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DZN2型自动土壤水分观测仪常见问题分析 总被引：3，自引：0，他引：3
根据DZN2型自动土壤水分观测仪的运行情况,结合在全国12个省(区、市)收集的设备故障和维修信息,从供电系统、采集器、传感器及数据异常变化等方面分析和说明了常见问题出现的原因,并给出了解决方法,提出了设备维护及场地维护的注意事项,旨在提高台站技术人员对设备的维护和检修能力,为仪器的日常维护检查、故障排查提供参考,也为提高自动土壤水分站运行的稳定性和数据质量的可靠性提供基础技术支持. 相似文献
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根据XDR-21雷达的故障现象，分析产生故障的原因，缩小排查故障的范围，应用检修故障的基本方法，达到尽快排除故障的目的。 相似文献
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随着电子科学技术的飞速发展和气象技术装备的更新换代,大量电子设备在气象台站安装使用,这些设备精密,线路复杂,出现故障往往是多种多样的,而产生故障的原因又是错综复杂的,因此排除故障的方法也必须灵活才能适应气象技术装备的检修,保证业务工作正常运转.在多年实践中,我坚持了"六十字维修方法",取得了较好的效果,现总结如下,供同行们共同探讨.六十字维修方法即:精通电路原理,压缩故障范围;了解设备状况,细察故障现象;熟悉维修方法, 相似文献
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Atmospheric nitric acid measurements by ACIMS (Active Chemical Ionization Mass Spectrometry) are based on ion-molecule reactions of CO3
-(H2O)
n
and NO3
-(H2O)
n
with HNO3. We have studied these reactions in the laboratory using a flow tube apparatus with mass spectrometric detection of reactant and product ions. Both product ion distributions and rate coefficients were measured. All reactions were investigated in an N2-buffer (1–3 hPa) at room temperature. The reaction rate coefficients of OH-, O2
-, O3
-, CO4
-, CO3
-, CO3
-H2O, NO3
-, and NO3
-H2O were measured relative to the known rate k=3.0×10-9 cm3 s-1 for the reaction of O- with HNO3. The main product ion of the reaction of CO3
-H2O with HNO3 was found to be (CO3HNO3)- supporting a previous suggestion made on the basis of balloon-borne ACIMS measurements. For the reaction of bare CO3
- with HNO3 three product ions were observed, namely NO3
-, (NO3OH)-, and (CO3HNO3)-. The reaction rate coefficients for CO3
-H2O (1.7×10-9 cm3 s-1) and NO3
-H2O (1.6×10-9 cm3 s-1) were found to be close to the collision rate. The measured k values for bare CO3
- (1.3×10-9 cm3 s-1) and NO3
- (0.7×10-9 cm3 s-1) are somewhat smaller. The collisional dissociations of CO3
-(H2O)
n
, NO3
-(H2O)
n
(n=1, 2), (CO3HNO3)- and (NO3HNO3)-, occasionally influencing ACIMS measurements, were also studied. Fragment ion distributions were measured using a triple quadrupole mass spectrometer. The results showed that previous stratospheric nitric acid measurements were unimpaired from collisional dissociation processes whereas these processes played a major role during previous tropospheric measurements leading to an underestimation of nitric acid concentrations. Previous ACIMS HNO3 detection was also affected by the conversion of CO3
-(H2O)
n
to NO3
-(H2O)
n
due to ion source-produced neutral radicals. A novel ACIMS ion source was developed in order to avoid these problems and to improve the ACIMS method. 相似文献
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Frank J. Millero J. Beter Hershey George Johnson Jia-Zhong Zhang 《Journal of Atmospheric Chemistry》1989,8(4):377-389
The pK
1
* and pK
2
* of H2SO3 have been determined in NaCl solutions as a function of ionic strength (0.1 to 6 m) and temperature (5 and 25 °C). The extrapolated values in water were found to be in good agreement with literature data. The experimental results have been used to determine the Pitzer interaction parameters for SO2, HSO
3
-
and SO
3
-
in NaCl solutions. The resultant parameters for NaHSO3 and Na2SO3 were found to be in reasonable agreement with the values for NaHSO4 and Na2SO4. It, thus, seems reasonable to assume that the interactions of Mg2+ and Ca2+ with HSO
3
-
and SO
3
-
can be estimated from the values with HSO
4
-
and SO
4
-
until experimental values are available. Measurements of pK
1
* and pK
2
* in artificial seawater were found to be in good agreement with the calculated values using the derived Pitzer parameters. It is, thus, possible to make reasonable estimates of the activity coefficients of HSO
3
-
and SO
3
-
ions and pK
1
* and pK
2
* for the ionization of H2SO3 in marine aerosols. 相似文献
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Rate coefficients have been measured for the reactions of hydroxyl radicals with five aliphatic ethers over the temperature range 242–328 K. Competitive studies were carried out in an atmospheric flow reactor in which the hydroxyl radicals were generated by the photolysis of methyl nitrite in the presence of air containing nitric oxide. The reaction of OH with 2,3-dimethyl-butane was used as the reference reaction and the following Arrhenius parameters have been obtained for the reactions: OH+RORproducts:
相似文献
| ROR | E/kJ mol–1 | 1012 A/cm3 molecule–1 s–1 |
|---|---|---|
| dethyl ether | –2.8±0.4 | 3.5±0.6 |
| di-n-propyl ether | –1.2±0.6 | 11.5±2.7 |
| methylt-butyl ether | 0.85±0.59 | 4.0±1.3 |
| ethyln-butyl ether | –1.3±0.5 | 8.7±1.7 |
| ethylt-butyl ether | –1.2±0.6 | 3.0±0.8 |
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Rate constants have been measured for the gas-phase reactions of hydroxyl radical with two halons and three of their proposed substitutes and also with CHClBr-CF3 using the discharge-flow-EPR technique over the temperature range 298–460 K. The following Arrhenius expressions have been derived (units are 10–13 cm3 molecule–1 s–1): (9.3
–0.9
+1.0
) exp{–(1326±33)/T} for CHF2Br; (7.2
–0.6
+0.7
) exp{–(1111±32)/T} for CHFBrCF3; (8.5
–0.8
+0.9
) exp{–(1113±35)/T} for CH2BrCF3; (12.8
–1.2
+1.5
) exp{–(995±38)/T} for CHClBrCF3. The rate constants at 298 K have been estimated to be <2×10–17 cm3 molecule–1 s–1 for CF3Br and CF2Br—CF2Br. The atmospheric lifetimes due to hydroxyl attack have been estimated to be 5.5, 3.3, 2.8, and 1.2 years for CHF2Br, CHFBr—CF3, CH2Br—CF3 and CHClBr—CF3, respectively. 相似文献
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Analysis of Carbon Dioxide Variations in the Atmosphere of Srednja Bijambarska Cave,Bosnia and Herzegovina 总被引：4，自引：0，他引：4
The results of one year’s monitoring in Srednja Bijambarska Cave (Bosnia and Herzegovina) are presented and discussed. Temporal
variations of the carbon dioxide (CO2) concentration are controlled by the switching between two ventilation regimes driven by outside temperature changes. A regression
model with a simple perfectly mixed volume applied to a cave sector (“Music hall”) resulted in an estimate of ventilation
rates between 0.02 h−1 and 0.54 h−1. Carbon dioxide input per plan surface unit is estimated by the model at around 50 × 10−6 mh−1 during the winter season and up to more than 1000 × 10−6 mh−1 during the first temperature falls at the end of summer (0.62 μmoles m−2 s−1 and 12.40 μmoles m−2 s−1 for normal conditions respectively). These values have been found to be related to the cave ventilation rate and dependent
on the availability of CO2 in the surrounding environment. For airflow close to zero the values of CO2 input per plan surface have a range in the order of magnitude of a few units × 10−6 mh−1. Based on two experiments, the anthropogenic contribution from cave visitors has been calculated, at between 0.35 lCO2 min−1 person−1 and 0.45 lCO2min−1person−1. 相似文献
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Chemical characteristics of wet precipitation at an urban site of Guangzhou, South China 总被引：5，自引：0，他引：5
The pH variation and chemical characteristics of rainwater were investigated from January 2006 to December 2006 at an urban site of Guangzhou, South China. The rainwater was typically acidic with a volume-weighted mean pH value of 4.49, which ranged from 3.52 to 6.28. The volume-weighted mean equivalent concentration of components followed the order: SO42− > Ca2+ > Cl− > NH4+ > Na+ > NO3− > K+ > Mg2+ > F−, indicating that SO42−, Cl− and NO3− were the main anions, while Ca2+ and NH4+, were the main cations. Ca2+ and NH4+ were major neutralization constituents of the precipitation. Furthermore, correlation analysis and principal component analysis method were performed to identify possible common sources of major ions. Sources of the major ions were assessed based on enrichment factor method. 相似文献
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Zusammenfassung Um die Wirksamkeit des Aufschlags von Wolkentröpfchen auf Eis (Faraday-Sohncke-Effekt) für die Elektrizitätserzeugung in Gewittern beurteilen zu können, werden quantitative Ladungsmessungen im Laboratorium beim Aufprall fallender Wassertropfen auf Hindernisse aus Eis unter möglichst variierten Bedingungen vorgenommen. Ein Tropfen von 20 mg und 20° C aus 75 cm Höhe befreit die Ladung von 3,6·10–13 Coul. Während eine Änderung der Tropfentemperatur den Effekt wenig beeinflußt wird er stark reduziert, wenn man die Temperatur der Eisplatte kräftig erniedrigt, da der Tropfen schließlich sofort festfriert. Veränderung der Fallhöhe und der Tropfenmasse führt zu dem Ergebnis, daß in gewissem Bereich die getrennte LadungQ in Annäherung allein der kinetischen EnergieW des Tropfens proportional ist:Q=2,75·10–16 Coul/erg·W für einen Tropfen von 20° C auf Eis von 0° C. Die Anwendbarkeit dieser Gleichung auf Wolkentröpfchen wird diskutiert. Messungen bei verringertem Reinheitsgrad des Wassers bestätigen die Erfahrung, daß gleichzeitig die befreite Ladung abnimmt.
Mit 3 Textabbildungen 相似文献
Summary To study the effect of the impact of cloud droplets upon ice (Faraday-Sohncke-effect) for the production of electricity in thunderstorms laboratory experiments were carried out under various conditions to measure quantitatively electric charges originating from the collision of falling water drops with ice. A droplet of 20 mg and 20° C falling from a height of 75 cm releases the charge of 3,6·10–13 Coul. While the effect is not considerably influenced by a change of the temperature of the droplet it is strongly reduced if the temperature of the ice plate is lowered to such a degree that the droplet immediately freezes. Variation of falling-height and mass of droplets leads to the result that, in a certain range, the separated chargeQ is approximately proportional solely to the kinetic energyW of the droplet:Q=2,75·10–16 Coul/erg·W for a droplet of 20° C on ice of 0° C. Applicability of this equation to cloud droplets is discussed. Measurements carried out with water of reduced purity confirm the experience that in such cases the released charge is smaller.
Résumé En vue d'étudier quantitativement la production d'électricité orageuse par la chute de gouttelettes d'eau sur des grêlons (effet Faraday-Sohncke), les auteurs ont réalisé des expériences et mesuré la charge libérée lors de la chute de gouttelettes sur de la glace dans des conditions variées. Une goutte de 20 mg à 20° C, tombant de 75 cm de hauteur libère la charge de 3,6·10–13 Coul. Tandis que l'effet ne dépend que peu de la température de la goutte, il est fortement réduit si la température de la glace s'abaisse, car la goutte se congèle alors aussitôt. Des essais avec des variations de la hauteur de chute et de la masse des gouttes ont en outre montré que la charge libéréQ est en première approximation proportionelle à la seule énergie cinétiqueW de la goutte:Q=2,75·10–16 Coul/erg·W pour une goutte à 20° C tombant sur de la glace à 0° C. On discute l'application de la formule à des gouttelettes nuageuses. Des mesures faites avec de l'eau non pure confirment le fait connu que la charge libérée diminue alors.
Mit 3 Textabbildungen 相似文献