Zr基块体非晶合金在过冷液相区的超塑性流变行为

研究了Zr41.25Ti13.75Ni10Cul2．5Be22.5(原子分数,%)块体非晶合金在玻璃转变终了温度Tg^end附近的4个特征温度点(616,636,656和676K)的等温拉伸行为．结果表明,块体非晶合金的超塑性能与环境温度及拉伸速度紧密相关．在656K,以5mm／min的速度拉伸时,获得了1625％的最大延伸率利用速度突变法测出了636,656及676K时的应力敏感指数分别为0．25,0．65和0．93．利用自由体积模型对块体非晶合金的超塑性流变行为的微观机制进行了分析．     

冲槽机冲槽错位原因分析与改善

文章通过介绍冲槽机冲孔原理和分析冲槽模具间隙对冲孔断面的影响，针对对位错品质报废率上升的原因分析采取冲槽模具设备改造措施，完成品质改善，为公司制作高难度板内层对位缺陷改善和控制起到了关键作用；同时，设备改造技术推广直接产生巨额经济节余。     

Control of grapevine powdery mildew with mineral oil: an assessment of oil concentration and spray volume

DC Tron, a highly refined mineral oil containing patented additives to prevent UV light induced breakdown, was evaluated in vineyards for control of powdery mildew. DC Tron suppressed development of powdery mildew but was not as effective as the conventional fungicide Topas. Of the oil treatments the 1% rate applied in spray volumes of 1000 L/ha was the most efficient. Poor control was achieved with oil rates less than 1% as well as spray volumes less than 1000 L/ha whereas phytotoxicity developed in many cases at concentrations greater than 1% or spray volumes higher than 1000 L/ha. In all oil treatments, powdery mildew developed less in leaves than on bunches. This difference was attributed to poor spray coverage on bunches compared to leaves.     

Adaptable Splatting for Irregular Volume Rendering

By employment of a footprint table in conducting intensity integration, splatting method has been very successful in rendering regular data volumes. Recently, the method has also been extended to render irregular data volumes. However, since samples in irregular volumes vary greatly in size and shape, the footprint table is unable to be employed in an efficient manner. This hinders the application of splatting approach from being used in the irregular volume case. In this paper, an adaptable splatting method is proposed, which provides an efficient way to integrate color intensity in terms of footprint table for the samples in various sizes. Experiments show that the new method may be used to produce better images without extra expense.     

Critical superparamagnetic/single-domain grain sizes in interacting magnetite particles: implications for magnetosome crystals

Magnetotactic bacteria contain chains of magnetically interacting crystals (magnetosome crystals), which they use for navigation (magnetotaxis). To improve magnetotaxis efficiency, the magnetosome crystals (usually magnetite or greigite in composition) should be magnetically stable single-domain (SSD) particles. Smaller single-domain particles become magnetically unstable owing to thermal fluctuations and are termed superparamagnetic (SP). Previous calculations for the SSD/SP threshold size or blocking volume did not include the contribution of magnetic interactions. In this study, the blocking volume has been calculated as a function of grain elongation and separation for chains of identical magnetite grains. The inclusion of magnetic interactions was found to decrease the blocking volume, thereby increasing the range of SSD behaviour. Combining the results with previously published calculations for the SSD to multidomain threshold size in chains of magnetite reveals that interactions significantly increase the SSD range. We argue that chains of interacting magnetosome crystals found in magnetotactic bacteria have used this effect to improve magnetotaxis.     

焦炭塔基础混凝土裂缝控制技术

焦炭塔类大型设备基础在施工过程中要求混凝土一次成型，不得留置施工缝，因此混凝土一次浇筑量较大，这种大体积混凝土的浇筑极易出现裂缝，如果不加以控制，会产生严重的隐患。文章对焦炭塔基础混凝土水化热的计算和大体积混凝土施工中的主要技术难点进行了简要的阐述．提出了混凝土配合比设计、材料选用，以及混凝土浇筑、降温及测温养护的一些可供借鉴的方法。     

尼龙梭坯注塑过程中的常见问题及探讨

简介尼龙梭坯注射成型前的物料准备,重点探讨了尼龙梭坯的成型工艺、注塑过程中常见的问题及影响因素,以及尼龙梭坯生产过程中的关键因素控制。按选定的工艺生产尼龙梭坯的合格率达95%以上,上机试验表明,尼龙梭的寿命达60d以上。     

非地层因素井下漏失原因分析及对策

钻井施工中发生井漏的原因是多方面的，主要有两大因素：一是地层原因，如存在溶洞，裂缝等。二是钻井工艺措施方面存在问题，如开泵过猛憋漏地层等，地层本身造成井漏的原因是客观存在的，这里不予分析，而开泵不畅是钻井工作者经常遇到的复杂情况之一，文中从环空间隙，排量，钻井液性能，地层的承压能力等方面入手，对一口因憋漏地层造成起套管的井井漏的原因进行计算，分析，并与其它2口井对比，提出预防和处理“主观井漏”的办法。     

浅谈烟煤胶质层指数测定及工作经验

天津第三煤气厂中化室胶质层测定采用先进的微机Ｐ．Ｉ．Ｄ参数控温调节技术，依照ＧＢ４７９要求，我们强化其测定的技术和技巧性，通过大量的试验研究，提高了试验结果的准确性和可比性，有力地服务了本厂生产。     

Density and viscosity of linear perfluoropolyethers under high pressures

New experimental data on the density and viscosity of linear, unbranched perfluoropolyethers are presented at temperatures from 273 to 333 K and pressures up to 180 MPa. The measurements were carried out by a high-pressure burrette apparatus and a falling-cylinder viscometer. The uncertainties of the measurements are estimated to be less than 0.09% for the specific volume and 2.5% for the viscosity. The P-V data at each temperature are correlated satisfactorily by the Tait equation. The viscosity data are also analyzed and correlated with pressure or molar volume by several empirical and theoretical equations.