Effect of Post Spinning Modification on the PAN Precursors and Resulting Carbon Fibres

The impregnation of a special grade polyacrylonitrile(PAN)precursor fibres was carried out in a 8 wt.% KMnO4 aqueous solution to obtain modified PAN precursor fibres.The focus is primarily on the effects of modification on the chemical structure and the physical mechanical properties of precursor fibres,thermal stabilised and their resulting carbon fibres,which were characterized by the combination use of densities,wide-angle X-ray diffraction(WAXD),X-ray photoelectron spectroscopy(XPS),Elemental analysis(EA),Fourier transform infrared(FT-IR)and scanning electron microscope(SEM),etc.KMnO4 as a strong oxidizer can swell,oxidize and corrode the skin of a precursor fibre,transform partly C≡N groups to CN ones,decrease the crystal size,increase the orientation index,increase the crystallinity index,furthermore increase the densities of modified PAN precursors and resulting thermal stabilised fibres.As a result,the carbon fibres developed from modified PAN fibres show an improvement in tensile strength of 31.25% and an improvement in elongation of 77.78%,but a decrease of 16.52% in Young's modulus.

Status Quo and Development Countermeasures of Suburban Picking and Sightseeing Tourism in Bayi Town,Linzhi City

On the basis of investigating picking and sightseeing resources in neighboring areas of Bayi Town,Linzhi City,this paper explored problems in the development of local leisure sightseeing and picking industry,and proposed scientific and reasonable countermeasures.

A new geographical language： A perspective of GIS

Language plays a vital role in the communication, sharing and transmission of in- formation among human beings. Geographical languages are essential for understanding, investigating, representing and propagating geo-spatial information. Geographical languages have developed and evolved gradually with improvements in science, technology and cogni- tive levels. Concerning the theoretical progress from geographical information ontology, epistemology and linguistic theory, this paper firstly puts forward the concept of a GIS lan- guage and discusses its basic characteristics according to changes in the structures, func- tions and characteristics of geographical languages. This GIS language can be regarded as a system of synthetic digital symbols. It is a comprehensive representation of geographical objects, phenomena and their spatial distributions and dynamic processes. This representa- tion helps us generate a universal perception of geographical space using geographical scenarios or symbols with geometry, statuses, processes, spatio-temporal relationships, semantics and attributes. Furthermore, this paper states that the GIS language represents a new generation of geographical language due to its intrinsic characteristics, structures, func- tions and systematic content. Based on the aforementioned theoretical foundation, this paper illustrates the pivotal status and contributions of the GIS language from the perspective of geographical researchers. The language of GIS is a new geographical language designed for the current era, with features including spatio-temporal multi-dimension representation, in- teractive visualization, virtual geographical scenarios, multi-sensor perception and expedient broadcasting via the web. The GIS language is the highest-level geographical language developed to date, integrat- ing semantic definitions, feature extraction, geographical dynamic representation and spa- tio-temporal factors and unifying the computation of geographical phenomena and objects. The GIS language possesses five important characteristics： abstraction, systematicness, strictness, precision and hierarchy. In summary, the GIS language provides a new means for people to recognize, understand and simulate entire geo-environments. Therefore, explora- tion of the GIS language＇s functions in contemporary geographical developments is becoming increasingly important. Similarly, construction of the conceptual model and scientific systems of the GIS language will promote the development of the disciplines of geography and geo- graphical information sciences. Therefore, this paper investigates the prospects of the GIS language from the perspectives of digital technology, geographical norms, geographical modeling and the disciplinary development of geography.

Vegetation pattern in Shell Ridge Island in China＇s Yellow River Delta

In general, coastal habitat conditions are extremely harsh, with the ecological equilibrium inextric- ably related to the plant community. Understanding the natural vegetation features of a coastal zone with little human disturbance could provide a reference for future vegetation restoration and ecosystem maintenance ser- vices. In this study, the vegetation patterns of Wangzi Shell Ridge Island in the Yellow River Delta were investigated. A total of 35 taxa of vascular plants were documented, representing 15 families and 33 genera （of which most were mono-specific）. Surveys identified only one to eight taxa in each plot. From sea to land, the vegetation showed a typical zonal distribution pattern. There was a correlation between the landform and important factors that influenced the plants including soil factors and distance from the sea. Thus, the taxa distribution and vegetation had a significant correlation with landform. The dune crest, backdune and interdune lowlands were areas with weak storm surges and were the important locations for the taxa to be become established. Plants along the high-tide line formed important defenses from large waves and high winds. The significant protection provided a suitable living environment for many organisms with high medicinal value. Special attention and protection could be provided to this area by reducing the use of the beach road and enclosing the complete section from sea to land with a protective fence. In addition, vegetation protection and restoration on Shell Ridge Island would aid in the formulation and implementation of reintroduction strate- gies for similar vegetation in similar habitats.