共查询到10条相似文献,搜索用时 109 毫秒
1.
E. Sideras-Haddad D. Heikkinen S. H. Connell M. W. Caffee M. L. Roberts G. S. Bench D. Morse A. Meike W. Bourcier 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》1997,130(1-4):259-263
An original system has been developed capable of performing three-dimensional Energy Recoil Detection Analysis (ERDA) of hydrogen in materials with scanned and finely focused heavy-ion beams. The technique is being used at the Lawrence Livermore National Laborotory Multi-user Tandem Laboratory to measure the hydrogen content in materials under consideration for use in the Yucca Mountain nuclear waste repository. From the measurement of hydrogen concentration profiles we can extrapolate reaction rates. A critical problem is the rate of dissolution of the glass being used. The HI-ERDA (Heavy Ion-ERDA) technique can provide this information which is needed in order to predict the overall rate of nuclear waste glass degradation in a waste repository. The technique is calibrated using a silicon wafer implanted with a known concentration of hydrogen. The sample is illuminated by a 35Cl ion beam that is micro-scanned across the sample. From these measurements we reconstruct three dimensional profiles of hydrogen content which can then be used to obtain spatially-resolved hydrogen depth profiles. 相似文献
2.
从全血中分出淋巴细胞,在含钙Hanks’液或含磷酸二酯酶抑制剂的缓冲液中孵育,加Carbachol能使细胞内cGMP含量增高66%-80%,这种升高可被阿托品阻断,说明cGMP的增高是由M受体介导的特异性反应。据此建立了一种反映M受体CGMP系统功能状态的方法并对孵育和反应条件作了探讨,初步实验结果表明老年大鼠淋巴细胞CGMP基础含量显著低于青年大鼠,由CarbacholGI起的cGMP升高反应也明显降低。 相似文献
3.
In this study, we report on the degradation of microcystin-LR (MC-LR) by gas- liquid interracial discharge plasma. The influences of operation parameters such as average input voltage, electrode distance and gas flow rate are investigated. Experimental results indicate that the input voltage and gas flow rate have positive influences on MC-LR degradation, while the electrode distance has a negative one. After 6 min discharge with 25 kV average input voltage and 60 L/h air aerati by discharge both in on, the degradation rate of MC-LR achieves 75.3%. distilled water and MC-LR solution are measured H202 and 03 generated Moreover, an emission spectroscopy is used as an indicator of the processes that take place on the gas-liquid boundary and inside plasma. Varied types of radicals (O, .OH, CO, 03, etc.) are proved to be present in the gas phase during gas-liquid interfacial discharge. 相似文献
4.
采用Fenton-紫外照射(Fenton-UV)联用工艺对核电厂超高浓度聚乙烯醇(PVA)有机废液进行处理,研究了PVA转化率、平均分子量、溶液黏度等随时间的变化规律。结果表明:对于50 g/L的PVA溶液,H2O2投加质量浓度为15 g/L,FeSO4·7H2O投加质量浓度为0.050 g/L,初始pH值为3,经过2 h Fenton反应和2 h UV照射(3 mW/cm2)之后,PVA转化率达到100%,溶液平均分子量从60 000~80 000 Da降低到1 000 Da以下,黏度降低到1.1 mPa·s,但总有机碳和化学需氧量(COD)变化不大。Fenton-UV法可作为预处理方法,前期Fenton阶段提高PVA的溶解度,增加反应溶液中的PVA含量,并进行初步降解和氧化;后期UV法进一步降解溶液中的PVA,有效降低其分子量和黏度,为后续处理提供有利条件,最终形成经济可行的超高浓度PVA有机废液处理工艺。 相似文献
5.
In this work,a plasma-solution system was applied to the degradation of Acid Orange 7(A07).The effects of initial concentration and type of feed gases(air,oxygen,nitrogen or argon) were studied.As the initial concentration increased from 100 mg/L to 160 mg/L,the discolouration rate of A07 decreased from 99.3%to 95.9%,whereas the COD removal rate decreased from 37.9%to 22.6%.Air provided the best discolouration and COD removal rates(99.3%and 37.9%,respectively).In the presence of a zero-valent iron(ZVI) catalyst,the A07 COD removal rate increased to 76.4%.The degradation products were analysed by a GC-MS,revealing that the degradation of the dye molecule was initiated through the cleavage of the-N=N- bond before finally being converted to organic acids. 相似文献
6.
《Journal of Nuclear Science and Technology》2013,50(1):83-85
A technique, based on the correlation analysis of signal pulses in time sequence, is proposed to determine the production rate of the pseudo multi-pulse in Geiger-Mueller (GM) counter. With a multi-channel scaler initiated by a signal pulse, subsequent pulses are recorded in sequence. The production of the multi-pulse increases the counting probability immediately after the initiation. By examining the deviation of the measured probability from the ideal counting probability, the production rate and the average lag time to produce the multi-pulse can be determined. By the use of the present technique, the production rate and the average lag time were obtained for the various GM tubes. These results indicate that the consumption of the quench gas results in a significant increase in the production rate but little variation in the lag time, and that the lag time strongly depends on the tube diameter. 相似文献
7.
Kefeng SHANG 《等离子体科学和技术》2019,21(7):75502-140
A double-chamber gas-liquid phase DBD reactor (GLDR), consisting of a gas-phase discharge chamber and a gas-liquid discharge chamber in series, was designed to enhance the degradation of benzene and the emission of NOx. The performance of the GLDR on discharge characteristics, reactive species production and benzene degradation was compared to that of the single-chamber gas phase DBD reactor (GPDR). The effects of discharge gap, applied voltage, initial benzene concentration, gas flow rate and solution conductivity on the degradation and energy yield of benzene in the GLDR were investigated. The GLDR presents a higher discharge power, higher benzene degradation and higher energy yield than that of the GPDR. NO2 emission was remarkably inhibited in the GLDR, possibly due to the dissolution of NO2 in water. The benzene degradation efficiency increased with the applied voltage, but decreased with the initial concentration, gas flow rate, and gas discharge gap, while the solution conductivity presented less influence on benzene degradation. The benzene degradation efficiency and the energy yield reached 61.11% and 1.45 g kWh–1 at 4 mm total gas discharge gap, 15 kV applied voltage, 200 ppm benzene concentration, 0.2 L min−1 gas flow rate and 721 μS cm−1 water conductivity. The intermediates and byproducts during benzene degradation were detected by FT-IR, GC-MS and LC-MS primarily, and phenols, COx, and other aromatic substitutes, O3, NOx, etc, were determined as the main intermediates. According to these detected byproducts, a possible benzene degradation mechanism was proposed. 相似文献
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9.
Fu LU 《等离子体科学和技术》2023,25(3):35506-192
Antibiotic contamination adversely affects human health and ecological balance.In this study,gasliquid underwater discharge plasma was employed to simultaneously degrade three antibiotics,sulfadiazine(SDZ),tetracycline(TC),and norfloxacin(NOR),to address the growing problem of antibiotic contaminants in water.The effects of various parameters on the antibiotic degradation efficiency were evaluated,including the discharge gas type and flow rate,the initial concentration and pH of the solution,and... 相似文献
10.
γ射线对水溶液中赭曲霉毒素A降解效果的研究 总被引:1,自引:0,他引:1
为了探讨γ射线辐照对于水溶液中赭曲霉毒素A的降解效果,采用60Coγ射线辐照水溶液中的赭曲霉毒素A.用赭曲霉毒素A标准溶液确定高效液相色谱检测技术的线性关系和检出限,然后基于高效液相色谱检测技术研究辐照对水溶液中赭曲霉毒素A的降解效果.结果显示,水溶液中赭曲霉毒素A的降解率随着辐照剂量的增加而增加;在4kGy的辐照剂量... 相似文献