排序方式: 共有46条查询结果,搜索用时 93 毫秒
1.
G. V. Kotelnikov Sophia P. Moiseyeva E. V. Mezhburd E. I. Maevsky Elena V. Grishina 《Journal of Thermal Analysis and Calorimetry》2005,81(2):255-259
Summary Measurements of energy transformation in mitochondria are done on a capillary differential titration calorimeter CTD2156. It is important to mention that a sediment is quickly formed by the mitochondria suspension without mixing by means of a vibrating needle. During the measurements, the vibrating needle is located inside the working volume of the chamber. The design of the calorimeter is substantiated theoretically. It provides a new mode of a reagent input in the measuring volume of the calorimetric chambers. It expands the spectrum of tasks that can be solved using this instrument. In the capillary calorimeter the calorimetric chambers unit is simple and small in size. These advantages of capillary chambers provide an opportunity to unite 20 capillary calorimetric chambers in one calorimetric block. It allows designing a multi-channel titration calorimeter. There are obvious advantages of such a calorimeter over other instruments in screening researches and in researches of objects maintaining stability only for a short time. 相似文献
2.
F. M. Karawajew A. F. Dričko H. Greupner K.-H. Sucker 《Isotopes in environmental and health studies》2013,49(11):396-399
In der Arbeit wird über eine Empfehlung zur Methodik der Weitergabe der Aktivitätseinheit für umschlossene γ-Strahlungsquellen von den Normalen der metrologischen Slaatsämter der UdSSR (WNIIM) und der DDR (ASMW) an Normale niederer Ordnung berichtet. Die Weitergabe der Aktivitätseinheit geschieht durch Vergleich mittels Ionisationskammern. Die Empfehlung bezieht sich auch auf solche Fälle, in denen neben dem Hauptnuklid ein Verunreinigungsnuklid in der Quelle enthalten ist, sowie auf solche, bei denen unterschiedlicher Aufbau der zu vergleichenden Quellen vorliegt. Auβerdem umfaβt die Empfehlung die Methode der Fehlerrechnung. 相似文献
3.
Mittels Aktivierungsanalyse wurde der Gehalt an Arsen, Antimon, Kupfer, Phosphor und Zink in Halbleitersilizium bestimmt. Die Methode besteht aus zwei Schritten: 1. Gruppentrennung durch Anionenaustausch mit einem Gemisch von Salz- und Fluorwasserstoffsäure, 2. Selektive substöchiometrische Extraktion von Arsen und Kupfer mit Diäthyldithiocarbamat, von Antimon mit Cupferron und von Zink mit Dithizon. Phosphor wurde extraktiv als Phosphomolybdat abgetrennt. 相似文献
4.
R. T. de Souza N. Le Neindre A. Pagano K. -H. Schmidt 《The European Physical Journal A - Hadrons and Nuclei》2006,30(1):275-291
This review on second- and third-generation multidetectors devoted to heavy-ion collisions aims to cover the last twenty years.
The presented list of devices is not exhaustive but regroups most of the techniques used during this period for nuclear reactions
at intermediate energy (≃ 10A MeV to 1A GeV), both for charged-particle and neutron detection. The main part will be devoted
to 4π multidetectors, projectile decay fragmentation, high-resolution magnetic spectrometers, auxiliary detectors and neutron
detection. The last part will present the progress in electronics and detection in view of the construction of future-generation
detectors. 相似文献
5.
New experimental data for the transmission loss of plenum chambers are compared to results obtained using several different and well known prediction models. Results for transmission loss as a function of frequency in 1/3 octave bands are presented for a series of plenum chamber configurations of various sizes and interior acoustical treatments. In the experimental work the transmission loss was determined from simultaneous measurements at two upstream and two downstream microphones. 相似文献
6.
J. Dyckmans H. Flessa Z. Shangguan F. Beese 《Isotopes in environmental and health studies》2013,49(1):63-78
Abstract A continuous dual 13CO2 and 15NH4 15NO3 labelling experimental set-up is presented that was used to investigate the C and N uptake and allocation within 3-year old beech (Fagus sylvatica L.) during one growing season. The C and N allocation pattern was determined after six, twelve and eighteen weeks of growth. The carbon uptake was distinctly different in the three phases examined: The first six weeks after budbreak were dedicated to leaf growth with a R/S (root to shoot) ratio of 0.14 for the new carbon. The second growth phase showed a balanced R/S ratio of C allocation and after week 13, the root compartment was the main carbon sink (R/S = 6.97). Nitrogen allocation was more basipetal as compared to carbon. In the second growth phase, R/S of Nnew was 5.57 but fell to 3.54 for the third growth phase probably due to formation of reserves in buds and stem. 相似文献
7.
Nachdem in ersten Teil der Arbeit eine Beschreibung der Normalmeβeinrichtungen (Freiluft-Ionisationskammern) des DAMW zur Darstellung der Einheit der Exposition für den Energiebereich der Röntgenstrahlung erfolgte, werden hier die entsprechenden Einrichtungen für die Gammastrahlung von 66Co und 137Cs behandelt. Grundlage für die definitionsgemäβe Bestimmung der Einheit bilden dabei verschidene Hohlraum-Inoisationskammern aus Reinstgraphit, deren Aufbau erläwtert wird. Sie sind vom zylindrischen Typ und haben Meβvolumina von ca. 2 cm3, 8 cm3 cm3 und 100 cm3. Als Ladungsmeβeinrichtung wird ebenfalls ein elektromctrischer Fotozellenkompensator verwendet. Die Bestimmung der in kollimierten Strahlenbündeln notwendigen Korrektionsfaktoren wird im einzelnen behandelt. Der maximale Fehler bei der Darstellung der Einheit der Exposition betrāgt 2%. 相似文献
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9.
With a view to measuring the structure coefficient of refractive index fluctuations in a turbulent premixed butane-air flame, a thin laser beam is sent into the flame perpendicular to the flow direction. The laser beam generally undergoes fluctuations of direction, phase, and amplitude. Only the random deflections of the laser beam may be taken into account. After having traversed the flame, the perturbed laser beam enters into an interferometric system. Materials and experimental procedure are described. In the unperturbed interference pattern, the zones only sensitive to fluctuations of the angle-of-arrival of the laser beam are detected. From the random displacements of the central bright fringe, the structure coefficient of refractive index fluctuations in the flame is measured. To prove that the method of measurement is satisfactory, the result obtained is applied for computing the power spectral density of the angle-of-arrival of the laser beam from the formula of correlations of the laser beam deflection angles which we have demonstrated in previous works. This computed power spectral density is compared to that measured from the effective position of the detector. A good agreement is observed between the two results. 相似文献
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