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1.
Phys Rev Lett ; 132(15): 156503, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38683001

RESUMO

The "symmetric mass generation" (SMG) quantum phase transition discovered in recent years has attracted great interest from both condensed matter and high energy theory communities. Here, interacting Dirac fermions acquire a gap without condensing any fermion bilinear mass term or any concomitant spontaneous symmetry breaking. It is hence beyond the conventional Gross-Neveu-Yukawa-Higgs paradigm. One important question we address in this Letter is whether the SMG transition corresponds to a true unitary conformal field theory. We employ the sharp diagnosis including the scaling of disorder operator and Rényi entanglement entropy in large-scale lattice model quantum Monte Carlo simulations. Our results strongly suggest that the SMG transition is indeed an unconventional quantum phase transition and it should correspond to a true (2+1)d unitary conformal field theory.

2.
Molecules ; 29(2)2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38257230

RESUMO

Hazel leaf, a by-product of hazelnuts, is commonly used in traditional folk medicine in Portugal, Sweden, Iran and other regions for properties such as vascular protection, anti-bleeding, anti-edema, anti-infection, and pain relief. Based on our previous studies, the polyphenol extract from hazel leaf was identified and quantified via HPLC fingerprint. The contents of nine compounds including kaempferol, chlorogenic acid, myricetin, caffeic acid, p-coumaric acid, resveratrol, luteolin, gallic acid and ellagic acid in hazel leaf polyphenol extract (ZP) were preliminary calculated, among which kaempferol was the highest with 221.99 mg/g, followed by chlorogenic acid with 8.23 mg/g. The inhibition of ZP on α-glucosidase and xanthine oxidase activities was determined via the chemical method, and the inhibition on xanthine oxidase was better. Then, the effect of ZP on hyperuricemia zebrafish was investigated. It was found that ZP obviously reduced the levels of uric acid, xanthine oxidase, urea nitrogen and creatinine, and up-regulated the expression ofOAT1 and HPRT genes in hyperuricemia zebrafish. Finally, the targeted network pharmacological analysis and molecular docking of nine polyphenol compounds were performed to search for relevant mechanisms for alleviating hyperuricemia. These results will provide a valuable basis for the development and application of hazel leaf polyphenols as functional ingredients.


Assuntos
Corylus , Hiperuricemia , Animais , Polifenóis/farmacologia , Ácido Clorogênico/farmacologia , Simulação de Acoplamento Molecular , Peixe-Zebra , Farmacologia em Rede , Quempferóis , Hiperuricemia/tratamento farmacológico , Xantina Oxidase , Extratos Vegetais/farmacologia
3.
Phys Rev Lett ; 128(1): 010601, 2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-35061478

RESUMO

We develop a nonequilibrium increment method to compute the Rényi entanglement entropy and investigate its scaling behavior at the deconfined critical (DQC) point via large-scale quantum Monte Carlo simulations. To benchmark the method, we first show that, at a conformally invariant critical point of O(3) transition, the entanglement entropy exhibits universal scaling behavior of area law with logarithmic corner corrections, and the obtained correction exponent represents the current central charge of the critical theory. Then we move on to the deconfined quantum critical point, where we still observe similar scaling behavior, but with a very different exponent. Namely, the corner correction exponent is found to be negative. Such a negative exponent is in sharp contrast with the positivity condition of the Rényi entanglement entropy, which holds for unitary conformal field theories (CFTs). Our results unambiguously reveal fundamental differences between DQC and quantum critical points described by unitary CFTs.

4.
Opt Express ; 29(4): 5427-5436, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33726079

RESUMO

We demonstrate the high-efficiency generation of water-window soft x-ray emissions from polyethylene nanowire array targets irradiated by femtosecond laser pulses at the intensity of 4×1019 W/cm2. The experimental results indicate more than one order of magnitude enhancement of the water-window x-ray emissions from the nanowire array targets compared to the planar targets. The highest energy conversion efficiency from laser to water-window x-rays is measured as 0.5%/sr, which comes from the targets with the longest nanowires. Supported by particle-in-cell simulations and atomic kinetic codes, the physics that leads to the high conversion efficiency is discussed.

5.
Opt Lett ; 46(16): 3969-3972, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-34388787

RESUMO

A number of applications require x rays of both high flux and narrow bandwidth. In this work, we experimentally demonstrate the high-efficiency generation of narrowband soft x rays from carbon nanotube foams irradiated by a femtosecond laser pulse at an intensity of 1019W/cm2. The building blocks of the foam, single-walled carbon nanotube bundles with diameters smaller than the laser skin length can be volumetrically heated and fully ionized on a femtosecond time scale. The three-dimensional network structure of the foam permits deep penetration and drastic absorption of the laser pulse, and results in bright line emissions without prominent Stark broadening. A single-shot yield of 3×1014photons in the carbon Lyα line at 3.37 nm was measured with a bandwidth of 0.013 nm.

6.
Proc Natl Acad Sci U S A ; 115(27): 6980-6985, 2018 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-29915036

RESUMO

Compact acceleration of a tightly collimated relativistic electron beam with high charge from a laser-plasma interaction has many unique applications. However, currently the well-known schemes, including laser wakefield acceleration from gases and vacuum laser acceleration from solids, often produce electron beams either with low charge or with large divergence angles. In this work, we report the generation of highly collimated electron beams with a divergence angle of a few degrees, nonthermal spectra peaked at the megaelectronvolt level, and extremely high charge (∼100 nC) via a powerful subpicosecond laser pulse interacting with a solid target in grazing incidence. Particle-in-cell simulations illustrate a direct laser acceleration scenario, in which the self-filamentation is triggered in a large-scale near-critical-density plasma and electron bunches are accelerated periodically and collimated by the ultraintense electromagnetic field. The energy density of such electron beams in high-Z materials reaches to [Formula: see text], making it a promising tool to drive warm or even hot dense matter states.

7.
Mar Drugs ; 18(9)2020 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-32854344

RESUMO

Atherosclerosis is a chronic disease characterized by lipid accumulation and chronic inflammation of the arterial wall, which is the pathological basis for coronary heart disease, cerebrovascular disease and thromboembolic disease. Currently, there is a lack of low-cost therapeutic agents that effectively slow the progression of atherosclerosis. Therefore, the development of new drugs is urgently needed. The research and development of marine-derived drugs have gained increasing interest from researchers across the world. Many marine organisms provide a rich material basis for the development of atherosclerotic drugs. This review focuses on the latest technological advances in the structures and mechanisms of action of marine-derived anti-atherosclerotic substances and the challenges of the application of these substances including marine polysaccharides, proteins and peptides, polyunsaturated fatty acids and small molecule compounds. Here, we describe the theoretical basis of marine biological resources in the treatment of atherosclerosis.


Assuntos
Organismos Aquáticos/química , Aterosclerose/tratamento farmacológico , Fármacos Cardiovasculares/farmacologia , Ácidos Graxos Insaturados/farmacologia , Polissacarídeos/farmacologia , Proteínas/farmacologia , Animais , Aterosclerose/metabolismo , Aterosclerose/patologia , Fármacos Cardiovasculares/química , Fármacos Cardiovasculares/isolamento & purificação , Ácidos Graxos Insaturados/química , Ácidos Graxos Insaturados/isolamento & purificação , Humanos , Estrutura Molecular , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Proteínas/química , Proteínas/isolamento & purificação , Relação Estrutura-Atividade
8.
Mar Drugs ; 18(8)2020 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-32726987

RESUMO

With twice the number of cancer's deaths, cardiovascular diseases have become the leading cause of death worldwide. Atherosclerosis, in particular, is a progressive, chronic inflammatory cardiovascular disease caused by persistent damage to blood vessels due to elevated cholesterol levels and hyperlipidemia. This condition is characterized by an increase in serum cholesterol, triglycerides, and low-density lipoprotein, and a decrease in high-density lipoprotein. Although existing therapies with hypolipidemic effects can improve the living standards of patients with cardiovascular diseases, the drugs currently used in clinical practice have certain side effects, which insists on the need for the development of new types of drugs with lipid-lowering effects. Some marine-derived substances have proven hypolipidemic activities with fewer side effects and stand as a good alternative for drug development. Recently, there have been thousands of studies on substances with lipid-lowering properties of marine origin, and some are already implemented in clinical practice. Here, we summarize the active components of marine-derived products having a hypolipidemic effect. These active constituents according to their source are divided into algal, animal, plant and microbial and contribute to the development and utilization of marine medicinal products with hypolipidemic effects.


Assuntos
Organismos Aquáticos/metabolismo , Aterosclerose/tratamento farmacológico , Dislipidemias/tratamento farmacológico , Hipolipemiantes/uso terapêutico , Metabolismo dos Lipídeos/efeitos dos fármacos , Animais , Aterosclerose/sangue , Aterosclerose/patologia , Dislipidemias/sangue , Humanos , Hipolipemiantes/química , Hipolipemiantes/isolamento & purificação , Lipídeos/sangue , Estrutura Molecular , Placa Aterosclerótica , Metabolismo Secundário
9.
Mar Drugs ; 18(3)2020 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-32121067

RESUMO

Alginate is a natural polysaccharide present in various marine brown seaweeds. Alginate oligosaccharide (AOS) is a degradation product of alginate, which has received increasing attention due to its low molecular weight and promising biological activity. The wide-ranging biological activity of AOS is closely related to the diversity of their structures. AOS with a specific structure and distinct applications can be obtained by different methods of alginate degradation. This review focuses on recent advances in the biological activity of alginate and its derivatives, including their anti-tumor, anti-oxidative, immunoregulatory, anti-inflammatory, neuroprotective, antibacterial, hypolipidemic, antihypertensive, and hypoglycemic properties, as well as the ability to suppress obesity and promote cell proliferation and regulate plant growth. We hope that this review will provide theoretical basis and inspiration for the high-value research developments and utilization of AOS-related products.


Assuntos
Alginatos/química , Oligossacarídeos/química , Alga Marinha , Animais , Oceanos e Mares , Relação Estrutura-Atividade
10.
Mar Drugs ; 18(12)2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33322296

RESUMO

Fucoxanthin is a natural carotenoid derived mostly from many species of marine brown algae. It is characterized by small molecular weight, is chemically active, can be easily oxidized, and has diverse biological activities, thus protecting cell components from ROS. Fucoxanthin inhibits the proliferation of a variety of cancer cells, promotes weight loss, acts as an antioxidant and anti-inflammatory agent, interacts with the intestinal flora to protect intestinal health, prevents organ fibrosis, and exerts a multitude of other beneficial effects. Thus, fucoxanthin has a wide range of applications and broad prospects. This review focuses primarily on the latest progress in research on its pharmacological activity and underlying mechanisms.


Assuntos
Anti-Inflamatórios/farmacologia , Fármacos Antiobesidade/farmacologia , Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Phaeophyceae , Xantofilas/farmacologia , Animais , Anti-Inflamatórios/isolamento & purificação , Fármacos Antiobesidade/isolamento & purificação , Antineoplásicos/isolamento & purificação , Antioxidantes/isolamento & purificação , Estabilidade de Medicamentos , Microbioma Gastrointestinal/efeitos dos fármacos , Humanos , Phaeophyceae/metabolismo , Xantofilas/isolamento & purificação
11.
Immunol Invest ; 47(7): 712-724, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29944018

RESUMO

Interleukin-9 (IL-9) is a multifunctional cytokine involved in protective immunity or immunopathology depending on the microenvironment and specific disease settings. Our early study determined that IL-9 and Th9 cells participate in and promote the progression of experimental autoimmune myasthenia gravis (EAMG). The data from this study showed that exogenous recombinant rat IL-9 (rrIL-9) acted as an IL-9 receptor antagonist, reduced the incidence of EAMG in rats, alleviated the severity of the disease, and reduced the anti-acetylcholine receptor (AChR) IgG antibody levels by altering the Th-subset distribution. These data suggest that administration of rrIL-9 may provide a novel therapeutic strategy against MG or related autoimmune diseases. Abbreviations: 2-Mercaptoethanol (2-ME); antibodies (Abs); ?-bungarotoxin (?-BTX); acetylcholine receptor (AChR); airway hyper-reactivity (AHR); allophycocyanin-conjugated (APC); antigen presenting cells (APCs); complete Freund's adjuvant (CFA); Cyanine dye 3 (Cy3); dendritic cells (DCs); experimental autoimmune encephalomyelitis (EAE); experimental autoimmune myasthenia gravis (EAMG); flow cytometry (FACS); fetal bovine serum (FBS); fetal calf serum (FCS); Fluorescein isothiocyanate (FITC); gamma chain (?c); intraperitoneally (i.p.); Incomplete Freund's adjuvant (IFA); interferon (IFN); immunoglobulin (Ig); Interleukin (IL); Janus kinase (JAK); myasthenia gravis (MG); Mononuclear cells (MNC); neuromuscular junctions (NMJ); optical density (OD); ovalbumin (OVA); phosphate-buffered saline (PBS); phycoerythrin (PE); Peridinin chlorophyll protein complex (Percp); Rat AChR ? subunit (R-AChR97-116); Recombinant Rat (rr); room temperature (RT); signal transducer and activator of transcription (STAT); T helper cells (Th).


Assuntos
Imunoterapia/métodos , Interleucina-9/imunologia , Miastenia Gravis Autoimune Experimental/terapia , Miastenia Gravis/terapia , Proteínas Recombinantes/imunologia , Animais , Autoanticorpos/sangue , Autoantígenos/imunologia , Feminino , Humanos , Interleucina-9/uso terapêutico , Miastenia Gravis/imunologia , Miastenia Gravis Autoimune Experimental/imunologia , Peptídeos/imunologia , Ratos , Ratos Endogâmicos Lew , Receptores Colinérgicos/imunologia , Receptores de Interleucina-9/antagonistas & inibidores , Proteínas Recombinantes/uso terapêutico
12.
Int J Syst Evol Microbiol ; 67(4): 920-924, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27911255

RESUMO

A Gram-stain-negative, aerobic, yellow-pigmented, non-flagellated, non-gliding, oxidase- and catalase-positive bacterium, designated CY01T, was isolated from seawater of the Yellow Sea. CY01T grew at 15-37 °C (optimum, 30 °C), pH 5-8 (optimum, 6.5-7.5) and with 0.5-12 % (w/v) NaCl (optimum, 0.5-3.5 %). It could not produce flexirubin-type pigment or reduce nitrate to nitrite. CY01T showed the highest 16S rRNA gene sequence similarity to the type strain of Euzebyella saccharophila (97.0 %) and clustered tightly with the species of the genus Euzebyella in the phylogenetic trees based on the 16S rRNA gene sequences. The major cellular fatty acids of CY01T were iso-C15 : 0, iso-C15 : 1G and iso-C17 : 0 3-OH and the major respiratory quinone was menaquinone MK-6. Polar lipids included phosphatidylethanolamine (PE), four unidentified lipids and one unidentified aminolipid. The genomic DNA G+C content was 38.2 mol%. Based on the results of the polyphasic characterization of CY01T, it represents a novel species of the genus Euzebyella, for which the name Euzebyella marina sp. nov. is proposed. The type strain is CY01T (=CCTCC AB 2014348T=KCTC 42440T).


Assuntos
Flavobacteriaceae/classificação , Filogenia , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Flavobacteriaceae/genética , Flavobacteriaceae/isolamento & purificação , Fosfatidiletanolaminas/química , Pigmentação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
13.
Food Funct ; 15(4): 1825-1839, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38315542

RESUMO

Ginsenosides are a class of natural products with hormone-like activity of triterpenoid saponins and have a variety of pharmacological activities such as anti-aging, immune regulation and cognitive improvement. With the great research interest in alternative medicine and natural products, they are gradually becoming research hotspots. Ginsenosides have a four-ring rigid steroid backbone similar to steroid hormones, and a series of experimental studies have shown that they can exhibit hormone-like activity by binding to nuclear receptors or affecting hormone levels, thereby affecting a wide range of inflammatory conditions, cancers, and menopause-related diseases. This review summarizes the mechanisms and potential health effects of ginsenosides exhibiting estrogen-like, glucocorticoid-like and androgen-like activities, providing an important reference for the exploration of safe phytohormone replacement therapy.


Assuntos
Produtos Biológicos , Ginsenosídeos , Panax , Ginsenosídeos/farmacologia , Ginsenosídeos/uso terapêutico , Estrogênios , Receptores Citoplasmáticos e Nucleares , Esteroides
14.
Int J Biol Macromol ; 256(Pt 2): 128538, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38043651

RESUMO

Hazelnut is one of the most popular nuts in the world, rich in nutrients and various active substances. In this study, soluble dietary fiber (SDF) was extracted from hazelnut kernels, and its physicochemical properties and absorbability were explored. Hazelnut-SDF exhibited ideal water-holding, oil-holding and swelling capacity, and glucose, cholesterol and cholate absorbing ability. Scanning electron microscopy and fourier transform infrared spectroscopy showed that hazelnut-SDF had typical polysaccharide structure of functional groups. The main monosaccharides were identified as arabinose, rhamnose, xylose, ribose, glucuronic acid, mannose and glucose by gas chromatography-mass spectrometry. In high-fat diet rats, hazelnut-SDF could improve serum lipid parameters, inhibit lipid accumulation in liver and adipocytes, and regulate the expression level of liver lipid synthesis-related genes. It also could adjust intestinal short chain fatty acids, promote the composition and structure of intestinal microbiota, and significantly balance the abundance of Alloprevotella, Fusicatenibacter, Lactobacillus, Roseburia, Ruminococcaceae_UCG-005, Ruminococcaceae_UCG-014 and Clostridiales. The results concluded that oral administration of hazelnut-SDF could alleviate hyperlipidemia and obesity, and might serve as a potential functional food ingredient.


Assuntos
Corylus , Microbioma Gastrointestinal , Ratos , Animais , Dieta Hiperlipídica/efeitos adversos , Fibras na Dieta/farmacologia , Fibras na Dieta/análise , Colesterol/farmacologia , Glucose/farmacologia
15.
ACS Appl Mater Interfaces ; 15(3): 4580-4590, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36630693

RESUMO

Newly emerged two-dimensional transition metal carbides and/or nitrides (MXenes) have attracted considerable interest in the field of electromagnetic wave absorption, but their excessive conductivity and single loss mechanism limit their applicability. Herein, an MXene decorated with SiCNWs@Co/C was prepared by in situ growth and carbonization processes, followed by electrostatic self-assembly. The electromagnetic wave absorption performance of MXene@SiCNWs@Co/C with a bird-nest-like structure could be effectively regulated and optimized by changing the proportion of MXene and SiCNWs@Co/C. The prepared MXene@SiCNWs@Co/C hybrid absorbers reveal superior impedance matching, complementary dissipation mechanism, and plentiful heterointerfaces. Profiting from the synergy of abovementioned factors, the resultant MXene@SiCNWs@Co/C absorber exhibits an optimum reflection loss (RL) value of -76.5 dB at 6.36 GHz under a thickness of 3.9 mm and broad effective absorption bandwidth (EAB, RL ≤ -10 dB) of 6.2 GHz (11.8-18.0 GHz) with a thickness of only 2.0 mm, covering the entire Ku band. This work offers new insights into designing and fabricating highly efficient MXene-based electromagnetic absorbers.

16.
Food Chem ; 413: 135576, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-36745946

RESUMO

As output of hazelnut increases worldwide, so does the amount of by-products, leading to huge waste and environmental stress. This paper focuses on the varieties of hazelnut that have been studied more in the past two decades, and summarizes the research status of hazelnut and its by-products from the aspects of nutritional value, phytochemicals, extraction methods, biological functions and applications. Hazelnut and its by-products are rich in a variety of bioactive constituents, mainly polyphenols, which have antioxidant, antibacterial and prebiotic effects. Moreover, hazelnut shells, husks, and leaves contain taxanes such as paclitaxel, which can inhibit the proliferation of cancer cells. They are potentially good natural sources of paclitaxel compared to the slower growing yew. Therefore, it is essential to further integrate the extraction techniques and health-promoting properties of these nutrients and bioactive substances to expand their application and enhance their value.


Assuntos
Corylus , Corylus/química , Antioxidantes/química , Polifenóis , Compostos Fitoquímicos , Paclitaxel
17.
J Colloid Interface Sci ; 639: 68-77, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36804794

RESUMO

The design and preparation of heterogeneous structures of dielectric materials has been the mainstream direction for the construction of superior microwave absorption materials (MAMs). We report a facile and efficient procedure combination of hydrothermal process and subsequent heat treatment for successfully prepared bilayer core-shell structure self-assembled V2O3 microspheres (BCSV). The microstructure, defects, dielectric properties and microwave absorption (MA) properties of BCSV were systematically investigated, and the effect of bilayer core-shell structure on the MA properties was discussed. By varying the heat treatment temperature, it is feasible to regulate the thickness of V2O3 bilayer and its unique structure defects, hence enhancing the attenuation and multiple polarization loss of electromagnetic waves inside the microspheres. Self-assembled V2O3 microspheres with bilayer core-shell structure exhibit high-performance MA property. The reflection loss (RL) gets to - 67.12 dB at 11.69 GHz covering the whole X-band after heat treatment at 600 °C, and the broad effective absorption bandwidth is 5.49 GHz with a thickness of 2.20 mm. The conductivity loss, multiple polarization loss and dielectric loss are ascribed to the specific bilayer core-shell structure. Thus, our work provides a good perspective on how to create vanadium oxide-based MAMs with effective absorption and broad bandwidth.

18.
Front Nutr ; 10: 1092071, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36819681

RESUMO

Hazel leaf, one of the by-products of hazelnut, which is widely used in traditional folk medicine around the world. In the present study, the profile of free, conjugated, and bound phenolic compounds from hazel leaf was detected and their antioxidant and anti-inflammatory activities were investigated. The potential health benefits of different phenolic compounds were also predicted. The results showed that the 35 phenolic substances of free, conjugated and bound forms were identified including phenolic acids, flavonoids and catechins. Most of the hazel leaf phenolics were presented in free form, followed by conjugated and bound form. All the fractions effectively inhibited the production of reactive oxygen species and malondialdehyde in TBHP-stimulated human umbilical vein endothelial cells by enhancing endogenous superoxide dismutase, and accordingly alleviated inflammatory cytokines (NO, IL-1ß, TNF-α, and IL-6) in LPS-stimulated RAW264.7 cells, showing obvious antioxidant and anti-inflammatory capacity. Moreover, combined with network pharmacology, the potential therapeutic effects and functional pathways of hazel leaf phenolics were predicted, which provided value basis for exploring their treatment on diseases and developing health products in the future.

19.
J Colloid Interface Sci ; 639: 160-170, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36804789

RESUMO

Biomass-carbon materials have excellent electromagnetic wave attenuation properties, which is one of the essential factors for developing ultra-thin matched-thickness, and high-performance microwave absorption materials. This study reports a two-step procedure consisting of carbonization and subsequent in-situ growth for preparing a wrinkle-like multilayer biomass-derived composites with magnetic Co particles and ZnO particles (CoZnO/C-X). The synergistic effect of a wrinkle-like multilayer structure and Co and ZnO particles, as well as the existence of many heterogeneous interfaces in the composites structure, and efficiently creates multiple scattering and reflections, which gives the composites the strong microwave absorption properties. The minimum reflection loss value (RLmin) of CoZnO/C-X reaches - 54.90 dB with a thickness of 1.8 mm, and the effective absorption bandwidth (lower than - 10 dB) is 7.2 GHz covering from 10.8 GHz to18.0 GHz with matching thickness of 2.0 mm. Furthermore, the reasonable dielectric/magnetic losses, optimized impedance matching and enhanced polarization loss play an indispensable role among improving microwave absorption performance. Thus, this result provides a good potential method for preparation of magnetic particle/metal oxide/biomass-derived carbon microwave absorbing structural materials.

20.
Sci Total Environ ; 869: 161791, 2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-36707003

RESUMO

Although the repaid development of China's apple industry heavily depends on excessive fertilizer-water-pesticide (FWP) inputs, little information is available that systematically evaluates environmental impacts, mitigation potential, and economical benefits of apple production systems in China. In this study, life cycle assessment (LCA) was conducted to elucidate environmental risks and mitigation potentials of rain-fed and irrigated apple production systems on China's Loess Plateau based on survey data from 847 farmers, and economic benefits were analyzed simultaneously. Results showed that irrigated orchards caused more severe environmental risks associated with energy depletion (ED), global warming potential (GWP) and acidification potential (AP) than those in rain-fed orchards, whereas an opposite was true for eutrophication potential (EP), human toxicity potential (HTP), aquatic toxicity potential (ATP) and soil toxicity potential (STP). ED and GWP occurred primarily in the agricultural material stage, while AP, EP, HTP, ATP, and STP occurred mostly in the orchard management stage. Optimized FWP management can markedly mitigate environmental impacts in both irrigated and rain-fed orchard systems. Synthetic fertilizer, because of production and field-associated emissions, was the greatest contributor to environmental impacts of an apple production system. An environmental pollution index (EPI) that integrated environmental categories was highest in conventional irrigated orchards (0.946), followed by conventional rainfed orchards (0.857), and optimized irrigated orchards (0.459), and the lowest EPI was in optimized rainfed orchards (0.389). Economic analysis revealed that the benefits of rainfed orchards were higher than those of irrigated orchards because of higher apple prices and lower labor costs. Optimized FWP management sharply decreased input costs, thereby substantially increasing net income in irrigated and rain-fed apple orchards. Overall, severe environmental risk and large mitigation potential co-exist in rain-fed and irrigated apple orchards on China's Loess Plateau. Integrated soil-crop-market management potentially exhibited considerable environmental and economic advantages, thereby efficiently developing high-quality apple production.


Assuntos
Malus , Praguicidas , Humanos , Fertilizantes , Meio Ambiente , Solo , Agricultura/métodos , Chuva , China , Água , Trifosfato de Adenosina
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