"支农70-2"电测仪锌汞电池充电器的设计与制作     

王意超  王路 《地下水》2003,25(1):46-46,51

“支农70-2”型电侧仪一直是基层水利单位进行地面电法找水和电测井的仪器之一。为解决该仪器内所用“锌汞电池”因电电压下降需要更换又难以购买的问题,笔者设计并制作出一种可给锌汞电池充电器,现撰文将其基本原理、线路结核、元件选用及制作方法作以介绍。  相似文献   

Atmospheric nitrous oxide observations above the oceanic surface during the first Chinese Arctic Research Expedition   总被引：1，自引：0，他引：1  

朱仁斌  孙立广  谢周清  赵俊琳 《极地研究(英文版)》2003,14(2)

339 gas samples above oceanic surface were collected on the cruise of "Xuelong" expeditionary ship and nitrous oxide concentrations were analyzed in the laboratory. Results showed that Atmospheric average N2O concentration was 309 ±3. 8nL/L above the surface of northern Pacific and Arctic ocean. N2O concentrations were significantly different on the northbound and southbound track in the range of the same latitude, 308.0 ±3.5 nL/L from Shanghai harbor to the Arctic and 311.9 ±2.5 nL/L from the Arctic to Shanghai harbor. N2O concentration had a greater changing magnitude on the mid- and high-latitude oceanic surface of northern Pacific Ocean than in the other latitudinal ranges. The correlation between the concentrations of the compositions in the aerosol samples and atmospheric N2 O showed that continental sources had a great contribution on atmospheric N2 O concentration above the oceanic surface. Atmospheric N2O concentration significantly increased when the expeditionary ship approached Shanghai h  相似文献   

Summertime Surface N_2O Concentration Observed on Fildes Peninsula Antarctica:Correlation with Total Atmospheric O_3 and Solar Activity     

朱仁斌  孙立广  尹雪斌  刘晓东  邢光熹 《大气科学进展》2004,(2)

Three-year summertime surface atmospheric N2O concentrations were observed for the first time on the Fildes Peninsula, maritime Antarctica, and the relationships among the N2O concentration, total atmospheric O3 amount, and sunspot number were analyzed. Solar activity had an important effect on surface N2O concentration and total O3 amount, and increases of sunspot number were followed by decreases in the N2O concentration and total O3 amount. A corresponding relationship exists between the N2O concentration and total atmospheric O3, and ozone destruction was preceded by N2O reduction. We propose that the extended solar activity in the Antarctic summer reduces the stratospheric N2O by converting it into NOx, increases the diffusion of N2O from the troposphere to the stratosphere, decreases the surface atmospheric N2O, and depletes O3 via the chemical reaction between O3 and NOx. Our observation results are consistent with the theory of solar activity regarding the formation of the Antarctic O3 hole.  相似文献   

紫金山铜矿原地破碎细菌浸出工艺的可行性分析     

王观石胡世丽  艾幼孙 《江苏地质》2004,28(4):228-232

根据紫金山铜矿的实际情况，分析采用原地破碎细菌浸出工艺回收紫金山铜矿资源的工程技术可行性，在此基础上进行经济方面的讨论。  相似文献   

有机配合物前驱体法合成纳米氧化镁研究及此法的应用前景          下载免费PDF全文

刘宁  张勇  杨建元 《盐湖研究》2006,14(4):61-65

综述了利用我国盐湖镁资源,以乙酰丙酮及其衍生物、有机胺和醋酸根为配位剂,采用有机配合物为前驱体合成纳米氧化镁的方法,前驱体形成的机理以及特点和优势。通过介绍此合成法在合成纳米金属粉体、其它金属氧化物粉体、无机盐粉体、氧化物薄膜或复合氧化物薄膜以及特殊结构化合物等方面广泛应用的实例,并预测了该法在合成其它高值化镁产品中的应用前景。  相似文献   

Sampling of Chemical Constituents in Electrically Active Convective Systems: Results and Cautions     

B. A. Ridley  M. A. Avery  J. V. Plant  S. A. Vay  D. D. Montzka  A. J. Weinheimer  D. J. Knapp  J. E. Dye  E. C. Richard 《Journal of Atmospheric Chemistry》2006,54(1):1-20

On flights of a P3-B turboprop and a WB-57F jet aircraft within thunderstorm systems, short term spikes (1–2 sec or less in duration) in NO and O₃ were recorded and are attributed to hot or cold discharges occurring on the aircraft fuselage or air sampling inlets. One such spike of only ∼300 msec duration reached 325 ppbv of NO on the flight of the jet aircraft while at 13.8 km altitude. In a lightning flash to the P3-B aircraft, production of NO (expected) and NO₂ (unexpected) were directly observed. The NO production was ∼ 1.7 x 10²² molecules/m of flash length. In the P3-B flight at 5.5 km altitude and over a distance of ∼ 275 km within a highly electrically active thunderstorm complex in the equatorial central Pacific Ocean, there was no evidence of production of O₃ or CO by lightning flashes or by any type of hot or cold discharge involved in the development of free-air lightning flashes.  相似文献   

等离子体发射光谱法测定重晶石中钡铁和硅   总被引：3，自引：0，他引：3  

杨德君  陈利平 《岩矿测试》1998,17(4):317-318

重晶石经Ｎａ２ＣＯ３熔融,水浸取,过滤。沉淀经ＨＣｌ溶解后,用电感耦合等离子体发射光谱法同时测定主成分ＢａＳＯ４和次量成分Ｆｅ２Ｏ３以及滤液中的ＳｉＯ２,结果与部颁标准方法符合。方法精密度好,主量组分ＢａＳＯ４测定的ＲＳＤ（ｎ＝６）为０．２４％,次量组分Ｆｅ２Ｏ３和ＳｉＯ２的ＲＳＤ（ｎ＝６）分别是３．６９％和１．４５％。  相似文献   

Enzyme leach anomalies associated with deep Mississippi Valley-type zinc ore bodies at the Elmwood Mine, Tennessee   总被引：1，自引：0，他引：1  

James R. Yeager  J. Robert Clark  Wallace Mitchell  Roy Renshaw 《Journal of Geochemical Exploration》1998,61(1-3)

Deeply buried Mississippi Valley-type deposits that have been or are currently being mined in North America were initially discovered by drilling. Conventional geochemical methods are ineffective for detecting these ‘blind' deposits when they occur deep within sequences of stable-platform carbonates and shales. The ‘enzyme' leach is a selective analytical technique for determining trace elements associated with amorphous Mn oxide coatings in soils. In many areas of the world, the enzyme leach method is useful for detecting low-level geochemical anomalies in soils, which are associated with blind mineral deposits. Enzyme leach analysis of soils, collected at the Elmwood Mine, Tennessee, revealed high-contrast anomalies over ore bodies 370 m below the surface. In areas where the soils are in chemical equilibrium, ‘combination' anomalies occur over Zn ore bodies. These are characterized by asymmetrical halogen halos which occur around a halogen ‘central low'. Commodity metals (Zn and Pb) and trace elements associated with the ore (Cd, Ba, and Mn) form apical anomalies, which occur over the ore bodies and within the halogen halo. Under most circumstances, agricultural practices do not affect enzyme leach results. However, agricultural activity in central Tennessee appears to have altered the proportion of amorphous Mn oxides in the soils in some locations. Where the MnO₂-form equilibrium of the soil has been disturbed, enzyme leach data are erratic. In the one instance where this was encountered, ratioing the data to Mn reveals anomalies which bracket the blind ore bodies.  相似文献   

氧化物晶胞参数和配位多面体几何要素的关系     

韩照信 《地球科学与环境学报》1998,20(4):27

氧化物矿物中的化学键主要是离子键,结构可看成配位多面体以不同方式相连形成,因此,晶胞参数可用配位多面体几何要素表示,这样求得的晶胞参数与实测晶胞参数间的相对误差一般在百分之几。  相似文献   

Estimates of global N2O emissions from cattle, pig and chicken manure, including a discussion of CH4 emissions     

M. G. M. Berges  P. J. Crutzen 《Journal of Atmospheric Chemistry》1996,24(3):241-269

Humans seem to have doubled the global rate of terrestrial nitrogen fixation. Globally 50–70% (85 Tg, 1 Tg=10¹² g) of the nitrogen supplied in fertilizer (80 Tg N/a) and leguminous crops (40–80 Tg N/a) are used to feed cattle. The aim of the present study was to derive some estimates of global N₂O production from animal manure. As the parameter giving the most stable numerical basis for regional and global extrapolation we adopted the molar emission ratios of N₂O to NH₃. These ratios were measured in cattle, pig and chicken housings with different manure handling systems, in dung-heaps and in liquid manure storage tanks. Individual molar emission ratios from outside manure piles varied over two orders of magnitude, strongly dependent on the treatment of the manure. A median emission ratio of 1.6×10^-2 (n=65) was obtained in cow-sheds with slatted floors and liquid manure stored underneath and a median ratio of 24×10^-2 (n=31) was measured in a beef cattle housing with a solid manure handling system.We next extrapolated to global NH₃ emissions from those estimated for Europe, using N uptake by the animals as a scaling factor. Multiplication with observed N₂O to NH₃ ratios next provided some estimates of regional and global N₂O emissions. To account for the great variability of the emission ratios of N₂O/NH₃, we developed upper and lower case emission scenarios, based on lower and upper quartiles of measured emission ratios. The global emission from cattle and swine manure is in the range of 0.2–2.5 Tg N-N₂O/a, representing 44+-39% of the annual atmospheric accumulation rate. This N₂O emission arises from about 40 Tg N/a of cattle and pig manure stored in or at animal housings. We did not account for N₂O emissions from another 50 Tg N/a excreted by grazing cattle, goats and sheep, and application of the manure to agricultural fields. Our study makes it clear that major anthropogenic N₂O emissions may well arise from animal manure. The large uncertainty of emission ratios, which we encountered, show that much more intense research efforts are necessary to determine the factors that influence N₂O emissions from domestic animal manure both in order to derive a more reliable global estimate of N₂O release and to propose alternative waste treatment methods causing smaller N₂O releases. In our studies we found large enhancements in N₂O releases when straw was added to the manure, which is a rather common practice. In view of the ongoing discussion in Europe to re-install the traditional solid manure system (bed down cattle) for environmental and animal welfare reasons, it is noteworthy that our measurements indicate highest N₂O release from this particulary system.In a similar manner, but based on a smaller data set, we also estimated the release of CH₄ from cattle and swine manure and from liquid manure only to be about 9 Tg/year in good agreement with the estimate by the Environmental Protection Agency (1994) of 8.6+-2.6 Tg/year. A total annual methane release as high as 34 Tg/a was derived for solid and liquid cattle and pig manure from animals in housings.  相似文献