Atmospheric trace gas measurements at Palmer Station,Antarctica: 1982–83

In early 1982 a station capable of sampling atmospheric trace gas constituents on a continuous basis was established at Palmer Station, Anvers Island, adjacent to the Antarctic Peninsula (64° 46S 64° 04W). Sampling operations began about 1 February 1982. This is an initial report on this station, its location, equipment and general research objectives along with some initial sampling results. The constituents being measured and recorded were: ozone, methane, carbon dioxide, carbon monoxide, CCl₃F (fluorocarbon-11), CCl₂F₂ (fluorocarbon-12), carbontetrachloride, methylchloroform, nitrous oxide, and Aitken nuclei (CN). Data storage, data processing, and sampling system control is handled by a Hewlett-Packard 85 system. Preliminary analyses of about the first 20–22 months of data are presented and show not only the expected long-term trends but also shorter period concentration cycles that seem to be related to synoptic meteorology.     

A three-dimensional model of the global ammonia cycle

Using a three-dimensional (3-D) transport model of the troposphere, we calculated the global distributions of ammonia (NH₃) and ammonium (NH ₄ ⁺ ), taking into account removal of NH₃ on acidic aerosols, in liquid water clouds and by reaction with OH. Our estimated global 10°×10° NH₃ emission inventory of 45 Tg N-NH₃ yr^– provides a reasonable agreement between calculated wet NH ₄ ⁺ deposition and measurements and of measured and modeled NH ₄ ⁺ in aerosols, although in Africa and Asia especially discrepancies exist.NH₃ emissions from natural continental ecosystems were calculated applying a canopy compensation point and oceanic NH₃ emissions were related to those of DMS (dimethylsulfide). In many regions of the earth, the pH found in rain and cloud water can be attributed to acidity derived from NO, SO₂ and DMS emissions and alkalinity from NH₃. In the remote lower troposphere, sulfate aerosols are calculated to be almost neutralized to ammonium sulfate (NH₄)₂SO₄, whereas in the middle and upper troposphere, according to our calculations, the aerosol should be more acidic, as a result of the oxidation of DMS and SO₂ throughout the troposphere and removal of NH₃ on acidic aerosols at lower heights. Although the removal of NH₃ by reaction with the OH radical is relatively slow, the intermediate NH₂ radical can provide a substantial annual N₂O source of 0.9 _–0.4 ^+0.9 Tg, thus contributing byca. 5% to estimated global N₂O production. The oxidation by OH of NH₃ from anthropogenic sources accounts for 10% of the estimated total anthropogenic sources of N₂O. This source was not accounted for in previous studies, and is mainly located in the tropics, which have high NH₃ and OH concentrations. Biomass burning plumes, containing high NO _x and NH₃ concentrations provide favourable conditions for gas phase N₂O production. This source is probably underestimated in this model study, due to the coarse resolution of the 3-D model, and the rather low biomass burning NH₃ and NO _x emissions adopted. The estimate depends heavily on poorly known concentrations of NH₃ (and NO _x ) in the tropics, and uncertainties in the rate constants of the reactions NH₂ + NO₂ N₂O + H₂O (R4), and NH₂ + O₃ NH₂O + O₂ (R7).     

温度对海洋硅藻吸收或释放一氧化氮的影响

基于全球变暖的背景,研究了温度对三角褐指藻(Phaeodactylumtricornutum)、小新月菱形藻(Nitzschiaclosteriumf.minutissima)和中肋骨条藻(Skeletonemacostatum)生长的影响,并初步探讨了温度对海洋硅藻生长过程中吸收或释放一氧化氮(NO)的影响。培养温度分别为20℃和25℃。结果显示,温度升高,中肋骨条藻的比生长速率降低(P0.05),而对三角褐指藻和小新月菱形藻的生长没有明显影响。不同种类硅藻对高温的适应能力不同,且在不同生长阶段对NO呈现不同的吸收或释放规律。与20℃培养条件相比,25℃条件下三角褐指藻对NO的净吸收速率在指数生长期、生长平台期和衰亡期分别升高了40.2%、98.2%和16.0%;小新月菱形藻对NO的净吸收速率在生长的平台期升高了5.7倍;中肋骨条藻对NO的净释放速率在生长的平台期升高幅度最大,为11.5倍。结果表明全球变暖对不同种类的硅藻代谢NO的促进程度不同。     

P507萃取色层分离ICP—AES法测定高纯氧化镱中14种稀土杂质元素

本文采用Ｐ５０７萃取树脂－盐酸体系色谱法对高纯氧化镱中１４种稀土杂质元素进行分离、富集,用ＩＣＰ－ＡＥＳ法测定其稀土元素含量。当上柱量为２００ｍｇＹｂ２Ｏ３时,所能达到的测定下限：Ｅｕ２Ｏ３为１μｇｇ－１;Ｙ２Ｏ３,Ｇｄ２Ｏ３,Ｄｙ２Ｏ３,Ｈｏ２Ｏ３,Ｔｍ２Ｏ３,Ｌｕ２Ｏ３为２μｇｇ－１;Ｌａ２Ｏ３,Ｅｒ２Ｏ３为４μｇｇ－１;Ｐｒ６Ｏ１１,Ｎｄ２Ｏ３,Ｓｍ２Ｏ３,Ｔｂ４Ｏ７为８μｇｇ－１;ＣｅＯ２为１６μｇｇ－１。５次取样分离,加入试验回收率在８８％—１１２％之间,相对标准偏差＜１０％。本方法可适用于纯度为９９．９５％—９９．９９％的氧化镱中１４种稀土杂质元素的测定。     

Si含量对镍基合金氧化保护膜影响机制的研究

本文对镍基合金中Si在弱氧化环境下表面氧化成膜特性进行了研究。利用XRD、SEM、EDS等检测手段对试样进行了检测分析,结果发现:合金表面氧化膜的形成动力学对镍基合金的Si含量非常敏感。当合金元素Si的含量较高时,由于连续的非晶SiO2膜在表层氧化铬与奥氏体基体之间的富集阻碍了Cr离子的向外扩散,导致在奥氏体区之上形成了较薄的氧化铬膜;共晶组织区域由于不会形成连续的SiO2非晶膜,仍然可以作为Cr离子的快速扩散通道,使得在该组织区域形成大量的脊状氧化物。奥氏体组织之上的氧化膜厚度与基体的Si含量成反比。     

Iron oxide precipitate in seepage of groundwater from a landslide slip zone

Orange precipitate was collected at the mouth of groundwater drainage tubes from the Kumanashi Landslide slip zone in Toyama prefecture, Northwest Japan. Data from XRF, X-ray diffraction, and Mössbauer spectroscopy determined the precipitate as hydrous ferric oxide (HFO) bearing multi-elements such as phosphorous, silica, calcium, etc. The occurrence of HFO may indicate an oxidation of ferrous iron in the percolated groundwater from the slip zone. Moreover, the precipitate iron should be mobilized with groundwater circulation from the slip zone, whose reducing condition was determined by the iron speciation on the same type of landslide profiles within the study area in previous studies. The HFO precipitate may be considered as a secondary reliable indicator to locate the seepage of a slip zone on surface, especially for a landslide newly investigated under wet-warm climate.     

利用钾长石粉体合成雪硅钙石的实验研究

以氧化钙为反应物料,在200～250℃的水热反应条件下分解钾长石。实验研究了在不同的Ca/(Si Al)摩尔比、水固比、反应温度和反应时间条件下,钾长石中K2O的溶出率和固相的物相变化。结果表明,液相中K2O的溶出率为40%～87%,固相反应产物为结晶良好雪硅钙石晶体。采用化学分析、XRD、SEM、DSC_TG和BET等方法对合成的雪硅钙石粉体进行了表征,结果表明,合成的雪硅钙石粉体是由长5～10μm、宽100～200nm、厚度为49～50nm的薄片纤维晶体交织成的直径为30～40μm的空心球形团聚体,耐火温度高于650℃,是制备硅酸钙保温材料的良好原料。     

亚热带富铁土的磁学性质及其磁性矿物学

通过５５个亚热带富铁土的磁化率（χ）、频率磁化率(χ_ｆｄ)、非滞后剩磁（ＡＲＭ）和饱 和等温剩磁（ＳＩＲＭ）等磁性参数测定,结合氧化铁化学形态分析和矿物鉴定,初步明确了亚热 带富铁土的磁学特征及其磁性矿物．磁测数据表明富铁土中存在强磁性的矿物,其磁化率χ 与土壤游离氧化铁（Ｆｅ_ｄ）含量呈极显著指数正相关（Ｒ^２＝０．５９７１）,频率磁化率χ_ｆｄ与土壤游离氧 化铁含量呈极显著直线正相关（Ｒ^２＝０．４２８９）．富铁土的χ_ｆｄ和非滞后磁化率χ_ＡＲＭ。值表明土壤 中的磁性矿物以超顺磁性（ＳＰ）和稳定单畴（ＳＳＤ）颗粒为主,富铁上的χ和χ_ＡＲＭ呈极显著直线 正相关（Ｒ^＝ ０．９４２９）,证明富铁土的磁性是由风化成土过程产生的 ＳＰ和 ＳＳＤ磁性颗粒贡献 的．矿物磁测结合Ｘ－衍射证明富铁土中的氧化铁矿物由赤铁矿、磁赤铁矿和针铁矿组成。