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Methotrexate (MTX), a widely used chemotherapeutic drug, is critical for achieving long-term complete remission in contemporary maintenance therapy of acute lymphoblastic leukemia (ALL). MTX is intracellularly converted into methotrexate polyglutamates (MTXPGn) by folylpolyglutamate synthase after transporting into the cells. The intracellular levels of active MTXPGn regulate the clinical efficacy and drug-related side effects, but it is still challenged by large inter-individual differences and narrow therapeutic index. Therefore, it is of great significance to develop a sensitive and stable method to monitor MTXPGs concentrations in the erythrocyte. To facilitate clinical application, an ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed for the quantification of MTX and MTXPGn in erythrocyte. Solid phase extraction was applied to sample clean-up followed by a gradient chromatographic separation. The elution consisting of methanol/water/2 mM ammonium acetate (flow rate: 0.4 mL/min). Linearity of the assay was assured in the range of 1-500 nM (R2 > 0.99). The co-efficient of variation ranged from 2–11% for intraday precision and 0.4–8% for inter day precision. Recovery ranged from 62.51–99.75%, and the matrix-effect varied from 63.24–96.33%. Blood samples from 89 pediatric ALL patients were detected. The concentrations and distribution of MTXPGn in these samples were basically consistent with the current literatures, which confirmed that the optimized method for quantitative detection of MTXPGn in red blood cells had high sensitivity and accuracy. The sensitive method has been fully validated and successfully applied to determine the erythrocyte MTXPGn in pediatric ALL patients during continuation therapy.

Understanding the transport behavior of a gel system in porous media is of great significance in enhancing oil recovery (EOR) for high water cut oil reservoirs. However, the length of the experiment models (sandpack or core sample) in current studies is usually in the range of centimeter scale, which is too short to track the full movement path of gel particles. In this work, 10-m long slim sandpacks were adopted to conduct gel flooding experiments. The pressure and polymer concentration distribution along the sandpack was tracked, and scanning electron microscope (SEM) technique was employed to observe the pore morphology after the gel flooding. The results show that the movement of polymer particles is usually within 7 m away from the inlet due to the adsorption and retention in the porous medium. For 0.4 PV injection cases, SEM images show that the pore morphology at the inlet region exhibits a stable polymer network, while the network structure disappears at the outlet, along with the decrease of fluid viscosity from 620.1 mPa·s to 1.2 mPa·s. However, we can still find the stringy state polymer after 5 m movement and the viscosity is 584.0 mPa·s for 1 PV gel injection cases. Four characterization parameters, including equivalent viscosity, breakthrough pressure gradient, dimensionless gelation gradient, and plugging ratio, were proposed to quantitatively characterize the performance of gel flooding. In addition, empirical models were also obtained to predict the four parameters through multi-parameters fitting, and these models facilitate the characterization of the gel flooding performance. This is the first work, to the best of the authors’ knowledge, using long slim sandpack (10 m) to experimentally study gel system transport in porous media, which provides theoretical implications in enhancing oil recovery.

A multi-well production enhanced geothermal system (EGS) with discrete fracture network is designed for heat extraction in this study. A thermal-hydraulic numerical simulation model is established,...

Under the targets of peaking CO2 emissions and carbon neutrality in China, it is a matter of urgency to reduce the CO2 emissions of road transport. To explore the CO2 emission reduction potential of road transport, this study proposes eight policy scenarios: the business-as-usual (BAU), clean electricity (CE), fuel economy improvement (FEI), shared autonomous vehicles (SAV), CO2 emission trading (CET) (with low, medium, and high carbon prices), and comprehensive (CS) scenarios. The road transport CO2 emissions from 2020 to 2060 in these scenarios are calculated based on the bottom-up method and are evaluated in the Low Emissions Analysis Platform (LEAP). The Log-Mean Divisia Index (LMDI) method is employed to analyze the contribution of each factor to road transport CO2 emission reduction in each scenario. The results show that CO2 emissions of road transport will peak at 1419.5 million tonnes in 2033 under the BAU scenario. In contrast, the peaks of road transport CO2 emissions in the CE, SAV, FEI, CET-LCP, CET-MCP, CET-HCP, and CS scenarios are decreasing and occur progressively earlier. Under the CS scenario with the greatest CO2 emission reduction potential, CO2 emissions of road transport will peak at 1200.37 million tonnes in 2023 and decrease to 217.73 million tonnes by 2060. Fuel structure and fuel economy contribute most to the emission reduction in all scenarios. This study provides possible pathways toward low-carbon road transport for the goal of carbon neutrality in China.

This study proposed a multi-well injection enhanced geothermal system (EGS) model for fracture-mode hot dry rock (HDR) heat extraction, which is capable of injecting sufficient mass flow and providing more fluid flow channels for fully heat mining. A thermal-hydraulic model was established and the variation of temperature and pressure distributions, conductive and convective heat fluxes in fracture-mode HDR reservoir were studied. Meanwhile, the sensitivity analysis of operation parameters and fracture parameters was conducted. The results indicated that multi-well injection system can obtain a high heat extraction ratio after 30 years in fracture-mode reservoir. The conduction process is much weaker than the convection process in HDR reservoir, convective heat transfer plays a leading role in the entire heat transfer process. Both the injection temperature and injection mass flow rate are the key parameters affecting the heat extraction performance under the simulation condition. When the injection temperature increased from 283.15 K to 293.15 K, the heat extraction ratio after 30 years decreased from 77.7 % to 71.8 %. When the injection mass flow rate increased from 80 kg/s to 160 kg/s, the heat extraction ratio after 30 years increased from 57.6 % to 84.7 %. The appropriate injection temperature and mass flow rate selection should be based on the specific reservoir conditions and production needs. The production pressure and fracture permeability mainly have effect on the variation of injection pressure, reasonable choice of these parameters is conducive to cost savings. The fracture aperture has little effect on the heat extraction performance. This study provides some reasonable suggestions on better heat extraction performance in multi-well injection EGS and has guidance effect for practical projects.

The Australian wildfires in 2019–2020 have brought suffering to the Australian people. It is essential to use models to help the Victorian government monitor and predict the occurrence and development of fires to the greatest extent possible under the principles of safety and economy to facilitate rapid response. Through the idea of K -means algorithm and greedy algorithm, we, respectively, analyzed cities and rural areas at different altitudes and combined the altitude with the obtained clusters; the analysis from the established model shows that, for cities, cluster areas with smaller clusters with an altitude of less than 1600 meters and areas with smaller clusters with an altitude of greater than or equal to 1800 meters are covered by an EOC; for areas with larger clusters less than or equal to 600 meters above the sea level and areas with larger clusters greater than or equal to 1000 meters above the sea level, we use two EOCs for coverage; for rural areas, all areas with smaller clusters are covered by one EOC, while for areas with larger clusters where the altitude is less than or equal to 1000 meters and the altitude is greater than or equal to 1600 meters, we use two EOCs for coverage; also, obtained through greedy algorithm analysis, one EOC corresponds to 14 SSA UAVs and 8 repeater UAVs, and two EOCs correspond to 12 repeater UAVs and 26 SSA UAVs. We have a reason to believe that, through our mathematical model and the leaps in drone technology, it will have a long-term and profound impact on Australia’s wildfire control.

Based on the fractal and bifurcation theory, a leaf-like bifurcated fracture network is introduced in the multi-well injection enhanced geothermal system (EGS) which could depict the heterogeneity of fractures. A thermal-hydraulic model is established to investigate the space-temporal evolution of temperature and pressure field, effects of leaf-like bifurcated fracture networks characteristic on heat extraction performance. The results show that fractures are the key channel for heat extraction of working fluid, investigating the fracture properties on heat extraction performance is necessary. For the leaf-like bifurcated fracture network EGS, a higher fracture bifurcation level and bifurcation length ratio is beneficial to obtain a better heat extraction performance because of the higher fracture uniformity. The fracture angle also has a positive effect on heat extraction, while its effect is weaker than bifurcation level and length ratio. The fracture aperture ratio has little effect on the heat extraction performance. Key findings of this study provide some reasonable suggestions on fracturing operation and production parameters selection of multi-well injection EGS.

Well layout and fracture network in the enhanced geothermal system (EGS) jointly determine the fluid flow path, affecting the fluid flow and heat transfer process. It is necessary to investigate the optimal well layout and fracture parameter to get an efficient EGS. In this paper, the combination of multi-well layout and fracturing technology is conceptualized, a thermal-hydraulic coupling model is established to study the heat extraction performance under various multi-well layout schemes and fracture networks. Results show that the heat extraction ratio of Case 1 is highest, which is the optimal well layout under the research conditions. The fracture aperture is negatively correlated with heat extraction ratio. A higher fracture aperture is more likely to cause a short circuit and thermal breakthrough. The heat extraction ratio increases with the fracture length, while the growth rate decreases with the fracture length. Increasing the fracture number can improve the heat extraction performance to some extent, but excessive fractures can be counterproductive because they aggravate the interference among fractures. Under the research conditions, the preferable fracture aperture, length and number are 0.05 mm, 140 m and 114, respectively. This paper provides some reasonable suggestions for improving heat extraction performance from the perspectives of well layout and fracture network.