关于管理专科教育若干问题的探讨

本文结合我院的实际情况对管理专业教育的性质、培养目标以及专科毕业生应具备的知识,能力和素质等问题进行了探讨。并就当前专科教育中存在的几个突出问题发表了自己的见解。     

可用于先进复合材料的一种中温固化环氧树脂

本文评价了一种可用于纤维缠绕先进复合材料的,以聚醚三胺进行固化的双酚F 环氧树脂。该树脂系统具有低粘度,长使用期,并能在中温下进行固化。使用这种树脂制造的复合材料,未发现明显的纤维微皱摺或分层现象,这意味着介于纤维和基体之间不同的热膨胀系数已不成为一个问题。该树脂系统浇注体典型力学性能(拉伸、压缩和剪切)已测得。拉伸:最大应力75.8兆帕(Mpa),最大应力下的应变为4.2%,模量为3171兆帕,断裂应力为71兆帕,断裂应变为5.8%。压缩:最大应力为87兆帕,最大应力下的应变为4.7%,模量为3150兆帕。剪切:断裂应力为52.2兆帕,冲击强度为32.6牛顿米/米。     

高温空气中主要分子带系的F—C因子

从计入分子振转相互作用的电子态波函数出发，按自编程序计算了高温空气中主要分子带系Ｏ２（Ｓ－Ｒ），Ｎ２（１＾＋），Ｎ２（２＾＋），Ｎ２＾＋（－），ＮＯ（β），ＮＯ（γ）的Ｆ－Ｃ。从而得出：当激波管低压端的空气压强为１３３３Ｐａ时，入射激波及反射激波后高温空气的温度与激波强度的关系；各主要分子带系转动态分布与温度的关系；高温空气中主要分子带系Ｆ－Ｃ因子与激波强度的关系。计算结果甚好，好既适用于高温，也     

装有重新设计燃料泵的YLR87-AJ-5火箭发动机涡轮泵瞬态试验及有关推进设备

试验目的已经达到了。两次试验是以抽吸侧脉动情况下作的,另一次试验是在排泄侧脉动情况下作的。重新设计燃料泵瞬态试验结果与产品燃料泵试验结果作了比较。从分析大力神Ⅱ纵向振动有关参数和减少纵向振动角度来看,比较起来,重新设计的泵显示出此产品泵有更显著的优越性。分析采用重新设计燃料泵对总系统的影响时,必须联系氧化剂系统。     

全息照相无损材料检验法

全息照相干涉测试法,是检验材料的极好方法。它可以采用双重曝光技术,或者也可采用“实时”干涉成象技术。在这两种技术的应用中,使一个不受应力的测试件立体象同一个测试件在另加应力情况下的立体象重叠起来。     

也谈位移度的计量

《航空标准化》1978年第1期刊登湘江机器厂标准化组写的《浅谈位移度误差的计量》一文,看后很受启发,但最后一部分,谈到用图解法来确定孔组位移度误差时,关于孔组偏心的一些提法,我们感到有一些不同意见。现将我们的看法简述如下。     

Coronal mass ejection (CME) activity of low mass M stars as an important factor for the habitability of terrestrial exoplanets. II. CME-induced ion pick up of Earth-like exoplanets in close-in habitable zones

Atmospheric erosion of CO2-rich Earth-size exoplanets due to coronal mass ejection (CME)-induced ion pick up within close-in habitable zones of active M-type dwarf stars is investigated. Since M stars are active at the X-ray and extreme ultraviolet radiation (XUV) wave-lengths over long periods of time, we have applied a thermal balance model at various XUV flux input values for simulating the thermospheric heating by photodissociation and ionization processes due to exothermic chemical reactions and cooling by the CO2 infrared radiation in the 15 microm band. Our study shows that intense XUV radiation of active M stars results in atmospheric expansion and extended exospheres. Using thermospheric neutral and ion densities calculated for various XUV fluxes, we applied a numerical test particle model for simulation of atmospheric ion pick up loss from an extended exosphere arising from its interaction with expected minimum and maximum CME plasma flows. Our results indicate that the Earth-like exoplanets that have no, or weak, magnetic moments may lose tens to hundreds of bars of atmospheric pressure, or even their whole atmospheres due to the CME-induced O ion pick up at orbital distances 相似文献   

Ultrastructural and geochemical characterization of Archean-Paleoproterozoic graphite particles: implications for recognizing traces of life in highly metamorphosed rocks

Abundant graphite particles occur in amphibolite-grade quartzite of the Archean-Paleoproterozoic Wutai Metamorphic Complex in the Wutaishan area of North China. Petrographic thin section observations suggest that the graphite particles occur within and between quartzite clasts and are heterogeneous in origin. Using HF maceration techniques, the Wutai graphite particles were extracted for further investigation. Laser Raman spectroscopic analysis of a population of extracted graphite discs indicated that they experienced a maximum metamorphic temperature of 513 +/- 50 degrees C, which is consistent with the metamorphic grade of the host rock and supports their indigenicity. Scanning and transmission electron microscopy revealed that the particles bear morphological features (such as hexagonal sheets of graphite crystals) related to metamorphism and crystal growth, but a small fraction of them (graphite discs) are characterized by a circular morphology, distinct marginal concentric folds, surficial wrinkles, and complex nanostructures. Ion microprobe analysis of individual graphite discs showed that their carbon isotope compositions range from -7.4 per thousand to -35.9 per thousand V-PDB (Vienna Pee Dee Belemnite), with an average of -20.3 per thousand, which is comparable to bulk analysis of extracted carbonaceous material. The range of their size, ultrastructures, and isotopic signatures suggests that the morphology and geochemistry of the Wutai graphite discs were overprinted by metamorphism and their ultimate carbon source probably had diverse origins that included abiotic processes. We considered both biotic and abiotic origins of the carbon source and graphite disc morphologies and cannot falsify the possibility that some circular graphite discs characterized by marginal folds and surficial wrinkles represent deflated, compressed, and subsequently graphitized organic-walled vesicles. Together with reports by other authors of acanthomorphic acritarchs from greenschist-amphibolite-grade metamorphic rocks, this study suggests that it is worthwhile to examine carbonaceous materials preserved in highly metamorphosed rocks for possible evidence of ancient life.