Propagation Dynamics of Forced Pulsating Waves for a Time Periodic Lotka-Volterra Cooperative System with Nonlocal Effects in Shifting Habitats

In this paper, we will concern the existence, asymptotic behaviors and stability of forced pulsating waves for a Lotka-Volterra cooperative system with nonlocal effects under shifting habitats. By using the alternatively-coupling upper-lower solution method, we establish the existence of forced pulsating waves, as long as the shifting speed falls in a finite interval where the endpoints are obtained from KPP-Fisher speeds. The asymptotic behaviors of the forced pulsating waves are derived. Finally, with proper initial, the stability of the forced pulsating waves is studied by the squeezing technique based on the comparison principle.

Who Is More Vulnerable?The Age-Period-Cohort Effect of Psychological Distress among Urban Residents in China

How does psychological distress evolve over time?This study utilizes cross-sectional data from the China General Social Survey from 2010 to 2017 to explore the differences in psychological distress among Chinese residents at various ages,periods,and cohorts.The dummy variable method and random effects hierarchical age-period-cohort model were employed to isolate the age,period,and cohort effects that impacted the psychological distress of Chinese urban residents.First,in terms of the age effect,the psychological distress experienced by residents tends to increase initially and then decrease with age.Middle-aged individuals,around 40 years old,often face a particularly severe form of psychological distress known as the“midlife crisis.”Additionally,middle-aged people who have larger families may experience more significant psychological distress due to increased family burdens.Second,in terms of the period effect,the psychological distress experienced by residents has been on the rise due to the continued development of society.Those who are at a disadvantage in market competition and work longer hours may be particularly vulnerable to increased psychological distress.Thirdly,the cohort effect refers to the different social behaviors and attitudes exhibited by individuals of different generations.In terms of this effect,psychological distress initially decreased and then increased among those born between 1945 and 1990.Individuals born in the 1980s and 1990s experienced higher levels of psychological distress,with internet use having a greater negative impact.Additionally,the positive effect of income on their psychological distress was reduced.The psychological distress of Chinese urban residents is affected by a variety of time-related factors,which are closely related to Chinese clan culture,market competition and social changes.The heavy family burden imposed by traditional clan culture,the different working conditions created by market competition,and the emergence of new lifestyles,such as internet use during social changes,have led to diverse psychological distress experiences among residents across different ages,time periods,and cohorts.In the future,longitudinal studies are needed to strengthen the robustness of the conclusions and consider the long-term impact of the COVID-19 pandemic.Mental health support should pay specific attention to the psychological distress of middle-aged individuals,long-time workers,and internet users.

Novel implementation of homogenization method to predict effective properties of periodic materials

Representative volume element （RVE） method and asymptotic homogenization （AH） method are two widely used methods in predicting effective properties of pe- riodic materials. This paper develops a novel implementa- tion of the AH method, which has rigorous mathematical foundation of the AH method, and also simplicity as the RVE method. This implementation can be easily realized using commercial software as a black box, and can use all kinds of elements available in commercial software to model unit cells with rather complicated microstructures, so the model may remain a fairly small scale. Several examples were car- fled out to demonstrate the simplicity and effectiveness of the new implementation.

The Response of Winter Wheat Root to the Period and the After-Effect of Soil Water Stress

To reveal the period and after-effect of soil water stress on winter wheat, the article employs the experiment results carried out in the greenhouse. The results showed that the root-restricted weights varied with stress degrees and stress times during and after water stressing. In the course of stress, the chief reason resticting the weight of root was the stress intensity at this time, and that of severe stress treatment was larger than that of mild stress treatment. After water stress was relieved, the results of the after-effect of soil water stress on root growth were that, the stress intensity of short-time and mild stress was larger than that of long-time and severe stress. Comparing two-stage stress intensities, root-restricted weight resulted from after-effect intensity of stress under all of the short-time treatment, and the mild and the long-time stress treatments, while that resulted from the period stress intensity under the severe and the long-time stress treatments. In general, the effects of water stress on root were attributed to the three factors, a formed basis in the previous stage, the after-effect of water condition before this stage and influence of water in this stage, which lead to the characters of root in the whole growth stage.

Effects of Amiodarone on Transmural Dispersion of Ventricular Effective Refractory Periods across Myocardial Layers in the Normal and Hypertrophic Canine Heart

The effects of amiodarone on transmural dispersion of ventricular effective refractory periods （ERPs） in the normal and hypertrophic canine heart were investigated in vivo. By using the programmed stimulation protocol, the ERPs of epicardium （Epi）, midmyocardium （Mid） and endocardium （Endo） were measured by inserting specially-designed electrodes into the three myocardial layers before and after mainlining of amiodarone. No significant ERPs-dispersion was observed in the three layers before and after mainlining of amiodarone in the normal group. In contrast, ERPs of all the three layers were prolonged in the hypertrophic heart, while the ERPs-dispersion was reduced significantly after mainlining of amiodarone. The ERPs-dispersion was significantly increased in the hypertrophic heart but not in the normal heart using ＂long-short＂ and ＂short-long＂ interval stimulation technique. It was concluded that （1） the differences in ERPs-dispersion among the three layers were significant in hypertrophic heart, and differences were not significant in normal canine heart; （2） ERPs of each three-myocardial layers were significantly prolonged after using amioda- rone, but the ERPs-dispersion decreased in hypertrophic heart and （3） the programmed extrastimulus technique of ＂long-short＂ and ＂short-long＂ intervals increased the transmural ERPs-dispersion in the hypertrophic heart.

Changes of Monophasic Action Potential Duration and Effective Refractory Period of Three Layers Myocardium of Canine during Acute Ischemia in Vivo

Summary： The effect of acute ischemia on the electrophysiological characteristics of the three layers myocardium of canine in vivo was investigated. Twelve canines were divided into two groups randomly： acute ischemia （AI） group and sham operation （SO） group. By using the monophasic action potential （MAP） technique, MAP and effective refractory period （ERP） of the three layers myocardium were measured by specially designed plunge needle electrodes and the transmural dispersion of repolarization （TDR） and transmural dispersion of ERP （TDE） were analyzed. The results showed that in the AI group, MAP duration （MAPD） was shortened from 201.67±21.42 ms to 169.50±13.81 ms （P〈0.05）, but ERP prolonged to varying degrees and TDE increased during ischemia. In the SO group, MAPD and ERP did not change almost. Among of the three layers myocardium of canine, MAPD was coincident in two groups. It was concluded that during acute ischemia, MAPD was shortened sharply, but there was no significant difference among of the three layers myocardium. The prolonged ERP was concomitant with increased TDE during acute ischemia, which may play an important role in the occurrence of arrhythmias induced by acute ischemia. These findings may have important implications in arrhythmogenesis.

Effect of β_3-adrenoceptors on Ventricle Fibrillation Threshold and Effective Refractory Period in Rats With Heart Failure

Objectives To observe the effect of β3-Adrenoceptor （AR） on ventricle fibrillation threshold （VFT） and effective refractory period （ERP） in rats with heart failure. Methods Rats were randomized into control group and heart failure group. The expression of β3-ARmRNA was detected with RTPCR; The VFT, ERP, LVESP,LVEDP, ＋dp/dtmax and -dp/dtmax was measured at the same time with administration of BRL37344 （ 2 nmol / kg, β3- AR agonist）. Results ①Both the expression of β3-AR mRNA and the proportion increased in rats with heart failure in comparison with control rats （0.028 vs. 0.011 and 5.4% vs 1.2%, P 〈 0.05）;② ERP was longer in rats with heart failure than control group （70.5±5.5 ms vs 59.5±6.4ms, P 〈 0.05） and there was no difference of ERP in rats with heart failure with administration of BRL37344 （73.0±4.8 ms vs 70.5± 5.5 ms, P 〉0.05）; ③VFT was lower in rats with heart failure than control group（10.9±0.8 mv vs 30.5± 1.3 mv, P〈 0.05） and decreased obviously in rats with heart failure with administration of BRL37344 （7.1±0.6 mv vs 10.9±0.8 mv, P 〈 0.05） ; The decrease of VFT correlated with the effect on LVESP, ＋dp/ dtmax,-dp/dtmax of BRL37344 and the expression of β3-AR mRNA （correlation coefficient： 0.788, 0.708, 0.759, 0.787; P 〈 0.05）. Conclusions The expression of β3-AR mRNA of left ventricle was obviously increased in rats with heart failure, and activation of β3-AR had no effect on ERP but could decreased VFT which correlated with the effect of β3-AR on LVESP, ＋dp/dtmax, -dp/dtmax and the expression of β3-AR mRNA.

On the Validity of the Effective Index Method for Long Period Grating Photonic Crystal Fibers

This paper focuses on the investigation of modal characteristics and sensing properties of long period grating photonic crystal fibers (LPG-PCFs). An improved effective index method is employed with an objective to study its limitations for various designs of LPG-PCFs. Results so obtained with the above method are compared with the corresponding values of multiple multipole (MMP) method results which points the range of validity and applicability of the improved effective index method to LPG-PCFs. It is shown that this method is excellent when the surrounding media is assumed to be air. However, it becomes less accurate when the fiber is immersed into a liquid with a refractive index close to that of the cladding.

基于Backroom Effect的生鲜品零售库存决策优化

本文基于传统的Backroom Effect,考虑生鲜品零售中普遍存在的现象——仓库较之货架具有更为优越的腐损控制和保鲜能力,重新定义了仓库在保管生鲜品过程中存在的数量与保鲜方面的双重Backroom Effect。基于此,面向生鲜品零售商,研究包括仓库-货架补给决策以及订货补给的库存决策优化问题,并利用数值算例剖析了Backroom Effect下,货架与仓库存在的腐损率差异对零售商库存决策和相应利润的影响。文章的主要结论包括:生鲜零售商应在零售库存决策中充分考虑Backroom Effect的影响,借助其提高生鲜品的最优订货量,从而带来单位时间平均利润的提升;随着Backroom Effect效果的提升,零售商的最优订货量和对应的平均利润也随之增加;不同品类的生鲜品对Backroom Effect的敏感程度不同,零售商在进行仓库保鲜投资时应优先投资更易腐损且具有更高边际利润的生鲜品品种。

A transparent electromagnetic-shielding film based on one-dimensional metal–dielectric periodic structures

In this study, we designed and fabricated optical materials consisting of alternating ITO and Ag layers. This approach is considered to be a promising way to obtain a light-weight, ultrathin and transparent shielding medium, which not only transmits visible light but also inhibits the transmission of microwaves, despite the fact that the total thickness of the Ag film is much larger than the skin depth in the visible range and less than that in the microwave region. Theoretical results suggest that a high dielectric/metal thickness ratio can enhance the broadband and improve the transmittance in the optical range. Accordingly, the central wavelength was found to be red-shifted with increasing dielectric/metal thickness ratio. A physical mechanism behind the controlling transmission of visible light is also proposed. Meanwhile, the electromagnetic shielding effectiveness of the prepared structures was found to exceed 40 dB in the range from 0.1 GHz to 18 GHz, even reaching up to 70 dB at 0.1 GHz, which is far higher than that of a single ITO film of the same thickness.

Effect of site amplification on inelastic seismic response

The available models for eff ective periods of site and structure are reviewed in context of frequency tuning in the inelastic seismic response of soil-structure system. The eff ect of seismic intensity and ductility demand, on the eff ective periods, is investigated, and inelastic site amplifi cation is shown to be strongly correlated to the normalized eff ective period. Two non-dimensional parameters, analogous to the conventional site amplifi cation factors in codes, are defi ned to quantify the inelastic site amplifi cation. It is shown that the inelastic site amplifi cation factor (i.e. ratio of constant ductility spectral ordinates at soil site to those at rock outcrop) is able to represent the site eff ects more clearly, as compared to the inelastic site amplifi cation ratio (i.e. ratio of inelastic spectral ordinates at soil site to the corresponding elastic spectral ordinates at rock outcrop). Further, the peak in the amplifi cation factor corresponding to the eff ective site period diminishes rapidly with increasing ductility demand.

Effect of Ultrasonic Vibration on Deformation in Micro-blanking Process with Copper Foil

Effect of ultrasonic vibration on deformation in micro-blanking was investigated with copper foils of different grain sizes using a developed device. It is found that maximum shearing strength is decreased by ultrasonic vibration, and this effect becomes bigger for coarse grain than that for fine grain, which can be attributed to acoustic softening effect considering the absorbed acoustic energy. Surface roughness R_a of smooth zone decreases for the polishing effect of vibration at the lateral contact surface. When ultrasonic vibration is applied, the sheared deformation area becomes relatively narrow, and it leads to the reduction of radius of rollover. The analysis of cross section in sheared deformation area shows that the crack initiation is inhabited for the existence of acoustic softening, and the proportion of smooth zone is increased. Also, angle of crack propagation becomes smaller because of periodic strain, and the angle of facture surface is decreased. As a result, the quality of micro-sheet parts is improved by applying ultrasonic vibration.

Spectra of seismic force reduction factors of MDOF systems normalized by two characteristic periods

Seismic force reduction factor(SFRF) spectra of shear-type multi-degree-of-freedom(MDOF) structures are investigated. The modified Clough model, capable of considering the strength-degradation/hardening and stiffnessdegradation, is adopted. The SFRF mean spectra using 102 earthquake records on a typical site soil type(type C) are constructed with the period abscissa being divided into three period ranges to maintain the peak features at the two sitespecific characteristic periods. Based on a large number of results, it is found that the peak value of SFRF spectra may also exist for MDOF, induced by large high-mode contributions to elastic base shear, besides the mentioned two peak values. The variations of the stiffness ratio λk and the strength ratio λF of the top to bottom story are both considered. It is found that the SFRFs for λF ≤λk are smaller than those for λF > λk. A SFRF modification factor for MDOF systems is proposed with respect to SDOF. It is found that this factor is significantly affected by the story number and ductility. With a specific λF(= λk0.75), SFRF mean spectra are constructed and simple solutions are presented for MDOF systems. For frames satisfying the strong column/weak beam requirement, an approximate treatment in the MDOF shear-beam model is to assign a post-limit stiffness 15%-35% of the initial stiffness to the hysteretic curve. SFRF spectra for MDOF systems with 0.2 and 0.3 times the post-limit stiffness are remarkably larger than those without post-limit stiffness. Thus, the findings that frames with beam hinges have smaller ductility demand are explained through the large post-limit stiffness.

卡瑞利珠单抗、阿帕替尼联合卡培他滨二线治疗晚期三阴性乳腺癌的临床研究

目的探究卡瑞利珠单抗、阿帕替尼联合卡培他滨二线治疗晚期三阴性乳腺癌的临床效果。方法前瞻性选取2020年1月至2022年1月郑州大学第二附属医院收治的122例晚期三阴性乳腺癌患者纳入研究,按随机数表法分为观察组和对照组各61例,对照组患者采用阿帕替尼+卡培他滨二线治疗,观察组患者在对照组治疗的基础上联合卡瑞利珠单抗治疗。一个疗程21 d,治疗2个疗程。治疗2个疗程后,比较两组患者的临床疗效,以及治疗前后的肿瘤标志物水平[糖类抗原15-3(CA15-3)、癌胚抗原(CEA)]和免疫功能,同时比较两组患者治疗期间的药物不良反应。随访1年,比较两组患者的生存情况。结果观察组患者的客观缓解率和疾病控制率分别为59.02%、81.97%,明显高于对照组的39.34%、65.57%,差异均有统计学意义(P<0.05);治疗前,两组患者的血清CA15-3、CEA水平比较差异均无统计学意义(P>0.05),治疗后,两组患者的血清CA15-3、CEA水平均降低,且观察组明显低于对照组,差异均有统计学意义(P<0.05);治疗后,两组患者的CD3+、CD8+水平均升高,且观察组明显高于对照组,治疗后,两组患者的CD4+均降低,且观察组明显低于对照组,差异均有统计学意义(P<0.05);两组患者治疗期间的不良反应发生率比较差异均无统计学意义(P>0.05)。随访1年,观察组失访1例,对照组失访2例,观察组患者的中位无进展生存时间为11.55个月,明显长于对照组的6.98个月,差异有统计学意义(P<0.05)。结论卡瑞利珠单抗、阿帕替尼联合卡培他滨二线治疗晚期三阴性乳腺癌,可有效调节患者的肿瘤标志物,提高客观缓解率,促进免疫功能的恢复、延长患者的生存期且安全性良好。

Effect of Altitude, Right Ascension of Ascending Node and Inclination on Lifetime of Circular Lunar Orbits

The lifetime of a lunar satellite orbit is constrained by the non-spherical nature of the Moon’s gravity field. The orbital lifetime of lunar orbits depends significantly on the initial conditions of the orbit. Right ascension of ascending node (Ω) is one of the important orbital parameter affecting the orbital lifetime. In the present work we have analyzed the effect of Ω on the variation of lifetime with altitude for circular lunar orbits. It is found that at a particular initial altitude, a small increase in the altitude results in substantial increase in the orbital lifetime due to effect of the long periodic terms of Earth’s gravity on eccentricity and this transition altitude is different for different Ω. Further, it is observed that the variation of transition altitude with Ω follows a definite, but different trend for orbits with different inclinations. The transition altitude for polar orbits is found to be higher without the effect of Sun and Earth gravity. Variation of transition altitude with orbital inclination is also analyzed. Lifetimes of high altitude circular lunar orbits are analyzed and it is observed that at high altitudes lifetime decreases with altitude.

P-Δ effect on inelastic displacement ratio spectra for inelastic structures

For the evaluation of structures with known ductility demands,the constant-ductility displacement ratio spectra(CDDRS) are particularly useful for providing inelastic displacement ratios to estimate maximum lateral inelastic displacement demands from maximum elastic displacement demands.The CDDRS are computed for single-degree-of-freedom systems(SDOF) by considering or ignoring P-Δ effect for different ductility levels when subjected to 344 earthquake ground motions recorded in four site classes.The modified expressions of CDDRS for P-Δ effect are proposed.It is concluded that the P-Δ effect on CDDRS is significant,and the effect increases with the increase of ductility level.In the long-period region,the CDDRS ignoring P-Δ effect almost conforms to the equal-displacement rule.But in the case of higher ductility level,the CDDRS considering P-Δ effect are much higher than 1.0,which do not conform to the equal-displacement rule.

Atmospheric Pollution Control Effect of Key Cities in Inner Mongolia in 2014

APEC conference was held in Beijing during November 3- 12,2014. Hohhot City and Baotou City fall into the peripheral key air pollution control cities in the ＂ Beijing- Tianjin- Hebei＂ region. Inner Mongolia government adopted powerful pollution control measures in the period of the conference. According to pollutant concentration data and meteorological data etc. in the course of the event and the same period of last year,the atmospheric pollution variations and control effect were discussed in this study. The results showed that during October 1- 25,2014,there were 16 days with air pollution in Hohhot City and 15 days with air pollution in Baotou City,respectively increasing by 8% and 34% compared with the same period of 2013,and the concentration of particulate matter was also higher than that of last year. During October 22- 24,2014,Hohhot and Baotou cities were polluted persistently. The variation features of hourly concentration of main pollutants PM（10） and PM2. 5were similar to those in the same period of 2013. That is,the pollutant concentration reached the maximum from 21：00 to 23：00,and the minimum appeared from 15： 00 to 19： 00 in the next day. In the course of the event,the concentration of particulate matter in the two cities stared to reduce greatly on October 26. From October 26 to November 13,there were no days with air pollution in Hohhot City,decreasing by 100% compared with the same period of 2013; there were five days with air pollution in Baotou City,and the numbers of days with slight,moderate and severe pollution reduced by 37%,100% and67% respectively compared with the same period of last year. The persistent air pollution from October 22 to the first 10 days of November was related to unfavorable meteorological conditions,and the meteorological condition in the same period of 2014 was even worse. In the course of the event,the Inner Mongolia Government adopted air pollution control measures around October 25 and began to adopt some powerful pollution control measures on November 1. As a result,air pollution in key cities has been controlled effectively. This event showed that urban atmospheric pollution problem can be resolved,and we should take an optimistic attitude towards this matter.

PROPAGATION BEHAVIORS OF SHEAR HORIZONTAL WAVES IN PIEZOELECTRIC-PIEZOMAGNETIC PERIODICALLY LAYERED STRUCTURES

This paper investigates shear horizontal （SH） waves propagating in a periodically layered structure that consists of piezoelectric （PE） layers perfectly bonded with piezomagnetic （PM） layers alternately. The explicit dispersion relations are derived for the two cases when the propagation directions of SH waves are normal to the interface and parallel to the interface, respectively. The asymptotic expressions for dispersion relations are also given when the wave number is extremely small. Numerical results for stop band effect and phase velocity are presented for a periodic system of alternating BaTiO3 and Terfenol-D layers. The influence of volume fraction on stop band effect and dispersion behaviors is discussed and revealed.

配方施肥对紫薇花序着花数和花期的影响

为探究紫薇花序着花数和花期对氮、磷、钾配方施肥的响应,获得氮、磷、钾优化的施肥量,以紫薇优良新品种“紫精灵”为研究对象,采用氮、磷、钾“3414”施肥设计进行田间施肥试验,测定不同处理的花序着花数和花期,拟合花序着花数的肥料效应模型,采用频次分析法获得优化施肥量。结果表明:氮、磷、钾配方施肥显著提高了紫薇花序着花数,能提早始花期和盛花期、推迟末花期;施肥对紫薇花序着花数、花期、始花期、盛花期、末花期的单因子影响效应均是N>K>P,交互作用影响效应都是NK>NP>PK;氮、磷、钾对花序着花数的单因素效应为正,氮与磷交互效应为正,氮与钾、磷与钾的交互效应都是负;花序着花数最大的施肥量为氮肥(N)19.50g·株^(-1)、磷肥(P_(2)O_(5))13.82g·株^(-1)、钾肥(K_(2)O)3.66g·株^(-1),此时花序着花数为117.94朵;用频次分析法获得的优化施肥量为氮肥(N)10.95~17.37g·株^(-1)、磷肥(P_(2)O_(5))5.89~9.37g·株^(-1)、钾肥(K_(2)O)7.01~10.25g·株^(-1),预期花序着花数平均值为126.52朵。

“一带一路”倡议与全球价值链升级——基于沿线国家的实证数据

基于2007—2020年“一带一路”沿线国家的样本数据,利用多期双重差分模型实证检验了“一带一路”倡议对沿线国家的价值链升级作用。研究结果证实:“一带一路”倡议对于沿线国家全球价值链发展具有显著正向影响。机制分析表明:“一带一路”倡议对沿线国家存在“虹吸效应”,有利于沿线国家的发展。此外,政策沟通对于倡议的推行具有积极的促进作用。研究结果不仅证实了倡议对于沿线国家价值链升级的正向影响,也论证了其中存在的影响机制,为未来进一步的研究提供了理论支撑和有益探索。