基于VC＋＋的齿轮传动系统可视化程序设计

以齿轮零件的常规设计方法为指导,以齿轮传动的基本公式为依据,构建了基于Visual C＋＋的齿轮传动系统程序化设计流程。针对设计过程中相关的线图和数表,提出了具体的解决方案,具有一定的借鉴意义。     

“子”语素“小称”探源———修辞与派生构词管窥

认为“子”语素“小称”的演变动因是言语环境促使隐含义素突显,即“小称”本 身来自于单音词“子”感情意义层的区别性义素,突显的触发机制是拟人、借代和借喻.派生词义是词汇化过程中,词根和词缀共同作用的结果.“小称”并非从意义角度判定“子”是否为词缀的标准.     

依坐标H=N-Z分布的稳定核素四边形区

在坐标为S=2Z-N、H=N-Z核素图中,讨论了坐标参量的物理意义及依坐标H常数列分布的8个稳定核素四边形区.它们分别是在坐标H16～26的一个有6×6种核素的正方形区,坐标H≤16的3个斜平行四边形,坐标H26～44的3个矩形区与最上边的小梯形.这些核素分布包含了稳定区23列偶坐标H列的大部分偶偶核素.最后研究了四边形内部核素个数的分布规律.     

Ag^＋交换沸石分子筛吸附小分子的结构与电子性质的密度泛函理论研究

采用密度泛函理论研究了Ag^＋交换沸石分子筛及其吸附NO，H2O，CO，H2S和SO2的结构及电子性质，并对簇模型进行了自然键轨道（NBO）分析，用分子中的原子（AIM）理论研究了相关键的拓扑性质．研究结果表明，NO，CO和SO2的吸附导致了Ag^＋和沸石骨架上氧的距离缩短，这主要是因为NO，CO和SO2的吸引电子能力较大使Ag-O1和Ag-O2共价性增强所致；而H2O，H2S的吸附导致了Ag^＋和沸石骨架上氧的距离增大，可归因于H2O，H2S的吸引电子能力弱使Ag-O1和Ag-O2共价性减小所致．     

Curcumin通过Wnt信号通路抑制乳腺癌细胞MCF-7增殖的研究

目的 观察姜黄素(Curcumin)对乳腺癌细胞MCF-7增殖的影响,以及对细胞内Wnt信号通路的影响,探索Curcumin可能存在的抑制乳腺癌细胞增殖的分子机制.方法 体外培养人乳腺癌细胞MCF-7,并用不同浓度的Curcumin作用不同的时间.用MTT检测Curcumin对MCF-7细胞生长情况的影响;流式细胞仪观察经Curcumin作用后细胞周期的改变;RT-PCR和Westernblot分别检测细胞内β -catenin和下游靶基因CyclinD1的mRNA和蛋白水平的表达.结果 MTT结果显示Curcumin可以抑制MCF-7的增殖,并具有剂量-时间依赖性.在浓度为20 μmol·L-1时,对细胞生长的抑制作用最为明显.流式细胞仪观察细胞周期的结果提示,Curcumin能够阻止MCF-7细胞由G1期进入S期,提高Go/G1期细胞的百分比.RT-PCR和Western blot结果显示,Curcumin显著降低了细胞内β-catenin和CyclinD1的mRNA和蛋白水平的表达,且呈剂量-时间依赖性.结论 Curcumin能够抑制MCF-7细胞胞浆内β -catenin蛋白进入胞核,阻断Wnt信号转导通路.进而抑制下游靶基因CyclinD1的表达,阻止MCF-7由G1期进入S期,有效抑制了MCF-7细胞的增殖.     

U型钢＋工字钢联锁与锚注加固技术在巷道维修中的应用

白坪煤业公司11采区轨道运输上山受地应力及采动影响，巷道变形严重，经过对围岩应力的分析，采取u型钢＋工字钢联锁与锚注加固技术对巷道进行维修加固。通过实践证明，使用U型钢＋工字钢联锁与锚注加固技术，效果比较明显，有效的控制了巷道的变形。满足了安全生产的需要。     

一类时滞中立型系统的无记忆反馈H_∞控制

本文采用Lyapunov函数和LMI不等式方法,研究了一类输出方程亦带有不确定性的中立型时滞系统在控制律的作用下鲁棒H∞控制问题.     

盐酸介质中黄铜缓蚀剂H612缓蚀性能研究

采用失重法研究了不同温度下不同质量浓度的H612在10%的盐酸介质中对黄铜的缓蚀作用.结果表明,H612在10%的盐酸介质中对黄铜的腐蚀有良好的抑制作用.采用失重法和SEM分析法评价H612的缓蚀性能,H612是一种性能优良的盐酸黄铜缓蚀剂.     

Receding horizon H∞ control for discrete-time Markovian jump linear systems

Receding horizon H∞ control scheme which can deal with both the H∞ disturbance attenuation and mean square stability is proposed for a class of discrete-time Markovian jump linear systems when minimizing a given quadratic performance criteria. First, a control law is established for jump systems based on pontryagin’s minimum principle and it can be constructed through numerical solution of iterative equations. The aim of this control strategy is to obtain an optimal control which can minimize the cost function under the worst disturbance at every sampling time. Due to the difficulty of the assurance of stability, then the above mentioned approach is improved by determining terminal weighting matrix which satisfies cost monotonicity condition. The control move which is calculated by using this type of terminal weighting matrix as boundary condition naturally guarantees the mean square stability of the closed-loop system. A sufficient condition for the existence of the terminal weighting matrix is presented in linear matrix inequality (LMI) form which can be solved efficiently by available software toolbox. Finally, a numerical example is given to illustrate the feasibility and effectiveness of the proposed method.     

Radiolarians from the British North‐Polar Expedition (1875–1876): re‐examination of the H. B. Brady (1878) collection

The earliest report on radiolarians from the Arctic Ocean (north of the Arctic Circle) was provided by H. B. Brady (1878 Brady, H. B. 1878. On the reticularian and radiolarian Rhizopoda (Foraminifera and Polycystina) of the North‐Polar Expedition of 1875–76.. Annals and Magazine of Natural History, Series 5, 1: 425–440. [Taylor & Francis Online] , [Google Scholar]). He documented the occurrences of 10 genera from soundings in northern Baffin Bay and north of Greenland, but he did not illustrate any specimens in his report. We have re‐examined Brady's original slide collection, housed at the Natural History Museum, London (NHM), in order to refine his radiolarian identifications to species level. We have identified 11 radiolarian taxa in his slides, but some are definitely more characteristic of tropical oceans rather than high northern latitudes. We conclude that this is most likely due to sample contamination or misidentification of samples. Therefore, the actual occurrence of tropically affiliated radiolarians recorded from the Arctic is uncertain and should be regarded with suspicion.