Venus: microwave detection of carbon monoxide

The 115-gigahertz microwave line of carbon monoxide has been detected in the spectrum of Venus. The measurement proves that the carbon monoxide mixing ratio increases above an altitude of 85 kilometers in the Venus stratosphere and provides quantitative information on carbon monoxide in the altitude region from 80 to 110 kilometers. This altitude region is well above that which has been previously sensed.     

Soil as a sink for atmospheric carbon monoxide

The rate of carbon monoxide oxidation by soil increased with increasing carbon monoxide concentration in the gas phase, in line with Michaelis-Menten kinetics. Rates of carbon monoxide oxidation were determined for 20 soils at 0 degrees , 10 degrees , 20 degrees , and 30 degrees C. The observed oxidation rates were used to calculate a global soil uptake rate of atmospheric carbon monoxide of 4.1 x 10(14) grams per year, which is slightly less than the amount of carbon monoxide believed to be produced annually as a result of fossil fuel combustion.     

Carbon monoxide balance in nature

Consideration of the steady-state equations for stable carbon monoxide and for radioactive carbon monoxide in the troposphere leads to the conclusion that carbon monoxide is produced at a rate of 5x10(15) grams per year, a value some 25 times greater than the rate of carbon monoxide production from combustion. The concomitant residence time for carbon monoxide is 0.1 year, in agreement with a previous estimate of Weinstock. Hydroxyl radicals are shown to account for both the production of this large amount of carbon monoxide by methane oxidation and for its removal by carbon monoxide oxidation. The average concentration of hydroxyl radicals in the troposphere required to achieve this effect is 2.3x10(6) molecules per cubic centimeter, with a daytime concentration of twice that. Levy and McConnell, McElroy, and Wofsy have deduced concentrations of hydroxyl radicals in the troposphere of the same magnitude from purely photochemical considerations, in support of this model.     

Carbon monoxide in rainwater

Concentrations of carbon monoxide in rainwater collected at widely diverse locations show up to a 200-fold supersaturation relative to the partial pressure of the gas in the atmosphere. These results indicate the existence of an additional natural source of carbon monoxide not heretofore considered. Production of carbon monoxide in clouds is tentatively attributed to the photochemical oxidation of organic matter or the slight dissociation of carbon dioxide induced by electrical discharges, or both. Methane concentrations measured in the same rainwater show that the partitioning of this gas, unlike that of carbon monoxide, is very close to a state of equilibrium.     

Carboxyhemoglobin elevation after exposure to dichloromethane

Inhalation of dichloromethane vapor in concentrations of 500 to 1000 parts per million for 1 to 2 hours promptly initiated the formation of significant quantities of carbon monoxide in human subjects. The evidence suggests that carbon monoxide may be a metabolite of dichloromethane and, that exposure to concentrations of dichloromethane below the industrial threshold limit values may result in the formation of carbon monoxide in amounts that exceed the allowable limits.     

Carbon monoxide: residence time in the atmosphere

A lower limit of 0.1 year for the residence time of carbon monIoxide in the atmosphere is derived from radiocarbon measurements. The action of certain microorganisms and atmospheric photochemical reactions are possible mechanisms for the removal of carbon monoxide. This value can be compared with 2.7 years, a value deduced from estimated rates of carbon monoxide production and global measurements of atmospheric concentrations of carbon monoxide.     

叶片加料回潮工序对卷烟叶组化学成分的影响

运用现代分析技术分析叶片加料回潮工序对卷烟叶组及其制品的化学成分的变化规律。结果表明：叶片加料回潮工序对卷烟叶组的总氮、烟气一氧化碳释放量影响较大,其中总氮含量升高11%,而一氧化碳释放量则降低11%,焦油释放量、烟碱和一氧化碳均与总植物碱的相关性较强,其中焦油释放量与总植物碱呈负相关,烟碱和一氧化碳则与其呈正相关。     

Titan's atmospheric temperatures, winds, and composition

Temperatures obtained from early Cassini infrared observations of Titan show a stratopause at an altitude of 310 kilometers (and 186 kelvin at 15 degrees S). Stratospheric temperatures are coldest in the winter northern hemisphere, with zonal winds reaching 160 meters per second. The concentrations of several stratospheric organic compounds are enhanced at mid- and high northern latitudes, and the strong zonal winds may inhibit mixing between these latitudes and the rest of Titan. Above the south pole, temperatures in the stratosphere are 4 to 5 kelvin cooler than at the equator. The stratospheric mole fractions of methane and carbon monoxide are (1.6 +/- 0.5) x 10(-2) and (4.5 +/- 1.5) x 10(-5), respectively.     

The ocean: a natural source of carbon monoxide

The surface waters of the western Atlantic are supersaturated with respect to the partial pressure of carbon monoxide in the atmosphere. Under these conditions, the net transport of carbon monoxide across the air-sea interface must be from the sea into the atmosphere. Thus, the ocean appears to act as a source of carbon monoxide. The ocean may be the largest known natural source of this gas, contributing possibly as much as 5 percent of the amount generated by burning of fuels by man.     

Cytochrome a3 structure in carbon monoxide-bound cytochrome oxidase

The iron-carbon monoxide stretching mode and the iron-carbon-oxygen bending mode in carbon monoxide-bound cytochrome oxidase have been assigned at 520 and 578 cm-1, respectively. The frequencies, widths, and intensities of these modes show that the Fe-C-O grouping in carbon monoxide-cytochrome a3 is linear but tilted from the normal to the heme plane; that the iron-histidine bond in both five- and six-coordinate cytochrome a3 is strained; and that the carbon monoxide and the proximal histidine each have characteristic, well-defined orientations in all molecules. These data can account for the binding affinities of carbon monoxide and dioxygen under physiological conditions.     

MATLAB在不同烤烟品种间主要烟气成分差异性分析中的应用

运用MATLAB 5.0分析云南地区3个烤烟品种的主要烟气成分,结果表明:在0.05显著性水平下有显著性差异的烟气指标,云系列与K326品种间为总粒相物、烟气水分、焦油量、一氧化碳量;云系列和红大品种间为烟气烟碱量、一氧化碳量;红大和K326品种间为烟气烟碱量、一氧化碳量。     

川西亚高山-高山土壤表层有机碳及活性组分沿海拔梯度的变化

青藏高原东缘亚高山-高山地带土壤碳被认为是我国重要的土壤碳库,作为高海拔低温生态系统,土壤碳对土壤暖化的响应可能也更加敏感。该区域亚高山森林一般分布在海拔3200 m以上,上缘接高山树线和灌丛草地,土壤有机碳含量高。海拔梯度上变化的土壤环境因子是主要土壤温度,海拔梯度上高寒土壤有机碳及活性有机碳组的分布格局,可体现海拔梯度上温度因子对土壤碳动态的影响。对沿海拔3200 m(亚高山针叶林)、3340 m(亚高山针叶林)、3540 m(亚高山针叶林)、3670 m(亚高山针叶林)、3740 m(亚高山针叶林)、3850 m(高山林线)、3940 m(高山树线)、4120 m(高山草地)的土壤表层(0-20 cm)有机碳和活性有机碳组分含量进行分析,结果表明在该海拔范围内,表层土壤总有机碳含量随着海拔的升高而增加,显示高海拔有利于土壤碳的固存;土壤活性有机碳组分中,颗粒态有机碳含量及其占总有机碳比例与海拔呈显著正相关,在海拔最高的4120 m含量和占有机碳总量比例分别达到50.81 g/kg和56.52%。在该海拔范围内海拔越高颗粒态有机碳占有机碳比例越高,显示高海拔土壤有机碳更多以土壤颗粒态碳形式贮存。微生物量碳、水溶性碳、轻组分有机碳与海拔高度没有明显的相关性,表明这些活性有机碳组分受海拔因素影响不大;易氧化有机碳含量与海拔高度显著正相关。因此,颗粒态有机碳含量及其比例可作为高海拔地带土壤活性有机碳库动态的特征指标,表征高海拔地带土壤有机碳动态与贮量受温度影响的指标。     

Microwave measurement of mesospheric carbon monoxide

Ground-based observation of atmospheric absorption of solar radiation at a wavelength of 2.6 millimeters has provided the first measurement of mesospheric carbon monoxide. The measurement agrees with photochemical predictions of a carbon monoxide source in the lower thermosphere due to dissociation of carbon dioxide by solar radiation, and has implications for the magnitude of vertical transport in the mesosphere.     

Airborne lead and carbon monoxide at 45th Street, New York City

Daily business-day traffic determines the diurnal lead concentration as well as diurnal carbon monoxide concentration. Daily averages of 7.5 micrograms per cubic meter for lead and 13 parts per million of carbon monoxide were found for the 10-week period of the study. Correlations were demonstrated for lead and traffic and lead and carbon monoxide.     

Soil: a natural sink for carbon monoxide

A potting soil mixture depleted carbon monoxide in a test atmosphere from a concentration of 120 parts per million to near zero within 3 hours. Maximum activity occurred at 30 degrees C. Steam sterilization of the soil, the addition of antibiotics or 10 percent (by weight) saline solution, and anaerobic conditions all prevented carbon monoxide uptake. Sterilized soil inoculated with nonsterile soil acquired activity with time. Samples of various natural soils differed in their ability to remove carbon monoxide from the air. Acidic soils with a high content of organic matter were generally the most active. The soil's ability to remove carbon monoxide from the atmosphere is ascribed to the activity of soil micro-organisms.     

非散射红外法测定卷烟烟气气相中一氧化碳的测量不确定度评定

通过对非散射红外法测定卷烟烟气气相中一氧化碳含量的分析,从测量重复性、一氧化碳示值、抽吸口数、抽吸容量及大气压力和温度等方面计算测定过程的不确定度分量,并计算相对合成标准不确定度和扩展不确定度,达到了对该方法测定一氧化碳的测量不确定度评定的目的,在一定程度上反映了实验室的检测水平。     

Carbon monoxide-induced arterial hypoxemia

Inhalation of carbon monoxide produces an increase in the alveolar to arterial oxygen gradient in the presence of veno-arterial shunts or ventilation-perfusion imbalance but has no such effect in normal subjects. The increase in the alveolar to arterial oxygen gradient with rising concentrations of carboxyhemoglobin results from changes induced by carbon monoxide in the shape of the oxyhemoglobin dissociation curve.     

Titan: discovery of carbon monoxide in its atmosphere

The 3-0 rotation-vibration band of carbon monoxide in the near-infrared spectrum of Titan has been identified, and a reflecting layer model mixing ratio of carbon monoxide to molecular nitrogen of 6 x 10(-5) has been determined. This result supports the probable detection of carbon dioxide by Samuelson and his co-workers and strengthens possible analogies between the atmosphere of Titan and conditions on primitive Earth.     

Volcanic gases in the april 1979 soufriere eruption

Six gas samples from the 17 April 1979 Soufriere eruption plume were analyzed for carbonyl sulfide, carbon disulfide, carbon monoxide, carbon dioxide, methane, nitrous oxide, fluorocarbon-11, fluorocarbon-12, methyl chloroform, and carbon tetrachloride. Only carbon monoxide, carbon dioxide, carbonyl sulfide, and carbon disulfide were found to have increased mixing ratios as compared with those in clean tropospheric air, but the increases were not sufficient to contribute greatly to the global budgets of these four components.     

Carboxyhemoglobin concentrations in blood from donors in Chicago, Milwaukee, New York, and Los Angeles

To determine the carbon monoxide exposure experienced by the residents of Chicago, Los Angeles, Milwaukee, and New York, venous blood samples were obtained from adults at arbitrarily chosen blood bank collection sites in the four cities and analyzed for circulating carbon monoxide, carboxyhemoglobin. For comparative purposes, blood was obtained from volunteers breathing carbon monoxide-free air and was found to contain 0.45 percent carboxyhemoglobin. By contrast a high percentage of all the nonsmoking blood donors breathing city air had carboxyhemoglobin saturations greater than 1.5 percent, which indicated that exposure to carbon monoxide in excess of that permitted by the quality standards of the Clean Air Act of 1971 was widespread and occurring regularly.