Silica Nanoparticles Modified by Biphenyl Groups for Crack-Free Coating on Synthetic Paper.

Water-based acrylic emulsions are a crucial component of water-based ink. Preventing visible cracks in emulsion coating during drying is a great challenge due to the high polarity and high surface tension of water. Herein, we propose that the cracking resistance of the coating can be enhanced through the incorporation of hydrophobic silica nanoparticles.

Synthesis of anisotropic silica nanoparticles by organic amine with diverse structures.

Herein, we synthesized anisotropic silica nanoparticles (AISNPs) with organic amines with different structures. Monoamines and diamines with distance between amine groups shorter than4 Å have been observed to facilitate the formation of isotropic silica nanoparticles (ISNPs). AISNPs were synthesized with diamines with distance between amine groups longer than4 Å and linear structures of triamines.

Efficiency calibration and self-attenuation correction in radioxenon measurement using β-γ coincidence method.

Measurement of the four radioxenon isotopes, namely Xe, Xe, Xe, and Xe, play a key role in underground nuclear test monitoring for ensuring compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). To improve detection sensitivity, a β-γ coincidence technique is commonly used. Due to the presence of the gas matrix, such as stable xenon, nitrogen, helium, the self-attenuation effects should be taken into account when measuring different types of sample.

Radioactivity measurement of Kr by using anti-cosmic HPGe γ spectrometer.

In order to improve the detection sensitivity of Kr, an anti-cosmic HPGe γ spectrometer was established and a specific Marinelli beaker was designed for Kr measurement. Comparing to the non-anticoincidence γ spectrum, the integral background counts rate range from 20 to 2400 keV was reduced by a factor of 5.17 using anticoincidence shielding.

Assessment of a compton-suppressed spectrometer for measurement of radioactive xenon isotopes.

Airborne radionuclide monitoring is considered to be the most certain way to detect a clandestine nuclear weapon test. The activity concentration of radioxenon samples collected by the radionuclide stations of the International Monitoring System (IMS) for the Comprehensive Nuclear-Test-Ban Treaty (CTBT) is generally performed at the low-level, hence it is necessary to improve the detection sensitivity of the radioactivity measuring apparatus for radionuclide monitoring. The Compton-suppressed spectrometer (CSS) has the advantage of reducing the background and improving the sensitivity in the environmental level measurement.

Measurement of the gamma-ray emission probability of Xe.

Xe has been standardized by means of an internal gas proportional counting system, employing a length-compensated method. The activity concentration of Xe was measured with a relative standard uncertainty of 0.6%.

Determination of 226Ra Activity Using Gamma Spectrometry with 226Ra-222Rn Disequilibrium.

Radium-226 (Ra) activity is normally determined indirectly by gamma spectrometry, in particular by measuring the characteristic γ-ray emitted from its progeny (Pb and Bi) when Ra-Rn secular equilibrium is reached. This article describes a measurement method involving the measurement of Pb ingrowth. The activity of Ra determined by this method agrees with that measured after Ra-Rn equilibrium.

Fitting formula for the injection volume of a gas chromatograph for radio-xenon sampling in the lower troposphere.

GC is usually used for xenon concentration and radon removal in the International Monitoring System of the Comprehensive Nuclear-Test-Ban Treaty. In a gas chromatograph, the injection volume is defined to calculate the column capacity. In this paper, the injection volume was investigated and a fitting formula for the injection volume was derived and discussed subsequently.

Inference and analysis of xenon outflow curves under multi-pulse injection in two-dimensional chromatography.

Multidimensional gas chromatography is widely applied to atmospheric xenon monitoring for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). To improve the capability for xenon sampling from the atmosphere, sampling techniques have been investigated in detail. The sampling techniques are designed by xenon outflow curves which are influenced by many factors, and the injecting condition is one of the key factors that could influence the xenon outflow curves.

Radioxenon monitoring in Beijing following the Fukushima Daiichi NPP accident.

This paper reports the brief process and results of radioxenon monitoring and analysis in Beijing following the Fukushima Daiichi nuclear power plant accident. The accident and release of volatile radionuclides were caused by 9.0 magnitude earthquake and tsunami on March 11, 2011.

The performance determination of a Compton-suppression spectrometer and the measurement of the low level radioactive samples.

The performance of a new Compton-suppression spectrometer consisting of one HPGe detector and three NaI(Tl) detectors was studied. The peak-to-Compton ratio for a (137)Cs source is 1150 and the integral background count rate is 0.3 5s(-1) over the energy interval 20-3000 keV.

The coincidence-summing correction of the Compton-suppression spectrometer.

The compton-suppression Spectrometer can suppress the Compton baseline and make weak full energy peaks prominent in low-level activity gamma spectra, so it is used to measure environmental radioactive samples. In order to quantify the activities of the radionuclides in the sample coincidence-summing corrections should be applied. In this article the expressions of coincidence-summing correction of Compton-Suppression Spectrometer were deduced and the validity of the expressions was verified.