256比特的混沌分组密码

由于密码分析研究的进展及DES自身的弱点,原64比特的DES将不能作为数据加密的标准算法而长期存在。在原来工作的基础上,本文提出了256比特的分组密码方案。密码算法由基于混沌映射的数字滤波器构造。     

The determinants of heat-shock element-directed lacZ expression in Saccharomyces cerevisiae.

Heat-shock induction of heat-shock protein genes is due to a specific promoter element (the heat-shock element, HSE). This study used lacZ under HSE control (HSE-lacZ) to characterize HSE activity in Saccharomyces cerevisiae cells of different physiological states and differing genetic backgrounds. In batch fermentations HSE-lacZ induction by heat shock was maximal in exponential growth, and showed marked decline with the approach to stationary phase. Expression in the absence of heat shock was unaffected by growth phase, indicating that the growth-dependent expression of many yeast heat-shock genes uses promoter elements in addition to the HSE. Heat-induced expression was strongly influenced by the temperature at which cultures were grown. While basal, uninduced expression was constant during growth at different temperatures to 30 degrees C, induction by transfer to 39 degrees C was reduced by increases in growth temperature as low as 18-24 degrees C. Maximal HSE-lacZ induction (30- to 50-fold) was in cultures grown at low temperatures (18-24 degrees C), then heat shocked at 39 degrees C. Ethanol was a poor inducer. Mutations having little effect on HSE-lacZ expression included a respiratory petite; ubi4 (which inactivates the poly-ubiquitin gene); also ubc4 and ubc5 (which each inactivate one of the ubiquitin ligases involved in degradation of aberrant protein). pep4-3 increased both basal and induced beta-galactosidase about two-fold, probably because of slower turnover of this enzyme in pep4-3 strains.     

中国第一口超千米深水钻井液技术

LW3-1-1探井位于中国南海珠江口盆地，作业水深1480m，完钻井深为3843m，地层以大套灰色泥岩和页岩为主，具有强水敏性．要求钻井液具有良好的流变性、润滑性、抑制性，良好的抗盐、抗钙、抗高温和抗低温能力，以及强的天然气水合物抑制能力。该井采用了PFMX钻井液体系，钻井周期为49d，介绍了钻井液工艺及现场应用情况。PFMX体系表现出很多油基钻井液的优点，如好的润滑性、高的钻进速率、膜效应、强的井眼稳定及页岩抑制性，解决了强水敏性地层的井壁稳定等问题，还解决了深水钻井中遇到的挑战，如低的破裂压力梯度、天然气永合物、浅层水流、深水低温等问题，满足了该区块作业需要。     

电解铝侧插自焙槽技术改造与环境保护

电解铝侧插自焙槽属于落后的生产工艺，由于其能耗高、物料消耗大、劳动强度大、环境污染严重，在国内电解铝中已开始进行大规模的淘汰改造。采用先进的预焙电解槽生产技术，降耗节能、改善生产劳动强度，环境污染得到有效治理，各项环境指标达标排放，经济技术指标提高，食业面貌发生了巨大大变化。     

Factors Affecting 1-Octen-3-ol in Mushrooms at Harvest and During Postharvest Storage

Harvesting experiments revealed that immature whole mushrooms with closed veils had higher 1-octen-3-0l levels than more mature whole mushrooms with open veils. The l-octen-3-01 content of the gills was higher in immature mushrooms with closed veils, gradually decreased with maturity as the veil opened, and finally increased after the gills were well exposed. Postharvest experiments demonstrated that storage temperature influenced the activity of lipoxygenase-hydroperoxide lyase, but no differences in 1-octen-3-01 content were observed. Enzyme activity as well as 1-octen-3-01 content decreased during storage. Addition of calcium chloride to irrigation water, employed to improve quality and shelf life of fresh mushrooms, increased the amount of l-octen-3-01 immediately after harvest.     

铸轧5052合金冷隔缺陷产生的机理研究

阐述了5052合金铸轧坯料生产时冷隔缺陷产生的机理,结合超型FATA—HUNTERΦ1003×1850mm机多年的生产实践经验,提出了消除铸轧冷隔缺陷的措施。     

矿区复杂地质条件下隧洞围岩塌方处理

主要介绍金堆城东川河改道工程隧洞施工过程中出现的一次较大塌方治理，塌方体松散并含孤石，传统方法无法处理，根据塌方体的特点，有针对性地采取自钻式锚杆、固结灌浆等施工工艺，并获得成功；对隧洞衬砌、地表陷坑进行了处理，确保了工程安全、质量。同时根据矿区隧洞围岩复杂多变的特点，对后期隧洞施工提出了建议。     

冷轧带肋钢筋现浇混凝土板开裂现象研究及探讨

本文总结了冷轧带肋钢筋在福州地区的应用情况,对现浇砼板裂缝现象进行现场调查,并探究其裂缝发生的机理,最后对高强带肋钢筋在砼楼板中的应用前景提出有益的建议和展望     

非规则分布相同结构的零件的计算机三维造型方法研究

这里根据轮盘、板类等常用机械零件一般含有规则和非规则分布的相同结构的特点，总结出应用功能强大的Solid Works软件进行该类零件三雏设计的多种实用方法，给出了含有非规则分布的相同结构零件的快速设计方法，并分析了各种方法的应用场合。     

西门子S7-200可编程控制器在气化油点火技术中的应用

以西门子S7—200PLC为核心。利用火检探头。温度、压力等传感器，结合STEP 7 MicmwIN V3．1以及ProTool Pro CS工业组态软件完成了对点火过程的自动控制。实现了西门子S7—200PLC在大型发电厂410吨级蒸汽锅炉“气化油直接点燃煤粉技术”中的应用。提高了锅炉点火系统运行的自动化水平。