Panorama of China's Oil Refining Industry in 2005

China＇s oil refining industry registered a loss of about 30 billion yuan （US$3,7 billion） in 2005, a sharp contrast to the 20.8 billion yuan in profits in 2004, according to the statistical figures made available from China＇s National Development and Reform Commission （NDRC）, which is in charge of industrial policy. The development of China＇s oil refining industry has witnessed tension between oil demand and straining supply as well as a steady increase of output in 2005, impacted by domestic and international factors.

Survey:UPSTREAM SECTOR OIL AND NATURAL GAS MOST PROFITABLE IN CHINA

The upstream sector of oil and natural gas industry becomes the most profitable industry in China in 2005, according to a survey released by the China＇s State Information Center in mid-February. The results of the study show that oil and natural gas mining made a profit of 292.7 billion yuan （about US$36 billion） made in the upstream sector of oil and gas industry, up 68 percent from 2004.

An effi cient scheme for multi-GPU TTI reverse time migration

Reverse time migration (RTM) is an indispensable but computationally intensive seismic exploration technique. Graphics processing units (GPUs) by NVIDIA■offer the option for parallel computations and speed improvements in such high-density processes. With increasing seismic imaging space, the problems associated with multi-GPU techniques need to be addressed. We propose an efficient scheme for multi-GPU programming based on the features of the compute-unified device Architecture (CUDA) using GPU hardware, including concurrent kernel execution, CUDA streams, and peer-to-peer (P2P) communication between the different GPUs. In addition, by adjusting the computing time for imaging during RTM, the data communication times between GPUs become negligible. This means that the overall computation effi ciency improves linearly, as the number of GPUs increases. We introduce the multi-GPU scheme by using the acoustic wave propagation and then describe the implementation of RTM in tilted transversely isotropic (TTI) media. Next, we compare the multi-GPU and the unifi ed memory schemes. The results suggest that the proposed multi- GPU scheme is superior and, with increasing number of GPUs, the computational effi ciency improves linearly.

Advances in the study of submarine groundwater discharge(SGD)in China

Submarine groundwater discharge(SGD)is a critical land-ocean process in coastal areas and an essential component of the global hydrological cycle.Thus,hydrologists and oceanographers are paying more attention to SGD.SGD transports large amounts of materials into the ocean,including nutrients,carbon,and metals,and thus plays a vital role in the cycling of marine materials and affects the ecological environments of nearshore areas.This study examined the research status of SGD and its environmental effects in China,including a systematic analysis of radium activities and nutrient contents in groundwater,SGD rates,and the contribution of SGD to nutrients in various coastal ecosystems(bays,estuaries,continental shelves,and lagoons).The results showed the median concentrations of groundwater nutrients(dissolved inorganic nitrogen DIN,dissolved inorganic phosphorus DIP,and dissolved inorganic silicon DSi),SGD rates,and SGD-derived DIN and DIP in estuarine areas far exceeded those in the other three ecosystems studied.This result could be attributed to the complex hydrodynamic conditions of estuary areas as well as the considerable influence of human activities.Conversely,the lowest SGD rates and three inorganic nutrient species via SGD were observed in large scale continental shelves.SGD-derived nutrient fluxes were comparable to riverine inputs along the entire coast of China,which significantly affected the nutrient budget,nutrient composition,and primary productivity of coastal waters.Finally,this review suggests further research of SGD in three aspects:(1)accurate assessment,(2)its environmental effects,and(3)its regulatory strategies.

Quantifying tidal contribution to submarine groundwater discharges: A review

Submarine groundwater discharges (SGD), consisting of groundwater flow from both terrestrial and marine origins, is an important source of nutrients, contaminants, and other chemicals to the coastal waters, and has significant impacts and implications on coastal environment and ecology. This paper reviews the recent advances in quantifying the tide-induced SGD in various beach aquifers around the world by means of mathematical modeling, laboratory experiments, and field observations or their combinations. Numerous studies have shown that (1) the order of magnitude of SGD around the world estimated by radium isotope tracers typically ranges from 102 to 103m3d-1m-1 of the shoreline, (2) SGD is mainly of marine origin, i.e. the re-circulated seawater across the aquifer-sea interface, and (3) tide is one of the major forces driving seawater-groundwater circulation. The order of magnitude of the tidal contributions to SGD from beach aquifers reported in the literature is only 10m3d-1m-1 length of shoreline, at least one order of magnitude smaller than the total SGD estimated by radium isotope tracers. This is obviously in contradiction with (3). The possible reasons for this contradiction may include (1) underestimation of the shoreline length due to neglecting many headlands, bays and banks of tidal rivers, and (2) negligence of the seawater-groundwater exchange from the seabed ranging from the nearshore areas to the continental shelf. Further research is needed to understand more about the contradiction.