Profile Control Research Articles

Evaluation of controllers for augmentative hip exoskeletons and their effects on metabolic cost of walking: explicit versus implicit synchronization.

Background: Efficient gait assistance by augmentative exoskeletons depends on reliable control strategies. While numerous control methods and their effects on the metabolic cost of walking have been explored in the literature, the use of different exoskeletons and dissimilar protocols limit direct comparisons. In this article, we present and compare two controllers for hip exoskeletons with different synchronization paradigms. Methods: The implicit-synchronization-based approach, termed the Simple Reflex Controller (SRC), determines the assistance as a function of the relative loading of the feet, resulting in an emerging torque profile continuously assisting extension during stance and flexion during swing. On the other hand, the Hip-Phase-based Torque profile controller (HPT) uses explicit synchronization and estimates the gait cycle percentage based on the hip angle, applying a predefined torque profile consisting of two shorter bursts of assistance during stance and swing. We tested the controllers with 23 naïve healthy participants walking on a treadmill at 4km ⋅ h-1, without any substantial familiarization. Results: Both controllers significantly reduced the metabolic rate compared to walking with the exoskeleton in passive mode, by 18.0% (SRC, p < 0.001) and 11.6% (HPT, p < 0.001). However, only the SRC led to a significant reduction compared to walking without the exoskeleton (8.8%, p = 0.004). The SRC also provided more mechanical power and led to bigger changes in the hip joint kinematics and walking cadence. Our analysis of mechanical powers based on a whole-body analysis suggested a reduce in ankle push-off under this controller. There was a strong correlation (Pearson's r = 0.778, p < 0.001) between the metabolic savings achieved by each participant with the two controllers. Conclusion: The extended assistance duration provided by the implicitly synchronized SRC enabled greater metabolic reductions compared to the more targeted assistance of the explicitly synchronized HPT. Despite the different assistance profiles and metabolic outcomes, the correlation between the metabolic reductions with the two controllers suggests a difference in individual responsiveness to assistance, prompting more investigations to explore the person-specific factors affecting assistance receptivity.

Dimensionless correlations of indoor thermal stratification in a non-enclosed large-space building under heating and cooling conditions

Indoor thermal stratification is a prevailing phenomenon in large-space buildings, which poses great pressure on their energy consumption and indoor built environment. This paper revealed the mechanism of indoor thermal stratification in a non-enclosed large-space building under heating and cooling conditions. It can be abstracted as a joint effect of the cold and hot air inflow (i.e., HVAC system and outdoor air infiltration), which are respectively depicted by two newly-defined Archimedes numbers (i.e., Arc and Arh). Then, we developed dimensionless correlations between the indoor thermal stratification (quantified by the dimensionless factor of the vertical temperature profile, CT) and the two streams of air inflow (quantified by Arc and Arh). For application, the dimensionless correlations can be coupled with our previously proposed theoretical model to accurately predict the air infiltration rate in a large-space building. Moreover, the dimensionless analysis reveals a principle of indoor vertical temperature profile control to minimize the buoyancy driving force of air infiltration in large-space buildings: Achieving a vertically uniform indoor thermal environment under heating condition and an effectively stratified indoor thermal environment under cooling condition. These findings help to provide practical guidelines to minimize buoyancy-driven air infiltration in large-space buildings.

A Review of Recent Progresses on Olive Oil Chemical Profiling, Extraction Technology, Shelf-life, and Quality Control.

Olive oil (OO) is widely recognized as a main component in the Mediterranean diet owing to its unique chemical composition and associated health-promoting properties. This review aimed at providing readers with recent results on OO physicochemical profiling, extraction technology, and quality parameters specified by regulations to ensure authentic products for consumers. Recent research progress on OO adulteration were outlined through a bibliometric analysis mapping using Vosviewer software. As revealed by bibliometric analysis, richness in terms of fatty acids, pigments, polar phenolic compounds, tocopherols, squalene, sterols, and triterpenic compounds justify OO health-promoting properties and increasing demand on its global consumption. OO storage is a critical post-processing operation that must be optimized to avoid oxidation. Owing to its great commercial value on markets, OO is a target to adulteration with other vegetable oils. In this context, different chemometric tools were developed to deal with this problem. To conclude, increasing demand and consumption of OO on the global market is justified by its unique composition. Challenges such as oxidation and adulteration stand out as the main issues affecting the OO market.

Advances in high-pressure laser floating zone growth: The Laser Optical Kristallmacher II (LOKII).

The optical floating zone crystal growth technique is a well-established method for obtaining large, high-purity single crystals. While the floating zone method has been constantly evolving for over six decades, the development of high-pressure (up to 1000bar) growth systems has only recently been realized via the combination of laser-based heating sources with an all-metal chamber. While our inaugural high-pressure laser floating zone furnace design demonstrated the successful growth of new volatile and metastable phases, the furnace design faces several limitations with imaging quality, heating profile control, and chamber cooling power. Here, we present a second-generation design of the high-pressure laser floating zone furnace, "Laser Optical Kristallmacher II" (LOKII), and demonstrate that this redesign facilitates new advances in crystal growth by highlighting several exemplar materials: α-Fe2O3, β-Ga2O3, and La2CuO4+δ. Notably, for La2CuO4+δ, we demonstrate the feasibility and long-term stability of traveling solvent floating zone growth under a record pressure of 700bar.

Micro and Macro Flooding Mechanism and Law of a Gel Particle System in Strong Heterogeneous Reservoirs.

To address the issue of ineffective injection resulting from the consistent channeling of injected water through highly permeable channels in ultra-deep, high-temperature, high-salinity, and strongly heterogeneous reservoirs during the production process, a gel particle profile control agent suitable for high-temperature and high-salinity conditions was chosen. With the help of the glass etching visual microscopic model and the heterogeneous long core model, the formation mechanism of a water flooding channeling path and the distribution law of the remaining oil were explored, the microscopic profile control mechanism of the different parameters was clarified, and the profile control effect of macroscopic core displacement was analyzed. The research shows that the formation mechanism of a water flooding channeling path is dominated by the distribution law of the permeability section and the connection mode between different penetration zones. The remaining oil types after water flooding are mainly contiguous block, parallel throats, and multi-branch clusters. The profile control effect of gel particles on reservoir vertical heterogeneity is better than that of reservoir lateral heterogeneity. It was found that 10 wt% submicron particles with a median diameter of 600 nm play a good role in profiling and plugging pores of 5-20 μm. In addition, 10 wt% micron-sized particles with a median diameter of 2.63 μm mainly play a strong plugging role in the pores of 20-30 μm, and 5 wt% micron-sized particles with a median diameter of 2.63 μm mainly form a weak plugging effect on the pores of 10-20 μm. The overall profile control effect of 10 wt% submicro particles is the best, and changes in concentration parameters have a more significant effect on the profile control effect. In the macroscopic core profile control, enhanced oil recovery (EOR) can reach 16%, and the gel particles show plugging, deformation migration, and re-plugging. The research results provide theoretical guidance for tapping the potential of the remaining oil in strong heterogeneous reservoirs. To date, the gel particles have been applied in the Tahe oilfield and have produced an obvious profile control effect; the oil production has risen to the highest value of 26.4 t/d, and the comprehensive water content has fallen to the lowest percentage of 32.1%.

Online Partition-Cooling System of Hot-Rolled Electrical Steel for Thermal Roll Profile and Its Industrial Application

The shape and convexity are crucial quality assessment indicators for hot-rolled electrical steel strips. Besides bending rolls, shifting rolls, and the original roll profile, the thermal roll profile also plays a significant role in controlling the shape and convexity during the hot-rolling process. However, it is always overlooked due to its dynamic uncertainty. To solve this problem, it is necessary to achieve online cooling-status control for the local thermal expansion of rolls. Based on the existing structure of a mill, a pair of special partition-cooling beams with an intelligent cooling system was designed. For high efficiency and practicality, a new online predictive model was established for the dynamic temperature field of the hot-rolling process. An equivalent treatment was applied to the boundary condition corresponding to the practical cooling water flow. In addition, by establishing the corresponding target distribution curve for the partitioned water flow cooling, online water-flow-partitioning control of the thermal roll profile was achieved. In the practical application process, a large number of onsite results exhibited that the predicted error was within 5% compared to the experimental results. The temperature difference between the upper and lower rolls was within 5 °C, and the temperature difference on both sides of the rolls was controlled within 0.7 °C. The hit rate of convexity (C40) increased by 33%. It was demonstrated that the partition-cooling processes of hot rolling are effective for the local shape and special convexity. They are able to serve as a better control method in the hot-rolling process.

Migration characteristics and plugging rules of self-aggregating nanoparticles in the porous media

Nanoparticle profile control agents have been widely used for water shut-off treatment due to their excellent properties. However, the contradiction between the injectability and the plugging characteristics of profile control agents seriously affects their sealing effect. Self-aggregating nanoparticles can effectively alleviate this contradiction by forming particle clusters in the formation to block water channels. In this study, the injection and plugging properties of self-aggregating nanoparticle profile control agents in porous media were investigated using visual porous media etching model and core model. Injectivity experiments showed that the flow of nanoparticles in porous media was divided into three phases: flow dispersion phase, self-aggregation migration phase, and aggregation plugging state. They could aggregate to form clusters similar to the pore throat size after 60 min. Core displacement experiments showed that the plugging performance of nanoparticles was influenced by solution concentration, injection volume, injection rate, and core permeability. When injecting a 3000 mg/L nanoparticle solution into the core at 60 °C, the residual resistance coefficient was larger than 1.83. The retention rate in pore throats was superior to 60%.

Evaluation of Profile Control and Oil Displacement Effect of Starch Gel and Nano-MoS2 Combination System in High-Temperature Heterogeneous Reservoir.

The Henan Oilfield's medium-permeability blocks face challenges such as high temperatures and severe heterogeneity, making conventional flooding systems less effective. The starch gel system is an efficient approach for deep profile control in high-temperature reservoirs, while the nano-MoS2 system is a promising enhanced oil recovery (EOR) technology for high-temperature low-permeability reservoirs. Combining these two may achieve the dual effects of profile control and oil displacement, significantly enhancing oil recovery in high-temperature heterogeneous reservoirs. The basic performance evaluation of the combination system was carried out under reservoir temperature. Displacement experiments were conducted in target blocks under different permeabilities and extreme disparity core flooding to evaluate the combination system's oil displacement effect. Additionally, the displacement effects and mechanisms of the starch gel and nano-MoS2 combination system in heterogeneous reservoirs were evaluated by simulating interlayer and intralayer heterogeneity models. The results show that the single nano-MoS2 system's efficiency decreases with increased core permeability, and its effectiveness is limited in triple and quintuple disparity parallel experiments. After injecting the starch gel-nano-MoS2 combination system, the enhanced oil recovery effect was significant. The interlayer and intralayer heterogeneous models demonstrated that the primary water flooding mainly affected the high-permeability layers, while the starch gel effectively blocked the dominant channels, forcing the nano-MoS2 oil displacement system towards unswept areas. This coordination significantly enhanced oil displacement, with the combination system improving recovery by 15.33 and 12.20 percentage points, respectively. This research indicates that the starch gel and nano-MoS2 combination flooding technique holds promise for enhancing oil recovery in high-temperature heterogeneous reservoirs of Henan Oilfield, providing foundational support for field applications.

Standardisation and Quality Control Parameters of &lt;i&gt;Phalatrikadi Ghana Vati&lt;/i&gt; – An &lt;i&gt;Ayurvedic&lt;/i&gt; Formulation

Drug standardisation, profiling, and quality control continue to be a challenge for Ayurvedic medicines due to their wide range of dosage forms. Different dosage forms like decoctions and powders result in non-compliance from the patient owing to their palatability or cumbersome methods of administration. The present study aims to pharmaceutically process a traditional decoction, Phalatrikadi Kwatha, and standardise it into tablet form, known as Phalatrikadi Ghana Vati (PGV). PGV was prepared and subjected to organoleptic, physicochemical, phytochemical analysis, and HPTLC analysis in an attempt to define its quality parameters and standardisation. Distinct fingerprints of Phalatrikadi Ghana Vati were obtained. Out of the eight components identified, the components with Rf values 0.08, 0.74, 0.65 and 0.83 were more predominant with more percent areas 9.65%, 14.91%, 18.02%, and 40.67%, respectively Quantitative physicochemical analysis revealed loss on drying as 1.33%, ash value as 4.53%, water-soluble extractive as 15.38%, alcohol extractive as 9.63% and pH as 5.1. The study also revealed the presence of alkaloids, glycosides, flavonoids, amino acids, and saponins. Preliminary profiling of PGV exhibited striking analytical characteristics. The physicochemical parameters were in the range of a standard tablet. The quantitative physicochemical parameters and HPTLC profile can be used as a reference standard for the quality control of Phalatrikadi Ghan Vati.

Study on the Structure-Activity Relationship and Oil Displacement Characteristics of the Polysurfactant Agent.

This study examines a versatile polymer known as polysurfactant, which is synthesized by co-polymerizing flexible acrylamide and sodium acrylate hydrocarbon chain. The polymer serves as a backbone and possesses active functional groups. Notably, the polysurfactant exhibits superior plugging and flooding abilities compared to conventional polymers. The primary objective of this paper is to investigate the properties and oil displacement characteristics of the polysurfactant through indoor physical simulation experiments. The results demonstrate that the multi-branched structure of the polysurfactant enhances its ability to associate, leading to the formation of a unique spatial network structure. The inclusion of multi-branched structures notably amplifies the association effect. The critical concentration for the association is estimated to be around 800 mg/L, at which juncture the polysurfactant exhibits a viscosity retention rate surpassing 90% subsequent to shearing. Furthermore, this spatial network structure exhibits self-recovery capabilities after experiencing shear failure and displaying strong viscosity and shear resistance. In addition, the concentration of the polysurfactant can control the hydrodynamic feature size, which shows its adaptability in regulation and oil-repelling functions at reservoir permeabilities ranging from 500 to 2000 × 10-3 μm2 with resistance coefficients ranging from 108 to 320. During the microscopic oil displacement process, the polysurfactant exerts a significant impact on mobility control, while the elastic pull clearly demonstrates a commendable viscoelastic oil displacement effect. The polysurfactant exhibits a specific degree of emulsification capability towards crude oil, leading to the emulsion exhibiting typical pseudoplastic fluid characteristics. The utilization of emulsification transportation and emulsification blockage contributes to the enhancement of oil recovery. As a result, the polysurfactant exhibits multifaceted capabilities, encompassing profile control, flooding, and plugging, owing to its unique structural characteristics. Through the implementation of a field test focused on flooding in the Daqing Oilfield, a significant enhancement in the recovery rate of 10.85% is observed, accompanied by a favorable input-output ratio of 1:3.86, thereby generating significant economic advantages.

Exact Boundary Controllability of Nodal Profile for Nonautonomous Quasilinear Hyperbolic Systems

Exact Boundary Controllability of Nodal Profile for Nonautonomous Quasilinear Hyperbolic Systems

Exact boundary controllability of nodal profile for the system of one-dimensional adiabatic flow

In this paper, we study the exact boundary controllability of nodal profile for the system of one-dimensional adiabatic flow by means of the specificity of the entropy S which is constant about the time t. By a constructive method, we realize the exact boundary controllability of nodal profile by controlling the velocity or the pressure on the side without the nodal profile. Moreover, for the case of the infinite time interval, under the suitable assumption, we can obtain that if the nodal profile and the given boundary function possess an exponential or polynomial decaying property, the boundary control possesses the same exponential or polynomial decaying property.

Research on the control strategy of coning amount and ASU adjustment considering profile and high-order flatness cooperative control

ABSTRACT In the production of a 20-high mill, high-order flatness defects occur frequently. To achieve collaborative control of the profile and high-order flatness of a 20-high mill, an integrated coupling model of the roll system and strip has been established based on ABAQUS software. It has been found that as the coning amount of the intermediate taper roll increased, the profile evaluation index C25 decreased, while the work roll axis exhibited high-order deflection deformation, which could lead to the generation of high-order flatness defects. Subsequently, a novel control strategy of the coning amount and backup roll segmented reduction (ASU) control adjustment has been proposed to ensure that the profile evaluation index C25 meets the requirements while eliminating the risk of high-order flatness defects caused by roll shifting (coning amount) control. The specific combination form of the control strategy has been determined by using the particle swarm optimisation (PSO) algorithm. The Industrial application results show that the maximum compressive stress in the area 75 mm-300 mm away from the edge can be reduced by more than 40% after using the novel control strategy.

Study on the channeling limit of polymer flooding in the conglomerate reservoir

The conglomerate reservoirs are known for their high degree of heterogeneity, which poses a challenge during polymer injection. Fluids tend to channel along dominant paths leading to premature appearance of polymer in the oil well. This phenomenon results in a rapid increase in water cut, leading to wastage of the polymer. Currently, there is no reliable method for identifying polymer channeling in such conglomerate reservoirs. To address this issue, this paper conducts physical simulation experiments on parallel cores under varying heterogeneous conditions based on the geological characteristics of the reservoir. The study analyzed and statistically evaluated the distribution ratio, water cut, and polymer concentration in the output under varying heterogeneous conditions. This analysis identified the distribution ratio and polymer concentration as key indicators of polymer channeling. Based on these findings, a comprehensive discriminant diagram of polymer channeling was established. The study found that the coefficient of permeability variation (CV) was the primary factor contributing to channeling. This diagram can be used to understand the underlying principles of polymer channeling and provide technical guidance for developing effective profile control schemes and optimizing site construction strategies.

Functional Gels and Chemicals Used in Oil and Gas Drilling Engineering: A Status and Prospective.

Research into functional gels and chemicals and their applications represents a cutting-edge international field of study. For example, investigating how they can be applied in oil and gas drilling (and extraction engineering) and developing novel functional chemical materials for the oil field could provide innovative solutions and technological methods for oil and gas drilling and extraction operations. Through a literature analysis, this paper presents a review of the current research status and application scenarios of different types of functional gels and chemicals, both domestically and internationally. The classification and preparation principles of various functional materials are systematically outlined and the current applications of functional gels and chemicals in oil and gas drilling and extraction engineering are introduced. These applications include drilling and plugging, enhanced oil recovery, water plugging, and profile control. The formation mechanisms and application scenarios of different types of gels and chemicals are also analyzed and summarized, with a discussion of their prospects in oil and gas drilling and extraction engineering. We broaden the scope of functional gels and chemicals by exploring new application fields and promoting the development of different types of gels and chemicals in a more intelligent direction.

Effects and safety of Ginkgo biloba on blood metabolism in type 2 diabetes mellitus: a systematic review and meta-analysis.

There has existed controversy regarding the use of Ginkgo biloba (GKB) for blood metabolism among type 2 diabetes mellitus(T2DM) patients, and we tried to analyze the effects and safety of GKB on T2DM patients. We conducted a literature search between January 2003 and December 2022 of seven online databases (PubMed, Scopus, Embase, Google Scholar, Web of Sciences, Cochrane Library, and China National Knowledge Infrastructure). A systematic literature review and meta-analysis were performed to compare the effects and safety of GKB among T2DM patients. Four groups of parameters were extracted and analyzed: hemorheology parameters, lipid profile, glycemic control markers, and adverse events. In the end, 13 eligible articles with 11 indicators among 1573 patients were included. In the hemorheology parameters section, GKB showed significantly lower plasma viscosity (PV) (SMD=-0.91, 95%CI [-1.45, -0.36], P<0.01) and hematocrit (Hct) (SMD=-0.60, 95%CI [-0.97, -0.24], P<0.01) than the control group. GKB shoed higher velocity of the dorsalis pedis artery (VDPA) (SMD=0.51, 95%CI [0.26, 0.76], P<0.01) and ankle brachial index (ABI) (SMD=0.71, 95%CI [0.32, 1.10], P<0.01) than the control. In both the lipid profile and glycemic control markers sections, we did not find any difference between GKB and control groups, including total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), hemoglobin A1c (HbA1c), and fasting serum glucose (FSG). In addition, we saw no difference in adverse events (AE). The sensitivity analysis and funnel plot showed that the results in this research were robust and had no publication bias. In conclusion, GKB might safely reduce the risk of peripheral arterial or even systemic cardiovascular disease. However, GKB did not directly improve lipid and blood glucose levels in T2DM patients. https://inplasy.com/, identifier INPLASY202350096.

Numerical Simulation Study on In‐Depth Profile Control of Core–Shell Coagulation System Considering the Time‐Variation of Permeability

The coring data in high water‐cut oilfields indicates that the reservoir permeability will change continuously with water flooding, while the existing reservoir numerical simulation software cannot consider the time‐varying phenomenon of permeability. With the enhancement of reservoir heterogeneity, the near‐wellbore profile control fails to stabilize the oil production and control the water cut. The in‐depth profile control has been widely used in oilfields as a new technology, and the types of profile control agents are diverse, with a complex mechanism that cannot be effectively described by the existing conventional numerical simulation software. Considering these two phenomena comprehensively, a new three‐dimensional, three‐phase, six‐component mathematical model that can take into account the time‐varying phenomenon of reservoir permeability is proposed for a new kind of in‐depth profile control system, namely, the core–shell coagulation system, and an integrated numerical simulation software is developed. The mechanism of the in‐depth profile control system can be perfectly demonstrated in the simulator with time‐variation of permeability. The results of sensitivity analysis show that the effect is influenced by three factors: the mix slug injecting concentration, the coagulant aid slug volume, and the concentration of the suspension dispersing agent.

Dorsomedial Ventromedial Hypothalamic Nucleus Growth Hormone-Releasing Hormone Neuron Steroidogenic Factor-1 Gene Targets in Female Rat.

The prospect that the ventromedial hypothalamic nucleus (VMN) transcription factor steroidogenic factor-1/NR5A1 (SF-1) may exert sex-dimorphic control of glucose counterregulation is unresolved. Recent studies in male rats show that SF-1 regulates transcription of co-expressed hypoglycemia-sensitive neurochemicals in dorsomedial VMN growth hormone-releasing hormone (Ghrh) neurons. Gene knockdown and laser-catapult-microdissection/single-cell multiplex qPCR techniques were used here in a female rat model to determine if SF-1 control of Ghrh neuron transmitter marker, energy sensor, and estrogen receptor (ER) variant mRNAs varies according to sex. Data show that in females, hypoglycemia elicits a gain of SF-1 inhibitory control of VMNdm Ghrh neuron Ghrh and Ghrh-receptor gene profiles and loss of augmentation of glutaminase transcription; SF-1 gene silencing diminished eu- and hypoglycemic patterns of neuronal nitric oxide gene transcription. SF-1 imposes divergent control of baseline and hypoglycemic glutamate decarboxylase65 (GAD)-1 (stimulatory) versus GAD2 (inhibitory) mRNAs in that sex. SF-1 stimulates baseline VMNdm Ghrh neuron PRKAA1/AMPKα1 and PRKAA2/AMPKα2 gene expression, yet causes opposite changes in these gene profiles during hypoglycemia. SF-1 exerts glucose-dependent control of ER-alpha and G-protein-coupled ER-1 transcription, but blunts ER-beta gene profiles during eu- and hypoglycemia. In females, SF-1 knockdown did not affect hypercorticosteronemia or hyperglucagonemia, but blunted hypoglycemic suppression of growth hormone secretion. Results show that SF-1 expression is critical for female rat VMNdm Ghrh neuron counterregulatory neurochemical, AMPK catalytic subunit, and ER gene transcription responses to hypoglycemia. Sex differences in direction of SF-1 control of distinctive gene profiles may result in observed disparities in SF-1 regulation of counterregulatory hormone secretion between sexes.

Preparation of polymer microspheres as oil displacement agent for extra-high temperature and extra-high salinity reservoirs

Based on the difficult problem that conventional polymer and gel can't be used for enhancing oil recovery in extra-high temperature (200 °C) and extra-high salinity (2 ×105 mg/L) reservoirs，an anti-temperature anti-salinity microspheres was prepared with 2,2′-bis[4-(4-aminophenoxy)phenyl] propane (BAPP), 3, 3′, 4, 4′-diphenyl ether dianhydride (ODPA) and phthalic anhydride (PA) as the monomers. The FTIR results showed that the temperature- and salt-resistant polyimide (PI) microspheres were prepared as target product. TGA showed that thermal decomposition of the unaged and aged PI-2 microspheres occurred over 281 °C and 252 °C, respectively; These values greatly exceed those of commercial HPAM, weak gel particles and pre-crosslinked gel particles. After the polyimide microspheres were aged for 120 d, the enhanced oil recovery of the PI-2 microspheres does not decrease significantly, so the long-term stability of two polyimide microspheres are very good at 200 °C and total dissolved solids (TDS) = 2 × 105 mg/L. The PI-2 microspheres had better properties than the conventional polymer and gel as profile control agent and water plugging agent. The microspheres possess the characteristics of being able to inject, block, and move, resulting in excellent oil displacement efficiency. The results of core displacement experiments revealed that PI-2 microspheres are highly efficient in oil displacement and have a strong ability to improve the water injection profile. Therefore, PI-2 microspheres can be used as an oil displacement agent in reservoirs with extremely high temperature and salt content.

Current status and prospects of burning plasma physics in magnetically confined fusion

Current status and challenges of key physics related to high-confinement operational scenarios and energetic particle confinement are briefly reviewed from the perspective of design and operation of tokamak-based fusion reactors. In the past few decades, significant progress has been made in the research on high-confinement mode physics, i.e. the main stability and confinement constraints on operational window of a fusion reactor have been identified, and some control methods for adjusting plasma kinetic profiles to optimize performance have been developed. Several operational scenarios, including inductive, hybrid and steady-state &lt;i&gt;etc&lt;/i&gt;, which are potentially applicable for future reactors, have been developed. In the conditions that fusion alpha particle self-heating is predominant and shear Alfvén wave (SAW) instabilities potentially dominate fusion alpha particle transport, the SAW linear stability properties and excitation mechanisms are understood in depth, and the SAW instabilities nonlinear saturation, alpha particle confinement, and the influence of the heating deposition and the micro-turbulence regulation on fusion profile are under extensive investigation. The magnetically confined fusion research has entered a new stage of ignition and burning plasma physics, and new challenges that are faced are addressed, including whether efficient self-heating of plasmas by fusion alpha particles can be achieved, how the plasma stability and high-confinement can be maintained through the active control of key plasma profiles under the condition of dominant alpha particle heating, and whether it is possible to establish accurate models to predict long time scale complex dynamical evolution of fusion plasmas &lt;i&gt;etc&lt;/i&gt;. Solving these key problems will lay a solid scientific foundation for designing and operating future fusion reactors as well as promote the development of plasma science.