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1.
Sci Total Environ ; 946: 173947, 2024 Oct 10.
Article in English | MEDLINE | ID: mdl-38880148

ABSTRACT

Mine fires caused by spontaneous coal combustion are major disasters in coal mines. The staged oxidation kinetic parameters of various coal samples at oxygen concentrations of 21 %, 15 %, 10 %, 5 %, and 3 % were analyzed using a programmed temperature testing system. Herein, the temperature increase rate of coal, the temperature difference between the furnace and coal, and the oxygen consumption characteristics were obtained. Based on the amount of CO produced and the temperature sensitivity coefficient, three characteristic temperatures and four stages of low-temperature oxidation (LTO) were identified. The results showed that at a critical temperature (TC), the amount of CO gas released from the coal samples increased with increasing oxygen concentration, and the difference in the oxygen consumption rate increased. After the limit temperature (Tu), the amount of CO gas increased steadily, and the increase in the oxygen consumption rate stagnated. CO production, the maximum heating rate, and the maximum heat release rate were positively correlated with the oxygen concentration. As the oxygen concentration increased, the activation energy during the oxygen absorption stage gradually decreased. The average reaction enthalpy (ΔH) of pre-oxidized water-immersed coal was 19.37 kJ/kg greater than that of raw coal. The equation for the conservation of energy of the coal oxidation warming process was normalized. The theoretical values of the awakening stage and the stable stage were τν and τν (1-B), respectively. When B was >1, pre-oxidized water-immersed coal at a low oxygen concentration was prone to crossover points during the oxygen absorption stage, which increased the risk of coal spontaneous combustion (CSC). The research results could provide a theoretical basis for the staged control of the spontaneous combustion of water-immersed coal in goaf areas.

2.
Sci Rep ; 14(1): 8195, 2024 Apr 08.
Article in English | MEDLINE | ID: mdl-38589564

ABSTRACT

Large floating raft vibration isolation systems (FRVISs) based on high-static-low-dynamic stiffness (HSLDS) technology offer excellent low frequency vibration isolation performance with broad application prospects. However, the design process for these complex high-dimensional coupled nonlinear systems remains poorly developed, particularly when applied for ocean-going vessels that experience rolling and pitching motions. The present work addresses this issue by establishing a six-degree-of-freedom HSLDS vibration isolation model for FRVISs composed of eight isolators, and the model is applied to fully analyze the swing stability and multidimensional vibration isolation performance of these systems. The influence of nonlinearity on the mechanical properties of the vibration isolators is analyzed more clearly by assuming that each vibration isolator realizes nonlinear HSLDS characteristics in the z direction and linear characteristics in the x and y directions. The results demonstrate that the swing displacement responses of the system are greatly reduced under weak nonlinearity, which reflects the high static stiffness and high static stability characteristics of an HSLDS system. The multidimensional vibration isolation performance of the system is evaluated according to the impacts of nonlinearity, the installation height Hz of the isolators, and the relative position Dr of the two middle isolators. The results of analysis demonstrate that applying a value of Hz = 0 produces the best vibration isolation performance overall under strong nonlinearity by avoiding unnecessary secondary peaks in the force transmission rate under harmonic mechanical excitation and ensuring a maximum high-frequency vibration isolation effect. However, applying a weak nonlinearity is better than a strong nonlinearity if Hz is not zero. In contrast, Dr has little effect on the vibration isolation effect of the raft in the x, y, and z directions. Therefore, an equidistant installation with Dr = 0.5 would be considered ideal from the standpoint of installation stability.

3.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 32(2): 458-465, 2024 Apr.
Article in Chinese | MEDLINE | ID: mdl-38660852

ABSTRACT

OBJECTIVE: To explore the correlation between peripheral blood B cell count and clinical features and prognosis of patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL). METHODS: The relationship of peripheral blood B cell count with clinical features, laboratory indexes and prognosis in 67 patients with newly diagnosed DLBCL was retrospectively analyzed. RESULTS: Patients were divided into low B-cell count group (B cell<0.1×109/L, n=34) and high B-cell count group (B cell≥0.1×109/L, n=33) according to the median B cell count values. Compared with the high B cell count group, the low B cell count group had a higher proportion of patients with Lugano stage III-IV, elevated LDH, elevated ß2-MG and IPI score 3-5 and increased CRP (P =0.033, 0.000, 0.023, 0.001, 0.033). The peripheral CD3+ and CD4+ cell counts of patients in the low B cell count group were significantly lower than those in the high B cell count group (P =0.010, 0.017). After initial treatment, overall response rate (ORR) and complete remission (CR) rate in high B cell count group were significantly higher than those in low B cell count group (P =0.032, 0.013). The median follow-up time of patients was 23(2-77) months, progression-free survival (PFS) and overall survival (OS) of patients in the high B cell count group were significantly better than those in the low B cell count group (P =0.001, 0.002). Univariate analysis showed that pretreatment low B cell count in the peripheral blood was associated with shortened PFS and OS (HR=4.108, P =0.002; HR=8.218, P =0.006). Multivariate analysis showed that low B cell count was an independent prognostic factor for shortened PFS (HR=3.116, P =0.037). CONCLUSION: Decreased peripheral blood B cell count in newly diagnosed DLBCL patients is associated with high-risk clinical features and may affect the efficacy of immunochemotherapy, which is associated with poor clinical prognosis.


Subject(s)
B-Lymphocytes , Lymphoma, Large B-Cell, Diffuse , Humans , Lymphoma, Large B-Cell, Diffuse/blood , Lymphoma, Large B-Cell, Diffuse/diagnosis , Prognosis , Retrospective Studies , Lymphocyte Count , Male , Female , Middle Aged
4.
Sensors (Basel) ; 24(8)2024 Apr 14.
Article in English | MEDLINE | ID: mdl-38676128

ABSTRACT

Conventional optical microscopes are only able to resolve objects down to a size of approximately 200 nm due to optical diffraction limits. The rapid development of nanotechnology has increased the demand for greater imaging resolution, with a need to break through those diffraction limits. Among super-resolution techniques, microsphere imaging has emerged as a strong contender, offering low cost, simple operation, and high resolution, especially in the fields of nanodevices, biomedicine, and semiconductors. However, this technology is still in its infancy, with an inadequate understanding of the underlying principles and the technology's limited field of view. This paper comprehensively summarizes the status of current research, the advantages and disadvantages of the basic principles and methods of microsphere imaging, the materials and preparation processes, microsphere manipulation methods, and applications. The paper also summarizes future development trends.

5.
PhytoKeys ; 239: 59-72, 2024.
Article in English | MEDLINE | ID: mdl-38510233

ABSTRACT

The genus Itea (Iteaceae) is recognised as a genus with about 21 extant species of shrubs and trees. Within the genus, most species have oblong to elliptical leaves. The lanceolate and obolanceolate leaves are only found in three species, vix Iteaamoena Chun, Iteariparia Collett & Hemsl. and Iteatenuinervia S. Y. Liu. The results of our examination of literature, specimens and living plants in the wild have shown that Iteatenuinervia is conspecific with Iteariparia and is here reduced to a synonym of the latter species. The morphological description, colour pictures, voucher specimens, distribution map of Iteariparia and its related Iteaamoena, together with the morphological comparisons between the two species, are provided in this study.

6.
Quant Imaging Med Surg ; 14(2): 2069-2088, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-38415152

ABSTRACT

Background and Objective: Deep learning (DL) has contributed substantially to the evolution of image analysis by unlocking increased data and computational power. These DL algorithms have further facilitated the growing trend of implementing precision medicine, particularly in areas of diagnosis and therapy. Thyroid imaging, as a routine means to screening for thyroid diseases on large-scale populations, is a massive data source for the development of DL models. Thyroid disease is a global health problem and involves structural and functional changes. The objective of this study was to evaluate the general rules and future directions of DL networks in thyroid medical image analysis through a review of original articles published between 2018 and 2023. Methods: We searched for English-language articles published between April 2018 and September 2023 in the databases of PubMed, Web of Science, and Google Scholar. The keywords used in the search included artificial intelligence or DL, thyroid diseases, and thyroid nodule or thyroid carcinoma. Key Content and Findings: The computer vision tasks of DL in thyroid imaging included classification, segmentation, and detection. The current applications of DL in clinical workflow were found to mainly include management of thyroid nodules/carcinoma, risk evaluation of thyroid cancer metastasis, and discrimination of functional thyroid diseases. Conclusions: DL is expected to enhance the quality of thyroid images and provide greater precision in the assessment of thyroid images. Specifically, DL can increase the diagnostic accuracy of thyroid diseases and better inform clinical decision-making.

7.
Front Oncol ; 14: 1204987, 2024.
Article in English | MEDLINE | ID: mdl-38390270

ABSTRACT

Objective: This study aimed to develop a deep learning system to identify and differentiate the metastatic cervical lymph nodes (CLNs) of thyroid cancer. Methods: From January 2014 to December 2020, 3059 consecutive patients with suspected with metastatic CLNs of thyroid cancer were retrospectively enrolled in this study. All CLNs were confirmed by fine needle aspiration. The patients were randomly divided into the training (1228 benign and 1284 metastatic CLNs) and test (307 benign and 240 metastatic CLNs) groups. Grayscale ultrasonic images were used to develop and test the performance of the Y-Net deep learning model. We used the Y-Net network model to segment and differentiate the lymph nodes. The Dice coefficient was used to evaluate the segmentation efficiency. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were used to evaluate the classification efficiency. Results: In the test set, the median Dice coefficient was 0.832. The sensitivity, specificity, accuracy, PPV, and NPV were 57.25%, 87.08%, 72.03%, 81.87%, and 66.67%, respectively. We also used the Y-Net classified branch to evaluate the classification efficiency of the LNs ultrasonic images. The classification branch model had sensitivity, specificity, accuracy, PPV, and NPV of 84.78%, 80.23%, 82.45%, 79.35%, and 85.61%, respectively. For the original ultrasonic reports, the sensitivity, specificity, accuracy, PPV, and NPV were 95.14%, 34.3%, 64.66%, 59.02%, 87.71%, respectively. The Y-Net model yielded better accuracy than the original ultrasonic reports. Conclusion: The Y-Net model can be useful in assisting sonographers to improve the accuracy of the classification of ultrasound images of metastatic CLNs.

8.
Am J Drug Alcohol Abuse ; : 1-16, 2024 Jan 17.
Article in English | MEDLINE | ID: mdl-38232346

ABSTRACT

Background: Sarcopenia is defined as a progressive loss of skeletal muscle mass plus a decline in muscle strength and/or reduced physical performance with advancing age. The results of current studies on the relationship between drinking and sarcopenia remain controversial.Objectives: The aim of this meta-analysis was to evaluate the association of alcohol consumption with the risk of sarcopenia.Methods: Systematic searches were conducted without language restrictions from the beginning of each database to September 20, 2023 on PubMed, Embase, Cochrane Library, Web of Science, Wanfang Data, Chinese BioMedical Literature, and China national knowledge infrastructure databases. Meta-analysis was conducted to pool the study-specific odds ratios (ORs) with 95% confidence interval (CI).Results: Sixty-two studies with 454,643 participants were enrolled. The meta-analysis of proportions revealed that alcohol consumption was not associated with the presence of sarcopenia, with a pooled OR of 0.964 (95% CI = 0.912-1.019). Further subgroup analysis indicated that alcohol consumption was correlated with lower risk of sarcopenia in men (OR = 0.763; 95% CI = 0.622-0.938; P = .010). The nonlinear dose-response analysis suggested a J-shaped association between alcohol consumption and the risk of sarcopenia, with a nadir at the amounts of alcohol consumption of 6.6 grams/day (OR = 0.765; 95% CI = 0.608-0.957; P < .05).Conclusions: The results of this meta-analysis indicate that alcohol consumption is not a risk factor for the development of sarcopenia. Any suggestion of a putative protective effect of alcohol should be treated with caution, particularly in light of the overall lack of relationship reported in the present comprehensive meta-analysis.

9.
Zookeys ; 1165: 137-154, 2023.
Article in English | MEDLINE | ID: mdl-37304570

ABSTRACT

Two new species, Samarangopustestudineussp. nov. from Hunan, South China and S.rotundifoliussp. nov. from Zhejiang, East China, are described and illustrated. Samarangopustestudineussp. nov. is characterized by unusual testudinal patterns on the dorsal side of the body and well-differentiated marginal protuberances on tergites. Samarangopusrotundifoliussp. nov. features large, round, leaf-shaped marginal protuberances and small, candle-like dorsal protuberances on tergites. Both of these species are compared to similar species in detail. In addition, Eurypauropusjaponicus Hagino & Scheller, 1985 is newly recorded from China.

10.
J Agric Food Chem ; 71(23): 8797-8807, 2023 Jun 14.
Article in English | MEDLINE | ID: mdl-37256838

ABSTRACT

Odorant-degrading enzymes in insects play a vital role in maintaining olfactory sensitivity. However, the role and molecular mechanism of glutathione S-transferases (GSTs) in odorant inactivation has been rarely studied. In the present study, 31 GSTs were identified from the antennal transcriptome of Holotrichia parallela. HpGSTd1 possesses the highest transcriptome expression level. Recombinant HpGSTd1 showed degradation activity toward various unsaturated aldehyde volatiles. Furthermore, the metabolite of cinnamaldehyde was identified by high-resolution mass spectrometry (HRMS). The molecular docking analysis and site-directed mutagenesis revealed the key residues of HpGSTd1 in degrading odorants. In addition, the unsaturated aldehyde volatiles elicited the behavioral and electrophysiological responses of H. parallela. Taken together, our findings suggest that HpGSTd1 may play an essential role in inactivating odorants in H. parallela, which provides new insights for identifying molecular targets and exploring effective olfactory regulators for this underground pest.


Subject(s)
Coleoptera , Receptors, Odorant , Animals , Odorants , Glutathione Transferase/genetics , Glutathione Transferase/metabolism , Aldehydes/metabolism , Molecular Docking Simulation , Arthropod Antennae/metabolism , Insect Proteins/metabolism , Coleoptera/metabolism , Receptors, Odorant/genetics , Receptors, Odorant/metabolism
11.
Sci Total Environ ; 890: 164354, 2023 Sep 10.
Article in English | MEDLINE | ID: mdl-37230362

ABSTRACT

With the normalization of deep mining, the risk of residual coal spontaneous combustion (CSC) in deeply mined areas has gradually increased. To investigate the thermal characteristics and microgroup transformation mechanisms during the secondary oxidation of deep-well oxidized coal, a deep-well oxidation process was simulated in a synchronous thermal analyzer, and the thermal parameters of the oxidized coal were tested. The correlated transformation pathways of microscopic active groups was studied by electron paramagnetic resonance (EPR) and in situ diffuse reflectance (in situ FTIR) experiments during the reoxidation of oxidized coal. The results showed that with increasing deep-well ambient temperature and oxidation temperature, the characteristic temperature of coal gradually decreased, exothermic heat release gradually increased, and active aliphatic structures and -OH, -CHO and other active functional groups gradually accumulated and became distributed more uniformly. When the thermal conditions and oxidation temperature were very high (> 160 °C), the active free radicals in the oxidized coal were rapidly consumed, resulting in a gradual decrease in the characteristic temperature and heat release during the secondary oxidation process, while the contents of peroxy and carboxyl groups continued to increase. In the slow oxidation stage of oxidized coal, methyl groups were mainly transformed with hydroxyl and peroxide groups (r > 0.96), and the associated oxidative consumption of -CHO and -COOH mainly occurred in the rapid oxidation stage (r > 0.99). Geminal diols and peroxy groups are important intermediates in the coal-oxygen composite reaction process. With an increase in the deep-well temperature and initial oxidation temperature, the reoxidation tendency and heat release capacity of residual coal in the goaf gradually increased, and the risk of CSC intensified. The research results provide a theoretical reference for the prevention and control of coal fires in deep mines and play an important role in guiding environmental management and gas emissions reduction measures in mining areas.


Subject(s)
Coal , Fires , Spontaneous Combustion , Temperature , Hot Temperature
12.
Zookeys ; 1152: 97-118, 2023.
Article in English | MEDLINE | ID: mdl-37214741

ABSTRACT

Seiraboneti Denis, 1948, comb. nov. is examined and redescribed based on syntypes and by a newly discovered Chinese population. Lectotype and paralectotypes were designated, and the type locality of the species has been fixed to Câuda, near Nhatrang, Vietnam. The species was first described in the genus Lepidocyrtinus, but based on morphological and molecular evidence it is here transferred to Seira. For the phylogenetic placement of Seiraboneticomb. nov., its mitogenome was included in a dataset comprising 19 species of Seirinae. Maximum Likelihood and Bayesian inferences clustered the species next to Seirasanloemensis Godeiro & Cipola, 2020 from Cambodia, forming a distinct Seira clade from the Old World, confirming the hypothesis of the existence of a different basal lineage of Seirinae in Southern Asia.

13.
Zookeys ; 1157: 145-161, 2023.
Article in English | MEDLINE | ID: mdl-37215163

ABSTRACT

Scutigerellasinensis Jin & Bu, sp. nov. from China is described and illustrated. It is characterized by a deeply emarginated posterior margin of tergite 2, less differentiated marginal setae on all tergites, absence of seta a3 around the antennal base, and 6-8 setae on the first tergite. The complete mitochondrial genome of the new species is also analyzed and compared with the mitogenome of Scutigerellacauseyae. In the reconstructed Neighbor-Joining tree based on COI gene sequences, S.sinensissp. nov. clusters with S.causeyae, however, with big distances. The genetic divergence among S.sinensissp. nov. and congeners, species of Hanseniella and Scutigerella, and both families of Symphyla was analyzed using COI gene sequences.

14.
Insects ; 14(2)2023 Feb 19.
Article in English | MEDLINE | ID: mdl-36835779

ABSTRACT

The group of soil arthropods known as Collembola is characterized by its abundance and sensitivity to environmental changes. They are ideal an species for soil indicators. In order to clarify the effects of species invasion and inundation on the Collembola community in coastal mudflat wetlands, the correlation between the collembolan functional traits and environmental factors was studied in Shanghai Jiuduansha Wetland National Nature Reserve for the first time. Five sample plots, including three vegetations-Spartina alterniflora (an invasive species), Phragmites australis, and Zizania latifolia-were set up following the differences in vegetation types and between high and low tidal flats. Data on the diversity of the Collembolan species and their functional traits were collected and combined with the soil physicochemical properties and vegetation environment factors in different tidal flats. The key findings and conclusions of the study are as follows: a total of 18 species, four families, and three orders make up the obtained Collembola, two species of Proisotoma are dominant species that account for 49.59% and 24.91% of the total, respectively. The maintenance of the species diversity of Collembola is disturbed by the higher conversion efficiency of Spartina alterniflora rather than Phragmites australis with lower organic carbon (C) content and higher total nitrogen (N) content. The primary environmental variables influencing species distribution were the C/N ratio, total N, and bulk soil density. The bulk density of the soil impacts the movement and dispersal of the functional traits. The depth of the soil layer is related to the functional traits of the sensory ability. The analysis of the functional traits and environment is fairly helpful in exploring how species respond to their environment and offers a better explanation for the habitat selection of Collembola.

15.
Zookeys ; 1138: 143-160, 2023.
Article in English | MEDLINE | ID: mdl-36760769

ABSTRACT

Symphylellamacrochaeta sp. nov. and Symphylellalongispina sp. nov. from China are described and illustrated. Symphylellamacrochaeta sp. nov. is characterized by 10 extremely long macrosetae arranged as 4/4/2 on the frons, tergites with broad triangular processes, and 4+4 setae on the first tergite. Symphylellalongispina sp. nov. is characterized by a thick and prominent labrum, distinctly long proximal spines on the mandible, eight macrosetae arranged as 4/2/2 on frons, 3+3 setae on first tergite, and narrow triangular processes on the tergites. Detailed comparisons of the new species with similar species are presented. In addition, the frons chaetotaxy of Symphylella is illustrated and discussed for the first time and proposed as a significant diagnostic character for the taxonomic study of the genus.

16.
JCI Insight ; 8(4)2023 02 22.
Article in English | MEDLINE | ID: mdl-36626233

ABSTRACT

Activin receptor-like kinase 7 (ALK7) is a type I receptor in the TGF-ß superfamily preferentially expressed in adipose tissue and associated with lipid metabolism. Inactivation of ALK7 signaling in mice results in increased lipolysis and resistance to both genetic and diet-induced obesity. Human genetic studies have recently revealed an association between ALK7 variants and both reduced waist to hip ratios and resistance to development of diabetes. In the present study, treatment with a neutralizing mAb against ALK7 caused a substantial loss of adipose mass and improved glucose intolerance and insulin resistance in both genetic and diet-induced mouse obesity models. The enhanced lipolysis increased fatty acid supply from adipocytes to promote fatty acid oxidation in muscle and oxygen consumption at the whole-body level. The treatment temporarily increased hepatic triglyceride levels, which resolved with long-term Ab treatment. Blocking of ALK7 signals also decreased production of its ligand, growth differentiation factor 3, by downregulating S100A8/A9 release from adipocytes and, subsequently, IL-1ß release from adipose tissue macrophages. These findings support the feasibility of potential therapeutics targeting ALK7 as a treatment for obesity and diabetes.


Subject(s)
Activin Receptors, Type I , Adiposity , Metabolic Diseases , Animals , Mice , Activin Receptors/metabolism , Activin Receptors, Type I/immunology , Activin Receptors, Type I/metabolism , Antibodies, Neutralizing , Fatty Acids , Metabolic Diseases/metabolism , Obesity/metabolism , Disease Models, Animal
17.
Mol Ecol Resour ; 23(1): 273-293, 2023 Jan.
Article in English | MEDLINE | ID: mdl-35962787

ABSTRACT

The collembolan Folsomia candida Willem, 1902, is widely distributed throughout the world and has been frequently used as a test organism in soil ecology and ecotoxicology studies. However, it is questioned as an ideal "standard" because of differences in reproductive modes and cryptic genetic diversity between strains from various geographical origins. In this study, we obtained two high-quality chromosome-level genomes of F. candida, for a parthenogenetic strain (named FCDK, 219.08 Mb, 25,139 protein-coding genes) and a sexual strain (named FCSH, 153.09 Mb, 21,609 protein-coding genes), reannotated the genome of the parthenogenetic strain reported by Faddeeva-Vakhrusheva et al. in 2017 (named FCBL, 221.7 Mb, 25,980 protein-coding genes) and conducted comparative genomic analyses of the three strains. High genome similarities between FCDK and FCBL based on synteny, genome architecture, mitochondrial and nuclear gene sequences suggest that they are conspecific. The seven chromosomes of FCDK are each 25%-54% larger than the corresponding chromosomes of FCSH, showing obvious repetitive element expansions and large-scale inversions and translocations but no whole-genome duplication. The strain-specific genes, expanded gene families and genes in nonsyntenic chromosomal regions identified in FCDK are highly related to the broader environmental adaptation of parthenogenetic strains. In addition, FCDK has fewer strain-specific microRNAs than FCSH, and their mitochondrial and nuclear genes have diverged greatly. In conclusion, FCDK/FCBL and FCSH have accumulated independent genetic changes and evolved into distinct species after 10 million years ago. Our work provides important genomic resources for studying the mechanisms of rapidly cryptic speciation and soil arthropod adaptation to soil ecosystems.


Subject(s)
Arthropods , Ecosystem , Animals , Arthropods/genetics , Genome , Synteny , Soil , Evolution, Molecular , Genetic Speciation
18.
Zookeys ; 1176: 181-193, 2023.
Article in English | MEDLINE | ID: mdl-38313823

ABSTRACT

The present paper reports the first occurrence of Seiraferrarii Parona, 1888 from Hungary. On this occasion, molecular analyses were performed on both S.ferrarii and another historical species of the genus, S.pallidipes Reuter, 1895, originally described from Hungary. Using low-coverage whole-genome sequencing, the complete mitogenomes were assembled and annotated using MitoZ. To test the phylogenetic placement of both species, we performed maximum likelihood and Bayesian analyses using a matrix containing 14 Seirinae species and two outgroups. Both resultant trees showed that the European populations of the sampled Seira spp. likely derive from ancestral branches of Seirinae, compared to the Asian and American populations. Our results put in question the monophyly of the genus Seira, as already observed in previous studies.

19.
Nanomaterials (Basel) ; 12(24)2022 Dec 11.
Article in English | MEDLINE | ID: mdl-36558276

ABSTRACT

In recent years, graphene has shown great application prospects in tunable microwave devices due to its tunable conductivity. However, the electromagnetic (EM) properties of graphene, especially the dynamic tunning characteristics, are largely dependent on experimental results, and thus are unable to be effectively predicted according to growth parameters, which causes great difficulties in the design of graphene-based tunable microwave devices. In this work, we systematically explored the impact of chemical vapor deposition (CVD) parameters on the dynamic tunning range of graphene. Firstly, through improving the existing waveguide method, the dynamic tunning range of graphene can be measured more accurately. Secondly, a direct mathematical model between growth parameters and the tunning range of graphene is established. Through this, one can easily obtain needed growth parameters for the desired tunning range of graphene. As a verification, a frequency tunable absorber prototype is designed and tested. The good agreement between simulation and experimental results shows the reliability of our mathematic model in the rapid design of graphene-based tunable microwave devices.

20.
Light Sci Appl ; 11(1): 307, 2022 Oct 25.
Article in English | MEDLINE | ID: mdl-36280662

ABSTRACT

Microwave transmission lines in wearable systems are easily damaged after frequent mechanical deformation, posing a severe threat to wireless communication. Here, we report a new strategy to achieve stretchable microwave transmission lines with superior reliability and durability by integrating a self-healable elastomer with serpentine-geometry plasmonic meta-waveguide to support the spoof surface plasmon polariton (SSPP). After mechanical damage, the self-healable elastomer can autonomously repair itself to maintain the electromagnetic performance and mechanical strength. Meanwhile, the specially designed SSPP structure exhibits excellent stability and damage resistance. Even if the self-healing process has not been completed or the eventual repair effect is not ideal, the spoof plasmonic meta-waveguide can still maintain reliable performance. Self-healing material enhances strength and durability, while the SSPP improves stability and gives more tolerance to the self-healing process. Our design coordinates the structural design with material synthesis to maximize the advantages of the SSPP and self-healing material, significantly improving the reliability and durability of stretchable microwave transmission lines. We also perform communication quality experiments to demonstrate the potential of the proposed meta-waveguide as interconnects in future body area network systems.

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