高校图书馆管理与使用的矛盾及应对策略

分析了高校图书馆管理中文献与读者需求、管理与使用、使用的人性化与读者管理等方面的矛盾,并提出了相应的应对策略。     

不同生育期菊花叶片生理指标的比较研究

对田间栽培的秋菊早花品种“唐宇金秋”和晚花品种“祥云”不同生育期叶片中可溶性糖含量、SOD活性、相对电导率等生理生化指标变化进行了测定．结果表明：“祥云”与“唐宇金秋”可溶性糖含量的变化趋势基本一致,“祥云”糖含量高于“唐字金秋”,但“唐宇金秋”淀粉含量在各个时期均高于“祥云”;从绿蕾期到末花期“祥云”的SOD活性始终高于“唐宇金秋”,中花期“祥云”叶片中SOD活性较“唐宇金秋”高24．1％;两个品种脯氨酸含量呈上升趋势,“祥云”明显高于“唐宇金秋”,如末花期“祥云”较“唐宇金秋”高175．9％．整个测定时期“祥云”和“唐宇金秋”叶片的相对电导率均呈上升状态,各个时期“祥云”高于“唐宇金秋”．晚花品种“祥云”在开花过程中叶片具有较高的SOD活性与脯氨酸含量,可能是其花期较晚且具有较强抗性的主要原因．     

不同链长烷基糖苷磷酸酯盐的合成

分别以十二、十四烷基糖苷(APG)为原料,P2O5为磷酸化试剂,直接酯化并水解,然后强碱中和的方法合成了不同链长烷基糖苷磷酸酯盐.通过正交试验确定了较佳工艺条件,在40℃强烈搅拌下分批投入P2O5.n(APG):n(P2O5) = 3:1,酯化温度60℃,酯化时间5 h.水解时加水量为总固体质量的4%,水解温度70℃,水解反应时间2 h.采用双指示剂滴定法测定产品中酯的含量,利用红外光谱和质谱对十四烷基糖苷磷酸酯钠盐的结构进行了表征,同时测定了烷基糖苷磷酸酯盐的表面张力.结果表明,烷基糖苷磷酸酯盐具有良好的表面活性.     

基于确认模式的多通道生物认证研究

单通道生物识别技术一直存在着很多问题,它们在准确率、用户接受程度、成本等方面都有不同的缺点,而采用多通道生物认证可以提高生物认证系统的识别性能,并且适应于各自的应用场合。本文介绍了多通道生物认证技术,在单通道生物认证系统模型的基础上,给出了多通道生物认证系统模型。最后基于人脸和语音特征的多通道生物认证系统进行相关实验,实验证明多通道生物认证大大改进了以往单通道认证在识别性能和用户接受程度等方面存在的不足,提高了生物认证系统的健壮性和实用性。     

色彩的概念与教学思考

色彩构成是学生学习设计专业的一门基础课程。它与平面构成、立体构成舍称为三大构成。本文指出了色彩构成教学环节中存在的问题．并对色彩构成教学实践进行了探索。     

对数正态回归模型的参数估计(MATLAB)

对数正态分布是一个广泛使用的寿命分布模型,有很多学者已证明特别用该模型来描述寿命分布是非常合适的.本文的主要内容是应用MATLAB程序对对数正态回归模型的参数进行估计,给出了估计的迭代算法,并就症医学数据进行了实例应用分析.     

民族类高校馆藏宣传指导思想探索

与专业类高校、综合类高校和民族地区高校进行比较,分析民族类高校图书馆的馆藏特点和读者特点,提出民族类高校图书馆馆藏宣传工作的指导思想,包括共性与个性的统一、各技术手段相结合、馆员与读者相结合以及理论与实践相结合.     

Enhancive effect of N,N′-dinitrosopiperazine on inducing precancerous lesion on nasal and/or nasopharyngeal epithelia of TgN(p53mt-LMP1)/HT mice

Objective: To investigate the enhancive effect of N,N′-dinitrosopiperazine (DNP) on induced carcinogenesis in nasal and/or nasopharyngeal epithelia among TgN(p53mt-LMP1)/HT transgenic mice to examine the underlying mechanism for the development of nasopharyngeal carcinoma (NPC). Methods: TgN(p53mt-LMP1)/HT transgenic mice and the same strain of C₅₇BL/6J wild-type mice both at the age of 5 months were randomly divided into 2 groups in parallel, respectively, i.e., TgN(p53mt-LMP1)/HT cancerous lesion-inducing group (TI), TgN(p53mt-LMP1)/HT control group (TC), C₅₇BL/6J cancerous lesion-inducing group (CI), and C₅₇BL/6J control group (CC). TI and CI mice were treated only with DNP for 16 weeks, twice each week, while TC and CC mice were given the same volume of saline as controls. At the end of treatment, animals were sacrificed to collect epithelial tissue samples from nasal cavity and nasopharynx for pathohistological evaluation by haematoxylin and eosin (HE) staining and for determination on the expression of TRAF2, c-Jun, and p16 by immunohistochemistry. Results: Atypical hyperplasia was more significant in the samples of TI than in those of TC, CI, and CC, with the rates of lesions being 90%, 10%, 0, and 0 (P<0.01) respectively, though DNP was used alone in a much shortened inducing period at less dosage and without the use of carcinogenic promoter 12-O-tetradecanoylphorbol-13-acetate as usual. The expressions of tumor necrosis factor (TNF) receptor-associated factor 2 (TRAF2) and c-Jun in these samples were significantly up-regulated in TI (P<0.01), while the expression of p16 was significantly lower in TI than in the other groups (P<0.01). Conclusion: TgN(p53mt-LMP1)/HT mice hold inherited constitutional defect in immune surveillance function, which can be aggravated by environmental carcinogens, such as DNP used even though in a much less strength. The enhanced carcinogenesis-inducing effect of DNP on TgN(p53mt-LMP1)/HT mice should be closely associated with abnormal signaling of activator protein-1 (AP-1) pathway, especially up-regulated expressions of TRAF2 and c-Jun, and down-regulated expression of p16.     

Scale invariant features extraction for stereo vision

Stable local feature detection is a fundamental component of many stereo vision problems such as 3-D reconstruction, object localization, and object tracking. A robust method for extracting scale-invariant feature points is presented. First, the Harris corners in three-level pyramid are extracted. Then, the points detected at the highest level of the pyramid are correctly propagated to the lower level by pyramid based scale invariant (PBSI) method. The corners detected repeatedly in different levels are chosen as final feature points. Finally, the characteristic scale is obtained based on maximum entropy method. The experimental results show that the algorithm has low computation cost, strong antinoise capability, and excellent performance in the presence of significant scale changes.     

DDFS spurious signals due to amplitude quantization in absence of phase-accumulator truncation

Spurious signals in direct digital frequency synthesizers (DDFSs) are partly caused by amplitude quantization and phase truncation, which affect their application to many wireless telecommunication systems. Thee signals are deterministic and periodic in the time domain, so they appear as line spectra in the frequency domain. Two types of spurious signals due to amplitude quantization are exactly formulated and compared in thetime and frequency domains respectively. Then the frequency spectra and power levels of the spurious signals due to amplitude quantization in the absence of phase-accumulator truncation are emphatically analyzed, and the effects of the DDFS parameter variations on the spurious signals are thoroughly studied by computer simulation. And several important conclusions are derived which can provide theoretical support for parameter choice and spurious performance evaluation in the application of DDFSs.