Black phosphorus (BP) is a new two-dimensional material with many unique properties, such as great biocompatibility, excellent surface activity, high carrier mobility, and tunable bandgap. Black phosphorus has been particularly attractive in sensor. However, black phosphorus isolated by traditional methods is easily oxidized and degraded by air, with poor stability, which limits its application as sensors. The modification and functionalization of black phosphorus enhance the stability, sensitivity, selectivity and biocompatibility of its application in sensor. This review describes recent progresses in sensor based on black phosphorus (2016–2020). Firstly, the structure and properties, synthesis methods, modification and functionalization of black phosphorus are briefly described. Then, the advancements in designing of various sensors based on black phosphorus are systematically provided, with a specific focus on electrochemical sensors, electrochemiluminescence sensors and photoelectrochemical sensors. Finally, latest challenges and further opportunities for developing new sensors with black phosphorus nanomaterial are discussed.
With the increasing penetration of renewable energy in power systems, fluctuation of renewable energy power plants has great influence on stability of the system, and renewable power curtailment is also becoming more and more serious due to the insufficient consumptive ability of local power grid. In order to maximize the utilization of renewable energy, this paper focuses on the generation scheduling optimization for a wind-solar-thermal hybrid system considering that the produced energy will be transmitted over a long distance to satisfy the demands of the receiving end system through ultra-high voltage (UHV) transmission lines. Accordingly, a bilevel optimization based on a non-cooperative game method is proposed to maximize the profit of power plants in the hybrid system. Users in the receiving end system are at the lower level of the bilevel programming, and power plants in the transmitting end system are at the upper level. Competitive behavior among power plants is formulated as a non-cooperative game and the profit of power plant is scheduled by adjusting generation and bidding strategies in both day-ahead markets and intraday markets. In addition, generation cost, wheeling cost, and carbon emissions are all considered in the non-cooperative game model. Moreover, a distributed algorithm is presented to obtain the generalized Nash equilibrium solution, which realizes the optimization in terms of maximizing profit. Finally, several simulations are implemented and analyzed to verify the effectiveness of the proposed optimization method.
We evaluated the role of syntrophic acetate oxidation coupled with hydrogenotrophic methanogens in three different methanogenic consortia.Three methanogenic hexadecane degrading consortia named Y15, M82 and SK were taken from the same oily sludge of Shengli oil-field and enriched. They were incubated at 15, 35 and 55 °C, respectively. The consortia amended with acetate and inhibitors of NH4Cl or CH3F were further transferred and incubated at corresponding temperatures. The cultures atlate logarithmic phase were collected for terminal restriction fragment length polymorphism (T-RFLP) combined with cloning and phylogenetic analysis of 16S rRNA gene fragments.Gas chromatograph analysis showed that all of the consortia could grow and produce methane, but the lag phase was delayed and the growth rate was retarded in the cultures amended with inhibitor. Combination analysis of T-RFLP and clone library revealed the predominance of obligate aceticlastic Methanosaeta in the acetate cultures of Y15, M82 and SK. Under the mesophilic and thermophilic conditions, after add inginhibitor the relative abundance of aceticlastic methanogen decreased but hydrogenotrophic methanogen increased.Syntrophic acetate oxidation during methanogenic degradation of petroleum hydrocarbons occurs under mesophilic and thermophilic conditions, although the situation at low temperature seems uncertain.
To investigate the effects of straw residues with reduced nitrogen (N) fertilizer on greenhouse gas (GHG) and N losses in paddy fields, we conducted a field experiment during two growing seasons in paddy rice systems in southern China to evaluate the impacts of the application of straw residues with reduced N fertilizer on rice yield, GHG emissions, and ammonia (NH3) volatilization. The four treatments included N100 (conventional dose of N fertilizer), SN100 (conventional dose of N fertilizer + straw), N60 (60% of the conventional dose of N fertilizer), and SN60 (60% of the conventional dose of N fertilizer + straw). We found that the yield of the SN60 treatment was slightly reduced, but the partial factor productivity of applied N (PFPN) was significantly increased by 63.9% compared to the N100 treatment. At the same N application rate, the application of straw increased soil organic C (SOC), methane (CH4) emissions, carbon dioxide (CO2) emissions, global warming potential (GWP), greenhouse gas intensity (GHGI), and net ecosystem carbon budget (NECB), but significantly decreased soil N2O emissions and NH3 volatilization. Compared with conventional fertilization (N100), straw residues with reduced N fertilization (SN60) reduced N2O emissions and NH3 volatilization by 42.1% and 23.9%, and increased GHGI and NECB by 11.1% and 18.3%, respectively. The results indicate that straw residues with reduced N fertilizer are a feasible strategy to reduce N losses in paddy fields while increasing carbon sequestration.
In order to study the operation of planetary gear transmission, the article takes the two-stage planetary gear transmission system as the research object to determine the correct meshing parameters between the sun gear, planetary gears and internal gears. With the help of a plug-in in SolidWorks, a three-dimensional planetary gear is carried out. Modeling and virtual assembly, using ANSYS Workbench to simulate and analyze the planetary gear transmission. Through the direct integration method of transient dynamics, the equivalent stress, equivalent strain, and equivalent deformation of the planetary gear tooth meshing are obtained, which can provide reference for the future planetary gear transmission design and simulation analysis.
