共查询到20条相似文献，搜索用时 475 毫秒
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本文介绍了塔西南医院住院部的供暖通、洁净、供氧吸引、热水系统的设计,给出了暖通、供氧、洁净主要设计参数,根据不同的职能岗位特点及要求,分别采用不同的系统形式,运行结果表明达到设计要求。 相似文献
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目的 探讨超高原地区某医院医务人员为主的群体睡眠状况,并探究导致睡眠障碍发生的原因。方法 2022年5月在位于4300m海拔的某医疗机构中招募志愿者95人作问卷调查,并对结果做数据分析,查阅相关研究文献作对比研究。结果 （1）受调查的医务人员PSQI状态与北京某三甲医院医务人员得分基本一致;（2）焦虑抑郁状态与远海岛礁驻扎医务人员状态基本一致;（3）造成睡眠状况较差的重要原因是抑郁、焦虑等异常心理状态,其中抑郁得分与睡眠障碍得分之间存在线性回归关系（PSQI得分=4.018+0.396*抑郁自评得分）;（4）医务人员职业特点对睡眠障碍有影响;（5）当前的供氧用氧方式对睡眠障碍的改善无明显影响,供氧、用氧方式需作进一步研究和改善。结论 （1）超高原地区医务人员睡眠质量较差,除了职业因素外特殊环境导致的心理因素是睡眠障碍的重要影响因素,因此需要予以重点关注和持续研究;（2）当前现有的供氧和用氧模式还有必要加大投入、使用和研究力度改善供氧效果。在后续针对不同民族的特点,有针对性地投放供氧资源提高资源使用效率。 相似文献
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介绍了超音速火焰喷涂装置的结构组成和工作原理,喷涂零件处理方法和应用效果。超音速火焰喷涂提高了水轮机、阀门等流体机械过流部件的抗磨蚀性能,已经成为目前国内外普遍采用的抗磨蚀工艺,在某些水电厂河流泥沙、水泥浆矿物体、硅粉等行业恶劣工况中得到了实际应用,并取得了良好的综合效益,具有较高的推广价值。 相似文献
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Jin Liu Chenxu Wang Chaojia Lv Xiaowan Su Yijin Liu Ruilian Tang Jiuhua Chen Qingyang Hu Ho-Kwang Mao Wendy L Mao 《国家科学评论(英文版)》2021,8(4)
As the reaction product of subducted water and the iron core, FeO2 with more oxygen than hematite (Fe2O3) has been recently recognized as an important component in the D” layer just above the Earth''s core-mantle boundary. Here, we report a new oxygen-excess phase (Mg, Fe)2O3+δ (0 < δ < 1, denoted as ‘OE-phase’). It forms at pressures greater than 40 gigapascal when (Mg, Fe)-bearing hydrous materials are heated over 1500 kelvin. The OE-phase is fully recoverable to ambient conditions for ex situ investigation using transmission electron microscopy, which indicates that the OE-phase contains ferric iron (Fe3+) as in Fe2O3 but holds excess oxygen through interactions between oxygen atoms. The new OE-phase provides strong evidence that H2O has extraordinary oxidation power at high pressure. Unlike the formation of pyrite-type FeO2Hx which usually requires saturated water, the OE-phase can be formed with under-saturated water at mid-mantle conditions, and is expected to be more ubiquitous at depths greater than 1000 km in the Earth''s mantle. The emergence of oxygen-excess reservoirs out of primordial or subducted (Mg, Fe)-bearing hydrous materials may revise our view on the deep-mantle redox chemistry. 相似文献
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The excessive generation of reactive oxygen species (ROS) by abnormal spermatozoa and contaminating leukocytes has been defined
as one of the few etiologies for male infertility. Administration of antioxidants in patients with ‘male factor’ infertility
has begun to attract considerable interest. The main difficulty of such an approach is our incomplete understanding of the
role of free radicals in normal and abnormal sperm function leading to male infertility. Mammalian spermatozoa membranes are
very sensitive to free radical induced damage mediated by lipid peroxidation, as they are rich in polyunsaturated fatty acids.
Limited endogenous mechanisms exist to reverse these damages. ROS attacks the fluidity of the sperm plasma membrane and the
integrity of DNA in the sperm nucleus. ROS induced DNA damage accelerate the germ cell apoptosis. Unfortunately spermatozoa
are unable to repair the damage induced by excessive ROS as they lack the cytoplasmic enzymes required to accomplish the repair.
Assessment of such oxidative stress status (OSS) may help in the medical treatment. Treatment strategies must be directed
toward lowering of ROS levels to keep only a small amount necessary to maintain normal cell function. 相似文献
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减压器是氧气呼吸器的重要组成部分,是氧气呼吸器的心脏,其原理是气瓶中的氧气通过一个根据输入压力和输出压力高低能自动调节出气通道横截面的大小的装置来达到减压目的,以保证基本稳定中压的输出。 相似文献
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氧化物催化剂表面过剩氧与氧化活性 总被引：1，自引：0，他引：1
本文采用肼法测定了金属氧化物催化剂表面过剩氧的浓度，并考察了吡啶的氧化活性。催化剂的氧化活性与表面氧浓度成正比。氧化活性和表面氧浓度的顺序为：Ｃｕ－Ｏ／Ａｌ＿２Ｏ＿３＞Ｍｎ－Ｏ／Ａｌ＿２Ｏ＿３＞Ｃｒ－Ｏ／Ａｌ＿２Ｏ＿３＞Ｆｅ－Ｏ／Ａｌ＿２Ｏ＿３≥Ｃｏ－Ｏ／Ａｌ＿２Ｏ＿３＞Ｎｉ－Ｏ／Ａｌ＿２Ｏ＿３＞Ｃｅ－Ｏ／Ａｌ＿２Ｏ＿３．随着催化剂焙烧温度的提高，催化剂表面氧浓度和氧化活性均下降。Ｃｕ－Ｏ／ＳｉＯ＿２催化剂中添加ＣｅＯ＿２后，催化剂表面氧浓度和氧化活性均有明显提高，同时催化剂的热稳定性也明显增加。 相似文献
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目的：探讨在间歇训练局部骨骼肌中肌氧变化特征,包括氧合血红蛋白（HbO2）,还原血红蛋白（Hb）和血流量（BV）,将它们与呼吸系统参数进行比较,期待为间歇训练提供新的辅助监测与评价手段。方法：选取武汉体院学院男子中长跑专业运动员16人在运动医学跑台MERCURY4.0上进行间歇训练。同时使用华中科技大学研发的近红外三波长便携式肌氧监测仪、MAX-II心肺功能仪和P-Lar心率表采集被试对象相关数据,包括HbO2、Hb、BV、VO2、VCO2、RER及心率（HR）,绘制曲线图比较,并对比较结果进行统计检验。结果：肌氧含量与呼吸系参数变化趋势高度相关,HbO2曲线下降速率与呼吸商变化高度相关,BV曲线呈逐级上升趋势,组间变化速率相差不明显。结论：可以利用近红外光谱技术实时监测间歇训练中的局部骨骼肌肌氧含量的相对变化,了解运动员局部运动状态并推测其整体运动状况,有望为间歇训练实时监测与评价提供简便有效的辅助监测手段。 相似文献
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氧枪是转炉炼钢的关键设备之一,它的控制系统性能关系到冶炼钢水的质量与效率。要想保证氧枪系统的安全稳定运行就必须有一套完善的控制体系。简介了转炉氧枪的控制系统以及控制系统中的重要电器设备,简述了编码器的分类及原理,详细说明了速度编码器和高度编码器在氧枪升降控制中起到的作用,并且初步构思了两种编码器所采集的数据共享的方法。 相似文献
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某火力发电厂2号机组凝结水中的溶解氧含量在冬季供暖期间一直不能达到合格范围,溶解氧合格率逐月下降.针对凝结水溶解氧超标问题进行全面排查调整,查找出了机组凝结水溶解氧超标的原因并对存在的问题进行处理,最后总结出凝结水溶解氧超标的调整方法. 相似文献
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Mei-Zhen Zou Wen-Long Liu Han-Shi Chen Xue-Feng Bai Fan Gao Jing-Jie Ye Han Cheng Xian-Zheng Zhang 《国家科学评论(英文版)》2021,8(2)
The hypoxic tumor microenvironment is characterized by disordered vasculature and rapid proliferation of tumors, resulting from tumor invasion, progression and metastasis. The hypoxic conditions restrict efficiency of tumor therapies, such as chemotherapy, radiotherapy, phototherapy and immunotherapy, leading to serious results of tumor recurrence and high mortality. Recently, research has concentrated on developing functional nanomaterials to treat hypoxic tumors. In this review, we categorize such nanomaterials into (i) nanomaterials that elevate oxygen levels in tumors for enhanced oxygen-dependent tumor therapy and (ii) nanomaterials with diminished oxygen dependence for hypoxic tumor therapy. To elevate oxygen levels in tumors, oxygen-carrying nanomaterials, oxygen-generating nanomaterials and oxygen-economizing nanomaterials can be used. To diminish oxygen dependence of nanomaterials for hypoxic tumor therapy, therapeutic gas-generating nanomaterials and radical-generating nanomaterials can be used. The biocompatibility and therapeutic efficacy of these nanomaterials are discussed. 相似文献