Heterogeneous responsibilities of three grassland resource governance modes in Inner Mongolia, China

Grassland resource governance is an important part of ecological civilization construction,and it directly af‐fects grassland governance performance.This study deploys principal-agent theory and uses social network analysis to compare grassland resource governance modes in China in terms of institutional settings and insti‐tutional network characteristics.This study found three types of grassland resource governance modes:self-designed,docked,and integrated.The self-designed mode forms a network structure with dual centers and multiple members,and has the second-best structural mode of the three types.The docked mode forms a net‐work structure with a single center in which the institution is the absolute core and is relatively divergent.It has the weakest structural advantage of the three types.The integrated mode forms a network structure with a single institution at the core and other institutions distributed evenly throughout the structure.This mode has the strongest structural advantage among the three types.This study offers the practical application of improv‐ing the practice of grassland governance in China and is theoretically significant because it can contribute to improving grassland governance modes and enriching the public goods resources governance.

Application of response surface methodology for optimization of Orange Ⅱ removal by heterogeneous Fenton-like process using Fe_3O_4nanoparticles

In this study, Fe3O4nanoparticles（Fe3O4NPs） were successfully prepared via oxidation–precipitation method and characterized by scanning electron microscopy（SEM）, X-ray diffraction（XRD） and Fourier transform infrared spectroscopy（FT-IR）. The characterization results indicated that Fe3O4 NPs with regular crystal structure and a narrow of diameters had been synthesized successfully and had high purity. A series of experiments were carried out to investigate the degradation of Orange II by the obtained heterogeneous Fe3O4 catalysts in the presence of H2O2. The response surface methodology（RSM） based on Box–Behnken design（BBD） was employed to design and optimize individual and interactive effects of the four main independent parameters（catalyst loading, initial p H, reaction temperature and H2O2concentration） on decolorization efficiency of Orange II. A significant quadratic model（p-value 〈0.0001, R2= 0.9369） was derived using analysis of variance（ANOVA）. Optimum conditions were catalyst loading of 1.5 g/L, initial p H of 2.7, reaction temperature of 42 8C and H2O2 concentration of 22 mmol/L, respectively. The predicted decolorization rate under the optimum conditions as determined by the proposed model was 99.55%. Confirmatory tests were carried out and the decolorization rate of 99.49% was observed under the optimum conditions, which agreed well with the model prediction.