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Search Results: 1 - 10 of 214461 matches for " 刘豪 "
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医学生运动损伤急救知识的调查
Investigation of the Knowledge of First Aid about Sports Injury among Medical Students in Guangzhou
 [PDF]

陈宇,
Nursing Science (NS) , 2015, DOI: 10.12677/NS.2015.42006
Abstract:
目的:了解广州市高校医学生运动损伤急救知识掌握情况,为有效开展、普及运动损伤急救知识教育提供科学依据。方法:采用自行设计的运动损伤急救知识问卷,对366名医学生在校期间的运动损伤发生情况及损伤急救知识进行匿名调查。结果:发放问卷380份,回收366份,有效回收率96.3%,损伤发生率71%,19道运动损伤急救知识测试题中,平均答对(10.72 ± 3.06)题,平均答对率(56.44 ± 16.09)%,答对12题及以上的有169人,合格率46.2%,答对≥16题的13人,优良率3.6%;男女之间的答对率比较,无显著性差异(P > 0.05),不同年级医学生的答对率、优良率、合格率比较,差异均有统计学意义(P < 0.05),低年级学生答对率较低。结论:医学生运动损伤发生率较高,而运动损伤急救知识匮乏,需要通过有针对性的培训来提高其急救能力。
Objective: To investigate the ability of first aid about sports injury among medical students in Guangzhou. Method: Using a self-developed questionnaire, a survey about sports injury and related knowledge was conducted among 380 medical students. Results: 366 valid questionnaires were retrieved. The average correct rate of the knowledge of first aid about sports injury was (56.44 ± 16.09)%, and there was no statistically significant difference between male and female students (P > 0.05). However, there was statistically significant difference (P > 0.05) between four grades. Conclusion: Medical students have a high incidence of sports injury and they are lack of first aid knowledge. Therefore, it is necessary to deliver first aid training of sports injury among medical students.
真空蒸镀Nd:YAG薄膜的工艺研究
Study on the Process of Nd:Y3Al5O12 Thin Films by Evaporation Deposition
 [PDF]

曾群, 周永恒,,
Material Sciences (MS) , 2012, DOI: 10.12677/ms.2012.21007
Abstract: 本文采用真空电子束蒸发镀膜工艺制备Nd:YAG薄膜,结合XRD、SEM等手段分析研究不同衬底材料、镀膜材料以及退火温度对薄膜材料结构的影响,并分析测试了Nd:YAG薄膜的光致发光特性。镀膜材料为Nd:YAG粉体块,Si片上沉积的Nd:YAG薄膜材料,经1100?C退火后,具有单一YAG晶相结构,薄膜结晶晶粒均匀细小,并在室温下测试获得1064 nm主荧光峰的宽带荧光光谱。
Nd:YAG thin films have been prepared by electron beam evaporation deposition in the study. The influences of different substrates, different coating materials and annealing temperatures on the structures of Nd:YAG thin films were investigated with XRD and SEM. Also, the optical properties of Nd:YAG thin films were characterized by spec-trophotometer. The Nd:YAG thin films deposited on Si from Nd:YAG powder blocks have single YAG crystal structure after annealing at 1100?C. And the grains of the thin film are uniform and fine. In addition, the photoluminescence spectra of Nd:YAG thin films were measured at room temperature, and photoluminescence spectrum in the region of 1064 nm peak was detected.
浅海陆棚环境下沉积坡折带及其对局部强制海退体系域的控制
,
沉积学报 , 2011,
Abstract: 南海珠江口盆地HZ地区珠江组沉积时期主要表现为一稳定沉积的陆棚环境。在研究区西部发育大型的古珠江水系,为整个珠江组大型三角洲沉积提供了丰富的陆源碎屑。本研究以PSQ6为例进行了详细分析,其沉积坡折带具有一定的规模,斜坡宽度约4km,高差为20~60m,横向延伸为80km左右。沉积坡折带主要发育在下伏层序高水位体系域三角洲沉积结束时期,与在前三角洲亚相以东的碳酸盐岩隆起之间构成了一个局部的“沟谷”体系,为PSQ6层序强制海退时期沉积和保存提供了良好的古地貌背景,并进一步控制了陆棚环境中局部强制海退楔的发育。陆棚背景下的“沟谷”古地貌地形往往易于导致强制海退砂的形成,进积砂体能够直接覆盖在下部层序高水位体系域所形成的浅海相泥岩上,其上覆盖着水进域和高位域暗色泥岩,可形成有利的生、储、盖组合,是本地区寻找地层—岩性油气藏的有利场所。
中小企业电子商务初探

科技进步与对策 , 2001,
Abstract: 通过应用电子商务,中小企业可以从中获得诸多的收益,这些收益可分为直接的和间接的,也可分为短期的和长期的,但推动中小企业持续开展电子商务的根本性动因是其中长期的间接收益。企业的电子商务发展有一定的阶段性,但中小企业电子商务发展的阶段有其特殊性,它必须是由外向内,先实现外部的应用,再以此来促进内部信息化的完善,并进一步实现电子商务的内外应用的完全整合,促进电商务列高阶段的发展。同时,中小企业电子商务的实施对中小企业本身和整个国民经济都具有极其重要的战略意义,我国的中小企业应该加快电子商务的应用和建设。中国信息化电子商务中小企业Internet
小尺度地幔对流及其与层序地层学的相关性
The Small-Scale Mantle Convection and the Correlating with Sequence Stratigraphic
 [PDF]

周小龙, , 赵春晨
Advances in Geosciences (AG) , 2013, DOI: 10.12677/AG.2013.36041
Abstract:
小尺度地幔对流理念的提出距今已有20多年,人们用它来解释一些较异常的地质现象,如青藏高原、天山的快速隆起等。这些构造的沉降与隆升直接影响着层序界面的划分,其形成时间也影响着层序级次的划分。根据Petersen的数值模拟实验显示,小尺度地幔对流的作用周期为2~20个百万年,与三级层序的周期范围最为吻合,对于区域构造的升降及海平面变化具有不可忽略的影响。虽然小尺度地幔对流对海底地形影响不大,但对于被动和主动大陆边缘,内陆塑、刚性岩石圈均有影响。笔者认为在进行层序划分时应考虑小尺度地幔对流的存在。
The concept of small-scale mantle convection has been proposed for more than 20 years. We use it to explain some of the more unusual geological phenomena, such as the rapid uplift of the Tibetan Plateau and the Tianshan etc. These tectonic subsidence and uplift are a direct impact on the division of sequence boundaries as well as the formation time. According to Petersen’s numerical simulations, it shows that small-scale convection driven stratigraphic sequences occur at periods of 2 to 20 million years. By correlating the third-order sequences, it is very important for the regional tectonic movements and sea level changes. Although small-scale mantle convection has little effect on the seafloor to- pography, it affected the passive and active continental margins, inland plastic and rigid lithosphere very differently. The author holds that the existence of small-scale mantle convection should be considered when dividing the sequences.

光学孤子与孤子激光器

科学通报 , 1992,
Abstract: 所谓“光学孤子”(optical solitons),是指光纤中传输的,满足一定条件的非线性光波波包脉冲。与KdY方程描述的浅水孤子波不太相同,光学孤子属于一般称为波包孤子的一类。 光学孤子由非线性Schrdinger(NLS)方程
固体连续激射的若干问题

科学通报 , 1965,
Abstract: 继气体连续激射器的出现,固体工作物质在脉冲工作的基础上,亦相继观察到连续激射现象。目前,除红宝石、钨酸钙和氟化钙外,还在半导体和玻璃工作物质中观察到连续激射现象。据报导,固体连续器件的输出功率已超过1瓦,激发阈值亦显著降低。对于CaF_2:Dy~(2+)晶体,用15瓦钨丝灯激发,即可获得连续激射光。为将固体连续激射器用于光学定位、导航、跟踪和通讯等方面,目前正在开展一系列工作:改进激发方式、提高输出功率和效
产生受激光发射的工作物质

科学通报 , 1964,
Abstract: 自1960年Maiman首先实现了红宝石的受激光发射以来,在寻找产生受激光发射的工作物质及改进器件的结构与性能方面,做了许多工作,取得了丰硕的成果。目前,实现受激光发射的工作物质已不下五十种之多,其中包括气体、液体(有机溶液)和固体等不同状态和不同结构的物质;输出波段已从紫外2542埃伸展到红外35微米;实现了低温和室温的连续操作器件;红宝石的输出能量已达500焦耳,已制成输出能量为113焦耳的玻璃受激光发射器,运用光开关技术,红宝石的脉冲峯值功率已从5仟瓦剧增至10亿瓦;半导体工作物质的出现,大大
产生受激光发射的工作物质

科学通报 , 1964,
Abstract: 自1960年Maiman首先实现了红宝石的受激光发射以来,在寻找产生受激光发射的工作物质及改进器件的结构与性能方面,做了许多工作,取得了丰硕的成果。目前,实现受激光发射的工作物质已不下五十种之多,其中包括气体、液体(有机溶液)和固体等不同状态和不同结构的物质;输出波段已从紫外2542埃伸展到红外35微米;实现了低温和室温的连续操作器件;红宝石的输出能量已达500焦耳,已制成输出能量为113焦耳的玻璃受激光发射器,运用光开关技术,红宝石的脉冲峯值功率已从5仟瓦剧增至10亿瓦;半导体工作物质的出现,大大提高了器件的效率并简化了整套装置的结构。
固体连续激射的若干问题

科学通报 , 1965,
Abstract: 继气体连续激射器的出现,固体工作物质在脉冲工作的基础上,亦相继观察到连续激射现象。目前,除红宝石、钨酸钙和氟化钙外,还在半导体和玻璃工作物质中观察到连续激射现象。据报导,固体连续器件的输出功率已超过1瓦,激发阈值亦显著降低。对于CaF2Dy2+晶体,用15瓦钨丝灯激发,即可获得连续激射光。为将固体连续激射器用于光学定位、导航、跟踪和通讯等方面,目前正在开展一系列工作改进激发方式、提高输出功率和效率,提高输出激射的稳定性和方向性,以及选择合适的调制方法等。
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