组合法制备MnO_2/活性碳复合电极材料及其电化学性能研究

在不同温度的反应釜中使KMnO_4与MnCl_2进行反应并掺杂活性碳,然后组合球磨工艺制备了超级电容器复合电极材料。XRD揭示MnO_2/活性碳复合物低于140℃烧结5h为水合非晶态,而165℃烧结时,开始呈现弱的衍射峰。通过SEM分析得出电活性复合物形貌呈现为细小环绕微纳米晶须球状。采用循环伏安、怛流充放电及阻抗谱测试MnO_2/活性碳复合电极的电化学性能。当扫描速率为10 mV/s时,MnO_2/活性碳复合电极的比电容值达365F/g且等效串联电阻值仅为1.32Ω。经3 000次循环后复合电极的比电容值仅下降约6%。     

基于D-CA和R-EEMD的液压系统故障识别

剖析液压系统故障特征,采用了一种双相关分析(D-CA)和改进的集合经验模态分解(R-EEMD)相结合的液压系统故障提取新方法。该方法首先对原信号进行自相关分析,突出信号中的周期成分和去噪,利用支持向量回归机(SVR)延拓来改进的EEMD对原信号的自相关函数进行分解;得到理论意义上的固有模态函数(IMF)。再通过求取IMF分量与自相关处理的信号的频域而非传统时域上的互相关系数,去除虚假IMF分量。最后对去除虚假分量重构信号进行Hilbert谱分析提取信号的故障特征。该方法提高了信噪比,减少了IMF的数量,抑制了端点效应,成功地提取了液压系统故障特征频率。     

水蒸气二氧化碳共活化制备聚苯胺基活性碳在离子液体超级电容器中的应用

通过水蒸气二氧化碳(H2 O(gas)-CO2)共活化的物理活化方法制备聚苯胺基活性碳被广泛应用于商业活性碳的规模化生产,相比于化学活化方法,该方法制备的活化产物无活化剂残留、 清洗简单且工艺过程环保.以聚苯胺为原料,探究了H2 O(gas)的量和CO2分压对活化产物的影响.采用氮气吸/脱附、 扫描电镜(SEM)、 透...     

环境检测中挥发性有机物检测方法的研究

挥发性有机物常规检测中,针对不同的物质需要不同的检测设备及检测方式,且检测中须多次采样,操作复杂,耗时也较长。为解决该问题,该文以气相色谱法为例,通过采用活性碳管进样+CS2为溶剂吸收剂对气相色谱法进行改进,并通过DB-FFAP毛细管柱及FID检测器检测出样品中挥发性有机物种类及浓度,进而可通过程序升温获得相应的标准色谱图,并可同时检测出21种挥发性有机物,检测相对标准差为0.5%～2.2%,挥发性有机物的检测相关系数均能达到0.999以上,可满足环境检测中挥发性有机物检测的要求。     

一种基于旋流分离原理光释光测年样品制备方法

光释光测年（OSL）样品制备的目标是提取土壤中一定粒径范围内的石英和长石颗粒（中颗粒38～63μm）。针对当前样品提取过程中效率低、耗时长等诸多问题,提出一种光释光测年样品制备新方法。该方法基于水力旋流分离原理,采用3D打印技术研制微型水力旋流器（浓缩器）,设计2种改进型带筛网的微型水力旋流器（粗选器和精选器）,根据旋流分离器分离特性选择适宜的参数;研制样品前处理装置,该装置包括四个模块（粗选模块、反应池模块、精选模块和控制模块）;通过该装置能快速分离提取5种理化性质各异的土壤颗粒,利用激光粒度仪测试分离效果,结果表明,分离提取的颗粒集中分布在35～65μm范围内,分离效率分别为77.8%、90.4%、77.2%、80.3%、80.9%,粒径均值为40～50μm。该方法提取的土壤长石、石英颗粒满足光释光测年样品制备的要求。     

低碳钢丝焊网热镀锌工艺的改进

根据低碳钢热镀锌原理,分析了低碳钢钢丝焊网热镀锌工艺中存在的问题,包括工艺不完善、锌液成分不合理、镀后抹拭材料及方法不当等而导致的热镀锌层质量不稳定、锌耗高.针对上述问题,提出了相应的改进方法,包括采用复合除锈剂进行酸洗除锈,强化除锈效果;以氯化锌与氯化铵比例为1.2～1.6、总浓度为12%～15%的混合溶液代替单一的氯化铵作为助镀剂;增加助镀后的烘干工序;采用无机物和珍珠岩混合材料作为抹拭剂等改进措施.通过改进与完善工艺,所得镀锌层表面光滑,焊接点处无积锌,锌耗比工艺改进前降低2%.     

一种基于贝叶斯正交匹配追踪的水下多径稀疏信道估计方法

使用训练序列构成的测量矩阵并采用稀疏恢复算法是近年来常用的多径稀疏信道估计思路。提出一种贝叶斯匹配追踪算法的正交化改进方法,有效地改善了原方法的收敛速度,并将其应用于水下多径稀疏信道估计。进行了新方法的理论推导和两种水下稀疏信道模型中的仿真试验,进而与传统贪婪迭代和贝叶斯估计方法的估计效果进行了对比。仿真结果证明,所提出的新方法比原方法的收敛速度更快,能更高效地进行多径稀疏信道估计。新方法在低信噪比和呈簇状集中分布的水下多径稀疏信道中也有更好的估计效果。     

2种泡沫碳活化用于超级电容器电极材料的充放电性能研究

分别以酚醛树脂和煤沥青泡沫碳为原料,经水蒸气活化、研磨制得比表面积和粒径相近的活性碳粉.采用扫描电镜、BET吸附仪和恒流充放电测试仪对2种活性碳的结构进行了表征并研究了其充放电性能.结果表明,微孔的孔径分布对充放电性能有很大影响,提高比表面积的同时增大微孔的孔径,有利于提高活性碳电极的充放电容量和功率.     

GC-MS结合微量QuEChERS法快速测定土壤中16种多环芳烃

为实现土壤样品中典型持久性污染物的快速、灵敏及批量测定,通过基于改进微量-QuEChERS(μ-QuEChERS)技术结合超声辅助方法,且与气相色谱质谱联用(GC-MS)分析,建立土壤中16种多环芳烃(PAHs)快速测定方法。少量土壤(1.0 g)样品经过2.0 mL乙腈与二氯甲烷(V/V=1∶2)辅助15.0 min超声提取后,利用N-丙基乙二胺(PSA)和C18混合分散剂快速涡旋净化,离心、转换溶剂后进行GC-MS外标法测定。结果表明,在2～800μg/L浓度范围内,16种PAHs呈现良好的线性关系,相关系数均在0.992 0以上,检测限(LOD,S/N=3)低于0.50μg/kg。在8.0,20.0,100.0μg/kg加标浓度下,16种PAHs的加标回收率在70.3%～109.1%(n=3)。该方法快速、简单、准确,需样量少、环境污染小,可为土壤中PAHs的快速筛查提供批量检测方法。     

QuEChERS-超高效液相色谱-串联质谱法测定土壤中10种酰胺类除草剂残留量

采用QuEChERS方法结合超高效液相色谱-串联质谱法测定土壤中10种酰胺类除草剂残留量。土壤样品经水和乙腈提取,4 g无水硫酸镁和1 g氯化钠盐析,100 mg PSA净化后用UPLC-MS/MS测定。质谱采用正离子电离和多反应监测模式(MRM),基质匹配标准溶液外标法定量。10种酰胺类除草剂在各自的浓度范围内线性关系良好(r~20.99)。10种酰胺类除草剂在高、中、低3个添加水平下,回收率为82.7%～114.2%,RSD为1.1%～8.5%,方法的定量限为0.5～100μg/kg。该方法操作简单、快速、灵敏度和准确度高,适合土壤样品中10种酰胺类除草剂多残留的检测分析。     

气相色谱法测定环境空气与废气中氯乙烯

环境空气或工业废气中氯乙烯以活性炭吸附采集后,用二硫化碳解吸,直接经聚乙二醇6000不锈钢填充柱分离,氢焰离子化检测器检测。方法最低检出浓度0.15mg/m3,相对标准偏差1.9%-5.8%,平均解吸率93.7%,本方法操作简便、快速,灵敏度完全能满足环境监测要求。     

Utilization of industrial waste products as adsorbents for the removal of dyes

A number of low cost adsorbents from steel and fertilizer industries wastes have been prepared and investigated for the removal of anionic dyes such as ethyl orange, metanil yellow and acid blue 113 from aqueous solutions. The results indicate that inorganic wastes, i.e. blast furnace dust, sludge and slag from steel plants are not suitable for the removal of organic materials, whereas a carbonaceous adsorbent prepared from carbon slurry of fertilizer industry was found to adsorb 198, 211 and 219mg/g of ethyl orange, metanil yellow and acid blue 113, respectively. The adsorption of dyes on this adsorbent was studied as a function of contact time, concentration, particle size and temperature by batch method. The adsorption isotherm conformed to Langmuir model and the adsorption was found to be exothermic and physical in nature. Kinetic data conforms to Lagergren's equation with good correlation coefficients varying from 0.9998 to 0.9999 indicating that the adsorption is a first-order process. The adsorption data on carbonaceous adsorbent was compared to a standard activated charcoal sample and it was found that the prepared adsorbent is about 80% as efficient as standard activated charcoal and therefore, can be used as low cost alternative ( approximately 100 US dollars per ton) for colour removal from effluents.     

Removal of endosulfan by sal wood charcoal

The removal efficiency of endosulfan from water by two low cost adsorbents viz. sal wood (Shorea robusta, family-Diptero carpaceae) charcoal and sand along with activated charcoal as the reference was investigated. For the selection of the suitable adsorbent for endosulfan uptake, the maximum adsorption capacity (Q(max)) was chosen as the main parameter. Using linearized forms of equilibrium models like Langmuir, BET, Freundlich, the maximum adsorptive capacities were determined. It was observed that the efficiency for removal of pesticide is higher in activated charcoal with 94% followed by sand 90%. The efficiency of sal wood charcoal is moderately high with 87% which can be regenerated after treatment with dilute HCl and HNO(3). Though the efficiency of sand is better than sal wood charcoal, it cannot be regenerated.     

Towards the use of small amounts of activated charcoal along with well-type NaI(Tl) detector for indoor radon measurements

The feasibility of using small quantities of activated charcoal and a 7.6 cm x 7.6 cm NaI(Tl) well-type detector was investigated for indoor radon measurements. Vials, filled with 10 g of charcoal, were exposed for different indoor radon concentration levels typical of Kuwait dwellings. After exposure, the vials were sealed and kept for 3 h to allow radon to come into radioactive equilibrium with its progenies and were then analysed by gamma-ray spectrometry using the well-type NaI(Tl) detector. The variation of radon absorption by the vials filled with charcoal with exposure time was also studied. A comparative study of the present technique with the standard technique of using 70 g charcoal canisters and flat NaI detector was also performed. After establishing the suitability of the technique, the charcoal vials were then used to investigate the effect of air-ventilation on the concentration levels of the indoor radon. Results show that there is a reduction in the radon concentration level (up to 25%) when the air-ventilation system was switched on. The paper presents the results of the study on the feasibility of combining small amounts of activated charcoal with a well-type NaI(Tl) detector in the measurement of indoor radon concentrations.     

Control of Rate of Solute Transport in Newly Developed Portable Agar Gel Blood Purification System

Ablood purification module was developed with edible agar or Gelrite, in which activated charcoal was dispersed. Tap water (or normal saline) was boiled, and agar (or Gelrite) powder was dissolved in it. The solution was hardened with no additive or activated charcoal in a plastic cylindrical hard shell with a perforated bottom plate to assemble module A (agar only), module AC (agar with various amounts of charcoal), or module GC (Gelrite with various amounts of charcoal), respectively. The hardened gel was thrust with a plastic straw 21 times in the flow direction. Aqueous test solution was prepared for device evaluation. Bromophenol blue (BPB) concentration decreased only by 10% with module A, whereas it gradually decreased according to the amount of activated charcoal dispersed in the agar with module AC; moreover, it reached its lower limit found by direct use of the same amount of intact activated charcoal. Module GC was shown to remove creatinine continuously from bovine whole blood. A portable artificial kidney system may be constructed by combining these modules with a small hemofilter for removing excess water.     

驱虫花露水中避蚊胺的定量分析研究

本文介绍了以邻苯二甲酸二丁脂为内标物,对5%避蚊胺驱虫花露水进行有效成份测定的气相色谱分析法。该方法的相关系数为0.9998;标准偏差为0.0336;变异系数为0.61%;平均回收率为100.8%。     

Use of activated charcoal for the purification of neon in the CLEAN experiment

Passage of neon gas through activated charcoal is planned to be the primary method of removing impurities from the liquid neon scintillator in the CLEAN experiment. In order to quantify this technique, the breakout curves for hydrogen, nitrogen, argon and krypton impurities in neon-saturated activated charcoal were measured. Adsorption coefficients and the number of theoretical stages were measured for hydrogen in the temperature range between 300 and 80 K, nitrogen between 300 and 200 K, and argon between 300 and 190 K. The adsorption coefficient for krypton was measured at 300 K.     

双波长K系数分光光度法测定镍钨合金镀液中的钨含量

以NH4SCN方法测定镍钨合金镀液中的钨含量,镀液中的Ni2+会对其产生干扰。应用双波长K系数分光光度法有效消除了共存Ni2+的影响。测定镍钨合金镀液中的钨时以420 nm为测量波长、370 nm为参比波长,钨的线性回归方程为y=0.426 0x+0.982 3,相对标准偏差为1.2%,加标回收率为96.89%～106.10%。此法用于镍钨合金镀液中钨含量的测定,结果准确。     

基于激光干涉仪数字信号解码的振动校准方法

提出了一种基于Polytec外差激光干涉仪输出S/PDIF数字信号解码的加速度计校准方法,优化了校准过程,并保障了加速度计的灵敏度幅值与相位校准精度。通过与ISO 16063-11推荐的外差激光干涉法在5 Hz～20 kHz频率范围内的校准结果对比,提出方法的灵敏度幅值相对误差与相位差分别小于0.969%和0.165°;灵敏度幅值相对标准差与相位标准差分别小于0.560%和0.356°。     

Formulation of Activated Charcoal for Per Os Administration to Addicted Subjects

The objective of this work was to develop a galenic form of activated charcoal appropriate for the needs of clinical toxicology. To preserve the adsorption capacity of charcoal, we developed an extemporaneous preparation of activated charcoal intended for clinical toxicology. To improve the wettability of activated charcoal, we used densification by wet granulation. The presence of a viscosity agent is necessary to ensure the homogeneity of the suspension and its adhesiveness on gastric mucous membrane. Five formulations with different viscosity agents were prepared, and their adsorption capacity, wettability, viscosity, and adhesiveness were studied.