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排序方式: 共有34条查询结果,搜索用时 562 毫秒
1.
刘跃  刘颖 《分析化学》2002,30(3):298-300
利用色谱-质谱联机技术,在红收获蚁P.barbatus和P.maricopa的毒腺体样品中检测到召引信息素甲基吡嗪(MP)、2,5-二吡嗪(DMP)、3-乙基-2,5-二甲基吡嗪(EDMP)、和三甲基吡嗪(TMP)。利用特征离子色谱技术,在P.barbatus样品中还检测到了含6个碳原子侧链烃基的吡嗪X。根据吡嗪X的质谱图推测其结构为3-仲丁基-2,5-二甲基吡嗪(BDMP)。P.barbatus中DMP,TMP和EDMP的平均相对百分比分别为60.71、26.49、12.80;标准偏差分别为6.91、4.92、5.11;P.maricopa中平均相对百分比和标准偏差分别为47.48、20.35、32.17和15.05、4.05、15.44。  相似文献   
2.
The study dealt with evolving an artificial fish bait by incorporating bioattractant concentrates derived from seafood processing wastes by enzymatic hydrolysis namely fish waste concentrate (FWC), squid waste concentrate (SWC), and shrimp processing concentrate (SPWC). They were characterized based on amino acid content and presence of different functional groups using FTIR. Among them, SWC was found to have the highest amino acid content of 60.85mg/100 mg followed by FWC (42.21mg/100 mg) and SPWC (24.82mg/100 mg). The developed artificial fish baits were subjected to protein leaching, solubility in seawater besides testing for acceptability by the red snapper. The study revealed that the bait incorporated with SWC at 3% level was found be the most ideal, with the protein leaching rate of 24.82 mg/g/h, solubility rate of 36.6 mg/g/h and the attractability score of 29/30. The amino acid leaching rate was 3.11 mg/h/100 mg and it was found to contain five amino acids such as glycine, proline, glutamic acid, alanine and serine. The study revealed that the hydrolyzed squid waste concentrate can be incorporated at 3% (w/w) with fish gelatin based biomatrix during gelation to prepare artificial bait.  相似文献   
3.
纳米金催化剂的抗水性能和抗硫中毒性能   总被引:2,自引:0,他引:2  
与Au/Al2O3相比,复合载体负载的Au/FeOx/Al2O3具有更高的催化CO氧化的低温活性和稳定性,且表现出湿度增强效果,水分压为550~1 600 Pa时催化剂活性较高.在完全无水的环境中,催化剂发生快速不可逆失活;在饱和水汽的环境中,催化剂发生缓慢可逆失活.在水汽作用下的失活与纳米金粒子的粒径长大有关.助剂对催化剂抗水性能影响不大,但对抗硫中毒性能的影响较大.Au/CeO2/Al2O3催化剂显示有最佳的抗硫中毒性能.催化剂表面硫化物和硫酸盐的生成是导致催化剂不可逆硫中毒失活的主要原因.  相似文献   
4.
稀土元素对Mn/TiO2-PILC低温SCR性能影响研究   总被引:1,自引:0,他引:1  
通过浸渍法制备了8%Mn/TiO2-PILC以及稀土元素R(Ce,La)改性的8%Mn-2%R/TiO2-PILC催化剂,考察了所制备催化剂的低温NH3-SCR活性和抗水抗硫特性。结果发现,Ce的添加改变了催化剂的物相以及氧化还原特性,从而改变了催化剂的NO去除活性;稀土元素的添加可以减缓催化剂的失活速率,但是抗水抗硫特性仍然不理想。  相似文献   
5.
Dimethylarsinic acid (DMA) is the most effective inducer of cell‐cycle disruption among the arsenic compounds and their metabolites. The present study was conducted to gain further insight into cell‐cycle disruption induced by DMA. The inhibition of cell proliferation and the mitotic arrest induced by DMA were significant and dose‐dependent in Chinese hamster V79 cells and the two seemed to be closely related. At less than 140 µM the DMA did not inhibit the proliferation of cells, but it significantly induced mitotic arrest. An indirect immunofluorescence assay using anti‐α‐tubulin antibodies revealed that DMA induced the formation of abnormal spindles in the metaphase cells even at 350 µM with 5 h of treatment. At 1.4 mM DMA no metaphase cells could form a definite spindle structure. The spindle figures were similar to those induced by colchicine (125 nM ) or vinblastine (110 nM ), major antimitotic agents. In DMA‐treated interphase cells, the microtubule networks were indistinguishable from those of normal cells. With the tubulin‐assembly assay estimated by turbidity, DMA at less than 200 µM suppressed tubulin assembly in a dose‐dependent manner, whereas at more than 700 µM it enhanced tubulin polymerization remarkably with or without addition of excess guanosine‐5′‐triphosphate. According to the above findings, we discussed the possibility that DMA, a primary metabolite of inorganic arsenic in mammals, is related to arsenic carcinogenicity. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
6.
In the attempt to synthesize substituted allenyl esters through a metathesis coupling of unsubstituted allenyl esters and alkenes using a variety of ruthenium catalysts, it was discovered that allenyl esters themselves cleanly arrested the activity of the catalysts. Further studies suggests possible utility of allene esters as general quenching agents for metathesis reactions. To explore this idea, several representative olefin metathesis reactions, including ring closing, were successfully terminated by the addition of simple allenyl esters for more convenient purification.  相似文献   
7.
气相色谱法测定大隆毒饵中的甘氟和氟乙酰胺   总被引:1,自引:0,他引:1  
用气相色谱法对大隆毒铒中的甘氟和氟乙酰胺进行了联合分析。毒铒用索氏提取器提取,以异丙醇为内标,在GDX-102色谱柱上进行分离,氢焰离子检测器。方法的平均回收率分别为:甘氟Ⅰ:98.3%,甘氟Ⅱ:97.7%,氟乙酰胺:98.2%,相对标准偏差分别为1.0%,1.5%,1.0%(n=10)。  相似文献   
8.
建立了生物样本中甲基苯丙胺和氯胺酮的定量检验方法,该方法应用固相萃取与工作曲线气相色谱法(GC/NPD)对中毒者血、尿、胃内容、肝、脑等检材进行含量测定.通过实际案件,验证了该法具有样品处理简单、提取效率高、分析速度快等优点.案件数据表明,由口服引起的中毒途径,胃内容的含量最高,其次是尿、肝、脑、血等检材,进一步证实了...  相似文献   
9.
A series of perovskite-type BaZrO3 catalysts are prepared by the sol-gel method. Their NOx storage capacity(NSC)and the resistance of SO2 poison are measured. XRD,XPS and FT-IR techniques are also used to characterize their structures and the influence of the structures on performance. The results indicate that,after calcinations at 750 and 900 ℃,the Ba and Zr species mainly exist in the form of perovskite BaZrO3 phase,and the BaCO3 and ZrO2 phases also exist. The presence of bulk nitrate is shown by XRD and FT-IR after BaZrO3 absorbing NOx . The Rh/BaZrO3 is prepared by doping 0.5%Rh on the BaZrO3 with the impregnation method. It is found that the Rh mainly deposits on the surface of catalyst. However,the noble metals 0.5% Rh or Pt well disperse on the surface of the sample after the BaZrO3 is mixed with γ-Al2O3 in equal weight proportion. The structure of perovskite BaZrO3 may be partly broken after doping Rh or Pt,because of the reduction by hydrogen in the process of preparing samples,and then some ZrO2 is enriched on the surface. The BaZrO3 catalysts possess high NSC and high resistance ability of SO2 poison. The NSC of Rh/BaZrO3 decreases compared to that of BaZrO3 . However,the NSC of the samples Pt/BaZrO3/γ-Al2O3 and Rh/BaZrO3/γ-Al2O3 increases by 78% and 15% respectively. It is noticed that the NSC enhances for all the samples containing noble metal Pt or Rh duing the 0.01%SO2 mixed with the NO and O2 . It implies that the NO oxidation is improved by SO2 .  相似文献   
10.
用浸渍法制备了一系列镍基催化剂并以苯加氢反应及二硫化碳中毒为手段考查了MoO3对Ni基催化剂的改性机制。结果表明,钼的加入能增加Ni催化剂的催化活性和抗二硫化碳毒性,原因是钼的加入增加了催化剂的活性中心数量和镍的分散度,改变了催化剂与反应物所形成中间体的活化焓及熵。根据过渡态理论,钼对Ni基催化剂的影响即有电子效应又有几何效应,但以电子效应为主。  相似文献   
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