[en] Highlights: • Novel theory of saving energy and its application in water loop heat pump. • Reverse energy caused by units to water loop and its solution. • New method for determining the energy-saving range of water loop heat pump. • Capacity model of auxiliary heat source and its size for all building types. • Advice for reducing total energy consumption of water loop heat pump. - Abstract: It is a difficult problem to how to determine the reverse energy caused by units to water loop when a water-loop heat pump (WLHP) is in cooling and heating simultaneous mode, which not only has a great impact on energy-saving rate but also decides the use of auxiliary heat source in winter. This paper presents a theory of energy level to improve the research on WLHP system by using the relationship among building, circulating water and units. In this theory, the circulating water replaces building load as a new method to convert the reverse energy into energy change of circulating water and the equation of energy level also is built to determine the energy-saving range of WLHP system and report the capacity model of auxiliary heat source for all building types. An office building with different auxiliary powers is tested to analyze system operation characteristic and the effect of auxiliary heat source on unit and system and the results validate previous conclusions and suggest that an energy balance should be considered between units and auxiliary power to improve overall operation.

No abstract available

No abstract available

No abstract available

No abstract available

[en] Many studies have been performed to evaluate the environmental risk caused by alternative flame retardants (AFRs) of polybrominated diphenyl ethers due to their ubiquitous occurrence in the environment. However, as an indispensable component of the environmental risk assessment, the information on atmospheric fate of AFRs is limited although some AFRs have been frequently and highly detected in the atmosphere. Here, a combined quantum chemical method and kinetics modeling were used to investigate atmospheric transformation mechanism and kinetics of AFRs initiated by ·OH in the presence of O₂, taking triphenyl phosphate (TPhP) as a case. Results show that the pathway involving initial ·OH addition to phenyl of TPhP to form TPhP-OH adduct, and subsequent reaction of the TPhP-OH adduct with O₂ to finally form phenol phosphate, is the most favorable for the titled reaction. The calculated overall reaction rate constant is 1.6 × 10⁻¹² cm³ molecule⁻¹ s⁻¹, translating 7.6 days atmospheric lifetime of TPhP. This clarifies that gaseous TPhP has atmospheric persistence. In addition, it was found that ice surface, as a case of ubiquitous water in the atmosphere, has little effect on the kinetics of the rate-determining step in the ·OH-initiated TPhP reaction. - Highlights: • We investigated the mechanism and kinetics of triphenyl phosphate initiated by ·OH. • The main products are TPhP-OH adduct and phenol phosphate. • The overall reaction rate constant is 1.6 × 10⁻¹² cm³ molecule⁻¹ s⁻¹ at 298 K. • The atmospheric lifetime of TPhP is estimated to be 7.6 days. • Ice surface has little effect on the kinetics of the ·OH-initiated TPhP reaction.

No abstract available

[en] Choice of atmospheric dispersion models for nuclear emergency decision making support is discussed. Comparisons are done between puff model and segmented Gaussian plume model for different flow fields. Simulation results of the two models are similar under stationary and homogeneous flow field; while under in-stationary or inhomogeneous flow field, concentration distributions obtained by segmented plume model are obviously discontinuous. Moreover, more realistic results are obtained by puff model under in-stationary flow field for short release. According to model characteristics, simulation results and operation time of puff model, segmented plume model and Lagrangian particle model, as well as requirements of nuclear emergency and site-specific characteristics of Chinese nuclear power plants, puff model is better for nuclear emergency decision making support

[en] The effect of changes of intervention levels and meteorological conditions on the early emergency countermeasures is analysed for nuclear power plant emergencies. A Lagrangian puff model RIMPUFF is used to predict dose distributions under stable and unstable meteorological conditions. The release scenario for PWR6 is used as an example to determine emergency areas for different intervention levels. The prediction results show that the evacuation area radius is 5 km and the radii for sheltering and intake-of stable iodine are both 10 km. The difference between the emergency areas determined by the intervention levels given in HAF0703/NEPA9002 and IAEA safety series No. 109 is only in the sheltering area which is much smaller using the IAEA guidelines

[en] The application of NaI-LaBr₃ double detectors for in situ measurement of seawater radiation can better realize the monitoring and early earning and activity analysis of artificial radionuclides. To study MC simulation method of the dual crystal detection system in situ γ-ray spectra, a dual-crystal detection system has been preliminarily built in the laboratory to perform point source energy spectrum acquisition experiments, the model of double crystal detection system by MCNP5 is built based on experiment condition, the normalized energy spectrum of γ-ray in double crystals is calculated, and double crystal Monte Carlo simulation and gaussian broadening is achieved by MATLAB, the error between the simulated spectrum and the experimental spectrum is small. The results show that MC simulation and gaussian broadening method is feasible and can be applied to calculate the response curve of seawater radioactive source activity concentration. (authors)