一种单晶光学晶体的晶面偏角及偏向测算方法

本文提出了一种运用三点法来求取单晶实际切割晶面相对于理想切割晶面方位角度的一种定向简便计算方法。单晶光学晶体晶面由于生长和切割误差等原因,往往造成实际切割晶面与理想切割晶面有偏角。为了获得这种偏角关系进行晶体的准确定向、切割加工,采用YX-2型X射线晶体定向仪与传统的数学计算方法相结合,运用三点法即可准确计算出实际切割晶面任意方位与理想切割晶面之间的偏角大小及具体偏向。晶体定向准确度高,操作方便,快速简捷,费用便宜,可准确地确定晶体的切割方向。     

TmxY1—xAl3（BO3）4晶体生长和光谱特性

用Ｋ２Ｍｏ３Ｏ１０－Ｂ２Ｏ３作助熔剂，采用缓慢降温自发成核的方法，生长了稀土四硼酸盐晶体ＴｍｘＹ１－ｘＡｌ３（ＢＯ３）４（简称ＴＹＡＢ），晶体尺寸为８×６×５ｍｍ３．对所获得晶体进行Ｘ射线结构分析，表明ＴＹＡＢ晶体属三方晶系，晶胞参数ａ＝９．２３７，ｃ＝７．１９２．测定了该晶体室温下的红外光谱、反射光谱、激发光谱及荧光光谱，当用２６１ｎｍ波长激发时，可产生３４５ｎｍ（３Ｐ０→３Ｈ４）蓝紫色及４５０ｎｍ（１Ｄ２→３Ｈ４）蓝绿色的荧光发射     

草酸钙结石结构中“菱形”晶体的性质——用弗氏台测定草酸钙结晶的光学常数

偏光显微镜下草酸钙晶体被描述为哑呤状、颗粒状、信封状或菱形状晶体,并把菱形结晶一直认为是二水草酸钙。有关其分类问题仍有争论。本文用弗氏台测定了结石中草酸钙的各种晶体形态的光学特征性常数和光率体成分(晶面夹角、晶棱与光学主轴之间关系,2V)。证实二水草酸钙属于中级晶族,四方晶系,晶体的形态是扁平四方双锥(信封状),一水草酸钙是低级晶族,单斜晶系,形态是斜方柱。本研究发现菱形晶属于一水和二水草酸钙的中问晶体,菱形晶有两种晶体形式,单锥和双锥的结晶形式,菱形晶不是二水草酸钙。     

Cu0.5Zr2（PO4）3中Cu^（2＋）离子中心各向异性g因子研究

采用3d离子斜方对称g因子的高阶微扰公式计算了Nasico型晶体Cu0.5Zr2（PO4）3中Cu^（2＋）离子中心各向异性g因子（gx，gy，gz），其中斜方晶场参量由重叠模型并联系晶体中Cu^（2＋）离子所处的局部结构确定。研究表明，晶体中Cu^（2＋）离子中心配体八面体平面键角相比理想斜方对称的90°要小10°左右，由此所得的因子计算结果与实验符合较好。     

Tb0.3Dy0.7（Fe,M）1.95合金的晶体轴向取向与磁致伸缩性能

研究了Ｔｂ０．３Ｄｙ０．７（Ｆｅ１－ｘＭｘ）１．９５（Ｍ＝Ｍｎ，Ａｌ，Ｂ，Ｔｉ，ｘ＝０．０３）合金在高温梯度区熔定向凝固过程中，晶体轴向取向，结晶形有晶体生长速度的变化规律和不同昌体轴向取向与磁致伸缩应变之间的关系，结果发现，晶体生长速度由低变，晶体由平面晶向胞状晶，胞技晶，树枝晶生长转化，晶体也相应地由〈１１０〉，〈１１２〉变化为〈１１０〉＋〈１１３〉＋〈１１２〉混合轴向取向，完全的〈１１２〉轴     

（C_6H_5）_3PO·p－ClC_6H_4OCH_2COOH的晶体结构

合成了（Ｃ６Ｈ５）３ＰＯ·ｐ－ＣｌＣ６Ｈ４ＯＣＨ２ＣＯＯＨ并解析了其单晶体结构。结果表明该晶体属于正交晶系，空间群是Ｐｂｃａ，ａ＝１．７１２２（４）ｎｍ，ｂ＝２．３８０３（７）ｎｍ，ｃ＝１．１３２８（４）ｎｍ，该晶体由三苯基氧膦和对氯苯氧乙酸组成，但晶体中对氯苯氧乙酸同单独的对氯苯氧乙酸晶体结构比较，相应的键长和键角有明显的差异。     

α－AL_2O_3单晶体的X射线衍射仪法分析

以α－ＡＬ２Ｏ３单晶体为例，探索了现代Ｘ射线衍射仪法分析技术在晶体取向和晶向偏离角测试方面的应用。采用该方法测试的（０００１）晶面的晶向偏离角为＝４．９７°，经ＴＥＭ电子衍射菊池线测试（０００１）晶面晶向偏离角△θ＝５．１１°，误差小于０．２°。表明本文提出的Ｘ射线衍射法测试单晶体晶体向偏离角具有简捷、精确及可靠性高的优点。     

三羟甲基氨基甲烷硫酸盐单晶的研究

报道一种三羟甲基氨基甲烷硫酸盐(THAMS)有机单晶。该晶体比较容易从水溶液中用降温法获得。用四圆衍射仪测定了晶体结构。发现在室温下该晶体属于三方晶系,空间群为 P3,其晶胞参数为α=7.5713,c=0.76099nm(7.6099),γ=120°。还给出了该晶体在可见光范围内的折射率。     

VO(H_2AsO_4)_2的合成与晶体结构

在五氧化二钒-三氧化二砷-砷酸-水体系中，以水热法合成了VO（H2AsO4）2蓝色四棱柱状晶体，晶体属四方晶系，P4／ncc群，a=b=0．9120（1）nm，c=0．8131（1）nm，V＝0．6763（2）nm3，Z＝4．     

立方晶系电子衍射自动检索程序

立方晶系晶体在常见合金相、夹杂物中几乎占二分之一.因此,编制立方晶系电子衍射自动检索程序是十分必要的.该程序能够计算晶面间距,标定与各衍射斑点相对应的晶面指数及晶带轴指数,而且,在上述基础上还给出可能的物相及晶格类型.该程序采用BASIC语言,可在PC—1500袖珍计算机上运行.     

含柔性间隔基团的主链型液晶高分子的分子场理论

研究了主链型液晶高分子中柔性间隔基因对聚合物结构和液晶性的影响规律。提出含柔性间隔基因液晶高分子中介品单元分子内取向的模型，及分子内取向分布和取向有序度参数等概念。探讨了分子内取向有序度参数和大分子中化学键的键角，内旋转二面角，内旋转位能等的定量关系。在上述概念和模型的基础上，提出了含柔性间隔基团液晶高分子的分子场理论。由此可从键角，内旋转二面角，内旋转位垒等结构参数计算液晶相变温度ＴＮＩ，取向有序度参数和热力学函数等。对上述理论的计算方法及应用也进行了讨论。理论和计算能较好地说明柔性间隔基团对ＴＮＩ等影响的规律。     

微接触印刷法制备新型液晶垂直取向膜

采用微接触印刷法在盖玻片表面制备了微米级沟槽状N′-β′-氨乙基-N-β-氨乙基-γ-氨丙基三甲氧基硅烷薄膜,通过在其表面组装Cu ²⁺制得了液晶垂直取向膜。当有机膦化合物甲基膦酸二甲酯(DMMP)气体通过薄膜表面时,液晶分子发生偏转;当新鲜空气通过时,液晶分子恢复垂直排列,从而实现对DMMP的定性检测。     

论陨石系列受晶格能控制的规律

利用计算方法求陨石的晶格能,从铁陨石、碳质球粒陨石、球粒陨石到无球粒陨石晶格能依次增高,陨石形成受晶格能控制并按晶格能由低到高的顺序出现,与地球上矿物和岩石结晶过程具有相同的晶格能控制规律。陨石晶格能系数与其平均克原子量,满足的函数关系。     

Relationship between structural order and the anomalies of liquid water

In contrast to crystalline solids--for which a precise framework exists for describing structure--quantifying structural order in liquids and glasses has proved more difficult because even though such systems possess short-range order, they lack long-range crystalline order. Some progress has been made using model systems of hard spheres, but it remains difficult to describe accurately liquids such as water, where directional attractions (hydrogen bonds) combine with short-range repulsions to determine the relative orientation of neighbouring molecules as well as their instantaneous separation. This difficulty is particularly relevant when discussing the anomalous kinetic and thermodynamic properties of water, which have long been interpreted qualitatively in terms of underlying structural causes. Here we attempt to gain a quantitative understanding of these structure-property relationships through the study of translational and orientational order in a models of water. Using molecular dynamics simulations, we identify a structurally anomalous region--bounded by loci of maximum orientational order (at low densities) and minimum translational order (at high densities)--in which order decreases on compression, and where orientational and translational order are strongly coupled. This region encloses the entire range of temperatures and densities for which the anomalous diffusivity and thermal expansion coefficient of water are observed, and enables us to quantify the degree of structural order needed for these anomalies to occur. We also find that these structural, kinetic and thermodynamic anomalies constitute a cascade: they occur consecutively as the degree of order is increased.     

Liquid crystal phase transitions in suspensions of polydisperse plate-like particles

Colloidal suspensions that form periodic self-assembling structures on sub-micrometre scales are of potential technological interest; for example, three-dimensional arrangements of spheres in colloidal crystals might serve as photonic materials, intended to manipulate light. Colloidal particles with non-spherical shapes (such as rods and plates) are of particular interest because of their ability to form liquid crystals. Nematic liquid crystals possess orientational order; smectic and columnar liquid crystals additionally exhibit positional order (in one or two dimensions respectively). However, such positional ordering may be inhibited in polydisperse colloidal suspensions. Here we describe a suspension of plate-like colloids that shows isotropic, nematic and columnar phases on increasing the particle concentration. We find that the columnar two-dimensional crystal persists for a polydispersity of up to 25%, with a cross-over to smectic-like ordering at very high particle concentrations. Our results imply that liquid crystalline order in synthetic mesoscopic materials may be easier to achieve than previously thought.     

基于FLAC3D复合顶煤大断面煤巷围岩数控模拟

为了解决某矿复合顶煤大断面开切眼施工困难问题,采用工程类比法确定支护方案,后运用FLAC3D软件在不同支护方式下进行模拟分析,研究其主要影响因素.模拟结果表明:锚杆、锚索间排距的改变不能从宏观上改变巷道围岩的应力分布特征,但能限制围岩最大位移量,能限制浅部围岩破坏形式和破坏程度.研究结果对该矿煤层切眼支护方式的选择、支护方案设计、支护材料布局、支护参数的确定提供了科学依据.     

混合稀土对AB5贮氢合金织构生长特性影响的PLS研究

利用偏最小二乘法（PLS）研究混合稀土组成对贮氢合金的织构生长特性的综合影响,并提出了合金织构择优取向的判据。对于平行于柱状晶织构,择优取向（101） (201)晶面受Nd的影响最为敏感,Ce的影响最小,同时Ce对择优取向的作用与La,Pr,Nd的作用相反;对于垂直柱状晶织构,择优取向（200） (110)晶面受Pr的影响最为敏感,而受Nd的影响最小。     

β型四钼酸铵的制备及结晶过程

研究了用晶种生长法制备β型四钼酸铵的方法．其制备分2步进行首先用酸沉法制备四钼酸铵;再以酸沉法制得的四钼酸铵为原料,氨浸后用晶种法制备β型四钼酸铵,其包含2个相关过程(一是晶核的生成过程,控制pH值为1.2;二是晶核的长大过程,控制pH值为2～3)．对2种结晶进行差热及热重分析,结果表明用酸沉法制得的为α型四钼酸铵,用晶种法制得的晶体为β型四钼酸铵．用晶种法制得的结晶的晶体形貌与用酸沉法制得结晶的晶体形貌相比,颗粒较大且均匀．对四钼酸铵的结晶过程进行了热力学分析和动力学分析,说明结晶反应自发进行的趋势很强,速度也较快．此外,初步探讨了四钼酸铵结晶过程机理和晶型的控制,阐明了晶体生长速度的大小对实际晶体的影响．     

点状籽晶法生长KDP晶体的(100)面位错分布

通过光学显微镜对点状籽晶法生长的KDP晶体（100）面位错蚀坑的观察和分析，发现柱区的位错线走向不同于片状籽晶法生长的晶体。晶体的位错主要来自籽晶的位错。通过籽晶成锥-微溶-生长的过程可以减少籽晶锥区位错向晶体中的延伸，在晶体内部，当两条夹角很小的位错线相交时会合并成一条位错线。     

High entropy state of orientationally-disordered clusters in Zr-based bulk metallic glass

A phase transformation of a metastable Zr2Ni intermetallic crystalline phase to vitrify was studied with molecular dynamics (MD) simulations based on a plastic crystal model (PCM), which utilizes the orientational disorder of molecules of plastic crystals in a class of soft matter. The simulation results show ed that computational operations in MD-PCM for the random rotati ons of the clusters in the crystalline phase around their center of gravity and subsequent annealing lead to form a dense random pa cking structure from the metastable Zr2Ni phase. These randomly-rotated clusters provide high degrees of freedom in terms of atomic positions, which results in enhancing the glass-forming ability of the alloy. The critical fraction of the number of rotated cl usters for forming the glassy phase ( fc^R) is evaluated to be 0.75 ? 0.80. Thus, the critical fraction of the number of un-rotated clusters (fc^U=1?fc^R) is close to the critical concentration of site percolation for metallic materials. The mechanism of the metastable Zr2Ni phase to vitrify with increasing f^R was analyzed with a concept of communal entropy in the free volume theory with solid- and liquid-like cells proposed by Cohen and Grest. The MD-PCM for the metastable Zr2Ni phase suggests that Zr-based bulk metallic glass (BMG) can be regarded as an alloy in a high rotation entropy state of cl usters and that glass transition takes place by percolation of th e nuclei of a liquid-like glassy phase.