Structure Of Matrix Research Articles

Cu-Atom Locations in Rocksalt SnTe Thermoelectric Alloy.

The development of functional thermoelectric materials requires direct evidence of dopants' locations to rationally design the electronic and phononic structure of the host matrix. In this study, Cs-corrected scanning transmission electron microscopy and energy dispersive X-ray spectroscopy is employed at the atomic scale to identify Cu atoms' locations in a Cu-doped SnTe thermoelectric alloy. It is revealed that Cu atoms in the rocksalt SnTe form solid solutions at both Sn and Te sites, contrary to their electronegativity order and the intentional Cu doping at Sn sites. Cu atoms are also located at the tetrahedral and crowdion sites of the face-centred cubic structure, with varying degrees of correlations. Such high flexibility of Cu atoms in the rocksalt SnTe offers diverse phonon-scattering mechanisms conducive to the ultra-low lattice thermal conductivity of singly Cu-doped SnTe. This study offers atomic-scale insights for achieving more precise dopant engineering, leading to the accelerated development of functional thermoelectric materials.

Refinement of eutectic structure and precipitates of Cu–20Ag alloy due to Y microalloying

Copper-silver alloy rod with high mechanical properties and stable conductivity are the key materials for the preparation of microfilaments used in endoscopy and other medical fields. In this paper, the microstructure of Cu–20Ag rod was regulated by adding trace rare earth Y in order to improve the comprehensive performance of copper-silver alloy further. and studies the distribution and existence of rare earth Y as well as the influence on the performance of copper-silver alloy rod billet. The results of research show that: rare earth Y mainly exists in the branching nodes of the eutectic organization, so that the alloy in the solidification of constitutional supercooling increases, thus refining the eutectic structure, and make it uniformly distributed. After addition of 0.01 wt%Y, Cu4Y was precipitated in the eutectic structure of the rod. After adding 0.03 wt%Y, the precipitates types increased to trace intermetallic compound AgY and nanoparticles Cu4Y. The increase of the interface between eutectic structure and Cu matrix decreases the electron scattering probability. This is the main factor to lead to the decrease of electrical conductivity. The precipitation hardening of precipitated phase and the increase of interface between eutectic structure and Cu matrix are the main factors for the increase of tensile strength of bar billet. The main factor of the decrease in the conductivity of rod billet is the increase of Ag phase dissolved in eutectic structure and the interface between eutectic structure and Cu matrix.

The influence of pulse cell wall structure and cellular protein matrix on the in vitro digestion kinetics of starch: A dual encapsulation mechanism

The intrinsic characteristics and extrinsic processing of whole-pulse food modulate the starch digestion rate and extent. This study investigated the dual encapsulation mechanism of cell wall structure and protein matrix on the in vitro digestion properties of intracellular starch, using an isolated whole-pulse food model of intact pea cotyledon cells subjected to alkaline buffer and enzymatic treatments. Results showed that intact cells with the maximum protein matrix content (18.9 %) exhibited the lowest peak temperature (71.4 °C, uncooked and 58.1 °C, cooked), enthalpy change (3.4 J/g, uncooked and 2.0 J/g, cooked), relative crystallinity (11.6 %), and starch digestion rate (0.0248 min−1) and extent (11.9 %) compared to alkaline buffer and enzymatic treatments. Even after enzymatic treatment, cells with minimal protein matrix content (1.8 %) exhibited a starch digestion rate (0.0387 min−1) and extent (39.7 %), which were still lower than those of isolated starch (0.0480 min−1 and 56.8 %). These findings indicate that the protein matrix and cell walls act as a dual encapsulation system to slow starch hydrolysis. This provides a theoretical basis and technical guidance for developing low-glycemic whole-pulse foods.

On coupled oscillators modeling bio-inspired acoustic sensors: Bifurcation analysis toward tunability enhancement.

Oscillators exhibiting an Andronov-Hopf bifurcation are candidates to mimic the functionality of the cochlea, since the transfer response of these oscillators is compressive and frequency selective. The former implies that small stimuli are amplified and strong stimuli are attenuated, while the latter means that the oscillator only reacts in a (small) frequency band. However, this implies that many oscillators are needed to cover a relevant frequency band. By introducing the notion of tunable characteristic frequencies, i.e., the characteristic frequency can be adjusted by a controllable input, the number of oscillators can be eventually reduced. Subsequently, the tunability enhancement of coupled oscillators is investigated by analyzing the local dynamics of a network of oscillators. For this, necessary conditions for the emergence of Andronov-Hopf bifurcations are determined for networks consisting of two groups, i.e., a group is a network of identical oscillators. By choosing the eigenvalues of the product of the cross-coupling matrix as bifurcation parameters and exploiting the structure of the transfer matrix of this network, the critical points and, thus, the characteristic frequency at this point can be derived. Tunability of the characteristic frequency is then enabled by controlling the asymmetry between the groups of oscillators.

Comparative analysis of polysaccharide and cell wall structure in Aspergillus nidulans and Aspergillus fumigatus by solid-state NMR

Invasive aspergillosis poses a significant threat to immunocompromised patients, leading to high mortality rates associated with these infections. Targeting the biosynthesis of cell wall carbohydrates is a promising strategy for antifungal drug development and will be advanced by a molecular-level understanding of the native structures of polysaccharides within their cellular context. Solid-state NMR spectroscopy has recently provided detailed insights into the cell wall organization of Aspergillus fumigatus, but genetic and biochemical evidence highlights species-specific differences among Aspergillus species. In this study, we employed a combination of 13C, 15N, and 1H-detection solid-state NMR, supplemented by Dynamic Nuclear Polarization (DNP), to compare the structural organization of cell wall polymers and their assembly in the cell walls of A. fumigatus and A. nidulans, both of which are key model organisms and human pathogens. The two species exhibited a similar rigid core architecture, consisting of chitin, α-glucan, and β-glucan, which contributed to comparable cell wall properties, including polymer dynamics, water retention, and supramolecular organization. However, differences were observed in the chitin, galactosaminogalactan, protein, and lipid content, as well as in the dynamics of galactomannan and the structure of the glucan matrix.

Aramid Nanofiber-modified Carbon Paper to Enhance Adaptability and Performance of Proton Exchange Membrane Fuel Cells

This study developed a novel method to enhance the comprehensive performance of carbon paper (CP) by using aramid nanofibers (ANF) modified phenol formaldehyde resin (PF). The effect of ANF modification ratios (0wt%, 0.6wt%, 1.2wt%, 1.8wt%, 2.4wt%) on ANF dispersion in PF impregnation solution, PF thermal stability, and PF carbon matrix structure were investigated. Compared to unmodified PF, ANF-modified PF matrix carbon exhibited increasingly regular and ordered structures, with the ID/IG value decreasing from 2.16 to 2.02. Furthermore, with ANF modification ratio increasing, the tensile strength, flexural strength, porosity and gas permeability of CP exhibited a pattern of initial increase followed by a decrease, and when increasing to 1.8%, reaching the optimal values of 14.28MPa, 531.61MPa, 85.94%, and 2520L·m-2·s-1, respectively. The limiting power density of proton exchange membrane fuel cells (PEMFCs) assembled with 1.8wt% ANF-modified CP gradually increased with different assembly torques of 2, 4 and 6N·m, reaching maximum values of 0.86, 0.98, and 1.1W·cm-2, respectively. Therefore, the novel ANF modification method of CP provides new insights into enhancing PEMFCs assembly adaptability, potentially addressing issues related to low mechanical stability and poor pore structure affecting PEMFCs performance.

Characterization of decellularized porcine oviduct- and uterine-derived scaffolds evaluated by spermatozoa-based biocompatibility and biotoxicity

Extracellular matrix-derived scaffolds (dECM) are widely utilized in regenerative medicine and tissue engineering due to their ability to promote cell growth, proliferation, and differentiation. In reproduction, research is focused on using these scaffolds to treat pathologies causing reproductive dysfunction or to improve assisted reproduction technologies (ARTs). We developed an efficient protocol employing the immersion-agitation technique to decellularize porcine oviductal and uterine sections, comparing the efficacy of fresh versus frozen treatments. Both methods successfully generated acellular matrices with less than 3% residual DNA, effectively preserving structural and protein integrity. Scanning and transmission electron microscopy confirmed the ultrastructural integrity, whereas Masson's Trichrome staining highlighted better collagen preservation in frozen treatments. Proteomic analysis of decellularized scaffolds revealed collagen and key macromolecules such as laminin, filamin, dermatopontin, and fibronectin, which are essential for extracellular matrix structure and cell functions such as adhesion and migration. Innovatively, we assessed the biocompatibility and cytotoxicity of the scaffolds using spermatozoa, demonstrating that thorough washing ensures the scaffold biocompatibility without compromising sperm viability or motility. Our findings not only contribute to the standardization of decellularization protocols for female reproductive organs but also emphasize the importance of evaluating sperm biocompatibility to ensure the safety of dECM scaffolds.

Weak dangling block reordering and multi-step block compression for efficiently computing and updating PageRank solutions

The PageRank model is a powerful tool for network analysis, utilized across various disciplines such as web information retrieval, bioinformatics, community detection, and graph neural network. Computing this model requires solving a large-dimensional linear system or eigenvector problem due to the ever-increasing scale of networks. Conventional preconditioners and iterative methods for general linear systems or eigenvector problems often exhibit unsatisfactory performance for such problems, particularly as the damping factor parameter approaches 1, necessitating the development of specialized methods that exploit the specific properties of the PageRank coefficient matrix. Additionally, in practical applications, the optimal settings of the hyperparameters are generally unknown in advance, and networks often evolve over time. Consequently, recomputation of the problem is necessary following minor modifications. In this scenario, highly efficient preconditioners that significantly accelerate the iterative solution at a low memory cost are desirable. In this paper, we present two techniques that leverage the sparsity structures and numerical properties of the PageRank system, as well as a preconditioner based on the computed matrix structure. Experiments demonstrate the positive performance of the proposed methods on realistic PageRank computations.

A simple method and case study of task planning for collaborative design based on FDSM

In multiperson collaborative mechanical product design, unreasonable task allocation can result in excessive coupling between tasks, complex design communication, and rework, particularly in small enterprises and teams that rely primarily on experience. Hence, this study proposes a simple and efficient task-planning method based on a fuzzy design structure matrix (FDSM), which involves single-level task decomposition, three-level number assignment of the coupling relationship, decoupling of the structural tree algorithm, and validation of the optimization results based on the G-value. Design tasks are promptly allocated into a single level based on the functional structure module of the product. The task-correlation degree is quantified based on three levels of numerical values through personal experience to construct an FDSM, the latter of which is decoupled by the correlation degree of the structural tree algorithm to obtain the optimized sequence and allocation of the collaborative design task. Finally, the effectiveness of the planning is verified by calculating the tightness of the corresponding matrix before and after the planning. A task-planning case of a riveting-machine design for capacitor cover plates is established to validate this method.

Alkali and Non-alkali Treated Coconut Coir Fiber-Reinforced Coconut Shell Powder/MWCNT-Filled Polyester Matrix Composite: An Experimental Comparison

Engineering, biomedical, and medicinal applications effectively employ the extraction of natural resources. Natural and recycled natural fibers are highly advantageous for producing hard-core and soft-core composite materials and equipment. Natural fiber processing can yield diverse material characteristics. Particularly, processes such as chemical treatment, heat treatment, fine coating, and polishing (gold) composites can significantly enhance the characteristics of these materials. A further selection of non-synthetic solutions is designated for material application and environmentally friendly biodegradation to the earth. Due to the non-destructive nature of composites, many synthetic resources are incorporated into the environment, which can lead to corrosion and atmospheric pollution. Therefore, the remarkable movement toward replacing these compounds with natural coconut fiber, whether refined or untreated, shell powder, and composites incorporating multi-walled carbon nanotubes (MWCNT) contributes to establishing a more environmentally sustainable society. This work included rigorous mechanical testing to compare the effects of alkali and non-alkali treatments. In particular, the tensile strength is 17.06% higher, the flexural strength is 7.35% higher, and the hardness on Shore D is 5.81% higher than that of non-alkali-treated material. The SEM analysis revealed the alkali-treated and untreated composites' consecutive failure zones, regions, and matrix structures.

Ethyl butyrate inhibits caudal fin regeneration in adult zebrafish by disrupting extracellular matrix remodeling

Wound healing and tissue regeneration are influenced by a variety of factors. Adverse lifestyle habits, such as excessive alcohol consumption, delay wound healing and increase the risk of secondary infections. Ethyl butyrate is a common food additive widely used to enhance the aroma of alcoholic beverages. This additive is generally considered harmless to human health in both industrial and domestic settings. However, the ecotoxicity and its effects on wound healing have not been elucidated. In this study, we used zebrafish as the experimental animal, and the caudal fins were amputated to explore the effects of ethyl butyrate on wound healing and tissue regeneration. The effect of ethyl butyrate on blastema and bone regeneration and its impact on the transcriptional levels of regeneration-related genes and inflammation-related genes were evaluated. RNA-seq was conducted to determine the differentially expressed genes (DEGs) between the treatment and the control groups. KEGG and GO analysis was conducted to explore the functions of DEGs. Significantly enriched GO terms and KEGG pathways were identified to explore the molecular mechanism underlying the inhibition of zebrafish caudal fin regeneration by ethyl butyrate. The results demonstrated that ethyl butyrate significantly inhibited the regeneration of zebrafish caudal fins, including blastema and bone regeneration. Ethyl butyrate exposure significantly downregulated the expression of genes associated with bone and blastema regeneration and inflammation response. KEGG and GO functional analyses revealed that the DEGs were associated with significant enrichment of extracellular matrix-receptor interactions. Ethyl butyrate treatment downregulated the expression of most extracellular matrix-related genes. These findings indicate that ethyl butyrate potentially modulates pathways associated with the structure, adhesion, modification, and degradation of the extracellular matrix, thereby disrupting extracellular matrix remodeling, inhibiting wound inflammation, impairing blastema and bone regeneration and ultimately hindering caudal fin regeneration. In summary, the findings demonstrate that ethyl butyrate disrupts extracellular matrix remodeling and inhibits the regeneration of zebrafish caudal fins. These results provide valuable insights into the rational use of ethyl butyrate and further investigation of wound healing mechanisms.

Epoxy resin-based polymer-wall stabilized liquid crystal films with low driving voltages and improved mechanical performance for smart window applications

Polymer stabilized liquid crystals (PSLCs) have wide applications in smart windows and light shutters. However, for most applications, it requires low driving voltages and high mechanical performance, which is arduous to achieve both. Herein, a novel epoxy resin-based PSLC device is prepared showing improved electro-optical and mechanical properties simultaneously. This is benefited from the construction of a period polymer wall structure in liquid crystal matrix through cationic polymerization of epoxy monomers and preparation of multi-functional surfaces through self-assembly of silane mixtures. The multi-functional surfaces could ensure homeotropic alignment of liquid crystals and photo-polymerize with the polymer networks. As a result, the polymer-wall stabilized liqduid crystal (PWSLC) film with multi-functional surfaces shows lower (24%) saturation voltage, higher (20%) contrast ratio and improved (2.4 times) peel strength than the PSLC film with only vertical alignment surfaces. This research provides important reference to experiment and manufacture of reverse-mode dimming films for smart windows applications.

Spirulina protein concentrate hydrogel reinforced by hydroxyapatite nanoparticles and hydroxychloroquin: A novel platform for bone regeneration

Among the fabrication methods, hydrogels have received significant attention due to their excellent ability to mimic the extracellular matrix structure. Spirulina is a type of unicellular blue-green algae. It is an excellent source of protein and a wide variety of other nutrients. Hydroxychloroquin (HCQ) reduces bone resorption and osteoclasts growth. This study hypothesized that the hydrogel, which is composed of Spirulina protein cross-linked by transglutaminase and reinforced by hydroxyapatite (HAP) nanoparticles loaded with HCQ, could potentially aid in bone regeneration. The protein from Spirulina was extracted using the probe sonication method. Afterwards, hydrogels were prepared by incorporating the Spirulina protein with gelatin and cross-linked with varying percentages of transglutaminase. HCQ-loaded HAP nanoparticles were used to enhance not only the mechanical properties of the hydrogels but also to stimulate bone mineralization. Hydrogels were studied for their mechanical and rheological properties in vitro, as well as their ability to swell, break down, injectability, and release HCQ. Cell adhesion, proliferation, and bone mineralization on MG-63 osteoblast cells were also studied using Alizarine red and alkaline phosphatase markers. The loading efficiency of HCQ in HAP nanoparticles was about 97 %. The HCQ release rate from hydrogel containing HAP was 85 % in 9 hours. The tensile strength and injectability force of the optimized hydrogel were in the range of 530.75 KPa and 21 N, respectively. The results showed that hydrogels made with 10 % protein, 150 units of transglutaminase, 6 % gelatin, and HAP loaded with HCQ had the best cell behavior and improved markers of bone regeneration. The promising results obtained suggest that the prepared hydrogel may act as a suitable construct for accelerating bone regeneration.

The impact of spent fluid catalytic cracking catalyst on the selected mechanical and physical performances of cement mortars

This paper presents the results of research aimed for evaluating the impact of applicability of spent fluid catalytic cracking catalyst as a substitute of 20, 40, 60 and 80% of cement, by mass, in cement mortars on their selected mechanical and physical performances. It was demonstrated that substitution of 20% of cement mass with spent catalyst enhanced mortar’s compressive strength for 16.7%. Further addition of spent catalyst tended to decrease strength, whilst, simultaneously, rose the values of capillary absorption and water absorptivity because of deterioration of cement matrix structure, documented by SEM photos. Based on the research and literature data, it was proved that spent cracking catalyst might be a promising additive to cement in the amount not exceeding 40% of its mass considering its pozzolanicity

INVESTIGATION OF RARE AND RARE-EARTH ELEMENTS LEACHING PROCESSES FROM THE WEATHERING CRUST ORES OF THE KUNDYBAY DEPOSIT

The weathering crust ore of the Kundybay deposit is a hard-enriched ore that contains such minerals as cherchite, bastnesite, kaolinite, etc., which are embedded in the matrix structure of other silicate rocks. These minerals contain rare earth (RE) and rare earth elements (REE). The multi-component structure and dense packing of minerals in the aluminosilicate matrix of the ore make it difficult to be blocking out. Determination of the optimal ore blocking method in order to extract RE and REE is an urgent task for today. The purpose of this work is to develop an effective method of leaching RE, REE and "white soot" from the weathering crust ores of the Kundybay deposit. Methods. Processing with soluble ammonium, magnesium and aluminium salts will allow estimation of the state of RE and REE in the ore. The indicator of RE and REE blocking out during leaching with sodium hydroxide is the transfer of silica into solution, due to which RE and REE form their own hydroxides, which can be subsequently transferred into solution by acid treatment. Acid leaching with sodium pyrosulfite, hydrofluoric acid and sulfuric acid will allow the RE and REE to be immediately transferred into solution. Results and Discussion. The main characteristics of the Kundybay deposit weathering crust ore were determined, such as: silica content, moisture content, base metals, RE and REE. Conclusion. The degree of extraction of RE and REE by soluble salts of ammonium, magnesium and aluminium did not exceed 2%, which indicates the existence of RE and REE in the form of their own minerals. Leaching with sodium hydroxide showed low recovery of silica, with RE and REE remaining in a difficult-torecover form. Leaching with a mixture of sodium pyrosulfite, hydrofluoric and sulfuric acids is a promising method for RE and REE recovery due to the complex effect of the components of this mixture.

Optimizing the Tensile and Flexural Properties of Flax/Sisal with SiO2 Nanocomposites Using Response Surface Methodology

This study aimed to examine the impact of fiber orientation on the tensile and flexural strengths of composites composed of Flax and sisal fibers, particularly at orientations of 0, 45, and 90 degrees. Furthermore, the research sought to determine the most effective parameters for the treatment process. The researchers utilized Response Surface Methodology (RSM) in conjunction with Central Composite Designs (CCD) to develop and analyze their studies. The main objective was to enhance crucial variables such as fiber alignment and the proportions of flax and sisal fibers. Quadratic models were employed in this study to forecast the tensile and bending characteristics of the materials. The best tensile strength (TS) was reached by meticulously experimenting with the fiber orientation and altering the amounts of flax and sisal fibers. The most effective parameter was a fiber orientation of 0 degrees, with a combination of flax and sisal fibers at a concentration of 60 percent each. Under these circumstances, the composite exhibited a significant improvement of 35% in tensile strength and 26% in bending strength when compared to the lowest values achieved with RSM optimization. The notable enhancements demonstrate that aligning the fibers can effectively increase the tensile and flexural strength (FS) and strengthen the bonding between natural fibers and polymer matrix structures.

Reinforcement structure design and matrix model establishment of tubular 3D weaving based on ordinary loom

In order to optimize the design of three-dimensional tubular woven (3DTW), a design method and matrix model of 3DTW were proposed based on normal loom, where 3D woven was used as tube wall and the weaving method of tubular fabric was applied. Herein, 3D woven was used as the tube wall to obtain the face weave diagram, and the back weave diagram was subsequently obtained by the “negative flip” method. According to the method of layering weaving, the structure diagram of 3DTW could be determined. In order to obtain back weave matrix, the elements in the face weave matrix were replaced and reordered by MATLAB function, and Kronecker product operation was used to achieve the proportional embedding of the face and the back weave matrix and the assignment of the face warp by lifting point elements when weaving the back weft. Finally, the weave matrix of 3DTW was obtained. The proposed design method and matrix model can improve the design efficiency and reduce weaving cost of 3DTW, which could provide a reference for the design and preparation of 3DTW.

Fabrication of 3D Bioactive Melt Electrowriting Composite Scaffold with High Osteogenic Potential

A key challenge in using melt electrowriting (MEW) technology is incorporating large amounts of bioactive inorganic materials, such as hydroxyapatite (HA). In the present study, following optimization of the fabrication parameters, 40%-HA (HA40) nanoparticles were pre-mixed into medical-grade polycaprolactone (PCL) and processed using the MEW (MEW) technique to mimic the structure and function of the natural extracellular matrix (ECM) for bone regeneration. The HA40 fibrous composite scaffolds showed continuous writing and obtained a well-connected and orderly stacked fibre with a small diameter size (67 ± 8.5µm). A major result of the present study was the successful enrichment and accumulation of the HA particles, which mostly occurred on the MEW fibre external surfaces. This design allows for direct interfacial interaction with human periodontal ligament cells (hPDLCs). We systematically investigated the behaviour and function of hPDLCs on the HA40 composite scaffold, alongside parameters related to mineralization. The HA40 scaffold demonstrated significantly higher metabolic activity and enhanced expression of osteonectin and RUNX2 compared to PCL-only scaffolds, as well as increased levels of ALP and COL1. The study’s findings demonstrate that bioactive composite scaffolds, incorporating 40% HA into m-PCL via MEW, effectively enhance the biological response of the ECM and are promising for potential applications in bone regeneration.

On Matrix Representation of Extension Field GF(pL) and Its Application in Vector Linear Network Coding.

For a finite field GF(pL) with prime p and L>1, one of the standard representations is L×L matrices over GF(p) so that the arithmetic of GF(pL) can be realized by the arithmetic among these matrices over GF(p). Based on the matrix representation of GF(pL), a conventional linear network coding scheme over GF(pL) can be transformed to an L-dimensional vector LNC scheme over GF(p). Recently, a few real implementations of coding schemes over GF(2L), such as the Reed-Solomon (RS) codes in the ISA-L library and the Cauchy-RS codes in the Longhair library, are built upon the classical result to achieve matrix representation, which focuses more on the structure of every individual matrix but does not shed light on the inherent correlation among matrices which corresponds to different elements. In this paper, we first generalize this classical result from over GF(2L) to over GF(pL) and paraphrase it from the perspective of matrices with different powers to make the inherent correlation among these matrices more transparent. Moreover, motivated by this correlation, we can devise a lookup table to pre-store the matrix representation with a smaller size than the one utilized in current implementations. In addition, this correlation also implies useful theoretical results which can be adopted to further demonstrate the advantages of binary matrix representation in vector LNC. In the following part of this paper, we focus on the study of vector LNC and investigate the applications of matrix representation related to the aspects of random and deterministic vector LNC.

Monolithic Nitrogen-Doped Carbon Electrode with Hierarchical Porous Structure for Efficient Electrochemical CO2 Reduction.

N-doped carbon materials have garnered extensive development in electrochemical CO2 reduction due to their abundant sources, high structural plasticity, and excellent catalytic performance. However, the use of powder carbon materials for electrocatalytic reactions limits their current density and mechanical strength, which pose challenges for industrial applications. In this study, we synthesized a monolithic N-doped carbon electrode with high mechanical strength for efficient electrochemical reduction of CO2 to CO through a simple pyrolysis method, using phenolic resin as the precursor and ZIF-8 as the sacrificial template. At 900 °C, the decomposition of ZIF-8 and the volatilization of Zn atoms promote the formation of a hierarchical porous structure in the carbon matrix, characterized by macropores with extended mesoporous channels. Simultaneously, N active species derived from ZIF-8 are effectively generated around the pores and fully exposed. The efficient mass transfer facilitated by the hierarchical porous structure and high activity of exposed nitrogen species enables efficient conversion of CO2 to CO. When the ZIF-8 content is 30%, the catalyst achieves a Faradaic efficiency of 88.9% for CO at a low potential of -0.7 V (vs RHE), with a CO production rate of 244.05 μmol h-1 cm-2. After 50 h of potentiostatic electrolysis, the current density and FECO remain stable. This work not only provides a strategy for the synergistic effects of hierarchical porous structures and nitrogen doping but also offers an effective method to avoid using powder binders and prepare integrated, stable monolithic electrodes.