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1.
Frequency responses associated with adsorption of gas-phase toluene, o-nitrotoluene, valproic acid and the pesticides parathion, malathion and disulfoton on uncoated and protein-coated piezoelectric sensors are reported. Valproic acid antiserum and antibody against parathion were included among the set of protein films studied. Responses, which were reversible in all cases, are attributed to chemisorption or physisorption on electrode and protein surfaces. Under the conditions used, no signals corresponding to selective immunochemical binding were found. Highly sensitive responses of protein-coated sensors to the pesticide species were confirmed, with the lower limit of detection being about 0.01 μg l?1 in nitrogen carrier gas. 相似文献
2.
Preparation and characterization of hexamethylenetetramine‐functionalized magnetic nanoparticles and their application as novel catalyst for the synthesis of pyranopyrazole derivatives 下载免费PDF全文
A new magnetic catalyst was prepared through the reaction of silanol groups, on the surface of silica‐coated Fe3O4 magnetic nanoparticles, with (3‐chloropropyl)triethoxysilane followed by hexamethylenetetramine and chlorosulfonic acid. The obtained magnetic catalyst was characterized using thermogravimetric analysis, vibrating sample magnetometry, scanning electron microscopy and energy‐dispersive X‐ray analysis. Its catalytic activity was investigated in the synthesis of pyranopyrazole compounds, and the results were excellent regarding high yield of the products and short reaction time. 相似文献
3.
Imre Petneházy Lajos Trézl Csaba Vida Zsuzsa M. Jászay 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1)
Abstract Chemical modification of wool by means of dimethyl phoaphitc and D-glucose results in an increase in dye pickup, while colour and light fastness properties did not decrease, in fact some features bccpme more favourable. Our invesigations showed that increase in fibre diameter occurred. which could rise the rate of dye penetration. Amino acid analysis of the treated wool sample h w e d a decrease in lysine and arginim content, which allows of supposing covalent bond formation betweecl dimcthyl phosphite, D-glucose and the amino and guanidino groups of wool. 相似文献
4.
[chemical reaction: see text]. Prior to detachment of compounds synthesized on sulfonamide based safety-catch linkers, the molecular anchor has to be activated. This is achieved by alkylation of the nitrogen atom of the N-acylsulfonamide using different established protocols. As an addition to the existing repertoire of activating reagents, we suggest the use of O,N,N'-trialkylisoureas. Besides the demonstration of the feasibility of these mild alkylating agents for this purpose, custom-tailored novel O,N,N'-trialkylisoureas prepared from electron-deficient alcohols are reported. 相似文献
5.
A natural-product-inspired photonic logic gate based on photoinduced electron-transfer-generated dual-channel fluorescence 总被引:1,自引:0,他引:1
[structure: see text] Modified 1-benzylisoquinoline N-oxides can operate as molecular logic gates. The combination of dual-channel fluorescence emissions and the preferred interaction for selected chemical inputs allows one to design multifunction and self-reprogrammable molecular logic gates. 相似文献
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The slope-number of a graph G is the minimum number of distinct edge slopes in a straight-line drawing of G in the plane. We prove that for Δ5 and all large n, there is a Δ-regular n-vertex graph with slope-number at least . This is the best known lower bound on the slope-number of a graph with bounded degree. We prove upper and lower bounds on the slope-number of complete bipartite graphs. We prove a general upper bound on the slope-number of an arbitrary graph in terms of its bandwidth. It follows that the slope-number of interval graphs, cocomparability graphs, and AT-free graphs is at most a function of the maximum degree. We prove that graphs of bounded degree and bounded treewidth have slope-number at most . Finally we prove that every graph has a drawing with one bend per edge, in which the number of slopes is at most one more than the maximum degree. In a companion paper, planar drawings of graphs with few slopes are also considered. 相似文献
8.
Zachary Abel Brad Ballinger Prosenjit Bose S��bastien Collette Vida Dujmovi? Ferran Hurtado Scott Duke Kominers Stefan Langerman Attila P��r David R. Wood 《Graphs and Combinatorics》2011,27(1):47-60
We prove the following generalised empty pentagon theorem for every integer ℓ ≥ 2, every sufficiently large set of points in the plane contains ℓ collinear points or an empty pentagon. As an application, we settle the next open case of the “big line or big clique” conjecture
of Kára, Pór, and Wood [Discrete Comput. Geom. 34(3):497–506, 2005]. 相似文献
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Orentienė A Olšauskaitė V Vičkačkaitė V Padarauskas A 《Journal of chromatography. A》2011,1218(39):6884-6891
The potential of 1.7 μm ethylene bridged hybrid silica phase was investigated for the separation of twelve imidazolium-based ionic liquid cations. U-shaped retention profile was observed for all solutes with an increase in retention at both low and high acetonitrile content. Chromatographic behaviour of imidazolium cations in both hydrophilic interaction chromatography (HILIC) and per aqueous liquid chromatography (PALC) modes was studied by varying key parameters such as buffer concentration and pH, acid additive, organic modifier and column temperature. Experimental data provided some evidences that under PALC conditions cationic solutes are retained predominantly by mixed hydrophobic/ion-exchange interactions. In the HILIC mode, both partitioning and ion-exchange interactions are responsible for the retention of solutes. Compared to PALC, HILIC provided significantly higher efficiencies with less or even no peak tailing, better separation selectivity and greater resistance to overload. In PALC mode gradient elution was required to achieve adequate retentivity of all solutes but selectivity was not sufficient to distinguish between solutes with very similar hydrophobicity. In contrast, under HILIC conditions twelve solutes were almost completely resolved in less than 4 min by using isocratic elution. Summarizing, it could be concluded that ethylene bridged hybrid silica column providing a dual retention mechanism offers the possibility of selecting between the two retention modes with opposite separation selectivity, just by changing the composition of the mobile phase. 相似文献