Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 3

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

System and Method for Simultaneous Measurement of Nitrogen Content and Uniformity of Nitration of Nitrocellulose

Liu Y., Shao Z., Wang W., Li W., Lv Y., Sun J.

Central European Journal of Energetic Materials

2018

Vol. 15, no. 4

554--571

Nitrocellulose (NC) is a common, commercially available, cellulosederived material and has been functionalized and widely applied in microfluidic technology, immunoassays and biochemical analyses. However, existing testing parameters always fail to completely and accurately reflect its inherent quality. In this study, we have designed and assembled a novel automatic polarizing microscope test system (PMTS) to scientifically test the nitrogen content and uniformity of nitration of NC based on the chromogenic principle of a polarization microscope. The advantages of this system are: (i) the PMTS requires less sample (only a few micrograms); (ii) the test period is shorter and the results can be obtained within 20 min; (iii) the method belongs to the nondestructive testing group, and the NC sample is not burned, dissolved, or damaged; and (iv) this method has increased accuracy, and the deviation of the nitrogen content is less than ±0.05%. The properties of various NC samples prepared by different nitricsulfuric acid systems from raw materials with diverse maturities were determined via PMTS. Five NC samples with different nitrogen contents (10.9%, 11.5%, 11.8%, 12.6% and 13.5%) were tested, and the variance of the corresponding uniformity of nitration of these samples were 3.17, 1.61, 1.15, 1.76, and 2.83. The uniformity of nitration initially decreased and then increased with increasing nitrogen content, and the best uniformity of nitration appeared at a nitrogen content of 12%. We also found that fibre maturity has a positive effect on the uniformity of nitration. This testing device and method, with its cost-effectiveness and field-portability, can significantly improve the accuracy of nitration content and uniformity, and has an important value in practical applications.

Large deformation and stability analysis of a cylindrical rubber tube under internal pressure

Sang J., Xing S., Liu H., Li X., Wang J., Lv Y.

Journal of Theoretical and Applied Mechanics

2017

Vol. 55 nr 1

177--188

Rubber tubes under pressure can undergo large deformations and exhibit a particular nonlinear elastic behavior. In order to reveal mechanical properties of rubber tubes subjected to internal pressure, large deformation analysis and stability analysis have been proposed in this paper by utilizing a modified Gent’s strain energy function. Based on the nonlinear elastic theory, by establishing the theoretical model of a rubber tube under internal pressure, the relationship between the internal pressure and circumferential principal stretch has been deduced. Meanwhile stability analysis of the rubber tube has also been proposed and the relationship between the internal pressure and the internal volume ratio has been achieved. The effects on the deformation by different parameters and the failure reasons of the rubber tube have been discussed, which provided a reasonable reference for the design of rubber tubes.

Flow injection chemiluminescence determination of polyhydroxy phenols in the presence of rhodamine B as a sensitiser

Lv Y., Zhang Z., He D., Hu Y.

Chemia Analityczna

2003

Vol. 48, No. 6

959-966

A novel flow injection chemiluminescence (CL) system for determination of polyhydroxy phenols, including phloroglucinol, pyrogallol, resorcinol and pyrocatechol has been described. The system utilises CL reaction of ferricyanide with polyhydroxy phenols in sodium hydroxide media sensitised by the fluorescent dye Rhodamine B. The proposed procedure has a linear range of 0.05-5.0 ng ml/' for phloroglucinol, and 0.01-1.0 ug mL(-1) for pyrogallol, resorcinol and pyrocatechol. The method is sensitive, simple, and fast. The chemiluminescence reaction mechanism has been also proposed and briefly discussed.

Opisano nową metodę analizy wstrzykowej z wykorzystaniem chemiluminescencji (CL) do oznaczania wielowodorotlenowych fenoli, włączając w to floroglucynę, pirogalol, rezor-cynę i pirokatechinę. Metoda jest oparta na chemiluminescencyjnej reakcji żelazocyjanku z fenolami wielowodorotlenowymi w środowisku wodorotlenku sodowego, sensybilizowanej za pomocą fluorescencyjnego barwnika rodaminy B. Procedura charakteryzuje się liniowym zakresem oznaczania: 0,05-5,0ug mL(-1) dla floroglucyny oraz 0,01-1,0 ug mL(-1) dla piro-galolu, rezorcyny i pirokatechiny. Metoda jest czuła, prosta i szybka. Przedsykutowano pokrótce możliwy mechanizm reakcji chemiluminescencyjnej.