Rare earth photoionization study by the resonant microwave cavity technique

Photoconductivity spectra of rare earth-doped insulating materials are measured using the resonant microwave cavity method. This technique is based on the detection of the cavity Q-factor changes induced by irradiation of the sample (inserted in the cavity) by a pulsed tunable laser. Results obtained with Lu₂(SiO₄)O:Ce³⁺ and BaF₂:Eu²⁺ are presented and discussed. Photoionization thresholds at 400 nm (3.1 eV) and 310 nm (4.0 eV) are measured for Lu₂(SiO₄)O:Ce³⁺ and BaF₂:Eu²⁺, respectively.     

易中天《品三国》补正

易中天教授在《品三国》中，把历史唯物主义具体化，提出了评论历史人物和历史事件的三项准则，即：“还原”、“比较”、“分析”。易教授在贯彻这三项原则时也难免有疏漏之处：一、把襄阳、赤壁之战说成曹刘之战不能成立；二、曹操一封信促成孙刘联盟的提法不妥；三、《白衣渡江》引用了《吕蒙传》上有两条错误的史料。     

t—BuNO二聚体在不同溶剂中裂解机理的研究

本文利用＾１ＨＮＭＲ，ＵＶ－Ｖｉｓ方法，研究了ｔ－ＢｕＮＯ二聚体在有机溶剂及水溶液中的裂解反应产物，分析了其反应的动力学，提出了在非极性的有机相中ｔ－ＢｕＮＯ二聚体为均裂反应，而在极性的水相中为均裂和异裂同时进行的竞争反应。     

鲁迅杂文的"个人性"言说

鲁迅杂文的社会性历来为研究者所看重，但我以为真正能够体现鲁迅杂文的历史价值和美学意义的应该是其“个人性”特征。这一特征主要体现在两个方面：强烈的抒情色彩使鲁迅杂文成为诗与政论的结合，坦诚地抒写自我内心世界更带上鲜明的作家主体特征。     

君子不器:当代大学育人目标探析

“君子不器”即君子不像器物，只有一种用途，而要学道得道，因道乃诸器之本。当今社会需要的是体无不备、用无不周的得道君子，即能够以不变的道应对万变的器的通才，而当今大学的育人目标与课程设置大都是为培养成器的专才而设立的，因此，应该调整大学的育人目标，变培养实用型人才为培养通用型人才。通过弘扬我国传统文化的精华，把传统与文艺鉴赏、现代科技知识结合起来，增设新课程，把学生培养成为能终生适应社会发展的有用人才。     

Chelatometric titration of tin in non-ferrous alloys with hedta

A new titrimetric method for determination of tin (4%) in aluminium alloys, tin- and lead-base alloys, solders, white bearing alloys, special bronzes and silver brazing alloys is proposed. HEDTA, Semi-Xylenol Orange and bismuth perchlorate are used as titrant, indicator and back-titrant respectively. Measures are taken to overcome the hydrolysis of Sn(IV). Monochloroacetic acid and ethylene glycol are added as auxiliary agents. The standard deviation of this method was found to be 0.2 mg and its coefficient of variation to vary from 0.25 to 2%, according to amount of tin. A novel method of sample decomposition and a modified method for separating Sn(IV) are also suggested.     

A hydrogen-1, nitrogen-15, and chlorine-35 NMR coordination study of Lu(ClO4)3 and Lu(NO3)3 in aqueous solvent mixtures

A coordination study of Lu(III) has been carried out for the nitrate and perchlorate salts in aqueous mixtures of acetone-d₆ and Freon-12 by¹H,¹⁵N and³⁵Cl NMR spectroscopy. At temperatures lower than –90°C, proton and ligand exchange are slow enough to permit the direct observation of¹H resonance signals for coordinated and free water molecules, leading to an accurate measure of the Lu(III) hydration number. In perchlorate solution, in the absence of inner-shell ion-pairing, Lu(III) exhibits a maximum coordination number of six over the allowable concentration range of study, contrasting markedly with the report of values of six to nine or greater as determined by a similar NMR method. The absence of contact ion-pairing was confirmed by³⁵Cl NMR chemical shift and linewidth measurements. Extensive ion-pairing was observed in the nitrate solutions as reflected by the lower Lu(III) hydration numbers of two to three in these systems, the observation of two coordinated water signals, and¹⁵N NMR signals for two complexes. The¹H and¹⁵N NMR spectra and the hydration number could be accounted for by the presence of (H₂O)₄Lu(NO₃)²⁺ and (H₂O)₂Lu(NO₃) ₂ ¹⁺ .     

试析鲁迅"立人"的理论支点--兼论鲁迅对民主科学的质疑

鲁迅思想和文学的逻辑起点是“立人”,但他以什么“立人”呢?考察鲁迅生平和著作所显现的思想脉络可以看出,他“立人”的理论支点是人的自由存在。鲁迅是以自由存在作为尺度去批判封建思想,解构封建体系的;同时,也以此质疑西方近代文明,审视民主与科学的有限性。自由存在的本原性使鲁迅思想更切近人的本质解放,因而他才成为现代中国最深刻的思想者。     

明朝前期吴与弼的兼采朱陆之学

吴与弼以一位程朱学身份，主要关注的却是心学问题。在他的心学理论中，心既是一个认识主体，又是一个伦理本体。他既认为仁义礼智本具于心中，又认为心之外存在着天命，人有时只能“一听于天”。他的修养方法偏重于“反求于心”，也注意到读书、应接事物一类下达功夫。他在坚持程朱理气学说的同时，又大量吸收陆九渊的心学。他的学说“实能兼采朱陆之长”。他的学说，通过弟子陈献章、再传弟子湛若水影响了王守仁，成为王守仁心学的源泉之一。