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11.
AimNeutron-activated holmium-166 (166Ho) is an excellent radionuclide for internal radiation therapy (Eβmax = 1.84 MeV) with an appropriate half-life (26.8 h), which emits photons (81 keV, 6.2%) suitable to be detected by gamma cameras. Preparing and injecting radiopharmaceuticals containing beta/gamma emitting holmium-166 implies a risk of exceeding the upper limit for skin and hand radiation equivalent doses (500 mSv/an). This study was aimed to estimate the whole body and finger exposure for staff responsible for dose preparation, dose dispensing, and dose injection of holmium-166 therapy.MethodsTo measure the finger dose from external exposure, all staff members wore TLD dosimeters. Personal dose equivalents Hp(10) were measured using electronic personal dosimeters (EPD MK2, Thermo Fischer Scientific) placed on the left side of the chest. During our study, staff members administered more than 40 166Ho-based therapies for preclinical trial. Appropriate radiation safety procedures and shielding were applied at each stage.ResultsIn this study, the whole body doses were 2.80 ± 1.56 nSv MBq−1 for one 166Ho-therapy preparation/formulation, and 2.68 ± 1.70 nSv MBq−1 for one intravenous injection. Maximum finger doses were 2.9 ± 0.2 μSv MBq−1 and 2.5 ± 0.3 μSv MBq−1 for preparation and injection, respectively (activities injected: 72 ± 3 MBq).ConclusionExtrapolated annual doses from 300 166Ho radionuclide therapies were lower than the annual limit doses for skin and the whole body, 500 mSv and 20 mSv, respectively, reported in the European Directive EURATOM 96/29 when applying appropriate radiation protection standards. However, these doses have to be added to other diagnostic or therapeutic protocols, performed in preclinical facilities. 相似文献
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Ho3+-doped low-phonon-energy heavy-metal gallate glasses (LKBPBG) have been prepared and efficient 1.199 μm emission originating from the 5I6 → 5I8 radiative transition has been observed under 900 nm excitation. The spontaneous emission probability and the maximum stimulated emission cross-section were derived to be 294.31 s− 1 and 3.46 × 10− 21 cm2, respectively. The ratio of quantum yields between ~ 1.2 and ~ 2.0 μm emissions was identified to be 16%, demonstrating that the 5I6 → 5I8 transition is favorable for optical amplification. The maximum gain coefficient of 1.84 dB/cm at 1.199 μm wavelength was anticipated in the ideal status. These results indicate that the Ho3+-doped LKBPBG glasses have a promising potential for the development of ~ 1.2 μm signal amplifier devices. 相似文献
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Pentathiepines fused with pyrrole, thiophene, or indole rings were obtained by reactions of the corresponding heterocycles
or their tetrahydro derivatives with a prepared mixture of sulfur monochloride and DABCO.
Dedicated to Academician O. M. Nefedov on the occasion of his 75th birthday.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2002–2005, November, 2006. 相似文献
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The electronic spectra of the titanium monohalides, TiCl and TiBr, have been investigated in the blue-violet region using a laser ablation molecular beam spectrometer. Five subbands assigned as 4Γ5/2-X4Φ3/2 (0, 0), 4Γ5/2-X4Φ3/2 (1, 1), 4Γ5/2-X4Φ5/2 (0, 0), 4Γ7/2-X4Φ5/2 (0, 0) and 4Γ7/2-X4Φ7/2 (0, 0) were observed and recorded at both low and high-resolution for titanium monochloride. A Hund’s case (a) rotational analysis has been carried out for the 48Ti37Cl and 48Ti35Cl isotopic species, and polynomial analyses for these, as well as the 46Ti35Cl, 47Ti35Cl, 49Ti35Cl, and 50Ti35Cl isotopologues have been completed. The same spectral region yielded several molecular transitions for titanium monobromide, 10 of which were recorded at high resolution. Six of these have been attributed to a 4Γ-X4Φ electronic transition at 23 484 cm−1, while the remaining four have been assigned to a second 4Γ-X4Φ electronic transition at 23 613 cm−1. A Hund’s case (a) global analysis has been carried out for the 48Ti79Br and 48Ti81Br isotopologues. 相似文献
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The high resolution molecular beam laser-induced fluorescence (LIF) spectrum of the (0, 0) band of the [17.6]7.5-X18.5 system of holmium monoxide, HoO, has been recorded field free and in the presence of a variable static electric field. The rotational constant, B0, and magnetic hyperfine structure constant, h, for the v = 0 levels of the [17.6]7.5 and X18.5 states were obtained by assigning and fitting the field-free spectral features. The Stark shifts and splittings in the LIF spectra were analyzed to produce values for the magnitude of the permanent electric dipole moments, |μ|, of 3.96(6) and 4.80(5) D for [17.6]7.5, v = 0 and X18.5, v = 0, respectively. 相似文献
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Nagarajan Amirtha Seshaiyer Viswanathan Ramachandran Ganesan 《Monatshefte für Chemie / Chemical Monthly》1984,115(1):35-43
The kinetics of the addition of iodine monochloride (ICl) to some vinyl compounds in nitrobenzene solvent was investigated. In all cases the reaction follows second order dependence on ICl and first order on the substrate, making the total order three. Rate constants were measured for each substrate at 20°, 30°, 40° and 50°C.Arrhenius plots were made from which activation energies were evaluated. Other kinetic and thermodynamic parameters are reported. A suitable mechanism is proposed for the reaction and based on this, the various parameters are discussed. Solvent effects are discussed and the data with nitrobenzene and acetic acid solvents are compared.
Kinetik und Mechanismus der Addition vonICl zu einigen Alkenen in Nitrobenzol als Lösungsmittel. Effekt der Polarität des Lösungsmittels
Zusammenfassung Die Kinetik der Addition von ICl zu einigen Vinylverbindungen in Nitrobenzol als Lösungsmittel wurde untersucht. In allen Fällen ist die Reaktion von zweiter Ordnung hinsichtlich ICl und von erster Ordnung hinsichtlich des Substrats, d. h. mit einer Gesamtordnung von drei. Geschwindigkeitskonstanten wurden für jedes Substrat bei 20°, 30°, 40° und 50°C gemessen. AusArrhenius-Diagrammen wurden Aktivierungsenergien ermittelt und auch andere kinetische und thermodynamische Parameter wurden bestimmt. Ein Mechanismus wird vorgeschlagen, wobei die verschiedenen Parameter diskutiert werden. Lösungsmitteleffekte werden ebenfalls diskutiert und die Daten mit Nitrobenzol und Essigsäure als Lösungsmittel miteinander verglichen.相似文献
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