固体激光棒的表面处理对热透镜效应的影响

实验研究了一个抛光表面的红宝石激光棒和三个未抛光表面的金绿宝石激光棒的热透镜效应讨论了它们之间的区别，进行了理论分析，实验结果与理论相符合。     

端面研磨Nd:YAG晶体棒热透镜焦距测量

主要分析和测量端面研磨凹面的Nd:YAG激光晶体棒的热透镜焦距。实验通过He-Ne光测试法,分别测量了不同功率下的端面研磨和未研磨晶体棒的热透镜焦距,并通过作图比较二者的热透镜焦距随泵浦功率变化情况,得出随着泵浦功率的增大,热透镜焦距逐渐减小的结论。文中对未研磨晶体棒热透镜焦距进行了理论和实验值的比较,曲线情况基本相符,故根据理论计算出补偿热透镜效应所需要的晶体棒的研磨半径。由于通过理论计算得出的研磨半径在实验过程中出现了出光阈值高,输出功率降低等一些现象,不利于生产的需要,故在实际经验的指导下,增大了晶体棒的研磨半径。结论指出端面研磨晶体棒的方法在一定条件下能对激光晶体棒的热透镜效应进行补偿,对大功率固体激光器的研发有一定积极作用。     

固体激光棒的表面处理对热透镜效应的影响

实验研究了一个抛光表面的红宝石激光棒和三个未抛光表面的金绿宝石激光棒的热透镜效应讨论了它们之间的区别,进行了理论分析实验结果与理论相符合     

激光V型谐振腔的等价腔分析法

为了分析激光谐振腔的稳定性,选取广泛应用的V型腔作为研究对象,将V型折叠腔等效为含有透镜的三镜直型腔(共轴球面腔),然后采用*g-参数等价腔分析法,将三镜直型腔等价为不含透镜的共轴球面腔,进而考虑激光晶体的热透镜效应,采用多元件光学谐振腔等价腔分析法推导出热透镜效应下V型腔的g?-、g?-等价空腔.该方法形象地将V型腔与共轴球面腔联系了起来,有效地体现V型谐振腔中各参量之间变化关系,通过对热透镜效应下V型腔的g?-、g?等价空腔的计算,便可对V型腔的稳定性的影响因素进行求解分析,为激光谐振腔的分析和设计提供重要参考.     

具有内透镜效应的等效激光谐振腔

具有内透镜效应的激光谐振腔可以简化为等效激光谐振腔。讨论了具有内透镜效应的激光谐振腔的稳定性。     

用光线传递矩阵讨论激光棒的端面负透镜修正

本文使用光线传递矩阵方法,讨论了热畸变激光棒的热焦距及其端面负透镜补偿,并对激光棒进行端面负透镜修正后的分布孔径和模体积作了计算。     

激光谐振腔内类透镜介质像差的校正

高能激光器谐振腔中，介质折射率随温度、压力、能量等物理量沿径向变化而呈类透镜分布，由此引起激光振荡特性的改变，产生动态的类透镜介质像差，根据光波的矩阵传输理论，以正支共焦望远型非稳腔为例，用几何方法对激光谐振腔内的类透镜介质效应及其像差校正进行了理论分析，计算结果显示，所给方法能有效消除该像差。     

单宽域有效动态稳定腔的理论与实验研究

单宽域有效动态稳定腔的理论与实验研究王建（扬州大学工学院科研处２２５００９）徐荣青夏厚勤（华中理工大学激光技术国家重点实验室武汉４３００７４）光泵Ｎｄ：ＹＡＧ激光器的热效应会在ＹＡＧ棒中引起轴向热伸长和径向折射率梯度，从而产生激光介质的热透镜效应。内...     

激光谐振腔内类透镜介质像差的校正

高能激光器谐振腔中，介质年射率随温度，压力，能量等物理量沿径向变化而呈类透镜分布，经引直民激光振荡的改变，产生动态的类透镜介质像差。根据光波的矩阵传输理论，以正支共焦望远型非稳腔为例，用几何方法对激光谐振腔内的类透镜介质效应及其像差校正进行了理论分析，计算结果显示，所给方法能有效消除该像差。     

Nd:YAG激光器的热透镜效应及其对激光输出的影响

对Nd：YAG激光器的热透镜效应进行了分析，给出了实验测量动态热效应的方法．利用矩阵光学的方法，分析了热透镜效应对激光输出功率和光束质量的影响，并计算了两种谐振腔参数下的束腰宽度ωo、远场发散角θo和模体积V随热焦距f的变化情况．     

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

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.     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

A computer generator for randomly layered structures

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

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

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.