Total nitrogen and community turnover determine phosphorus use efficiency of phytoplankton along nutrient gradients in plateau lakes

Numerous studies support that biodiversity predict most to ecosystem functioning, but whether other factors display a more significant direct impact on ecosystem functioning than biodiversity remains to be studied. We investigated 398 samples of the phytoplankton phosphorus resource use efficiency (RUE_P = chlorophyll-a concentration/dissolved phosphate) across two seasons in nine plateau lakes in Yunnan Province, China. We identified the main contributors to phytoplankton RUE_P and analyzed their potential influences on RUE_P at different lake trophic states. The results showed that total nitrogen (TN) contributed the most to RUE_P among the nine lakes, whereas community turnover (measured as community dissimilarity) explained the most to RUE_P variation across the two seasons. Moreover, TN also influenced RUE_P by affecting biodiversity. Species richness (SR), functional attribute diversity (FAD2), and dendrogram-based functional diversity (FDc) were positively correlated with RUE_P in both seasons, while evenness was negatively correlated with RUE_P at the end of the rainy season. We also found that the effects of biodiversity and turnover on RUE_P depended on the lake trophic states. SR and FAD2 were positively correlated with RUE_P in all three trophic states. Evenness showed a negative correlation with RUE_P at the eutrophic and oligotrophic levels, but a positive correlation at the mesotrophic level. Turnover had a negative influence on RUE_P at the eutrophic level, but a positive influence at the mesotrophic and oligotrophic levels. Overall, our results suggested that multiple factors and nutrient states need to be considered when the ecosystem functioning predictors and the biodiversity-ecosystem functioning relationships are investigated.     

总氮、总磷联合测定方法的改进

采用钼锑分光光度法测定总氮,考察了在提高温度的条件下,缩短消解时间对测定结果的影响。试验结果表明,调节氢氧化钠和过硫酸钾的用量,在同一溶液内测定总氮、总磷,并且将测定条件改为126～128℃,消解10min,其测定结果和与标准方法对照,精密度及准确度均令人满意。     

水溶液中非离子氨百分比的计算

根据平衡常数与温度的关系，求出非离子氨百分比α（ｐＨ，ｔ）的表达式，运用公式计算可以提高数据的准确性和批量计算的工作效率。     

Verification of carrier status for Becker muscular dystrophy from analysis of a blighted ovum

The polymerase chain reaction (PCR) was used on material from a blighted ovum to confirm indirectly the carrier status of a woman with a family history of Becker muscular dystrophy. Conventional testing including creatine kinase levels, muscle biopsy, and EMG had been inconclusive, and on the basis of one elevated creatine kinase level, the woman had been designated a possible carrier. Ultrasound examination at 10 weeks of pregnancy indicated a blighted ovum, from which DNA was subsequently extracted and subjected to PCR testing for determination of sex and genotypic status with respect to the known familial deletion of the dystrophin gene. The blighted ovum was found to have a Y chromosome and also to be deleted for at least exon 6 of the dystrophin gene, indirectly indicating that the mother most likely carried the family mutation for Becker muscular dystrophy.     

Effect of long-term fertilization on soil nitrate distribution

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大气中氨对农作物的影响

本文利用实验结论，阐述了大气中对农作物生长的影响及表现症状，分析了大气中不同浓度氨对农作物不同生长期的影响，对受氨污染地区农作物的种植选择及农业损失鉴定具有参考价值。     

水中溶解氧快速测试管的研制

水中溶解氧不稳定，需要现场即时测定。本文旨在研究现场快速测定水中的溶解氧。本研究运用比色分析的朗伯——比尔定律和真空工艺设计，将复杂繁琐的实验室测试方法和操作程序有机的融合在测试管中。该测试管能快速、简便地测定水中的溶解氧。测定范围为0.01—12mg／1，检出限为0.0lmg／1。常规法测定时间需要3—5小时，而该测试管法仅需1—2分钟，分析成本也大为降低。     

利用EXCEL求算水中非离子氨

Excel是办公自动化中非常重要的一款软件，它的数据处理功能在现有的文字处理软件中可以说是独占螯头，通过简单的学习，结合国家标准给出的换算公式，利用EXCEL编制程序，方便快捷地计算水中非离子氨浓度，计算结果表明，当实际测得水温和pH与表中数据吻合时三种计算方法结果无明显差异，当实际测得的水温和pH与表中不对应时，查表法存在明显偏差，而使用EXCEL运算就能与笔算结果一致，准确可靠。     

硝酸银滴定法与硫氰酸汞分光光度法测定水中氯化物（Cl^-）的方法比对

用硝酸银滴定法、硫氰酸汞分光光度法分别测定高浓度的考核已知样及低浓度的考核未知样，均合格。说明两种方法都能满足水和废水中氯化物（Cl^-）测定的需要。     

应用被动扩散管监测分析葫芦岛市环境空气NO2时空分布特征

被动扩散技术以其低成本、操作简单、空间覆盖率较高等优点已在西方国家广泛应用于环境空气质量监测与调查，辽宁省环保局通过欧盟项目引进，本技术在葫芦岛市环境空气质量监测应用有4年时间。依据4年环境空气被动扩散管监测基础数据，分析了解葫芦岛市城区大气中NO2时空分布特征：高浓度值出现在交通区，季节上呈现春季明显低于其它季节。