针对性护理在神经外科危重患者人工气道管理中的应用效果

目的:探讨针对性护理在神经外科危重患者人工气道管理中的应用效果。方法:选取2021年6月—2023年6月广东三九脑科医院收治的94例神经外科危重患者,根据随机数表法将其分为研究组和对照组,各47例。对照组给予常规人工气道护理,研究组给予针对性护理。比较两组不良事件,护理前后生活质量、心理状态,住院情况,护理满意度。结果:研究组不良事件发生率低于对照组,差异有统计学意义(P<0.05)。护理后,研究组健康调查简表(SF-36)评分均高于对照组,差异有统计学意义(P<0.05)。研究组ICU入住时间、机械通气时间及住院时间均短于对照组,差异有统计学意义(P<0.05)。研究组护理总满意度高于对照组,差异有统计学意义(P<0.05)。护理后,研究组焦虑自评量表(SAS)与抑郁自评量表(SDS)评分均低于对照组,差异有统计学意义(P<0.05)。结论:在人工气道管理中实施针对性护理可以减少不良事件发生,改善心理状态。

横风作用下地铁车辆运行平稳性及安全性分析

[目的]城市轨道交通列车在高架线路上运行时,横风对车辆运行的平稳性和安全性有较大影响,需要对横风作用下地铁车辆的动力学性能进行更为深入的研究。[方法]在MATLAB软件中分别采用3种经典的横风风载模型(定常稳态风载模型、瞬态中国帽风载模型及非定常随机风载模型)模拟动态风场,在SIMPACK软件中建立单节编组车辆的精细化刚体动力学模型,将3种风载模型作为外部激励分别施加到车辆上;对比分析了车辆在直线上运行时不同风载模型、不同风速、不同车速对地铁车辆运行平稳性的影响;从安全设计角度出发,选取非定常随机风载模型,对车辆在曲线上运行时的平稳性及安全性进行分析,探究了不同风速下车辆运行速度的安全域。[结果及结论]在横风作用下,地铁车辆车速、风速均对车辆的运行平稳性及安全性有显著影响。车辆高速运行时,风速对车辆的横向振动影响更为突出。3种横风风载模型中,非定常随机风载模型对车辆的平稳性影响最明显;基于对车辆平稳性及安全性的分析,给出了不同线路形态(直线或曲线)、不同风速下的车辆限速值。

基于致灾机理分析的公路滑坡稳定性评价及治理方案研究

以永德至耿马高速公路K41+000~K41+300段滑坡为工程背景,先开展其致灾机理分析,再进行滑坡稳定性评价及治理方案筛选,旨在为其安全施工提供理论支持。经分析,该滑坡的致灾成因相对较多,内部成因是其致灾的固有属性,外部成因是其致灾的诱发因素。在稳定性评价结果中,HP02滑坡加载前稳定系数范围为0.758~1.151,属不稳定-基本稳定状态;加载后,稳定系数均小于1,属不稳定状态。HP21滑坡加载前的稳定系数范围为0.763~1.099,状态属不稳定-基本稳定;加载后,稳定系数范围为0.721~1.039,状态属不稳定-欠稳定。最后,经过方案比选,方案一在可行性、经济投资等指标上均具明显优势,故决定采用“新桩+老桩”的治理方案。

热增强的光催化二氧化碳还原技术

利用太阳光驱动二氧化碳(CO_(2))催化转化合成燃料是缓解能源危机和降低温室效应的理想途径。然而,当前面临的主要挑战在于CO_(2)固有的化学稳定性使得光催化反应的转化效率低下。热量被认为是促进催化转化反应过程的重要推动力,可以有效提升光催化转化的效率。本文综述了不同形式的热增强光催化在CO_(2)还原生产燃料方面的应用,包括外加热源的光催化CO_(2)还原、光热效应促进的光催化CO_(2)还原以及等离激元增强的光催化CO_(2)还原体系。文章指出:热增强的光催化技术继承了光催化的高选择性和热催化的高反应活性的优势,实现了CO_(2)还原反应的高效进行。具体分析如下:外加热源主要通过直接加热装置或者聚焦太阳光能实现,产物的生成效率明显增强,选择性影响不大;光热效应发挥着局部提高催化剂反应温度的作用,使能量利用效率更高,大幅度降低CO_(2)还原反应所需的能量;等离激元效应除了发挥光热效应的作用,同时兼备增强光吸收、促进载流子分离和加速表面反应动力学的作用。文章最后指出,通过对反应机理进行深度研究,合理调控反应体系的反应条件,将极大促进热增强的光催化CO_(2)还原技术发展,为CO_(2)利用提供有效手段。

首发未治疗青少年特发性全面性癫痫脑白质磁共振成像研究

目的特发性全面性癫痫(idiopathic generalized epilepsy,IGE)患者脑白质微结构的改变已在儿童和成人中广泛报道,然而这些研究多集中在慢性用药后的癫痫患者,本研究采用扩散张量成像(diffusion tensor imaging,DTI)技术观察首发未治疗青少年特发性全面性癫痫患者脑白质的结构改变。材料与方法选取符合纳入标准的IGE患者45例(年龄:5~18岁,男:女=26:19)和健康志愿者32名(年龄:5~18岁,男:女=21:11)。采用基于体素的方法比较两组脑白质部分各向异性分数(fractional anisotropy,FA)和平均弥散系数(mean diffusivity,MD)的差异(将年龄和性别作为协变量),进一步将病例组脑白质发生改变脑区的FA值和MD值与临床变量进行相关分析。结果 FWE(family-wise error)校正后病例组仅左侧中央旁小叶、右侧楔前叶及右侧顶上小叶的MD值低于正常对照组,采用相对宽松的Alpha Sim校正后发现病例组双侧额中上回深部脑白质区的FA值较对照组增加,MD值和FA值改变与临床变量间无相关性。结论首发未治疗IGE患者存在脑白质微结构的损害,在IGE早期阶段,MD可能较FA能更敏感地检测出脑白质微结构的改变。不同于慢性期IGE患者的研究结果,本研究发现首发未治疗青少年IGE的MD值下降和FA值升高可能是IGE患者认知功能减退前的一种代偿机制。

基于PSR模型的珠江口海域富营养化特征与评价

本研究依据2020年4月(春季)和2020年10月(秋季)珠江口海域的调查数据,根据“压力-状态-响应”(PSR)模型对珠江口海域进行富营养化状况评价,并通过主成分分析以及相关性分析来说明各环境因子对珠江口富营养化的影响。结果表明:在“优、良、中、差、劣”5个富营养化等级中,珠江口PSR综合评价等级为“差”等级,近几年内变化趋于稳定。有机污染物与营养盐对珠江口富营养化的影响较大,其次为叶绿素a和溶解氧。珠江口营养盐与盐度呈显著负相关,与叶绿素a呈显著正相关。周边城市的陆源排放输入是导致珠江口富营养化的主要因素,河口稀释混合作用以及浮游植物对珠江口的富营养化程度有影响。

投我以钯 报之以琼琚

钯元素自从被发现就开始逐渐在我们的生活中扮演起重要的角色,本文以钯的广泛应用为引,着重结合科研前沿问题对钯纳米催化剂的设计、合成以及催化机理展开介绍。

基于金属氧化物的光催化甲烷转化:原理、进展与挑战

随着可燃冰和页岩气开采技术的迅速发展,甲烷的储量逐年增加.因此,甲烷不仅被视为一种清洁能源,同时也被认为是一种可用于生产高附加值化工产品的碳原料.然而,由于甲烷分子具有十分稳定的成键结构,所以传统的甲烷转化技术(尤其是甲烷水汽重整反应)通常需要大量的能量输入.针对这一问题,光催化技术可以利用具有高能量的光生载流子来打破甲烷转化的热力学势垒,被认为是在温和条件下实现甲烷转化的一种非常具有前景的途径.在光催化甲烷转化领域,金属氧化物基光催化剂已经得到了广泛的研究,这主要归因于它们的强氧化能力.在本文中,我们首先基于光催化甲烷转化反应的基本原理对金属氧化物在该反应中所具备的优势进行了讨论.随后,我们回顾了近年来金属氧化物基光催化剂在目前各类甲烷转化反应中的研究进展,包括甲烷完全氧化(TOM)、甲烷部分氧化(POM)、甲烷干重整(DRM)、甲烷无氧偶联(NOCM)以及晶格氧辅助的甲烷偶联(LOCM)等几类反应.最后,我们对基于金属氧化物的光催化甲烷转化技术所面临的挑战与机遇进行了展望.

基于参数化功率谱估计的车轮多边形动态识别

由于传统频谱估计方法存在固有缺陷,对车轮多边形振动频率的识别容易产生较大误差,尤其对于初期车轮多边形的识别更是困难。为解决上述问题,基于参数化功率谱估计理论,提出一种车轮多边形动态识别方法。首先,根据车轮多边形的动态特性,建立了谐波频率恢复模型;其次,基于奇异值分解法与归一化误差分析对谐波恢复模型的阶数进行确定;然后,采用总体最小二乘法对谐波恢复模型的参数进行计算;最后,根据Cadzow估计理论对异常磨耗信号进行功率谱估计,并以某地铁车辆的轴箱垂向振动加速度实测信号为例,对该方法的可行性与正确性进行了验证。结果表明:该方法可基于短时序列数据实现高精度频域估计,且对谐波信号敏感,尤其适用于早期车轮多边形异常磨耗信号的识别。

Students'Political Belief Education in Agricultural and Forestry Colleges and Universities in Network Environment:Taking Northwest A&F University as an Example

The influence of the network environment on the education of political beliefs of college students in China cannot be ignored.Taking Northwest A&F University as an example,starting from the current situation of students'political belief education in agricultural and forestry colleges and universities,the impact of network environment on the education of political beliefs of students in agricultural and forestry colleges and universities was analyzed,and the implementation path of improving political belief education in the network environment was explored,in order to provide a reference for improving the effectiveness of ideological and political education of students in agricultural and forestry colleges and universities.

Legislation Characteristics and Implementation Recommendations for Ecological and Environmental Protection Regulations on Qinling Mountains in Shaanxi Province

This paper analyzed status and significance of Ecological and Environmental Protection Regulations on Qinling Mountains in Shaanxi Province in structure of Shaanxi local environmental laws.Theses Regulations have two outstanding characteristics:firstly,integrated protection and development,accurately regulating and guiding relation coordination;secondly,attaching great importance to using economic means to protect ecological environment and provide basis for administration according to law.It came up with specific methods for speeding up formulation of Regulations,making effort to explore implementation cases for development of Guanzhong economic zone and Qinling Mountains ecological protection,establishing methods and systems for ecological and environmental protection follow-up monitoring and evaluation of Qinling Mountains,and raising these Regulations to national laws of Ecological and Environmental Protection for Qinling Mountains.

Incorporation of Xi Jinping Thought on Socialism with Chinese Char-acteristics for a New Era into Teaching of Ideological and Political Theories in Colleges and Universities--A Case Study of Accomplishments in Morality and Introduction to Law

Xi Jinping Thought on Socialism with Chinese Characteristics for a New Era is an important achievement of the 19 th National Congress of the Communist Party of China. Taking the course of accomplishments in morality and introduction to law as an example,the incorporation of Xi Jinping Thought on Socialism with Chinese Characteristics for a New Era into teaching of ideological and political theories in colleges and universities is discussed in this article from the three following aspects of why should be incorporated,what to be incorporated,and how to incorporate to promote the spread of Xi Jinping Thought on Socialism with Chinese Characteristics for a New Era among the student groups.

Cultivation Path of ＂Four Matters of Confidence＂ of Agricultural and Forestry College Students A Case Study of Northwest A＆F University

" Four matters of confidence" are the core and ideal foundation of socialist construction. Taking Northwest A&F University as an example,this paper analyzes and explores the cultivation path of " four matters of confidence" around the education problem of " four matters of confidence" of agricultural and forestry college students,in order to improve the value identity and belief of " four matters of confidence" among college students of agriculture and forestry.

Analysis on the System of Compensation for Eco-environmental Damage

The eco-environmental damage compensation system is not only an important part of the central government's Overall Plan for the Reform of Ecological Civilization System and special plan,but also a blank point and weak link in the construction of eco-environmental protection system.From the construction of ecological civilization system,the fragility of ecological environment and the history of past damage,the comparative analysis of relevant laws and regulations,and the connotation of the concept of ecological environment,this paper expounds the importance,urgency and necessity of the reform of eco-environmental damage compensation system and the technical complexity of damage compensation judgment.In accordance with the local legislation and practical cases in the reform of eco-environmental damage compensation system in Shaanxi Province,this paper puts forward legislative and policy suggestions to accelerate the reform of eco-environmental damage compensation system.

TiO2/石墨烯复合材料的光生电荷分离调控与光催化产氢性能研究

半导体光生电荷分离是光催化过程中的关键步骤之一,其效率极大地影响了最终光催化性能.将TiO2纳米片与石墨烯复合,能够促进TiO2中光生电子和空穴的分离,从而提高其光催化活性.为了研究光生电荷的分离对TiO2/石墨烯复合材料光催化性能的影响,通过调控TiO2纳米片的尺寸来调节TiO2/石墨烯复合材料中光生电荷分离的能力,然后研究其对TiO2/石墨烯复合材料光催化性能的影响.合成了一系列不同厚度的TiO2纳米片,将其与石墨烯复合,并通过光沉积负载Pt纳米颗粒作为助催化剂,用于光催化产氢.实验结果显示,随着TiO2纳米片厚度减小,其与石墨烯形成的复合结构的光催化性能显著提高.这主要是由于TiO2纳米片厚度减小时,光生电子沿厚度方向穿过TiO2纳米片迁移到石墨烯的距离缩短,从而减少了光生电子在迁移过程中与空穴的复合;同时TiO2纳米片厚度减小使其比表面积增大,使得TiO2/石墨烯界面面积增大,从而使石墨烯更好地分离出TiO2中的光生电子,有更多的光生电子到达石墨烯参与催化反应,提高TiO2/石墨烯复合材料的光催化性能.此研究表明通过控制TiO2纳米片的尺寸来调控TiO2/石墨烯复合材料中光生电子和空穴的分离,是显著提高其光催化性能的有效途径.

Influence of adjacent shield tunneling construction on existing tunnel settlement: field monitoring and intelligent prediction

Urban subway tunnel construction inevitably disturbs the surrounding rock and causes the deformation of existing subway structures. Dynamic predictions of the tunnel horizontal displacement, tunnel ballast settlement, and tunnel differential settlement are important for ensuring the safety of buildings and tunnels. First, based on the Hangzhou Metro project, we analyzed the influence of construction on the deformation of existing subway structures and the difficulties and key points in monitoring. Then, a deformation prediction model, based on a back propagation(BP) neural network, was established with massive monitoring data. In particular, we analyzed the influence of four structures of the BP neural network on prediction performance, i.e., single input–single hidden layer–single output, multiple inputs–single hidden layer–single output, single input–double hidden layers–single output, and multiple inputs–double hidden layers–single output, and verified them using measured data.