共查询到20条相似文献，搜索用时 841 毫秒
1.
2.
在"催化氧化脱硫"与"再生"分开的新型LO-CAT脱硫装置中,以海水为吸收介质,络合铁为载体,针对H2S质量浓度为10g/m3的模拟气进行了海上钻井平台石油伴生气脱除H2S的再生系统实验研究。主要考察了再生系统中碱性液体流速、空气过剩因子(ε)和再生温度等参数对脱硫效果的影响,并对反应产生的固体产物进行了SEM和XRD表征。实验结果分析得出,脱除H2S的最佳再生条件为:液体流速v=8.77mL/min,空气过剩因子ε=90,再生温度T2=45℃。表征得出,产生的固体物质为硫磺,可能含有少量Fex Sy杂质。 相似文献
3.
4.
针对浮式消波海流机样机测试时出现的问题,对其吃水深度线和叶片安装角度进行优化。根据装置结构特点,用Gambit建立了装置横截面的二维网格模型。根据浮式消波海流机实际工作环境,利用Fluent流体仿真软件,使用VOF(volume of fluid)两相流模型,分配空气相与液态水相在流域中的不同比例,来确定不同的吃水深度线。并且结合k-epsilon紊流模型建立模拟仿真环境。先对3种水线进行仿真分析,然后进行实验验证。通过分析对比装置的3种不同吃水深度线的模拟与实验结果,得到装置的最优吃水深度线为1/3水线。基于最优吃水深度线,分别对叶片的4种安装角度在相同的仿真环境中进行模拟仿真。利用仿真得到的扭矩数据,计算扭矩系数、功率系数,分析对比仿真数据以及仿真过程中扭矩趋势图得出4种叶片安装角度的最优角度是90°。吃水深度线决定了装置的消波能力,并且为叶片获能提供条件,叶片安装角度直接影响着装置的获能效率,所以最优的吃水深度线和叶片安装角度对海流机的消波能力和获能效率具有重要意义。 相似文献
5.
据美国《自然与生物工程》科学杂志电子版报道，由美国海军研究所等组成的研究小组，利用海底的海泥和海水之间产生的电位差，研制出海泥发电装置，经过长期的实验，终于发电实验成功。该小组称，在海底的海泥中，有许多微生物把生物的遗骸等沉积的有机物当作食物，由于这些微生物在分解有机物消耗氧气的活动时，能使海泥和海水之间产生出不同的电压。他们在美国新泽西州等２处的实验海域，先把石墨制成直径约４８厘米、厚１．３厘米的圆盘状，再用电线连接２个电极。一个电极悬挂在海水中，另一个电极埋在海泥中，利用其电位差进行实验发电，经过约７个月时间，这种装置发出了稳定电压的电流。据说对电极再进行改善后，就能产生转动研究机器的电力。这种既能发电又能分解海底有机物的发电装置，将对净化海洋，保护环境有无可比拟的作用。□编译／新洲海泥发电@新洲 相似文献
6.
吸附材料再生可以实现吸附材料的循环使用,降低处理成本。本文研究了壳聚糖-生物炭复合材料上诺氟沙星(NOR)解吸的影响因素,考察了NOR解吸动力学过程,并通过多次再生实验探讨了其重复使用潜力。结果表明,以NaOH为解吸剂时有利于促进壳聚糖-生物炭复合材料上NOR的解吸,随NaOH浓度的提高,NOR的解吸率增大。溶液离子强度提高了NOR的解吸率,离子强度为0.1mol/L时NOR的解吸效果最好。热力学参数ΔG和ΔS表明该解吸过程是自发进行的吸热反应。NOR在壳聚糖-生物炭复合材料上的解吸主要受慢解吸和极慢解吸控制。双常数方程和Elovich方程可较好描述复合材料上NOR的解吸动力学行为。壳聚糖-生物炭复合材料重复使用6次后,NOR的解吸率为66.88%,吸附量为8.675mg/g,表明壳聚糖-生物炭复合材料具有较好的可循环利用潜能。 相似文献
7.
8.
拖曳水池中进行立管涡激振动实验时,为了保证采样时间长度,难以达到较高的Re数。流速增大装置可以在不提高拖车车速的情况下增大立管外的流速。利用这种流速增大装置还可实现流速分层流场中细长柔性立管涡激振动实验。经过对流速增大装置中的进流段曲线进行优选,发现Witozinsky曲线的总体性能最好。在对流速增大装置进行水池实验和数值模拟后,发现流速增大区域的流速增大倍数接近进流段收缩比,流速增大区域流场比较稳定、均匀,流速增大装置对其外的流场影响很小。此流速增大装置不但可应用于拖曳水池中的立管涡激振动实验,还可以应用于对流速要求较高的水下航行体的水池试验,如鱼雷、水下机器人等。 相似文献
9.
金枪鱼(Katsuwonus pelamis)碎肉蛋白降压肽的酶解制备及活性研究 总被引：2，自引：0，他引：2
以血管紧张素转换酶(ACE)抑制率为指标,通过正交试验L9(34)确定碱性蛋白酶(Alcalase)对金枪鱼(Katsuwonus pelamis)碎肉蛋白的最佳酶解条件,利用D101大孔树脂建立了酶解物的脱盐工艺,利用超滤、葡聚糖凝胶(G-25)色谱和反相-高效液相色谱(RP-HPLC)分离降压肽,并确定其纯度,利用氨基酸序列分析和ESI-MS鉴定纯化多肽的结构。结果表明,碱性蛋白酶酶解金枪鱼碎肉蛋白制备降压肽的最佳酶解条件是:pH 9.5,酶用量1.5%,酶解温度50°C,酶解时间5h;D101大孔吸附树脂脱盐工艺条件为:上样浓度10 mg/mL、上样流速1.5 BV/h、解吸剂为75%乙醇;酶解物经超滤和Sephadex G-25分离获得一个纯度较高的四肽,经氨基酸序列分析和ESI-MS鉴定结构为Phe-GlyGly-Val(FGGV),ESI-MS检测给出分子离子峰m/z 379.50([M+H]+)。利用碱性蛋白酶酶解并经超滤和色谱技术制备的金枪鱼碎肉蛋白降压肽具有良好的ACE抑制活性,可作为降压药物、保健食品或添加剂进行开发。 相似文献
10.
离心转速对渤海灰白冰脱盐作用的实验研究 总被引：11，自引：0，他引：11
通过实验室离心实验,研究了离心转速对渤海灰白冰脱盐、脱盐效果以及主要超标水质参数的影响.实验结果表明,在实验条件相同的情况下,离心转速的变化对灰白冰的脱盐、脱盐效果均有显著影响.离心转速达到2000r/min左右时,脱盐冰的全盐量基本降到标准要求.实验中,灰白冰的离心脱盐率保持在较高的水平,一般可达80%～90%以上,在3000～4000r/min离心转速时,渤海灰白冰脱盐率最大,可达到90 96%.离心转速的变化对灰白冰中主要超标物质的去除有不同程度的影响,其中硫酸盐含量变化幅度最大,下降了73.19%～96.52%;盐度也有较大程度的降低,但降低幅度小于硫酸盐,降幅在71.86%～93.55%之间.pH值没有发生恶化,保持在7.5左右.因此,离心转速是渤海灰白冰离心脱盐过程中的主要控制性因子之一.渤海灰白冰经过实验室离心脱盐后,全盐量等各项水质指标均可达到工农业生产和人们生活用水的指标要求. 相似文献
11.
Chandralata Raghukumar G. Sheelu P. A. Loka Bharathi Shanta Nair C. Mohandass 《Marine Georesources & Geotechnology》2001,19(1):1-16
In order to assess the impact of deep-sea mining on the in situ benthic life, we measured the microbial standing stock and concentration of organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin in the Indian pioneer area. Sediments were collected using box core and grab samples during September 1996. The total bacterial numbers ranged from 10 10 -10 11 cells per g -1 dry weight sediment. There was a marginal decrease in the number of bacteria from surface to 30 cm depth, though the subsurface section registered a higher number than did the surface. The highest numbers were encountered at depths of 4-8 cm. The retrievable number of bacteria were two orders less in comparison with the direct total counts of bacteria. An almost homogeneous distribution of bacteria, total organic carbon, living biomass, and lipids throughout the depth of cores indicates active microbial and benthic processes in the deep sea sediments. On the other hand, a uniform distribution of total counts of bacteria, carbohydrates, and total organic carbon in all the cores indicates their stable nature and suggests that they can serve as useful parameters for long-term monitoring of the area after the benthic disturbance. Further studies on temporal variability in this region would not only verify the observed norms of distribution of these variables but would also help to understand restabilization processes after the simulated benthic disturbance. 相似文献
12.
Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 相似文献
13.
海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。 相似文献
14.
Geoacoustic Inversion via Genetic Algorithm and Its Application to Manganese Sediment Identification
An acoustic inversion method using a wide-band signal and two near field receivers is proposed and applied to multiple layered seabed models including a manganese sediment. The inversion problem can be formulated into a probabilistic model comprised of signals, a forward model, and additive noise. The forward model simulates wide-band signals, such as chirp signals, and is chosen to be the source-waveletconvolution plane wave modeling method. The wavelet matching technique, using weighted least-squares fitting, estimates the sediment sound-speed and thickness on which determination of the possible numerical ranges for a priori uniform distribution is based. The genetic algorithm is applied to a global optimization problem to find a maximum a posteriori solution for determined a priori search space. Here the object function is defined by an L 2 norm of the difference between measured and modeled signals. Not only the marginal pdf but also its statistics are calculated by numerical evaluation of integrals using the samples selected during importance sampling process of the genetic algorithm. 相似文献
15.
Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
16.
17.
Oedometer tests have been carried out on 70 undisturbed surficial clays (at approximately 250 mm below the mudline), mostly collected by free-fall corers from sites widely scattered throughout the deep-sea North Atlantic. Acoustic measurements were also made, initially on contiguous samples and ultimately on the same sample using a geophysically instrumented oedometer which also collected electrical resistivity data. Apart from those quiescent areas below the carbonate compensation depth, such as north of the West Indies where very fine clays exist, most of the samples are silty clays whose geotechnical-geophysical properties are dependent on the type of clay minerals present (and their ability to take in moisture), the sand-size fraction, and the quantity of carbonate present. Thus the pure clays have high compressibilities which decrease on the addition of coarse particles, while the converse is true for the acoustic parameters, these increasing with the sand fraction. Using the notion of the intrinsic compression line for all samples, and comparison to it of the measured compression curves, it is clear that, contrary to some previously held ideas, most deep-sea clays are normally consolidated; the addition of carbonate has the effect of creating an open, stronger sediment skeleton. Interestingly, where information is available, the variation with depth of a sample's acoustic velocity follows the void ratio pressure relationship of the compression curve. This allows the construction of an in-situ sediment compression curve using the in-situ geophysical observations. 相似文献
18.
19.
Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans 总被引：1，自引：0，他引：1
A set of 27 marine planktonic bacteria isolated from the polar regions was characterized by 16S rDNA sequencing and physiological and biochemical testing. More than half of these bacteria were positive for caseinase, gelatinase and 13-glucosidase, and could utilize glucose, maltose or malic acid as carbon source for cell growth. Twelve isolates expressed nitrate reduction activities. Except for one antarctic isolate BSwlO175 belonging to Actinobacteria phylum, these isolates were classified as γ-Proteobacteria, suggesting that γ-Proteobacteria dominated in cultivable marine bacterioplankton at both poles. Genus Pseudoalteromonas was the predominant group in the Chukchi Sea and the Bering Sea, and genus ShewaneUa dominated in cultivable bacterioplankton in the Prydz Bay. With sequence similarities above 97%, genus Psychrobacter was found at both poles. These 27 isolates were psychrotolerant, and significant 16S rDNA sequence similarities were found not only between arctic and antarctic marine bacteria （ 〉 99% ）, but also between polar marine bacteria and bacteria from other aquatic environments （ ≥ 98.8% ）, including temperate ocean, deep sea, pond and lake, suggesting that in the polar oceans less temperature-sensitive bacteria may be cosmopolitan and have a bipolar, even global, distribution at the species level. 相似文献
20.
The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics. 相似文献