用AFM观测凝胶法下KClO4晶体的生长机理

用原子力显微镜(atomic force microscopy,AFM)对凝胶法生长的KClO4晶体的最重要面{001}面微观形貌进行了研究。结果表明,在不同的过饱和度下,KClO4晶体分别表现为二维成核生长、三维成核生长、层核生长以及多层堆垛生长等生长机理。从热力学角度解释了过饱和度对KClO4晶体生长机理的影响。对二维成核生长机理,揭示了KClO4晶体生长中二维核的形状和取向,及生长台阶的取向。研究结果还表明,杂质的存在将阻止台阶的向前推进,并导致聚并台阶及弯曲台阶的形成。     

用AFM研究杜仲抗真菌蛋白的晶体生长

随着后基因组时代的到来以及蛋白质组学研究的深入开展,研究蛋白质晶体生长成为生物化学和结构生物学领域一个广泛关注的课题.通过使用原子力显微镜(Atomic Force Microscope,简称AFM)对杜仲抗真菌蛋白(eucommia antifungal protein,简称EAFP)的晶体在有母液存在下原位实时动态地进行了晶面生长观察.研究结果表明:不同过饱和度对EAFP晶体生长形貌的影响较大,较高的过饱和度下生长很快,生长台阶密度高,较高的过饱和度下主要进行各向异性二维台阶的发生、发展,较低的过饱和度下主要采用螺旋位错的生长方式,当过饱和度极低时生长缓慢,且晶体表面有很多小孔存在,晶面生长很不完整;还对不同过饱和度下晶体生长速率进行了定量的测量,也反映了过饱和度对EAFP晶体生长的影响;同时对在AFM观察过程中由探针的扫描速度和方向对表面形貌的影响进行了讨论.     

基于光测法的晶种量对结晶动力学影响研究

为进一步探究晶种添加量对于结晶动力学尤其是生长动力学的影响,以KNO3-H2O溶液为模型体系,结合光测法开展了添加晶种的间歇冷却结晶动力学实验.通过测定可反映结晶固相信息的体系透光率的变化曲线,结合溶液质量比和相对过饱和度等实测数据,借用前期所建的模型方程,拟合得到了结晶体系的成核与生长动力学参数.在此基础上,运用回代计算的方法,考察并分析了晶种添加量对于结晶成核与生长动力学的影响.结果表明:随着晶种添加量的提高,结晶体系的成核效应逐渐减弱,生长效应逐渐增强,晶体产品的粒度更趋于均匀;同时,单个晶体的线性生长速率却有所下降,从而导致产品的平均粒度减小.     

地塞米松磷酸钠的反应结晶动力学

利用连续稳态法在混合悬浮混合产品排除(MSMPR)结晶器中研究了地塞米松磷酸钠反应结晶动力学。以粒数密度衡算方程为基础，由实验得到的晶体粒度分布数据，采用非线性最优化方法直接进行参数估计，确定了地塞米松磷酸钠晶体的成核和生长速率方程．动力学方程的分析结果表明，地塞米松磷酸钠晶体生长速率与粒度相关，合适的过饱和度、悬浮密度和温度是得到理想地塞米松磷酸钠晶体的关键因素．     

杜仲抗真菌蛋白(EAFP)晶体动态生长研究

杜仲抗真菌蛋白(eucommia antifungal protcin,EAFP),含有41个氨基酸残基,其中有10个半胱氨酸,半胱氨酸间形成的二硫桥键使分子构象很稳定.EAFP的晶体属单斜晶系,空间群为P2 1.晶胞参数为:a=1.908 5 nm,b=2.322 5 nm,c=3.085 4 nm10-6,β=98.64,分子量为4158.9.EAFP晶体生长速度快,对X射线的衍射能力强,很值得研究其生长的机理.利用原子力,显微镜(AFM)对EAFP晶体的{100}面进行动态的生长研究,发现在中低过饱和度下主要以各向异性的单双链螺旋位错的生长模式进行生长,详细研究了这种螺旋的形成机制,并探讨了其结构基础.     

超细CaCO_3合成过程中的形态控制

利用电导率仪及pH计跟踪Ca(OH)_2碳化反应过程。研究结果表明:高浓度Ca(OH)_2悬浮液吸收CO_2形成CaCO_3的过程中,反应前期过程速率受CO_2吸收控制,反应末期受Ca(OH)_2的溶解控制,其中吸收控制为整个过程的关键步骤。利用TEM及X衍射分析研究了超细CaCO_3的成核生长机理,探讨了CaCO_3粒子均相成核形成非晶态CaCO_3,并与Ca(OH)_2结合形成线性中间体,而后转变成方解石晶型CaCO_3粒子的过程。考察了添加剂的作用机理,提出添加剂能促进CaCO_3粒子的成核过程,阻止粒子的凝并生长。实验成功地合成出不同形态的超细CaCO_3粒子。     

原子力显微镜研究蛋白质晶体生长机理及进展

原子力显微镜(AFM)这种能进行微尺度测量的精密仪器是目前研究晶体生长机理最为有效的方法之一,在晶体生长机理研究中起到了重要的作用,尤其是对于蛋白质晶体生长的研究显得更为突出.分别简明地阐述了利用AFM进行蛋白质晶体生长研究的工作原理,以及在这方面已经取得的研究成果,包括二维台阶生长、螺旋位错生长、法向生长、三维成核生长、台阶发展的不对称性、及杜仲抗真菌蛋白(EAFP)和天花粉蛋白(TCS)晶体生长的新进展.论述了利用空间微重力环境进行蛋白质晶体生长及空间蛋白质晶体生长的科研和应用, 指出今后进行蛋白质晶体生长研究的趋势和前景.     

陨石高压矿物学研究为地球板块俯冲带高压相转变机制提供新认识

橄榄石是石陨石和地幔的主要造岩矿物之一,它在高温高压条件下转变为高密度的似尖晶石(wadsleyite)和尖晶石(ringwoodite,林伍德石)矿物多形.橄榄石的高压相转变机制对认识地球和星球内部物质组成、结构以及地球动力学等具有极其重要的科学意义.高温高压实验研究表明,橄榄石的高压相转变可以经由颗粒边界成核生长,或沿晶体内部特殊方位成核生长而转变为高压相.然而,过去在天然岩石(受冲击陨石)中,仅发现通过颗粒边界物质扩散作用形成的林伍德石多晶集合体,一直未能观测到在橄榄石晶体内部发生的林伍德石片晶状成核生长的相转变现象.     

高温化学气相沉积法生长碳化硅晶体(HTCVD)

研究了SiC晶体高温化学气相沉积生长机理,从Sic晶体高温化学气相沉积生长过程的化学原理、反应条件、反应过程、一般工艺等方面进行探讨,并分析了沉积温度、气体压力、本底真空及各反应气体分压(配比)对SiC单晶生长及其缺陷形成的影响,基于以上分析,得出高温化学气相沉积法生长碳化硅晶体最佳的工艺条件.     

二水硫酸钙成核及生长现象的研究

研究了过饱和溶褐蠧aSO4*2H2O晶体成核及生长现象,同时对垢的形成机理进行了探讨.实验表明,成核延迟时间随溶液过饱和度增大而减小;CaSO4*2H2O晶体生长属于表面反应控制,且与粒径相关,晶体生长速度在(0.5×108～5.8×108)m/s之间(30℃,粒径(28～67)μm,Ca2+浓度0.035mol/L).乙     

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.     

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.     

A computer generator for randomly layered structures

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

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.