不断创新管理机制努力做好学生工作

当我国的素质教育在知识经济崛起的世纪之交迅猛推进的时候,"如何才能全面有效地提高大学生的素质"就成为了教育者执着探询的重要课题.多年的教育实践使我们深深地认识到,全面推进素质教育就必须要坚持与时俱进,不断创新管理机制.具体来讲,就是要实施四个创新:     

在Fe-Al-C系统中合成优质Ⅱa型宝石级金刚石单晶

和优质Ib型宝石级金刚石单晶生长相比，作为当今高温高压晶体生长的一种高精尖技术，优质1／a型宝石级金刚石单晶对合成技术提出了更高更苛刻的要求：枢研究从晶体的生长速度出发，发现一开始阶段（大约几个小时）的晶体生长速度对优质宝石级金刚石单晶的后期生长争关重要。埘Fe-Al-C系统（Al含量不大于2．5wt％）来说，采用多品种法将晶体开始阶段的晶体生长速度由1．5mg／h降至0．5mg／h后，对生长过程中金属包裹体的进入有了明显的抑制作用，晶体的质量有了很大提高。从晶体中包裹体的存任形式来看，为了获得优质Ⅱa型宝石级金刚石单晶，在触媒中人为地添加除氮剂给晶体生长过程中的排杂过程带来了很大的难度：为了更好的实现排杂，必须很好的处理晶体表面的径向平铺生长速度和晶体轴向的堆积生长速度之间的火系。     

氰化氢在终冷塔中气液两相之间转移的研究

分析了煤气中氰化氢的形成,论述了氰化氢在煤气和其冷凝液中的平衡机理,讨论了影响氰化氢相平衡的因素,研究了直接终冷、间接终冷时煤气中氰化氢的转移情况。     

陶瓷坯体增强剂聚丙烯酸钠在艺术瓷成形过程的应用

本文合成了一系列不同相对分子质量的聚丙烯酸钠,应用于艺术瓷的坯体中,研究了聚丙烯酸钠对艺术瓷坯体强度、变形率的影响,并对聚丙烯酸钠增强机理进行了探讨。结果表明:聚丙烯酸钠可有效地提高艺术瓷坯体的成形强度,减少了坯体的变形率,当增强剂c加入的质量分数为0.6%时,坯体的干燥强度增加率达167.5%,坯体的变形率从50%降低到10%。     

A novel spherical-ordered macroporous CuO nanocatalyst for the electrochemical reduction of carbon dioxide

Journal of Applied Electrochemistry - The electrocatalytic reduction of CO2 is a promising research direction in resource utilization and sustainable energy development. However, there is still a...     

Evaluation of Localization Attacks on Power-Modulated Challenge–Response Systems

Location information should be verifiable in order to support new computing and information services. In this paper, we adapt the classical challenge-response method for authentication to the task of verifying an entity's location. Our scheme utilizes a collection of transmitters, and adapts the power allocations across these transmitters to verify a user's claimed location. This strategy, which we call a power-modulated challenge response, is able to be used with existing. wireless sensor networks. First, we propose a direct method, where some transmitters are selected to send ldquochallengesrdquo that the claimant node should be able to witness based on its claimed location, and for which the claimant node must correctly respond to in order to prove its location. Second, we reverse the strategy by presenting an indirect method, where some transmitters send challenges that the claimant node should not be able to witness. Then, we present a signal-strength-based method, where the node responds with its received signal strength and thereby provides improved location verification. To evaluate our schemes, we examine different adversarial models for the claimant, and characterize the performance of our power-modulated challenge response schemes under these adversarial models. Further, we propose a new localization attack, where a set of nodes collaborates to pretend that there is a node at the claimed location. This collusion attack can do tremendous harm to localization and the performance of the aforementined methods under collusion attack are explained. Finally, we propose the use of a rotational directional power-modulated challenge response, where directional antennas are used to defend against collusion attacks.     

Determination of the modified effect of nano-SiO2 by titration in nonaqueous phase

The dispersion of nanosilica that was modified and original in organic solvents could be judged directly by using methyl red as the indicator, and the principle of color development was also discussed. A method has been developed for the determination of the acidity of solid surfaces, which consists of titration of the solid suspended in benzene with n-butyl amine, using neutral red as the indicator. Basic indicator forms a red color on acidic solids, and the end-point of the titration is the disappearance of the red color. The text was submitted by the authors in English.     

Influence of interfacial strength on the fracture toughness of glass-ceramic matrix composites

Nine kinds of glass-ceramic matrix composites with different compositions and interfacial strength (τ _s) were prepared. The influence of τ _s on the fracture toughness(K _1c) of composites was studied. It was discoved that, for the system no chemical reaction taking place at the interface, K _1c increased proportionally with τ _s increasing at the first stage, then decreased when τ _s reached a certain value. According to this result, a model of relationship between τ _s, thermal mismatch (Δα _r) and K _1c was built up. If a chemical reaction took place and a new phase was formed in the interface, the K _1c of composite was effected by the combination of τ _s, chemical bonding, radial interfacial stress and other factors. Project supported by the National Natural Science Foundation of China Synopsis of the first author Wang Lingsen, professor, born in 1938, current research field: special ceramic and ceramic matrix composite, etc.     

Curvilinear lattice in chiral carbon nanotubes

In this paper, the energy bands of chiral-type single-walled carbon nanotubes are studied employing a new curvilinear lattice theory and its reciprocal lattice aided by the spherical triangle theory. In this theory, the notion of a distance law is introduced as a constraint to determine the electronic characteristics of carbon nanotubes. The chiral tubes are proven to be semiconducting or metallic, depending on the diameters and helical angles of the tubes. The distance law also predicts an uncertainty for the electronic characteristics of chiral tubes due to the metallic states tightly surrounding the semiconducting states on the direct lattice, and vice versa. Results predicted by the distance law agree well with theoretical calculations of the electron density of states and published measurements.     

吉林延边金谷山金矿床地球化学特征

以金谷山金矿床的成矿地质特征为基础, 研究了区域地球化学场及异常特征、岩(矿)石微量元素地球化学特征.矿床位于金及其它成矿元素的高背景场中,与成矿有关的元素组合为Au-Sb-As,异常强度高,分带性明显;地层、岩浆岩、构造等地质单元的地球化学特征表明,成岩作用、构造作用与成矿作用关系密切.