Relation of the Second Type Thermal Helicity to Precipitation of Landfalling Typhoons:A Case Study of Typhoon Talim

This study utilized the MM5 mesoscale model to simulate the landfalling process of Typhoon Talim.The simulated typhoon track,weather patterns,and rainfall process are consistent with the observation.Using the simulation results,the relation of the second type thermal helicity（H2） to rainfall caused by the landfalling typhoon Talim was analyzed.The results show that H2 could well indicate the heavy inland rainfall but it did not perform as well as the helicity in predicting rainfall during the beginning stage of the typhoon landfall.In particular,H2 was highly correlated with rainfall of Talim at 1-h lead time.For 1-5-h lead time,it also had a higher correlation with rainfall than the helicity did,and thus showing a better potential in forecasting rainfall intensification.Further analyses have shown that when Talim was in the beginning stage of landfall,1） the 850-200-hPa vertical wind shear around the Talim center was quite small（about 5 m s-1）;2） the highest rainfall was to the right of the Talim track and in the area with a 300-km radius around the Talim center,exhibiting no obvious relation to low-level temperature advection,low-level air convergence,and upper-level divergence;3） the low-level relative vorticity reflected the rainfall change quite well,which was the main reason why helicity had a better performance than H2 in this period.However,after Talim moved inland further,1） it weakened gradually and was increasingly affected by the northern trough;2） the vertical wind shear was enhanced as well;3） the left side of the down vertical wind shear lay in the Lushan and Dabieshan mountain area,which could have contributed to triggering a secondary vertical circulation,helping to produce the heavy rainfall over there;hence,H2 showed a better capacity to reflect the rainfall change during this stage.

Construction of convex solutions for the second type of Feigenbaum's functional equations

In this paper, convex solutions for the second type of Feigenbaum's equation f (x) = λ1 f (f (λx)), 0 < λ < 1, f (0) = 1, 0 f (x) 1, x ∈ [0, 1] are investigated. Using constructive methods, we discuss the existence and uniqueness of continuous convex solutions, C1-convex solutions and C2-convex solutions of the above equation.

OSCILLATION CRITERIA FOR SECOND ORDER NONLINEAR DIFFERENTIAL EQUATIONS OF NEUTRAL TYPE

In this paper,the oscillation criteria for the solutions of the nonlinear differential equations of neutral type of the forms:[x(t)+p(t)x(σ(t))]″+q(t)f(x(τ(t)))g(x′(t))=0and[x(t)+p(t)x(σ(t))]″+q(t)f(x(t),x(τ(t)))g(x′(t))=0are obtained.

Some Identities of the Higher-Order Type 2 Bernoulli Numbers and Polynomials of the Second Kind

We introduce the higher-order type 2 Bernoulli numbers and polynomials of the second kind.In this paper,we investigate some identities and properties for them in connection with central factorial numbers of the second kind and the higher-order type 2 Bernoulli polynomials.We give some relations between the higher-order type 2 Bernoulli numbers of the second kind and their conjugates.

ON LEVIN TYPE COMPARISON THEOREMS FOR CERTAIN SECOND ORDER DIFFERENTIAL EQUATIONS

In this paper we establish Levin type comparison theorems for certain second order differential equations. The results obtained here generalize and extend some of the earlier ones related to the Levin's comparison theorems.

A simplified fragility analysis of fan type cable stayed bridges

A simplified fragility analysis of fan type cable stayed bridges usingProbabilistic Risk Analysis (PRA) procedure is presented for determining their failure probabilityunder random ground motion. Seismic input to the bridge support is considered to be a riskconsistent response spectrum which is obtained from a separate analysis. For the response analysis,the bridge deck is modeled as a beam supported on springs at different points. The stiffnesses ofthe springs are determined by a separate 2D static analysis of cable-tower-deck system. The analysisprovides a coupled stiffness matrix for the spring system. A continuum method of analysis usingdynamic stiffness is Used to determine the dynamic properties of the bridges .The response of thebridge deck is obtained by the response spectrum method of analysis as applied to multi-degree offreedom system which duly takes into account the quasi - static component of bridge deck vibration.The fragility analysis includes uncertainties arising due to the variation in ground motion,material property, modeling, method of analysis, ductility factor and damage concentration effect.Probability of failure of the bridge deck is determined by the First Order Second Moment (FOSM)method of reliability. A three span double plane symmetrical fan type cable stayed bridge of totalspan 689 m, is used as an illustrative example. The fragility curves for the bridge deck failure areobtained under a number of parametric variations. Some of the important conclusions of the studyindicate that (ⅰ) not only vertical component but also the horizontal component of ground motionhas considerable effect on the probability of failure; (ⅱ) ground motion with no time lag betweensupport excitations provides a smaller probability of failure as compared to ground motion with verylarge time lag between support excitation; and (ⅲ) probability of failure may considerablyincrease for soft soil condition.

Second-Order Adjoint Sensitivity Analysis Methodology for Computing Exactly Response Sensitivities to Uncertain Parameters and Boundaries of Linear Systems: Mathematical Framework

This work presents the “Second-Order Comprehensive Adjoint Sensitivity Analysis Methodology (2nd-CASAM)” for the efficient and exact computation of 1st- and 2nd-order response sensitivities to uncertain parameters and domain boundaries of linear systems. The model’s response (i.e., model result of interest) is a generic nonlinear function of the model’s forward and adjoint state functions, and also depends on the imprecisely known boundaries and model parameters. In the practically important particular case when the response is a scalar-valued functional of the forward and adjoint state functions characterizing a model comprising N parameters, the 2nd-CASAM requires a single large-scale computation using the First-Level Adjoint Sensitivity System (1st-LASS) for obtaining all of the first-order response sensitivities, and at most N large-scale computations using the Second-Level Adjoint Sensitivity System (2nd-LASS) for obtaining exactly all of the second-order response sensitivities. In contradistinction, forward other methods would require (N2/2 + 3 N/2) large-scale computations for obtaining all of the first- and second-order sensitivities. This work also shows that constructing and solving the 2nd-LASS requires very little additional effort beyond the construction of the 1st-LASS needed for computing the first-order sensitivities. Solving the equations underlying the 1st-LASS and 2nd-LASS requires the same computational solvers as needed for solving (i.e., “inverting”) either the forward or the adjoint linear operators underlying the initial model. Therefore, the same computer software and “solvers” used for solving the original system of equations can also be used for solving the 1st-LASS and the 2nd-LASS. Since neither the 1st-LASS nor the 2nd-LASS involves any differentials of the operators underlying the original system, the 1st-LASS is designated as a “first-level” (as opposed to a “first-order”) adjoint sensitivity system, while the 2nd-LASS is designated as a “second-level” (rather than a “second-order”) adjoint sensitivity system. Mixed second-order response sensitivities involving boundary parameters may arise from all source terms of the 2nd-LASS that involve the imprecisely known boundary parameters. Notably, the 2nd-LASS encompasses an automatic, inherent, and independent “solution verification” mechanism of the correctness and accuracy of the 2nd-level adjoint functions needed for the efficient and exact computation of the second-order sensitivities.

Two Optimal Inequalities Related to the Sándor-Yang Type Mean and One-parameter Mean

In this paper, we establish two optimal the double inequalities for Sandor- Yang type mean and one-parameter mean.

Computational Aspect For Function-Valued Padé-Type Approximation

The computational problems of two special determinants are investigated. Those determinants appear in the construction of the function-valued Pade-type approximation for computing Fredholm integral equation of the second kind. The main tool to be used in this paper is the well-known Schur complement theorem.

环保投资对第二类代理成本的影响——兼论内部控制的调节效应

基于我国2011—2021年沪深A股上市公司数据,实证分析了环保投资、内部控制与第二类代理成本三者之间的关系。结果表明:环保投资有利于第二类代理成本的降低,且内部控制对环保投资降低第二类代理成本具有抑制作用。机制检验表明,环保投资能够通过提高公司信息透明度和提升ESG表现降低第二类代理成本。进一步分析发现,环保投资对第二类代理成本的影响在外部监督压力大、非重污染和大股东“掏空”动机较低企业显著,且内部控制的抑制作用在外部监督压力弱和大股东“掏空”动机低组企业显著,而在其他方面并不具有显著性差异。研究从经济后果视角揭示了环保投资所具有的公司治理功效,这对于“双碳”战略践行、公司治理效率提升以及投资者利益保护均有现实意义。

李洁教授运用温阳祛瘀通脉汤治疗二度Ⅱ型房室传导阻滞经验

二度Ⅱ型房室传导阻滞属于中医“心悸”范畴,是一种较为严重的缓慢性心律失常,临床表现为心悸、头晕、乏力、黑朦甚至晕厥,严重者可危及生命。二度Ⅱ型房室传导阻滞心电图表现为P波规律出现,PR间期恒定不变,部分P波后QRS波脱漏。西医在治疗二度Ⅱ型房室传导阻滞时主要应用抗心律失常药物和安装人工心脏起搏器,然而抗心律失常药物的不良反应及禁忌证较多,在临床用药时对医生及患者产生极大困扰;人工心脏起搏器的电极放电会直接导致心肌损伤,并会长期存在心肌细胞慢性炎症反应。西药治疗和介入治疗均存在不可避免的弊端,因此临床上患者接纳程度普遍偏低。李洁教授从中医角度分析认为本病为本虚标实之证,本虚的病机多为心阳不振或气血亏虚,标实的病机多为痰饮停滞或瘀血阻滞。温阳祛瘀通脉汤是李洁教授根据其治疗心血管疾病的30多年临床经验总结创立而成,具有温通心阳、活血化瘀、益气复脉之功,主要用于治疗二度Ⅱ型房室传导阻滞,可明显改善患者症状,阻止病情进展,收效甚佳。现根据一则验案分析李洁教授运用温阳祛瘀通脉汤诊治二度Ⅱ型房室传导阻滞的思路与经验。

船闸单侧闸墙主廊道输水系统岔管水动力特性研究

船闸单侧闸墙主廊道输水系统具有结构简单、开挖量小、工程投资省等优点,在河谷狭窄、边坡陡峭等地形受限地区具有明显的技术优势,但工程应用难点之一在于如何保证廊道内断面流速的均匀性,避免出现严重的偏流、脱流现象。依托嘉陵江草街二线船闸工程,采用通用CFD软件FLUENT,对船闸单侧闸墙主廊道双阀门输水系统布置中的岔管水动力特性进行较为详细的研究,探讨岔管分岔角、墩头曲线形式以及外壁曲线形式对岔管水力特性的影响,提出外壁采用正弦曲线,内壁采用圆弧-直线-圆弧形曲线的单侧输水廊道阀门段岔管布置体形,可为类似工程设计提供参考。

Stokes公式的自由度及其在计算积分中的应用

考察了Stokes公式中蕴含的自由度问题.基于这种自由度,得到了计算第二类曲面积分(或一般的流形上的积分)的分部积分法和更改被积曲面积分法的两个对偶公式.用具体例子说明了这两个公式的应用.

关于二阶Fermat型常微分方程的整函数解

本文研究了二阶Fermat型常微分方程(a_(1)f+b_(1)f′+c_(1)f")^(2)+(a_(2)f+b_(2)f′+c_(2)f")^(2)=γ的整函数解的问题,其中γ是C上的整函数.利用Nevanlinna值分布理论的方法,获得了方程存在整函数解的充要条件,并且给出了解的表达形式.

中国南北两地2型糖尿病患者二线用药偏好差异研究

背景近年来我国糖尿病患病人数位列全球第一。《中国老年2型糖尿病防治临床指南(2022年版)》推荐二甲双胍为一线降糖用药的同时,强调“以患者为中心”,根据患者的临床特征及其偏好选择适当的二线降糖药进行联合用药。由于我国南北两地2型糖尿病患病率、生活行为等方面存在较大差异,两地2型糖尿病患者二线用药偏好是否存在差异还有待进一步论证。目的分析南北两地2型糖尿病患者二线用药偏好差异,为临床和卫生管理决策提供实证依据。方法于2021年10月—2022年1月,采用离散选择实验设计调查问卷,多阶段随机整群抽样与方便抽样相结合,调查南北两地2型糖尿病患者二线用药偏好,构建混合Logit模型进行偏好分析。结果本研究共发放问卷1443份,回收有效问卷1388份,有效回收率为96.19%。Logit模型分析结果显示,血糖控制效果、发生低血糖事件的风险、发生胃肠道不良反应的风险、能否保护心血管、服药方式、自付费用是南方患者对二线用药偏好的影响因素(P<0.05),南方2型糖尿病患者偏好自付费用为0元/月、无胃肠道不良反应风险、血糖控制效果很强、无低血糖事件风险、能保护心血管和服药方式为口服的二线降糖药物(P<0.05),当发生胃肠道不良反应的风险由较高换为无风险时,南方患者每月愿意支付408.06元。血糖控制效果、发生低血糖事件的风险、发生胃肠道不良反应的风险、能否保护心血管、服药方式、自付费用、半年内体质量变化是北方患者对二线用药偏好的影响因素(P<0.05),北方2型糖尿病患者偏好自付费用为0元/月、血糖控制效果很强、无低血糖事件风险、能保护心血管、无胃肠道不良反应风险、服药方式为口服和半年内体质量变化降低2.0 kg的二线降糖药物(P<0.05),当治疗血糖控制效果很弱换为很强时,北方患者每月愿意支付435.98元。结论除自付费用外,南方2型糖尿病患者更关注胃肠道不良反应,而北方2型糖尿病患者更重视血糖控制效果,南北两地2型糖尿病患者二线用药偏好存在差异。地域差异为2型糖尿病患者个性化治疗提供了依据,临床诊治需要“以患者为中心”,注重个体偏好差异。

WaveOneGold和ProTaperNext在预备C形根管成形能力和清理能力中的应用效果比较

目的:比较WaveOneGold和ProTaperNext在预备弯曲根管成形能力和清理能力中的应用效果。方法:选取2022年1月-2022年6月新疆维吾尔自治区中医医院收治的接受根管治疗术的180例下颌第二磨牙C形根管患者为研究对象,采用随机数字表法将患者分为WG组(90例,接受WaveOneGold根管预备)与PN组(90例,接受ProTaperNext根管预备);比较两组根管预备时间、成形能力、疼痛情况、清理能力以及根管充填质量。结果:PN组预备时间显著大于WG组(P<0.05);PN组患者根尖部以及根管中部未预备面积明显小于WG组(P<0.05);PN组在距根尖1.5 mm、5.5 mm处根管偏移值明显小于WG组(P<0.05);PN组在距根尖1.5 mm、4.5 mm处中心定位力优于WG组(P<0.05);两组患者术后7 d内约诊间疼痛发生情况、预备后根管壁碎屑评分、根管壁玷污层评分比较差异无统计学意义(P>0.05);根管充填1年后,两组根管填充情况比较差异无统计学意义(P>0.05)。结论:ProTaperNext在预备弯曲根管时相较于WaveOneGold在疼痛情况、清理能力以及充填质量方面无明显差异,WaveOneGold预备时间更短,但ProTaperNext预备具有更好的成形能力。

山区增建二线铁路桥式方案比选

以山区某地方重载铁路增建二线工程为例,选取一处代表性的桥梁工点,分别采用1×32 m简支T梁+1×(32+48+32)m连续梁、1×(64+64)m T构2个桥式方案,通过综合分析对既有线的影响、水文条件、工程经济性、施工组织、景观要求等因素,选择采用1×(64+64)m T构的桥式方案。

基于森林资源二类调查数据的森林碳储量和固碳潜力评估——以西藏自治区扎囊县为例

基于森林资源二类调查数据,运用生物量转换因子法和单位面积平均生物量法,估算西藏自治区扎囊县森林生物量,再乘以含碳系数估算森林碳储量。根据生物群落演替的顶级理论和空间代替时间法,以成熟林碳储量作为森林生物量碳容量参照,应用森林生物量碳容量与当前(或某一年)森林碳储量的差值估算森林固碳潜力。结果表明,扎囊县森林植被碳储量为768751.91 t。灌木林是青藏高原的原生植被,碳储量占森林碳储量的84%,发挥着重要的固碳作用。扎囊县森林资源以发挥生态防护功能为主要目的,有利于森林自然生长积累碳储量,防护林面积和碳储量占森林面积和碳储量比例均高达99%。乔木林碳储量按起源以人工林为主,占91%;按树种以柳树和杨树为主,占90%;在龄组方面,中龄林、近熟林和成熟林碳储量较大,占88%。随着龄组增大,从幼龄林、中龄林、近熟林、成熟林到过熟林,碳密度依次增大,从1.17 t/hm2到55.67 t/hm2。乔木幼龄林、中龄林和近熟林在乔木林面积中占88%,但是碳密度远低于乔木成熟林的平均碳密度40.28 t/hm2。随着乔木林从幼龄林逐步成长为成熟林,碳储量将显著增大。乔木林固碳潜力为251782.90 t,是乔木林碳储量的2.21倍。宜林地、无立木林地、未成林造林地和苗圃地固碳潜力与面积大小正相关,固碳潜力为365947.81 t。相应的措施可以进一步提高森林碳汇:封山(沙)育林等措施促进灌木林资源发展,稳定并提高灌木林面积和覆盖度;全面提升森林经营管理水平,提高森林资源质量;继续推进重点林业工程建设,因地制宜开展人工造林和封山育林,提升森林资源培育水平,确保人工造林成效。

海淀田村地区第二类疫苗接种情况分析

目的分析海淀田村地区5种第二类疫苗接种情况。方法选取田村地区3618例3～4周岁儿童为研究对象,分析其第二类疫苗接种情况。结果本市儿童5种第二类疫苗接种率在22%～78%之间,平均接种率为60.6%,各种疫苗接种率间差异具有统计学意义;流动儿童5种第二类疫苗接种率在17%～53%之间,平均接种率为40.4%,各种疫苗接种率间差异具有统计学意义;本市儿童5种第二类疫苗接种率高于流动儿童5种第二类疫苗接种率。结论加大国家免疫规划投入,将更多的第二类疫苗种类纳入第一类疫苗管理,对流动儿童家长加强宣传,能提高第二类疫苗的接种率,降低相应传染病的发病率。

萨中开发区“二三结合”开发实验数值模拟

应用数值模拟方法，分析大庆油田萨中开发区二、三类油层（萨Ⅱ10～萨Ⅲ10）“二三结合”开发实验井网部署，实验层段组合优化方案，注聚开发合理衔接时机，二、三类油层最佳组合开发模式等．结果表明：二、三类油层各自部署一套新井网，协调布井，同步钻井选择性射孔、同步水驱挖潜，协调平面和纵向注采关系，同期注入不同相对分子质量的聚合物进行三次采油能有效地挖潜油藏剩余油，提高采收率．