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排序方式: 共有1723条查询结果,搜索用时 62 毫秒
1.
建立了小体积海水中134Cs、137Cs和60Co的联合分析方法,确定了最佳实验条件。采用磷钼酸铵富集法对海水中放射性铯进行浓集后,其上清液利用氢氧化钴沉淀载带海水中的60Co,用γ能谱仪进行测量。结果表明:该法对海水中放射性134Cs、137Cs和60Co的回收率分别为87%~95%、87%~95%和89%~93%,检测限分别为0.048、0.051、0.046 Bq/L。另外,对2017年IAEA国际比对(IAEA-RML-2017-01)海水样品中的134Cs、137Cs和60Co进行分析测量,核素分析结果的最终评价均为“通过”,验证了本实验室采用的134Cs、137Cs和60Co联合分析方法的可行性和可靠性,为今后该方法在常规海洋环境放射性监测中的应用推广奠定了基础。 相似文献
2.
The corrosion behavior and mechanism of iron‐oxidizing bacteria (IOB) on X65 steel in seawater are studied. This study uses the methods of weight loss, electrochemical measurements, and surface analysis. The results show that the IOB increases the corrosion damage degree of steel. Pittings are observed in the medium with IOB. The potentiodynamic polarization curves show that the anodic reaction rate is accelerated in the corrosion process of IOB. The synergies in corrosion between the metal surface, abiotic corrosion products, and bacterial cells, and the pitting corrosion mechanism of X65 steel are discussed. 相似文献
3.
《International Journal of Hydrogen Energy》2020,45(27):13876-13883
In this study, marine microalgae Chlorella pyrenoidosa produced 186 ml H2/l under nitrogen deprivation in natural seawater, and adding 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) to medium reduced the total volume of hydrogen production by 85%. This suggested water was the main electron donor for hydrogenase. An active starch accumulation was observed during the first two days in nitrogen deprivation. But the starch content in cell decreased only by 7% at the end of the hydrogen evolution stage. This was shown the absence of a large contribution of starch to the hydrogen production by C. pyrenoidosa in nitrogen deprivation. Different from the hydrogen production by Chlamydomonas reinhardtii under sulfur deprivation condition, the concentration of acetate in the medium decreased not only at the stage of oxygen consumption but also during the stage of hydrogen evolution by C. pyrenoidosa. Thus, acetate is involved not only in the establishment of anaerobiosis but also plays an important role in the production of hydrogen by C. pyrenoidosa as an exogenous electron donor. 相似文献
4.
Yuang Zhang Gagik G. Gurzadyan Rongwen Lu Shufen Zhang Xin Jin Bingtao Tang 《American Institute of Chemical Engineers》2020,66(6):e16975
In solar thermal utilization, effective photo capture and photothermal conversion are crucial. Improving the nonradiative transition rate of photoexcited electrons is important to enhance the photothermal conversion efficiency and develop efficient solar thermal utilization. Herein, we designed a new kind of light absorption-enhanced and efficient photothermal conversion material, namely, Fe2O3-functionalized reduced graphene oxide (Fe2O3–RGO). On the basis of the selective absorption (350–560 nm) of Fe2O3 and the synergistic effect of RGO on the quenching energy transfer of the excited state of Fe2O3 and ultrafast nonradiative thermal decay of RGO, the optical absorption capacity, and photothermal conversion efficiency of the composites were effectively improved. Fe2O3–RGO can be successfully applied to photothermal conversion phase change materials and seawater solar desalination, showing excellent photothermal conversion ability and application prospect. 相似文献
5.
Zibin Wu Haitao Zhang Jing Zou Ke Qin Chunyan Ban Jianzhong Cui Hiromi Nagaumi 《工业材料与腐蚀》2020,71(10):1680-1690
The electrochemical performance and discharge behavior of Al–0.8Sn–0.05Ga–0.9Mg–1.0Zn (wt%) alloys in as-cast, homogenized, and annealed states were investigated through electrochemical means, corrosion rate test, and discharge test in a 3.5 wt% NaCl solution. Results suggest that the discharge performance of this alloy is enhanced by rolling and subsequent annealing treatment. This is attributed to the fact that the microstructure of the alloy is greatly improved through rolling and subsequent annealing treatment. The 400°C-annealed alloy exhibits the most excellent discharge activity than alloys in other states, which is due to more regions being activated by a finer and more uniform Sn-rich phase. Furthermore, the anode efficiency of the 400°C-annealed alloy is higher than that of as-cast and homogeneous alloys due to the more uniform distribution of Sn in the aluminum matrix. 相似文献
6.
海水中微量氟的测定 总被引:7,自引:0,他引:7
孙红英 《广东有色金属学报》2002,12(1):68-71
用柠檬酸钠和EDTA来消除Al^3 ,Fe^3+等干扰离子的影响;采用标准加入法消除盐类对电位的影响;在pH=6.5时,用氟离子选择电极测海水中氟的电位。最后,通过格氏作图法测得海水中氟的含量。回收率为98%-105%。此方法分析快速、结果准确、可靠。 相似文献
7.
8.
采用生物接触氧化法对含海水城市污水进行了试验研究 .试验结果表明 :当海水比例不超过 35 %时 ,生物接触氧化系统对CODcr的去除率在 84 %以上 ,出水CODcr<10 0mg/L ,NH3 N去除率>90 % ,出水NH3 N <8.0mg/L ,可满足城市污水二级排放要求 ;当海水比例超过 4 5 %时 ,生物接触氧化系统受到了明显影响 ,CODcr去除率仅为 5 5 %~ 75 % ,出水CODcr〉12 0mg/L ,NH3 N去除率也降到 6 7%左右 ;并且随着污水中海水含量的增加 ,生物膜上微生物的种类和数量逐渐减少 相似文献
9.
Evidence that dissolved organic matter is one of the most significant sources of chlorine demand of seawaters (Fig. 1) used in cooling circuits is now well recognized. Nevertheless the specific role of the different kinds of compounds which form this organic material has seldom been studied and even less quantified; this is not surprising as less than 20% of the organic substances are identified. In this paper our objective was to define more quantitatively the effect of the dissolved free and combined amino-acids in the oxidant decay. Two main criteria justified the choice of these solutes:
- 1. (i)|the reactivity of chlorine and/or bromine towards amino groups;
- 2. (ii)|the role of these nitrogenous compounds in some biological mechanisms.
10.
为了验证LY-K01新型药剂在TOC去除率上的高效性,拟定了该药剂与传统药剂对海水TOC处理的对比实验,并对其实验方法与实验步骤进行了介绍,结合该药剂的药剂机理得出该处理药剂可真正做到将氧化、吸附、混凝结合为一体,效果良好,值得推广使用。 相似文献