The operator formalism of quantum mechanics from the viewpoint of short disturbances in nonrelativistic classical motion

The effect of short disturbances on nonrelativistic motion is formulated in terms of operators. Analogies with quantum mechanics are developed and some disparities noted. For the one-dimensional particle we obtain analogues of the de Broglie wave commonly associated with particle motion, Heisenberg's commutation relation, Schrödinger's equation, and the statistical interpretation. Whether these results have any bearing on quantum mechanics itself is left an open question.     

Trace identities for solutions of the wave equation with initial data supported in a ball

Suppose u is the solution of the initial value problem Suppose n ≥ 1 is odd, f and g are supported in a ball B with boundary S, and one of f or g is zero. We derive identities relating the norm of f or g to the norm of the trace of u on S × [0,∞) . These identities are derived using integral geometric and multiplier methods. Copyright © 2005 John Wiley & Sons, Ltd.     

International inter-comparison exercise on $${}^{153}\hbox {Sm}$$

Samarium-153 (\({}^{153}\hbox {Sm}\)) is a short-lived radionuclide that decays to stable europium-153 via beta emission, with subsequent de-excitation via gamma emission and internal conversion. Historical measurements of \({}^{153}\hbox {Sm}\) by gamma spectrometry and beta liquid scintillation counting have shown a low bias compared to beta proportional counting. In order to investigate this, four national laboratories jointly conducted an experimental inter-comparison exercise on a certified \({}^{153}\hbox {Sm}\) sample, created from neutron activation of samarium-152. Radiometric measurements were conducted using gamma spectrometry, liquid scintillation counting, gas proportional counting, and passivated implanted planar silicon detectors and compared across the four institutions against the certified value. The results from this experiment are presented together with a number of conclusions which suggest that the current published cumulative fission yield for \({}^{153}\hbox {Sm}\), as used by many laboratories, is approximately 15% high and is the likely cause of the previously observed bias.     

Mass selective separation applied to radioisotopes of cesium

A technique that uses the intrinsic mass‐based separation capability of a quadrupole mass spectrometer has been used to resolve spectral radiometric interference of two isotopes of the same element. In this work the starting sample was a mixture of ¹³⁷Cs and ¹³⁴Cs and was (activity) dominated by ¹³⁷Cs. This methodology separated and ‘implanted’ ¹³⁴Cs that was later quantified for spectral features and activity with traditional radiometric techniques. This work demonstrated a ¹³⁴Cs/¹³⁷Cs activity ratio enhancement of >4 orders of magnitude and complete removal of ¹³⁷Cs spectral features from the implanted target mass (i.e. 134). Copyright © 2016 John Wiley & Sons, Ltd.     

19飞秒激光脉冲的产生与测量

本文介绍产生19飞秒激光脉冲的被动锁模四棱镜补偿群速度分散的环型染料激光器的特点;讨论了二次谐波强度自相关法和二次谐波干涉自相关法。用该激光器产生的超短而高稳定的光源对同步扫描条纹相管作了评价。     

An excellent reagent for the removal of the t-butyldimethylsilyl protecting group

Aqueous hydrofluoric acid is an excellent reagent for the removal of $\text{t}$-butyldimethylsilyl protecting groups.     

On-line sensing of aluminium in zinc hot-dip galvanizing baths using novel techniques

Measurement and control of the dissolved aluminium levels in zinc hot-dip galvanizing baths, is of great importance to the steel industry. Current attempts at the cost-effective production of an aluminium sensor, for use in molten zinc, have not proved to be very successful. Possible sensor systems, based upon two contrasting electrolytes are proposed within this paper. A sensor based upon thein-situ formation of sodium aluminium chloride, through D.C charging, is proposed. The charging process and EMF versus time relationship, for different aluminium concentrations, has been investigated. A second system, based upon the trivalent ion conducting electrolyte, aluminium tungstate, has also been studied. Aluminium tungstate, Al₂(WO₄)₃, has been prepared by a simple calcination step. Modification of the structure of the electrolyte, to improve its conduction properties, has been investigated. Paper presented at the 6th Euroconference on Solid State Ionics, Cetraro, Calabria, Italy, Sept. 12–19, 1999.