Acid precipitation: natural versus anthropogenic components

The concentrations of H(+), SO(4)(2-), and NO(3)(-) in the precipitation of eastern North America are greater now than they were historically as a result of fossil-fuel combustion. Because of a lack of data prior to 1950, the absolute increases in the concentrations of these three ions are unknown. This problem can be addressed by comparing the composition of precipitation from areas sensitive to acidic deposition with that of precipitation from remote areas. An analysis of precipitation data indicates that many areas of eastern North America receive precipitation with substantially greater H(+), SO(4)(2-), and NO(3)(-) concentrations than remote areas. For example, SO(4)(2-), the most ecologically significant indicator of change, is enriched 2 to 16 times in eastern North American precipitation relative to its concentration in remote areas.     

Ground-water radon anomaly before the kobe earthquake in Japan

Radon concentration in ground water increased for several months before the 1995 southern Hyogo Prefecture (Kobe) earthquake on 17 January 1995. From late October 1994, the beginning of the observation, to the end of December 1994, radon concentration increased about fourfold. On 8 January, 9 days before the earthquake, the radon concentration reached a peak of more than 10 times that at the beginning of the observation, before starting to decrease. These radon changes are likely to be precursory phenomena of the disastrous earthquake.     

A thiosulfate shunt in the sulfur cycle of marine sediments

The oxidation of sulfide, generated by bacterial sulfate reduction, is a key process in the biogeochemistry of marine sediments, yet the pathways and oxidants are poorly known. By the use of (35)S-tracer studies of the S cycle in marine and freshwater sediments, a novel shunt function of thiosulfate (S(2)O(3)(2-)) was identified. The S(2)O(3)(2-) constituted 68 to 78 percent of the immediate HS(-)-oxidation products and was concurrently (i) reduced back to HS(-), (ii) oxidized to SO(4)(2-), and (iii) disproportionated to HS(-) + SO(4)(2-). The small thiosulfate pool is thus involved in a dynamic HS(-) - S(2)O(3)(2-) cycle in anoxic sediments. The disproportionation of thiosulfate may help account for the large difference in isotopic composition ((34)S/(32)S) of sulfate and sulfides in sediments and sedimentary rocks.     

利比亚Wadi Bay地区地下水水化学特征及成因分析（英文）

[目的]分析利比亚WadiBay干谷地区地下水水化学特征的形成原因,为地下水资源合理开发利用以及地下水环境保护提供科学依据。[方法]以利比亚Wadi 8Bay（Bay干谷）地区为例,运用Piper三线图示法、描述性统计、离子比例系数法、同位素证据,系统研究了利比亚WadiBay地区干旱气候条件下浅层地下水特殊的水化学特征。[结果]区域地下水含盐量很高,矿化度（TDS）在3.2～8.4g/L,地下水类型主要为Cl、SO4--Na、Ca,其次为Cl.SO4-Na、Ca、Mg;地下水中Cl-、Na＋、SO42-等在距海70km处浓度产生突变,而Mn2＋、Ba2＋、Si2＋、NH4＋与NO3-并无同样突变现象。[结论]比亚WadiBay干谷地区浅层地下水水化学特征与溶虑作用、蒸发浓缩作用以及人类活动关系不大,主要成因为海水入侵过程中的咸淡水混合作用。     

Metastable phases in polar stratospheric aerosols

Phase changes in stratospheric aerosols were studied by cooling a droplet of sulfuric acid (H(2)SO(4)) in the presence of nitric acid (HNO(3)) and water vapor. A sequence of solid phases was observed to form that followed Ostwald's rule for phase nucleation. For stratospheric partial pressures at temperatures between 193 and 195 kelvin, a metastable ternary H(2)SO(4)-HNO(3) hydrate, H(2)SO(4) . HNO(3) . 5H(2)O, formed in coexistence with binary H(2)SO(4) . kH(2)O hydrates (k = 2, 3, and 4) and then transformed to nitric acid dihydrate, HNO(3) . 2H(2)O, within a few hours. Metastable HNO(3) . 2H(2)O always formed before stable nitric acid trihydrate, HNO(3).3H(2)O, under stratospheric conditions and persisted for long periods. The formation of metastable phases provides a mechanism for differential particle growth and sedimentation of HNO(3) from the polar winter stratosphere.     

Magmatic vapor source for sulfur dioxide released during volcanic eruptions: evidence from mount pinatubo

Sulfur dioxide (SO(2)) released by the explosive eruption of Mount Pinatubo on 15 June 1991 had an impact on climate and stratospheric ozone. The total mass of SO(2) released was much greater than the amount dissolved in the magma before the eruption, and thus an additional source for the excess SO(2) is required. Infrared spectroscopic analyses of dissolved water and carbon dioxide in glass inclusions from quartz phenocrysts demonstrate that before eruption the magma contained a separate, SO(2)-bearing vapor phase. Data for gas emissions from other volcanoes in subduction-related arcs suggest that preeruptive magmatic vapor is a major source of the SO(2) that is released during many volcanic eruptions.     

长期施用含氯和含硫肥料对土壤性质的影响

在湖南祁阳的红壤稻田进行了26年的长期定位试验，结果表明，多年连续施用含氯和含硫肥料尤其是含硫肥料会造成土壤酸化。Cl^-1易随水流失，长期连续施用不会在土壤中大量残留；而长期施用含硫肥料，SO4^2-在表土层和底土层中有明显的累积，累积的SO4^2-因改变了土壤的化学性质而对水稻生长有显的影响。     

Electrochemical growth of highly conducting inorganic complexes

The formation of single crystals of highly conducting inorganic complexes, for example, K(2)Pt(CN)(4)X(0.3) . 3H(2)O (X = Cl, Br), K(1.75)Pt(CN)(4) . 1.5 H(2)O, or K(1.64)Pt(O(2)C(2)O(2)) . 2H(2)O, has been effected via electrochemical growth from concentrated aqueous solutions of potassium tetracyanoplatinate(II) and potassium bis(oxalato)platinate(II).     

Erratum

In the report "Cloud droplet deposition in subalpine balsam fir forests: Hydrological and chemical inputs" by G. M. Lovett et al. (24 Dec., p. 1303), two errors appeared in Table 2 on page 1304. The cloud deposition of SO(4)(2-), incorrectly reported as 275.8 kg ha(-1) year(-1), should have been 137.9 kg ha(-1) year(-1). The percentage of the sum contributed by clouds, reported as 81 for SO(4)(2-), should have been 68.     

Correlation of volcanic activity with sulfur oxyanion speciation in a crater lake

The Yugama crater lake at Kusatsu-Shirane volcano, Japan, contains nearly 2200 tons (2800 parts per million) of polythionate ions (Sn O(6)(2-), where n = 4 to 9). Analytical data on lake water sampled before and during eruptions in 1982 showed that the concentrations of polythionates decreased and sulfate increased in response to the preeruption activities of the subaqueous fumaroles. These changes were observed 2 months before the first phreatic explosion on 26 October 1982. The monitoring of polythionates and sulfate in crater lake water is a promising means of anticipating potential volcanic eruption hazards.     

烤烟烘烤工场附近空气SO2质量浓度分析

选取烤烟烘烤工场为监测对象,对其附近SO2质量浓度进行为期两年的监测,分析了烘烤工场周围SO2质量浓度空间分布.分析结果表明:SO2地面质量浓度高值出现在烘烤工场顺风向50 m的频率最大,且离地面0.9～2.1 m空间范围的SO2质量浓度超出限值;烘烤工场顺风向200～300 m内的作物成长环境内SO2质量浓度超出阈值.建立烘烤工场的”控硫”、”降硫”、”避硫”系统,可以从供热方式的转换,洁净能源的使用以及作物敏感期和敏感区的调整来改善烘烤工场超标排放SO2的现状.     

大豆蛋白-三聚氰胺-尿素-甲醛树脂胶黏剂固化剂的研究

以大豆蛋白降解液、三聚氰胺、尿素和高浓度甲醛为原料,合成了一种低摩尔比的大豆蛋白-三聚氰胺-尿素-甲醛共缩聚树脂胶黏剂(SMUF)。选用(NH4)2SO4、(NH4)2S2O8、(NH4)2HPO4和H3PO4作为SMUF树脂的固化剂,研究了固化剂对SMUF树脂基本理化性能的影响。结果表明:1)传统固化剂(NH4)2SO4不能使SMUF树脂充分固化,最终树脂胶合强度低、耐水性差,固化后的胶层断面疏松、多孔;2)H3PO4和(NH4)2S2O8属于中强酸体系,两者均能一定程度加速SMUF树脂的固化,树脂胶合强度和耐水性均得到改善,固化温度显著降低,固化放热量有所提高;3)(NH4)2HPO4是一种缓冲型酸,其催化SMUF树脂的固化速度较为均匀,树脂综合性能较优,树脂的胶合强度和耐水性较好,固化温度也有所降低,树脂交联程度高,树脂固化层断面相对较为均匀。     

阿瓦提县地下水化学特征及其形成机理

根据研究区37组样品水化学测试结果,利用SUFFER软件根据样点测试值绘制等值线图分析。由于区内各地段起主导作用的水文地球化学作用不同,地下水水化学特征形成具有在水平与垂直分布上的双重特征。分析结果表明:在研究区平面上,由北向南,地下水矿化度总体由低变高,水化学类型由HCO3.SO4—Mg.Ca型向C l.SO4—Na型过渡。在垂直方向上,地下水在200m勘探深度内存在"上咸下淡"和"上淡下咸"两种类型。     

新疆主要城市地下水水质现状分析

将2003年4至6月份新疆7个城市地下水42个水样监测结果,以各城市为评价单元,以《地下水环境质量标准》（GB/T 14848-93）为评价标准,选择总硬度、矿化度、氨氮、挥发酚、高锰酸钾指数、硫酸盐和氯化物这7个项目作为评价因子,运用灰色关联度分析方法对新疆7个城市的地下水水质进行分析。评价结果表明,矿化度和总硬度较大,总体水质较好。应加强地下水保护及地下水资源质量管理,实现地下水资源可持续利用,并对地下水污染防治提出建议。     

Disulfate ion as an intermediate to sulfuric Acid in Acid rain formation

The oxidation of the bisulfite ion by dissolved oxygen to produce sulfate ion involves the formation of a previously undetected intermediate. This intermediate has a fairly strong Raman band at 1090 wave numbers and a weak Raman band at 740 wave numbers, both of which are probably due to sulfur-oxygen stretches. The intermediate is proposed to be the disulfate ion S(2)O(7)(2-), which hydrolyzes into H(+) and either SO(4)(2-) or HSO(4)(2-) with a half-life of about 52 seconds at 25 degrees C.     

Oxygen-isotope ratios in phosphate from fossil marine organisms

Well-preserved fossil marine organisms generally yield very positive delta(18)(PO(4)(3-)) values which are considered to result from relatively good preservation of the original oxygen-isotope composition of phosphatic material deposited under isotopic equilibrium conditions in oceanic water whose O(18):O(16) ratio was more positive than that of modern oceans.     

西安盐渍土发生规律及其防治途径

通过定位、定期采集土壤样品分析 ,发现 0～ 2 0 0 cm土层盐分平均含量 1年中无明显变化 ,说明盐分离子主要在 0～ 2 0 0 cm土层内迁移、转化 ;土壤表层 (0～ 1 cm)盐分含量与蒸发量和降水量密切相关 ,蒸发量大 ,降水量小 ,土壤表层盐分含量就高 ,反之相反 ;作物受害区土壤剖面中 Ca2 、Mg2 、K 、SO4 2 - 、HCO3-含量与对照区无明显差异 ,而 Na 、Cl-、CO32 -含量明显高于对照区 ,说明土壤中 Na 、Cl-、CO32 -增高是导致农作物受害的主要原因 ;通过田间试验提出了施用有机肥、磷石膏、用水洗盐等综合防治盐分危害农作物生长的有效措施     

不同阴离子化肥对黄瓜生长及土壤EC、pH的影响

试验采用 3种含不同阴离子的化肥 ,设 3个施肥水平 ,研究了它们对黄瓜生长、根系活力及对土壤EC、pH的影响。研究结果表明 :在 3个施肥水平下 ,化肥的不同阴离子对黄瓜生长的抑制作用是Cl->SO42 ->NO3 -,土壤中浓度越大 ,抑制作用越明显。土壤中随 3种离子浓度增高 ,EC值明显增大 ,pH值明显下降 ,其影响是Cl->SO42 ->NO3 -。     

A synthetic nickel electrocatalyst with a turnover frequency above 100,000 s⁻¹ for H₂ production

Reduction of acids to molecular hydrogen as a means of storing energy is catalyzed by platinum, but its low abundance and high cost are problematic. Precisely controlled delivery of protons is critical in hydrogenase enzymes in nature that catalyze hydrogen (H(2)) production using earth-abundant metals (iron and nickel). Here, we report that a synthetic nickel complex, [Ni(P(Ph)(2)N(Ph))(2)](BF(4))(2), (P(Ph)(2)N(Ph) = 1,3,6-triphenyl-1-aza-3,6-diphosphacycloheptane), catalyzes the production of H(2) using protonated dimethylformamide as the proton source, with turnover frequencies of 33,000 per second (s(-1)) in dry acetonitrile and 106,000 s(-1) in the presence of 1.2 M of water, at a potential of -1.13 volt (versus the ferrocenium/ferrocene couple). The mechanistic implications of these remarkably fast catalysts point to a key role of pendant amines that function as proton relays.     

落叶前根外追肥对苹果休眠期营养状况的影响

本文于落叶前向苹果树根外追施矿质肥料,落叶后采样测定了氨基酸、可溶性糖和Ｐ、Ｋ、Ｂ、Ｃａ的含量。结果表明,喷含Ｃａ２＋、Ｋ＋、ＳＯ２－４、Ｈ２ＰＯ－４、ＮＯ－３及尿素等肥料均使粗根中氨基酸含量下降,除ＳＯ２－４外其它肥料能促进氨基酸由长枝下运至根系;ＫＮＯ３、Ｂ使根枝中可溶性糖含量增加,而Ｋ２ＳＯ４、ＣａＳＯ４、Ｃａ（ＮＯ３）２、ＫＨ２ＰＯ４使其含量下降;根外追肥促进Ｐ在粗根和枝条中贮存,其效果依次是：ＫＨ２ＰＯ４＞Ｋ２ＳＯ４＞尿素＞ＫＮＯ３,ＫＨ２ＰＯ４、尿素促进Ｃａ在短枝中的贮藏;Ｂ在喷肥后略有减少;根外追肥对Ｋ＋在粗根贮藏影响不显著。