In this paper, a penetrating analysis is first made of the superluminal and negative group velocities that occur in the EM wave propagation. Discussed then are the superluminal and negative group velocities which are ...In this paper, a penetrating analysis is first made of the superluminal and negative group velocities that occur in the EM wave propagation. Discussed then are the superluminal and negative group velocities which are in the state of evanescent waves in the waveguide below cutoff(WBCO).Through an experiment in the coaxial photonic crystal a group velocity of 1.5-2.4 times the speed of light are observed in the stop band.展开更多
This paper proves that a necessary condition for a composition operator on the Bloch space of the unit disk to be bounded below given by Ghatage, Yan and Zheng is also sufficient. Given furthermore are a sufficient co...This paper proves that a necessary condition for a composition operator on the Bloch space of the unit disk to be bounded below given by Ghatage, Yan and Zheng is also sufficient. Given furthermore are a sufficient condition and a necessary condition of the boundedness from below for a composition operator on the Bloch space of a unit ball with dimensions bigger than one.展开更多
For a study of the movement and deformation of coal-rock mass and low protected seams below a stope,as well as for fracture developments and rules of evolution of permeability,we designed a plane strain model test sta...For a study of the movement and deformation of coal-rock mass and low protected seams below a stope,as well as for fracture developments and rules of evolution of permeability,we designed a plane strain model test stand to carry out model tests of similar materials in order to improve the effect of gas drainage from low protected seams and to measure the movement and deformation of coal-rock mass using a method of non-contact close-range photogrammetry.Our results show that 1) using paraffin melting to take the place of coal seam mining can satisfy the mining conditions of a protective seam;2) coal-rock mass under goafs has an upward movement after the protective seam has been mined,causing floor heaving;3) low protected seams become swollen and deformed,providing a good pressure-relief effect and causing the coal-rock mass under both sides of coal pillars to become deformed by compression and 4) the evolution of permeability of low protected seams follows the way of initial values→a slight decrease→a great increase→stability→final decrease.Simultaneously,the coefficient of air permeability increased at a decreasing rate with an increase in interlayer spacing.展开更多
Lightweight design requires an accurate life prediction for structures and components under service loading histories. However, predicted life with the existing methods seems too conservative in some cases, leading to...Lightweight design requires an accurate life prediction for structures and components under service loading histories. However, predicted life with the existing methods seems too conservative in some cases, leading to a heavy structure. Because these methods are established on the basis that load cycles would only cause fatigue damage, ignore the strengthening effect of loads. Based on Palmgren-Miner Rule （PMR）, this paper introduces a new method for fatigue life prediction under service loadings by taking into account the strengthening effect of loads below the fatigue limit. In this method, the service loadings are classified into three categories： damaging load, strengthening load and none-effect load, and the process for fatigue life prediction is divided into two stages： stage I and stage II, according to the best strengthening number of cycles. During stage I, fatigue damage is calculated considering both the strengthening and damaging effect of load cycles. While during stage II, only the damaging effect is considered. To validate this method, fatigue lives of automobile half shaft and torsion beam rear axle are calculated based on the new method and traditional methods, such as PMR and Modified Miner Rule （MMR）, and fatigue tests of the two components are conducted under service loading histories. The tests results show that the percentage errors of the predicted life with the new method to mean life of tests for the two components are –3.78% and –1.76% separately, much lesser than that with PMR and MMR. By considering the strengthening effect of loads below the fatigue limit, the new method can significantly improve the accuracy for fatigue life prediction. Thus lightweight design can be fully realized in the design stage.展开更多
The United Nations Framework Convention on Climate Change （UNFCCC） requires reporting net carbon stock changes and anthropogenic greenhouse gas emissions, including those related to forests. This paper describes the...The United Nations Framework Convention on Climate Change （UNFCCC） requires reporting net carbon stock changes and anthropogenic greenhouse gas emissions, including those related to forests. This paper describes the status of carbon stocks in sub tropical forests of Pakistan. There are two major sub types in subtropical forests of Pakistan viz a viz Subtropical Chir Pine and Subtropical broadleaved forests. A network of sample plots was laid out in four selected site. Two sites were selected from sub tropical Chir Pine （Pinus roxburghii） forests and two from Subtropical broadleaved forests. Measurement and data acquisition protocols were developed specifically for the inventory car- ried out from 2005 to 2010. In total 261 plots （each of lha.） were established. Estimation of diameter, basal area, height, volume and biomass was carried out to estimate carbon stocks in each of the four carbon pools of above- and below-ground live biomass. Soil carbon stocks were also determined by doing soil sampling. In mature （-100 years old） pine forest stand at Ghoragali and Lehterar sites, a mean basal area of 30.38 and 26.11 m2.ha-1 represented mean volume of 243 and 197 m3·ha-1, respectively. The average biomass （t.ha-1） was 237 in Ghoragali site and 186 tha-1 in Lehterar site, which is equal to 128 and 100 t·ha-1 including soil C. However, on average basis both the forests have 114.5± 2.26 t.ha-1 of carbon stock which comprises of 92% in tree biomass and only 8% in the top soils. In mixed broadleaved evergreen forests a mean basal area （m2.ha-1）was 3.06 at Kherimurat with stem volume of 12.86 and 2.65 at Sohawa with stem volume of 11.40 m3.ha-1. The average upper and under storey biomass （t·ha-1） was 50.93 in Kherimurat site and 40.43 t.ha-1 in Sohawa site, which is equal to 31.18 and 24.36 t ·ha-1 including soil C stocks. This study provides a protocol monitoring biomass and carbon stocks and valuable baseline data for in Pakistan＇s managed and unmanaged sub-tropical forests.展开更多
We have introduced a new approach to calculate the orbital angular momentum(OAM)of bound states in continuum(BICs)and below-continuum-resonance(BCR)modes in the rotational periodic system nested inside and outside by ...We have introduced a new approach to calculate the orbital angular momentum(OAM)of bound states in continuum(BICs)and below-continuum-resonance(BCR)modes in the rotational periodic system nested inside and outside by transforming the Bloch wave number from the translational periodic system.We extensively classify and study these BICs and BCR modes,which exhibit high-quality(high-Q)factors,in different regions relative to the interface of the system.These BICs and BCR modes with a high-Q factor have been studied in detail based on distinctive structural parameters and scattering theory.The outcomes of this research break the periodic limitation of interface state-based BICs,and realize more and higher symmetry interface state-based BICs and BCR modes.Moreover,we can control the region where light is captured by adjusting the frequency,and show that the Q factor of BICs is more closely related to the ordinal number of rings and the rotational symmetry number of the system.展开更多
The impact of thermal remediation on soil function has drawn increasing attention.So far,as the most active fraction of soil organic matter,the evolution of dissolved organic matter(DOM)during the thermal remediation ...The impact of thermal remediation on soil function has drawn increasing attention.So far,as the most active fraction of soil organic matter,the evolution of dissolved organic matter(DOM)during the thermal remediation lacks in-depth investigation,especially for the temperatures value below 100℃.In this study,a series of soil thermal treatment experiments was conducted at 30,60,and 90℃ during a 90-d period,where soil DOM concentration increased with heating temperature and duration.The molecular weight,functional groups content and aromaticity of DOM all decreased during the thermal treatment.The excitation-emission matrices(EEM)results suggested that humic acid-like substances transformed into fulvic acid-like substances(FIII/FV increased from 0.27 to 0.44)during the heating process,and five DOM components were further identified by EEM-PARAFAC.The change of DOM structures and components indicated the decline of DOM stability and hydrophilicity,and can potentially change the bioavailability and mobility.Elevated temperature also resulted in the decline of DOM complexation ability,which may be caused by the loss of binding sites due to the decrease of polar function groups,aromatic structures and hydrophilic components.This study provides valuable information about the evolution of DOM during thermal remediation,which would potentially change the fate of metal ions and the effectiveness of the post-treatment technologies in the treated region.展开更多
The test floor effects seen in standardised tests lead to a standardised score of 1 or less with a flat profile that hides a child’s individual strengths and needs. The Griffiths III community of practitioners reques...The test floor effects seen in standardised tests lead to a standardised score of 1 or less with a flat profile that hides a child’s individual strengths and needs. The Griffiths III community of practitioners requested advice on the reporting of children’s development below the floor of the test, so that individual strengths and needs can be described. This paper reports the third phase of research following an earlier Scoping Review and a wider literature review. To confirm quality control, Phase 3 was conducted in a retrospective manner using the same methodology as the earlier phases but in a reverse direction. Peer reviewer comments and key elements from the Scoping Review and keywords from the publications were tabulated. Data analysis included a change of perspective to that of the child and their individual rights with respect to the literature themes already described in Phase 2. These confirmed that there is little specific guidance in the literature, but that computational advances for homogeneous populations and especially disaggregated data offer some solutions. A greater balance between broad biopsychosocial models and standardised models of assessment should be sought by practitioners together with the use of disaggregated data to highlight issues that pertain to individual subsets of results. This will ensure that the child’s right for their individual strengths and needs to be described together with a plan for management, may be met.展开更多
Osteomyelitis of the calcaneus can be a limb threatening diagnosis, which is typically treated with antibiotic therapy with or without partial resection of the bone. Extensive infection of the bone commonly results in...Osteomyelitis of the calcaneus can be a limb threatening diagnosis, which is typically treated with antibiotic therapy with or without partial resection of the bone. Extensive infection of the bone commonly results in limb amputation via transtibial or transfemoral amputation, which can increase morbidity and mortality. This case report involves a 29-year-old male who sustained bilateral calcaneal fracture after a fall, who developed osteomyelitis of the right calcaneus after being treated with internal/external fixation and antibiotic therapy. In order to preserve the limb total calcaneal replacement with 3D printed implant was done.展开更多
Let S = {1,1/2,1/2^2,…,1/∞ = 0} and I = [0, 1] be the unit interval. We use ↓USC（S） and ↓C（S） to denote the families of the regions below of all upper semi-continuous maps and of the regions below of all conti...Let S = {1,1/2,1/2^2,…,1/∞ = 0} and I = [0, 1] be the unit interval. We use ↓USC（S） and ↓C（S） to denote the families of the regions below of all upper semi-continuous maps and of the regions below of all continuous maps from S to I and ↓C0（S） = {↓f∈↓C（S） ： f（0） = 0}. ↓USC（S） endowed with the Vietoris topology is a topological space. A pair of topological spaces （X, Y） means that X is a topological space and Y is its subspace. Two pairs of topological spaces （X, Y） and （A, B） are called pair-homeomorphic （≈） if there exists a homeomorphism h ： X→A from X onto A such that h（Y） = B. It is proved that, （↓USC（S）,↓C0（S）） ≈（Q, s） and （↓USC（S）,↓C（S）／ ↓C0（S））≈（Q, c0）, where Q = [-1,1]^ω is the Hilbert cube and s = （-1,1）^ω,c0= {（xn）∈Q ： limn→∞= 0}. But we do not know what （↓USC（S）,↓C（S））is.展开更多
Tropical rainforests are crucial in maintaining about 70% of the world’s plant and animal biodiversity and are also the highest terrestrial carbon reservoir. This study aimed to determine the tree species composition...Tropical rainforests are crucial in maintaining about 70% of the world’s plant and animal biodiversity and are also the highest terrestrial carbon reservoir. This study aimed to determine the tree species composition, structure and carbon stocks of the Deng Deng National Park which is a semi-deciduous tropical forest (plots 1 and 2 and the transition zone to the savannah (plot 3). Plots demarcation and enumeration followed standard protocols for permanent monitoring plots. The inventory of tree species ≥ 2 cm revealed a total of 5523 individuals of 64 species in 53 genera belonging to 26 families with plot 2 having the highest (2135 individuals/ha) and plot 3 the least (1291 individuals/ha). Tabernaemontana crassa was the most important tree species in the tropical forest and Lecythis idatimon in the savannah. Basal area was highest in the tropical forest and least in the savannah. The diameter distribution of trees in all forest types displayed a reverse J-pattern. Aboveground biomass was highest in the tropical forest (530.2 ± 66.4 t·C/ha) and least in the savannah (184.3 ± 20.1 t·C/ha). The carbon stock of the above ground biomass was twice as much as that of the below ground biomass, soil organic matter and litter. The total carbon stock estimated in all pools was 278.75 t·C/ha. The study site was poor in plant diversity, biomass and carbon stock, indicating a disturbed site with the absence of large trees and undergoing natural regeneration. This underlines an urgent need for efficient restoration management practices.展开更多
This article introduces the project overview, construction goal and design philosophy of Hong Kong- Zhuhai-Macao Bridge. Based on large scale, factory production, standardization and assemble line, the innova- tive co...This article introduces the project overview, construction goal and design philosophy of Hong Kong- Zhuhai-Macao Bridge. Based on large scale, factory production, standardization and assemble line, the innova- tive concept is taken as the general principle for design with the emphasis on description of the new material, new technology, new construction method and new equipment used in the design. The application of innovative technology has provided a solid foundation and favorable guarantee for project quality and design service展开更多
High-order harmonic generation below ionization threshold of He atom in the laser field is investigated by solving the three-dimensional time-dependent Schrodinger equation. An angular momentum-dependent model potenti...High-order harmonic generation below ionization threshold of He atom in the laser field is investigated by solving the three-dimensional time-dependent Schrodinger equation. An angular momentum-dependent model potential of He atom was used for getting the accurate energy levels of singlet states. The satellite-peak structures of the below-threshold harmonic generation(BTHG) of He are observed. We analyze the emission properties of the BTHG by employing a synchrosqueezing transform technique. We find that the satellite-peak structures have two types related to two kinds of transitions. One is the transition of the dressed states of the excited states, the other is the transition between the excited states and the ground state in the field-free case. Furthermore, our results show that the maximum Stark shift of the 2 p state is about 0.9 Up(penderomotive energy), and that of the 4 p state is about 1.0 Up. It indicates that the energy difference between some satellite-and main-peaks of the BTHG can be used to measure the maximum Stark shift of the excited states of He atom in the laser field.展开更多
Purpose:The aim of this study was to analyze if any difference exists on the type of immobilisation(above elbow vs.below elbow)in the conservative treatment of distal end radius fractures in adults.Methods:The study w...Purpose:The aim of this study was to analyze if any difference exists on the type of immobilisation(above elbow vs.below elbow)in the conservative treatment of distal end radius fractures in adults.Methods:The study was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses.An electronic literature search was performed up to 1st October 2021 in Medline,Embase,Ovid and Cochrane database using the search terms,"distal end radius fractures OR fracture of distal radius","conservative treatment OR non-surgical treatment","above elbow immobilisation"and"below elbow immobilisation".Randomized clinical trials written in English,describing outcome of distal end radius fractures in adults by conservative or non-surgical means using above elbow immobilisation or below elbow immobilisation were included and assessed according to the risk of bias assessment(RoB2)tool by Cochrane collaboration.Non-randomized clinical trials,observational studies,retrospec-tive studies,review articles,commentaries,editorials,conference presentations,operative techniques and articles without availability of full text were excluded from this review.The meta-analysis was performed using Review Manager version 5.4.1(The Cochrane Collaboration,Copenhagen,Denmark).Results:Six randomized clinical trials were included for quantitative review.High heterogeneity(I2>75%)was noted among all the studies.The standard mean difference(MD)between the disability of the arm,shoulder and hand scores in both the groups was 0.52(95%CI:-0.28 to 1.32)which was statistically non-significantt.There was no statistical difference in the radial height(MD=0.10,95%CI:-0.91 to 1.12),radial inclination(MD=0.5,95%CI:-1.88 to 2.87,palmar tilt(MD=1.06,95%CI:-0.31 to 2.43)and ulnar variance(MD=0.05,95%CI:-0.74 to 0.64).It was observed that shoulder pain occurred more commonly as a complication in above elbow immobilisation and the values were statistically significant(above elbow:38/92,41.3%;below elbow:19/94,20.2%).Conclusion:This two-arme展开更多
Based on regional compensation and experimental isostasy, the calculating formula of theoretical isostatic response function is deduced when the loads on top correlate with loads from below. A variety of curves of the...Based on regional compensation and experimental isostasy, the calculating formula of theoretical isostatic response function is deduced when the loads on top correlate with loads from below. A variety of curves of theoretical isostatic response function were calculated with different effective elastic thickness of the plate and by using different proportions between loads on top and loads from below. And preliminary discussion is made on shapes of the curves.展开更多
Based on regional compensation model and experimental isostasy, the isostatic response function of the Okinawa Trough is calculated by using gravity and topographic data. The results are shown as follows: the effectiv...Based on regional compensation model and experimental isostasy, the isostatic response function of the Okinawa Trough is calculated by using gravity and topographic data. The results are shown as follows: the effective elastic thickness of the plate and compensation depth in the southern Okinawa Trough is obviously greater than those in the middle Okinawa Trough. In reference with other geological and geophysical data, the differences between the two portions are explained to be caused mainly by their differences in temperature of the lithosphere and the compensation mechanism.展开更多
Tunnel excavation below existing tunnels produces ultimate and serviceability problems to the existing tunnels.The behaviours of induced stresses on the existing tunnels haven’t yet been fully recognized.In this stud...Tunnel excavation below existing tunnels produces ultimate and serviceability problems to the existing tunnels.The behaviours of induced stresses on the existing tunnels haven’t yet been fully recognized.In this study,a centrifuge model test was adopted to investigate the effects of new tunnelling on two existing overlying tunnels.One existing tunnel model simulated a prototype composite lining tunnel and the other simulated a prototype segmental lining tunnel.The volume loss produced by new tunnel excavation was modelled by an in-flight actuator system.The surface settlements,the existing tunnels settlements,the soil pressures on existing tunnels,the bending movements of existing tunnels,and the joint behaviours of existing tunnels were monitored.The volume of surface settlement trough was much smaller than the soil volume moving into the tunnel,due to the heave of the tunnel bottom and the dilation of sand during shearing.The maximum settlement of the segmental lining model was larger than that of the composite lining model as the equivalent bending stiffness of the composite lining model was larger than that of the former.Due to new tunnel excavation,the soil pressures on different positions of the existing tunnel behaved differently,and the bending movements of the existing tunnels decreased.Moreover,the joint deformation of existing tunnel caused by new tunnel excavation could be classified into three types:(1)translation,(2)rotation,and(3)combination of both.展开更多
Coastal defenses such as the breakwaters are important structures to maintain the navigation conditions in a harbor.The estimation of their hydrodynamic characteristics is conventionally done using physical models,sub...Coastal defenses such as the breakwaters are important structures to maintain the navigation conditions in a harbor.The estimation of their hydrodynamic characteristics is conventionally done using physical models,subjecting to higher costs and prolonged procedures.Soft computing methods prove to be useful tools,in cases where the data availability from physical models is limited.The present paper employs adaptive neuro-fuzzy inference system(ANFIS)and artificial neural network(ANN)models to the data obtained from physical model studies to develop a novel methodology to predict the reflection coefficient(Kr)of seaside perforated semicircular breakwaters under low wave heights,for which no physical model data is available.The prediction was done using the input parameters viz.,incident wave height(Hi),wave period(T),center-to-center spacing of perforations(S),diameter of perforations(D),radius of semicircular caisson(R),water depth(d),and semicircular breakwater structure height(hs).The study shows the prediction below the available data range of wave heights is possible by ANFIS and ANN models.However,the ANFIS performed better with R^2=0.9775 and the error reduced in comparison with the ANN model with R2=0.9751.Study includes conventional data segregation and prediction using ANN and ANFIS.展开更多
文摘In this paper, a penetrating analysis is first made of the superluminal and negative group velocities that occur in the EM wave propagation. Discussed then are the superluminal and negative group velocities which are in the state of evanescent waves in the waveguide below cutoff(WBCO).Through an experiment in the coaxial photonic crystal a group velocity of 1.5-2.4 times the speed of light are observed in the stop band.
基金spporte in part by the National Natural Sience Poundaio of China(Grant No.19631140)
文摘This paper proves that a necessary condition for a composition operator on the Bloch space of the unit disk to be bounded below given by Ghatage, Yan and Zheng is also sufficient. Given furthermore are a sufficient condition and a necessary condition of the boundedness from below for a composition operator on the Bloch space of a unit ball with dimensions bigger than one.
基金the Major Programs of the National Basic Research Program of China (No.2005CB221503)the National Natural Science Foundation of China (Nos. 70533050 and 50674089) for their support of this project
文摘For a study of the movement and deformation of coal-rock mass and low protected seams below a stope,as well as for fracture developments and rules of evolution of permeability,we designed a plane strain model test stand to carry out model tests of similar materials in order to improve the effect of gas drainage from low protected seams and to measure the movement and deformation of coal-rock mass using a method of non-contact close-range photogrammetry.Our results show that 1) using paraffin melting to take the place of coal seam mining can satisfy the mining conditions of a protective seam;2) coal-rock mass under goafs has an upward movement after the protective seam has been mined,causing floor heaving;3) low protected seams become swollen and deformed,providing a good pressure-relief effect and causing the coal-rock mass under both sides of coal pillars to become deformed by compression and 4) the evolution of permeability of low protected seams follows the way of initial values→a slight decrease→a great increase→stability→final decrease.Simultaneously,the coefficient of air permeability increased at a decreasing rate with an increase in interlayer spacing.
基金Supported by National High Technology Research and Development Program of China (Grant No.2011AA11A265)National Natural Science Foundation of China (Grant Nos.50875173,51105241)Shanghai Municipal Natural Science Foundation of China (Grant No.11ZR1414700)
文摘Lightweight design requires an accurate life prediction for structures and components under service loading histories. However, predicted life with the existing methods seems too conservative in some cases, leading to a heavy structure. Because these methods are established on the basis that load cycles would only cause fatigue damage, ignore the strengthening effect of loads. Based on Palmgren-Miner Rule （PMR）, this paper introduces a new method for fatigue life prediction under service loadings by taking into account the strengthening effect of loads below the fatigue limit. In this method, the service loadings are classified into three categories： damaging load, strengthening load and none-effect load, and the process for fatigue life prediction is divided into two stages： stage I and stage II, according to the best strengthening number of cycles. During stage I, fatigue damage is calculated considering both the strengthening and damaging effect of load cycles. While during stage II, only the damaging effect is considered. To validate this method, fatigue lives of automobile half shaft and torsion beam rear axle are calculated based on the new method and traditional methods, such as PMR and Modified Miner Rule （MMR）, and fatigue tests of the two components are conducted under service loading histories. The tests results show that the percentage errors of the predicted life with the new method to mean life of tests for the two components are –3.78% and –1.76% separately, much lesser than that with PMR and MMR. By considering the strengthening effect of loads below the fatigue limit, the new method can significantly improve the accuracy for fatigue life prediction. Thus lightweight design can be fully realized in the design stage.
文摘The United Nations Framework Convention on Climate Change （UNFCCC） requires reporting net carbon stock changes and anthropogenic greenhouse gas emissions, including those related to forests. This paper describes the status of carbon stocks in sub tropical forests of Pakistan. There are two major sub types in subtropical forests of Pakistan viz a viz Subtropical Chir Pine and Subtropical broadleaved forests. A network of sample plots was laid out in four selected site. Two sites were selected from sub tropical Chir Pine （Pinus roxburghii） forests and two from Subtropical broadleaved forests. Measurement and data acquisition protocols were developed specifically for the inventory car- ried out from 2005 to 2010. In total 261 plots （each of lha.） were established. Estimation of diameter, basal area, height, volume and biomass was carried out to estimate carbon stocks in each of the four carbon pools of above- and below-ground live biomass. Soil carbon stocks were also determined by doing soil sampling. In mature （-100 years old） pine forest stand at Ghoragali and Lehterar sites, a mean basal area of 30.38 and 26.11 m2.ha-1 represented mean volume of 243 and 197 m3·ha-1, respectively. The average biomass （t.ha-1） was 237 in Ghoragali site and 186 tha-1 in Lehterar site, which is equal to 128 and 100 t·ha-1 including soil C. However, on average basis both the forests have 114.5± 2.26 t.ha-1 of carbon stock which comprises of 92% in tree biomass and only 8% in the top soils. In mixed broadleaved evergreen forests a mean basal area （m2.ha-1）was 3.06 at Kherimurat with stem volume of 12.86 and 2.65 at Sohawa with stem volume of 11.40 m3.ha-1. The average upper and under storey biomass （t·ha-1） was 50.93 in Kherimurat site and 40.43 t.ha-1 in Sohawa site, which is equal to 31.18 and 24.36 t ·ha-1 including soil C stocks. This study provides a protocol monitoring biomass and carbon stocks and valuable baseline data for in Pakistan＇s managed and unmanaged sub-tropical forests.
基金supported by the National Natural Science Foundation of China (Grant Nos.61405058 and 62075059)the Natural Science Foundation of Hunan Province (Grant Nos.2017JJ2048 and 2020JJ4161)+2 种基金the Scientific Research Foundation of Hunan Provincial Education Department (Grant No.21A0013)the Open Project of State Key Laboratory of Advanced Optical Communication Systems and Networks of China (Grant No.2024GZKF20)the Guangdong Basic and Applied Basic Research Foundation (Grant No.2024A1515011353)。
文摘We have introduced a new approach to calculate the orbital angular momentum(OAM)of bound states in continuum(BICs)and below-continuum-resonance(BCR)modes in the rotational periodic system nested inside and outside by transforming the Bloch wave number from the translational periodic system.We extensively classify and study these BICs and BCR modes,which exhibit high-quality(high-Q)factors,in different regions relative to the interface of the system.These BICs and BCR modes with a high-Q factor have been studied in detail based on distinctive structural parameters and scattering theory.The outcomes of this research break the periodic limitation of interface state-based BICs,and realize more and higher symmetry interface state-based BICs and BCR modes.Moreover,we can control the region where light is captured by adjusting the frequency,and show that the Q factor of BICs is more closely related to the ordinal number of rings and the rotational symmetry number of the system.
基金supported by the National Natural Science Foundation of China(No.42077171).
文摘The impact of thermal remediation on soil function has drawn increasing attention.So far,as the most active fraction of soil organic matter,the evolution of dissolved organic matter(DOM)during the thermal remediation lacks in-depth investigation,especially for the temperatures value below 100℃.In this study,a series of soil thermal treatment experiments was conducted at 30,60,and 90℃ during a 90-d period,where soil DOM concentration increased with heating temperature and duration.The molecular weight,functional groups content and aromaticity of DOM all decreased during the thermal treatment.The excitation-emission matrices(EEM)results suggested that humic acid-like substances transformed into fulvic acid-like substances(FIII/FV increased from 0.27 to 0.44)during the heating process,and five DOM components were further identified by EEM-PARAFAC.The change of DOM structures and components indicated the decline of DOM stability and hydrophilicity,and can potentially change the bioavailability and mobility.Elevated temperature also resulted in the decline of DOM complexation ability,which may be caused by the loss of binding sites due to the decrease of polar function groups,aromatic structures and hydrophilic components.This study provides valuable information about the evolution of DOM during thermal remediation,which would potentially change the fate of metal ions and the effectiveness of the post-treatment technologies in the treated region.
文摘The test floor effects seen in standardised tests lead to a standardised score of 1 or less with a flat profile that hides a child’s individual strengths and needs. The Griffiths III community of practitioners requested advice on the reporting of children’s development below the floor of the test, so that individual strengths and needs can be described. This paper reports the third phase of research following an earlier Scoping Review and a wider literature review. To confirm quality control, Phase 3 was conducted in a retrospective manner using the same methodology as the earlier phases but in a reverse direction. Peer reviewer comments and key elements from the Scoping Review and keywords from the publications were tabulated. Data analysis included a change of perspective to that of the child and their individual rights with respect to the literature themes already described in Phase 2. These confirmed that there is little specific guidance in the literature, but that computational advances for homogeneous populations and especially disaggregated data offer some solutions. A greater balance between broad biopsychosocial models and standardised models of assessment should be sought by practitioners together with the use of disaggregated data to highlight issues that pertain to individual subsets of results. This will ensure that the child’s right for their individual strengths and needs to be described together with a plan for management, may be met.
文摘Osteomyelitis of the calcaneus can be a limb threatening diagnosis, which is typically treated with antibiotic therapy with or without partial resection of the bone. Extensive infection of the bone commonly results in limb amputation via transtibial or transfemoral amputation, which can increase morbidity and mortality. This case report involves a 29-year-old male who sustained bilateral calcaneal fracture after a fall, who developed osteomyelitis of the right calcaneus after being treated with internal/external fixation and antibiotic therapy. In order to preserve the limb total calcaneal replacement with 3D printed implant was done.
基金The NNSF （10471084） of China and by Guangdong Provincial Natural Science Foundation（04010985）.
文摘Let S = {1,1/2,1/2^2,…,1/∞ = 0} and I = [0, 1] be the unit interval. We use ↓USC（S） and ↓C（S） to denote the families of the regions below of all upper semi-continuous maps and of the regions below of all continuous maps from S to I and ↓C0（S） = {↓f∈↓C（S） ： f（0） = 0}. ↓USC（S） endowed with the Vietoris topology is a topological space. A pair of topological spaces （X, Y） means that X is a topological space and Y is its subspace. Two pairs of topological spaces （X, Y） and （A, B） are called pair-homeomorphic （≈） if there exists a homeomorphism h ： X→A from X onto A such that h（Y） = B. It is proved that, （↓USC（S）,↓C0（S）） ≈（Q, s） and （↓USC（S）,↓C（S）／ ↓C0（S））≈（Q, c0）, where Q = [-1,1]^ω is the Hilbert cube and s = （-1,1）^ω,c0= {（xn）∈Q ： limn→∞= 0}. But we do not know what （↓USC（S）,↓C（S））is.
文摘Tropical rainforests are crucial in maintaining about 70% of the world’s plant and animal biodiversity and are also the highest terrestrial carbon reservoir. This study aimed to determine the tree species composition, structure and carbon stocks of the Deng Deng National Park which is a semi-deciduous tropical forest (plots 1 and 2 and the transition zone to the savannah (plot 3). Plots demarcation and enumeration followed standard protocols for permanent monitoring plots. The inventory of tree species ≥ 2 cm revealed a total of 5523 individuals of 64 species in 53 genera belonging to 26 families with plot 2 having the highest (2135 individuals/ha) and plot 3 the least (1291 individuals/ha). Tabernaemontana crassa was the most important tree species in the tropical forest and Lecythis idatimon in the savannah. Basal area was highest in the tropical forest and least in the savannah. The diameter distribution of trees in all forest types displayed a reverse J-pattern. Aboveground biomass was highest in the tropical forest (530.2 ± 66.4 t·C/ha) and least in the savannah (184.3 ± 20.1 t·C/ha). The carbon stock of the above ground biomass was twice as much as that of the below ground biomass, soil organic matter and litter. The total carbon stock estimated in all pools was 278.75 t·C/ha. The study site was poor in plant diversity, biomass and carbon stock, indicating a disturbed site with the absence of large trees and undergoing natural regeneration. This underlines an urgent need for efficient restoration management practices.
文摘This article introduces the project overview, construction goal and design philosophy of Hong Kong- Zhuhai-Macao Bridge. Based on large scale, factory production, standardization and assemble line, the innova- tive concept is taken as the general principle for design with the emphasis on description of the new material, new technology, new construction method and new equipment used in the design. The application of innovative technology has provided a solid foundation and favorable guarantee for project quality and design service
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11674268,11764038,and 11765018)the Scientific Research Foundation of Physics of CPEE–NWNU and NWNU-LKQN-17-1,China
文摘High-order harmonic generation below ionization threshold of He atom in the laser field is investigated by solving the three-dimensional time-dependent Schrodinger equation. An angular momentum-dependent model potential of He atom was used for getting the accurate energy levels of singlet states. The satellite-peak structures of the below-threshold harmonic generation(BTHG) of He are observed. We analyze the emission properties of the BTHG by employing a synchrosqueezing transform technique. We find that the satellite-peak structures have two types related to two kinds of transitions. One is the transition of the dressed states of the excited states, the other is the transition between the excited states and the ground state in the field-free case. Furthermore, our results show that the maximum Stark shift of the 2 p state is about 0.9 Up(penderomotive energy), and that of the 4 p state is about 1.0 Up. It indicates that the energy difference between some satellite-and main-peaks of the BTHG can be used to measure the maximum Stark shift of the excited states of He atom in the laser field.
文摘Purpose:The aim of this study was to analyze if any difference exists on the type of immobilisation(above elbow vs.below elbow)in the conservative treatment of distal end radius fractures in adults.Methods:The study was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses.An electronic literature search was performed up to 1st October 2021 in Medline,Embase,Ovid and Cochrane database using the search terms,"distal end radius fractures OR fracture of distal radius","conservative treatment OR non-surgical treatment","above elbow immobilisation"and"below elbow immobilisation".Randomized clinical trials written in English,describing outcome of distal end radius fractures in adults by conservative or non-surgical means using above elbow immobilisation or below elbow immobilisation were included and assessed according to the risk of bias assessment(RoB2)tool by Cochrane collaboration.Non-randomized clinical trials,observational studies,retrospec-tive studies,review articles,commentaries,editorials,conference presentations,operative techniques and articles without availability of full text were excluded from this review.The meta-analysis was performed using Review Manager version 5.4.1(The Cochrane Collaboration,Copenhagen,Denmark).Results:Six randomized clinical trials were included for quantitative review.High heterogeneity(I2>75%)was noted among all the studies.The standard mean difference(MD)between the disability of the arm,shoulder and hand scores in both the groups was 0.52(95%CI:-0.28 to 1.32)which was statistically non-significantt.There was no statistical difference in the radial height(MD=0.10,95%CI:-0.91 to 1.12),radial inclination(MD=0.5,95%CI:-1.88 to 2.87,palmar tilt(MD=1.06,95%CI:-0.31 to 2.43)and ulnar variance(MD=0.05,95%CI:-0.74 to 0.64).It was observed that shoulder pain occurred more commonly as a complication in above elbow immobilisation and the values were statistically significant(above elbow:38/92,41.3%;below elbow:19/94,20.2%).Conclusion:This two-arme
文摘Based on regional compensation and experimental isostasy, the calculating formula of theoretical isostatic response function is deduced when the loads on top correlate with loads from below. A variety of curves of theoretical isostatic response function were calculated with different effective elastic thickness of the plate and by using different proportions between loads on top and loads from below. And preliminary discussion is made on shapes of the curves.
文摘Based on regional compensation model and experimental isostasy, the isostatic response function of the Okinawa Trough is calculated by using gravity and topographic data. The results are shown as follows: the effective elastic thickness of the plate and compensation depth in the southern Okinawa Trough is obviously greater than those in the middle Okinawa Trough. In reference with other geological and geophysical data, the differences between the two portions are explained to be caused mainly by their differences in temperature of the lithosphere and the compensation mechanism.
基金the financial support by the Key Project of High-speed Rail Joint Fund of National Natural Science Foundation of China(Grant No.U1934210)the Natural Science Foundation of Beijing(Grant No.8202037)+1 种基金the National Natural Science Foundation of China(Grant No.52108363)the China Postdoctoral Science Foundation(Grant No.2021M700654).
文摘Tunnel excavation below existing tunnels produces ultimate and serviceability problems to the existing tunnels.The behaviours of induced stresses on the existing tunnels haven’t yet been fully recognized.In this study,a centrifuge model test was adopted to investigate the effects of new tunnelling on two existing overlying tunnels.One existing tunnel model simulated a prototype composite lining tunnel and the other simulated a prototype segmental lining tunnel.The volume loss produced by new tunnel excavation was modelled by an in-flight actuator system.The surface settlements,the existing tunnels settlements,the soil pressures on existing tunnels,the bending movements of existing tunnels,and the joint behaviours of existing tunnels were monitored.The volume of surface settlement trough was much smaller than the soil volume moving into the tunnel,due to the heave of the tunnel bottom and the dilation of sand during shearing.The maximum settlement of the segmental lining model was larger than that of the composite lining model as the equivalent bending stiffness of the composite lining model was larger than that of the former.Due to new tunnel excavation,the soil pressures on different positions of the existing tunnel behaved differently,and the bending movements of the existing tunnels decreased.Moreover,the joint deformation of existing tunnel caused by new tunnel excavation could be classified into three types:(1)translation,(2)rotation,and(3)combination of both.
文摘Coastal defenses such as the breakwaters are important structures to maintain the navigation conditions in a harbor.The estimation of their hydrodynamic characteristics is conventionally done using physical models,subjecting to higher costs and prolonged procedures.Soft computing methods prove to be useful tools,in cases where the data availability from physical models is limited.The present paper employs adaptive neuro-fuzzy inference system(ANFIS)and artificial neural network(ANN)models to the data obtained from physical model studies to develop a novel methodology to predict the reflection coefficient(Kr)of seaside perforated semicircular breakwaters under low wave heights,for which no physical model data is available.The prediction was done using the input parameters viz.,incident wave height(Hi),wave period(T),center-to-center spacing of perforations(S),diameter of perforations(D),radius of semicircular caisson(R),water depth(d),and semicircular breakwater structure height(hs).The study shows the prediction below the available data range of wave heights is possible by ANFIS and ANN models.However,the ANFIS performed better with R^2=0.9775 and the error reduced in comparison with the ANN model with R2=0.9751.Study includes conventional data segregation and prediction using ANN and ANFIS.
