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991.
越南石油生产和出口形势变化及其对中国的影响 总被引:3,自引:0,他引:3
越南石油产量快速上升,在2006年达到峰值后而迅速下降。为改变油品几乎全靠进口的状况,着手大力兴建炼厂。因而石油进出口形势将发生逆转。预计2013年后就可成为原油净进口国(进口量可达3—5千万吨)且将大量出口油品。此前越南是中国的原油进口源国和油品(特别是轻质油)的出口目的地。越南石油形势的重大变化将对中国和东亚石油格局产生一定的影响。 相似文献
992.
Surface water deficiency zoning of China based on surface water deficit index (SWDI) 总被引:1,自引:0,他引:1
Yaohuan Huang Jianhua Wang Dong Jiang Kang Zhou Xiangyi Ding Jingying Fu 《Water Resources》2014,41(4):372-378
China’s economic and social development is severely restricted by regional water deficiency, and the determination of water deficiency level in different regions is an important basis of water resource management. In this study, we zoned 32 provinces of China into five surface water deficiency levels based on surface water deficit index derived from the Chinese meteorological satellite FY-2C images. The result shows that China is facing serious water shortage crisis with only 15.44% of total area without water deficiency, which is located in the south and southeast coast. More than 60% of total area of China suffered from severe or extremely water deficiency, which are mainly distributed in western and northern regions. Jingjinji area (namely Beijing, Tianjin and Hebei province), which is a special region with high amount of gross domestic product and relative abundant water resources, is suffering from severe water deficiency. It revealed that water resources were interacted with regional development and water management should consider local conditions. To Jingjinji area, water management should focus on adjustment of industrial structure, urban expansion control and scientific water resources allocation. In general, the surface water deficit index based water deficiency zoning will be of significant value to be applied in water resources management at regional scales. 相似文献
993.
采用超限率方法,分析滁州地震台2011-2013年电磁扰动数据,结果发现,2012年7月20日江苏高邮M4.9地震前,电磁扰动脉冲超限频次和超限幅度均出现明显增强;进一步分析该台电磁扰动子夜时段(00:00-04:00)的脉冲变化,结果显示,子夜时段的电磁扰动脉冲在震前明显增强.分析认为,2012年滁州地震台电磁扰动脉冲增强变化与高邮M4.9地震具有明显的相关性. 相似文献
994.
砂岩侵入体是由沉积后的砂岩再活动并侵入到周围地层中形成的一种特殊砂体。为了研究其演化过程,设计了砂岩侵入体形成过程的模拟实验。针对实验结果,提出了基于体素模型法和Petrel软件的三维重建方法:在实验切片的基础上,对所得到的实验照片进行预处理,将其转化为Petrel软件能够识别的Gslib格式的数据体,再使用克里金插值算法进行模拟。结果表明,克里金算法可以很好地再现砂岩侵入体的外部形态,多组切片的特征参数统计可以定量地刻画出侵入体的形态,以期为实际岩性油气藏中的规模预测提供理论指导。 相似文献
995.
Suryun Ham Song-You Hong Yign Noh Soon-Il An Young-Hwa Byun Hyun-Suk Kang Johan Lee Won-Tae Kwon 《Asia-Pacific Journal of Atmospheric Sciences》2012,48(4):457-463
This paper investigates the effects of river discharge on simulated climatology from 1979 to 1988 using the Hadley Centre Global Environmental Model version 2. Two experiments are performed with and without the inclusion of Total Runoff Integrating Pathways. The results show that the inclusion of flow routing can lead to the decrease of salinity over the coastal region due to freshwater. This reduction results in a shallower mixed layer depth, which in turn leads to the weakening of trade winds and a decrease in vertical mixing in the ocean. The enhanced sensible and latent heat fluxes over warmed SST improve the simulated precipitation and thermodynamic circulation. As a result, the experiment with flow routing is capable of improving the large-scale climate feature with an increase in precipitation over the eastern tropical equatorial Pacific region. 相似文献
996.
Yulan Zhang Shichang Kang Chaoliu Li Zhiyuan Cong Qianggong Zhang 《Journal of Atmospheric Chemistry》2012,69(3):187-200
Chemical compositions of precipitation samples collected from a remote and high elevation site (Nam Co Station, 30°46.44??N, 90°59.31??E, 4730?m?a.s.l.) in central Tibetan Plateau (TP, hereafter) from August 2005 to August 2009 are investigated. During the study period, Ca2+ and HCO 3 - have the highest concentrations among ions and are the dominant cation and anion in precipitation, taking 27.46?% and 30.84?% to the total ions respectively. Empirical Orthogonal Functions (EOFs) analyses reveal that crustal aerosol inputs significantly contributed to the loading of Ca2+, Mg2+, SO 4 2- and HCO 3 - in precipitation, while lake salt plays a major source of K+ and Cl-. Seasonal variations of ionic wet deposition fluxes show high values during monsoon seasons due to large precipitation amount. Among the cations, annual Ca2+ flux is the largest (86.26?eq hm?2), Na+ and NH 4 + fluxes are following. Among anions, HCO 3 - has the highest flux (98.66?eq hm?2) while that of NO 3 - is the lowest. Annual wet deposition of nitrogen has varied considerably with the average value of 0.70?kg?ha?1 a?1 at Nam Co Station. About 80?% of total nitrogen flux occurs during the monsoon seasons when precipitation is concentrated, in which NH 4 + and NO 3 - contributed to 61?% and 39?% of the total nitrogen deposition. Thus, our ionic concentrations and wet deposition fluxes in precipitation can provide a useful dataset to assess atmospheric environment and its impacts on ecosystem in the inland TP. 相似文献
997.
Natural Hazards - The purpose of this study is to evaluate the effectiveness of agricultural drought risk management using news media data (NMD) by elucidating the relationships among the... 相似文献
998.
Jong Ryeol Choe Yoon Sub Shin Ji Yong Choi Tae Hwan Kim Min-Min Jung Cheol Young Choi 《Ocean Science Journal》2017,52(4):501-509
We investigated the effect of light wavelengths on antioxidant and immunity parameters in juvenile rock bream, Oplegnathus fasciatus, exposed to thermal stress (25 and 30°C). We exposed the fish to light emitting diodes (LEDs) emitting green (520 nm) and red light (630 nm) of 0.25 and 0.5 W/m2 intensity, and measured the activity, and mRNA and protein expression levels of the antioxidant enzymes, superoxide dismutase, catalase, and glutathione peroxidase. We also determined the levels of plasma hydrogen peroxide (H2O2), melatonin, and lysozyme. Furthermore, the mRNA and protein levels of caspase-3 were measured and terminal transferase dUTP nick end labeling (TUNEL) assays were performed. We observed that mRNA expression and activities of antioxidant enzymes and plasma H2O2 levels were significantly higher after exposure to high temperatures. However, increases in these parameters were significantly lower after exposure to green LED light. The plasma melatonin and lysozyme levels were significantly lower in the different groups after exposure to high temperatures; however, in groups exposed to green LED light, their levels were significantly higher than those in the control group. The expression pattern of caspase-3 mRNA was similar to that of H2O2. The TUNEL assay showed that apoptosis was markedly higher at higher water temperatures than that at 20°C. These results indicate that high water temperatures induce oxidative stress and decrease the immunity in juvenile rock bream but green LED light inhibits the rise in oxidative stress and combats the decrease in immunity and should, thus, be useful in the culture of rock bream. 相似文献
999.
B. Jung R. Sivasubramanian B. Batchelor A. Abdel-Wahab 《International Journal of Environmental Science and Technology》2017,14(1):123-134
Chlorate is one of the disinfection byproducts that are formed when chlorine/chlorine dioxide is used as a primary disinfectant. This study investigated the removal of chlorate by photochemical degradation using an advanced reduction process, which is a treatment method that combines a reducing agent with an activating method to generate reducing radicals. The effectiveness of combinations of reducing agents and three UV light sources having a peak output at 254, 365, and 312 nm were evaluated for chlorate removal. Dithionite irradiated by broad-band UVB lamp having the peak energy at 312 nm showed the highest chlorate removal. In pursuit of finding the optimum advanced reduction process conditions, the environmental process variables including pH, reducing agent dose, and light intensity were investigated. Dithionite/UV-B advanced reduction process was effective in weakly acidic conditions (pH < 5), and chlorate removal occurred in two steps. The first was an initial rapid decrease in chlorate concentration that occurred before initiating UV irradiation and was attributed to reaction with dithionite decomposition products. The second step was a slow decrease during UV irradiation that is caused by radicals produced by photolysis of the products of dithionite decomposition. The major product of chlorate destruction was chloride, with negligible amounts of chlorite produced. 相似文献
1000.
KANG Kyoung Ho 《中国海洋大学学报(英文版)》2010,9(2):157-161
To investigate sulfide detoxification in Urechis unicinctus,oxygen consumption rate and sulfide detoxification productswere analyzed during sulfide exposure under controlled laboratory conditions.The results showed that oxygen consumption rateswere elevated significantly during 3 h sulfide exposure compared to the control(P0.05).The concentration of sulfite in body walland hindgut of experimental worms increased significantly(P0.05)when exposed to 50μmolL-1sulfide,reached a maximum at24 h and then decreased.Similar result was observed in worms exposed to 150μmolL-1sulfide except that sulfite concentrationreached a maximum at 12 h.Contents of thiosulfate in body wall and hindgut of U.unicinctus exposed to sulfide were also significantly higher than that of the control without sulfide exposure.In conclusion,during short-time sulfide exposure U.unicinctus mayraise oxygen consumption to detoxify toxic sulfide into sulfite and thiosulfate.Sulfide detoxification was restrained when the expo-sure time was prolonged or sulfide concentration was increased,which was indicated by decrease of sulfite,the intermediate productof sulfide detoxification. 相似文献