Influence of China‘s WTO Entry on Petroleum Taxation

China has formulated a series of preferential taxation policies for the country 's petroleum enterprises. Those state policies are the important factors influencing reform and development of petroleum enterprises. The taxes turned over to the State by CNPC in 1998, 1999 and 2000 are 31.4 billion yuan, 31.7 billion yuan and 41 billion yuan respectively, accounting for 11.64 percent, 9.06 percent and 10.15 percent of the annual sales income.With China 's entry into WTO, it is necessary for t…     

Fivefold symmetry in real and reciprocal spaces

Tetrahedrally close-packed structures with juxtaposed pentagonal antiprisms, such as the μ, C14 Laves and the newly found C phases, were studied by means of HREM and SAD. It was found that each bright spot in the structural image corresponds to an antiprism. Differently oriented domains of these phases intergrow frequently with a fairly good match at the interphase boundary. All diffraction patterns of these phases show a fivefold distribution of spot-pairs, and it is shown that this fivefold symmetry comes from the pentagons and spot-pairs from two pentagonal prisms superposed in antisymmetrical positions.     

AC hot-carrier effects in MOSFETs with furnaceN2O-nitrided gate oxides

AC hot-carrier effects in n-MOSFETs with thin (~85 Å) N₂O-nitrided gate oxides have been studied and compared with control devices with gate oxides grown in O₂. Results show that furnace N₂O-nitrided oxide devices exhibit significantly reduced AC-stress-induced degradation. In addition, they show weaker dependences of device degradation on applied gate pulse frequency and pulse width. Results suggest that the improved AC-hot-carrier immunity of the N₂O-nitrided oxide device may be due to the significantly suppressed interface state generation and neutral electron trap generation during stressing     

Multiband properties of a fractal tree antenna generated byelectrochemical deposition

Experimental results on a fractal tree-like antenna are reported. The fractal structure is generated by electrochemical deposition. The antenna presents a multiband behaviour with a denser band distribution than the previously reported Sierpinski fractal antenna. The matched frequencies are related to the length distribution over the fractal shape     

Anaerobic digestion of alkaline black liquor using an up-flow anaerobic sludge blanket reactor

The anaerobic digestion of alkaline black liquor from a cereal straw pulping mill was studied in batch (serum bottles) and continuous systems (up-flow anaerobic sludge blanket reactor—UASB). The batch digestion studies confirmed that lignin and related compounds (LRC) in the alkaline black liquor were the main inhibitory substances and could not be decomposed by anaerobic bacteria. At organic loading rates of 5–10 kg COD m^?3 day^?1, the UASB reactor achieved 50–60% COD removal efficiencies. Gas production was 2–3 dm³ per dm³ of alkaline black liquor. Two different sludge types were examined in the reactor: granular and cluster-like sludges. Sludge in a cluster, which involved many small granules and flocs, tended to form larger aggregates and possessed good settling ability.     

A methodology for modeling the distributions of medical images and their stochastic properties

The probabilistic distribution properties of a set of medical images are studied. It is shown that the generalized Gaussian function provides a good approximation to the distribution of AP chest radiographs. Based on this result and a goodness-of-fit test, a generalized Gaussian autoregressive model (GGAR) is proposed. Its properties and limitations are also discussed. It is expected that the GGAR model will be useful in describing the stochastic characteristics of some classes of medical images and in image data compression and other applications.     

Scaling effects on flow hydrodynamics of confined microdroplets induced by Rayleigh surface acoustic wave

This paper reports an experimental and numerical investigation on the scaling effects in the flow hydrodynamics for confined microdroplets induced by a surface acoustic wave (SAW). The characteristic parameters of the flow hydrodynamics were studied as a function of the separation height, H, between the LiNbO₃ substrate and a top glass plate, for various droplets volumes and radio-frequency powers. The ratio of the gap height to attenuation length of the SAW, H/l _SAW, is shown to be an important parameter affecting the streaming flow induced in this confined regime. The reported numerical and experimental results are in good agreement over the range examined in this study and demonstrate that, at a lower gap heights of H?≤?100?μm, a significant decrease in streaming velocity or Reynolds number is induced, with the velocity approaching zero when the gap height is decreased to ~50?μm. An increase in the gap height results in an increased streaming velocity; however, if the gap height exceeds 70?% of the SAW attenuation length, any further increase in the gap height induces a drop in the streaming velocity.     

Observations of slip patterns on the surface of fatigued gold using the scanning tunnelling microscope

Observations of fatigue-induced slip patterns on the surface of polycrystalline gold (+99.9%) using the scanning tunnelling microscope (STM) are presented. The samples were cycled in four-point bending between zero and 0.0025 strain for 250 and 2500 cycles. STM observations of the sample fatigued for 250 cycles revealed broad slip bands 0.38–0.69 m wide containing narrow slip bands 0.015–0.123 m wide and fine slip lines 0.006 m wide. The depth of these features are 20–57 nm for broad slip bands, 3–7 nm for narrow slip bands, and approximately 2–4 nm for fine slip lines. The sample fatigued for 2500 cycles showed similar values for the width of the slip bands and slip lines except that their depth was increased by a factor of between 2 and 4 times for the narrow slip bands and the fine slip lines. Apparent persistent slip bands (PSBs) spaced 2.4 m, 300–500 nm deep were also observed. These results demonstrate that STM is a significant new tool for observing and distinguishing various types of fatigue-induced surface slip patterns on suitably prepared samples. The vertical resolution obtained with STM is vastly superior to current SEM and TEM methods.