Despite numerous research investigations to understand the influences of various structural parameters,to the authors'knowledge,no research has been the effect of different angles of incidence on stab response and...Despite numerous research investigations to understand the influences of various structural parameters,to the authors'knowledge,no research has been the effect of different angles of incidence on stab response and performance of different types of protective textiles.Three distinct structures of 3D woven textiles and 2D plain weave fabric made with similar high-performance fiber and areal density were designed and manufactured to be tested.Two samples,one composed of a single and the other of 4-panel layers,from each fabric type structure,were prepared,and tested against stabbing at[0○],[22.5○],and[45○]angle of incidence.A new stabbing experimental setup that entertained testing of the specimens at various angles of incidence was engineered and utilized.The stabbing bench is also equipped with magnetic sensors and a UK Home Office Scientific Development Branch(HOSDB)/P1/B sharpness engineered knives to measure the impact velocity and exerted impact energy respectively.A silicon compound was utilized to imprint the Back Face Signature(BFS)on the backing material after every specimen test.Each silicon print was then scanned,digitized,and precisely measured to evaluate the stab response and performance of the specimen based on different performance variables,including Depth of Trauma(DOT),Depth of Penetration(DOP),and Length of Penetration(LOP).Besides,the post-impact surface failure modes of the fabrics were also measured using Image software and analyzed at the microscale level.The results show stab angle of incidence greatly influences the stab response and performance of protective textiles.The outcome of the study could provide not only valuable insights into understanding the stab response and capabilities of protective textiles under different angle of incidence,but also provide valuable information for protective textile manufacturer,armor developer and stab testing and standardizing organizations to consider the angle of incidence while developing,testing,optimizing,and using protective textiles in various applications.展开更多
The Fabry–Perot(FP) resonant cavity is widely used in laser and spectroscopic measurements due to its unique interference transfer function(ITF). In the ideal case of parallel incident light, the ITF of the FP resona...The Fabry–Perot(FP) resonant cavity is widely used in laser and spectroscopic measurements due to its unique interference transfer function(ITF). In the ideal case of parallel incident light, the ITF of the FP resonant cavity can be expressed by the Airy function. However, in reality, it is difficult to achieve perfect parallelism with collimated beams. In this article, a theoretical model is established for non-parallel light incidence, which assumes that the non-parallel incident light is a cone-shaped beam, and the cone angle is used to quantify the non-parallelism of the beam. The transmittance function of the FP resonant cavity under non-parallel light incidence is derived. The accuracy of the model is experimentally verified. Based on this model, the effects of divergence angle, tilt angle and FP cavity parameters(reflectivity, cavity length)on the ITF are studied. The reasons for the decrease in peak value, broadening and asymmetry of the interference peak under non-parallel light incidence are explained. It is suggested that a fine balance between the interference peak and the collimation effect of the incident light should be considered in the design and application of FP resonant cavities, especially for tilted applications such as angle-scanned spectroscopy. The research results of this article have certain significance for the design and application of FP resonant cavities.展开更多
Background Major depressive disorders(MDDs)impose substantial burdens on individuals and society;however,further detailed analysis is still needed for its long-term trends.Aims This study aimed to analyse the gender-s...Background Major depressive disorders(MDDs)impose substantial burdens on individuals and society;however,further detailed analysis is still needed for its long-term trends.Aims This study aimed to analyse the gender-specific temporal trends and cohort variations of MDD incidence among Chinese residents over the past three decades.Methods Employing the age-period-cohort-interaction model and leveraging data from the Global Burden of Disease Study 2019,this research identified and analysed incidence trends of MDD among Chinese males and females aged 5-94 years from 1990 to 2019 across three dimensions,encompassing age,period and birth cohort.Results The analysis reveals age-related effects,indicating heightened MDD risk among adolescents and older adults.Specifically,individuals entering the older adulthood at the age of 65-69 significantly increased the risk of MDD by 64.9%.People aged 90-94 years witnesseda 105.4%increase in MDD risk for the overall population,with females and males in this age group experiencing a 75.1%and 103.4%increase,respectively.In terms of period effects,the risk of MDD displayed a decline from 1990 to 1994,followed by a rebound in 2008.Cohort effects demonstrated diverse generational patterns,with generationⅠand generationⅢmanifesting opposing‘age-as-level'trends.GenerationⅡand generationⅣexhibited'cumulative disadvantage'and'cumulative advantage'patterns,respectively.Age effects indicated an overall higher risk of MDD incidence in females,while cohort effects showed greater variations of MDD incidence among females.Conclusions The study underscores the substantial effects of age,period and cohort on MDD across genders in China.Priority interventions targeting vulnerable populations,including children,adolescents,older adults,females and the post-millennium birth cohort,are crucial to mitigate the impact of MDD.展开更多
To extend the traditional generalized grey incidence model, a novel grey incidence model based on inter- val grey numbers is constructed. Considering the numerical information of indexes cannot be accurately obtained ...To extend the traditional generalized grey incidence model, a novel grey incidence model based on inter- val grey numbers is constructed. Considering the numerical information of indexes cannot be accurately obtained and can be defined as interval grey numbers, the interval grey numbers are defined as standard interval grey num- bers which are split in white part and grey part. The absolute degree of incidence and relative degree of incidence based on the interval grey numbers are constructed and their arithmetic are given. Finally, an example about commercial aircraft index selection illuminates the effectiveness of the model. The results show that the model can sort indexes better and can extend the grey incidence models significantly.展开更多
The concept of the incidence chromatic number of a graph was introduced by Brualdi and Massey. They conjectured that every graph G can be incidence colored with Δ (G) +2 colors. In this paper, the trueness of this co...The concept of the incidence chromatic number of a graph was introduced by Brualdi and Massey. They conjectured that every graph G can be incidence colored with Δ (G) +2 colors. In this paper, the trueness of this conjecture for complete k partite graph was proved, and the incidence chromatic number of complete k partite graphs was calculated.展开更多
An estimation method for aircraft similarity based on fuzzy theory and grey incidence analysis is presented. This estimation method is made up of the triangular fuzzy transforming model of linguistic variables and the...An estimation method for aircraft similarity based on fuzzy theory and grey incidence analysis is presented. This estimation method is made up of the triangular fuzzy transforming model of linguistic variables and the method of grey incidence analysis. Nine feature attributes of aircraft are selected to estimate the similarity between the new aircraft and the existing aircraft. A new aircraft X and other six existing aircrafts are taken as examples. Analyses show that similarity estimation results obtained from the method are in accordance with practice.展开更多
The analysis result of absolute degree of grey incidence for multivariate time series is often inconsistent with the qualitative analysis. To overcome this shortage, a multivariate absolute degree of grey incidence ba...The analysis result of absolute degree of grey incidence for multivariate time series is often inconsistent with the qualitative analysis. To overcome this shortage, a multivariate absolute degree of grey incidence based on distribution characteristics of points is proposed. Based on the geometric description of multivariate time se- ries, the neighborhood extrema are extracted in the different regions, and a characteristic point set is constructed. Then according to the distribution of the characteristic point set, a characteristic point sequence reflecting the ge- ometric features of multivariate time series is obtained. The incidence analysis between multivariate time series is transformed into the relational analysis between characteristic point sequences, and a grey incidence model is established. The model possesses the properties of translational invariance, transpose and rank transform invari- ance, and satisfies the grey incidence analysis axioms. Finally, two cases are studied and the results prove the ef- fectiveness of the model.展开更多
Objective Acute aortic dissection （AAD） is a catastrophic event with high early mortality rate, but to date, no data on the incidence of AAD in China's Mainland is available. This study aimed to estimate the inc...Objective Acute aortic dissection （AAD） is a catastrophic event with high early mortality rate, but to date, no data on the incidence of AAD in China's Mainland is available. This study aimed to estimate the incidence of AAD in China and characterize the clinical profile, management and in-hospital outcomes of this vascular event. Methods We used the China Health Insurance Research Data （the CHIRA Data） 2011 which comprises all inpatient hospital records （300,886） during the period of Jan. 1st 2011 to Dec. 31 2011 of 3,335,000 randomly sampled beneficiaries （1,718,500 men and 1,616,500 women） from 25 cities and counties in different economic-geographic regions of China's Mainland. Patients with acute aortic dissection were identified according to International Classification of Disease 10m Revision （ICD-10） of I71.0, The estimated incidence of AAD was calculated using the equation： estimated incidence = 2.0 × （40% × hospital admission rate） ＋ 60% × hospital admission rate. Results The hospital admission rate was 2.0/100,000 （65/3,325,000, 95% CI： 1.2-2.8）. The estimated annual incidence of AAD was 2.8/100,000 （95% CI： 1.9-3.6） and was higher in male than in female （3.7 vs. 1.5, P 〈 0.001）. The mean age was 58.9 ± 13.4 years. During the mean hospital stay of 23 ±6 days, the overall in-hospital mortality was 13.9% （9/65）. Conclusions Our study showed relatively lower but not negligible incidence and in-hospital mortality of AAD in the mainland of China. The mean age of patients with AAD in Chinese was younger than that reported by researches from west countries, while the male to female incidence ratio is similar to those reported by other studies.展开更多
This article proposes a diffused hepatitis B virus （HBV） model with CTL immune response and nonlinear incidence for the control of viral infections. By means of different Lyapunov functions, the global asymptotical ...This article proposes a diffused hepatitis B virus （HBV） model with CTL immune response and nonlinear incidence for the control of viral infections. By means of different Lyapunov functions, the global asymptotical properties of the viral-free equilibrium and immune-free equilibrium of the model are obtained. Global stability of the positive equilibrium of the model is also considered. The results show that the free diffusion of the virus has no effect on the global stability of such HBV infection problem with Neumann homogeneous boundary conditions.展开更多
In this article, we establish the global asymptotic stability of a disease-free equilibrium and an endemic equilibrium of an SIRS epidemic model with a class of nonlin- ear incidence rates and distributed delays. By u...In this article, we establish the global asymptotic stability of a disease-free equilibrium and an endemic equilibrium of an SIRS epidemic model with a class of nonlin- ear incidence rates and distributed delays. By using strict monotonicity of the incidence function and constructing a Lyapunov functional, we obtain sufficient conditions under which the endemic equilibrium is globally asymptotically stable. When the nonlinear inci- dence rate is a saturated incidence rate, our result provides a new global stability condition for a small rate of immunity loss.展开更多
The propagation characteristics of oblique incidence terahertz(THz) waves through non-uniform plasma are investigated by the shift-operator finite-difference time-domain(SO-FDTD) method combined with the phase matchin...The propagation characteristics of oblique incidence terahertz(THz) waves through non-uniform plasma are investigated by the shift-operator finite-difference time-domain(SO-FDTD) method combined with the phase matching condition.The electron density distribution of the non-uniform plasma is assumed to be in a Gaussian profile. Validation of the present method is performed by comparing the results with those obtained by an analytical method for a homogeneous plasma slab.Then the effects of parameters of THz wave and plasma layer on the propagation properties are analyzed. It is found that the transmission coefficients greatly depend on the incident angle as well as on the thickness of the plasma, while the polarization of the incident wave has little influence on the propagation process in the range of frequency considered in this paper. The results confirm that the THz wave can pass through the plasma sheath effectively under certain conditions,which makes it a potential candidate to overcome the ionization blackout problem.展开更多
This study proposes a wind farm active power dispatching(WFAPD) algorithm based on the grey incidence method, which does not rely on an accurate mathematical model of wind turbines. Based on the wind turbine start-sto...This study proposes a wind farm active power dispatching(WFAPD) algorithm based on the grey incidence method, which does not rely on an accurate mathematical model of wind turbines. Based on the wind turbine start-stop data at different wind speeds, the weighting coefficients, which are the participation degrees of a variable speed system and a variable pitch system in power regulation, are obtained using the grey incidence method. The incidence coefficient curve is fitted by the B-spline function at a full range of wind speeds, and the power regulation capacity of all wind turbines is obtained. Finally, the WFAPD algorithm, which is based on the regulating capacity of each wind turbine, is compared with the wind speed weighting power dispatching(WSWPD) algorithm in MATLAB. The simulation results show that the active power fluctuation of the wind farm is smaller, the rotating speed of wind turbines is smoother, and the fatigue load of highspeed turbines is effectively reduced.展开更多
Objective To construct a model of Seasonal Autoregressive Integrated Moving Average （SARIMA） for forecasting the epidemic of Japanese encephalitis （JE） in Xianyang, Shaanxi, China, and provide valuable reference ...Objective To construct a model of Seasonal Autoregressive Integrated Moving Average （SARIMA） for forecasting the epidemic of Japanese encephalitis （JE） in Xianyang, Shaanxi, China, and provide valuable reference information for JE control and prevention. Methods Theoretically epidemiologic study was employed in the research process. Monthly incidence data on JE for the period from Jan 2005 to Sep 2014 were obtained from a passive surveillance system at the Center for Diseases Prevention and Control in Xianyang, Shaanxi province. An optimal SARIMA model was developed for JE incidence from 2005 to 2013 with the Box and Jenkins approach. This SARIMA model could predict JE incidence for the year 2014 and 2015. Results SARIMA （1, 1, 1） （2, 1, 1）12 was considered to be the best model with the lowest Bayesian information criterion, Akaike information criterion, Mean Absolute Error values, the highest R2, and a lower Mean Absolute Percent Error. SARIMA （1, 1, 1） （2, 1, 1）12 was stationary and accurate for predicting JE incidence in Xianyang. The predicted incidence, around 0.3/100 000 from June to August in 2014 with low errors, was higher compared with the actual incidence. Therefore, SARIMA （1, 1, 1） （2, 1, 1）12 appeared to be reliable and accurate and could be applied to incidence prediction. Conclusions The proposed prediction model could provide clues to early identification of the JE incidence that is increased abnormally （≥0.4/100 000）. According to the predicted results in 2014, the JE incidence in Xianyang will decline slightly and reach its peak from June to August.The authors wish to thank the staff from the CDCs from 13 counties of Xianyang, Shaanxi province, China, for their contribution to Japanese encephalitis cases reporting.展开更多
A locally resonant sonic material （LRSM） is an elastic matrix containing a periodic arrangement of identical local resonators （LRs）, which can reflect strongly near their natural frequencies, where the wavelength ...A locally resonant sonic material （LRSM） is an elastic matrix containing a periodic arrangement of identical local resonators （LRs）, which can reflect strongly near their natural frequencies, where the wavelength in the matrix is still much larger than the structural periodicity. Due to the periodic arrangement, an LRSM can also display a Bragg scattering effect, which is a characteristic of phononic crystals. A specific LRSM which possesses both local resonance and Bragg scattering effects is presented. Via the layered-multiple-scattering theory, the complex band structure and the transmittance of such LRSM are discussed in detail. Through the analysis of the refraction behavior at the boundary of the composite, we find that the transmittance performance of an LRSM for oblique incidence depends on the refraction of its boundary and the transmission behaviors of different wave modes inside the composite. As a result, it is better to use some low-speed materials （compared with the speed of waves in surrounding medium） as the LRSM matrix for designing sound blocking materials in underwater applications, since their acoustic properties are more robust to the incident angle. Finally, a gap-coupled LRSM with a broad sub-wavelength transmission gap is studied, whose acoustic performance is insensitive to the angle of incidence.展开更多
Based on a full vector-diffraction theory, a detailed theoretical study is carried out, aiming at providing a clear insight into the effects of different focusing and off-axis parabola parameters on far-field vector-d...Based on a full vector-diffraction theory, a detailed theoretical study is carried out, aiming at providing a clear insight into the effects of different focusing and off-axis parabola parameters on far-field vector-diffraction properties of an offaxis parabolic mirror in the presence of misalignments of the incoming beam. The physical origin of these effects is also explored. The results show that the far-field intensity profile is altered by the distortion-, coma-, and astigmatism-like aberrations, which are caused by oblique incidence rather than inherent aberrations for the off-axis configuration. The radius of 90% encircled energy also increases but does not change monotonically with incident beam size increasing, or rather,it first decreases and then increases. The focal shift strongly depends on the effective focal length and oblique incidence angle, but it is almost independent of the beam size, which affects the focusing spot patterns. The intensity distribution produces a higher astigmatic image with off-axis angle increasing. Coma-like aberration starts to become dominant with beam size increasing and results in larger curved propagation trajectory. The incident polarization also affects the intensity distribution. The variation in the Strehl ratio with oblique incidence angle strongly depends on the misalignment direction and beam size as well. In addition, we find that the difference in locus between the catacaustic and the diffraction focus in the meridian is small. But the locus of the sagittal foci is obviously different from the locus of the meridian foci and the catacaustic focus. Moreover, the peak intensity of the sagittal focus is maximum, and the ratio of the peak intensity to that in the meridian plane is approximately 1.5. Understanding these effects is valuable for assessing a practical focused intensity and describing the motion of charged particles under a strong electric field in ultraintense laser–matter interaction.展开更多
The high prevalence of interatrial block （IAB） is widely neglected due to its frequent underdiaguosis. Its prevalence depends mainly on age and also on the presence of associ- ated heart disease. In patients without...The high prevalence of interatrial block （IAB） is widely neglected due to its frequent underdiaguosis. Its prevalence depends mainly on age and also on the presence of associ- ated heart disease. In patients without structural heart dis- ease, it is mainly an elderly condition. This is particularly true for advanced IAB, rarely found in global population before 65 years but with prevalence of 8% in the 70＇s and 25% in centenarians,tll When studying prevalence data of this condition, three factors should be taken into account in order to interpret differences that are frequently related with the methodology used （Table 1, Figure 1）.展开更多
On the multilingual online social networks of global information sharing,the wanton spread of rumors has an enormous negative impact on people's lives.Thus,it is essential to explore the rumor-spreading rules in m...On the multilingual online social networks of global information sharing,the wanton spread of rumors has an enormous negative impact on people's lives.Thus,it is essential to explore the rumor-spreading rules in multilingual environment and formulate corresponding control strategies to reduce the harm caused by rumor propagation.In this paper,considering the multilingual environment and intervention mechanism in the rumor-spreading process,an improved ignorants–spreaders-1–spreaders-2–removers(I2SR)rumor-spreading model with time delay and the nonlinear incidence is established in heterogeneous networks.Firstly,based on the mean-field equations corresponding to the model,the basic reproduction number is derived to ensure the existence of rumor-spreading equilibrium.Secondly,by applying Lyapunov stability theory and graph theory,the global stability of rumor-spreading equilibrium is analyzed in detail.In particular,aiming at the lowest control cost,the optimal control scheme is designed to optimize the intervention mechanism,and the optimal control conditions are derived using the Pontryagin's minimum principle.Finally,some illustrative examples are provided to verify the effectiveness of the theoretical results.The results show that optimizing the intervention mechanism can effectively reduce the densities of spreaders-1 and spreaders-2 within the expected time,which provides guiding insights for public opinion managers to control rumors.展开更多
The status of the incidence of the bark beetle Scolytus kashmirensis Schedl on elm （Ulmus spp.） trees was determined in four districts of the Kashmir Valley in 2009. The incidence of the borer was higher in the Anan...The status of the incidence of the bark beetle Scolytus kashmirensis Schedl on elm （Ulmus spp.） trees was determined in four districts of the Kashmir Valley in 2009. The incidence of the borer was higher in the Anantnag （25.93%） and Shopian （22.35%） districts of the Kashmir Valley, followed by the Ganderbal （17.14%） and Baramulla （16.67%） districts. The overall infestation re- corded in these districts was 20.52%. The beetle under study chewed the scars on twigs of both the host and tentative non-host plants supplied to them in cages but bored and laid eggs in only one of them （the host plant）. Both species of elm, Ulmus wallichiana and U. villosa, were susceptible to borer attacks; however, U. villosa showed low susceptibility and high resistance compared to U. wallichiana. Older, taller elms were preferred for feeding by bark beetles and are therefore much more susceptible to its infestation compared to younger elms. This bark beetle species also preferred to oviposit in branches of the host plants with diameters of 9-12 mm.展开更多
The airlines need to select the optional equipment according to their individual development demands and the manufacture′s standard specification manual when purchasing a new airplane.For this customization process,t...The airlines need to select the optional equipment according to their individual development demands and the manufacture′s standard specification manual when purchasing a new airplane.For this customization process,the selection theory is mainly based on qualitative analysis and quantitative analysis.The grey incidence analysis(GIA)is used for modeling,which evaluates the correlations between optional equipment and airlines′individual demands.Meanwhile,the customization demands are quantitatively processed as different weights in evaluation index system with analytical hierarchy process.Then,the value of grey incidence degree is obtained which shows whether the optional equipment is on the purchasing list or not.Finally,two airlines′customization demands are applied in the example of aircraft cabin′s seats,so two different purchasing priorities and equipment installation lists can be obtained.The results and comparisons verify the reasonable of modeling,which provides an objective scheme of aircraft equipment selection.展开更多
文摘Despite numerous research investigations to understand the influences of various structural parameters,to the authors'knowledge,no research has been the effect of different angles of incidence on stab response and performance of different types of protective textiles.Three distinct structures of 3D woven textiles and 2D plain weave fabric made with similar high-performance fiber and areal density were designed and manufactured to be tested.Two samples,one composed of a single and the other of 4-panel layers,from each fabric type structure,were prepared,and tested against stabbing at[0○],[22.5○],and[45○]angle of incidence.A new stabbing experimental setup that entertained testing of the specimens at various angles of incidence was engineered and utilized.The stabbing bench is also equipped with magnetic sensors and a UK Home Office Scientific Development Branch(HOSDB)/P1/B sharpness engineered knives to measure the impact velocity and exerted impact energy respectively.A silicon compound was utilized to imprint the Back Face Signature(BFS)on the backing material after every specimen test.Each silicon print was then scanned,digitized,and precisely measured to evaluate the stab response and performance of the specimen based on different performance variables,including Depth of Trauma(DOT),Depth of Penetration(DOP),and Length of Penetration(LOP).Besides,the post-impact surface failure modes of the fabrics were also measured using Image software and analyzed at the microscale level.The results show stab angle of incidence greatly influences the stab response and performance of protective textiles.The outcome of the study could provide not only valuable insights into understanding the stab response and capabilities of protective textiles under different angle of incidence,but also provide valuable information for protective textile manufacturer,armor developer and stab testing and standardizing organizations to consider the angle of incidence while developing,testing,optimizing,and using protective textiles in various applications.
基金Project supported by the National Natural Science Foundation of China (Grant No.U19A2044)the National Natural Science Foundation of China (Grant No.41975037)the Key Technologies Research and Development Program of Anhui Province (Grant No.202004i07020013)。
文摘The Fabry–Perot(FP) resonant cavity is widely used in laser and spectroscopic measurements due to its unique interference transfer function(ITF). In the ideal case of parallel incident light, the ITF of the FP resonant cavity can be expressed by the Airy function. However, in reality, it is difficult to achieve perfect parallelism with collimated beams. In this article, a theoretical model is established for non-parallel light incidence, which assumes that the non-parallel incident light is a cone-shaped beam, and the cone angle is used to quantify the non-parallelism of the beam. The transmittance function of the FP resonant cavity under non-parallel light incidence is derived. The accuracy of the model is experimentally verified. Based on this model, the effects of divergence angle, tilt angle and FP cavity parameters(reflectivity, cavity length)on the ITF are studied. The reasons for the decrease in peak value, broadening and asymmetry of the interference peak under non-parallel light incidence are explained. It is suggested that a fine balance between the interference peak and the collimation effect of the incident light should be considered in the design and application of FP resonant cavities, especially for tilted applications such as angle-scanned spectroscopy. The research results of this article have certain significance for the design and application of FP resonant cavities.
基金supported by the National Natural Science Foundation of China(grant number 82103955)the Cyrus Tang Foundation(grant number 050459)the Clinical Medicine Plus X-Young Scholars Project,Peking University,the Fundamental Research Funds for the Central Universities(grant number 7100604313).
文摘Background Major depressive disorders(MDDs)impose substantial burdens on individuals and society;however,further detailed analysis is still needed for its long-term trends.Aims This study aimed to analyse the gender-specific temporal trends and cohort variations of MDD incidence among Chinese residents over the past three decades.Methods Employing the age-period-cohort-interaction model and leveraging data from the Global Burden of Disease Study 2019,this research identified and analysed incidence trends of MDD among Chinese males and females aged 5-94 years from 1990 to 2019 across three dimensions,encompassing age,period and birth cohort.Results The analysis reveals age-related effects,indicating heightened MDD risk among adolescents and older adults.Specifically,individuals entering the older adulthood at the age of 65-69 significantly increased the risk of MDD by 64.9%.People aged 90-94 years witnesseda 105.4%increase in MDD risk for the overall population,with females and males in this age group experiencing a 75.1%and 103.4%increase,respectively.In terms of period effects,the risk of MDD displayed a decline from 1990 to 1994,followed by a rebound in 2008.Cohort effects demonstrated diverse generational patterns,with generationⅠand generationⅢmanifesting opposing‘age-as-level'trends.GenerationⅡand generationⅣexhibited'cumulative disadvantage'and'cumulative advantage'patterns,respectively.Age effects indicated an overall higher risk of MDD incidence in females,while cohort effects showed greater variations of MDD incidence among females.Conclusions The study underscores the substantial effects of age,period and cohort on MDD across genders in China.Priority interventions targeting vulnerable populations,including children,adolescents,older adults,females and the post-millennium birth cohort,are crucial to mitigate the impact of MDD.
基金Supported by the National Natural Science Foundation of China(70901041,71171113)the Joint Research Project of National Natural Science Foundation of China and Royal Society of UK(71111130211)+3 种基金the Major Program of National Funds of Social Science of Chinathe Doctoral Fund of Ministry of Education of China(20093218120032,200802870020)the Qinglan Project for Excellent Youth Teacher in Jiangsu Province(China)the Research Funding of Nanjing University of Aeronautics and Astronautics(NR2011002,NJ2011009)~~
文摘To extend the traditional generalized grey incidence model, a novel grey incidence model based on inter- val grey numbers is constructed. Considering the numerical information of indexes cannot be accurately obtained and can be defined as interval grey numbers, the interval grey numbers are defined as standard interval grey num- bers which are split in white part and grey part. The absolute degree of incidence and relative degree of incidence based on the interval grey numbers are constructed and their arithmetic are given. Finally, an example about commercial aircraft index selection illuminates the effectiveness of the model. The results show that the model can sort indexes better and can extend the grey incidence models significantly.
文摘The concept of the incidence chromatic number of a graph was introduced by Brualdi and Massey. They conjectured that every graph G can be incidence colored with Δ (G) +2 colors. In this paper, the trueness of this conjecture for complete k partite graph was proved, and the incidence chromatic number of complete k partite graphs was calculated.
文摘An estimation method for aircraft similarity based on fuzzy theory and grey incidence analysis is presented. This estimation method is made up of the triangular fuzzy transforming model of linguistic variables and the method of grey incidence analysis. Nine feature attributes of aircraft are selected to estimate the similarity between the new aircraft and the existing aircraft. A new aircraft X and other six existing aircrafts are taken as examples. Analyses show that similarity estimation results obtained from the method are in accordance with practice.
基金Supported by the National Natural Science Foundation of China(71101043,70901041,71171113)the Joint Research Project of National Natural Science Foundation of China and Royal Society of UK(71111130211)+4 种基金the Major Program of National Funds of Social Science of China(10ZD&014,11&ZD168)the Doctoral Fundof Ministry of Education of China(20093218120032,200802870020)the Qinglan Project for Excellent Youth Teacherin Jiangsu Province(China)Research Funding in Nanjing University of Aeronautics and Astronautics(NR2011002)the Central University Scientific Research Expenses of HoHai University(2011B09914,2010B11114)~~
文摘The analysis result of absolute degree of grey incidence for multivariate time series is often inconsistent with the qualitative analysis. To overcome this shortage, a multivariate absolute degree of grey incidence based on distribution characteristics of points is proposed. Based on the geometric description of multivariate time se- ries, the neighborhood extrema are extracted in the different regions, and a characteristic point set is constructed. Then according to the distribution of the characteristic point set, a characteristic point sequence reflecting the ge- ometric features of multivariate time series is obtained. The incidence analysis between multivariate time series is transformed into the relational analysis between characteristic point sequences, and a grey incidence model is established. The model possesses the properties of translational invariance, transpose and rank transform invari- ance, and satisfies the grey incidence analysis axioms. Finally, two cases are studied and the results prove the ef- fectiveness of the model.
文摘Objective Acute aortic dissection （AAD） is a catastrophic event with high early mortality rate, but to date, no data on the incidence of AAD in China's Mainland is available. This study aimed to estimate the incidence of AAD in China and characterize the clinical profile, management and in-hospital outcomes of this vascular event. Methods We used the China Health Insurance Research Data （the CHIRA Data） 2011 which comprises all inpatient hospital records （300,886） during the period of Jan. 1st 2011 to Dec. 31 2011 of 3,335,000 randomly sampled beneficiaries （1,718,500 men and 1,616,500 women） from 25 cities and counties in different economic-geographic regions of China's Mainland. Patients with acute aortic dissection were identified according to International Classification of Disease 10m Revision （ICD-10） of I71.0, The estimated incidence of AAD was calculated using the equation： estimated incidence = 2.0 × （40% × hospital admission rate） ＋ 60% × hospital admission rate. Results The hospital admission rate was 2.0/100,000 （65/3,325,000, 95% CI： 1.2-2.8）. The estimated annual incidence of AAD was 2.8/100,000 （95% CI： 1.9-3.6） and was higher in male than in female （3.7 vs. 1.5, P 〈 0.001）. The mean age was 58.9 ± 13.4 years. During the mean hospital stay of 23 ±6 days, the overall in-hospital mortality was 13.9% （9/65）. Conclusions Our study showed relatively lower but not negligible incidence and in-hospital mortality of AAD in the mainland of China. The mean age of patients with AAD in Chinese was younger than that reported by researches from west countries, while the male to female incidence ratio is similar to those reported by other studies.
基金supported by the National Natural Science Foundation of China(10971166,10901131)the National High Technology Research and Development Program of China(863 Program,2009AA01A135)the Natural Science Foundation of Xinjiang Province(2010211B04)
文摘This article proposes a diffused hepatitis B virus （HBV） model with CTL immune response and nonlinear incidence for the control of viral infections. By means of different Lyapunov functions, the global asymptotical properties of the viral-free equilibrium and immune-free equilibrium of the model are obtained. Global stability of the positive equilibrium of the model is also considered. The results show that the free diffusion of the virus has no effect on the global stability of such HBV infection problem with Neumann homogeneous boundary conditions.
基金supported in part by JSPS Fellows,No.237213 of Japan Society for the Promotion of Science to the first authorthe Grant MTM2010-18318 of the MICINN,Spanish Ministry of Science and Innovation to the second authorScientific Research (c),No.21540230 of Japan Society for the Promotion of Science to the third author
文摘In this article, we establish the global asymptotic stability of a disease-free equilibrium and an endemic equilibrium of an SIRS epidemic model with a class of nonlin- ear incidence rates and distributed delays. By using strict monotonicity of the incidence function and constructing a Lyapunov functional, we obtain sufficient conditions under which the endemic equilibrium is globally asymptotically stable. When the nonlinear inci- dence rate is a saturated incidence rate, our result provides a new global stability condition for a small rate of immunity loss.
基金Project supported by the National Basic Research Program of China(Grant No.2014CB340203)the National Natural Science Foundation of China(Grant Nos.61431010 and 61501350)the Natural Science Foundation of Shaanxi Province,China(Grant Nos.2018JM6016 and 2016JM1001)
文摘The propagation characteristics of oblique incidence terahertz(THz) waves through non-uniform plasma are investigated by the shift-operator finite-difference time-domain(SO-FDTD) method combined with the phase matching condition.The electron density distribution of the non-uniform plasma is assumed to be in a Gaussian profile. Validation of the present method is performed by comparing the results with those obtained by an analytical method for a homogeneous plasma slab.Then the effects of parameters of THz wave and plasma layer on the propagation properties are analyzed. It is found that the transmission coefficients greatly depend on the incident angle as well as on the thickness of the plasma, while the polarization of the incident wave has little influence on the propagation process in the range of frequency considered in this paper. The results confirm that the THz wave can pass through the plasma sheath effectively under certain conditions,which makes it a potential candidate to overcome the ionization blackout problem.
基金supported by the Special Scientific Research Project of the Shaanxi Provincial Education Department (22JK0414)。
文摘This study proposes a wind farm active power dispatching(WFAPD) algorithm based on the grey incidence method, which does not rely on an accurate mathematical model of wind turbines. Based on the wind turbine start-stop data at different wind speeds, the weighting coefficients, which are the participation degrees of a variable speed system and a variable pitch system in power regulation, are obtained using the grey incidence method. The incidence coefficient curve is fitted by the B-spline function at a full range of wind speeds, and the power regulation capacity of all wind turbines is obtained. Finally, the WFAPD algorithm, which is based on the regulating capacity of each wind turbine, is compared with the wind speed weighting power dispatching(WSWPD) algorithm in MATLAB. The simulation results show that the active power fluctuation of the wind farm is smaller, the rotating speed of wind turbines is smoother, and the fatigue load of highspeed turbines is effectively reduced.
基金Supported by the Youth Project of Shaanxi University of Chinese Medicine(2015QN05)
文摘Objective To construct a model of Seasonal Autoregressive Integrated Moving Average （SARIMA） for forecasting the epidemic of Japanese encephalitis （JE） in Xianyang, Shaanxi, China, and provide valuable reference information for JE control and prevention. Methods Theoretically epidemiologic study was employed in the research process. Monthly incidence data on JE for the period from Jan 2005 to Sep 2014 were obtained from a passive surveillance system at the Center for Diseases Prevention and Control in Xianyang, Shaanxi province. An optimal SARIMA model was developed for JE incidence from 2005 to 2013 with the Box and Jenkins approach. This SARIMA model could predict JE incidence for the year 2014 and 2015. Results SARIMA （1, 1, 1） （2, 1, 1）12 was considered to be the best model with the lowest Bayesian information criterion, Akaike information criterion, Mean Absolute Error values, the highest R2, and a lower Mean Absolute Percent Error. SARIMA （1, 1, 1） （2, 1, 1）12 was stationary and accurate for predicting JE incidence in Xianyang. The predicted incidence, around 0.3/100 000 from June to August in 2014 with low errors, was higher compared with the actual incidence. Therefore, SARIMA （1, 1, 1） （2, 1, 1）12 appeared to be reliable and accurate and could be applied to incidence prediction. Conclusions The proposed prediction model could provide clues to early identification of the JE incidence that is increased abnormally （≥0.4/100 000）. According to the predicted results in 2014, the JE incidence in Xianyang will decline slightly and reach its peak from June to August.The authors wish to thank the staff from the CDCs from 13 counties of Xianyang, Shaanxi province, China, for their contribution to Japanese encephalitis cases reporting.
基金the China Scholarship Council for funding him to study at the University of Southampton in the UK
文摘A locally resonant sonic material （LRSM） is an elastic matrix containing a periodic arrangement of identical local resonators （LRs）, which can reflect strongly near their natural frequencies, where the wavelength in the matrix is still much larger than the structural periodicity. Due to the periodic arrangement, an LRSM can also display a Bragg scattering effect, which is a characteristic of phononic crystals. A specific LRSM which possesses both local resonance and Bragg scattering effects is presented. Via the layered-multiple-scattering theory, the complex band structure and the transmittance of such LRSM are discussed in detail. Through the analysis of the refraction behavior at the boundary of the composite, we find that the transmittance performance of an LRSM for oblique incidence depends on the refraction of its boundary and the transmission behaviors of different wave modes inside the composite. As a result, it is better to use some low-speed materials （compared with the speed of waves in surrounding medium） as the LRSM matrix for designing sound blocking materials in underwater applications, since their acoustic properties are more robust to the incident angle. Finally, a gap-coupled LRSM with a broad sub-wavelength transmission gap is studied, whose acoustic performance is insensitive to the angle of incidence.
基金Project supported by the Science Foundation for Youth Scholars of Minjiang University,China(Grant No.Mj9n201602)the National Science and Technology Major Project of the Ministry of Science and Technology of China。
文摘Based on a full vector-diffraction theory, a detailed theoretical study is carried out, aiming at providing a clear insight into the effects of different focusing and off-axis parabola parameters on far-field vector-diffraction properties of an offaxis parabolic mirror in the presence of misalignments of the incoming beam. The physical origin of these effects is also explored. The results show that the far-field intensity profile is altered by the distortion-, coma-, and astigmatism-like aberrations, which are caused by oblique incidence rather than inherent aberrations for the off-axis configuration. The radius of 90% encircled energy also increases but does not change monotonically with incident beam size increasing, or rather,it first decreases and then increases. The focal shift strongly depends on the effective focal length and oblique incidence angle, but it is almost independent of the beam size, which affects the focusing spot patterns. The intensity distribution produces a higher astigmatic image with off-axis angle increasing. Coma-like aberration starts to become dominant with beam size increasing and results in larger curved propagation trajectory. The incident polarization also affects the intensity distribution. The variation in the Strehl ratio with oblique incidence angle strongly depends on the misalignment direction and beam size as well. In addition, we find that the difference in locus between the catacaustic and the diffraction focus in the meridian is small. But the locus of the sagittal foci is obviously different from the locus of the meridian foci and the catacaustic focus. Moreover, the peak intensity of the sagittal focus is maximum, and the ratio of the peak intensity to that in the meridian plane is approximately 1.5. Understanding these effects is valuable for assessing a practical focused intensity and describing the motion of charged particles under a strong electric field in ultraintense laser–matter interaction.
文摘The high prevalence of interatrial block （IAB） is widely neglected due to its frequent underdiaguosis. Its prevalence depends mainly on age and also on the presence of associ- ated heart disease. In patients without structural heart dis- ease, it is mainly an elderly condition. This is particularly true for advanced IAB, rarely found in global population before 65 years but with prevalence of 8% in the 70＇s and 25% in centenarians,tll When studying prevalence data of this condition, three factors should be taken into account in order to interpret differences that are frequently related with the methodology used （Table 1, Figure 1）.
基金the National Natural Science Foundation of People’s Republic of China(Grant Nos.U1703262 and 62163035)the Special Project for Local Science and Technology Development Guided by the Central Government(Grant No.ZYYD2022A05)Xinjiang Key Laboratory of Applied Mathematics(Grant No.XJDX1401)。
文摘On the multilingual online social networks of global information sharing,the wanton spread of rumors has an enormous negative impact on people's lives.Thus,it is essential to explore the rumor-spreading rules in multilingual environment and formulate corresponding control strategies to reduce the harm caused by rumor propagation.In this paper,considering the multilingual environment and intervention mechanism in the rumor-spreading process,an improved ignorants–spreaders-1–spreaders-2–removers(I2SR)rumor-spreading model with time delay and the nonlinear incidence is established in heterogeneous networks.Firstly,based on the mean-field equations corresponding to the model,the basic reproduction number is derived to ensure the existence of rumor-spreading equilibrium.Secondly,by applying Lyapunov stability theory and graph theory,the global stability of rumor-spreading equilibrium is analyzed in detail.In particular,aiming at the lowest control cost,the optimal control scheme is designed to optimize the intervention mechanism,and the optimal control conditions are derived using the Pontryagin's minimum principle.Finally,some illustrative examples are provided to verify the effectiveness of the theoretical results.The results show that optimizing the intervention mechanism can effectively reduce the densities of spreaders-1 and spreaders-2 within the expected time,which provides guiding insights for public opinion managers to control rumors.
文摘The status of the incidence of the bark beetle Scolytus kashmirensis Schedl on elm （Ulmus spp.） trees was determined in four districts of the Kashmir Valley in 2009. The incidence of the borer was higher in the Anantnag （25.93%） and Shopian （22.35%） districts of the Kashmir Valley, followed by the Ganderbal （17.14%） and Baramulla （16.67%） districts. The overall infestation re- corded in these districts was 20.52%. The beetle under study chewed the scars on twigs of both the host and tentative non-host plants supplied to them in cages but bored and laid eggs in only one of them （the host plant）. Both species of elm, Ulmus wallichiana and U. villosa, were susceptible to borer attacks; however, U. villosa showed low susceptibility and high resistance compared to U. wallichiana. Older, taller elms were preferred for feeding by bark beetles and are therefore much more susceptible to its infestation compared to younger elms. This bark beetle species also preferred to oviposit in branches of the host plants with diameters of 9-12 mm.
文摘The airlines need to select the optional equipment according to their individual development demands and the manufacture′s standard specification manual when purchasing a new airplane.For this customization process,the selection theory is mainly based on qualitative analysis and quantitative analysis.The grey incidence analysis(GIA)is used for modeling,which evaluates the correlations between optional equipment and airlines′individual demands.Meanwhile,the customization demands are quantitatively processed as different weights in evaluation index system with analytical hierarchy process.Then,the value of grey incidence degree is obtained which shows whether the optional equipment is on the purchasing list or not.Finally,two airlines′customization demands are applied in the example of aircraft cabin′s seats,so two different purchasing priorities and equipment installation lists can be obtained.The results and comparisons verify the reasonable of modeling,which provides an objective scheme of aircraft equipment selection.
