高浓度城市污水处理正交试验研究

针对新疆石河子市城市污水CODcr高于1000mg／L的特点，采用SBR工艺进行处理试验，并用正交试验的方法对最佳工艺条件进行了探讨。试验表明，该工艺对高浓度城市污水有较好的处理效果。通过控制运行条件，可使出水各项指标分别满足污水综合排放标准和农业灌溉的要求。     

Seasonal changes in the crude protein concentration of mixed swards of white clover/perennial ryegrass grown without fertilizer N in an organic farming system in the United Kingdom

Changes in the crude protein (CP) concentration of white clover and perennial ryegrass herbage from a mixed sward were determined on six sampling dates from May to October in each of 2 years. The swards were grown without fertilizer N in an organic farming system and continuously grazed by dairy cows during the grazing season. The annual mean contents of white clover in the dry matter (DM) of the sward were 272·3 and 307·0 g kg⁻¹ in Years 1 and 2. The mean CP concentrations of the white clover and perennial ryegrass herbage were 251·6 and 151·9 g kg⁻¹ DM in Year 1 and 271·9 and 174·0 g kg⁻¹ DM in Year 2 respectively. The CP concentration of the white clover increased significantly during the grazing season from 220·0 to 284·1 g kg⁻¹ DM in Year 1 and from 269·0 to 315·5 g kg⁻¹ DM in Year 2. In the perennial ryegrass herbage the CP concentration increased from 112·2 to 172·6 g kg⁻¹ DM in Year 1 and from 142·7 to 239·5 g kg⁻¹ DM in Year 2. The rate of increase during the season in the CP concentration of the perennial ryegrass herbage was similar to the rate of increase recorded in the white clover herbage.     

石灰性土壤上NaCO_3对不同品种水稻生长效应的研究

在石灰性土壤上，通过盆栽试验研究了ＮａＨＣＯ３对耐缺Ｚｎ敏感品种水稻生长和Ｚｎ、Ｆｅ、Ｍｎ、Ｃｕ含量的影响。ＮａＨＣＯ３显著降低Ｚｎ敏感品种地上部和根部的干重，而对耐性品种没影响。ＮａＨＣＯ３减少Ｚｎ敏感品种ＺＮ、Ｆｅ、Ｍｎ的含量，而对耐性品种影响很小，耐性品种和敏感品种的Ｃｕ含量不受ＮａＨＣＯ３的影响。以上结果表明：水稻耐缺Ｚｎ与水稻对土壤中ＮａＨＣＯ３的高忍耐力有关。     

CO2浓度和抗药性对褐飞虱刺吸取食行为的影响

【目的】明确CO2浓度升高是否影响褐飞虱的取食行为以及抗药褐飞虱品系的刺吸行为是否与敏感品系存在差异,从而为预测CO2浓度升高条件下不同抗药性褐飞虱对水稻的致害性提供依据。【方法】采用刺吸电位技术（EPG）观察褐飞虱抗、感噻嗪酮品系（抗性水平相差约480倍）对当前（390 μL•L-1）和升高CO2浓度（780 μL•L-1）下生长水稻的口针刺吸行为,用双因素方差分析比较CO2浓度和抗药性2因素对口针刺吸显示的6种波形持续时间和频次的差异。【结果】CO2浓度加倍倾向于缩短感噻嗪酮褐飞虱在韧皮部摄取汁液的总时间,与抗药性互作显著影响开始刺探行为的频次：CO2浓度加倍条件下（780 μL•L-1）抗性褐飞虱开始刺探的频次低于当前CO2浓度下（390 μL•L-1）。抗噻嗪酮褐飞虱口针朝维管束移动和在木质部摄取汁液的时间延长,但在韧皮部内部活动的时间缩短;口针在韧皮部内部活动的频次增多,但在韧皮部和木质部摄取汁液的频次减少。【结论】抗噻嗪酮褐飞虱对水稻的致害性明显强于感噻嗪酮褐飞虱;CO2浓度升高可能使感噻嗪酮褐飞虱对水稻的致害性减弱,但对抗噻嗪酮褐飞虱没有显著影响。     

Needle Collection Time for Nutrient Evaluation in Christmas Tree Production

Christmas tree needle sampling to evaluate nutrient need is an established practice. Data to support the recommended fall sampling time in Oregon and Washington were not found. In addition, the recommendation for needle sampling of Fraser fir in North Carolina was made without data from winter months. The goal for this article is to affirm or modify recommended needle sampling time. Needles of Douglas fir, Turkish fir, Nordmann fir, Noble fir, Grand fir, and Fraser fir Christmas trees were collected monthly for a year, dried, and analyzed for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and boron (B). No single period was found for any species when needle nutrient concentration was stable for all elements determined. Needle collection time was chosen by integrating cultural practices, likelihood of nutrient deficiency, and needle nutrient concentration changes for species grown in an area. Needle collection is recommended during February in western Oregon and Washington. The current sampling time, fall, is logical for Fraser fir Christmas tree production in North Carolina.     

Phosphorus Response and Fertilizer Recommendations for Wheat Grown on Nitisols in the Central Ethiopian Highlands

The provision of farmers with proper and balanced fertilizer recommendations is becoming increasingly important, for reasons of crop productivity, food security, and sustainability. Phosphorus (P) response trials with wheat were conducted on Nitisols at 14 sites in the central Ethiopian highlands during the 2010 and 2011 cropping seasons. The treatments, comprising six levels of P fertilizer (0, 10, 20, 30, 40, and 50 kg P ha^?1), were arranged in a randomized complete block design with three replicates. Based on a yield difference between the control and the P treatments, 90% of sites responded to P fertilizer. Application of P fertilizer increased wheat grain yield, up to 30% more than the control. Extractable soil P concentrations (Bray 2, 0–15 cm deep) 3 weeks after planting significantly responded to P fertilizer rate. The critical P concentration (for 90% relative yield) was 13.5 mg kg^?1. Most sites tested had Bray 2 P values <10 mg kg^?1. In the absence of a soil test, a recommendation of 40 kg P ha^?1, resulting in the best response overall, could be made for the first year of application. We also recommend that to prevent a potential loss of wheat yield, a maintenance application of at least 5–12 kg P ha^?1 be applied every year, irrespective of the calculated recommended rate, in order to replace P exported from the field in produce. Further field trials are required to determine interactions between P response and the effects of climate, soil properties, and other management practices.     

Excess trace metal effects on cotton: 4. Chromium and lithium in Yolo loam soil

Abstract

Two cultivars of cotton (Gossypium spp) were grown in Yolo loam soil in a glasshouse to determine phytotoxicity effects of Cr and Li and possible interactions with other metals. The Cr at 100 μg/g soil had no adverse effects on either cultivar studied. A Cr increase was not observed in either stems or leaves. Both cultivars tolerated 25 and 50 μg Li/g soil. The 50 μg Li/g soil resulted in leaves of Acala SJ‐2 with 432 μg Li/g leaves and 720 in Giza 45. The 100 μg Li/g soil resulted in 74% and 87% leaf yield reductions in Acala SJ‐2 and Giza 45 respectively. Leaf concentrations of Li respectively were 1950 and 1850 μg/g. Except at the highest level of Li, leaves had higher concentrations of Li than did roots. The Cr and Li resulted in some plant metal interactions.     

典型浓度路径(RCP)情景下长江中下游地区气温变化预估

为探明典型浓度路径下(高端路径RCP8.5和稳定路径RCP4.5)长江中下游地区未来30a平均气温的时空变化趋势和分布特征,运用联合国政府间气候变化委员会(IPCC)AR5提出的模拟能力较强的BCC-CSM1-1(Beijing Climate Center Climate System Model version1-1)气候系统模式,基于典型浓度情景RCP(Representative Concentration Pathway)输出的2021-2050年0.5×0.5格点主要气象要素的逐日模式模拟数据资料,应用双线性内插法降尺度到长江中下游及邻近区域62个基本气象站点。以1961-1990为基准年,根据同期等长模拟数据和观测数据的非线性函数关系建立订正模型,并利用方差订正法对2021-2050年模拟数据进行误差订正。结果表明:RCP情景输出数据的模拟效果良好,方差订正可降低模拟值与观测值的相对误差和方差,更加真实反应未来气候变化趋势。RCP8.5和RCP4.5两种排放情景下,长江中下游地区2021-2050年年平均气温均呈显著上升趋势,增温幅度总体表现为自南向北逐渐减少。就季节而言,四季均呈现升温趋势,夏季增温幅度最高,变化倾向率大,春冬两季RCP8.5情景下增温幅度大于RCP4.5下,夏秋季则相反;RCP8.5情景下,研究区域年平均气温呈现自中部向东西递减,春夏季增温幅度高于秋季,冬季增温幅度最小,且变化倾向率低,大部分地区未通过0.05水平的显著性检验。RCP4.5情景下,研究区年平均气温自北向南逐渐降低,变化倾向率则表现为北部大于南部,夏季变化速率较大,增温幅度达1.2℃·10a~(-1)(P0.01),冬季较小且未通过显著性检验。     

Cu2+和Cd2+对斑节对虾幼虾的毒性作用

研究了Cu^2 和Cd^2 对斑节对虾幼虾 的急性和亚急性毒性作用，获得了Cu^2 和Cd^2 的半致死浓度、安全浓度和累积量。