Products of the Radiation-Chemical and Thermal Decomposition of Mercury Fulminate

The products of the radiation-chemical and thermal decomposition of mercury fulminate were examined by IR spectroscopy and X-ray diffraction analysis. Upon radiolysis to 20% conversion, the fulminate ion underwent decomposition (G (decomposition) = 20 molecule/100 eV) with the formation of HgO (G = 9 ± 1 molecule/100 eV), CN^– ions, and CO₂. The final solid products of the radiolysis are Hg(CNH)₂, a cyanide complex, the mercury carbonate oxide HgCO₃ · 3HgO, the mercury cyanide oxide Hg(CN)₂ · HgO, and paracyanogen (CN)_n. In the thermolysis, the final solid products of decomposition are the mercury carbonate oxide HgCO₃ · 2HgO, a cyanide complex, and the cluster Hg_nC_mN_oO_p.     

Piezoectric Crystal Detection of Hydrogen Chloride Via Sulfur Dioide/Mercury Displacement

Abstract

Magnesium thiosulfate converts hydrogen chloride to sulfur dioxide, which then reduces mercurous ion to free mercury. This is detected as a mercurygold amalgam using a piezoelectric crystal detector. the reaction sequence has a response time of 2 minutes, is fully reversible, and is made specific for the analyte by the use of appropriate scrubber reagents placed before and after the magnesium thiosulfate. the detector has a linear response with a sensitivity of 8.3 Hz per ppm in the 0.5–92 ppm range, a relative standard deviation less than 5 percent, and an estimated limit of detection of approximately 20 ppb HCI.     

Effects of Water Vapor and Ammonia on SO2 Removal from Flue Gases Using Pulsed Corona Discharge

Plasma Chemistry and Plasma Processing - In the study of SO2 removal using pulsed corona discharge, there exists a serious confusion, that is, which kind of reactions, the thermal chemical...     

Simulation of the Kinetics of Methane Conversion in the Presence of Water in a Barrier Discharge

A method is proposed for the simulation of chemical kinetics in a dielectric barrier discharge (DBD) with the use of an effective rate constant of electron–molecule reaction and a simple expression for its estimation. The results of the simulation of the kinetics of methane conversion in DBD in the presence of water are presented.     

天然气中微痕量氢同位素的在线连续分析

为实现天然气中丰度很低的氢同位素分析,自制氢气富集分离装置,利用在159和77 K温度条件下5A分子筛对不同气体组分的物理吸附性能差异,使天然气样品中微痕量氢与烃类组分分离,并进一步富集后,由载气送入色谱-同位素质谱计系统,分析其同位素组成。分析过程为在线连续流模式,与色谱同位素质谱工作站联动控制,从根本上解决了微痕量氢同位素分析的技术瓶颈。采用本方法分析了已知氢同位素组成的不同浓度人工混合样品,结果表明,本分析方法具有较高的精确度和良好线性,能够满足天然气中氢浓度低至1×10-5(V/V)样品准确分析的要求,标准偏差小于3.3‰。用此方法对不同含油气盆地6个天然气样品进行了分析检测,并对样品中氢同位素组成特征及成因进行了探讨。     

Simulation of the Radiation-Chemical Formation of Peroxyacetyl Nitrates and Aromatic Nitro Compounds

The feasibility of formation of peroxyacetyl nitrates and aromatic nitro compounds in the electron-beam removal of sulfur oxides and nitrogen oxides from the combustion products of organic fuels was studied. A kinetic model of the process was proposed. According to this model, the concentration of the resulting peroxyacetyl nitrates is comparable to the initial concentration of aliphatic hydrocarbons. The degradation of aromatic molecules is accompanied by nitration; in this case, both of the processes occur at approximately equal rates.     

Polymerization of Vinyl Chloride in the Presence of Alcohols

Precipitation polymerization of vinyl chloride in solution in the presence of alcohols was studied. The reaction mechanism was suggested, and the product composition was estimated by IR spectroscopy and selective extraction.     

Diffusion of Vapor in the Presence of a Growing Droplet

As is shown, the solution to the diffusion equation for the concentration of vapor in the presence of a droplet growing in it, derived for the usual initial condition and equilibrium boundary conditions at the droplet surface, fails to ensure an equality between the numbers of molecules that have left the vapor due to diffusion by the current moment and those that have been included in the growing droplet. The difference between the total numbers of vapor molecules at the initial moment (when the vapor had a given uniform concentration) and at the current moment (when the size of the growing droplet is much larger than its initial size) differs from the total number of molecules in the droplet by a factor of 3/2. By substituting the usual boundary condition at the droplet surface by a time-dependent boundary condition at the surface of a constant-radius sphere with the center in the center of the growing droplet, a solution to the diffusion problem for the vapor concentration is derived. This solution describes the evolution of the vapor concentration field, which agrees with the rate of the vapor absorption by the growing droplet and with the law of the conservation of matter.     

冷原子荧光光谱法测定净水剂聚氯化铝中汞含量

提出了冷原子荧光光谱法测定净水剂聚氯化铝中痕量汞,采用断续流动进样,并对仪器的工作条件负高压、灯电流、载气流量、屏蔽气流量作了优化。在优化条件下,荧光强度与汞的质量浓度在0.1～2.0μg.L-1范围内呈线性关系,检出限(3s)为0.05μg.L-1。按此方法分析了聚氯化铝样品,汞测定值的相对标准偏差(n=7)为1.93%。     

Behavior of Mercury Vapor Upon Irradiation by a Mercury Lamp in an Inert Gas

Abstract

The behavior of mercury vapor during irradiation by a mercury lamp is investigated. Using the flameless atomic absorption technique for mercury determination, it was found that when mercury vapor in an inert gas is irradiated by a mercury lamp, the atomic absorption signal of mercury is decreased rapidly and the signal may be restored by heating to 70°C. These phenomena indicate that the irradiation products of mercury vapor in the quartz tube are deposited on the tube, and are dissociated into the mono-atomic state of mercury upon heating.     

Oxidative Cracking of Propane in the Presence of Hydrogen

Russian Journal of Applied Chemistry - An effect of hydrogen additions to the initial mixture on the parameters of the oxidative cracking of propane at atmospheric pressure, temperatures of...     

Assay of Peracid in the Presence of Excess Hydrogen Peroxide

ABSTRACT

A simple and rapid colorimetric method for the determination of peracids in the presence of excess hydrogen peroxide is described. The method is based on the selective destruction of hydrogen peroxide by the enzyme catalase, a procedure which leaves the peracid unaffected. The residual solution, then containing only peracid, can be assayed using the stoichiometric oxidation of 2, 2′-azino-bis-(3-ethyl-benzthiazoline-6-sulfonate) diammonium salt (ABTS) in the presence of peroxidase, a reaction that can be quantified photometrically at 405 run. The double-enzyme method was extended to microtiter plate-based systems, thus providing an easy way of analyzing multiple samples for their peracid content.     

Palladium-Catalyzed Hydroesterification of Alkenes in the Presence of Molecular Hydrogen

The effects of molecular hydrogen on the palladium-catalyzed alkene-alcohol-carbon monoxide and alkene-formate reactions have been studied. Yields of esters were generally increased, especially in the alkene-formate reaction, in which an improvement up to 46% yield has been observed. A possible explanation is proposed in which the molecular hydrogen promotes the oxidative addition of formate to palladium. Decarbonylation of formate ester is unlikely to be the initial step.     

Kinetics of Natural Langbeinite Conversion in Magnesium Chloride Solutions

The mechanism of conversion of natural langbeinite with magnesium chloride solutions was studied. The dependence of the degree of conversion on the process time, temperature, MgCl₂ concentration in solution, and grain size of natural langbeinite was studied.     

微波消解-冷原子吸收光谱法测定消毒剂中的汞

建立了微波消解-冷原子吸收光谱法测定消毒剂中汞的方法。将消毒产品经过微波消解后,其中的汞被氧化为离子状态的汞,利用冷原子吸收光谱测汞仪对样品进行测定,结果表明汞在0~10ng/mL范围内呈良好的线性关系,线性相关系数r=0.999 7(n=6),平均加标回收率为97.08%,相对标准偏差(RSD)为4.0%(n=9)。方法简便、准确、灵敏度高、重现性好,可用于测定消毒剂中的汞。     

Features of Radical Polymerization of Vinyl Chloride in the Presence of Nitroxyl Radicals

Radical polymerization of vinyl chloride in the presence of C-phenyl-N-tert-butylnitrone, 2-meth- yl-2-nitrosopropane, and 1-tert-butyl-3-phenyl-1-oxytriazene as potential sources of free radicals was studied.