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31.
研究非那西汀分子印迹聚合物的固相萃取性能。用本体聚合法制备非那西汀分子印迹聚合物,通过静态平衡吸附试验及固相萃取试验,研究其固相萃取性能。非那西汀模板聚合物的吸附能力明显强于空白聚合物。模板聚合物对浓度为0.03mmol/L的非那西汀标准溶液一次性萃取率为74.2%。非那西汀印迹聚合物对非那西汀具有特异性识别性能,可作为固相萃取固定相的应用研究。  相似文献   
32.
A series of artificial compounds, phenanthroline or aromatic bridged indoline derivatives, have been designed and synthesized. The interaction of these compounds with biologically important anions fluoride (F?), acetate (AcO?), dihydrogen phosphate (H2PO4?), chloride (Cl?), bromide (Br?) and iodide (I?) was determined by UV–vis, fluorescene titration and theoretical experiments. Results indicate that compound 1 (Di((1″,2″-dihydro-indol-3″-one-2″-hydrazone-1′-hydrazyl)-2′-methylene)-1,3-did-ehydebenzo) and 2 (Di((1″,2″-dihydro-indol-3″-one-2″-hydrazone-1′-hydrazyl)-2′-methylene)-1,3-didehyde-5-nitrobenzo) containing aromatic bridge do not show binding ability for various anions, and that compound 3 (Di((1″,2″-dihydro-indol-3″-one-2″-hydrazone-1′-hydrazyl)-2′-methylene)-2,9-dial-dehyde-1,10-phenanthroline) containing phenanthroline bridge shows the strongest binding ability for F? among various anions, the moderate binding ability for AcO? and H2PO4?, and almost no binding ability for Cl?, Br?, I?. The different binding ability of aromatic and phenanthroline bridged compounds may be related to the conjugative effect. What's more, the binding ability of compound 3 with F? is not interfered by the existence of other anions. Hence, theoretical investigations explore the reasons of different binding ability between compound 3 and anions.  相似文献   
33.
Two new compounds ( 1 and 2 ) containing 2‐sulfydryl‐1,3,4‐thiodiazole have been synthesized and optimized. They both showed wide antibacterial activity for colon bacillus, Staphylococcus aureus, S. albus, dysentery bacillus and inferior activity for Bacillus subtilis. In addition, their binding properties were evaluated for biologically important anions (F, Cl, Br, I, AcO, and H2PO4) by theoretical investigation, UV–vis, fluorescence, and 1H NMR titration experiments, and they displayed strong binding ability for H2PO4 without the interference of other anions tested. Especially the binding ability of compound 2 containing anthracene with H2PO4 was 1000 times stronger than that of compound 1 containing nitrobenzene. Two compounds based on 2‐sulfydryl‐1,3,4‐thiodiazole have both properties of anion recognition and antibacterial activity.  相似文献   
34.
粉煤灰在环境材料中利用的研究进展   总被引:1,自引:0,他引:1  
能源转化的燃煤过程产生大量粉煤灰,其资源化利用不但减少环境污染而且提高经济效益,已成为人们研究的热点。本文综述了粉煤灰作为吸附剂在去除烟气NOx、SOx、汞、有机芳烃和污水中重金属离子、磷和氟离子以及有机化合物中的应用。粉煤灰中未燃尽的炭在吸附过程中起重要作用。粉煤灰合成沸石控制污染物是粉煤灰在环境材料方面利用的发展方向。基于"以废治污"科学理念,提出了利用粉煤灰制备DeNOx添加剂降低流化催化裂化(FCC)再生过程NOx排放新工艺,开辟粉煤灰资源化利用新途径,同时为FCC再生过程NOx污染物控制技术提供理论支持。  相似文献   
35.
Homogenous thin films are preferable for high‐performance gas sensors because of their remarkable reproducibility and long‐term stability. In this work, a low‐temperature fabrication route is presented to prepare crack‐free and homogenous metal oxide periodic porous thin films by oxygen plasma irradiation instead of high temperature annealing by using a sacrificial colloidal template. Rutile SnO2 is taken as an example to demonstrate the validity of this route. The crack‐free and homogenous porous thin films are successfully synthesized on the substrates in situ with electrodes. The SnO2 porous thin film obtained by plasma irradiation is rich in surface OH groups and hence superhydrophilic. It exhibits a more homogenous structure and lower resistance than porous films generated by annealing. More importantly, such thin films display higher sensitivity, a lower detection threshold (100 ppb to acetone) and better durability than those that have been directly annealed, resulting in enhanced gas‐sensing performance. The presented method could be applied to synthesize other metal oxide homogenous thin films and to fabricate gas‐sensing devices with high performances.  相似文献   
36.
乌鲁木齐VLBI站25m天线定向方法及测站座标   总被引:1,自引:0,他引:1  
我们根据乌鲁木齐VLBI站的1954北京座标系的座标(x,y),利用Gauss的反算公式,计算出乌鲁木齐VLBI站的大地座标(L,B),并通过有关公式得到了天文座标(λ,ψ)值,然后根据测站的天文座标计算北极星大距时的位置,再由北极星大距时的位置找到天极的方向,最后解决了大型天文测量设备的定向问题。  相似文献   
37.
任金莲  张明铎  牛勇 《应用声学》2002,21(3):46-48,20
本文介绍一种无需任何清洗液且有别于常规超声波清洗机理的超声波显像管振动清洗机。从理论上分析说明超声波干振动清洗的机理和方法,阐明各超声参量的选取标准和超声振动系统中应注意的问题。  相似文献   
38.
Ir is the most interesting as an effective oxygen diffusion barrier for super high-temperature structural materials. In this study, an Ir coating, approximately 7 μm thick, was deposited onto Mo substrate by double glow plasma at substrate temperature of about 1,120 K in an argon atmosphere. The crystal orientation, morphology and mechanical property of the Ir coating were investigated by XRD, SEM, AFM, TEM, nanoindentation and scratch test. The results indicated that the (220)-oriented Ir coating was composed of the columnar grains. The surface roughness of the Ir coating was higher than that of the substrate. The hardness and the elastic modulus of the Ir coating were about 9.5 and 340 GPa, respectively. The coating had a high hardness due to the sub-micrometer size grains. The coating had good scratch resistance due to the strong adhesion of the coating to the substrate.  相似文献   
39.
The blending of synthetic chemistry with biosynthetic processes provides a powerful approach to synthesis. Biosynthetic halogenation and synthetic cross-coupling have great potential to be used together, for small molecule generation, access to natural product analogues and as a tool for chemical biology. However, to enable enhanced generality of this approach, further synthetic tools are needed. Though considerable research has been invested in the diversification of phenylalanine and tyrosine, functionalisation of tryptophans thorough cross-coupling has been largely neglected. Tryptophan is a key residue in many biologically active natural products and peptides; in proteins it is key to fluorescence and dominates protein folding. To this end, we have explored the Heck cross-coupling of halo-indoles and halo-tryptophans in water, showing broad reaction scope. We have demonstrated the ability to use this methodology in the functionalisation of a brominated antibiotic (bromo-pacidamycin), as well as a marine sponge metabolite, barettin.  相似文献   
40.
Bistachybotrysins D and E (1 and 2), one stereoisomeric pair of phenylspirodrimane dimers, were isolated from Stachybotrys chartarum CGMCC 3.5365. They represent novel phenylspirodrimane dimers with a central [6,5,6]-tricyclic carbon scaffold containing a cyclopentanone core. The structures of 1 and 2 were elucidated through extensive spectroscopic data analysis, and their absolute configurations were characterized by calculated electronic circular dichroism (ECD). Compounds 1 and 2 displayed potent cytotoxic activity against the four human tumor cell lines HCT116, BGC823, Daoy and HepG2 with IC_ (50)values ranging from 6.7 μmol/L to 11.6 μmol/L. Furthermore, a plausible biogenetic pathway for 1 and 2 is proposed.  相似文献   
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