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Search Results: 1 - 10 of 202174 matches for " 吴文勇 "
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石油企业折旧制度的改革与完善
,
天然气工业 , 1994,
Abstract: ?新增固定资产是对油气工业发展的重要投入,而固定资产的保值、增值又是油气工业发展的前提.油气工业企业现行折旧制度折旧率偏低,折旧方法单一,未考虑设备的无形磨损和设备占用资金的时间价值、通货膨胀等因素,加之折旧制度不健全,使企业不能针对具体设备采取灵活、有效和健全的折旧方式提取折旧费.面对这些问题,应遵循市场经济客观规律,借鉴发达国家的经验,按固定资产的重置价值适当提高折旧率,并加强对固定资产折旧提取和使用的监督管理,使国有资产保值增值.
石油天然气企业转换经营机制的问题与对策
,
天然气工业 , 1993,
Abstract: ?本文从管理体制、经营机制和价格政策等三个方面进行分析,提出了改革现行管理体制,落实生产经营决策权、投资决策权、外贸自主权,健全和完善市场体系,改变价格形成机制及深化企业改革等一系列促使经营机制转换的有效对策。
脉冲电流处理对AZ31B镁合金孪晶含量的影响
Effect of Electric Current Parameters on the Microstructural Evolution in AZ31B Magnesium Alloy
 [PDF]

, , 王新丽,
Modern Physics (MP) , 2016, DOI: 10.12677/MP.2016.63006
Abstract:
借助扫描电子显微镜及其配备的背散射电子(SEM-EBSD)系统研究了脉冲电压强度和脉冲作用次数对AZ31B镁合金中孪晶的影响。研究发现随着脉冲电压强度或脉冲作用次数的增加,孪晶含量均会呈现增加趋势,尤其电压强度的影响更明显。
The effect of electric current parameters, including electric pulse voltage intensity and electric pulse acting times on twin content in AZ31B Magnesium alloy is studied. Results showed that twin contents enhanced not only with the increase of pulse voltage intensity but also with that of acting times. Especially, the enhancement became more obvious with the increase of pulse voltage inten-sity.
脉冲电流处理工艺参数对AZ31B镁合金的微观形貌的影响
Effect of Electric Current Parameters on the Microstructural Evolution in a AZ31B Magnesium Alloy
 [PDF]

, , 王新丽,
Metallurgical Engineering (MEng) , 2016, DOI: 10.12677/MEng.2016.31001
Abstract:
通过改变脉冲电压强度和脉冲作用次数,借助金相分析系统研究了脉冲电流处理工艺参数对AZ31B镁合金的微观形貌的演变规律。研究发现随着脉冲电压强度或脉冲作用次数的增加,平均晶粒尺寸均会呈现长大趋势,尤其电压强度的影响更明显。且脉冲电流处理后样品中生成大量的拉伸孪晶,这主要是由于脉冲电流作用瞬间晶粒内部热膨胀和升温不同引起的热压应力所致。
The effect of electric current parameters, including the pulsed voltage intensity and the electric pulse repeating times on the microstructural evolution of AZ31B magnesium alloy was investigated by optical microscope method. The results showed that the grains become coarser with increasing either the pulsed voltage intensity or the repeating times. In addition, the application of electric current was beneficial to the formation of tensile twins, which could be ascribed to the thermal compressive stress formed due to the nonsynchronous between the temperature increment and the thermal expansion inter the grains during current passing.
薄层色谱法快速测定饮料中的几种添加剂
运军,宗清,
中国公共卫生 , 2000, DOI: 10.11847/zgggws2000-16-04-32
Abstract: ?在市场上的固体和液体饮料中,许多生产厂家为了防止其中成分变质和腐败,使用一些防腐剂如苯甲酸和山梨酸等;为了增加甜度,有时也使用一些甜味剂如糖精等.这些添加剂多数存在一定的毒性.在食品卫生检查中,为了判断食品中是否含有这些添加剂,通常采用薄层分析法.
基于环境同位素技术的再生水灌区水循环特征解析
A Study of Water Cycle in Reclaimed Water Irrigation District with Isotopic
 [PDF]

潘兴瑶, , 刘洪禄, 尹世洋
Journal of Water Resources Research (JWRR) , 2012, DOI: 10.12677/JWRR.2012.16067
Abstract: 再生水灌区水源包括再生水、地表水、地下水等,准确、客观的表征再生水灌区各水源之间的相互转换关系是开展多水源联合调度保障灌区用水安全和提高水资源利用率的关键。本研究采用环境同位素和水化学成分作为平原灌区水循环研究的示踪剂,揭示了灌区水循环特征。结果表明,灌区地表水和地下水之间存在强烈的水力联系,整个灌区的补给排泄关系主要是地表水补给地下水,人工抽取河道再生水灌溉农田产生深层渗漏,补给地下水是导致灌区地下水电导率明显波动变化的主要原因,同位素分析结果显示灌区再生水、地表水和地下水均呈现出强烈的蒸发浓缩作用,地表再生水对地下水的补给从北到南逐渐减弱。
In reclaimed water irrigated district, the water resources characteristic with synthetic reclaimed water, stream water, ground water and so on. It is essential for security and efficiency utilization of reclaimed water to precisely assess the transformation among different water bodies in reclaimed water irrigation district. This study uses isotopic and hydrochemical data of water samples to quantity study the regional water cycle. It has shown that there is intense hydraulic connection between surface water and ground water. Most ground water is recharged from surface water. The reclaimed water irrigation is one of most important way for reclaimed water recharged to groundwater and results in obvious unstable variation of EC. The results of ground water isotopic composition showed an intense evaporation-concentration process during recharge from precipitation and surface water. The ground water isotopic concentration gradually decreases from Northwest to Southeast and results by decrease of surface water recharge to ground water.

 

北京市再生灌区地下水动态特征及数值模拟研究
Groundwater Dynamic Characteristics and Numerical Simulation for Reclaimed Water Reclaimed Water Irrigation District
 [PDF]

尹世洋, , 刘洪禄, 潘兴瑶, 徐小元
Journal of Water Resources Research (JWRR) , 2012, DOI: 10.12677/JWRR.2012.16070
Abstract: 本文基于GMS软件建立了北京市再生水灌区地下水数值模型,预测了不同情景下地下水的动态变化趋势及调控方案。研究表明,随着再生水灌区的再生水利用率逐步提高,灌区内的地下水水位逐步抬升,向下游地区的侧向排泄量也呈加大趋势;为了减少下游的侧向排泄量、避免该区域由于地下水位过高而产生土壤次生盐渍化,应控制灌区内的地下水位埋深;再生水利用率达到50%时,每年需开采出3307.2m3置换的浅层地下水资源,再生水利用率达到70%时,每年需开采出4567.0m3置换的浅层地下水资源,再生水利用率达到90%时,每年需开采出6128.3m3置换的浅层地下水资源。研究成果对再生水的安全利用、地下水资源的涵养具有重要意义。
 In order to predict the changing trends of groundwater under different scenarios and make regulation programs, a groundwater numerical model of reclaimed water irrigation district is developed based on GMS software. Research results indicate that with the gradual increase of reclaimed water utilization, irrigation area groundwater level progressive uplift, lateral excretion to the lower reaches also show a trend of increase. In order to avoid the soil salinization, shallow groundwater resources must be mining to control the depth of groundwater according to the different utilization rates of the reclaimed water. 50% of total water consumption is reclaimed water, 33.1 million m3 replacement of shallow
一般柱形边界区分场的谱方法计算
陈耀松,
力学学报 , 1993, DOI: 10.6052/0459-1879-1993-4-1995-657
Abstract: 本文设计了一种计算方法,使谱方法可用于一般边界问题,方法分两步1.用谱方法解具有简单边界的方程;2、修正复杂边界处的解以满足边界条件。算例是孤立波绕椭圆柱的问题,计算结果显示为不同时刻的二维等值线图与三维波动图。
结构专业PDMS平台数字化设计探究
,,常显
重庆大学学报 , 2014,
Abstract: 介绍VANTAGEPDMS在土建结构专业协同设计数据流转的应用。通过开发SmartPPDS软件(VANTAGEPDMS与MIDASGEN双向接口软件),工艺专业在PDMS中提出荷载与构件要求(虚梁),结构专业在GEN中接收审核工艺荷载及需求,由GEN计算并可出埋件图。将专业结构数据回导入PDMS中,做到结构专业与PDMS平台无缝互通。通过SmartPPDS,可大大减轻工艺专业与结构专业配合工作量,提高设计效率。
多单片机在放射性试剂分装仪中的应用
,,郭兴隆
同位素 , 2006,
Abstract: 放射性试剂分装仪通过液晶显示器和键盘实现人机交互,5个高精度的步进电机实现吸液臂的三维定位和大小针筒吸液量的控制。在整个分装系统中共用到了6片单片机,所有单片机通过串行口连接成一个相互协作的系统,实现了医用放射性试剂的高精度、零污染分装和稀释。
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