各国动态

1992年世界塑料材料产量1992年世界塑料总产量达到9989.7万吨,比1991年世界塑料材料总产9951.7,万吨增长0.4%。1992年英国塑料材料总产量3000万吨(推算值)比1991年增长5.3%。1992年日本塑料材料总产量1279.6.万吨,比1991年下降1.7%。     

日本第一台商用多种固体流化床（MSFB）锅炉的设计和运行经验

0 引言近年来,在日本营造燃用低质固体燃料的锅炉日益增多,其中主要集中在循环流化床(CFB)锅炉上,这是因为它具有:1)广泛的燃料适应性;2)低的 NO_x 和 SO_2 污染排放。1986年三井公司建造了日本第一台商用 MSFB 锅炉,它被用作 Kuraray 化纤公司的自备动力装置。在此锅炉的设计与运行之前,作者利用试验装置研究了 MSFB 密相床的特性,以保证其性能和运行稳定性。此外,作者还研究了 MSFB 中所采用的固体循环系统在增加燃烧稳定     

对小学教学资源平台建设的探究

教学资源作为教学过程中的关键点,资源平台的建设显得尤为重要,本文旨在对小学教学资源平台的建设以及研究意义做出讨论。     

REACTIVE DIFFUSION BETWEEN Si AND NbC AT 1300℃

ＲＥＡＣＴＩＶＥＤＩＦＦＵＳＩＯＮＢＥＴＷＥＥＮＳｉＡＮＤＮｂＣＡＴ１３００℃Ｃ．Ｒ．Ｋａｏ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｃａｌＥｎｇｉｎｅｅｒｉｎｇＮａｔｉｏｎａｌＣｅｎｔｒａｌＵｎｉｖｅｒｓｉｔｙＣｈｕｎｇＬｉ，Ｔａｉｗａｎ）Ｊ．Ｗｏｏｄｆ...     

淬火条件对变截面圆柱体裂纹的影响

前言为了防止淬火裂纹和变形,普遍采用分级淬火和延迟淬火。分级淬火是将奥氏体化后的试样,先浸入到稍高于上马氏体点(马氏体开始转变点)的淬火液中等温停留一段适当时间,然后取出空冷,以获得马氏体组织的淬火方法。延迟淬火是将奥氏体化温度的试样从加热炉中取出,先在空气中停留一定时间,然后再进行淬火。     

SD—1型高刚度无牌坊三辊机的研究

介绍了一咱新型的高刚度三辊轧机，该轧机具有刚度高、调整性能好及稳定性高等特点。用这种轧机生产的产品不仅精度得到改善，而且轧机成材率、作业率高，并具有节能效果。     

基于遗传算法改进后的新常德动态交通路网分析

2013年来,常德政府实施了全城的三改四化工作,工作至今仍在继续,全城人民从当初的不理解不支持,到今天给予的高度肯定,足以说明了三改四化工作给常德城市建设带来了若干变化:城市变漂亮了,道路变开阔了,交通拥堵缓解了……阐述了三改四化后常德动态路网模型改进遗传算法的研究基础上,进行仿真实验分析,进一步探讨改进后的遗传算法在动态交通路网中的应用优化情况.     

MOTO选择做非凡的自我

2013年因为种种原因MOTO选择退出中国市场,从此淡出了人们的眼球。曾经风生水起的手机巨头瞬间消失,殊不知MOTO的离开是迫不得已。当时有句话是:"离开是为了更好的回来!"。虽然离开了中国市场近两年,但是期间MOTO凭借着倾力打造的第一代Moto X、Moto G、Moto Droid系列及Moto E在北美,在巴西、在欧洲、在印度依然风光无限。     

Spatial and functional relationships between air conduits and blood capillaries in the pulmonary gas exchange tissue of adult and developing chickens

The documented data regarding the three-dimensional structure of the air capillaries (ACs), the ultimate sites of gas exchange in the avian lung is contradictory. Further, the mode of gas exchange, described as cross-current has not been clearly elucidated. We studied the temporal and spatial arrangement of the terminal air conduits of the chicken lung and their relationship with the blood capillaries (BCs) in embryos as well as the definitive architecture in adults. Several visualization techniques that included corrosion casting, light microscopy as well as scanning and transmission electron microscopy were used. Two to six infundibulae extend from each atrium and give rise to numerous ACs that spread centrifugally. Majority of the ACs are tubular structures that give off branches, which anastomose with their neighboring cognates. Some ACs have globular shapes and a few are blind-ending tapering tubes. During inauguration, the luminal aspects of the ACs are characterized by numerous microvillus-like microplicae, which are formed during the complex processes of cell attenuation and canalization of the ACs. The parabronchial exchange BCs, initially inaugurated as disorganized meshworks, are reoriented via pillar formation to lie predominantly orthogonal to the long axes of the ACs. The remodeling of the retiform meshworks by intussusceptive angiogenesis essentially accomplishes a cross-current system at the gas exchange interface in the adults, where BCs form ring-like patterns around the ACs, thus establishing a cross-current system. Our findings clarify the mode of gas exchange in the parabronchial mantle and illuminate the basis for the functional efficiency of the avian lung.     

西班牙灌溉现代化对水质和水量的影响研究

以西班牙埃布罗（Ebro）河流域为例,分析了灌溉现代化过程对水量和水质的影响,旨在对优化农业用水进行深入分析和讨论,研究过程使用了基于水量核算的概念性方法。结果表明,如果灌区的位置和灌溉回流水质允许再次使用回流水,则灌溉现代化仍涉及耗水量增加的问题。另外,灌溉现代化减少了灌溉回流的水量和污染物的含量,提高了接收水体的水质。水管理现代化是使新的灌溉基础设施所产生的经济、社会和环境效益最大化的需要。