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在碱性溶液中,非离子表面活性剂──乳化剂OP存在下,银与对二甲基苄基罗丹宁(PDR)显色生成极红色配合物,溶于水相。本文研究应用双波长β修正分析理论直接测定水相中微量银。银0~1.6mg/l浓度范围,修正吸光度Ac遵守比耳定律。废水测定表明方法相对标准偏差RSDS4≤4%,加标回收率94.5%~106%。银最低检测浓度0.02mg/l。 相似文献
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以钛酸丁酯为原料,采用超声法制备了纳米TiO2,以该TiO2作为光催化剂,对模拟氯苯废水进行超声光催化降解研究,考察了TiO2的加入量、氯苯的初始浓度、溶液pH值、过氧化氢的浓度等对氯苯降解率的影响。结果表明,pH值对氯苯的超声光催化影响较小,H2O2的浓度、氯苯的初始浓度影响较大。在TiO2质量浓度为200mg/L、氯苯质量浓度为110.6mg/L、pH为7.0、反应时间为90min的条件下,氯苯降解率可达92.94%。探讨了氯苯TiO2光催化降解的机理,氯苯超声光催化降解的中间产物主要是邻氯苯酚和间氯苯酚。 相似文献
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为了研究聚苯胺(PANI)/银复合薄膜对不锈钢的防腐蚀性能,采用循环伏安法在不锈钢表面沉积一层Ag后,再通过对苯胺的电化学聚合制备了PANI膜。利用阳极极化法和交流阻抗法研究了PANI/Ag复合膜的耐蚀性及其影响因素。结果表明:在0.1 mol/L NaC l溶液中,不锈钢覆盖复合膜后的自腐蚀电位比无膜时有所提高,其耐蚀性能得到增强;电化学聚合溶液浓度、扫描速率及扫描上限等因素对复合膜耐蚀性的影响情况为:电解液中苯胺和硫酸浓度过高或过低都会影响膜的致密度,从而影响复合膜的耐蚀性;电化学参数的变化会影响复合膜的聚合速率,使复合膜的抗腐蚀能力不同;当苯胺单体浓度为0.2 mol/L、硫酸浓度为1 mol/L、扫描电位上限为1 V、扫描次数为50次、扫描速率为50 mV/s时,采用循环伏安法聚合苯胺,可形成沉积致密度高、耐蚀性好的复合膜。 相似文献
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高效降解苯胺的菌株AD9的分离、生理生化特性分析和分子鉴定 总被引:4,自引:0,他引:4
从活性污泥中分离到一株能以苯胺为唯一碳源、氮源生长的苯胺降解菌株AD9,该菌株最适生长的苯胺浓度为1000mg/L,降解效率可达90%,对苯胺耐受程度高达4500mg/L,降解苯胺的最适pH值为7.0,最适温度为30℃。以上实验结果表明,AD9具有降解苯胺速率快、耐受苯胺浓度高的特性。该菌具有氨苄青霉素、卡那霉素和利福平抗性,无氯霉素、四环素抗性,其16SrDNA序列与多株Delftia sp.菌有很高的同源性,其G+C含量为66.8mol%,非常接近于标准菌株D.tsuruhatensis T7(66.2mol%)。另外该菌和17的DNA-DNA杂交率为83.8%。结合AD9的表型鉴定将该菌株归属为D.tsuruhatensisas。这是D.tsuruhatensis菌种苯胺降解细菌菌株的首次报道。 相似文献
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文中建立了HPLC-DAD同时测定头发中碱性橙31等9种碱性染料的方法。方法以甲醇为提取溶剂,采用xB—c18柱,以乙腈-0.02mol/L乙酸铵(含0.05%甲酸)为流动相进行梯度洗脱,二极管阵列检测器检测。试验的平均回收率为93.9%~102.5%,相对标准偏差为1.2%~3.5%,最低检测浓度为0.15~0.60mg/kg。结果表明该方法前处理简单、快速,适用于测定头发中碱性橙3l等9种碱性染料组分的含量。 相似文献
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《材料科学与工程学报》2020,(2)
采用水热法,以钛酸四丁酯为原料制备形貌可控的TiO2纳米颗粒。利用HCl调控水热反应溶液的H+浓度,实现了对TiO2晶型的调控;通过改变钛酸丁酯与硫酸的反应时间,实现了对TiO2晶面的调控。采用多种表征手段对TiO2的晶型和晶面进行表征。通过在LED灯下降解10mg/L的罗丹明B溶液测定TiO2的光催化性能。研究结果表明:在晶型调控的实验中随着HCI浓度的增大,锐钛矿相和板钛矿相的比例逐渐减小,金红石相逐渐增大。当HCl浓度为0.5mol/L时锐钛矿比例约为75%,此时TiO2的光催化性能最好。控制晶面的实验中,钛酸丁酯与硫酸的反应促进了{001}高能面的暴露,在反应时间为15h时TiO2的光催化性能最好。 相似文献
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《International journal for numerical methods in engineering》2018,113(9):1488-1506
In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method. 相似文献
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Standards are the basis for production enterprises to organize production ex-factory inspection trade 《中国标准化(英文版)》2008,25(1):24-25
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.…… 相似文献
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A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa. 相似文献
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Steffen Müller-Probandt 《材料科学与工程:中英文B版...》2018,(4):161-177
We associate a variety of innovations with the term "Industry 4.0". The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di... 相似文献
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On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.…… 相似文献
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Janet Lang 《Materials and Manufacturing Processes》2017,32(7-8):857-866
ABSTRACTThe production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them. 相似文献
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Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß. 相似文献
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C. Qihong W. Zhan‐Wen J. Yi J. Yehua L. Fei F. Hanguang 《Materialwissenschaft und Werkstofftechnik》2014,45(7):582-590
In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M2(B,C), (W,Mo)2(B,C), M3(B,C), M23(B,C)6 type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm2. The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K1 mill housing of bar mill. 相似文献
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Dimiter Hadjistamov 《材料科学与工程:中英文B版...》2019,(2):56-65
The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ... 相似文献