We report the results of a search for radio pulsars in five supernova remnants(SNRs)with the FAST telescope.The observations were made using the 19-beam receiver in“snapshot”mode.The integration time for each pointi...We report the results of a search for radio pulsars in five supernova remnants(SNRs)with the FAST telescope.The observations were made using the 19-beam receiver in“snapshot”mode.The integration time for each pointing was 10 min.We discovered a new pulsar,PSR J1845–0306,which has a spin period of 983.6 ms and a dispersion measure of 444.6±2.0 cm^(−3)·pc,in observations of SNR G29.6+0.1.To judge the association between the pulsar and the SNR,further verification is needed.We also re-detected some known pulsars in the data from SNRs G29.6+0.1 and G29.7–0.3.No pulsars were detected in the observations of the other three SNRs.展开更多
In this paper,Let M_(n)denote the maximum of logarithmic general error distribution with parameter v≥1.Higher-order expansions for distributions of powered extremes M_(n)^(p)are derived under an optimal choice of nor...In this paper,Let M_(n)denote the maximum of logarithmic general error distribution with parameter v≥1.Higher-order expansions for distributions of powered extremes M_(n)^(p)are derived under an optimal choice of normalizing constants.It is shown that M_(n)^(p),when v=1,converges to the Frechet extreme value distribution at the rate of 1/n,and if v>1 then M_(n)^(p)converges to the Gumbel extreme value distribution at the rate of(loglogn)^(2)=(log n)^(1-1/v).展开更多
Discrete feedback control was designed to stabilize an unstable hybrid neutral stochastic differential delay system(HNSDDS) under a highly nonlinear constraint in the H_∞ and exponential forms.Nevertheless,the existi...Discrete feedback control was designed to stabilize an unstable hybrid neutral stochastic differential delay system(HNSDDS) under a highly nonlinear constraint in the H_∞ and exponential forms.Nevertheless,the existing work just adapted to autonomous cases,and the obtained results were mainly on exponential stabilization.In comparison with autonomous cases,non-autonomous systems are of great interest and represent an important challenge.Accordingly,discrete feedback control has here been adjusted with a time factor to stabilize an unstable non-autonomous HNSDDS,in which new Lyapunov-Krasovskii functionals and some novel technologies are adopted.It should be noted,in particular,that the stabilization can be achieved not only in the routine H_∞ and exponential forms,but also the polynomial form and even a general form.展开更多
Using archival Fermi-LAT data with a time span of~12 yr,we study the population of Millisecond Pulsars(MSPs)in Globular Clusters(GlCs)and investigate their dependence on cluster dynamical evolution in the Milky Way.We...Using archival Fermi-LAT data with a time span of~12 yr,we study the population of Millisecond Pulsars(MSPs)in Globular Clusters(GlCs)and investigate their dependence on cluster dynamical evolution in the Milky Way.We show that theγ-ray luminosity(L_(γ))and emissivity(i.e.,ε_(γ)=L_(γ)/M,with M the cluster mass)are good indicators of the population and abundance of MSPs in GlCs,and they are highly dependent on the dynamical evolution history of the host clusters.Specifically speaking,the dynamically older GlCs with more compact structures are more likely to have larger L_(γ)andε_(γ),and these trends can be summarized as strong correlations with cluster stellar encounter rateΓand the specific encounter rate(Λ=Γ/M),with L_(γ)∝Γ^(0.7±0.11)andε_(γ)∝Λ^(0.73±0.13)for dynamically normal GlCs.However,as GlCs evolve into deep core collapse,these trends are found to be reversed,implying that strong encounters may have lead to the disruption of Low-Mass X-ray Binaries and ejection of MSPs from core-collapsed systems.Besides,the GlCs are found to exhibit largerε_(γ)with increasing stellar mass function slope(ε_(γ)∝10^((0.52±0.1)α)),decreasing tidal radius(ε_(γ)∝R_(t)^(-10±0.22))and distances from the Galactic Center(GC,ε_(γ)∝R_(gc)^(-1.13±0.21)).These correlations indicate that,as GlCs losing kinetic energy and spiral in toward the GC,tidal stripping and mass segregation have a preference in leading to the loss of normal stars from GlCs,while MSPs are more likely to concentrate to cluster center and be deposited into the GC.Moreover,we gaugeε_(γ)of GlCs is~10-1000 times larger than the Galactic bulge,the latter is thought to reside thousands of unresolved MSPs and may be responsible for the GC 7-ray excess,which supports that GlCs are generous contributors to the population of MSPs in the GC.展开更多
The traditional standard wet sieving method uses steel sieves with aperture?0.063 mm and can only determine the particle size distribution(PSD)of gravel and sand in general soil.This paper extends the traditional meth...The traditional standard wet sieving method uses steel sieves with aperture?0.063 mm and can only determine the particle size distribution(PSD)of gravel and sand in general soil.This paper extends the traditional method and presents an extended wet sieving method.The extended method uses both the steel sieves and the nylon filter cloth sieves.The apertures of the cloth sieves are smaller than 0.063 mm and equal 0.048 mm,0.038 mm,0.014 mm,0.012 mm,0.0063 mm,0.004 mm,0.003 mm,0.002 mm,and 0.001 mm,respectively.The extended method uses five steps to separate the general soil into many material sub-groups of gravel,sand,silt and clay with known particle size ranges.The complete PSD of the general soil is then calculated from the dry masses of the individual material sub-groups.The extended method is demonstrated with a general soil of completely decomposed granite(CDG)in Hong Kong,China.The silt and clay materials with different particle size ranges are further examined,checked and verified using stereomicroscopic observation,physical and chemical property tests.The results further confirm the correctness of the extended wet sieving method.展开更多
Introduction: Gastroesophageal reflux disease (GERD) is a benign and chronic disease that can impair the quality of life. Objective: To study the epidemiological, clinical aspects and factors associated with typical G...Introduction: Gastroesophageal reflux disease (GERD) is a benign and chronic disease that can impair the quality of life. Objective: To study the epidemiological, clinical aspects and factors associated with typical GERD in the general population of Parakou in the Republic of Benin. Methods: This was a descriptive and analytical cross-sectional study with prospective data collection which took place from May 1, 2019 to June 30, 2019. The study population consisted of any subject aged at least 15 years and living in Parakou. Subjects aged at least 15 years, present on the day of the survey and having given their free and informed verbal consent were included. The Short form of QRS®(Reflux-Qual Short form) questionnaire and the “Hospital Anxiety and Depression” score were used to assess the quality of life and anxiety/depression, respectively. The sampling was probabilistic through a 2-stage cluster sampling. The variable of interest was the presence of GERD. Results: Out of 390 subjects surveyed, 28 had symptoms of typical GERD, representing a prevalence of 7.18%. The average age of these subjects was 27.11 ± 7.88 years. Fifteen subjects (53.57%) were male, giving a sex ratio of 1.15. Fourteen (50%) had a secondary level of education, 12 (42.86%) were pupils/students, 18 (64.29%) were single. The monthly income of 22 subjects (78.57%) was lower than the guaranteed interprofessional minimum wage (40,000 FCFA). The average duration of progression of symptoms was 15.89 ± 4.97 months. Symptoms occurred less than twice a week in 22 subjects (78.57%). The clinical manifestations were both diurnal and nocturnal in 12 subjects (42.86%). None of the 28 subjects with GERD had clinical warning signs. Asthma, diabetes, consumption of high fat or spice foods, carbonated drinks, non-steroidal anti-inflammatory drugs, alcoholic beverages and tobacco were statistically associated with the occurrence of GERD. Each of the 28 subjects had at least one associated factor. A significant impair in quality of life was observed in 27 patients (96.43%). Conclusion: Typical GERD is relatively common in the general population of Parakou in the Republic of Benin. It often affects young males. Among the risk factors identified, the most common are carbonated drinks, spicy meals and diabetes. GERD significantly impairs quality of life. Raising awareness about the disease and its associated factors is necessary among the general population.展开更多
Background: Neuraxial anesthesia with intrathecal morphine is the reference technique in cesarean section anesthesia for the management of postoperative analgesia. If there is a contraindication to this, general anest...Background: Neuraxial anesthesia with intrathecal morphine is the reference technique in cesarean section anesthesia for the management of postoperative analgesia. If there is a contraindication to this, general anesthesia is required. The objective of the study was to evaluate the analgesic effectiveness of 4 analgesic techniques performed during cesarean section under general anesthesia in two centers with different anesthetic practices (North Franche Comté Hospital and Omar Bongo Ondimba Army Training Hospital). Method: This is a retrospective and descriptive study over 2 years, from January 1, 2019 to December 31, 2020. It involved evaluating the analgesic effectiveness and tolerance of morphine in the epidural catheter, wound infiltration, intravenous analgesia and Transversus Abdominous Plane block (TAP block) from the post-anesthesia care unit (PACU) until the 4<sup>th</sup> post-operative day. Results: Of the 354 cesarean sections performed, 84 (11.14%) received general anesthesia. The average age was 32.27 years. Acute fetal distress was the first indication for cesarean section (45.2%), followed by hemorrhagic placenta previa (10.7%) and prolapse of the cord (8.33%). Morphine in the epidural catheter was the most used (47.6%) followed by parietal infiltration (36.9%), intravenous analgesia (13.1%) and TAP block (2.38%). The analgesic effectiveness was comparable between the techniques from postoperative day 0 to day 4. No difference in side effects. Postoperative morphine consumption was significantly reduced (p = 0.011) in the infiltration (9 mg) and TAP block (9mg) groups compared to the epidural catheter (16 mg) and intravenous analgesia (17 mg). No difference in 02 rehabilitation criteria (ambulation, first bowel movement). No difference in the occurrence of chronic pain. Conclusion: In the event of a cesarean section under general anesthesia, there are effective and well-tolerated alternatives to neuraxial anesthesia, particularly regional anesthesia techniques (nerve blocks), particularly in countries with low availability of morphine.展开更多
Planck scale plays a vital role in describing fundamental forces. Space time describes strength of fundamental force. In this paper, Einstein’s general relativity equation has been described in terms of contraction a...Planck scale plays a vital role in describing fundamental forces. Space time describes strength of fundamental force. In this paper, Einstein’s general relativity equation has been described in terms of contraction and expansion forces of space time. According to this, the space time with Planck diameter is a flat space time. This is the only diameter of space time that can be used as signal transformation in special relativity. This space time diameter defines the fundamental force which belongs to that space time. In quantum mechanics, this space time diameter is only the quantum of space which belongs to that particular fundamental force. Einstein’s general relativity equation and Planck parameters of quantum mechanics have been written in terms of equations containing a constant “K”, thus found a new equation for transformation of general relativity space time in to quantum space time. In this process of synchronization, there is a possibility of a new fundamental force between electromagnetic and gravitational forces with Planck length as its space time diameter. It is proposed that dark matter is that fundamental force carrying particle. By grand unification equation with space-time diameter, we found a coupling constant as per standard model “α<sub>s</sub>” for that fundamental force is 1.08 × 10<sup>-23</sup>. Its energy calculated as 113 MeV. A group of experimental scientists reported the energy of dark matter particle as 17 MeV. Thorough review may advance science further.展开更多
In recent years,the national higher education reform has proposed the concept of curriculum ideological and political education as a major element.This integration into the standardized training of general practice re...In recent years,the national higher education reform has proposed the concept of curriculum ideological and political education as a major element.This integration into the standardized training of general practice residents(commonly referred to as general resident training)is an unavoidable trend in the teaching field.Based on the actual situation of our unit at The First Affiliated Hospital of Xi’an Medical University,this paper emphasizes the necessity of incorporating ideological and political education into the general resident training curriculum,despite the absence of pertinent practical experience in how to effectively incorporate such courses into comprehensive residential training.In our hospital,we must assess the ideological and political education in the curriculum of general resident training,proposing a scientific,reasonable ideological and political education concept system for general practice courses,integrating ideological and political education with general practice resident training,and strengthening the team of ideological and political education physicians to teach them to carry out such education,this would foster enthusiasm and initiative.Strengthening admission education and training for general practice resident training,as well as regularly hosting symposiums to share ideas and understand the mission of doctors can provide effective experience for ideological and political education in general resident training courses.展开更多
A summary of the exploration of the teaching mode of the general practice teaching clinic, a summary of the deficiencies of the teaching clinic and a summary of the significance of the establishment of the general pra...A summary of the exploration of the teaching mode of the general practice teaching clinic, a summary of the deficiencies of the teaching clinic and a summary of the significance of the establishment of the general practice teaching clinic are presented with a view to promoting the development of general practice and cultivating more excellent successors in general practice.展开更多
The paper is devoted to a spherically symmetric problem of General Relativity (GR) for a fluid sphere. The problem is solved within the framework of a special geometry of the Riemannian space induced by gravitation. A...The paper is devoted to a spherically symmetric problem of General Relativity (GR) for a fluid sphere. The problem is solved within the framework of a special geometry of the Riemannian space induced by gravitation. According to this geometry, the four-dimensional Riemannian space is assumed to be Euclidean with respect to the space coordinates and Riemannian with respect to the time coordinate. Such interpretation of the Riemannian space allows us to obtain complete set of GR equations for the external empty space and the internal spaces for incompressible and compressible perfect fluids. The obtained analytical solution for an incompressible fluid is compared with the Schwarzchild solution. For a sphere consisting of compressible fluid or gas, a numerical solution is presented and discussed.展开更多
With the continuous expansion of medical student enrollment,the number of clinical teaching bases is gradually increasing.However,there are significant differences in clinical teaching management models and teaching l...With the continuous expansion of medical student enrollment,the number of clinical teaching bases is gradually increasing.However,there are significant differences in clinical teaching management models and teaching levels among different bases.Most clinical teaching bases have incomplete teaching management systems,inadequate teaching management institutions,insufficient teaching personnel,and inadequate implementation of teaching rules and regulations.This article combines the construction practice of three-level clinical teaching base of the General Medicine College and the First Affiliated Hospital of Xi’an Medical University.We establish a standardized management system for the three-level clinical teaching base;implement a teaching supervision system and strengthen the monitoring of teaching quality;adopt multiple evaluations to test the effectiveness of clinical teaching implementation;explore the path of homogenization construction of teaching bases in terms of unified teacher training,promoting the development of teacher teaching abilities with equal quality and excellence,and providing a reference for improving the quality of medical talent training.展开更多
Objective:This study aims to investigate the impact of combining general anesthesia with bronchial intubation and thoracic paravertebral nerve block during surgery for patients with tuberculous pyothorax.Methods:Eight...Objective:This study aims to investigate the impact of combining general anesthesia with bronchial intubation and thoracic paravertebral nerve block during surgery for patients with tuberculous pyothorax.Methods:Eighty patients diagnosed with tuberculous pyothorax,admitted to the hospital between January 2023 and September 2023,were randomly selected for this study.The patients were divided into control and study groups using a numerical table method.The control group underwent general anesthesia with bronchial intubation,while the study group received general anesthesia with bronchial intubation in conjunction with thoracic paravertebral nerve block.Subsequently,the patients were monitored to assess mean arterial pressure,heart rate variations,and adverse reactions to anesthesia.Results:The study group exhibited significantly lower mean arterial pressure and heart rate levels during the post-surgical incision,immediate end of surgery,and immediate extubation periods compared to the control group(P<0.05).Furthermore,the Ricker and Ramsay scores in the study group were significantly lower than those in the control group(P<0.05).Conclusion:The combined use of general anesthesia via bronchial intubation and thoracic paravertebral nerve block has been found to stabilize mean arterial pressure and heart rate while providing effective sedation for surgical treatment in patients with tuberculous septic thorax.展开更多
In this article we modify our previous model for the mechanisms underlying the glitch phenomena in pulsars. Accordingly, pulsars are born with embryonic cores that are made of purely incompressible superconducting glu...In this article we modify our previous model for the mechanisms underlying the glitch phenomena in pulsars. Accordingly, pulsars are born with embryonic cores that are made of purely incompressible superconducting gluon-quark superfluid (henceforth SuSu-cores). As the ambient medium cools and spins down due to emission of magnetic dipole radiation, the mass and size of SuSu-cores must grow discretely with time, in accordance with the Onsager-Feynmann analysis of superfluidity. Here we argue that the spacetime embedding glitching pulsars is dynamical and of bimetric nature: inside SuSu-cores the spacetime must be flat, whereas the surrounding region, where the matter is compressible and dissipative, the spacetime is Schwarzschild. It is argued here that the topological change of spacetime is derived by the strong nuclear force, whose operating length scales are found to increase with time to reach O (1) cm at the end of the luminous lifetimes of pulsars. The here-presented model is in line with the recent radio- and gravitational wave observations of pulsars and merger of neutron stars.展开更多
We investigate the single-pulse emission variations of two pulsars,PSRs J0211+4235 and J0553+4111,observed with the Five-hundred-meter Aperture Spherical radio Telescope at the 1.25 GHz central frequency.The observati...We investigate the single-pulse emission variations of two pulsars,PSRs J0211+4235 and J0553+4111,observed with the Five-hundred-meter Aperture Spherical radio Telescope at the 1.25 GHz central frequency.The observation sessions span from 2020 December to 2021 July,with 21 and 22 observations for them respectively.The integrated pulse profile of PSR J0211+4235 shows that there is a weak pulse component following the main component,and PSR J0553+4111 displays a bimodal profile with a bridge component in the middle.PSR J0211+4235 presents significant nulling phenomenon with nulling duration lasting from 2 to 115 pulses and burst duration lasting from 2 to 113 pulses.The NF of each observation is determined to be 45%-55%.No emission greater than threeσis found in the mean integrated profile of all nulling pulses.In most cases,the pulse energy changes abruptly during the transition from null to burst,while in the transition from burst to null there are two trends:abrupt and gradual.We find that the nulling phenomenon of PSR J0211+4235 is periodic by the Fourier transform of the null and burst state.In addition,the single-pulse modulation characteristics of these two pulsars are investigated,and the distributions of modulation index,LRFS and 2DFS are analyzed with PSRSALSA.The left peak of PSR J0553+4111 has intensity modulation.Finally,the polarization properties of these two pulsars are obtained through polarization calibration,and their characteristics are analyzed.The possible physical mechanisms of these phenomena are discussed.展开更多
Pulsar polarization profiles form a very basic database for understanding the emission processes in a pulsar magnetosphere.After careful polarization calibration of the 19-beam L-band receiver and verification of beam...Pulsar polarization profiles form a very basic database for understanding the emission processes in a pulsar magnetosphere.After careful polarization calibration of the 19-beam L-band receiver and verification of beamoffset observation results,we obtain polarization profiles of 682 pulsars from observations by the Five-hundredmeter Aperture Spherical radio Telescope(FAST)duringthe Galactic Plane Pulsar Snapshot survey and other normal FAST projects.Among them,polarization profiles of about 460 pulsars are observed for the first time.The profiles exhibit diverse features.Some pulsars have a polarization position angle curve with a good S-shaped swing,some with orthogonal modes;some have components with highly linearly polarized components or strong circularly polarized components;some have a very wide profile,coming from an aligned rotator,and some have an interpulse from a perpendicular rotator;some wide profiles are caused by interstellar scattering.We derive geometric parameters for 190 pulsars from the S-shaped position angle curves or with orthogonal modes.We find that the linear and circular polarization or the widths of pulse profiles have various frequency dependencies.Pulsars with a large fraction of linear polarization are more likely to have a large Edot.展开更多
BACKGROUND Radical gastrectomy(RG)is commonly used in the treatment of patients with gastric cancer(GC),but this procedure may lead to stress responses,postoperative cognitive dysfunction,and blood coagulation abnorma...BACKGROUND Radical gastrectomy(RG)is commonly used in the treatment of patients with gastric cancer(GC),but this procedure may lead to stress responses,postoperative cognitive dysfunction,and blood coagulation abnormalities in patients.AIM To investigate the influences of dexmedetomidine(DEX)on stress responses and postoperative cognitive and coagulation functions in patients undergoing RG under general anesthesia(GA).METHODS One hundred and two patients undergoing RG for GC under GA from February 2020 to February 2022 were retrospectively reviewed.Of these,50 patients had received conventional anesthesia intervention[control group(CG)]and 52 patients had received DEX in addition to routine anesthesia intervention[observation group(OG)].Inflammatory factor(IFs;tumor necrosis factor-α,TNF-α;interleukin-6,IL-6),stress responses(cortisol,Cor;adrenocorticotropic hormone,ACTH),cognitive function(CF;Mini-Mental State Examination,MMSE),neurological function(neuron-specific enolase,NSE;S100 calciumbinding protein B,S100B),and coagulation function(prothrombin time,PT;thromboxane B2,TXB2;fibrinogen,FIB)were compared between the two groups before surgery(T0),as well as at 6 h(T1)and 24 h(T2)after surgery.RESULTS Compared with T0,TNF-α,IL-6,Cor,ACTH,NSE,S100B,PT,TXB2,and FIB showed a significant increase in both groups at T1 and T2,but with even lower levels in OG vs CG.Both groups showed a significant reduction in the MMSE score at T1 and T2 compared with T0,but the MMSE score was notably higher in OG compared with CG.CONCLUSION In addition to a potent inhibitory effect on postoperative IFs and stress responses in GC patients undergoing RG under GA,DEX may also alleviate the coagulation dysfunction and improve the postoperative CF of these patients.展开更多
The braking indices of pulsars may contain important information about the internal physics of neutron stars(NSs),such as neutron superfluidity and internal magnetic fields.As a subsequent paper of Cheng et al.,we per...The braking indices of pulsars may contain important information about the internal physics of neutron stars(NSs),such as neutron superfluidity and internal magnetic fields.As a subsequent paper of Cheng et al.,we perform the same analysis as that done in the previous paper to other young pulsars with a steady braking index,n.Combining the timing data of these pulsars with the theory of magnetic field decay,and using their measured magnetic tilt angles,we can set constraints on the number of precession cycles,ξ,which represents the interactions between superfluid neutrons and other particles in the NS interior.For the pulsars considered in this paper,the results show thatξis within the range of a few×10~3 to a few×10~6.Interestingly,for the Crab and Vela pulsars,the constraints onξobtained with our method are generally consistent with that derived from modeling of the glitch rise behaviors of the two pulsars.Furthermore,we find that the internal magnetic fields of pulsar with n<3 may be dominated by the toroidal components.Our results may not only help to understand the interactions between the superfluid neutrons and other particles in the interior of NSs but also be important for the study of continuous gravitational waves from pulsars.展开更多
We present a method by using the phase characteristics of radio observation data for pulsar search and candidate identification.The phase characteristics are relations between the pulsar signal and the phase correctio...We present a method by using the phase characteristics of radio observation data for pulsar search and candidate identification.The phase characteristics are relations between the pulsar signal and the phase correction in the frequency-domain,and we regard it as a new search diagnostic characteristic.Based on the phase characteristics,a search method is presented:calculating dispersion measure(DM)—frequency data to select candidate frequencies,and then confirming of candidates by using the broadband characteristics of pulsar signals.Based on this method,we performed a search test on short observation data of M15 and M71,which were observed by Five-hundredmeter Aperture Spherical radio Telescope,and some of the Galactic Plane Pulsar Snapshot survey data.Results show that it can get similar search results to PRESTO(Pulsa R Exploration and Search TOolkit)while having a faster processing speed.展开更多
Up to 2022 November,267 pulsars had been discovered in 36 globular clusters(GCs).In this paper,we present our studies on the distribution of GC pulsar parameters and the detection efficiency.The power law relation bet...Up to 2022 November,267 pulsars had been discovered in 36 globular clusters(GCs).In this paper,we present our studies on the distribution of GC pulsar parameters and the detection efficiency.The power law relation between average dispersion measure(■)and dispersion measure difference(ΔDM)of known pulsars in GCs is lgΔDM∝1.52lg■.The sensitivity could be the key to finding more pulsars.As a result,several years after the construction of a large radio telescope facility,the number of known GC pulsars will likely be increased accordingly.We suggest that currently GCs in the southern hemisphere could have higher possibilities for finding new pulsars.展开更多
基金supported by the National SKA Program of China (Grant No. 2020SKA0120200)the National Natural Science Foundation of China (Grant Nos. 12041303, 12273100, 12041304, and 12288102)+5 种基金the National Key R&D Program of China (Grant No. 2022YFC2205201)the West Light Foundation of the Chinese Academy of Sciences (Grant No. WLFC 2021-XBQNXZ-027)the Major Science and Technology Program of Xinjiang Uygur Autonomous Region (Grant No. 2022A03013-4)the Natural Science Foundation of Xinjiiang Uygur Autonomous Region (Grant No. 2022D01D85)the open program of the Key Laboratory of Xinjiang Uygur Autonomous Region (Grant No. 2020D04049)partly supported by the Operation, Maintenance and Upgrading Fund for Astronomical Telescopes and Facility Instruments, budgeted from the Ministry of Finance of China and administrated by the CAS
文摘We report the results of a search for radio pulsars in five supernova remnants(SNRs)with the FAST telescope.The observations were made using the 19-beam receiver in“snapshot”mode.The integration time for each pointing was 10 min.We discovered a new pulsar,PSR J1845–0306,which has a spin period of 983.6 ms and a dispersion measure of 444.6±2.0 cm^(−3)·pc,in observations of SNR G29.6+0.1.To judge the association between the pulsar and the SNR,further verification is needed.We also re-detected some known pulsars in the data from SNRs G29.6+0.1 and G29.7–0.3.No pulsars were detected in the observations of the other three SNRs.
文摘In this paper,Let M_(n)denote the maximum of logarithmic general error distribution with parameter v≥1.Higher-order expansions for distributions of powered extremes M_(n)^(p)are derived under an optimal choice of normalizing constants.It is shown that M_(n)^(p),when v=1,converges to the Frechet extreme value distribution at the rate of 1/n,and if v>1 then M_(n)^(p)converges to the Gumbel extreme value distribution at the rate of(loglogn)^(2)=(log n)^(1-1/v).
基金supported by the National Natural Science Foundation of China(61833005)the Humanities and Social Science Fund of Ministry of Education of China(23YJAZH031)+1 种基金the Natural Science Foundation of Hebei Province of China(A2023209002,A2019209005)the Tangshan Science and Technology Bureau Program of Hebei Province of China(19130222g)。
文摘Discrete feedback control was designed to stabilize an unstable hybrid neutral stochastic differential delay system(HNSDDS) under a highly nonlinear constraint in the H_∞ and exponential forms.Nevertheless,the existing work just adapted to autonomous cases,and the obtained results were mainly on exponential stabilization.In comparison with autonomous cases,non-autonomous systems are of great interest and represent an important challenge.Accordingly,discrete feedback control has here been adjusted with a time factor to stabilize an unstable non-autonomous HNSDDS,in which new Lyapunov-Krasovskii functionals and some novel technologies are adopted.It should be noted,in particular,that the stabilization can be achieved not only in the routine H_∞ and exponential forms,but also the polynomial form and even a general form.
基金supported by the Youth Program of the National Natural Science Foundation of China No.12003017。
文摘Using archival Fermi-LAT data with a time span of~12 yr,we study the population of Millisecond Pulsars(MSPs)in Globular Clusters(GlCs)and investigate their dependence on cluster dynamical evolution in the Milky Way.We show that theγ-ray luminosity(L_(γ))and emissivity(i.e.,ε_(γ)=L_(γ)/M,with M the cluster mass)are good indicators of the population and abundance of MSPs in GlCs,and they are highly dependent on the dynamical evolution history of the host clusters.Specifically speaking,the dynamically older GlCs with more compact structures are more likely to have larger L_(γ)andε_(γ),and these trends can be summarized as strong correlations with cluster stellar encounter rateΓand the specific encounter rate(Λ=Γ/M),with L_(γ)∝Γ^(0.7±0.11)andε_(γ)∝Λ^(0.73±0.13)for dynamically normal GlCs.However,as GlCs evolve into deep core collapse,these trends are found to be reversed,implying that strong encounters may have lead to the disruption of Low-Mass X-ray Binaries and ejection of MSPs from core-collapsed systems.Besides,the GlCs are found to exhibit largerε_(γ)with increasing stellar mass function slope(ε_(γ)∝10^((0.52±0.1)α)),decreasing tidal radius(ε_(γ)∝R_(t)^(-10±0.22))and distances from the Galactic Center(GC,ε_(γ)∝R_(gc)^(-1.13±0.21)).These correlations indicate that,as GlCs losing kinetic energy and spiral in toward the GC,tidal stripping and mass segregation have a preference in leading to the loss of normal stars from GlCs,while MSPs are more likely to concentrate to cluster center and be deposited into the GC.Moreover,we gaugeε_(γ)of GlCs is~10-1000 times larger than the Galactic bulge,the latter is thought to reside thousands of unresolved MSPs and may be responsible for the GC 7-ray excess,which supports that GlCs are generous contributors to the population of MSPs in the GC.
基金The work described in this paper was partially supported by grants from the Research Grant Council of the Hong Kong Special Administrative Region,China(Project Nos.HKU 17207518 and R5037-18).
文摘The traditional standard wet sieving method uses steel sieves with aperture?0.063 mm and can only determine the particle size distribution(PSD)of gravel and sand in general soil.This paper extends the traditional method and presents an extended wet sieving method.The extended method uses both the steel sieves and the nylon filter cloth sieves.The apertures of the cloth sieves are smaller than 0.063 mm and equal 0.048 mm,0.038 mm,0.014 mm,0.012 mm,0.0063 mm,0.004 mm,0.003 mm,0.002 mm,and 0.001 mm,respectively.The extended method uses five steps to separate the general soil into many material sub-groups of gravel,sand,silt and clay with known particle size ranges.The complete PSD of the general soil is then calculated from the dry masses of the individual material sub-groups.The extended method is demonstrated with a general soil of completely decomposed granite(CDG)in Hong Kong,China.The silt and clay materials with different particle size ranges are further examined,checked and verified using stereomicroscopic observation,physical and chemical property tests.The results further confirm the correctness of the extended wet sieving method.
文摘Introduction: Gastroesophageal reflux disease (GERD) is a benign and chronic disease that can impair the quality of life. Objective: To study the epidemiological, clinical aspects and factors associated with typical GERD in the general population of Parakou in the Republic of Benin. Methods: This was a descriptive and analytical cross-sectional study with prospective data collection which took place from May 1, 2019 to June 30, 2019. The study population consisted of any subject aged at least 15 years and living in Parakou. Subjects aged at least 15 years, present on the day of the survey and having given their free and informed verbal consent were included. The Short form of QRS®(Reflux-Qual Short form) questionnaire and the “Hospital Anxiety and Depression” score were used to assess the quality of life and anxiety/depression, respectively. The sampling was probabilistic through a 2-stage cluster sampling. The variable of interest was the presence of GERD. Results: Out of 390 subjects surveyed, 28 had symptoms of typical GERD, representing a prevalence of 7.18%. The average age of these subjects was 27.11 ± 7.88 years. Fifteen subjects (53.57%) were male, giving a sex ratio of 1.15. Fourteen (50%) had a secondary level of education, 12 (42.86%) were pupils/students, 18 (64.29%) were single. The monthly income of 22 subjects (78.57%) was lower than the guaranteed interprofessional minimum wage (40,000 FCFA). The average duration of progression of symptoms was 15.89 ± 4.97 months. Symptoms occurred less than twice a week in 22 subjects (78.57%). The clinical manifestations were both diurnal and nocturnal in 12 subjects (42.86%). None of the 28 subjects with GERD had clinical warning signs. Asthma, diabetes, consumption of high fat or spice foods, carbonated drinks, non-steroidal anti-inflammatory drugs, alcoholic beverages and tobacco were statistically associated with the occurrence of GERD. Each of the 28 subjects had at least one associated factor. A significant impair in quality of life was observed in 27 patients (96.43%). Conclusion: Typical GERD is relatively common in the general population of Parakou in the Republic of Benin. It often affects young males. Among the risk factors identified, the most common are carbonated drinks, spicy meals and diabetes. GERD significantly impairs quality of life. Raising awareness about the disease and its associated factors is necessary among the general population.
文摘Background: Neuraxial anesthesia with intrathecal morphine is the reference technique in cesarean section anesthesia for the management of postoperative analgesia. If there is a contraindication to this, general anesthesia is required. The objective of the study was to evaluate the analgesic effectiveness of 4 analgesic techniques performed during cesarean section under general anesthesia in two centers with different anesthetic practices (North Franche Comté Hospital and Omar Bongo Ondimba Army Training Hospital). Method: This is a retrospective and descriptive study over 2 years, from January 1, 2019 to December 31, 2020. It involved evaluating the analgesic effectiveness and tolerance of morphine in the epidural catheter, wound infiltration, intravenous analgesia and Transversus Abdominous Plane block (TAP block) from the post-anesthesia care unit (PACU) until the 4<sup>th</sup> post-operative day. Results: Of the 354 cesarean sections performed, 84 (11.14%) received general anesthesia. The average age was 32.27 years. Acute fetal distress was the first indication for cesarean section (45.2%), followed by hemorrhagic placenta previa (10.7%) and prolapse of the cord (8.33%). Morphine in the epidural catheter was the most used (47.6%) followed by parietal infiltration (36.9%), intravenous analgesia (13.1%) and TAP block (2.38%). The analgesic effectiveness was comparable between the techniques from postoperative day 0 to day 4. No difference in side effects. Postoperative morphine consumption was significantly reduced (p = 0.011) in the infiltration (9 mg) and TAP block (9mg) groups compared to the epidural catheter (16 mg) and intravenous analgesia (17 mg). No difference in 02 rehabilitation criteria (ambulation, first bowel movement). No difference in the occurrence of chronic pain. Conclusion: In the event of a cesarean section under general anesthesia, there are effective and well-tolerated alternatives to neuraxial anesthesia, particularly regional anesthesia techniques (nerve blocks), particularly in countries with low availability of morphine.
文摘Planck scale plays a vital role in describing fundamental forces. Space time describes strength of fundamental force. In this paper, Einstein’s general relativity equation has been described in terms of contraction and expansion forces of space time. According to this, the space time with Planck diameter is a flat space time. This is the only diameter of space time that can be used as signal transformation in special relativity. This space time diameter defines the fundamental force which belongs to that space time. In quantum mechanics, this space time diameter is only the quantum of space which belongs to that particular fundamental force. Einstein’s general relativity equation and Planck parameters of quantum mechanics have been written in terms of equations containing a constant “K”, thus found a new equation for transformation of general relativity space time in to quantum space time. In this process of synchronization, there is a possibility of a new fundamental force between electromagnetic and gravitational forces with Planck length as its space time diameter. It is proposed that dark matter is that fundamental force carrying particle. By grand unification equation with space-time diameter, we found a coupling constant as per standard model “α<sub>s</sub>” for that fundamental force is 1.08 × 10<sup>-23</sup>. Its energy calculated as 113 MeV. A group of experimental scientists reported the energy of dark matter particle as 17 MeV. Thorough review may advance science further.
文摘In recent years,the national higher education reform has proposed the concept of curriculum ideological and political education as a major element.This integration into the standardized training of general practice residents(commonly referred to as general resident training)is an unavoidable trend in the teaching field.Based on the actual situation of our unit at The First Affiliated Hospital of Xi’an Medical University,this paper emphasizes the necessity of incorporating ideological and political education into the general resident training curriculum,despite the absence of pertinent practical experience in how to effectively incorporate such courses into comprehensive residential training.In our hospital,we must assess the ideological and political education in the curriculum of general resident training,proposing a scientific,reasonable ideological and political education concept system for general practice courses,integrating ideological and political education with general practice resident training,and strengthening the team of ideological and political education physicians to teach them to carry out such education,this would foster enthusiasm and initiative.Strengthening admission education and training for general practice resident training,as well as regularly hosting symposiums to share ideas and understand the mission of doctors can provide effective experience for ideological and political education in general resident training courses.
文摘A summary of the exploration of the teaching mode of the general practice teaching clinic, a summary of the deficiencies of the teaching clinic and a summary of the significance of the establishment of the general practice teaching clinic are presented with a view to promoting the development of general practice and cultivating more excellent successors in general practice.
文摘The paper is devoted to a spherically symmetric problem of General Relativity (GR) for a fluid sphere. The problem is solved within the framework of a special geometry of the Riemannian space induced by gravitation. According to this geometry, the four-dimensional Riemannian space is assumed to be Euclidean with respect to the space coordinates and Riemannian with respect to the time coordinate. Such interpretation of the Riemannian space allows us to obtain complete set of GR equations for the external empty space and the internal spaces for incompressible and compressible perfect fluids. The obtained analytical solution for an incompressible fluid is compared with the Schwarzchild solution. For a sphere consisting of compressible fluid or gas, a numerical solution is presented and discussed.
基金2022 Education and Teaching Reform Research Project of Xi’an Medical University“Construction and Practice of the Teaching Quality Assurance System in the Three-Level Teaching Base of General Practice Medicine Under the Internet+Model”(Project number:2022JG-05)。
文摘With the continuous expansion of medical student enrollment,the number of clinical teaching bases is gradually increasing.However,there are significant differences in clinical teaching management models and teaching levels among different bases.Most clinical teaching bases have incomplete teaching management systems,inadequate teaching management institutions,insufficient teaching personnel,and inadequate implementation of teaching rules and regulations.This article combines the construction practice of three-level clinical teaching base of the General Medicine College and the First Affiliated Hospital of Xi’an Medical University.We establish a standardized management system for the three-level clinical teaching base;implement a teaching supervision system and strengthen the monitoring of teaching quality;adopt multiple evaluations to test the effectiveness of clinical teaching implementation;explore the path of homogenization construction of teaching bases in terms of unified teacher training,promoting the development of teacher teaching abilities with equal quality and excellence,and providing a reference for improving the quality of medical talent training.
基金Research Project of the Xi’an Municipal Health Commission(No.2023yb40,Project leader:Duan Chunyu)。
文摘Objective:This study aims to investigate the impact of combining general anesthesia with bronchial intubation and thoracic paravertebral nerve block during surgery for patients with tuberculous pyothorax.Methods:Eighty patients diagnosed with tuberculous pyothorax,admitted to the hospital between January 2023 and September 2023,were randomly selected for this study.The patients were divided into control and study groups using a numerical table method.The control group underwent general anesthesia with bronchial intubation,while the study group received general anesthesia with bronchial intubation in conjunction with thoracic paravertebral nerve block.Subsequently,the patients were monitored to assess mean arterial pressure,heart rate variations,and adverse reactions to anesthesia.Results:The study group exhibited significantly lower mean arterial pressure and heart rate levels during the post-surgical incision,immediate end of surgery,and immediate extubation periods compared to the control group(P<0.05).Furthermore,the Ricker and Ramsay scores in the study group were significantly lower than those in the control group(P<0.05).Conclusion:The combined use of general anesthesia via bronchial intubation and thoracic paravertebral nerve block has been found to stabilize mean arterial pressure and heart rate while providing effective sedation for surgical treatment in patients with tuberculous septic thorax.
文摘In this article we modify our previous model for the mechanisms underlying the glitch phenomena in pulsars. Accordingly, pulsars are born with embryonic cores that are made of purely incompressible superconducting gluon-quark superfluid (henceforth SuSu-cores). As the ambient medium cools and spins down due to emission of magnetic dipole radiation, the mass and size of SuSu-cores must grow discretely with time, in accordance with the Onsager-Feynmann analysis of superfluidity. Here we argue that the spacetime embedding glitching pulsars is dynamical and of bimetric nature: inside SuSu-cores the spacetime must be flat, whereas the surrounding region, where the matter is compressible and dissipative, the spacetime is Schwarzschild. It is argued here that the topological change of spacetime is derived by the strong nuclear force, whose operating length scales are found to increase with time to reach O (1) cm at the end of the luminous lifetimes of pulsars. The here-presented model is in line with the recent radio- and gravitational wave observations of pulsars and merger of neutron stars.
基金supported by National Key Research and Development Program of China(2022YFC2205203)the Major Science and Technology Program of Xinjiang Uygur Autonomous Region(No.2022A03013-1)+3 种基金the National Natural Science Foundation of China(NSFC,Grant Nos.U1838109,12041304)supported by the 2021 project Xinjiang Uygur autonomous region of China for Tianshan elitesthe Youth Innovation Promotion Association of CAS under No.2023069support from the Natural Science Foundation of Shanghai(Grant No.20ZR1467600)。
文摘We investigate the single-pulse emission variations of two pulsars,PSRs J0211+4235 and J0553+4111,observed with the Five-hundred-meter Aperture Spherical radio Telescope at the 1.25 GHz central frequency.The observation sessions span from 2020 December to 2021 July,with 21 and 22 observations for them respectively.The integrated pulse profile of PSR J0211+4235 shows that there is a weak pulse component following the main component,and PSR J0553+4111 displays a bimodal profile with a bridge component in the middle.PSR J0211+4235 presents significant nulling phenomenon with nulling duration lasting from 2 to 115 pulses and burst duration lasting from 2 to 113 pulses.The NF of each observation is determined to be 45%-55%.No emission greater than threeσis found in the mean integrated profile of all nulling pulses.In most cases,the pulse energy changes abruptly during the transition from null to burst,while in the transition from burst to null there are two trends:abrupt and gradual.We find that the nulling phenomenon of PSR J0211+4235 is periodic by the Fourier transform of the null and burst state.In addition,the single-pulse modulation characteristics of these two pulsars are investigated,and the distributions of modulation index,LRFS and 2DFS are analyzed with PSRSALSA.The left peak of PSR J0553+4111 has intensity modulation.Finally,the polarization properties of these two pulsars are obtained through polarization calibration,and their characteristics are analyzed.The possible physical mechanisms of these phenomena are discussed.
基金supported by the National Natural Science Foundation of China(NSFC,grant Nos.11988101 and 11833009),supported by the National Natural Science Foundation of China(NSFC,grant No.U2031115)supported by the National Key R&D Program of China(No.2021YFA1600401 and 2021YFA1600400)+1 种基金National Natural Science Foundation of China(NSFC,grant Nos.11873058 and 12133004)the National SKA program of China(No.2020SKA0120200)。
文摘Pulsar polarization profiles form a very basic database for understanding the emission processes in a pulsar magnetosphere.After careful polarization calibration of the 19-beam L-band receiver and verification of beamoffset observation results,we obtain polarization profiles of 682 pulsars from observations by the Five-hundredmeter Aperture Spherical radio Telescope(FAST)duringthe Galactic Plane Pulsar Snapshot survey and other normal FAST projects.Among them,polarization profiles of about 460 pulsars are observed for the first time.The profiles exhibit diverse features.Some pulsars have a polarization position angle curve with a good S-shaped swing,some with orthogonal modes;some have components with highly linearly polarized components or strong circularly polarized components;some have a very wide profile,coming from an aligned rotator,and some have an interpulse from a perpendicular rotator;some wide profiles are caused by interstellar scattering.We derive geometric parameters for 190 pulsars from the S-shaped position angle curves or with orthogonal modes.We find that the linear and circular polarization or the widths of pulse profiles have various frequency dependencies.Pulsars with a large fraction of linear polarization are more likely to have a large Edot.
基金Supported by Project of Guangxi Health and Health Commission,No.Z20201268。
文摘BACKGROUND Radical gastrectomy(RG)is commonly used in the treatment of patients with gastric cancer(GC),but this procedure may lead to stress responses,postoperative cognitive dysfunction,and blood coagulation abnormalities in patients.AIM To investigate the influences of dexmedetomidine(DEX)on stress responses and postoperative cognitive and coagulation functions in patients undergoing RG under general anesthesia(GA).METHODS One hundred and two patients undergoing RG for GC under GA from February 2020 to February 2022 were retrospectively reviewed.Of these,50 patients had received conventional anesthesia intervention[control group(CG)]and 52 patients had received DEX in addition to routine anesthesia intervention[observation group(OG)].Inflammatory factor(IFs;tumor necrosis factor-α,TNF-α;interleukin-6,IL-6),stress responses(cortisol,Cor;adrenocorticotropic hormone,ACTH),cognitive function(CF;Mini-Mental State Examination,MMSE),neurological function(neuron-specific enolase,NSE;S100 calciumbinding protein B,S100B),and coagulation function(prothrombin time,PT;thromboxane B2,TXB2;fibrinogen,FIB)were compared between the two groups before surgery(T0),as well as at 6 h(T1)and 24 h(T2)after surgery.RESULTS Compared with T0,TNF-α,IL-6,Cor,ACTH,NSE,S100B,PT,TXB2,and FIB showed a significant increase in both groups at T1 and T2,but with even lower levels in OG vs CG.Both groups showed a significant reduction in the MMSE score at T1 and T2 compared with T0,but the MMSE score was notably higher in OG compared with CG.CONCLUSION In addition to a potent inhibitory effect on postoperative IFs and stress responses in GC patients undergoing RG under GA,DEX may also alleviate the coagulation dysfunction and improve the postoperative CF of these patients.
基金supported by the National Natural Science Foundation of China(Grant Nos.12003009,and 12033001)CAS“Light of West China”Program(Grant No.2019-XBQNXZ-B-016)the National SKA program of China(Grant No.2020SKA0120300)。
文摘The braking indices of pulsars may contain important information about the internal physics of neutron stars(NSs),such as neutron superfluidity and internal magnetic fields.As a subsequent paper of Cheng et al.,we perform the same analysis as that done in the previous paper to other young pulsars with a steady braking index,n.Combining the timing data of these pulsars with the theory of magnetic field decay,and using their measured magnetic tilt angles,we can set constraints on the number of precession cycles,ξ,which represents the interactions between superfluid neutrons and other particles in the NS interior.For the pulsars considered in this paper,the results show thatξis within the range of a few×10~3 to a few×10~6.Interestingly,for the Crab and Vela pulsars,the constraints onξobtained with our method are generally consistent with that derived from modeling of the glitch rise behaviors of the two pulsars.Furthermore,we find that the internal magnetic fields of pulsar with n<3 may be dominated by the toroidal components.Our results may not only help to understand the interactions between the superfluid neutrons and other particles in the interior of NSs but also be important for the study of continuous gravitational waves from pulsars.
基金supported by the National Natural Science Foundation of China(Nos.12203039 and 11873083)the National Natural Science Foundation of China(Nos.12173053 and 12041303)+4 种基金supported by the National SKA Program of China(No.2020SKA0120100)the Youth Innovation Promotion Association of CAS(id.2018075)the CAS“Light of West China”Programthe Specialized Research Fund for State Key Laboratoriesthe Science and Technology Program of Guizhou Province([2021]4001)。
文摘We present a method by using the phase characteristics of radio observation data for pulsar search and candidate identification.The phase characteristics are relations between the pulsar signal and the phase correction in the frequency-domain,and we regard it as a new search diagnostic characteristic.Based on the phase characteristics,a search method is presented:calculating dispersion measure(DM)—frequency data to select candidate frequencies,and then confirming of candidates by using the broadband characteristics of pulsar signals.Based on this method,we performed a search test on short observation data of M15 and M71,which were observed by Five-hundredmeter Aperture Spherical radio Telescope,and some of the Galactic Plane Pulsar Snapshot survey data.Results show that it can get similar search results to PRESTO(Pulsa R Exploration and Search TOolkit)while having a faster processing speed.
基金supported by the National SKA Program of China No.2020SKA0120100the National Natural Science Foundation of China(NSFC,Grant Nos.11963002,11703047,11773041,U2031119,12173052,12003047 and 12173053)+7 种基金the fostering project of Guizhou University with No.201911Cultivation Project for FAST Scientific Payoff and Research Achievement of CAMS-CASsupported by the Specialized Research Fund for State Key Laboratoriessupported by the CAS“Light of West China”Programthe Youth Innovation Promotion Association of CAS(id 2023064)supported by the Youth Innovation Promotion Association of CAS(id.2018075 and Y2022027)supported by Guizhou Provincial Basic Research Program(Natural Science)(ZK[2023]039)Key Technology R&D Program([2023]352)。
文摘Up to 2022 November,267 pulsars had been discovered in 36 globular clusters(GCs).In this paper,we present our studies on the distribution of GC pulsar parameters and the detection efficiency.The power law relation between average dispersion measure(■)and dispersion measure difference(ΔDM)of known pulsars in GCs is lgΔDM∝1.52lg■.The sensitivity could be the key to finding more pulsars.As a result,several years after the construction of a large radio telescope facility,the number of known GC pulsars will likely be increased accordingly.We suggest that currently GCs in the southern hemisphere could have higher possibilities for finding new pulsars.