This work revisits the analysis of charged Casimir wormhole solutions within the framework of Einstein–Gauss–Bonnet(EGB)gravity,addressing a critical inconsistency in the approach presented by Farooq et al.Specifica...This work revisits the analysis of charged Casimir wormhole solutions within the framework of Einstein–Gauss–Bonnet(EGB)gravity,addressing a critical inconsistency in the approach presented by Farooq et al.Specifically,we show that their use of four-dimensional Casimir and electric field energy densities are incompatible with the higher-dimensional nature of EGB gravity,which requires D≥5.We provide the correct formulation for the energy densities and revise the wormhole properties under this framework,offering a refined perspective on the interplay between extra dimensions and Casimir effects in EGB gravity.展开更多
The tensile creep anisotropy of a dilute-alloyed Mg-0.3wt%Ca sheet is investigated along the rolling direction(RD)and normal direction(ND).Strong creep anisotropy is shown between the RD and ND,owing to the easy twinn...The tensile creep anisotropy of a dilute-alloyed Mg-0.3wt%Ca sheet is investigated along the rolling direction(RD)and normal direction(ND).Strong creep anisotropy is shown between the RD and ND,owing to the easy twinning and the Ca-segregation along twin boundaries during creep loading along the ND.To weaken the creep anisotropy,hot-compression parallel to the RD-ND plane is performed and the continuous dynamic recrystallization mechanism induces a bimodal microstructure with the coexistence of unrecrystallized and recrystallized grains.The creep anisotropy is successfully weakened after hot-compression,and the creep resistance is also significantly enhanced along both loading directions.With the assistance of microstructural characterization,the weakened creep anisotropy is ascribed to the dislocation arrays in the interiors of recrystallized grains and the Ca-segregation along the boundaries of recrystallized grains.Compared to commercial Mg alloys with poor creep property and rare-earth alloyed Mg with high price,good creep performance and low production cost can be synchronously realized in the hot-compressed Mg-0.3wt%Ca alloy.Thus,this work proposes a new perspective for producing creep-resistant Mg alloys.展开更多
Annealing behaviors of hot-deformed magnesium alloy AZ31 were studied at temperatures from 300 to 673 K by optical and SEM/EBSD metallographic observation. Temperature dependence of the average grain size(D) is catego...Annealing behaviors of hot-deformed magnesium alloy AZ31 were studied at temperatures from 300 to 673 K by optical and SEM/EBSD metallographic observation. Temperature dependence of the average grain size(D) is categorized into three temperature regions, i.e. an incubation period for grain growth, rapid grain coarsening, and normal grain growth. The number of fine grains per unit area, however, is reduced remarkably even in incubation period. This leads to grain coarsening taking place continuously in the whole temperature regions. In contrast, the deformation texture scarcely changes even after full annealing at high temperatures. It is concluded that the annealing processes operating in hot-deformed magnesium alloy with continuous dynamic recrystallized grain structures can be mainly controlled by grain coarsening accompanied with no texture change, that is, continuous static recrystallization.展开更多
The effects of bacterial strain, salinity and pH on the bioleaching of a complex ore using mesophilic and extremely thermophilic bacteria were investigated and the statistical analysis of the results was performed usi...The effects of bacterial strain, salinity and pH on the bioleaching of a complex ore using mesophilic and extremely thermophilic bacteria were investigated and the statistical analysis of the results was performed using ERGUN’s test. The extreme thermophiles were shown to display superior kinetics of dissolution of zinc compared with the mesophiles as confirmed by the statistical analysis. Bioleaching performance of the extreme thermophiles is found to improve in response to the increase in acidity (pH from 2.0 to 1.0) whilst the activity of the mesophiles is adversely affected by decreasing pH. Statistical analysis of the bioleaching data indicates that the effect of pH is insignificant in the range of pH 1.0-1.2 for the extreme thermophiles and pH 1.4-2.0 for the mesophiles. Salinity is shown to have a suppressing effect on the mesophiles. However, the extreme thermophiles appear to be halophilic in character as they could operate efficiently under saline conditions (1%-4%Cl- (w/v)).展开更多
The dynamic recrystallization(DRX) and texture development, taking place during hot deformation of magnesium alloy AZ31 with a strong wire texture, were studied in compression at 673 K (0.73 Tm). Two kinds of samples ...The dynamic recrystallization(DRX) and texture development, taking place during hot deformation of magnesium alloy AZ31 with a strong wire texture, were studied in compression at 673 K (0.73 Tm). Two kinds of samples were machined parallelly to the extruded and transverse directions of Mg alloy rods. New fine grains are evolved at original grain boundaries corrugated at low strains and develop rapidly in the medium range of strain, finally leading to a roughly full evolution of equiaxial fine grains. Kink bands are evolved at grain boundaries corrugated and also frequently in grain interiors at low strains. The boundary misorientations of kink band increase rapidly with increasing strain and approach a saturation value in high strain. The average size of the regions fragmented by kink band is almost the same as that of new grains evolved in high strain. These characteristics of new grain evolution process are not changed by the orientation of the samples, while the flow behaviors clearly depend on it. It is concluded that new grain evolution can be controlled by a deformation-induced continuous reaction, i.e. continuous dynamic recrystallization(DRX). The latter is discussed by comparing with conventional, i.e. discontinuous DRX.展开更多
Grain size and texture changes of magnesium alloy AZ31 were studied in multidirectional forging(MDF) under decreasing temperature conditions.MDF was carried out up to large cumulative strains of 4.8 with changing the ...Grain size and texture changes of magnesium alloy AZ31 were studied in multidirectional forging(MDF) under decreasing temperature conditions.MDF was carried out up to large cumulative strains of 4.8 with changing the loading direction during decrease in temperature from pass to pass.MDF can accelerate the uniform development of fine-grained structures and increase the plastic workability at low temperatures.As a result,the MDFed alloy shows excellent higher strength as well as moderate ductility at room temperature even at the grain size below 1μm.Superplastic flow takes place at 423 K and depends on the anisotropy of MDFed samples.The mechanisms of strain-induced fine-grained structure development and of the plastic deformation were discussed in detail.展开更多
The hourly data of the vertical Z and the horizontal H components of 37 ground-based DC-ULF geomagnetic stations are examined during 20 April-12 May 2008. On 9 May 2008, three days before the Wenchuan MS 8.0 shock, an...The hourly data of the vertical Z and the horizontal H components of 37 ground-based DC-ULF geomagnetic stations are examined during 20 April-12 May 2008. On 9 May 2008, three days before the Wenchuan MS 8.0 shock, anomalies-a double low-point and a decreased amplitude-are registered on the curves of the Z component at 25 stations in a large-scale area surrounding the Wenchuan epicentral area. The H component shows none of the double low-point phenomenon but does exhibit a reduced magnitude at the same time. The geomagnetic index Kp is also examined and indicates that the anomalies appear at a solar quiet period. The appearing time shift(Tzs) between the first low-point on May 9 and the minimum point occurring time of May 1-5, 2008 is also checked.The results show that Tzs is on the order of 1-2 hours earlier or later than usual and there is a 2-6 hours’ gap between these two lowpoints. However, there is still a transition area which includes the epicenter where Tzs=0. Variation amplitude examined on vertical Z increases as the distance from the epicenter decreases. An Earth-air-ionosphere model has been employed to investigate a possible mechanism of this phenomenon and positive results have been unexpectedly attained. All these above-related results tend to prove that the variations of the Z and H on May 9, 2008 during the solar quiet period are probably associated with the forthcoming Wenchuan MS 8.0 earthquake.展开更多
Deciduous trees with high-density wood that occur in dry seasonal tropical regions respond to rainfall seasonality with synchrony in phenophases. However, they may exhibit interannual differences in synchrony and inte...Deciduous trees with high-density wood that occur in dry seasonal tropical regions respond to rainfall seasonality with synchrony in phenophases. However, they may exhibit interannual differences in synchrony and intensity of phenophases, as strategy for large variations in duration and intensity of rainfall pulses. Nevertheless, it remains unknown how phenophases of deciduous trees of the Brazilian semi-arid region respond to rainfall variations. The phenology of Cordia oncocalyx was monitored in deciduous thorny woodland （Caatinga）, from April 2009 to March 2011, and was correlated with rainfall, soil humidity, temperature, and photoperiod. The rainy years 2009 and 2011 exhibited higher duration of rainfall pulses and lower frequency of interpulses, but in 2010 pulse duration and total rainfall were lower. Circular statistics showed leaf flush followed by flowering and fruiting in the rainy season, and leaf fall and seed dispersal in the dry season.展开更多
Objectives:This article reviews the advantages and disadvantages of endoscopic ear surgery(EES).Method:Pubmed,Google and the Proquest Central Database at Kirikkale University were queried using the keywords"endos...Objectives:This article reviews the advantages and disadvantages of endoscopic ear surgery(EES).Method:Pubmed,Google and the Proquest Central Database at Kirikkale University were queried using the keywords"endoscopic ear surgery","ear surgery"and"endoscopy"to identify the literature needed for the review.Results:Endoscopes allow for enhanced surgical visualisation.The distal part of the apparatus is illuminated and contains lenses angled to allow a wider view of the operative area.Transcanal endoscopic techniques have transformed the external ear canal(EAC)into an operative gateway.The benefits EES can offer include wider views,enhanced imaging capabilities and increased magnification,and ways to see otherwise poorly visualisable portions of the middle ear.EES permits surgeons to operate using minimally invasive otological techniques.When compared with microscope-assisted surgery,endoscopic tympanoplasty has been shown to require a shorter operating time in some instances.There are a number of drawbacks to EES,however,which include the fact that it is a single-handed technique,that the light source may produce thermal injury and that visualisation using the endoscope is severely curtailed if bleeding is profuse.Conclusion:EES is a safe and effective technique.The current literature supports the idea that the results achieved by endoscopic methods are usually comparably beneficial to results obtained using conventional microscopic methods.展开更多
Medicinal plants have been used to treat various ailments of the poor population around the world;hence the interest among researchers to know the active ingredients of certain plants has being increased.The Calotropi...Medicinal plants have been used to treat various ailments of the poor population around the world;hence the interest among researchers to know the active ingredients of certain plants has being increased.The Calotropis procera(C.procera) is a plant original from Africa,commonly found in northeastern Brazil.It is well known for their pharmacological properties,since it produces large amounts of latex.The important role that medicinal plants play in folk medicine has led us to develop this article in order to review the major pharmacological activities of C. procera.展开更多
There have been published many papers on VLF (very low frequency) characteristics to study seismo-ionospheric perturbations. Usually VLF records (amplitude and/or phase) are used to investigate mainly the temporal evo...There have been published many papers on VLF (very low frequency) characteristics to study seismo-ionospheric perturbations. Usually VLF records (amplitude and/or phase) are used to investigate mainly the temporal evolution of VLF propagation anomalies with special attention to one particular propagation path. The most important advantage of this paper is the simultaneous use of several propagation paths. A succession of earthquakes (EQs) happened in the Kumamoto area in Kyusyu Island;two strong foreshocks with magnitude of 6.5 and 6.4 on 14 April (UT) and the main shock with magnitude 7.3 on 15 April (UT). Because the EQ epicenters are not far from the VLF transmitter (with the call sign of JJI in Miyazaki prefecture), we can utilize simultaneously 8 observing stations of our network all over Japan. Together with the use of theoretical computations based on wave-hop theory, we try to trace both the temporal and spatial evolutions of the ionospheric perturbation associated with this succession of EQs. It is found that the ionospheric perturbation begins to appear about two weeks before the EQs, and this perturbation becomes most developed 5 - 3 days before the main shock. When the perturbation is most disturbed, the maximum change in vertical direction is depletion in the VLF effective ionospheric height of the order of 10 km, and its horizontal scale (or its radius) is about 1000 km. These spatio-temporal changes of the seismo-ionospheric perturbation will be investigated in details in the discus-sion, a comparison has made with the VLF characteristics of the 1995 Kobe with the same magnitude and of the same fault-type, and a brief discussion on the generation mechanism of seismo-ionospheric perturbation is finally made.展开更多
This study aims to evaluate the possible allelopathic effects of young and mature leaf extract from of two eucalyptus genetic materials on the physiological performance of millet seeds. The experiment was carried out ...This study aims to evaluate the possible allelopathic effects of young and mature leaf extract from of two eucalyptus genetic materials on the physiological performance of millet seeds. The experiment was carried out in a completely randomized design, in a 5 × 2 × 2 factorial arrangement [five concentrations of the extract (0, 25%, 50%, 75%, and 100%) × two genetic materials (1 - Eucalyptus grandis × Eucalyptus urophylla and 2 - Eucalyptus grandis × Eucalyptus camaldulensis) × two maturation stages of leaves (young and mature leaves)] with four replicates, each one with 25 seeds. Seeding was performed on the germitest paper substrate distributed in Petri dishes, moistened with the extract according to the treatments, being allocated in biochemical oxygen demand (B.O.D) adjusted at 25°C and 12 h photoperiod. Percentage, speed index, mean germination time, aerial part and primary root length, and dry matter weight of aerial part and root system of seedlings were evaluated. The leaf extracts of the two eucalyptus clones had all the analyzed variables changed with effect more evident on young leaf extract of the genetic material 1. It can be concluded that the tested genetic materials have a detrimental effect on the physiological performance of millet seeds.展开更多
Study of seismo-ionospheric coupling mechanism demands the quiet geomagnetic condition to eliminate any kind of contamination in the lower atmospheric and ionospheric parameters. In this manuscript, we present the eff...Study of seismo-ionospheric coupling mechanism demands the quiet geomagnetic condition to eliminate any kind of contamination in the lower atmospheric and ionospheric parameters. In this manuscript, we present the effect of back to back two geomagnetic storms before a strong earthquake happened in Imphal, India on January 4, 2016 (M</span><span style="font-family:""> </span><span style="font-family:Verdana;">=</span><span style="font-family:""> </span><span style="font-family:Verdana;">6.7). We studied the lower ionospheric irregularities for </span><span style="font-family:Verdana;">the</span><span style="font-family:Verdana;"> duration of 31 days by computing the nighttime fluctuations in Very Low Frequency (VLF) radio signal received transmitter JJI (22.2 kHz) in Japan at Ionospheric and Earthquake Research Centre & Optical Observatory (IERCOO), Sitapur, India. We also studied the presence of Atmospheric Gravity Wave (AGW) in nighttime VLF signal in lower ionospheric heights and the same computed that from SABER/TIMED satellite. Two geomagnetic storms occurred on December 21, and 31, 2015. By the conventional analysis, we found that there is a significant decrease in nighttime trend and an increase in nighttime fluctuations around 15 days before the earthquake and just on the first storm and thus the pre-seismic effects on VLF signal gets contaminated due to the presence of storms. The wave-like structure in VLF fluctuations shows significant increase in intensity by using Fourier and Wavelet analysis before the earthquake. By analysis of SABER data, we found significant enhancement in AGW around 10 days before the earthquake. As the wavelike structures are coming from neutral acoustics reasons from pressure or temperature variations, this paper exhibits a significant example of contamination in ionospheric parameters due to geomagnetic storm where the acoustics parameters remain un-contaminated.展开更多
Induction vectors have been extensively calculated using data from 19 Japanese observatories for a dozen years preceding the huge 2011 Tohoku earthquake (EQ). At 6 observatories anomalous variations of induction vecto...Induction vectors have been extensively calculated using data from 19 Japanese observatories for a dozen years preceding the huge 2011 Tohoku earthquake (EQ). At 6 observatories anomalous variations of induction vectors were separated in the years of 2008-2010 that can be identified as middle-term precursors. These observatories are located not at the shortest distance from the EQ epicenter, that is in agreement with the widely known phenomenon of spatial selectivity of EQ precursors. The analysis of horizontal tensors reveals a conductivity anomaly under the central part of the Boso peninsula (at 30 km from Tokyo) with a WNW-ESE strike coinciding both with the Sagami trough strike and the strike of well conducting 3 km thick sediments. A joint analysis of geoelectric and tectonic data leads to a preliminary conclusion that the Boso conductivity anomaly connects two large scale conductors: Pacific sea water and a deep magma reservoir beneath a volcanic belt. Between two so different conductors an unstable transition zone can be expected which should be sensitive to changes of stress. Applying our original processing including two steps analysis and elimination of annual and monthly periods, a short-term two-month-long precursor of bay-like form was successfully separated at the observatory of Kanozan, KNZ (over the Boso anomaly) despite its strong noise. All the results were obtained with advanced multi-windows multi-rr (remote reference) robust programs with a coherency control. Dependence of the results of induction vector calculation on geomagnetic activity was carefully studied, and this dependence is relatively strong when the magnetotelluric field and noise have approximately the same magnitude. But even in this case we could identify the precursor field.展开更多
The ultra-low frequency (ULF) magnetic field data at a station very close to the 2008 Sichuan earthquake (EQ) (on 12 May, 2008;M = 8.0) are extensively studied on the basis of combined statistical and natural time ana...The ultra-low frequency (ULF) magnetic field data at a station very close to the 2008 Sichuan earthquake (EQ) (on 12 May, 2008;M = 8.0) are extensively studied on the basis of combined statistical and natural time analyses. Two effects in ULF are treated: one is the well-known ULF radiation from the lithosphere, and the other is the non-conventional depression of ULF horizontal magnetic field. The simple statistical analysis has yielded: 1) no clear evidence of the presence of precursory ULF radiation, and 2) a significant effect of depression of ULF horizontal field a few days before the EQ (as a signature of ionospheric perturbations). The recently introduced natural time analysis has also been performed in order to study the critical features of the lithosphere and essentially new information has been brought about. The parameter “polarization”, as the ratio of vertical to horizontal components, showed critical features in the time period of 17 - 27 April, about one month to two weeks before the EQ as a signature of lithospheric radiation. Then, the natural time analysis has reconfirmed the presence of ionospheric perturbations a few days before the EQ, together with an additional time window found on 19 - 23 April, about one month before the EQ, exhibiting critical features in the ULF depression.展开更多
Background: Accessibility enables the effective participation of disabled persons in public and private areas and the use of urban equipment and street furniture. Objective: This study aimed to analyze the physical ac...Background: Accessibility enables the effective participation of disabled persons in public and private areas and the use of urban equipment and street furniture. Objective: This study aimed to analyze the physical accessibility of toilet facilities in urban and rural primary health care units. Methods: It was a quantitative descriptive study conducted in 157 Primary Health Care Units of 16 municipalities in the Baturité Massif region, Ceará, Brazil. The study took place from August 2014 to May 2015, with a checklist type form, designed from the Technical Standard 9050 of the Brazilian National Standards Organization, specifying the ideal access conditions established by law to allow mobility of persons with physical disabilities. Data were processed through the Statistical Package for the Social Sciences software and organized into tables. Results: Toilets designed for physically disabled people were accessible as the location and signs (59.9%), identified with symbols for males and females (57.3%);however, the doorway width was smaller than needed to accommodate a wheelchair (77.7%). Inside the bathroom, only the forward approach was possible (59.9%). Grab bars positioned on the side and rear walls were inadequate or nonexistent (67.6%);toilet seats (91.1%) and toilet paper dispensers (96.2%) were mostly in inaccessible heights;flush controls in appropriate height (59.2%) and activated by light pressure (58%). Sinks without pedestal (51%), but higher than recommended (80.3%) and without single handle faucets (95.6%). It was verified that the toilets of basic health units located in urban areas had better accessibility conditions compared to those in rural areas. Conclusion: Results showed that the analyzed units presented physical inaccessibility in some toilet facilities, making it difficult or even impossible the accessibility for the disabled. The inclusion of accessibility features in health services for this clientele provides equal opportunities and social inclusion.展开更多
There have been reported several papers on the ionospheric F region perturbations prior to the 2008 Sichuan earthquake (EQ) (magnitude 8.0), but it seems that very few reports have been published on the characteristic...There have been reported several papers on the ionospheric F region perturbations prior to the 2008 Sichuan earthquake (EQ) (magnitude 8.0), but it seems that very few reports have been published on the characteristics of ground-based ULF (ultra low frequency) magnetic field variations for this EQ. This paper deals with two different aspects of ground-based ULF magnetic field variations: 1) ULF radiation from the lithosphere, and 2) depression of ULF horizontal magnetic field as a signature of lower ionospheric perturbations. ULF data from two Chinese stations [Chengdu (epicentral distance, 80 km) and Xichang (about 300 km away from the EQ epicenter)] are analyzed, with paying attention to the local nighttime period (LT = 22 h to 02 h, UTC = 14 h to 18 h) in order to avoid man-made noise. We have analyzed powers of the horizontal component (H2), vertical component (Z2), polarization as their ratio (Z2/H2), depression of the horizontal component (as an inverse of horizontal magnetic field component power, 1/H2) and δDep as a variation of depression at a particular frequency of 0.01 - 0.02 Hz (10 - 20 mHz). It is then found that there seems no clear signature of lithospheric ULF radiation. Whilst, the most evident fact is the finding of depression of ULF horizontal magnetic field at Chengdu a few days before the Sichuan EQ, which suggests that the lower ionosphere was perturbed before the EQ. The characteristics of the lower ionospheric perturbations are compared with those of upper ionospheric perturbations reported before.展开更多
Background: Colles’ fracture is a type of fracture of the distal third of the radius and its most common cause is falling from patient’s own height and, epidemiologically, it is more common in the elderly. Objective...Background: Colles’ fracture is a type of fracture of the distal third of the radius and its most common cause is falling from patient’s own height and, epidemiologically, it is more common in the elderly. Objectives: The main objective of this study is to analyze the epidemiology of Colles’ fracture retrospectively, in patients admitted to Fernandes Távora Hospital. Materials and Methods: This retrospective study conducted at the Fernandes Távora Hospital used 1030 radiographic images of patients with wrist fractures. Results: (After a careful analysis) It was found that this type of fracture occurred with a greater frequency in age groups of 50 to 69, 60 to 69, and 40 to 49 years old, which corresponds to 59.5% of patients and the most affected sex were females (51.1%). Conclusion: The study concluded that this type of bone injury is more common in people aged 40 to 69 years old, especially in women, because of their geometry and bone composition. It is evident that Colles’ fracture impacts the life of the affected person, therefore, an adequate diagnosis and treatment having utmost importance.展开更多
Schumann resonance （SR） is an electromag- netic resonance phenomenon in the Earth-ionosphere cavity exited by global lightning activities when the wavelength matches the circumference of the Earth, and the lowest fo...Schumann resonance （SR） is an electromag- netic resonance phenomenon in the Earth-ionosphere cavity exited by global lightning activities when the wavelength matches the circumference of the Earth, and the lowest four peak frequencies of SR are about 8, 14, 20, and 26 Hz. This article presents the new observational data of SR in China. The observations of two horizontal mag- netic components （BNs and BEw） in the frequency band range of 3-29 Hz at Yongsheng observatory （26.7°N, 100.8°E） in southwestern China were mainly analyzed. It is found that the SR amplitudes at peak frequencies in BNs and BEw components all showed diurnal and seasonal variations, and that the SR amplitude in BNS component is always higher than that in BEw component. Diurnal vari- ation of SR amplitude around equinoxes and solstices inBNs component is related to active intervals of three global thunderstorm centers, while SR amplitude in BEw com- ponent is the most significant at around 16 LT, corre- sponding to Asian center. SR amplitudes both in BNs and BEw components increase in the rainy season from May to September. In addition, the SR anomalies in association with the 2011 Japan earthquake are exhibited. The anom- alous effect was characterized by an increase in amplitude at the lowest four SR modes beginning at 4 days before this earthquake. Upon analyzing the wave interference between the direct wave and disturbed wave scattered by localized modification of lower ionosphere over the epicenter, Asian and African thunderstorm centers are found to contribute to anomalous effect observed at Yongsheng station. Modeling results of SR regular and disturbed spectra at different local times led to the similar conclusion.展开更多
We investigate the Schr6dinger equation for a particle with a nonuniform solitonic mass density. First, we discuss in extent the （nontrivial） position-dependent mass V（x） = 0 case whose solutions are hypergeometri...We investigate the Schr6dinger equation for a particle with a nonuniform solitonic mass density. First, we discuss in extent the （nontrivial） position-dependent mass V（x） = 0 case whose solutions are hypergeometric functions in tanh2 x. Then, we consider an external hyperbolic-tangent potential. We show that the effective quantum mechanical problem is given by a Heun class equation and find analytically an eigenbasis for the space of solutions. We also compute the eigenstat, es for a potential of the form V （x） = Vo sinh2 z.展开更多
基金the National Council for Scientific and Technological Development-CNPq(PQ 315926/2021-0)FUNCAP,through the project BP5-0197-00117.01.00/22,for financial support。
文摘This work revisits the analysis of charged Casimir wormhole solutions within the framework of Einstein–Gauss–Bonnet(EGB)gravity,addressing a critical inconsistency in the approach presented by Farooq et al.Specifically,we show that their use of four-dimensional Casimir and electric field energy densities are incompatible with the higher-dimensional nature of EGB gravity,which requires D≥5.We provide the correct formulation for the energy densities and revise the wormhole properties under this framework,offering a refined perspective on the interplay between extra dimensions and Casimir effects in EGB gravity.
基金financial supports received from the National Key Research and Development Program of China(No.2022YFE0109600)the Science and Technology Innovation Program of Hunan Province(No.2024RC3010)the National Natural Science Foundation of China(No.51974376).
文摘The tensile creep anisotropy of a dilute-alloyed Mg-0.3wt%Ca sheet is investigated along the rolling direction(RD)and normal direction(ND).Strong creep anisotropy is shown between the RD and ND,owing to the easy twinning and the Ca-segregation along twin boundaries during creep loading along the ND.To weaken the creep anisotropy,hot-compression parallel to the RD-ND plane is performed and the continuous dynamic recrystallization mechanism induces a bimodal microstructure with the coexistence of unrecrystallized and recrystallized grains.The creep anisotropy is successfully weakened after hot-compression,and the creep resistance is also significantly enhanced along both loading directions.With the assistance of microstructural characterization,the weakened creep anisotropy is ascribed to the dislocation arrays in the interiors of recrystallized grains and the Ca-segregation along the boundaries of recrystallized grains.Compared to commercial Mg alloys with poor creep property and rare-earth alloyed Mg with high price,good creep performance and low production cost can be synchronously realized in the hot-compressed Mg-0.3wt%Ca alloy.Thus,this work proposes a new perspective for producing creep-resistant Mg alloys.
基金Project(AF-2005006) supported by the Amada Foundation for Metal Work Technology and the Light Metals Educational Foundation, Japan
文摘Annealing behaviors of hot-deformed magnesium alloy AZ31 were studied at temperatures from 300 to 673 K by optical and SEM/EBSD metallographic observation. Temperature dependence of the average grain size(D) is categorized into three temperature regions, i.e. an incubation period for grain growth, rapid grain coarsening, and normal grain growth. The number of fine grains per unit area, however, is reduced remarkably even in incubation period. This leads to grain coarsening taking place continuously in the whole temperature regions. In contrast, the deformation texture scarcely changes even after full annealing at high temperatures. It is concluded that the annealing processes operating in hot-deformed magnesium alloy with continuous dynamic recrystallized grain structures can be mainly controlled by grain coarsening accompanied with no texture change, that is, continuous static recrystallization.
文摘The effects of bacterial strain, salinity and pH on the bioleaching of a complex ore using mesophilic and extremely thermophilic bacteria were investigated and the statistical analysis of the results was performed using ERGUN’s test. The extreme thermophiles were shown to display superior kinetics of dissolution of zinc compared with the mesophiles as confirmed by the statistical analysis. Bioleaching performance of the extreme thermophiles is found to improve in response to the increase in acidity (pH from 2.0 to 1.0) whilst the activity of the mesophiles is adversely affected by decreasing pH. Statistical analysis of the bioleaching data indicates that the effect of pH is insignificant in the range of pH 1.0-1.2 for the extreme thermophiles and pH 1.4-2.0 for the mesophiles. Salinity is shown to have a suppressing effect on the mesophiles. However, the extreme thermophiles appear to be halophilic in character as they could operate efficiently under saline conditions (1%-4%Cl- (w/v)).
文摘The dynamic recrystallization(DRX) and texture development, taking place during hot deformation of magnesium alloy AZ31 with a strong wire texture, were studied in compression at 673 K (0.73 Tm). Two kinds of samples were machined parallelly to the extruded and transverse directions of Mg alloy rods. New fine grains are evolved at original grain boundaries corrugated at low strains and develop rapidly in the medium range of strain, finally leading to a roughly full evolution of equiaxial fine grains. Kink bands are evolved at grain boundaries corrugated and also frequently in grain interiors at low strains. The boundary misorientations of kink band increase rapidly with increasing strain and approach a saturation value in high strain. The average size of the regions fragmented by kink band is almost the same as that of new grains evolved in high strain. These characteristics of new grain evolution process are not changed by the orientation of the samples, while the flow behaviors clearly depend on it. It is concluded that new grain evolution can be controlled by a deformation-induced continuous reaction, i.e. continuous dynamic recrystallization(DRX). The latter is discussed by comparing with conventional, i.e. discontinuous DRX.
文摘Grain size and texture changes of magnesium alloy AZ31 were studied in multidirectional forging(MDF) under decreasing temperature conditions.MDF was carried out up to large cumulative strains of 4.8 with changing the loading direction during decrease in temperature from pass to pass.MDF can accelerate the uniform development of fine-grained structures and increase the plastic workability at low temperatures.As a result,the MDFed alloy shows excellent higher strength as well as moderate ductility at room temperature even at the grain size below 1μm.Superplastic flow takes place at 423 K and depends on the anisotropy of MDFed samples.The mechanisms of strain-induced fine-grained structure development and of the plastic deformation were discussed in detail.
基金supported by NSFC (National Natural Science Foundation of China) under grant agreement No.41774084National Key R & D Program of China under grant No.2018YFC 1503506
文摘The hourly data of the vertical Z and the horizontal H components of 37 ground-based DC-ULF geomagnetic stations are examined during 20 April-12 May 2008. On 9 May 2008, three days before the Wenchuan MS 8.0 shock, anomalies-a double low-point and a decreased amplitude-are registered on the curves of the Z component at 25 stations in a large-scale area surrounding the Wenchuan epicentral area. The H component shows none of the double low-point phenomenon but does exhibit a reduced magnitude at the same time. The geomagnetic index Kp is also examined and indicates that the anomalies appear at a solar quiet period. The appearing time shift(Tzs) between the first low-point on May 9 and the minimum point occurring time of May 1-5, 2008 is also checked.The results show that Tzs is on the order of 1-2 hours earlier or later than usual and there is a 2-6 hours’ gap between these two lowpoints. However, there is still a transition area which includes the epicenter where Tzs=0. Variation amplitude examined on vertical Z increases as the distance from the epicenter decreases. An Earth-air-ionosphere model has been employed to investigate a possible mechanism of this phenomenon and positive results have been unexpectedly attained. All these above-related results tend to prove that the variations of the Z and H on May 9, 2008 during the solar quiet period are probably associated with the forthcoming Wenchuan MS 8.0 earthquake.
基金supported by Fundacāo Cearense de Apoio ao Desenvolvimento Científicoe Tecnológico (FUNCAP) (093.01.00/09)National Council for Scientific and Technological Development(CNPq),Brazil
文摘Deciduous trees with high-density wood that occur in dry seasonal tropical regions respond to rainfall seasonality with synchrony in phenophases. However, they may exhibit interannual differences in synchrony and intensity of phenophases, as strategy for large variations in duration and intensity of rainfall pulses. Nevertheless, it remains unknown how phenophases of deciduous trees of the Brazilian semi-arid region respond to rainfall variations. The phenology of Cordia oncocalyx was monitored in deciduous thorny woodland （Caatinga）, from April 2009 to March 2011, and was correlated with rainfall, soil humidity, temperature, and photoperiod. The rainy years 2009 and 2011 exhibited higher duration of rainfall pulses and lower frequency of interpulses, but in 2010 pulse duration and total rainfall were lower. Circular statistics showed leaf flush followed by flowering and fruiting in the rainy season, and leaf fall and seed dispersal in the dry season.
基金supported by Continuous Education and Scientific Research Association
文摘Objectives:This article reviews the advantages and disadvantages of endoscopic ear surgery(EES).Method:Pubmed,Google and the Proquest Central Database at Kirikkale University were queried using the keywords"endoscopic ear surgery","ear surgery"and"endoscopy"to identify the literature needed for the review.Results:Endoscopes allow for enhanced surgical visualisation.The distal part of the apparatus is illuminated and contains lenses angled to allow a wider view of the operative area.Transcanal endoscopic techniques have transformed the external ear canal(EAC)into an operative gateway.The benefits EES can offer include wider views,enhanced imaging capabilities and increased magnification,and ways to see otherwise poorly visualisable portions of the middle ear.EES permits surgeons to operate using minimally invasive otological techniques.When compared with microscope-assisted surgery,endoscopic tympanoplasty has been shown to require a shorter operating time in some instances.There are a number of drawbacks to EES,however,which include the fact that it is a single-handed technique,that the light source may produce thermal injury and that visualisation using the endoscope is severely curtailed if bleeding is profuse.Conclusion:EES is a safe and effective technique.The current literature supports the idea that the results achieved by endoscopic methods are usually comparably beneficial to results obtained using conventional microscopic methods.
文摘Medicinal plants have been used to treat various ailments of the poor population around the world;hence the interest among researchers to know the active ingredients of certain plants has being increased.The Calotropis procera(C.procera) is a plant original from Africa,commonly found in northeastern Brazil.It is well known for their pharmacological properties,since it produces large amounts of latex.The important role that medicinal plants play in folk medicine has led us to develop this article in order to review the major pharmacological activities of C. procera.
文摘There have been published many papers on VLF (very low frequency) characteristics to study seismo-ionospheric perturbations. Usually VLF records (amplitude and/or phase) are used to investigate mainly the temporal evolution of VLF propagation anomalies with special attention to one particular propagation path. The most important advantage of this paper is the simultaneous use of several propagation paths. A succession of earthquakes (EQs) happened in the Kumamoto area in Kyusyu Island;two strong foreshocks with magnitude of 6.5 and 6.4 on 14 April (UT) and the main shock with magnitude 7.3 on 15 April (UT). Because the EQ epicenters are not far from the VLF transmitter (with the call sign of JJI in Miyazaki prefecture), we can utilize simultaneously 8 observing stations of our network all over Japan. Together with the use of theoretical computations based on wave-hop theory, we try to trace both the temporal and spatial evolutions of the ionospheric perturbation associated with this succession of EQs. It is found that the ionospheric perturbation begins to appear about two weeks before the EQs, and this perturbation becomes most developed 5 - 3 days before the main shock. When the perturbation is most disturbed, the maximum change in vertical direction is depletion in the VLF effective ionospheric height of the order of 10 km, and its horizontal scale (or its radius) is about 1000 km. These spatio-temporal changes of the seismo-ionospheric perturbation will be investigated in details in the discus-sion, a comparison has made with the VLF characteristics of the 1995 Kobe with the same magnitude and of the same fault-type, and a brief discussion on the generation mechanism of seismo-ionospheric perturbation is finally made.
文摘This study aims to evaluate the possible allelopathic effects of young and mature leaf extract from of two eucalyptus genetic materials on the physiological performance of millet seeds. The experiment was carried out in a completely randomized design, in a 5 × 2 × 2 factorial arrangement [five concentrations of the extract (0, 25%, 50%, 75%, and 100%) × two genetic materials (1 - Eucalyptus grandis × Eucalyptus urophylla and 2 - Eucalyptus grandis × Eucalyptus camaldulensis) × two maturation stages of leaves (young and mature leaves)] with four replicates, each one with 25 seeds. Seeding was performed on the germitest paper substrate distributed in Petri dishes, moistened with the extract according to the treatments, being allocated in biochemical oxygen demand (B.O.D) adjusted at 25°C and 12 h photoperiod. Percentage, speed index, mean germination time, aerial part and primary root length, and dry matter weight of aerial part and root system of seedlings were evaluated. The leaf extracts of the two eucalyptus clones had all the analyzed variables changed with effect more evident on young leaf extract of the genetic material 1. It can be concluded that the tested genetic materials have a detrimental effect on the physiological performance of millet seeds.
文摘Study of seismo-ionospheric coupling mechanism demands the quiet geomagnetic condition to eliminate any kind of contamination in the lower atmospheric and ionospheric parameters. In this manuscript, we present the effect of back to back two geomagnetic storms before a strong earthquake happened in Imphal, India on January 4, 2016 (M</span><span style="font-family:""> </span><span style="font-family:Verdana;">=</span><span style="font-family:""> </span><span style="font-family:Verdana;">6.7). We studied the lower ionospheric irregularities for </span><span style="font-family:Verdana;">the</span><span style="font-family:Verdana;"> duration of 31 days by computing the nighttime fluctuations in Very Low Frequency (VLF) radio signal received transmitter JJI (22.2 kHz) in Japan at Ionospheric and Earthquake Research Centre & Optical Observatory (IERCOO), Sitapur, India. We also studied the presence of Atmospheric Gravity Wave (AGW) in nighttime VLF signal in lower ionospheric heights and the same computed that from SABER/TIMED satellite. Two geomagnetic storms occurred on December 21, and 31, 2015. By the conventional analysis, we found that there is a significant decrease in nighttime trend and an increase in nighttime fluctuations around 15 days before the earthquake and just on the first storm and thus the pre-seismic effects on VLF signal gets contaminated due to the presence of storms. The wave-like structure in VLF fluctuations shows significant increase in intensity by using Fourier and Wavelet analysis before the earthquake. By analysis of SABER data, we found significant enhancement in AGW around 10 days before the earthquake. As the wavelike structures are coming from neutral acoustics reasons from pressure or temperature variations, this paper exhibits a significant example of contamination in ionospheric parameters due to geomagnetic storm where the acoustics parameters remain un-contaminated.
文摘Induction vectors have been extensively calculated using data from 19 Japanese observatories for a dozen years preceding the huge 2011 Tohoku earthquake (EQ). At 6 observatories anomalous variations of induction vectors were separated in the years of 2008-2010 that can be identified as middle-term precursors. These observatories are located not at the shortest distance from the EQ epicenter, that is in agreement with the widely known phenomenon of spatial selectivity of EQ precursors. The analysis of horizontal tensors reveals a conductivity anomaly under the central part of the Boso peninsula (at 30 km from Tokyo) with a WNW-ESE strike coinciding both with the Sagami trough strike and the strike of well conducting 3 km thick sediments. A joint analysis of geoelectric and tectonic data leads to a preliminary conclusion that the Boso conductivity anomaly connects two large scale conductors: Pacific sea water and a deep magma reservoir beneath a volcanic belt. Between two so different conductors an unstable transition zone can be expected which should be sensitive to changes of stress. Applying our original processing including two steps analysis and elimination of annual and monthly periods, a short-term two-month-long precursor of bay-like form was successfully separated at the observatory of Kanozan, KNZ (over the Boso anomaly) despite its strong noise. All the results were obtained with advanced multi-windows multi-rr (remote reference) robust programs with a coherency control. Dependence of the results of induction vector calculation on geomagnetic activity was carefully studied, and this dependence is relatively strong when the magnetotelluric field and noise have approximately the same magnitude. But even in this case we could identify the precursor field.
文摘The ultra-low frequency (ULF) magnetic field data at a station very close to the 2008 Sichuan earthquake (EQ) (on 12 May, 2008;M = 8.0) are extensively studied on the basis of combined statistical and natural time analyses. Two effects in ULF are treated: one is the well-known ULF radiation from the lithosphere, and the other is the non-conventional depression of ULF horizontal magnetic field. The simple statistical analysis has yielded: 1) no clear evidence of the presence of precursory ULF radiation, and 2) a significant effect of depression of ULF horizontal field a few days before the EQ (as a signature of ionospheric perturbations). The recently introduced natural time analysis has also been performed in order to study the critical features of the lithosphere and essentially new information has been brought about. The parameter “polarization”, as the ratio of vertical to horizontal components, showed critical features in the time period of 17 - 27 April, about one month to two weeks before the EQ as a signature of lithospheric radiation. Then, the natural time analysis has reconfirmed the presence of ionospheric perturbations a few days before the EQ, together with an additional time window found on 19 - 23 April, about one month before the EQ, exhibiting critical features in the ULF depression.
文摘Background: Accessibility enables the effective participation of disabled persons in public and private areas and the use of urban equipment and street furniture. Objective: This study aimed to analyze the physical accessibility of toilet facilities in urban and rural primary health care units. Methods: It was a quantitative descriptive study conducted in 157 Primary Health Care Units of 16 municipalities in the Baturité Massif region, Ceará, Brazil. The study took place from August 2014 to May 2015, with a checklist type form, designed from the Technical Standard 9050 of the Brazilian National Standards Organization, specifying the ideal access conditions established by law to allow mobility of persons with physical disabilities. Data were processed through the Statistical Package for the Social Sciences software and organized into tables. Results: Toilets designed for physically disabled people were accessible as the location and signs (59.9%), identified with symbols for males and females (57.3%);however, the doorway width was smaller than needed to accommodate a wheelchair (77.7%). Inside the bathroom, only the forward approach was possible (59.9%). Grab bars positioned on the side and rear walls were inadequate or nonexistent (67.6%);toilet seats (91.1%) and toilet paper dispensers (96.2%) were mostly in inaccessible heights;flush controls in appropriate height (59.2%) and activated by light pressure (58%). Sinks without pedestal (51%), but higher than recommended (80.3%) and without single handle faucets (95.6%). It was verified that the toilets of basic health units located in urban areas had better accessibility conditions compared to those in rural areas. Conclusion: Results showed that the analyzed units presented physical inaccessibility in some toilet facilities, making it difficult or even impossible the accessibility for the disabled. The inclusion of accessibility features in health services for this clientele provides equal opportunities and social inclusion.
文摘There have been reported several papers on the ionospheric F region perturbations prior to the 2008 Sichuan earthquake (EQ) (magnitude 8.0), but it seems that very few reports have been published on the characteristics of ground-based ULF (ultra low frequency) magnetic field variations for this EQ. This paper deals with two different aspects of ground-based ULF magnetic field variations: 1) ULF radiation from the lithosphere, and 2) depression of ULF horizontal magnetic field as a signature of lower ionospheric perturbations. ULF data from two Chinese stations [Chengdu (epicentral distance, 80 km) and Xichang (about 300 km away from the EQ epicenter)] are analyzed, with paying attention to the local nighttime period (LT = 22 h to 02 h, UTC = 14 h to 18 h) in order to avoid man-made noise. We have analyzed powers of the horizontal component (H2), vertical component (Z2), polarization as their ratio (Z2/H2), depression of the horizontal component (as an inverse of horizontal magnetic field component power, 1/H2) and δDep as a variation of depression at a particular frequency of 0.01 - 0.02 Hz (10 - 20 mHz). It is then found that there seems no clear signature of lithospheric ULF radiation. Whilst, the most evident fact is the finding of depression of ULF horizontal magnetic field at Chengdu a few days before the Sichuan EQ, which suggests that the lower ionosphere was perturbed before the EQ. The characteristics of the lower ionospheric perturbations are compared with those of upper ionospheric perturbations reported before.
文摘Background: Colles’ fracture is a type of fracture of the distal third of the radius and its most common cause is falling from patient’s own height and, epidemiologically, it is more common in the elderly. Objectives: The main objective of this study is to analyze the epidemiology of Colles’ fracture retrospectively, in patients admitted to Fernandes Távora Hospital. Materials and Methods: This retrospective study conducted at the Fernandes Távora Hospital used 1030 radiographic images of patients with wrist fractures. Results: (After a careful analysis) It was found that this type of fracture occurred with a greater frequency in age groups of 50 to 69, 60 to 69, and 40 to 49 years old, which corresponds to 59.5% of patients and the most affected sex were females (51.1%). Conclusion: The study concluded that this type of bone injury is more common in people aged 40 to 69 years old, especially in women, because of their geometry and bone composition. It is evident that Colles’ fracture impacts the life of the affected person, therefore, an adequate diagnosis and treatment having utmost importance.
基金supported by the Basic Research Project of Institute of Earthquake Science,CEA (2013IES0101,2010IES0202)
文摘Schumann resonance （SR） is an electromag- netic resonance phenomenon in the Earth-ionosphere cavity exited by global lightning activities when the wavelength matches the circumference of the Earth, and the lowest four peak frequencies of SR are about 8, 14, 20, and 26 Hz. This article presents the new observational data of SR in China. The observations of two horizontal mag- netic components （BNs and BEw） in the frequency band range of 3-29 Hz at Yongsheng observatory （26.7°N, 100.8°E） in southwestern China were mainly analyzed. It is found that the SR amplitudes at peak frequencies in BNs and BEw components all showed diurnal and seasonal variations, and that the SR amplitude in BNS component is always higher than that in BEw component. Diurnal vari- ation of SR amplitude around equinoxes and solstices inBNs component is related to active intervals of three global thunderstorm centers, while SR amplitude in BEw com- ponent is the most significant at around 16 LT, corre- sponding to Asian center. SR amplitudes both in BNs and BEw components increase in the rainy season from May to September. In addition, the SR anomalies in association with the 2011 Japan earthquake are exhibited. The anom- alous effect was characterized by an increase in amplitude at the lowest four SR modes beginning at 4 days before this earthquake. Upon analyzing the wave interference between the direct wave and disturbed wave scattered by localized modification of lower ionosphere over the epicenter, Asian and African thunderstorm centers are found to contribute to anomalous effect observed at Yongsheng station. Modeling results of SR regular and disturbed spectra at different local times led to the similar conclusion.
文摘We investigate the Schr6dinger equation for a particle with a nonuniform solitonic mass density. First, we discuss in extent the （nontrivial） position-dependent mass V（x） = 0 case whose solutions are hypergeometric functions in tanh2 x. Then, we consider an external hyperbolic-tangent potential. We show that the effective quantum mechanical problem is given by a Heun class equation and find analytically an eigenbasis for the space of solutions. We also compute the eigenstat, es for a potential of the form V （x） = Vo sinh2 z.
