将数学建模思想融入工科“概率统计”教学中

提出‘概率统计”课程的一种教学改革思路,注重理论联系实际,强调应用案例中融入数学建模思想的新的教学法.改革课堂教学方法,探索新的教学模式.加强学生的实践性教学环节,培养学生的应用能力和创新能力.     

Effect of Rotation Rate on the Formation of Platinum-modified Polyaniline Film and Electrocatalytic Oxidation of Methanol

The oxidation of methanol was investigated on platinum-modified polyaniline electrode.Changes in the electrode rotation rates (Ω) during platinum electrodeposition remarkably affect the formation and distribution of platinum in the polymer matrix and consequently lead to different currents of methanol oxidation. The results show that platinum loading is proportional to rotation rates Ω^1/2.     

Thermodynamics of interaction between sodium bis(2‐ethylhexyl) sulfosuccinae and polymers in aqueous solutions by isothermal titration microcalorimetry

The interactions between sodium bis(2‐ethylhexyl) sulfosuccinae (AOT) and two nonionic water‐soluble polymers, including polyvinyl pyrrolidone (PVP) and polyethylene glycol (PEG) have been investigated by using isothermal titration microcalorimetry in aqueous solutions at 298.15 K. The results show that the critical aggregation concentration, which corresponding to the first turning point in the curve of experimental interaction heat versus concentration of the surfactant, is lower than the critical micellar concentration (cmc), confirming the existence of polymer‐surfactant interactions. The value of cac is not sensitive to the relative amount of polymer in low concentration range of the polymer. The mono‐layer saturated adsorption concentration, which corresponding to the second turning point, rises as the polymer concentration is increased. The interaction between PVP and AOT is stronger than that between PEG and AOT. The results also indicate that the aggregation of AOT in water and polymers solutions is entropically driven. The observed thermal effects have been interpreted in terms of the interactions of the polymer molecules with AOT monomers or the molecular clusters. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 275–283, 2006     

+3价离子掺杂钨酸铅晶体发光性能和微观缺陷的研究

通过透射光谱、x射线激发发射光谱（XSL）的测试，研究了Bridgman法生长的几种不同+3价离子掺杂钨酸铅晶体的发光性能，并利用正电子湮没寿命谱（PAT）和x光电子能谱（XPS）的实验手段，对不同钨酸铅晶体的微观缺陷进行研究.实验表明，不同的+3价离子掺杂，对钨酸铅晶体发光性能的改善不同，并使得晶体中正电子俘获中心和低价氧的浓度发生不同变化.其中掺镧晶体的正电子俘获中心和低价氧浓度均上升，而掺钇和掺铋晶体的正电子俘获中心和低价氧浓度均下降，掺锑晶体则出现了正电子俘获中心浓度上升、低价氧浓度下降的情况.提 关键词： 钨酸铅晶体 +3价离子掺杂 正电子湮没寿命谱 x光电子能谱     

Laser beam alignment by fast feedback control of both linear and angular drifts

A new way to enhance the directional stability of laser beams with alternating intensity by fast feedback control of both linear and angular drifts has been proposed for alignment of laser beams at higher accuracy. Both linear and angular drifts of laser beams, processed through light intensity modulation and primary alignment using single-mode optical fiber (SMOF), are separated using light path arrangement and detected using phase-lock technique, and are controlled using fast feedback control mechanisms according to their detected magnitudes, so that both linear and angular drifts are suppressed to enhance the directional stability of the emitting laser beams. Theoretical analyses and preliminary experimental results indicate that the approach proposed can be used to achieve an alignment accuracy of more than 10⁻⁸ rad.     

KINETIC STUDY OF THE OXIDATIVE COUPLING OF METHANE OVER La_2O_3/BaSO_4 CATALYST

IntroductionOxidativccouplingofmethanc(0CM)hasbccnthcsubjcctofmuchintcrcstrcccntl}Man}'mctaloxides,alkali-mctaI-promotcdmctaloxidcs-mixcdmcta1oxidcsandchlorinc-prom0tedmCtuloxidcshavcbecnf0undtobcactivcfor0CMHot` cvcr.thcrcisatprcscntnoclearagreemcntaboutthcmcchanismofthecouplingrcaction.T\`omodclsll1.thcthdeal-rcdoxandthcLangmuir-Hinshtt-oodmcchanisms.havcbccndcvcIopcdtodcscr1bc0CMreation-thecsscntialdiffercnccbctt"ccnthctt"omodclsisthatthclattcrinvolvcsadsorbedmothancasarcactionintcrmcd…     

现场拉曼光谱研究多种铂氧化物还原过程及其对甲醇氧化的影响

采用原位拉曼光谱技术研究方波电位循环氧化还原 (ORC)过程中产生的铂氧化物的还原过程 ,其中过氧化物和超氧化物消失的电位在 0 2V左右 ,晶格氧化物和氧化铂则分别消失在 0V和 -0 2 5V左右。我们还初步探讨了不同还原电位下形成的铂电极表面纳米微粒对甲醇电催化活性的影响     

链球状纯铁磁粉的磁粘滞性

报道了对激光法制备的链球状纯铁超细磁粉磁粘滞性研究结果。结果表明,n个链球段构成反磁化单元,并等效于一个单轴单畴粒子。不同条件下制备的粉体激活体积的变化趋势与磁性针状氧化物相似。 关键词：     

弱于H~1空间的L~2-临界非线性Schrdinger方程的柯西问题

讨论H~s(R~n)(n≥1,1-ε0是一个可以表出的很小的数.主要结论给出了在有限时间破裂解的L~2集中现象.同时,作为推论,得到了小初值解的整体存在性.     

关于G-M成果研究的若干新动态Ⅰ——G-M型空间的若干品种

结合自己的工作，对Gowers-Maurey系列成果获Fields奖以来的研究的新动态作一综述。本是上篇，主要讨论含遗传不可分解空间在内的G－M型空间的若干品种。