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.

EXISTENCE OF PERIODIC SOLUTIONS FOR A DIFFERENTIAL INCLUSION SYSTEMS INVOLVING THE p(t)-LAPLACIAN

We study a nonlinear periodic problem driven by the p（t）-Laplacian and having a nonsmooth potential （hemivariational inequalities）. Using a variational method based on nonsmooth critical point theory for locally Lipschitz functions, we first prove the existence of at least two nontrivial solutions under the generalized subquadratic and then establish the existence of at least one nontrivial solution under the generalized superquadratic.

Development of Rainfall Intensity Duration Frequency Curves for Mumbai City, India

The change in rainfall pattern and intensity is becoming a great concern for hydrologic engineers and planners. Many parts of the world are experiencing extreme rainfall events such as experienced on 26th July 2005 in Mumbai, India. For the appropriate design and planning of urban drainage system in an area, Intensity Duration Frequency (IDF) curves for given rainfall conditions are required. The aim of the present study is to derive the IDF curves for the rainfall in the Mumbai city, Maharashtra, India. Observed rainfall data from 1901 pertaining to Colaba and from 1951 of the Santacruz rain gauge stations in Mumbai are used in the present study to derive the IDF curves. Initially, the proposed IDF curves are derived using an empirical equation (Kothyari and Garde), by using probability distribution for annual maximum rainfall and then IDF curves are derived by modifying the equation. IDF curves developed by the modified equation gives good results in the changing hydrologic conditions and are compatible even with the extreme rainfall of 26th July 2005 in Mumbai.

REDUCING PERIODIC NOISE USING SOFT MORPHOLOGY FILTER

A novel spatial domain method--soft morphology filter is presented for reducing the periodic noise in image processing. The simulation results are presented to demonstrate the effectiveness of the method in comparison with a frequency domain method and other spatial domain filters.

Impact of Educational Materials on the Duration of Exclusive Breastfeeding Assured by Women Who Delivered at the Souissi Maternity Hospital in Rabat

Background: The practice of exclusive breastfeeding (EB) in Morocco has witnessed a worrying decline in recent decades, contrary to the recommendations of the World Health Organization (WHO) which advocates it during the first six months as a significant public health tool. The present study aims to assess the impact of educational materials on mothers’ behaviour with regard to keeping up EB as long as six months, at least. Methods: This is a cohort study with a prospective collection of data over a period of one year, through a questionnaire-based survey of 500 women who delivered at the Souissi Maternity Hospital in Rabat. The subjects were divided into an intervention group sensitized, during the medical visit, by means of information delivered orally about breastfeeding and a booklet containing instructions on breastfeeding management and the benefits of EB, especially when extended for the first six months;and a control group attending the same operation with no awareness-rising through educational materials. To assess EB rates, the subjects had been followed for six months through telephone. Results: 372 women who delivered were followed, 194 from the intervention group and 178 from the control group. The remaining 128 women not followed were lost sight of. A higher percentage of mothers in the intervention group exclusively breastfed their babies up to the age of six months compared to the control group, 55.2% against 38.8% (p = 0.002). The main reason produced by most mothers who ceased to exclusively breastfeed their babies is milk insufficiency. Conclusion: The postnatal nutritional education strategy based on the distribution of educational materials has considerably raised the number of women who exclusively breastfed their babies until the age of six months.

COVID-19 patient with an incubation period of 27 d:A case report

BACKGROUND As a highly contagious disease,coronavirus disease 2019(COVID-19)is wreaking havoc around the world due to continuous spread among close contacts mainly via droplets,aerosols,contaminated hands or surfaces.Therefore,centralized isolation of close contacts and suspected patients is an important measure to prevent the transmission of COVID-19.At present,the quarantine duration in most countries is 14 d due to the fact that the incubation period of severe acute respiratory syndrome coronavirus type 2(SARS-CoV-2)is usually identified as 1-14 d with median estimate of 4-7.5 d.Since COVID-19 patients in the incubation period are also contagious,cases with an incubation period of more than 14 d need to be evaluated.CASE SUMMARY A 70-year-old male patient was admitted to the Department of Respiratory Medicine of The First Affiliated Hospital of Harbin Medical University on April 5 due to a cough with sputum and shortness of breath.On April 10,the patient was transferred to the Fever Clinic for further treatment due to close contact to one confirmed COVID-19 patient in the same room.During the period from April 10 to May 6,nucleic acid and antibodies to SARS-CoV-2 were tested 7 and 4 times,respectively,all of which were negative.On May 7,the patient developed fever with a maximum temperature of 39℃,and his respiratory difficulties had deteriorated.The results of nucleic acid and antibody detection of SARS-CoV-2 were positive.On May 8,the nucleic acid and antibody detection of SARS-CoV-2 by Heilongjiang Provincial Center for Disease Control were also positive,and the patient was diagnosed with COVID-19 and reported to the Chinese Center for Disease Control and Prevention.CONCLUSION This case highlights the importance of the SARS-CoV-2 incubation period.Further epidemiological investigations and clinical observations are urgently needed to identify the optimal incubation period of SARS-CoV-2 and formulate rational and evidence-based quarantine policies for COVID-19 accordingly.

Multifactor dimensionality reduction analysis of syndrome characteristics of chronic persistent asthma

Objective:To analyze the syndrome characteristics in patients with chronic persistent asthma.Methods:365 patients(121 males,244 females,60.829.1 years old)with chronic persistent asthma were enrolled in this cross-sectional study.The information of syndrome,symptoms,signs,tongue coating and pulse were collected from all patients.The syndrome characteristics of chronic persistent asthma were examined through the multifactor dimensionality reduction(MDR)analysis and the results were verified by the Chi-square test.Results:The results of the MDR analysis and the Chi-square test showed the following positive correlation of the interaction among:the deficiency syndrome of the lung and spleen and deep pulse,disinclination to talk due to lack of qi,fatigue,lassitude and thick tongue coating;the deficiency syndrome of the lung and kidney and dizziness and disinclination to talk due to lack of qi,fatigue,lassitude and pallid complexion;the syndrome of phlegm-heat obstructing the lung and rapid pulse,abdominal distension,disinclination to talk due to lack of qi,frequent urination and lassitude;the syndrome of phlegm-dampness obstructing the lung and disinclination to talk due to lack of qi,greasy coating,fatigue and lassitude.(P<.05 for all).Conclusion:The syndrome of chronic persistent asthma is characterized by fatigue and lassitude due to dysfunction of the lung,spleen and kidney.

Study on Nursing Effects of Liposuction and Volume Reduction Surgery for Lymphedema Perioperative Nursing Care

Objective:To study the nursing effect of liposuction and volume reduction in the treatment of lymphedema during the perioperative period.Method:A total of 68 patients treated with liposuction volume reduction surgery for pseudo-lymphedema of lower limbs admitted from May 2019 to May 2020 in a tertiary hospital in Xi’an,Shaanxi Province were selected,and they were divided into observation group and control group by random grouping method.There were 34 cases in each group.The control group took routine care during the perioperative period,while the observation group performed full care during the perioperative period.The complication rate and pain degree of the two groups were compared.Results:The complication rate of the study group was 5.88%,while that of the control group was 26.67%.Compared with the study group,the complication rate was significantly higher than that of the control group,and the gap was statistically significant(P>0.05).The pain scores of patients in the study group were significantly lower than those in the control group at 3 and 6 days after surgery,and the gap was statistically significant(P>0.05).Conclusion:Lymphedema should be taken care of during the perioperative period of liposuction and volume reduction,which can effectively reduce the occurrence of pain and complications.It is worthy of extensive clinical promotion.

早期应用贝利尤单抗治疗系统性红斑狼疮患者的效果及对激素减量的影响分析

目的观察早期应用(诱导缓解期3个月内)贝利尤单抗治疗系统性红斑狼疮(SLE)的效果及对激素减量的影响。方法选取83例使用贝利尤单抗治疗的SLE患者,两组均使用甲泼尼龙及吗替麦考酚酯作为背景用药。根据患者诱导缓解期开始使用贝利尤单抗的时间分为早期组(35例)和对照组(48例)。早期组在诱导缓解期≤3个月时开始使用贝利尤单抗治疗,对照组在诱导缓解期>3个月时开始使用贝利尤单抗治疗。比较两组血常规指标[白细胞计数(WBC)、中性粒细胞计数(Neut)、淋巴细胞计数(Lym)、血小板计数(PLT)、血红蛋白(Hb)]、肝肾功能指标[白蛋白(ALB)、血肌酐(SCr)]和血沉(ESR)水平、免疫功能指标[免疫球蛋白G(IgG)、免疫球蛋白A(IgA)、免疫球蛋白M(IgM)、球蛋白、补体C3、补体C4]、激素减量值和系统性红斑狼疮疾病活动指数(SLEDAI-2000评分)及主要器官损害情况。结果早期组治疗24周时的Neut水平(4.39±1.59)×10^(9)/L明显低于对照组的(6.56±3.09)×10^(9)/L,治疗12周时的Lym水平(1.73±0.49)×10^(9)/L、Hb水平(122.85±15.38)g/L和治疗24周时的Lym水平(1.59±0.49)×10^(9)/L、Hb水平(123.20±16.70)g/L明显高于对照组的(1.48±0.42)×10^(9)/L、(105.89±16.91)g/L和(1.38±0.34)×10^(9)/L、(103.42±25.63)g/L,有统计学差异(P<0.05)。早期组治疗24周时的ALB水平(41.20±3.07)g/L明显高于对照组的(38.50±6.06)g/L,治疗12周时的SCr水平(55.46±16.40)μmol/L和治疗24周时的SCr水平(54.79±16.15)μmol/L明显低于对照组的(74.46±24.21)、(69.34±20.95)μmol/L,治疗12周时的ESR水平(24.44±10.63)mm/h明显低于对照组的(32.37±11.21)mm/h,有统计学差异(P<0.05)。早期组治疗12和24周时的IgG和IgA水平明显低于对照组,治疗12周时的球蛋白水平明显低于对照组,治疗12和24周时的C3水平明显高于对照组,有统计学差异(P<0.05)。治疗12和24周时,早期组的激素减量值(60.49±27.42)、(68.23±22.12)mg明显高于对照组的(21.00±6.96)、(28.37±7.60)mg,SLEDAI-2000评分(3.77±1.06)、(2.74±0.44)分明显低于对照组的(4.79±1.46)、(2.96±0.40)分,有统计学差异(P<0.05)。两组各种主要器官损害发生率对比,无统计学差异(P>0.05)。结论早期应用贝利尤单抗治疗SLE患者可改善贫血情况、肝肾功能、ESR水平及免疫功能,有利于更快降低激素用量,且不会增加主要器官损害发生风险。

轴向流作用下均布非线性弹簧支承二维壁板的复杂响应

考虑刚性导流段和尾流段对流场的影响,建立轴向流作用下二维板的非线性流固耦合运动控制方程,用有限差分法对控制方程进行离散。为了克服差分网格较多时带来的计算规模较大的问题,对控制方程用主模态缩减法缩减自由度,然后对离散方程进行数值积分,得到系统的复杂响应,分析其分岔和混沌特性。计算结果表明,以来流流速幅值和阻尼参数为可变参数时,系统具有极其复杂的动态响应,通过分岔图、相图和庞加莱截面图等方法判断了系统多种形式的周期、拟周期和混沌运动,在以来流流速幅值为可变参数时,系统一开始经由周期倍化分岔的方式进入混沌;在以阻尼系数为可变参数时,经由倒周期倍化分岔的方式从混沌运动退回到周期振动。

正念减压疗法在大隐静脉曲张伴睡眠障碍患者围术期中的应用效果

目的探究正念减压疗法在大隐静脉曲张伴睡眠障碍患者围术期中的应用效果。方法选取2020年1月—2022年6月收治的90例大隐静脉曲张伴睡眠障碍,采用随机数字表法随机将其分为试验组和对照组2组各45例。试验组围术期在常规治疗基础上给予正念减压疗法,对照组围术期给予常规治疗。比较2组入院当天和出院当天应对方式(采用简易应对方式问卷评估)、心理状态[采用焦虑自评量表(SAS)及抑郁自评量表(SDS)评估]和睡眠质量[采用匹兹堡睡眠质量指数量表(PSQI)评估],以及出院当天住院满意度。结果出院当天,2组积极应对评分、消极应对评分、SAS评分、SDS评分和PSQI评分均优于入院当天;试验组积极应对评分、消极应对评分、SAS评分、SDS评分、PSQI评分和住院满意度均优于对照组(P<0.05)。结论围术期实施正念减压疗法有助于改善大隐静脉曲张伴睡眠障碍患者应对方式、心理状态、睡眠质量,且患者住院满意度较高。

全产业链贯通布局下钒液流电池长时储能发展思考

清洁能源的发展和“双碳”目标的实施推动了能源结构调整和电网系统升级,这必将催生巨大的万亿长时储能需求,麦肯锡预测2030年全球可再生能源占比将升至60%~70%,长时储能比2025年增加5~10倍(预计2025年30~40 GW)。全钒液流电池相比其他电化学储能具有安全长寿、灵活可靠、资源丰富等优点,2018~2023年国家和地方发布了多项清洁能源储能配置标准的政策性文件,在此背景下钒储能电池行业企业持续高速增长,行业集中度提升,宏观领域表现为我国钒储能产业正处在加速发展期。目前,钒储能电池总体成本较高,主要原因是钒原料价格高,降低成本的核心环节是钒资源提取成本和电解液生产制造成本。中国恩菲研发的短流程制备钒电解液技术相对于传统钒电解液制备技术具有流程短、钒利用率高的特点,制造成本降低了30%~50%,后期随着钒资源开发和新工艺的研发成功,钒储能产业降本优势将愈发突出。在国家政策支持下,钒液流电池储能系统有望在短期内实现规模化、商业化应用,成为储能领域的重要选择。未来,钒液流电池储能系统仍需从多方面进行优化,如重视技术创新和研发、健全回收利用体系等,以实现钒液流电池长时储能产业的可持续发展。

应用主被动节能技术改造严寒地区玻璃温室

玻璃温室由于墙体热损失大,造成能耗高,为降低温室能耗。以严寒地区Venlo型玻璃温室为研究对象,提出主动光伏发电和被动围护结构节能改造两种方法来降低温室的能耗。采用能耗、碳减排量和回收期对方案进行比较,通过综合对比选出最优方案。结果表明采用三层玻璃夹气层为9mm氪气的Venlo型光伏温室(CgⅢ)为最优节能改造方案。方案改造下的温室每年可节约130MWh能耗,有助于玻璃温室在严寒地区的推广。

降雨雨型对城市雨水系统内涝弹性的影响

为探究降雨雨型对城市雨水系统内涝弹性的影响,基于MIKE FLOOD平台,以济南市新旧动能转换起步区大桥分区为研究对象,对7种重现期、3种降雨历时和3种雨峰系数的设计降雨雨型进行内涝过程场景推演,并结合层次分析法,以积水量、积水面积和平均积水深度为基础量化系统内涝弹性。结果表明:积水量峰值、积水面积峰值均随重现期、降雨历时的增大而增大,平均积水深度波动较大;系统性能前后主要发生两次波动,分别由降雨强度变化和研究区大部分洼地深度较浅导致;随着重现期的增加,系统内涝弹性越小,单位雨峰系数引起的系统内涝弹性极值对应的降雨量差异越来越大,整体上,降雨雨峰越居中和降雨历时越大,系统内涝弹性越小。

考虑周期折减的结构弹性时程分析调整方法

针对结构弹性时程分析时无法考虑周期折减的问题展开研究,通过对比结构时程分析的过程中,地震波的选取是否考虑周期折减的差异,提出采用增大系数放大时程分析法输入地震波有效峰值加速度以及地震响应;考虑弹性时程分析过程中,周期折减对结构地震作用的增大效应。理论分析增大系数取值的影响因素,并基于单自由度体系对比两种调整方法的效果及差异,采用实际算例以验证所提出弹性时程分析中考虑周期折减调整方法的有效性。结果表明:增大系数的取值与周期折减系数、结构自振周期及场地特征周期等因素有关;对于单自由度体系,两种调整方法具有完全相同的调整效果;按文章提出方法考虑周期折减的算例结构,弹性时程分析所得各楼层地震剪力及层间位移角与考虑周期折减的反应谱(CQC)计算结果均较为接近。

昆明不同历时降水极值变化特征及其重现期研究

利用昆明气候基准站1958~2022年不同历时年最大降水资料,结合短历时降水指标分析、趋势分析、小波分析和极值分析等方法,揭示了昆明不同历时年最大降水的基本演变特征,并完成了不同历时降水极值的分布拟合和重现期成果推算,结果表明:(1)昆明地区不同历时年最大降水的各项降水指标值小于郑州、北京、浙江等地区,这来自不同地区的气候禀赋差异。(2)昆明地区不同历时年最大降水具有明显的年际变化特征,总体较弱增强趋势。除了历时120 min和180 min的年最大降水显示出显著的11~14年周期性变化外,其他时段降水的周期性变化不甚明显。(3)在统计检验指标和实测关键数据点的检验中,显示耿贝尔分布适用于昆明,可用于不同历时任意重现期的降水强度推算。以上研究成果可为昆明区域强降水认识、预测预警气象服务和城市防灾减灾等提供依据和参考,并为其他地区相关工作提供借鉴。

一维周期基础的带隙解析解及其优化设计研究

周期结构的带隙特征为土木工程隔震领域提供了新思路,其中一维周期基础结构因其构造简单且经济适用而倍受关注。本文通过研究一维周期基础结构的振动特性,推导了用于计算一维橡胶-混凝土周期基础带隙的近似解析解,并在此基础上提出了基于上部结构共振区的一维橡胶-混凝土周期基础优化设计方法。频域和时域数值算例表明,由该优化方法所设计的周期基础可保证其上部结构在一个宽且连续的频段内均有较好的减震效果。

周期性堆载体Rayleigh波减振特性分析及试验研究

为了揭示周期性堆载体Rayleigh波的振动作用波特性,实现对低频表面波的有效衰减,研究了衰减域内的减振机理及效果。首先,构建传输模型,确定了合适的堆载几何尺寸。其次,基于复频散曲线和频域曲线,分析了堆载高度和弹性模量影响下振动波的作用规律及其衰减效果。最后,开展缩尺扫频试验,调取X、Z方向的加速度数据绘制频域曲线,并与复频散曲线做进一步对比分析,研究了各衰减域减振机理。结果表明:扫频试验结果出现了X、Z方向衰减域不一致的现象,不同方向的衰减域恰好与复频散曲线中的衰减域内作用波型一致,X方向会出现一个低频段衰减域,Z方向会在第2衰减域终止频率时出现衰减减弱趋势;进一步说明周期性堆载体可以激发出水平极化共振衰减域和Bragg散射衰减域;而高度是影响伪表面波的重要因素,表现为高度高,容易在第1衰减域内产生伪表面波,高度低,容易在第2衰减域内产生伪表面波;弹性模量是影响高速伪表面波的重要因素,表现为当其达到混凝土弹性模量单位数量级(10 GPa)时,第3衰减域可能会出现高速伪表面波作用范围,否则,将直接进入SV波和P波耦合作用的凋落波模态。研究结果将进一步启发环境隔振领域利用表面波阻块开展减振工作。

基于热减量法2/1樟发射药安全贮存寿命预估

目的 预估2/1樟发射药的安全贮存寿命,建立一种基于加速热减量试验,利用热减量曲线和贝瑟洛特(Berthelot)方程预估其安全贮存寿命的方法。方法 首先对2/1樟发射药分别进行85、95、105、115℃下的加速热减量试验,获得样品在各个温度下不同加速时间的热减量数据。然后基于热减量曲线,得到2/1樟发射药在各个温度下的延滞期。最后利用各个温度下的半延滞期,根据Berthelot方程拟合得到2/1樟发射药安全贮存寿命预估模型。结果 根据其安全贮存寿命预估模型计算得到2/1樟发射药在30℃下的安全贮存寿命约为50.9 a。结论 预测结果与文献值接近,且试验时间比文献减少了近1/2,验证了该方法的有效性,可为2/1樟发射药或其他发射药的安全贮存寿命预估提供一种可行的技术途径。

江西信江八字嘴航电枢纽节能降碳综合管理平台概念设计与碳资产开发探讨

航电枢纽工程既是交通基础设施,又是绿色发电基础设施,可有效支撑地方节能减排工作。然而目前针对航电枢纽建设节能降碳综合管理平台、进行碳资产开发的研究相对较少。江西信江八字嘴航电枢纽工程(以下简称工程)是交通运输部绿色智慧科技示范工程,本文聚焦工程运营期,在科学界定航电枢纽运营期节能降碳综合管理平台系统边界的基础上,提出了综合管理平台总体框架和建设时序安排。最后,针对航电枢纽开发中国核证自愿减排量的工作进行了探讨。