三星技术创新的经验及启示

曾经在世界品牌价值排行榜上找不到身影的三星电子,只用短短几年时间就跃居到全球品牌前20名,是什么力量改变这一切?答案可以从三星的技术创新里找到,从三星的技术创新动因以及三星如何进行技术创新加以剖析,最后阐述三星的技术创新对我国企业的启示。     

弹性支承隔振可行性准则探讨

综合论述了利用弹性支承进行隔振的可行性,采用惯性平衡振幅的概念,建立了隔振可行性准则——平衡指标;并将平衡指标和国际标准ISO. No1940中规定的振动烈度建立了直接数值关系,可为振动控制中的隔振设计标准提供参考。     

一相能量型stefan问题

本文讨论了一相能量型stefan问题.首先利用迭代方法及紧性讨论证明了古典解的存在性;其次给出了解的比较原理,由此证明了解的唯一性。     

本地电信网综合计费系统模型探讨

针对我国目前电信网计费管理上存在的问题，详细剖析了国际计费系统的发展趋势，提出了本地电信网综合计资系统模型。该模型克服了人工、分散的计资系统的缺点，具有集中、综合和实时的优点．该系统模型的提出完善了ＣＳＳ（用户服务系统）功能结构，有利于电信管理网的建设。     

增加XENIX系统屏幕编辑命令的文件加密功能

本文叙述了一种在XENIX系统中为屏幕编辑命令增加文件加密功能的实现方法及途径。     

Stereoselectivity in mammalian chemical communication: Male mouse pheromones

Two male mouse pheromones, 3,4-dehydro-exo-brevicomin (DHB) and 2-sec-butyldihydrothiazole (SBT), are chiral molecules which were previously tested in their respective bioasays as racemic mixtures. The focus of this study has been to determine the absolute configuration of their natural forms and its relation to stereospecific biological action. DHB was established as the R,R-enantiomer possessing biological activity. Due to an extremely easy racemization of SBT under very mild conditions, enantioselectivity of its transmission and its action at the receptor site appear to be of secondary importance.     

精细小件化学热处理滚筒炉的研制

研制了适于精细小零件大批量化学热处理的滚筒炉,有效地解决了薄片状小零件在其它类型炉中散料处理时,由于零件相互堆叠、不能更位而导致加热和与活性气氛接触不均匀所带来的质量问题。为照相机、仪表、标准件等行业提供了一种新型工艺装备。     

New evidence on the earliest human presence at high northern latitudes in northeast Asia

The timing of early human dispersal to Asia is a central issue in the study of human evolution. Excavations in predominantly lacustrine sediments at Majuangou, Nihewan basin, north China, uncovered four layers of indisputable hominin stone tools. Here we report magnetostratigraphic results that constrain the age of the four artefact layers to an interval of nearly 340,000 yr between the Olduvai subchron and the Cobb Mountain event. The lowest layer, about 1.66 million years old (Myr), provides the oldest record of stone-tool processing of animal tissues in east Asia. The highest layer, at about 1.32 Myr, correlates with the stone tool layer at Xiaochangliang, previously considered the oldest archaeological site in this region. The findings at Majuangou indicate that the oldest known human presence in northeast Asia at 40 degrees N is only slightly younger than that in western Asia. This result implies that a long yet rapid migration from Africa, possibly initiated during a phase of warm climate, enabled early human populations to inhabit northern latitudes of east Asia over a prolonged period.     

GCC box in<Emphasis Type="Italic">Arabidopsis PDF1.2</Emphasis> promoter is an essential and sufficient cis-acting element in response to MeJA treatment

The expression of Arabidopsis PDF1.2 gene isregulated by jasmonic acid (JA) and ethylene (ET). It also has been well documented that GCC box is an element responsive to ET, however, the responsive mechanism of JA in such plant defense gene expression is unclear. In this paper, the authors define the essential cis-acting element in PDF1.2 promoter responsive to methyl jasmonate (MeJA) through fragment deletions and site-directed mutageneses combiningAgrobacterium-mediated transient reporter gene expression in tobacco leaves. Firstly, the MeJA inducible expression o fPDF1.2 was confirmed by using the upstream -1.86 kb fragment of PDFI.2 gene. Secondly, the upstream -300— -243 bp fragment of the promoter was evidenced to respond to MeJA. To further characterize this promoter region, three point mutations were introduced into the -300— -243 bp fragment of the promoter. This result showed that the mutation of GCC box abolished MeJA induction, whereas the mutations of the G box-like and the imperfect palindrome sequence did not significantly decrease MeJA inducible effect, indicating that GCC box in PDFI.2 is essential for MeJA induction. The sufficient responsiveness to MeJA of this GCC box was further investigated by 4xGCC fused upstream to the CaMV 35S minimal promoter. This result suggested that the fused promoter was able to activate reporter gene expression in response to MeJA. Thus these results indicate that the GCC box in PDFI.2 is an essential and sufficient element to confer MeJA induction.     

Infectious foot-and-mouth disease virus derived from a cloned full-length cDNA of OH／CHA／99

The China foot-and-mouth virus (FMDV) isolate OH/CHA/99 was isolated from swine, which was unable to infect bovine thyroid cells in vitro or to cause typical disease in bovines following intradermal inoculation in the tongue. To enhance antigenicity, replication, maturation and pathogenicity studies of OH/CHA/99, an infectious fulllength cDNA clone, designated pBIFMDV, was prepared. The in vitro and in vivo biological properties of the virus derived from pBIFMDV were studied by analyzing antigenicity, plaque morphology and virulence in pigs. The results showed that the virus derived from pBIFMDV had the same biological properties as the parent strain OH/CHA/99; the fulllength infections cDNA clone, pBIFMDV, will be very useful in studies of the antigenicity, virulence, pathogenesis, maturation and replication of FMDV.