首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 140 毫秒
1.
技术使用的情境实际上是人类使用者通过技术的使用所建构出来的一个实践语境和社会境域.随着使用者主要使用的技术所展现出来的不同历史形态,技术使用也展现出三种面貌的情境-经验型技术使用情境、实体型技术使用情境以及知识型技术使用情境.  相似文献   

2.
目的:了解清洁手术抗菌药物预防使用情况,分析存在问题,以促进抗菌药物的合理使用.方法:采用回顾性调查方法,对3种清洁手术(甲状腺手术、乳腺手术、疝气修补术)186例中预防用抗菌药物的使用品种、使用频率、使用时间等进行调查分析.结果:清洁手术抗菌药物预防使用存在多方面不合理性.结论:清洁手术抗菌药物预防使用需进一步规范管理.  相似文献   

3.
介绍片状管换热器在鞍钢的使用情况。包括换热器型号、配置方法及其相应的使用效果,同时以两个使用实例逐一分析了换热器材质的金相组织、制造工艺、使用方法及破损原因,对如何提高片状管换热器的质量和正确地加以使用提供了依据。  相似文献   

4.
Jarvis clark(却维斯克拉克)国际镍公司,自1972年以来设计使用了电动铲运机之后,共销售出70台电动铲运机,加拿大、美国和墨西哥的十七个公司的各个矿山都在使用。目前使用的电动铲运机只占矿山使用的铲运机总数的3%弱,随着使用经验的不断积累,电动铲运机在市场的销售及使用范围将会不断扩大。  相似文献   

5.
正确掌握工业气瓶的使用常识是企业安全生产的保障。工业气瓶在企业日常生产活动中的使用非常普及,但大多数单位在充装、运输、使用及贮存等环节都存在着各种问题。从安全角度论述工业气瓶现存的使用与管理隐患,如何正确使用及事故应急措施。  相似文献   

6.
陆文国 《宽厚板》2011,17(1):43-45
介绍了沙钢5 m宽厚板轧机支承辊的使用环境、使用技术和使用水平,指出适用的轧辊材质和性能、合理可控的换辊周期、优化的配辊和磨削技术以及完善的检测技术是轧辊使用和维护的关键。并对支承辊使用技术的发展作了展望。  相似文献   

7.
在日常生活中我们常常会使用到微波炉,但是又有多少人知道微波炉的使用禁忌呢?现在我们就来学习下微波炉烹饪的一些使用禁忌,以免使用过程中伤害到自己或他人.  相似文献   

8.
介绍了油气润滑在济钢强力矫直机支承辊轴承的使用原理、使用特点和使用中应注意的问题。  相似文献   

9.
介绍了预付费磁卡电能表的工作原理、性能特点和使用方法。总结了承钢的使用情况和使用效果。  相似文献   

10.
《黄金》1993,(9)
第三章著作权许可使用合同第二十三条 使用他人作品应当同著作权人订立合同或者取得许可,本法规定可以不经许可的除外.第二十四条 合同包括下列主要条款:(一)许可使用作品的方式;(二)许可使用的权利是专有使用权或者非专有使用权;(三)许可使用的范围、期间;  相似文献   

11.
Theoretical models featuring cognitive processes have played a fundamental role in advancing knowledge of psychopathology and its treatment and have emphasized the importance of cognition in psychotherapy. Recognition of the importance of cognition in psychotherapy has led to a number of questions that are addressed by the articles in this special section of the Journal of Consulting and Clinical Psychology. Cognitive therapy is well represented in the articles in this special section, but therapeutic procedures that do not represent typical cognitive therapy are also examined. The articles in this special section focus on homework in the modification of cognition, cognition in the treatment of anxiety in adults and in children, change in depressive cognitions in children, cognition and rapid change in the treatment of depression, and the role of cognition in the treatment and prevention of depression that is recurrent. Examination of these types of questions holds the possibility of advances in existing treatments and the possibility of innovations in new treatments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

12.
摘要:对链箅机回转窑工艺中各段球团样品进行实验分析,研究了氯元素和硫元素在链箅机回转窑工艺中的迁移规律,明晰了烟气中HCl的生成机制。结果表明,球团原料中的氯元素主要是以NaCl的形式存在,氯元素有一部分在链箅机抽风干燥段会转变成HCl气体并进入烟气,一部分在链箅机预热Ⅱ段之后以NaCl的形式汽化进入烟气,剩余的氯元素仍以NaCl的形式存在于成品球团矿中。烟气中的HCl气体是在抽风干燥段,由富含SO2的烟气与含水球团料层中的NaCl发生反应生成的,烟气中SO2转变成Na2SO4重新固定于料层中。在预热Ⅰ段和预热Ⅱ段,烟气中的SO2与原料中碳酸钙分解生成的游离CaO反应生成CaSO4,也会重新固定烟气中的SO2。  相似文献   

13.
O. Chanute, C.E.     
Octave Chanute was one of the leading civil engineers in the United States in the period between 1850 and 1890. His work on eastern and western railroads was unsurpassed. He began his bridge building career in 1856 and designed his last major bridge in 1888. Starting in 1890, he began his study in the work that others conducted in the area of manned flight and designed and tested many of his own gliders. He later assisted the Wright Brothers in their experiments in Dayton and at Kitty Hawk.  相似文献   

14.
以水稻土—地表水铀含量为视角,从水稻土剖面铀含量分布规律、水稻土与下伏岩体稀土元素特征、不同河流不同河段水稻土—地表水—稻米铀含量特征、水稻土与稻米铀含量关系4个方面研究721铀矿区稻米铀含量成因。结果表明,水稻土剖面铀含量从表层至半风化花岗质基岩层呈明显降低的特征,说明水稻土铀含量高的原因不是土壤母质铀含量高;岩石与水稻土稀土元素标准化模式均表现为向右倾斜型,均属轻稀土富集型,轻稀土分馏明显,表明水稻土为还原环境,吸附作用较强;不同河流不同河段水稻土—地表水—稻米铀含量平均值的特性均为上游最低、中游最高、下游次之。铀矿区地表水环境符合铀元素在水稻土中被平衡吸附的动力学条件,有利于铀元素在矿区内河流中游地区的水稻土中沉淀富集;正在采矿区水稻土与稻米铀含量具有高度的空间耦合性,呈指数正相关关系,相关系数0.749。矿区内河流沿岸稻米铀含量的分布特征是由铀元素的迁移途径决定的"采矿活动(铀尾矿露天堆放)→地表水→水稻土"。  相似文献   

15.
总结"十一五"期间武钢炼铁生产技术装备及环保等方面的总体情况,分析高炉高强化生产的工艺技术与设备保障,阐述了高炉主要指标创历史水平的技术措施,提出了存在的问题与应对方法等。  相似文献   

16.
简要归纳了国内目前焦炭硫分预测方法,指出了不足。通过32个单种煤硫分形态与焦炭硫分关系研究,分析了硫分形态对焦炭硫分的影响;通过分析炼焦过程炼焦煤硫分变化,提出传统室式炼焦过程脱硫反应和固硫反应并存,煤气中H2具有脱硫功能,灰中CaO和MgO是固硫剂;60个样品试验数据的回归分析结果表明,煤的全硫和灰中(CaO+MgO)含量是影响焦炭硫分的主要因素。  相似文献   

17.
李斌 《黄金》2016,(9):72-76
在研究区采集了132组植物样品,并对样品中As、Hg、Cu、Zn、Pb、Cd、Cr、Ni 8种重金属含量进行了测试,采用环境指数作为植物重金属污染评价方法来描述受污染程度,得出了不同种类植物的重金属污染状况。通过对比分析富集系数,研究了重金属在植物中的富集特征。其研究结果表明:不同植物中重金属含量超标倍数和吸收量明显不同,显示出选择性富集特征。该次采集的所有植物中As、Hg的含量都不超标;红薯中Cd和Pb的含量超标倍数最高,玉米中Zn的含量超标倍数最高,Cu也比较容易在粮食作物中累积且以红薯最为突出;蔬菜中Pb、Cd、Zn的含量超标倍数最高,以白萝卜、白菜最为突出;水果中Pb的含量超标倍数最高,且苹果和柿子都较为突出。该次采集的植物对Pb的吸收能力都很强,只有玉米对Zn的吸收能力比其对Pb的吸收能力略强。受到重金属污染的土壤所种植的粮食、蔬菜和水果均有不同程度的富集,其对重金属吸收强弱的排序分别为:白菜、白萝卜和胡萝卜中,PbZnCuNiCrCdHgAs;红薯和茄子中,PbCuZnNiCrHgCdAs;南瓜和苹果中,PbCuZnNiCrHgAsCd;柿子中,PbNiCuZnCrHgAsCd;玉米中,ZnPbCuNiCrHgAsCd;西红柿中,PbZnCuNiCrAsCdHg。  相似文献   

18.
Ambient flow field and circulation patterns induced by circular bubble plumes and water jets in tanks of different sizes were studied in rectangular and square water tanks. A nonstationary nature of the flow was observed in all experiments and its dominant oscillation frequency was found to directly relate to the tank size. The flow circulation patterns were similar for bubble plumes and water jets, but changed significantly with tank size and geometry. Strong three-dimensional effects were observed in a rectangular tank, resulting in flow entraining in the longer plane and flow detraining in the shorter plane, especially for the bubble plume tests. A relationship was developed to relate the tank size to the patterns of circulation cells. Nearly isotropic turbulent flow conditions were obtained in all experiments, but the effect of tank size and geometry on the magnitude of the turbulent stresses was more pronounced in the bubble plume tests.  相似文献   

19.
The formation and geomorphic evolution of the Jiuduansha Shoal are investigated over the past 50 years in this paper. The sedimentary processes, formation, and geomorphic evolution of the Jiuduansha Shoal in the Yangtze River Estuary, eastern China, are analyzed based on digitized sea maps from 1945 to 2001, satellite images from 1975 to 2001, and field survey data in the spring-neap tidal cycle in the dry and flood seasons in 2003. The suspended sediment concentration and hydrodynamics of the North Passage and South Passage during the dry and flood seasons in the spring-neap tidal cycle in 2003 were investigated, and relations between the North Passage and South Passage of the Jiuduansha Shoal are analyzed. Results show that seasonal and spring-neap tidal cycle variations in sediment and water discharge from the drainage basin correspond to erosion and deposition on the Jiuduansha Shoal. The results and data can provide useful information for the management of the Yangtze River Estuary and restoration of the estuarine tidal flat ecology.  相似文献   

20.
The authors have recently demonstrated that the high serum estradiol level during the proestrus phase of the estrous cycle and that the administration of estradiol or progesterone in ovariectomized female and of testosterone in orchiectomized male rats significantly decrease formalin-induced temporomandibular joint (TMJ) nociception. In this study, the authors investigate the contribution of endogenous opioids to this antinociceptive effect of gonadal hormones in the TMJ formalin test. The opioid receptor antagonist naloxone was administrated either in the surrounding of the trigeminal sensory complex or in the TMJ region. The antinociceptive effect induced by endogenous estradiol in proestrus females and by exogenous estradiol in ovariectomized females was blocked by the administration of naloxone in the surrounding of the trigeminal sensory complex, but not in the TMJ region. The antinociceptive effect induced by the administration of progesterone in ovariectomized females and of testosterone in orchiectomized males was blocked by the administration of naloxone either in the surrounding of the trigeminal sensory complex or in the TMJ region. The authors conclude that central and peripheral opioid mechanisms mediate the antinociceptive effect of progesterone and testosterone, and central opioid mechanisms mediate the antinociceptive effect of estradiol. These findings suggest that the enhanced pain perception during low gonadal hormone periods in women and animals may be mediated by a decrease in endogenous opioid activity. This suggestion helps explain the higher severity of some pain conditions, such as temporomandibular dysfunctions in women than in men, that have no hormonal fluctuations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号