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基于热交换的放出法测试流量特性的研究 被引量:1
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作者 杨丽红 刘成良 叶骞 《仪器仪表学报》 EI CAS CSCD 北大核心 2006年第z1期41-43,共3页
给出了固定容积放气过程的热力学模型,提出了仅根据“停止法”的瞬态压力曲线求出容器壁和内部空气换热系数的方法,并应用于定容积放出法测量电磁阀的流量特性的数据处理过程中。从测试结果可以看出,在定容积放出法中考虑热交换可以很... 给出了固定容积放气过程的热力学模型,提出了仅根据“停止法”的瞬态压力曲线求出容器壁和内部空气换热系数的方法,并应用于定容积放出法测量电磁阀的流量特性的数据处理过程中。从测试结果可以看出,在定容积放出法中考虑热交换可以很大程度提高测试结果的精度。并分析了换热系数对测试结果的影响。 展开更多
关键词 热力学模型 换热系数 放出法 流量特性 音速流导
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定容积放出法中几种数据处理方法的对比 被引量:1
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作者 杨丽红 刘成良 叶骞 《上海交通大学学报》 EI CAS CSCD 北大核心 2006年第12期2093-2096,共4页
为准确得到电磁阀的声速流导,把多变指数引入放气法测试气动元件流量特性的数据处理过程.首先介绍了3种数据处理原理:部分多变指数法、完全多变指数法和等熵绝热法;然后对一个电磁阀的放气压力曲线分别用这3种方法进行数据处理,计算得... 为准确得到电磁阀的声速流导,把多变指数引入放气法测试气动元件流量特性的数据处理过程.首先介绍了3种数据处理原理:部分多变指数法、完全多变指数法和等熵绝热法;然后对一个电磁阀的放气压力曲线分别用这3种方法进行数据处理,计算得到放气电磁阀的声速流导.对比的结果表明:完全多变指数法的精度最高,基本收敛于一定值,但其测试和数据处理过程比较复杂;部分多变指数法比等熵绝热法得到的声速流导随时间的分散度可以提高1倍,能较准确地得到电磁阀的声速流导.在实际测试中,由于部分多变指数法测试简便并且结果相对比较准确,故有很高的应用价值. 展开更多
关键词 多变指数 放出法 声速流导
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多变指数在放出法中的应用 被引量:1
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作者 杨丽红 刘成良 叶骞 《机床与液压》 北大核心 2005年第8期84-86,共3页
为了准确测试电磁阀的音速流导,把多变指数引入放气法测试气动元件流量特性的数据处理过程。首先介绍了数据处理原理,接着对一个电磁阀的放气压力曲线进行了数据处理,分别把放气过程看作绝热过程和多变过程,通过计算得到放气电磁阀的音... 为了准确测试电磁阀的音速流导,把多变指数引入放气法测试气动元件流量特性的数据处理过程。首先介绍了数据处理原理,接着对一个电磁阀的放气压力曲线进行了数据处理,分别把放气过程看作绝热过程和多变过程,通过计算得到放气电磁阀的音速流导。实验结果表明:放出法中把放气过程看作多变过程,比绝热过程得到的音速流导的随时间的分散度提高一倍,表明更能准确地得到电磁阀的音速流导。在实际测试中,多变过程法有着很高的应用价值。 展开更多
关键词 多变指数 放出法 音速流导
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Technology of gas drainage and utilization in Huaibei mining area 被引量:3
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作者 LI Wei XU Rui 《Journal of Coal Science & Engineering(China)》 2009年第3期278-283,共6页
With the characteristics of coal seam geology and gas occurrence,a'ground-underground' integrated gas drainage method was formed,which can relieve gaspressure and increase permeability by mining the protection... With the characteristics of coal seam geology and gas occurrence,a'ground-underground' integrated gas drainage method was formed,which can relieve gaspressure and increase permeability by mining the protection seams in conditional regions.After coal seam gas drainage,high gas outburst seam was converted to low gas safetyseam.In the coal face mining process,safety and high efficient coal mining were realizedby the measure of gas-suction over mining.In addition to the drainage gas for civil gasand gas power generation,the Huaibei Mining Group has actively carried out research onthe utilization technology of methane drainage by ventilation.On the one hand,it can saveprecious energy;on the other hand,it can protect the environment for people's survival.In2007,the amount of coal mine gas drainage was 120 hm3;the rate of coal mine gasdrainage was 44%.Compared with the year 2002,the amount of coal mine gas drainageincreased by two times.Meanwhile,the utilization rate of gas increased rapidly. 展开更多
关键词 gas drainage gas utilization Huaibei mining area
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In vitro dissolution and oral bioavailability study of fenofibrate nanomatrix system prepared by hot-melt extrusion
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作者 Yajie Yin Xiaofei Zhang +6 位作者 Zheng Cui Wei Qu Bing He Wenbing Dai Hua Zhang Xueqing Wang Qiang Zhang 《Journal of Chinese Pharmaceutical Sciences》 CAS CSCD 2019年第5期329-338,共10页
Solvent evaporation method for preparation of nanomatrix has the disadvantages,such as residual organic solvent,environmental pollution,explosion-proofing and so on.To overcome these shortcomings,a series of fenofibra... Solvent evaporation method for preparation of nanomatrix has the disadvantages,such as residual organic solvent,environmental pollution,explosion-proofing and so on.To overcome these shortcomings,a series of fenofibrate nanomatrix drug delivery system(NDDS)consisting of nano-porous silica Sylysia■350(S350)and pH sensitive material Eudragit■L100-55(EL100-55)were prepared using hot-melt extrusion(HME),and their in vitro dissolution and in vivo bioavailability were compared.Finally,the formulation with the highest in vivo bioavailability was selected as the optimized formulation for DSC and PXRD characterization.The results showed that the optimized NDDS showed a higher bioavailability than the reference formulation,although there was crystalline form drug remaining in NDDS.The relative bioavailability of the optimized formulation was 157.1%compared with the commercial product Lipanthyl■.In addition,the relative bioavailability of the optimized formulation was 124.8%in comparison with the formulation prepared by solvent evaporation method,showing that the NDDS prepared by the HME method was effective in improving the bioavailability of fenofibrate.In conclusion,HME was a promising method to prepare NDDS. 展开更多
关键词 Nanomatrix drug delivery system Hot-melt extrusion FENOFIBRATE DISSOLUTION BIOAVAILABILITY
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