Latest ArticlesThe influencing factors on the reservoir development of Upper Taiyuan Formation in the eastern Ordos Basin were investigated. Experimental methods such as casting thin sections, high-pressure mercury intrusion, and constant-rate mercury intrusion were employed to examine the pore structure characteristics of Upper Taiyuan Formation, Tai 2 Member. Results show that the average porosity of Tai 2 Member reservoir is 7.84%, with an average permeability of 0.396 mD, primarily characterized by ultra-low porosity and permeability. The pore structure is complex, with strong heterogeneity. Various types of pores were developed in the reservoir, including intragranular dissolution pores, intergranular dissolution pores, intercrystalline pores, and rock fragment dissolution pores. Based on the frequency of pore development, porosity, and permeability in each region, the pore combinations are classified into three types: intragranular dissolution pores, intragranular dissolution pores combined with intercrystalline pores, and intragranular dissolution pores combined with intergranular dissolution pores. The experimental methods of high-pressure mercury intrusion and constant-rate mercury intrusion could effectively characterize the reservoir characteristics of these three types of pore combinations, among which the combination of intragranular dissolution pores and intercrystalline pores represents a favorable reservoir pore type. Based on the laws of sedimentary differentiation and pore differentiation, a set of criteria for evaluating high-quality reservoirs is established on the basis of experimental results. Upper Taiyuan Formation reservoir was classified into Class Ⅰ, Ⅱ, and Ⅲ from good to poor, and predictions were made for favorable areas of high-quality reservoirs.
In order to study the disaster susceptibility of debris flow in Yongsheng County, the research area was Yongsheng County of Lijiang City, Yunnan Province, and it was divided into 475 sub-watershed units. Grey correlation analysis method was used to calculate the correlation degree of each factor, and the factor with the lowest correlation degree was eliminated. The independence of factors was tested by collinearity diagnosis. In the end, eight factors including average slope, average annual maximum rainfall, average vegetation coverage, average elevation, average melton ratio, average water system density, average landslide core density and average road density were retained. The information volume of the factors was calculated by the information volume method, and the correlation degree value was taken as the weight value of the superposition of each factor. The grey correlation analysis-information volume model was further constructed to carry out the evaluation research on the vulnerability of debris flow in Yongsheng County. The results show this as follows. The requency ratio of debris flow disaster points in the extremely vulnerable area is as high as 4.06, and the area under the ROC (receiver operating characteristic) curve is 0.818, indicating that the selected eight factors and the grey correlation analysation-information volume method have good forecasting ability for the evaluation of debris flow disaster vulnerability. The results can also be used as reference for the prevention and control of debris flow disaster in Yongsheng County.
In order to study the task-based functional connectivity of the whole brain in schizophrenia patients and healthy controls during task switching, the NSP(nested-spectral partition) method was used to quantify the degree of integration and segregation of the whole brain network and explain differential remodeling patterns of brain networks in schizophrenia patients and healthy controls. Results show that changes in whole-brain functional connectivity patterns in schizophrenia are driven by lower network integration and higher segregation, suggesting global and network-wide local information transfer during task switching in schizophrenia patients efficiency was lower than that of healthy controls. Furthermore, the association between task switching costs (reaction time and switching costs) and task state modularity was analyzed using simple linear correlation. Lower whole-brain modularity and lower salience network modularity in schizophrenia were found to be associated with larger switch costs but not with mean reaction times across the task. In contrast, higher cortical network modularity in healthy control patients was associated with faster task reaction times but not with shorter switch costs. Taken together, the results suggest that quantifying functional network configurations across different task states can provide information about cognitive control performance.
Considering the characteristics of poor permeability, mixed particle sizes, and complex pore structures of conglomerates, a study was conducted on the pore structure characteristics and connectivity of the Mahu Urho Formation conglomerates using CT(computed tomography)scanning and 3D reconstruction techniques. By establishing a pore structure extraction method combining conventional threshold segmentation and top-hat algorithm, the challenge of extracting microcracks was overcome. The study reveals that the main types of pores in the Urho Group conglomerates are intergranular pores, dissolved pores, and microfractures, with the 3D pore types are mainly lamellar pore structures and isolated pore structures. Although pores with equivalent radii of conglomerate samples smaller than 30 μm account for a high proportion, their contribution to the total pore volume is relatively low. Pores larger than 60 μm, while fewer in number, occupy over 50% of the total pore volume, serving as the primary storage space. Experimental samples are predominantly characterized by level III connected domains, exhibiting good connectivity conducive to the accumulation and extraction of oil and gas. The investigation into the pore structure characteristics of strongly inhomogeneous conglomerates holds significant theoretical and practical value for an in-depth understanding of such characteristics and for the exploration and development of oil and gas reservoirs in sand conglomerates.
Myocardial ischemia is caused by the incoordination between myocardial oxygen consumption and oxygen delivery in coronary artery disease, and due to its high morbidity and mortality rate, the number of patients who die from ischemic heart disease in China is increasing year by year. In order to verify that the active ingredients of Jinlume have anti-myocardial ischemic efficacy. The maximum tolerated concentration (MTC) was determined to be 15.63 μg/mL by the pre-test, and the high school and low dose groups were divided into 7.81 μg/mL (1/2 MTC), 2.60 μg/mL (1/6 MTC) based on the MTC, respectively, 0.868 μg/mL (1/18 MTC), and the positive drug group was N-acetylcysteine (125 μg/mL). With the help of network pharmacology and molecular docking technology, the possible mechanism of action of the active ingredients of Jinlume in inhibiting cardiomyocyte apoptosis and slowing down myocardial ischemia was investigated. The results showed that the aqueous extract of Jinlume had significant effects against myocardial ischemia in comparison with the positive drug group by means of zebrafish cardiac fluorescence intensity phenotyping, and its mechanism of action was related to five pathways, namely, Rap1 signaling pathway, cancer pathway, proteoglycans in cancer, PI3K-Akt signaling pathway, lipids, and atherosclerosis. It can be seen that exploring the anti-myocardial ischemic mechanism of the active ingredients of Jinlume has certain theoretical significance for the prevention and treatment of myocardial ischemia.
The vibration excitation transmission of the platform should be suppressed while ensuring the safe and reliable operation of equipment. Currently, most research on vibration reduction focuses on individual pedestals or pedestal-platform plate structures, with few studies comprehensively considering the relationship between equipment, pedestal, and platform bottom plate vibrations. ultra-deep water semi-submersible drilling platform equipment’s long base was taken as the research object and impedance analysis and optimization design technology was utilized to control input power flow of the platform bottom plate in key frequency bands. Design variables such as mass and stiffness were optimized to improve base plate thickness while maintaining support strength and stiffness. A coupling vibration control model for “equipment-pedestal-platform” was established, using a particle swarm optimization algorithm with linear weight decline for optimization. Finite element method verification results show that this technical process is feasible, reducing optimized input power flow by 95.43% in low frequencies below 300 Hz and decreasing total response level of vibration acceleration by 18.1 dB.
In order to reasonably evaluate, screen, and optimize the exterior design schemes of suspended monorail train with regional cultural characteristics, an optimization method for exterior design of suspended monorail train based on fuzzy analytic hierarchy process was proposed. Firstly, the characteristics and trends of the exterior design of suspended monorail trains both domestically and internationally were analyzed, and an evaluation index system which focusing on cultural factors for the exterior design of suspended monorail train was constructed. Then, estimate matrix based on experts scores and gained weights of each individual index by calculation was established. Finally, taking the design case of a suspended monorail train with regional cultural characteristics of Guangzhou as an example, the integration of typical regional culture and design idea, as well as the evaluation and optimization of design schemes were explained. The results show that the method can be used to screen and obtain suspension monorail train design schemes with high comprehensive satisfaction in terms of exterior form, painting, and cultural relevance. It can quantitatively evaluate design schemes from multiple dimensions and provide a basis and direction for the screening and iterative optimization of design schemes.
In order to solve the efficiency issues in distributed load responses to frequency regulation commands, an innovative strategy was introduced based on reinforcement learning for load aggregators’ pricing incentives in response to frequency commands. Within this strategy, a game-theoretic model between the load aggregators and load clusters was constructed, and the load aggregators adjust incentive prices based on frequency commands and their pricing strategies, while loads adjust their power consumption based on their own electricity costs to flexibly respond to the frequency commands. The multi-agent soft actor-critic (MASAC) algorithm was used to investigate the solution. The results show that the pricing incentive method enables effective load response to frequency commands, and the use of the MASAC algorithm not only optimizes the decision-making process but also significantly reduces computational complexity, achieving efficient dynamic adjustment. It is concluded that this method provides an effective solution for frequency regulation in power systems, offering significant theoretical significance and practical value.
When the integrated energy system (IES) participates in electricity spot market transactions, the transaction price is uncertain due to changes in market supply and demand. In order to deal with this problem, a detailed analysis of the operating marginal cost of the integrated energy system was used to investigate the optimal dispatch strategy that fully utilizes the flexible resources of the integrated energy system to participate in the market. Firstly, the typical scenarios of market price uncertainty under the external spot market environment were analyzed, and the internal multiple source-load adjustable resources and operation cost structure of the integrated energy system were investigated. Secondly, a trading optimization model considering the marginal cost of the system under the condition of price uncertainty in the electric power market was established, and the sand cat swarm optimization algorithm was proposed to solve the problem. Finally, simulation verification was conducted based on actual cases. The result shows that this strategy can not only reduce the operating cost of IES, but also enhance its adaptability to market price uncertainty. The strategy provides new ideas for the operation of integrated energy systems in the power spot market environment, which is also helpful to realize the double optimization of economy and reliability of energy system participating in the market scheduling.
The Yakela region is located in the northern part of the Tarim Basin. The review of old wells in 2021 shows that the new proven geological reserves of oil in the Paleogene Kumugeliemu Formation in the YK6H block of Yakela are 86.7×104 t, and the structural amplitude of the oil and gas reservoirs that have been discovered so far is low, and it is difficult to identify similar low-amplitude structural traps, and the matching relationship between the accumulation conditions is not clear. In order to find new favorable zones for oil and gas development and strengthen the development of remaining oil reservoirs, based on the high-precision 3D seismic data of the Yakela area and guided by the theory of high-precision sequence stratigraphy, the high-precision stratigraphic division and comparative analysis of the Yakela area were carried out. Through ant body extraction, automatic layer tracking, and variable velocity mapping technology, 105 micro-faults were identified, the identification accuracy of low-amplitude structures was improved, and the distribution of low-amplitude structural traps with a minimum closure height of 2 meters was implemented. Based on the reservoir control factors such as structural location, trap characteristics, sedimentary reservoirs and oil and gas migration channels, the newly implemented low-amplitude structural traps were analyzed and evaluated, and favorable targets were selected, and then the favorable reservoir zones were comprehensively analyzed. The “three-element reservoir control” favorable target optimization method suitable for low-amplitude structural traps was summarizes, which is suitable for low-amplitude structural traps, and provides a reference for the evaluation of favorable targets in areas with similar geological conditions.