短波激励下高速铁路桥上列车走行性研究

本文用车桥耦合动力学的理论 ,分析了短波不平顺激励下列车走行时的动力响应结果 ,并以列车的安全性和旅客的舒适性为管理标准 ,提出了轨道不平顺的安全限值。

关于项目可行性研究之探讨

就项目可行性研究现状及存在问题进行分析 。

基于公路工程选线可行性分析的探讨

公路作为至关重要且必不可少的基础设施,在人们工作生活和社会经济发展等诸多方面,都发挥着不可替代的重要作用,因此公路工程也被各个地区视为重点建设项目。但是在可用建设用地急剧缩减的形势下,交通规划也面对着一些前所未有的新挑战,做好公路工程可行性分析的重要性随之愈加突出。基于此本文首先简要梳理总结公路工程选线可行性分析基本原则与工程可行性分析影响因素,继而深入研究探讨某项公路工程可行性分析的实际案例。

Feasibility Research on Fatigue Damage Evaluation Based on Magnetic Memory Method

To confirm whether Magnetic Memory Method can be used to evaluate the fatigue damage of ferromagnetic part or not,this paper stated the principle of magnetic memory method.Also, the relationship between testing parameter of magnetic memory method and fatigue damage was analyzed based on the experiment. The results show that magnetic memory method can be used to evaluate the fatigue damage represented by stress concentration. However, the relationship between the parameter of magnetic memory method and fatigue damage still needs to be studied.

An exploration of the breastfeeding behaviors of women aftercesarean section: A qualitative study

Objectives:To explore the factors affecting breastfeeding behaviors in women after cesarean section.Methods:This is a qualitative study that used a phenomenological approach.This study used individual face-to-face interviews with 19 women who underwent a cesarean section in a Women and Children’s Hospital in China between July to September 2019.Information saturationwas used to determine sample size.Data were analyzed using a thematic content analysis method.Themes were developed based on the theory of planned behavior.Results:Thirteen(68.42%)had a planned cesarean section,and six(31.58%)cesarean sections were unplanned or emergent.Three major themes emerged:ambivalent attitude about breastfeeding,motivation to comply with the traditional cultural norms,and barriers and challenges.The motivating factors for breastfeeding after cesarean sections included perceived benefits of human milk,support from healthcare professionals,and responsibility for breastfeeding.The challenges for breastfeeding after cesarean sections included physical discomfort,knowledge and skills deficit of breastfeeding,lactation deficiency,and lack of knowledge and coping skills in managing their depressive mood after cesarean sections.There were a couple of neutral factors,such as the influences of family and peers.These factors could influence women either positively as facilitators or negatively as barriers.Conclusions:The findings can offer valuable information for healthcare professionals to help women breastfeed after cesarean sections.To promote women’s breastfeeding behaviors after cesarean sections,it is necessary to change women’s attitudes,belief systems,and the external environments and help them become more confident.

Preliminary Feasibility Study on Application of Very Large Scale-Photovoltaic Power Generation in China

Some energy experts believe that solar energy photovoltaic power generation is hopeful to be applied in a large amount and possesses a certain proportion in the structure of energy in the future. In this paper, based on the forecasting of electric load demand and energy structure of power generation in the middle of 21 century, the pictures of VLS-PV power genera- tion is composed, the operation characteristic of VLS-PV power generation and the adaptability of electric power grid for it is analyzed, the ways for transmitting large amount of PV power and the economic and technical bottlenecks for applying VLS-PV power generation are discussed. Finally, the steps and suggestions for developing VLS-PV power generation and its electric power system in China are proposed.

A DSS DEVELOPMENT AND APPLICATION FOR SUSTAINABLE DEVELOPMENT

The characteristics of sustainable development problems in the developing countries is discussed.In order to develop and use decision support system (DSS) for supporting sustainable development problem decision making in the developing countries,this paper presents a strategy of constructing the DSS for sustainable development.A methodology of representing the model of sustainable development problems and developing a nonprocedural modeling language that is used to define sustainable development problems,a methodology of numeric and non numeric operation based theorem proving is given in this paper.

Study on Adoption of 750 kV Voltage Class in Northwest China Power Network

This paper introduces the selection and scheme demonstration of higher voltage class in Northwest ChinaPower Network, and conclusions made by main research institutes and experts’ comments.[

The social determinants of health influencing obesity for the aged in the Pakpoon community context:A qualitative study

Objective:This study aimed to describe the social determinants of health influencing obesity for the aged in a community context and based on the perspectives of various stakeholders.Methods:This was qualitative content analysis study using data from the focus group,individual in-depth interview,and observation.The study population was domiciled in Pakpoon Village,Mung Dis-trict,Nakhon Si Thammarat Province,a tight-knit settlement typical of most retirement communities.Data were collected through two focus group discussions,direct observation,and in-depth interviews with 19 participants.Respondents represented key community groups:local nurses and public health officers,elderly residents,family caregivers(family members),and village health volunteers.Results:The participants shared similar perspectives about the social determinants of health influencing obesity in the aged,which spanned three themes.These were:1)neighborhood food environment(easy access to unhealthy food,no choice to recruit healthy food);2)social networks influencing obesity(family affects food choices and prohibitions on exercise;belief,and socially imposed body image per-ceptions contributing to obesity in the aged);and 3)knowledge,attitudes,and beliefs behind lifestyle choices that cause obesity in the elderly(lack of awareness,personal attitudes,job and familial duties as barriers to engaging in physical activities;over-consumption behaviors lead to obesity in older people).Conclusion:These three themes were the root causes of obesity in the elderly in Pakpoon’s retirement community.This finding suggests that policymakers and nurses can create healthy environments,both to treat and prevent obesity,by raising awareness in younger generations,providing aging the provision of healthy food choices for older adults,encouraging health care professionals to share knowledge,and by modifying the attitudes and beliefs of both caregivers and older adults.

Review:Recent advances in nonlinear control technologies for shape memory alloy actuators

This paper reviews recent developments in nonlinear control technologies for shape memory alloy (SMA) actuators in robotics and their related applications. SMA possesses large hysteresis, low bandwidth, slow response, and non-linear behavior, which make them difficult to control. The fast response of the SMA actuator mostly depends upon, (1) type of controller, (2) rate of addition and removal of heat, and (3) shape or form of the actuator. Though linear controllers are more desirable than nonlinear ones, the review of literature shows that the results obtained using nonlinear controllers were far better than the former one. Therefore, more emphasis is made on the nonlinear control technologies taking into account the intelligent controllers. Various forms of SMA actuator along with different heating and cooling methods are presented in this review, followed by the nonlinear control methods and the control problems encountered by the researchers.

Understanding the pregnant women’s experiences during the COVID-19 pandemic:A qualitative study

Objective To explore and interpret the experiences of pregnant women in Macao region,China during the COVID-19 pandemic.Methods Recruitment advertisements were published through multiple social platforms in Macao region,China.A purposive snowball sampling method was adopted to select interviewees.Eighteen women who were confirmed as pregnant from January to May 2020 participated in this qualitative study.Data was collected from November to December 2020 using in-depth personal interviews.One-to-one interviews were conducted by telephone to avoid personal contact.Thematic analysis was used to perform the data analysis and identify emergent themes.Results Five themes emerged from the data analysis:changes in daily life,psychological distress,unique experiences of pregnancy follow-up,trying to pay attention to health information but also feeling overwhelmed,and change in hygiene behaviors due to fear of infection.Six sub-themes were identified:being confined at home but understanding the reasons,financial pressures and timely support from the government,perceived risk of catching the infection,retaining optimism with various help and support,adequate personal protections,and obsessive hygiene behaviors.Conclusion During a pandemic,there is a risk of greater individual isolation,particularly for vulnerable groups such as women in pregnancy.The humanized attention to and support for the residents from the government buffered the adverse impact on the study participants.Preplanning for such events is needed to focus on psychological distress,financial constraints,and prenatal health services.Alternative service delivery,such as telemedicine,online counseling,and virtual reality(VR)technology,should be applied to offer pregnant women timely support and avoid a crisis.

Study on the pyrolysis behavior of Shendong Shangwan coal and its macerals concentrate

The pyrolysis characteristics of Shendong Shangwan coal and its macerals concentrate were investigated using thermogravimetry （TG） coupled with mass spectrometry （MS）. The evolved gases were analyzed online by MS spectroscopy. The results of TG/DTG （derivative thermogravimetry） show ths vitrinite concentrate has greater weight loss rate and higher volatile yield than the other two samples. More light hydrocarbons C1-C5 are released from the vitfinite concentrate than from the Shendong Shangwan coal and inertinite concentrated in the process of pyrolysis. Three samples have similar shape curves of evolved gases of C2~C5 with different intensities. When the pyrolysis temperature was lower than 418℃, the amount of C6H6 evolved in the process of pyrolysis of inertinite concentrated was higher than that of raw coal and vitrinite concentrate. As the temperature rising, the production rate of C6H6 increased. Below 672℃, C6H6 evolution rate of vitrinite concentrate was far greater than the other two samples; the main evolution temperature range of C7H8 was 400℃ to 700℃ for the three samples. The amount of HE and H20 released first increased and then decreased with the temperature increase while more H2 released for pyrolysis of inertinite concentrated and more H20 released for the pyrolysis of vitrinite concentrate.

Numerical Study of Viscous Wave-Making Resistance of Ship Navigation in Still Water

The prediction of a ship＇s resistance especially the viscous wave-making resistance is an important issue in CFD applications. In this paper, the resistances of six ships from hull 1 to hull 6 with different hull forms advancing in still water are numerically studied using the solver naoe-FOAM-SJTU, which was developed based on the open source code package OpenFOAM. Different components of the resistances are computed and compared while considering two speed conditions （12 kn and 16 kn）. The resistance of hull 3 is the smallest while that of hull 5 is the largest at the same speed. The results show hull 3 is a good reference for the design of similar ships, which can provide some valuable guidelines for hull form optimization.

Electrochemical study on adsorption behavior of surfactants at β-2CaO·SiO2/NaAlO2 interface

β-2CaO＇SiO2 was obtained with analytical grade reagents. Polyethylene glycol （PEG）, sodium polyacrylate （PAAS） and their mixture were used to inhibit the decomposition of β-2CaO·SiO2 in sodium aluminate solution. The potential of solid-liquid interface and the adsorption mechanism were studied by the methods of Zeta potential measurement and XPS. The results indicate that PEG and PAAS have synergistic effect on the inhibition of secondary reaction. The inhibitory effect is the best when the volume ratio of PAAS to PEG is 1：1 and the total concentration is 12.5 mg/L. PAAS adsorbs on the surface of β-2CaO-SiO2 by the formation of --COOCa coordinate bond, and the negative charge enters into Stem layer, which results in the decrease of particle potential and the obvious change of binding energy of Ca 2p, Si 2p and O Is. PEG only physically adsorbs on the surface ofβ-2CaO·SiO2, and had little effect on particle potential and binding energy of Ca 2p, Si 2p and O Is.

Synthesis of Amphiphilic Polyelectrolyte and Study of Their Association Behavior in Hydroalcoholic Media

The objective of the work involves the synthesis of comb-like amphiphilic cationic polymers with repeating units methacylamides laterally substituted by a group containing a quaternary ammonium site and a hydrophobic n-alkyl side chain with 8-10 carbon atoms. Two synthesis methods were developed successfully. The first method is consisted to synthesizing first amphiphilic cationic methacrylamide monomers. In the second method the tertiary amine groups of polymers precursors were quaternised with various n-alkyl bromides. All the polymers obtained in this way were characterized by spectroscopic methods： 1^H NMR and by viscometry. The reduced viscosity of hydro-alcoholic polymer solution decreases with polymer concentration. Viscometry study showed that these polymers display typical polysoap behavior in hydro-alcoholic mixtures.

Vitamin E-derived copolymers continue the challenge to hemodialysis biomaterials

Improving material biocompatibility has been a continu-ous effort and remains a major goal of dialysis therapy. In this respect, vitamin E-modified copolymers have been used to produce a generation of biomaterials that has offered new clinical challenges and the chance of further improving the quality of synthetic hemodialyser membranes. This mini review article describes the evo-lution of these copolymers that only recently have been adopted to develop new vitamin E-modifed polysulfone hemodialysers. Biomaterial characteristics and clinical aspects of these membranes are discussed, starting from the most recent contributions that have appeared in the literature that are of interest for the community of nephrology and dialysis specialists, as well as bioma-terial scientists.

Necessities and feasibilities of the establishment of traditional Chinese medicine clinical research protocol database

With the internationalization and modernization of traditional Chinese medicine （TCM）, TCM clinical research has accumulated a lot of research information resources. However, these information resources are often scattered in various retrieval systems, which brings some difficulties to the reference and use of this information. Therefore, we collected TCM clinical research protocols which were published in international journals and established Traditional Chinese Medicine Clinical Research Protocol Database （TCMCRPD）, in order to promote the localization of high-quality researches and improve the ability of TCM clinical research in China. After analyzing the major existing problems of TCM clinical research protocols, this essay describes the necessities and feasibilities of building Traditional Chinese Medicine Clinical Research Protocol Database （TCMCRPD） and puts forward some basic technological ideas, so as to provide a theoretical foundation for building the database.

Female Leadership and Organizational Climate in a University Institute

This paper addresses the case of the Professional Institute of the Southern Region （IPRES）, an institute of higher education in the State University of Morelos, with the aim of showing the measurement results of organizational climate before and after the change of the principal to know some internal features and describe the organizational climate of workers＇ perception in a transition stage; besides, the influence of the current director＇s leadership is analyzed in the achievement of organizational goals and how the perception of organizational climate or working environment can be affected by female leadership is also dealt with. In Mexico, there are more and more women running various organizations, including those belonging to the field of education, and universities are no exception. On the other hand, the type of leadership being exercised can promote or hinder the proper performance of the institute and may be a factor of distinction and influence the behavior of those who integrate it; therefore, knowing how it works provides feedback about the processes that determine organizational behavior and the working environment.

Study on Low-Temperature Traction Behavior of a Space Lubricating Oil No.4116

The traction behavior of space lubricating oil No. 4116 was measured and analyzed at various oil inlet temperatures below 0 ℃ and various rolling speeds under normal loads by a test rig simulating the operating conditions of space bearings. A traction coefficient calculation model was presented. The rheological property and rheological parameters of the lubricant at a low oil inlet temperature were analyzed based on the Tevaarwerk-Johnson model. The results showed that the lubricating oil No. 4116 was sensitive to the rolling speed and had lower sensitivity to the normal load. This lubricating oil is more suitable for applications under high speed when it is used below 0 ℃. It behaves as an elastic-plastic fluid operating below 0 ℃. Both the average limiting shear stress and the average elastic shear modulus have a negative correlation with the rolling speed and oil inlet temperature and have a positive correlation with the normal load.

Participatory Action Research for Catalyzing Adaptive Management： Analysis of a ＂Fits and Starts＂ Process

This paper argues that contextual constraints can significantly interfere with the conduct of research and development, and accordingly should be analyzed more honestly. It describes a five country research project, Landscape Mosaics, in which participatory action research （PAR） was intended as one of two central approaches in the original research design （the other approach being more conventional research）. The five sites, in Cameroon, Indonesia, Laos, Madagascar, and Tanzania, are described, with an emphasis on their implementation of PAR. The fact that personnel and partners on three of the five sites failed to implement PAR is analyzed, to determine the constraints to such action. These findings are then compared with our experience with two other similar projects in which PAR was more widely implemented. We conclude by identifying the most important constraints to be overcome in implementing a PAR process, something we consider important in efforts to deal with change processes in developing countries.