用氟化氢标气模拟固定污染源中气态氟化氢采样研究

以氟化氢/氮气混合气模拟固定污染源废气中氟化氢采集过程,对吸收瓶类型、吸收液种类、采集流量及热损耗对测定的影响进行了研究.结果表明:采用氟化氢渗透管结合动态标准气体发生器,自行配制氟化氢标准气体作为气源考察采样单元的采样效率是可行的,吸收瓶类型、吸收液种类、采集流量均对氟化氢的吸收效率影响很小,在实验条件下,气态氟化氢的采样效率均超过90％,满足环境监测要求,在装有冷凝装置条件下,高温废气对吸收液挥发损耗的影响可以忽略.     

高纯六氟化钨去除氟化氢的工艺研究

对高纯六氟化钨制备过程中,采用综合措施抑制电解制氟时氟化氢的挥发、球状氟化钠吸收氟化氢、液氮冷冻固化氟化氢而提纯氟气、六氟化钨低温冷冻抽真空除去氟化氢等物理过程,以及利用六氯化钨与氟化氢发生反应而去除氟化氢的化学过程。结果表明,电解产生的氟气中质量分数4.5%的HF,经过多步聚去除氟化氢后,精馏产品六氟化钨达到HF的质量分数小于5×10-6的高纯要求。解决了氟化氢与六氟化钨2者难以分离的技术问题。     

HFC-134a生产过程氟化氢回收利用方法

简要综述了HFC-134a生产过程中氟化氢的回收利用方法。分别介绍了吸附法、硫酸洗涤法、氢氟酸洗涤法等氟化氢直接回收利用工艺和氟化氢经过水吸收后制成氢氟酸后制取氟化钙、氟化镁、氟硅酸钾等衍生物盐类实现对氟化氢的再利用方法。HFC-134a生产过程中浪费的氟化氢得到有效地回收和利用,对氟资源的综合利用和环境保护具有积极意义。     

利用普钙工业付产二氧化硅制取白炭黑的研究

在普通过磷酸钙的生产中,当硫酸分解磷矿时,除了生成磷酸二氢钙以外,同时还生成了硫酸钙和氟化氢。氟化氢进一步与磷矿石中的二氧化硅反应,生成四氟化硅气体逸出。这种气体一般在吸收室中用水循环吸收,生成氟硅酸和二氧化硅沉淀。其反应如     

氟化氢纯化方法

一种不纯氟化氢气流的纯化方法，该气流含有氟化氢和磷杂质，而且几乎不含硫酸。该方法包括：将不纯的气流吸收到酸的水溶液中形成液流；将液流导入蒸馏柱进行蒸馏，以形成上层氟化氢流，其磷含量低于原不纯的气流，以及含有酸的水溶液和杂质的下层液流。     

氟化铵吸收液中铵含量的测定方法

无水氟化氢生产过程中,对于含有硫酸和氟化氢等多种混合酸的氟化氨吸收液,采用在低温下先去除杂酸再用甲醛法的分析方法,能及时准确地分析出铵的含量,该项工作对生产工艺的适时检验工作及进一步扩大工艺奠定了良好的基础。     

氟化氢的回收

上海第五制药厂在“强力霉素”生产过程中,每天使用的脱水剂无水氟化氢约840公斤。过去,脱水后在40℃和负压条件下用水吸收,蒸出的氟化氢生成浓度为40％左右的氢氟酸,每天约三吨左右,无法全部利用,如放入下水道会严重危害人民健康。现在,将脱水物通过夹套加热,他氟化氢     

氟化氢气体吸收装置的设计及研制

针对工业废气中对氟化氢的治理，通过理论研究和实验验证，对含氟化氢（硫化氢等）酸性气体进行化学反应处理，并对实验结果加以优化和调整。把实验结果和实验路线通过中试装置来放大模拟吸收、处理氟化氢气体，工艺流程、设备选型及控制方案全部经过验证。所研发的氟化氢酸性气体的处理装置简易操作、针对性强、耐腐蚀、易检修、安全性能高、经济合理的多项综合性能，很适合对化学实验室或化工企业的工业废气的处理。     

从磷肥副产氟硅酸制氢氟酸

本文介绍了用硫酸分解氟硅酸制氢氟酸及吸收——解吸法生产氟化氢的方法。     

简述万吨级无水氟化氢引进项目

简述万吨级无水氟化氢引进项目的来源、装置的组成、现状及存在的问题;着重介绍该装置的工艺流程特点及装置的消化与吸收。它将为我国无水氟化氢生产普遍存在的工艺落后、消耗高、腐蚀严重、污染大等问题的解决起一定的指导作用。     

Effect of surface treatment on hair fiber as reinforcement of HDPE composites: Mechanical properties and water absorption kinetics

The objective of this work was to investigate the effect of surface improvement on human hair fiber (HF) based high-density polyethylene (HDPE) reinforced polymer composites. A universal testing machine was used for the characterization of the mechanical behaviors of different types of HF base reinforced HDPE composites, and studies were conducted for the optimization of male/female fiber percentage (15% HF) in polymer composites. The alkali treatment (AT) and acrylic acid treatment (AAT) of HF reinforced HDPE composites showed a remarkable improvement in tensile strength (upto 15.487MPa and 15.638MPa, respectively), which was significantly changed in comparison to the tensile strength of untreated composites. FTIR and SEM test were used to characterize the fiber surface and HF/HDPE reinforced composites. Water absorption kinetics was investigated for the study of diffusion mechanism and kinetics of composites materials, which would be useful to boost the applications of the composite in different areas.     

氟苯清洁生产工艺

开发了以苯胺为原料的氟苯清洁生产工艺。新工艺去掉原工艺中的粗氟苯水洗操作 ,采用三级水循环吸收废气中的 HF,混凝沉降和活性炭吸附法处理含氟废水 ,有效地降低了生产过程中废液排放量 ,废液和废气均达到国家排放标准。同时可提高氟苯收率 ,副产 Na F,回收无水氟化氢循环使用 ,原料成本降低 3 0 %以上     

Dietary Supplementation of Calcium may Counteract Obesity in Mice Mediated by Changes in Plasma Fatty Acids

The scope of this study was to assess the impact of calcium and conjugated linoleic acid (CLA) supplementation on plasma fatty acid profiles and to evaluate potential synergistic effects of both compounds against dietary obesity. Mice separated into five experimental groups were followed: control (C), high-fat diet (HF), HF with calcium (Ca), HF plus CLA and HF with both Ca and CLA. Plasma metabolites and fatty acids were determined by commercial kits and gas chromatography, respectively. Both dietary calcium and CLA supplementation contributed to lower body fat gain under a HF diet. Maximum efficacy was seen with calcium; no additional effect was associated with the combined treatment with CLA. Plasma leptin, adiponectin and HOMA index were in accordance with an altered glucose/insulin homeostasis in the HF and HF + CLA groups, whereas control levels were attained under Ca-enriched diets. Plasma fatty acids showed minor changes associated to CLA treatment, but a high impact on PUFA was observed under Ca-enriched diets. Our results show that the mechanism underlying the anti-obesity effects of calcium supplementation is mediated mainly by changes in PUFA plasma profile. In addition, the lack of synergy on body weight reduction in combination with associated lipid profiles of calcium and CLA suggests that calcium may interfere with absorption and/or bioactivity of CLA, which can be of relevance when using CLA-fortified dairy products against human obesity.     

Removal of CO2 and/or SO2 from gas streams by a membrane absorption method

Studies were made on the membrane absorption of CO₂ and/or SO₂ using hydrophobic microporous hollow-fibre (HF) membrane modules. The absorbent liquids used were aqueous solutions of NaOH, K₂CO₃, alkanolamines and Na₂SO₃, flowing on the lumen side of the HF in laminar flow. A semi-empirical correlation was derived for the gas-phase mass-transfer coefficient on the shell side, by including geometrical factors of the HFs and the shell tube in the general correlation for mass transfer. It was found that the CO₂ absorption rate in various aqueous solutions of alkalis and alkanolamines is successfully described by a model based on gas diffusion through the membrane pores subsequent to gas absorption accompanied by chemical reaction. The simultaneous membrane absorption of SO₂ and CO₂ was also studied using aqueous Na₂SO₃ solution, the selective removal of SO₂ to CO₂ being successfully achieved when both the liquid flow rate and solute concentration are low. This suggests that this membrane absorption method provides an energy saving process for SO₂ removal from flue gases.     

The shape evolution of TiCx prepared by mechanical alloying of Ti-Al-C system after HF treatment

This work has investigated the shape evolution of the TiC particles after immersion in the hydrofluoric acid (HF) solutions at different times. The TiC particles were prepared by mechanical alloying of the Ti-Al-C system. The field-emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) patterns were used to study the phase and morphological evolution of the powders. In addition, the changes in the chemical composition of the solutions were investigated by atomic absorption spectroscopy (AAS). However, the relative intensity, X-ray diffraction full width at half maximum (FWHM) value and the position of the peaks were significantly changed after HF treatment. Results showed that the only detected phase in the XRD patterns of HF-treated samples was TiC. However, there were significant differences between the peaks of the XRD patterns. The results showed that the relative intensity of the (111) planes increased as a function of the immersion time up to 48?h. Moreover, the FWHM values of the peaks revealed that a recrystallization phenomenon occurred for TiC particles after immersion into the HF solutions. The FESEM observations demonstrated that with increasing the time of HF treatment the shape of TiC particles changed from near-spherical to the octahedron and finally cubic morphology.     

火焰原子吸收法测定催化剂中镍的含量

本文采用了以硫酸和氢氟酸溶解催化剂，以柠檬酸铵为掩蔽剂直接用火焰原子吸收法测定催化剂中镍的含量，并对火焰原子吸收法和其他方法进行比较，结果表明该方法简捷快速，准确。     

火焰原子吸收法测定催化剂中铁的含量

本文采用了以盐酸和氢氟酸溶解催化剂，以氯化锶为掩蔽剂，直接用火焰原子吸收法测定催化剂中铁的含量。并对火焰原子吸收法和其它方法进行了比较，结果表明，该方法简便，省时，准确。     

恒流阳极氧化法制备TiO2光催化剂及其光电化学性能

以纯钛片为基体,在质量分数为1％的氢氟酸溶液中,采用恒电流阳极氧化法制备了TiO2光催化材料,利用FE—SEM、XRD、UV-Vis等方法对其微结构和光致特性等进行了表征,通过测定光电流-时间和光电压-电流等曲对TiO2的光电化学性能进行了研究,发现在氧化电流为0．15A条件下制得的TiO2结构均匀,光响应最灵敏,光电催化活性最佳。     

Anti-Kasha Behavior of 3-Hydroxyflavone and Its Derivatives

Excited state intramolecular proton transfer (ESIPT) in 3-hydroxyflavone (3HF) has been known for its dependence on excitation wavelength. Such a behavior violates Kasha’s rule, which states that the emission and photochemistry of a compound would only take place from its lowest excited state. The photochemistry of 3HF was studied using femtosecond transient absorption spectroscopy at a shorter wavelength excitation (266 nm), and these new experimental findings were interpreted with the aid of computational studies. These new results were compared with those from previous studies that were obtained with a longer wavelength excitation and show that there exists a pathway of proton transfer that bypasses the normal first excited state from the higher excited state to the tautomer from first excited state. The experimental data correlate with the electron density difference calculations such that the proton transfer process is faster on the longer excitation wavelength than compared to the shorter excitation wavelength.     

原子吸收法测定热镀锌液中有害元素的含量

提出采用原子吸收法连续测定热镀锌镀液中Fe、Pd、Pb等6种有害元素的含量,从而发现热镀锌厂镀件表面出现麻点、无光泽、发黑问题的原因为镀液中Fe和Pb含量严重超标。该法采用HNO3和HF溶液溶解试样。介绍了最佳的仪器工作条件,并进行了相关的干扰试验。该法快速、准确、回收率高,相对标准偏差为1．7%～2．6％,具有推广价值。