用中子飞行时间分析氢同位素深度分布

论述了一种注入或者吸附在材料中的氚和氘的深度分布的测量方法.样品为氚(钛)靶和氘(钛)靶.用2MeV入射质子束,T(p,n)反应研究氚的深度分布;用1MeV入射氘束,D(d,n)反应研究氘的深度分布.用标准的飞行时间方法测量中子能谱。由中子能量确定起反应的质子或氘核的能量。进而得出氚或者氘在钛层中的深度分布.本方法的灵敏度可达0.1at.％.对氚(钛)靶,当靶厚为5mg/cm~2时,深度分辩好于0.5mg/cm~2.     

余辉末期金属卤化物蒸汽激光卤素原子密度

本文由动态平衡时金属卤化物分子与卤素原子的热力学配分函数,得到了金属卤化物蒸汽激光余辉末期随温度变化的卤素原子密度。当温度T～1300 k时,溴原子密度n～1×14~(14)cm~(-3),它比溴化亚铜分子密度小～1个量级.     

靶温对Ti注入H13钢表面强化机制的研究

给出了不同靶温下的Ti注入H13钢的抗磨损特性,并研究了不同靶温对强化机理的影响。注入时靶温为液氮冷却、150和400℃,注入能量和注量分别为180keV和3×10~(17)cm~(-2)。不同靶温下注入后,样品表面硬度不同。但均比未注入样品硬度有明显提高。抗磨损能力也有提高,从液氮靶温注入的1.75倍,150℃靶温的7.7倍到400℃靶温的11.2倍。硬度和抗磨损能力的提高程度取决于不同靶温下注入H13钢表面强化机理的差异。低温注入以位错强化和超过饱和强化为主,150和400℃注入TiC,Fe_2Ti等析出相明显增多,它们以析出相的弥散质点强化为主。     

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。     

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。     

热处理温度对金属Al增韧氧化铝多孔陶瓷支撑体断裂韧性的影响

采用干压成型法,通过添加适量的金属Al粉来增韧Al2O3多孔支撑体,详细考察了热处理温度对多孔Al2O3/Al支撑体力学性能的影响,并借助于扫描电子显微镜(SEM)分析了样品的微观结构. 研究结果表明:当热处理温度较低时,支撑体内部大量未氧化的铝相是支撑体断裂韧性提高的主要的原因;当热处理温度较高时,铝氧化产生体积膨胀,膨胀裂纹对支撑体断裂韧性的提高贡献很大.     

PbTiO3薄膜的热释电性和铁电性研究

采用Sol—Gel工艺制备了较大面积不裂的PbTiO_3薄膜,对样品做了不同烧结温度下的X射线衍射实验,经550℃保温30min的样品已形成了单一晶相的PbTiO_3多晶膜。对样品的热释电系数随温度、薄膜厚度和胶液浓度的变化关系研究,发现热释电系数随胶液浓度和薄膜厚度的增加而增大,最后达到饱和。样品的室温热释电系数为3.6×10~(-8)C/cm~2·K,介电常数为15～26,介电损耗为0.001—0.05,居里温度为515℃,自发极化强度和剩余极化强度分别为6.54μc/cm~2和3.37μc/cm~2,矫顽场强为54.8kV/cm。     

铁铝原子在金属间化合物形成中的扩散

采用铁铝扩散偶,研究铁铝原子在化合反应中的扩散和金属间化合物的形成机理,扩散偶在铁铝低共熔反应温度上下进行热处理,结果表明,扩散偶在低于共熔反应温度处理时,在扩散偶铁－铝界面铁的一侧,通过铝原子的扩散,形成了富铝相金属间化合物ＦｅＡｌ２;而在高于共熔反应温度处理时,则在铁－铝界面上,通过铁、铝原子的互扩散形成了金属间化合物Ｆｅ３Ａｌ５,并随时间向两旁生长,两种化合物均为多孔体。研究发现铁、铝原子的     

铯在铝中扩散的研究

详细地研究了铯在铝中的扩散和释放过程。铝衬底中的铯是由离子注入引入的。采用2MeV~4He~ 离子的卢瑟福背散射技术测量铝衬底中铯浓度的深度分布。通过分析恒时退火过程中铯在铝中的迁移和从表面释放的资料,得到了铯在铝中的扩散系数。实验表明,铯在单晶和多晶铝中有十分类似的扩散行为。铯离子注入剂量N_d(?)6×10~(16)ionscm~(-2)的情况下,铯在铝中的扩散系数随温度的变化可表示为D(?)0.02exp(-46000/RT)cm~2·sec~(-1).而在剂量较底的情况下(N_d(?)10~(16)ions cm~(-2)),可表示为D(?)0.02exp(-44000/RT)cm~2·sec.~(-1)。实验证实了永久性的强陷阱中心的存在。     

太阳能电池用低掺杂率多晶硅薄膜的制备

通过铝诱导晶化非晶硅(Aluminum-Induced Crystallization, AIC)制备的多晶硅薄膜具有较高的铝掺杂浓度(2×10¹⁸ cm^-3), 不适宜作为薄膜太阳能电池的吸收层. 我们提出了QCGE AIC法, 即: 硅原子的快速扩散; 冷却成核; 晶粒的慢速生长; 铝原子的向外扩散.通过精确控制AIC过程中退火温度及模式制备了掺杂率为2×10¹⁶ cm^-3的高品质多晶硅薄膜. 二次离子质谱(Secondary-Ion-mass Spectroscopy, SIMS)结果表明: 制备多晶硅薄膜中铝残留浓度依赖于退火的温度模式; 霍尔效应测试结果表明: 制备多晶硅薄膜的掺杂率依赖于退火的温度和退火模式; 拉曼光谱表明: 通过QCGE AIC 制备的多晶硅薄膜中包含有少量由小颗粒硅组成的区域.     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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-