鄂尔多斯盆地北部东胜铀矿区沉积有机质中脂肪酸甲酯的检出及意义

从鄂尔多斯盆地北部东胜铀矿区侏罗系沉积有机质中检出了丰富的脂肪酸甲酯系列化合物。脂肪酸甲酯系列化合物与相应样品中的正构烷烃化合物在分布特征上极为相似。在碳同位素组成方面,脂肪酸甲酯系列化合物与相应样品中正构烷烃系列也具有完全相同的变化范围。因此,脂肪酸甲酯系列化合物很可能就是正构烷烃系列化合物十分重要的母质来源。地质体中脂肪酸甲酯化合物的存在需要在相应的沉积体中维持一个比较严格的弱碱性—中性的环境。这种弱碱性—中性的成岩环境不仅对该地区有机质中脂肪酸甲酯化合物的形成和保存产生重要影响,而且有可能对该地区砂岩型铀矿床的形成产生了某些积极的作用。     

Dissolved manganese and silicic acid in the Columbia River plume: A major source to the California current and coastal waters off Washington and Oregon

The spatial distributions of dissolved manganese and nutrients were examined in the Columbia River plume off Oregon and Washington during the summer of 2004 and 2005 as part of the River Influence on Shelf Ecosystems (RISE) program. Factors influencing the hydrochemical characteristics of the freshly formed and aged Columbia River plume were investigated. Hydrographic data and nutrient concentrations were used to delineate three distinct water sources for the Columbia River Plume: California Current surface water, coastal upwelled water, and Columbia River water. The warm, intermediate salinity, nutrient poor California Current water contains low levels of dissolved manganese (< 5 nM) and silicic acid (< 5 μM), and is depleted in nitrate. The cold, high salinity, nutrient rich, freshly upwelled water is highly variable (2–20 nM) in dissolved manganese and can be as high as  45 μM in silicic acid and  30 μM nitrate. The variable Columbia River has summer temperatures ranging from  13 to 24 °C, high silicic acid concentrations (ranging from  120 to 200 μM), and lower nitrate concentrations (ranging from  2 to 20 μM). During the summer, the concentrations of silicic acid and dissolved manganese can exceed 100 μM and 200 nM, respectively, in near-field Columbia River plumes. These values are markedly greater than those of surface coastal waters (even during upwelling conditions). As the plume advects and mixes, the concentrations of these two constituents remain relatively high within plume waters. The concentrations of dissolved manganese in the near-field plume vary with tidal amplitude, exhibiting much higher concentrations for a given salinity during spring tides than during neap tides. For example, the Columbia River plume at a salinity of 20 has a concentration of dissolved manganese of  240 nM during spring tides, as compared to only  60 nM during low amplitude tides. Silicic acid concentrations in the near-field plume remain relatively constant throughout the tidal month. Calculations indicate there is roughly an equivalent yearly delivery of dissolved manganese and silicic acid to the coastal waters off Oregon and Washington by upwelled waters and by the Columbia River plume.     

Effect of Long-term Experimental Warming on the Nutritional Quality of Alpine Meadows in the Northern Tibet

The nutritional quality of grasslands is closely related to recruitment of young and population dynamics of livestock and wild herbivores. However, the response of nutritional quality to climate warming has not been fully understood in the alpine meadow on the Tibetan Plateau, especially in the Northern Tibet. Here, we investigated the effect of experimental warming ( beginning in 2008) on nutritional quality in three alpine meadows (site A: 4313 m, B: 4513 m and C: 4693 m) in the Northern Tibet. Crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), crude ash (Ash), ether extract (EE) and water-soluble carbohydrate (WSC) were examined in 2018-2019. Experimental warming only increased the content of CP by 27.25%, ADF by 89.93% and NDF by 41.20%, but it decreased the content of Ash by 57.76% in 2019 at site B. The contents of CP and WSC both increased with soil moisture (SM). The content of CP decreased with vapor pressure deficit (VPD). The combined effect of SM and VPD was greater than air temperature (T_a) in controlling the variations of the CP content, ADF content and nutritional quality. Compared to T_a, VPD explained more of the variation in NDF and Ash content. All of these findings suggest that warming effects on nutritional quality may vary with site and year, and water availability may have a stronger effect on the nutritional quality than temperature in the alpine meadow of the Northern Tibet.     

舒心片的质量标准研究

目的：建立中药舒心片中丹酚酸B含量的测定方法。方法：采用高效液相色谱法（HPLC）测定舒心片中丹酚酸B的含量,色谱柱为Agilent TC-C₁₈（2）色谱柱（4.6 mm×250 mm,5 μm）,以乙腈-0.1%的磷酸溶液（25∶75）为流动相;检测波长为286 nm;柱温为25℃;流速为1.0 ml/min。结果：供试品和对照品溶液中丹酚酸B与他峰分离度良好;在0.050～1.642 μg之间丹酚酸B呈良好线性关系,R=0.9993,丹酚酸B平均加样回收率为97.58%,RSD=0.25%。结论：经方法学验证,本法可用于舒心片的质量控制。     

天津市酸雨及其成因初探

根据1992年6月到2004年12月的酸雨观测记录,对近10余年天津市酸雨的变化规律和趋势进行了统计分析。结果表明:天津市酸雨发生呈明显的季节性变化,酸雨发生频次和强度呈现不同的季节变化趋势,酸雨主要分布在夏秋两季,但酸雨较强的季节却是在秋冬季;天津市酸雨呈逐年减少趋势,进一步的分析表明天津地区SO2排放量的逐年减少是酸雨减弱的主要原因。     

酸雨观测中pH测量负偏差来源

通过现场调查、实验室测试,对酸雨观测中发现的pH测量负偏差现象进行了验证和分析。现场个例调查发现,在正常保存、使用期限内的pH电极也有可能出现老化现象,老化的pH测量电极给出的pH测量结果为负偏差,其数量级与文献指出的在观测资料质量评估中发现的pH测量负偏差相吻合。实验室测试结果显示,老化的pH测量电极的测量负偏差与模拟雨水样品的电导率和pH值有关:电导率越小,pH测量偏差则越大;在电导率差别不大时,该负偏差大小与水样pH值呈现一定的正相关线性关系,且电导率越小时两者的线性斜率越大。经过综合分析,初步确认pH电极的老化是造成历史观测资料中pH测量负偏差的重要原因。根据分析结果,提出了在台站检测pH测量电极老化的替代性技术方法,以更好地保证酸雨观测数据质量。     

1992-2006年河南省酸雨分布特征分析

利用南阳、商丘和郑州3个观测站1992-2006年酸雨观测数据进行统计,分析其15 a来年际、季节变化特征。结果表明：1992-1995年间,3站酸雨发生频率、降水年均pH值和酸雨雨量与全年雨量比值均呈现减弱趋势,1998-2006年间均出现加强趋势,且在期末明显变强;酸雨频率1、9和12月出现高值,pH值在9-12月份出现低值;1992-2000年由南到北酸雨区域逐渐变小,2000年后由南到北、由西到东酸雨区域迅速扩大。     

Ammonium Variational Trends and the Ammonia Neutralization Effect on Acid Rain over East Asia

The distribution and variations of ammonium and the ammonia neutralization effect on acid rain were examined in East Asia during the period of 2000-05 using observed wet deposition data from the Acid Deposition Monitoring Network in East Asia (EANET). Observational trends show a high proportion of NH4+ in the total cations, with a six-year mean proportion of over 20% for continental and inland regions. The concentrations and deposition of NH4+ were higher in western China and Vietnam than in other regions. The annual variations in NH4+ concentration were smooth in most of the regions, except for southern China and Vietnam, where the NH4+ concentrations increased, and western China, where the NH4+ concentrations decreased. The neutralization factors (NFs) of NH4+ indicate that ammonia has a great neutralization capability toward acid rain, including for the regions with low NH4+ concentrations, such as Japan. The NFs were high in summer, with no obvious discrepancies between the northern and southern stations. However, the correlation coefficients between NH4+ concentrations and rain pH values imply that the ammonia neutralization effects on the pH values were distinct only at southern China and southern Japan stations. The neutralization of precipitation by ammonia was estimated by comparing the discrepancies between the observed pH values and the pH values calculated without ammonia consuming the H+ in NH4+. The results demonstrate that ammonia may increase annual mean pH values by 0.4-0.7 in southern China and by 0.15-0.25 in southern Japan.     

栽培条件下甘草的甘草酸及多糖含量

通过对3年生相同人工栽培条件下的不同种甘草及2种不同栽培措施的乌拉尔甘草为分析样本,采用高效液相色谱和苯酚-硫酸比色法对其甘草酸及多糖含量进行测定,分析比较甘草酸与甘草多糖含量之间的相互关系,并筛选出乌拉尔甘草的最优栽培措施。结果表明：甘草酸含量顺序为乌拉尔甘草〉胀果甘草〉黄甘草〉光果甘草;多糖含量以光果甘草3．76％为最高,其余3个种间含量相差不大。正交试验的方差分析表明：（1）对于播种3年生乌拉尔甘草,以甘草酸含量为评价指标,最优栽培措施为：灌溉量4500m^3／hm^2、二铵0kg／hm^2、种子（对照）、尿素0 kg/hm^2、播种量90kg/hm^2;若以甘草多糖含量为获取目标,最优栽培措施为：灌溉量1500m^3／hm^2、二铵300kg/hm^2、种子（包衣,尿素0．5％浸泡24h）、尿素300kg／hm^2、播种量90kg/hm^2。（2）对于移栽3年生乌拉尔甘草,以甘草酸含量为评价指标,最优栽培措施为：灌溉量1500m^3／hm^2、移栽苗（对照）处理、二铵0 kg／hm^2、尿素0kg/hm^2、株距5cm;若以甘草多糖含量为评价指标,最优栽培措施为灌溉量3000m^3／hm^2、移栽苗（对照）处理、二铵150kg／hm^2、尿素300kg／hm^2、株距10cm。