This research uses a theoretical conceptual method based on Chantal Mouffe's Radical Democracy which blended with Derrida's deconstruction thesis about "democracy to come" to reach findings on the state of South A...This research uses a theoretical conceptual method based on Chantal Mouffe's Radical Democracy which blended with Derrida's deconstruction thesis about "democracy to come" to reach findings on the state of South Africa's media freedom landscape. The method is contained in the conceptual framework. The article provides the constitutional legal landscape--or the overarching laws of the land--and the co-regulatory framework within which journalists work. There are four research explications: the Protection of State Information Bill (dubbed the Secrecy Bill), a painting of the president and Freedom of Expression, an arson attack on a community radio station and finally, the death of a photojournalist at the hands of police. The argument here is that the death, the arson attack, the Secrecy Bill, and the shut-down of dissent during the exhibition of the painting of the president all undermine democracy and signify significant closures for the media in the now 20-year-old post-apartheid South Africa. The analysis and reflections will be framed within theories of radical democracy, which argue for more fights and contestations and more voices from the margins in order to deepen democracy, rather than rational consensus which closes the spaces for greater plurality.展开更多
In this paper we study the structure of k-transitive closures of directed paths and formulate several properties. Concept of k-transitive orientation generalizes the traditional concept of transitive orientation of a ...In this paper we study the structure of k-transitive closures of directed paths and formulate several properties. Concept of k-transitive orientation generalizes the traditional concept of transitive orientation of a graph.展开更多
Shell-model studies on the N =14 and 16 shell closures in neutron-rich Be, C, O and Ne isotopes are presented. We calculate, with the WBT interaction, the excited states in these nuclei. The calculations agree with re...Shell-model studies on the N =14 and 16 shell closures in neutron-rich Be, C, O and Ne isotopes are presented. We calculate, with the WBT interaction, the excited states in these nuclei. The calculations agree with recent experiment data. Excited energies and B(E2) values are displayed to discuss the shell closures. Our results support the N =16 shell closure in these isotopes, while indicating a disappearance of N =14 shell closure in Be and C isotopes.展开更多
Introduction:Low energy balance closure(EBC)at a particular eddy-covariance flux site has increased the uncertainties of carbon,water,and energy measurements and has thus hampered the urgent research of scaling up and...Introduction:Low energy balance closure(EBC)at a particular eddy-covariance flux site has increased the uncertainties of carbon,water,and energy measurements and has thus hampered the urgent research of scaling up and modeling analyses through site combinations in regional or global flux networks.Methods:A series of manipulative experiments were conducted in this study to explore the role of net radiation(Rn)in the EBC in relation to spatial variability of vegetation characteristics,source area,and sensor type in three sites of the Inner Mongolian grassland of northern China.Results:At all three sites,the residual fluxes of EBC peaked consistently at 110 W m^(-2).The spatial variability in net radiation was 19 W m^(-2)(5%of R_(n))during the day and 7 W m^(-2)(16%)at night,with an average of 13 W m^(-2)(11%)from eight plot measurements across the three sites.Large area measurements of Rn significantly increased by 9 W m^(-2)during the day and decreased by 4 W m^(-2)at night in the unclipped treatments.Net radiation decreased by 25 W m^(-2)(6%of Rn)at midday and 81 MJ m^(-2)(6%)during a growing season with heavier regular clipping than that in unclipped treatments.The Rn was lower by 11–21 W m^(-2)(~20–40%of Rn)measured by CNR1 than by Q7.1 at night,while there was only 6 W m^(-2)(~1–2%of Rn)difference during the daytime between these two types of commonly used net radiometers.Conclusions:Overall,the inclusion of the uncertainty in available energy accounted for 65%of the~110 W m^(-2)shortfalls in the lack of closure.Clearly,the unclosed energy balance at these three grassland sites remains significant,with unexplored mechanisms for future research.展开更多
Background:School closure is a common mitigation strategy during severe infuenza epidemics and pandemics.However,the efectiveness of this strategy remains controversial.In this study,we aimed to explore the efectivene...Background:School closure is a common mitigation strategy during severe infuenza epidemics and pandemics.However,the efectiveness of this strategy remains controversial.In this study,we aimed to explore the efectiveness of school closure on seasonal infuenza epidemics in provincial-level administrative divisions(PLADs)with varying urbanization rates in China.Methods:This study analyzed infuenza surveillance data between 2010 and 2019 provided by the Chinese National Infuenza Center.Taking into consideration the climate,this study included a region with 3 adjacent PLADs in Northern China and another region with 4 adjacent PLADs in Southern China.The efect of school closure on infuenza transmission was evaluated by the reduction of the efective reproductive number of seasonal infuenza during school winter breaks compared with that before school winter breaks.An age-structured Susceptible-Infected-Recovered-Susceptible(SIRS)model was built to model infuenza transmission in diferent levels of urbanization.Parameters were determined using the surveillance data via robust Bayesian method.Results:Between 2010 and 2019,in the less urbanized provinces:Hebei,Zhejiang,Jiangsu and Anhui,during school winter breaks,the efective reproductive number of seasonal infuenza epidemics reduced 14.6%[95%confdential interval(CI):6.2–22.9%],9.6%(95%CI:2.5–16.6%),7.3%(95%CI:0.1–14.4%)and 8.2%(95%CI:1.1–15.3%)respectively.However,in the highly urbanized cities:Beijing,Tianjin and Shanghai,it reduced only 5.2%(95%CI:-0.7–11.2%),4.1%(95%CI:-0.9–9.1%)and 3.9%(95%CI:-1.6–9.4%)respectively.In China,urbanization is associated with decreased proportion of children and increased social contact.According to the SIRS model,both factors could reduce the impact of school closure on seasonal infuenza epidemics,and the proportion of children in the population is thought to be the dominant infuencing factor.Conclusions:Efectiveness of school closure on the epidemics varies with the age structure in the population and social contact patterns.School closure should be recommended in the low urbanized regions in China in the infuenza seasons.展开更多
Let D be an integral domain with quotient field K,D be the integral closure of D in K,and D^[w] be the ω-integral closure of D in K;so D ■ D^[w],and equality holds when D is Noetherian or dim(D)=1.The Mori-Nagata th...Let D be an integral domain with quotient field K,D be the integral closure of D in K,and D^[w] be the ω-integral closure of D in K;so D ■ D^[w],and equality holds when D is Noetherian or dim(D)=1.The Mori-Nagata theorem states that if D is Noetherian,then D is a Krull domain;it has also been investigated when D is a Dedekind domain.We study integral domains D such that D^[w] is a Krull domain.We also provide an example of an integral domain D such that D ■ D ■ D^[w],t-dim(D)=1,D is a Priifer multiplication domain with v-dim(D)=2,and D^[w] is a UFD.展开更多
In this study,we systematically investigate theαdecay preformation factors,Pα,and theαdecay half-lives of 152 nuclei around Z=82,N=126 closed shells based on the generalized liquid drop model(GLDM)with Pαbeing ext...In this study,we systematically investigate theαdecay preformation factors,Pα,and theαdecay half-lives of 152 nuclei around Z=82,N=126 closed shells based on the generalized liquid drop model(GLDM)with Pαbeing extracted from the ratio of the calculatedαdecay half-life to the experimental one.The results show that there is a remarkable linear relationship between Pαand the product of valance protons(holes)Np and valance neutrons(holes)Nn.At the same time,we extract theαdecay preformation factor values of the even–even nuclei around the Z=82,N=126 closed shells from the study of Sun et al.[J.Phys.G:Nucl.Part.Phys.,45:075106(2018)],in which theαdecay was calculated by two different microscopic formulas.We find that theαdecay preformation factors are also related to NpNn.Combining with our previous studies[Sun et al.,Phys.Rev.C,94:024338(2016);Deng et al.,ibid.96:024318(2017);Deng et al.,ibid.97:044322(2018)]and that of Seif et al.,[Phys.Rev.C,84:064608(2011)],we suspect that this phenomenon of linear relationship for the nuclei around the above closed shells is model-independent.This may be caused by the effect of the valence protons(holes)and valence neutrons(holes)around the shell closures.Finally,using the formula obtained by fitting theαdecay preformation factor data calculated by the GLDM,we calculate theαdecay half-lives of these nuclei.The calculated results agree with the experimental data well.展开更多
Deep shale gas reservoirs have geological characteristics of high temperature,high pressure,high stress,and inferior ability to pass through fluids.The multi-stage fractured horizontal well is the key to exploiting th...Deep shale gas reservoirs have geological characteristics of high temperature,high pressure,high stress,and inferior ability to pass through fluids.The multi-stage fractured horizontal well is the key to exploiting the deep shale gas reservoir.However,during the production process,the effectiveness of the hydraulic fracture network decreases with the closure of fractures,which accelerates the decline of shale gas production.In this paper,we addressed the problems of unclear fracture closure mechanisms and low accuracy of shale gas production prediction during deep shale gas production.Then we established the fluid—solid—heat coupled model coupling the deformation and fluid flow among the fracture surface,proppant and the shale matrix.When the fluid—solid—heat coupled model was applied to the fracture network,it was well solved by our numerical method named discontinuous discrete fracture method.Compared with the conventional discrete fracture method,the discontinuous discrete fracture method can describe the three-dimensional morphology of the fracture while considering the effect of the change of fracture surface permeation coefficient on the coupled fracture—matrix flow and describing the displacement discontinuity across the fracture.Numerical simulations revealed that the degree of fracture closure increases as the production time proceeds,and the degree of closure of the secondary fractures is higher than that of the primary fractures.Shale creep and proppant embedment both increase the degree of fracture closure.The reduction in fracture surface permeability due to proppant embedment reduces the rate of fluid transfer between matrix and fracture,which has often been overlooked in the past.However,it significantly impacts shale gas production,with calculations showing a 24.7%cumulative three-year yield reduction.This study is helpful to understand the mechanism of hydraulic fracture closure.Therefore,it provides the theoretical guidance for maintaining the long-term effectiveness of hydraulic fractures.展开更多
The stability and mobility of proppant packs in hydraulic fractures during hydrocarbon production are numerically investigated by the lattice Boltzmann-discrete element coupling method(LB-DEM).This study starts with a...The stability and mobility of proppant packs in hydraulic fractures during hydrocarbon production are numerically investigated by the lattice Boltzmann-discrete element coupling method(LB-DEM).This study starts with a preliminary proppant settling test,from which a solid volume fraction of 0.575 is calibrated for the proppant pack in the fracture.In the established workflow to investigate proppant flowback,a displacement is applied to the fracture surfaces to compact the generated proppant pack as well as further mimicking proppant embedment under closure stress.When a pressure gradient is applied to drive the fluid-particle flow,a critical aperture-to-diameter ratio of 4 is observed,above which the proppant pack would collapse.The results also show that the volumetric proppant flowback rate increases quadratically with the fracture aperture,while a linear variation between the particle flux and the pressure gradient is exhibited for a fixed fracture aperture.The research outcome contributes towards an improved understanding of proppant flowback in hydraulic fractures,which also supports an optimised proppant size selection for hydraulic fracturing operations.展开更多
In this work,anisotropic fatigue crack growth rate(FCGR)behaviour in a hot-rolled Mg-3wt%Al-0.5wt%Ce alloy was investigated using compact tension(CT)specimens with notch(an)parallel to the rolling direction(RD)and tra...In this work,anisotropic fatigue crack growth rate(FCGR)behaviour in a hot-rolled Mg-3wt%Al-0.5wt%Ce alloy was investigated using compact tension(CT)specimens with notch(an)parallel to the rolling direction(RD)and transverse direction(TD).The FCGR tests were conducted at a constant load ratio(R=0.1)and maximum stress intensity factor(KMax=15.6 MPa√m)to investigate the crack closure effect.For both constant R and KMax conditions:(i)the load-displacement curves for every loading cycle were linear for a_(n)∥ to RD and TD,indicating no crack closure;(ii)the FCGR was found to be lower for an∥RD than an∥TD over the entire stress intensity factor range(△K).The hot-rolled sample contained long-aligned Al11Ce3 intermetallic phase within grain boundaries that are elongated along RD.During the FCGR test,{10.12}<10.11>extension twins(ET)with lamellae∼⊥and c-axis∼∥to these elongated intermetallics along RD developed irrespective of the notch orientation.During the loading cycle,these intermetallics along RD generate back-stresses,reducing the in-plane tensile stress∼||and∼⊥to crack-tip to∼0 for a_(n)∥to RD and TD,respectively.Hence,lenticular ET∼||⊥and∼||,with c-axis∼||and∼⊥to crack path activates,leading to trans and inter lamellar crack for anto RD and TD,respectively,and anisotropic FCGR.Translamellar crack in a_(n)∥RD reduces the FCGR due to plastic energy dissipation as perceived by comparatively more geometrically necessary boundaries(GNBs).On the other hand,faster FCGR was obtained for a_(n)∥TD due to interlamellar cracking.Thus,the crack growth through the matrix-ET interfaces was favoured due to strain incompatibility.The Fractography for a_(n)∥RD shows smaller elongated grooves along crack propagation,which indicates crack arrest.However,larger elongated grooves for a_(n)||TD indicated easy crack propagation due to favourable interlamellar crack.展开更多
The crack-closure effect is a crucial factor that affects the crack growth rate and should be considered in simulation analysis and testing.A mixed-mode I+II loading fatigue crack growth test was performed using EA4T ...The crack-closure effect is a crucial factor that affects the crack growth rate and should be considered in simulation analysis and testing.A mixed-mode I+II loading fatigue crack growth test was performed using EA4T axle steel specimens.The variation of the plastic-induced crack closure(PICC)effect and the roughness-induced crack closure(RICC)effect during crack deflection in the mixed-mode is examined in this study.The results show that the load perpendicular to the crack propagation direction hinders the slip effect caused by the load parallel to the crack propagation direction under mixed-mode loading,and the crack deflection is an intuitive manifestation of the interaction between the PICC and RICC.The proportion of the RA value change on the crack side caused by contact friction was reduced by the interaction between PICC and RICC.The roughness of the crack surface before and after the crack deflection is different,and the spatial torsion crack surface is formed during the crack propagation process.With the increase of the crack length,the roughness of the fracture surface increases.During the crack deflection process,the PICC value fluctuates around 0.2,and the RICC value is increased to 0.15.展开更多
China has embarked on an extensive and sustained endeavor to harness its coal resources for a substantial period.However,the depletion of coal reserves in mining regions has necessitated the closure or abandonment of ...China has embarked on an extensive and sustained endeavor to harness its coal resources for a substantial period.However,the depletion of coal reserves in mining regions has necessitated the closure or abandonment of numerous mines,resulting in a marked increase in the number of such facilities.Parallel to this,China is vigorously advancing the development of a novel energy power system,aimed at transitioning the power sector from a high-carbon,fossil fuel-dependent paradigm to a low-carbon,clean energy footing.展开更多
Recently,much interest has been given tomulti-granulation rough sets (MGRS), and various types ofMGRSmodelshave been developed from different viewpoints. In this paper, we introduce two techniques for the classificati...Recently,much interest has been given tomulti-granulation rough sets (MGRS), and various types ofMGRSmodelshave been developed from different viewpoints. In this paper, we introduce two techniques for the classificationof MGRS. Firstly, we generate multi-topologies from multi-relations defined in the universe. Hence, a novelapproximation space is established by leveraging the underlying topological structure. The characteristics of thenewly proposed approximation space are discussed.We introduce an algorithmfor the reduction ofmulti-relations.Secondly, a new approach for the classification ofMGRS based on neighborhood concepts is introduced. Finally, areal-life application from medical records is introduced via our approach to the classification of MGRS.展开更多
We present the case of a patient with iridoschisis complicated with cataract,peripheral anterior synechiae(PAS),secondary glaucoma,and corneal endothelial damage.The patient was initially misdiagnosed with acute angle...We present the case of a patient with iridoschisis complicated with cataract,peripheral anterior synechiae(PAS),secondary glaucoma,and corneal endothelial damage.The patient was initially misdiagnosed with acute angle-closure glaucoma.Iridoschisis is a rare condition characterized by the splitting of the iris into two layers:the anterior layer breaks down into fibers,floating freely in the anterior chamber with a“shredded wheat”appearance.展开更多
Dear Editor,The choice of surgical intervention for nanophthalmos patients with secondary angle-closure glaucoma poses a challenging decision for ophthalmologists.Because nanophthalmos patients who have undergone filt...Dear Editor,The choice of surgical intervention for nanophthalmos patients with secondary angle-closure glaucoma poses a challenging decision for ophthalmologists.Because nanophthalmos patients who have undergone filtration surgery or other intraocular procedures are more susceptible to severe complications,including choroidal effusion,malignant glaucoma,and explosive choroidal hemorrhage,all of which can lead to vision loss[1].This dilemma is particularly pronounced in patients with shorter axial lengths.Micropulse transscleral laser therapy(M-TLT),also known as micropulse transscleral cyclophotocoagulation(MP-TSCPC),is a nonincisional laser therapy surgery for glaucoma[2].In 2015,Golan and Kurtz[3]were the first to report four patients with secondary angle-closure glaucoma in nanophthalmos with axial lengths ranging between 17 and 19 mm(mean 18 mm)who were successfully treated with M-TLT,and choroidal detachment was observed in all patients(recovery spontaneously in two patients and recovery after systemic steroid treatment in the other two),of which two had a slight decrease in visual acuity.展开更多
Background:Transcatheter closure(TCC)has emerged as the preferred treatment for selected congenital heart disease(CHD).While TCC offers benefits for patients with postoperative residual shunts,understanding its mid-an...Background:Transcatheter closure(TCC)has emerged as the preferred treatment for selected congenital heart disease(CHD).While TCC offers benefits for patients with postoperative residual shunts,understanding its mid-and long-term efficacy and safety remains crucial.Objective:This study aims to assess the mid-and long-term safety and efficacy of TCC for patients with residual atrial or ventricular septal shunts following CHD correction.Methods:In this consecutive retrospective study,we enrolled 35 patients with residual shunt who underwent TCC or surgical repair of CHD between June 2011 to October 2022.TCC candidacy was determined based on established criteria.Echocardiography and electrocardiogram were conducted during the perioperative period and continued as part of long-term follow-up.Results:Among the patients,5(14.3%)exhibited interatrial shunt-ing,while 30(85.7%)had interventricular shunting.TCC was successfully implemented in 33 of 35 patients,with exceptions in two cases of post-ventricular septal defect repair due to anatomical challenges involving the shape and aortic angulation.This resulted in a TCC success rate of 94.3%.Trace residual shunt was detected in two interventricular shunting cases and a mild residual shunt in one interventricular shunting case;all resolved by the three-month follow-up after TCC.Minor complications included one hematoma at the puncture site and one transient junctional rhythm during the perioperative period.During a median follow-up of 73 months,there were no instances of residual shunt,device embolization,occluder displacement,valve insufficiency,malignant arrhythmia,infective endocarditis,death,or other serious complications.Conclusion:TCC is an effective and safe therapy for patients with residual atrial or ventricular septal shunts following CHD correction.Thesefindings support the consideration of TCC as the preferred treatment option for appropriate patient populations.展开更多
AIM:To investigate Omicron’s impact on clinical presentation of acute primary angle closure(APAC)in China.METHODS:A consecutive case series with historical controls was conducted at Shenzhen Eye Hospital,the largest ...AIM:To investigate Omicron’s impact on clinical presentation of acute primary angle closure(APAC)in China.METHODS:A consecutive case series with historical controls was conducted at Shenzhen Eye Hospital,the largest specialized hospital in Shenzhen,China.Medical records from a two-month period during the Omicron pandemic(December 1,2022,to January 31,2023)were compared with records from two control groups(12/2018–1/2019 and 12/2021–1/2022)before pandemic.Patients with APAC were included,and the prevalence of APAC and demographic characteristics in Omicron-infected and noninfected patients were compared.RESULTS:Seventy-one(23.43%)out of 303 patients were diagnosed with APAC in the pandemic cohort,which was 2.98 and 2.61 times higher than that in control cohorts(7.87%in 2019,8.96%in 2022,P<0.001).The pandemic cohort has significantly higher Omicron-infected rate(78.87%vs 0 vs 0;P<0.001),lower proportion of glaucoma history(16.90%vs 42.86%vs 41.67%,P=0.005),higher surgical rate(95.77%vs 83.33%vs 78.57%,P=0.024),higher total medical costs and larger pupil diameter(5.63±0.15 vs 4.68±0.15 vs 4.69±0.22 mm,P<0.01).In 83%Omicron-infected patients,ocular symptoms appeared within 3d after systemic symptoms onset.In multivariate analysis,Omicron infection(P<0.001)was the only independent predictor of pupil diameter.CONCLUSION:In the Omicron epidemic in China,there is an increase of prevalence and severity of APAC,particularly focusing on the first 3d following infection.展开更多
Background:Atrial septal defect(ASD)is a common form of adult congenital heart disease that can lead to long-term adverse outcomes if left untreated.Early closure of ASD has been associated with excellent outcomes and...Background:Atrial septal defect(ASD)is a common form of adult congenital heart disease that can lead to long-term adverse outcomes if left untreated.Early closure of ASD has been associated with excellent outcomes and lower complication rates.However,there is limited evidence regarding the prognosis of ASD closure in older adults.This study aims to evaluate the mortality rates in older ASD patients with and without closure.Methods:A retrospective cohort study was conducted on patients aged 40 years or older with ASD between 2001 and 2017.Patients were followed up to assess all-cause mortality.Univariable and multivariable analyses were performed to identify the predictors of mortality.A p-value of<0.05 was considered statistically significant.Results:The cohort consisted of 450 patients(mean age 56.6±10.4 years,77.3%female),with 66%aged between 40 and 60 years,and 34%over 60 years.Within the cohort,299 underwent ASD closure(201 with transcatheter and 98 with surgical closure).During the median follow-up duration of 7.9 years,51 patients died.The unadjusted cumulative 10-year rate of mortality was 3%in patients with ASD closure,and 28%in patients without ASD closure(log-rank p<0.001).Multivariable analysis revealed that age(hazard ratio[HR]1.04,95%confidence interval[CI]1.006–1.06,p=0.01),NYHA class(HR 2.75,95%CI 1.63–4.62,p<0.001),blood urea nitrogen(BUN)(HR 1.07,95%CI 1.03–1.12,p<0.001),right ventricular systolic pressure(RVSP)(HR 1.07,95%CI 1.003–1.04,p=0.01),and lack of ASD closure(HR 15.12,95%CI 5.63–40.59,p<0.001)were independently associated with mortality.Conclusion:ASD closure demonstrated favorable outcomes in older patients.Age,NYHA class,BUN,RVSP,and lack of ASD closure were identified as independent factors linked to mortality in this population.展开更多
AIM:To describe the gonioscopic profile and intraocular pressure(IOP)in primary angle-closure(PAC)disease in patients presenting to a tertiary eye care network in India.METHODS:A cross-sectional hospital-based study t...AIM:To describe the gonioscopic profile and intraocular pressure(IOP)in primary angle-closure(PAC)disease in patients presenting to a tertiary eye care network in India.METHODS:A cross-sectional hospital-based study that included 31484 new patients presenting between 2011 and 2021.Patients with a clinical diagnosis of PAC/suspect/glaucoma were included.The data was collected from an electronic medical record system.RESULTS:PAC glaucoma(PACG)(47.55%)was the most common diagnosis followed by PAC(39.49%)and PAC suspect(PACS;12.96%).Female preponderance(54.6%)was noted with higher mean age at presentation among males(P<0.0001).PACS and PAC showed the highest prevalence in 6th decade but PACG was higher at 7th decade.The probability of angle opening was 95.93%,90.32%and 63.36%in PACS,PAC and PACG eyes respectively post peripheral iridotomy(PI).Plateau iris syndrome(PIS)was noted in 252 eyes and all showed post dilated rise of IOP.A post dilated IOP rise was also noted with 8.86%,33.95%and 57.19%eyes with PACS,PAC and PACG respectively with IOP rise between 6-8 mm Hg across the disease spectrum.CONCLUSION:The superior quadrant is the narrowest angle and difficult to open with indentation and post PI.The probability of angle opening is less in PIS especially the complete variety along with post dilated IOP rise.The post dilated IOP rise in angle closure eyes warrants a careful dilatation,especially with PIS.展开更多
文摘This research uses a theoretical conceptual method based on Chantal Mouffe's Radical Democracy which blended with Derrida's deconstruction thesis about "democracy to come" to reach findings on the state of South Africa's media freedom landscape. The method is contained in the conceptual framework. The article provides the constitutional legal landscape--or the overarching laws of the land--and the co-regulatory framework within which journalists work. There are four research explications: the Protection of State Information Bill (dubbed the Secrecy Bill), a painting of the president and Freedom of Expression, an arson attack on a community radio station and finally, the death of a photojournalist at the hands of police. The argument here is that the death, the arson attack, the Secrecy Bill, and the shut-down of dissent during the exhibition of the painting of the president all undermine democracy and signify significant closures for the media in the now 20-year-old post-apartheid South Africa. The analysis and reflections will be framed within theories of radical democracy, which argue for more fights and contestations and more voices from the margins in order to deepen democracy, rather than rational consensus which closes the spaces for greater plurality.
文摘In this paper we study the structure of k-transitive closures of directed paths and formulate several properties. Concept of k-transitive orientation generalizes the traditional concept of transitive orientation of a graph.
基金Supported by National Natural Science Foundation of China (10735010, 10525520)Chinese Major State Basic Research Development Program (2007CB815000)
文摘Shell-model studies on the N =14 and 16 shell closures in neutron-rich Be, C, O and Ne isotopes are presented. We calculate, with the WBT interaction, the excited states in these nuclei. The calculations agree with recent experiment data. Excited energies and B(E2) values are displayed to discuss the shell closures. Our results support the N =16 shell closure in these isotopes, while indicating a disappearance of N =14 shell closure in Be and C isotopes.
基金This study was supported by the Natural Science Foundation of China(31170454,31229001,31130202)the State Key Basic Research Development Program of China(2013CB956600)the NASA-NEWS Program(NN-H-04-Z-YS-005-N),and the USCCC。
文摘Introduction:Low energy balance closure(EBC)at a particular eddy-covariance flux site has increased the uncertainties of carbon,water,and energy measurements and has thus hampered the urgent research of scaling up and modeling analyses through site combinations in regional or global flux networks.Methods:A series of manipulative experiments were conducted in this study to explore the role of net radiation(Rn)in the EBC in relation to spatial variability of vegetation characteristics,source area,and sensor type in three sites of the Inner Mongolian grassland of northern China.Results:At all three sites,the residual fluxes of EBC peaked consistently at 110 W m^(-2).The spatial variability in net radiation was 19 W m^(-2)(5%of R_(n))during the day and 7 W m^(-2)(16%)at night,with an average of 13 W m^(-2)(11%)from eight plot measurements across the three sites.Large area measurements of Rn significantly increased by 9 W m^(-2)during the day and decreased by 4 W m^(-2)at night in the unclipped treatments.Net radiation decreased by 25 W m^(-2)(6%of Rn)at midday and 81 MJ m^(-2)(6%)during a growing season with heavier regular clipping than that in unclipped treatments.The Rn was lower by 11–21 W m^(-2)(~20–40%of Rn)measured by CNR1 than by Q7.1 at night,while there was only 6 W m^(-2)(~1–2%of Rn)difference during the daytime between these two types of commonly used net radiometers.Conclusions:Overall,the inclusion of the uncertainty in available energy accounted for 65%of the~110 W m^(-2)shortfalls in the lack of closure.Clearly,the unclosed energy balance at these three grassland sites remains significant,with unexplored mechanisms for future research.
基金funded by grants from the Shenzhen Science and Technology Program(Grant No.KQTD20180411143323605)the National Natural Science Foundation of China(Grant No.82003509)+1 种基金the Natural Science Foundation of Zhejiang Province(Grant No.LQ20H260009)Fundamental Research Funds for the Central Universities.
文摘Background:School closure is a common mitigation strategy during severe infuenza epidemics and pandemics.However,the efectiveness of this strategy remains controversial.In this study,we aimed to explore the efectiveness of school closure on seasonal infuenza epidemics in provincial-level administrative divisions(PLADs)with varying urbanization rates in China.Methods:This study analyzed infuenza surveillance data between 2010 and 2019 provided by the Chinese National Infuenza Center.Taking into consideration the climate,this study included a region with 3 adjacent PLADs in Northern China and another region with 4 adjacent PLADs in Southern China.The efect of school closure on infuenza transmission was evaluated by the reduction of the efective reproductive number of seasonal infuenza during school winter breaks compared with that before school winter breaks.An age-structured Susceptible-Infected-Recovered-Susceptible(SIRS)model was built to model infuenza transmission in diferent levels of urbanization.Parameters were determined using the surveillance data via robust Bayesian method.Results:Between 2010 and 2019,in the less urbanized provinces:Hebei,Zhejiang,Jiangsu and Anhui,during school winter breaks,the efective reproductive number of seasonal infuenza epidemics reduced 14.6%[95%confdential interval(CI):6.2–22.9%],9.6%(95%CI:2.5–16.6%),7.3%(95%CI:0.1–14.4%)and 8.2%(95%CI:1.1–15.3%)respectively.However,in the highly urbanized cities:Beijing,Tianjin and Shanghai,it reduced only 5.2%(95%CI:-0.7–11.2%),4.1%(95%CI:-0.9–9.1%)and 3.9%(95%CI:-1.6–9.4%)respectively.In China,urbanization is associated with decreased proportion of children and increased social contact.According to the SIRS model,both factors could reduce the impact of school closure on seasonal infuenza epidemics,and the proportion of children in the population is thought to be the dominant infuencing factor.Conclusions:Efectiveness of school closure on the epidemics varies with the age structure in the population and social contact patterns.School closure should be recommended in the low urbanized regions in China in the infuenza seasons.
基金supported by the Academic Research Fund of Hoseo University in 2017(no.2017-0047).
文摘Let D be an integral domain with quotient field K,D be the integral closure of D in K,and D^[w] be the ω-integral closure of D in K;so D ■ D^[w],and equality holds when D is Noetherian or dim(D)=1.The Mori-Nagata theorem states that if D is Noetherian,then D is a Krull domain;it has also been investigated when D is a Dedekind domain.We study integral domains D such that D^[w] is a Krull domain.We also provide an example of an integral domain D such that D ■ D ■ D^[w],t-dim(D)=1,D is a Priifer multiplication domain with v-dim(D)=2,and D^[w] is a UFD.
基金Supported in part by the National Natural Science Foundation of China(11205083,11505100,11705055)the Construct Program of the Key Discipline in Hunan Province,the Research Foundation of Education Bureau of Hunan Province,China(15A159,18A237)+4 种基金the Natural Science Foundation of Hunan Province,China(2015JJ3103,2015JJ2121,2018JJ3324)the Innovation Group of Nuclear and Particle Physics in USC,the Shandong Province Natural Science Foundation,China(ZR2015AQ007)the Hunan Provincial Innovation Foundation For Postgraduate(CX20190714,CX20200909)the National Innovation Training Foundation of China(201910555161)and the Opening Project of Cooperative Innovation Center for Nuclear Fuel Cycle Technology and Equipment,University of South China(2019KFZ10)。
文摘In this study,we systematically investigate theαdecay preformation factors,Pα,and theαdecay half-lives of 152 nuclei around Z=82,N=126 closed shells based on the generalized liquid drop model(GLDM)with Pαbeing extracted from the ratio of the calculatedαdecay half-life to the experimental one.The results show that there is a remarkable linear relationship between Pαand the product of valance protons(holes)Np and valance neutrons(holes)Nn.At the same time,we extract theαdecay preformation factor values of the even–even nuclei around the Z=82,N=126 closed shells from the study of Sun et al.[J.Phys.G:Nucl.Part.Phys.,45:075106(2018)],in which theαdecay was calculated by two different microscopic formulas.We find that theαdecay preformation factors are also related to NpNn.Combining with our previous studies[Sun et al.,Phys.Rev.C,94:024338(2016);Deng et al.,ibid.96:024318(2017);Deng et al.,ibid.97:044322(2018)]and that of Seif et al.,[Phys.Rev.C,84:064608(2011)],we suspect that this phenomenon of linear relationship for the nuclei around the above closed shells is model-independent.This may be caused by the effect of the valence protons(holes)and valence neutrons(holes)around the shell closures.Finally,using the formula obtained by fitting theαdecay preformation factor data calculated by the GLDM,we calculate theαdecay half-lives of these nuclei.The calculated results agree with the experimental data well.
基金the supports provided by China University of Petroleum,Beijing(Grand No.ZX20230042)the National Natural Science Foundation of China(Grand No.52334001and Grand No.51904314)。
文摘Deep shale gas reservoirs have geological characteristics of high temperature,high pressure,high stress,and inferior ability to pass through fluids.The multi-stage fractured horizontal well is the key to exploiting the deep shale gas reservoir.However,during the production process,the effectiveness of the hydraulic fracture network decreases with the closure of fractures,which accelerates the decline of shale gas production.In this paper,we addressed the problems of unclear fracture closure mechanisms and low accuracy of shale gas production prediction during deep shale gas production.Then we established the fluid—solid—heat coupled model coupling the deformation and fluid flow among the fracture surface,proppant and the shale matrix.When the fluid—solid—heat coupled model was applied to the fracture network,it was well solved by our numerical method named discontinuous discrete fracture method.Compared with the conventional discrete fracture method,the discontinuous discrete fracture method can describe the three-dimensional morphology of the fracture while considering the effect of the change of fracture surface permeation coefficient on the coupled fracture—matrix flow and describing the displacement discontinuity across the fracture.Numerical simulations revealed that the degree of fracture closure increases as the production time proceeds,and the degree of closure of the secondary fractures is higher than that of the primary fractures.Shale creep and proppant embedment both increase the degree of fracture closure.The reduction in fracture surface permeability due to proppant embedment reduces the rate of fluid transfer between matrix and fracture,which has often been overlooked in the past.However,it significantly impacts shale gas production,with calculations showing a 24.7%cumulative three-year yield reduction.This study is helpful to understand the mechanism of hydraulic fracture closure.Therefore,it provides the theoretical guidance for maintaining the long-term effectiveness of hydraulic fractures.
基金Funding support from Heilongjiang"Open Competition"project(Grant No.DQYT2022-JS-758)is greatly acknowledgedFinancial support from the National Natural Science Foundation of China(Grant Nos.52304025 and 52174025)is acknowledged+1 种基金supports from Northeast Petroleum University and Guangdong Basic and Applied Basic Research Foundationsupport from the Heilongjiang Touyan Innovation Team Program.
文摘The stability and mobility of proppant packs in hydraulic fractures during hydrocarbon production are numerically investigated by the lattice Boltzmann-discrete element coupling method(LB-DEM).This study starts with a preliminary proppant settling test,from which a solid volume fraction of 0.575 is calibrated for the proppant pack in the fracture.In the established workflow to investigate proppant flowback,a displacement is applied to the fracture surfaces to compact the generated proppant pack as well as further mimicking proppant embedment under closure stress.When a pressure gradient is applied to drive the fluid-particle flow,a critical aperture-to-diameter ratio of 4 is observed,above which the proppant pack would collapse.The results also show that the volumetric proppant flowback rate increases quadratically with the fracture aperture,while a linear variation between the particle flux and the pressure gradient is exhibited for a fixed fracture aperture.The research outcome contributes towards an improved understanding of proppant flowback in hydraulic fractures,which also supports an optimised proppant size selection for hydraulic fracturing operations.
基金support provided by the Science and Engineering Research Board(Ref.no.:ECR/2016/000125)Department of Science and Technology,Government of India.SB acknowledges the funding by Alexander von Humboldt Foundation,Germany.
文摘In this work,anisotropic fatigue crack growth rate(FCGR)behaviour in a hot-rolled Mg-3wt%Al-0.5wt%Ce alloy was investigated using compact tension(CT)specimens with notch(an)parallel to the rolling direction(RD)and transverse direction(TD).The FCGR tests were conducted at a constant load ratio(R=0.1)and maximum stress intensity factor(KMax=15.6 MPa√m)to investigate the crack closure effect.For both constant R and KMax conditions:(i)the load-displacement curves for every loading cycle were linear for a_(n)∥ to RD and TD,indicating no crack closure;(ii)the FCGR was found to be lower for an∥RD than an∥TD over the entire stress intensity factor range(△K).The hot-rolled sample contained long-aligned Al11Ce3 intermetallic phase within grain boundaries that are elongated along RD.During the FCGR test,{10.12}<10.11>extension twins(ET)with lamellae∼⊥and c-axis∼∥to these elongated intermetallics along RD developed irrespective of the notch orientation.During the loading cycle,these intermetallics along RD generate back-stresses,reducing the in-plane tensile stress∼||and∼⊥to crack-tip to∼0 for a_(n)∥to RD and TD,respectively.Hence,lenticular ET∼||⊥and∼||,with c-axis∼||and∼⊥to crack path activates,leading to trans and inter lamellar crack for anto RD and TD,respectively,and anisotropic FCGR.Translamellar crack in a_(n)∥RD reduces the FCGR due to plastic energy dissipation as perceived by comparatively more geometrically necessary boundaries(GNBs).On the other hand,faster FCGR was obtained for a_(n)∥TD due to interlamellar cracking.Thus,the crack growth through the matrix-ET interfaces was favoured due to strain incompatibility.The Fractography for a_(n)∥RD shows smaller elongated grooves along crack propagation,which indicates crack arrest.However,larger elongated grooves for a_(n)||TD indicated easy crack propagation due to favourable interlamellar crack.
基金Supported by National Natural Science Foundation of China (Grant No.52375159)National Railway Administration of China (Grant No.KF2023-025)the Independent Research Project of the State Key Laboratory of Traction Power (Grant No.2022TPL_T03)。
文摘The crack-closure effect is a crucial factor that affects the crack growth rate and should be considered in simulation analysis and testing.A mixed-mode I+II loading fatigue crack growth test was performed using EA4T axle steel specimens.The variation of the plastic-induced crack closure(PICC)effect and the roughness-induced crack closure(RICC)effect during crack deflection in the mixed-mode is examined in this study.The results show that the load perpendicular to the crack propagation direction hinders the slip effect caused by the load parallel to the crack propagation direction under mixed-mode loading,and the crack deflection is an intuitive manifestation of the interaction between the PICC and RICC.The proportion of the RA value change on the crack side caused by contact friction was reduced by the interaction between PICC and RICC.The roughness of the crack surface before and after the crack deflection is different,and the spatial torsion crack surface is formed during the crack propagation process.With the increase of the crack length,the roughness of the fracture surface increases.During the crack deflection process,the PICC value fluctuates around 0.2,and the RICC value is increased to 0.15.
文摘China has embarked on an extensive and sustained endeavor to harness its coal resources for a substantial period.However,the depletion of coal reserves in mining regions has necessitated the closure or abandonment of numerous mines,resulting in a marked increase in the number of such facilities.Parallel to this,China is vigorously advancing the development of a novel energy power system,aimed at transitioning the power sector from a high-carbon,fossil fuel-dependent paradigm to a low-carbon,clean energy footing.
文摘Recently,much interest has been given tomulti-granulation rough sets (MGRS), and various types ofMGRSmodelshave been developed from different viewpoints. In this paper, we introduce two techniques for the classificationof MGRS. Firstly, we generate multi-topologies from multi-relations defined in the universe. Hence, a novelapproximation space is established by leveraging the underlying topological structure. The characteristics of thenewly proposed approximation space are discussed.We introduce an algorithmfor the reduction ofmulti-relations.Secondly, a new approach for the classification ofMGRS based on neighborhood concepts is introduced. Finally, areal-life application from medical records is introduced via our approach to the classification of MGRS.
基金Supported by the Cadre Health Research Program of the Sichuan Province(No.2023-119).
文摘We present the case of a patient with iridoschisis complicated with cataract,peripheral anterior synechiae(PAS),secondary glaucoma,and corneal endothelial damage.The patient was initially misdiagnosed with acute angle-closure glaucoma.Iridoschisis is a rare condition characterized by the splitting of the iris into two layers:the anterior layer breaks down into fibers,floating freely in the anterior chamber with a“shredded wheat”appearance.
文摘Dear Editor,The choice of surgical intervention for nanophthalmos patients with secondary angle-closure glaucoma poses a challenging decision for ophthalmologists.Because nanophthalmos patients who have undergone filtration surgery or other intraocular procedures are more susceptible to severe complications,including choroidal effusion,malignant glaucoma,and explosive choroidal hemorrhage,all of which can lead to vision loss[1].This dilemma is particularly pronounced in patients with shorter axial lengths.Micropulse transscleral laser therapy(M-TLT),also known as micropulse transscleral cyclophotocoagulation(MP-TSCPC),is a nonincisional laser therapy surgery for glaucoma[2].In 2015,Golan and Kurtz[3]were the first to report four patients with secondary angle-closure glaucoma in nanophthalmos with axial lengths ranging between 17 and 19 mm(mean 18 mm)who were successfully treated with M-TLT,and choroidal detachment was observed in all patients(recovery spontaneously in two patients and recovery after systemic steroid treatment in the other two),of which two had a slight decrease in visual acuity.
文摘Background:Transcatheter closure(TCC)has emerged as the preferred treatment for selected congenital heart disease(CHD).While TCC offers benefits for patients with postoperative residual shunts,understanding its mid-and long-term efficacy and safety remains crucial.Objective:This study aims to assess the mid-and long-term safety and efficacy of TCC for patients with residual atrial or ventricular septal shunts following CHD correction.Methods:In this consecutive retrospective study,we enrolled 35 patients with residual shunt who underwent TCC or surgical repair of CHD between June 2011 to October 2022.TCC candidacy was determined based on established criteria.Echocardiography and electrocardiogram were conducted during the perioperative period and continued as part of long-term follow-up.Results:Among the patients,5(14.3%)exhibited interatrial shunt-ing,while 30(85.7%)had interventricular shunting.TCC was successfully implemented in 33 of 35 patients,with exceptions in two cases of post-ventricular septal defect repair due to anatomical challenges involving the shape and aortic angulation.This resulted in a TCC success rate of 94.3%.Trace residual shunt was detected in two interventricular shunting cases and a mild residual shunt in one interventricular shunting case;all resolved by the three-month follow-up after TCC.Minor complications included one hematoma at the puncture site and one transient junctional rhythm during the perioperative period.During a median follow-up of 73 months,there were no instances of residual shunt,device embolization,occluder displacement,valve insufficiency,malignant arrhythmia,infective endocarditis,death,or other serious complications.Conclusion:TCC is an effective and safe therapy for patients with residual atrial or ventricular septal shunts following CHD correction.Thesefindings support the consideration of TCC as the preferred treatment option for appropriate patient populations.
基金Supported by the National Natural Science Foundation of China(No.82301223No.82271102)+2 种基金the Guangdong Basic and Applied Basic Research Foundation(No.2022A1515111155)the Shenzhen Science and Technology Program(No.KCXFZ20211020163813019)the Shenzhen Science and Technology Program(No.RCBS20210706092347043).
文摘AIM:To investigate Omicron’s impact on clinical presentation of acute primary angle closure(APAC)in China.METHODS:A consecutive case series with historical controls was conducted at Shenzhen Eye Hospital,the largest specialized hospital in Shenzhen,China.Medical records from a two-month period during the Omicron pandemic(December 1,2022,to January 31,2023)were compared with records from two control groups(12/2018–1/2019 and 12/2021–1/2022)before pandemic.Patients with APAC were included,and the prevalence of APAC and demographic characteristics in Omicron-infected and noninfected patients were compared.RESULTS:Seventy-one(23.43%)out of 303 patients were diagnosed with APAC in the pandemic cohort,which was 2.98 and 2.61 times higher than that in control cohorts(7.87%in 2019,8.96%in 2022,P<0.001).The pandemic cohort has significantly higher Omicron-infected rate(78.87%vs 0 vs 0;P<0.001),lower proportion of glaucoma history(16.90%vs 42.86%vs 41.67%,P=0.005),higher surgical rate(95.77%vs 83.33%vs 78.57%,P=0.024),higher total medical costs and larger pupil diameter(5.63±0.15 vs 4.68±0.15 vs 4.69±0.22 mm,P<0.01).In 83%Omicron-infected patients,ocular symptoms appeared within 3d after systemic symptoms onset.In multivariate analysis,Omicron infection(P<0.001)was the only independent predictor of pupil diameter.CONCLUSION:In the Omicron epidemic in China,there is an increase of prevalence and severity of APAC,particularly focusing on the first 3d following infection.
基金This study was approved by the Siriraj Institutional Review Board(SIRB),Faculty of Medicine Siriraj Hospital,Mahidol University(COA no.Si 760/2021).The need for consent was waived by the board due to its retrospective nature and as all personal identifying information was obliterated.The study protocol conforms to the ethical guidelines of the 1975 Declaration of Helsinki.
文摘Background:Atrial septal defect(ASD)is a common form of adult congenital heart disease that can lead to long-term adverse outcomes if left untreated.Early closure of ASD has been associated with excellent outcomes and lower complication rates.However,there is limited evidence regarding the prognosis of ASD closure in older adults.This study aims to evaluate the mortality rates in older ASD patients with and without closure.Methods:A retrospective cohort study was conducted on patients aged 40 years or older with ASD between 2001 and 2017.Patients were followed up to assess all-cause mortality.Univariable and multivariable analyses were performed to identify the predictors of mortality.A p-value of<0.05 was considered statistically significant.Results:The cohort consisted of 450 patients(mean age 56.6±10.4 years,77.3%female),with 66%aged between 40 and 60 years,and 34%over 60 years.Within the cohort,299 underwent ASD closure(201 with transcatheter and 98 with surgical closure).During the median follow-up duration of 7.9 years,51 patients died.The unadjusted cumulative 10-year rate of mortality was 3%in patients with ASD closure,and 28%in patients without ASD closure(log-rank p<0.001).Multivariable analysis revealed that age(hazard ratio[HR]1.04,95%confidence interval[CI]1.006–1.06,p=0.01),NYHA class(HR 2.75,95%CI 1.63–4.62,p<0.001),blood urea nitrogen(BUN)(HR 1.07,95%CI 1.03–1.12,p<0.001),right ventricular systolic pressure(RVSP)(HR 1.07,95%CI 1.003–1.04,p=0.01),and lack of ASD closure(HR 15.12,95%CI 5.63–40.59,p<0.001)were independently associated with mortality.Conclusion:ASD closure demonstrated favorable outcomes in older patients.Age,NYHA class,BUN,RVSP,and lack of ASD closure were identified as independent factors linked to mortality in this population.
文摘AIM:To describe the gonioscopic profile and intraocular pressure(IOP)in primary angle-closure(PAC)disease in patients presenting to a tertiary eye care network in India.METHODS:A cross-sectional hospital-based study that included 31484 new patients presenting between 2011 and 2021.Patients with a clinical diagnosis of PAC/suspect/glaucoma were included.The data was collected from an electronic medical record system.RESULTS:PAC glaucoma(PACG)(47.55%)was the most common diagnosis followed by PAC(39.49%)and PAC suspect(PACS;12.96%).Female preponderance(54.6%)was noted with higher mean age at presentation among males(P<0.0001).PACS and PAC showed the highest prevalence in 6th decade but PACG was higher at 7th decade.The probability of angle opening was 95.93%,90.32%and 63.36%in PACS,PAC and PACG eyes respectively post peripheral iridotomy(PI).Plateau iris syndrome(PIS)was noted in 252 eyes and all showed post dilated rise of IOP.A post dilated IOP rise was also noted with 8.86%,33.95%and 57.19%eyes with PACS,PAC and PACG respectively with IOP rise between 6-8 mm Hg across the disease spectrum.CONCLUSION:The superior quadrant is the narrowest angle and difficult to open with indentation and post PI.The probability of angle opening is less in PIS especially the complete variety along with post dilated IOP rise.The post dilated IOP rise in angle closure eyes warrants a careful dilatation,especially with PIS.