Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 34
Filtrar
Mais filtros

Base de dados
Tipo de documento
País de afiliação
Intervalo de ano de publicação
2.
Mol Breed ; 44(5): 37, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38745883

RESUMO

Apyrase is a class of enzyme that catalyzes the hydrolysis of nucleoside triphosphates/diphosphates (NTP/NDP), which widely involved in regulation of plant growth and stress responses. However, apyrase family genes in maize have not been identified, and their characteristics and functions are largely unknown. In this study, we identified 16 apyrases (named as ZmAPY1-ZmAPY16) in maize genome, and analyzed their phylogenetic relationships, gene structures, chromosomal distribution, upstream regulatory transcription factors and expression patterns. Analysis of the transcriptome database unveiled tissue-specific and abiotic stress-responsive expression of ZmAPY genes in maize. qPCR analysis further confirmed their responsiveness to drought, heat, and cold stresses. Association analyses indicated that variations of ZmAPY5 and ZmAPY16 may regulate maize agronomic traits and drought responses. Our findings shed light on the molecular characteristics and evolutionary history of maize apyrase genes, highlighting their roles in various biological processes and stress responses. This study forms a basis for further exploration of apyrase functions in maize. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-024-01474-9.

3.
Small ; 19(45): e2302788, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37431201

RESUMO

Prussian blue analogs are well suited for sodium-ion battery cathode materials due to their cheap cost and high theoretical specific capacity. Nax CoFe(CN)6 (CoHCF), one of the PBAs, has poor rate performance and cycling stability, while Nax FeFe(CN)6 (FeHCF) has better rate and cycling performance. The CoHCF@FeHCF core-shell structure is designed with CoHCF as the core material and FeHCF as the shell material to enhance the electrochemical properties. The successfully prepared core-shell structure leads to a significant improvement in the rate performance and cycling stability of the composite compared to the unmodified CoHCF. The composite sample of core-shell structure has a specific capacity of 54.8 mAh g-1 at high magnification of 20 C (1 C = 170 mA g-1 ). In terms of cycle stability, it has a capacity retention rate of 84.1% for 100 cycles at 1 C, and a capacity retention rate of 82.7% for 200 cycles at 5 C. Kinetic analysis shows that the composite sample with the core-shell structure has fast kinetic characteristics, and the surface capacitance occupation ratio and sodium-ion diffusion coefficient are higher than those of the unmodified CoHCF.

4.
Phys Chem Chem Phys ; 25(46): 31928-31935, 2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-37974438

RESUMO

The phase transition of the ß-HMX crystal has been widely studied under high pressure, but the microscopic transition mechanism is not sufficiently understood. In this article, we perform a series of ab initio molecular dynamics simulations focusing on structure deformation and the corresponding vibration spectra resolution of ß-HMX at 0-40 GPa. Several typical pressure-induced phase transition processes are confirmed by analyzing the chemical bond, dihedral angle, charge transfer, and IR and Raman spectra. The corresponding relationship between molecular structure and spectral signal is constructed through the partial spectra calculations of special functional groups within the HMX molecule. The anisotropic effects of different groups on the initial structural phase transition are uncovered. The equatorial C-N and axial N-N bonds have the largest compression ratio as pressure increases, which is the intrinsic factor for the initiation of structure transformation. The C-N molecular ring plays an important role in the entire phase transition process. In addition, the phase transition of ß â†’ ζ is also closely related to the deformation of NO2, while that of ζ → ε is induced by the axial N-NO2 group. Regarding the higher-pressure phase transition, the synergetic effect of N-NO2, CH2 groups, and molecular rings becomes more considerable.

5.
Int J Mol Sci ; 24(16)2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37628750

RESUMO

The structure and properties of nano-carbon materials formed in explosives detonation are always a challenge, not only for the designing and manufacturing of these materials but also for clearly understanding the detonation performance of explosives. Herein, we study the dynamic evolution process of condensed-phase carbon involved in 2,4,6-Triamino-1,3,5-trinitrobenzene (TATB) detonation using the quantum-based molecular dynamics method. Various carbon structures such as, graphene-like, diamond-like, and "diaphite", are obtained under different pressures. The transition from a C sp2- to a sp3-hybrid, driven by the conversion of a hexatomic to a non-hexatomic ring, is detected under high pressure. A tightly bound nucleation mechanism for diamond-like carbon dominated by a graphene-like carbon layer is uncovered. The graphene-like layer is readily constructed at the early stage, which would connect with surrounding carbon atoms or fragments to form the tetrahedral structure, with a high fraction of sp3-hybridized carbon. After that, the deformed carbon layers further coalesce with each other by bonding between carbon atoms within the five-member ring, to form the diamond-like nucleus. The complex "diaphite" configuration is detected during the diamond-like carbon nucleation, which illustrates that the nucleation and growth of detonation nano-diamond would accompany the intergrowth of graphene-like layers.


Assuntos
Substâncias Explosivas , Grafite , Carbono , Núcleo Celular , Trinitrobenzenos
6.
Ophthalmic Res ; 65(2): 152-161, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34942626

RESUMO

BACKGROUND: Although observational studies have suggested that prior intravitreal therapy may predict posterior capsule rupture (PCR) during cataract surgery, this finding is still controversial. OBJECTIVE: This study aimed to summarize current evidence on the association between prior intravitreal injection (IVI) and PCR during cataract surgery. METHODS: A systematic literature search was performed up to October 27, 2021. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using random-effects models. The potential association between IVI and PCR in future cataract surgeries was assessed using the following two models: "pooling the ORs of PCR in eyes with and without previous IVI(s)" and "pooling the ORs for PCR relative to each increase in the number of prior injections." The quality of included studies was appraised using the Newcastle-Ottawa Scale. RESULTS: Six cohort studies were included in this meta-analysis, with a total of 1,051,097 eyes that underwent cataract surgery. Of these, 7,034 eyes were associated with previous IVI. The pooled odds of PCR in eyes with prior IVI was 2.01 (95% CI: 1.35-3.00) times higher than that of eyes without an IVI history. An increase in the number of previous IVI conferred increased odds of PCR of 1.03 (95% CI: 1.01-1.06). After excluding studies that failed to account for confounders, the significantly increased risk was not altered, and the significant heterogeneity was minimized in both models. CONCLUSION: This meta-analysis provides evidence that previous IVI significantly increases the risk of PCR during future cataract surgery. The risk of PCR should be discussed preoperatively with patients. Further studies are required to validate our findings and explore the underlying mechanisms.


Assuntos
Extração de Catarata , Catarata , Catarata/etiologia , Extração de Catarata/efeitos adversos , Humanos , Injeções Intravítreas , Estudos Retrospectivos , Acuidade Visual
7.
Molecules ; 27(9)2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35566138

RESUMO

Plastic-bonded explosives (PBXs) consisting of explosive grains and a polymer binder are commonly synthesized to improve mechanical properties and reduce sensitivity, but their intrinsic chemical behaviors while subjected to stress are not sufficiently understood yet. Here, we construct three composites of ß-HMX bonded with the HTPB binder to investigate the reaction characteristics under shock loading using the quantum-based molecular dynamics method. Six typical interactions between HMX and HTPB molecules are detected when the system is subjected to pressure. Although the initial electron structure is modified by the impurity states from HTPB, the metallization process for HMX does not significantly change. The shock decompositions of HMX/HTPB along the (100) and (010) surface are initiated by molecular ring dissociation and hydrogen transfer. The initial oxidations of C and H within HTPB possess advantages. As for the (001) surface, the dissociation is started with alkyl dehydrogenation oxidation, and a stronger hydrogen transfer from HTPB to HMX is detected during the following process. Furthermore, considerable fragment aggregation is observed, which mainly derives from the formation of new C-C and C-N bonds under high pressure. The effect of cluster evolution on the progression of the following reaction is further studied by analyzing the bonded structure and displacement rate.

8.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 45(4): 395-399, 2020 Apr 28.
Artigo em Inglês, Zh | MEDLINE | ID: mdl-32879063

RESUMO

OBJECTIVES: To analyze the risk factors for postoperative deep vein thrombosis (DVT) in neurosurgical patients to provide the basis for the prevention of postoperative DVT. METHODS: A total of 141 patients underwent neurosurgery were enrolled. Thrombelastography (TEG) test was performed before and at the end of surgery. According to whether there was DVT formation after operation, the patients were divided into a thrombosis group and a non-thrombosis group. T-test and rank sum test were used to compare the general clinical characteristics of the 2 groups, such as age, gender, intraoperative blood loss, D-dimer, intraoperative crystal input, colloid input, blood product transfusion, operation duration, length of postoperative hospitalization. The application of chi-square test and rank-sum test were used to compared TEG main test indicators such as R and K values between the 2 groups. Logistic regression was used to analyze the possible risk factors for postoperative DVT in neurosurgical patients. RESULTS: There were significant differences in postoperative TEG index R, clotting factor function, intraoperative blood loss, hypertension or not, length of postoperative hospital stay, and postoperative absolute bed time (all P<0.05). Logistic regression analysis showed hypercoagulability, more intraoperative blood loss and longer postoperative absolute bed time were risk factors for DVT formation after craniotomy. CONCLUSIONS: Hypercoagulability in postoperative TEG test of patients is an important risk factor for the formation of postoperative DVT after neurosurgery, which can predict the occurrence of postoperative DVT to some extent.


Assuntos
Trombofilia , Trombose Venosa/epidemiologia , Trombose Venosa/etiologia , Craniotomia/efeitos adversos , Humanos , Complicações Pós-Operatórias/epidemiologia , Período Pós-Operatório , Fatores de Risco
9.
Int J Mol Sci ; 20(14)2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31336603

RESUMO

As the core components of abscisic acid (ABA) signal pathway, Clade A PP2C (PP2C-A) phosphatases in ABA-dependent stress responses have been well studied in Arabidopsis. However, the roles and natural variations of maize PP2C-A in stress responses remain largely unknown. In this study, we investigated the expression patterns of ZmPP2C-As treated with multiple stresses and generated transgenic Arabidopsis plants overexpressing most of the ZmPP2C-A genes. The results showed that the expression of most ZmPP2C-As were dramatically induced by multiple stresses (drought, salt, and ABA), indicating that these genes may have important roles in response to these stresses. Compared with wild-type plants, ZmPP2C-A1, ZmPP2C-A2, and ZmPP2C-A6 overexpression plants had higher germination rates after ABA and NaCl treatments. ZmPP2C-A2 and ZmPP2C-A6 negatively regulated drought responses as the plants overexpressing these genes had lower survival rates, higher leaf water loss rates, and lower proline accumulation compared to wild type plants. The natural variations of ZmPP2C-As associated with drought tolerance were also analyzed and favorable alleles were detected. We widely studied the roles of ZmPP2C-A genes in stress responses and the natural variations detected in these genes have the potential to be used as molecular markers in genetic improvement of maize drought tolerance.


Assuntos
Proteína Fosfatase 2C/metabolismo , Estresse Fisiológico , Zea mays/metabolismo , Ácido Abscísico/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Secas , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteína Fosfatase 2C/genética , Tolerância ao Sal/genética , Cloreto de Sódio/farmacologia , Estresse Fisiológico/genética , Zea mays/classificação , Zea mays/efeitos dos fármacos , Zea mays/genética
10.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 44(4): 377-385, 2019 Apr 28.
Artigo em Zh | MEDLINE | ID: mdl-31113912

RESUMO

OBJECTIVE: To investigate whether mammalian target of rapamycin (mTOR) signaling pathway is involved in peripheral nerve injury-induced hyperalgesia through activation of spinal dorsal astrocytes in rats.
 Methods: A total of 30 male Sprague-Dawley (SD) rats were randomly divided into 6 groups (n=5): the 1 day group (D1 group), the 4 days group (D4 group), the 7 days group (D7 group), the 14 days group (D14 group), the normal group and the sham group. The sciatic nerve chronic constriction injury (CCI) model was established in the D1, D4, D7 and D14 group. The normal group received no treatment while the sham group was only exposed the sciatic nerve. Paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL) were measured at the 1st, 4th, 7th, and 14th day after CCI in the different groups. Lumbar spinal cord were harvested on the 1st, 4th, 7th and 14th day in the D1, D4, D7, D14 group correspondingly, which were harvested on the 14th day in the normal group and the sham group. Distribution of mTOR in rat spinal cord was assessed by immunohistochemistry. The expressions of mTOR mRNA and protein in the spinal cord in different groups were determined by real-time PCR and Western blotting, respectively. Another 30 male intrathecal catheterized SD rats were randomly divided into 6 groups (n=5): a blank group, a CCI group, a CCI+early rapamycin (RAPA) group, a CCI+early dimethylsulfoxide (DMSO) group, a CCI+ later RAPA group, and a CCI+later DMSO group. The blank group didn't received any treatment; The CCI group was carried out the treatment of CCI model in the left hind limbs. 10 µL of 1% RAPA was given to the CCI+early RAPA group intrathecally at 4 hours after CCI for 3 days; the CCI+later RAPA group were treated with the same dose of RAPA on the 7th days after CCI for 3 days; the CCI+early DMSO group and the CCI+later DMSO group were injected with the same volume of 4% DMSO at the corresponding time as controls. The PWTL and PWMT were measured before and after intrathecal catheterization, and every other day after CCI. The lumbar spinal cords were selected and the expression of glial fibrillary acidic protein (GFAP) in spinal dorsal horn were examined by immunohistochemistry in the 14th day after CCI.
 Results: The immunohistochemistry positive particles of mTOR were widely distributed in the cytoplasm of the normal spinal neurons. Compared with the base line, the PWMT in the D14 group on the 1st, 4th, 7th and 14th day after CCI were significantly lower, and the PWTL on the 4th, 7th and 14th day after CCI were also significantly lower (P<0.05 or P<0.01). The expressions of mTOR mRNA and protein in the CCI groups (D1, D4, D7 and D14 group) were significantly increased than those in the normal group (P<0.05 or P<0.01). Compared with the CCI+early DMSO group, the PWMT and PWTL in the CCI+early RAPA group were obviously increased on 4th, 6th, 8th, 10th, 12th or 14th day after CCI (P<0.05 or P<0.01); compared with the CCI+later DMSO group, the PWMT and PWTL in the CCI+later RAPA group were also significantly increased at the 8th, 10th or 14th day after CCI (P<0.01 or P<0.05). The GFAP immunohistochemistry positive area and absorbance value in the dorsal horn of the lumbar spinal cord in the CCI rats were decreased in the CCI+early RAPA group compared with the CCI+early DMSO group (P<0.05 or P<0.01), and which were also decreased in the CCI+later RAPA group compared with the CCI+later DMSO group (P<0.05 or P<0.01).
 Conclusion: mTOR signaling pathway may be involved in hyperalgesia induced by peripheral nerve injury via spinal astrocyte activation in the dorsal horn of the spinal cord.


Assuntos
Neuralgia , Traumatismos dos Nervos Periféricos , Animais , Hiperalgesia , Masculino , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Medula Espinal , Serina-Treonina Quinases TOR
11.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 44(1): 40-45, 2019 Jan 28.
Artigo em Zh | MEDLINE | ID: mdl-30837401

RESUMO

OBJECTIVE: To analyze the prognostic factors for patients with or without cardiovascular diseases after craniotomy for aneurysm clipping, and to provide evidences for the improvement of perioperative management in these patients.
 Methods: We collected 297 patients who underwent craniotomy for aneurysm clipping in Xiangya Hospital of Central South University from May 2016 to February 2017. The patients were divided into two groups: the cardiovascular disease group and the non-cardiovascular disease group. The perioperative clinical data, neurological function assessments at admission and discharge and Glasgow Outcome Scale (GOS) scores of one-year-follow-up after discharge were analyzed. The primary outcome of this study was the GOS scores collected at one year after discharge. The secondary outcomes were the lengths of their ICU stay, neurological functions at discharge and adverse events morbidity during the hospitalization.
 Results: A total of 241 patients were eventually enrolled. There was no significant difference in their general data between the two groups except for their ages. The GOS scores of the one-year-follow-up were significantly different between the two groups (P=0.007). The lengths of ICU stay, neurological dysfunctions at discharge and adverse events morbidity during hospitalization were also significantly different (P=0.036, P=0.011, P=0.005, respectively). A multivariate logistic regression analysis in which GOS score was the dependent variable with age adjusted also supported the previous results that long-term prognosis was not significantly correlated with the age of patients (P>0.05), but it was correlated with cardiovascular disease and sanity at admission (P=0.001). In patients with cardiovascular diseases, there was significantly different in perioperative mortality and neurological recovery of patients who had or had not cardiovascular events (P=0.006, P=0.001, respectively).
 Conclusion: Undergoing craniotomy for aneurysm clipping, patients with cardiovascular diseases have worse outcomes in both of short and long terms. Perioperative treatments for cardiovascular disease could not only improve postoperative neurological deficits, but also reduce mortality for these patients.


Assuntos
Aneurisma Intracraniano , Craniotomia , Humanos , Período Pós-Operatório , Prognóstico , Resultado do Tratamento
12.
Phys Chem Chem Phys ; 16(46): 25498-507, 2014 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-25347135

RESUMO

In order to disclose the reason that the N-doped carbon support can enhance the stability of Au-based catalysts for acetylene hydrochlorination, we established a big graphene cluster model of C110H28 to investigate the effect of different nitrogen-doped carbon supports on three kinds of gold species models of Au dimers, Au2Cl2 and Au2Cl6, through DFT calculations. Comparing the adsorption energy of each Au complex and the transferred charge from the support to the Au complex, it is observed that on the N-doped support GRN-I (the pyridinic N-doped graphene) the adsorption energies of the Au dimer, Au2Cl2 and Au2Cl6, are much higher than those on other three kinds of supports, and the Au complex accepts most of the transferred charges from the support of GRN-I. The effect of different supports on the adsorption of C2H2 and HCl was studied on Au2Cl6/supports, suggesting that the co-adsorption of both reactants occurs on Au2Cl6/GRN-I. The results indicate that the N-doped support of GRN-I can stabilize the gold species Au2Cl6 and enhance the interaction between Au2Cl6 and HCl, which can inhibit the reduction of Au(3+) and then increase the long-term stability of Au-based catalysts.

13.
Chem Asian J ; 18(6): e202201283, 2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36782100

RESUMO

Herein, CoF2 was synthesized by a solvothermal method. The characterization results of the phase and morphology of the sample show that it was successfully synthesized and its morphology is composed of micron particles with uneven size and shape. The electrochemical test results of SCs in different electrolytes show that CoF2 has electrochemical activity only in alkaline electrolytes. Notably, the electrochemical behavior of CoF2 in LiOH solution is different from that in other alkaline solutions in that charge-discharge curve has a quasi-isosceles triangle shape and the CV curve has no obvious redox peak. That is, it has pseudocapacitance behavior in LiOH. Furthermore, CoF2 as catalyst for HER requires an overpotential of only 168 mV to obtain current density of 10 mA cm-2 and a Tafel slope of 116 mV dec-1 in 1 M KOH solution. This research provides a novel way to explore excellent performance electrode materials for SC and HER.

14.
ACS Omega ; 7(24): 21255-21261, 2022 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-35755330

RESUMO

How to improve the dehydrogenation properties of ammonia borane (AB, NH3BH3) is always a challenge for its practical application in hydrogen storage. In this study, we reveal the enhanced effect of an external electric field (E ext) on AB dehydrogenation by means of the ab initio molecular dynamics method. The molecular rotation induced by an electrostatic force can facilitate the formation of the H-N···B-H framework, which would aggregate into poly-BN species and further suppress the generation of the volatile byproducts. Meanwhile, the dihydrogen bond (N-Hδ+···Î´-H-B) is favorably formed under E ext, and the interaction between relevant H atoms is enhanced, leading to a faster H2 liberation. Correspondingly, the apparent activation energy for AB dissociation is greatly reduced from 18.42 to around 15 kcal·mol-1 with the application of an electric field, while that for H2 formation decreases from 20.4 to about 16 kcal·mol-1. In the whole process, the cleavage of the B-H bond is more favorable than that of the N-H bond, no matter whether the application of E ext. Our results give a deep insight into a positive effect of an electric field on AB dehydrogenation, which would provide an important inspiration for hydrogen storage in industry applications.

15.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 36(5): 392-7, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21685693

RESUMO

OBJECTIVE: To investigate the intervention effect of lentivirus expressing human IL-10 (LV-hIL-10) on activated astrocytes. METHODS: DI TNC1 cell line was treated with different concentrations of lipopolysaccharide (LPS) and time points. The expression of proinflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukinb-1ß (IL-1ß) was detected by RT-PCR and ELISA. Moreover, the effect on the expression of proinflammatory cytokines TNF-α and IL-1ß was analyzed in DI TNC1 cell lines infected with and without LV-hIL-10. RESULTS: The expression of TNF-α and IL-1ß was increased in DI TNC1 induced by LPS. The expression of IL-10 was upregulated in DI TNC1 infected with LV-hIL-10. TNF-α and IL-1ß were inhibited by IL-10 overexpression in DI TNC1 actived by LPS. CONCLUSION: DI TNC1 is activated by LPS and secretes proinflammatory cytokines TNF-α and IL-1ß as immune-like cells, and these activation is inhibited by hIL-10 overexpression.


Assuntos
Astrócitos/metabolismo , Interleucina-10/metabolismo , Interleucina-1beta/metabolismo , Lipopolissacarídeos/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Animais , Astrócitos/citologia , Encéfalo/citologia , Linhagem Celular , Humanos , Interleucina-10/genética , Interleucina-1beta/genética , Ratos , Fator de Necrose Tumoral alfa/genética
16.
Materials (Basel) ; 14(14)2021 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-34300736

RESUMO

Herein, a simple and efficient method is proposed for fabricating Fe81Ga19 alloy thin sheets with a high magnetostriction coefficient. Sharp Goss texture ({110}<001>) was successfully produced in the sheets by rapid secondary recrystallization induced by nanosized NbC particles at low temperatures. Numerous NbC precipitates (size ~90 nm) were obtained after hot rolling, intermediate annealing, and primary recrystallization annealing. The relatively higher quantity of nanosized NbC precipitates with 0.22 mol% resulted in finer and uniform grains (~10 µm) through thickness after primary recrystallization annealing. There was a slow coarsening of the NbC precipitates, from 104 nm to 130 nm, as the temperature rose from 850 °C to 900 °C in a pure nitrogen atmosphere, as well as a primary recrystallization textured by strong γ fibers with a peak at {111} <112> favoring the development of secondary recrystallization of Goss texture at a temperature of 850 °C. Matching of the appropriate inhibitor characteristics and primary recrystallization texture guaranteed rapid secondary recrystallization at temperatures lower than 950 °C. A high magnetostriction coefficient of 304 ppm was achieved for the Fe81Ga19 sheet after rapid secondary recrystallization.

17.
Materials (Basel) ; 14(18)2021 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-34576607

RESUMO

Matrix microstructure and texture controlling is an important way to optimize Goss ({110}<001>) abnormal grain growth (AGG) in high magnetic induction grain-oriented silicon (Hi-B) steel during primary recrystallization. In the present work, a matrix with homogeneous grain size and favorable texture components was obtained through two-stage normalized annealing followed by primary recrystallization. Furthermore, secondary recrystallization was performed for sharp Goss orientation by slow heating and purified annealing. It was found that plenty of island grains, which occurred and disappeared gradually, accompanied the process of AGG. Through analyzing the evolution of microstructure and texture, we realized that the formation of island grains was related to the large-size grains in matrix, and the elimination of that was attributed to the special grain boundaries which satisfied both coincident site lattice (CSL) and high-energy (HE) models. It was essential to control grain size and favorable orientations in matrix comprehensively for the high-efficient abnormal growing of sharp Goss orientation, through which excellent magnetic properties could be obtained simultaneously.

18.
J Colloid Interface Sci ; 598: 283-301, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-33901853

RESUMO

Lithium-ion capacitors (LICs) are emerging as one of the most advanced energy storage devices by combining the virtues of both supercapacitors (SCs) and lithium-ion batteries (LIBs). However, the kinetic and capacity mismatch between anode and cathode is the main obstacle to wide applications of LICs. Therefore, the effective strategy of constructing a high-performance LIC is to improve the rate and cycle performance of the anode and the specific capacity of the cathode. Herein, the nickel cobalt phosphate (NiCoP) microspheres anode is demonstrated with robust structural integrity, high electrical conductivity, and fast kinetic feature. Simultaneously, the watermelon-peel biomass-derived carbon (WPBC) cathode is demonstrated a sustainable synthesis strategy with high specific capacity. As expected, the NiCoP exhibits high specific capacities (567 mAh g-1 at 0.1 A g-1), superior rate performance (300 mAh g-1 at 1A g-1), and excellent cycle stability (58 mAh g-1 at 5 A g-1 after 15,000 cycles). The WPBC possesses a high specific surface area (SSA) of 3303.6 m2 g-1 and a high specific capacity of 226 mAh g-1 at 0.1 A g-1. Encouragingly, the NiCoP//WPBC-6 LIC device can deliver high energy density (ED) of 127.4 ± 3.3 and 67 ± 3.8Wh kg-1 at power density (PD) of 190 and 18240 W kg-1 (76.4% capacity retention after 7000 cycles), respectively.

19.
Dalton Trans ; 50(30): 10471-10481, 2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34259285

RESUMO

In our study, a simple method was employed to prepare ultra-micropore-dominated carbon materials with controllable pore size. A mass of heteroatoms was introduced by surface functional group grafting, resulting in enhanced electrochemical performance: the maximum specific capacity of 327.5 F g-1 was obtained at 0.5 A g-1 in 6 M KOH, while that of un-grafted original ultra-microporous carbon was only 188 F g-1, with long-term cycle stability (90.5% of the initial after 10 000 cycles), and excellent rate performance (over 82% at the current density from 0.5 A g-1 to 10 A g-1). The mechanism behind the improved performance was due to the presence of the introduced functional groups that improved the surface wettability of the material and provided additional redox active sites. Their synergistic effects promoted the enhanced electrochemical performance of the ultra-microporous carbon. This study provides a basis for the study of the energy storage mechanism of ultra-microporous carbon and the grafted modification of carbon materials with heteroatom-containing functional groups.

20.
ACS Appl Mater Interfaces ; 13(8): 10071-10088, 2021 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-33617222

RESUMO

The paramount focus in the construction of lithium-ion capacitors (LICs) is the development of anode materials with high reversible capacity and fast kinetics to overcome the mismatch of kinetics and capacity between the anode and cathode. Herein, a strategy is presented for the controllable synthesis of cobalt-based phosphides with various morphologies by adjusting the time of the phosphidation process, including 3D hierarchical needle-stacked diabolo-shaped CoP nanorods, 3D hierarchical stick-stacked diabolo-shaped Co2P nanorods, and 3D hierarchical heterostructure CoP@Co2P nanorods. 3D hierarchical nanostructures and a highly conductive project to accommodate volume changes are rational designs to achieve a robust construction, effective electron-ion transportation, and rapid kinetics characteristics, thus leading to excellent cycling stability and rate performance. Owing to these merits, the 3D hierarchical CoP, Co2P, and CoP@Co2P nanorods demonstrate prominent specific capacities of 573, 609, and 621 mA h g-1 at 0.1 A g-1 over 300 cycles, respectively. In addition, a high-performance CoP@Co2P//AC LIC is successfully constructed, which can achieve high energy densities of 166.2 and 36 W h kg-1 at power densities of 175 and 17524 W kg-1 (83.7% capacity retention after 12000 cycles). Therefore, the controllable synthesis of various simultaneously constructed crystalline phases and morphologies can be used to fabricate other advanced energy storage devices.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA