Analysis of Characteristics and Driving Mechanisms of Non-Grain Production of Cropland in Mountainous Areas at the Plot Scale-A Case Study of Lechang City.

With the continuous advancement of urbanization and industrialization, non-grain production on cropland (NGPCL) is gradually becoming more widespread. This phenomenon will compress the space for grain production and trigger a global food crisis. How to scientifically understand and effectively control NGPCL has become a scientific issue. This study, conducted at the plot scale, establishes a measurement index for NGPCL and further explores the characteristics and driving mechanisms of NGPCL in mountainous areas. The results indicate the following: (1) Compared to plots for food-growing, plots for non-grain production tend to be more dispersed, with terraces showing the most significant dispersion, while plains exhibit the highest degree of aggregation. (2) In terms of irrigation conditions, irrigated land and dry land are more likely to undergo NGPCL. In terms of topography, slope croplands have the highest probability of being used for NGPCL. (3) Regions with steeper slopes, higher elevations, greater differences in altitude from the settlement, farther distances from settlements and roads, yet closer proximity to forests, are more likely to engage in NGPCL. (4) Different plot characteristics have varying impacts on NGPCL. Plot characteristics primarily affect the costs and returns of grain production, driving farmers to change their production patterns and triggering NGPCL.

Salt Effect on the Isobaric Vapor-Liquid Equilibrium Study of Binary Mixtures H2O-NMP (N-Methyl-2-pyrrolidone).

To study the salt effect of recovering N-methyl-2-pyrrolidone (NMP) from the waste liquid produced in the polyphenylene sulfide (PPS) synthesis process, this study presents vapor-liquid equilibrium (VLE) measurement and correlation for water + NMP, water + NMP + lithium chloride, and water + NMP + sodium chloride at p = 101.3 kPa. The salt effect is discussed and the salts follow the order of lithium chloride > sodium chloride. The NRTL model was used for the correlation with binary parameters of water + NMP, water + NMP + lithium chloride, and water + NMP + sodium chloride. The correlation showed good agreement with experimental data; root-mean-square deviations are less than 0.48 K for the equilibrium temperature and 0.005 for the vapor-phase mole fraction of water.