نتایج جستجو برای: ion detection

تعداد نتایج: 762730  

2011
T. H. Bertram J. R. Kimmel T. A. Crisp O. S. Ryder R. L. N. Yatavelli J. A. Thornton M. J. Cubison M. Gonin D. R. Worsnop

We constructed a new chemical ionization timeof-flight mass spectrometer (CI-TOFMS) that measures atmospheric trace gases in real time with high sensitivity. We apply the technique to the measurement of formic acid via negative-ion proton transfer, using acetate as the reagent ion. A novel high pressure interface, incorporating two RF-only quadrupoles is used to efficiently focus ions through f...

1997
J. D. D. Martin J. W. Hepburn

The energetic thresholds for ion-pair photodissociation of diatomic oxygen fO2 1 hn ! O 1 OsP3y2, P1y2dg were measured using a novel technique. The technique depends on the production and selective detection of highly vibrationally excited ion-pair states which last for at least 5 ms following single photon excitation from the ground electronic state of O2. These ion-pair states are analogous t...

2014
P. U. Singare

Ion exchange resins are used in several chemical decontamination or cleaning processes and in nuclear industries for removal of radionuclides.1–5 Nowadays, ion exchange resins are not only used for separation but also as catalysts. In the past decade, inorganic ion exchange materials have emerged as an increasingly important replacement or complement to conventional organic ion exchange resins....

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه زنجان - پژوهشکده برق و کامپیوتر 1391

امروزه استفاده از منابع انرژی پراکنده کاربرد وسیعی یافته است . اگر چه این منابع بسیاری از مشکلات شبکه را حل می کنند اما زیاد شدن آنها مسائل فراوانی برای سیستم قدرت به همراه دارد . استفاده از میکروشبکه راه حلی است که علاوه بر استفاده از مزایای منابع انرژی پراکنده برخی از مشکلات ایجاد شده توسط آنها را نیز منتفی می کند . همچنین میکروشبکه ها کیفیت برق و قابلیت اطمینان تامین انرژی مشترکان را افزایش ...

Journal: :journal of physical & theoretical chemistry 2008
n. farahani h. aghaie

fe2+ ion-selective membrane sensor has been fabricated from polyvinyl chloride (pvc) matrixmembrane containing neutral carrier tetra phenyl porphyrin (tpp) ionophore. the addition ofsodium tetraphenylborate (natpb) and the plasticizer dbp has been found to substantiallyimprove the performance of the sensor. the best performance was obtained with the sensor havinga membrane of composition of tpp...

2006
C. Weber K. Blaum M. Block R. Ferrer A. Herlert J. Ketelaer D. Neidherr

A Penning trap mass spectrometer is a well established instrument for the precise mass determination of both, stable and short-lived nuclides. For this purpose two different concepts are employed. Masses of stable species are mostly determined by the non-destructive detection of image currents induced in the trap electrodes and a subsequent Fourier transformation (FT). For short-lived nuclides ...

2016
Tapas K. Mandal Yi Hou Zhenyu Gao Haoran Ning Wensheng Yang Mingyuan Gao

Visual fluoride ion detection with a detection limit down to pmol L-1 is achieved through quenching/reactivating the fluorescence of N-doped graphene oxide.

Journal: :Chemphyschem : a European journal of chemical physics and physical chemistry 2012
Xiaoyong Huang Xiaogang Liu

Beyond detection: Detection of a single lanthanide ion can be optically achieved by implementing a two-step upconversion process in YAG:Pr(3+) nanocrystals (see picture).

Journal: :Organic & biomolecular chemistry 2011
Bamaprasad Bag Ajoy Pal

The new signaling probes 2-6, rhodamine-B derivatives of various receptors which contain different donor atoms for effective metal ion coordination, were synthesized and their absorption as well as fluorescence spectral responses were evaluated in the presence of various metal ions. All these probes along with the reference probe 1 have exhibited optimal metal ion-induced absorption and fluores...

Journal: :The Analyst 2013
Ansgar T Kirk Maria Allers Philipp Cochems Jens Langejuergen Stefan Zimmermann

Drift tube ion mobility spectrometers (IMS) are widely used for fast trace gas detection in air, but portable compact systems are typically very limited in their resolving power. Decreasing the initial ion packet width improves the resolution, but is generally associated with a reduced signal-to-noise-ratio (SNR) due to the lower number of ions injected into the drift region. In this paper, we ...

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