Adhesion strength of tetrahydrofuran hydrates is dictated by substrate stiffness

Understanding the hydrate adhesion is important to tackling hydrate accretion in petro-pipelines.Herein,the relationship between the Tetrahydrofuran(THF)hydrate adhesion strength(AS)and surface stiffness on elastic coatings is systemically examined by experimental shear force measurements and theoretical methods.The mechanical factor-elastic modulus of the coatings greatly dictates the hydrate AS,which is explained by the adhesion mechanics theory,beyond the usual factors such as wettability and structural roughness.Moreover,the hydrate AS increases with reducing the thickness of the elastic coatings,resulted from the decrease of the apparent surface elastic modulus.The effect of critical thickness for the elastic materials with variable elastic modulus on the hydrate AS is also revealed.This study provides deep perspectives on the regulation of the hydrate AS by the elastic modulus of elastic materials,which is of significance to design anti-hydrate surfaces for mitigation of hydrate accretion in petro-pipelines.

Evaluation of radiation environment in the target area of fragment separator HFRS at HIAF

In this work, the radiation environment in the target area of a fragment separator is evaluated using FLUKA code. The energy deposition in quadrupole coils is presented to provide guidance for a radiation-resistant magnets design. Results show that neutrons dominate in the prompt radiation field. A compact shielding design is recommended for high radiation areas along with the minimization of air activation in the tunnel in order to minimize the radiation effect on nearby beam lines. The displacements per atom results for the graphite target and copper coils indicate that the effect is insignificant. In addition, the activation level of the target is estimated for workers under possible hands-on maintenance condition.

A New Type of Combination Forecasting Method Based on PLS——The Application of It in Cigarette Sales Forecasting

Cigarette market is a kind of monopoly market which is closed loop running, it depends on the plan mechanism to schedule producing, supplying and selling, but the “bullwhip effect” still exists. So it has a fundamental significance to do sales forecasting work. It needs to considerate the double trend characteristics, history sales data and other main factors that affect cigarette sales. This paper depends on the panel data of A province’s cigarette sales, first we established three single forecasting models, after getting the predicted value of these single models, then using the combination forecasting method which based on PLS to predict the province’s cigarette sales of the next year. The results show that the prediction accuracy is good, which could provide a certain reference to cigarette sales forecasting in A province.

Neutron penetration in labyrinths under different beam losses

Multiple analytical methods and Monte Carlo simulations were performed to evaluate neutron penetration in straight and curved labyrinths. Factors studied included variations in beam losses of off-axis point source,on-axis point source,and line source. For the straight labyrinth, it was found that the analytical expressions neglect the dose rate platform appearing at the bend of the labyrinth, and the agreement between analytical methods and Monte Carlo estimation was related to the type of neutron source term. For the curved labyrinth, the neutron attenuation length obtained under different conditions was nearly identical and appeared to be in quite good accord with the empirical formula calculation. Moreover, the neutron energy spectra along the centerline distance of the labyrinth were also analyzed. In the first leg, differences in beam loss led to variance in the distribution of spectra,while in the second and subsequent legs, the spectra were similar, where the main contributors were thermal neutrons. This work is valuable for practical design of the labyrinths in the accelerator facilities.

A Type of Combination Forecasting Method Based on Time Series Method and PLS

This paper depends on the panel data of Anhui province and its 17 cities’ cigarette sales. First we established three single forecasting models (Holter-Wintel Season product model, Time series model decomposing model and Partial least square regression model), after getting the predicted value of cigarette sales from these single models, we then employ the combination forecasting method based on Time Series method and PLS to predict the province and its 17 cities’ cigarette sales of the next year. The results show that the accuracy of prediction is good which could provide a reliable reference to cigarette sales forecasting in Anhui province and its 17 cities.