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为提高船用907钢的耐冲刷腐蚀性能,设计了一种可与船用907钢海水管路内壁表面形成稳定化合物的NiMoB合金镀层,并采用正交试验优选了该化学镀液中NiCl_2,EDTA,Na_2MoO_4,KBH_4的浓度。采用扫描电镜观察合金镀层形貌;采用阻抗谱、极化曲线分析了合金镀层在模拟海水中的耐蚀性,并在模拟海水冲刷腐蚀环境下分析了Ni Mo B镀层的抗冲刷腐蚀特性。结果表明:不同的镀液参数对Ni Mo B镀层的性能影响较大,当NiCl_245.0g/L、EDTA 9.0 g/L、Na_2MoO_415.0 g/L、KBH_40.8 g/L,乙二胺45.0 g/L,NaOH 90.0 g/L时,NiMoB非晶态薄膜表面呈胞状物陈列,具有致密的表面形貌,镀层的耐腐蚀、抗冲刷腐蚀性能优良。 相似文献
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多相流动淡水体系中碳钢冲刷腐蚀电化学行为的研究 总被引:1,自引:0,他引:1
在含砂淡水流动体系中对HG60碳钢进行了电化学测量,用旋转圆柱电极方法研究了冲刷腐蚀条件下影响20A碳钢阴极行为的两个因素。结果显示,水流速度的提高、固体颗粒物的存在都能使氧的传输加强,提高氧的极限扩散电流,使碳钢的冲蚀情况加剧,在1800-3000r/min(线速度小于2.17m/s)转速条件下,碳钢在0.1mol/L硫酸钠介质中的冲刷腐蚀由氧的扩散控制;当水流速度进一步提高(≥8m/s)时,碳钢的阴极反应可能转变为扩散和活化共同控制。 相似文献
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中原油田腐蚀现状中原油田污水矿化度高,一般在8~14×10~5mg/L之间,最高达37×10~5mg/L;Cl~-约占总矿化度的60%;pH一般在5.0~6.0之间;同时,含有CO_2和H_2S气体以及硫酸盐还原菌。所以腐蚀性极强,均匀腐蚀率一般为..5~0.762mm/a。濮一联滤后污水的均匀腐蚀率为2.6mm/a,濮二联滤后污水的均匀腐蚀率高达3.0mm/a;点蚀指数一般为150左右,点蚀速度一般在5~6mm/a,个别高达10mm/a以上。例如:中原油田原文一联污水处理站投产仅8个月, 相似文献
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为了提高316L不锈钢在冲刷腐蚀类环境中的耐腐蚀性,在其表面激光熔覆Co Ni Cr Al Y合金层。采用冲刷腐蚀试验比较了316L不锈钢及Co基合金熔覆层在含固相颗粒酸碱溶液中的耐冲刷腐蚀性能。采用X射线衍射仪分析熔覆层物相,采用金相显微镜及扫描电镜观察熔覆层腐蚀前后的形貌。结果表明:在低浓度酸碱、低含砂量及低速冲刷条件情况下,Co Ni Cr Al Y熔覆层的耐冲刷腐蚀性略高于316L不锈钢;在高浓度酸碱、高含砂量及高速冲刷条件下,Co基合金熔覆层的耐冲刷腐蚀性能明显优于316L不锈钢的;Co基合金熔覆层中析出的Cr2Ni3,Al Co和Al Ni硬质相以及Co元素本身的抗腐蚀性的综合作用使Co基合金熔覆层的耐冲刷腐蚀性能远远高于316L不锈钢的。 相似文献
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为了查找西北油田S135钻杆大面积腐蚀的原因,研究了当模拟试验工况为80℃、pH=10、溶解氧3~4 mg/L、试验周期120h、不同氯离子浓度溶液对S135钻杆腐蚀速率的影响.结果表明:在模拟试验工况条件下,S135钻杆腐蚀机理均为以氧腐蚀为主的均匀腐蚀,当氯离子浓度含量较低时(10 000~50 000 mg/L),随着氯离子含量增加,S135钻杆的腐蚀速率呈现出一定的降低(0.25~0.02 mm/a);当氯离子浓度含量达到110 000 mg/L时,腐蚀速率降低至0.05 mm/a,这与当氯离子含量升高时,对溶解氧的排驱作用相关. 相似文献
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Biogeo-optics: particle optical properties and the partitioning of the spectral scattering coefficient of ocean waters 总被引:1,自引:0,他引:1
We propose a direct method of partitioning the particulate spectral scattering coefficient of the marine hydrosol based on the concurrent determination of the concentrations of particulate mineral and organic matter (the total mass of optically active scattering material exclusive of water) with the particulate spectral scattering coefficient. For this we derive a Model II multiple linear regression model. The multiple linear regression of the particulate spectral scattering coefficient against the independent variables, the concentrations of particulate inorganic matter and particulate organic matter, yields their mass-specific spectral scattering cross sections. The mass-specific spectral scattering cross section is simply the particle scattering cross section normalized to the particle mass, a fundamental optical efficiency parameter for the attenuation of electromagnetic radiation [Absorption and Scattering of Light by Small Particles, (Wiley-Interscience, 1983), pp. 80-81, 289]. It is possible to infer the optical properties of the suspended matter from the mass-specific spectral scattering cross sections. From these cross sections we partition the particulate spectral scattering coefficient into its major components. 相似文献
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J. T. Carstensen Carolyn Ertell Jean-Marie Geoffroy 《Drug development and industrial pharmacy》1993,19(1):195-219
In dealing with particulate matter, it is important to distinguish between properties on the microscopic level and attribute bulk properties. It is the latter with which the practitioner is concerned, but knowledge of the former is of utmost importance.
The attribute properties of particulate matter in the manufacturing of solid state pharmaceutics are blending propensity, compressibility, powder flow, apparent density and compression potential. 相似文献
The attribute properties of particulate matter in the manufacturing of solid state pharmaceutics are blending propensity, compressibility, powder flow, apparent density and compression potential. 相似文献
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《Drug development and industrial pharmacy》2013,39(1-2):195-219
AbstractIn dealing with particulate matter, it is important to distinguish between properties on the microscopic level and attribute bulk properties. It is the latter with which the practitioner is concerned, but knowledge of the former is of utmost importance.The attribute properties of particulate matter in the manufacturing of solid state pharmaceutics are blending propensity, compressibility, powder flow, apparent density and compression potential. 相似文献
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鉴于当前水资源短缺、环境恶化、水产养殖业高速发展,以及保障食品安全等问题的不断呈现,促使资源型工厂化流水养殖模式急需向高效型循环水养殖方向转变,这是产业发展提升的必然趋势。本文以工业化养殖理念为指导、节能减排为目标,以鲆鲽类产业技术体系构建的循环水养殖模式为样板,按循环水养殖系统(RAS)的设计原理,优化养殖工艺流程,构建一种设施型精准化的RAS,并初步分析探讨了海水鱼类在此集成系统中的应用效果。该系统将为广大水产养殖企业提供一种建设成本低廉、系统运行稳定可控、容易管理的实用新型养殖模式,也可为下一步发展现代水产精准养殖工程体系提供理论和实践依据。 相似文献
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Distribution, partitioning and sources of polycyclic aromatic hydrocarbons in Daliao River water system in dry season, China 总被引:5,自引:0,他引:5
Eighteen polycyclic aromatic hydrocarbons (PAHs) were analyzed in 29 surface water, 29 suspended particulate matter (SPM), 28 sediment, and 10 pore water samples from Daliao River water system in dry season. The total PAH concentration ranged from 570.2 to 2318.6 ng L(-1) in surface water, from 151.0 to 28483.8 ng L(-1) in SPM, from 102.9 to 3419.2 ng g(-1) in sediment and from 6.3 to 46.4 microg l(-1) in pore water. The concentration of dissolved PAHs was higher than that of particulate PAHs at many sites, but the opposite results were generally observed at the sites of wastewater discharge. The soluble level of PAHs was much higher in the pore water than in the water column. Generally, the water column of the polluted branch streams contained higher content of PAHs than their mainstream. The environmental behaviors and fates of PAHs were examined according to some physicochemical parameters such as pH, organic carbon, SPM content, water content and grain size in sediments. Results showed that organic carbon was the primary factor controlling the distribution of the PAHs in the Daliao River water system. Partitioning of PAHs between sediment solid phase and pore water phase was studied, and the relationship between logK(oc) and logK(ow) of PAHs on some sediments and the predicted values was compared. PAHs other than naphthalene and acenaphthylene would be accumulated largely in the sediment of the Dalaio River water system. The sources of PAHs were evaluated employing ratios of specific PAHs compounds and different wastewater discharge sources, indicating that combustion was the main source of PAHs input. 相似文献
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Zoubeir L Adeline S Laurent CS Yoann C Truc HT Benoît le G Federico A 《Journal of hazardous materials》2007,148(3):606-612
The work presented in this article concerns polluted marine sediments. The article is divided into three parts. The first part discusses existing industrial procedures of treatment. The second part introduces the Novosol((R)) process, which was used for the treatment of polluted marine sediments. This process is based on the stabilization of heavy metals in the solid matrix by phosphatation and the destruction of organic matter by calcination. Finally, after a comparison had been made between environmental results obtained on both polluted marine sediments and inert ones, treated sediments were introduced in the production of clay bricks. The results obtained show that the Novosol process leads to the immobilization of most heavy metals and can be considered as an efficient tool for the stabilisation of polluted marine sediment. Thus, the results of physical and mechanical tests as compressive strength and water absorption indicate that performances obtained were comparable to standard brick values. These results confirm that, once treated, polluted sediments can be recycled. 相似文献
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The measurement and analysis of inherent optical properties (IOPs) of the main water constituents are necessary for remote-sensing-based water quality estimation and other ecological studies of lakes. This study aimed to measure and analyze the absorption and backscattering coefficients of the main water constituents and, further, to analyze their relations to the water constituent concentrations in Poyang Lake, China. The concentrations and the absorption and backscattering coefficients of the main water constituents at 47 sampling sites were measured and analyzed as follows. (1) The concentrations of chlorophyll a (C(CHL)), dissolved organic carbon (C(DOC)), suspended particulate matter (C(SPM)), including suspended particulate inorganic matter (C(SPIM)) and suspended particulate organic matter (C(SPOM)), and the absorption coefficients of total particulate (a(p)), phytoplankton (a(ph)), nonpigment particulate (a(d)), and colored/chromophoric dissolved organic matter (a(g)) were measured in the laboratory. (2) The total backscattering coefficients, including the contribution of pure water at six wavelengths of 420, 442, 470, 510, 590, and 700 nm, were measured in the field with a HydroScat-6 backscattering sensor. (3) The backscattering coefficients without the contribution of pure water (b(b)) were then derived by subtracting the backscattering coefficients of pure water from the total backscattering coefficients. (4) The C(CHL), C(SPM), C(SPIM), C(SPOM), and C(DOC) of the 41 remaining water samples were statistically described and their correlations were analyzed. (5) The a(ph), a(d), a(p), a(g), and b(b) were visualized and analyzed, and their relations to C(CHL), C(SPM), C(SPIM), C(SPOM), or C(DOC) were studied. Results showed the following. (1) Poyang Lake was a suspended particulate inorganic matter dominant lake with low phytoplankton concentration. (2) One salient a(ph) absorption peak was found at 678 nm, and it explained 72% of the variation of C(CHL). (3) The a(d) and a(p) exponentially decreased with increasing wavelength, and they explained 74% of the variation of C(SPIM) and 71% variation of C(SPM), respectively, at a wavelength of 440 nm. (4) The a(g) also exponentially decreased with increasing wavelength, and it had no significant correlation to C(DOC) at a significance level of 0.05. (5) The b(b) decreased with increasing wavelength, and it had strong and positive correlations to C(SPM), C(SPIM) and C(SPOM), a strong and negative correlation to C(CHL), and no correlation to C(DOC) at a significance level of 0.05. Such results will be helpful for the understanding of the IOPs of Poyang Lake. They, however, only represented the IOPs during the sampling time period, and more measurements and analyses in different seasons need to be carried out in the future to ensure a comprehensive understanding of the IOPs of Poyang Lake. 相似文献
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Valavanidis A Iliopoulos N Gotsis G Fiotakis K 《Journal of hazardous materials》2008,156(1-3):277-284
The production and use of polymeric materials worldwide has reached levels of 150 million tonnes per year, and the majority of plastic materials are discarded in waste landfills where are burned generating toxic emissions. In the present study we conducted laboratory experiments for batch combustion/burning of commercial polymeric materials, simulating conditions of open fire combustion, with the purpose to analyze their emissions for chemical characteristics of toxicological importance. We used common types of plastic materials: poly(vinyl chloride) (PVC), low and high density poly(ethylene) (LDPE, HDPE), poly(styrene) (PS), poly(propylene) (PP) and poly(ethylene terephthalate) (PET). Samples of particulate smoke (soot) collected on filters and residue solid ash produced by controlled burning conditions at 600-750 degrees C are used for analysis. Emissions of particulate matter, persistent free radicals embedded in the carbonaceous polymeric matrix, heavy metals, other elements and PAHs were determined in both types of samples. Results showed that all plastics burned easily generating charred residue solid ash and black airborne particulate smoke. Persistent carbon- and oxygen-centered radicals, known for their toxic effects in inhalable airborne particles, were detected in both particulate smoke emissions and residue solid ash. Concentrations of heavy metals and other elements (determined by Inductively Coupled Plasma Emission Spectrometry, ICP, method) were measured in the airborne soot and residue ash. Toxic heavy metals, such as Pb, Zn, Cr, Ni, and Cd were relatively at were found at low concentrations. High concentrations were found for some lithophilic elements, such as Na, Ca, Mg, Si and Al in particulate soot and residue solid ash. Measurements of PAHs showed that low molecular weight PAHs were at higher concentrations in the airborne particulate soot than in the residue solid ash for all types of plastic. Higher-ringed PAHs were detected at higher concentrations in the residue solid ash of PVC as compared to those from the other types of plastic. The open-air burning of plastic material and their toxic emissions is of growing concern in areas of municipal solid waste where open-fires occur intentionally or accidentally. Another problem is building fires in which victims may suffer severe smoke inhalation from burning plastic materials in homes and in working places. 相似文献
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施工现场的地下预制加工间普遍存在施工强度大,作业人员密集,不规律的气流组织导致施工环境质量恶劣等问题.对西安市某施工项目的地下预制加工间内可吸入颗粒物进行了实测和数据分析,其中通风加工间和给捧水加工间分别有等离子切割机、共板式法兰机、型材切割机和台式砂轮机等加工部件装置.经测试,等离子切割机为产尘量最高的机械装置,该装... 相似文献
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黑鲷肠道乳酸杆菌的分离与鉴定及其抑菌特性 总被引:1,自引:1,他引:0
无菌条件下取黒鲷肠道研磨液在MRS培养基厌氧培养,分离乳酸菌株经鉴定后命名为L-1、L-2,并分别进行两分离株的体外抑菌试验和胞外产物的稳定性研究.结果表明,2株乳酸菌胞外产物对热稳定且对副溶血弧菌有较强抑制作用,可以作为开发海水鱼用微生态制剂的备用菌株. 相似文献