改进的尼龙6固相缩聚模型及其模拟

根据尼龙6固相缩聚反应动力学基础,建立了尼龙6固相缩聚两相两段模型。按末端基官能团分布的影响,将固相缩聚模型分为两段,同时考虑了结晶对尼龙6聚合反应的影响。用更加符合实际的手段获得预聚体切片的初始值,重新优化获得模型最佳参数值。     

全国计算机等级考试考务管理系统

介绍一种在FoxPro编程环境下开发的全国计算机等级考试考务管理系统,该系统采用交互式人机对话和模块化设计方式,实现对考点考务的日常维护和管理,减轻了考务管理人员的工作负担.该系统经过考点的长期运行操作,表明该系统是安全、可靠的.     

二十一世纪成人高等教育发展战略的几点思考

我国成人高等教育的发展,不仅为社会主义现代化建设培养和输送了大批急需的人才,而且推动了整个高等教育体系改革,促进了人们教育观念改变,受到了国家的重视和社会各界的认同.但仍存在着不少缺陷,随着改革的逐步深化,又遇到了许多新问题,面临更为严峻的挑战和考验.如何进一步发展成人高等教育,成为成人高教工作者面临的一项重大课题.笔者从分析成人高教的现状入手,对今后的发展战略提出几点思考.     

在弹性波导槽中非线性应变波的指数吸引子

研究了在弹性波导槽中非线性应变波方程生成的非线性连续半群的性质,通过算子分解和构造渐近紧不变集,得到了在空间Ｅ１中半群 Ｓ（ｔ）导出的紧的指数吸引子．     

一种改进的MNVS自适应滤波算法

提出一种改进的归一化变步长自适应滤波算法（ＡＮＶＳ）,它对归一化变步最小均方误差自适应乍法（ＭＮＶＳ）作了进一步的改进,使之既具有愉收敛速度,又有快速跟踪能力,计算机仿真结果表明,该算法的性能明显优于ＭＮＶＳ算法,而其计算量与ＭＮＶＳ算法相当。     

膨润土基多孔材料对红色染料的脱色作用

研制成型化的膨润土基多孔粘土材料,应用于红色染液废水的脱色处理,初步探讨该多孔材料对染料阳离子红Ｘ－ＧＲＬ和直接大红ＦａＧ的脱色作用及其影响因素。结果表明,该多孔材料对染液具有良好的脱色效果,用于染料阳离子红Ｘ－ＧＲＬ的脱色可以多次再生循环使用。     

迭层空腹桁架转换层结构的静力性能分析

迭层空腹桁架是一种新型的转换层结构型式。,本文分析了弦杆截面尺寸、腹杆布置对结构受力性能的影响,从而给出了其设计建议。     

New O-superfamily conotoxins fromConus striatus inhabited near Chinese Hainan Island

Conotoxins are short peptide-toxins with specific targets and large diversity. They are useful in analgesia, neuroprotection, detection of some kinds of deseases, and receptor and ion channel study. In order to explore the conotoxin resourses of Chinese oceans, rapid amplification of 3′ cDNA ends (RACE) method was utilized to systemically analyze the O-superfamily conotoxin content ofConus striatus inhabited near Chinese Hainan Island. Six new O-superfamily conopeptides were identified, one of which is highly homologous to MVIIA, an N-type calcium channel antagonist.     

Regulatory role of the sequences downstream fromnodD3 P1 promoter ofRhizobium meliloti

The 660 bp region betweennodD3 P1 promoter and the following coding region ofRhizobium meliloti has been studied. This region is designated “downstream sequences”. It consists of two potential open reading frames, ORF1 and ORF2. Studies on the role of the downstream sequences on the activity ofnocD3 P1 with nod D3(P1)-IacZ fusion show that deletion of the sequences containing ORF2 causes the increase of the activity of the fusion; on the contrary, addition of extra copies of ORF2 markedly decreases the activity of the fusion. These results indicate that the product of ORF2 plays a negative role in the expression ofnod D3.     

Menadione-induced apoptosis and its mechanism in plants

Menadione can induce apoptosis in tobacco protoplasts. Typical characteristics are detected including the condensation of chromatin, the formation of apoptotic bodies and the degradation of genomic DNA into “DNA ladder”. Specific DNase is activated during this process. Ca²⁺ and Mg²⁺ are necessary for its activation, while Zn²⁺ and EDTA (Ethylenediaminetetraacetic acid) can inhibit its activation. The fragmentation of DNA and lamin can be inhibited by DEVD (Ac-Asp -Glu- Val- Asp-aldehyde). The fragmentation of lamin can also be inhibited by PMSF (Phenylmethylsulfonyl fluoride) and CH (Cyclohexinide). These results show that activation of specific DNase and proteases is involved in menadion-induced apoptosis in plants.