Seasonal responses of monthly mean sea levels in the Bohai Sea to hydrometeorological forcing and their double screening regression models

-In this paper, the maximum entropy spectral, the cross-spectral and the frequency response analyses are madeon the basis of the data of monthly mean sea levels at coastal stations in the Bohai Sea during 1965-1986. The results show that the annual fluctuations of the monthly mean sea levels in the Bohai Sea are the results of the coupling response of seasonal variations of the marine hydrometeorological factors. Furthermore, the regression prediction equation is obtained by using the double screening stepwise regression analysis method . Through the prediction test , it is proved that the obtained results are desirable.

Mean platelet volume as a novel predictor of systematic inflammatory response in cirrhotic patients with culturenegative neutrocytic ascites

AIM: To identify a mean platelet volume(MPV) cutoff value which should be able to predict the presence of bacterial infection.METHODS: An observational, analytic, retrospective study. We evaluated medical records of cirrhotic patients who were hospitalized from January 2012 to January 2014 at the Gastroenterology Department of "Hospital General de México Dr. Eduardo Liceaga", we included 51 cirrhotic patients with ascites fluid infection(AFI), and 50 non-infected cirrhotic patients as control group. Receiver operator characteristic curves were used to identify the best cutoff value of several parameters from hematic cytometry, including MPV, to predict the presence of ascites fluid infection.RESULTS: Of the 51 cases with AFI, 48 patients(94.1%) had culture-negative neutrocytic ascites(CNNA), 2(3.9%) had bacterial ascites, and one(2%)had spontaneous bacterial peritonitis. Infected patients had greater count of leucocytes and polymorphonuclear cells, greater levels of MPV and cardiac frequency(P < 0.0001), and lower mean arterial pressure compared with non-infected patients(P = 0.009). Leucocytes, polymorphonuclear count, MPV and cardiac frequency resulted to be good or very good predictive variables of presence of AFI in cirrhotic patients(area under the receiving operating characteristic > 0.80). A cutoff MPV value of 8.3 fl was the best to discriminate between cirrhotic patients with AFI and those without infection. CONCLUSION: Our results support that MPV can be an useful predictor of systemic inflammatory response syndrome in cirrhotic patients with AFI, particularly CNNA.

Immunological responses of HIV/AIDS patients treated with Nevirapine versus Efavirenz based highly active anti-retroviral therapy in Addis Ababa, Ethiopia: A retrospective cohort study

Background: There are two approved non-nucleoside reverse transcriptase inhibitor antiretroviral drugs;namely Nevirapine (NVP) and Efavirenz (EFV). Nevirapine and EFV have comparable clinical efficacy when administered in combination regimens. But there is a lack of recent evidence showing the effect of NVP and EFV-based ARTs on immunological responses in HIV infected individuals in Ethiopia in general and Addis Ababa in particular. Methods: Retrospective cohort study design was used to compare immunological response rate of NVP and EFV based HAART regimen in Addis Ababa. Four hundred ninety two HIV infected patients who started HAART in ten selected health facilities were included in the study. Rate of immunologic response was examined at the 6th, 12th, 18th, and 24th months of follow-up period. The time required to get immunological response was analyzed by Kaplan-Meier survival curve. Adjusted hazard ratio was calculated with a 95% confidence interval by Cox proportional hazards model to determine the rate of immunological response. To ascertain the association, bivariate and multi variable Cox proportional hazard model was used. Statistical significance was considered with two sides P-value of 0.05. Results: The mean CD4 count ranged between 132.2 cell/μl at baseline and 302.3 cell/μl at the end of the follow-up period. This change was significant at 95% of CI but did not show significant differences among the comparison group. The median time to get immunological response was 18 (75% percental 12) months. At the end of the follow-up period, 73.2% (76.6% for NVP and 69.8% for EVF P-value 0.13) of the study population had immunological response. Conclusion: As a conclusion, there was a robust and sustained CD4 response and the effect of NVP and EFV based ART on change of mean CD4 count and immunological response was comparable and effective. Initiation of ART with high baseline CD4 count, in combination of IPT and with either NVP or EFV based NNTI was recommended.

Erroneous presentation of respiratory-hemodynamic disturbances and postsurgical inflammatory responses in patients having undergone abdominal cavity cancer surgery

In this letter to the editor,the authors discuss the findings and shortcomings of a published retrospective study,including 120 patients undergoing surgery for gastric or colon cancer under general anesthesia.The study focused on perioperative dynamic respiratory and hemodynamic disturbances and early postsurgical inflammatory responses.

Exponential Ratio Type Estimators of Population Mean under Non-Response

This paper proposes some exponential ratio type estimators of population mean under the situations when certain observations for some sampling units are missing. These missing observations may be for either auxiliary variable or study variable. The biases and mean square errors of the proposed estimators have been derived, up to the first order of approximation. The proposed estimators are compared theoretically with that of the existing ratio type estimators defined by [1]. It has been found that the proposed exponential ratio type estimators perform better than the mean per unit estimator even for the low positive correlation between study variable and auxiliary variable. Moreover, we obtained the conditions for which our proposed estimators are better than the corresponding ratio type estimators of [1]. To verify the theoretical results obtained, a simulation study is carried out finally.

Dynamic design of a nonlinear energy sink with NiTiNOL-steel wire ropes based on nonlinear output frequency response functions

A novel vibration isolation device called the nonlinear energy sink(NES)with NiTiNOL-steel wire ropes(NiTi-ST)is applied to a whole-spacecraft system.The NiTi-ST is used to describe the damping of the NES,which is coupled with the modified Bouc-Wen model of hysteresis.The NES with NiTi-ST vibration reduction principle uses the irreversibility of targeted energy transfer(TET)to concentrate the energy locally on the nonlinear oscillator,and then dissipates it through damping in the NES with NiTi-ST.The generalized vibration transmissibility,obtained by the root mean square treatment of the harmonic response of the nonlinear output frequency response functions(NOFRFs),is first used as the evaluation index to analyze the whole-spacecraft system in the future.An optimization analysis of the impact of system responses is performed using different parameters of NES with NiTi-ST based on the transmissibility of NOFRFs.Finally,the effects of vibration suppression by varying the parameters of NiTi-ST are analyzed from the perspective of energy absorption.The results indicate that NES with NiTi-ST can reduce excessive vibration of the whole-spacecraft system,without changing its natural frequency.Moreover,the NES with NiTi-ST can be directly used in practical engineering applications.

Stability evaluation of radial growth of Picea schrenkiana in different age groups in response to climate change in the eastern Tianshan Mountains

Global warming causes an unstable response in tree radial growth at high latitudes in the Northern Hemisphere.Additionally,different climatic responses of different age groups of trees have been found due to their different physiological mechanisms.In this study,the response stability and growth trend of three age groups(young<100 a,middle 100-200 a,old≥200 a)of Picea schrenkiana(Schrenk spruce)to climate change and the causes of the different responses in different age groups were analyzed in the relatively dry climate of the eastern Tianshan Mountains.The results showed that:(1)With the abrupt increase in temperature in 1989,the annual mean minimum temperature became the dominant radial growth-limiting factor of the three age groups of Schrenk spruce.(2)The radial growth of the middle and young groups was more sensitive than that of the old group based on growth-climate correlation analysis.(3)The radial growth of the different age groups had different responses to climate factors,and all age groups were unstable on time scales.(4)The trend of the linear regression simulation of the basal area increment(BAI)indicated that the Schrenk spruce had the same growth trends in different age groups with growth first increased and then decreased;however,the decreased growth rate was higher in the middle and young age groups than in the old age group after the abrupt increase in temperature.Therefore,we should pay active attention to the impact of drought on Schrenk spruce in the eastern Tianshan Mountains and should particularly strengthen the conservation and management of the middle and young age groups.

AN EQUIVALENT NONLINEARIZATION METHOD FOR ANALYSINGRESPONSE OF NONLINEAR SYSTEMS TO RANDOM EXCITATIONS

In this paper, a new equivalent nonlinearization method is developed and used in analysing the response of nonlinear systems to Gaussian while noise excitation. Its basic idea and calculation method are expounded. With the help of the presented method, several kinds of usual nonlinear random vibration systems are analyzed. The numerical results show that the mean square responses of the proposed approach are much closer to the exact solutions or Monte Carlo solutions, than that obtained from equivalent linearization method.

Seismic Response of Base-Isolated Structures underMulti-component Ground Motion Excitation

An analysis of a base-isolated structure for multi-component random ground motion is presented. The mean square respond of the system is Obtained under different parametric variations. The effectiveness of main parameters and the torsional component during an earthquake is quantified with the help of the response ratio and the root mean square response with and without base isolation. It is observed that the base isolation has considerable influence on the response and the effect of the torsional component is not ignored.

Stochastic HIV Infection Model with CTLs Immune Response Driven by Lévy Jumps

This paper mainly investigates the effect of the lévy jumps on the stochastic HIV infection model with cytotoxic T lymphocytes (CTLs) immune response. First, we prove that there is a unique global positive solution in any population dynamics, then we find sufficient conditions for the extinction of the disease. For proofing the persistence in mean, a special Lyapunov function be established, we obtain that if the infected CD4+ T-cells and virus particles will persistence in mean. Finally, numerical simulations are carried out to illustrate the theoretical results.

Governing for the Global Good the Greening of Diverse Responsibilities

This paper discusses methods for governing the global good. It holds that justice for both people and non-human creatures requires a change at the foundations of our view of life. What is needed is not only a few more government regulations or a little more international cooperation based on the unquestioned presupposition of the priority of national sovereignty and economic growth,but also a different perspective on our responsibilities for the wellbeing of the commons, recognizing that increasingly the environmental commons is global in scope and requires some transnational means of governance. It also holds that a"responsibilities"approach calls for the greening of all kinds of responsibility and not only those of national governments and international organizations.

基于k-means聚类的多谐波源责任划分方法研究

针对谐波发射水平动态变化情况下的多谐波源责任划分问题,提出了一种基于k-means聚类的多谐波源责任划分方法。首先,以谐波电流幅值作为提取特征划分数据集合,对所要计算谐波责任的谐波源谐波电流数据进行k-means聚类处理;然后,分别对每个数据集合进行相关性计算,得到各数据集合的谐波责任;最后,将各数据集合谐波责任加权求和,得到被观测时段内的谐波责任。经过实验表明,所提方法综合评估了被观测时间段内多谐波源的谐波责任,提高了谐波发射水平动态变化情况下多谐波源责任评估的有效性。

船用柴油机均值模型建模及仿真研究

柴油机模型的研究是探究柴油机性能、实现虚拟仿真的基础,可缩短仿真计算时间、有效节约柴油机开发成本。本文以RK270柴油机为研究对象,使用GT-POWER软件建立稳态性能仿真模型,在此基础上,采用仿真精度高、计算速度快的平均值法,以C++语言建立柴油机平均值模型,并归纳通用的平均值模型建模标定校核流程;提出二元响应拟合的方法,解决了涡轮增压器特性参数处理困难的问题,并借助数学工具,获得了压气机主要工作区域内拟合精度较高的模型。完成模型开发后,分析了8组工况下的仿真结果,通过误差分析,验证了模型的准确性,丰富完善了柴油机建模理论和方法,可应用于实时控制模型的动态仿真或者实现与船舶动力系统的交互。

平均听阈正常的听神经瘤患者临床及听力学特征分析

目的 分析平均听阈正常(PTA≤25 dB HL)的单侧听神经瘤患者的临床特征及听力学特征,为听神经瘤早期筛查及诊断提供参考。方法 选取平均听阈正常的单侧听神经瘤患者32例(32耳)作为试验组,选取与年龄、性别相匹配的平均听阈正常的耳鸣患者20例(32耳)作为对照组,试验组和对照组均在符合国家标准的隔声室行纯音测听、声导抗、听性脑干反应、畸变产物耳声发射检查,回顾性分析两组临床及听力学特征。结果 单纯耳鸣、耳鸣伴反复发作且可治愈的突发性听力下降为平均听阈正常听神经瘤患者常见的首发症状,占50.00%,多见于30~40岁人群。试验组听性脑干反应异常率为75.00%(24/32),畸变产物耳声反射异常率为78.12%(25/32),患耳的同侧镫骨肌声反射和健耳的交叉声反射异常率分别为28.13%、56.25%,健耳的同侧镫骨肌声反射和患耳的交叉声反射异常率分别为6.25%、62.50%。通过对比分析试验组和对照组听力学特征,两组听性脑干反应的波Ⅲ、波Ⅴ潜伏期、波Ⅰ-波Ⅲ波间期、波Ⅰ-波Ⅴ波间期,患耳的交叉声反射和健耳的交叉声反射(0.5、1、2、4 kHz)、患耳的同侧声反射(2 kHz),均存在统计学差异(P<0.05),两组间畸变产物耳声反射异常率未见统计学差异(P>0.05)。结论 听性脑干反应及镫骨肌声反射检测有助于听神经瘤早期诊断,DPOAE是敏感性高但特异性差的检测指标。对门诊平均听阈正常的单侧耳鸣,或伴有反复发作的、可治愈的突发性听力下降患者,建议联合应用听性脑干反应、镫骨肌声反射、畸变产物耳声发射综合评估,为听神经瘤的早期诊断提供依据。

基于CFD方法的FPSO的波浪荷载和运动响应研究

针对浮式生产储油船(Floating production storage and offloading, FPSO)在深水作业时面临的恶劣海况问题,为保证其服役期间的安全性及作业效率,需要准确计算非线性波浪荷载和运动响应。本文应用基于计算流体动力学(Computational fluid dynamics, CFD)的软件STAR-CCM+建立了针对实尺度FPSO模型的数值水池,基于Richardson外推法,针对时间步长和网格尺寸,分析了二者的收敛性和数值不确定度。使用该数值水池模拟了不同波浪工况作用下FPSO的运动响应,计算其受到的二阶波浪力,并与势流结果进行对比。结果发现,随着波陡增大,平均波浪力的CFD结果逐渐大于势流结果,且呈现差异化增大。而波陡大于1/15时,纵摇的CFD结果明显大于势流结果。说明大波陡条件下,黏性效应对平均波浪力和纵摇影响明显,为恶劣海况下预报及修正FPSO的二阶波浪力和运动提供了参考。

考虑路网和用户满意度的集群电动汽车主从博弈优化调度策略

传统的电动汽车(electric vehicle,EV)集中优化方法在实际应用中面临调度困难、计算量大、缺乏真实数据支撑等问题,无法准确揭示各主体间的交互行为。为此,提出一种考虑路网和用户满意度的集群EV主从博弈优化调度策略。首先基于真实出行数据和路网数据模拟用户出行行为。其次,负荷聚合商(load aggregator,LA)整合EV负荷资源,对相似出行特性的EV进行聚类。在双层主从博弈模型中,LA作为上层领导者,聚类后的各EV子群作为下层跟随者。考虑EV用户不同消费偏好,通过优化LA定价策略、新能源及储能系统出力计划、EV集群充放电策略实现纳什均衡,达到各主体共赢,并使用改进遗传算法进行求解。最后,利用仿真验证了所提模型可有效提升LA收益及EV用户消费者剩余,增加新能源消纳,并可为不同消费偏好的用户提供差异化服务。

对数律和指数律风剖面的差异分析及其对桥梁抗风性能评价的影响

现有的公路桥梁抗风设计采用指数律风速剖面来计算各个基准高度的平均风速,然而气象学实践和一些国家规范中早已采用对数律风速剖面,两种风速剖面在不同高度处的平均风速差异及其对桥梁抗风的影响应当值得关注。对比了不同地表粗糙类型下对数律模型和指数律模型在不同高度处的风速差异,并采用ANSYS有限元软件计算了实桥在风荷载下的位移和桥塔弯矩差异。结果表明,在地表粗糙度较大和离地高度较大时,对数律和指数律模型的风速差异较为明显,风荷载的差异对桥梁内力和位移造成的影响不可忽略。有必要进一步研究这两种风速剖面模型在高空处的准确性,以更好地指导桥梁的抗风设计。

我国最低刑事责任年龄规定的关键问题

已满12周岁不满14周岁的未成年人犯故意杀人、故意伤害罪,既包括犯故意杀人罪、故意伤害罪,也包括犯其他罪时实施的故意杀人行为、故意伤害行为。“特别残忍手段”是指常规手段之外的,能够额外增加被害人精神或身体上的痛苦,明显违背人伦道德与善良风俗使社会一般公众难以忍受的伤害行为。作为已满12周岁不满14周岁的未成年人承担刑事责任的条件之一,“情节恶劣”在性质上属于立法拟制的客观处罚条件,可以是事中情节,也可以是事前或事后的情节,但不包括过往违反学校纪律或法律法规的偏差行为或造成的社会影响等。根据责任事由或者综合评价各类量刑情节,可以对已满12周岁不满14周岁的未成年人适用较轻的法定刑幅度。对已满12周岁不满14周岁的未成年人的量刑,应当着重分析各低龄未成年人在共同犯罪中的分工以及所起的作用,结合各自的主观恶性与人身危险性,做到区别对待以实现量刑个别化。

改进麻雀搜索算法求解带削峰需求响应的混合流水车间调度问题

电力需求响应是用电高峰时期维护电网供需平衡的重要手段,而削峰是智能电网实现电力需求响应的主要方式。为了使采用混合流水车间生产的企业更好地参与削峰需求响应,优化生产调度,在混合流水车间调度问题中引入了削峰需求响应,建立了新的问题模型,并提出了一种改进麻雀搜索算法用于模型求解。针对标准麻雀搜索算法易陷入局部最优的问题,所提算法通过加入K-均值聚类替换策略改进了标准麻雀搜索算法的局部搜索能力。实验结果表明,所提模型和算法能够提供较好的削峰生产调度方案,满足企业实施削峰需求响应调度的需要。

春夏季热带东印度洋海温的季节内振荡及大气响应

基于1982—2020年OISSTv2.1数据集、NOAA Interpolated OLR数据集和NCEP/DOE II再分析数据资料,通过功率谱分析、位相合成法等方法研究了春夏季(3—8月)热带东印度洋海温季节内振荡的特征及大气的响应。结果发现春夏季热带东印度洋海温季节内振荡的显著周期主要集中在20~50天,强海温振荡事件主要分布在4—7月,关键区内对流抑制超前暖海温异常1/8周期,滞后冷海温异常3/8周期,反之亦然。春夏季海温异常激发的对流异常呈经向偶极子分布,且有明显的北移演变特征,但北侧的对流中心较南侧弱,即对流在北移过程中迅速衰减。使用K-means聚类法提取了两种具有显著差异的环流响应类型:北移型和局地型。北移型主要分布在夏季,表现为更有组织性的对流偶极子对,南北中心的强度和影响范围相当且北移特征更为清晰。在对流偶极子北移的过程中显著影响阿拉伯海上西南季风的强弱,对印度半岛夏季风季节内变化的影响较大。局地型主要分布在春夏转换季节,对流异常呈单一中心结构,移动性较弱,主要在热带东印度洋上空发展和消亡。热带东印度洋海温季节内振荡耦合的大气环流异常主要影响赤道印度洋地区,对热带外的影响较弱。进一步探究发现,背景东风切变的差异是导致两种对流响应差异的原因。夏季,北印度洋东风切变强,垂直风切变机制导致对流明显北移,春夏转换季节,东风切变弱,垂直风切变机制不成立,较弱的正压涡度平流机制引起对流微弱的北移,但主要在局地生消。