共查询到20条相似文献，搜索用时 171 毫秒
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对用对氨基二甲基苯胺光度法测定水中硫化物的酸化—吹气—吸收预处理新装置进行研究，对相关实验条件进行了讨论与验征．实验数据表明该预处理装置对硫化物有较好的吸收效果，适用于硫化物含量在4Mg／L以下的水和废水的测定． 相似文献
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碳在浓硝酸中燃烧这一实验,按现行化学课本中的操作方法演示,生成的二氧化氮会造成室内空气严重污染,不利于师生健康。若改变其装置,分别用“吹气排放”、“吸气溶解”、“管内吸收”、“管外吸收”,“分离吸收”等方法处理二氧化氮,就可防止这种情况产生,从而增强演示实验的示范性,提高教学效果。 相似文献
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通过对现有化工原理吸收实验装置的分析,设计出了一种多功能化工原理吸收实验装置,并将实验室的现有吸收实验装置进行了改造。与传统装置相比,新开发的实验装置具有以下功能:可以测定多种散装填料的吸收传质系数;不同类型填料的吸收传质系数;单一的规整填料的吸收传质系数以及规整填料和散装填料的混合吸收传质系数。通过填料吸收塔实验装置的改进,使学生对填料吸收实验的印象更加深刻,实验教学内容更加丰富,增强学生的创新意识,锻炼了学生的实践能力。 相似文献
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实验装置的设计依据工业生产碳酸氢铵工艺流程,严格按照国家标准。考虑到实验装置的规模、尺寸,并结合本实验教学的具体情况,通过物料衡算及能量衡算初步确定了氨法吸收 CO2实验装置主要部分的尺寸参数及实验装置工艺系统,该实验装置将为学生提供氨法吸收 CO2生产碳酸氢铵工艺的实验教学保证。 相似文献
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《向澄清的石灰水中吹气》实验是九年义务教育三年制初中生物第二册第六章第二节的内容。其目的要求是：验证人体呼出的气体中，含有较多的二氧化碳。其实验装置如图１所示。从实验装置和实验结果显然可知，本实验只能检验呼出气体中含有较多的二氧化碳，不能检验吸入的气体中二氧化碳含量图１原实验装置澄清的石灰水甲乙吹气图２改进后的实验装置的多少。怎样去比较吸入的气体中二氧化碳的含量与教材中【看一看，想一想】相吻合呢？若教师简单地按照教材程序进行，总觉得有些缺陷，而且导致学生只能机械地听信吸入气体中二氧化碳含量少，却… 相似文献
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陈华仕 《遵义师范学院学报》2010,12(4):101-102,108
随着人们环保意识的提高,有机化学实验的微型化越来越受到人们的重视。作者针对毛细管法在沸点测定中所暴露出的不足,探讨了毛细管沸点测定微型化实验装置的改进,改进后的装置不但提高了沸点测定的效率,也克服了微型化实验不利于集体观摩的不足,极大地增强了微型化学实验的演示功能。 相似文献
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单一电解质水溶液汽液界面张力的测定 总被引：1，自引：1，他引：1
本文选择滴体积法作为实验方法 ,建立了汽液界面张力实验装置 ,用纯液体界面张力值校验后 ,在 2 5℃下 ,测定了KNO3、ZnCl2 、kBr、K2 CO34个单一电解质水溶液体系在 0 0 5 2mol/L浓度范围的气液界面张力。实验结果表明 ,采用滴体积法所建立的实验装置能够准确并方便地测定电解质水溶液的汽液界面张力。 相似文献
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采用实验室简易熏气装置模拟大气中的氯气污染,结合植物叶片内氯含量的测定,可以估测氯气污染对植物的危害程度,以便进行环境质量的生物学评价和了解各种植物吸收和净化污染气体的能力。采用密闭熏蒸装置产生氯气,提高其密封性,增加了NaOH吸收余氯步骤,提高了安全性,具有简单易操作等优点。植物氯含量测定采用硫氰酸钾回滴法,易脱色、滴定终点明显和重现性好,结果令人满意。 相似文献
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以废气再循环EGR双闭环控制为研究对象,借助PID和PWM控制理论,结合EGR率的测定方法,提出了一种双闭环控制策略,解决了EGR阀双闭环控制中EGR率测定关键技术,形成了基于氮氧化物测量的EGR率测定装置(EGR率传感器)和实验测定方法。 相似文献
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自主设计开发了基于二极管激光光源的气体分子高分辨吸收光谱测量实验方案,展示了乙炔气体分子吸收光谱的测量装置、测量方法和测量结果。实验系统的光谱分辨率为0.01 pm,光谱采集速率10 Hz,最低可探测吸收0.03%,乙炔气体传感分辨率7 ppm。实验系统构建成本低、扩展性强、易于推广,可丰富光学类实验课程内容。该实验系统已开展了两学年的教学实践,取得了很好的教学效果。 相似文献
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This paper presents a novel method of identifying coal type based on mechanistic methods. The ratio of the resonance line spectrum of a luminous flame and the continuous spectrum at the same wavelength eliminates the influence of temperature on spectral intensity. The atomic line spectra of Na and K are typical and significant over continuous flame spectra. The concentrations of elemental Na and K in the flame are exclusively relative to coal type and composition. Using an experimental furnace and charge-coupled device (CCD) optical spectrometer apparatus, the continuous spectra and atomic line spectra of Na and K elements were sampled from coal flames in real time. An empirical fitting method was used to simplify the formulas of absorption strength and flame temperature calculation, and rational solutions were obtained by using an iterative algorithm. Due to the change in reaction rate and absorption by soot particles, the relative contents of Na and K in a flame vary with the temperature and absorption strength. Arrhenius’s equation for temperature compensation was adopted. Compensation for soot density in the furnace was also satisfied by an exponential expression. At any one sampling position, the compensation parameters were identical for all coal types. After compensation for temperature and density of soot particles, the relative strength of the Na and K signals and the ratio between them uniquely matched the coal type burnt in various conditions. The results were replicated and verified in various conditions, and the response time of the system was of the order of seconds. 相似文献
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苏州河底泥重金属形态分析 总被引：2，自引：0，他引：2
Nine elements （As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn） in sediment samples at 7 sites （Site 1-7） from Suzhou Creek in Shanghai were analyzed with the Community Bareau of Reference （BCR） （sequential extraction （SE）） protocol and simultaneously extracted metals （SEM）/acid volatile sulfide （AVS） procedure to assess the metal bioavailability and toxicology in this area. The results showed that the BCR extraction can be utilized as an additional tool with the AVS method for assessing the potential bioavailability and toxicity of metals in sediments. Pollution from S5 （Site 5） was more severe than from other sites, especially Pb, Cu and Zn. Among all the sites, more than 80% of the total concentration of Fe existed in the residual fraction, As, Cr, Mn also dominated in the residual fraction （more than 50%）. While Cd, Ni and Zn （more than 35%） were mainly in the non-stable phase. Cu had a strong affinity with oxidizable phase and Pb varied from site to site. The SEM/AVS ratio was less than one in these sediments and results implied that the majority of Zn and Ni （〉 40%） were bound to AVS. In contrast, Pb, Cu and Cd were little bound to AVS due to their low ration of SEM-Pb, Cu, Cd to corresponding total concentration and relatively high Dorewater concentration. 相似文献
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芦丁在玻碳电极上的电化学行为研究 总被引：3，自引：0，他引：3
在0.lmol／L B-R缓冲溶液(pH=3．10)中，用循环伏安法可得到芦丁的一对氧化还原峰。峰电位Epc=0．405V，Epa=0．467V(vs．SCE)。实验表明，Rt在玻碳电极上的电极过程为一受吸附和扩散同时控制的准可逆过程。测得还原峰的电子转移系数为0．39，标准速率常数为kn=0．48s^-1。用该法测定了芦丁片中Rt的含量。 相似文献
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Experiments were conducted using cohesionless sand particles with median diameter of 0.48 mm to investigate the time variation of sediment transport rate under the influence of local downward seepage.The experimental results show that the bedload transport rate in terms of volumetric sediment transport rate per unit width increased rapidly with time in the presence of suction,eventually reaching a peak beyond which it started to decrease.The trend of reduction was significantly reduced beyond 8 400 s after the test started.The analytical expression was derived in terms of dimensionless sediment transport rate and dimensionless time.The hypothesized relationships were compared with the experimental data,indicating a good agreement with each other. 相似文献
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以锥形瓶作为反应器,KMnO4与FeSO4溶液反应,测量出温度-时间数据,然后用外推法对温度进行校正计算其反应热.实验测定只需2-4h,测定误差小于0.1%.该方法具有实验装置简单,测定时间短,准确度高等优点,适合在一般院校推广. 相似文献
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铜与浓硫酸反应的实验探索 总被引：1，自引：0，他引：1
对高中化学第一册中“铜与浓硫酸反应”演示实验的实验装置和实验方法进行了改进,用可移动的铜丝代替铜片,并对硫酸的浓度进行了探索。结果表明,当硫酸的浓度为80％时,实验现象鲜明,反应时问短,教学效果明显。 相似文献