La1—xSrxCoO3—y导电陶瓷制备工艺的研究

用固相反应法制备了Ｌａ１－ｘＳｒｘＣｏＯ３－ｙ导电陶瓷瓷材料，研究了制备工艺对烧性能的影响。实验结果表明，烧结体的致密度取决于预烧温度，烧成温度及保温时间，此外还与成型方法等因素有关，在１０００～１３００℃保温２～１５ｈ获得了高密度，导电性良好的立方钙钛矿型Ｌａ１－ｘＳｒｘＣｏＯ３－ｙ（ｘ＝０．５，０．６）陶瓷材料。用Ｘ射线分析了材料的相组成和结构。     

高温燃料电池阴极材料La（Sr）MnO3的电导性能研究

用固相合成法合成了（Ｌａ１－ｘＳｒｘ）１－ｙＭｎＯ３（ｘ＝０～５，ｙ＝０～０．１）单纯相化合物。在空气中用直流四探针法测定了各组成的电导率。测试温度范围为１００～９５０℃。其中（Ｌａ０．７Ｓｒ０．３）０．９５ＭｎＯ３具有最大的电导率。讨论了Ｌａ（Ｓｒ）ＭｎＯ３的电导机理。     

用于燃料电池的Ln_（1－x）Sr_xMnO_3系阴极材料的研究

用固相反应合成了Ｌｎ１－ｘＳｒｘＭｎＯ３（Ｌｎ＝Ｐｒ，Ｎｄ，Ｓｍ，Ｇｄ，Ｙｂ和Ｙ，ｘ≤０．５）系钙钛矿型多元氧化物，用Ｘ光衍射分析测定了反应产物的相组成和结构类型．离子半径＞０．１Ａ的Ｐｒ，Ｎｄ，Ｓｍ，Ｇｄ等取代后的Ｌｎ１－ｒＳｒｘＭｎＯ３仍具有正交ＬａＭｎＯ３的结构，而离子半径＜０．９５Ａ的Ｙ和Ｙｂ取代后的产物，则为六方结构（Ｙｂ，Ｙ）ＭｎＯ３及第二相Ｓｒ（Ｙｂ，Ｙ）２Ｏ４还测定了产物的烧结性能和电导率．发现（Ｐｒ，Ｎｄ，Ｓｍ）１－ｘＳｒｘＭｎＯ３的电导率比Ｌａ１－ｘＳｒｘＭｎＯ３约高一个数量级以上，而且都能在ＺｒＯ２固体电解质上形成结合良好的膜材，所以有可能成为另一类性能良好的燃料电池的阴极材料．     

SOFC阴极材料（La0.85Sr0.15）y（Mn1—zCrz）O3的物理性能和化学稳定性

采用烧结法制备阴极材料（Ｌａ０．８５Ｓｒ０．１５）ｙ（Ｍｎ－ｚＣｒｚ）（ｙ＝０．８５，１；ｚ＝０．１，０．２）。研究了多孔锰酸镧致密ＺｒＯ２（８ｍｏｌ％Ｙ２Ｏ３）界面的成分变化和显微形貌。     

多孔La0.6Sr0.4Co0.2Fe0.8O3-δ的制备及表征

多孔Ｌａ０．６Ｓｒ０．４Ｃｏ０．２Ｆｅ０．８Ｏ３－δ陶瓷具有一定的强度、良好的透气和电传导性能,可用于中温ＳＯＦＣ阴极支撑和氧分离膜活性支撑体。本文用固相反应法制备了多孔Ｌａ０．６Ｓｒ０．４Ｃｏ０．２Ｆｅ０．８Ｏ３－δ陶瓷。考察了烧结条件１成型压力有机添加剂量对孔隙率和孔径的影响,研究发现气体渗透随机孔隙率线性增长,电导率随孔隙率的增大而下降,并满足关系式σ＝σ０（１－Ｐ）＾３．１。     

超负磁致伸缩晶体Sm－Fe、Sm－Dy－Fe和Sm－Dy－Fe－Al的研究

本文研究了轻稀土负磁致伸缩ＳｍＦｅ＿ｘ（１．４０＜ｘ＜１．９４），Ｓｍ＿ｘＤｙ＿（１－ｘ）Ｆｅ＿ｙ（０．８４＜ｘ＜０．９２．１．８０＜ｙ＜１．９０），Ｓｍ＿（０．９０）Ｄｙ＿（０．１０）（Ｆｅ＿（０．９５）Ａｌ＿（０．０５））＿（１．８０）晶体的制备、热处理及磁学性能，发现ＳｍＦｅ＿ｘ合金的λ－ｘ曲线存在两个峰值，峰值的ｘ点随热处理发生的变化有一定的规律性，还比较了热处理前后，Ｓｍ－Ｆｅ、Ｓｍ－Ｄｙ－Ｆｅ和Ｓｍ－Ｄｙ－Ｆｅ－Ａｌ的相组成对性能的影响。热处理用于改善磁致伸缩性能，并且制得了高磁致伸缩性能的ＳｍＦｅ＿２和（Ｓｍ，Ｄｙ）Ｆｅ＿２合金。     

多孔La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)的制备及表征

多孔Ｌａ０．６Ｓｒ０．４Ｃｏ０．２Ｆｅ０．８Ｏ３－δ陶瓷具有一定的强度、良好的透气和电传导性能,可用于中温 ＳＯＦＣ阴极支撑体和氧分离膜活性支撑体．本文用固相反应法制备了多孔Ｌａ０．６Ｓｒ０．４Ｃｏ０．２Ｆｅ０．８Ｏ３－δ陶瓷．考察了烧结条件、成型压力和有机添加剂量对孔隙率和孔径的影响．研究发现气体渗透率随孔隙率线性增长,电导率随孔隙率的增大而下降,并满足关系式σ＝σ０（１— Ｐ）３．１．     

用甲酸盐／柠檬酸盐制备（Sr_（1－x）Ca_x）TiO_3微粉的研究

本文采用甲酸盐／柠檬酸盐溶液酒精脱水的方法制备出均匀的、结晶的、立方钙钛矿结构的（Ｓｒ１－ｘＣａｘ）ＴｉＯ３微粉．借助于ＸＲＤ、ＳＥＭ、ＴＥＭ及粒度分析等现代分析手段，研究了粉末的相结构、粒度、组成以及微观形态．研究表明，（Ｓｒ１－ｘＣａｘ）ＴｉＯ３粉末的粒径和组成与溶液的ｐＨ值、焙烧温度、酒精与溶液的比例，以及酒精清洗、干燥步骤等因素有关．此外，还考察了粉末的烧结性能．     

La1-xCaxFe1-yCoyO3对氧气还原的催化活性

为了提高燃料电池、金属－空气电池中氧电极的性能,本工作合成了Ｌａ１－ｘＡ′ｘＦｅ１－ｙＣｏｙＯ３（Ａ′＝Ｃａ、Ｓｒ、ＢＡ）,作为氧气还原的催化剂,制成了氧电极,在碱性介质中以Ｈｇ／ＨｇＯ为参比电极测量了电极的极化曲线,考察了组成催化剂的电催化活性和化学稳定性的影响。用ＢＥＴ法测量了催化剂的表面积,发现ｘ＝０．４时,催化剂的比表面积最大,同时电催化性能也最强,本工作表明Ｌａ０．６Ｃａ０．４Ｃｏ０．４     

钙钛矿型复合氧化物LaM_yM_（1－y）~＇O_3的氧化还原性能的研究

用ＴＰＲ、ＸＲＤ和ＸＰＳ手段研究了Ｂ位二元复合钙钛矿型复合氧化物ＬａＭｙＭＯ３（Ｍ、Ｍ’＝Ｍｎ、Ｆｅ、Ｃｏ；ｙ＝０．０～１．０）中过渡金属离子的氧化还原性能和还原过程·ＬａＭｎＯ３和ＬａＣｏＯ３及富Ｍｎ和富Ｃｏ样品的还原分为两步：第一步对应于高价过渡金属离子的还原，且不破坏钙钛矿的骨架结构，但可使晶体的对称性及缺陷浓度发生改变；第二步还原使钙钛矿结构破坏，还原产物中出现单元氧化物和金属单质如Ｌａ２Ｏ３、ＭｎＯ、Ｃｏ．ＬａＦｅＯ３和富铁样品的还原过程比较复杂，温度低于１１２３Ｋ时结构基本保持不变，此温度范围内的还原主要是缺陷浓度的变化和高价金属离子数量的减少，第二种离子的加入及其之间的相互作用对样品的还原温度和氧化还原性能有明显的影响，这种影响的程度与样品的结构有关．Ｍｎ、Ｆｅ、Ｃｏ离子的氧化还原性能的强弱可用如下的反应表示：     

La0.5Y0.5Ni4.8Mn0.1Al0.1和La0.5Y0.5Ni4.8Al0.2合金的储氢性能研究

针对两种新型稀土型储氢合金La0.5Y0.5Ni4.8Mn0.1Al0.1和La0.5Y0.5Ni4.8Al0.2的储氢特性进行研究分析。实验表明,相同温度下,La0.5Y0.5Ni4.8Mn0.1Al0.1和La0.5Y0.5Ni4.8Al0.2合金的PCT曲线基本重合,且都具有优良的吸氢动力学性能;相比之下,后者的滞后系数要小于前者,吸氢量较大,吸氢速率也较快,故其储氢性能较优。300次吸放氢循环实验结果表明,La0.5Y0.5Ni4.8Al0.2合金的吸氢动力学性能虽然略有下降,但抗粉化性能较好。     

Dy0.6Tb0.3Pr0.1(Fe0.95Mn0.05)x取向晶体的结构与磁致伸缩

采用Ｃｚｏｃｈｒａｌｓｋｉ方法生长了Ｄｙ０．６Ｔｂ０．３Ｐｒ０．１（Ｆｅ０．９５Ｍｎ０．０５）ｘ（１．８５≤ｘ≤１．９５）取向合金。所有合金主相为立方Ｌａｖｅｓ相结构,择优取向不完整择优取向的方向与Ｘ的大小有关。研究了沿着这些样品的生长方向的磁致伸缩性能以及磁致伸缩性能与压力之间的关系。     

Thermal Stability of Amorphous Hydride Mg_(50)Ni_(50)H_(54) and Mg_(30)Ni_(70)H_(45)

The thermal stability of amorphous ternary hydrides Mg_(50)Ni_(50)H_(54) and Mg_(30)Ni_(70)H_(45) and their corre-sponding amorphous binary alloys Mg_(50)Ni_(50) and Mg_(30)Ni_(70) were studied with X-ray diffraction(XRD) and differential scanning calorimetry(DSC). Samples of the amorphous alloys were preparedby mechanical alloying and the amorphous hydrides were obtained by charging the alloys with gas-eous hydrogen at 3.0 MPa and 423 K. It was found that the amorphous hydrides released most oftheir hydrogen before the crystallization of the essentially hydrogen depleted amorphous alloy. Thecrystallization temperature of amorphous Mg_(50)Ni_(50)H_(54) elevated and that of amorphousMg_(30)Ni_(70)H_(45) did not change in relation to the original binary amorphous alloy. This is very excep-tional for amorphous hydrides. The reason for the effects of hydrogen absorption/desorption on thecrystallization of amorphous alloys was discussed.     

Plasma surface treatments of poly(l-lactic acid) (PLLA) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV)

The surfaces of poly(l-lactic acid) (PLLA) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) were modified by oxygen and nitrogen plasma treatments. The physical and chemical surface characteristics were evaluated by contact angle tests, scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The plasma treatments caused an increase in both contact angle and roughening, altered the surface morphology, inserted polar groups, and, consequently, enhanced the hydrophilicity for both PLLA and PHBV polymers.     

Nanomechanical characterization of one-step combustion-synthesized Al(4)B(2)O(9) and Al(18)B(4)O(33) nanowires

Two kinds of aluminum borate nanowires, Al(4)B(2)O(9) and Al(18)B(4)O(33), were successfully synthesized by a one-step combustion method through control of the Al:B atomic ratio and synthesis temperature. Both nanowires are single crystalline but have distinguishing growth habits. Nanoindentation tests were performed directly on individual nanowires to reveal their mechanical properties. A 70% reduction in elastic modulus was found in Al(18)B(4)O(33) nanowires compared with their bulk counterpart. Al(18)B(4)O(33) nanowires exhibited higher hardness and elastic modulus than Al(4)B(2)O(9) nanowires.     

非晶态半导体 As_(24)Se_(76)、As_(40)Se_(60)和 As_(50)Se_(50)的光量子效率研究

光量子效率是非晶态光电导材料的一个重要参数。本文利用静电放电的方法,探讨和研究了 As—Se 系统非晶态半导体材料的光量子效率与电场和组份的关系,得出的结果与 Onsager 理论描述的相一致。由分析而得到了等剂量组份、富 As 和富 Se 系统光量子效率的变化趋势。     

Natural Passivity of Amorphous Fe_(40)Ni_(40)P_(14)B_6 and Fe_(54.6)Ni_(38)Si_(4.1)B_(2.3)V_1 Alloys

The natural passive films forrned on Fe_(40)Ni_(40)P_(14)B_6 and Fe_(54.6)Ni_(38)Si_(4.1)B_(2.3)V_1 amorphous alloys long-term exposed in air have been studied by X-ray photoelectron spectroscopy (XPS) and Auger electron (including Ar+ ion depth profiling) spectroscopy (AES). The following aspects have been investigated: (1) chemical states of the elements in the films. binding energies and the chemical shifts measured by XPSf (2) structure and composition of the films fand (3) thickness of the passive films determined by AES depth profiling and XPS analysis.     

Work Functions of Pd_(83.5)Si_(16.5)and Cu_(70)Ti_(30)Glassy Alloys

The work functions before and aftercrystallization of two glassy alloys,Pd_(83.5)Si_(16.5) andCu_(70)Ti_(30) have been measured by means of the con-tact potential difference method in the secondaryelectron field at room temperature under 10~(-5) Pavacuum.The results show that the work functionsof both glassy alloys are higher than those of thecorresponding crystalline alloys.     

An SANS Study of Decomposition Kinetics in Amorphous Cu_(12.5)Ni_(10)Zr_(41)Ti_(14)Be_(22.5)

Phase decomposition in amorphous Cu12.5Ni10Zr411Ti14Be22.5 alloy as annealed in the super-cooled liquid range was studied by applying small angle neutron scattering (SANS). As annealed between 600 K and 700 K, the alloy was observed to decompose into two new amorphous phases,with the second phase precipitates embedded in the matrix of the first. Long time annealing of the alloy results in crystallization in addition to evolution of the decomposed microstructure.The kinetic diagram of the decomposition and crystallization for this alloy is given. The second phase precipitates have several nanometers in size and occupy a quite low volume fraction. The decomposition of the supercooled liquid in overall temperature range exhibits the features of spinodal reaction.