聚醚酮酮第Ⅱ晶型结构的WAXD研究

聚醚酮酮显著特征是结构多晶型现象，其第Ⅱ晶型晶胞参数：ａ＝０．４１８ｎｍ，ｂ＝１．、１４１ｎｍ，ｃ＝１．００７ｎｍ，明显不同于第Ⅰ晶型。广角Ｘ射线研究聚醚酮酮熔融，玻璃态及溶剂结晶表明，Ⅰ，Ⅱ晶型可以共存并在一定条件下Ⅱ转化为Ⅰ型晶型。故可将两种晶型分开，所得第Ⅱ晶型晶胞体积比第Ⅰ晶型小。     

生物材料PCL的晶体结构

用ＷＡＸＤ方法测定了生物高分子材料ＰＣＬ的晶体结构。求出晶胞参数数ａ＝０．７４７２ｎｍ，ｂ＝０．４９９５ｎｍ，ｃ＝＝１．７０５０ｎｍ，Ｖ＝０．６３６３ｎｍ＾３及晶体密度Ｄｃ＝１．２０ｇ／ｃｍ＾３；ｚ＝４属正交晶系；对称性分离，属Ｐ２２２空间群，Ｎ＝２，分子链构橡为ＰＺ型，并给出了晶结构模型。     

一个与准晶相关的新Al—Cu相

本文报道一个新Ａｌ－Ｃｕ相，具有正交结构，空间群Ｆｄｄｄ，点阵常数为：ａ＝０．８１６６ｎｍ，ｂ＝０．９９９５ｎｍ，ｃ＝１．４１４９ｎｍ，表达式为Ａｌ４３．２Ｃｕ５６．８，该相与Ａｌ－Ｃｕ－Ｆｅ准晶的价电子浓度相同，是一个由ＣｓＣｌ结构衍生的类似相。     

一个与准晶相关的新Al－Cu相

本文报道一个新Ａｌ－Ｃｕ相具有正交结构，空间群Ｆｄｄｄ．点阵常数为：ａ＝０．８１６６ｎｍ，ｂ＝０．９９９５ｎｍ，ｃ＝１．４１４９ｎｍ，表达式为Ａｌ４３．２Ｃｕ５６．８．该相与Ａｌ－Ｃｕ－Ｆｅ准晶的价电子浓度相同，是一个由ＣｓＣｌ结构衍生的类似相．     

环十二酮肟在硫酸中热效应

使用ＲＤ－１型热导式自动量热计测量了不同温度下环十二酮肟在９８％硫酸中热效应。结果表明：当Ｔ＜３３３Ｋ时，仅产生溶解热效应，３０３Ｋ下溶解热△Ｈ＿（ｓ，ｍ）＝－５１．７ｋＪ·ｍｏｌ￣（－１）（ｍ＝４．２８５ｍｏｌ·ｋｇ￣（－１））；当Ｔ＞３４３Ｋ时发生环十二酮肟重排反应，３９３Ｋ下反应热△Ｈ＿（Ｒ，ｍ）＝－２３１．８ｋＪ·ｍｏｌ￣（－１）（ｍ＝４．９６×１０￣（－３）ｍｏｌ·ｋｇ￣（－１））和△Ｈ＿（Ｒ，ｍ）＝－２３７．０ｋＪ·ｍｏｌ￣（－１）（ｍ＝１．７×１０￣（－２）ｍｏｌ·ｋｇ￣（－１））。     

国产金属有机化合物TMGa,TMAl,TMIn和TMSb的MOVPE鉴定

利用我们研制的常压ＭＯＶＰＥ设备对国产ＴＭＧａ、ＴＭＡｌ、ＴＭＩｎ和ＴＭＳｂ进行了鉴定，为此分别生长了ＧａＡｓ、ＡｌＧａＡｓ、ＩｎＰ、ＧａＳｂ外延层和ＧａＡｓ／ＡｌＡｓ、ＧａＳｂ／ＩｎＧａＳｂ超晶格和ＧａＡｓ／ＡｌＧａＡｓ量子阱结构。表征材料纯度的７７Ｋ载流予迁移率分别达到ＧａＡｓ：μ＿ｎ＝５６６００ｃｍ￣２／Ｖ·ｓ，Ａｌ＿（０．２５）Ｇａ＿（０．７５）Ａｓ：μ＿ｎ＝５１６０ｃｍ￣２／Ｖ·ｓ，ＩｎＰ：μ＿ｎ＝６５３００ｃｍ￣２／Ｖ·ｓ，ＧａＳｂ：μ＿ｐ＝５０７６ｃｍ￣２／Ｖ·ｓ。由１０个周期的ＧａＡｓ／ＡｌＡｓ超晶格结构组成的可见光区布拉格反射器已观测到很好的反射光谱和双晶Ｘ射线回摆曲线上高达±２０级的卫星峰。ＧａＡｓ／Ａｌ＿（０．３５）Ｇａ＿（０．６５）Ａｓ量子阱最小阱宽为１０，在ｌｉＫ下由量子尺寸效应导致的光致发光峰能量移动为３９０ｍｅＶ，其线宽为１２ｍｅＶ。这些结果表明上述金属有机化合物已达到较高质量。     

以Ba云母为主晶相的可切削玻璃陶瓷

基于Ｂａ０．５Ｍｇ３（Ｓｉ３ＡｌＯ１０）Ｆ２－Ｍｇ２Ａ１４Ｓｉ５Ｏ１８－Ｃａ３（ＰＯ４）２系统，制备出了以含Ｂａ碱士云母为主晶相的可切削玻璃陶瓷，弯曲强度σｂ＝２２９ＭＰａ，断裂韧性Ｋｌｃ＝２．４８ＭＰ·ｍ１／２；钻孔速度大于７ｍｍ／ｍｉｎ．优良性能的获得借助于Ｂａ云母玻璃陶瓷可控的显微组织，即相互交错的云母体和“卷心菜”的组织特征．观察到了两类类型的断口形貌：云母晶体层内断的层状花样和沿（００１）晶面层间断的小刻面花样．     

一氧化碳和苯乙烯交替共聚物的合成与表征

利用乙酸钯和２，２′－联吡啶组成的催化剂体系催化一氧化碳和苯乙烯交替共聚合成出聚（１－氧代－２－苯基丙撑）（ＳＴＣＯ）。采用ＩＲ、ＮＭＲ、元素分析以及广角Ｘ光散射对该聚合物以表征。该共聚物晶体为单斜晶胞，晶胞参数为ａ＝１５．７×１０－１０ｍ，ｂ＝６．１７×１０－１０ｍ，ｃ＝７．４５×１０－１０ｍ，α＝９０．０°，β＝１０４．３°，γ＝９０．０°；晶胞体积为６９７．２×１０－３０ｍ３；空间点群为Ｐ２１／ｃ。此外，对该共聚物热降解进行了初步研究。     

二磷酸钕钾晶体的生长与光谱

Ｋ３Ｎｄ（ＰＯ４）２晶体是一种高稀土浓度的激光晶体．本文报道从ＫＦ－ＫＣｌ体系中采用助熔剂法培养出Ｋ３Ｎｄ（ＰＯ４）２晶体．该晶体呈淡紫红色，属单斜晶系，Ｐ２_１／ｍ空间群，晶胞参数为ａ＝９．５３４　，ｂ＝５．６２９　，ｃ＝７．４４３　，β＝９０．９６°．测定了晶体室温下的吸收光谱、荧光光谱、激发光谱和红外光谱．     

n型GaSb,InGaAsSb的MBE生长和特性研究

本文报导了非故意掺杂ＩｎＧａＡｓＳｂ本底浓度的降低和掺Ｔｅｎ型ＧａＳｂ和ＩｎＧａＡｓＳｂ的ＭＢＥ生长与特性的研究结果。结果表明，通过生长工艺的优化，ＧａＳｂ和ＩｎＧａＡｓＳｂ的背景空穴浓度可分别降至１．１×１０~（１６）ｃｍ~（－３）和４×１０~（１６）ｃｍ~（－３），室温空穴迁移率分别为９４０ｃｍ２／ｖ．ｓ和２６０ｃｍ~２／ｖ．ｓ。用Ｔｅ作ｎ型掺杂剂，可获得载流子浓度在１０~（１６）～１０~（１８）ｃｍ~（－３）的优质ＧａＳｂ和ＩｎＧａＡｓＳｂ外延层，所研制的材料已成功地制备出Ｄ_λ~＊＝４×１０~（１０）ｃｍＨｚ~（１／２）／Ｗ的室温ＩｎＧａＡｓＳｂ红外探测器和室温脉冲ＡｌＧａＡｓＳｂ／ＩｎＧａＡｓＳｂ双异质结激光器。     

聚醚酮酮及其低聚物晶体的多晶型结构

利用WAXD研究PEKK的晶型，得到两种晶型其点阵常数（nm）为：I型a=0．775,b=0.609，c=101及II型a=0．418，b=1.13，c=1.007;表明多晶型不仅与结晶条件也与分子结构有关改变分子结构，在二氯乙烷中结晶都可将两种晶型完全分开对PEKK低聚物在二氯乙烷中结晶样品的研究证实了上述晶到     

Mn(C_2Cl_3O_2)Cl(C_(12)H_8N_2)_2的合成、表征及其纳米晶体参数计算

以Cl3CCOOH、1,10-菲罗啉为配体,以MnCl2·4H2O为金属离子盐,通过溶液蒸发法合成了具有纳米级金属骨架的三元配合物Mn(C2Cl3O2)Cl(C12H8N2)2。通过元素分析、红外光谱、X单晶衍射测得配合物属于单斜晶系,其空间群为P21/c,a=1.8155nm,b=1.0638nm,c=1.4685nm,β=112.9°,z=4,V=2.6110nm3。通过纳米化计算的方法,计算出总晶胞数、总原子数、及表面参数随粒径变化的关系,得出Mn(C2Cl3O2)Cl(C12H8N2)2最佳纳米化尺度为115nm。     

新型酰腙类Cu(Ⅱ)配合物的合成、晶体结构及荧光性质

由5-溴-2-羟基苯基乙酮与2-羟基苯甲酰肼在乙醇溶剂中反应得到5-溴-2-羟基苯基乙酮-2-羟基苯甲酰腙。以该酰腙、吡啶和氯化铜水热合成配合物(C15H11N2O3Br)Cu(C5H5N)。通过元素分析和X射线单晶衍射对其进行了表征,结果表明,配合物属单斜晶系,P21/c空间群,晶胞参数a=0.98929(19)nm,b=2.4177(5)nm,c=0.78755(16)nm,β=97.285(4)°,V=1.8685(6)nm3,Dc=1.745mg/m3,F(000)=984。荧光光谱表明,配体和配合物均具有荧光性,配合物在360.0～410.0nm处的荧光强度得到了增强。     

CO-DEPOSITION OF FULLERENES AND SULFUR FROM DILUTED SOLUTION

A new method to synthesize fullerene and sulfur compounds has been developed. Using this method, C₆₀S₁₆ and C₇₀S₁₆ compounds were grown from dilute fullerene and sulfur toluene solution. Their atomic structures were analyzed by x-ray diffraction with the single crystal. The C₆₀S₁₆ crystal is C-centered monoclinic structure of a=2.0874 nm, b=2.1139 nm, c=1.05690 nm and β=111.93°, and the C₇₀S₁₆ has a primitive monoclinic, P2₁/c, with lattice parameters of a=1.5271 nm, b=1.49971 nm, c=2.18024 nm and β=109.791°. In this compound, the structure of fullerenes is maintained and sulfur atoms form S₈ rings placed around the fullerenes.     

Structure, growth, and optical properties of TbAl3(BO3)4 single crystal

TbAl(3)(BO(3))(4) single crystal was grown from a K(2)Mo(3)O(10)-B(2)O(3) system using the top-seeded high temperature solution method (TSSG), 20 mm×9 mm×7 mm in size. The grown crystal was characterized by x-ray diffraction analysis showing that the crystal has a trigonal structure and the space group is R32 with lattice parameters of a = b = 9.293(13) ?, c = 7.249(6) ?. Faraday rotations of TbAl(3)(BO(3))(4) crystal were investigated at room temperature at wavelengths of 532, 633, and 1064 nm. Finally, the Verdet constants were measured at V = -108.8, -85.7, and -20.8 rad/mT for 532, 633, and 1064 nm, respectively.     

Fabrication and characterization of flexible high performance thermoplastic foams derived from rigid polyetherketoneketone via a VOC-free foaming method

There is a high demand for a volatile-organic-compound (VOC)-free approach to converting high performance polymers (HPPs), such as polyetherketoneketone (PEKK), to porous structures. This is particularly true for achieving flexible foams from these very rigid HPPs. This current work introduces a facile and environmentally benign approach to fabricating flexible PEKK foams via a hydration-induced foaming and desulfonation treatment. This foaming technique possesses three major advantages: energy efficiency, environment friendliness, and super flexibility. The resultant flexible PEKK foam has a uniform porous structure with a cell diameter of ca. 5 μm, as well as low mass density of ca. 0.42 g/cm³. Thermal analysis revealed that the porous PEKK showed a high thermal stability with a thermal degradation temperature of 520 °C, showing superiority over other reported flexible polymer foams. Compared with solid PEKKs fabricated by compression molding, the porous PEKK has a higher crystallinity and more thermodynamically stable crystal structures. According to nanoindentation analysis, the flexibility of porous PEKK may be a result of the better chain mobility in porous PEKK. The reduced modulus and hardness of porous PEKK are 0.73 ± 0.16 and 0.09 ± 0.03 GPa, respectively. The porous structures also efficiently reduced the dielectric constant from ca. 4.0 to 2.6 in a wide frequency range.     

Structure of metastable precipitate in some Al–Cu–Mg–Ag alloys

Abstract

The high strength of some Al–Cu–Mg–Ag alloys has been attributed to very thin (~2·5 nm), but broad, hexagonal-shaped precipitates. Previous work has shown that the precipitates have a hexagonal unit cell, but different lattice parameters have been reported. In the present paper, the intensities of X-ray diffraction reflections from the precipitates have been measured on Buerger precession photographs, and it is shown that the crystal structure is monoclinic (space group P2/m) with the parameters a = b = 0·496 nm, c = 0·848 nm, γ = 120°. The special values of these parameters confer a hexagonal symmetry on the lattice. This unusual structure is a slightly distorted form of θ-CuAl₂, to which it appears to change after long aging times at 200°C.     

Mg－PSZ中二种析出相的初步研究

本文采用了较简便的烧成工艺制度制备Ｍｇ－ＰＳＺ材料．用ＴＥＭ对这种Ｍｇ－ＰＳＺ材料中的析出相进行了观察，对析出相的结构进行了初步的研究，发现了其中的二种未知析出相Ｘ１相和Ｘ２相．Ｘ１相具有简单四方结构，点阵常数约为ａ＝１．４４８ｎｍｃ＝２．１００ｎｍ．Ｘ２相也具有简单四方结构，点阵常数约为ａ＝１．４４０ｎｍ，ｃ＝４．０７２ｎｍ．     

Negative thermal expansion in one-dimension of a new double sulfate AgHo(SO4)2 with isolated SO4 tetrahedra

A double holmium-silver sulfate was obtained for the first time.The temperature intervals for the for-mation and stability of the compound were determined by differential scanning calorimetry.The crystal structure of AgHo(SO4)2 was determined by Rietveld method.The X-ray diffraction(XRD)analysis showed that the compound crystallizes in the monoclinic syngony,space group P21/m,with the unit cell param-eters a=4.71751(4)?,b=6.84940(6)? and c=9.89528(9)?,β=95.1466(4)°,V=318.448(5)?3,Z=2,RB=1.55％,T=303K.Two types of sulfate tetrahedra were found in the structure,which significantly affected the spectral properties in the infrared range.In the temperature range of 143-703 K,a negative thermal expansion along the b direction accompanied by a positive thermal expansion along the a and c directions was observed.It was established that negative thermal expansion is the result of the deforma-tion of sulfate tetrahedra,which is affected by the movement of holmium and silver atoms.The excitation in the blue spectral range(457.9 nm)produces a luminescence in light blue(489 nm),green(545 nm)and red(654 nm)spectral ranges,and the latter two were of comparable intensity that is favorable for WLED sources.The observed luminescent band distribution is ascribed to the specific crystal field at Ho3+ion sites rather than a variation of radiationless probability.     

Precipitations in an Yttrium-Containing Low-Expansion Superalloy

The resistance to stress-accelerated grain-boundary oxygen embrittlement and notch-bar rupture strength in Fe–Ni–Co–Nb–Ti low-expansion superalloy has been improved significantly by trace yttrium addition. The precipitates in the matrix as well as along the grain boundaries have been studied systematically. The platelet precipitates in the matrix and along the grain boundaries have a hexagonal crystal structure (space group, P6/mmm) with lattice parameters a = 0.498 nm and c = 0.408 nm. The crystallographic orientation relationship between the phase and the matrix is found to be . The semi-continuous discrete precipitates along the grain boundaries have an orthorhombic crystal structure with lattice parameters a = 0.45 nm, b = 0.80 nm and c = 1.20 nm. High-resolution images show that the interface between the precipitates and the matrix is semicoherent.