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141.
142.
Preparation by enzymolysis and bioactivity of iron complex of fish protein hydrolysate (Fe-FPH)from low value fish 总被引:6,自引:0,他引:6
Preparation of Fe^2+ chelate of fish protein hydrolysate (Fe-FPH) obtained from low value fish proteins was introduced and its bioactivity was studied by compound enzymolysis. The optimum conditions for hydrolysate chelating Fe^2+ are DH (degree of hydrolysis) at 5%, pH 7.0, 20℃ and 15 min chelating time for FM (material not being defatted). Four types of Fe-FPH including CA (deposit after chelating), CB (deposit in 50% of absolute ethanol solution), CC (suspended deposit in 80% of absolute ethanol solution), and CD (bottom deposit in 80% of absolute ethanol solution) were fractionated with absolute ethanol from FM. Structural analysis through infra-red spectrum revealed that Fe^2+ was combined strongly with amino-group and carboxyl-group in each chelate and each Fe^2+ could form two five-member ring structures. All of the four chelates were shown more significant antioxidative activity and can be used as natural hydrophobic and hydrophilic antioxidant. Among all the chelates, the CB possesses the most effective antioxidative activity at 92% as high as that of a-tocopherol. Among all Fe-FPHs, only CD showed the most effective antibacterial activity against Escherichia coli, Staphylococcus aureus, Salmonella typhi, and Bacillus subtilis and can be used as natural antibacterial. It provides a more effective way for utilization of low value fish proteins and key information of Fe-FPH as additive in food industry. 相似文献
143.
硅酸盐、氧化物的氧同位素测定分析,是成岩成矿物质 源区鉴定、矿物岩石形成温度确定、成岩成矿地球化学机理 推测的重要手段之一[1]。在固体地球科学的诸多学科[2]以 及环境科学、水文、古气候、天体化学等其他学科均有着广泛 的应用。因此,随着样品量的增加,提高实验室的BrF5法氧 同位素实验系统的工作效率颇有意义。 图1为BrF5法氧同位素实验系统装置。当系统真空抽 至3×10-3Pa时,充入氩气。分别将已称好的200目干燥样 品12mg加入各反应器,经2小时200℃去气抽真空后,将化 学计算量 相似文献
144.
采用土壤深松 45cm、30 cm处理打破犁底层 ,1 996~ 1 998年连续进行 2个年度的冬小麦保墒、增产效应田间试验 .试验结果表明 :土壤深松处理后可减少冬小麦全生育期 0~ 1 0 0 cm的作物耗水量 ,促进根系对 1 0 0~ 2 0 0 cm土层土壤水分的利用 ,提高冬小麦的产量耗水比 .土壤深松处理能明显增加 0~ 30 cm土层的土壤湿度和含水量 ,降低 0~ 50 cm土层的土壤容重 .有利于冬小麦根系、茎、叶的生长发育和总生物量的累积 .土壤深松 45cm处理 2年平均冬小麦增产 7.0 % ,土壤深松 30 cm处理第一年增产 7.7% .冬小麦土壤深松保墒增产效应的适宜深松深度为 30 cm. 相似文献
145.
尽管40Ar和36Ar之间质量相差达1/10,但是受放射性成因40Ar的影响,一般认为难以进行氩同位素分馏研究.本文通过自行设计的一套氩扩散迁移实验分析系统,对比研究了氩在不同的扩散介质条件下扩散迁移前后氩同位素组成变化情况,证实氩在致密的扩散介质条件下以分子流形式从一个储库向另一个储库的迁移过程中,由于36Ar和40Ar的迁移速率不同,扩散后的40Ar/36Ar值比扩散前的值要小,也即发生了氩同位素分馏.氩同位素分馏的特征表现为最初的一段时间内分馏程度逐步增强,在一定时间后,由于储库之间压力逐渐达到平衡,分馏程度逐步减小.研究自然界中存在的氩同位素分馏,不仅可以判别油气田中油气运移的方向、增强油气远景评价和地球化学勘探,而且对深源岩浆的起源、迁移等研究也可提供新的研究思路和途径. 相似文献
146.
147.
???VRS???????????????????????????????????????????????????????????????????????????????????????????????????·??Ч???????????????????ò??????????????????????????????????????????????????????鶼????????????????????????????????VRS?????????????????????? 相似文献
148.
It is very common that a submarine pipeline has to pass through a ship mooring area near a harbor zone in the Bohai Bay, China. The risk assessment of accidental events induced by the potential anchoring ships is carried out, which will lead to external interference with the pipeline. A procedure to calculate the probability for the anchoring activity in the ship mooring area to damage the underlying pipeline is proposed. The adopted methodology is based on the recommendations suggested by the DNV Codes. The same philosophy is also applied to estimate the damage probability that is concerned with sinking ships. 相似文献
149.
Groundwater simulation using a numerical model under different water resources management scenarios in an arid region of China 总被引:2,自引:1,他引:1
Shaoyuan Feng Zailin Huo Shaozhong Kang Zejun Tang Fengxin Wang 《Environmental Earth Sciences》2011,62(5):961-971
Groundwater plays an important role in the economic development and ecological balance of the arid area of northwest China.
Unfortunately, human activity, for example groundwater extraction for irrigation, have resulted in excessive falls in groundwater
level, and aquifer overdraft in the oasis, disrupting the natural equilibrium of these systems. A groundwater numerical model
for Minqin oasis, an arid area of northwest China, was developed using FEFLOW software to simulate regional groundwater changes
under transient conditions. The vertical recharge and discharge (source/sink terms) of the groundwater models were determined
from land-use data and irrigation systems for the different crops in the different sub-areas. The calibrated model was used
to predict the change for the period from 2000 to 2020 under various water resources management scenarios. Simulated results
showed that under current water resources management conditions groundwater levels at Minqin oasis are in a continuous drawdown
trend and groundwater depth will be more than 30 m by 2020. Reducing the irrigation area is more effective than water-saving
irrigation to reduce groundwater decline at Minqin oasis and the annual groundwater budget would be −0.978 × 108 m3. In addition, water-diversion projects can also reduce the drawdown trend of groundwater at Minqin oasis, and the groundwater
budget in the Huqu sub-area would be in zero equilibrium if the annual inflow into the oasis was enhanced to 2.51 × 108 m3. Furthermore, integrative water resources management including water-diversion projects, water-saving irrigation, and reducing
the irrigation area are the most effective measures for solving groundwater problems at Minqin oasis. 相似文献
150.
Mechanism and geo-mechanics models of landslides triggered by 5.12 Wenchuan Earthquake 总被引:5,自引:1,他引:4
Due to the extremely high magnitude, long duration, and the complicated geo-environment in the disaster area, the great 5.12 Wenchuan Earthquake not only produced a huge number of landslides and rockfalls, but also involved complicated dynamic processes. These processes are quite different from the characteristics of landslides and rockfalls under general gravitational force, and presently human knowledge is very poor in this field. In order to describe the special dynamic processes, some terms such as shattering-cracking, shattering-sliding, shattering-falls and ejection are defined in this paper. Combined with slope structures, a mechanism classification system of strong earthquake-triggered landslide and rockfall is suggested, which is divided into 5 categories and 14 types. This paper also analyzes the basic characteristics, dynamic processes and geo-mechanics conceptual models of some typologies, especial the type of shattering-sliding for most large-scales landsides. This paper initially reveals the formation mechanism, geo-mechanics models and dynamic features of landslides and rockfalls triggered by the great Wenchuan Earthquake. 相似文献