Dual-objective pattern optimization method for land suitability zoning in mountain counties

As the basic administrative unit of China,counties have grown rapidly in recent years in the context of rapid urbanization,especially for counties located in mountainous areas.The drastic changes in land in mountainous areas can easily cause irreversible damage to the sensitive ecological environment.Through the dual-objective suitability zoning of ecological and construction balance,regional sustainable land use patterns can be realized.In this study,Hantai District in Southern Shaanxi province,China,was chosen as the research area aiming at creating a balance between ecological supply and the development of construction in spatial planning.A dual-objective process evaluation system for ecological protection and construction development was proposed with 15 resistance factors selected from three attributes:natural ecology,economic society,and policy.The minimum resistance surface discrimination methods for ecological land and construction development land were proposed based on vertical space superposition and horizontal minimum cumulative resistance models.Finally,the land in Hantai District was divided into four development grades from the optimal angle of dual goals,i.e.,the construction core zone being 134.56 km^(2),the suitable construction zone 115.77 km2,the ecological buffer zone 153.74 km^(2),and the ecological control zone 151.93 km^(2),using the method combining resistance difference and threshold division.In addition,the development direction of each town under jurisdiction was identified.This study compensates for the deficiency of traditional methods that evaluate land only from a single vertical or horizontal process.

Three-dimensional tracking of multiple particles in large depth of field using dual-objective bifocal plane imaging

Tracking moving particles in cells by single particle tracking is an important optical approach widely used in biological research. In order to track multiple particles within a whole cell simultaneously, a parallel tracking approach with large depth of field was put forward. It was based on distorted grating and dual-objective bifocal imaging, making use of the distorted grating to expand the depth of field, dual-objective to gather as many photons as possible, and bifocal plane imaging to realize three-dimensional localization. Simulation of parallel tracking of two particles moving along the z axis demonstrated that even when the two are axially separated by10 μm, they can both be localized simultaneously with transversal precision better than 5 nm and axial precision better than 20 nm.

Optimization of depreciation subsidy policy strategies for electric two-wheelers for improving traffic safety

To improve the traffic safety of electric two-wheelers(ETW),China has promulgated ETW standardization policies.This policy requires local governments to take measures to guide the illegal ETWs out of use.Governments have implemented a depreciation subsidy scheme to encourage users to scrap illegal ETWs early.When designing the subsidy scheme,effectively improving the ETWs’traffic safety at the road network level while saving government expenses is essential for the sustainable implementation of the policy.This study proposes an optimization method for depreciation subsidy design incorporating traffic safety evaluation.Based on the policy scheme,this study formulates a risk assessment model for the ETW traffic network to characterize the effect of the subsidy on improving safety.Then,we use the bi-level programming approach to model the subsidy strategy design problem.The upper-level problem reflects the goal of policymakers to maximize safety improvement and minimize government expenses.The lower-level problem describes the route choices of ETW users.The optimal subsidy design under different safety-expense trade-offs is analysed based on the Nguyen and Dupuis network and a real network extracted from Changsha City in China.The results show that specific subsidy schemes effectively improve road safety without a large government spending.When themarket price or service life of ETWs increases,the government spending on the same safety goal increases.The government should comprehensively consider the safety effect of financial expense and the situation of the local ETW market before selecting reasonable subsidy strategies.