Study on the properties of poly(beta-hydroxybutyrate) grafted with maleic anhydride

The thermal stability, crystallization behavior and biodegradability of poly(beta -hydroxybutyrate) (PHB) grafted with maleic anhydride (MA) were studied by DSC,TGA, optical microscopy and WAXD. The results showed that thermal stability of maleated PHB was obviously improved, comparing with that of pure PHB. The temperature of decomposition was enhanced about 20 degreesC After grafting MA, the crystallization behavior of PHB changed evidently. The rate of spherulite growth decreased, the crystallization temperature from the melt state reduced, and the cold crystallization temperature from the glass state increased. With the increase in graft degree, the banding texture of spherulite became more distinct and orderly. Moreover, the introduction of MA groups promoted the biodegradation of PHB.

Synthesis and characterization of chiral smectic side-chain liquid crystalline polysiloxanes and ionomers containing sulfonic acid groups

The synthesis of new chiral smectic A (S-A) side-chain liquid crystalline polysiloxanes (LCPs) and ionomers (LCIs) containing 4-allyloxy-benzoyl-4-(S-2-ethylhexanoyl) p-benzenediol his ate (ABB) as mesogenic units and 4-[[4-(2-propenyloxy)phenyl] azo]benzensulfonic acid (AABS) as nonmesogenic units is presented. The chemical structures of the monomers and polymers are confirmed by FTIR spectroscopy or H-1-NMR. Differential scanning calorimetry (DSC), optical polarizing microscopy, and X-ray diffraction measurements reveal that all the polymers P-I-P-IV and ionomers P-V-P-VI exhibit S-A texture. The results seem to demonstrate that the tendency toward the S-A-phase region increases with increasing sulfonic acid concentration, and the thermal stability of the S-A phase is determined by the flexibility of the polymer backbones and the interactions of sulfonic acid groups. (C) 2001 John Wiley & Sons, Inc.

Synthesis and characterization of side chain liquid crystal M5MPP/MMEANB copolymers containing NLO active group

A new series of side chain liquid crystal polymers based on the backbone of polymethacrylate containing 4-nitroazobenzene and 4-methoxybiphenyl group as side chain mesogen were prepared and characterized, FTIR, H-1 NMR, POM and WAXD were used to study the structure, phase behavior and mesophase texture of this series of SCLC copolymers. The researches show that polymer PM5MPP and copolymer M5MPP/MMEANB are enantiotropic liquid crystalline polymers, but polymer PMMEANB has no liquid crystalline properties. DSC results showed that the thermal stability of the mesophase of this series of copolymers was enhanced by the existence of intermolecular electron donor-acceptor interaction. It was found that the temperature range of the mesophase of the copolymers was broadened with increasing 4-nitroazobenzene units. The focal-conic texture observed by POM indicated that this series of the copolymers possessed the characteristics of smectic liquid crystal.

Miscibility and crystallization of PHB PMA blends

The miscibility, crystallization behavior and morphological structure of PHB/PMA blends have been studied by the differential scanning calorimeter (DSC) and polarized optical microscopy (POM). The chemical repeat units of the two components of the blend are isomers. The results indicate that PHB and PMA are miscible in the melt. The addition of PMA into PHB results in a depression in the spherulite growth rate of PHB. With increasing PMA content in the blends, the texture of PHB spherulite becomes more open.

Synthesis and Characterization of Side-Chain Liquid Crystalline (M6MPP/M6NPAP) Copolymers with NLO Properties

A series of novel thermotropic side-chain liquid crystalline polymer based on polymethacrylate backbone containing electron-accepting 4-(4'-nitrophenylazo)phenoxy as nonlinear optical active group and electron-donating 4(4'-methoxyphenyl) phenoxy group as mesogen attached covalently to the backbone through the flexible spacer was prepared and characterized, respectively. The results from differential scanning calorimetry showed that these series of copolymers were enantiotropic liquid crystal with single mesophase. The melting points and the relative enthalpy change of the copolymers depressed with increasing the molar percent of 4'-nitroazobenzene monomer units over 0 similar to 50mol%, but the enthalpies change of the transition from mesophase to isotropic state increased for the copolymers containing 0 similar to 50mol% 4'-nitroambenzene units. The texture observed under polarized optical microscope identified that the copolymers containing 24molar% or more than 24mol% 4-nitroambenzene monomer units could form smectic mesophase with the focal-conic texture. The results detected by WAXD were in good agreement with the results observed by POM.

Miscibility and crystallization behavior of solution-blended PEEK/PI blends

Miscibility and crystallization behavior of solution-blended poly(ether ether ketone)/polyimide (PEEK/PI) blends were investigated by using DSC, optical microscopy and SAXS methods. Two kinds of PIs, YS-30 and PEI-E, which consist of the same diamine but different dianhydrides, were used in this work. The experimental results show that blends of PEEK/YS-30 are miscible over the entire composition range, as all the blends of different compositions exhibit a single glass transition temperature. The crystallization of PEEK was hindered by YS-30 in PEEK/YS-30 blends, of which the dominant morphology is interlamellar. On the other hand, blends of PEEK/PEI-E are immiscible, and the effect of PEI-E on the crystallization behavior of PEEK is weak. The crystallinity of PEEK in the isothermally crystallized PEEK/YS-30 blend specimens decreases with the increase in PI content. But the crystallinity of PEEK in the annealed samples almost keeps unchanged and reaches its maximum value, which is more than 50%. The spherulitic texture of the blends depends on both the blend composition and the molecular structure of the PIs used. The more PI added, the more imperfect the crystalline structure of PEEK. (C) 1998 John Wiley & Sons, Inc.

The synthesis and characterization of the novel poly(aryl ether ketone)s with liquid crystallinity

The novel poly(aryl ether ketone)s with liquid crystallinity were synthesized by nucleophilic substitution reactions of 4,4'-biphenol and substituted hydroquinone with 4,4'-difluorobenzophenone and their thermotropic liquid crystalline properties were characterized by DSC, PLM and WAXD, The copolymers containing 70% biphenol formed nematic phase while the copolymer containing 50% biphenol exhibited smectic texture, The banded textures were formed after shearing the sample in the nematic liquid crystalline state. The identification of the structures in each mesogenic phase has been carried out by combining WAXD with PLM and DSC.

Synthesis and characterization of the side chain liquid crystalline poly(monoester {6-[4-(p-nitrophenyl)azo]phenoxy-1-hexyloxy} of maleic anhydride)

The poly(monoester (6-[4-(p-nitrophenyl) azo]phenoxy-1-hexyloxy) of maleic anhydride) shows a smectic phase with a focal conic fan texture. With the decrease of the monoestering degree the phase transition temperature decreases and the mesomorphic temperature range becomes narrow. The hydrogen bonding between two carboxylic acid groups was found to play a very important role in forming the smectic phase structure. The smectic bilayer structure has been built through self-assembly via. intermolecular hydrogen bonding.

The synthesis and thermotropic liquid crystalline behaviour of novel main chain poly(aryl ether ketone)s containing a lateral phenyl group

Novel main chain poly(aryl ether ketone)s containing a lateral phenyl group were synthesized by nucleophilic substitution reactions of 4,4'-biphenol and phenylhydroquinone with either 4,4'-difluorobenzophenone or 1,4-bis(4-fluorobenzoyl)benzene and their thermotropic liquid crystalline properties were characterized by a variety of experimental techniques. Thermotropic liquid crystalline behaviour was observed in the copolymers containing 50 and 70mol% biphenol. Melting (T-m) and isotropization (T-i) transitions both appeared on the DSC thermograms. A banded texture was formed after shearing the sample in the liquid crystalline nematic state. As expected, each of the copolymers had a relatively lower melting transition than the biphenol-based homopoly(aryl ether ketone)s because of the copolymerization effect of the crystal-disrupting monomer phenylhydroquinone.

The synthesis and thermotropic liquid crystalline behavior of the novel poly(aryl ether ketone)s containing chloro-side group

The novel poly(aryl ether ketone)s containing chloro-side group were synthesized by nucleophilic substitution reactions of 4,4'-biphenol and chlorohydroquinone with either 4,4'-difluorobenzophenone(BP/CH/DF) or 1,4-bis(p-fluorobenzoyl)benzene (BP/CH/BF) and their thermotropic liquid crystalline properties were characterized by a variety of experimental techniques. The thermotropic liquid crystalline behavior was observed in the copolymers containing 50 and 70% biphenol. Melting transition (Tm) and isotropization transition (Ti) both appeared in the DSC thermograms. A banded texture was formed after shearing the sample in the liquid crystalline state. The novel poly(aryl ether ketone)s had relatively higher glass transition temperature (Tg) in the range of 168 similar to 200 degrees C and lower melting temperature (Tm) in the range of 290 similar to 340 degrees C. The thermal stability (Td) was in the range of 430 similar to 490 degrees C.

POLY(AZOMETHINE SULFONES) WITH THERMOTROPIC LIQUID-CRYSTALLINE BEHAVIOR

New poly(azomethine sulfones) with linear structures containing sulfonyl bis(4-phenoxyphenylene) and oxo bis(benzylideneaniline) or methylene bis(benzylideneaniline) units were prepared in the conventional literature manner by condensing the dialdehyde sulfone monomer (V) with diamines such as 4,4'-oxydianiline (IIIa) and 4,4'-methylenedianiline (IIIb), or by condensing an azomethine biphenol (IX) with 4,4'-sulfonyldichlorobenzene (II). Three model compounds which reproduced the above structures were also synthesized. The resulting polymers were confirmed by IR, H-1-NMP, and elemental analysis, and were characterized by inherent viscosities, thermogravimetric analysis (TGA), and x-ray diffraction. The thermotropic liquid crystalline (TLC) behavior was studied using polarization light microscopy (PLM), thermooptical analysis (TOA), and DSC. A nematic texture was observed only for 4,4'-oxydianiline-units-based polymers. The reaction of polymer VIIIb containing -CH2- links between the mesogens with the model compound IX led to polymer X which exhibited TLC behavior.

Crystallization of Clinopyroxene NaAlSi2O6 from Glass

Clinopyroxene NaAlSi2O6 was synthesized under varying pressures of 3.0-5.0GPa and at the temperature range of 1150.1750 degrees C, for periods of 1.480min. The glass material was completely transformed into homogeneous penetrating fibrous texture of clino

基于纹理的视觉伺服研究

视觉伺服是机器人控制中的一种重要方法，也是计算机视觉领域的研究热点之一。基于图像的视觉伺服方法通常选用角点、边线、孔洞或重心等明显的几何信息作为视觉特征，伺服过程中需要进行特征匹配。如果工作环境中只含有纹理结构，这些方法将难以应用。事实上，当摄像机产生运动时，所拍摄图像的某些纹理特征也将发生相应的改变；反过来，图像中某些纹理特征的变化也在一定程度上反映了摄像机的运动。本文对图像纹理特征变化与摄像机运动之间的关系进行了研究，提出了基于纹理的视觉伺服思想，该思想的提出可以为机器人在纹理结构环境中进行伺服控制提供一种新手段，为视觉伺服提供一种新的视觉特征，也扩展了纹理研究的领域。 本文简要介绍了利用图像雅克比矩阵进行视觉伺服的原理之后，给出了基于纹理的视觉伺服图像特征定义及其求取方法。这部分内容中，给出了基于图像共生矩阵的纹理特征参数及基于自相关函数的纹理粗糙度计算方法；定义了纹理基元密度特征，提出了用纹理基元密度特征表示纹理粗糙度的方法；分析了利用纹理特征进行视觉伺服的可行性；论述了如何根据具体的场景选择适合于视觉伺服的纹理特征。 本文针对特定的一类纹理，进行了基于纹理基元密度特征的视觉伺服方法研究。该部分研究中，推导了图像上纹理基元密度特征与摄像机位姿之间的关系；设计了李亚普诺夫函数；在李亚普诺夫稳定性条件下，设计了利用纹理基元密度特征进行视觉伺服的控制律；证明了当特征考察点位置满足一定条件时，图像雅克比矩阵非奇异。仿真实验结果表明了该方法正确有效。 论文还进行了另外两种基于纹理的视觉伺服实验研究。 第一种为基于纹理特征区域搜索的视觉伺服方法。该方法通过分析目标区域与背景区域的纹理特征差异，论述了目标区域几何特征及纹理特征参数与摄像机运动之间的关系，得到了视觉伺服控制流程。基于纹理特征区域搜索的视觉伺服方法不受纹理基元形状和大小约束，但要求目标区域纹理特征明显区别于背景。 第二种为基于纹理区域特征差异的视觉伺服方法。本文分析图像上不同区域之间的纹理粗糙度差异变化与摄像机运动之间的关系，得到视觉伺服控制方法。相对基于图像纹理基元密度的视觉伺服方法，基于区域特征差异的视觉伺服方法受纹理基元数量影响较小，而且不必对纹理基元进行分割、计数，减少了计算量。但这种方法需要较好的图像质量。 半物理仿真实验证明了基于纹理特征区域搜索的视觉伺服方法和基于纹理区域特征差异的视觉伺服方法的有效性。

三塘湖盆地牛圈湖区储层特征研究—以齐古组、头屯河组为例

In view of few researches into pore textures and anisotropy characteristics of Qiguzu-toutunhezu reservoir in Niuquanhu block in Santanghu Basin, in order to enhance the hydrocarbon recovery of the region of interest and improve the reservoir development effect, with the employment of the experiments like cast thin slice, scanning electron microscope, conventional high pressure mercury penetration, constant speed mercury penetration and nuclear magnetic resonance, the thesis makes a thorough research into pore texture characteristics and anisotropy characteristics of the sandstone reservoir. The research shows that the microscopic pore textures are complicated, the anisotropy is high and waterflood development water/oil displacement efficiency is low, which are mainly caused by the high microscopic anisotropy of the reservoir. Specially, the research shows that Qiguzu-toutunhezu reservoir belongs to braided delta front intrafacies, the intergranular pore is the main type of pores, which take up 65.50 percent of total pores, intergranular dissolved pores, feldspar dissolved pores and lithic dissolved pores are on the second place, and there are few carbonate dissolved pores. The reservoir belongs to mesopore-fine throat and mesopore-medium throat. The pore distribution of the sandstone reservoir is comparatively centralized. The reservoir inhomogeneity is mainly caused by the throat inhomogeneity. Diagenesis mainly includes compaction, cementation, metasomatism and dissolution. Compared with compaction， cementation exerts more direct impact on the decline of the porosity of the sandstone reservoir ( pore loss factor is 63.75 percent in the cementing process). Based on the classification of diagenetic stages, the reservoir diagenesis is on the stage of the late period of early diagenetic stage to early period of late diagenetic stage. The study area of the small sandstone reservoir layer of the anisotropy of the relatively strong; plane, the anisotropy of the relatively weak. microscopic anisotropy of its relatively strong.

塔里木盆地塔中—巴楚地区早二叠世岩浆岩地球化学特征及其成因

Tazhong-Bachu region is located in the Western Tarim basin.The early Permian magmatic rocks occur in the earth surface of Tazhong-Bachu region are mainly distributed in Kepintag,Mazhartag and Wajilitag region. There are a lot of wells, in which researchers found the early Permian magmatic rocks,in desert cover area.Most magmatic rocks are basic rocks, a few of which are ultrabasic rocks and intermediate-acid magmatic rocks.The ultrabasic rocks are are mainly occur in the Cryptoexplosive Breccia Pipes ,which is located in the volcanic complex body of Wajilitag region.The basic rocks can be divided into three rock types：The first type of the magmatic rocks in Tazhong-Bachu region is volcanic rock ,which occurs in the Lower Permian Kupukuziman Formation and Kaipaizileike Formation. Most Volcanic rocks are basalts,a few of which are volcanic breccias and pyroclastic rocks.The basalts are distributed in stratiform occurrences and interbeded the clastic rocks in Kepintag region.The attitudes of the basalts are nearly horizontal.Columnar Joints, gas pore textures and amygdaloidal structure are to develop in basalts.The second type of the magmatic rocks in Tazhong-Bachu region is diabase,which occurs in Mazhartag region.Diabase dike swarms occur in the stratums of Silurian, Devonian, Carboniferous and Lower Permian.They make from NNW direction to SSE direction, the obliquity of stratum is greater than 60°, and the dike thickness is form several cm to several meters. Diabasic texture is found in the rocks .The first type of the magmatic rocks in Tazhong-Bachu region are gabbro- pyroxenite rocks ,which occur in the Wajilitag igneous complex body. The intermediate-acid magmatic rocks, which are mainly syenites, are located in Mazhartag and Wajiltag region. But they are small in the whole Tazhong-Bachu region.There are intermediate-acid magmatic rocks,which are mainly dacite,in the northeast part of the wells in Tazhong-Bachu region.But ,it is not found in earth surface.Through systematical geochemical research of early Permian magmatic rocks,which are distributed in Kepintag,Mazhartag, Wajilitag region and the wells such as F1 well、Z1 well、Z13 well、TZ18 well、H3 well、H4 well et al., the focus on the geochronologic characteristics, the main element,trace element and REE geochemistry, the mineralogic characteristics, the Sr-Nd and Pb isotopic characteristics are put forward. The main points are: 1、A combined study of CL imaging and LA-ICP-MS U-Pb dating were carried out for zircon grains of the magmatic rocks in the Tazhong-Bachu region from the Tarim basin.The results of the systematic zircon LA-ICP-MS U-Pb dating reveal 272±6Ma to 291±10Ma for the magamatic rocks. It indicated that Early Permian is an important period of magmatic acvivity in the Tazhong-Bachu region. 2、There are a big hunch in the curves of primitive mantle-normalized trace element concentrations in the early Permian magmatic rocks from Kepintag, Mazhartag, Wajilitag region and the 14 wells. Light rare earth elements are comparatively rich and heavy rare earth elements are comparatively poor. The slope rates are same between light rare erath elements and heavy rare earth elements. It is not like the curves of the basalts in the convergent margin of plate , in which the slope rates of light rare erath elements is bigger than the alope rates of heavy rare erath elements, and the curves of heavy rare earth elements are comparatively flat. The magmatic rocks of Tazhong-Bachu region rarely have the characteristics of the basalts in the convergent margin of plate, which is that Tantalum, Niobium and Titanium are much poor, and Zirconium, Hafnium and Phosphorus are moderately poor. The magamatic rocks are mostly alkaline, which is indicated by the dots of the (Na2O+K2O)-SiO2 identification diagram. All of these indicate that the early Permian magmatic rocks were formed in an extension environment of intraplate. 3、The Thorium abundance is high and Tantalum abundance is low in most magmatic rocks from Tazhong-Bachu reguion, which is formed for crustal contamination.In the Th/Yb-Ta/Yb identification diagram，most dots are in the region, which means active continental margin, but a few dots are in the region, which means mantle source. It indicated the feeding of continental crust materials. 4、The magnesium content of the olvines from Wagilitag region is richest, and the olvines from Kepintag region is poorest in the tree region. 5、Through the the Sr-Nd and Pb isotopic study of the basalts and diabases from the F1 well core, Z1 well core, Z13 well core,TZ18 well core, and the basalts，gabbros, diabases(diabase-prophyrites) and pl-peridotites from Kepintag,Mazhartag, Wajilitag region , it indicated that all isotopic data is similar and close to enriched mantle.