采用混沌扩频序列的异步码分多址通信系统仿真

为了获取适用于异步码分多址系统的混沌序列 ,提出了一种基于扩频序列性能分析准则的优选方法 ,并用系统仿真的方法进行了验证。通过对异步码分多址系统的性能分析 ,总结了扩频序列的性能准则 ,以此为依据对初值不同的混沌序列进行筛选 ,可以得到性能优异的混沌扩频序列。采用 Monte Carlo的方法 ,在无线衰落信道下对采用混沌序列和 Gold序列的异步码分多址系统进行了仿真。结果表明 :优选的混沌序列性能要优于 Gold序列 ,是扩频序列的一种新的选择     

Research at channel level on the effect of LaCl3 on Radish (Raphanus satirus L.) vacuolar membrane

We recorded slow vacuolar (SV-type) channel currents of Radish vacuoles successfully for the first time by using the whole-vacuolar patch-clamp recording mode. SVtrye currents would increase and threshold potentials of activation would shift towards more negative values with the increase of concentrations of cytosolic Ca2+. When 2.5 mmol/L LaCl3 and 4 mmol/L EGTA were added to bath solutions,SV-type currents were suppressed remarkably. Then adding LaCl3 with different concentrations to pipette solutions, we found that LaCl3 with higher concentrations (＞ 4 × 10-7 mol/L)had a strong inhibitory effect on SV-type currents, while LaCl3 with lower concentrations (≤4 × 10-7 mol/L) promoted channel currents. This promoting effect provides an important basis at channel level for researching further the effects of rare earth on physiological activities of plants and the production-increase effects of rare earth fertilizers on crops.``     

Study of transmembrane La3+ movement in rat ventricular myocytes by the patch-clamp technique

We have studied transmembrane La3+ movement in rat ventricular myocytes for the first time by using the whole-cell patch-clamp recording mode. La3+ (0.01-5.0 mmol/L) could not bring out inward currents through the L-type calcium channel in rat ventricular myocytes, while it could enter the cells by the same way carried by 1μmol/L ionomycin. When the outward Na+ concentration gradient is formed, La3+ can enter the cells via Na-Ca exchange, and the exchange currentsincrease with the increase of external La3+ concentrations. But compared with Na-Ca exchange currents in the same concentration, the former is only 14%-38% of the latter. The patch-clamp experiment indicates that La3+ normally can not enter ventricular myocytes through L-type calcium channel, but it can enter the cells via Na-Ca exchange.     

Calmodulin modulation of ion channels and receptors

Ion channels and receptors are the structural basis for neural signaling and transmission. Recently, the function of ion channels and receptors has been demonstrated to be modulated by many intracellular and extracellular chemicals and signaling molecules. Increasing evidence indicates that the complexity and plasticity of the function of central nervous system is determined by the modulation of ion channels and receptors. Among various mechanisms, Ca 2+ signaling pathways play important roles in neuronal activity and some pathological changes. Ca 2+ influx through ion channels and receptors can modulate its further influx in a feedback way or modulate other ion channels and receptors. The common feature of the modulation is that Ca 2+ /calmodulin (CaM) is the universal mediator. CaM maintains the coordination among ion channels/receptors and intracellular Ca 2+ homeostasis by feedback modulation of ion channels/receptors activity. This review focuses on the modulating processes of ion channels and receptors mediated by CaM, and further elucidates the mechanisms of Ca 2+ signaling.     

A possible configuration of H 5 + cluster

On the basis of our previous work, a configuration of H ₅ ⁺ has been presented that is a square center structure, and the energy for the structure of H ₅ ⁺ has been obtained by IACQM. The result showed that there is an extreme energy E_e: −2.45981 [2 Ry] atR = 2.50a ₀. It indicates that the square center structure of H ₅ ⁺ system has the certain stability, which is a possible configuration of H ₅ ⁺ .     

一种多级安全系统模型的隐通道流量分析

利用Markov状态机形式化地描述了一种多级的，基于模式转换的安全系统模型，该模型利用系统可分分性构筑，将一个多级的安全系统划分成多个运行模式，利用该模式可提高所设计系统的灵活性，但该模型存在隐通道问题，利用香农信息论和广义图灵测试模型证明该模型中隐通道流量存在上限并给出定量分析，从而为达到可控的系统安全性和灵活性平衡提供了理论基础，采用该系统模型和隐通道流量分析，通过限制模式转换频率和限制参与转换的资源数目等方法可控制隐通道隐患。     

筛管砾石充填井筒附近压降计算方法

认识到套管射孔砾石充填井井筒附近压降发生在 3个流动区域内 ,近井地带向射孔炮眼的汇聚流动区域 ,炮眼内砾石层的线性流动区域以及筛套环空砾石层中的发散流动区域 .以 Bernoulli压降方程为基础导出了计算向炮眼的汇聚流产生的压降的新方法 .以 Forchheimer方程为基础导出了筛套环空锥形发散流的压降简化计算公式 .结果表明 :井筒附近压降主要发生在汇聚流区域和炮眼内砾石层 ,而环空砾石层的压降相对较小 ;射孔参数及砾石渗透率是影响砾石充填井井筒附近压降的主要因素 ,砾石充填井应采用孔径大于 1 5 mm,孔密 30孔 / m左右的参数射孔 ,砾石层渗透率至少应保持在 30～ 40 μm2以上 .     

苏里格庙地区盒8段高渗储层成岩相研究

针对苏里格庙地区盒8段砂岩强烈的成岩作用是造成储层非均质性强的主要原因，不同的沉积微相其胶结类型不同，从而导致酸性水溶蚀次生孔隙发育的程度迥异。通过沉积微相分析以及大量岩石显微薄片的观察，总结出7种苏里格庙地区中二叠统石盒子组盒8段砂岩储层成岩相，并分析了5种沉积充填类型（序列）与成岩相的关系。总结出高渗储层发育的有利成岩相带为净砂岩溶蚀相和净砂岩弱压实弱胶结成岩相，它们主要发育在辫状河心滩和三角洲平原分流河道微相中。根据沉积相展布及成岩相发育规律，对苏里格庙及其外围地区的高渗储集层发育带进行了预测。     

一种新型低噪声MCP的研究

背景噪声是造成二代像管成品率低的重要因素，微通道板产生的噪声是二代像管背景噪声的主要来源，该文分析微通道板的主要噪声来源，阐明产生光子散射和电子散射的机理，通过对微通道板输入表面采用扩口技术，提高微通道板的开口面积比，降低微通道板的噪声，提高其分辨率，为进一步的工艺研究提供依据。     

影响乒乓球运动员竞赛心理的因素

运动员不仅要具有良好的身体素质和技战术水平,而且还要具有最佳的竞技心理状态,只有这样才能在比赛中立于不败之地。本文分析了影响乒乓球运动员竞赛心理变化的因素,从重视心理训练等方面提出了减少消极影响的途径。