Observation of twisting growth of branched polyethylene single crystals formed from the melt

The twisting growth of a branched polyethylene single crystal formed from the melt was observed directly by means of transmission electron and atomic force miscroscopy. The surface stress asymmetry arising from the asymmetry of the surface-fold structure and, chain tilting resulted in the twisting growth of the single crystals. The handedness of the twisting lamellae was consistent With the chain-tilting direction. When multilayer lamellae piled up in a thicker film, the lamellar twist would be inevitably causing screw dislocations.

Color filters with negative birefringence for liquid crystal display use

We have developed a special color film with negative birefringence, which can work as a color filter and a viewing angle extension film for liquid crystal displays (LCDs). A high-performance polyimide (PI), which can be dissolved in the usual organic solvent and shows negative birefringence after lamination, was synthesized to fabricate the film. By mixing PI with suitable proportions of green, blue or red pigment in the solvent, then laminating them onto a glass substrate, we obtained color films with good transmission spectra and suitable chromatic coordinates. The results of our experiments show that the color filters still have negative birefringence but a little lower than that of the pure PI film. and can therefore work as compensation films for normal white twist nematic liquid crystal displays (TN-LCD).

THE RING-BANDED SPHERULITE STRUCTURE OF POLY(EPSILON-CAPROLACTONE) IN ITS MISCIBLE MIXTURES WITH POLY(STYRENE-CO-ACRYLONITRILE)

The structure of the PCL spherulite in poly(epsilon-caprolactone)/poly(styrene-co-acrylonitrile) (PCL/SAN) blends was investigated by optical microscopy and small angle light scattering. The spherulite structure with a Maltese cross has been observed in pure PCL. Similar PCL/SAN blends exhibited not only spherulites with a Maltese cross, but also distinct extinction rings. The H(v) light scattering pattern especially caused diffraction rings in PCL/SAN blends but not in pure PCL. The spherical symmetry of spherulite PCL becomes more incomplete and the twist of the lamella becomes more irregular with increasing SAN content. It is found that the spherulite structure of PCL/SAN blends is dependent on the crystallization temperature and the concentration of SAN in PCL/SAN blends.

FROM DIMER TO POLYMER .2. EXTENDED TO SYSTEMS POSSESSING 2-FOLD SCREW AXIS OR GLIDE PLANE

The approach for constructing the qualitative band structure of a polymer from corresponding dimer has been extended to the system possessing two-fold screw axis or. glide plane. The classification of energy levels of the dimer in the present case depends on pseudo-symmetry/antisymmetry instead of psendo-in-phase/out-of-phase property of the orbitals. Several typical conductive polymers are then discussed follow this approach. Among them are cis-polyacetylene, polyparaphenylene with a twist ang...

蛇形机器人的扭转运动研究

通过扭转运动,蛇形机器人能够在粗糙的地面运动,甚至可以翻越一些障碍物。对扭转运动进行了运动学解析,提出了实现扭转运动的简化输入模型。实现了蛇形机器人二维平面内的U形和V形扭转运动,并将扭转运动与其他运动方式结合,实现蛇形机器人的复合运动方式。通过实验验证了所提出的简化模型的有效性。

地震岩性与物性联合反演技术研究和应用

This paper studies how to more effectively invert seismic data and predict reservoir under complicated sedimentary environment, complex rock physical relationships and fewer drills in offshore areas of China. Based on rock physical and seismic amplitude-preserving process, and according to depositional system and laws of hydrocarbon reservoir, in the light of feature of seismic inversion methods present applied, series methods were studied. A joint inversion technology for complex geological condition had been presented, at the same time the process and method system for reservoir prediction had been established. This method consists four key parts. 1)We presented the new conception called generalized wave impedance, established corresponding inversion process, and provided technical means for joint inversion lithology and petrophysical on complex geological condition. 2)At the aspect of high-resolution nonlinear seismic wave impedance joint inversion, this method used a multistage nonlinear seismic convolution model rather than conventional primary structure Robinson seismic convolution model, and used Caianiello neural network implement inversion. Based on the definition of multistage positive and negative wavelet, it adopted both deterministic and statistical physical mechanism, direct inversion and indirect inversion. It integrated geological knowledge, rock physical theory, well data, and seismic data, and improved the resolution and anti-noise ability of wave impedence inversion. 3)At the aspect of high-resolution nonlinear reservoir physical property joint inversion, this method used nonlinear rock physical model which introduced convolution model into the relationship between wave impedance and porosity/clay. Through multistage decomposition, it handles separately the large- and small-scale components of the impedance-porosity/clay relationships to achieve more accurate rock physical relationships. By means of bidirectional edge detection with wavelets, it uses the Caianiello neural network to finish statistical inversion with combined applications of model-based and deconvolution-based methods. The resulted joint inversion scheme can integrate seismic data, well data, rock physical theory, and geological knowledge for estimation of high-resolution petrophysical parameters. 4)At the aspect of risk assessment of lateral reservoir prediction, this method integrated the seismic lithology identification, petrophysical prediction, multi-scale decomposition of petrophysical parameters, P- and H-spectra, and the match relationship of data got from seismics, well logging and geology. It could describe the complexity of medium preferably. Through applications of the joint inversion of seismic data for lithologic and petrophysical parameters in several selected target areas, the resulted high-resolution lithologic and petrophysical sections(impedance, porosity, clay) show that the joint inversion can significantly improve the spatial description of reservoirs in data sets involving complex deposits. It proved the validity and practicality of this method adequately.

内蒙古中部道郎和都格铜多金属矿的地质特征矿床类型及找矿模式研究

Daolangheduge copper polymetallic deposit is located on east edge of Ondor Sum-Bainaimiao metallogenic belt, which is a prospective area of porphyry copper deposit, in Xianghuangqi of central Inner Mongolia. Geotectonically, it occurred in the continental margin accretion belt along the north margin of North China Plate, south of the suture zone between North China Plate and Siberian Plate. The intrusive rocks in this area mainly consist of intermediate-acid magmatic rocks, and the quartz veins, tourmaline veins and the transitional phase are comparatively developed. According to our research, the ore-bearing rock body is mainly quartz diorite while the surrounding rock is mainly biotite granite. Besides, the wall rock alteration are mainly propylitization, pyritization and silicification, which consist of epidotization, actinolitization, chloritzation and so on. The metallic minerals are mainly chalcopyrite and pyrite. In addition, the primary ore is mainly of quartz-chalcopyrite-pyrite type. Above all, Daolangheduge copper polymetallic deposit is suggested to be categorized in the porphyry copper type. With isotopic dating and geochemical research on quartz diorite of ore-bearing rock body, the zircon LA-ICP-MS U-Pb dating of two samples yields an age of 266±2 Ma, falling into the range of late Permian Epoch. It is the first accurate age data in Xianghuangqi area, so it should play a key role in the research of deposit and magmatic rocks in this area. With the major elements and trace elements analysis of 14 samples, the quartz diorite should be among the calc-alkaline series, the geochemical characteristics show higher large-ion lithophile elements of Rb, Sr and LREE, low high-field strength elements of Nb, Ta and high transition elements of Cu, Cr . Also, the REE patterns have negative Eu anomalies. With the same analysis of 4 sample for the biotite granite, the geochemical characteristics show higher Rb, Th,, Zr, Hf and LREE, low Nb, Sm and HREE and Eu has no anomaly. It should be among the calc-alkaline series, over aluminum quality and has characteristics of Adakites. According to isotopic dating and geochemical characteristics of ore-bearing rock body, it is suggested that its materials mainly derived from upper mantle that had fractional crystallization and its magma source region may be affected by fluid metasomatism of paleo-asian ocean. It should be an extensional process of post-orogeny according to regional tectonic evolution. Consequently, because of the decrease of temperature and pressure, the ore forming fluid was raised to surface and mineralized accompanied by magmatic activity which might occur in south of the suture zone. By geological survey, further geophysical and geochemical work is needed. In this area, we have accomplished high precision magnetic prospecting, high density electrical survey, gravity prospecting, soil geochemical prospecting, X-ray fluorescence analyzer prospecting and so on. According to geophysical and geochemical abnormal and surface occurrence, 11 drills are arranged to verification. The type of ores are mainly quartz-chalcopyrite-pyrite ores within 3 drills by drill core logging. Although the grade as well as the scale of already-found Cu deposits are insufficient for industrial exploitation, the mineralization prospect in this region is supposed to be great and the potential in mineral exploration at depth is excellent.

塔里木盆地塔中地区寒武-奥陶系烃源岩古地温及成烃演化史研究

The present maturity of Cambrian and Ordovician source rocks in Tazhong area, Tarim basin, is studied using several organic petrology methods and conodont CAI method. The highest palaeotemperature that the Cambrian-Ordovician undergone is revealed by Laser Roman Microprobe (LRM) analysis and by simulating experiment of the kerogen chemical kinetics. In according to all above study, the thermal history of Cambrian and Ordovician is reconstructed based on numerical simulating approaches. The characteristics of secondary hydrocarbon generating are studied by inclusions analysis. The reflectances of the samples in the drills located in Tazhong area show that the maturities of Cambrian source rocks are in the stages of condense oil-dry gas, and that of Ordovician source rocks range from peak of oil generating to wet gas stage. The palaeotemperature data of Cambrian-Orovician source rocks from well Tacan 1, based on LRM analysis, are in coincidence with that from other methods. Also are the palaeotemperature data of Cambrian-Orovician source rocks in well Tacan 1 based on the simulating experiments of kerogen pyrolysis, similar to the homogenization temperatures of inclusions in the source rocks. Aaccording to the vitrinite inflectance data of the TZ12 well and Tacan 1 well, the paleotemperature gradients are analysized and reconstructed. These data show that the paleotemperature gradient in Tazhong area was the highest during Cambrian-Ordovician period, it was up to 3.5°C/100m. Following, the temperature gradient descended gradually and it reached to the lowest at present (2.2°C/100m). The histories of maturation and hydrocarbon generation of Cambrian and Ordovician source rocks in Tazhong area are researched systematically and quantitatively, the results show that periods of oil generation from Cambrian and Ordovician source rocks lasted for a long time from Ordovician to Carbonferious periods because the central Cambrian stratum in the north slope of Tazhong area is buried differently in depth. The top of the Cambrian entered into the peak of oil generation in middle-late Ordovician, and most area of the north slope of Tazhong area entered into the peak of oil generation in Carbonferious period, and on the uplift belt some of source rocks entered into the peak of oil generation in Permian period. In early Devonian, the central of the Lower Ordovician source rocks near the Manjiaer depression reached the peak of oil generation and near the top of the Tazhong uplift did not reached the peak of oil generation until early Cretaceous. The middle-upper Ordovician entered into the peak of oil generation in early-middle Jurassic. The time of the middle-upper Ordovician in the top of the uplift belt entering into the peak of oil generation was delayed, because the source rock was buried shallowly, and it did not reached the peak of oil generation until middle Cretaceous. Middle-upper Ordovician in the top of the north slope has been in the peak of oil generation now, it is consistent with the maturity (1.0-1.2%Ro) of the source rocks. The characteristics of the inclusions formed by kerogens are different from that by crystal-enclosed organic matters(OM) during secondary hydrocarbon generation of Cambrian and Ordovician source rocks. The secondary hydrocarbon generation mainly occurred in Mesozoic-Cenozoic period, in an area of about 9000km2 in the north slope. The intensity of the secondary hydrocarbon generation of Cambrian and Ordovician is up to 21kg/torg and 36kg/torg) respectively. Using the staged gas chromatography, the high-over maturated carbonate source rocks are analysized to release the adsorbed OM, inclusions OM and crystal-enclosed OM, respectively, and to evaluate their relative contributions to secondary hydrocarbon generation. The three periods of oil and gas migration and petroleum pools formation in Tazhong area are determined according to organic inclusions and solid bitumen.