increasing content to reach 61 % at 1 g/L. Polarisation curves indicate that RO acts as a cathodic inhibitor. The inhibition efficiency of naturally oil remains slightly constant with the rise of temperature. Chemical analysis of R.~officinalis essential oil was carried out using capillary GC and GC/MS. The oil composition was characterized by high amount of oxygenated monoterpene (77 %) with 1,8-cineol (52.1 %) as main component. Discussion of adsorption was investigated on the basis of essential oil composition. Finally, the isotherm adsorption of essential oil on the steel has been also reported.
关键词:
Rosmarinus officinalis oil
