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西门子AVENTO 1.5T磁共振维修浅析 被引量:6
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作者 彭国意 蔡世华 《医疗装备》 2013年第4期59-60,共2页
目的:磁共振作为科学技术含量最高的大型影像设备,无论设备如何精密的系统都存在一定的故障率,一个由许多部件组成的庞大系统,每一个部件都存在故障风险,如何尽快地将故障定位并加以排除,是本文将要叙述的关键。方法:找到故障首先要有... 目的:磁共振作为科学技术含量最高的大型影像设备,无论设备如何精密的系统都存在一定的故障率,一个由许多部件组成的庞大系统,每一个部件都存在故障风险,如何尽快地将故障定位并加以排除,是本文将要叙述的关键。方法:找到故障首先要有良好的理论基础,下面笔者分为4个方面,针对性的进行介绍。结果:无论多么高精尖的设备,只要我们熟悉了它的基础理论,胆大心细的去分析问题,一切困难都可以迎刃而解。 展开更多
关键词 磁共振 理论基础 硬件和软件系统 人为因素环境因素
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西门子Avanto 1.5T磁共振设备维修浅析 被引量:5
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作者 肖先雁 《中国卫生产业》 2015年第24期100-102,共3页
如何及时维护好设备和解决磁共振成像系统(MRI)设备故障,已经成为了当前医疗机构关注的热点话题,结合实际情况,本文以西门子Avanto 1.5T磁共振设备为例,对磁共振故障维修方式和效果进行了介绍。这对于提升维修能力,确保设备正常运行,有... 如何及时维护好设备和解决磁共振成像系统(MRI)设备故障,已经成为了当前医疗机构关注的热点话题,结合实际情况,本文以西门子Avanto 1.5T磁共振设备为例,对磁共振故障维修方式和效果进行了介绍。这对于提升维修能力,确保设备正常运行,有着重要的现实意义。 展开更多
关键词 磁共振设备 故障 人为因素环境因素 维修
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Review of Soil Nutrients of Forest Nature Reserve 被引量:1
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作者 刘晓梅 李小英 +1 位作者 袁勇 申佳艳 《Agricultural Science & Technology》 CAS 2016年第6期1412-1421,共10页
Based on a large number of relevant literatures, the effects of environmental factors and human factors on forest soil nutrients in nature reserve were summarized, as well as the soil quality assessment and correlatio... Based on a large number of relevant literatures, the effects of environmental factors and human factors on forest soil nutrients in nature reserve were summarized, as well as the soil quality assessment and correlation of soil. nutrients, to provide references for a deep research on forest nature reserve soil and its protection. The distribution of forest soil nutrients has significant spatial heterogeneity, and its final distribution pattern is the result of joint action of environmental factors, including topography, vegetation, soil type, seasonal change as well as soil microorganism, and human factors. In natural ecosystem, environmental factors are the main factors that determine the differences of soil nutrients. Effective human management can promote the accumulation of forest soil nutrients, but improper interference will cause a significant loss of soil nutrients. Accurate soil quality evaluation can objectively clarify the impact of different soil management practices on soil, contributing to the timely adjustment of management measures. The establishment of long-term soil monitoring stations in forest nature reserves is a good way to master the influencing factors and the mechanism of forest soil nutrients, and can ultimately provide theoretical guidance for a sustainable and healthy operation of forest nature reserve. 展开更多
关键词 Soil quality Environmental factor Human factor CORRELATION
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Environmental and Paddy Soil Organic and Lower Yangtze Anthropogenic Factors Matter: A Case Study River Plain of China Driving Changes in in the Middle
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《Pedosphere》 SCIE CAS CSCD 2017年第5期926-937,共12页
Changes in soil organic matter (SOM) can affect food security, soil and water conservation, and climate change. However, the drivers of changes in SOM in paddy soils of China are not fully understood because the eff... Changes in soil organic matter (SOM) can affect food security, soil and water conservation, and climate change. However, the drivers of changes in SOM in paddy soils of China are not fully understood because the effects of agricultural management and environmental factors are studied separately. Soil, climate, terrain, and agricultural management data from 6 counties selected based on representative soil types and cropping systems in China were used in correlation analysis, analysis of variance, and cforest modeling to analyze the drivers of changes in SOM in paddy soils in the Middle and Lower Yangtze River Plain from 1980 to 2011. The aims of this study were to identify the main factors driving the changes in SOM and to quantitatively evaluate their individual impacts. Results showed that the paddy SOM stock in the study area increased by 12.5% at an average rate of 0.023 kg m-2 year-1 over the 31-year study period. As a result of long-term rice planting, agricultural management practices had a greater influence than soil properties, climate, and terrain. Among the major drivers, straw incorporation, the most influential driver, together with fertilization and tillage practices, significantly increased the accumulation of SOM, while an increase in temperature significantly influenced SOM decomposition. Therefore, to confront the challenge of rising temperatures, it is important to strengthen the positive effects of agricultural management. Rational fertilizer use for stabilizing grain production and crop straw incorporation are promising measures for potential carbon sequestration in this region. 展开更多
关键词 agricultural management practices cforest modeling environmental factors carbon sequestration fertilizer use strawincorporation temperature TILLAGE
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