With the increasing penetration of distributed generations (DGs) and flexible loads in the distribution network (DN), the existing DN planning methods need an improvement. This paper proposes a two-layer multistage expansion planning method for DN adaptability enhancement, where the optimal construction/upgrade strategy of substations and lines along with the optimal PV configuration strategy are considered. A two-layer adaptive planning model is established and solved by the non-dominated sorting genetic algorithm II (NSGA II). The obtained Pareto-optimal front represents a set of optimal planning schemes meeting the demand of DN economy and adaptability, which is of great significance in theory and practice.

For shallow exploration, high-frequency pseudo-random binary sequence is used in the time-domain airborne electromagnetic system. This system is working in the on-time and the earth response could be derived from system identification, which is different from the previous time-domain electromagnetic systems. The early time data is crucial for obtaining a detailed resolution. It could be severely disturbed by the primary field, the receiver response and noise. Here we present an approach for removing the primary field by matching subtraction in transformation of correlation calculation. The noise is suppressed as not correlated with the pseudo-random binary sequence. This approach is proved efficient by applying to simulation data based on forward modeling. The receiver influence is analyzed through the response of the equivalent electronic circuit. The 1D inversion results indicate that critical damping state and high cut-off frequency could reduce the adverse effect on the resolution of shallow exploration.

In the research and development of nuclear instruments, the simulation and shaping of nuclear pulse signals are very important. Since the output signal of nuclear detectors is very weak and has noise interference, it cannot be processed well by the data acquisition system, so it is necessary to filter and shape the nuclear pulse signals. Using MATLAB 2019a simulation software to superimpose random noise to simulate the output signal of the CdZnTe nuclear radiation detector, the output signal of the preamplifier and the output signal of the main amplifier. The final result is basically the same as the actual signal, which is a simulated nuclear pulse signal, laying the foundation for the nuclear-simulated pulse signal generator.

To investigate the difference in responses of the tail beam of the top coal caving hydraulic support caused by different shapes and falling postures of coal-rock particles and study the vibrational signal changes, we conducted a dynamic analysis of single particle impact on the tail beam. First, formula of the contact force generated by the particle striking the tail beam slope was derived using Hertz theory. Then we used the finite element analysis software Abaqus to simulate the impact of different shapes of coal-rock particles on the tail beam. The results show the contact force generated by the coal-rock particles with different shapes and same mass impact the tail beam differently. The larger the radius of curvature of the particle contact point, the greater the contact force generated and the greater the vibration generated by the tail beam. Therefore, when the vibration signal of the tail beam is detected and used as the basis for judging the coal-rock particles, attention should be paid to the vibration difference because of the particle shape to prevent misjudgment.

With abundant oil and gas resources, limestone oil and gas resources are characterized by complex composition, uneven distribution, low natural productivity, and susceptibility to contamination, acidizing is an important measure to put this kind of oil and gas wells into production and increase production, but the effect of acidizing measure varies from block to block. This paper attempts to identify the difficulties in acidizing process by analyzing the reservoir character of multiple limestone reservoir systems in D Oilfield region, and to finalize matrix acidizing, retarded acidizing fracturing and multi-stage injection fracturing as three alternatives through single-well and block analysis, according to the permeability, pore throat development and lithological character. After the acidizing measure was implemented, good results were attained.

As an important renewable alternative energy source, one of the most critical aspects that can be used reasonably is the improvement of the biomass energy supply chain. In view of the uncontrollable transportation process in the biomass energy supply chain, Blockchain technology(BT) is introduced to optimize the biomass energy collection, transportation, and storage processes. On this basis, the game model is applied to analyze the impact of BT on the members of the biomass supply chain and the overall profit of the supply chain. Research shows that the application of BT is beneficial to increase the profits of biomass energy supply chain members within the threshold range, and for the overall benefit of the supply chain, the overall benefit of the supply chain under centralized decision-making is the highest.