FCC催化剂中锑含量

工业上经常采用锑金属钝化剂防止FCC催化剂失活,但必须严格控制钝化剂的添加量,否则会起副作用,本文采用高温盐消解法处理FCC平衡剂,然后用火焰原子吸收光谱法测定催化剂中锑含量,考察了消解温度、消解时间、酸度等对测量结果的影响,优选出了最佳分析测试条件.所建方法简便、灵敏、准确,该方法回收率在95%～99%之间,变异系数小于2.5%,最小检出限为0.092 mg/L.     

FCC催化剂中锑含量

工业上经常采用锑金属钝化剂防止FCC催化剂失活,但必须严格控制钝化剂的添加量,否则会起副作用,本文采用高温盐消解法处理FCC平衡剂,然后用火焰原子吸收光谱法测定催化剂中锑含量,考察了消解温度、消解时间、酸度等对测量结果的影响,优选出了最佳分析测试条件。所建方法简便、灵敏、准确,该方法回收率在95％～99％之间,变异系数小于2．5％,最小检出限为0．092mg／L。     

原子吸收法测定催化剂中的镧含量

工业上经常采用镧金属钝化剂防止催化剂失活,但必须严格控制钝化剂的添加量,否则会起副作用.采用高温酸消解法处理平衡剂,然后用火焰原子吸收光谱法测定催化剂中镧含量,考察了温度、消解酸度等对测量结果的影响,优选出了最佳分析测试条件.所建方法简便、灵敏、准确,该方法回收率在96%～101%之间,变异系数小于2.1%.最小检出限为0.048 mg/L.     

微波消解-钼锑抗光度法测定蔬菜中总磷

采用微波消解-钼锑抗光度法测定蔬菜中的总磷,为获得最佳试验条件,对微波消解条件中的酸的种类、消解时间和消解温度等影响因素进行优化,结果表明:硝酸和过氧化氢(体积比7∶1)为最佳消解酸系,最高消解温度180℃,保持时间20 min。对紫外-可见光波长和显色时间对试验结果的影响进行探讨,结果表明710 nm和20 min为最佳试验条件。为评价该方法的可靠性,选用两种蔬菜标准物质GBW 10048和GBW 10049对该方法进行分析验证,测定值与标准值相符,相对标准偏差(RSD)分别为0.884%和0.938%,添加回收率大于89.93%,表明该方法拥有良好的准确性和精密度。微波消解-钼锑抗光度法具有简单、省时省力、试剂用量少等优点,能够满足蔬菜中总磷的测定。     

有机酸在超声作用下对废FCC催化剂中有害金属脱除的影响

有害金属Fe、V、Ni是石油流化催化裂化(FCC)催化剂中毒的根源，导致FCC催化剂的活性降低。针对现有废FCC催化剂再生工艺存在有害金属脱除率低、废剂颗粒的微观形貌和分子筛骨架易被破坏、废剂无法回用等问题，以有机酸为浸出剂，提出超声协同有机酸脱除废催化剂中有害金属的强化处理工艺。本研究以保留废FCC催化剂的球状颗粒结构和Y型分子筛骨架结构为前提，研究在超声作用下氧化预处理、有机酸种类、反应温度、时间以及超声功率对废FCC催化剂中有害金属脱除的影响。实验结果表明，在超声作用下，不同有机酸对有害金属的脱除效果从弱到强的顺序为乙酸、EDTA、草酸+乙酸、草酸，而废剂微观结构被破坏的程度也增加。在草酸和乙酸的混合液为浸出剂、超声功率为250 W、浸出温度为70℃、浸出时间为30 min的条件下，V、Fe、Ni脱除率分别高达40.7%、27.5%和17.2%,且浸出后的FCC催化剂球状结构和分子筛骨架结构完整。与常规浸出相比，超声浸出对有害金属的脱除起到强化作用，V、Fe、Ni的浸出率分别提高了19.9%、13.1%和7.7%。     

化妆品中锑检测方法研究

锑元素对人体存在一定的安全隐患,在化妆品生产过程中禁止添加的一类重金属。目前,锑金属的前处理方法主要分为湿法消解和微波消解两种,除此之外本文还简要介绍金属锑的法原子荧光光谱法、石墨炉原子吸收法、电感耦合等离子光谱法等检测方法。目的是为加强锑元素的化妆品监管及检测研究奠定基础。     

一种自动石墨消解-ICP-MS法监测工业区土壤中微量砷、汞、硒、锑元素残留方法的建立

建立电感耦合等离子体质谱法监测工业区土壤样品中砷、汞、硒、锑4种微量元素残留的分析方法。利用全自动石墨消解仪消解工业园区土壤样品,盐酸-硝酸-氢氟酸体系作为消解酸体系,按照程序设置进行密闭消解,消解液用3%稀硝酸定容,电感耦合等离子体质谱仪定量检测砷、汞、硒、锑4种元素残留量。4种元素质量浓度在0.02～10μg/L范围内线性关系良好,相关系数(r2)0.995;4种元素加标回收率范围为84.5%～107.2%;检出限:砷0.001 8μg/L、汞0.003 4μg/L、硒0.007 4μg/L、锑0.001 0μg/L;精密度相对标准偏差RSD(n=6)在1.35%～3.51%之间,重复性相对标准偏差RSD(n=6)在2.47%～4.89%之间。结果表明,该方法具有前处理快速、检出限低、重复性好、检测结果准确可靠等优点,适用于工业园区土壤中微量元素残留的检测。     

径向气流对旋风分级器的影响

为了改善分级器性能,试验引入径向气流对旋风分级器中的颗粒进行再次分离;试验物料选用催化裂化(FCC)和S-Zorb催化剂,对分级机进行了5组不同径向气速的试验。结果表明:该分级机对2种物料的最小切割粒径分别为6.5、3.3μm;试验中分级粒径为2μm时,FCC和S-Zorb催化剂的牛顿分级效率分别为91.9%和54.1%;径向风的引入破坏了康达效应的形成条件,有利于提高分级效果;进出口压降随着径向气流量的增大而降低;分级机对FCC催化剂的去"细"能力较好,对S-Zorb催化剂的去"粗"能力较好。     

微波消解-电感耦合等离子体质谱(ICP-MS) 同时测定塑料包装材料中有毒有害元素

采用硝酸-过氧化氢消解体系,及高压密闭微波技术处理塑料包装材料,建立了电感耦合等离子体质谱法同时测定塑料包装材料中铅、镉、砷、铬、锑、汞、硒、钡、镍、锡、锶、铊多种有毒有害元素的方法。方法的检出限为0.02~0.20μg/L,相对标准偏差(RSD)小于10%,加标回收率为88.0%~117.0%。该方法简单、快速、灵敏、准确度好。     

测定土壤中总磷的消解方法

通过微波消解、电热板消解、水浴锅消解三种不同的前处理方法,应用钼锑抗分光光度法测定土壤中的总磷。结果表明:三种消解方法得到的数据在检出限、精密度和准确度上满足现行标准,与现行标准相比,三种消解方式具有省时、省力、节能、环保等优点,有更广泛的应用潜力。     

Evaluation of charge transfer characteristics of metal-free phthalocyanine thin films by displacement current measurement

We have investigated phthalocyanine thin films using displacement current measurement. Two types of samples were prepared by vacuum evaporation method. One is the sample with a passivation film. The other is the sample without a passivation film. The passivation films were prepared by casting toluene solution containing 3 wt.% of polystyrene. The results obtained by measuring the samples elucidate the relation between carrier behavior and ambience. It is clarified that there are many traps in the sample without the passivation film. On the other hand, in the sample with the passivation film, traps are not observed. Therefore, it is concluded that the passivation film provides the constraint of oxygen doping as well as the preservation of carrier transfer system.     

钝化方式对镀锡钢板耐蚀性及铬含量的影响

使用化学分析、X射线光电子能谱分析以及电化学测试等试验方法,研究化学钝化以及电化学钝化得到的镀锡板的铬含量、铬元素组成及耐蚀性。结果表明:对于镀锡钢板铬酸盐钝化膜,电解钝化膜的总铬含量高于化学钝化膜的总铬含量。钝化膜中主要含有Cr,O以及Sn元素。不同钝化方式得到的钝化膜中铬元素的的价态、组成均不同,化学钝化膜及电解钝化膜中铬元素的组成分别为Cr2O3,Cr(OH)3以及Cr2O3,Cr(OH)3,Cr。电化学钝化膜的耐蚀性高于化学钝化膜。     

镀锌层硅酸盐无铬黑色钝化工艺

硅酸盐环境友好、成本低、性能稳定,用于镀锌件无铬黑色钝化,目前尚无报道。以硅酸为主盐对镀锌件进行了无铬黑色钝化,研究了钝化液各组分、钝化工艺条件对钝化膜外观及耐蚀性能的影响,获得了最优的钝化工艺。结果显示:镀锌件钝化膜外观乌黑、光亮,色泽均匀;耐5%NaCl盐雾腐蚀达160 h,优于现有的三价铬盐钝化工艺。     

热浸镀锌层有机物-无机物复合钝化工艺优选及其性能

为了进一步提高热浸镀锌层钝化膜的耐蚀性能,针对目前无铬钝化多为独立体系的有机物钝化或无机物钝化的情况,运用有机物与无机物进行复合钝化。通过正交试验法确立了热浸镀锌层无色钝化工艺,采用单因素变量法、点滴试验、中性盐雾腐蚀试验及电化学测试技术,研究了复合钝化工艺参数对钝化膜外观和耐蚀性的影响。结果表明:最佳复合钝化工艺为40 g/L丙烯酸树脂,20 g/L硝酸钠,40 g/L硅酸钠,15 m L/L过氧化氢;p H值11,钝化时间30 s,温度30℃,恒温烘干;钝化膜的耐蚀性能接近于三价铬钝化。     

Passivation of cobalt nanocluster assembled thin films with hydrogen

The effect of hydrogen passivation on bare and Pd capped cobalt nanocluster assembled thin films was studied with Rutherford backscattering spectrometry (RBS) and magnetic force microscopy (MFM) after exposure to ambient conditions. The nanoclusters are produced in a laser vaporization cluster source in which the helium carrier gas was mixed with hydrogen. RBS revealed that oxidation of the Co nanoclusters is considerably reduced by the presence of hydrogen during cluster formation. The capping did not modify the influence of the passivation. The hydrogen passivation method is especially effective in cases when capping of the films is not desirable, for example for magnetic studies. Clear differences in the magnetic domain structures between hydrogen passivated and non-passivated Co nanocluster films were demonstrated by MFM and are attributed to a difference in inter-cluster magnetic interaction, which is critically depending on the CoO content. The hydrogen passivation method may be used to tailor and stabilize properties of nanocluster assembled thin films.     

Intermolecular π–π Conjugation Self-Assembly to Stabilize Surface Passivation of Highly Efficient Perovskite Solar Cells

Surface passivation is an effective approach to eliminate defects and thus to achieve efficient perovskite solar cells, while the stability of the passivation effect is a new concern for device stability engineering. Herein, tribenzylphosphine oxide (TBPO) is introduced to stably passivate the perovskite surface. A high efficiency exceeding 22%, with steady-state efficiency of 21.6%, is achieved, which is among the highest performances for TiO₂ planar cells, and the hysteresis is significantly suppressed. Further density functional theory (DFT) calculation reveals that the surface molecule superstructure induced by TBPO intermolecular π–π conjugation, such as the periodic interconnected structure, results in a high stability of TBPO–perovskite coordination and passivation. The passivated cell exhibits significantly improved stability, with sustaining 92% of initial efficiency after 250 h maximum-power-point tracking. Therefore, the construction of a stabilized surface passivation in this work represents great progress in the stability engineering of perovskite solar cells.     

Structure and electrical properties of PMNSZT/PVDF pyroelectric composites doped with BiCl3

Lead manganese niobate stibium zirconate titanate (PMNSZT) ceramic powder fabricated by the conventional method has been incorporated into a poly(vinylidene fluoride) (PVDF) copolymer matrix to form the pyroelectric composites. Furthermore, the composites doped with BiCl₃ were fabricated by solvent casting method, and their microstructure was investigated by scanning electron microscopy and X-ray diffraction. The dielectric, piezoelectric, and pyroelectric properties of the composites with different mass fractions of BiCl₃ were studied. It was found that the electric properties were enhanced with the addition of BiCl₃. In addition, when 2% BiCl₃ was added, the composites exhibited the best electric properties, especially the pyroelectric properties that can satisfy the need for their applications in pyroelectric devices.     

锌镀层硅酸盐钝化膜的耐腐蚀性能

为了考察锌镀层硅酸盐钝化膜的耐腐蚀性能,通过中性盐雾试验、3%CuSO4点滴试验对比研究了锌镀层、硅酸盐钝化膜及低铬酸盐钝化膜的耐腐蚀性能,并用极化曲线电化学测试方法研究了硅酸盐钝化膜的电化学性能。结果表明:硅酸盐钝化膜明显提高了锌镀层的耐腐蚀性能,其耐蚀性优于低铬酸盐钝化膜;硅酸盐钝化膜也明显提高了锌镀层的自腐蚀电位,有效地控制了其腐蚀的电化学过程,属阳极控制型。锌镀层硅酸盐钝化膜具有较高的耐蚀性能。     

Effect of aluminum content on the passivation behavior of Fe–Al alloys in sulfuric acid solution

The passivation behavior of Fe–Al alloys (3.4, 10.4, 18.7, 19.4, 29.5, and 41.7 at % Al) and Fe–Al alloys (19.5 and 29.0 at % Al) with 5.1 at % Cr addition in 0.1 N H₂SO₄ is reported in this paper. The behavior has been evaluated by potentiodynamic polarization measurements. The results show the Fe–Al alloys, which the Al content of alloy exceeds 19 at %, have wide passivation regions with low passivation current. However, when the Al content of Fe–Al alloys exceeds this range, the increment of Al content has slight influence on passivation behavior compared with ternary Cr addition.     

Matching Charge Extraction Contact for Infrared PbS Colloidal Quantum Dot Solar Cells

Infrared solar cells (IRSCs) can supplement silicon or perovskite SCs to broaden the utilization of the solar spectrum. As an ideal infrared photovoltaic material, PbS colloidal quantum dots (CQDs) with tunable bandgaps can make good use of solar energy, especially the infrared region. However, as the QD size increases, the energy level shrinking and surface facet evolution makes us reconsider the matching charge extraction contacts and the QD passivation strategy. Herein, different to the traditional sol-gel ZnO layer, energy-level aligned ZnO thin film from a magnetron sputtering method is adopted for electron extraction. In addition, a modified hybrid ligand recipe is developed for the facet passivation of large size QDs. As a result, the champion IRSC delivers an open circuit voltage of 0.49 V and a power conversion efficiency (PCE) of 10.47% under AM1.5 full-spectrum illumination, and the certified PCE is over 10%. Especially the 1100 nm filtered efficiency achieves 1.23%. The obtained devices also show high storage stability. The present matched electron extraction and QD passivation strategies are expected to highly booster the IR conversion yield and promote the fast development of new conception QD optoelectronics.