Tetra­kis(4-chloro­anilinium) hexa­chlorido­stannate(IV) dichloride

The asymmetric unit of the title compound, (C6H7ClN)4[SnCl6]Cl2, comprises two 4-chloro­anilinium cations, half of an [SnCl6]2− anion and a Cl− anion. The SnIV atom, located on a special position on a twofold rotation axis, exhibits an octa­hedral environment. In the crystal, mol­ecules are linked by N—H⋯Cl hydrogen bonds between the 4-chloro­anilinium cations, [SnCl6]2− anions and Cl− anions

Investigation Of Hydrate Growth Rate On The Interface Between Liquid and Solid Film

Hydrate slurry has been reported to be suitable secondary fluid for refrigeration and air-conditioning systems. The latent heat of CO2 hydrate is 387 kJ/kg under phase equilibrium condition of 7 °C and 30 bar. The utilization of CO2 hydrate slurry in air-conditioning systems is promising in improving the energy efficiency and shifting energy supply and demand load as well as relieving greenhouse effect caused by normal refrigerant like CFCs, HCFCs etc. The production of CO2 hydrate slurry in a coil heat exchanger is investigated in this study. Crystals are supposed to firstly form on the wall of the tube, generating a solid layer. The appearance of the solid layer increases the heat resistance from liquid to the refrigerant. Type-III antifreeze proteins have been added to the solution to better control the crystallization process of hydrate formation since AFPs have been proved to be an effective hydrate formation preventer which is environment friend. A kinetic model is developed based on the gas hydrate growth model of Skovborg and Rusmussen (1994), taking the mass transfer process to be the rate-control step. The diffusion coefficient of gas to liquid is investigated to be influenced by pressure, temperature and concentration of the hydrate formation preventer. Results show that the growth rate decreases with the increase of the concentration of AFPs while the thickness of the crystal layer doesn’t show the same trend

RoGAT: a robust GNN combined revised GAT with adjusted graphs

Graph Neural Networks(GNNs) are useful deep learning models to deal with the non-Euclid data. However, recent works show that GNNs are vulnerable to adversarial attacks. Small perturbations can lead to poor performance in many GNNs, such as Graph attention networks(GATs). Therefore, enhancing the robustness of GNNs is a critical problem. Robust GAT(RoGAT) is proposed to improve the robustness of GNNs in this paper, . Note that the original GAT uses the attention mechanism for different edges but is still sensitive to the perturbation, RoGAT adjusts the edges' weight to adjust the attention scores progressively. Firstly, RoGAT tunes the edges weight based on the assumption that the adjacent nodes should have similar nodes. Secondly, RoGAT further tunes the features to eliminate feature's noises since even for the clean graph, there exists some unreasonable data. Then, we trained the adjusted GAT model to defense the adversarial attacks. Different experiments against targeted and untargeted attacks demonstrate that RoGAT outperforms significantly than most the state-of-the-art defense methods. The implementation of RoGAT based on the DeepRobust repository for adversarial attacks

The Effect Of Type-III Antifreeze Proteins (AFPs) On CO2 Hydrate Slurry Formation

CO2 hydrate slurry is a favourable direct coolant of fresh products due to its large latent heat and phase change temperature around 5°C. Continuous production of this slurry is, however, difficult to realise due to the high rate of hydrate formation. The use of additives is proposed with the purpose of decreasing the formation rate so that the controllability of the process is improved. Type-III Antifreeze Proteins (AFPs) are non-poisonous additives which have proven to be inhibitors of hydrate formation. These additives have also shown to protect the bio-cells of fresh products from damaging by freezing. The effect of these additives on the CO2 hydrate formation rate is experimentally investigated. The experiments have been performed in a coil heat exchanger with 6 mm internal diameter under operating conditions corresponding to hydrate formation conditions. The concentration of Type-III AFPs has been varied: no additives, 5 ppm and 10 ppm. The mixture of additives and CO2-water solution is cooled down until the hydrate formation conditions are attained. The growth rate of hydrates on the wall of the heat exchanger has been derived from the variation of the overall heat transfer coefficient with time. Results show that the addition of AFPs changes the supersaturation degree of CO2 water solution needed to initiate the hydrate formation process. A low concentration of the proposed additives is sufficient to slow down the formation rate of CO2 hydrate improving significantly the controllability of the hydrate production process

Risk Factors of Suicide Ideation in Chinese Graduate Students: CHAID Tree Analysis

The present study aims to identify the risk factors and develop a decision tree model of suicide ideation in Chinese graduate students. A chi-square automatic interaction detection tree analysis was conducted in a graduate students sample (N=1036). Measurements included University Personality Inventory (UPI), Symptom Checklist 90 (SCL-90), and Eysenck Personality Questionnaire (EPQ). Results showed that suicide incidence of Chinese graduate students was 1.15%, with males’ was higher than females. Seventeen potential variables were considered and only three of them (depression, obsession, and neuroticism) were found to be risk factors of suicide ideation in Chinese graduate students, and the interactions between them constructed a decision tree model. These findings should be helpful for school and mental health providers to detect graduate students with a high possibility of suicide ideation, which will aid in planning of early suicide intervention and prevention for at risk students