多元素测试仪测定二氧硅烷中的痕量磷

二氯硅烷的沸点只有8.3℃,常温下呈气体状态,用常规的方法取样和检测难度很大.用高温富氢还原的方法,使二氯硅烷中的磷还原为PH_3,用气相色谱法测定.并在炉口设计了锥形惰性气氛保护炉口装置,有效的防止了氢爆.保证测试安全并能连续进样、操作简便、省时.同时利用NaOH富集,解决了主体干优杂质的问题.方法灵敏、可靠、简便、灵敏度由0.1μg/1提高到0.04μg/1

塔里木河中游洪水漫溢区荒漠河岸林实生苗更新/Seedling recruitment in desert riparian forest following river flooding in the middle reaches of the Tarim River[J]

以塔里木河中游荒漠河岸林为研究对象,2008年6月至2009年8月,对洪水漫溢区河漫滩裸地、林下及林隙3种生境植物1年生实生苗进行了调查.结果表明:实生苗更新主要依赖洪水漫溢,在非漫溢区没有发现实生苗存在;洪水降低了漫溢区的土壤盐度,更重要的是其提供了宝贵的水分条件,在时间和水量上有效地满足了胡杨等植物种子萌发和幼株生长的水分需求;河漫滩是河岸林种子实生苗产生的基地,洪水漫溢后的河漫滩种子实生苗密度显著大于其余两生境内实生苗密度,同时该生境内物种多样性也显著高于林下和林隙生境;光照决定着漫溢区实生苗能否成林,光照不同的空间样点上,实生苗发生数量和个体生长均存在显著差异,光照强的河漫滩,实生苗发生数量较多且幼苗能保持较高的生长活力和较多的生物量积累

新疆艾丁湖区中全新世以来孢粉记录与古环境/POLLEN RECORDS AND PALEOENVIRONMENT SINCE MID-HOLOCENE IN THE AYDINGKOL LAKE OF XINJIANG[J]

内陆干旱、半干旱封闭湖泊对气候变化的响应十分敏感,是较为理想的古环境研究场所.艾丁湖位于新疆维吾尔自治区吐鲁番盆地南部,湖面海拔-154.4m,是全国最低的洼地,故艾丁湖特殊的地理位置与独特的地质环境,使其在西北干旱区环境变化研究中有着重要的意义.取自艾丁湖湖区东北方向中全新世以来两个剖面共计88个沉积物样品,通过对该剖面进行年代测定、粒度分析与孢粉鉴定统计后,根据其孢粉组合与粒度特征,发现艾丁湖中全新世的环境演变经历了两个干-湿的变化过程,并且艾丁湖地区受西风带影响明显,即中晚全新世以来气候相对比较湿润,尤其在小冰期时期受西风带影响降水增加,从而进一步揭示了西北干旱区生态演化过程以及干旱区湖泊的演化过程

不同施氮量对蓖麻产量和生物及营养性状的影响/Effects of nitrogen levels on yield and biological and nutritional characters of castor[J]

为确定绿洲灌溉区蓖麻栽培的最佳施氮量，采用田间试验方法，对不同施氮量下蓖麻产量和生物、营养性状的变化规律进行了研究。结果表明：（1）通过数据拟合得出：蓖麻种植的最佳施氮量为195 kg·hm-2，预计最高产量为8×103 kg·hm-2；（2）蓖麻株高、茎粗和穗数等生物性状总体上随施氮量提高逐渐增大，而主穗长、主穗种仁数、百粒重及产量均随施氮量增加呈现出抛物线变化趋势，其中产量峰值出现在施氮量200 kg · hm-2时，其余指标均在施氮量150 kg·hm-2时达到最高值；（3）在花果期，增加氮肥施用量能够促进蓖麻对氮素和钾素的积累，磷素积累量随施氮量增加呈抛物线上升的趋势，峰值出现在施氮量150 kg·hm-2时；（4）施氮量与叶片氮素、磷素含量表现出明显的相关性。蓖麻在灌浆期对钾素的需求很高，叶片钾素大量转移到穗部

塔里木河中游典型绿洲土壤含盐量的光谱特征[J]

土壤含盐量是土地质量的一个重要因素。光谱反射率以快速获取和高质量等特点,在土壤研究方面广泛受到重视。选择塔里木河中游典型绿洲作为研究区,探讨了利用土壤光谱反射率来估算土壤含盐量,为该区域农业的可持续发展提供参考。首先,对土壤光谱反射率做了17种形式的变换,寻找能突现土壤含盐量的最佳的光谱波段。其次,对土壤光谱反射率与土壤含盐量进行耦合分析,建立了光谱反射率与含盐量的相关性方程。最后,使用统计软件SPSS16.0利用验证土壤验证方程的精度。结果显示,非盐渍土的最好估算方程为土壤光谱反射率的一阶微分形式,总均方根差RMSE为0.457。盐渍土的最好估算方程为对数倒数的二阶微分形式,总均方根差RMS..

John Fryer and The Translator’s Vade-mecum: the identification of the “Vocabulary of Terms in Naval Architecture"

John Fryer was one of the most important foreign translators in China after the Opium Wars. The work that is the final result of his experience at the Jiangnan Arsenal is The Translator’s Vade-mecum. Among the preparatory manuscripts of the glossaries that were published in the Vade-mecum, the author has identified the “Vocabulary of Terms in Naval Architecture.” The purpose of this article is to examine the main features of the Vocabulary, its sources and the peculiarities of the manuscript. In the first and second sections, the Vade-mecum is concisely analysed; providing numerous references and simultaneously sketching an outlook of the production and circulation of knowledge in the period considered, the author presents theoretical discussions concerning the norms of translation applied in the Vade-mecum, its purpose and the patronage of the translation activity. In the third and main section, studying the historical significance and linguistic quality of some of the translated terms annotated in the “Vocabulary,” the author compares its terminology with the concurrent Japanese one and with other Chinese relevant nomenclatures, demonstrating the complicate interaction in the “Vocabulary” between lexical innovation and recovery of existing terms

Prediction of Energy Resolution in the JUNO Experiment

International audienceThis paper presents the energy resolution study in the JUNO experiment, incorporating the latest knowledge acquired during the detector construction phase. The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV. To achieve this ambitious goal, significant efforts have been undertaken in the design and production of the key components of the JUNO detector. Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution, extending beyond the statistical fluctuations of the detected number of photons, such as the properties of liquid scintillator, performance of photomultiplier tubes, and the energy reconstruction algorithm. To account for these effects, a full JUNO simulation and reconstruction approach is employed. This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution. The study reveals an energy resolution of 2.95% at 1 MeV. Furthermore, the study assesses the contribution of major effects to the overall energy resolution budget. This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data taking. Moreover, it provides a guideline in comprehending the energy resolution characteristics of liquid scintillator-based detectors