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61.
基于GM(1,1)模型的某高校招生人数预测   总被引:1,自引:0,他引:1  
分析了近年来我国高校招生人数的变化趋势,并利用GM(1,1)模型对某高校2008年的招生人数进行了预测.从而为高校招生人数决策提供了依据。  相似文献   
62.
魏访 《科技资讯》2008,(36):21-21
随着信息时代的到来,互联网和多媒体技术迅猛发展,数字多媒体信息在网上传播越来越便捷,同时也带来了信息安全的隐患问题。小波变换具有良好的时频特性且小波的多分辨分析与人眼视觉特性是一致的。在小波域对图像进行分解,可以根据HVS特性更好地隐藏信息,解决信息安全的问题。  相似文献   
63.
The purposes of this research were to study the stable expression of exogenous gene encoding therapeutic protein in attenuated Salmonella typhimurium, observe the metabolism of oral gene vaccine carried by attenuated Salmonella typhimurium in BALB/c mouse, and investigate the feasibility of prevention and treatment of tumors by the recombinant bacteria. Recombinant plasmid pcDNA3.1 VEGFR2(n1-7) was transformed into competent attenuated Salmonella typhimurium SL3261 to develop oral DNA vaccine SL3261-pcDNA3.1 VEGFR2(n1-7). To observe whether the exogenous gene can be expressed in the recombinant bacteria, PCR was performed to amplify the CMV promoter of the eukaryotic expression vector as the proof of stable expression of exogenous protein; transmission elec- tron microscopy (TEM) was applied to observe the morphology of the recombinant bacteria to confirm that the exogenous gene has no impact on the growth of the bacteria, and then BALB/c mice were immunized with the gene vaccine. After inoculation of the gene vaccine, the recombinant bacteria SL3261 could be detected in the tissues such as small intestine, colon, liver and spleen. And then, mice in each group were challenged with tumor cells. The results of animal experiment showed that tumor growth of the mice in experimental group was inhibited and survival time of immunized mice was prolonged compared with control groups. A higher lymphocyte infiltration in tumors from animals treated with DNA vaccine was observed. Immunohistochemical analysis of tumor samples revealed an en- hanced accumulation of CD8 cytotoxic T lymphocytes, as well as an increase in CD4 cells in the tumors of animals treated with the oral gene vaccine compared to tumors from control group mice. Ultrastructure of the tumor tissue showed that tumor cells in the samples of the immunized mice were well-differentiated. Our research confirmed that the exogenous gene can be stably expressed in the attenuated Salmonella typhimurium and has no impact on the growth of the recombinant bacteria; the exogenous gene can de delivered to the host by attenuated Salmonella typhimurium to produce anti-tumor effect with no obvious cytotoxity to the host. In this study, it is established that attenuated Salmonella typhimurium could be used as a vector for oral gene vaccine, and our study provided a theoretical basis for the body distribution and the metabolism of the recombinant bacteria. This strategy may provide a simple, safe and effective way for the prevention and treatment of tumors.  相似文献   
64.
In this experiment, using the methods of drought-stress in the pot and PEG simulative drought-stress, three native rocky-slope grasses Pogonatherum panideum(Lam.) Hack, Erioophorum comosum nees and Cynodon dactylon cultivated in the pots were selected as materials to study their drought-resistance by analyzing the indexes such as the leaf area index, the drying roots accumulation, the holding water ability of leaf, the relative conductance of leaf, the soluble protein, chlorophyll. At the same time, by comparing with membership function value of each index, the order of each grass drought-resistance was decided. The results showed that the drought-resistance of Erioophorum comosum nees was stronger than Cynodon dactylon and drought-resistance of Cynodon dactylon was stronger than Pogonatherum panideum (Lam.) Hack. The purpose of the experimental results was to find theoretical foundations for selecting and cultivating native protecting-slope vegetations to adapt to rocky slopes.  相似文献   
65.
High-density event-related potentials (ERPs) were measured when participants were required to evaluate oneself, significant others (father and mother) and the most familiar public figures (Lei Feng and Jiang Qing) based on trait adjectives. There were three referential conditions and a non-referential control condition including self-evaluation (SE), significant other-evaluation (SOE), general other-evaluation (GOE), and semantic positivity-evaluation (SPE). The behavioral data showed that RTs to GOE condition were longer than the other three conditions. Scalp ERP analysis revealed that (1) SPE condition elicited a more negative N2 than SE condition, which was associated with inhibition of responses; (2) SE condition elicited a more positive P300 than SPE condition, which was an index of attention to self-relevant stimuli; (3) there was no difference on the amplitude and latency of P300 between SE and SOE conditions, which reflected that the concept of “self” included intimate others (e.g., father and mother) in Chinese culture.  相似文献   
66.
通过引进积分算子P(I),研究了反周期函数插值及反周期函数的2-周期(0,P(I))插值,得到了解存在的条件,并给出对应条件下解的显式.  相似文献   
67.
QUANTITATIVE STRUCTURE ACTIVITY RELATIONSHIP (QSAR) IS A VERY IMPORTANT TOPIC FOR MANY SCIENTIFIC FIELDS AND CAN BE TERMED AS QUANTITATIVE SEQUENCE ACTIVITY MODELS(QSAM)[1] WHEN REFERRED TO THE RESEARCH ON RELATION- SHIPS BETWEEN STRUCTURES AND ACTIVITIES OF BIOLOGICAL MOLECULES, SUCH AS PROTEINS, AND NUCLEIC ACIDS. HOW- EVER, IT IS VERY DIFFICULT TO ESTABLISH A QSAM MODEL,…  相似文献   
68.
通过试验筛选出适合万寿菊、满天星快速繁殖的培养基.矮壮素可使满天星和万寿菊丛苗数量减少,植株生长明显受抑制,使其节间缩短,叶片增厚,叶色浓绿.矮壮素还有使万寿菊根系发达粗壮,分支较少的作用.500mg/L的矮壮素比较适宜矮化培养,既达到了矮化的效果又不至于阻碍植株正常生长,且试管苗株形紧凑、美观.  相似文献   
69.
运用临界点理论中的极小极大方法得到一类次二次Hamilton系统的次调和解的存在性定理.  相似文献   
70.
工程中常用的几种氧化沟及其发展   总被引:2,自引:0,他引:2  
简要介绍了当今工程中常用的几种氧化沟技术的特点及其发展历程,主要包括Carrousel氧化沟、Orbal氧化沟、交替式氧化沟以及一体化氧化沟。  相似文献   
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