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41.
J. Holzhey G. Krüger J. Vogel W. Giehler 《Isotopes in environmental and health studies》2013,49(9-10):345-349
Es wird ein zuvelässiges und sehr empfindliches radiometrisches Verfahren zur Bestimmung des Ziehsteinverschleiβes beim Ziehen von Stahldraht beschrieben. Im Vergleich zu den in der Literatur angegebenen radiometrischen Meβverfahren ist das behandelte Verfahren weniger zeitaufwending und gestattet es, bei einem vertretbaren Aufwand gröβere Verscuhsreihen durchzuführen. Mit Hilfe dieser Methode ist es möglich, langwierige groβtechnische Versuche zu umgehen und gleichzeitig eine wesentlich exaktere Aussage ūber den Verschleiβ unter verschiedenen Ziehbedingungen zu erhalten. 相似文献
42.
K. Lemke 《Isotopes in environmental and health studies》2013,49(7):245-248
Die Anforderungen an die Meβapparatur in bezug auf Meβgemaiogkeit, örtliche Auflösung, Meβgeometrie und Strahlenschutz werden dargelegt. Die Meβgemauigkeit soll ±2% (Meβbereich: Q = 2,0 2,4g/cm3) und die örtliche Auflösung 20cm (maximale Fertigungsgeschwindigkeit: υmax = 1,5m/min) betragen. Es wird die Meβapparatur beschrieben und über ihre Eichung berichtet. Die Eichkurven, die mit Festbetonquadern aufgenommen wurden, können für die Messungen am Frischbetonstrang verwendet werden, wenn man die Einflüsse des Wassergehaltes und der Bewehrung durch Korrektionen berücksichtigt. Die Erprobung der Versuchseinrichtung erfolgte am Gleitfertiger bei der Herstellung schlaff bewehrter Straβenbauplatten. 相似文献
43.
S. Koch H.-J. Schreiber P. Jugelt J. Knorr 《Isotopes in environmental and health studies》2013,49(9):350-354
Bei der Elementanaylse mittels Szintillalionsspektrometrie im Ausgangskanal der (n, γ)-Reaktion tritt ein hoher Linienuntergrund auf. Dieser Untergrund lafit läβt herabsetzen durch Puhung des Neutronengenerators (Plasyna-Pulsung), zweckmäβige Dimensionierung der Meβanordnung und Optimierung des Meβzeilintervalls. 相似文献
44.
D. Hebert K. Froöhlich A. Andreeff 《Isotopes in environmental and health studies》2013,49(10):358-361
Aufbau, Arbeitsweise und Eigenschaften einer Apparatur, mit der naturliche l4C-Aktiviäten in Grund- und Oberflächenwässern gemessen werden können, werden beschrieben. Die Messung erfordert 3 Arbeitsschritte: Probenahme, Synthese von Benzol, welches dann den Probenkohlenstoff enthält, und Messung der 14C-Aktivität in einem Flüssigkeitsszintillationszähler. Die Apparatur kann zur Datierung von Wasserproben im Altersbereich zwischen 200 und 37000 a verwendet werden. 相似文献
45.
A. V. Belushkin 《Pramana》2008,71(4):639-651
Different types of neutron scattering experiment for the study of condensed matter properties pose specific and often contradictory
requirements for detector characteristics. There is no single type of detector which satisfies all the criteria. Therefore,
compromise is inevitable and some of the characteristics are trade off in favour of others.
Present report gives an overview of detector systems presently operating at the leading neutron scattering facilities as well
as some development work around the globe.
相似文献
46.
A. M. Shaikh 《Pramana》2008,71(4):663-672
Design and development of neutron detectors and R&D work in neutron radiography (NR) for non-destructive evaluation are important
parts of the neutron beam and allied research programme of Solid State Physics Division (SSPD) of Bhabha Atomic Research Centre
(BARC). The detectors fabricated in the division not only meet the in-house requirement of neutron spectrometers but also
the need of other divisions in BARC, Department of Atomic Energy units and some universities and research institutes in India
and abroad for a variety of applications. The NR facility set up by SSPD at Apsara reactor has been used for a variety of
applications in nuclear, aerospace, defense and metallurgical industries. The work done in the development of neutron detectors
and neutron radiography is reported in this article.
相似文献
47.
The powder diffractometer and Hi-Q diffractometer at Dhruva reactor make use of five identical 1-D position sensitive detectors (PSDs) to scan scattering angles in the range 3° to 140°. In order to improve the overall throughput of these spectrometers, it is planned to install a bank of 15 high-efficiency and high-resolution PSDs arranged in three layers with five PSDs in each layer. With each high pressure PSD (3He 10 bar + Kr 2 bar) showing the efficiency gain of 1.8 at 1.2 Å, detector bank is expected to show overall gain of 5.5 times the present detection efficiency and reduction in data collection time by equivalent factor. The 1-D PSDs are developed in batches of five, and are characterized so that all PSDs operate at uniform parameters such as position resolution, uniformity of efficiency and linearity of response. Position spectrum indicates the differential position resolution to be ~1 mm and integral position resolution to be 3–4 mm. Broadening of position spectrum at the extreme end of sensitive length of PSD is analysed using fine shift of the beam. Dependence of position resolution and dynamic range of output pulse on the input impedance of pre-amplifier is also presented. 相似文献
48.
Technetium is a synthetic element with no stable isotopes, produced as waste in nuclear power plants and in cyclotrons used for nuclear medicine. The element has high mobility, in the form of TcO4−; its determination is therefore important for environmental protection. Technetium is found in low concentrations and therefore common methods for its analysis include long treatments in several steps and require large amounts of reagents for its purification and preconcentration. Plastic scintillation resins (PSresin) are novel materials used to separate, preconcentrate and measure radionuclides in a single step. The objective of this study is to prepare and characterise a PSresin for the preconcentration and measurement of 99Tc. The study first evaluates the reproducibility of the production of PSresins between batches and over time; showing good reproducibility and storage stability. Next, we studied the effect of some common non-radioactive interferences, showing small influences on measurement, and radioactive interferences (36Cl and 238U/234U). 36Cl can be removed by a simple treatment with 0.5 M HCl and 238U/234U can be removed from the column by cleaning with a mixture of 0.1 M HNO3 and 0.1 M HF. In the latter case, a slight change in the morphology of the PSresin caused an increase in detection efficiency. Finally, the PSresin was applied to the measurement of real spiked samples (sea water and urine) with deviations lower than 10% in all cases. 相似文献
49.
In this paper we investigate the light response to fast neutrons and estimate the pulse height resolution of a deuterated liquid organic scintillator, EJ-315, considering the detector's non-linear light response to gamma-rays. Initially, collision data and a neutron beam trigger are recorded in coincidence mode, and incident neutron energy is calculated with a time-of-flight technique. Fast neutrons are further discriminated from gamma-ray background based on the scintillation material decay patterns using a pulse shape discrimination algorithm. A light response matrix composed of multiple neutron energy and their corresponding light outputs is derived. The pulse height resolution property of the EJ-315 is characterized utilizing the derivatives of the pulse height distributions with corrections of the measurements setup uncertainties. Additionally, the EJ-315's pulse height resolution is also characterized by comparing the smoothed derivatives of quasi-monoenergetic neutron pulse height distributions, given by the Peierls-formula-based analytic model, to match the measurement data. Results show rather consistent 10–13% pulse resolution for mono-energetic neutrons with kinetic energy above 2 MeV. The resolution decreases slightly with an increase in neutron energy indicating the improved resolution performance of EJ-315 in the higher energy events. 相似文献
50.
氟化钡(BaF2)晶体是已知响应最快的闪烁晶体,在高能物理、核物理及核医学等领域有着广泛的应用前景。抑制BaF2晶体的慢发光成分对其工程应用至关重要。本文利用坩埚下降法制备了高Y3+掺杂浓度5%、8%、10%(摩尔分数)的BaF2晶体,并采用Y3+与碱金属离子(Li+、Na+)共掺杂的方法形成电荷补偿阻止间隙F-的产生,制备了双掺杂型BaF2快响应闪烁晶体,进而基于优化的5 ns和2 500 ns时间门宽测试方法,研究了Y3+掺杂浓度以及Y3+与碱金属离子(Li+、Na+)共掺杂浓度对BaF2闪烁晶体快/慢成分比的影响规律。结果表明,生长的高浓度Y3+掺杂BaF2晶体的光学质量优异,在220 nm和300 nm处透过率分别高于90%和92%;随着Y3+掺杂浓度由0提高至10%,BaF2晶体的慢发光成分显著降低,快/慢成分比由0.15提高至1.21;生长的Y3+/Li+及Y3+/Na+共掺杂BaF2晶体的慢发光成分较Y3+掺杂BaF2晶体进一步降低,快/慢成分比最高分别可达1.63和1.61。研制的双掺杂BaF2快响应闪烁晶体有望应用于高能物理、核物理前沿实验等重要领域。 相似文献