Unusual Threshold Anomaly in the ^6Li＋^208Pb System

The angular distributions of elastic scattering for the ^6Li ＋^208Pb system have been measured at several energies around the Coulomb barrier. The parameters of optical potential are extracted by means of a phenomenological optical model analysis. It is found that the real and imaginal potentials show a pronounced energy dependence. The behaviour of the potential at the nearly especially sub-barrier energies in the ^6Li＋^208Pb system is quite different from the results of some previous reports observed in other systems, such as ^19F＋^208Pb and ^16O＋^208Pb. This unusual threshold phenomenon indicates that breakup channel is strongly coupled with the elastic channel and has obvious effects on optical potential.     

面向物联网的室内ZigBee监控系统设计

设计一种基于ZigBee的室内监控系统,该系统采用低功耗无线收发芯片CC2530及传感器构建室内局域网,包含物联网的感知层、网络层及应用层三层结构,传输协议选用ZigBee;感知层包括温湿度、光敏、摄像头图片数据采集;网络层主要是ZigBee无线网络,数据汇聚至网关;应用层包括手机、PC机等;网络拓扑结构采用星形网络结构;给出软硬件实现方法,主要有节点设计、网络组建及软件设计等;实验在长6m宽3m的室内进行,测试正常室温,温度传感器附近放置低于室温10℃和高于室温10℃物体改变环境温度;光敏传感器测试采用日照强度,遮挡及部分遮挡传感器改变光照强度;人员在摄像区域内外移动测试摄像清晰度及监控范围;测试结果表明系统工作正常,PC机终端软件显示各传感器随环境变化相应变化值。     

例说高考平面向量问题的“两化”策略

近年来,高考对平面向量知识的考查已趋向于灵活多变,对考生能力的要求提高,本文试介绍求解平面向量问题的两个策略——代数化策略和图形化策略,这两个策略是破解平面向量问题的“利刃”．     

Distinct Superconducting Gap on Two Bilayer-Split Fermi Surface Sheets in Bi_2Sr_2CaCu_2O_(8+δ) Superconductor

High resolution laser-based angle-resolved photoemission measurements are carried out on an overdoped superconductor Bi_2Sr_2CaCu_2O_(8+)with a_(c )of 75 K.Two Fermi surface sheets caused by bilayer splitting are clearly identified with rather different doping levels:the bonding sheet corresponds to a doping level of 0.14,which is slightly underdoped while the antibonding sheet has a doping of 0.27 that is heavily overdoped,giving an overall doping level of 0.20 for the sample.Different superconducting gap sizes on the two Fermi surface sheets are revealed.The superconducting gap on the antibonding Fermi surface sheet follows a standard d-wave form while it deviates from the standard d-wave form for the bonding Fermi surface sheet.The maximum gap difference between the two Fermi surface sheets near the antinodal region is～2 meV.These observations provide important information for studying the relationship between the Fermi surface topology and superconductivity,and the layer-dependent superconductivity in high temperature cuprate superconductors.     

近垒及垒下能区28Si+174Yb体系的裂变碎片质量分布

使用两块大面积平行板雪崩计数器,测量了近垒及垒下28Si+174Yb熔合裂变碎片质量-角度关联分布及质量分布。质量-角度二维图显示在该反应能量区间内并没有发现明显的准裂变成分。运用单高斯曲线拟合了裂变碎片的质量分布并抽取了质量宽度。结果表明:在库仑势垒以上,质量宽度随着反应能量的升高而增大;在库仑势垒以下能区,发现质量宽度随着反应能量的降低而呈现轻微增大的趋势。运用鞍点统计模型对本次实验数据拟合发现,需用比文献给出的更大的刚度系数才能重现实验结果,其物理原因还需要进一步研究。In order to study the fission mechanism, the mass distributions and mass-angle distributions of the fission fragments for 28Si+174Yb were measured near the Coulomb barrier. The mass-angle correlations do not indicate any possible quasi-fission events in this bombarding energy range. The mass distributions were fitted by the single Gaussian distribution and then the mass widths were extracted. At above-barrier energies, the mass widths were found to increase with the energy. However, the mass widths show slight increase with decreasing energy below the barrier. Additionally, the mass widths can not be reproduced in the framework of the saddle statistic model with the given parameter, so further study is still needed.     

光学元件激光预处理技术研究进展及其应用

光学元件中的杂质和缺陷会引起其激光损伤阈值的大幅降低,现阶段这一问题已成为激光装置向高功率、高能量方向发展的“瓶颈”,亟待解决。在对光学元件激光损伤的研究中发现,用低于光学元件损伤阈值的激光对元件表面进行预处理,可以有效提高光学元件的抗激光损伤能力。对激光预处理技术的提出背景、定性作用机理、定量理论模型及国内外技术应用现状进行了概述。并且介绍了一种可在薄膜制备过程中进行原位实时激光预处理的新型薄膜制备技术。最后指出,激光预处理技术作为一种无污染,可有效改善光学薄膜、光学玻璃、光学晶体元件损伤阈值的最有效方法之一,其作用机理、实用化、仪器化还有待进一步发展。     

高效液相色谱法测定富含油脂辣椒制品中的辣椒素类物质

建立了高效液相色谱法测定高油脂辣椒制品中3种主要辣味成分的方法.样品以70%乙醇提取,采用反相高效液相色谱分离,紫外检测器;根据色谱峰的保留时间定性,以外标峰面积法定量辣椒素(C)、二氢辣椒素(DC)、去甲二氢辣椒素(NDC),结果以斯氏指数(SHU)计.NDC的色谱行为与C极其类似,NDC可采用C的标准曲线定量.采用色谱柱,ZORBAX SB-C18;流动相,V(甲醇)∶V(水)=70∶30;UV检测波长,230 nm;辣椒素和二氢辣椒素RSD分别为1%,1.5%(n=5);回收率分别为97.5%、94.5%.辣椒素和二氢辣椒素在0.001～0.1 mg/mL范围内线性良好;LOD 0.1 mg/L,LOQ 0.5 mg/L.供试品溶液稳定,12 h内测定RSD为1%.方法满足辣味水平评价要求.     

线性分式规划优化分析的元模型方法

1引言线性分式规划(LFP): min f(x)=(p~Tx α)/(q~Tx β) s.t. Ax=b (1) x≥0有着重要的应用背景,特别在经济管理中受到广泛关注．例如,以净收益率为优化目标函数的海洋运输问题;当价格系数为随机变量时,优化目标为获得满意的收益水平概率最大的资源分配问题等[11]．线性分式规划是一类特殊的非线性规划,除一般的非线性规划求解方法外,它还有一些特殊的专用算法．这里,我们要考虑的问题是;当右端资源约束向量在一定范围内(即L≤b≤U,L,U分别为b的下界和上界)变化时,目标函数的最优值如何变化?我们把这一问题称之为线性分式规划的优化分析．     

Interaction between collinear periodic cracks in an infinite piezoelectric body

The problem of collinear periodic cracks in an infinite piezoelectric body is studied. Effect of saturation strips at the crack-tips is taken into account. By means of the Stroh formalism and the conformal mapping technique, the general periodic solutions for collinear cracks are obtained. The stress intensity factors and the size of saturation strips are derived analytically, and their dependencies on the ratio of the periodicity on the half-length of the crack are analyzed in detail. Numerical results show the following two facts. (1) When h/l>4.0, the stress intensity factors become almost identical to those of a single crack in an infinite piezoelectric body. This indicates that the interaction between cracks can be ignored in establishing the criterion for the crack initiation in this case. (2) The speed of the saturation strip size of periodic cracks approaching that of a single crack depends on the electric load applied at infinity. In general, a large electric load at infinity is associated with a slow approaching speed.     

钠原子双激发［2p,3s］→［4p,kl］光电离截面计算

用多体微扰理论和原子体系图示法,研究和讨论了钠原子双激发 ［2p,3s］→［4p,kl(kp+kf)］并计算了钠原子的光电离激发截面,计算结果与实验结 果相符。