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971.
972.
973.
本文利用1957~1998年的资料,以统计分析的方法,对长江中下游梅雨及热带气旋活动的对应关系进行了初步分析,归纳出几点有参考价值的结论以求对热带气旋活动的长期预报有所裨益。 相似文献
974.
6-O-羧甲基壳多糖的细胞毒性效应研究 总被引:5,自引:0,他引:5
Chen Xiguang 《中国海洋大学学报(自然科学版)》2000,30(Z1):221-224
采用溶血试验和细胞毒性试验研究6 -O-羧甲基壳多糖的细胞毒性效应,结果表明:1% 浓度的6-O-羧甲基壳多糖对红细胞溶 血率小于5%,说明该材料无溶血现象。以手术缝合线和500μg/mL的苯酚为对照研究不同分 子量的6-O-羧甲基壳多糖分别在1000μg/mL和2000μg/mL浓度下对大白鼠皮肤成纤维细胞 生长的影响,经过2d,4d,7d细胞培养,细胞增殖率均大于100%,说明该材料对成纤维细胞 无毒性效应且对大白鼠皮肤成纤维细胞有促进生长的作用,分子量越小促生长作用越强,随 着培养时间延长促生长作用亦增强。此研究在一定程度上证明,6-O-羧甲基壳多糖作为医 用生物材料在细胞毒性方面是安全的。 相似文献
975.
976.
厦门海区潮间带海洋动植物共附生微生物的抗菌活性 总被引:20,自引:0,他引:20
从厦门海区潮间带石纯、浒苔、江蓠、海兔、海葵及鲨鱼肠道分离得289株共附生微生物,以8种敏感菌为指示菌,从中获得拮抗活性的幼苗28株,放线菌17株,真菌8株。拮抗细菌以假单胞菌(39%)、弧菌(25%)和芽直菌(14%)为主,主要为抗革兰氏阳性细菌,抗真菌的菌株比例较低。拮抗放线菌分属于链霉菌和小单孢菌,其抗革兰氏阳性菌、阴性菌和真菌的菌株比例分别为65%、47%和23%。拮抗真菌分青霉属和芽枝霉 相似文献
977.
Using the outputs of projections under the highest emission scenario of the representative concentration pathways performed by Earth system models (ESMs), we evaluate the ocean acidification rates of subsurface layers of the western North Pacific, where the strongest sink of atmospheric CO2 is found in the mid-latitudes. The low potential vorticity water mass called the North Pacific Subtropical Mode Water (STMW) shows large dissolved inorganic carbon (DIC) concentration increase, and is advected southwestward, so that, in the sea to the south of Japan, DIC concentration increases and ocean acidification occurs faster than in adjacent regions. In the STMW of the Izu-Ogasawara region, the ocean acidification occurs with a pH decrease of ~0.004 year?1 , a much higher rate than the previously estimated global average (0.0023 year?1), so that the pH decreases by 0.3–0.4 during the twenty-first century and the saturation state of calcite (ΩCa) decreases from ~4.8 down to ~2.4. We find that the ESMs with a deeper mixed layer in the Kuroshio Extension region show a larger increase in DIC concentration within the Izu-Ogasawara region and within the Ryukyu Islands region. Comparing model results with the mixed layer depth obtained from the Argo dataset, we estimate that DIC concentration at a depth of ~200 m increases by 1.4–1.6 μmol kg?1 year?1 in the Izu-Ogasawara region and by 1.1–1.4 μmol kg?1 year?1 in the Ryukyu Islands region toward the end of this century. 相似文献
978.
Mohammad Abdelfattah Sarhan A. M. K. Basal Ibrahim Mohamed Ibrahim 《Marine Geophysical Researches》2017,38(3):271-290
This paper focuses on seismic and well log interpretations for evaluating the sandstones of the Cenomanian Bahariya Formation in the southwest Qarun Field, Gindi Basin, northern Western Desert of Egypt. The seismic profiles display a clear anticlinal structure intersected by reverse faults in the study area. This faulted anticline has been interpreted to be one of the Syrian arc system folds formed by Upper Cretaceous tectonic inversion, which resulted from the NW movement of the African Plate relative to Laurasia. This anticline has been recommended as a target for exploration by the present work as it may represent a structural trap for hydrocarbon accumulation. The sandstones of the Lower Bahariya Formation in the southwest Qarun Field display good reservoir characteristics. The interpretation of the available well log data for the SWQ-21 and SWQ-25 wells for the Lower Bahariya Formation reflects a good reservoir quality for oil production in its topmost part. This reservoir possesses low SW (<50%), high porosity (16%), low SW/SXO and low BVW (<0.09) which all reflect a high potential for oil production. 相似文献
979.
The ‘Coral Health Chart’ has become a popular tool for monitoring coral bleaching worldwide. The scleractinian coral Acropora downingi (Wallace 1999) is highly vulnerable to temperature anomalies in the Persian Gulf. Our study tested the reliability of Coral Health Chart scores for the assessment of bleaching-related changes in the mitotic index (MI) and density of zooxanthellae cells in A. downingi in Qeshm Island, the Persian Gulf. The results revealed that, at least under severe conditions, it can be used as an effective proxy for detecting changes in the density of normal, transparent, or degraded zooxanthellae and MI. However, its ability to discern changes in pigment concentration and total zooxanthellae density should be viewed with some caution in the Gulf region, probably because the high levels of environmental variability in this region result in inherent variations in the characteristics of zooxanthellae among “healthy” looking corals. 相似文献
980.
We examined the contribution of submarine groundwater discharge (SGD) to nutrient budgets in Hwasun Bay, Jeju Island, Korea in August 2009, October 2014, and May 2015. The concentrations of dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) in fresh groundwater were in the range of 285?716 μM and 2.3?3.2 μM, respectively, which were each 1?2 orders of magnitude higher than those in the bay seawater. The outer-bay seawater flowing into the bay was oligotrophic (2.9 ± 1.9 μM for DIN and 0.2 ± 0.3 μM for DIP). Nutrient budget calculations were performed for each season by accounting for submarine fresh groundwater discharge (SFGD) and water residence times. In August 2009 (DIN = 1.8 μM and DIN:DIP ratio = 4.6 for the outerbay water), DIN inputs from SFGD accounted for approximately 40% of the DIN inventory in the bay seawater. In October 2014 (DIN = 1.1 μM and DIP < 0.05 μM for the outer-bay water), DIP from SFGD accounted for approximately 100% of the DIP inventory in the bay seawater. In May 2015, mean concentrations of DIN and DIP in the bay seawater were 8.6 ± 12 μM and 0.11 ± 0.04 μM, respectively, with conservative behaviors in the bay seawater in association with excessive groundwater inputs. These results imply that SGD plays a critical but different role in nutrient budgets and stoichiometry in coastal waters off a volcanic island depending on open-ocean nutrient conditions. 相似文献