在硫酸铵存在下，乙醇水溶液能够分为醇／水两相，在分相过程中， C2 H5 OH2＋与[ Sn （SCN）5～6][（5～6）－4]－生成的[C2H5OH2]1～2[Sn（SCN）5～6]三元缔合物能被乙醇相萃取，使Sn（Ⅳ）与Mo（Ⅵ）、Ga（Ⅲ）、Ce（Ⅲ）和W（Ⅵ）离子分离。该方法在微量锡的分离和富集分析中有一定的实用价值。

The ethanol aqueous solution could be well divided into two phases of ethanol /water under the effect of ammonium sulphate. The associated [ C2H5OH2 ]1~2 [ Sn ( SCN )5~6 ] formed from C2H5OH2+ and [ Sn (SCN)5~6][(5~6) -4] -could be extracted during this process .Sn(Ⅳ) could be separated from Mo(Ⅵ), Ga(Ⅲ), Ce (Ⅲ) and W(Ⅵ) by extraction.This method is practical to the separation and enrichment of trace stannum .

The thermodynamic optimization of the Sn-Y and Mg-Sn-Y systems was critically carried out by means of the CALPHAD(CALculation of PHAse Diagram) technique. In the Sn-Y system, the solution phases(liquid, bcc, bct and hcp) were described by the substitutional solution model. The compound Sn3Y5, which has a homogeneity range, was treated as the formula(Sn, Y)3(Sn, Y)2Y3 by a three-sublattice model in accordance with the site occupancies. In the Mg-Sn-Y system, the liquid phase was treated as the formula(Mg, Sn, Y, Mg2Sn) using an associated solution model, and bcc, bct and hcp were treated as the formula(Mg, Sn, Y). The compound Sn3Y5 was treated as the formula(Sn, Y, Mg)3(Sn, Y, Mg)2Y3. The ternary compound MgSnY was treated as stoichiometric compound. A set of self-consistent thermodynamic parameters of the Mg-Sn-Y system was obtained. The projection of the liquidus surfaces and the reaction scheme of the Mg-Sn-Y system were predicted.

The thermodynamic optimization of the Sn-Y and Mg-Sn-Y systems was critically carried out by means of the CALPHAD (CALculation of PHAse Diagram) technique. In the Sn-Y system, the solution phases (liquid, bcc, bct and hcp) were described by the substitutional solution model. The compound Sn3Y5, which has a homogeneity range, was treated as the formula (Sn, Y)3(Sn, Y)2Y3 by a three-sublattice model in accordance with the site occupancies. In the Mg-Sn-Y system, the liquid phase was treated as the for-mula (Mg, Sn, Y, Mg2Sn) using an associated solution model, and bcc, bct and hcp were treated as the formula (Mg, Sn, Y). The compound Sn3Y5 was treated as the formula (Sn, Y, Mg)3(Sn, Y, Mg)2Y3. The ternary compound MgSnY was treated as stoichiomet-ric compound. A set of self-consistent thermodynamic parameters of the Mg-Sn-Y system was obtained. The projection of the liq-uidus surfaces and the reaction scheme of the Mg-Sn-Y system were predicted.

在熔炼过程中以单质形式加入 Sb,研究了0~1.8%(质量分数,下同)范围内不同含量的 Sb 对Mg-3 Sn-1.5 Al-1 Zn-1.2 Si合金显微组织和力学性能的影响。结果表明,Sb 能与 Mg 基体优先生成 Mg3 Sb2相,加入1.0%的Sb 对Mg2 Si相的汉字状结构变质作用显著,Mg2 Si中的Si能与 Sn 发生取代反应,生成富Sn的Mg2(Si,Sn)。随着Sb 的增加,铸态合金和挤压态合金的延伸率逐渐减小,而抗拉强度呈现先增加后降低的趋势,塑性和强度的最佳配合点约为1.0%,Sb含量的增加有利于改善 Mg-3 Sn-1.5 Al-1 Zn-1.2 Si 合金的耐热性能。

The effects of Sb on microstructure and mechanical properties of Mg-3Sn-1.5Al-1Zn-1.2Si magnesium alloy were studied when Sb was added into melt in the form of pure metal with the range of 0-1 .8% (mass frac-tion,similarly hereinafter).The results demonstrate that Sb element and Mg matrix preferentially combine to form Mg3 Sb2 phases,the addition of 1 .0% Sb has a strong modification for Chinese script morphology Mg2 Si phases.Sn can replace Si of Mg2 Si then form Sn-rich Mg2 (Si,Sn)compound phase,whose physical properties lie between Mg2 Si and Mg2 Sn.With the increase of Sb content,the elongations of as-cast and extruded alloy decrease,and tensile strengths increase firstly and then decrease,a best combination of strength and plasticity was 1.0% or so.The increase of Sb was beneficial to improve the heat resistance of Mg-3Sn-1.5Al-1Zn-1.2Si alloy.

通过回流焊工艺制备了Sn0.7Cu-xEr/Cu（x=0,0.1,0.5）钎焊接头，研究钎焊温度及等温时效时间对接头的界面金属间化合物（IMC）的形成与生长行为的影响。结果表明：Sn0.7Cu钎料中微量稀土Er元素的添加，能有效抑制钎焊及时效过程中界面IMC的形成与生长。在等温时效处理过程中，随着时效时间的延长，界面反应IMC层不断增厚，在相同时效处理条件下，Sn0.7Cu0.5Er/Cu焊点界面IMC层的厚度略小于Sn0.7Cu0.1Er/Cu焊点界面的厚度。通过线性拟合方法，得到Sn0.7Cu0.1Er/Cu和Sn0.7Cu0.5Er/Cu焊点界面IMC层的生长速率常数分别为3.03×10-17 m2/s和2.67×10-17 m2/s。

The effects of soldering temperature and isothermal aging on the formation and growth behavior of interfacial intermetallic compound (IMC) of Sn0.7Cu-xEr/Cu solder joints prepared by using reflow method were investigated. The results show that the addition of Er could effectively suppress the formation and growth of IMC. The IMC thickness increases with aging time increasing. The interfacial IMC thickness of Sn0.7Cu0.5Er/Cu joint is slight smaller than that of Sn0.7Cu0.1Er/Cu joint under the same aging condition. The growth rate constants of interfacial IMC layers are 3.03×10-17 m2/s and 2.67×10-17 m2/s for Sn0.7Cu0.1Er/Cu and Sn0.7Cu/Cu joints by using linear regression method, respectively.

目的四川盆地特殊的高温寡照气候，使得作物间套作十分广泛。“麦／玉／豆”体系有利于资源循环高效利用和农业可持续发展。本项目研究了“麦／玉／豆”周年套作体系中各作物的氮素积累分配和花后氮素转运特征，旨在明确体系各作物的氮素营养吸收特性，为该体系的氮肥合理施用及高产高效提供理论依据。方法通过2011、2012连续两年田间定位试验，研究了“小麦／玉米／大豆”套作体系在不同氮用量下（小麦设N 0、60、120、180、240 kg／hm2，分别表示为WN1、WN2、WN3、WN4、WN5；玉米设N 0、97.5、195、292.5、390 kg／hm2，分别表示为MN1、MN2、MN3、MN4、MN5；大豆不施肥，依前作的施氮处理依次记为SN1、SN2、SN3、SN4、SN5）各作物的氮素积累分配、花后氮素的转运。结果1）小麦各部位氮积累量都随氮用量增加而增大，籽粒、茎鞘、叶片和颖壳穗轴分别占地上部总氮积累量（平均为218.6 kg／hm2）的71.5％、12.2％、9.2％和7.1％；小麦花后从营养器官向籽粒转移的氮量及其贡献率随施氮量增加而增大，但转移率在不同氮处理下差异不显著，平均为61.5％；随氮用量增加，籽粒的氮分配比例逐渐减少，而非籽粒部分的氮分配比例则随之增大；小麦籽粒产量随施氮量增加而增大，但W

Objectives]The Sichuan Basin is hot but short of sunlight resources, the intercropping systems are popular in this area.Wheat/maize/soybean system is a typical efficient relay intercropping for the recycling use ofthe natural resources and sustainable development of agriculture.In this paper, the characteristics of nitrogen accumulation, distribution and translocation after anthesis stage of crops in the relay intercropping system were studied, so providing a base for the reasonable fertilization and high yield and high profitable production.[Methods]A field experiment was carried out in 2011 and 2012, and different nitrogen application rates in wheat (0, 60, 120, 180 and 240 kg/ha, marked as WN1 ,WN2 ,WN3 ,WN4 and WN5 ) , maize (0, 97.5, 195, 292.5 and 390 kg/ha, marked as MN1 ,MN2 ,MN3 ,MN4 and MN5 ) and soybean ( non-fertilized, marked as SN1 , SN2 , SN3 , SN4 and SN5 according to the previouse crop N rates ) were designed.[Results]1 ) The nitrogen accumulation in differen