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Experimental study of the effects of a multistage pore-throat structure on the seepage characteristics of sandstones in the Beibuwan Basin:Insights into the flooding mode

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Petroleum Science 2024年第2期21卷 1044-1061页

作者： Lei Wang xiao Lei Qiao-Liang Zhang Guang-Qing Yao Bo Sui xiao-Jun chen Ming-Wei Wang Zhen-Yu Zhou Pan-Rong Wang xiao-Dong peng Zhanjiang Branch China National Offshore Oil Corporation(CNOOC)LimitedZhanjiang524057GuangdongChina Faculty of Earth Resources China University of Geosciences(Wuhan)Wuhan430074HubeiChina School of Resources and Safety Engineering Chongqing UniversityChongqing400044China School of Engineering University of ManchesterManchester M139WJUK Hainan Branch China National Offshore Oil Corporation(CNOOC)LimitedHaikou570311HainanChina

To investigate the relationship between grain sizes, seepage capacity, and oil-displacement efficiency in the Liushagang Formation of the Beibuwan Basin, this study identifies the multistage pore-throat structure as a crucial factor through a comparison of oil displacement in microscopic pore-throat experiments. The two-phase flow evaluation method based on the Li-Horne model is utilized to effectively characterize and quantify the seepage characteristics of different reservoirs, closely relating them to the distribution of microscopic pores and throats. It is observed that conglomerate sandstones at different stages exhibit significant heterogeneity and noticeable differences in seepage capacity, highlighting the crucial role played by certain large pore throats in determining seepage capacity and oil displacement efficiency. Furthermore, it was found that the displacement effects of conglomeratic sandstones with strong heterogeneity were inferior to those of conventional homogeneous sandstone, as evidenced by multiple displacement experiments conducted on core samples with varying granularities and flooding systems. Subsequently, core-based experiments on associated gas flooding after water flooding were conducted to address the challenge of achieving satisfactory results in a single displacement mode for reservoirs with significant heterogeneity. The results indicate that the oil recovery rates for associated gas flooding after water flooding increased by 7.3%-16.4% compared with water flooding alone at a gas-oil ratio of approximately 7000 m^(3)/m^(3). Therefore, considering the advantages of gas flooding in terms of seepage capacity, oil exchange ratio, and the potential for two-phase production, gas flooding is recommended as an energy supplement mode for homogeneous reservoirs in the presence of sufficient gas source and appropriate tectonic angle. On the other hand, associated gas flooding after water flooding is suggested to achieve a more favorable develop

关键词： Beibuwan Basin Multistage pore-throat structure Multistage seepage characteristics Microscopic visualization Heterogeneity Gas/water flooding Flooding mode

A topology approach to overcome the pore size/volume trade-offs for autonomous indoor humidity control

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Science China Chemistry 2024年第9期67卷 2968-2974页

作者： Zhi-Shuo Wang Xue-Wen Zhang Kai Zheng xiao-Xian chen Dong-Dong Zhou Jie-peng Zhang MOE Key Laboratory of Bioinorganic and Synthetic Chemistry GBRCE for Functional Molecular EngineeringSchool of ChemistryIGCMESun Yat-Sen UniversityGuangzhou 510275China Chemistry and Chemical Engineering Guangdong Laboratory Shantou 515021China

Autonomous indoor humidity control is gaining more and more attention but is limited by the trade-offs among pore volume,pore size and water stability of water *** solve this problem by using a unique coordination network topology combined with hydrolytically stable M(Ⅲ)carboxylate *** extending the ligand length from 9.0 to 11.2 and 13.7?,the pore volume significantly increases from 0.99 to 1.40 and 1.78 cm^(3)g^(-1),which proportionally increases the saturated water adsorption ***,the pore size slightly increases from 10.4 to 11.0 and 13.5A,which restricts the isotherm inflection pressure and hysteresis width to meet the requirement of indoor humidity *** single-crystals suitable for Xray diffraction studies were obtained by using Fe(Ⅲ)salts,while isostructural frameworks with sufficiently high water stabilities were synthesized by using Cr(Ⅲ)salts,which offer record working capacity of 0.90 and 1.10 g g^(-1)for indoor humidity control.

关键词： metal-organic frameworks water adsorption indoor humidity control water stability pore engineering

Stretchable fiber strain sensors for wearable biomonitoring

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National Science Review 2024年第7期11卷 70-71页

作者： Shumao Xu xiao xiao Jun chen Department of Bioengineering University of California

Wearable bioelectronics have gained significant attention since they may play a role in transforming current healthcare from a reactive and disease-centric model to a personalized one with a focus on disease preventio...

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Bioinspired nanomaterials for wearable sensing and human–machine interfacing

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Nano Research 2024年第2期17卷 445-461页

作者： Vishesh Kashyap Junyi Yin xiao xiao Jun chen Department of Bioengineering University of CaliforniaLos AngelesLos AngelesCA 90095USA Department of Mechanical and Aerospace Engineering University of CaliforniaLos AngelesLos AngelesCA 90095USA

The inculcation of bioinspiration in sensing and human–machine interface(HMI)technologies can lead to distinctive characteristics such as conformability,low power consumption,high sensitivity,and unique properties like self-healing,self-cleaning,and *** sensing and HMI are fields rife with opportunities for the application of bioinspired nanomaterials,particularly when it comes to wearable sensory systems where biocompatibility is an additional *** review discusses recent development in bioinspired nanomaterials for wearable sensing and HMIs,with a specific focus on state-of-the-art bioinspired capacitive sensors,piezoresistive sensors,piezoelectric sensors,triboelectric sensors,magnetoelastic sensors,and electrochemical *** also present a comprehensive overview of the challenges that have hindered the scientific advancement in academia and commercialization in the industry.

关键词： bioinspired nanomaterials human–machine interface wearable sensors wearable bioelectronics

Matrix metalloproteinase 2 degrades collagen I to regulate ovarian development by association with an insulin-like peptide

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Insect Science 2024年第4期31卷 1090-1106页

作者： Yi Wei xiao-Lin Zhou peng chen Tai-Hang Liu cheng Lu Min-Hui Pan State Key Laboratory of Silkworm Genome Biology Southwest UniversityChongqingChina Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry Southwest UniversityChongqingChina Wenzhou Institute University of Chinese Academy of SciencesWenzhouZhejiang ProvinceChina

The ovary generally undergoes tissue remodeling during larval to pupal transition,which includes membrane degeneration and ovariole *** the same time,the hormones produced by insects significantly change during ***,the regulatory mechanism for ovarian development and hormones is not fully understood in ***,we found that matrix metalloproteinase 2(MMP2)was highly expressed in the ovarian capsules and ovarioles,and the development was abnormal after knocking out MMP2 in Bombyx *** process of abnormal degradation of collagen I due to MMP2 deletion,which resulted in abnormal development of ovarioles and eggs,was analyzed in *** proteomics of ovaries in the MMP2-knock out and wild type strains showed a critically significant difference in the expression of a protein,insulin-like peptide(ILP).Additional analysis revealed significant alteration of ILP during ovarian development,and abnormal expression of ILP significantly affected ovarian development in vivo and MMP2 expression in vitro and in *** results showed that MMP2 regulation of ovarian tissue remodeling is closely related to ILP *** study provides new insights into the regulatory mechanism of MMP2 and ovarian development in ***.

关键词： Bombyx mori collagen I insulin-like peptide matrix metalloproteinase ovarian development

Brain-inspired chaotic spiking backpropagation

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National Science Review 2024年第6期11卷 169-179页

作者： Zijian Wang peng Tao Luonan chen Key Laboratory of Systems Health Science of Zhejiang Province School of Life ScienceHangzhou Institute for Advanced StudyUniversity of Chinese Academy of Sciences Key Laboratory of Systems Biology Shanghai Institute of Biochemistry and Cell Biology Center for Excellence in Molecular Cell Science Chinese Academy of Sciences Guangdong Institute of Intelligence Science and Technology Pazhou Laboratory(Huangpu)

Spiking neural networks(SNNs) have superior energy efficiency due to their spiking signal transmission,which mimics biological nervous systems, but they are difficult to train effectively. Although surrogate gradient-based methods offer a workable solution, trained SNNs frequently fall into local minima because they are still primarily based on gradient dynamics. Inspired by the chaotic dynamics in animal brain learning, we propose a chaotic spiking backpropagation(CSBP) method that introduces a loss function to generate brain-like chaotic dynamics and further takes advantage of the ergodic and pseudo-random nature to make SNN learning effective and robust. From a computational viewpoint, we found that CSBP significantly outperforms current state-of-the-art methods on both neuromorphic data sets(***-CIFAR10 and DVS-Gesture) and large-scale static data sets(e.g. CIFAR100 and Image Net) in terms of accuracy and robustness. From a theoretical viewpoint, we show that the learning process of CSBP is initially chaotic, then subject to various bifurcations and eventually converges to gradient dynamics,consistently with the observation of animal brain activity. Our work provides a superior core tool for direct SNN training and offers new insights into understanding the learning process of a biological brain.

关键词： spiking neural networks surrogate gradient local minima backpropagation brain-inspired learning chaos

Novel stacking models based on SMOTE for the prediction of rockburst grades at four deep gold mines

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Underground Space 2024年第6期19卷 169-188页

作者： peng xiao Zida Liu Guoyan Zhao pengzhi Pan State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China School of Resources and Safety Engineering Central South UniversityChangsha 410083China

Rockburst is a frequently encountered hazard during the production of deep gold *** prediction of rockburst is an important measure to prevent rockburst in gold *** study considers seven indicators to evaluate rockburst at four deep gold *** research and rock tests were performed at two gold mines in China to collect these seven indicators and rockburst *** collected database was oversampled by the synthetic minority oversampling technique(SMOTE)to balance the categories of rockburst *** models combining tree-based models and logistic regression(LR)were established by the balanced *** datasets from another two deep gold mines were implemented to verify the applicability of the predictive *** stacking model combining extremely randomized trees and LR based on SMOTE(SMOTE-ERT-LR)was the best model,and it obtained a training accuracy of 100%and an evaluation accuracy of 100%.Moreover,model evaluation suggested that SMOTE can enhance the prediction performance for weak rockburst,thereby improving the overall ***,sensitivity analysis was performed for *** results indicated that the SMOTE-ERT-LR model can achieve satisfactory performance when only depth,maximum tangential stress index,and linear elastic energy index were available.

关键词： Rockburst prediction Gold mine Stacking model SMOTE

State-of-the-art on the anchorage performance of rock bolts subjected to shear load

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International Journal of Coal Science & Technology 2024年第1期11卷 1-30页

作者： Yu chen Haodong xiao School of Civil Engineering Sun Yat-sen UniversityZhuhai519082China

Rock bolts are extensively utilized in underground engineering as a means of offering support and stability to rock masses in tunnels,mines,and other underground *** environments of high ground stress,faults or weak zones can frequently arise in rock formations,presenting a significant challenge for engineering and potentially leading to underground engineering *** bolts serve as a crucial structural element for the transmission of tensile stress and are capable of withstanding shear loads to prevent sliding of weak zones within rock ***,a complete understanding of the behavior of rock bolts subjected to shear loads is *** paper presents a state-of-the-art review of the research progress of rock bolts subjected to shear load in three categories:experiment,numerical simulation,and analytical *** review focuses on the research studies and developments in this area since the 1970s,providing a comprehensive overview of numerous factors that influence the anchorage performance of rock *** factors include the diameter and angle of the rock bolt installation,rock strength,grouting material,bolt material,borehole diameter,rock bolt preload,normal stress,joint surface roughness and joint expansion *** paper reviews the improvement of mechanical parameter setting in numerical simulation of rock bolt ***,it delves into the optimization of the analytical model concerning rock bolt shear theory,approached from the perspectives of both Elastic foundation beam theory coupled with Elastoplasticity theory and Structural mechanic *** significance of this review lies in its ability to provide insights into the mechanical behavior of rock *** paper also highlights the limitations of current research and guidelines for further research of rock bolts.

关键词： Rock bolt Shear load Shear test Numerical simulation Analytical model

Reveal the pharmacodynamic substances and mechanism of an edible medicinal plant Rhodiola crenulate in DSS-induced colitis through plasma pharmacochemistry and metabolomics

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Food Science and Human Wellness 2024年第4期13卷 2116-2131页

作者： Yu peng xiaoao xiao Tingting Ji Xinyuan Wang Yixuan Xu Jianbo xiao Hui Cao Zhiyong chen Huifan Liu Yuanqing Gao Hongxun Tao Key Laboratory of Cardiovascular and Cerebrovascular Medicine School of PharmacyNanjing Medical UniversityNanjing 211166China School of Food and Biological Engineering Jiangsu UniversityZhenjiang 212013China Department of Analytical Chemistry and Food Science Faculty of ScienceUniversity of VigoVigo 36310Spain CISPAC Fontan BuildingCity of CultureSantiago de Compostela 15707Spain Shaanxi Academy of Traditional Chinese Medicine Xi'an 710003China Guangdong Key Laboratory of Science and Technology of Lingnan Specialty Food Zhongkai University of Agriculture and EngineeringGuangzhou 510550China State Key Laboratory of Southwestern Chinese Medicine Resources Chengdu 610075China

Rhodiola crenulate is the edible medicinal herbal medicine widely used for altitude sickness in ***,our previous work has found that *** extract(RCE)could significantly improve the pathology associated with dextran sulfate sodium-induced ***,the current research aims to reveal the pharmacodynamic material basis of RCE,as well as its mechanism against *** chemical characterization of RCE was performed by UHPLC-HR-MS,through which a total of 88 constituents were ***,our results also found 29 constituents absorbed into blood and 8 metabolized absorbable *** decreased flavonoids prototype and the elevated sulfated products of phenols were observed under pathophysiological conditions of *** metabolomics study revealed that colitis caused the alternation of fatty acid metabolism,steroid hormone biosynthesis and bile acid ***,RCE could prevent colitis by improving fatty acid metabolism and secondary bile acid metabolism.

关键词： Rhodiola crenulate Colitis Chemical characterization Plasma pharmacochemistry Metabolomics

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