MeV P^＋／Si^＋共注入SI—GaAs制备高品质n^＋埋层

采用不同注量和注入顺序的MeV能量的P~+(3MeV,1×10~(14)～3×10~(14)cm~(-2))与MeV能量的Si~+(3MeV,1×10~(14)cm~(-2))共注入于SI-LEC GaAs晶体中。对不同退火条件的共注入样品的有源层电特性、载流子浓度分布、晶格的损伤和恢复状况以及剩余缺陷等进行了分析。研究表明,较大注量的P~+与Si~+共注入,可以降低注区薄层电阻,有效地提高MeV Si~+的激活效率,改善有源层迁移率,得到高品质的n~+埋层。共注入样品的HALL迁移率大于2400cm~2/(V·s),激活率可达95％以上。     

MeV硅,氧离子注入SI—GaAs形成相互隔离的双导电层

用Mev的硅、氧离子注入SI-GaAs形成了相互隔离的N-SI-N双导电层结构.6 MeV的Si离子注入半绝缘的GaAs,在950℃5s条件下进行快速退火,可以得到最佳电特性,在表面下2.8μm深处形成n~+深埋层.采用双能量的硅离子注入半绝缘GaAs:6 MeV(1×10~(14)cm~(-2))+80 key(5×10~(13)cm~(-2)),在950℃5s退火,然后用1.2MeV的氧离子注入该样品,注量为10~(10)～10~(11)cm~(-2)时,形成了上、下相互隔离的双导电层,隔离击穿电压为10～20V,该结构在600℃以下是稳定的.     

不同离子束辅助沉积生物玻璃陶瓷膜的结构和溶解特性

用能量 60keV、辅助注量为 2× 10 16 和 7× 10 15ions/cm2 的N+和Ar+离子束 ,分别将生物玻璃陶瓷 (BGC)辅助沉积于钛合金表面 .通过XRD ,FTIR ,XPS和EDAX对沉积膜进行表征发现 ,膜均呈非晶或无明显的结晶度 ,沉积膜中均出现C和O的污染 ,还引入了CO2 - 3 根基团 .N+离子束辅助沉积膜的Ca/P比低于BGC原材料 ,而Ar+离子束辅助沉积膜的Ca/P比高于BGC原材料 .在Hanks溶液中 ,N+离子辅助沉积膜的抗溶解特性略优于Ar+离子辅助沉积膜 ,二者均优于Ti合金 .作者对实验中观察到的上述现象进行了一定的讨论     

高剂量的~(40)Ar~+离子注入硅热退火行为的研究

用沟道—卢瑟福背散射技术(RBS)研宄了能量为50 KeV,剂量为3.8×10~(16)/cm~2和1.9×10~(16)/cm~2的~(40)Ar~+离子注入(111)硅衬底中的恒温等时热退火行为。结果表明,离子注入层中Ar 原子的扩散和释放以及非晶硅层的再结晶行为明显地依赖于~(40)Ar~+离子的注入剂量和退火温度。注入剂量为3.8×10~(16)/cm~2的样品,当退火温度为700℃时,表面层硅的密度明显减小,退火温度为750℃时,注入层中的大部分Ar 发生外扩散并从样品表面释放。注入剂量为1.9×10~(16)/cm~2的样品,退火过程中没有发现衬底硅表面密度的变化,而且当退火温度为900℃时,残留在注入层中的Ar 仍旧比较多。最后对这些现象进行了讨论和解释。     

~(65)Cu(n,2n)~(64)Cu,~(63)Cu(n,α)~(60)Co 和~(46)Ti(n,p)~(46)Sc反应截面测量

本文用活化法以~(27)Al(n,α)~(24)Na 反应截面为中子注量标准,测得的14.9 MeV 中子~(65)Cu(n,2n)~(54)Cu 和~(46)Ti(n,p)~(46)Sc 反应截面分别为9334±32和297±10mb,测得的14.62MeV中子~(63)Cu(n,α)~(60)Co 反应截面值为42.3±1.5 mb.单能中子由 T(d,n)~4He 反应获得,中子能量是用铌锆截面比法测定的.在文中还把本文的结果与其他一些作者的数据进行了比较.     

Xe^＋离子注入聚合物Q膜的拉曼光谱研究

分析了Xe~+离子注入聚合物Q膜的拉曼光谱,对原始Q膜的拉曼谱线进行了指定.实验结果表明,随离子注入量的增加,其分子结构的特征谱线逐渐消失,当注入剂量达1×10~(17)Xe~+/cm~2时,注入层中原始膜的全部谱线消失,只在～1550cm~(-1)处出现宽的拉曼峰,说明注入层的分子结构遭到破坏,出现类似非晶碳的结构,注入层的电导率增加与其结构变化密切相关.     

InGaAs/InGaAsP量子阱激光器材料带隙蓝移研究

为了在光开关器件的制作中实现低传输损耗的光波导 ,对InGaAs/InGaAsP分别限制异质结多量子阱 (SCH MQW )激光器结构进行了一系列带隙蓝移实验 .将能量 12MeV、注量 15×10 13cm- 2 的P+注入到实验样品后 ,在 70 0℃下快速热退火 90s.发现光致发光谱的峰值位置发生蓝移 989nm .蓝移量随着注入能量和注量的增大而增大 ,并且能量比注量对蓝移的影响更大 .     

催化光度法测定痕量银

本文研究了2.2'一联吡啶作活化剂,银(Ⅰ)催化过硫酸铵氧化甲基红褪色的新指标反应,对影响催化褪色反应速度的最佳条件进行了研究和选择,建立了测定痕量银(Ⅰ)的新方法.方法灵敏度为2.5×10~(-10)g银(Ⅰ)/ml,测定范围为5.0×10~(-10)～4.0×10~(-7)g银(Ⅰ)/ml,有较高的选择性,可直接用于测定矿井水中痕量银(Ⅰ),方法可靠,获得了满意的结果.     

化学发光法测定天然水中正磷酸盐

本文报道一种测定天然水中正磷酸盐的化学发光方法,原理是基于磷酸根对钼酸铵氧化Ⅰ~-生成Ⅰ_2的催化作用.检测限达4ng/mLPO_4~(3-),线性范围是1×10(-7)—1×10~(-5)M,对2×10~(-7)M PO_4~(3-)测定(n=11)的相对标准偏差小于±2%.     

K(Ⅰ)离子印迹双极膜的制备及对海水中钾的富集

以羧甲基纤维素钠(CMC)为功能单体,KNO3为模板分子,18-冠醚-6(18-C-6)为致孔剂,去除模板离子(K(Ⅰ))后制备了钾离子印迹膜层(K-IIM).以戊二醛(GA)改性壳聚糖(CS)得到阴膜液,将阴膜液流延于上述K-IIM上形成了K(Ⅰ)离子印迹双极膜(K-IIBPM).采用扫描电镜(SEM)观察了K-IIBPM的形貌.K-IIM具有沟壑状的孔穴结构,孔穴半径约为0.130~0.170 nm,与K(Ⅰ)的半径(0.137~0.164 nm)和形状相匹配,且具有规则性;经戊二醛改性后的阴膜层具有不规则的粗糙纹理.采用已循环使用十次的K-IIBPM富集海水中的钾,当海水中Na∶K∶Ca∶Mg的质量浓度(g·L-1)比为10.70∶0.41∶0.42∶1.32,压力差为0.03 MPa,渗透时间为60 min时,K(Ⅰ)的透过率高达96%,其它被分离离子的截留率均在85%以上,从而实现富集海水中钾的目的.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with