CHINESE CUSTOMS TO IMPOSE EXPERIMENTAL SPECIFIC AND COMPOUND IMPORT DUTIES

By a State Council decision, effective on July 1, Chinais to impose specific duties on three import commodities including beer, and compound duties on two otherimport commodities including video player on an trial basis. As this is an unprecedented experiment in China, Office of the Customs Tariff Commission under the StateCouncil, and the Customs Tariff Department of the GeneralAdministration of Customs are carrying out public consultation on these trial policies. In order to give the public abetter idea concepts, characteristics and purposes of specific and compound duties, our reporter visited the officerin charge at Guangzhou Customs.

Oil-source rock correlation and quantitative assessment of Ordovician mixed oils in the Tazhong Uplift, Tarim Basin

The origin of the marine oils in the Tarim Basin has long been a disputed topic. A total of 58 DST （drill stem test） crude oil and 8 rock samples were investigated using a comprehensive geochemical method to characterize and identify the origin of the Ordovician oils in the Tazhong Uplift, Tarim Basin, northwest China. Detailed oil–oil and oil–source rock correlations show that the majority of the oils have typical biomarker characteristics of the Middle-Upper Ordovician （O2＋3） source rock and the related crude oil. These characteristics include a distinct ＂V-shaped＂ relative abundance of C27, C28 and C29 regular steranes, low abundance of dinosterane, 24-norcholestanes, triaromatic dinosteroids and gammacerane. Only a few oils display typical biomarker characteristics indicating the Cambrian–Lower Ordovician （∈-O1） genetic affinity, such as linear or anti ＂L＂ shape distribution of C27, C28 and C29 regular sterane, with relatively high concentrations of dinosterane, 24-norcholestanes, triaromatic dinosteroids and gammacerane. It appears that most of the Ordovician oils in the Tazhong Uplift were derived from the O2＋3 intervals, as suggested by previous studies. However, the compound specific n-alkane stable carbon isotope data indicate that the Ordovician oils are mixtures from both the ∈-O1 and O2＋3 source rocks rather than from the O2＋3 strata alone. It was calculated that the proportion of the∈-O1 genetic affinity oils mixed is about 10.8%-74.1%, with an increasing trend with increasing burial depth. This new oil-mixing model is critical for understanding hydrocarbon generation and accumulation mechanisms in the region, and may have important implications for further hydrocarbon exploration in the Tarim Basin.

Origin of Crude Oil in the Lunnan Region,Tarim Basin

The oil source of the Tarim Basin has been controversial over a long time. This study characterizes the crude oil and investigates the oil sources in the Lunnan region, Tarim Basin by adopting compound specific isotopes of n-alkanes and biomarkers approaches. Although the crude oil has a good correlation with the Middle-Upper Ordovician （02＋3） source rocks and a poor correlation with the Cambrian-Lower Ordovician （C-O1） based on biomarkers, the ~3C data of n-alkanes of the Lunnan oils show an intermediate value between C-O1 and 02＋3 genetic affinity oils, which suggests that the Lunnan oils are actually of an extensively mixed source. A quantification of oil mixing was performed and the results show that the contribution of the Cambrian-Lower Ordovician source rocks ranges from 11% to 70% （averaging 36%）, slightly less than that of the Tazhong uplift. It is suggested that the inconsistency between the biomarkers and od3C in determining the oil sources in the Lunnan Region results from multiple petroleum charge episodes with different chemical components in one or more episode（s） and different sources. The widespread marine mixed-source oil in the basin indicates that significant petroleum potential in deep horizons is possible. To unravel hydrocarbons accumulation mechanisms for the Lunnan oils is crucial to further petroleum exploration and exploitation in the region.

Sedimentary Environments of Cambrian-Ordovician Source Rocks and Ultra-deep Petroleum Accumulation in the Tarim Basin

The Tarim Basin is the only petroliferous basin enriched with marine oil and gas in China.It is presently also the deepest basin for petroleum exploration and development in the world.There are two main sets of marine Source Rocks(SRs)in the Tarim Basin,namely the high over-mature Cambrian-Lower Ordovician(∈-O_(1))and the moderately mature Middle-Upper Ordovician(O_(2-3)).The characteristic biomarkers of SRs and oils indicate that the main origin of the marine petroleum is a mixed source of∈-O_(1) and O_(2-3) SRs.With increasing burial,the hydrocarbon contribution of the∈-O_(1) SRs gradually increases.Accompanied by the superposition of multi-stage hydrocarbon-generation of the SRs and various secondary alteration processes,the emergence and abnormal enrichment of terpenoids,thiophene and trimethylaryl isoprenoid in deep reservoirs indicate a complex genesis of various deep oils and gases.Through the analysis of the biofacies and sedimentary environments of the∈-O_(1) and O_(2-3) SRs,it is shown that the lower Paleozoic high-quality SRs in the Tarim Basin were mainly deposited in a passive continental margin and the gentle slope of the platform,deep-water shelf and slope facies,which has exhibited a good response to the local tectonic-sedimentary environment.The slope of the paleo-uplift is the mutual area for the development of carbonate reservoirs and the deposition of marine SRs,which would be favorable for the accumulation of petroleum.Due to the characteristics of low ground temperature,the latest rapid and deep burial does not cause massive oil-cracking in the paleo-uplift and slope area.Therefore,it is speculated that the marine reservoirs in the slope of the Tabei Uplift are likely to be a favorable area for deep petroleum exploration,while the oilcracking gas would be a potential reserve around the west margin of the Manjiaer Depression.Hydrocarbons were generated from various unit SRs,mainly migrating along the lateral unconformities or reservoirs and the vertical faults.They eventually brought up three major types of exploration fields:middle and lower Cambrian salt-related assemblages,dolomite inner reservoirs and Middle and Lower Ordovician oil-bearing karst,which would become the most favorable target of marine ultra-deep exploration in the Tarim Basin.

Long chain n-alkanes and their carbon isotopes in lichen species from western Hubei Province： implication for geological records

Five coticolous lichen samples were collected from western Hubei Province of China to analyze the long chain n-alkanes and their carbon isotope compositions. The n-alkanes range in carbon number from C17 to C33 with strong odd-over-even predominance between C21 and C33. Lichens are dominated by n-C29 in the samples of Dajiuhu, Shennongjia Mountain, but by both n-C23 and n- C29 at Qizimei Mountain. This difference may result from the different environmental conditions in these two sites. The δ13C values of long chain n-alkanes in lichen samples show the signature of C3 plants. Based on compound- specific carbon isotopic values and previous results, we state that alkane homologs 〉 C23 mainly originate from the symbiotic fungi, while symbiotic algae only contribute trace amount of long chain alkanes. Of great interesting is the occurrence of long chain 3-methylalkanes in the Qizimei samples. These anteiso compounds range from C24 to C32, displaying obvious even-over-odd predomi- nance. This study reveals that the association of long chain 3-methylalkanes with n-C23 alkane might be used as proxies to reconstruct the paleoecological implications of lichens in Earth history.

[bmim]OH： An efficient catalyst for the synthesis of mono and bis spirooxindole derivatives in ethanol at room temperature

A rapid and efficient, one pot synthesis of spirooxindole derivatives has been attempted by three- component reaction of isatin, malononitrile and carbonyl compound possessing a reactive c^-methylene group by using task specific ionic liquid, 1-butyl-3-methyl imidazolium hydroxide [bmim]OH as a catalyst. The important features of this methodology are straight forward route in short reaction time at room temperature and avoid any hazardous organic solvent, toxic catalyst, tedious purification step. Interestingly, this protocol is not only limited to mono-systems but also to the synthesis of newer bis- spirooxindole system. The separation of the product and reusability of the catalyst are easy with excellent yield. The [bmim]OH catalyst system could be reused up to five recycles without appreciable loss of activity.

Habitat Influence on the Molecular, Carbon and Hydrogen Isotope Compositions of Leaf Wax n-Alkanes in a Subalpine Basin, Central China

Epidermal leaf waxes of terrestrial higher plants have been widely utilized for the reconstructions of paleoenvironment and paleoclimate in peat deposits. In this study, specimens of four plant species growing in both peatland and non-peatland habitats were retrieved to compare their molecular, carbon(δ13 C) and hydrogen(δ2 H) isotopic compositions of leaf wax n-alkanes from a closed subalpine basin in Central China. Three of the four species show quite higher total concentrations of n-alkanes in the relatively dry non-peatland setting than in the peatland. In addition, the δ2 H values of long-chain n-alkanes are generally less depleted in the peatland and are comparable among different plant species, which is interpreted as the influence of inundation condition and the possible limited supply of photosynthetic products. This study reveals different patterns of plant wax molecular and isotopic compositions between peatland and the surrounding non-peatland conditions, and confirms the paleoenvironmental potential of leaf wax ratios on the peat sequences.