偶数阶中立型微分方程的振动准则

给出了判断一类n阶微分方程振动性的充分条件,推广和改进了中立时滞微分方程的许多结果。     

包含平面四价碳的一个新家族(英文)

本文预测一类由碱土金属包围的含平面四价碳的新化合物,通过原子轨道分析和对键临界点的拓扑电子密度分析分别研究了其电荷稳定和成键情况。并且研究了分子的磁性质。这些包含平面四价碳的分子体系通过电子和力学性质得以稳定。D4hSi4B4H4还可以用来稳定平面四价氮离子。     

ROCKWELL工控软件在三工位成型机中的应用

德国KHD公司生产的三工位振动成型机在炭素行业生产有着广泛的应用,本文主要阐述该设备的自控系统LOGIX5000编程软件和RSVIEW32在线监控软件的应用。     

Comparisons of low carbon policies in supply chain coordination

This paper investigates the influence of low-carbon policies on channel coordination for a two-echelon supply chain consisting of one supplier and one retailer. Four different models are considered： the basic model, the carbon emission model, the carbon emission trading model and the carbon tax model. We find that the government policy on all carbon emission models is not universal among the firms as well as the customers. The carbon emission trading policy is always better than the carbon emission policy and the carbon tax policy when the allocated carbon emission quotas are greater than the carbon emissions. The carbon emission trading policy is proved to be an effective mechanism which can motivate the supply chain to reduce carbon emissions. Under certain conditions, the supply chain prefers the carbon emission trading policy with higher carbon price to other policies. In the framework of Stackelberg game with the supplier as the leader, for each carbon policy, the paper presents coordination mechanism with the all-unit wholesale quantity discount contract （AWQD）. We analyze and compare the influence of low-carbon policies on channel coordination for the foul＂ low-carbon policies. Numerical experiments are conducted to examine our findings.     

In situ small angle X-ray scattering investigation of the thermal expansion and related structural information of carbon nanotube composites

In-situ thermal expansion tests on a series of carbon nanotube bucky-paper composites were performed with direct heating within a synchrotron SAXS source. The impact of the samples density and morphology as well as the chemistry and degree of decoration of the carbon nanotubes on the scattering patterns were investigated and correlated to the materials macro-properties. The results demonstrate that simple densification techniques, such as acetone dipping or gold electroless deposition, could reduce greatly the displacements of the carbon nanotubes within the structure and lead to more thermally stable material.     

碳纳米管CNT(5,5)内环氧乙烷的阴离子聚合机理

采用B3LYP/6-311++G**和ONIOM(B3LYP/6-311++G**:UFF)方法分别对环氧乙烷非受限状态以及在单壁碳纳米管CNT(5,5)内的阴离子聚合反应进行计算。结果表明,环氧乙烷与其亲核试剂(OH-)进攻产物形成的复合物进入CNT(5,5)碳纳米管内是一个放热过程,说明反应复合物进入CNT(5,5)形成包结物在能量上是有利的。由于碳纳米管的限制作用,环氧乙烷阴离子聚合的反应物、过渡态以及产物的结构与非受限状体下有所不同,在碳纳米管内的反应过程中分子构型会发生一定的扭转,以适应碳纳米管内的空间限制。与非受限状相比,环氧乙烷阴离子聚合反应的活化能垒增加了13.2 kcal/mol,表明碳纳米管CNT(5,5)对环氧乙烷阴离子聚合反应起到一定的抑制作用。     

CFRP复杂型面构件的孔隙率超声检测方法

针对碳纤维复合材料(CFRP)复杂型面构件给出一种孔隙率超声自动检测方法;首先对已知孔隙率的CFRP试块进行超声测量,利用相位展开法求得不同孔隙率条件下的相速度,通过相速度与孔隙率之间的内在联系建立CFRP超声检测模型.针对CFRP复杂型面构件先利用超声测距原理采集其表面的坐标信息,根据曲面反求获得其CAD模型,检测路径规划生成探头运动点位;基于多自由度机械手的喷水耦合超声透射法采集超声信号,结合己建立相速度模型计算CFRP复杂型面构件的孔隙率.为验证本文方法的有效性,通过对已测CFRP复杂型面构件进行试片剖切和抛光,利用显微照相法检测其孔隙率.实验结果表明:2种方法的检测结果吻合良好.     

高阶中立型微分方程非振动解的渐近性态

获得了非线性高阶中立型微分方程的非振动解具有渐近性质的充分条件。所得结果推广或改进了文献中的有关结果。     

稀土低碳白口铸铁磨球的研制与应用

本文分析了一种珠光体型白口铸铁－稀土低碳白口铸铁作为电厂磨煤机磨球材料的可行性、 讨论了它的成分与配料、熔炼控制与变质处理、铸型工艺与铸件冷却等问题。耐磨试验与工业应 用试验表明：稀土低碳白口铸铁磨球使用情况良好，在软磨料磨损条件下是优良的抗冲击磨损材料。     

Pre-and post-natal ontogeny of neutral endopeptidase 24-11 (‘enkephalinase’) studied by in vitro autoradiography in the rat

Neutral endopeptidase (NEP, enkephalinase, CALLA) which is present in various neural and non-neural tissues, is able to cleave a variety of regulatory peptides. The distribution of NEP has been studied during rat pre-and post-natal development by autoradiography after in vitro binding of the tritiated inhibitor [³H]HACBO-Gly to whole-body and organ sections. In the central nervous system (CNS), where the presence of NEP has been related to the termination of the action of enkephalins, the external layer of the olfactory bulbs is the only structure prominently labeled before birth. Other CNS structures rich in NEP in the adult, such as the nigrostriatal tract, are progressively labeled after birth. Outside the CNS, the progressive appearance of NEP in the kidney, the lungs and the salivary glands suggests its concomitant involvement in adult physiological functions, including fluid balance control, possibly by cleaving the atrial natriuretic peptide (ANP) and other peptides. On the other hand, transient or enhanced expression of NEP is observed during the development of several organs such as the sensory organs, the heart and the major blood vessels, the intestine, the bones and the genital tubercle. In addition to the still incompletely known physiological functions of the enzyme, the developmental pattern of its expression in several tissues strongly suggests a modulatory role for NEP in the ontogeny of a large number of organs.