芯片毛细管电泳-激光诱导荧光-电荷耦合器件检测系统

采用自组建的芯片毛细管电泳－激光诱导荧光－电荷耦合器件（CCD）检测系统在数十秒内满意地分离了曙红和荧光素。设计了一种进样、分 离电路,可以有效地消除进样通道的样品溶液向分离通道的渗漏。解决了由这种渗漏所引起的电泳峰变宽、拖尾等问题。提高了芯片毛细管电泳的分辨率和分离效率。     

石灰岩溶大突泥化学灌浆

本文阐述了利用割裂灌浆整治岩溶流塑粘土大突泥的方法及其原理,对粘土的灌浆固结机理进行了探索,提出了新的看法,并援引了南岭隧道大突泥的灌浆整治工程为实例。     

云南鹤庆盆地岩溶地下水稀土元素地球化学特征

为揭示云南鹤庆盆地岩溶地下水中稀土元素地球化学特征,对该盆地内主要岩溶泉水和地下河水样进行了水化学常规指标测试和稀土元素测试,分析研究了该地区地下水中稀土元素质量浓度、配分模式以及分异特征和影响因素。结果表明:由于含水岩组的截然不同,造成盆地东部岩溶地下水比西部岩溶地下水ΣREE质量浓度高,该地区岩溶地下水中ΣREE浓度与Eh,HCO_3~-,Ca~(2+)有负相关性,与pH,DO,Fe和Mn有较好的正相关关系,高含量HCO_3~-和Ca~(2+)在一定程度上制约了REE在水中的溶解,铁锰氧化物矿物的还原性溶解是REE进入地下水的主要途径。地下水中LREE有富集、有亏损,还有部分既不富集也不亏损,盆地东部地区地下水中HREE富集程度远远大于西部地区地下水。该地区岩溶地下水表现出明显的Ce负异常和Eu正异常,可能与含水岩组岩性和还原环境有关,同时高Ca~(2+)和HCO_3~-的环境中,Eu~(2+)更容易被释放出来进入地下水中。在地下河管道中,地下水经过长距离的地下径流后,地下河出口∑REE质量浓度高于岩溶泉水,且与入口相比,出口地下水中轻稀土富集和Eu正异常有所增强,Ce负异常程度减少。     

防渗止水用弹性聚氨酯胶片

本文系统地研究了影响弹性聚氨酯作为防渗漏止水胶片性能的各种因素。结果表明,采用亲油性和亲水性聚氮酯相结合,并控制适当工艺条件,可制得粘结力高、形变能力大的防渗漏止水胶片,可望在防渗漏处理中得到应用。     

Experimental study on the Karst area fracture zones of the synthesizing geophysical methods

岩溶地区地形、地质情况相对复杂,各种物探方法的应用都受到一定条件限制,进行岩溶断裂破碎带勘察时,应进行综合物探勘察,为设计和施工提供可靠的原始资料;本文采用综合物探方法对广州地铁九号线工程田美断裂进行探测,详细查明田美断裂的走向、破碎带宽度、构造破碎特征、断裂的性质、规模和产状等;同时辅以少量勘察验证孔施工对断裂做验证,以便有效地揭示断裂特征,通过实验取得较理想的成果,并意外地发现了田美断裂的次一级断裂。     

化学系统性思维的背景、应用与特征*

当今地球与社会系统所面临的可持续发展、气候变化、环境退化等全球性挑战问题,用还原主义方法不足以应对,需要化学教育等领域的工作者采用系统性思维方法。梳理了国外学者在应用化学系统性思维理解化学学科系统复杂性、化学学习系统层级性、化学教育系统整合性的研究进展。概述了化学系统性思维具有重视跨学科关联、整体综合思考目标系统问题、强调可持续发展的全球观念等特征。建议加强化学教育内外部系统的协作,注重各学段化学课程与教学的跨学科、系统性,重视学生解决化学问题的认识方式差异。     

能量连续传递的超分子人工光捕获系统构筑及其在光催化反应中应用

光捕获系统在自然界光合作用过程中起着至关重要的作用.模拟自然界的光捕获体系,在生物成像、发光器件、光催化以及解决人类面临的能源问题等方面均具有重要意义[1].目前,在水相中构筑高效的人工光捕获系统已取得一系列重要进展[2].然而,为了更好地理解并模拟自然界中以多通道信息通讯为特征的捕光天线系统[3],构筑具有多步连续能量转移特征并能实现光能到化学能转化的人工光捕获体系仍然是一项具有挑战性的工作.     

从精品到精彩:化学微课的现状、创作与使用

国内现有化学微课的整体水平可以从3个角度进行分析: 拍摄方式、拍摄内容和拍摄技术。分析精品化学微课, 主要有4个典型特征。关于微课使用, 提出了精品微课在“翻转课堂”中需要“自主任务学习单”支撑的观点。对于未来的微课创作与使用, 需要破除6大疑惑, 解决创作中的8大问题。     

基于学生出错诊断的试题难度影响因素分析

以问题解决理论构建化学试题的问题解决行为图,以高考化学试题为例,通过分析构成试题的要素,收集学生作答试题时出现的主要错误,建立学生的出错原因和被试内部认知特征之间的关系,从问题解决的角度对学生的答题错误进行诊断,并据此分析得出影响试题难度的因素。     

工业循环冷却水中硫化物测定方法的改进

<正>由于中煤龙化哈尔滨煤化工有限公司煤制甲醇主工艺漏硫事件时有发生,因此对主工艺介质进行冷却的循环水面临着污染,随之而来的问题是循环水系统的腐蚀和渗漏、消耗循环水水处理药剂、影响缓蚀阻垢效果并增加药剂费用,长此以往,不但起不     

Co-ion leakage through bipolar membranes Influence on I–V responses and water-splitting efficiency

The influence of co-ion leakage through a bipolar membrane on both I–V response and current efficiency of water dissociation was studied. The monofilm bipolar membrane was synthetized from a pretreated ETFE film functionalized by quaternized ammonium groups on one side and sulphonic groups on the other. The co-ion leakage of this bipolar membrane immersed in NaCl solutions was measured by means of radiotracers. The results showed that the greater the co-ion leakage, the lower was the current efficiency of water dissociation. A theoretical analysis of ion transfer through the bipolar membrane pointing out the effect of boundary layer on the limiting leakage current is presented.     

环氧灌浆材料在莞惠城际轨道工程GZH-5标渗漏水治理中的应用

针对当前聚氨酯灌浆材料在渗漏水治理中存在的问题,提出了依靠堵水环氧灌浆材料和高渗透环氧灌浆材料进行渗漏水治理的新思路。环氧类灌浆材料既能够对混凝土裂缝等缺陷进行修复,也能够封堵渗漏水,希望修复后的缺陷能够保持和恢复混凝土结构的耐久性。     

Rationalisation of the relationship between proton leakage and water flux through anion exchange membranes

Electromembrane concentration of nitric acid using anion exchange membranes has been studied in a laboratory pilot rig. The main factor limiting acid concentration has previously been reported to be proton leakage but in the present work water flux is also shown to be significant. Differential current efficiencies and mean water transport numbers are determined for each system via methematical manipulation of batch data. Water flux appears to be closely linked to proton leakage as an improvement in one of these leads to a deterioration of the other. Previous proton leakage theories have been developed further and a proton leakage and water flux model, based on sorbed species and their interactions within the membrane, has been postulated. It is suggested that the absolute amount of sorbed acid is more significant than the sorbed acid:water ratio. The model is validated by numerous cited publications, in addition to the data presented herein, to explain the performance variation of a given membrane when subjected to different operating conditions. Future work should consider water flux along with proton leakage as figures of merit for process evaluation, and investigate the applicability of the model to the comparative performance of different membranes when subjected to identical operating conditions.     

Mechanisms of passive ion permeation through lipid bilayers: insights from simulations

Multistate empirical valence bond and classical molecular dynamics simulations were used to explore mechanisms for passive ion leakage through a dimyristoyl phosphatidylcholine lipid bilayer. In accordance with a previous study on proton leakage (Biophys. J. 2005, 88, 3095), it was found that the permeation mechanism must be a highly concerted one, in which ion, solvent, and membrane coordinates are coupled. The presence of the ion itself significantly alters the response of those coordinates, suggesting that simulations of transmembrane water structures without explicit inclusion of the ionic solute are insufficient for elucidating transition mechanisms. The properties of H(+), Na(+), OH(-), and bare water molecules in the membrane interior were compared, both by biased sampling techniques and by constructing complete and unbiased transition paths. It was found that the anomalous difference in leakage rates between protons and other cations can be largely explained by charge delocalization effects rather than the usual kinetic picture (Grotthuss hopping of the proton). Permeability differences between anions and cations through phosphatidylcholine bilayers are correlated with suppression of favorable membrane breathing modes by cations.     

电动汽车热泵系统中易燃制冷剂R290的燃烧特性

研究了制冷剂R290在电动汽车热泵空调系统潜在泄漏过程中的燃烧特性,通过实验得到了不同泄漏温度和体积流量下R290的燃烧特性,并与制冷剂R134a进行对比。实验表明:R290在低温下更难点燃,而在高泄漏体积流量下和高泄漏温度下会发生喷射火焰的吹灭现象,且当泄漏温度在30~60℃之间时,泄漏体积流量的增大会提高其燃烧强度。R290制冷剂气体温度越高,其火焰燃烧强度越大,燃烧火焰越细,火焰心高度越低;R290制冷剂气体的体积流量越大,火焰燃烧区域越大,火焰高度越低,热辐射通量越大。     

可控组装方法制备脂质体

利用可控组装方法制备了单仓脂质体。这种制备方法分为两个步骤: (a)利用超声振荡形成油包水(W/O)的微乳液, (b)微乳中小水滴在离心作用下通过油水界面的单分子膜并被其包裹, 在水相中形成脂质体。脂质体直径在50-200nm。脂质体的双分子膜间基本没有残留有机溶剂存在, 并且在制备过程中包封的试剂没有泄漏。可控组装方法制备脂质体具有操作简单、生成脂质体一般不需进一步分离、包封效率较高(57%)等特点。     

Is condensation the cause of plasma leakage in microporous hollow fiber membrane oxygenators

Extracorporeal membrane oxygenators are comprised of large bundles of microporous hollow fiber membranes (HFMs) across which oxygen and carbon dioxide are transferred to and from blood. Long term use of extracorporeal oxygenators is limited by plasma leakage through the pores of the HFM walls, requiring replacement of the oxygenator. Condensation of water vapor on the pore walls is thought to be a possible precursor to plasma leakage. To explore this mechanism, a simple theoretical analysis is used to examine the temperature of the gas flow through the HFMs. For conditions representative of two commercially available oxygenators, the analysis predicts that the gas heats up to the temperature of blood flow outside of the fibers after passing through less than 0.5% of the fiber lengths. Once the gas temperature and hence the fiber wall temperature equilibrates with the blood, condensation of water vapor is no longer possible. In vitro testing of microporous HFMs under gas flow rates and temperature conditions similar to those of extracorporeal oxygenators but with the fibers submerged in water is also presented. The fibers showed negligible degradation in carbon dioxide transfer over a four-day period. These results of both the theoretical and experimental analyses indicate that the condensation of water vapor within the pores of the HFMs is unlikely to be the cause of plasma leakage in clinically used extracorporeal oxygenators.     

Rapid and Simple Method for Extraction of n-Alkanes in Sewage Using a Modified Steam Distillation Extraction Apparatus

Oil pollution of water and soil caused by transportation accidents and leakage has become more and more of environmental concern. In recent years, major advances have been achieved in the analytical methods and techniques. Usually, the enrichment of n-alkanes from oil pollution in water sample could be carried out by liquid-liquid extraction method, which organic reagent was used as an extractant and, consecutively concentration and cleanup steps were needed. The total procedure was time-consuming and a great amount of organic solvent used could cause environmental risks.     

Using MgO fibers to immobilize molten electrolyte in thermal batteries

In this study, MgO fibers were used to immobilize the molten electrolyte in thermal batteries, which replaced the current MgO powders. MgO fibers were synthesized via a facile hydrothermal method. Solvent concentration was found to influence the aspect ratio of MgO fiber regularly. A lower concentration led to a larger aspect ratio. The effects of fiber’s aspect ratio on the electrolyte (LiCl-KCl) leakage, discharge properties, and ionic conductivity of model cell were evaluated. The higher the fiber aspect ratio was, the lower the molten electrolyte leakage was. The electrolyte leakage of pellet using fiber was obviously lower than that using powder. Moreover, during the discharge process, the cell using fiber maintained a longer discharge time than that using powder, while the ionic conductivities were very close. The well performance of MgO fiber-filled cell was due to its dimensional stability and large contact area with molten electrolyte, which was generated from low aggregation and similar net structure.     

Quantification of partial structures of aquatic humic substances by 1H-NMR under WATR conditions

Aquatic humic substances (HS) isolated from surface water, leakage water and ground water have been investigated by ¹H-NMR. The overlapping HOD signal was eliminated by adding ammonium chloride and applying the multiecho method CPMG (Carr, Purcell, Meiboom, Gill) under WATR conditions (water attenuation by transverse relaxation) permitting quantification of partial structures of HS. The proportion of carbohydrates/alcohols/ethers decreases and the proportion of alkyl moieties increases with increasing water or soil depth and thus microbial diagenesis. Also, increasing deoxygenation of aromatic substituents is observed with increasing water or soil depth. In some cases, elimination of the NMR signal of HOD is accompanied by the appearance of another HOD signal which is slightly shifted and much smaller in intensity; this signal probably results from water strongly bound by hydrogen bonding within the HS macromolecules.