聚氨酯张力筛板的研制和应用

介绍了以聚酯多元醇为原料制作聚氨酯张力筛板的工艺过程 ,讨论了聚酯分子量、NCO%含量、NH2 /NCO比对聚氨酯弹性体性能的影响 ,从而确定了聚氨酯张力筛板的配方及工艺条件     

B-Si及无胺型Fe-Si-ZSM-5沸石合成规律的研究

用几种伯胺及TEA,TMA为模板剂合成了B-Si-ZSM-5沸石。在不使用有机胺等模板剂的前提下,用加入晶种的方法合成了Fe-Si-ZSM-5沸石。讨论了制备上述沸石的水热合成条件,用X射线衍射、红外光谱、热分析、B.E.T.等手段研究了它们的一些物理化学性质。     

高偏压Al-MgF_2-Au(Cu)隧道结的结构、导电和发光

本文对我们所发明的Al-MgF_2-Au(Cu)薄膜发光器件[1]的内层结构、导电过程和发光机理做了进一步的研究,对以前报导的一些结论作了原则性的修正:前所报导的Al-MgF_2-Au结内层的实际结构是Al-Al_2O_3-MgF_2-Au,而不仅仅是Al-MgF_2-Au;且正是由于Al_2O_3膜的存在,方才使MgF_2膜得以具有绝缘作用。是来之负电极的隧穿电子,而不是MgF_2膜内的热电子,导致了该结的导电和发光。据此,本文对该结在高偏压下的logL∝V的新型伏安特性曲线及其发射光谱中位于3.4ev(3600)附近的截止频率给出了理论解释;从而得出:电子隧穿,激发SPP,然后SPP退激发光的这一物理过程,即使在Al、Au两电极间的绝缘层厚度由3μm左右增加到20μm左右时,也可依然存在。     

WNT7b mediates macrophage-induced programmed cell death in patterning of the vasculature

Macrophages have a critical role in inflammatory and immune responses through their ability to recognize and engulf apoptotic cells. Here we show that macrophages initiate a cell-death programme in target cells by activating the canonical WNT pathway. We show in mice that macrophage WNT7b is a short-range paracrine signal required for WNT-pathway responses and programmed cell death in the vascular endothelial cells of the temporary hyaloid vessels of the developing eye. These findings indicate that macrophages can use WNT ligands to influence cell-fate decisions--including cell death--in adjacent cells, and raise the possibility that they do so in many different cellular contexts.     

基于关联规则的日志分析系统的设计与实现

网上广告势必成为中国广告业不可取代的部分,广告人总是期望广告能获得最好的效果.为此,本文设计并实现了一个基于关联规则数据挖掘的日志分析系统,数据挖掘引擎在实现过程中针对挖掘数据的特点对Apriori算法进行了改进,并通过仿真数据库对挖掘结果进行了验证,日志分析系统获得的"知识"可以直接用于改善Web的信息服务.     

Breakdown of lawsonite subsequent to peak UHP metamorphism in the Dabie terrane and its implication for fluid activity

Abundant occurrences of quartz vein within eclogites in the Dabie-Sulu orogen provide us an opportunity to study metamorphic fluid flow during subduction and exhumation of continental crust. It is, however, usually short of petrological constraints on pressure and temperature of vein formation. This study focuses on kyanite-quartz veins within Iow-T/high-P eclogite in the Dabie terrane that contain unique polycrystalline aggregates, interpreted as pseudomorphs after porphyroblasts of lawsonite. Coesite pseudomorphs were found for the first time in garnet from eclogite, resulting in a revised estimate of peak P-T conditions at 670℃ and 3.3 GPa for the eclogite. This indicates a stability field at graphite/diamond transition, thus upgrading the HP unit to a UHP unit. Neither foliation texture, undulose extinction of quartz nor coesite were observed in quartz veins,although the peak P-T conditions were estimated the same as that in host eclogite in light of thermodynamic calculation based on mineral assemblage in kyanite-quartz veins.Therefore, the formation of the kyanite-quartz veins as wellas the breakdown of lawsonlte into the kyanite-quartz-zoisite assemblage took place during exhumation subsequent to the peak UHP conditions. In this regard, the continental subduction not only brought the water of water-bearing mineral such as lawsonite into the deep mantle, but also released the water from the mineral during exhumation.     

论艺术的失落与回归--从贺敬之的诗说起

贺敬之的诗是新中国诗歌创作中的杰出代表,但在当下遭到了贬低和排斥,产生这种情况的原因主要是“美”的失落、诗歌史的失落、艺术本质的失落,而评价诗歌应实行六维的艺批评标准。     

一种新型的单芯片级可进化硬件系统

针对可进化硬件（EHW）系统的需求,设计实现了FDP-2-SOPC芯片,芯片中嵌入了CPU和FPGA两种IP核,可实现硬件电路的重构和进化;以该芯片为系统核心建立了一种新型的软硬件结合的单芯片级EHW系统.为了提高电路重构速度,设计了针对EHW需求的快速局部重配置技术;为提高遗传算法的执行速度,设计了专用的随机数产生器...     

我国移动通信量差异的人口学分析

引人了地理迁移关系模型和社会网络人类动力学模型,将前一个模型中的“1个原型网络系统和2个变形网络系统”转换为演变过程的原始状态、迁移及适应3个阶段,将后一个模型中的“社会网络的典型特征——较高的集聚和较短的平均路径”分解为2个类型(非群体类型和群体类型),作为我国移动通信量人口学分析的研究方法.构建了我国各省的包括3个人口迁移指标、4个人口技术构成指标在内的人口学数据系统,针对3个重要的移动通信指标,分别解释人口学要素与移动通信量的内在联系.研究发现:1)应用地理迁移关系模型可以较好地描述不同演变阶段人口迁移对移动通信使用的影响,这种影响是通过保持原有链接、构建产生新链接而完成的;2)应用社会网络人类动力学模型可以较好地描述人口技术构成因素对移动通信使用的影响.     

聚氨酯复合乳液制备研究进展

聚氨酯乳液具有环境友好和节能减排的特点,但是其耐水、耐溶剂以及机械性能等不足,限制了它的应用价值。为了充分发挥其优点,与其它材料复合是提高其性能的重要手段。总结了近年来国内外关于环氧树脂、丙烯酸酯、聚硅氧烷、含氟聚合物、SiO2、聚倍半硅氧烷、粘土、碳纳米管、石墨和生物纳米材料改性聚氨酯复合乳液的制备方法并比较了性能之间的差异。