In situ AFM study of the growth of banded hedritic structures in thin films of isotactic polystyrene

The growth of banded hedrites of isotactic polystyrene (iPS) is followed in situ, using atomic force microscopy (AFM). The melt layer surrounding the growing hedritic front is much thinner than both the hedrite front and the far-field melt. Growth occurs simultaneously in three dimensions: radially, circumferentially and height. The height of the hedrite growth front being so much higher than the adjacent molten pool, the observed propagation of the front requires that it be covered by a thin film of molten material, likely drawn up the face of the front by capillarity. As the hedritic front grows in height, it demands material at a higher rate than can be delivered from the far-field melt and the stacked lamellae stop growing, layer by layer, from the top downward, until only the basal lamella continues to grow (at a constant velocity). The kinetics of the position of the lowest point ahead of the growth front slows with time during this process. Supplying only the basal layer, the adjacent molten pool is replenished and now begins to feed new layers of growing lamellae as the process repeats itself. The creation of the new lamellar layers appears to be coupled to morphological instability of the basal layer, in the form of growth front serrations, likely causal of the giant screw dislocations.     

幼儿教育新理念影响下的现代幼儿园建筑设计初探

随着社会的发展，经济水平的大幅度提高，幼儿教育也越来越受到家长及社会的关注。幼儿教育开始了一种新的教育理念，幼儿园建筑设计也需要进行创新，以便打破现有的僵化模式，创造一种灵活多变，满足现代幼儿园教育要求的建筑形式。本文针对当前我国幼儿园建筑与现代幼儿园教育理念不相适应的状况，探讨开放式现代幼儿园建筑设计的模式。     

Preparation and application of zeolite beta with super-low SiO<Subscript>2</Subscript>/Al<Subscript>2</Subscript>O<Subscript>3</Subscript> ratio

This paper presents the direct synthesis of super-low SiO₂/Al₂O₃ ratio zeolite beta molecular sieve through a novel route, by which some of aluminium species are added during crystaling process. The IR results show that with the increase of aluminium content in the framework, the frequency of the band in the range of framework vibration (1060–1090 cm⁻¹) shifts to the lower wave-number; the BET surface-area decreases and the basicity of zeolite becomes stronger. In a second step, new adsorbents were obtained by solid-state ion exchanging zeolite beta with Cu(I), Ag(I) cations. The deep-desulfurization (sulfur levels of <1 ppmw) tests were performed using fixed-bed adsorption technique, the sulfur content of the treated and untreated gasoline was analyzed by microcoulometry. The experimental results show that the desulfurization performance of sorbents decreases in order: Cu(I)beta > Ag(I)beta > Na-beta. The best sorbent, Cu(I)beta, has breakthrough adsorption capacities of 0.236 mmolS/g of sorbent for model gasoline.     

合成氨装置除尘新技术的探讨和应用

介绍了合成氨装置废气中含水粉尘分离新技术和使用效果 ,以及在气固分离领域推广应用的价值     

悬挑结构坍塌的原因及其对策

目前,在新建房屋及旧房改造中,有关悬挑结构倾覆、坍塌的事故时有发生,从悬挑结构坍塌实例来看,表现为三种形式:整体倾覆坍塌、沿悬臂梁根部的断塌及悬挑构件下砌体局部受压破坏.本文从设计、施工及使用角度系统地分析了悬挑结构坍塌事故发生的原因,如采用不正确的计算方法、模板支撑方案不当、施工超载、拆模过早、不正确地使用等,并对这些原因提出了切实可行的防治措施和处理方法.     

大型电站锅炉大板梁CAD系统

介绍了哈尔滨锅炉厂有限责任公司在 Ａｕｔｏ Ｃ Ａ Ｄ支持系统上研制开发的大板梁施工图 Ｃ Ａ Ｄ系统，实现了大板梁施工图的参数化设计、零件清单和材料定额汇总表的编制，并能自动生成用于整台锅炉材料汇总的接口文件。     

The study of diffraction radiation oscillation

Theoretical and experimental study of Diffraction Radiation Oscillator (DRO) is reported in this paper, it is the first work done in P. R. China. The sphere-cylindrical open cavity used in the DRO has been analysed, the method for testing the field profile and the cold measurement of the open cavity have been worked out. The experimental device was manufactured in our lab. and the theoretical analysis and experimental study of the device have been carried out. The main experimental results are: from 2000 V to 4000 V, the tube operates in the 60–87 GHz band, and the maximum output power is about 800 mW.     

High step-up converter with coupled-inductor

In this study, a high step-up converter with a coupled-inductor is investigated. In the proposed strategy, a coupled inductor with a lower-voltage-rated switch is used for raising the voltage gain (whether the switch is turned on or turned off). Moreover, a passive regenerative snubber is utilized for absorbing the energy of stray inductance so that the switch duty cycle can be operated under a wide range, and the related voltage gain is higher than other coupled-inductor-based converters. In addition, all devices in this scheme also have voltage-clamped properties and their voltage stresses are relatively smaller than the output voltage. Thus, it can select low-voltage low-conduction-loss devices, and there are no reverse-recovery currents within the diodes in this circuit. Furthermore, the closed-loop control methodology is utilized in the proposed scheme to overcome the voltage drift problem of the power source under the load variations. As a result, the proposed converter topology can promote the voltage gain of a conventional boost converter with a single inductor, and deal with the problem of the leakage inductor and demagnetization of transformer for a coupled-inductor-based converter. Some experimental results via examples of a proton exchange membrane fuel cell (PEMFC) power source and a traditional battery are given to demonstrate the effectiveness of the proposed power conversion strategy.     

一种适用于复合制导的中末制导弹道交接班方法

导弹武器系统的发展趋势是由单一制导模式向复合制导过渡,而中末制导的可靠交接班是复合制导的关键步骤。针对复合制导中的中末制导弹道交接班问题,在分析中末制导弹道平滑过渡约束条件的基础上,提出了一种简单有效的线性中末制导交接班算子,详细计算了平滑算子的加权系数。通过直升机载空地导弹的中末制导弹道交接班的仿真试验,验证所提方法的可行性。试验结果表明,在较小中末制导律差异条件下,所提算子可实现弹道的平滑过渡和良好衔接。