一类Bernstein型算子的逼近性质

本文构造了一类Bemstein型算子序列,并研究了该算子序列的一些逼近性质。     

不同碳纤维集合体材料电磁屏蔽性能的实验研究

碳长丝束平行排列;;碳长丝束织物;;短切碳长丝束复合材料;;屏蔽效能 选取碳长丝束平行排列复合片、碳长丝束织物和短切碳长丝束复合材料三种不同类型碳纤维集合体材料,测试其在0.05～2.0GHz内的电磁波屏蔽效能。结果表明,碳长丝束平行排列束间距越小,屏蔽效能越高,在所测频率范围内,其在两端屏蔽效能值较高,中端较差;碳长丝束织物密度越大,屏蔽效能值越高,碳长丝束针织物在1.1～2.0GHz内的屏蔽效能平均值为17.03dB,屏蔽效果优异;短切碳长丝束长度为10mm的复合材料屏蔽效果最佳,2mm次之,6mm最差,其在所测频率范围内屏蔽效能整体差异最小,但屏蔽效能值不高,10mm试样平均效能值为10.33dB。     

丙烯酰胺降解细菌生长特性的研究

从化工厂的活性污泥中筛选出具有降解丙烯酰胺能力的细菌12株,经鉴定均为不动杆菌属。在实验室条件下,这些菌株中对丙烯酰胺的最大耐受力可达40mg/ml;12株菌株都对氨苄青霉素有抗性,而对链霉素、卡那霉素、庆大霉素及氯霉素无抗性;在以丙烯酰胺为唯一碳源的无机盐培养基中,菌株DAW01在30℃,108r/min旋转式摇床振荡培养6d后,对丙烯酰胺降解能力可达45.01％。     

近年国内氮化碳薄膜的研究现状与应用展望

叙述了氮化碳的理论研究成果及各种特性，就1998年后国内一些研究机构及大学院校的研究成果进行了介绍，对今后制备碳氮薄膜需要解决的问题及在某些领域中的应用前景进行了展望。     

Pr掺杂对欠氧YBa2 Cu3O7-δ结构与超导电性的影响

由于稀土Pr的特殊性,在Y-123中用Pr替代Y被人们广泛研究,但报道的结果常不一致,甚至相互矛盾。本文详细研究了Pr掺杂对YBa2Cu3O7-δ(Y-123)的结构与输运性质的影响。借助Rietveld方法,对不同掺杂的样品进行了细致的结构分析,并从结构的变化及替代所引起的结构应变、电荷变化的角度解释了Pr掺杂样品所具有的输运性质的变化。     

Experimental Study on Mechanical Properties of Micro-Structured Porous Silicon Film

Mechanical properties of micro-structured porous silicon film (PS) were studied combining X-ray diffraction with micro-Raman spectroscopy. The micro-structured porous silicon samples with different porosities ranging from 30.77% to 96.25% were obtained by chemical etching. Lattice parameters of the samples were measured using X-ray diffraction and its maximal change is up to 1.0%. This lattice mismatch with the bulk silicon substrate may introduce residual stress to the porous film. The residual stress measurement by micro-Raman spectroscopy reveals that the maximum of tensile residual stress has reached GPa level in the porous film. Moreover, the lattice mismatch and its corresponding residual stress are increasing with the porosity of PS, but average elastic modulus is about 14.5 GPa, one order of magnitude lower than that of substrate Si. The mechanical properties of PS have aclose relation with its micro-pore structure.     

光电感烟探测器散射灵敏度优化设计

介绍一种灵敏度优化设计的散射型光电感烟探测器，采用OPTEK公司的OP231和OP801SL光电组合套件作为发射管和接收管。文章重点探讨了两管之间角度变化对探测器灵敏度的影响，并对光信号引起的光电三极管的输出进行了估算。     

显示器视觉特性化研究

目前显示器特性化常用仪器测量的方法使出版系统和一些网络用户要求更方便、快速地进行颜色通信和再现．实验利用人的眼睛视觉特点,采用同色闪烁光度测量法估计GoG参数,进行显示器特性化研究。实验表明,这种方法对L^o,a^o、b^o控制的精度分别是0．16,0．84,1．95,对色差CIELAB的控制糟度是2.31．     

关于必然命题种类的探讨

必然命题是逻辑学中一类重要命题，自从有了可能世界的理论．关于必然命题种类的探讨越来越深入，具体。本文初步探讨了关于必然命题的一些主要种类。     

在n维赋范空间中单位球体积及其渐进性质

Let Bnp={x ∈ Rn‖|x ‖p≤l} be the unit ball ofp norm in the n-dimensional normed space p. The formula for the volume of Bnp was obtained and its asymptotic properties were found out as n→∞and p→∞.